HK1263131A1 - Polymeric anti-skinning and drier compounds - Google Patents

Description

Polymer antiskinning and drying agent compounds

Technical Field

The present disclosure relates to polymers as desiccants and antiskinning agents, and in particular to polymers for use in coatings, paints or inks.

Background

Since the drying rate of uncatalyzed air drying systems, such as alkyd paints, is too slow for commercial applications, it is common practice to accelerate the drying process by adding metal driers (also known as siccatives) to the system. Without a drier, a typical alkyd paint may take as long as weeks to days to dry, which is clearly undesirable for most applications.

The primary desiccant catalyzes the formation and/or decomposition of peroxide, which is formed by the reaction of oxygen with the air drying vehicle or drying oil. Metal carboxylates, especially cobalt carboxylates, have hitherto been the main component of desiccants, at least if drying has to take place at room temperature and within a reasonable time. The use of cobalt carboxylates, and in particular cobalt octoates, has been widely described and is common practice throughout the paint industry (see, for example, j.h. Bieleman, editivefor Coatings, edited by j.h. Bieleman, Wiley NCH, Weinheim, 2000, page 202).

However, cobalt has been shown to be carcinogenic in vivo inhalation testing. This toxicity is generally considered to be associated with cobalt ions because the compounds tested have relatively high aqueous solubility and produce appreciable cobalt ion concentrations. The data obtained for most standard cobalt carboxylates justifies serious concerns about their carcinogenicity, making their use as driers in autoxidisable paint and ink systems problematic in the future.

Although cobalt carboxylates are the primary desiccant, other transition metals such as manganese also play a role in the process. The effect of manganese carboxylates is most pronounced at higher temperatures or at room temperature when used as a co-desiccant for cobalt. The higher temperature required for the development of the catalytic activity of manganese as the main drying agent is about 80 ℃, which is the condition normally seen on printing presses. Thus, manganese driers can be used in these applications.

Although manganese is an essential component of life, for example, as a central atom in superoxide dismutase (SOD), the toxicity of manganese compounds is also well known. Manganese carboxylates have not been classified, but have been shown to release manganese ions in aqueous solution. Therefore, the interest in future classification of manganese carboxylates is justified.

It is known to apply printing inks on fast running rotary printing presses to form an aerosol of fine ink droplets around the press. Thus, since the main risk for the worker is to be absorbed by inhalation, it is important to reduce the water solubility and thus the release of metal ions at the pH values (around neutral) typically seen in lung fluids.

As mentioned above, metal carboxylates are used in a wide range of applications, of particular importance in the paint and varnish industry, where they are used as drying agents and rheology modifiers, as accelerators for unsaturated polyesters, as lubricating oil additives, as biocides, and the like.

Thus, while metal carboxylates have had a wide range of uses and applications, the introduction of stricter regulations on chemicals has made future uncertainty, particularly with respect to certain metal carboxylates, such as cobalt and manganese compounds, where unacceptable toxicity characteristics are suspected.

The toxicity of these compounds has been found to be related to aqueous solubility. High water solubility and subsequent hydrolysis increase the concentration of metal ions in the aqueous medium. It must be borne in mind that such higher metal ion concentrations will occur in biological fluids, which in turn increases the likelihood of toxic effects.

It is possible to reduce the water solubility by including metal atoms in the polymer structure and additionally reduce the resulting metal ion concentration. The increased molecular weight with more complex molecular structure reduces the water solubility of the compound such that the threshold for toxicity is not reached.

However, existing polymer compounds having reduced water solubility with toxic metal ion concentrations have several technical problems and disadvantages. A first technical problem and drawback is the limitation of the metal content, which can be obtained while still having a usable viscosity level. For example, the existing metal content of cobalt and manganese is typically below 6% by weight, thereby placing restrictions on the catalytic, drying, modifier and/or accelerator functions of the polymer compound. A second disadvantage is the limitation of the viscosity of the polymer compound solution, which is usually higher compared to conventional products, thereby limiting the choice of solvent for the product to very strong solvents, such as glycol derivatives, which are themselves substances of interest due to their toxicological properties.

Alkyd-containing vegetable oil-based coating systems have been investigated to alleviate or solve problems associated with water-based/emulsion-based systems, including but not limited to: the difficulty of obtaining high gloss, high proportions of Volatile Organic Compounds (VOCs), the use of biocides, high carbon footprint and pollution of domestic sewage systems.

However, vegetable oil based systems also require two separate types of additives with unfavorable toxicological properties to function properly. One additive is the above-mentioned desiccant and the other additive is an anti-skinning agent as described further below.

While drying of emulsion-based paints is based on coalescence of polymer droplets and absorption and evaporation of the associated carrier (combination of water and co-solvent), drying of oil-based paints and varnishes is based on chemical reactions and evaporation of volatile components.

The chemical reaction is initiated by the absorption of oxygen by the paint vehicle, such as alkyd resin. This oxygen forms peroxides and hydroperoxides with the unsaturated fatty acid chains in the alkyd resin. These oxidation products are unstable and decompose according to a free radical mechanism, which results in polymerization of the binder molecules and formation of a dry film.

Alkyd paints or varnishes containing primary siccatives or a combination of primary and secondary siccatives will polymerize when contacted with air. Since paint cans or containers usually leave a space above the paint, and the paint must be available even after repeated opening of the container, the resulting air ingress will initiate the above-described dry film process, and the film begins to form on the paint surface. This is known in the related art as "skinning" and the "skinned" paint must be filtered to remove the "skin". Thus, skinning poses a problem for users of the skinned paint or varnish, which requires the user to remove the skin (preferably without pouring or user contact) prior to using the paint or varnish.

To mitigate skinning, the industry has investigated the use of antiskinning agents as additives to paints and coatings. Previously, anti-skinning agents were primarily oxime products such as methyl ethyl ketoxime (also known as Methyl Ethyl Ketoxime) (MEKO). Unfortunately, as with desiccants, regulations on chemicals, as described in the REACH project (EU), require thorough inspection of each chemical used in consumer products, showing a very unfavorable toxicological profile of such oxime-type products. Since these oximes are volatile substances and must be evaporated from the film to start the drying process, users are often exposed to oximes by inhaling the evaporated material. Attempts have been made to replace methyl ethyl ketoxime with other products, in particular with oximes of higher molecular weight, but these are at best only partial solutions.

Thus, the industry has previously used separate drying and antiskinning agents, both types of agents having toxic and hazardous effects on the user and/or the environment. Thus, there remains a need in the art for desiccants and antiskinning agents for coatings, paints or inks that are safer and environmentally friendly to the user while maintaining their effectiveness as desiccants and antiskinning agents.

Brief description of the invention

The present invention provides a new class of metal-containing and antioxidant-containing carbamated polymer compounds that allow both the catalytic effect of the metal on the oxidative drying of the polymer and the antiskinning effect of the antioxidant component in a single polymer compound. The carbamated polymer compounds also have low water solubility to advantageously reduce the likelihood of worker exposure to metals. In one example, the polymer compound is soluble in "green" and low VOC solvents. For example, the solvent may be biologically derived, biodegradable and have a low VOC content. Thus, the carbamated polymer compounds of the present invention largely avoid toxic effects by eliminating the use of oximes, reduce the availability of metal ions in aqueous systems, and are soluble in "green" (e.g., biodegradable) and low VOC solvents while providing both anti-skinning and drying functions in a single compound.

According to one embodiment disclosed herein, a polymeric compound is described for use as both a drying agent and an antiskinning agent in a coating, paint or ink. In one embodiment, the polymer compound comprises a metal-containing and antioxidant-containing carbamated polymer having a metal, an antioxidant and a water solubility according to OECD105 of less than 20 mg/l.

According to another embodiment, the polymer compound comprises a metal-containing and antioxidant-containing carbamated polymer having the following formula (I):

wherein M is a metal, A is an antioxidant group, R₁Is an alkyl group, and R₂Is an alkyl group. In one example, the metal M is selected from cobalt, manganese, cerium, and iron; r₁Is an alkyl group having 6 carbon atoms; and/or R₂Is an alkyl group having 7 carbon atoms.

According to one example, the antioxidant group a may have the following formula (II):

。

according to yet another embodiment, the metal-containing and antioxidant-containing carbamated polymer described herein is dissolved in a low VOC solvent, wherein the low VOC solvent is at least one member selected from the group consisting of a lactate ester (e.g., ethyl lactate, methyl lactate, or another ester of lactic acid with an alcohol) and a fatty acid ester (e.g., butyl linoleate), and any combination thereof.

Another embodiment disclosed herein relates to a series of coating, paint and ink compositions comprising the polymeric compounds described herein as curing catalysts. In one embodiment, the composition comprises a carbamated polymer as described herein mixed with a vehicle based on an unsaturated fatty acid modified polymer.

Also described herein is a method for preparing the polymer compound of the present disclosure. In one embodiment, a method for preparing a polymer compound comprises: providing a carboxylic acid, reacting the carboxylic acid with a metal hydroxide or metal acetate to form an intermediate product, and mixing the intermediate product with a solvent (e.g., a lactate ester solvent) to form a first mixture. The method of making further includes providing a coupling agent (e.g., an amine coupling agent) to the first mixture to form a second mixture, providing an antioxidant (e.g., including at least one of citric acid, ethyl ascorbic acid, resveratrol, or any combination thereof) to the second mixture to form a third mixture, and polymerizing the third mixture with an isocyanate to form a metal-containing and antioxidant-containing carbamated polymer. In one example, a carbamated polymer having a metal, an antioxidant, and a water solubility according to OECD105 of less than 20mg/l is formed.

In another example, a carbamated polymer may be formed that: has a metal content of greater than 6% by weight; the metal content is between 4% and 8% by weight; such that the metal is an integral part of the backbone of the polymer compound; wherein the metal is selected from cobalt, manganese, cerium and iron; wherein the carboxylic acid is provided in the form of a hydroxycarboxylic acid or a saturated fatty acid; wherein the carboxylic acid is ricinoleic acid, the metal hydroxide is cobalt hydroxide or manganese hydroxide, the coupling agent is an alkanolamine, the isocyanate is toluene diisocyanate, isophorone diisocyanate (IPDI) or hexamethylene diisocyanate (HMDI); wherein the coupling agent is provided in the form of an amine selected from the group consisting of monohydroxy amine, dihydroxy amine, trihydroxy amine, and combinations thereof; wherein a carbamated polymer having a viscosity of less than 3000cP at 20 ℃ is formed; wherein a carbamated polymer having an average molecular weight of less than 2000 Da is formed; or any suitable combination of the above attributes of the carbamated polymer. It should also be noted that the various components of the polymer compounds described above may be alternatives that may be combined in various suitable and functional combinations within the scope of the present invention.

Further described herein are methods for curing polymer-based coating compositions. In one embodiment, a method of curing a polymer-based coating composition includes providing a polymer compound as described herein, mixing the polymer compound with a vehicle based on an unsaturated fatty acid modified polymer, and then drying the coating of the mixture of polymer compound and vehicle.

Another embodiment relates to the use of the polymer compounds described herein as curing catalysts for hardening unsaturated polyesters.

Advantageously, the polymer compounds and methods for preparing the polymer compounds disclosed herein produce drier and antiskinning compounds for coatings, paints or inks that are more environmentally friendly and safe to the user. The use of oximes has been eliminated, and instead, antioxidants have been incorporated into metal-containing and antioxidant-containing polymer structures, thereby eliminating toxic components while allowing solubility in low VOC solvents and maintaining effectiveness as both desiccants and antiskinning agents.

Brief Description of Drawings

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings. Unless otherwise noted, the drawings may not be to scale.

FIG. 1 illustrates the general structure of a metal-containing and antioxidant-containing carbamated polymer compound of the type described in accordance with one embodiment of the present disclosure.

Figure 2 illustrates exemplary antioxidant groups according to one embodiment described in the present disclosure.

Fig. 3 is a flow chart of a method of making a polymer compound according to one embodiment described in the present disclosure.

Fig. 4 is another flow diagram of a method of making a polymer compound according to one embodiment described in the present disclosure.

Detailed Description

Compound (I)

The present invention relates to a series of metal-containing and antioxidant-containing polymeric compounds (both metal and antioxidant components in a single compound) for use as both a drier and an anti-skinning agent in coatings, paints or inks. The present invention also relates to drier and antiskinning compositions comprising a polymer compound dissolved in a low VOC solvent, and also to coating compositions comprising a polymer compound in combination with a binder. The invention further relates to a process for the preparation of the polymer compound. It should be noted that the polymer compound of the present invention may also be used as an accelerator in a coating, paint or ink or have various other functions.

Referring now to fig. 1, a general structure of such metal-containing and antioxidant-containing polymer compounds is shown according to one embodiment described in the present disclosure. In one embodiment, the polymer compound is characterized by comprising a metal-containing and antioxidant-containing carbamated polymer having the following formula (I) and also shown in figure 1:

wherein M is a metal, A is an antioxidant group, R₁Is a first alkyl group, and R₂Is a second alkyl group.

In one example, the metal M may include one of cobalt, manganese, cerium, and iron. In one example, the alkyl radical R₁Alkyl groups which may include 6 carbon atoms (e.g., C)₆H₁₃). In one example, the alkyl radical R₂Alkyl groups which may include 7 carbon atoms (e.g., C)₇H₁₄)。

According to one example, the antioxidant group a may have the following formula (II) and is also shown in fig. 2:

。

in another example, the antioxidant group a may be formed from the reaction of citric acid, ethyl ascorbic acid, resveratrol, ascorbic acid, or any combination thereof.

It has been demonstrated that the carbamated polymer compound having formula (I) as shown in figure 1 has a reduced toxicity risk by using a polyurethane structure (thus introducing nitrogen into the molecule) on the reacted carboxylic acid and antioxidant to advantageously provide both the metal and the antioxidant within the polymer structure.

According to the scope of the present invention, the carbamated polymer compound of formula (I) may: has a water solubility according to OECD105 of less than 20 mg/l; has a viscosity of less than 3000cP at 20 ℃; has an average molecular weight of less than 2000 Da; has a metal content of greater than 6% by weight; having a metal content of between 4% and 8% by weight; a low VOC solvent, wherein the low VOC solvent is an ester solvent selected from the group consisting of lactates and fatty acid esters; and any suitable combination thereof.

Furthermore, the carbamated polymer compound of formula (I) may be formed at least in part from a carboxylic acid, a metal hydroxide or metal acetate, a coupling agent, an antioxidant and an isocyanate. The coupling agent may be an amine selected from the group consisting of monohydroxy amine, dihydroxy amine, trihydroxy amine, and any combination thereof. The antioxidant can be an antioxidant mixture comprising ascorbic acid, ethyl ascorbic acid, resveratrol, citric acid, and any combination thereof. The carboxylic acid may be a hydroxycarboxylic acid or a saturated fatty acid. In one example, the carboxylic acid is ricinoleic acid, the metal hydroxide is cobalt hydroxide or manganese hydroxide, the coupling agent is an alkanolamine, the antioxidant mixture comprises ascorbic acid, ethyl ascorbic acid, and resveratrol, and the isocyanate is toluene diisocyanate, isophorone diisocyanate (IPDI), or hexamethylene diisocyanate (HMDI).

According to one embodiment described herein, an advantageous polymeric compound is disclosed for use as both a drying agent and an antiskinning agent in a coating, paint or ink. The polymer compound comprises a metal-containing and antioxidant-containing carbamated polymer having a metal, an antioxidant and a water solubility according to OECD105 of less than 20 mg/l.

According to one embodiment described herein, the carbamated polymer may have a metal content of greater than 6% by weight; a metal content between 4% and 8% by weight; the metal may be an integral part of the backbone of the polymer compound; the metal is selected from cobalt, manganese, cerium and iron; or any suitable combination of the above descriptions of metals.

According to one embodiment described herein, the carbamated polymer is soluble in "green" and low VOC solvents. The low VOC solvent may include an ester solvent selected from lactate esters, fatty acid esters, and combinations thereof.

According to one embodiment described herein, the carbamated polymer is formed, at least in part, from a carboxylic acid, a metal hydroxide or metal acetate, a coupling agent, an antioxidant, and an isocyanate.

According to one embodiment, the carboxylic acid may be a hydroxycarboxylic acid or a saturated fatty acid, or a combination thereof.

According to one embodiment, the coupling agent may be an amine. In one example, the coupling agent may be an alkanolamine selected from the group consisting of monohydroxy amine, dihydroxy amine, tris-hydroxy amine, or a combination thereof. It should be noted that combinations of alkanolamines may be used to obtain desired properties such as viscosity, solubility, and the like. It should also be noted that the coupling agent amine includes hydroxyl functionality for reaction with the isocyanate.

According to one embodiment, the antioxidant may be formed from an antioxidant mixture comprising one of ascorbic acid (0% -100% by weight), ethyl ascorbic acid (0% -100% by weight), resveratrol (0% -100% by weight), citric acid (0% -100% by weight), or any suitable combination thereof. For example, the antioxidant may be formed from an antioxidant mixture of ascorbic acid, ethyl ascorbic acid, and resveratrol.

According to another embodiment described herein, the carboxylic acid is ricinoleic acid, the metal hydroxide is cobalt hydroxide or manganese hydroxide, the coupling agent is an alkanolamine, the antioxidant mixture comprises ascorbic acid, ethyl ascorbic acid and resveratrol, and the isocyanate is toluene diisocyanate, isophorone diisocyanate (IPDI) or hexamethylene diisocyanate (HMDI).

Further, according to one example described herein, the carbamated polymer has a viscosity of less than 3000cP at 20 ℃. In yet another example, the carbamated polymer has an average molecular weight of less than 2000 Da.

It should be noted that the polymeric compounds "used as polymerization agents" have to be at least partially soluble in the target coatings, paints and inks, which are usually based on organic compounds, in particular on oils such as vegetable oils. The average molecular weight can be estimated from the remaining free functional groups (functionalities) of the polymer and/or the polymer synthesis sequence, or by an appropriate analytical technique such as Gel Permeation Chromatography (GPC). Fatty acids are preferred carboxylic acids because such alkyd based polymers are more compatible with alkyd vehicles used in paints and inks. The polymer compound may be unsaturated to increase its solubility in unsaturated vehicles of paints or inks and not only participate as a catalyst in the drying process. According to one embodiment, the polymer compound is completely soluble in the printing ink medium such as a hydrocarbon or alkyd resin or any mixture thereof.

The metal atoms in the polymer compounds described herein, such as cobalt, manganese, cerium or iron atoms, are preferably an integral part of the backbone of the polymer. In other words, the metal atom forms a bond in the main chain of the polymer. The metals thus incorporated confer a complete catalytic action on the polymer while greatly inhibiting its water solubility. In one embodiment, the carbamated backbone is aliphatic or aromatic. In addition, the polymer compounds described in this disclosure are typically unsaturated, although saturated forms are also possible. The unsaturated form has the advantage of copolymerizing with the main vehicle in the system, resulting in lower water solubility of the dried paint, which is advantageous in toxicological terms.

The polymer compounds and the processes for preparing the polymer compounds disclosed herein yield numerous advantages over the prior art. One embodiment of the present invention provides a desiccant and antiskinning compound for use in coatings, paints or inks that is more environmentally friendly and safe for the user while maintaining its effectiveness as both a desiccant and an antiskinning agent. The carbamated polymer compounds of the present invention largely avoid toxic effects by eliminating the use of oximes, reducing the availability of metal ions in aqueous systems, and being soluble in low VOC solvents.

In addition, the polymer compounds disclosed herein result in drier and antiskinning compounds that address compatibility issues with coatings, paints or inks. Mixing or blending antioxidants into paint formulations can cause compatibility problems because the resins are generally hydrophilic. However, the present invention advantageously incorporates an antioxidant into the polymer compound and thus allows the antioxidant to be compatible with the target paint or coating formulation.

In addition, because the antioxidant groups are fixedly located close to the metal on the polymer (rather than being randomly mixed or blended into the paint formulation), the chemical activity and effectiveness of the antioxidant groups is enhanced. Otherwise, if the antioxidant is simply blended into the paint formulation, a higher concentration of antioxidant must be added to achieve the same antiskinning effect, and such higher concentration of antioxidant will result in a slower drying time.

In addition to the drier and antiskinning functions, the polymer compounds and methods for preparing the polymer compounds disclosed herein result in narrower molecular weight distributions in the polymer compounds, thereby providing polymer compounds with better solubility and therefore lower viscosity in the same solvent, which can be more easily dispersed in a coating, paint, or ink system. Furthermore, the selection of suitable solvents has become much larger than previously possible, so that environmentally friendly solvents can now be used.

Since the carbamated polymer compounds of the present invention provide both anti-skinning and drying functions in a single compound, improved efficiency, ease of use, and ease of production are achieved.

It is further disclosed that the novel compounds described herein can be prepared at metal contents of greater than 6% w/w (weight percent) (e.g., in the case of cobalt and manganese) to improve the efficacy of the polymer compound. Furthermore, instead of the previously required diol derivatives such as hexylene glycol, the solvent can now be replaced with a low VOC solvent such as ethyl lactate, which is advantageously biologically derived, biodegradable and has a low VOC content. This is a considerable advantage to alkyd paint formulators, since the maximum concentration of VOC solvents in alkyd paints is limited.

Since previous products were formulated using a combination of dimer acid and monomeric fatty acid as the primary starting materials, previous polymeric materials have very broad molecular weight distributions. Polymerization is achieved by balancing the ratio of dimer acid and fatty acid, followed by esterification or carbamation. Dimer acids are themselves complex mixtures of monomeric fatty acids, true dimer acids, trimer acids, and even some high molecular weight compounds. Starting from such complex materials, a wide range of molecules is disadvantageously generated, wherein in particular the high molecular weight components have a negative influence on the viscosity, solubility and compatibility, and the low molecular weight components in the mixture have a negative influence on the water solubility.

Advantageously, the polymer compounds described in this disclosure are formed from a mixture of carboxylic acids and/or hydroxycarboxylic acids that react with a metal hydroxide or metal acetate, react with an antioxidant, and then further react with an isocyanate, thereby eliminating the oxime, while incorporating the antioxidant into the polymer desiccant structure, thereby eliminating toxic components, while allowing solubility in "green" and low VOC solvents. After carbamation, the resulting mixture may have: (1) very low levels of low molecular weight species; (2) the desired low water solubility without a significant amount of high molecular weight fraction. It should be noted that the various components making up the polymer compound or describing the polymer compound disclosed above may be alternatives that may be combined in various suitable and functional combinations within the scope of the present invention.

Composition comprising a metal oxide and a metal oxide

Another embodiment described in the present disclosure relates to a series of coating, paint and ink compositions comprising the polymer compounds described herein and used as curing catalysts. In one embodiment, the coating composition comprises a vehicle mixed with the polymer compound described herein. In one embodiment, the vehicle polymer is selected from alkyd polymers and alkyd-oil combinations.

Another embodiment relates to a coating formulation wherein the carbamated polymeric compound described herein is used as the sole drier in a paint or ink system. In one example of a cobalt-or manganese-containing urethanized polymer compound, the resulting metal concentration in the ready-to-use paint or ink is typically in the range of 0.05% to 0.1%, based on the weight of the auto-oxidative vehicle in the system.

In another embodiment of the composition, the composition can include a first metal-containing urethanized polymer compound and can optionally include a second metal-containing compound, where the first metal and the second metal are different metals. In one example, the first metal may be manganese and the second metal may be cobalt. The cobalt-containing compound may comprise a cobalt carboxylate or a polymeric cobalt carboxylate. The vehicle preferably comprises an unsaturated fatty acid modified polymer. The polymer compound may be tailored to copolymerize with the vehicle.

According to one embodiment, the composition is advantageously prepared as a solution in a low VOC solvent or a mixture of low VOC solvents. The solvent may for example be one or more selected from lactate (e.g. ethyl lactate, methyl lactate or another ester of lactic acid with an alcohol) and fatty acid ester (e.g. butyl linoleate) or a combination thereof.

The metal-containing and antioxidant-containing urethanized polymer compounds described herein are also suitable for use as composites for curing agents in unsaturated polyesters. Advantageously, the compounds described herein provide effective and uniform dispersion in the unsaturated polyester-based matrix of the composite material, and provide effective curing thereof. Unlike coating, paint and ink applications where oxygen from the environment is used as an initiator, composite applications require peroxide initiators to initiate cure.

General synthetic method

One embodiment described in the present disclosure relates to a process for preparing a polymer compound described herein. According to one embodiment, a method for preparing a polymer compound includes providing a carboxylic acid, reacting the carboxylic acid with a metal hydroxide or a metal acetate to form an intermediate product, and mixing the intermediate product with a solvent (e.g., lactate) to form a first mixture. The preparation method further includes providing an amine coupling agent to the first mixture to form a second mixture, providing an antioxidant comprising at least one of citric acid, ethyl ascorbic acid, resveratrol, or a combination thereof to the second mixture to form a third mixture, and polymerizing the third mixture with a multifunctional isocyanate to form a metal-containing and antioxidant-containing carbamated polymer. In one example, a carbamated polymer having a metal, an antioxidant, and a water solubility according to OECD105 of less than 20mg/l is formed. Advantageously, in one embodiment, the metal ion and the antioxidant react with the isocyanate, thus allowing both drying and antiskinning functions in the same compound. The urethanized polymer may be formed within the scope of the present invention to have the other attributes described herein in various combinations.

Referring now to fig. 3, a flow diagram of a method 100 for preparing a polymer compound according to one embodiment described in the present disclosure is shown. The method 100 includes providing a carboxylic acid at step 102 and reacting the carboxylic acid with a metal hydroxide or metal acetate at step 104 to form an intermediate product. The method 100 further includes mixing the intermediate product with a solvent to form a first mixture at step 106, providing a coupling agent to the first mixture to form a second mixture at step 108, providing an antioxidant to the second mixture to form a third mixture at step 110, and polymerizing the third mixture with an isocyanate to form the metal-containing carbamated polymer having the antioxidant at step 112.

According to one embodiment, the carboxylic acid may be provided at step 102 as a hydroxycarboxylic acid or a saturated fatty acid.

According to one embodiment, a urethanized polymer having a metal content of greater than 6 wt%, or between 4 wt% and 8 wt%, may be formed. The urethanized polymer may also be formed such that the metal is an integral part of the backbone of the polymer compound.

In one embodiment, the metalliferous feed material in step 104 is a cobalt or manganese hydroxide salt or oxide, such as manganese (II) acetate tetrahydrate in one example. In other embodiments, the reaction scheme is applicable to polyvalent metals that are available in reactive form. In addition to cobalt (Co) and manganese (Mn), metals such as cerium (Ce) and iron (Fe) may also be used.

According to one embodiment, the carboxylic acid may be ricinoleic acid, the metal hydroxide may be cobalt hydroxide or manganese hydroxide, the coupling agent may be an alkanolamine, and the isocyanate may be toluene diisocyanate, isophorone diisocyanate (IPDI), or hexamethylene diisocyanate (HMDI).

According to one embodiment, the method 100 may include dissolving the carbamated polymer in a low VOC solvent (e.g., at step 106, after step 112, and/or at each of steps 102-112), wherein the low VOC solvent is at least one member selected from a lactate ester (e.g., ethyl lactate, methyl lactate, or another ester of lactic acid with an alcohol), a fatty acid ester (e.g., butyl linoleate), or a combination thereof. It should be noted that the carbamated polymer may be diluted with a solvent to have the desired suitable viscosity, but in one example, the viscosity of the carbamated polymer is less than 3000cP at 20 ℃.

According to one embodiment, the coupling agent may be provided at step 108 as an amine selected from the group consisting of monohydroxy amines, dihydroxy amines, trihydroxy amines, and combinations thereof.

According to one embodiment, the antioxidant may be provided at step 110 as an antioxidant comprising at least one of citric acid, ethyl ascorbic acid, resveratrol, or combinations thereof, for mixing with the second mixture to form the third mixture. Thus, the antioxidant mixture may comprise one of ascorbic acid (0-100% by weight), ethyl ascorbic acid (0-100% by weight), resveratrol (0-100% by weight), citric acid (0-100% by weight), or any suitable and functional combination thereof.

The polymerization at step 112 is conducted with an isocyanate (e.g., a multifunctional isocyanate), typically a difunctional isocyanate, in one example isophorone diisocyanate (IPDA). Other suitable isocyanates include, but are not limited to, Toluene Diisocyanate (TDI), hexamethylene diisocyanate (HMDI), and the like. Mixtures of diisocyanates and monoisocyanates (e.g., methylene isocyanate) can also be used to control the average molecular weight.

According to one embodiment, a urethanized polymer having a water solubility according to OECD105 of less than 20mg/l may be formed, advantageously providing a reduced level of metal exposure to the user.

The composition may also be modified by the addition of a non-metal containing polymer as a diluent. The solvent may be left, removed, or altered to adjust the final viscosity of the ready-to-use product.

To be useful for this purpose, the final product is soluble in most polymers used in the manufacture of coatings, paints and inks.

Referring now to fig. 4, a flow diagram of a method 200 for preparing a polymer compound according to another embodiment described in the present disclosure is shown. The method 200 includes providing a hydroxycarboxylic acid at step 202, and reacting the hydroxycarboxylic acid with a metal hydroxide or metal acetate at step 204 to form an intermediate product. The method 200 further includes mixing the intermediate product with a lactate ester solvent at step 206 to form a first mixture, and providing an amine coupling agent to the first mixture at step 208 to form a second mixture. The method 200 further includes providing an antioxidant mixture including at least one of citric acid, ethyl ascorbic acid, resveratrol, or a combination thereof to the second mixture to form a third mixture at step 210. The method 200 further includes polymerizing the third mixture with an isocyanate to form a metal-containing and antioxidant-containing carbamated polymer that is soluble in a low VOC solvent and has a metal, an antioxidant, and a water solubility of less than 20mg/l according to OECD 105.

Several methods are known to determine the molecular weight of these types of compounds. The main method used is the conventional Gel Permeation Chromatography (GPC) method. The analysis was performed on a polystyrene column and the sample was diluted with tetrahydrofuran. Calibration was performed using polystyrene standards, and the method was then examined on standard vegetable and polymer oils (bodied oil) for validation. Prior to injection, the sample can be decomposed and the molecular weight calculated back to the original material.

Synthesis examples of Metal-containing Polymer Compounds containing an antioxidant

Example 1

311 g of Ricinoleic Acid (RA) was added under a nitrogen blanket to a cylindrical reaction flask or reactor equipped with a heated high torque stirrer with heating and cooling capabilities. The flask was heated to 130 ℃.

At 130 ℃ 50 g of cobalt hydroxide were gradually added to the reactor until the temperature reached 150 ℃. When the addition of cobalt hydroxide was complete, the reactor was set at 160 ℃ and stirred under vacuum for 1 hour to form an intermediate compound.

50 g of anhydrous (water content below 0.1%) Ethyl Lactate (EL) were added to the reactor and the heating was turned off. When the temperature reached 110 ℃, 40 g of anhydrous EL was added to the reactor. When the temperature was reduced to 100 ℃, 50 g of Diethanolamine (DEA) was added as a coupling agent to the reactor.

When the mixture was cooled to 90 ℃, the antioxidant mixture was added to the reactor. 20 g of ethyl ascorbic acid, 15 g of Ascorbic Acid (AA) and 4 g of resveratrol were slurried in 85 g of anhydrous EL and gradually added to the reactor. Then 55 g of anhydrous EL were added to the reactor.

15 g of isophorone diisocyanate (IPDI) were added to the reactor at a temperature of 90 ℃. The mixture was stirred for half an hour to react the IPDI, then 100g EL was added to the reactor. The homogeneous mixture was cooled to room temperature and the reactor was emptied.

The resulting product was a stable purple liquid, analyzed for cobalt content and adjusted to 4% cobalt content (w/w) with EL.

The sample was treated under high vacuum to remove the solvent. The resulting product was tested for water solubility according to OECD 105. After stirring for 24 hours at 20 ℃ a value of 11 mg Co/l was found.

Example 2

The same initial reaction and mixture was prepared with RA, cobalt hydroxide and anhydrous EL in the same proportions and temperature settings under the same equipment and under the same conditions as described in example 1.

311 g of Ricinoleic Acid (RA) was charged under a nitrogen blanket to a cylindrical reaction flask or reactor equipped with a heated high torque stirrer with heating and cooling capabilities. The flask was heated to 130 ℃.

50 g of cobalt hydroxide were gradually added to the reactor at 130 ℃ until the temperature reached 150 ℃. When the addition of cobalt hydroxide was complete, the reactor was set at 160 ℃ and stirred under vacuum for 1 hour to form an intermediate compound.

50 g of anhydrous (water content below 0.1%) Ethyl Lactate (EL) were added to the reactor and the heating was turned off. When the temperature reached 110 ℃, 40 g of anhydrous EL was added to the reactor. Similarly, when the temperature was decreased to 100 ℃, 50 g of DEA was added as a coupling agent to the reactor.

When the mixture was cooled to 90 ℃, a different antioxidant mixture was added to the reactor. 10 g of ethyl ascorbic acid, 25 g of AA and 4 g of resveratrol were slurried in 85 g of anhydrous EL and added to the reaction mixture. Then 55 g of anhydrous EL were added to the reactor.

After complete reaction, the product was carbamated using IPDI in the same proportions and temperature settings in the same manner as described in example 1. 15 g of IPDI were introduced into the reactor at a temperature of 90 ℃. The mixture was stirred for half an hour to react the IPDI, then 100g EL was added to the reactor. The homogeneous mixture was cooled to room temperature and the reactor was emptied. The product was completed by adding EL until the cobalt content was 4% (w/w).

A sample of the product was treated under high vacuum to remove the solvent and the resulting product was tested for water solubility according to OECD 105. After stirring for 24 hours at 20 ℃ a value of 14 mg Co/l was found.

Example 3

350 g of castor oil are introduced into a 1 l glass reaction vessel or reactor equipped with a stirrer, inert gas (N)₂) And a heating device. 50 g of DEA were added and the temperature was then raised to 90 ℃. A slurry of 20 g of ethyl ascorbic acid, 15 g of AA and 4 g of resveratrol in 85 g of anhydrous ethyl lactate was then added to the reactor and stirred at 90 ℃ until complete reaction.

The product mixture was then carbamated with 15 g IPDI at 90 ℃ until the isocyanate controlled by FTIR was negative. The mixture was then further diluted with EL to a solids content of 70% w/w. The product was a clear, light yellow liquid.

Results of anti-skinning test

Antiskinning activity was tested as follows. Samples of commercially produced high gloss paint were obtained without the addition of siccatives and (or) antiskinning agents. Transparent alkyd varnishes, white paints, red paints, blue paints and black paints are used. The resin solids of the clear varnish was 62% and the resin solids of the pigmented paint samples were about 40%.

To all of these systems, a cobalt-containing reagent was added to a concentration of 0.05% Co, based on resin solids. This was done using standard cobalt octoate (without anti-skinning agent) (control 1), standard cobalt octoate with 0.15% Methyl Ethyl Ketoxime (MEKO) (control 2), example 1 as desiccant/anti-skinning agent, example 2 as desiccant/anti-skinning agent, and example 2 modified with 0.3g of example 3 per 100g of finished product as desiccant/anti-skinning agent.

From each formulation, three (3) 100 ml wide-necked glass flasks were filled as follows: one filled to 50% to open every two weeks, one filled to 95%, to remain closed. All flasks were inverted once to ensure complete sealing. All these samples were stored together at 20 ℃.

For testing, the flask was periodically turned over because the skin could be easily seen. Skinning generally prevents the product from flowing. One of the 50% filled flask and the 95% filled flask was opened every two weeks to simulate actual use. The second sample flask, filled 95%, was never opened. The results of the varnish formulations are summarized in table 1 below.

TABLE 1

All samples with cobalt octoate (control 1) skinned heavily overnight, indicating that the system used is representative. Furthermore, the embodiments of the present invention provide an anti-skinning function that is comparable or improved over the conventional oxime products used as control 2. For flask samples filled to 50% and opened every two weeks, skinning occurred within 12 weeks with control 2 reagent, within 10 weeks with example 1 reagent, within 6 weeks with example 2 reagent, and within 20 weeks with example 2 + example 3 reagent. For flask samples filled to 95% and opened every two weeks, skinning occurred within 16 weeks with control 2 reagent, within 14 weeks with example 1 reagent, within 8 weeks with example 2 reagent, and within 36 weeks with example 2 + example 3 reagent. For flask samples filled to 95% and never opened, all samples did not crust over a year.

Drying test results

Drying times were measured on varnishes prepared with commercially available sunflower long chain oleyl acid resin (long oil alkyd) obtained at 70% solids in aliphatic solvents. The resin was first diluted to 60% with Exxsol D60 to obtain the application viscosity. The drying agent was added to obtain a cobalt content of 0.05% cobalt, calculated on resin solids.

The reagents used were standard cobalt octoate (control 2), example 1, example 2 and example 2 + example 3 containing 0.15% Methyl Ethyl Ketoxime (MEKO) added to the varnish.

A wet film having a thickness of 75 μ was applied to a glass plate and the drying time was recorded on a Beck Koller drying time recorder. The results are summarized in table 2 below.

TABLE 2

For the samples with cobalt octoate and MEKO reagent, the coating was dry to the touch in about 2 hours and dried through in about 6 hours. For the samples with the reagents of example 1, the coating was touch dry in about 3 hours and 30 minutes and allowed to dry through in about 7 hours. For the samples with the reagents of example 2, the coating was touch dry in about 3 hours 50 minutes and drained in about 7 hours. For the sample of example 2 with the reagent of example 3 modified, the coating was touch dried within about 5 hours 20 minutes and drained in about 16 hours.

Tests have shown that embodiments of the present invention can achieve the correct combination of drying times, avoid the problem of skinning, and should be suitable for most oily alkyds. The novel compounds and products disclosed herein do not exist in the gas phase and therefore work completely differently from the oxime type products previously used, which must be evaporated to dry, potentially leading to user exposure to toxic vapors. The products of the invention can be adapted to the various working conditions typical in the paint industry.

Use of compounds

One embodiment described in the present disclosure relates to the use of the polymer compounds described herein as catalysts for drying unsaturated polymer-based coatings, paints and inks.

In one embodiment, the polymer compounds disclosed herein may be mixed with a vehicle based on an unsaturated fatty acid modified polymer, and the coating of the mixture of polymer compounds and vehicle may be dried.

Another embodiment relates to the use of the cobalt-containing polymer compounds described herein as curing catalysts for hardening unsaturated polyesters.

Advantageously, the present invention provides a novel class of metal-containing and antioxidant-containing carbamated polymer compounds that allow for the catalytic action of the metal on the oxidative drying of the polymer and the antiskinning action of the antioxidant component. The carbamated polymer compound is also soluble in low VOC solvents. Thus, the carbamated polymer compounds of the present invention greatly avoid toxic effects by eliminating the use of oximes, reducing the availability of metal ions in aqueous systems, and being soluble in low VOC solvents, while providing both anti-skinning and drying functions in a single compound that can be used as an additive.

The foregoing examples are provided for the purpose of illustration only and are not to be construed as limiting the present invention in any way. While the present invention has been disclosed with reference to exemplary embodiments, the words used herein are words of description and illustration, rather than words of limitation. Although the invention has been described with reference to particular materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein. For example, the various components that make up or describe the above-disclosed polymer compounds, or the various process steps disclosed above, may be alternatives that may be combined in various suitable and functional combinations within the scope of the present invention. Rather, the invention extends to all functionally equivalent structures, materials and uses, such as are within the scope of the appended claims. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. All terms used in this disclosure should be interpreted in the broadest possible manner consistent with the context.

Claims (45)

1. A polymer compound for use as both a drier and an antiskinning agent in coatings, paints or inks, the polymer compound comprising a carbamated polymer having a metal, an antioxidant and a water solubility according to OECD105 of less than 20 mg/l.

2. The polymer compound according to claim 1, wherein the carbamated polymer has a metal content of greater than 6% by weight.

3. A polymer compound according to claim 1, wherein the carbamated polymer has a metal content of between 4% and 8% by weight.

4. A polymer compound according to any one of claims 1 to 3, wherein the metal is an integral part of the backbone of the polymer compound.

5. The polymer compound according to any one of claims 1 to 4, wherein the metal is selected from cobalt, manganese, cerium and iron.

6. The polymer compound according to any one of claims 1 to 5, wherein the carbamated polymer is soluble in a low volatile organic compound (low VOC) solvent.

7. The polymer compound according to claim 6, wherein the low VOC solvent is an ester solvent selected from the group consisting of lactate esters, fatty acid esters, and any combination thereof.

8. The polymer compound according to any one of claims 1 to 7, wherein the carbamated polymer is formed at least in part from a carboxylic acid, a metal hydroxide or metal acetate, a coupling agent, an antioxidant mixture and an isocyanate.

9. The polymer compound according to claim 8, wherein the coupling agent is an amine selected from the group consisting of monohydroxy amine, dihydroxy amine, trihydroxy amine, and any combination thereof.

10. A polymer compound according to claim 8, wherein the antioxidant mixture comprises ascorbic acid, ethyl ascorbic acid and resveratrol.

11. The polymer compound according to claim 8, wherein the antioxidant mixture comprises ascorbic acid, ethyl ascorbic acid, resveratrol and citric acid.

12. The polymer compound according to claim 8, wherein the carboxylic acid is a hydroxycarboxylic acid or a saturated fatty acid.

13. A polymer compound according to claim 8, wherein the carboxylic acid is ricinoleic acid, the metal hydroxide is cobalt hydroxide or manganese hydroxide, the coupling agent is an alkanolamine, the antioxidant mixture comprises ascorbic acid, ethyl ascorbic acid and resveratrol, and the isocyanate is toluene diisocyanate, isophorone diisocyanate (IPDI) or hexamethylene diisocyanate (HMDI).

14. A polymer compound according to any of claims 1 to 13, wherein the carbamated polymer has a viscosity of less than 3000cP at 20 ℃.

15. The polymer compound according to any one of claims 1 to 14, wherein the carbamated polymer has an average molecular weight of less than 2000 Da.

16. A polymer compound for use as both a drier and an antiskinning agent in a coating, paint or ink, the polymer compound comprising a metal-containing and antioxidant-containing urethanized polymer having the formula:

wherein

M is a metal;

a is an antioxidant group;

R₁is a first alkyl group; and

R₂is a second alkyl group.

17. A polymer compound according to claim 16, wherein the antioxidant group a has the formula:

。

18. the polymer compound according to any one of claims 16 to 17, wherein the metal M is selected from cobalt, manganese, cerium and iron, wherein the alkyl group R₁Having 6 carbon atoms and wherein the alkyl radical R₂Having 7 carbon atoms.

19. The polymer compound according to any of claims 16 to 18, wherein the carbamated polymer has a water solubility according to OECD105 of less than 20 mg/l.

20. The polymer compound according to any of claims 16-19, wherein the carbamated polymer has a metal content of more than 6% by weight.

21. The polymer compound according to any of claims 16 to 19, wherein the carbamated polymer has a metal content between 4 and 8 wt%.

22. The polymer compound according to any one of claims 16-21, wherein the carbamated polymer is soluble in a low volatile organic compound (low VOC) solvent.

23. The polymer compound according to claim 22, wherein the low VOC solvent is an ester solvent selected from the group consisting of lactic acid esters, fatty acid esters, and any combination thereof.

24. A polymer compound according to any one of claims 16 to 23, wherein the carbamated polymer is formed at least in part from a carboxylic acid, a metal hydroxide or metal acetate, a coupling agent, an antioxidant and an isocyanate.

25. The polymer compound according to claim 24, wherein the coupling agent is an amine selected from the group consisting of monohydroxy amine, dihydroxy amine, trihydroxy amine, and any combination thereof.

26. A polymer compound according to claim 24, wherein the antioxidant is an antioxidant mixture comprising ascorbic acid, ethyl ascorbic acid and resveratrol.

27. A polymer compound according to claim 24, wherein the antioxidant is an antioxidant mixture comprising ascorbic acid, ethyl ascorbic acid, resveratrol and citric acid.

28. The polymer compound according to claim 24, wherein the carboxylic acid is a hydroxycarboxylic acid, a saturated fatty acid, or a combination thereof.

29. A polymer compound according to claim 24, wherein the carboxylic acid is ricinoleic acid, the metal hydroxide is cobalt hydroxide or manganese hydroxide, the coupling agent is an alkanolamine, the antioxidant mixture comprises ascorbic acid, ethyl ascorbic acid and resveratrol, and the isocyanate is toluene diisocyanate, isophorone diisocyanate (IPDI) or hexamethylene diisocyanate (HMDI).

30. A polymer compound according to any one of claims 16 to 29, wherein the carbamated polymer has a viscosity of less than 3000cP at 20 ℃.

31. The polymer compound according to any one of claims 16-30, wherein the aminomethylated polymer has an average molecular weight of less than 2000 Da.

32. A desiccant and antiskinning composition comprising a polymer compound according to any of claims 1-31 dissolved in a low VOC solvent, wherein the low VOC solvent is at least one member selected from the group consisting of lactates, fatty acid esters, and any combination thereof.

33. A coating composition comprising a polymer compound according to any one of claims 1 to 31 and a vehicle based on an unsaturated fatty acid modified polymer.

34. The coating composition of claim 33, wherein the polymer compound is a first metal-containing carbamated polymer, wherein the coating composition further comprises a second metal-containing compound, and wherein the first metal and the second metal are different metals.

35. A method for preparing a polymer compound, the method comprising:

providing a carboxylic acid;

reacting a carboxylic acid with a metal hydroxide or metal acetate to form an intermediate product;

mixing the intermediate product with a solvent to form a first mixture;

providing a coupling agent to the first mixture to form a second mixture;

providing an antioxidant comprising at least one of citric acid, ethyl ascorbic acid, resveratrol, or a combination thereof to the second mixture to form a third mixture; and

polymerizing the third mixture with an isocyanate to form a urethanized polymer having a metal, an antioxidant, and a water solubility according to OECD105 of less than 20 mg/l.

36. The method of claim 35, wherein a carbamated polymer having a metal content of greater than 6% by weight is formed.

37. The method of claim 35, wherein a carbamated polymer having a metal content between 4% and 8% by weight is formed.

38. The method of any of claims 35-37, wherein the carbamated polymer is formed such that the metal is an integral part of a backbone of the polymer compound.

39. The method of any one of claims 35-38, wherein the metal is selected from the group consisting of cobalt, manganese, cerium, and iron.

40. The method of any one of claims 35-39, wherein the carboxylic acid is provided in the form of a hydroxycarboxylic acid or a saturated fatty acid.

41. The process of any of claims 35-39, wherein the carboxylic acid is ricinoleic acid, the metal hydroxide is cobalt hydroxide or manganese hydroxide, the coupling agent is an alkanolamine, and the isocyanate is toluene diisocyanate, isophorone diisocyanate (IPDI), or hexamethylene diisocyanate (HMDI).

42. The method of any of claims 35-41, wherein the coupling agent is provided in the form of an amine selected from the group consisting of monohydroxy amine, dihydroxy amine, trihydroxy amine, and combinations thereof.

43. The method of any of claims 35-42, wherein a carbamated polymer is formed having a viscosity of less than 3000cP at 20 ℃.

44. The process of any one of claims 35 to 43 wherein a carbamated polymer having an average molecular weight of less than 2000 Da is formed.

45. The method of any of claims 35-44, further comprising dissolving the carbamated polymer in a low VOC solvent, wherein the low VOC solvent is at least one member selected from the group consisting of lactate esters, fatty acid esters, and any combination thereof.