JPH0327595B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a copolymer suitable for use as a polymeric stabilizer in a stable dispersion and a stable dispersion made therewith, the copolymer being suitable for use as a polymeric stabilizer in a stable dispersion. Contains pendant ethylenic unsaturation that can react with monomers used in random copolymerization reactions. The present invention provides that the stabilizer copolymer comprises segments of random copolymers of ethylenically unsaturated monomers, some of which monopolymers are substantially present in the organic liquid used to form the stable dispersion. Some of these monomers are characterized in that their sole polymer is substantially soluble in the organic liquid used to form the stable dispersion. be. The present invention also relates to a stable crosslinked dispersion comprising microgel particles, the dispersion comprising (a) first and second particles each containing mutually crosslinkable functional groups; an ethylenically unsaturated monomer and (b) at least one monoethylenically unsaturated monomer in (a) a solvent for the polymerizable monomer but a non-solvent for the resulting polymer; It is prepared by addition polymerization in the presence of an organic liquid and () the polymeric dispersion stabilizer described above. The present invention also provides a hydroxy-functional film former and a novel crosslinked dispersion system as described above which enhances the smoothness and uniformity of the coating film and improves the flow properties of the coating composition. It also relates to a coating composition comprising a flow control additive. These coating set compositions are particularly suitable for automotive coatings where metallic pigments are included in the coating composition. Preferred compositions containing stable crosslinked dispersions have an automotive topcoat
Medium solids and high solids thermosetting compositions suitable for providing high gloss, excellent durability, and excellent resistance to solvents and water. As regulatory regulations regarding solvent emissions have become increasingly stringent in recent years, low solvent emission paints have become desirable. A number of medium solids and high solids paint compositions have been proposed to meet these low solvent emission requirements. However, many of these compositions have defects due to difficulty in painting, poor flowability, lack of smoothness and uniformity, and poor distribution of pigments, especially metal flake pigments. Defects in compositions containing metal flakes are caused by undesirable reorientation of the metal flakes that occurs during application and curing of the paint. Flake reorientation occurs primarily due to the very low viscosity resins used in medium and high solids coatings. The viscosity of these resins is not sufficient to immobilize flakes that tend to redistribute and exhibit "reverse, flop" and non-uniform distribution. Preferred coating compositions of the present invention combine the desirable properties of low solvent content and low coating viscosity due to the improved flow control agents contained therein, while also providing the desired combination of low solvent content and low coating viscosity, as well as the advantages of previously proposed medium solids and high solids coatings. The inventors have succeeded in overcoming to some extent the drawbacks of the invention, thereby making medium solids and high solids paints particularly suitable for automotive topcoats, and especially for automotive topcoats containing metal flakes as pigments. Finally, the present invention provides a simple crosslinked dispersion of the above type, in which the dispersion is further stabilized by an additional stabilizer, which, apart from the solvent, consists essentially of a butylated formaldehyde resin, or It relates to a dispersion contained in a composition as a flow control agent. Stable dispersions, or nonaqueous dispersions as they are typically called, of the type produced using the stabilizers of the present invention have recently been used for the efficient application of protective or decorative coatings to various objects. It was developed in 1995 and became particularly widely used for coating automobile bodies and parts. If you are a person skilled in the art,
You may have noticed that there is a large body of prior art literature regarding non-aqueous dispersion technology. Among the related prior art documents, those that are closely related to the present invention teach various improved stabilizers and methods for their preparation. These documents include U.S. Pat. No. 3,317,635 and U.S. Pat. No. 3,514,500 by Osmond et al.
No. 3607821 by Clarke, No. 3814720 and No. 3814720 by Maker et al.
No. 3814721 and Makhlouf
No. 4147688 by et al. Osmond et al., U.S. Pat. No. 3,317,635, disclose block or graft copolymers of ethylenically unsaturated monomers and precursors containing polymer chains and unsaturated groups, wherein the unsaturated groups and monomers are of the vinyl type. Stabilized dispersions or non-aqueous dispersions are taught that are stabilized by copolymers that undergo polymerization to yield polymeric vinyl chains of different polarity than the original polymer chains (see 2 columns, lines 1-9). According to the method of Osmond et al., a stable dispersion of synthetic monomers in an organic liquid is prepared by solvating one polymer chain with the organic liquid, precipitating the polymer into the organic liquid in the presence of a stabilizer; The other polymer chain is produced by associating with an unsolvated polymer without being solvated (the second
Column lines 50-56). No. 3,514,500 to Osmond et al. teaches a stabilizer for non-aqueous dispersions that includes a polymer backbone and at least five side chains attached thereto and having a polarity different from that of the backbone (excerpt). (see column). The side chains are attached to the main chain by a condensation reaction between the side chain containing only one reactive group per molecule and the main chain having at least five complementary reactive groups per molecule. (first column, line 71 to second column, line 1). Clark U.S. Pat. No. 3,607,821 teaches stabilizers for non-aqueous dispersions that are chemically reacted with dispersed particles in the dispersion (Col. 1, Nos. 36-42).
line). Each co-reacted stabilizer molecule is
1 to 10 (preferably 1 to 10) between the dispersed polymer and
4)) form a covalent bond (column 1, 50-52)
line). The covalent bond between the stabilizer and the dispersed polymer is
It is formed by a reaction or copolymerization reaction between the chemical group of the stabilizer and the complementary chemical group of the dispersed polymer (column 1, lines 63-67). Manufacturers' U.S. Pat. No. 3,814,720, assigned to Ford Motor Company, assignee of the present invention, discloses the use of methylolated addition copolymers of ethene-based monomers and amides of unsaturated acids. teaches non-aqueous dispersions (see excerpt and claims section). Manufacturer's US Pat. No. 3,814,721, also assigned to Ford Motor Company, teaches a non-aqueous dispersion that is made using a precursor addition copolymer. The addition copolymer is prepared by reacting an active ethene-based monomer with functional epoxy, hydroxy, cyanato or carboxy groups with another active ethene-based monomer containing no active groups in an aromatic or alcoholic solvent, and then Adding a lipoprotective liquid such that the polymer does not dissolve, then adding a third ethene monomer having one of the above functional groups and a fourth ethene monomer not containing the above functional group; For the second addition copolymer, which is dispersed throughout the medium, the aliphatic liquid is prepared in such a way that it is a non-solvent (see excerpt, examples and claims). A stable crosslinked dispersion containing microgel particles is
These are well known in the art. U.S. Pat. No. 4,147,688 to Maklauff et al.
A crosslinked dispersion in which crosslinked acrylic polymer microgel particles are formed by free radical addition polymerization of a crosslinker monomer in the presence of a hydrocarbon dispersion liquid is taught (excerpt section,
(See Examples and Claims). Other crosslinked dispersions containing microgel particles are disclosed in the patent applications and patents cited in Maklauff et al. Coating compositions of the type described in this invention are similar to those developed by our collaborators prior to the present invention, with the exception of the addition of a stable crosslinked dispersion flow control agent. It's the same. Some of these compositions were made with flow control agents, while others were made without them. However, preferred compositions are those made using flow control agents made in accordance with the teachings of US Pat. No. 4,147,688 to McClough et al. U.S. Patent by Porter et al.
No. 4,025,474 discloses polyester-based coating compositions containing the crosslinked dispersion disclosed by McClough et al. U.S. Patent by Porter et al.
No. 4,074,141 discloses carboxylic acid amide interpolymer-base coating compositions containing the same crosslinked dispersion. U.S. Pat. No. 4,115,472 to Porter et al. discloses a urethane-based coating composition that also includes a crosslinked dispersion of McLaugh. U.S. Pat. No. 4,055,607 to Sullivan et al.
a solution acrylic polymer, (b) at least 0.5% microgel particles formed by polymerizing a hydroxyl group-containing monomer and a hydroxyl group-free monomer in the presence of a stabilizer as disclosed by McClough et al.; (c) A thermosetting composition comprising a melamine resin is disclosed. Therefore, the microgel dispersion system by Sullivan et al. contains a functional group that can react with a melamine-based crosslinking agent. The stabilizers according to the invention are copolymers suitable for use as stabilizers in stable dispersions in organic liquids. These copolymers have pendant ethylenically unsaturation and are composed of an ethylenically unsaturated monomer (A) and
It consists of the reaction product with the copolymer reactant (B). Ethylenically unsaturated monomer (A) is a copolymer reactant
Contains a functional group capable of condensation reaction with the complementary functional group contained in (B). Copolymer reactant (B) is an ethylenically unsaturated monomer, the sole polymer of which is substantially insoluble in the selected organic liquid; are substantially soluble in the same organic liquid, and a random copolymer of ethylenically unsaturated monomer (A) and an ethylenically unsaturated monomer containing complementary functional groups capable of condensation reaction.
The ethylenically unsaturated monomer (A) is reacted with the copolymer (B) in an amount sufficient to react with at least about 10% of the complementary functional groups of the copolymer. Also,
The invention also relates to stable dispersions produced using said stabilizers and to methods for producing stable dispersions of this kind. The stable crosslinked microgel-containing dispersion prepared according to the present invention comprises (a) first and second ethylenically unsaturated monomers each containing functional groups capable of crosslinking with each other, and ( b) at least one other ethylenically unsaturated monomer with an organic liquid that is a solvent for the polymerizable monomer but a non-solvent for the resulting polymer;
() by addition polymerization in the presence of the polymeric dispersion stabilizers described above, as described in U.S. Pat. No. 4,147,688 to Maklauf et al. According to the invention, the addition polymerization reaction described above is carried out at elevated temperatures, so that first a dispersed polymer is formed and then it is crosslinked. The present invention also provides a hydroxy-functional film-forming agent;
The present invention relates to a coating composition of the type containing a crosslinking agent containing a functional group capable of reacting with the hydroxyl group of the film-forming agent. A feature of the coating composition of the present invention is that it contains a flow control agent consisting of a stable crosslinked dispersion containing the aforementioned microgel particles. The flow control agent has a resin solid content of about 0.5 to about 30 parts, preferably about 3 parts, based on 100 parts of the total resin solid content contained in the composition.
or about 15 parts. Furthermore, a feature of the present invention is that regardless of whether the crosslinked dispersion is used alone or included in the composition as a flow control agent as described above, the number average molecular weight _o Another stabilizing agent is included in the crosslinked dispersion consisting essentially of a butylated melamine formaldehyde resin having a range of from about 700 to about 2500. This additional stabilizer is based on the total resin solids content of the crosslinked dispersion.
It is included in the crosslinked dispersion in an amount such that the resin solids content is from about 25 to about 75 parts per 100 parts. Preferred improved medium solids coating compositions according to the present invention include () a coating component comprising a hydroxy-functional copolymer, () a butylated melamine formaldehyde crosslinker, and () the aforementioned with or without another stabilizer. Flow control agent. The film forming components have a number average molecular weight greater than approximately 5000
_o and a glass transition temperature of about -25°C to about 70°C, the hydroxy functionality is formed by about 5 to about 50% by weight of monoethylenically unsaturated monomers, with the remainder being other monoethylenically unsaturated monomers. hydroxy-functional copolymer. Butylated melamine formaldehyde crosslinker is
It has a number average molecular weight of about 700 to about 2500 and is included in the composition in an amount ranging from about 20 to about 100 parts per 100 parts of the film forming component. The flow control agent controls the total resin solids contained in the composition.
For every 100 parts, the resin solids content due to the flow control agent is from about 0.5 to about 30, preferably from about 3 to about 15 parts. The improved high solids coating composition of the present invention comprises:
() a film-forming component consisting essentially of a polymer component having a molecular weight less than about 5000; () a crosslinking agent consisting of a monomeric methylated melamine resin; and () a fluid as described above, with or without another stabilizer. Consists of a regulator. The film-forming component consists essentially of a polymeric component having a number average molecular weight of about 5000 or less, the polymeric component having a number average molecular weight of about 1500 to about 5000 and about -
Consisting of at least about 50% by weight hydroxy functional copolymer having a glass transition temperature of 25°C to about 70°C. The hydroxy-functional copolymer contains about 15 to about 35 weight percent hydroxy-functional monoethylenically unsaturated monomer, about 2 to about 5 weight percent alpha, beta-olefinically unsaturated carboxylic acid, and the remainder other monoethylenically unsaturated monomers. Formed from monomers. The crosslinking agent of the present invention comprises a monomeric methylated melamine resin having a number average molecular weight of about 350 to about 1000, and is present in the composition in an amount ranging from about 20 to about 100 parts per 100 parts of the film-forming component. included. The flow control agent controls the total resin solids contained in the composition.
For every 100 parts, the resin solids content due to the flow control agent is about 0.5 to about 30 parts, preferably about 3 to about 15 parts.
Contain in an amount within the range such that Polymeric Dispersion Stabilizer The stabilizer of the present invention is an ethylenically unsaturated monomer.
(A) and the random copolymer reactant (B) are combined into monomers.
(A) and a random copolymer reactant (B) by reacting through complementary functional groups present on the reactants. Copolymer reactant (B) comprises (i) an ethylenically unsaturated monomer, the sole polymer of which is substantially insoluble in the selected organic liquid, preferably from about 25 to about 45; (ii) from about 40 to 75, preferably from about 50 to about 65% by weight of an ethylenically unsaturated monomer, the sole polymer of which is substantially soluble in the same organic liquid; iii) Random copolymers comprising from about 2 to about 15, preferably from about 5 to about 10% by weight of ethylenically unsaturated monomers having complementary functional groups capable of condensation reaction with ethylenically unsaturated monomer (A).
Ethylenically unsaturated monomer (A) is reacted with the copolymer reactant (B) in an amount sufficient to react with at least about 10% of the complementary functional groups of the copolymer reactant (B). The term "ethylenically unsaturated monomer" as used herein refers to any monomer that has ethylenically unsaturated properties and can be polymerized into a vinyl type, including monomers that have double unsaturated groups (for example, butadiene). It means. Ethylenically unsaturated monomer (A) and the ethylenically unsaturated monomer used to make the copolymer reactant
The condensation reaction between said random copolymer reactant (B) brought about by (iii) can be chosen from a large number of condensation reactions known to those skilled in the art. Common condensation reaction bonds are ester bonds, especially those formed by transesterification or esterification, such as carboxyl/glycidyl, hydroxyl/anhydride or hydroxyl/acid chloride;
ether bonds, especially those formed by addition reactions between alkylene oxides and hydroxyl groups, urethane bonds, especially those formed in the reaction between isocyanates and hydroxyls, as well as amide bonds,
In particular, those formed by amine/acid chloride reactions. Among the many complementary groups that carry out condensation reactions, the following examples may be mentioned: anhydride/hydroxyl, anhydride/amine, anhydride/mercaptan, epoxide/acid, epoxide/amine, isocyanate/ Hydroxyl, hemiformal/amide, carbonate/amine, cycloamide/amine and cycloimide/hydroxyl.
Among the numerous monomers that can impart reactive groups, in the case of the ethylenically unsaturated monomer (A) or in the case of the ethylenically unsaturated monomer (iii) used to obtain the random copolymer reactants, are: The following may be mentioned by way of example: maleic anhydride, maleic acid, itaconic acid, acid esters of maleic and itaconic acid, glycidyl methacrylate, glycidyl acrylate, hydroxyalkyl methacrylate, acrylamide, methacrylamide, dimethylaminoethyl. methacrylate, vinylidene carbonate, N-carbamylmaleimide, vinyl isocyanate, etc. The first (i) and second (ii) types of ethylenically unsaturated monomers used to prepare copolymer reactant (B) above, if formed into a single polymer, are They are characterized by being substantially insoluble and soluble, respectively, in organic liquids. The organic liquid chosen is described herein only as a guide to identify the relative solubility of the first two types of monomer components (i) and (ii) of the random copolymer, and It should be understood that the agent composition does not necessarily have to be contained in an organic liquid. Although it is not a requirement to keep the stabilizer in the organic liquid, in general terms this is a guideline for determining the relative solubility of monomers (i) and (ii) of the random copolymer reactants used in stabilizer production. The organic liquid selected to be used as the stabilizer will be the same organic liquid used when producing a stable dispersion using the stabilizer of the present invention. Stable dispersions produced using stabilizers are discussed in detail below. "Substantially soluble" or "substantially insoluble" in a selected organic liquid means that the subject monopolymer is soluble or substantially insoluble in the selected organic liquid to an extent of about 90%. This means that it is insoluble. The organic liquid selected was used to determine the solubility and insolubility for the first two types of monomers used in the random copolymer.
Since the organic liquids used to form the stable dispersion are generally the same, the question of relative solubility and insolubility in a particular organic liquid is important in the preparation of stable non-aqueous dispersions. It will be appreciated that this determination is determined by the same factors that guide the decision to use. For this purpose, in determining the monomers for a given polymer, or random copolymer, it is essential to consider whether the single polymer will be soluble or insoluble in a given organic liquid. It will be seen that there are three types of systems or reasons. First of all, due to its relative polarity to the organic liquid, a single polymer can be soluble or insoluble. Second, a single polymer can be soluble or insoluble due to its relative non-polar nature with respect to organic solvents. Third, it may be soluble or insoluble in all common organic liquids due to its molecular structure, regardless of relative polarity. Therefore, to choose a monomer whose sole polymer is characterized by being substantially insoluble in the chosen organic liquid, consider the type of organic liquid that should be used to determine solubility or insolubility; and it is necessary to select monomers that will exhibit the desired insolubility when homopolymerized.
Regarding the second type of ethylenically unsaturated monomers, i.e. monomers whose homopolymer is characterized in that they are substantially soluble in an organic liquid, when homopolymerized they are soluble in a given organic liquid. It is necessary to choose the one that is. The types of monomers for which the polymerized homopolymer is soluble in a given type of organic liquid will be apparent to those skilled in the art of non-aqueous dispersions. See the prior art patent specifications cited above for details on relative solubility and insolubility. Generally speaking, if the organic liquid is nonpolar, such as an aliphatic hydrocarbon, suitable monomers whose sole polymers are insoluble or substantially insoluble in the organic liquid include (a) acrylics, methacrylates; or esters of ethacrylic acid and _C1 - _C3C aliphatic alcohols, (b) acrylic and methacrylic acids, and (c) acrylic monomers selected from ethylene and propylene glycol monoesters of acrylic, methacrylic or ethacrylic acid. Ru.
These are monomers that are polar in nature or form polar homopolymers, and
Monomers that are substantially insoluble in nonpolar solvents such as aliphatic hydrocarbons. Particularly suitable for use as the first type of monomer that will be insoluble in aliphatic hydrocarbons or other non-polar solvents is the polar monomer methyl methacrylate. Examples of monomers suitable for use as the second type, characterized by substantial solubility of the sole polymer in non-polar solvents such as aliphatic hydrocarbons, include acrylic, methacrylic or ethacrylic acid. _C4 to _C18 aliphatic alcohol esters. Monomers which are characterized by forming homopolymers with a high degree of polarity can be used in more polar organic liquids, such as aromatic hydrocarbons, fatty esters and fatty ketones, and still substantially It will be understood that they may be insoluble. A person skilled in the art will be able to make various choices. If the organic liquid selected is polar rather than nonpolar, the random copolymer reactant (B)
The first two types (i) used to produce
The ethylenically unsaturated monomer selected as and (ii) will be different. Among the many polar solvents that immediately come to mind for those skilled in the art are various alcohols such as methanol and ethanol, glycols, esters, ethers, polyols, and ketones. When using such a polar organic liquid, the first type of monomer (i)
(i.e., those characterized by being substantially insoluble in the chosen organic liquid) can be selected from a number of monomers familiar to those skilled in the art. Although it would be too long to list them one by one, typical examples include styrene, vinyltoluene, divinylbenzene, isoprene, butadiene, isobutylene, and ethylene. Of course, higher fatty acid esters of unsaturated acids such as acrylic, methacrylic and ethacrylic acids, in which the alcohol component in the ester contains a long carbon-carbon chain, can also be used. _C4 ~ _C18 aliphatic alcohol and acrylic,
Esters with methacrylic or ethacrylic acid are
This is the preferred category among them. Polar monomers, or monopolymers of which are polar and therefore soluble in organic liquids of this type, include (a) combinations of C ₁ -C ₃ aliphatic alcohols with acrylic, methacrylic or ethacrylic acid; A number of monomers are included, including acrylic monomers selected from esters, (b) acrylic and methacrylic acid, and (c) ethylene and propylene glycol monoesters of acrylic, methacrylic or ethacrylic acid. Monomer (A) or any of the three types of monomers (i), (ii) or (iii) used in the random polymerization to form the copolymer reactant (B) which is reacted with monomer (A). For one thing, as previously mentioned, many types of ethylenically unsaturated monomers can be used in the production of stabilizers;
Preferably, this type of monomer is an acrylic monomer. As used herein, "acrylic monomer" refers to monomers based on acrylic, methacrylic or ethacrylic acid. monomer
It goes without saying that the acid itself can be used in cases where a complementary functional group is desired for the reaction between (A) and the random copolymer reactant (B). Other types of acrylic monomers commonly known to those skilled in the art and desirable for making the stabilizers of the present invention include:
A number of well-known esters of acrylic, methacrylic and ethacrylic acid. The random copolymer reactant (B) used to make the stabilizers of the present invention has a molecular weight of about 4000 to about
It has a number average molecular weight of 15,000, preferably from about 6,000 to about 10,000. The ethylenically unsaturated monomer (A) is reacted with the random copolymer reactant (B) in an amount sufficient to react with about 10% of the complementary functional groups contained in the copolymer reactant (B). , each reactant is desirably combined in an amount such that monomer (A) reacts with about 0.5 to about 3.0% by weight of copolymer reactant (B). Dispersion General Stable dispersions of the type contemplated for use with the stabilizers of the present invention are well known and commonly referred to as non-aqueous dispersions. The production of such dispersions requires that the addition polymer formed in the solvent be substantially insoluble in the organic liquid;
Therefore, the properties of the organic liquid depend on the properties of the polymer to be dispersed. Moreover, the nature of the polymer to be dispersed will determine the type of stabilizer and the combination of monomers used to prepare the stabilizer according to the invention. The problem of selecting a given organic liquid for a particular type of polymer to be dispersed involves the same logic as discussed above for determining various solubility and insolubility in solvents.
Although any of the various monomer combinations previously described can be utilized to produce stabilizers suitable for producing dispersions according to the invention, particularly preferred stabilizers are dispersions in aliphatic hydrocarbons. It is a stabilizer used in manufacturing the system. In that case, the monomer from which the monomer is polymerized is substantially insoluble in the aliphatic hydrocarbon, and the monomer from which the monomer is polymerized is substantially soluble in the aliphatic hydrocarbon is methyl methacrylate. - ethylhexyl acrylate. In particularly preferred types of stabilizers mentioned above, the monomers with complementary functional groups are glycidyl acrylate or glycidyl methacrylate on the one hand and acrylic acid or methacrylic acid on the other hand. The methods for forming stable dispersions using the stabilizers of the present invention are essentially the same as well-known methods used in the art to prepare non-aqueous dispersions using other well-known stabilizers. . Generally, if the stabilizers of the present invention are used in an amount within the range of about 2 to about 20, preferably about 5 to about 10% by weight, based on the combined weight of the dispersion formed and the stabilizer itself,
It can easily be expected that the addition polymer formed will be adequately stabilized by the stabilizer. It should be understood that the ethylenic unsaturation contained in the stabilizer itself aids in the addition copolymerization reaction to form the dispersed polymer. Crosslinked Dispersion The stable crosslinked dispersion of microgel particles comprises (a) from about 1 to about 1 to about 100% of each of first and second ethylenically unsaturated monomers each having a mutually crosslinkable functional group;
10 mole %, preferably about 2 to 5 mole % each, and (b) about 98 to about 80 mole % of at least one other monoethylenically unsaturated monomer, preferably about
It is produced by addition polymerization of 96 to about 90 mol%.
This addition polymerization is carried out in the presence of an organic liquid that is a solvent for the polymerizable monomer but a non-solvent for the resulting polymer, and in the presence of the polymeric dispersion stabilizer described above. be done. The polymerization is carried out at elevated temperatures so that the dispersed polymer is first formed and then crosslinked. The crosslinking functional groups of the first and second ethylenically unsaturated monomers (a) can be selected from a wide range of functional groups familiar to those skilled in the art. Examples of preferred pairs of crosslinking functional groups that may be included in the first and second ethylenically unsaturated monomers include: acid and epoxide, epoxide and amine, acid anhydride and hydroxyl, Acid anhydrides and amines, acid anhydrides and mercaptans, isocyanates and hydroxyls, hemiformals and amides, carbonates and amines, cycloimides and amines, cycloimides and hydroxyls, imines and alkoxysilanes, etc. First and second ethylenically unsaturated monomers (a)
Although the monomers may be any ethylenically unsaturated monomers within the framework as defined above, it is preferred that these monomers are acrylic monomers as defined above. A preferred class of crosslinked dispersions within the scope of the present invention comprises from about 1 to about 10 α,β-ethylenically unsaturated monocarboxylic acids, preferably from about 1 to about 10, preferably about 2 to about 5 mole percent, about 80 to about 98 weight percent of at least one other copolymerizable monoethylenically unsaturated monomer, and about a crosslinking monomer selected from the group consisting of an ethylenically unsaturated monoepoxide. 1 to about 10, preferably about 2 to about 5% by weight
It is formed by free radical addition copolymerization of Preferred α,β-ethylenically unsaturated monocarboxylic acids for use in this class of crosslinked dispersions are acrylic acid and methacrylic acid, with methacrylic acid being particularly preferred. In the production of crosslinked dispersions belonging to this category, various monoethylenically unsaturated monomers other than those mentioned above can be copolymerized with acid monomers. Although essentially any copolymerizable monoethylenically unsaturated monomer can be utilized depending on the properties desired, preferred monoethylenically unsaturated monomers include alkyl esters of acrylic or methacrylic acid, especially those with alkyl groups. having about 1 to about 4 carbon atoms. Examples of such compounds include alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate and butyl acrylate, and alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate and butyl methacrylate. Other ethylenically unsaturated monomers which may be advantageously used include, for example, vinyl aromatic hydrocarbons such as styrene, α-methylstyrene, vinyltoluene;
unsaturated esters of organic or inorganic acids, such as vinyl acetate, vinyl chloride, etc., and acrylonitrile,
There are unsaturated nitrites such as methacrylonitrile, ethacrylonitrile, etc. Although numerous ethylenically unsaturated monoepoxides will occur to those skilled in the art, glycidyl acrylate and glycidyl methacrylate represent the most preferred monoepoxides for this class of crosslinked dispersions. In particularly preferred crosslinked dispersion embodiments belonging to the above class, the monomers used in the addition copolymerization reaction to form the dispersed polymer are α,
It is characterized in that the β-ethylenically unsaturated monocarboxylic acid is methacrylic acid, the other copolymerizable monoethylenically unsaturated monomer is methyl methacrylate, and the crosslinking monomer is glycidyl methacrylate. In this particularly preferred crosslinked dispersion embodiment, the preferred polymeric dispersion stabilizer is an ethylenic polymer used to prepare the copolymer reactant (B), which is a precursor to the polymeric dispersion stabilizer. saturated monomer
(i) and (ii) are methyl methacrylate and 2-ethylhexyl acrylate, respectively, and one of the ethylenically unsaturated monomers (A) or (iii) contained in the copolymer reactant (B) is glycidyl acrylate or glycidyl acrylate. methacrylate and the other of said ethylenically unsaturated monomers (A) or (iii) is acrylic or methacrylic acid. Most preferably, the ethylenically unsaturated monomer (iii) of copolymer reactant (B) is glycidyl acrylate or glycidyl methacrylate and the ethylenically unsaturated monomer (A) consists of acrylic or methacrylic acid. It is believed that the present invention will be more clearly understood by the detailed examples that follow, which are merely illustrative of a number of compositions within the scope of the present invention, to illustrate the uses of the stabilizer compositions of the present invention. . Coating Composition The coating composition of the present invention is a stable crosslinked dispersion comprising a hydroxy-functional film-forming agent, a cross-linking agent having a functional group capable of reacting with the hydroxy-functional group contained in the film-forming agent, and microgel particles. The system consists of a flow regulator. Furthermore, the coating compositions of the invention can contain conventional additives such as catalysts, antioxidants, UV absorbers, wetting agents, antistatic agents, pigments, plasticizers, solvents, etc. Flow Control Agent The flow control agent used in the compositions of the present invention is a stable crosslinked dispersion containing microgel particles, with or without other additional stabilizers described below, and the total resin of the composition. The resin solid content of the flow regulator is about 0.5 to about 30 per 100 parts of solid content,
It is preferably incorporated into the composition in an amount ranging from about 3 to about 15 parts. As already mentioned, flow modifiers improve the flow properties of the composition and
Improves the smoothness and uniformity of the coating film. Therefore, it is particularly effective when metal pigments are added to automotive top enamel. Film Forming Component The film forming component of the composition of the present invention is a hydroxy-functional material that is crosslinkable with a crosslinking agent having a functional group suitable for reacting with the hydroxyl group of the film forming agent. Those skilled in the art will appreciate that there are many types of hydroxy-functional coating materials that can be crosslinked to form a cured coating on a substrate. The film forming agent comprises one or more hydroxy functional polymers or copolymers and optionally
Can be composed of additional hydroxy functional monomer materials. It will be appreciated that additional film-forming components that do not contain hydroxy functionality or that contain additional functional groups may be included in the composition. These variations are well known to those skilled in the art. Among the many hydroxy-functional copolymers that can be used as film-forming agents in compositions that are the subject of improvements in accordance with the present invention are a variety of acrylic acid-based copolymers, particularly from at least about 150 to up to Included are those having a number average molecular weight up to 20,000 and a glass transition temperature within the range of about -25°C to about 70°C. Typically, such copolymers contain from about 5 to about 50% by weight of monoethylenically unsaturated monomers having hydroxy functional groups and about 50% by weight of other monoethylenically unsaturated monomers.
50 to about 95% by weight. The hydroxy-functional monomer is what imparts its hydroxy functionality to the copolymer and is typically
selected from hydroxyalkyl esters of monoethylenically unsaturated carboxylic acids. Lists of hydroxy-functional monomers suitable for forming copolymers of this type are well known to those skilled in the art. Among them, for example, 2-hydroxyethyl acrylate, 3-chloro-2-hydroxypropyl acrylate, 2-hydroxyethyl acrylate,
-hydroxy-1-methylethyl acrylate,
2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2,3-dihydroxypropyl acrylate, 3-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, diethylene glycol acrylate, 5-
Hydroxypentyl acrylate, 6-hydroxyhexyl acrylate, triethylene glycol acrylate, 7-hydroxyheptyl acrylate, 2-hydroxyethyl methacrylate,
3-chloro-2-hydroxypropyl methacrylate, 2-hydroxy-1-methylethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate,
2,3-dihydroxypropyl methacrylate,
2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, 3,4-dihydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 6-hydroxyhexyl methacrylate, 1,3-dimethyl-3-hydroxybutyl methacrylate, 5,6-dihydroxyhexyl Included are methacrylate and 7-hydroxyheptyl methacrylate. Preferred hydroxy-functional monomers in this type of composition are often _C5 - _C7 hydroxyalkyl acrylates and/or _C6 - _C8 hydroxyalkyl methacrylates, i.e. _C2 - _C3 dihydric alcohols and acrylic or methacrylic acids. It is an ester of The remainder of the monomers forming this type of hydroxy-functional copolymer are other monoethylenically unsaturated monomers, these monomers preferably being α,β-olefinically unsaturated monomers, i.e. aliphatic carbon-carbon chains. α and β for the terminal
A monomer having olefinic unsaturation between two carbon atoms in the . As you know,
Representative among the many α,β-olefinically unsaturated monomers that can be used in copolymers of this type are acrylates and mixtures of acrylates and vinyl hydrocarbons as defined herein. Generally, in this type of composition, the ester of _C1 - _C12 monohydric alcohol and acrylic or methacrylic acid exceeds 50% by weight of the total. Representative monovinyl hydrocarbons suitable for forming this type of copolymer are those containing 8 to 12 carbon atoms and include styrene, alpha-methylstyrene, vinyltoluene, t-butylstyrene and chlorostyrene. is included. Generally, when monovinyl hydrocarbons are used, their amount will be 50% of the copolymer.
less than % by weight. Other monomers, such as vinyl chloride, acrylonitrile, methacrylonitrile, and vinyl acetate, may also be included in these compositions as modifying monomers, and the amounts of these modifying monomers used range from about 0 to about 40% in the copolymer. It should be limited to % by weight. As mentioned above, one or more hydroxy-functional polymers or copolymers can be used as the deposition material. For example, it may be desirable to use hydroxy-functional copolymers of different molecular weights. It may also be desirable to include other hydroxy-functional materials that have monomeric properties that act as reactive diluents in the composition. These examples are just a few of the many types of combinations and variations of deposition materials that may be employed. Representative of the many types of compositions intended to be included within the scope of improvements made by the present invention are U.S. Pat. Application No.
945027, as well as U.S. Patent Application No. 157705, filed June 9, 1980 (U.S. Patent Application No.
U.S. Patent Application No. 000852 dated January 4, 1979) and U.S. Patent Application No. 157706 filed June 9, 1980 (U.S. Patent Application No. 041208 dated May 21, 1979; No. 000855, filed January 4, 2008, Continuation-in-Part). Crosslinking Agents Another major conventional ingredient included in the compositions to be improved by the present invention is a crosslinking agent capable of reacting with the hydroxyl groups of the hydroxy-functional coating material to cure the composition. Representative crosslinkers are isocyanates and well known amino compounds, although it will be appreciated that the selection of a particular crosslinking agent is not critical to the invention, and that many suitable materials may be selected. . Typical isocyanate compounds useful as crosslinking agents in thermosetting compositions that may be the subject of improvements in accordance with the present invention are polyisocyanates, i.e., 2 or more, preferably 3 or more, reactive molecules per molecule. It is a compound having an isocyanate group. These polyisocyanate crosslinking agents are included in the composition in an amount typically ranging from about 0.5 to about 1.6 isocyanate groups for each hydroxyl group included in the composition. Polyisocyanates are well known in the art, and those skilled in the art will be aware that there are many suitable isocyanates containing two or more reactive isocyanate groups per molecule. Among the many suitable polyisocyanates are aliphatic, cycloaliphatic and aromatic isocyanate compounds. Referenced U.S. Patent Application No. 157705
The specification lists many typical polyisocyanate crosslinking agents. Amino-based crosslinking agents useful in compositions that may be the subject of improvements in accordance with the present invention are generally preferred to be condensation products of formaldehyde and melamine, substituted melamines, urea, or substituted and unsubstituted benzoguanamines. Polyfunctional amino compounds of this type, which are widely used in the paint industry, can be used in various forms: monomeric, polymeric, or mixed monomeric and polymeric forms.
Numerous examples of such representative amino compounds are also described in US Patent Application No. 157,705. Preferred Medium Solids Compositions As previously mentioned, the preferred medium solids coating compositions of the present invention consist of three major components: (i) a film-forming component comprising a hydroxy-functional copolymer; (ii) a butylated melamine formaldehyde crosslinker. , and (iii) a flow regulator comprising the above-mentioned stable crosslinked dispersion system. The film forming components of the medium solids composition have a number average molecular weight _of greater than about 5000 and a temperature of about -25°C to about 70°C.
It consists of a hydroxy-functional copolymer with a glass transition temperature of . The hydroxy functional copolymer has about 5 to about 50, preferably about 10 to about 30
% by weight of hydroxy-functional monoethylenically unsaturated monomers and the remainder by other monoethylenically unsaturated monomers. Although a number of hydroxy-functional monoethylenically unsaturated monomers can be used to prepare copolymers useful as film-forming components of the compositions of this invention, preferred monomers of this type include hydroxyl group-containing aliphatic alcohols. and α,β-monoethylenically unsaturated carboxylic acid esters. Most preferably, the hydroxy-functional monomer that imparts hydroxy functionality to the copolymer is selected from hydroxyalkyl esters of monoethylenically unsaturated carboxylic acids. This kind of α,
Typical β-monoethylenically unsaturated carboxylic acids are acrylic, methacrylic and ethacrylic acid. Among the monomers suitable for preparing the copolymers of the film-forming components of medium solids compositions, there are many in this category, but representative ones are those described above in the general discussion of hydroxy-functional film-forming agents. It is a hydroxy functional monomer. The remaining other monoethylenically unsaturated monomers forming the hydroxy-functional copolymer of the film-forming component, i.e., from about 50 to about 95, preferably from about 70 to about 90% by weight, are α,β-olefinically unsaturated monomers, That is, monomers having olefinic unsaturation between the two carbon atoms in the alpha and beta positions with respect to the end of the aliphatic carbon-carbon chain are desirable. In a preferred embodiment of the medium solids composition, up to about 2% by weight, based on the total weight of monomers used to make the hydroxy-functional copolymer, contains an α,β-monoethylenically unsaturated carboxylic acid, e.g. Acrylic, methacrylic or ethacrylic acid is included among the remaining monoethylenically unsaturated monomers. For the remaining monoethylenically unsaturated monomers other than the carboxylic acids mentioned above, acrylates (meaning esters of acrylic or methacrylic acid),
esters of C ₁ -C ₁₂ monohydric alcohols with acrylic, methacrylic or ethacrylic acid, such as methyl methacrylate,
Ethyl acrylate, butyl acrylate, butyl methacrylate, hexyl acrylate, 2-
Ethylhexyl acrylate, lauryl methacrylate, etc. are preferred. Representative monovinyl hydrocarbons suitable for forming this type of copolymer are those having 8 to 12 carbon atoms, including styrene, alpha-methylstyrene, vinyltoluene, t-butylstyrene, and chlorostyrene. is included. When using such monovinyl hydrocarbons, it is necessary to ensure that less than about 50% by weight of the copolymer is comprised by these monomers. This remaining monoethylenically unsaturated monomer can also include other modifying vinyl monomers. These vinyl monomers, such as vinyl chloride, acrylonitrile, methacrylonitrile,
Vinyl acetate and the like should be used in amounts of about 0 to about 40% by weight of the monomers contained in the hydroxy-functional copolymer. To prepare such copolymers suitable for use as hydroxy-functional film forming agents in medium solids compositions, in proportions such that the desired copolymer is obtained,
The hydroxy-functional monomer and the remaining monoethylenically unsaturated monomer are mixed and reacted, typically using conventional free radical initiated polymerization techniques. A large number of free radical initiators are known to those skilled in the art, all of which are suitable for this purpose. It is desirable to conduct the polymerization in a solvent that dissolves the hydroxy-functional copolymer. It will be apparent to those skilled in the art that there are many solvents. In addition to the hydroxy-functional copolymers described above, other hydroxy-functional materials may be present in lesser amounts in the hydroxy-functional component of the medium solids composition (i.e. up to a total of up to 50 parts per 100 parts of total hydroxy-functional component, preferably Less than 35 parts, and generally but not necessarily 10 parts or more of other hydroxy-functional materials) can also be included. For example, the coating composition can further include one or more hydroxy-functional copolymers having a number average molecular weight _o of about 1500 to about 5000 and a glass transition temperature of about -25°C to about 70°C. Low molecular weight hydroxy-functional copolymers of this type contain from about 15 to about 35, preferably from about 20 to about 30, hydroxy-functional monoethylenically unsaturated monomers;
The remainder is generally formed with other monoethylenically unsaturated monomers. Suitable hydroxy-functional monomers and other monoethylenically unsaturated monomers are the same as those described above for the high molecular weight hydroxy-functional copolymers. The hydroxy-functional film forming component of the medium solids coating composition of the present invention may include, for example, an amount of one or More hydroxy-functional oligoesters can also be included. These preferred oligoesters were introduced in June 1980.
Ser _. contains hydroxyl groups, and
(iii) an esterification reaction product of (a) a polycarboxylic acid with a monoepoxide; (b) an ester of a polyepoxide with a monocarboxylic acid, preferably free of ethylenic unsaturation and also free of hydroxy functionality; (c) an esterification reaction product of a hydroxy-functional carboxylic acid and a mono- or polyepoxide, preferably a monoepoxide; (d) an esterification reaction product of a mono-carboxylic acid and a hydroxy-functional mono- or polyepoxide, preferably a monoepoxide. and (e) esters selected from the group consisting of mixtures of (a) to (d) above. In addition to the above, other hydroxy-functional materials may be included in minor amounts as will be apparent to those skilled in the art. The medium solids composition of the present invention includes a butylated compound having a number average molecular weight of about 700 to about 2500, in a proportion of about 20 to about 100 parts, preferably about 30 to about 80 parts, per 100 parts of the film-forming components. Contains melamine formaldehyde crosslinker. Suitable butylated melamine formaldehyde resins can be prepared using a one-step process under acidic conditions or a two-step process in which melamine and formaldehyde are reacted under basic conditions, followed by an etherification reaction under acidic conditions. It is a resin obtained by condensing formaldehyde and butyl alcohol. Molecular weight is determined by the ratio of the three components. High formaldehyde to melamine ratios and high alcohol to formaldehyde ratios tend to produce low molecular weight resins. The molar ratio of formaldehyde to melamine ranges from 3.0 to 6, while the ratio of butanol to memelamine ranges from 6 to 12. Only part of the alcohol reacts and the rest acts as a solvent. The molecular weight distribution is generally wide;
The range for M _W is from about 2,000 to about 10,000, and the range for M _o is as described above. Preferred High Solids Compositions As previously mentioned, preferred high solids coating compositions of the present invention consist essentially of three main components: (i) a polymeric component having a number average molecular weight of less than about 5000; It is composed of a film-forming component, (ii) a crosslinking agent made of a monomeric methylated melamine resin, and (iii) a flow regulator made of the above-mentioned stable crosslinked dispersion system. The film forming component of the high solids composition consists essentially of a polymeric component having a number average molecular weight of less than about 5000. The polymer component consists of at least about 50% by weight hydroxy-functional copolymer having a number average molecular weight _o of about 1500 to about 5000 and a glass transition temperature of about -25°C to about 70°C. The hydroxy-functional copolymer comprises from about 15 to about 35, preferably from about 20 to about 30% by weight hydroxy-functional monoethylenically unsaturated monomer and from about 2 to about 5% by weight α,β-olefinically unsaturated carbonyl. It is formed from the acid and the remainder from other monoethylenically unsaturated monomers. Although a variety of hydroxy-functional monoethylenically unsaturated monomers may be used to prepare copolymers useful as film-forming components in the compositions of the present invention, preferred monomers of this type include the preferred medium solids content of the present invention. The monomers described above with respect to the composition. Among the preferred hydroxy-functional copolymers useful in the preferred high solids compositions of the invention are:
an α,β-olefinically unsaturated carboxylic acid selected from acrylic, methacrylic and ethacrylic acid in an amount within the range of about 2 to about 4% by weight as a component of the monomer mix for preparing the hydroxy-functional copolymer; Include. It will be appreciated that other α,β-olefinically unsaturated carboxylic acids may also be utilized. the remaining other monoethylenically unsaturated monomers forming the hydroxy-functional copolymer of the film-forming component, i.e., from about 60 to about 83% by weight, preferably about 65% by weight;
From about 78% by weight are α,β-olefinically unsaturated monomers, i.e. monomers having olefinic unsaturation between two carbon atoms in the α and β positions with respect to the end of the aliphatic carbon-carbon chain. It is desirable to have one. The remaining monoethylenically unsaturated monomers are preferably chosen from acrylates (meaning esters of acrylic or methacrylic acid) and mixtures of acrylates and vinylic hydrocarbons. More than 30% by weight of the total monomers in the copolymer
Esters of C ₁ to _{C 12} monohydric alcohols and acrylic, methacrylic or ethacrylic acids, such as methyl methacrylate, ethyl acrylate, butyl acrylate, butyl methacrylate, hexyl acrylate, 2-ethylhexyl acrylate, lauryl methacrylate, etc. desirable. Representative monovinyl hydrocarbons suitable for use in forming such copolymers are those containing 8 to 12 carbon atoms, including styrene, alpha-methylstyrene, vinyltoluene, t-butyl Included are styrene and chlorostyrene. When such monovinyl hydrocarbons are used, they should be used in amounts less than about 50% by weight of the copolymer. This remaining monoethylenically unsaturated monomer can also contain other modifying vinyl monomers. The amount of modified inhibiting vinyl monomers such as vinyl chloride, acrylonitrile, methacrylonitrile, vinyl acetate, etc. should be limited to about 0 to about 40% by weight of the monomers contained in the hydroxy-functional copolymer. In preparing this type of copolymer suitable for the polymer component of the film-forming component of the high solids composition of the present invention, the hydroxy-functional monomer and the remaining monoethylenically unsaturated monomer are combined as described above. They are mixed and reacted, typically using conventional free radical initiator polymerization techniques. In addition to the hydroxy-functional copolymers described above, other hydroxy-functional polymeric materials can also be used in the polymeric or film-forming components of the compositions of the present invention. Such other hydroxy-functional polymeric materials may be used in lesser amounts (i.e., up to about 50 parts total of such hydroxy-functional materials per 100 parts of polymeric component of the film-forming component of the composition, preferably (less than approximately 30 copies). For example, one or more hydroxy-functional oligoesters, such as those listed above, can also be included in the polymeric component. Other hydroxy-functional materials, which are well known to those skilled in the art, can be included in minor amounts in the polymeric component of the film-forming component of the high solids compositions of the present invention. Furthermore, a small proportion of other polymeric materials (i.e., 100 parts of polymer component) that do not contain hydroxy functional groups or contain other functional groups that do not interfere with the crosslinking reaction between the hydroxy functional material and the crosslinking agent. (up to about 25 parts, preferably less than about 10 parts) can be used. The high solids coating composition of the present invention includes film forming components.
About 20 to about 100 parts per 100 parts, preferably about
A crosslinking agent comprising a monomeric methylated melamine resin having a number average molecular weight of about 350 to about 1000 is included in an amount of 40 to about 80 parts. Monomeric methylated melamine resins are produced by co-condensing melamine, formaldehyde and methyl alcohol, usually in a two-step process. In order to increase the amount of monomer structure, the ratio of condensed formaldehyde to melamine is high, usually greater than 5:1, and preferably
5.5: Make it greater than 1. Melamine formaldehyde condensation is usually carried out under basic conditions. The amount of methanol is then increased in excess and the etherification is carried out under acidic conditions to maximize etherification and minimize condensation reactions resulting in dimers, trimers, etc. In this reaction step, the ratio of methanol to melamine can be between 8 and 30. The molecular weight of this type of crosslinking material is about 450 to 1500 in terms of weight average molecular weight, and about 350 to 1000 in number average molecular weight as mentioned above. The ratio of condensed methanol to melamine is within the range of about 4.8 to about 6. The high solids compositions of the present invention contain up to about a butylated melamine formaldehyde crosslinker of the type previously described in connection with the preferred medium solids compositions of the present invention, based on the total weight of the crosslinker. 50
It can also be included up to % by weight, preferably up to about 30% by weight. Additional stabilization of the crosslinked dispersion alone or as a flow control agent for the coating compositions of the present invention, apart from any solvent included in the stabilizer composition, may be This is achieved by adding to the crosslinked dispersion another stabilizer consisting essentially of a butylated melamine formaldehyde resin having a number average molecular weight of . About 25 to about 100 parts of total resin solids contained in the crosslinked dispersion
The stabilizer is added to the crosslinked dispersion in an amount resulting in a resin solids content of 75 parts, preferably from about 40 parts to about 60 parts. Preferably, the additionally stabilized dispersion of the present invention contains a solids content in the range of 30 to 70% after addition of another stabilizer and any additional solvent desired; A range of 40-60% is most desirable. Additional additives are generally added to the crosslinked dispersion as a solution containing one or more solvents for the butylated melamine formaldehyde. Preferably, the additional stabilizer is extracted essentially from a solution of the butylated melamine formaldehyde resin dissolved in the organic solvent in an amount such that the solids percentage of the butylated melamine formaldehyde resin in the solvent is from about 50 to about 90%. should be. In a particularly preferred embodiment, the additional stabilizer consists essentially of a 65% solids solution of butylated melamine formaldehyde resin dissolved in a 2:1 solution of butyl acetate and butyl alcohol. Butylated melamine formaldehyde resins suitable for use as additional stabilizers in the present invention can be obtained by a one-step process under acidic conditions or by reacting melamine and formaldehyde under basic conditions followed by etherification under acidic conditions. Using a two-step method,
It is a resin obtained by condensing melamine, formaldehyde, and butyl alcohol. The molecular weight is determined by the ratio of the three types of components. High formaldehyde to melamine ratios and high alcohol to formaldehyde ratios tend to produce low molecular weight resins. The molar ratio of formaldehyde to melamine is approximately
3.0-6, while the molar ratio of butanol to melamine is 6-12. Only a portion of the alcohol reacts; the remainder acts as a solvent. The molecular weight distribution is generally broad, with M _W from about 2000 to ca.
10000, and the ranges for M _o are as above. The invention will be more fully understood by the following detailed examples, which are merely illustrative of the many compositions that fall within the scope of the invention. Example 1 A 2 volume flask equipped with a stirrer, thermometer, addition funnel and water condenser was charged with 590 g of n-butyl acetate and 0.4 g of t-butyl perbenzoate initiator. The initiator solution was heated to 120°C.
While maintaining the temperature at 120°C, 496 g of 2-ethylhexyl acrylate, 224 g of methyl methacrylate, 80 g of glycidyl methacrylate and 4.2 g
of t-butyl peroctoate was added dropwise over a period of 3 hours. One hour after adding
0.84 g t-butyl peroctoate and 25 g n-
A mixture with butyl acetate was added and the reaction continued for an additional 2 hours. A mixture of 1.28 g hydroquinone, 6.4 g methacrylic acid, 1.2 g dimethyldodecylamine and 140 g n-butyl acetate was then added to the reaction mixture. Acid value is 0.2mgKOH/
The reaction was maintained at 120°C until the The reaction product was determined by gel permeation chromatography using a solids content of 50.6%, a Gardner viscosity of F, a number average molecular weight of 8545, and a polystyrene calibration.
It was a dark colored solution with a weight average molecular weight of 28,865. Examples 2-7 Various stabilizers were prepared according to the procedure of Example 1, varying the type and ratio of monomers. The monomer ratio and properties of some typical stabilizers are summarized in the table.

[Table] Example 8 In a 5 volume flask equipped with a stirrer, thermometer, addition funnel and water condenser, 991 g of heptane, 41 g
of methyl methacrylate, 8 g of the stabilizer of Example 5, and 0.7 g of azobisisobutyronitrile were heated to 90°C to prepare a non-aqueous acrylic dispersion polymer. After maintaining the reaction at 90℃ for 30 minutes,
1022 g methyl methacrylate, 55 g glycidyl methacrylate, 34 g methacrylic acid, 3.4 g dimethyldodecylamine, 152 g stabilizer of Example 5,
427g Espesol 260H (Charter Chemical Co. product)
and 7.7 g of azobisisobutyronitrile were added dropwise. One hour after the end of the addition, n-
0.77 g of azobisisobutyronitrile dissolved in 150 g of butyl acetate was added. The reaction was allowed to continue for an additional 2 hours. The resulting opalescent acrylic dispersion polymer had a solids content of 43.0% and a Ford No. 2 cup viscosity of 28.9 seconds. Example 9 An acrylic dispersion polymer was prepared following the procedure of Example 8 and using the stabilizer of Example 6. The resulting dispersion polymer had a solids content of 43.5% and a feed No. 2 cup viscosity of 26.3 seconds. Example 10 (A) Flow regulator According to the method of Example 1, the blending ratio of 2-ethylhexyl acrylate/methyl methacrylate/glycidyl methacrylate/methacrylic acid is 55/35/10/
An acrylic stabilizer copolymer of 0.8 was prepared.
The copolymer had a viscosity (Gardner-Holdt) at 50% solids in n-butyl acetate. Following the method of Example 8, methyl methacrylate
1063 parts of glycidyl methacrylate, 55 parts of glycidyl methacrylate, and 34 parts of methacrylic acid were reacted in the presence of the above acrylic stabilizer solution to produce a flow regulator. This modifier had a solids content of 43% in 60/25/15 heptane/coating naphtha/butyl acetate. (B) Silver metallic enamel A silver metallic enamel was prepared by mixing the following components. Acrylic resin A ^(a) 2166 Acrylic resin B ^(b) 1634 Melamine resin X ^(c) 1509 Flow regulator 640 Aluminum paste (aluminum flakes)
60%) 175 Polybutyl acrylate (60% in xylene) 31 Isobutyl acetate 1000 Ethylene glycol ethyl ether acetate
745 The enamel was sprayed onto primed steel panels and cured for 17 minutes at 265°C in a forced draft oven.
The panels had excellent gloss and clear images due to the even distribution of aluminum flakes within the paint. The control enamel without flow modifier was much darker and exhibited uneven distribution of aluminum flakes or mottling. (a) Acrylic resin A is a typical automotive thermosetting acrylic resin with a monomer composition of styrene/methyl methacrylate/butyl acrylate/hydroxypropyl methacrylate/acrylic acid of 37/20/27/15/1. be. This resin is
The viscosity measured at 55% solids in a 70/20/18 mixture of cellosolve acetate/butanol/toluene was Y. (b) Acrylic resin B is styrene/butyl methacrylate/2-ethylhexyl acrylate/
This is a thermosetting acrylic resin for automobiles with a blending ratio of hydroxypropyl methacrylate/acrylic acid of 30/30/20/19/1. This resin is 50/50
The viscosity expressed as 50% nonvolatile content in cellosolve acetate/isopropyl was T. (c) Melamine resin
and mineral spirit tolerance according to ASTM D1198
300. Example 11 White enamel was prepared by mixing the following ingredients. Titanium dioxide millpigment ^(d) 2891 Acrylic resin C ^(e) 1241 Acrylic resin D ^(f) 1099 Melamine resin Ether acetate 558 Flow regulator 133 Spray paint on primed panels.
After baking the panel for 17 minutes at 265 mm, the paint thickness wedge from 1.7 mil to 3.5 mil
wedge) is now realized. At the 2.5 mil thickness area, the coating began to sag. The control enamel without added rheology agent sagged at about 1.9 mil. (d) This millbase was prepared from the following raw materials: Titanium dioxide 600 parts Acrylic resin 250 Coating naphtha 110 Methyl amyl ketone 50 Butyl acetate 40 Toluene 40 Xylene 8 ( e) Acrylic resin C is an acrylic copolymer consisting of 30/30/20/18/2 styrene/butyl methacrylate/2-ethylhexyl acrylate/hydroxypropyl methacrylate/acrylic acid. The viscosity of this resin at 50% solids in xylene was Z. (f) Acrylic resin D is an acrylic copolymer consisting of 28/30/20/20/2 styrene/butyl methacrylate/ethylhexyl acrylate/hydroxypropyl methacrylate/acrylic acid. The viscosity of this resin at 60% solids in 1/1 methyl amyl ketone/coating naphtha was T. Example 12 (A) Flow regulator According to the method of Example 1, the comonomer blending ratio of ethylhexyl acrylate/methyl methacrylate/glycidyl methacrylate/methacrylic acid is 59/3.
An acrylic stabilizer was prepared that was 5/6/1. The copolymer had a viscosity L at 58% solids in butyl acetate. Following the procedure of Example 8, a flow regulator was prepared using the following ingredients: Methyl methacrylate 1016g Glycidyl methacrylate 52g Methacrylic acid 32g Acrylic stabilizer 186g Azobisisobutyronitrile 8.8g Dimethyldodecaneamine 3.2g Octyl mercaptan 7.4 g Heptane 930g Paint grade naphtha 394g Butyl acetate 134g The non-volatile content of this dispersion was 43% and the No. 2 Ford Cup viscosity was 29.1 seconds. (B) Silver metallic high solids enamel A silver metallic enamel was prepared by mixing the following components. Acrylic resin E ^(g) 3475 Cymel 325 ^(h) 1799 RG-82 ⁽ⁱ⁾ 360 Flow regulator (6.5% solids/total solids) 700 Aluminum flake dispersion (60% Al) 205 Methyl ethyl ketone 209 Ethylene glycol ethyl ether acetate
767 Isopropyl alcohol 330 Ethyl acetate 250 Diethylene glycol monobutyl ether 160 This enamel is spray-painted on a primed metal panel, and after baking at 285° for 30 minutes, the thickness of the wedged film is 1.5~1.5~ It was set to 3.0 mil. Paint sagging occurred when the film thickness was greater than 2.0 mils. Adjusting the paint formulation to include 7.5% flow modifier improved sag resistance to 2.2 mils.
The same paint without flow modifiers exhibited sag at film thicknesses below 1.0 mil. (g) Acrylic resin E is a copolymer consisting of 25/23/20/30/2 styrene/butyl methacrylate/ethylhexyl acrylate/hydroxyethyl acrylate/acrylic acid and has a Z3 content of 78% non-volatile content in methyl amyl ketone. It has a viscosity of (h) Cymel 325 is a methylated melamine formaldehyde resin commercially available as an 80% non-volatile product from American Cyanamid Company. (i) RG-82 is manufactured by Eastman Chemical Products, Inc.
The product is described as a reactive diluent with a hydroxy equivalent weight of 91. Example 13 In a 5 volume flask equipped with a stirrer, thermometer, addition funnel and water condenser, 838 g of heptane, 65 g of methyl methacrylate, 4.6 g of azobisisobutyronitrile and 11 g of the stabilizer from Example 7 are brought to 90°C. A non-aqueous acrylic dispersion polymer was prepared by heating. 90℃
The reaction was maintained for 30 minutes. Next, 156g of hydroxyethyl acrylate, 40g of methacrylic acid, and styrene.
467g, butyl methacrylate 303g, ethylhexyl acrylate 311g, stabilizer from Example 7 395g, octyl mercaptan 11g, methyl methacrylate
A mixture of 211 g and 10 g of azobisisobutyronitrile was added dropwise over a period of 4 hours. One hour after the addition, 12 g of azobisisobutyronitrile dissolved in 258 g of n-butyl acetate were added. The reaction was continued for an additional 2 hours. 200g n
-Butyl acetate was added. The solids content of the resulting milky white dispersion was approximately 52%. The stability of the dispersion system was excellent. Many modifications to the present invention will be apparent to those skilled in the art from this disclosure. All such modifications that fall within the true scope of the invention are intended to be embraced within the scope of the following claims. Example 14 Stabilized flow regulator Following the method of Example 1, the composition of 2-ethylhexyl acrylate/methyl methacrylate/glycidyl methacrylate/methacrylic acid was 65/24/10/
An acrylic stabilizer copolymer of 1.0 was prepared.
The viscosity (Gardner-Holt) of the copolymer at 50% solids in n-butyl acetate was G. A flow control agent was prepared according to the procedure of Example 8 from 1063 parts of methyl methacrylate, 55 parts of glycidyl methacrylate and 34 parts of methacrylic acid in the presence of 160 parts of the above acrylic stabilizer solution. This modifier had a viscosity of 26.5 seconds with a No. 2 food cup at 42.9% solids. A stabilized flow control agent was prepared by mixing 1400 parts of this regulator with 938 parts of syn U Tex 4113E ^(a) and 148 parts of isopropyl acetate. The viscosity of this stabilized flow modifier at 47.5% solids in a No. 2 food cup is 34.2 seconds. (a) Shinyu Techs 4113E is manufactured by Celanese Plastics and Specialties.
Company). The specifications for this material are viscosity (Gardner-Holt) T-W at 65±1% non-volatile content in 2/1 butyl acetate/butanol. Example 15 Silver metallic enamel acrylic resin A ^(a) 2166 Acrylic resin B ^(b) 1634 Shin-Yu-Tex 4113E 1066 Flow regulator (Example 14) 1152 Aluminum paste (aluminum flakes)
60%) 175 Polybutyl acrylate (60% in xylene) 31 Isobutyl acetate 930 Ethylene glycol ethyl ether acetate
745 Primed steel panels were sprayed with the enamel and cured for 17 minutes at 265°C in a forced draft oven. Due to the even distribution of aluminum in the paint, the panels exhibited excellent gloss and clear images. The control enamel without added rheology agent was much darker in color and exhibited an uneven distribution of flakes. (a) Acrylic resin A is a typical thermosetting acrylic resin for automobiles having a monomer composition of styrene/methyl methacrylate/butyl acrylate/hydroxypropyl methacrylate/acrylic acid of 37/20/27/15/1. 70/1 of this resin
The viscosity at 55% solids in 2/18 cellosolve acetate/butanol/toluene is Y. (b) Acrylic resin B is styrene/butyl methacrylate/2-ethylhexyl acrylate/
This is an automotive thermosetting resin with a hydroxypropyl methacrylate/acrylic acid composition of 30/30/20/19/1. Non-volatile content of this resin in 50/50 cellosolve acetate/isopropyl acetate
The viscosity at 50% was T. Example 16 White enamel White enamel was prepared by mixing the following ingredients. Titanium dioxide millpigment ^(d) 2891 Acrylic resin C ^(e) 1241 Acrylic resin D ^(f) 1099 Shin-Yu-Tex 4113E 1173 Flow regulator (Example 14) 229 Polybutyl acrylate (60% in xylene) 25 Isobutyl acetate 2268 Ethylene glycol monoethyl ether acetate 558 Sprayed on primed panel, 265〓
Coating thickness wedges from 1.7 mils to 3.5 mils were achieved after baking the panels for 17 minutes. The coating began to sag in the 2.5 mil thick area. The control enamel without flow modifier showed sag at about 1.9 mil. (d) This milled pigment was made from the following raw materials: Titanium dioxide 600 parts Acrylic resin D 250〃 Paint naphtha 110〃 Methyl amyl ketone 50〃 Butyl acetate 40〃 Toluene 40〃 Xylene 8〃 (e) Acrylic resin C is an acrylic copolymer consisting of 30/30/20/18/2 styrene/butyl methacrylate/2-ethylhexyl acrylate/hydroxypropyl methacrylate/acrylic acid. The viscosity of this resin at a solid content of 50% in xylene was Z. (f) Acrylic resin D is an acrylic copolymer consisting of 28/30/20/20/2 styrene/butyl methacrylate/ethylhexyl acrylate/hydroxypropyl methacrylate/acrylic acid. 1/1 methyl amyl ketone of this resin/
The viscosity at a solid content of 60% in the paint naphtha was T. Example 17 Stabilized Flow Control Agent An acrylic stabilizer having a comonomer composition of ethylhexyl acrylate/methyl methacrylate/glycidyl methacrylate/methacrylic acid 62/32/6/1 was prepared as described in Example 14. The viscosity of this copolymer at a solids content of 56.2% in butyl acetate was R. A flow control agent was prepared according to the procedure of Example 8 using the following raw materials: Methyl methacrylate 1063g Glycidyl methacrylate 55g Methacrylic acid 34g Acrylic stabilizer 160g Azobisisobutyronitrile 8.4g Dimethyldodecanoic acid amine 3.4g Octyl mercaptan 7.7g Heptane 991g Paint grade naphtha 427g Butyl acetate 150g The % non-volatile content of this dispersion is 43%, and
The viscosity measured by No. 2 food cup was 26.8 seconds. 1000g of this dispersion,
A stabilized flow control agent was prepared by mixing 670 g of 4113E and 106 g of isopropyl acetate. At 48.2% solids content of this stabilized flow regulator
The viscosity measured by No. 2 food cup was 37.0 seconds. Example 18 High solids white enamel A white enamel was prepared by mixing the following ingredients. Acrylic resin C ^(a) 3362 Cymel 325 ^(b) 1381 Flow regulator (Example 17) 618 Phenylic acid phosphate 32 White millpigment 3077 Butanol 361 Methanol 242 2-ethylhexyl acetate 245 Monobutyl ether of diethylene glycol
140 Methyl amyl ketone 441 The above white millpigment was prepared using the following raw materials: Titanium dioxide 2215 Acrylic resin H ^(c) 385 Methyl amyl ketone 446 Isopropyl acetate 25 This enamel has a solids content of 66% and 31.5
It has a No. 4 Ford Cup viscosity of seconds. When it was sprayed onto a primed panel and cured for 20 minutes at 265%, no sagging was observed when the coating thickness was less than 70μ. (a) Acrylic resin G is an acrylic copolymer consisting of 71/25/4 butyl methacrylate/hydroxyethyl acrylate/acrylic acid, and the viscosity at 80% in methyl amyl ketone is
It is Z1. (b) Cymel 325 is a methylated formaldehyde-memelamine resin with 80% non-volatile content and is a product of American Cyanamid Company. (c) Acrylic resin H is an acrylic copolymer consisting of 68/30/2 butyl methacrylate/hydroxyethyl acrylate/acrylic acid and has a viscosity of Z at 80% non-volatile content in methyl amyl ketone. Example 19 High Solids Green Metallic Enamel The following ingredients were mixed to prepare a dark green enamel with improved aluminum control and good sag resistance. Acrylic resin G 5580 Cymel 325 1370 Flow regulator (Example 17) 1000 Phenyl acid phosphate 24 Aluminum paste ⁽¹⁾ 128 Yellow milled pigment ⁽²⁾ 603 Blue milled pigment ⁽³⁾ 185 Black milled pigment ⁽⁴⁾ 254 Methanol 225 Ethyl acetate 177 Butyl acetate 177 Methyl amyl ketone 201 Cellosolve acetate 112 Butyl alcohol 203 Ethylhexyl acetate 81 This enamel contained 60 weight solids and had a No. 4 food cup viscosity of 29 seconds. (1) This aluminum paste was a mixture of the following components: Acrylic resin H 3125 Aluminum flakes 25 Paint naphtha 12.2 Butyl alcohol 6.5 Cellosolve acetate 25 (2) This yellow millpigment was a mixture of the following components: Yellow tone Phthalocyanine green 90 Acrylic resin H 181 Methyl amyl ketone 120 Butyl alcohol 211 (3) The blue millbase was a mixture of the following components: Phthalocyanine blue 15 Melamine resin X 37 Butyl alcohol 133 (4) The black millbase was a mixture of the following components: It was a mixture of components: Furnace Black 13 Acrylic Resin H 196 Methanol 21 Xylene 24 Many modifications to the present invention will be apparent to those skilled in the art from the above disclosure. All such modifications that fall within the true scope of this invention
It is intended to be encompassed within the scope of the following claims.

Claims (1)

[Scope of Claims] 1 () Formed by 5 to 50% by weight of hydroxy-functional monoethylenically unsaturated monomers and 95 to 50% by weight of other monoethylenically unsaturated monomers, from 150 or more up to 20,000 a film-forming component consisting of a hydroxy-functional copolymer having a number average molecular weight M _{o of} and a glass transition temperature T _g within the range of -25°C to 70°C; ) Total resin solids content in coating composition 100
%, the resin solids contained in the flow control agent is in the range of 0.5 to 30 parts, the flow control agent being a stable coating containing microgel particles. a crosslinked dispersion, and the dispersion comprises (a) an α,β-ethylenically unsaturated monocarboxylic acid 1
~10 mol%, (b) 1 to 10 mol% of a crosslinking monomer selected from the group consisting of ethylenically unsaturated monoepoxides, and (c) at least one other copolymerizable monoethylenically unsaturated monomer80 ~98 mol% is comprised of (1) an organic hydrocarbon dispersing liquid that is a solvent for the polymerizable monomer but a non-solvent for the resulting polymer; and (2) an ethylenic non-solvent. It is formed by free radical addition copolymerization in the presence of a polymeric dispersion stabilizer consisting of a reaction product of a saturated monomer (A) and a copolymer reactant (B). ) is (i) 20 to 45% by weight of an ethylenically unsaturated monomer, the sole polymer of which is substantially insoluble in the organic liquid; (ii) an ethylenically unsaturated monomer and 40 to 75% by weight of monomers, the sole polymer of which is substantially soluble in the organic liquid, and (iii) has a complementary functionality capable of condensation reaction with the ethylenically unsaturated monomer (A). It consists of a random copolymer of 2 to 15% by weight of ethylenically unsaturated monomers, and the ethylenically unsaturated monomers (i) and (ii) are such that a homopolymer of these monomers is formed by a combination of the homopolymer and the organic liquid. selected to be substantially soluble or insoluble in the organic liquid due to the relative polarity between the ethylenically unsaturated monomers;
One of (i) or (ii) consists of an ester of a _C4 to _C18 aliphatic alcohol with acrylic, methacrylic or ethacrylic acid, and the other ethylenically unsaturated monomer (i) or (ii) , (a) esters of _C1 - _C3 aliphatic alcohols with acrylic, methacrylic or ethacrylic acid, (b) acrylic and methacrylic acid, and (c) ethylene and propylene glycol monoesters of acrylic, methacrylic or ethacrylic acid. said ethylenically unsaturated monomer (A) has a functionality capable of condensation reaction with said complementary functionality contained in said copolymer reactant (B); The dispersion stabilizer binds the ethylenically unsaturated monomer (A) to the copolymer reactant (B) in an amount sufficient to react with at least 10% of the supplemental functionality contained in the copolymer reactant (B). (B), wherein said addition copolymerization reaction is carried out at an elevated temperature so that the dispersed polymer is first formed and then crosslinked. Composition. 2 the hydroxy-functional copolymer has a number average molecular weight _o greater than 5000, and the crosslinker
2. The coating composition according to 1 above, which contains 20 to 100 parts of butylated melamine formaldehyde having a number average molecular weight _o of 700 to 2,500, based on 100 parts of the film forming component. 3. The film-forming component consists essentially of a polymer component having a number average molecular weight M _o of less than 5000 _;
and at least 50% by weight of a hydroxy-functional copolymer with a glass transition temperature T _g of -25°C to 70°C
The hydroxy-functional copolymer contains 15 to 35% by weight of a hydroxy-functional monoethylenically unsaturated monomer and 2 α,β-olefinically unsaturated carboxylic acids.
~5% by weight, the remainder being formed by other monoethylenically unsaturated monomers, and the crosslinking agent forms a monomeric methylated melamine resin having a number average molecular weight _o of 350 to 1000. The film forming component
The coating composition according to 1 above, containing 20 to 100 parts per 100 parts. 4. The flow control agent further comprises therein, apart from the solvent, another stabilizer consisting essentially of a butylated melamine formaldehyde resin having a number average molecular weight _o within the range of 700 to 2500. and the other stabilizer is included in the flow control agent in an amount resulting in a resin solids content of 15 to 75 parts per 100 parts of total resin solids contained in the flow control agent. The coating composition according to 1, 2 or (3) above. 5. the organic liquid of the flow control agent comprises an aliphatic hydrocarbon, and the copolymer reactant (B) used to prepare the polymeric dispersion stabilizer of the flow control agent comprises the ethylene unsaturated monomer
Coating composition according to claim 1, characterized in that (i) is methyl methacrylate and the ethylenically unsaturated monomer (ii) is 2-ethylhexyl acrylate. 6. The polymeric dispersion stabilizer of the flow control agent is
one of said ethylenically unsaturated monomers (A) or (iii) is glycidyl acrylate or methacrylate; and said ethylenically unsaturated monomer
6. The coating composition according to 5 above, wherein the other of (A) or (iii) is acrylic or methacrylic acid. 7 The monomer used in the addition copolymerization reaction to form the dispersion polymer of the flow control agent is
1, wherein the α,β-ethylenically unsaturated monocarboxylic acid is methacrylic acid and the other copolymerizable monoethylenically unsaturated monomer is glycidyl methacrylate. Coating composition. 8. the hydroxy-functional monoethylenically unsaturated monomer used to prepare the hydroxy-functional copolymer is selected from the group consisting of hydroxy-containing aliphatic alcohol esters of α,β-monoethylenically unsaturated carboxylic acids; 4. A coating composition as described in 2 or 3 above. 9. The other monoethylenically unsaturated monomers mentioned above constitute up to 2% by weight, based on the total weight of monomers used to prepare the hydroxy-functional copolymer.
The coating composition according to 1 above, comprising an α,β-monoethylenically unsaturated carboxylic acid. 10 The other monoethylenically unsaturated monomers other than the carboxylic acid are selected from the group consisting of acrylates, methacrylates, monovinyl hydrocarbons containing 8 to 12 carbon atoms, and other modifying vinyl monomers. 9. A coating composition as described in 9 above. 11 (a) the hydroxy-functional copolymer comprises 10 to 30% by weight of hydroxyl-containing aliphatic alcohol esters of acrylic and methacrylic acids and up to 2% by weight, based on the total weight of monomers used to form the copolymer; with the remaining monoethylenically unsaturated monomers containing acrylic or methacrylic acid, wherein said remaining other monomers other than acrylic or methacrylic acid are acrylates, methacrylates, monovinyl containing from 8 to 12 carbon atoms. 3. The coating composition of claim 2, wherein the coating composition is selected from the group consisting of hydrocarbons and other modifying vinyl monomers, and (b) said butylated melamine crosslinking agent comprises a reaction product of butyl alcohol, melamine and formaldehyde. 12 50-90% by weight of said hydroxy-functional copolymer in which said film-forming component has a number average molecular weight _o greater than 5000, and a glass transition temperature _between -25°C and 70°C; At least one hydroxy-functional copolymer having T _g
10 to 50% by weight, and their hydroxy-functional copolymers are formed of 15 to 35% by weight of hydroxy-functional monoethylenically unsaturated monomers, and the remainder is other monoethylenically unsaturated monomers. The coating composition described in . 13. The coating composition according to item 3, wherein the amount of the α,β-olefinically unsaturated carboxylic acid used to form the hydroxy-functional copolymer is within the range of 2 to 4% by weight. 14. The method according to 3 above, wherein the remaining monotylenically unsaturated monomer is selected from the group consisting of acrylates, methacrylates, monovinyl hydrocarbons containing 8 to 12 carbon atoms, and other modifying vinyl monomers. Coating composition. 15 The hydroxy-functional copolymer described above is 2300
3. The coating composition according to claim 3, having a number average molecular weight _o in the range of .about.3600 and formed from 20 to 30% by weight of hydroxy-functional monoethylenically unsaturated monomer. 16 The crosslinking agent _has a number average molecular weight of 700 to 2500
butylated melamine formaldehyde crosslinker having a maximum of 30% by weight based on the total crosslinker.
15. The coating composition according to 14 above, comprising: 17 (a) The hydroxy-functional copolymer comprises 20-3% by weight of hydroxy-containing aliphatic alcohol esters of acrylic and methacrylic acid, 2-4% by weight of acrylic or methacrylic acid, 8-12 acrylates, methacrylates, etc. and (b) the crosslinking agent has a number average of 350 to 1000. consisting of a monomeric methylated melamine resin having a molecular weight _o and a butylated melamine formaldehyde crosslinking agent with a number average molecular weight _o between 700 and 2500, present in an amount of up to 30% by weight, based on the weight of the crosslinking agent. 3. The coating composition according to 3 above. 18. React with at least a portion of the ethylenically unsaturated monomers (i), (ii) and (iii) used in the production of the copolymer reactant (B) to form the polymeric reactant (B). 11 above, wherein at least a part of the ethylenically unsaturated monomer (A) forming the dispersion stabilizer consists of an acrylic monomer.
or 17. The coating composition according to 17. 19 The organic liquid of the flow control agent comprises an aliphatic hydrocarbon and the copolymer reactant (B) used in the preparation of the polymeric dispersion stabilizer of the flow control agent comprises the ethylenically unsaturated monomer. 19. A coating composition according to claim 18, characterized in that (i) is methyl methacrylate and the ethylenically unsaturated monomer (ii) is 2-ethylhexyl acrylate. 20 The polymeric dispersion stabilizer of the flow control agent is characterized in that one of the ethylenically unsaturated monomers (A) or (iii) is glycidyl acrylate or methacrylate, and the ethylenically unsaturated monomer (A) or (iii) is glycidyl acrylate or methacrylate; 20. The coating composition according to claim 19, wherein the other of A) or (iii) is acryl or methacrylic acid. 21 The dispersion system of the above-mentioned flow control agent is prepared by adding 1 to 10 mol % of an α,β-ethylenically unsaturated monocarboxylic acid and at least one other copolymerizable monocarboxylic acid in the presence of a hydrocarbon dispersion liquid. Monomer 1 selected from the group consisting of 80 to 98 mol% of ethylenically unsaturated monomers and ethylenically unsaturated monoepoxides
21. The coating composition as described in 20 above, which is formed by free radical addition copolymerization of ~10 mol %. 22 The fluidity regulator, apart from the solvent, has a
further stabilized by including therein another stabilizer consisting essentially of a butylated melamine formaldehyde resin having a number average molecular weight _o in the range of 2500; 15 to 100 parts of total resin solids contained in flow regulator
18. The coating composition according to 11 or 17 above, which is included in the flow control agent in an amount resulting in a resin solids content of 75 parts.