FR3160176A1 - Alkyd emulsion neutralized by N,N-dialkylglucamine - Google Patents

Abstract

The present invention relates to an alkyd emulsion comprising an alkyd resin neutralized with an N,N-dialkylglucamine. The invention also covers a process for preparing the alkyd emulsion and its use in obtaining a coating, particularly a decorative or industrial coating.

Description

Alkyd emulsion neutralized by N,N-dialkylglucamine

The present invention relates to an alkyd emulsion comprising an alkyd resin neutralized by an N,N-dialkylglucamine. The invention also covers a process for preparing the alkyd emulsion and its use for obtaining a coating, in particular a decorative or industrial coating.

Polyester resins are made by reacting polyacids and polyols. Polyester resins can be modified by adding a fatty component, such as an oil or fatty acid, to form a special type of polyester resin: alkyd resins. Alkyd resins have been used for over 50 years to form coatings, including decorative and industrial paints.

The presence of a fatty component in alkyd resins gives flexibility and gloss to the resulting coating. When the fatty component contains unsaturations, the alkyds can dry by auto-oxidation (siccativation).

Alkyd resins in organic solvent medium, otherwise known as solvent-based alkyd resins, have long been known to those skilled in the art, generally used in coatings and decorative and industrial paint formulations. To address issues of ease of use, odor, and toxicity related to the use of volatile organic compounds (VOCs), alkyd emulsions have been developed. Alkyd emulsions, also known as post-emulsified alkyd resins, can be obtained by emulsifying an alkyd resin by adding a surfactant and water. Alkyd emulsions can advantageously have a high bio-based renewable carbon (BRC) content due to the use of bio-sourced acids and/or alcohols such as rosin, vegetable oil fatty acids, plant-based diacids, glycerol, and polyglycerols.

To improve the storage stability of bio-based alkyd emulsions, it is known to neutralize the acid functions of the alkyd resin, particularly with lithium salts. However, alkyd resins neutralized with lithium salts contain residual lithium hydroxide, which is toxic and will likely be classified as CMR in the near future.

Surprisingly, the Applicant discovered that the use of an N,N-dialkylglucamine containing 75% of material of renewable origin, to neutralize the acid functions of the alkyd made it possible to obtain a stable emulsion while maintaining acceptable properties in terms of gloss, adhesion to the substrate, flexibility, abrasion resistance, mechanical strength and resistance to yellowing and improving water resistance and resistance to self-adhesion (blocking). This thus leads to a solution that is friendly to humans and the environment due to the absence of both organic solvents, residual lithium hydroxide and siccative agents but also by the choice of essential raw materials, insofar as a high proportion of these raw materials can be of renewable and sustainable origin. Thus, the alkyd emulsion according to the invention can contain a proportion of renewable raw materials of 40-50% by weight, on the overall composition of the resin, while having a competitive cost price.

The subject matter of the present invention relates to an alkyd emulsion comprising an alkyd resin, the alkyd resin being based on an acid component A and an alcohol component B, the acid component A comprising an aromatic polyacid, the alkyd resin comprising ammonium carboxylate groups of formula (I)

(I)

wherein R ₁ and R ₂ are independently C1-C4 alkyl.

The invention also relates to a process for preparing an emulsion according to the invention, the process comprising the following steps:

(i) preparing a molten alkyd resin, the alkyd resin being based on an acid component A and an alcohol component B, the acid component A comprising an aromatic polyacid component A1;

ii) addition of a surfactant component T and water;

iii) neutralization of at least part of the acidity of the reaction mixture by adding an N,N-dialkylglucamine of formula (II):

(II)
wherein R ₁ and R ₂ are independently C1-C4 alkyl;

iv) emulsification by phase inversion;

v) possibly adjustment of the dry extract of the alkyd emulsion.

The invention also relates to a composition comprising an alkyd emulsion according to the invention.

The invention also relates to the use of the alkyd emulsion according to the invention, as a binder for obtaining a coating, an adhesive or a mastic, in particular for obtaining a coating, more particularly for obtaining a film, a paint, a varnish, a lacquer, a stain, an adhesion primer or an ink.

The invention also relates to a coating, an adhesive or a sealant obtained by applying and drying the composition according to the invention.

Detailed description Definitions

In this application, the terms "includes a" and "includes a" mean respectively "includes one or more" and "includes one or more".

Unless otherwise stated, percentages by weight in a compound or composition are expressed relative to the weight of the compound or composition.

For the purposes of the present invention, an ethylenically unsaturated group or compound is a group or compound containing a polymerizable carbon-carbon double bond.

For the purposes of the present invention, a polymerizable carbon-carbon double bond is a carbon-carbon double bond that can react with another carbon-carbon double bond in a polymerization reaction. A polymerizable carbon-carbon double bond is generally comprised in a group selected from acrylate (including cyanoacrylate), methacrylate, acrylamide, methacrylamide, styrene, maleate, fumarate, itaconate, allyl, propenyl, vinyl and combinations thereof, preferably selected from acrylate, methacrylate, allyl and vinyl. Carbon-carbon double bonds of an aromatic ring are not considered to be polymerizable carbon-carbon double bonds.

For the purposes of the present invention, an alkyl group is a monovalent saturated acyclic group of formula –C _n H _2n+1 . An alkyl may be linear or branched. A C1-C6 alkyl means an alkyl comprising 1 to 6 carbon atoms.

For the purposes of the present invention, an alkenyl group is a monovalent acyclic group having one or more C=C double bonds. An alkenyl can be linear or branched.

For the purposes of the present invention, an alkoxy group is a group of formula -O-alkyl.

For the purposes of the present invention, an aryl group is a group containing at least one aromatic ring. An aryl may contain a single aromatic ring or several rings, at least one of which is aromatic. An aromatic ring corresponds to a ring complying with Hückel's rule. Examples of aryl groups are phenyl, biphenyl, naphthyl and anthracenyl. The aryl groups of the invention preferably comprise from 6 to 12 carbon atoms. Even more preferably, the aryl group of the invention is a phenyl group.

For the purposes of the present invention, an alkylaryl group is a group of formula -A-aryl, in which A is alkylene. Preferably, an alkylaryl is a group of formula -CR ₂ R ₃ -Ph and R ₂ and R ₃ are independently H or Me, more preferably a group of formula -CH(CH ₃ )-Ph.

For the purposes of the present invention, an alkylene group is a divalent aliphatic radical derived from an alkane of formula C _m H _2m+2 with m = 2 to 50, by removing a hydrogen atom at each point of attachment of the radical. An alkylene may be linear or branched. A C2-C4 alkylene means an alkylene comprising 2 to 4 carbon atoms.

For the purposes of the present invention, an oxyalkylene group is a group of formula -O-A- in which A is an alkylene.

For the purposes of the present invention, a polyoxyalkylene group is a group of formula -O-[AO] _n - in which each A is independently C2-C4 alkylene, preferably ethylene or propylene; and n ranges from 1 to 100, from 2 to 60, from 3 to 50, from 4 to 40 or from 5 to 30.

For the purposes of the present invention, an aliphatic group or compound is a non-aromatic acyclic group or compound. It may be linear or branched, saturated or unsaturated, substituted or unsubstituted. It may comprise one or more bonds/functions, for example chosen from ether, ester, amide, urethane, urea and mixtures thereof.

For the purposes of the present invention, a cycloaliphatic group or compound is a non-aromatic group or compound comprising a ring. It may be substituted or unsubstituted. It may comprise one or more bonds/functions as defined for the term "aliphatic".

For the purposes of the present invention, an aromatic group or compound is a group or compound comprising an aromatic ring, i.e. complying with Hückel's rule of aromaticity, in particular a group or compound comprising a phenyl group. It may be substituted or unsubstituted. It may comprise one or more bonds/functions as defined for the term "aliphatic".

For the purposes of the present invention, a saturated group or compound means a group or compound which does not comprise a carbon-carbon double or triple bond.

For the purposes of the present invention, an unsaturated group or compound means a group or compound which comprises a carbon-carbon double or triple bond, in particular a carbon-carbon double bond.

For the purposes of the present invention, a substituted group or compound is a group or compound in which one or more hydrogen atoms have been replaced by a group or function independently selected from alkyl, hydroxyl (-OH), alkoxy, halogen (Br, Cl, I), cyano (-CN), isocyanate (-NCO), oxo (=O), amine (-NR ₂ ), carboxylic acid (-COOH), ester (-COOR'), anhydride (-CO-O-COR'), a sulfonyl group (-S(=O) ₂ OR), a phosphonyl group (-P(=O)(OR'') ₂ ), a sulfated group (-OS(=O) ₂ OR'') and a phosphate group (-OP(=O)(OR'') ₂ ), each R being independently H or alkyl, each R' being independently alkyl and each R'' being independently a hydrogen atom, a salt metallic or a hydrocarbyl chain.

Alkyd emulsion

The invention firstly relates to an alkyd emulsion comprising an alkyd resin. The alkyd emulsion may further comprise at least one surfactant component T and water.

An emulsion may in particular correspond to a liquid organic phase (discontinuous phase) dispersed in the form of droplets in an aqueous phase (continuous phase), the droplets being optionally stabilized by a surfactant. According to a particular embodiment, the alkyd emulsion is not in the form of a dispersion of a solid or semi-solid organic phase in an aqueous phase, in other words it is not in the form of a colloidal suspension or a latex.

The aqueous phase may in particular be a liquid comprising water. This liquid may also comprise a solvent other than water, such as, for example, butyl glycol.

According to one embodiment, the alkyd emulsion comprises less than 10%, in particular less than 5%, more particularly less than 1%, more particularly still less than 0.1%, by weight of solvent other than water relative to the weight of the emulsion. Thus, the alkyd emulsion has a low content of volatile organic compounds (VOCs), i.e. less than 10%, in particular less than 5%, more particularly less than 1%, more particularly still less than 0.1%, by weight of VOCs relative to the weight of the emulsion.

The liquid organic phase may in particular comprise an alkyd resin as described below. According to a particular embodiment, the alkyd resin is not self-emulsifiable, that is to say that it does not contain a sufficient quantity of ionizable functional groups to spontaneously form an emulsion after addition of water with stirring. In other words, a surfactant is preferably added to stabilize the alkyd emulsion according to the invention.

The surfactant may in particular be as described below.

According to one embodiment, the alkyd emulsion has a solids content (also called dry extract) of 35 to 65%, in particular 40 to 60%, more particularly 45 to 55% by weight. The dry extract can be measured by the ISO 3251:2008 method.

The alkyd emulsion can have a pH of 7 to 9, particularly 7.5 to 8.5.

The viscosity of the alkyd emulsion may in particular range from 1 to 1000 mPa s, in particular 2 to 500 mPa s, more particularly 5 to 100 mPa.s. The viscosity may be measured at 23°C according to the measuring method described below.

The alkyd emulsion may in particular have an average particle size of 50 to 1000 nm, in particular 75 to 500 nm, more particularly 100 to 300 nm. The average particle size may correspond to the volume average size measured by laser granulometry.

The alkyd emulsion may in particular be substantially free of free lithium hydroxide, that is to say that the alkyd emulsion may have a free lithium hydroxide content which is less than 10 ppm, preferably less than 1 ppm, more preferably equal to 0 ppm.

Alkyd resin

The alkyd emulsion according to the invention comprises an alkyd resin.

Alkyd resin is based on an acid component A and an alcohol component B. In other words, alkyd resin is obtained by polycondensation of an acid component A and an alcohol component B.

Acid component A comprises at least one acid. Acid component A may comprise a mixture of acids. Preferably, acid component A consists of all the acids used to prepare the alkyd resin.

The alcohol component B comprises at least one alcohol. The alcohol component B may comprise a mixture of alcohols. Preferably, the alcohol component B consists of all the alcohols used to prepare the alkyd resin.

For the purposes of the present invention, the term “acid” means a compound comprising at least one carboxylic acid function (-COOH) or a function capable of generating a carboxylic acid function in situ (in particular by hydrolysis). The term “acid” therefore includes acid derivatives such as anhydrides and esters. When the acid contains a single carboxylic acid function (or a single function capable of generating a carboxylic acid function in situ), it is a monoacid. When the acid contains more than one carboxylic acid function (or more than one function capable of generating a carboxylic acid function in situ), it is a polyacid.

For the purposes of the present invention, the term “alcohol” means a compound comprising at least one hydroxyl function (-OH). When the alcohol contains a single hydroxyl function, it is a monoalcohol. When the alcohol contains more than one hydroxyl function, it is a polyol.

Component A may in particular represent from 50 to 95%, in particular from 60 to 90%, more particularly from 70 to 80% of the total weight of components A and B. In other words, the alkyd resin comprises from 50 to 95%, in particular from 60 to 90%, more particularly from 70 to 80%, by weight of units derived from an acid relative to the total weight of the alkyd resin.

Component B may in particular represent from 5 to 50%, in particular from 10 to 40%, more particularly from 20 to 30% of the total weight of components A and B. In other words, the alkyd resin comprises from 5 to 50%, in particular from 10 to 40%, more particularly from 20 to 30%, by weight of units derived from an alcohol relative to the total weight of the alkyd resin.

In particular, the total weight of components A and B represents the total weight of the alkyd resin.

The alkyd resin comprises ammonium carboxylate groups of formula (I):

(I)

wherein R ₁ and R ₂ are independently C1-C4 alkyl, preferably methyl or ethyl, more preferably methyl.

These groups come in particular from the specific neutralization method used in the process described below.

The alkyd resin can in particular have an oil length of 10 to 60%, in particular 20 to 50%, more particularly 20 to 40%.

The oil length of an alkyd resin may in particular correspond to the % by weight of fatty component used to obtain the alkyd resin (or the % by weight of units derived from a fatty component) relative to the total weight of the alkyd resin. The fatty component includes in particular all the fatty acids used to prepare the alkyd resin.

For the purposes of the present invention, the term "fatty acid" means an acid having a fatty chain, i.e. a (non-cyclic) hydrocarbyl chain comprising from 10 to 60, in particular 12 to 55, more particularly 14 to 50, consecutive carbon atoms. A fatty acid may be saturated or unsaturated. A saturated fatty acid is a fatty acid which does not comprise a C=C double bond. An unsaturated fatty acid comprises at least one C=C double bond. A monounsaturated fatty acid contains a single C=C double bond. A polyunsaturated fatty acid contains more than one C=C double bond. The hydrocarbyl chain of the fatty acid may be substituted, in particular by one or more hydroxyl or carbonyl functions. The term "fatty acid" includes fatty acid derivatives, i.e. compounds capable of generating a fatty acid in situ, in particular by hydrolysis, as well as compounds obtained by reaction between several fatty acids (in particular dimerization, trimerization, standolization, estolidation). Fatty acid derivatives include in particular fatty acid esters (in particular fatty acid alkyl esters and triglycerides or oils), stand oils, estolides as well as fatty acid dimers and trimers.

Component A4 as described below is not considered a fatty component and therefore does not enter into the calculation of oil length.

The acid component A includes an aromatic polyacid component, also called component A1.

Component A1 comprises at least one aromatic polyacid. Component A1 may comprise a mixture of aromatic polyacids. In particular, component A1 consists of all the aromatic polyacids used to prepare the alkyd resin.

The aromatic polyacid may in particular be chosen from an aromatic dicarboxylic acid, an aromatic tricarboxylic acid, a derivative thereof, as well as a mixture thereof. The aromatic polyacid may in particular comprise 8 to 54, in particular 8 to 20, more particularly 8 to 12, carbon atoms.

The aromatic polyacid may in particular have a functionality (number of carboxylic acid or carboxylic acid derivative functions) ranging from 2 to 3, in particular the functionality may be equal to 2.

Examples of aromatic polyacids are phthalic acid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, trimellitic acid, 2,5-furan dicarboxylic acid and mixtures thereof.

The aromatic polyacid may be an aromatic polyacid derivative. Such a derivative may be converted into an aromatic polyacid by hydrolysis. Aromatic polyacid derivatives include partially or fully esterified forms of the aromatic polyacids defined above, including C1-C6 alkyl mono-, di-, and triesters of the polyacids defined above, as well as cyclic anhydrides. Aromatic polyacid derivatives may include, in particular, 8 to 60, in particular 8 to 25, more particularly 8 to 18, carbon atoms.

Examples of suitable ester-type aromatic polyacid derivatives are dimethyl phthalate, diethyl phthalate, dimethyl isophthalate, diethyl isophthalate, dimethyl terephthalate, diethyl terephthalate.

The aromatic polyacid derivative may in particular be an aromatic cyclic anhydride. An example of an aromatic cyclic anhydride is phthalic anhydride.

According to a preferred embodiment, component A1 comprises phthalic anhydride.

Component A1 may represent from 5 to 50%, in particular 10 to 45%, more particularly 20 to 40% of the total weight of components A and B. In other words, the alkyd resin may comprise from 0 to 50%, in particular from 10 to 45%, more particularly from 20 to 40% by weight of units derived from an aromatic polyacid relative to the total weight of the alkyd resin.

The A-acid component may include a conjugated fatty acid component, also called the A2 component.

Component A2 comprises at least one conjugated fatty acid. Component A2 may comprise a mixture of conjugated fatty acids. In particular, component A2 consists of all of the conjugated fatty acids used to prepare the alkyd resin.

For the purposes of the present invention, the term “conjugated fatty acid” means a polyunsaturated fatty acid comprising two C=C double bonds separated by a single C-C bond. A conjugated fatty acid may in particular result from the isomerization of a polyunsaturated fatty acid (in particular of natural origin, more particularly of plant or animal origin) such as linoleic acid, alpha-linolenic acid, gamma-linoleic acid, stearidonic acid, icosapentaenoic acid, docosahexaenoic acid. A conjugated fatty acid may also result from the dehydration of a hydroxylated unsaturated fatty acid (in particular of natural origin, more particularly of plant origin) such as ricinoleic acid.

Examples of conjugated fatty acids are 9,11-octadecadienoic acid, 10,12-octadecadienoic acid, 8,10,12-octadecatrienoic acid, 9,11,13-octadecatrienoic acid, 9,11,15-octadecatrienoic acid, 9,13,15-octadecatrienoic acid, 6,9,11-octadecatrienoic acid, 10,12,14-octadecatrienoic acid, 9,11,13,15-octadecatetraenoic acid, 10,12-nonadecadienoic acid, 5,7,9,14,17-icosapentaenoic acid, 5,8,10,12,14-icosapentaenoic acid. Preferably, the conjugated fatty acid is 9,11-octadecadienoic acid.

Component A2 may represent from 0 to 50%, preferably from 2 to 40%, more preferably from 5 to 35% of the total weight of components A and B. In other words, the alkyd resin may comprise from 0 to 50%, preferably from 2 to 40%, more preferably from 5 to 35%, by weight of units derived from a conjugated fatty acid relative to the total weight of the alkyd resin.

The conjugated fatty acid may in particular be introduced in the form of a mixture of fatty acids comprising one or more conjugated fatty acids as well as one or more fatty acids chosen from a saturated fatty acid, a monounsaturated fatty acid, a non-conjugated polyunsaturated fatty acid, as well as derivatives thereof. Such mixtures may in particular be derived from an oil or fat of natural origin, in particular a vegetable or animal oil, such as castor oil, sunflower oil, linseed oil, soybean oil, tall oil (tallol or "tall oil"), tung oil, chia seed oil, perilla oil, poppy seed oil, cottonseed oil, lesquerella oil, safflower oil, oiticica oil, rapeseed oil, corn oil, calendula oil, hemp oil, fish oil. The oil may in particular be a vegetable oil modified by a dehydration and/or isomerization reaction to generate conjugated double bonds.

In particular, the conjugated fatty acid may be derived from a modified vegetable oil, preferably chosen from dehydrated castor oil, isomerized sunflower oil, isomerized linseed oil, isomerized soybean oil, more preferably dehydrated castor oil.

Examples of mixtures comprising a conjugated fatty acid are Nouracid® DE 656, DE 655, DE 554, DE 503, DE 402 or DZ 453 (Dehydrated castor oil fatty acid - available from Oléon); Nouracid® HE 456, HE 306, HE 305, HE 304, HE 303 or HE 301 (Isomerized sunflower oil fatty acid - available from Oléon); Nouracid® LE 805 (Isomerized linseed oil fatty acid - available from Oléon); Nouracid® SE 305 (Isomerized soybean oil fatty acid - available from Oléon); Dedico® 5981 (Dehydrated castor oil fatty acid - available from Croda).

Acid component A may comprise a non-aromatic polyacid component, also referred to as component A3. Component A3 comprises at least one non-aromatic polyacid. Component A3 may comprise a mixture of non-aromatic polyacids. In particular, component A3 consists of all the non-aromatic polyacids used to prepare the alkyd resin.

The non-aromatic polyacid may in particular be unsaturated or saturated, in particular saturated. The non-aromatic polyacid may in particular be chosen from a dicarboxylic acid, a tricarboxylic acid, a monocarboxylic acid dimer, a monocarboxylic acid trimer, a derivative thereof, as well as a mixture thereof. The non-aromatic polyacid may in particular comprise 3 to 54, in particular 4 to 20, more particularly 5 to 15, carbon atoms. According to one embodiment, the non-aromatic polyacid is a saturated or unsaturated polyacid. According to one embodiment, the non-aromatic polyacid is an aliphatic or cycloaliphatic polyacid.

The non-aromatic polyacid may in particular have a functionality (number of carboxylic acid or carboxylic acid derivative functions) ranging from 2 to 4, in particular from 2 to 3, more particularly equal to 2.

Examples of saturated aliphatic polyacids are malonic acid, succinic acid, 2-methylsuccinic acid, 2,2-dimethylsuccinic acid, glutaric acid, 3,3-diethylglutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, citric acid, propane-1,2,3-tricarboxylic acid, a dimer of a saturated C32-C36 fatty acid, a trimer of a saturated C54 fatty acid, and mixtures thereof.

Examples of unsaturated aliphatic polyacids are itaconic acid, maleic acid, fumaric acid, glutaconic acid, muconic acid, and mixtures thereof.

An example of a saturated cycloaliphatic polyacid is cyclohexane dicarboxylic acid.

An example of an unsaturated cycloaliphatic polyacid is tetrahydrophthalic acid.

The non-aromatic polyacid may be a non-aromatic polyacid derivative. Such a derivative may be converted into a non-aromatic polyacid by hydrolysis. The non-aromatic polyacid derivatives include the partially or fully esterified forms of the non-aromatic polyacids defined above, in particular the C1-C6 alkyl mono-, di- and triesters of the non-aromatic polyacids defined above as well as the cyclic anhydrides. The non-aromatic polyacid derivatives may in particular comprise 5 to 60, in particular 6 to 25, more particularly 7 to 20, carbon atoms.

Examples of suitable non-aromatic ester polyacid derivatives are dimethyl malonate, diethyl malonate, dimethyl adipate, dimethyl glutarate, dimethyl succinate.

The polyacid derivative may in particular be a cyclic anhydride. The cyclic anhydride may be saturated or unsaturated, in particular unsaturated. The cyclic anhydride may be cycloaliphatic.

Examples of saturated cyclic anhydrides are succinic anhydride and hexahydrophthalic anhydride. Examples of cycloaliphatic unsaturated anhydrides are maleic anhydride, fumaric anhydride, and tetrahydrophthalic anhydride.

According to a preferred embodiment, the polyacid component A3 comprises at least one saturated aliphatic polyacid, in particular sebacic acid, succinic acid and mixtures thereof.

Component A3 may represent from 0 to 50%, in particular 0 to 30%, more particularly 0 to 15% of the total weight of components A and B. In other words, the alkyd resin may comprise from 0 to 50%, in particular from 0 to 30%, more particularly from 0 to 15% by weight of units derived from a non-aromatic polyacid relative to the total weight of the alkyd resin.

Acid component A may comprise a non-fatty monoacid component, also referred to as component A4. Component A4 comprises at least one non-fatty monoacid. Component A4 may comprise a mixture of non-fatty monoacids. In particular, component A4 consists of all the non-fatty monoacids for preparing the alkyd resin.

For the purposes of the present invention, the term “non-fatty monoacid” means a C2-C9 monoacid, i.e. a monoacid having 2 to 9 carbon atoms.

The non-fatty monoacid may be an aliphatic, cycloaliphatic or aromatic monoacid, especially aliphatic or aromatic.

Examples of suitable non-fatty monobasic acids are benzoic acid, 3-methylbenzoic acid, tert-butylbenzoic acid, hexahydrobenzoic acid, caproic acid, caprylic acid, 2-ethylhexanoic acid, pentenoic acid, pentadienoic acid, hexenoic acid, hexadienoic acid, heptenoic acid, heptadienoic acid, octenoic acid, octadienoic acid, nonenoic acid, nonadienoic acid, and mixtures thereof.

According to a particular embodiment, component A4 comprises an aromatic non-fatty monoacid, more particularly benzoic acid.

According to a particular embodiment, component A4 comprises an unsaturated non-fatty monoacid, more particularly a hexadienoic acid, in particular sorbic acid.

Component A4 may represent from 0 to 50%, in particular from 5 to 30%, more particularly from 10 to 20% of the total weight of components A and B. In other words, the alkyd resin may comprise from 0 to 50%, in particular from 5 to 30%, more particularly from 10 to 20% by weight of units derived from a non-fatty monoacid relative to the total weight of the alkyd resin.

Acid component A may comprise a saturated fatty acid component, also referred to as component A5. Component A5 comprises at least one saturated fatty acid. Component A5 may comprise a mixture of saturated fatty acids. In particular, component A5 consists of all of the saturated fatty acids used to prepare the alkyd resin.

Examples of saturated fatty acids are capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, 9-hydroxy stearic acid, 10-hydroxy stearic acid, 12-hydroxy stearic acid, icosanoic acid, 14-hydroxy icosanoic acid and mixtures thereof. The saturated fatty acid may be derived from, among other things, palm oil, coconut oil, hydrogenated castor oil, animal fat and mixtures thereof.

Component A5 may represent from 0 to 20%, in particular from 1 to 10%, more particularly from 2 to 8% of the total weight of components A and B. In other words, the alkyd resin may comprise from 0 to 20%, in particular from 1 to 10%, more particularly from 2 to 8%, by weight of units derived from a saturated fatty acid relative to the total weight of the alkyd resin.

Acid component A may comprise a monounsaturated fatty acid component, also referred to as component A6. Component A6 comprises at least one monounsaturated fatty acid. Component A6 may comprise a mixture of monounsaturated fatty acids. In particular, component A6 consists of all of the monounsaturated fatty acids used to prepare the alkyd resin.

Examples of monounsaturated fatty acids are myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, gadoleic acid, ricinoleic acid (12-hydroxy-9-octadecenoic acid), elaidic acid, trans-vaccenic acid, erucic acid, nervonic acid, brassidic acid, lesquerolic acid (14-hydroxy-11-icosenoic acid) and mixtures thereof.

The monounsaturated fatty acid can in particular come from a vegetable oil as described above.

Component A6 may represent from 0 to 20%, in particular from 1 to 10%, more particularly from 2 to 8% of the total weight of components A and B. In other words, the alkyd resin may comprise from 0 to 20%, in particular from 1 to 10%, more particularly from 2 to 8%, by weight of units derived from a monounsaturated fatty acid relative to the total weight of the alkyd resin.

Acid component A may comprise an unconjugated polyunsaturated fatty acid component, also referred to as component A7. Component A7 comprises at least one unconjugated polyunsaturated fatty acid. Component A7 may comprise a mixture of unconjugated polyunsaturated fatty acids. In particular, component A7 consists of all of the unconjugated polyunsaturated fatty acids used to prepare the alkyd resin.

Examples of unconjugated polyunsaturated fatty acids are omega-3 and omega-6 fatty acids, such as linoleic acid, α-linolenic acid, γ-linolenic acid, 7,10,13-hexadecatrienoic acid, 9,12,15-octadecatrienoic acid, 6,9,12,15-octadecatetraenoic acid, 11,14,17-icosatrienoic acid, 8,11,14,17-icosatetraenoic acid, 5,8,11,14,17-icosapentaenoic acid, 6,9,12,15,18-heneicosapentaenoic acid, 7,10,13,16,19-docosapentaenoic acid, 4,7,10,13,16,19-docosahexaenoic acid, 9,12,15,18,21-tetracosapentaenoic acid, 6,9,12,15,18,21-tetracosahexaenoic acid, 9,12-octadecadienoic acid, 6,9,12-octadecatrienoic acid, 11,14-icosadienoic acid, 8,11,14-icosatrienoic acid, 5,8,11,14-icosatetraenoic acid, 13,16-docosadienoic acid, 7,10,13,16-docosatetraenoic acid, acid 4,7,10,13,16-docosapentaenoic acid, 9,12,15,18-tetracosatetraenoic acid, 6,9,12,15,18-tetracosapentaenoic acid, and mixtures thereof.

The polyunsaturated fatty acid may in particular be derived from a vegetable oil as described for the conjugated fatty acid (preferably without modification such as isomerization). Preferably, the non-conjugated polyunsaturated fatty acid is derived from a vegetable oil chosen from soybean oil, sunflower oil or tall oil (tallol).

Component A7 may represent from 0 to 50%, in particular from 1 to 35%, more particularly from 5 to 30% of the total weight of components A and B. In other words, the alkyd resin may comprise from 0 to 50%, in particular from 1 to 35%, more particularly from 5 to 30%, by weight of units derived from a non-conjugated polyunsaturated fatty acid relative to the total weight of the alkyd resin.

Components A1, A2, A3, A4, A5, A6 and A7 are distinct from each other.

Alkyd resin is based on an alcohol component B.

The alcohol component B may comprise a polyol component B1. Component B1 comprises at least one polyol. Component B1 may comprise a mixture of polyols. In particular, component B1 consists of all the polyols used to prepare the alkyd resin.

Component B1 may in particular have a functionality (number of hydroxyl functions) ranging from 2 to 6, in particular from 2.5 to 5.5, more particularly from 3 to 5. When component B1 comprises a mixture of polyols, the functionality of component B1 corresponds to the average functionality of the polyol component, also called f _B1 .

The average functionality f _B1 of a polyol component comprising a mixture of n polyols can in particular be determined with the following equation:

in which

x _i is the mole fraction of polyol i (corresponding to the number of moles of polyol i divided by the total number of moles of polyols in component B1);

f _i is the functionality of polyol i (corresponding to the number of hydroxyl functions of polyol i).

Component B1 may in particular comprise an aliphatic, cycloaliphatic or aromatic polyol, in particular an aliphatic or cycloaliphatic polyol. Component B1 may in particular comprise a saturated polyol. Preferably, component B1 comprises a saturated aliphatic polyol.

According to one embodiment, the polyol(s) contained in component B1 have a molar mass of less than 400 g/mol, less than 350 g/mol, less than 300 g/mol, less than 250 g/mol, less than 200 g/mol or less than 150 g/mol.

Examples of suitable polyols are ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,10-decanediol, 1,12-dodecanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyalkylene glycols such as polyethylene glycol or polypropylene glycol (preferably with a number average molecular weight Mn, calculated from the OH number, ranging from 250 to 3000 g/mol), 1,4-cyclohexanedimethanol, 1,6-cyclohexanedimethanol, 1,4-cyclohexanediol, bisphenol A, hydrogenated bisphenol A, glycerol, diglycerol, triglycerol, tetraglycerol, pentaglycerol, a polyglycerol (i.e. a mixture of glycerol oligomers such as Polyglycerol-3 which is a mixture of glycerol oligomers containing a majority proportion of triglycerol), tricyclodecane dimethanol, trimethylolpropane, di(trimethylolpropane), trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, erythritol, pentaerythritol, di(pentaerythritol), neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,3-propanediol, 2-methyl-1,2-propanediol, sorbitol, mannitol, xylitol, isosorbide, isoidide, isomannide, methyl glucoside, polyester polyols (especially polycaprolactone polyol), polycarbonate polyols, polyorganosiloxane polyols (in particular polydimethylsiloxane polyol), a hydroxy-terminated polybutadiene, a diol derived from a dimer or trimer of hydrogenated or non-hydrogenated fatty acid, alkoxylated derivatives (in particular ethoxylated and/or propoxylated) of the polyols mentioned above, and mixtures thereof.

According to a particular embodiment, component B1 comprises a saturated aliphatic polyol chosen from trimethylolethane, trimethylolpropane, glycerol, diglycerol, triglycerol, tetraglycerol, pentaglycerol, a polyglycerol, di(trimethylolpropane), pentaerythritol, dipentaerythritol, sorbitol, a diol derived from a dimer or trimer of hydrogenated or non-hydrogenated fatty acid, alkoxylated derivatives (in particular ethoxylated and/or propoxylated) of the polyols cited above, and mixtures thereof.

Component B1 represents from 0 to 50%, in particular from 10 to 40%, more particularly from 20 to 30% of the total weight of components A and B. In other words, the alkyd resin comprises from 0 to 50%, in particular from 10 to 40%, more particularly from 20 to 30%, by weight of units derived from a polyol relative to the total weight of the alkyd resin.

The alcohol component B may comprise a monoalcohol component B2. The component B2 comprises at least one monoalcohol. The component B2 may comprise a mixture of monoalcohols. In particular, the component B2 consists of all the monoalcohols used to prepare the alkyd resin.

The monoalcohol may in particular be an aliphatic, cycloaliphatic or aromatic monoalcohol, in particular aliphatic or cycloaliphatic. The monoalcohol may in particular be a saturated monoalcohol. Preferably, the monoalcohol is a saturated aliphatic monoalcohol.

The monoalcohol may in particular be a C6-C60 monoalcohol, in particular C8-C55, more particularly C10-C50.

Examples of suitable monoalcohols are octan-1-ol, octan-2-ol, 2-ethyl-1-hexanol, nonan-1-ol, decan-1-ol, undecan-1-ol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, docosanol, alkoxylated (especially ethoxylated and/or propoxylated) derivatives of the above-mentioned monoalcohols, and mixtures thereof.

Component B2 represents from 0 to 20%, in particular from 0 to 10%, more particularly from 0 to 5% of the total weight of components A and B. In other words, the alkyd resin comprises from 0 to 20%, in particular from 0 to 10%, more particularly from 0 to 5%, by weight of units derived from a monoalcohol relative to the total weight of the alkyd resin.

The alkyd resin may in particular have a number-average molecular weight Mn ranging from 2500 to 9000 g/mol, in particular from 3500 to 6000 g/mol. The number-average molecular weight can in particular be measured by GPC in THF in polystyrene equivalents.

The acid number of the alkyd resin may in particular be less than 25 mg KOH/g, preferably 5 to 20 mg KOH/g, more preferably 6 to 13 mg KOH/g.

The hydroxyl number of the alkyd resin may in particular be 20 to 150 mg KOH/g, preferably 30 to 100 mg KOH/g.

In particular, alkyd resin can have an average functionality f ranging from 1.8 to 2.1. This average functionality is defined according to the following relationship:
f = 2 Σ _i n _i f _i / Σ _i n _i
with n _i and f _i being respectively the number of moles and functionality of the acid or alcohol component i (average over all the reactive acid and alcohol components).

The alkyd resin may in particular have a cone-plate viscosity at 125°C according to the ISO 2884-1:1999 method ranging from 1,500 to 4,000 mPa.s, preferably from 2,000 to 3,000 mPa.s.

The weight ratio of the alkyd resin relative to the weight of the alkyd emulsion can range from 35 to 65%, in particular from 40 to 60%, more particularly from 45 to 55%.

Surfactant

The alkyd emulsion according to the invention may comprise a surfactant component, also called component T.

Component T comprises a surfactant. Component T may comprise a mixture of surfactants.

For the purposes of the present invention, a surfactant is an amphiphilic compound (i.e. having both a hydrophilic part and a hydrophobic part). The surfactant must in particular be capable of stabilizing the alkyd resin in the form of droplets dispersed in water. In particular, a surfactant suitable for forming an oil-in-water emulsion may have a hydrophilic-lipophilic balance (HLB) value greater than 8, in particular greater than 10, more particularly greater than 12.

Component T may comprise a surfactant selected from an anionic surfactant, a cationic surfactant and mixtures thereof. Preferably, component T comprises a mixture of an anionic surfactant and a non-ionic surfactant. For example, the weight ratio of anionic surfactant to non-ionic surfactant may be 1 to 4, preferably 1 to 3, more preferably 1.5 to 2.5.

Component T may in particular comprise an anionic surfactant selected from an alkyl sulfate, an alkyl ether sulfate, an alkylsulfonate, an alkylbenzenesulfonate, an optionally substituted diphenyl oxide disulfonate, an optionally alkoxylated sulfosuccinate mono- or diester, a phosphonate mono- or diester, a phosphate mono- or diester, a polymerizable anionic surfactant and mixtures thereof. A list of suitable surfactants is available in the book "Surfactants and Polymers in Aqueous Solutions" (Holmberg et al., 2002, John Wiley & Sons).

Examples of suitable alkyl sulfates and alkyl ether sulfates are optionally ethoxylated C6-C22 fatty alcohol sulfates, such as decyl sulfate, lauryl sulfate (such as Disponil® SLS), stearyl sulfate, C12-C14 fatty alcohol ether sulfate with 2 to 50 EO units (such as Disponil® FES 77, Disponil® FES 27, Disponil® FES 993, Disponil® FES 32, Rhodapex LA 120s).

Examples of suitable alkylsulfonates are C6-C22 fatty alcohol sulfonates such as decyl sulfonate, lauryl sulfonate and stearyl sulfonate.

Examples of suitable alkylbenzenesulfonates are benzenesulfonates substituted with a linear or branched C6-C22 alkyl group, such as sodium dodecylbenzenesulfonate (such as POLYSTEP® A-16-22, Rhodacal® DS-4, Maxemul® 7201).

An example of a suitable diphenyl oxide disulfonate is sodium dodecyl diphenyl oxide disulfonate (such as Dowfax® 2A1, Calfax® DB45).

Examples of suitable sulfosuccinate mono- or diesters are optionally alkoxylated C6-C22 alkyl monoesters or diesters of sulfosuccinic acid (such as Aerosol® A-102, Aerosol® MA-80, Aerosol® GPG).

Examples of suitable phosphate mono- or diesters are compounds of formula (I) or (II) (such as Rhodafac® Rs 410, Rhodafac® Rs 610, Rhodafac® Rs 710, Rhodafac® Rs 960, Rhodafac® Re 610, Hostaphat® 1306):

monoester RO(R'O) _n - P(=O) [-O ^- M ⁺ ] ₂ (I)

diester [RO(R'O) _n ] ₂ - P(=O)-O ^- M ⁺ (II)

in which
each R is independently C6 to C50, preferably C8 to C30, more preferably C alkyl₁₀to C20;
each R’ is independently ethylene or propylene;
n ranges from 2 to 50, preferably from 4 to 40, more preferably from 8 to 30;
M is chosen from hydrogen, a metal cation (in particular sodium or potassium) or an ammonium.

Phosphate mono- and diesters may in particular be in the form of a mixture, the weight ratio of phosphate monoester to phosphate diester being able to be from 0.8 to 1.2.

The anionic surfactant may be a polymerizable anionic surfactant (i.e. an ethylenically unsaturated surfactant), in particular a polymerizable surfactant based on phosphate, phosphonate, sulfate, sulfonate, sulfosuccinate or carboxylate, more particularly a polymerizable surfactant based on sulfate.

The polymerizable anionic surfactant may comprise an aromatic ring. In particular, the polymerizable anionic surfactant may comprise a carbon-carbon double bond in the alpha or beta position of the aromatic ring, more particularly in the alpha position of the aromatic ring.

The polymerizable anionic surfactant may in particular correspond to the following formula (Ia):

in which
Z is an ethylenically unsaturated group, preferably a group of formula -CH=CH ₂ , -CH=CHCH ₃ or -CH ₂ -CH=CH ₂
each R ¹ is independently selected from H, alkyl, alkenyl, alkoxy, aryl and alkylaryl;
L is a bond, alkylene, oxyalkylene or polyoxyalkylene;
X comprises a hydrophilic group, preferably chosen from -SO ₃ M, -CO ₂ M, -P(Y)O ₂ M, -C(=O)-CH(SO ₃ M)-CH ₂ -C(=O)-Y or -C(=O)-CH ₂ -CH(SO ₃ M)-C(=O)-Y, more preferably -SO ₃ M;
M is H, a metal cation (especially sodium or potassium) or ammonium;
Y is OM or a residue of the following formula (Ib):

.

The polymerizable anionic surfactant may in particular correspond to the following formula (Ic):

in which R ¹ and M are as defined above;
each A is independently C2-C4 alkylene, preferably ethylene or propylene;
n ranges from 1 to 100, from 2 to 60, from 3 to 50, from 4 to 40 or from 5 to 30.

The polymerizable anionic surfactant may in particular correspond to the following formula (Id):

in which A, M and n are as defined above;
m is 1 or 2.

Examples of suitable polymerizable anionic surfactants are available under the references Hitenol® BC-3025, Hitenol® AR-1025, Hitenol® AR-10, Hitenol® KH-1025, Hitenol® KH-10, Hitenol® KH-05, Hitenol® BC-20, Hitenol® BC-1025, Hitenol® BC-20 from Dai-Ichi Kogyo Seiyaku.

According to a particular embodiment, component T comprises an anionic surfactant chosen from an alkylbenzenesulfonate and mixtures thereof.

Component T may in particular comprise a non-ionic surfactant selected from an optionally alkoxylated fatty alcohol, an optionally alkoxylated fatty acid, an optionally alkoxylated sorbitol ester, an optionally alkoxylated fatty ester, an ethoxy-propoxy block copolymer (EO-PO copolymer), a polymerizable non-ionic surfactant and mixtures thereof. A list of suitable surfactants is available in the book "Surfactants and Polymers in Aqueous Solutions" (Holmberg et al., 2002, John Wiley & Sons).

Examples of suitable fatty alcohols are C6-C22 alkoxylated fatty alcohols with 2-50 alkoxy units, such as C12-C14 alcohol ethoxylates (such as Tergitol® 15-S-20), C13 alcohol ethoxylates (such as Emulan® TO 4070, Emulan® TO 2080), C16-C18 alcohol ethoxylates (such as Empilan® KM80), propoxylated/ethoxylated _C4 - _C8 alcohols with a propoxy/ethoxy weight ratio of the order of 1, ethoxylated iso _C10 fatty alcohol (2-40 EO), ethoxylated _C10 - _C18 monobranched fatty alcohols (2-40 EO).

Examples of suitable sorbitol esters are _C18 sorbitol esters and ethoxylated sorbitol esters (5-20 EO units).

Examples of suitable fatty acids are ethoxylated C ₁₂ -C ₁₈ fatty acids (7-100 EO), ethoxylated castor oil (30-40 EO), ethoxylated hydrogenated castor oil (7-60 EO).

Examples of suitable fatty esters are glycerol palmitate, glycerol stearate, ethylene glycol stearate, diethylene glycol stearate, propylene glycol stearate, polyethylene glycol 200 stearate (PEG of Mn = 200) or C ₁₈ ethoxylated (2-15 EO) fatty esters.

Examples of ethoxy-propoxy block copolymers are Butoxy EO-PO copolymers (such as Maxemul® 7101).

The non-ionic surfactant may be a polymerizable non-ionic surfactant (i.e. an ethylenically unsaturated surfactant), in particular a polymerizable surfactant based on a polyether.

The polymerizable nonionic surfactant may comprise an aromatic ring. In particular, the polymerizable nonionic surfactant may comprise a carbon-carbon double bond in the alpha or beta position of the aromatic ring, more particularly in the alpha position of the aromatic ring.

The polymerizable non-ionic surfactant may in particular correspond to the following formula (IIa):

in which
Z' is an ethylenically unsaturated group, preferably a group of formula -CH=CH ₂ , -CH=CHCH ₃ or -CH ₂ -CH=CH ₂
each R ³ is independently selected from H, alkyl, alkenyl, alkoxy, aryl and alkylaryl;
each A is independently C2-C4 alkylene, preferably ethylene or propylene;
n ranges from 1 to 100, from 2 to 60, from 3 to 50, from 4 to 40 or from 5 to 30.

The polymerizable non-ionic surfactant may in particular correspond to the following formula (IIb):

in which R ³ , A and n are as defined above.

The polymerizable non-ionic surfactant may in particular correspond to the following formula (IIc):

in which A and n are as defined above;
Alk is alkyl, preferably C6-C30.

The polymerizable nonionic surfactant may be an aliphatic surfactant.

The polymerizable non-ionic surfactant may in particular correspond to the following formula (IIIa):

in which
L is a C6-C30 alkylene, preferably branched;
Z'' is an ethylenically unsaturated group, preferably a group of formula -C(=O)-CR ⁴ =CH ₂ , -CH ₂ -CR ⁵ =CH ₂
R ⁴ and R ⁵ are independently selected from H and methyl;
each A is independently C2-C4 alkylene, preferably ethylene or propylene;
n ranges from 1 to 100, from 2 to 60, from 3 to 50, from 4 to 40 or from 5 to 30.

Examples of suitable polymerizable nonionic surfactants are available under the references Noigen® RN-10, Noigen® RN-20, Noigen® RN-30, Noigen® RN-40, Noigen® RN-5065, Noigen® KN-10, Noigen® AN 5065, Noigen® AN-30, Noigen® AN-20, Noigen® AN-10 from Dai-Ichi Kogyo Seiyaku.

According to a particular embodiment, component T comprises a non-ionic surfactant chosen from an ethoxy-propoxy block copolymer.

The weight ratio of component T relative to the weight of the alkyd emulsion varies from 1 to 15%, preferably from 2 to 12% and more preferably from 3 to 10%.

The alkyd emulsion according to the invention can in particular be prepared according to the process described below.

Process for the preparation of an alkyd emulsion

The invention also relates to a process for preparing an alkyd emulsion, the process comprising the following steps:

(i) preparing a molten alkyd resin, the alkyd resin being based on an acid component A and an alcohol component B, the acid component A comprising an aromatic polyacid component A1;

ii) addition of a surfactant component T and water;

iii) neutralization of at least part of the acidity of the reaction mixture by adding an N,N-dialkylglucamine of formula (II):

(II)
wherein R ₁ and R ₂ are independently C1-C4 alkyl;

iv) emulsification by phase inversion;

v) possibly adjustment of the dry extract of the alkyd emulsion.

The alkyd resin of step i) may in particular be prepared by polycondensation of an acid component A and an alcohol component B. Components A and B may in particular be as described above. Components A and B may be heated to a temperature ranging from 80 to 250°C. The water formed during the polycondensation may be gradually removed by distillation. The progress of the polycondensation may be controlled by the acid number of the reaction mixture. Once the desired acid number is reached, the alkyd resin may be cooled to room temperature (20-30°C) to be stored for subsequent emulsification. Alternatively, the alkyd resin may be directly introduced in the molten state (for example at a temperature of 80 to 110°C) into step ii) of the process according to the invention.

Step ii) may be carried out by adding component T and water to the reaction medium. Component T may in particular be as described above. Step ii) may be carried out at a temperature ranging from 80 to 100°C.

Step iii) may in particular be carried out by adding N,N-dialkylglucamine of formula (II), in particular by adding an aqueous solution of N,N-dialkylglucamine of formula (II). The R ₁ and R ₂ groups of the N,N-dialkylglucamine of formula (II) may in particular be as defined for the ammonium carboxylate groups of formula (I).

Step iii) may be carried out at a temperature ranging from 60 to 85°C. The amount of N,N-dialkylglucamine of formula (II) introduced into the reaction medium may in particular range from 4 to 15%, preferably from 6 to 12%, relative to the weight of the alkyd resin. Step iii) may be carried out at a temperature ranging from 60 to 85°C. The neutralization carried out in step iii) is not necessarily total, i.e. the alkyd resin may have carboxylic acid groups in free form (-COOH) at the end of step iii).

Step iv) can in particular be carried out by gradually adding water to the reaction mixture with stirring. The temperature of the reaction mixture can be maintained at a temperature ranging from 60 to 85°C. Once emulsification is complete, the temperature of the reaction medium can be allowed to return to room temperature (20 to 25°C).

Optional step v) may be carried out by adding water to obtain the desired dry extract. In particular, the dry extract may be adjusted to reach 35 to 65%, preferably 40 to 60%, more preferably 45 to 55%.

Composition, coating and use

Another subject, according to the invention, relates to a coating composition comprising an alkyd emulsion as defined above.

The composition may include a drying agent. The drying agent increases the polymerization rate of the alkyd resin. Drying agents are typically metal salts, including salts of cadmium, tin, cobalt, manganese, zirconium, lead, iron, or calcium; or organic compounds such as fatty acids.

According to another embodiment, the composition does not include a drying agent and dries simply with the oxygen in the air. It is then sufficient for the aqueous phase to be eliminated naturally by drying.

The composition according to the invention can be applied to a wide variety of substrates, including wood, metal, stone, plaster, concrete, glass, fabric, leather, paper, plastic, composite. The application can be carried out in a conventional manner, in particular with a brush or roller, by spraying, immersion or covering.

After applying the composition, the water can be removed naturally by air drying, particularly at room temperature or by heating.

The composition may in particular be a coating, sealant or adhesive composition.

In particular, the composition may be a coating composition, more particularly a decorative coating composition, in particular a film, paint, varnish, lacquer, stain, adhesion primer or ink composition.

According to a particular embodiment, the composition is a paint, varnish or stain composition, in particular a finishing paint, varnish or stain composition. Such a composition can in particular be applied indoors or outdoors, for example on wood, metal, a wall or plastic.

The composition can in particular be used to obtain a coating (in particular a film, a paint, a varnish, a lacquer, a stain, an adhesion primer or an ink), an adhesive or a mastic.

Another subject of the invention relates to the use of the alkyd emulsion according to the invention, as a binder for obtaining a coating (in particular a film, a paint, a varnish, a lacquer, a stain, an adhesion primer or an ink), an adhesive or a mastic.

The invention also relates to a coating (in particular a film, a paint, a varnish, a lacquer, a stain, an adhesion primer or an ink), an adhesive or a mastic obtained by applying and drying the composition according to the invention.

The following examples illustrate the invention and its performance and in no way limit its scope.

EXPERIMENTAL PART Raw materials

The raw materials used in the examples are described in Table 1 below.

Name
(Supplier) Chemical name Technical function Nouracid® DE 656
(Oleon) Dehydrated castor oil
(mixture of fatty acids containing by weight relative to the weight of the mixture
60 to 65% conjugated fatty acid,
2 to 5% saturated fatty acid
5 to 8% monounsaturated fatty acid,
22 to 30% unconjugated polyunsaturated fatty acid)


A2
A5
A6
A7 Nouracid® SZ 35
(Oleon) Soybean fatty acid (SOFA)
(mixture of fatty acids containing, by weight relative to the weight of the mixture,
2 to 10% saturated fatty acid,
20 to 30% monounsaturated fatty acid,
51 to 70% unconjugated polyunsaturated fatty acid)


A5
A6
A7 Pentaerythritol Pentaerythritol B1 Phthalic anhydride Phthalic anhydride A1 Benzoic acid Benzoic acid A4 Genamin® Gluco 50 (Clariant) N,N-dimethylglucamine
(50% aqueous solution by weight) Base LiOH monohydrate 10% Lithium hydroxide monohydrate
(10% by weight aqueous solution) Base Maxemul® 7201 (Croda) Dodecylbenzenesulfonate in the form of ammonium salt based on isopropylamine Anionic surfactant Maxemul® 7101
(Croda) Ethoxy-propoxy block copolymer Non-ionic surfactant

Tests and measurement methods

These tests and methods are generally valid for the characteristics cited in the description and in particular in the examples presented.

Dry extract

Evaluation according to ISO 3251:2008 according to the conditions: 1 g of dispersion for 1 hour at 125°C and the result is expressed in %.

Cone-plate viscosity

The cone-plate viscosity of alkyd resin is measured at 125°C according to ISO 2884-1:1999 and expressed in mPa.s.

Brookfield Viscosity

The Brookfield viscosity of the alkyd emulsion is measured at 23°C, with a Brookfield DVII apparatus (S34 spindle) according to ISO 3219:1993.

Particle size

The particle size of the alkyd emulsion is measured using a Zetasizer-Malvern Instruments Ltd. apparatus. The dispersion sample is diluted in a transparent tank using filtered deionized water. The volume average particle size (Dv50) is measured by 90° laser scattering.

Acid Number and Hydroxyl Number

The acid value of alkyd resin is evaluated according to ISO 3682:1996.

The hydroxyl value of alkyd resin is evaluated according to ISO 4326:2019.

Storage stability

Storage stability is the variation in the dry extract of the alkyd emulsion at 50°C for 1 month. Storage stability consists of measuring the dry extract on the surface of the sample and comparing it with the dry extract measured at the bottom of the sample. If after one month of storage at 50°C, the difference in the measured dry extract is not greater than 2%, the stability is considered good.

Water resistance

The water resistance of a coating is measured on films with a thickness of 150 µm obtained by applying a formulation using a filmograph on Leneta P121-10N card and drying for 24 hours at 23°C (+/-2°C) with a humidity level of 50%. After drying, water drops are placed on the surface of the paint film. As many water drops as the chosen contact time (for example: 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 8 h, 16 h or even 24 h) can be covered (with a watch glass, a bottle cap, etc.) and/or placed on a small piece of filter paper to slow down evaporation (recommended for long contact times). After the chosen contact time has elapsed, gently remove the drop with absorbent paper and assess the condition of the test surface. A rating will be made immediately after removing the water drop. A second rating will be made after reconditioning the test specimen for 24 hours in a climate-controlled room at 23°C and 50% RH, in order to assess the coating's ability to regain its initial appearance. Water resistance is assessed qualitatively according to the following scale:

4: No visible change

3: Slight change in gloss visible when the light source is reflected on the test surface / Swelling of the coating / Variation in color (whitening) / Softening of the coating

2: Appearance of a modification of the structure of the coating (light blistering, wrinkling)

1: Significant modification of the structure of the coating (intense blistering)

Shine

The measurements are carried out using a BYK Gardner GmbH “micro-TRI-gloss” gloss meter with a geometry of 20°/60° after 24 hours of drying in an air-conditioned room (at 23°C ± 1°C and at 50% ± 5% RH) of wet films of 200 µm deposited on glass plates and according to the ISO 2813 (2014) standard.

Resistance to blocking

The formulations to be evaluated are applied to two Leneta 2A cards at a thickness of 150 µm, using a filmograph. The cards are stored in an air-conditioned room (at 23°C ± 1°C and 50% ± 5% RH or at 50°C ± 1°C and 50% ± 5% RH) for a given time. The painted faces of these cards are then placed face to face between two glass plates. The assembly is pressed with a mass to obtain a pressure of 50 g/cm ² over the entire test surface. The painted faces are left in contact in an air-conditioned room for a given time. At the end of the contact time, the cards are gently separated by pulling on the two cards in all directions.

The damage caused to the paint films is then quantified on a scale ranging from 0 to 8 according to the indications given in the table below (with 0 meaning the best performance and 8 the worst):

[Table 2]: Blocking resistance assessment scale 0 No adhesion between films and no noise when separating cards 1 Detachment of films with a slight noise, but without alteration of the test surface 2 Tear-off < 10 points on the test surface 3 Tear-off < 50 points on the test surface 4 Tear-off > 50 points on the test surface 5 Surface tearing < 20% of the test surface 6 Surface tearing between 20 and 50% of the test surface 7 Surface tearing > 50% of the test surface 8 Total tearing of the test surface

Yellowing index

The formulations to be evaluated were applied to two Leneta 2A cards at a thickness of 150 µm, using a filmograph. These paints were stored in an air-conditioned room (at 23°C ± 1°C and 50% ± 5% RH or at 50°C ± 1°C and 50% ± 5% RH) for a given time. The yellowing index Yi (= “Yellowing Index”) was determined on a “Konica Minolta” CM26D spectrocolorimeter according to ASTM 313-96 standard on dry films at different drying times.

The 150 µm wet film thickness is applied to Leneta cards using a Bird filmograph.

Example 1 (according to the invention)

1.1) Synthesis of alkyd resin

• une canne plongeante pour l’introduction d’azote,
• une sonde de température,
• un réfrigérant alimenté par de l’eau à 12°C, et
• un ballon pour récupérer l’eau issue de la polycondensation,

In a 1.5 liter reactor comprising:

• a diving rod for introducing nitrogen,
• a temperature probe,
• a refrigerant supplied with water at 12°C, and
• a tank to collect the water from polycondensation,

• 285 g de Nouracid® SZ 35,
• 95 g de Nouracid® DE 656,
• 265,9 g de pentaérythritol,
• 287,1 g d’anhydride phtalique et
• 166,3 g d’acide benzoïque.

the following raw materials were used:

• 285 g of Nouracid® SZ 35,
• 95 g of Nouracid® DE 656,
• 265.9 g of pentaerythritol,
• 287.1 g of phthalic anhydride and
• 166.3 g of benzoic acid.

• Indice d’acide :11,5 mg KOH/g
• Extrait sec : 100%
• Viscosité cône-plan : 2 500 mPa.s

The raw materials were introduced under nitrogen bubbling. The mixture was heated to 240°C using an electric heating cylinder and the resulting water was distilled as it formed until an acid number of 12 mg KOH/g was obtained. At the end of the synthesis, a viscous alkyd resin with the following characteristics was obtained:

• Acid number: 11.5 mg KOH/g
• Dry extract: 100%
• Cone-plate viscosity: 2,500 mPa.s

1.2) Emulsification of alkyd resin to obtain an alkyd emulsion

• Extrait sec : 49.8%
• pH : 8.1
• Viscosité Brookfield à 23°C : 66 mPa.s
• Taille des particules : 167 nm
• Stabilité au stockage : bonne
• Teneur en hydroxyde de lithium libre : 0 ppm

In a 1 liter reactor, 399 g of alkyd resin obtained according to the operating conditions of 1.1) described above, previously melted at 80-100°C, were introduced. When the reactor temperature was stabilized at 85°C, 7.98 g of Maxemul® 7201 and 18.2 g of Maxemul® 7101 were introduced. The mixture was left stirring for 30 minutes. 112 g of water were then introduced. When the temperature reached 65°C, 22.54 g of Genamin® Gluco 50 (50% by weight aqueous solution) were introduced to neutralize the reaction mixture. The mixture was left stirring at 60°C for 30 minutes. Finally, 302 g of water were introduced over a period of 2 hours, while maintaining the temperature at 60°C. The reactor was then cooled to room temperature and the dry extract adjusted to 50%. The final emulsion was obtained alkyd which has the following characteristics:

• Dry extract: 49.8%
• pH: 8.1
• Brookfield viscosity at 23°C: 66 mPa.s
• Particle size: 167 nm
• Storage stability: good
• Free lithium hydroxide content: 0 ppm

Example 2 (comparative)

Example 1 was reproduced by carrying out a single neutralization step with 28 g of LiOH monohydrate (10% by weight aqueous solution).

• Extrait sec : 50%
• pH : 7,5
• Viscosité Brookfield à 23°C : 31 mPa.s
• Taille des particules : 194 nm
• Stabilité au stockage : bonne
• Teneur en hydroxyde de lithium libre : > 10 ppm et < 100 ppm

In the end, we obtained an emulsion alkyd which has the following characteristics:

• Dry extract: 50%
• pH: 7.5
• Brookfield viscosity at 23°C: 31 mPa.s
• Particle size: 194 nm
• Storage stability: good
• Free lithium hydroxide content: > 10 ppm and < 100 ppm

Formulation

The alkyd emulsions were formulated into a gloss paint with a pigment volume concentration (PVC) of 19% and with a TiO ₂ content of 24% with an iron-based drying agent.

The raw materials used for the formulation are detailed in Table 3.

Component / Reference Function Parts by weight Water 132.76 Acticide® BCL 2 Biocide 2.5 Coadis® 790 Dispersing Agent 6 Byk® 022 Antifoam 1.5 Tiona® 595 Titanium Dioxide 240 Alkyd emulsion
(at 49.3% Dry Extract) Binder 583.6 Borchi Oxy-Coat® 1101 Iron-based desiccant 1.44 Coapur® 2025 Thickening 26.4 Coapur® 830W Thickening 5.8

The properties of the paints obtained are detailed in Table 4.

Alkyd emulsion Example 1
(invention) Example 2
(comparative) Water resistance 4 3 Blocking resistance
24 hours drying and 24 hours contact 1 8 Shine 20° / 60° / (24h at 23°C) 90 / 95 92 / 97 Yellowing index 14 days at 23°C 2.5 2.4 14 days at 50°C 8.7 7.3

The coating based on an alkyd neutralized with N,N-dialkylglucamine is free of free lithium hydroxide and has equivalent properties in terms of gloss and yellowing index and better properties in terms of water resistance and blocking resistance compared to a coating based on an alkyd neutralized with lithium salts.

Claims (19)

Alkyd emulsion, characterized in that it comprises an alkyd resin, the alkyd resin being based on an acid component A and an alcohol component B, the acid component A comprising an aromatic polyacid component A1, the alkyd resin comprising ammonium carboxylate groups of formula (I)
(I)
wherein R ₁ and R ₂ are independently C1-C4 alkyl. Alkyd emulsion according to claim 1, characterized in that the alkyd resin has an oil length of 10 to 60%, in particular 20 to 50%, more particularly 20 to 40%. Alkyd emulsion according to claim 1 or 2, characterized in that component A1 comprises phthalic anhydride. Alkyd emulsion according to any one of claims 1 to 3, characterized in that component A comprises a conjugated fatty acid component A2, preferably component A2 comprises at least one conjugated fatty acid derived from a modified vegetable oil, more preferably at least one conjugated fatty acid derived from dehydrated castor oil, isomerized sunflower oil, isomerized linseed oil, isomerized soybean oil, more preferably still a conjugated fatty acid derived from dehydrated castor oil. Alkyd emulsion according to any one of claims 1 to 4, characterized in that the acid component A comprises a non-fatty monoacid component A4, in particular the component A4 comprises at least one aromatic non-fatty monoacid, more particularly benzoic acid. An alkyd emulsion according to any one of claims 1 to 5, characterized in that the acid component A comprises a saturated fatty acid component A5, in particular the component A5 comprises a saturated fatty acid selected from capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, 9-hydroxy stearic acid, 10-hydroxystearic acid, 12-hydroxystearic acid, icosanoic acid, 14-hydroxyicosanoic acid and mixtures thereof. An alkyd emulsion according to any one of claims 1 to 6, characterized in that the acid component A comprises a monounsaturated fatty acid component A6, in particular the component A6 comprises a monounsaturated fatty acid selected from myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, gadoleic acid, ricinoleic acid, elaidic acid, trans-vaccenic acid, erucic acid, nervonic acid, brassidic acid, lesquerolic acid, and mixtures thereof. Alkyd emulsion according to any one of claims 1 to 7, characterized in that the acid component A comprises a non-conjugated polyunsaturated fatty acid component A7, in particular the component A7 comprises a non-conjugated polyunsaturated fatty acid selected from linoleic acid, α-linolenic acid, γ-linolenic acid, 7,10,13-hexadecatrienoic acid, 9,12,15-octadecatrienoic acid, 6,9,12,15-octadecatetraenoic acid, 11,14,17-icosatrienoic acid, 8,11,14,17-icosatetraenoic acid, 5,8,11,14,17-icosapentaenoic acid, 6,9,12,15,18-heneicosapentaenoic acid, 7,10,13,16,19-docosapentaenoic acid, 4,7,10,13,16,19-docosahexaenoic acid, 9,12,15,18,21-tetracosapentaenoic acid, 6,9,12,15,18,21-tetracosahexaenoic acid, 9,12-octadecadienoic acid, 6,9,12-octadecatrienoic acid, 11,14-icosadienoic acid, 8,11,14-icosatrienoic acid, 5,8,11,14-icosatetraenoic acid, 13,16-docosadienoic acid, 7,10,13,16-docosatetraenoic acid, 4,7,10,13,16-docosapentaenoic acid, 9,12,15,18-tetracosatetraenoic acid, 6,9,12,15,18-tetracosapentaenoic acid, and mixtures thereof. Alkyd emulsion according to one of claims 1 to 8, characterized in that the alcohol component B comprises a polyol component B1, in particular a polyol component B1 having a functionality ranging from 2 to 6, in particular from 2.5 to 5.5, more particularly from 3 to 5. Alkyd emulsion according to claim 9, characterized in that component B1 comprises at least one saturated aliphatic polyol chosen from trimethylolethane, trimethylolpropane, glycerol, diglycerol, triglycerol, tetraglycerol, pentaglycerol, a polyglycerol, di(trimethylolpropane), pentaerythritol, dipentaerythritol, sorbitol, a diol derived from a dimer or trimer of hydrogenated or non-hydrogenated fatty acid, alkoxylated derivatives of the polyols mentioned above, and mixtures thereof. Alkyd emulsion according to one of claims 1 to 10, characterized in that the weight content of the alkyd resin relative to the weight of the alkyd emulsion varies from 35 to 65%, preferably from 40 to 60%, more preferably from 45 to 55%. Alkyd emulsion according to one of claims 1 to 11, characterized in that the acid number of the alkyd resin is less than 25 mg KOH/g, preferably 5 to 20 mg KOH/g, more preferably 6 to 13 mg KOH/g. Alkyd emulsion according to any one of claims 1 to 12, characterized in that the emulsion comprises a surfactant component T, in particular a component T comprising a surfactant chosen from an anionic surfactant, a non-ionic surfactant and mixtures thereof. Alkyd emulsion according to claim 13, characterized in that the weight content of component T relative to the weight of the alkyd emulsion varies from 1 to 15%, preferably from 2 to 12% and more preferably from 3 to 10%. Process for preparing an alkyd emulsion as defined according to one of claims 1 to 14, characterized in that the process comprises the following steps:
(i) preparing a molten alkyd resin, the alkyd resin being based on an acid component A and an alcohol component B, the acid component A comprising an aromatic polyacid component A1;
ii) addition of a surfactant component T and water;
iii) neutralization of at least part of the acidity of the reaction mixture by adding an N,N-dialkylglucamine of formula (II):
(II)
wherein R ₁ and R ₂ are independently C1-C4 alkyl;
iv) emulsification by phase inversion;
v) possibly adjustment of the dry extract of the alkyd emulsion. Composition characterized in that it comprises an alkyd emulsion as defined according to one of claims 1 to 14 or obtained by the process as defined according to claim 15. Composition according to claim 16, characterized in that it is a coating, mastic or adhesive composition, in particular a coating composition, more particularly a film, paint, varnish, lacquer, stain, adhesion primer or ink composition. Use of the alkyd emulsion as defined according to one of claims 1 to 14 or obtained by the process as defined according to claim 15, as a binder for obtaining a coating, an adhesive or a sealant, in particular for obtaining a coating, more particularly for obtaining a film, a paint, a varnish, a lacquer, a stain, an adhesion primer or an ink. A coating, adhesive or sealant obtained by applying and drying the composition according to claim 16 or 17.