HK1191663B

HK1191663B - Resin compositions for thermosetting powder coating compositions

Info

Publication number: HK1191663B
Application number: HK14104799.9A
Authority: HK
Inventors: 黄鲁宾; 于尔根．博尔克斯; 保罗斯．弗郎西斯．安娜．比基森; 朱尔．奎杰博斯; 吉恩-保罗．伯瑞加．范
Original assignee: 科思创(荷兰)有限公司
Priority date: 2011-03-25
Filing date: 2012-03-22
Publication date: 2015-12-18

Abstract

The invention relates to a resin composition comprising at least an organophosphorous compound and a branched amorphous carboxylic acid functional polyester, said polyester having a Tg of at least 40 C, said polyester comprising at least 1 to 45 % mol of 2,2-dimethyl-1,3-propanediol; a C3 to C5 aliphatic diol AD1 not including 2,2-dimethyl-1,3-propanediol; a C6 to C50 aliphatic or cycloaliphatic diol AD2; 0.1 to 10 % mol of an at least trifunctional monomer; 1 to 55 % mol of terephthalic acid, wherein the % mol is based on the polyester. The powder coatings of the present invention derived upon curing at low temperature of the thermosetting powder coating compositions of the invention that were storage stable and comprised said resin composition and a crosslinker having functional groups that are reactive with the carboxylic acid groups of the polyester, have limited or no blooming, good smoothness sufficient reverse impact resistance and preferably have also good degassing limit.

Description

Resin composition for thermosetting powder coating composition

The present invention relates to a resin composition comprising a polyester and an organophosphorus compound chemically different from the polyester. The invention also relates to a thermosetting powder coating composition comprising said resin composition and a crosslinker having functional groups capable of reacting with a polyester. The invention also relates to powder coatings prepared from the thermosetting powder compositions, to substrates coated with the thermosetting powder coating compositions and to the use of organophosphorus compounds or polyesters or resin compositions in thermosetting powder coating compositions which are storage-stable, can be cured at low temperatures and can provide powder coatings which have no blooming (blooming), good smoothness, sufficient Reverse Impact Resistance (RIR) and preferably also a good degassing limit (degassing limit).

Powder coating compositions are dry, finely divided, free-flowing solid materials at room temperature and atmospheric pressure and have gained in popularity in recent years over liquid coating compositions for a number of reasons. One reason for this is that powder coatings are user-and environmentally-friendly materials because they contain little harmful, volatile organic solvent carriers that are typically present in liquid coating compositions. Thus, upon curing, the powder coating emits little, if any, volatile materials into the environment. This eliminates solvent emission problems associated with liquid coating compositions, such as air pollution, as well as health hazards to workers employed in coating operations. The use of powder coating compositions (also commonly referred to as powders) is also clean and convenient. Because they are in dry solid form, they are applied to the substrate in a clean manner. Powder is easy to clean in the case of scattering, and does not require special cleaning and spill containment as liquid paint does. Thus improving construction sanitation conditions. Furthermore, the powder coating composition is essentially 100% recyclable, since the sprayed powder can be completely recycled and recombined with fresh powder feed. Liquid coatings are often not recyclable in application, which results in increased waste and hazardous waste disposal costs. In addition, the powder coating composition is ready to use, i.e., does not require desalting or dilution.

In the case of thermosetting powder coating compositions, the powder coating compositions are usually finely divided particles of polymer and crosslinker, usually also containing pigments, fillers and other additives. After application to a substrate, the individual powder particles are melted and coalesced in an oven to form a continuous film (commonly referred to as a powder coating) having the decorative and protective properties associated with conventional organic coatings. The method of applying the powder coating composition is known as a melt coating process; that is, the powder particles must be melted or fused at some time during the coating process. While this is typically done in a convection oven, infrared heating, resistive heating, and inductive heating methods have also been used. Thus, with few exceptions, powder coatings are factory applied in fixed installations, which substantially precludes their use in maintenance applications. Powder coating compositions are typically applied to a substrate by an electrostatic spray process; the powder coating composition is dispersed in an air stream and passed through a corona discharge field where the particles acquire an electrostatic charge. The charged particles are attracted to and deposited on the grounded object to be coated. The object is then placed in an oven, typically at room temperature. The powder melts in the oven and forms a powder coating. Based on a combination of high-voltage electrostatic charging and fluidized bed application techniques (electrostatic fluidized bed) and triboelectric spray coating methods, hybrid processes have evolved. Powder coating compositions and methods of their application are preferred coating compositions and preferred methods for coating a variety of familiar items such as lawn and garden equipment, patios and other metal furniture, electrical cabinets, lighting equipment, shelving and storage devices, and many automotive components. Today, powder coating compositions are widely accepted, having thousands of devices in factories of Original Equipment Manufacturers (OEMS) and custom paint shops.

The powder coating composition may be thermosetting or thermoplastic. The present invention relates to the field of thermosetting powder coating compositions. Misev, in Powder Coatings, Chemistry and Technology (page 224-300; 1991, John Wiley), describes the preparation of thermosetting Powder coating compositions.

Powder coating compositions are often divided into decorative and functional grades. The decorative grades are generally finer in granularity and color and appearance are important. They are applied to cold substrates using electrostatic techniques at relatively low film thicknesses (e.g., 20-75 μm). The functional stages are typically applied to the preheated part in a thick film (e.g., 200-. In functional coatings, corrosion resistance and electrical, mechanical and other functional properties are more important. Another difference in powder coating compositions is the distinction between indoor (inside) and outdoor (outside) grades. The outdoor grade typically exhibits improved weatherability over the indoor grade.

One major class of interior grade powder coating compositions is based on the combination of acid functional polyester resins and epoxy resins, also commonly referred to as "hybrid" powder coating compositions. An "epoxy resin", or commonly referred to as an "epoxy derivative" or "epoxy compound", is an important class of polymeric materials characterized by the presence of more than one three-membered ring (also referred to as an "epoxy", "epoxide", "oxirane" or "epoxy group"). The terms cyclic "oxygen compounds" or "epoxy resins" or "epoxy derivatives" are used interchangeably in the context of the present invention. Epoxy resins are one of the most common classes of compounds that have gained wide acceptance as the material of choice for numerous coating applications.

Since their method of application involves heating at a certain point in time at the temperature required to melt and cure the thermosetting powder coating composition, the substrates must be able to withstand this temperature, which in most cases limits the application of the powder coating compositions to metal, ceramic and glass substrates.

In order to comply with stricter environmental regulations, there is an increasing interest in the development of thermosetting powder coating compositions that are capable of curing at low temperatures. A reduction in the temperature at which thermosetting powder coating compositions can be cured is desirable because it is economically, environmentally and technically advantageous. The reduction of the curing temperature while keeping the curing time constant reduces the energy consumption, which is beneficial both ecologically and economically, while making such thermosetting powder coating compositions attractive to powder coaters, since the throughput of their powder coating lines can also be increased significantly. Furthermore, heat-sensitive substrates can also be used due to the reduction in curing temperature, thus widening the field of application of such thermosetting powder coating compositions.

Furthermore, since coating compositions based solely on epoxy resin mixtures are expensive, it is desirable to replace part of the epoxy resin with another type of polymer, which is less expensive, to produce, for example, a polyester that does not impair the properties of the final coating.

EP1067159a1 discloses thermosetting compositions for powder coatings comprising: linear or branched carboxylic acid group containing isophthalic acid rich polyester, linear or branched hydroxyl group containing polyester and a curing agent system having functional groups reactive with the polyester carboxylic acid groups and hydroxyl groups, characterized in that the carboxylic acid group containing isophthalic acid rich polyester is amorphous and the hydroxyl group containing polyester is semi-crystalline.

US6660398B1 discloses powder thermosetting coating compositions comprising a binder comprising a blend of:

(a) an isophthalic acid rich amorphous polyester comprising carboxyl groups, prepared from an acid component comprising 55 to 100 mole% isophthalic acid, 0 to 45 mole% of at least one dicarboxylic acid other than isophthalic acid, and 0 to 10 mole% of a polycarboxylic acid comprising at least 3 carboxyl groups, and an alcohol component comprising 60 to 100 mole% neopentyl glycol, 0 to 40 mole% of at least one dihydroxy compound other than neopentyl glycol, and 0 to 10 mole% of a polyhydroxy compound containing at least three hydroxyl groups, said amorphous polyester having a glass transition temperature (Tg) of at least 50 ℃ and an acid number of 15 to 100 mg;

(b) a semi-crystalline polyester comprising carboxyl groups, which is either (b 1) prepared from 1, 12-dodecanoic acid and from a saturated aliphatic diol having a linear chain containing from 2 to 16 carbon atoms and optionally from a polycarboxylic acid containing at least 3 carboxyl groups or from a polyol comprising at least 3 hydroxyl groups, or (b 2) prepared from 40 to 100mol% of 1, 12-dodecanoic acid and from 0 to 60mol% of an aliphatic dicarboxylic acid having a linear chain containing from 4 to 9 carbon atoms, from a cycloaliphatic diol having from 3 to 16 carbon atoms and optionally from a polycarboxylic acid having at least 3 carboxyl groups or from a polyol having at least 3 hydroxyl groups, said semi-crystalline polyester having a melting point (Tm) of at least 40 ℃ and an acid number of from 5 to 50mg of KOH/g;

(c) a crosslinking agent.

EP0600546a1 discloses binder compositions for thermosetting powder coating compositions comprising (i) a polymer capable of reacting with epoxy groups, such as a polyester, polyacrylate or bisphenol-based polyether, and (ii) a crosslinking agent comprising epoxy groups.

Accordingly, a thermosetting powder coating composition is desired which has the ability to be cured at low temperatures (e.g., in the range of 110-225 ℃) preferably for up to 60 minutes and which is storage stable. In addition to the desire for storage stable thermosetting powder coating compositions that can be cured at low temperatures (curing at low temperatures, also referred to herein as low-temperature baking), it is also desirable that powder coating compositions made from low-temperature baking powder coating compositions have a range of properties, such as limited or no blooming, good smoothness, sufficient reverse impact resistance, preferably also a good degassing limit (degassing limit), and that the powder coatings are also economically attractive.

However, powder coatings obtained from low bake thermosetting powder coating compositions may exhibit poor physical and/or mechanical properties, such as poor smoothness and/or poor reverse impact resistance, due to insufficient curing and/or extensive blooming and/or poor degassing limit. In particular, the development of surface haze caused by blooming can become a significant problem. The blooming itself is usually manifested as surface haze, which is usually examined visually and evaluated qualitatively. When deposition of white or off-white material occurred and appeared as surface haze, the range was noted. The visual inspection can be performed on either a white coating or a dark coating. The Polyester blooming has been attributed to The presence of 22-membered cyclic oligomers formed by The condensation of two molecules of terephthalic acid and neopentyl glycol according to Focus on Powder Coatings, Vol.2003 (6), 6 months, 3-4 years, and The Navin Shah and Edward Nicholl of Rohm & Haas Powder Coatings, Inc., at International Waterborn, High Solids and Powder Coatings Symposium (New Orleans, 26-28 days 2.2003), references entitled "The Development of Non-bloating Polyester Resin and itsApplication to Low Temperature Process Powder Coatings". The 22-membered cyclic oligomer has a crystalline melting temperature of about 275 ℃ and 280 ℃ and is generally non-volatile at low curing temperatures (e.g., a curing temperature of 120 ℃ and 160 ℃).

It is therefore an object of the present invention to provide a storage stable, low bake thermosetting powder coating composition comprising a polyester and a crosslinker having functional groups capable of reacting with the functional groups of the polyester, which thermosetting powder coating composition, after curing, provides a powder coating with limited or preferably no blooming, good smoothness, sufficient Reverse Impact Resistance (RIR) and preferably also a good degassing limit.

This object is achieved by a resin composition comprising at least:

a. an organic phosphorus compound;

b. a branched amorphous carboxylic acid functionalized polyester having a T of at least 40 ℃_g，T_gSaid polyester comprising at least:

bi)1-45% mol of 2, 2-dimethyl-1, 3-propanediol;

bii) C other than 2, 2-dimethyl-1, 3-propanediol₃To C₅Aliphatic diols AD 1;

biii)C₆to C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)1 to 55 mol% of terephthalic acid;

wherein the% mol are based on the polyester.

Further, the present invention provides the resin composition according to claim 1.

When the resin composition of the invention is used in thermosetting powder coating compositions, the latter are storage stable and are capable of curing at low temperatures of 170 ℃, preferably 160 ℃, more preferably 150 ℃, even more preferably 140 ℃ for up to 30 minutes, preferably up to 15 minutes, to provide powder coatings with limited or preferably no blooming, good smoothness, sufficient Reverse Impact Resistance (RIR) and preferably also good degassing limit (measured according to ASTM D714 and the description of the invention) and good 20 °/60 ° specular gloss (measured at 20 ° or60 ° according to ASTM D523).

Additional advantages of thermosetting powder coating compositions comprising the resin composition of the present invention may be: thermosetting powder coating compositions have improved cost-efficiency, good storage stability (equal to or higher than 6 in the scale 1 representing very poor storage stability to 10 representing excellent storage stability), determined after 28 days at 40 ℃ using DIN 55990-7. Furthermore, the thermosetting powder coating compositions offer the manufacturers of metal coated articles the possibility of increased productivity and throughput of their coating lines, thus directly establishing a more cost-effective commercially and environmentally attractive solution.

As used herein, the plural form of a term (e.g., composition, component, resin, polymer) is to be understood to include the singular form and vice versa, unless the context clearly dictates otherwise.

For the upper and lower bounds of any parameter given herein, the bounds value is included in each range for each parameter. All combinations of minimum and maximum values of the parameters described herein can be used to define the parameter ranges for the various embodiments and preferences of the invention.

In the context of the present invention, unless otherwise stated to the contrary, the disclosure of alternative values for the upper or lower limits of the permissible ranges of parameters, plus the statement that one of said values is more preferred than the other, can be interpreted as implicit statements: each intermediate value of said parameter between said more preferred alternative value and said less preferred alternative value is itself preferred to said less preferred alternative value and also to each value between said less preferred alternative value and said intermediate value.

The terms "effective," "acceptable," "active," and/or "suitable" (e.g., with respect to any process, use, method, application, manufacture, product, material, formulation, compound, composition, monomer, oligomer, polymer precursor, and/or polymer of the present invention and/or described as appropriate herein) will be understood to refer to: if those features of the invention are used in the correct manner, they provide the desired properties to the materials to which they are added and/or incorporated for the purposes described herein. Such uses may be direct, for example when the material has the properties required for the aforementioned uses, or indirect, for example when the material is used as a synthetic intermediate and/or diagnostic tool to prepare other materials with direct effect. As used herein, these terms also refer to functional groups that are compatible with producing an effective, acceptable, reactive, and/or suitable end product.

As used herein, the term "comprising" means that the list that follows is non-exhaustive and may or may not include any other additional suitable item, such as one or more additional feature(s), component(s), ingredient(s) and/or substituent(s), as appropriate. As used herein, "substantially comprises" means that the component or list of components is present in the given material in an amount greater than or equal to about 90% w/w, preferably greater than or equal to 95% w/w, more preferably greater than or equal to 98% w/w of the total amount of the given material. As used herein, the term "consisting of … …" means that the list that follows is exhaustive and does not include additional items.

By "thermosetting powder coating composition" is meant herein a mixture of components, the composition of which, after curing, preferably after curing by heating, is capable of forming an irreversible crosslinked network (the so-called cured form). In the thermosetting composition of the present invention, crosslinking is carried out by: the permanent covalent bond is formed by a chemical reaction involving the carboxylic acid functional groups of the polyester of the invention and the functional groups of the crosslinker capable of reacting with the polyester (e.g. oxirane groups or β -hydroxyalkylamide groups). The result of these crosslinking reactions is: the cured form of the thermosetting powder coating composition becomes a "fixed" material, i.e., a material that is no longer capable of flowing or melting. For convenience, the term "material" as used herein may also refer to cured thermoset compositions suitable for use as materials optionally having other components, unless the context clearly indicates otherwise.

In the context of the present invention, a thermosetting powder coating composition is considered to have good storage stability when it is equal to or higher than 6 on a scale from 1 (very poor storage stability) to 10 (excellent storage stability). The storage stability was measured after 28 days at 40 ℃ using DIN 55990-7.

By "low bake thermosetting powder coating composition" herein is meant that the composition provides a powder coating (using the method of measuring RIR as described herein) that is capable of withstanding 60linch/lbs on a 75 μm thick film after curing at a temperature in the range of 140 ℃ to 160 ℃ for up to 30 minutes, preferably after curing at 160 ℃ for 10 minutes.

In the context of the present invention, "powder coating exhibiting limited or no blooming" means a powder coating exhibiting limited or no blooming using the evaluations described herein if prepared from a thermosetting powder coating composition cured at a temperature above 140 ℃. "blooming" refers to the formation of a white or off-white powder or crust on the surface of the coating upon curing. Blooming is assessed by the naked eye as described herein. For thermosetting powder coating compositions of the invention comprising the resin composition of the invention, the corresponding powder coating exhibits limited or preferably no blooming at a curing temperature above 140 ℃.

In the literature, the term "smoothness" is also referred to as "leveling". The smoothness of the powder coatings obtained by full curing of the corresponding thermosetting powder coating compositions of the present invention was determined by the following method: the Smoothness of the Coating was visually compared to a PCI Powder Coating Smoothness board (PCI Powder Coating Smoothness Board [ ACT Test papers Inc., APR22163(A) Batch:50708816]) at a Coating thickness of about 60 μm. The smoothness ratings ranged from PCI1 to PCI10, PCI1 representing the roughest coating and PCI10 representing the smoothest coating. For the thermosetting powder coating compositions of the present invention, it is desirable that their corresponding powder coatings exhibit smoothness equal to or higher than PCI 2. As proposed herein, the good smoothness of the powder coating is the smoothness of at least PCI2, preferably at least PCI3, more preferably at least PCI4, even more preferably at least PCI 5.

The Reverse Impact Resistance (RIR) of the powder coating obtained by curing a thermosetting powder coating composition at a certain temperature and time (line/lbs, l line/lbs =0.055997m/kg) is defined as: a75 μm thick powder coating prepared from the thermosetting powder coating composition of the present invention on a 0.8mm thick S-46 plate withstood the impact force of 160linch/lbs using 5/8 "balls (pass" according to ASTM D2794) as tested. RIR is determined using ASTM D2794 according to the methods described herein. "pass" in the RIR line indicates that the powder coating is able to withstand impact (showing no cracking or delamination) when the corresponding thermosetting powder coating composition is cured at 160 ℃ for 10 minutes. By "failure" is meant that the coating is unable to withstand the impact. Powder coatings with sufficient reverse impact resistance mean: the powder coatings were able to withstand reverse impact testing (as described herein) when cured at 160 ℃ for only 10 minutes.

The degassing limit (degassing limit) of the thermosetting powder coating composition of the invention is determined according to ASTM D714, as described herein. The degassing limit of the thermosetting powder coating compositions was tested on the powder coatings made therefrom and expressed as coating thickness (μm). The degassing limit is reported as the thickness of the coating (μm) at which blistering, pinholes or other coating defects begin to be visible to the naked eye. Higher degassing limit values are preferred compared to lower values. In the context of the present invention, a good degassing limit is a degassing limit at least equal to or higher than 90 μm

By "powder" or equivalently "powdered" is meant herein a solid substance reduced to a fine, loose particulate state, wherein the individual particles have a maximum particle size of at most 100 μm at 23 ℃ and atmospheric pressure, for example a particle size of at most 90 μm at 23 ℃. A particle is defined as a small object that (a) has the dimensions described below and (b) behaves as a whole in terms of its transport and properties. The particle size distribution (particle size distribution, PSD) of a powder is a list of values or a mathematical function defining the relative amount of particles present, sorted by size. In the context of the present invention, the terms "particle size" and "particle size distribution" are used interchangeably when used in relation to powders. The method used for determining the particle size of the particulate material according to the invention is sieve analysis. Accordingly, the powders are separated on sieves of different sizes. Accordingly, when using sieves of these sizes, the PSD is defined in terms of a discrete size range, e.g. "percent of the sample powder has a particle size in the range of 10 to 20 microns".

As used herein, "pulverizing" refers to the process of making a material into a powder.

The meaning of "resin" is herein understood to have the same meaning as understood by a person skilled in the art in thermal curing chemistry, i.e. to be understood as a low molecular weight polymer having reactive groups. The term low molecular weight refers to a molecular weight between several hundred g/mol (e.g., 1000) and several thousand g/mol (e.g., 10000). Ideally, the number of reactive groups per molecule is at least two.

By "composition" herein is meant a composition in which different chemical species are combined into a single entity. It is understood that the sum of any number expressed as a percentage herein cannot (allow for rounding errors) exceed 100%. For example, the sum of all components comprised by a composition of the invention (or a portion thereof) can total 100%, when expressed as a weight (or other) percentage of the composition (or the same portion thereof), allowing for rounding errors. However, when a list of components is non-exhaustive, the sum of the percentages of each of such components may be less than 100%, thereby allowing for a certain percentage of additional amounts of any additional components not expressly described herein.

By "resin composition" herein is meant a combination of a resin as defined herein and at least one other different chemical species.

By "dry" resin or polyester or composition is meant herein a resin or polyester or composition which does not contain any intentionally added water or moisture, but any of which may contain moisture absorbed from the atmosphere in an amount of up to 30, preferably up to 20% w/w based on the weight of the resin or polyester or composition respectively.

Herein, "room temperature" refers to a temperature of 23 ℃.

"solidification" herein refers to the process of becoming "fixed," that is, the material is no longer able to flow, melt, or dissolve. The term "curing" may be used interchangeably herein with "curing". Preferably, the curing of the thermosetting composition of the invention is carried out using heat, in which case the curing may be referred to as "thermal curing" (for clarity, the term heating does not include UV-induced curing or electron beam-induced curing). Optionally, a combination of heat and pressure may be used to cure the thermosetting composition of the present invention. In the context of the present invention, the term "thermally curing" does not exclude the use of pressure and heat for curing the thermosetting composition of the present invention.

An "article of manufacture" as used herein refers to a class of objects or items or elements designed for a certain purpose or to perform a specified function, which may stand alone. For example, the article may be a substrate. Exemplary substrates include, but are not limited to, non-heat sensitive substrates such as glass, ceramic, fiber cement board; or metals, such as aluminum, copper, steel; or heat-sensitive substrates such as wood (e.g., low density fiberboard, medium density fiberboard and high density fiberboard), and plastics, etc.; or a combination thereof.

In the context of the present invention, carboxylic acid functionalized polyesters refer to polyesters having predominantly carboxylic acid functional groups. The carboxylic acid functionalized polyester has an acid value higher than its hydroxyl value. In general, the carboxylic acid functionalized polyesters have an acid number between 14 and 120mg KOH/g polyester, while the hydroxyl number of the polyester is less than 13mg KOH/g polyester. For clarity, the OHV of the hydroxyl-functionalized polyester is higher than its AV. The acid number (AV) and hydroxyl number (OHV) of the polyester can be determined titratively according to ISO2114-2000 and ISO4629-1978, respectively. The carboxylic acid functionalized polyester may be prepared by: the synthesis conditions and the ratio of alcohol to carboxylic acid or anhydride are selected such that the carboxylic acid or anhydride is in excess of the alcohol to form a polyester having terminal carboxylic acid groups and/or carboxylic acid anhydride groups.

By "functional group" (functional group) herein is meant a covalently bonded group of atoms within a molecule, such as a carboxyl group in a carboxylic acid or a hydroxyl group in an alcohol or an oxirane group in an epoxy resin, which determines the chemical behavior of the compound and enables those molecules to perform a characteristic chemical reaction. In the case of carboxylic acid functionalized polyesters, the functional groups of the polyester are those covalently bonded atoms in the polyester which appear as a whole in a chemical reaction and which are capable of reacting with the functional groups of the crosslinking agent (e.g., with the oxirane groups of an epoxy resin crosslinking agent). Typically, in the case of carboxylic acid functionalized polyesters, the carboxylic acid functional groups are end groups (terminal groups) located at the end of the polyester macromolecular structure of each polyester molecule, including the end groups on the side chains which form part of the main chain and longer chains (as compared to the side chains) of the macromolecule.

In the context of the present invention, the branched amorphous carboxylic acid functional polyester of the resin composition of the present invention is referred to as "polyester" for short. The functional group of the polyester is a carboxylic acid end group or a carboxylic acid anhydride end group.

"branched" means a polyester having a functionality at least equal to or higher than 2.02 and at most 10.

Curing (cure) is used interchangeably with the terms "crosslinking" or "curing" in the present invention, while the powder coating is the object obtained when the thermosetting powder coating composition of the present invention is cured. "curing" herein refers to the process of becoming a "fixed" material. Preferably, the curing of the thermosetting powder coating composition is carried out using only thermal energy. For clarity, in the context of the present invention, the term "thermal energy" does not include UV-initiated curing or electron beam initiated curing. Thermal energy curing may be used interchangeably with heat curing or thermal curing.

By "powder" is meant herein a collection of solid particles wherein the largest particle size of the individual particles is at most 130 μm at 23 ℃, e.g. the particle size is at most 110 μm, e.g. at most 90 μm at 23 ℃.

As used herein, the term "powder coating" is a partially or fully cured (crosslinked) form of the thermosetting powder coating composition of the present invention. In other words, the powder coating results from the partial or full cure of the thermosetting powder coating composition.

Resin composition

In the context of the present invention, the resin composition comprises at least:

a. an organic phosphorus compound;

b. a branched amorphous carboxylic acid functionalized polyester having some specific characteristics.

Preferably, the resin composition of the present invention is solid at 23 ℃ and atmospheric pressure (═ 1 atm). Preferably, the resin composition is dry, even more preferably the resin composition is dry and solid at 23 ℃ and atmospheric pressure (═ 1 atm). Preferably, the resin composition is particularly suitable for use in thermosetting powder coating compositions. More preferably, the resin composition is particularly suitable for use in thermosetting powder coating compositions.

Organic phosphorus compound of resin composition

By "organophosphorus compound" herein is meant an organic compound having a molecular weight below 1500, which contains direct phosphorus-carbon bonds and which is chemically different from the polyester. Preferably, the organophosphorus compound has a molecular weight of less than 1200, even more preferably less than 1000, most preferably less than 800, for example less than 600.

Preferably, the organophosphorus compound is selected from the group of phosphonium salts having at least one phosphorus-carbon bond and/or organophosphines having at least one phosphorus-carbon bond. Even more preferably, the organophosphorus compound is selected from the group of quaternary phosphonium salts and/or tertiary organophosphines. Most preferably, the organophosphorus compound is selected from the group of quaternary phosphonium halides and/or tertiary organophosphines. In particular, the organophosphorus compound is a quaternary phosphonium salt comprising at least one phenyl group covalently bonded to phosphorus. More particularly, the organophosphorus compound is a quaternary phosphonium salt comprising at least two phenyl groups, each of which is covalently bonded to the same phosphorus. More particularly, the organophosphorus compound is a quaternary phosphonium salt comprising at least three phenyl groups, each of which is covalently bonded to the same phosphorus, e.g., the organophosphorus compound is a triphenylethyl phosphonium halide, e.g., the organophosphorus compound is a triphenylethyl phosphonium chloride, and the organophosphorus compound is a triphenylethyl phosphonium bromide.

Preferred counter anions in any of the above-mentioned preferred groups of organophosphorus are halide counter anions. In particular, the preferred counter anion in the quaternary phosphonium salt is bromine or chlorine.

Examples of quaternary phosphonium salts include, but are not limited to, dodecyltriphenylphosphonium halide, decyltriphenylphosphonium halide, octyldiphenylphosphonium halide, trioctylphosphonium halide, triphenylethylphosphonium bromide, tetraphenylphosphonium chloride, tetramethylphosphonium iodide, and mixtures thereof.

The organophosphines having at least one phosphorus-carbon bond are alkyl and/or aryl and/or phenyl derivatives of phosphines. Tertiary organic phosphorus of the formula R₃P, wherein R is, for example, alkyl, aryl, phenyl.

Examples of tertiary organic phosphines include, but are not limited to, dodecyldiphenylphosphine, decyldiphenylphosphine, octyldiphenylphosphine, trioctylphosphine, triphenylphosphine, and mixtures thereof. Preferably, the tertiary phosphine is triphenylphosphine and/or trimethylphenylphosphine.

Amine and/or amine salt of resin composition

The resin composition may also contain an amine and/or an amine salt, which is chemically different from the organophosphorus compound and the polyester. The amine of the resin composition is preferably a tertiary amine and the amine salt of the resin composition is preferably a quaternary amine salt. Preferably, the resin composition of the present invention further comprises a tertiary amine and/or a quaternary ammonium salt.

Amines are organic compounds and are derivatives of ammonia in which one or more hydrogen atoms are replaced by an organic substituent (e.g., an alkyl or aryl group or a phenyl group).

Tertiary amines are formed when all three hydrogen atoms are replaced by organic substituents, such as alkyl or aryl groups or phenyl groups. Examples of tertiary amines include, but are not limited to, octyldimethylamine, decyldimethylamine, dodecyldimethylamine, tetradecyldimethylamine, hexadecyldimethylamine (also known as palmityldimethylamine), octadecyldimethylamine, didodecylmonomethylamine, ditetradecylmethylamine, dihexadecylmethylamine, ditallowalkylmonomethylamine (hydrogenated tallowalkyl-dimethylamine), trioctylamine, tridecylamine, or mixtures thereof. Preferably, the tertiary amine is hexadecyldimethylamine and/or dodecyldimethylamine and/or tetradecyldimethylamine. More preferably, the tertiary amine is hexadecyldimethylamine.

There may also be four organic substituents on the nitrogen. These compounds are not amines, but are also known as quaternary ammonium salts, have a charged nitrogen center and have anions. Preferred counter anions are halide anions, and preferred halide anions in the quaternary ammonium salts are bromide or chloride.

Examples of quaternary ammonium salts include, but are not limited to, octyltrimethylammonium halide, decyltrimethylammonium halide, dodecyltrimethylammonium halide, tetradecyltrimethylammonium halide, hexadecyltrimethylammonium halide, octadecyltrimethylammonium halide, didodecyldimethylammonium halide, ditetradecylmethylammonium halide, dihexadecylmethylammonium halide, ditallowakylmonomethylammonium halide, trioctylammonium halide, tridecylammonium halide, tridodecylammonium halide, and mixtures thereof. Preferably, the quaternary ammonium salt is cetyltrimethylammonium bromide and/or cetyltriethylammonium bromide and/or cetyltrimethylammonium bromide.

The organic phosphorus compound and any tertiary amine and/or quaternary ammonium salt present are in the range of at least 0.05 to at most 5% w/w based on the total weight of the polyester and the organic phosphorus compound and any tertiary amine and/or quaternary ammonium salt present. Preferably, the amount of organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present is in the range of from at least 0.06 to at most 4% w/w based on the total weight of the polyester and organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present. More preferably, the amount of organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present is from at least 0.08 to at most 3% w/w based on the total weight of the polyester and organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present. Even more preferably, the amount of organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present is from at least 0.1 to at most 2% w/w based on the total weight of the polyester and organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present.

The resin composition may comprise all possible mixtures of organophosphorus compounds and/or amines and/or amine salts, including all the preferred compounds of these types of compounds mentioned above, such as phosphonium salts, tertiary organophosphines, tertiary amines and quaternary ammonium salts; and particularly most preferred are all possible mixtures of compounds such as triphenylethylphosphonium bromide, triphenylphosphine, trimethylphenylphosphine, hexadecyldimethylamine, dodecyldimethylamine, tetradecyldimethylamine, hexadecyltrimethylammonium bromide, decaalkyltriethylammonium bromide, hexadecyltrimethylammonium bromide.

Preferably, the organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present in the resin composition are added to the polyester at any stage in its preparation, while the polyester is maintained in the chemical reactor at a temperature of at least 140 ℃, up to 240 ℃, in particular up to 200 ℃. More preferably, the organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present in the resin composition are added to the polyester, while the polyester is maintained in the chemical reactor at a temperature of at least 140 ℃, up to 240 ℃, particularly up to 200 ℃, and at a point in time wherein the polyester has reached its target and desired physical properties, such as Mn, acid number, hydroxyl, functionality, and Tg as described herein. This provides greater control over the entire process of preparing the resin composition. Once prepared at a temperature in the range of 140 ℃ to 240 ℃ while still in the reactor, the polyester is treated in a liquid state.

By "reactor" or "chemical reactor" herein is meant a vessel designed to accommodate a chemical reaction. Typical examples of chemical reactors are tank reactors, pipeline reactors or tubular reactors. For clarity, the reaction vessel is not a substrate.

Polyester of resin composition

In addition to the organophosphorus compound, the resin composition comprises at least one branched amorphous carboxylic acid-functionalized polyester, referred to herein as "polyester".

Polyesters may, for example, be based on condensation reactions between alcohol-functional monomers (the polyol component of the polyester) and carboxylic acid-functional monomers (the polyacid component of the polyester).

The polyesters may be prepared by esterification or transesterification according to conventional polycondensation procedures, optionally in the presence of a conventional esterification catalyst such as dibutyltin oxide or tetrabutyl titanate. The preparation conditions and the-COOH/-OH ratio can be chosen so as to obtain a polyester having an acid number and/or a hydroxyl number within the targeted value range. Preferably, the polyester is prepared in large quantities without the use of solvents. The polycondensation reaction can occur at a temperature of 100 ℃ 350 ℃, preferably 290 ℃ or less, more preferably 150 ℃ 270 ℃. The reaction time may be from 2 to 96 hours, preferably less than 72 hours, more preferably less than 60 hours. The polycondensation reaction is preferably carried out in a reactor. The polycondensation reaction is preferably carried out under a nitrogen atmosphere. Preferably, the reaction is carried out under reduced pressure to remove water generated in the polycondensation reaction. The dry polyester can be isolated in any known manner, including directly from the reactor, from temperatures up to, for example, 140 ℃ to ambient temperature (e.g., 23 ℃), in any known manner: spray drying, freeze drying, flash evaporation to dryness or by devolatilization in a polycondensation reaction or combinations thereof.

The polyester may be obtained in two steps, comprising mixing and reacting a polyacid component with an excess of a polyol component, thereby forming a hydroxyl-functional polyester at the end of the first step; next, the hydroxyl functional polyester is reacted with an excess of carboxylic acid functional monomers to obtain the polyester of the present invention which is a branched amorphous carboxylic acid functional polyester.

The polyester at least comprises:

bi)1-45% mol of 2, 2-dimethyl-1, 3-propanediol;

bii) C other than 2, 2-dimethyl-1, 3-propanediol₃To C₅Aliphatic diols AD 1;

biii)C₆to C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)1 to 55 mol% of terephthalic acid;

wherein the% mol is based on the polyester.

For the sake of clarity, the total amount of monomers for the preparation of the polyester adds up to 100% mol. Preferably, the sum of the amounts of at least trifunctional monomer, terephthalic acid, 2-dimethyl-1, 3-propanediol (often referred to as neopentyl glycol or NPG) and aliphatic diol other than neopentyl glycol is at least 80% mol, preferably more than 85% mol, even more preferably at least 90% mol, most preferably at least 92% mol, such as at least 95% mol, such as 97% mol, such as 98% mol, such as 100% mol, based on the polyester.

Preferably, the polyester comprises at least:

bi)1-45% mol of 2, 2-dimethyl-1, 3-propanediol;

bii)2 to 21 mol% of C other than 2, 2-dimethyl-1, 3-propanediol₃To C₅Aliphatic diols AD 1;

biii)1-10% mol of C₆To C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)10 to 55 mol% of terephthalic acid;

wherein the% mol is based on the polyester.

The polyesters of the invention have an acid number of from 14 to 240mg/KOH/g of polyester. Preferably, the polyester has an acid number of at least 14, more preferably at least 18, even more preferably at least 20, most preferably at least 25, preferably at least 26, for example at least 28mg/KOH/g of polyester. Preferably, the polyester has an acid number of at most 120, more preferably at most 90, even more preferably at most 80, most preferably at most 75, such as at most 72, such as at most 69, such as at most 65, such as at most 60mg/KOH/g of polyester.

The polyester of the invention has a functionality of at least 2.02, more preferably at least 2.05, even more preferably at least 2.10, most preferably at least 2.15, for example at least 2.20. The polyester of the invention has a functionality of at most 10, preferably a functionality of at most 8, more preferably a functionality of at most 7, most preferably a functionality of at most 6, such as a functionality of at most 5, such as at most 4.5, such as at most 4.0, such as at most 3.5, such as at most 3.0, such as at most 2.9, such as at most 2.85, such as at most 2.80, such as at most 2.75, such as at most 2.7, such as at most 2.65.

In the context of the present invention, the functionality (f) of the polyester refers to the average content of carboxylic acid functional groups capable of reacting with, for example, ethylene oxide or β -hydroxyalkylamide groups per molecule of polyester. The functionality f of a polyester having a certain Mn (theoretical value) and acid number (AV) is calculated according to the following formula:

f=(M_n×AV)/56110

number average molecular weight (M)_n) The definition is as follows:

M_n＝(∑_iN_iM_i)/(∑_iN_i)

wherein N is_iIs the molecular weight M_nThe number of molecules of (c).

M_nThe calculation (theoretical value) is as follows: by using the target functionality (f) multiplied by 56110 and then dividing the result by the target acid number (AV, mg KOH/g polyester), calculated according to the following formula:

M_n＝(56110×f)/AV

number average molecular weight (M) of polyester_nTheoretical value) may be in the range of, for example, 1000-. Preferably, M of the polyester_nIs at least 1200, more preferably at least 1400, even more preferably at least 1700, most preferably at least 2000, such as at least 2200, such as at least 2400, such as at least 2500. Preferably, M of the polyester_nIs at most 10000, more preferably at most 9000, even more preferably at most 8000, most preferably at most 7500, such as at most 7000, such as at most 6800, such as at most 6500 g/mol.

At 23 ℃ and atmospheric pressure, the polyester is a solid. Preferably, the resin composition is dry. Even more preferably the resin composition is dry and solid at 23 ℃ and atmospheric pressure (═ 1 atm). Glass transition temperature (T) of polyester_g) Preferably at least 40, more preferably at least 42, even more preferably at least 45, most preferably at least 48, for example at least 50 ℃. Glass transition temperature (T) of polyester_g) Preferably at most 100, more preferably at most 90, even more preferably at most 80, most preferably at most 75, such as at most 70, such as at most 68 ℃. More preferably, the glass transition temperature (T) of the polyester_g) Ranging from40 to 70 ℃ since this range results in the best combination of storage stability and handleability of the thermosetting powder coating composition.

The polyesters of the invention are amorphous. Herein, "amorphous" means: the polyester has a glass transition temperature (T) in Differential Scanning Calorimetry (DSC) measurement at a heating rate of 5 deg.C/min as seen from a second heating curve to be described later_g) No apparent melting temperature (T)_m) And its melting enthalpy Δ H_fRanging from 0 to 40J/g, enthalpy of fusion is measured by DSC at a scan rate of 5 ℃/min from a second heating curve as will be explained below. Preferably of polyesters_fRanging from 0 to 30J/g, more preferably from 2 to 20J/g, even more preferably from 0 to 10J/g, for example 0J/g. Typically, amorphous polyester or amorphous resin compositions are characterized by high transparency (clarity)

In the context of the present invention, the glass transition temperature (T)_g) And melting temperature (T)_m) The assay was as follows: differential Scanning Calorimetry (DSC) was used on a Mettler Toledo, TA DSC821 by heating 10mg of the sample from 20 ℃ to 150 ℃ at a heating rate of 40 ℃/min, holding the sample at 150 ℃ for 15 minutes and then cooling the sample to 0 ℃ at a cooling rate of 40 ℃/min, holding the sample at 0 ℃ for 30 seconds and reheating the sample to 200 ℃ at a heating rate of 5 ℃/min and revealing the heat flow (heat flow). The melting temperature and Δ H of the polyester were recorded by melting peaks from the thermogram of the second heating_f. The glass transition temperature was measured from the step transition signal in the thermogram of the second heating with the temperature at which the step transition with a half-peak high temperature occurred.

The viscosity of the polyester at 160 ℃ is preferably at most 150, more preferably at most 125, most preferably at most 100, such as at most 80, such as at most 75, such as at most 70, such as at most 65, such as at most 60, such as at most 55 pa.s. The viscosity of the polyester at 160 ℃ is preferably at least 5, more preferably at least 8, even more preferably at least 12, most preferably at least 15, for example at least 17 pa.s. Rheology at 160 ℃ using cone and plateThe apparatus Brookfield CAP2000+ uses a rotor CAP-S-05 at 21rpm (shear rate 70S)^-1) The viscosity of the polyester was measured at the rotation speed of (1). The polyester is in the liquid state as it has just been prepared while still being maintained in the reactor at a temperature in the range of 130-240 ℃. The polyester solidifies as long as it is introduced at a temperature below its glass transition temperature (e.g., the polyester is discharged from the reactor onto a cooling belt maintained at room temperature or lower).

In addition to polyesters, other resins may be present in the resin composition of the present invention, as will be apparent to the skilled artisan. Advantageously, the resin composition of the invention comprises substantially only the polyester of the invention in addition to the organic phosphorus compound, since this provides a technically simple, less labour-saving and economically more attractive solution.

Preferably, the amount of polyester in the resin composition is at least 90% w/w, preferably at least 93% w/w, more preferably at least 95% w/w, even more preferably at least 97% w/w, in particular at least 98% w/w, more in particular at least 99% w/w, and most preferably 100% w/w, based on the total amount of resin present in the resin composition.

By at least trifunctional monomers is meant monomers having at least three functional groups. For example, the at least trifunctional monomer may be selected from the group consisting of: at least trifunctional carboxylic acids, at least trifunctional alcohols, at least trifunctional hydroxycarboxylic acids, and mixtures thereof. Depending on the chemical nature of the functional groups of the at least trifunctional monomers, the trifunctional monomers form either part of the polyol component of the polyester or part of the polyacid component of the polyester. If, for example, the at least trifunctional alcohol is a triol (trifunctional alcohol), then the triol forms part of the polyol component of the polyacid. If, for example, at least the trifunctional monomer is a trifunctional carboxylic acid, the trifunctional carboxylic acid forms part of the polyacid component of the polyacid.

The at least trifunctional carboxylic acids are monomers having at least three functional "carboxylic acid" groups. The carboxylic anhydride group should be counted as two "carboxylic acid" groups. The sum of the carboxylic acid groups should be at least three; for example, in the context of the present invention, the monomer having an anhydride group and a carboxylic acid group is a trifunctional carboxylic acid.

Examples of at least trifunctional carboxylic acids include, but are not limited to, trimellitic acid, trimellitic anhydride, and pyromellitic acid. If at least trifunctional carboxylic acids or anhydrides are used in the preparation of the polyesters, preference is given to using trimellitic acid or trimellitic anhydride. If the polyester has an acid number of above 45mg KOH/g of polyester, trimellitic acid and/or trimellitic anhydride are particularly preferred.

The at least trifunctional hydroxycarboxylic acid is a monomer having both a carboxylic acid (anhydride) functional group and an alcohol functional group. The sum of the "carboxylic acid" groups and the alcohol groups should be at least three. Also herein, a carboxylic anhydride group is counted as two "carboxylic acid" groups. An example of an at least trifunctional hydroxycarboxylic acid is dimethylolpropionic acid (DMPA).

The at least trifunctional alcohols are monomers having at least three alcohol groups. At least trifunctional alcohols may be used in the preparation of the polyesters. Examples of at least trifunctional alcohols include glycerol, hexanetriol, trimethylolethane, trimethylolpropane, pentaerythritol and sorbitol. If an at least trifunctional alcohol is used in the preparation of the polyester, trimethylolpropane is preferably used.

The at least trifunctional monomer is selected from the group consisting of: at least trifunctional carboxylic acids, at least trifunctional alcohols, at least trifunctional hydroxycarboxylic acids, and mixtures thereof. Preferably, the at least trifunctional monomer is a trifunctional alcohol or a trifunctional carboxylic acid.

The amount of at least trifunctional monomers is in the range from 0.05 mol% to 10mol%, based on the polyester. Preferably, the amount of the at least trifunctional monomer is in the range of at least 0.05%, more preferably at least 0.1%, even more preferably at least 0.2%, most preferably at least 0.3%, such as at least 0.4%, such as at least 0.5% mol, based on the polyester. Preferably, the amount of the at least trifunctional monomer is in the range of at most 10% mol, more preferably at most 8% mol, even more preferably at most 7% mol, most preferably at most 6% mol, such as at most 5% mol, such as at most 4% mol, such as at most 3% mol, such as at most 2% mol, based on the polyester. The amount and choice of the at least trifunctional monomer determines the functionality of the polyester.

Terephthalic acid forms part of the polyacid component of the polyester. The amount of terephthalic acid is preferably from 1 to 55 mol%, based on the polyester. For example, the amount of terephthalic acid is preferably at least 10% mol, more preferably at least 15% mol, even more preferably at least 20% mol, most preferably at least 22% mol, such as at least 24% mol, such as at least 26% mol, such as at least 28% mol, such as at least 30% mol, such as at least 32% mol, based on the polyester. For example, the amount of terephthalic acid is preferably at most 55% mol, preferably at most 53% mol, more preferably at most 52% mol, even more preferably at most 51% mol, most preferably at most 50% mol, such as at most 48% mol, such as at most 47% mol, such as at most 46% mol, such as at most 45% mol, based on the polyester. Since the thermosetting powder coating composition comprises the polyester of the resin composition of the present invention, the presence of terephthalic acid will increase the reverse impact resistance of the powder coating compared to a polyester not comprising terephthalic acid.

Preferably, the polyacid component of the polyester comprises terephthalic acid and Adipic Acid (AA). In this case, the polyester preferably contains at least:

bi)1-45% mol of 2, 2-dimethyl-1, 3-propanediol;

bii) C other than 2, 2-dimethyl-1, 3-propanediol₃To C₅Aliphatic diols AD 1;

biii)C₆to C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)1 to 55 mol% of terephthalic acid;

bvi)0 to 15% mol of adipic acid;

wherein the% mol is based on the polyester.

The amount of adipic acid is preferably from 0 to 15% mol, based on the polyester. For example, the amount of adipic acid is preferably at least 1% mol, more preferably at least 1.5% mol, even more preferably at least 2% mol, most preferably at least 2.5% mol, for example at least 3% mol, based on the polyester. For example, the amount of adipic acid is preferably at most 15% mol, preferably at most 12% mol, more preferably at most 10% mol, even more preferably at most 8% mol, most preferably at most 7% mol, for example at most 6.5% mol, based on the polyester.

More preferably, the polyacid component of the polyester comprises terephthalic acid, Adipic Acid (AA) and isophthalic acid (IPA), in which case the polyester preferably comprises at least:

bi)1-45% mol of 2, 2-dimethyl-1, 3-propanediol;

bii) C other than 2, 2-dimethyl-1, 3-propanediol₃To C₅Aliphatic diols AD 1;

biii)C₆to C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)1 to 55 mol% of terephthalic acid;

bvi)0 to 15% mol of adipic acid;

bvii)0 to 45mol% of isophthalic acid;

wherein the% mol is based on the polyester.

The amount of isophthalic acid is preferably from 0 to 45% by mol, based on the polyester. For example, the amount of isophthalic acid is preferably at least 1% mole, more preferably at least 2% mole, even more preferably at least 2.2% mole, most preferably at least 2.5% mole based on the polyester. For example, the amount of isophthalic acid is preferably at most 45% mol, more preferably at most 40% mol, even more preferably at most 35% mol, most preferably at most 30% mol, such as at most 25% mol, such as at most 20% mol, such as at most 15% mol, based on the polyester.

The acid component of the polyacid of the polyester may also comprise other carboxylic functional monomers than terephthalic acid, or isophthalic acid or adipic acid, for example dicarboxylic acids having preferably 3 to 40 carbon atoms, more preferably selected from dicarboxylic acids preferably having 8 to 14 carbon atoms of aromatic dicarboxylic acids, preferably having 4 to 12 carbon atoms of aliphatic dicarboxylic acids and/or preferably having 8 to 12 carbon atoms of cycloaliphatic dicarboxylic acids. The dicarboxylic acids may be branched, non-linear or linear. Examples of dicarboxylic acid functional monomers suitable for use in the polyester include, for example, 2, 6-naphthalenedicarboxylic acid, 4 '-diphenyletherdicarboxylic acid, tetrahydrophthalic acid, trimellitic acid, pyromellitic acid, hexahydroterephthalic acid (cyclohexanedicarboxylic acid), phthalic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, succinic acid, maleic acid, phthalic acid, 1, 4-cyclohexanedicarboxylic acid, cyclohexanediacetic acid, diphenyl-4, 4' -dicarboxylic acid, phenylenedi (oxyacetic acid), glutaric acid, and fumaric acid, and mixtures thereof. These carboxylic acid functional monomers may be used as such or as their anhydrides, acid chlorides or lower alkyl esters available. Preferred carboxylic acids are carboxylic acid functional monomers other than terephthalic acid, or isophthalic acid, or adipic acid.

Preferably, the polyacid component of the polyester comprises terephthalic acid and/or adipic acid and/or combinations thereof.

Aromatic acids of monocarboxylic acids, such as benzoic acid, tert-butylbenzoic acid or hexahydrobenzoic acid, may also be used in the preparation of the polyesters.

The 2, 2-dimethyl-1, 3-propanediol (neopentyl glycol, NPG) used to prepare the polyester typically ranges from 1% mol to 45% mol based on the polyester. Preferably, the amount of NPG is at least 5% mol, more preferably at least 8% mol, even more preferably at least 10% mol, most preferably at least 15% mol, such as at least 16% mol, such as at least 18% mol, based on the polyester. Preferably, the amount of NPG is at most 45% mol, more preferably at most 43% mol, even more preferably at most 40% mol, most preferably at most 38% mol, for example at most 35% mol, based on the polyester.

AD1 is aliphatic C excluding 2, 2-dimethyl-1, 3-propanediol (neopentyl glycol)₃To C₅Diol, AD1 is not neopentyl glycol for clarity. For clarity, herein "C₃To C₅"means" three to five carbon atoms ". For clarity, AD1 may also have at least one ether linkage (-C-O-C-) in its chemical structure. Preferably AD1 is a saturated aliphatic diol. More preferably, AD1 is a saturated aliphatic diol having only hydrogen-carbon bonds, carbon-carbon single bonds, carbon-oxygen-carbon single bonds, and two hydroxyl groups, each hydroxyl group being attached to a carbon atom. Even more preferably, AD1 is a saturated aliphatic diol having only hydrogen-carbon bonds, single carbon-carbon bonds, and two hydroxyl groups, with each hydroxyl group attached to a carbon atom. The amount of AD1 is preferably in the range of 2-21% mol based on the polyester. Preferably, the amount of AD1 is at least 2% mol, more preferably at least 3% mol, even more preferably at least 4% mol, most preferably at least 4.5% mol, for example at least 5% mol based on the polyester. Preferably, the amount of AD1 is at most 20% mol, more preferably at most 19% mol, even more preferably at most 18% mol, most preferably at most 17% mol, such as at most 16% mol, such as at most 15% mol, based on the polyester.

AD1 aliphatic C₃To C₅Examples of diols include, but are not limited to, diethylene glycol, 1, 3-propanediol, 1, 2-propanediol, 1, 4-butanediol, 1, 3-butanediol, 1, 2-butanediol. Preferably, AD1 is 1, 2-propanediol.

Use of AD1 aliphatic C₃To C₅One of the advantages of diols may be: it is advantageous to improve the storage stability of thermosetting powder coating compositions.

AD2 is aliphatic or cycloaliphatic C₆To C₅₀A diol. For clarity, herein "C₆To C₅₀"means" six to fifty carbon atoms ". Preferably AD2 is at least C₆Aliphatic or cycloaliphatic diols. More preferably, AD2 is at most C₄₀Aliphatic or cycloaliphatic diols. Even more preferably AD2 is at most C₃₀Aliphatic or cycloaliphatic diols. Most preferably, AD2 is at most C₂₅Aliphatic or cycloaliphatic diols. In particular AD2 is at most C₂₂Aliphatic or cycloaliphatic diols. More particularly AD2 of at mostC₂₀Aliphatic or cycloaliphatic diols. Even more particularly, AD2 is at most C₁₈Aliphatic or cycloaliphatic diols. Most particularly, AD2 is at least C₁₆Aliphatic or cycloaliphatic diols. For example AD2 is at most C₁₄Aliphatic or cycloaliphatic diols. For example AD2 is at most C₁₂Aliphatic or cycloaliphatic diols. For example AD2 is at most C₁₀Aliphatic or cycloaliphatic diols. For clarity, AD2 may also contain at least one ether linkage (-C-O-C-) in its chemical structure. Preferably, AD2 is a saturated aliphatic or cycloaliphatic diol. More preferably AD2 is a saturated aliphatic or cycloaliphatic diol. Even more preferably, AD2 is a saturated aliphatic or cycloaliphatic diol having only hydrogen-carbon bonds, carbon-carbon single bonds, carbon-oxygen-carbon single bonds, and two hydroxyl groups, each hydroxyl group being attached to a carbon atom. Most preferably, AD2 is a saturated aliphatic or cycloaliphatic diol having only hydrogen-carbon bonds, single carbon-carbon bonds, and two hydroxyl groups, each hydroxyl group being attached to a carbon atom.

The amount of AD2 is preferably in the range of 1-10% mol based on the polyester. Preferably, the amount of AD2 is at least 1% mol, more preferably at least 1.5% mol, even more preferably at least 2% mol, most preferably at least 2.5% mol, for example at least 3% mol, based on the polyester. Preferably, the amount of AD2 is at most 10% mol, more preferably at most 9.5% mol, even more preferably at most 9% mol, most preferably at most 8.5% mol, such as at most 8% mol, such as at most 7.5% mol, such as at most 7% mol, based on the polyester. AD2 aliphatic C₆To C₅₀Examples of diols include, but are not limited to, 1, 6-hexanediol, 1, 7-heptanediol, dipropylene glycol, 2-bis- (4-hydroxy-cyclohexyl) -propane (hydrogenated bisphenol A), 1, 4-dimethylolcyclohexane, hydroxypivalate of neopentyl glycol, 2-bis [4- (2-hydroxyethoxy) -phenyl-pivalate]Propane, 2-ethyl-2-butylpropanediol-1, 3(═ butylethylpropanediol), 2-ethyl-2-methylpropanediol-1, 3(═ ethylmethylpropanediol). Preferably, AD2 is 1, 6-hexanediol.

Using AD2 aliphatic or cycloaliphatic C₆To C₅₀Diols and especially C₆To C₂₀One of the advantages of diols may be: it is advantageous to improve the smoothness and/or the reverse impact resistance of the powder coatingAnd (4) sex.

Preferably, the polyester comprises 3 to 21% mol of AD1 and 2 to 10% mol of AD2, based on the polyester.

Preferably, the molar ratio of AD1 to AD 2(═ mol AD1/mol AD2) in the polyester is at least equal to or higher than 1 and at most equal to 10.

Preferably, AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

Preferably, the resin composition of the present invention comprises at least:

a. an organic phosphorus compound;

b. a branched amorphous carboxylic acid functionalized polyester having a T of at least 40 ℃_gT is measured by differential scanning calorimetry at a heating rate of 5 ℃/min_gSaid polyester comprising at least:

bi)1-45% mol of 2, 2-dimethyl-1, 3-propanediol;

bii)2-21% mol of C other than 2, 2-dimethyl-1, 3-propanediol₃To C₅Aliphatic diols AD 1;

biii)1-10% mol of C₆To C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)10 to 55 mol% of terephthalic acid;

wherein the% mol is based on the polyester.

Preferably, the resin composition of the present invention comprises at least:

a. an organic phosphorus compound;

bi)1-45% mol of 2, 2-dimethyl-1, 3-propanediol;

bii) C other than 2, 2-dimethyl-1, 3-propanediol₃To C₅Aliphatic diols AD 1;

biii)C₆to C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)10 to 55 mol% of terephthalic acid;

wherein the% mol is based on the polyester.

Preferably, the resin composition of the present invention comprises at least:

a. an organic phosphorus compound;

bi)18-35% mol of 2, 2-dimethyl-1, 3-propanediol;

bii) C other than 2, 2-dimethyl-1, 3-propanediol₃To C₅Aliphatic diols AD 1;

biii)C₆to C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)10 to 55 mol% of terephthalic acid;

wherein the% mol is based on the polyester.

Preferably, the resin composition of the present invention comprises at least:

a. an organic phosphorus compound;

b. a branched amorphous carboxylic acid functionalized polyester having a T of at least 40 ℃_gMeasured by differential scanning calorimetry at a heating rate of 5 ℃/minQuantity T_gSaid polyester comprising at least:

bi)18-35% mol of 2, 2-dimethyl-1, 3-propanediol;

bii)3 to 21 mol% of C other than 2, 2-dimethyl-1, 3-propanediol₃To C₅Aliphatic diols AD 1;

biii)2-10% mol of C₆To C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)10 to 55 mol% of terephthalic acid;

wherein the% mol is based on the polyester.

Preferably, the resin composition of the present invention comprises at least:

a. an organic phosphorus compound;

bi)18-35% mol of 2, 2-dimethyl-1, 3-propanediol;

biii)2-10% mol of C₆To C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)10 to 55 mol% of terephthalic acid;

the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10, where the% mol is based on the polyester.

Preferably, the resin composition of the invention is solid at 23 ℃ and atmospheric pressure, comprising at least:

a. an organic phosphorus compound;

b. branched amorphous carboxylic acid functionalized polyester having a theoretical M of at least 1500g/mol and at most 8000g/mol_nAn acid number of at least 25 and at most 90mg KOH/g polyester, a hydroxyl number of at most 8mg KOH/g polyester, a T of at least 40 ℃ and at most 90 ℃_gSaid polyester comprising at least:

bi)18-35% mol of 2, 2-dimethyl-1, 3-propanediol;

biii)2-10% mol of C₆To C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)10 to 55 mol% of terephthalic acid;

wherein the% mol is based on the polyester.

Preferably, the resin composition of the present invention comprises at least:

a. an organic phosphorus compound;

bi)18-35% mol of 2, 2-dimethyl-1, 3-propanediol;

bii)3 to 21% mol of 1, 2-propanediol;

biii)2 to 10% mol of 1, 6-hexanediol;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)10 to 55 mol% of terephthalic acid;

the molar ratio of 1, 2-propanediol to 1, 6-hexanediol in the polyester (═ mol1, 2-propanediol/mol 1, 6-hexanediol) is at least equal to or higher than 1 and at most equal to 10, where the% mol is based on the polyester.

Other suitable diols which can be used to prepare the polyesters are, for example, ethylene glycol.

Any feature or preferred combination of features or preferred combinations of ranges of features disclosed in the present invention and associated with the organophosphorus compounds, amines, amine salts and polyesters of the resin composition of the present invention can be combined.

In another aspect, the present invention provides a process for preparing a resin composition according to the invention, which is solid at 23 ℃ and atmospheric pressure, comprising at least the following steps:

a. preparing a polyester according to the invention in a chemical reactor;

b. at least the organophosphorus compound defined herein is added at any stage in the preparation of the polyester, at a temperature between 140 and 240 ℃, and while the polyester is still in the chemical reactor, so as to obtain a mixture of the organophosphorus compound and the polyester already prepared;

c. curing the mixture obtained in step b) to obtain the resin composition according to the invention.

In another embodiment, the present invention provides a process for preparing a resin composition according to the present invention, said resin composition being solid at 23 ℃ and atmospheric pressure, comprising at least the steps of:

a. preparing a polyester according to the invention in a chemical reactor;

b. adding at least the organophosphorus compound and any amine and/or amine salt as defined herein at any stage in the preparation of the polyester, and while the polyester is still in the chemical reactor, at a temperature between 140 and 240 ℃, to obtain a mixture of the organophosphorus compound and any amine and/or amine salt with the polyester already prepared;

a. preparing a polyester according to the invention in a chemical reactor;

b. adding at least an organophosphorus compound as defined herein to the already produced polyester at a temperature of between 140 and 240 ℃ and while the polyester is still in the chemical reactor, so as to obtain a mixture of the organophosphorus compound and the already produced polyester;

a. preparing a polyester according to the invention in a chemical reactor;

adding at least the organophosphorus compound and any amine and/or amine salt defined herein to the already-produced polyester at a temperature of between 140 and 240 ℃ while the polyester is still in the chemical reactor, to obtain a mixture of the organophosphorus compound and any amine and/or amine salt with the already-produced polyester;

Thermosetting powder coating composition

The thermosetting powder coating composition of the present invention comprises the resin composition of the present invention and at least one crosslinker having functional groups capable of reacting with the carboxylic acid functional groups of the polyester.

The thermosetting powder coating composition of the present invention comprises the polyester in an amount of 50-98% w/w and the crosslinker having functional groups capable of reacting with the carboxylic acid functional groups of the polyester in an amount of 2-50% w/w based on the total amount of polyester and crosslinker.

The cross-linking agent in the thermosetting powder coating composition according to the invention may be a compound having at least two β -hydroxyalkylamide (BHA) groups or a compound having at least two oxirane rings. In the context of the present invention, a compound having at least two oxirane rings is referred to as "epoxy compound" and a compound having at least two β -hydroxyalkylamide (BHA) groups is referred to as "BHA compound". Preferably, the crosslinker in the thermosetting powder coating composition according to the invention is an epoxy compound.

Suitable examples of commercially available BHA compounds are N, N, N ', N' -tetrakis- (2-hydroxyethyl) -adipamide (R) from EMS Chemie AGXL-552) and N, N, N ', N' -tetrakis (2-hydroxypropyl) -adipamide (II)QM1260）。

If the crosslinker is a BHA compound, the amount of polyester in the thermosetting coating composition is preferably in the range of 85-98% w/w, more preferably 90-98% w/w, even more preferably 93-97% w/w, based on the total amount of polyester and crosslinker.

Preferably, the crosslinker in the thermosetting powder coating composition of the invention is an epoxy compound. More preferably, the crosslinker in the thermosetting powder coating composition of the invention is only an epoxy compound.

Examples of epoxy compounds (also referred to as epoxy resins or epoxy crosslinkers) include bisphenol-a resins, bisphenol-F epoxy resins, glycidyl esters, triglycidyl isocyanurates, and combinations thereof. Preferably, an epoxy compound selected from the group consisting of bisphenol-a resins, bisphenol-F epoxy resins, glycidyl esters, and combinations thereof is used. More preferably, the epoxy compound is selected from the group consisting of bisphenol-a resins, glycidyl esters, and combinations thereof. Most preferably, the epoxy compound is a bisphenol-a resin.

Suitable examples of commercially available bisphenol-A resins includeGT-7004(Huntsman)、1002(Shell) andand(Dow)。

suitable examples of commercially available glycidyl esters includePT910 andPT 912. Examples of triglycidyl isocyanurate include TGIC, which may be referred to asPT810 was purchased.

The molecular weight of the epoxy compound can vary widely. This is usually expressed as Epoxy Equivalent Weight (EEW). The epoxy equivalent is the weight of the epoxy compound containing exactly one mole of epoxy groups, expressed in g/mol. Preferably the EEW ranges from 100-.

If the crosslinking agent is an epoxy compound, the amount of polyester in the thermosetting coating composition preferably ranges from 50-98% w/w, more preferably 50-90% w/w, even more preferably 50-85% w/w, most preferably 50-80% w/w, such as 50-75% w/w, such as 60-75% w/w, such as 65-75% w/w, such as 67-75% w/w, based on the total amount of polyester and crosslinking agent.

Especially preferred are thermosetting powder coating compositions wherein the crosslinking agent is an epoxy compound and the amount of polyester is in the range of 67-75% w/w based on the total amount of polyester and crosslinking agent.

Glass transition temperature (T) of uncured thermosetting powder coating composition_g) Preferably at least 20 deg.c, more preferably at least 25 deg.c, even more preferably at least 35 deg.c, most preferably at least 45 deg.c. Glass transition temperature (T) of uncured thermosetting powder coating composition_g) Preferably at most 100 deg.c, more preferably at most 90 deg.c, even more preferably at most 80 deg.c, most preferably at most 70 deg.c. Having T in a thermosetting powder composition_gAlso has T_mWhen, T_mPreferably at least 30 deg.c, more preferably at least 40 deg.c, even more preferably at least 45 deg.c, most preferably at least 50 deg.c. Preferably, T of the uncured thermosetting powder coating composition_mAt most 160 deg.c, more preferably at most 140 deg.c, even more preferably at most 120 deg.c, most preferably at most 100 deg.c. Glass transition temperature (T) of uncured thermosetting powder coating composition_g) And/or T_mMeasured by temperature-Modulated DSC (MDSC). T is performed using a TA instruments Q2000MDSC with RCS22-90 cooling unit_gAnd/or T_mThe test of (1). The test was conducted in a nitrogen atmosphere with indium, zinc and water to calibrate the MDSC meter. The software used to manipulate the MDSCs and analyze the heat map spectra was a Q series modified version 2.8.0394 from taiinstruments. Approximately 10mg of the sample sealed in an aluminum DSC pan was heated from 0 ℃ to 200 ℃ at a heating rate of 5 ℃/minute with a temperature modulation amplitude of 40 seconds within 0.5 ℃. Determination of T occurring in reversible heat flow by using analysis software_gA signal.

In addition to polyesters, other resins may be present in the thermosetting powder coating compositions of the present invention, as will be apparent to the skilled person. Preferably, the amount of polyester in the thermosetting powder coating composition is 90% w/w, preferably at least 93% w/w, more preferably at least 95% w/w, even more preferably at least 97% w/w, in particular at least 98% w/w, more in particular at least 99% w/w and most preferably 100% w/w based on the total amount of resin present in the thermosetting powder coating composition. Preferably, the thermosetting powder coating composition of the invention comprises only the polyester of the invention, as this provides technical simplicity.

It is advantageous to use only the polyester of the invention in thermosetting powder coating compositions, since the use of only polyester in thermosetting powder coating compositions is more labour-saving and economically attractive than the use of resin mixtures.

Any feature or preferred combination of features or preferred combinations of ranges of features disclosed herein and associated with the resin composition and crosslinker of the invention may be combined.

Any feature or preferred combination of features or preferred combinations of ranges of features disclosed herein and associated with the resin composition and thermosetting powder coating composition of the present invention may be combined.

The thermosetting powder coating compositions according to the invention may also comprise waxes, pigments, fillers and/or customary (processing) additives, such as degassing agents, levelling (smoothing) agents, appearance enhancers or (light) stabilizers. The pigments may be inorganic or organic. Suitable inorganic pigments include, for example, titanium dioxide, zinc sulfide, zinc phosphate, mica, iron oxide, and/or chromium oxide. Suitable organic pigments include, for example, azo compounds. Suitable fillers include, for example, metal oxides, silicates, carbonates, and sulfates. Suitable stabilizers include, for example, primary and/or secondary antioxidants and UV stabilizers, such as quinones, (sterically hindered) phenolic compounds, phosphonites, phosphites, thioethers and HALS (hindered amine light stabilizers). Examples of suitable degassing agents include cyclohexane dimethanol dibenzoate, benzoin, and benzoin derivatives, such as those described in W002/50194. Other additives, such as additives to improve triboelectric chargeability, may also be added. Some of these additives may be added after the polyester is synthesized in the chemical reactor and before the polyester is discharged from the reactor. Alternatively, some of these additives may be added to a premix of the thermosetting powder coating composition as described above or to an extruder, for example by liquid injection.

In another aspect, the present invention provides a process for preparing a thermosetting powder coating composition according to the invention, comprising at least the following steps:

a. mixing a resin composition as defined herein with a cross-linking agent having functional groups capable of reacting with the carboxylic acid groups of the polyester of the resin composition to obtain a pre-mix;

b. heating the obtained premix, preferably in an extruder, to obtain an extrudate;

c. cooling the extrudate obtained in step b) to obtain a solidified extrudate;

d. the obtained solidified extrudate is broken up into smaller particles to obtain a thermosetting powder coating composition and the prepared powder particles are preferably classified by sieving, collecting the sieve fraction with a particle size below 130 μm, preferably below 90 μm.

In a preferred embodiment, the present invention provides a process for preparing a thermosetting powder coating composition according to the present invention, comprising at least the following steps:

a. preparing a resin composition as described in any one of the examples herein;

b. mixing the resin composition obtained in step a) with a crosslinking agent having functional groups capable of reacting with the carboxylic acid groups of the polyester of the resin composition to obtain a premix;

c. heating the obtained premix, preferably in an extruder, to obtain an extrudate;

d. cooling the extrudate obtained in step c) to obtain a solidified extrudate;

e. the obtained solidified extrudate is broken up into smaller particles to obtain a thermosetting powder coating composition and the prepared powder particles are preferably classified by sieving, collecting the sieve fraction with a particle size below 130 μm, preferably below 90 μm.

Preferably, the premix is heated at a temperature in the range of 80-130 ℃, more preferably in the range of 90-120 ℃. If the premix is heated in an extruder, it is preferred to use temperature control to avoid excessive temperatures that would result in curing of the thermosetting coating composition in the extruder. Other ways of controlling the temperature, especially in large extruders, may be to control the temperature by controlling the overall throughput, the feeding of the pellets, the geometry and speed of the screw.

In another aspect, the present invention relates to a method of coating a substrate comprising the steps of:

a) applying the thermosetting powder coating composition according to the invention on a substrate such that the coating partially or completely coats the substrate;

b) the resulting partially or fully coated substrate is heated for a time and at a temperature to at least partially cure the coating.

The thermosetting powder coating compositions of the present invention can be applied by techniques known to those of ordinary skill in the art, such as by electrostatic spraying or by electrostatic fluidized bed.

Heating of the coated substrate can be carried out using conventional methods, for example with a convection oven and/or an infrared lamp or flame spray gun.

In case a convection oven is used to heat the coating, the time for at least partially curing the coating is preferably below 60 minutes and usually above 1 minute. More preferably, if a convection oven is used to heat the coating, the cure time is less than 40 minutes. The curing temperature is typically in the range of 110-. The thermosetting powder coating composition of the invention can be cured at a temperature as low as 170 ℃, preferably 160 ℃, more preferably 150 ℃, even more preferably 140 ℃ for up to 30 minutes, preferably up to 15 minutes, even more preferably up to 10 minutes. For example, the curing time and temperature of the powder coating composition of the invention may be 5 minutes at 170 ℃, or 10 minutes at 160 ℃, or 15 minutes at 150 ℃ or 30 minutes at 140 ℃.

The thermosetting powder coating composition of the invention is suitable not only for low-temperature baking but also for rapid curing. Thermosetting powder coating compositions which can be cured at lower temperatures are known and at the same time can be cured at relatively higher temperatures, but the curing time is significantly reduced, allowing the end user (powder coating applicator) to select the optimum curing conditions as desired, thus maximizing process efficiency and throughput of the powder coating line.

In another aspect, the present invention relates to a method of forming a coating on a substrate comprising the steps of: the thermosetting powder coating composition according to the invention is applied to a substrate and the composition is cured to form a coating layer, which in the context of the present invention is referred to as "powder coating". Curing of the composition is carried out at a temperature in the range of at least 110 ℃ to at most 225 ℃ for a period of time in the range of at least 1 minute to at most 60 minutes. Preferably, the curing of the composition is carried out at a temperature in the range of at least 130 ℃ to at most 180 ℃ for a period of time in the range of at least 1 minute to at most 45 minutes. More preferably, the curing of the composition is carried out at a temperature in the range of at least 140 ℃ to at most 170 ℃ for a period of time in the range of at least 5 minutes to at most 30 minutes.

In another aspect, the present invention relates to powder coatings prepared by partial or complete curing of the thermosetting powder coating compositions according to the invention. The powder coating may be a primer, a topcoat or a midcoat, the latter acting, for example, as an interlayer adhesion promoter or as a protective coating.

In another aspect, the present invention relates to a coated substrate comprising a coating obtained when the thermosetting powder coating composition according to the invention is cured.

The invention also relates to a substrate which is partially or completely coated with a thermosetting powder coating composition according to the invention or a substrate coated with a coating according to the invention.

The invention also relates to a substrate partially or completely coated with a thermosetting powder coating composition according to the invention or coated with a coating according to the invention, wherein the substrate is selected from the group consisting of glass, ceramic, fiber cement board, or metal such as aluminum, copper or steel.

Typical examples of substrates include glass, ceramic, fiber cement board, or metal (such as aluminum, copper, or steel). The steel substrate includes, for example, carbon steel in which carbon is a main alloying component. Carbon steels typically contain 0.2-1.5% w/w carbon based on the total weight of the alloy composition, and often contain other components such as manganese, chromium, nickel, molybdenum, copper, tungsten, cobalt or silicon depending on the desired steel properties. The properties of the steel are similar to iron if the carbon content is not very high (e.g. not more than 1.5% w/w based on the total weight of the alloy composition). The steel may be surface treated (with zinc or zinc phosphate or iron phosphate, etc.) or not.

In another aspect, the present invention relates to an article comprising a substrate according to the present invention and at least one or more substrates with which the coated substrate is in contact or which encapsulates said coated substrate.

In a further aspect, the present invention also relates to the use of the thermosetting powder coating composition according to the invention for coating a substrate.

Use of the polyester according to the invention in automotive applications, marine applications, aeronautical applications, medical applications, protective applications, sports/recreational applications, architectural applications, bottle filling applications, household applications and mechanical applications.

Use of the resin composition according to the invention in automotive applications, marine applications, aeronautical applications, medical applications, protective applications, sports/recreational applications, construction applications, bottle filling applications, household applications and mechanical applications.

Use of the thermosetting powder coating composition according to the invention in automotive applications, marine applications, aeronautical applications, medical applications, protective applications, sports/recreational applications, construction applications, bottle filling applications, household applications and mechanical applications.

Use of the coated substrate according to the invention in automotive applications, marine applications, aeronautical applications, medical applications, protective applications, sports/recreational applications, construction applications, bottle filling applications, household applications and mechanical applications.

Use of the article according to the invention in automotive applications, marine applications, aeronautical applications, medical applications, protective applications, sports/recreational applications, architectural applications, bottle filling applications, household applications and mechanical applications.

Use of a polyester according to the invention in a thermosetting powder coating composition according to the invention to provide a coating upon curing of the composition, which coating is free of blooming and has a smoothness of at least PCI2, wherein the smoothness of the coating is compared to the smoothness of a PCI powder coating smoothness board [ ACT Test Panels inc., APR22163(a) ] at a coating thickness of about 60 μm.

Use of an organophosphorus compound in a thermosetting powder coating composition according to the invention to provide, upon curing of the composition, a coating which is free of blooming and has a smoothness of at least PCI2, wherein the smoothness of said coating is compared to the smoothness of a PCI powder coating smoothness board [ ACT Test Panels inc., APR22163(a) ] at a coating thickness of about 60 μm.

Use of an organophosphorus compound and any amine and/or amine salt in a thermosetting powder coating composition according to the invention to provide a coating upon curing of the composition, which coating is free of blooming and has a smoothness of at least PCI4, wherein the smoothness of said coating is compared to the smoothness of a PCI powder coating smoothness board [ ACT TestPanels inc., APR22163(a) ] at a coating thickness of about 60 μm.

Use of a resin composition in a thermosetting powder coating composition according to the invention to provide a coating upon curing of the composition, which coating is free of blooming and has a smoothness of at least PCI2, wherein the smoothness of the coating is compared to the smoothness of a PCI powder coating smoothness board [ ACT Test Panels inc., APR22163(a) ] at a coating thickness of about 60 μm.

Use of a resin composition in a thermosetting powder coating composition according to the invention to provide a coating upon curing of the composition, which coating is free of blooming and has a smoothness of at least PCI4, wherein the smoothness of the coating is compared to the smoothness of a PCI powder coating smoothness board [ ACT Test Panels inc., APR22163(a) ] at a coating thickness of about 60 μm.

Examples of automotive applications include, but are not limited to, automotive parts, agricultural machinery, composite structures, ceramic structures, and the like.

Examples of marine applications include, but are not limited to, marine components, ship components, ships.

Examples of aerospace applications include, but are not limited to, aircraft, helicopters, composite structures, ceramic structures, and the like.

Examples of medical applications include, but are not limited to, prosthetic joints, meshes, woven or non-woven sheets, tapes, ribbons, tapes, cables, tubular products such as ligament substitutes, composite structures, ceramic structures, and the like.

Examples of protective applications include, but are not limited to, ballistic equipment, body armor, bullet resistant vests, bullet resistant helmets, bullet resistant vehicles, composite structures, ceramic structures, and the like.

Examples of sports/entertainment applications include, but are not limited to, fencing, skating, skateboarding, snowboarding, slings in sports parachutes, paragliders, kites, kite strings for kite sports, mountaineering gear, composite structures, ceramic structures, and the like.

Examples of architectural applications include, but are not limited to, windows, doors, (false) walls, cables, and the like.

Examples of home applications include, but are not limited to, home appliances, white goods, furniture, office furniture, home appliances, computer housings, and the like.

Examples of mechanical applications include, but are not limited to, tank and bottle handling machine components, moving parts on textile machines, bearings, gears, composite structures, ceramic structures, and the like.

In addition, another aspect of the present invention is a resin composition selected from the group of resin compositions according to examples 7-11.

In addition, another aspect of the present invention is a thermosetting powder coating composition selected from the group of thermosetting powder coating compositions according to examples 18-24.

In addition, another aspect of the present invention is a powder coating selected from the group of powder coatings according to examples 31-37.

Many other variations of embodiments of the invention will be apparent to those skilled in the art and are encompassed within the broad scope of the invention.

All embodiments disclosed herein may be combined with each other and/or with preferred elements of the present invention.

Other aspects of the invention and preferred features thereof are set out in the claims herein.

The invention will now be described in detail, by way of illustration only, with reference to the following non-limiting examples.

Examples

In the examples section, the abbreviation "Comp" denotes a comparative example of a resin (e.g. Comp rc 1) or a thermosetting powder coating composition (e.g. Comp pcc 1) or a powder coating (e.g. Comp pc 1).

Analytical methods and techniques for determining properties of polyesters of resin compositions

Table 1 shows the composition and properties of the polyesters used in the resin compositions CompRC1-CoompR6 and RC7-RC 11. The amounts of monomers used to prepare the polyesters in Table 1 are expressed in% based on the polyester. The amounts of phosphonium salt and tertiary amine used to prepare the resin compositions in Table 1 are expressed in% w/w based on the total weight of the polyester and the phosphonium salt and tertiary amine.

The measurement of the glass transition temperature (Tg) of the polyester was carried out by Differential Scanning Calorimetry (DSC) on a Mettler Toledo, TA DSC821, calibrated with indium, zinc and water in a nitrogen atmosphere. The processing of the signals (DSC thermogram, heat flow vs. temperature) was performed by star software version 9.10 provided by Mettler Toledo a.g. Approximately 10mg of the sample was heated from room temperature to 150 ℃ at a heating rate of 40 ℃/min. Once the sample reached 150 ℃, the temperature was held constant for 15 minutes. The sample was then cooled to 0 ℃ at a cooling rate of 40 ℃/min. After the sample reached 0 ℃, the sample was held at this temperature for 30 seconds, and then the sample was heated to 200 ℃ at a heating rate of 5 ℃/min. At the glass transition temperature, a so-called step transition (manifested as a shift in the baseline) results due to a change in the thermal properties of the polyester molecules. The "step" is used to determine the T of the polyester resin_g. The midpoint of this step in the thermal profile, defined as the T of the polyester, was calculated using software supplied with a Mettler Toledo DSC apparatus_g. The accuracy of the method is +/-0.5 ℃.

The viscosity of the polyester was measured at 160 ℃ using a cone/plate rheometer Brookfield CAP2000+ Viscometer with a rotor CAP-S-05 at 21rpm (shear rate 70S-1).

The acid number (AV) (mg KOH/g polyester) and the hydroxyl number (OHV) (mg KOH/g polyester) of the polyesters were determined by titration according to ISO2114-2000 and ISO4629-1978, respectively.

T_gViscosity, AV and OHV were measured in the polyester without any additives.

Having a certain molecular weight M_n(theoretical value) and the functionality f of the polyester of the target acid number (AV), calculated according to the following formula:

f=(M_n×AV)/56110

M_n(theoretical value) is calculated according to the following formula: multiply the target functionality (f) by 56110 and divide the result by the target acid number (AV) (mg KOH/g polyester):

M_n=(56110Xf)/AV

M_nand the theoretical value of f refers to the polyester without any additives added.

The target AV (mg KOH/g polyester) for all of the polyesters of examples 1-11 was equal to 35.

Testing and evaluation of properties of thermosetting powder coating compositions

The storage stability of the thermosetting powder coating compositions according to the invention was determined according to ISO 8130/part 8 at 40 ℃ for a total of 28 days. The thermosetting powder coating compositions were allowed to cool to room temperature for at least 2 hours before evaluating storage stability. The degree of caking was assessed visually and graded in the range of 1-10 according to the following scale [ 1: very poor stability (high number of lumps, thermosetting powder coating composition solidified into one solid block) and 10: excellent stability (no caking, free-flowing powder, powder flowability identical to that of the just prepared thermosetting powder coating composition) ]. In the context of the present invention, thermosetting powder coating compositions rated at least 6 are considered "storage stable".

Testing and evaluation of powder coating Properties

All properties were evaluated using well-defined steel Q-plates (S-46, 0.8mm X102 mm X152 mm) from Q-Lab Corporation. Evaluation of powder coating properties was performed on the following powder coatings: the powder coating was cured at 160 ℃ for 10 minutes at atmospheric pressure (1 bar).

The coating thickness was determined by a positecor 6000 coating thickness meter from DeFelsko Corporation.

Blooming was assessed by visual observation. AlMg3 plaques were coated with the white thermosetting powder coating composition of the invention and the coating formed after curing of the powder coating for 30 minutes in a gradient oven set at a temperature of from 100 to 200 ℃ was visually inspected. Blooming can be viewed as surface haze on the coating and the temperature range at which blooming occurs is recorded. Evaluation of the degree of blooming: a) no blooming; b) limited blooming and c) high blooming. For the thermosetting powder coating compositions of the present invention, their corresponding powder coatings that exhibit limited to no blooming are preferred.

The Reverse Impact Resistance (RIR) of powder coatings obtained by curing thermosetting powder coating compositions at a certain temperature and time (inch/lbs, link/lbs =0.055997m/kg) is defined as: a75 μm thick powder coating prepared from the thermosetting powder coating composition of the present invention on a 0.8mm thick S-46 plate withstood the impact force of 160linch/lbs using 5/8 "balls (pass" according to ASTM D2794) as tested. RIR is determined using ASTM D2794 according to the methods described herein. "pass" in the RIR line indicates that the powder coating is able to withstand impact (showing no cracking or delamination) when the corresponding thermosetting powder coating composition is cured at 160 ℃ for 10 minutes. By "failure" is meant that the coating is unable to withstand the impact. Powder coatings with sufficient reverse impact resistance mean: the powder coatings were able to withstand reverse impact testing (as described herein) when cured at 160 ℃ for only 10 minutes. For the thermosetting powder coating compositions of the present invention, their corresponding powder coatings that exhibit no blooming are preferred.

The fully cured (or fully cured thermosetting powder coating composition) of a thermosetting powder coating composition is defined herein as: the curing temperature and time conditions, which enable a powder coating with a coating thickness of 75 μm to show no cracking or separation after being subjected to a test for reverse impact resistance according to ASTM D2794 as described above.

The gloss of the powder coatings obtained after complete curing of the corresponding thermosetting powder coating compositions on S-46 panels was determined according to ASTM D523 using a BYK-Gardner GmbH haze-gloss meter. Gloss is reported in gloss units at angles of 20 ° and 60 °.

The smoothness of the powder coatings obtained by fully curing the corresponding thermosetting powder coating compositions was determined by the following method: the Smoothness of the Coating was visually compared to a PCI Powder Coating Smoothness board (PCI Powder Coating Smoothness Board [ ACT Test papers Inc., APR22163(A) Batch:50708816]) at a Coating thickness of about 60 μm. The smoothness rating is from 1 to 10, with 1 representing the roughest coating and 10 representing the smoothest coating. For the thermosetting powder coating compositions of the present invention, it is desirable that their corresponding powder coatings exhibit a smoothness equal to or higher than 2.

The degassing limit of the thermosetting powder coating compositions of the invention was determined according to ASTM D714. The degassing limit of the thermosetting powder coating compositions was tested on the powder coatings made therefrom and expressed as coating thickness (μm). More specifically, in the context of the present invention, it is determined according to the following experimental procedure: the thermosetting powder coating compositions were electrostatically sprayed on S-46 plates to give a thickness gradient, typically in the range of 40 to 160 μm, by curing at 160 ℃ for 10 minutes. The resulting powder coating was visually inspected for coating defects. The outgassing limit is reported as the thickness of the coating (μm) at which blistering, pinholes or other coating defects begin to be visible to the naked eye. Higher degassing limit values are preferred compared to lower values.

Examples 1 to 11: preparation of polyester synthetic/resin composition

The polyester compositions of the resin compositions CompRC1-CompRC6 and RC7-RC11 indicated in the description of the examples and in Table 1 mean 4Kg of polyester. The polyesters used to prepare the resin compositions of examples 1-11 were prepared by a two-stage (two-step) polycondensation reaction. Obtaining a hydroxy-functional polyester in a first stage; next, the hydroxyl functional polyester is further reacted with an excess of carboxyl functional monomer to obtain the branched amorphous carboxylic acid functional polyester of examples 1-11. All polyesters of examples 1-11 were solid at room temperature and atmospheric pressure.

All of the resin compositions of examples 1-11 were solids at room temperature and atmospheric pressure.

Example 1: synthesis of polyester and preparation of resin composition CompRC1

A reactor (6.0L) equipped with a thermometer, stirrer and distillation apparatus was charged with a tin-based catalyst, neopentyl glycol (1459.59 g, 14.01 mol), ethylene glycol (115.02 g, 1.85 mol) and trimethylolpropane (59.49 g, 0.44 mol). The vessel was heated to 150 ℃ until the mixture melted. Terephthalic acid (2431.32 g, 14.64 mol) and isophthalic acid (63.46 g, 0.38 mol) were then added and the temperature was gradually increased to 260 ℃ under a stream of nitrogen while distilling the water of reaction until the acid number of the precursor of the polyester was below 20mg KOH/g. The reaction mixture was cooled to 220 ℃ and then adipic acid (237.98 g, 1.63 mol) and a second portion of isophthalic acid (162.62 g, 0.98 mol) used in the second stage were added. The temperature was raised to 240 ℃ and 250 ℃ while distilling the water. In the final stage, reduced pressure was used until the polyester reached the desired acid number (35.0 mg KOH/g). The vacuum was stopped and the polyester was cooled to 195 ℃ and then discharged onto aluminum foil maintained at room temperature.

Example 2: synthesis of polyester and preparation of resin composition CompRC2

A reactor (6.0L) equipped with a thermometer, stirrer and distillation unit was charged with tin-based catalyst, neopentyl glycol (1408.97 g, 13.53 mol), diethylene glycol (214.06 g, 2.02 mol) and glycerol (60.58 g, 0.66 mol). The vessel was heated to 150 ℃ until the mixture melted. Terephthalic acid (2718.20 g, 16.36 mol) was then added and the temperature was gradually increased to 260 ℃ under a stream of nitrogen while distilling the water of reaction until the acid number of the precursor of the polyester was below 20mg KOH/g. The reaction mixture was cooled to 220 ℃ and then adipic acid (181.75 g, 1.24 mol) used in the second stage was added. The temperature was raised to 240 ℃ and 250 ℃ while distilling the water. In the final stage, reduced pressure was used until the polyester reached the desired acid number (35.0 mg KOH/g). The vacuum was stopped and the polyester was cooled to 195 ℃ and then discharged onto aluminum foil maintained at room temperature.

Example 3: synthesis of polyester and preparation of resin composition CompRC3

A reactor (6.0L) equipped with a thermometer, stirrer and distillation unit was charged with a tin-based catalyst, neopentyl glycol (719.23 g, 6.91 mol), 1, 2-propanediol (405.67 g, 5.33 mol), ethylene glycol (202.83 g, 3.27 mol), 1, 6-hexanediol (162.27 g, 1.37 mol) and trimethylolpropane (60.90 g, 0.45 mol). The vessel was heated to 150 ℃ until the mixture melted. Terephthalic acid (2614.27 g, 15.74 mol) and isophthalic acid (40.57 g, 0.24 mol) were then added and the temperature was gradually increased to 260 ℃ under a stream of nitrogen while distilling the water of reaction until the acid number of the precursor of the polyester was below 20mg KOH/g. The reaction mixture was cooled to 220 ℃ and then adipic acid (252.07 g, 1.72 mol) and a second portion of isophthalic acid (165.45 g, 1.00 mol) used in the second stage were added. The temperature was raised to 240 ℃ and 250 ℃ while distilling the water. In the final stage, reduced pressure was used until the polyester reached the desired acid number (35.0 mg KOH/g). The vacuum was stopped and the polyester was cooled to 195 ℃ and then discharged onto aluminum foil maintained at room temperature.

Example 4: synthesis of polyester and preparation of resin composition CompRC4

A reactor (6.0L) equipped with a thermometer, stirrer and distillation apparatus was charged with a tin-based catalyst, neopentyl glycol (1459.59 g, 14.01 mol), ethylene glycol (115.02 g, 1.85 mol) and trimethylolpropane (59.49 g, 0.44 mol). The vessel was heated to 150 ℃ until the mixture melted. Terephthalic acid (2431.32 g, 14.64 mol) and isophthalic acid (63.46 g, 0.38 mol) were then added and the temperature was gradually increased to 260 ℃ under a stream of nitrogen while distilling the water of reaction until the acid number of the precursor of the polyester was below 20mg KOH/g. The reaction mixture was cooled to 220 ℃ and then adipic acid (237.98 g, 1.63 mol) and a second portion of isophthalic acid (162.62 g, 0.98 mol) used in the second stage were added. The temperature was raised to 240 ℃ and 250 ℃ while distilling the water. In the final stage, reduced pressure was used until the polyester reached the desired acid number (35.0 mg KOH/g). The vacuum was stopped and the polyester was cooled to 195 ℃. An amine-containing reagent (0.8% w/w based on the total weight of the polyester and additives) and a phosphonium-containing reagent (0.6% w/w based on the total weight of the polyester and additives) were added to the polyester. Subsequently, the polyester was stirred at 195 ℃ for at least 20 minutes and then discharged onto an aluminum foil maintained at room temperature.

Example 5: synthesis of polyester and preparation of resin composition CompRC5

A reactor (6.0L) equipped with a thermometer, stirrer and distillation unit was charged with tin-based catalyst, neopentyl glycol (1389.24 g, 13.34 mol), diethylene glycol (211.07 g, 1.99 mol) and glycerol (59.74 g, 0.65 mol). The vessel was heated to 150 ℃ until the mixture melted. Terephthalic acid (2680.14 g, 16.13 mol) was then added and the temperature was gradually increased to 260 ℃ under a stream of nitrogen while distilling the water of reaction until the acid number of the precursor of the polyester was below 20mg KOH/g. The reaction mixture was cooled to 220 ℃ and then adipic acid (179.21 g, 1.23 mol) used in the second stage was added. The temperature was raised to 240 ℃ and 250 ℃ while distilling the water. In the final stage, reduced pressure was used until the polyester reached the desired acid number (35.0 mg KOH/g). The vacuum was stopped and the polyester was cooled to 195 ℃. An amine-containing reagent (0.8% w/w based on the total weight of the polyester and additives) and a phosphonium-containing reagent (0.6% w/w based on the total weight of the polyester and additives) were added to the polyester. Subsequently, the polyester was stirred at 195 ℃ for at least 20 minutes and then discharged onto an aluminum foil maintained at room temperature.

Example 6: synthesis of polyester and preparation of resin composition CompRC6

A reactor (6.0L) equipped with a thermometer, stirrer and distillation unit was charged with a tin-based catalyst, neopentyl glycol (709.16 g, 6.81 mol), 1, 2-propanediol (400.00 g, 5.26 mol), ethylene glycol (200.00 g, 3.22 mol), 1, 6-hexanediol (160.00 g, 1.35 mol) and trimethylolpropane (60.05 g, 0.45 mol). The vessel was heated to 150 ℃ until the mixture melted. Terephthalic acid (2577.67 g, 15.52 mol) and isophthalic acid (40.00 g, 0.24 mol) were then added and the temperature was gradually increased to 260 ℃ under a stream of nitrogen while distilling the water of reaction until the acid number of the precursor of the polyester was below 20mg KOH/g. The reaction mixture was cooled to 220 ℃ and then adipic acid (248.54 g, 1.70 mol) and a second portion of isophthalic acid (163.13 g, 0.98 mol) used in the second stage were added. The temperature was raised to 240 ℃ and 250 ℃ while distilling the water. In the final stage, reduced pressure was used until the polyester reached the desired acid number (35.0 mg KOH/g). The vacuum was stopped and the polyester was cooled to 195 ℃. An amine-containing reagent (1.4% w/w based on the total weight of the polyester and additives) was added to the polyester. Subsequently, the polyester was stirred at 195 ℃ for at least 20 minutes and then discharged onto an aluminum foil maintained at room temperature.

Example 7: synthesis of polyester and preparation of resin composition CompRC7

A reactor (6.0L) equipped with a thermometer, stirrer and distillation unit was charged with a tin-based catalyst, neopentyl glycol (709.16 g, 6.81 mol), 1, 2-propanediol (400.00 g, 5.26 mol), ethylene glycol (200.00 g, 3.22 mol), 1, 6-hexanediol (160.00 g, 1.35 mol) and trimethylolpropane (60.05 g, 0.45 mol). The vessel was heated to 150 ℃ until the mixture melted. Terephthalic acid (2577.67 g, 15.52 mol) and isophthalic acid (40.00 g, 0.24 mol) were then added and the temperature was gradually increased to 260 ℃ under a stream of nitrogen while distilling the water of reaction until the acid number of the precursor of the polyester was below 20mg KOH/g. The reaction mixture was cooled to 220 ℃ and then adipic acid (248.54 g, 1.70 mol) and a second portion of isophthalic acid (163.13 g, 0.98 mol) used in the second stage were added. The temperature was raised to 240 ℃ and 250 ℃ while distilling the water. In the final stage, reduced pressure was used until the polyester reached the desired acid number (35.0 mg KOH/g). The vacuum was stopped and the polyester was cooled to 195 ℃. A phosphonium containing reagent (1.4% w/w based on the total weight of the polyester and additives) was added to the polyester. Subsequently, the polyester was stirred at 195 ℃ for at least 20 minutes and then discharged onto an aluminum foil maintained at room temperature.

Example 8: synthesis of polyester and preparation of resin composition CompRC8

To a reactor (6.0L) equipped with a thermometer, stirrer and distillation apparatus were charged a tin-based catalyst, neopentyl glycol (1208.83 g, 11.62 mol), 1, 2-propanediol (200.15 g, 2.63 mol), 1, 6-hexanediol (200.13 g, 1.69 mol) and trimethylolpropane (48.12 g, 0.36 mol). The vessel was heated to 150 ℃ until the mixture melted. Terephthalic acid (2452.75 g, 14.76 mol) and isophthalic acid (40.96 g, 0.25 mol) were then added and the temperature was gradually increased to 260 ℃ under a stream of nitrogen while distilling the water of reaction until the acid number of the precursor of the polyester was below 20mg KOH/g. The reaction mixture was cooled to 220 ℃ and then adipic acid (236.50 g, 1.62 mol) and a second portion of isophthalic acid (155.53 g, 0.94 mol) used in the second stage were added. The temperature was raised to 240 ℃ and 250 ℃ while distilling the water. In the final stage, reduced pressure was used until the polyester reached the desired acid number (35.0 mg KOH/g). The vacuum was stopped and the polyester was cooled to 195 ℃. A phosphonium containing reagent (1.0% w/w based on the total weight of the polyester and additives) was added to the polyester. Subsequently, the polyester was stirred at 195 ℃ for at least 20 minutes and then discharged onto an aluminum foil maintained at room temperature.

Example 9: synthesis of polyester and preparation of resin composition CompRC9

To a reactor (6.0L) equipped with a thermometer, stirrer and distillation apparatus were charged a tin-based catalyst, neopentyl glycol (955.98 g, 9.18 mol), 1, 2-propanediol (403.52 g, 5.30 mol), 1, 6-hexanediol (201.76 g, 1.71 mol) and trimethylolpropane (47.93 g, 0.36 mol). The vessel was heated to 150 ℃ until the mixture melted. Terephthalic acid (2488.86 g, 14.98 mol) and isophthalic acid (40.65 g, 0.24 mol) were then added and the temperature was gradually increased to 260 ℃ under a nitrogen stream while distilling the water of reaction until the acid number of the precursor of the polyester was below 20 mgKOH/g. The reaction mixture was cooled to 220 ℃ and then adipic acid (239.98 g, 1.64 mol) and a second portion of isophthalic acid (157.51 g, 0.95 mol) used in the second stage were added. The temperature was raised to 240 ℃ and 250 ℃ while distilling the water. In the final stage, reduced pressure was used until the polyester reached the desired acid number (35.0 mg KOH/g). The vacuum was stopped and the polyester was cooled to 195 ℃. An amine-containing reagent (0.8% w/w based on the total weight of the polyester and additives) and a phosphonium-containing reagent (0.6% w/w based on the total weight of the polyester and additives) were added to the polyester. Subsequently, the polyester was stirred at 195 ℃ for at least 20 minutes and then discharged onto an aluminum foil maintained at room temperature.

Example 10: synthesis of polyester and preparation of resin composition CompRC10

A reactor (6.0L) equipped with a thermometer, stirrer and distillation unit was charged with a tin-based catalyst, neopentyl glycol (723.26 g, 6.94 mol), 1, 2-propanediol (401.30 g, 5.27 mol), ethylene glycol (200.07 g, 3.22 mol), 1, 6-hexanediol (160.06 g, 1.35 mol) and trimethylolpropane (47.30 g, 0.35 mol). The vessel was heated to 150 ℃ until the mixture melted. Terephthalic acid (2574.18 g, 15.49 mol) and isophthalic acid (40.00 g, 0.24 mol) were then added and the temperature was gradually increased to 260 ℃ under a stream of nitrogen while distilling the water of reaction until the acid number of the precursor of the polyester was below 20mg KOH/g. The reaction mixture was cooled to 220 ℃ and then adipic acid (246.22 g, 1.68 mol) and a second portion of isophthalic acid (162.92 g, 0.98 mol) used in the second stage were added. The temperature was raised to 240 ℃ and 250 ℃ while distilling the water. In the final stage, reduced pressure was used until the polyester reached the desired acid number (35.0 mg KOH/g). The vacuum was stopped and the polyester was cooled to 195 ℃. An amine-containing reagent (0.8% w/w based on the total weight of the polyester and additives) and a phosphonium-containing reagent (0.6% w/w based on the total weight of the polyester and additives) were added to the polyester. Subsequently, the polyester was stirred at 195 ℃ for at least 20 minutes and then discharged onto an aluminum foil maintained at room temperature.

Example 11: synthesis of polyester and preparation of resin composition CompRC11

A reactor (6.0L) equipped with a thermometer, stirrer and distillation unit was charged with a tin-based catalyst, neopentyl glycol (709.16 g, 6.81 mol), 1, 2-propanediol (400.00 g, 5.26 mol), ethylene glycol (200.0. g, 3.22 mol), 1, 6-hexanediol (160.00 g, 1.35 mol) and trimethylolpropane (60.05 g, 0.45 mol). The vessel was heated to 150 ℃ until the mixture melted. Terephthalic acid (2577.67 g, 15.52 mol) and isophthalic acid (40.00 g, 0.24 mol) were then added and the temperature was gradually increased to 260 ℃ under a stream of nitrogen while distilling the water of reaction until the acid number of the precursor of the polyester was below 20mg KOH/g. The reaction mixture was cooled to 220 ℃ and then adipic acid (248.54 g, 1.70 mol) and a second portion of isophthalic acid (163.00 g, 0.98 mol) used in the second stage were added. The temperature was raised to 240 ℃ and 250 ℃ while distilling the water. In the final stage, reduced pressure was used until the polyester reached the desired acid number (35.0 mg KOH/g). The vacuum was stopped and the polyester was cooled to 195 ℃. An amine-containing reagent (0.8% w/w based on the total weight of the polyester and additives) and a phosphonium-containing reagent (0.6% w/w based on the total weight of the polyester and additives) were added to the polyester. Subsequently, the polyester was stirred at 195 ℃ for at least 20 minutes and then discharged onto an aluminum foil maintained at room temperature.

Examples 12 to 24: preparation of thermosetting powder coating compositions

Preparation of thermosetting powder coating compositions CompPCC1-CompPCC6 and PCC7-PCC 13: chemicals used and general procedures

The chemicals used to prepare the thermosetting powder coating compositions CompPCC1-CompPCC6 and PCC7-PCC13 in the examples below are described in Table 2.GT7004(EEW =714-752) is an epoxy crosslinker from Huntsman, d.e.r.(EEW =590-630) is an epoxy crosslinker from DOW,2160 is titanium dioxide from Kronos Titan GmbH,PV-5 is a flow control agent from Worlge-Chemie GmbH. Benzoin was used as a degassing agent.

Thermosetting powder coating compositions were prepared by mixing the components shown in table 2 in a mixer, followed by extrusion of the components in a PRISM TSE16PC twin screw extruder at a screw speed of 400rpm at 100 ℃. The extrudate was cooled to room temperature and crushed into flakes. The flakes were ground in an ultracentrifugal pulverizer at 18000rpm and sieved in a Retsch ZM100 sieve. The sieve fractions with particle size below 90 μm were collected and used for further experiments.

Examples 25 to 37: preparation of powder coatings CompPC1-CompPC6 and PC7-PC 13: general procedure

Thermosetting powder coating compositions CompPCC1-CompPCC6 and PCC7-PCC13 (Table 2) prepared in examples 12-24 were electrostatically sprayed (corona, 60kV) onto S-46 test panels to give coating thicknesses suitable for each test described herein and cured in an air circulating oven (Heraeus instruments UT6120) at 160 ℃ for 10 minutes to provide a white powder coating.

As can be seen from the examples in table 3 in combination with the examples in table 1, only when the resin composition of the present invention as set forth in claim 1 is used to prepare a thermosetting powder coating composition, the thermosetting powder coating composition is storage stable, it is low temperature baked, and furthermore the powder coating obtained when the thermosetting powder coating composition is cured is free from blooming, has a smoothness of at least PCI2, has sufficient reverse impact resistance and a good degassing limit.

This can be seen by comparing comparative examples CompPC1-CompPC6 with examples according to the invention (PC 7-PC13, Table 3 and taking into account their corresponding polyesters shown in Table 1).

Claims

1. A resin composition comprising at least:

a. an organic phosphorus compound;

b. a branched amorphous carboxylic acid functionalized polyester having a T of at least 40 ℃_gThe T is_gSaid polyester comprising at least:

bi)1-45% mol of 2, 2-dimethyl-1, 3-propanediol;

bii)2-21% mol of C₃To C₅Aliphatic diols AD1, which do not include 2, 2-dimethyl-13-propanediol;

biii)1-10% mol of C₆To C₅₀Aliphatic or cycloaliphatic diols AD 2;

biv)0.1 to 10mol% of at least trifunctional monomers;

bv)10 to 55 mol% of terephthalic acid;

wherein the% mol is based on the polyester.

2. The composition of claim 1, wherein the composition further comprises a tertiary amine and/or a quaternary ammonium salt.

3. The composition of claim 1 wherein the amount of organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present is in the range of from at least 0.1 to at most 5% w/w based on the total weight of polyester and organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present.

4. The composition of claim 1 wherein the composition further comprises a tertiary amine and/or a quaternary ammonium salt, and wherein the amount of organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present is in the range of at least 0.1 to up to 5% w/w based on the total weight of the polyester and organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present.

5. The composition of claim 1 wherein the amount of organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present is in the range of at least 0.1 up to 2% w/w based on the total weight of polyester and organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present.

6. The composition of claim 1 wherein the composition further comprises a tertiary amine and/or a quaternary ammonium salt, and wherein the amount of organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present is in the range of at least 0.1 to at most 2% w/w based on the total weight of the polyester and organophosphorus compound and any tertiary amine and/or quaternary ammonium salt present.

7. The composition of claim 1, wherein the organophosphorus compound is a quaternary phosphonium salt.

8. The composition of claim 2, wherein the organophosphorus compound is a quaternary phosphonium salt.

9. The composition of claim 3, wherein the organophosphorus compound is a quaternary phosphonium salt.

10. The composition of claim 4, wherein the organophosphorus compound is a quaternary phosphonium salt.

11. The composition of claim 5, wherein the organophosphorus compound is a quaternary phosphonium salt.

12. The composition of claim 6, wherein the organophosphorus compound is a quaternary phosphonium salt.

13. The composition of claim 1, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

14. The composition of claim 2, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

15. The composition of claim 3, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

16. The composition of claim 4, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

17. The composition of claim 5, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

18. The composition of claim 6, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

19. The composition of claim 7, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

20. The composition of claim 8, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

21. The composition of claim 9, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

22. The composition of claim 10, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

23. The composition of claim 11, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

24. The composition of claim 12, wherein the molar ratio of AD1 to AD2 in the polyester (═ mol AD1/mol AD2) is at least equal to or higher than 1 and at most equal to 10.

25. The composition of claim 1, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

26. The composition of claim 2, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

27. The composition of claim 3, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

28. The composition of claim 4, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

29. The composition of claim 5, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

30. The composition of claim 6, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

31. The composition of claim 7, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

32. The composition of claim 8, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

33. The composition of claim 9, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

34. The composition of claim 10, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

35. The composition of claim 11, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

36. The composition of claim 12, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

37. The composition of claim 13, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

38. The composition of claim 14, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

39. The composition of claim 15, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

40. The composition of claim 16, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

41. The composition of claim 17, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

42. The composition of claim 18, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

43. The composition of claim 19, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

44. The composition of claim 20, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

45. The composition of claim 21, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

46. The composition of claim 22, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

47. The composition of claim 23, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

48. The composition of claim 24, wherein AD1 is 1, 2-propanediol and AD2 is 1, 6-hexanediol.

49. The composition of any one of claims 1-48, wherein the polyester further comprises 1 to 15 mole% adipic acid.

50. A thermosetting powder coating composition comprising the resin composition of any one of claims 1 to 49 and a crosslinker having functional groups capable of reacting with the carboxylic acid functional groups of the polyester.

51. The composition of claim 50, wherein

i. The amount of the polyester ranges from 50 to 98% w/w based on the total weight of the polyester and the crosslinking agent;

the amount of the cross-linking agent ranges from 2 to 50% w/w based on the total weight of the polyester and the cross-linking agent;

52. the composition of claim 50 or 51, wherein the crosslinking agent is a compound having at least two oxirane rings.

53. The composition of claim 50 or 51, wherein the crosslinking agent is a compound having at least two β -hydroxyalkylamide (BHA) groups.

54. A process for preparing a composition as claimed in any one of claims 50 to 53, comprising the steps of:

a. mixing the resin composition of any one of claims 1 to 49 with a crosslinking agent having functional groups capable of reacting with the carboxylic acid groups of the polyester of the resin composition to obtain a pre-mixture;

c. cooling the extrudate obtained in step b) to obtain a solidified extrudate;

d. breaking up the obtained solidified extrudate into smaller particles, thereby obtaining the thermosetting powder coating composition.

55. The method of claim 54, further comprising the steps of: the powder particles prepared in step d are classified by a sieve and a sieve fraction with a particle size below 130 μm is collected.

56. The method of claim 54, further comprising the steps of: the powder particles prepared in step d are classified by a sieve and a sieve fraction with a particle size below 90 μm is collected.

57. A method of forming a coating on a substrate comprising the steps of: applying the composition of any one of claims 50-53 to the substrate and curing the composition to form the coating.

58. A powder coating prepared by partially curing or fully curing the thermosetting powder coating composition of any one of claims 50-53.

59. A coated substrate comprising a coating resulting from curing the composition of any one of claims 50-53.

60. Use of the resin composition of any one of claims 1 to 49 or the thermosetting powder coating composition of any one of claims 50 to 53 or the coated substrate of claim 59 in automotive applications, marine applications, aerospace applications, medical applications, protective applications, sports/recreational applications, construction applications, bottle filling applications, household applications and mechanical applications.