JPH0778200B2 - High solids coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is a cured coating excellent in hot water resistance and acid resistance, which is capable of achieving high solidification while maintaining a newly useful coating workability. A high solids coating composition capable of providing a film.

[Conventional technology]

Conventionally, a composition comprising a hydroxyl group-containing polymer, an amino resin, and a fine particle polymer has a good metal stop when the aluminum coating is added to form a metalic coating film, and has an excellent appearance. In the case of a clear coating film, it has been said that it does not cause "dripping" even if it is applied thickly.

[Problems to be Solved by the Invention] However, in such a conventional coating composition, when butylated methylolmelamine is used as an amino resin as a curing agent, the coating nonvolatile content of the coating is low. On the other hand, when methylated methylolmelamine is used, although the coating non-volatile content can be increased, there are problems in terms of hot water resistance and acid resistance of the cured coating film.

[Means for solving problems]

However, in order to solve the various drawbacks in the various conventional techniques as described above, the present inventors have added a specific amino resin to a system consisting of hydroxyl group-containing polymers and fine particle polymers, thereby making these The present invention has been completed by finding that a high solid content coating composition in which the drawbacks of (1) and (2) are improved and the coating workability is good can be obtained.

That is, the present invention includes, as essential components, 90 to 30 parts by weight of a hydroxyl group-containing polymer (A), 10 to 70 parts by weight of a methylbutyl-mixed alkylated methylolmelamine (B), and these (A) component and (B). ) 0.1 per 100 parts by weight of the total amount of ingredients
A high solids coating composition comprising from about 100 parts by weight of particulate polymer (C), and an appropriate amount of solvent (C).

Here, first, the above-mentioned hydroxyl group-containing polymers (A)
The term "(condensed) polymer having at least one, preferably two or more hydroxyl groups in one molecule" means that it is necessary and sufficient for highly solidifying the composition of the present invention. Those having a molecular weight range are designated.

Therefore, if these conditions are met,
Although any of these can be used, a specific resin that meets the following conditions is preferable.

Vinyl resins having a number average molecular weight (▲ ▼) of 500 to 8,000 and a hydroxyl value (OHV) of 40 to 250, ▲ ▼ of 200 to 3,000 and OHV of 40 to 6
At least one resin selected from the group consisting of alkyd resin, oil-free alkyd resin and urethane resin in the range of 00, and a mixture of the above resins and resins.

Among these, in order to prepare the resins, a hydroxyl group-containing monomer and another monomer having a copolymerizability therewith may be copolymerized by a conventional method. Specific examples include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate and 3-hydroxybutyl (meth) acrylate. , 4-hydroxybutyl (meth) acrylate, 3-
Hydroxyalkyl esters of (meth) acrylic acid such as chloro-2-hydroxypropyl (meth) acrylate and polyethylene glycol mono (meth) acrylate; monomers containing an acid anhydride group such as maleic anhydride and itaconic anhydride, and ethylene glycol Unsaturated-alkyl-containing hydroxyalkyl ester monocarboxylic acids such as adducts with glycols; or unsaturated-bond-containing polyhydroxyalkyl esters such as dihydroxyalkyl esters of polyvalent carboxylic acids such as maleic acid and fumaric acid; hydroxy There are hydroxyalkyl vinyl ethers such as ethyl vinyl ether.

On the other hand, typical examples of other copolymerizable monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2- (meth) acrylate.
(Meth) acrylic acid esters such as ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate and benzyl (meth) acrylate; unsaturated dicarboxylic acids and monohydric alcohols such as dimethyl maleate, diethyl fumarate and dibutyl itaconate With diesters; vinyl acetate, vinyl benzoate, "Veova"
Vinyl esters such as (Ciel, Netherlands);
"Viscoat 8F, 8FM, 3F or 3FM" [fluorine-containing (meth) acrylic monomers manufactured by Osaka Organic Chemical Co., Ltd.] or perfluorocyclohexyl (meth) acrylate,
J-Perfluorocyclohexyl fumarate or N
Perfluoroalkyl group-containing vinyl esters such as -iso-propyl perfluorooctanesulfonamidoethyl (meth) acrylate; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride; ethylene; Α-olefins such as propylene; styrene, α-methylstyrene, p
Aromatic vinyl monomers such as -tert-butylstyrene, o-methylstyrene, p-methylstyrene; (meth)
Acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid-containing carboxyl group-containing monomers (unsaturated mono- or dicarboxylic acids); maleic anhydride, itaconic anhydride-containing acid anhydride group-containing monomers; (Meth) acrylamide, N, N-dimethyl (meth)
Acrylamide, N-alkoxymethylated (meth) acrylamide, diacetone (meth) acrylamide, N-
Carboxylamide group-containing monomers such as methylol (meth) acrylamide; p-styrenesulfonamide, N
-Sulfonamide group-containing monomers such as methyl-p-styrenesulfonamide and N, N-dimethyl-p-styrenesulfonamide; N, N-dialkylaminoalkyl such as N, N-dimethylaminoethyl (meth) acrylate (Meth) acrylates; such as adducts of the above-mentioned acid anhydride group-containing monomers with a compound having an active hydrogen group capable of reacting with an acid anhydride group such as N, N-dimethylaminopropylamine and a compound having a tertiary amino group. Monomers containing primary amino groups; Monomers containing cyano groups such as (meth) acrylonitrile; Hydroxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids such as hydroxyalkyl esters of (meth) acrylic acid, and phosphoric acid or Monomers having a phosphate ester bond, which is a condensation product with a phosphate ester; or 2- Acrylamide-2-methyl - sulfonic acid group-containing monomers or organic amine salts such as propane sulfonic acid and the like.

Of the various monomers described above, the amount of the hydroxyl group-containing monomers used varies depending on the molecular weight of the vinyl resin to be obtained, but it is desirable that the amount of hydroxyl group-containing monomers generally occupy 10 to 50% by weight of all the monomers. The remaining 90 to 50% by weight of the above-mentioned other copolymerizable monomers are the physical properties of the finally obtained cured coating film, the pigment dispersibility, etc.
It may be freely selected in consideration of other desired factors.

In addition, among the other copolymerizable monomers as described above, a carboxyl group-containing one which also serves as a latent catalyst for a crosslinking reaction between the vinyl resin and the methylbutyl-mixed alkylated methylolmelamine as a curing resin is included. Since there are acidic group-containing monomers such as monomers and sulfonic acid group-containing monomers, it is desirable to use these specific monomers.

Then, in order to prepare such a hydroxyl group-containing vinyl resin, a known conventional method such as a solution polymerization method, a solution pressure polymerization method, a bulk polymerization method, an emulsion polymerization method or a suspension polymerization method can be directly applied. The solution radical polymerization method is the simplest.

Typical solvents used at that time are:
Toluene, xylene, cyclohexane, n-hexane,
Hydrocarbons such as octane; methanol, ethanol,
Alcohol systems such as iso-propanol, n-butanol, iso-butanol, sec-butanol, ethylene glycol monomethyl ether; ester systems such as methyl acetate, ethyl acetate, n-butyl acetate, amyl acetate; acetone, methyl ethyl ketone, methyl-iso There are ketone-based compounds such as butyl ketone, methyl amyl ketone, and cyclohexanone; and amide-based compounds such as dimethylformamide and dimethylacetamide, and it goes without saying that any mixture thereof can also be used.

Polymerization may be carried out by a conventional method using the solvent and various radical polymerization initiators such as azo type or peroxide type. Further, if necessary, lauryl mercaptan as a molecular weight regulator may be used. , Various chain transfer agents such as octyl mercaptan, 2-mercaptoethanol or α-methylstyrene dimer can also be used. In particular, when a hydroxyl group-containing chain transfer agent such as 2-mercaptoethanol is used, it is possible to efficiently introduce such a hydroxyl group into a fraction having an average molecular weight of the obtained resin or less, but the weather resistance Due to its inferiority, it should be directed to limited applications.

Further, as a method for preparing such a hydroxyl group-containing vinyl resin,
In addition to the solution radical polymerization method described above, there is an ionic polymerization method, and the resin obtained by this ionic polymerization method is also
It can be used in the present invention without any trouble.

According to such an ionic polymerization method, polymerization is performed using an ionic polymerization initiator in a form in which functional groups are previously blocked, and then the blocking agent at the terminal of the obtained resin is eliminated, so that the molecular weight distribution is extremely narrow. Moreover, it is possible to obtain a resin having one or more functional groups in one molecule without fail, and such an ionic polymerization method is disclosed in JP-A-58-13.
The details described in Japanese Patent No. 608 can be applied as they are.

The glass transition point of the hydroxyl group-containing vinyl resin thus obtained is suitably within the range of -20 to + 50 ° C.

Next, all of the above-mentioned alkyd resin, oil-free alkyd resin and / or urethane resin are characteristic in that the raw material components and ▲ ▼ and OHV are limited, and so-called synthetic conditions such as esterification method are Well-known and conventional means can be applied as they are.

Here, the urethane resin refers to a resin having one or more urethane bonds in one molecule, such as an isocyanate-modified acrylic resin, an isocyanate-modified alkyd resin, or an isocyanate-modified polyester resin. It is preferable to use an isocyanate-modified alkyd resin and / or polyester resin from the standpoint of relatively low risk of gelation.

First, as a method for preparing a urethane resin, it is preferable to extend the molecular chain by reacting an alkyd oligomer or polyester oligomer having one or more hydroxyl groups in one molecule with an organic diisocyanate compound.

Typical examples of the organic diisocyanate compound that can be used include aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; alicyclic diisocyanates such as xylylene diisocyanate and isophorone diisocyanate; or tolylene diisocyanate, 4,4 ′. -Aromatic diisocyanates such as diphenylmethane diisocyanate, etc. may be mentioned, and it is needless to say that they may be used in combination, but from the viewpoint of the weather resistance of the coating film, it is preferable to use aliphatic diisocyanates. .

In addition, terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid and 4,4'-diphenyl are typical polybasic acid components used in synthesizing the polyester component of the resins. Enyldicarboxylic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid, methyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid Adipic acid,
Reactivity of azelaic acid, pimelic acid, speric acid, sebacic acid or dimer fatty acid (dimer acid), or trimellitic acid, trimesic acid, pyromellitic acid or cyclopentanetetracarboxylic acid, or their alkyl esters or anhydrides Examples of the derivative include hexahydrophthalic acid, methylhexahydrophthalic acid, hexahydroterephthalic acid, and one or more kinds of various reactive derivatives thereof in an amount of 50 mol% or more in all polybasic acid components. When used as described above, the composition of the present invention is excellent in terms of curability and weather resistance of the coating film, as well as solubility and low viscosity, with less "repellence" in the cured coating film. Will be done.

As described above, these polybasic acid components should be appropriately selected in consideration of the physical properties of the coating film and the economical efficiency.

On the other hand, typical alcohol components used in synthesizing the polyester component of the resins include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,3-butanediol, Alkylene glycols such as 1,5-pentanediol, 1,6-hexanediol and neopentyl glycol; 1,4-cyclohexanedimethanol, bis-hydroxyethyl terephthalate, hydrogenated bisphenol A, or hydrogenated bisphenol A There are aromatic or alicyclic glycols such as alkylene oxide, and a monoepoxy compound can also be used in combination as the alcohol component, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol,
Polyester compounds such as dipentaerythritol, mannitol, or adducts of the various glycol components listed above with ε-caprolactone can also be used, but there is little "repellency" in the cured coating film, and this coating film From the viewpoint of weather resistance, the use of neopentyl glycol in an amount of 30 mol% or more of all alcohol components gives good results.

Therefore, these alcohol components should be appropriately selected according to the required performance of the cured coating film finally obtained.

In addition, typical fatty acids used in obtaining the alkyd resin include octylic acid, palmitic acid, and
Including stearic acid, versatic acid, oleic acid, linoleic acid, linoleic acid, coconut oil fatty acid, hydrogenated coconut oil fatty acid, tall oil fatty acid, castor oil fatty acid, dehydrated castor oil fatty acid, rice bran oil fatty acid, flaxseed oil fatty acid, large oil fatty acids, but saturated or unsaturated monobasic acids such as C ₈ or longer chains, such as safflower oil fatty acids, which are soluble in solvents such, the weather resistance and economic efficiency of the coating film in consideration Should be selected accordingly.

In this way, the polyester component used for preparing the alkyd resin, oil-free alkyd resin and / or urethane resin is obtained. In addition to the above, the total polybasic acid component and the total polybasic acid component, respectively, as the polyester forming component are obtained. 40 to 90 based on the total amount of alcohol
It is also possible to use a polyester component obtained by adding ε-caprolactone in the range of mol%. In such a case, the occurrence of "repellency" in the cured coating film is small and the cured coating film can be easily removed. The composition of the present invention having excellent flexibility is provided.

Thus, the hydroxyl group-containing resins (A) used in the present invention can be obtained, and the alkyd resin, oil-free alkyd resin and / or urethane resin can be used alone or as a mixture of two or more thereof. It is needless to say that such a vinyl resin and an alkyd resin, an oil-free alkyd resin and / or a urethane resin can be used as a mixture, and for example, in the case of obtaining the composition of the present invention having good weather resistance, In the case of using a large amount of vinyl resin and obtaining the composition of the present invention having good flexibility, by using a large amount of alkyd resin, oil-free alkyd resin and / or urethane resin, The coating film performance can be adjusted arbitrarily.

Next, the above-mentioned methylbutyl mixed alkylated methylolmelamine (B) is a methylolmelamine obtained by reacting melamine with a methylolating agent such as formaldehyde from an n-butyl group, an iso-butyl group and a sec-butyl group. It refers to an alkylated product of at least one butyl group and a methyl group selected from the group consisting of:

To prepare the methylbutyl-mixed alkylated methylol melamine (B), for example, 1 to 1 mol of melamine is reacted with 3 to 15 mol, preferably 5 to 10 mol of a methylolating agent such as formaldehyde. Is a slightly alkaline solution and produces polymethylolmelamine in a form in which the methylol groups are added in a ratio of 3 or more, preferably 5 to 6 per 1 of the melamine nucleus.
Then, methylation is further carried out using 10 mol or more of methanol for the methylol compound in the presence of an acidic catalyst. Alternatively, hemiformal may be used from the beginning so as to obtain a methylated product similarly to methylolation.

In such a case, the water produced from methylolmelamine by the methylation reaction and the water remaining during the methylolation reaction are removed under reduced pressure under slightly alkaline conditions.

This vacuum concentrate, or by further adding 10 mol or more of methanol to produce substantially completely methylated methylolmelamine by a known method in the presence of an acidic catalyst,
1 in vacuum concentrate from which methanol and water were removed under reduced pressure
Butylation is carried out by a known method in the presence of an acidic catalyst by adding a molar amount of butanol.

At this time, preferably, butanol is added at a ratio of 1 mol or more with respect to methylolmelamine in which 4 or more methylol groups are methylated per 1 melamine nucleus,
A slow reaction is carried out in the presence of an acidic catalyst at a temperature of 80 ° C or lower to remove the by-produced methanol and water out of the system, and to promote the condensation reaction by suppressing the formation of inconvenient methylene bonds. Good.

A viscous liquid is obtained by removing the unreacted alcohol content from the methylbutyl-mixed alkylated methylolmelamine thus produced under a slightly alkaline reduced pressure. Among the methylbutyl-mixed alkylated methylolmelamine (B), Preferably for one of the methyl groups
Those in which there are 0.1 to 10, more preferably 0.2 to 5, butyl groups are suitable.

Next, the above-mentioned fine particle polymer (C) is added in order to impart pseudoplastic viscosity behavior to the mixture of the components (A) and (B) detailed above.

Such a mixture of both components (A) and (B) exhibits substantially Newtonian flow characteristics, and it has no yield value or has a small yield value. "Sagging" is likely to occur when the coating work is performed vertically, or when the temperature rises during baking, and the compounds belonging to the component (A) also become components (B). Since the compounds to which they belong are both relatively low-molecular-weight substances, there is a drawback that "repellency" easily occurs during coating or baking.

However, as in the present invention, such (A),
By adding and blending the fine particle polymers (C) to the mixture of (B) both components, the apparent viscosity during standing is increased, but when high shearing force is applied to such a system, That is, during spraying, the viscosity becomes sufficiently low, so that the spraying work becomes easy, and the structural viscosity is developed within a short time of several seconds to several minutes after applying the base material. result,
Film defects such as "repellency" and "dripping" do not occur.

By the way, the fine particle polymers (C) refer to polymers that can be stably dispersed in the mixture of the above-mentioned component (A) and component (B) while maintaining the particle shape. is there.

Here, "the particles can be stably dispersed in the shape of the particles" means that in the medium in which the polymer in question exists, the difference in polarity or the difference in affinity between the medium and the polymers. Therefore, if the shape of the particles is retained, the polymers and the medium can be easily dissolved, that is, if the affinity between them is strong, a particulate structure is formed in the medium. It may be in the form of having some kind of chemical bond.

Specific examples of the fine particle polymers (C) include inorganic compounds represented by fine powder silica, and organic compounds represented by low molecular weight polyolefin polymers or non-aqueous dispersion type polymers. There are some. Among these, particularly preferred are non-aqueous dispersion type polymers.

Such non-aqueous dispersion-type polymers, as is known, in a solvent such as an aliphatic or alicyclic hydrocarbon-based segment and a segment soluble in these solvents, on the other hand, insoluble in these solvents, or In the presence of a dispersion stabilizer having a swellable segment, the monomer is soluble in the solvent but the polymer is insoluble in the solvent (hereinafter, abbreviated as nuclear monomer). .) Is polymerized by a conventional method to chemically or physically bind to the dispersion stabilizer as described above, and has a particle shape capable of being stably dispersed in the solvent. It refers to a kind.

The method for preparing such non-aqueous dispersion type polymers is specifically described as follows.

That is, first, the solvent used is non-polar and has a relatively small dissolving power, and the polymer formed from the above nuclear monomers (hereinafter abbreviated as a nuclear polymer) does not dissolve, but the above-mentioned dispersion stability Any solvent can be used as long as it can dissolve or swell the agent, and typical solvents include aliphatic hydrocarbons such as hexane, heptane, and octane; petroleum benzine, ligroin, mineral spirits. , Petroleum naphtha, kerosene, and other hydrocarbon mixtures having a boiling point of 30 to 300 ° C .; cyclohexane, methylcyclohexane, ethylcyclosan, alicyclic hydrocarbons, and mixtures thereof.

In some cases, in addition to these aliphatic hydrocarbons, hydrocarbon mixtures and / or alicyclic hydrocarbons, up to about 70% by weight of all solvents, aromatic hydrocarbon-based, ester-based, You may use what included the polar compound of alcohol type, ketone type, ether type, etc.

The amount of the solvent used is appropriately in the range such that the solid content of the obtained non-aqueous dispersion type polymers is 30 to 70% by weight, preferably 40 to 60% by weight.

Typical examples of the dispersion stabilizer include unsaturated bond-containing polymers such as i polybutadiene and polyisoprene, and one or more kinds of various kinds of nuclear monomers as described below. A graft copolymer obtained by polymerization, or a graft copolymer obtained by copolymerizing the above-mentioned unsaturated bond-containing polymers with a nuclear monomer and (meth) acrylic acid as described below, Glycidyl (meth) is added to the carboxyl group in this latter graft copolymer.
Unsaturated bond-containing graft copolymer obtained by addition reaction of unsaturated bond-containing epoxy compound such as acrylate; ii alkyd resin; iii alkyl etherified melamine resin condensate etherified with C _{4 to} C ₁₂ alkyl alcohol Which is soluble in various solvents as described above; iv The carboxyl group at the terminal position of the self-condensation polyester of a hydroxyl group-containing saturated fatty acid such as 12-hydroxystearic acid, the unsaturated bond-containing epoxy compound described above. A graft copolymer obtained by polymerizing a terminal-unsaturated bond-containing graft copolymer obtained by addition with a core monomer as described below, or the above-mentioned terminal unsaturated bond-containing polyester and the core monomer as described below. And (meth) acrylic acid are copolymerized, and then the unsaturated group is added to the carboxyl group. Unsaturated bond-containing graft copolymer obtained by addition reaction of a containing epoxy compound; or vn-butyl (meth) acrylate, iso-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, (Co) polymers obtained by mainly copolymerizing (meth) acrylic acid esters of C ₄ or higher alkyl alcohols such as stearyl (meth) acrylate and optionally copolymerizing other vinyl monomers, A copolymer obtained by copolymerizing (meth) acrylic acid ester of C ₄ or more alkyl alcohol as a main component, and copolymerizing this with (meth) acrylic acid and optionally other vinyl-based monomer Unsaturation obtained by addition reaction of the above unsaturated bond-containing epoxy compound with the carboxyl group in Compound-containing copolymers, graft copolymers obtained by copolymerizing the unsaturated bond-containing polymers with one or more of the following nuclear monomers, and the unsaturated bond-containing copolymers. Unsaturated bond obtained by addition-reacting the above unsaturated bond-containing epoxy compound to the carboxyl group in the copolymer obtained by copolymerizing the above-mentioned nuclear monomers with (meth) acrylic acid Including graft copolymers.

Of these, the dispersion stabilizers of the above-mentioned groups ii and iii and the dispersion stabilizers of the above-mentioned group v, respectively,
(Co) polymers containing alkyl esters of (meth) acrylic acid as a main component, which are esterified with an alkyl alcohol of C ₄ or more, or unsaturated bond-containing copolymers derived from the (co) polymers When polymers are used as dispersion stabilizers, none of these dispersion stabilizers have the solvent-insoluble segment as mentioned above, but they are still of this class. When the non-aqueous dispersion type polymers are prepared by using the above, the above-mentioned solvent-insoluble segment is formed at the initial stage of the polymerization of the core monomers to obtain the desired non-aqueous dispersion type polymers.

Here, as the core monomers, various monomers such as those used in obtaining the hydroxyl group-containing polymers (A) can be directly applied, and a hydroxyalkyl ester of (meth) acrylic acid can be used. s, the unsaturated bond-containing hydroxyalkyl esters monocarboxylic acids, unsaturated bond-containing polyhydroxyalkyl esters, to the like C ₁ -C ₃ consisting of alcohol (meth) acrylic acid alkyl esters or cyano group-containing monomers, On the other hand, typical examples of the other monomer copolymerizable with the core monomers include (meth) acrylic acid alkyl esters of C ₄ or higher alcohols; dialkyl esters of unsaturated dicarboxylic acids as described above. Kinds; Perfluoroalkyl group-containing vinyl esters; α-Olefins; Aromatic vinyl mono -Vinyl halides (vinylidene) s; acid anhydride group-containing monomers; carboxylic acid amide group-containing monomers; sulfonic acid amide group-containing monomers; tertiary amino group-containing monomers; phosphoric acid ester bond-containing monomers; or Examples thereof include sulfonic acid group-containing monomers or their organic amine salts.

In addition to the dispersion stabilizers listed above, the dispersion stabilizer in the form of having a hydrolyzable silyl group and the bond between the solvent-soluble segment and the insoluble segment are hydrolyzed. It is known that a dispersion stabilizer and the like, which is carried out by the reaction of a polymerizable silyl group and a group capable of reacting with the silyl group, can give stable non-aqueous dispersion type polymers, The present inventors have confirmed that these classes of non-aqueous dispersion type polymers are extremely useful as the fine particle polymers (C) used in the present invention.

The dispersion stabilizer having such a hydrolyzable silyl group is
It can be prepared by the following method.

That is, for example, the main component is an alkyl ester of (meth) acrylic acid esterified with an alkyl alcohol having a carbon number of ₄ or more as shown by v above, and these are used together with a hydrolyzable silyl group-containing monomer such as γ- ( (Meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane,
one of γ- (meth) acryloyloxypropylmethyldimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinylmethyldiethoxysilane, vinyltris (β-methoxyethoxy) silane or allyltrimethoxysilane or A method in which two or more kinds are copolymerized with another copolymerizable monomer, or a polymer (stem polymer) obtained by such a method, and a group capable of reacting with a hydrolyzable silyl group as described above, For example, hydroxyl and /
Alternatively, a method in which a monomer having a carboxyl group and one or more of the above-described core monomers are graft-copolymerized can be applied.

Among these methods, in the case of the former method, a group capable of reacting with the silyl group in the hydrolyzable silyl group-containing monomer as described above (carboxyl group, hydroxyl group, etc.)
Therefore, it is necessary to use monomers having N as a nucleus monomer, and by doing so, the nucleus monomers having a group capable of reacting with a silyl group contribute to the bonding of the grafting point.

By the way, when the obtained non-aqueous dispersion type polymers are not dissolved in the above-mentioned mixture of the respective components (A) and (B), the fine particle polymers (C However, in the case where it can be dissolved, on the contrary, formation of a structure capable of maintaining the particles of the non-aqueous dispersion type polymer (for example, formation of an insoluble portion)
In order to achieve this, it is necessary to intramolecularly cross-link the core portion to be a non-aqueous dispersion type polymer.

As a method for performing such intramolecular cross-linking, a method of using a pair of monomers having two kinds of functional groups capable of reacting with each other in combination with core monomers, or a polyfunctional vinyl-based monomer, that is, at least 2 in one molecule Examples include a method in which a vinyl-based monomer having a single unsaturated bond is used in combination with nuclear monomers.

Among these intramolecular cross-linking methods, as in the former method, a typical combination of two types of functional groups capable of reacting with each other or a combination of monomers having such a functional group includes an epoxy group and an epoxy group. Examples of carboxyl groups include (β-methyl) glycidyl (meth) acrylate and (meth) acrylic acid, and examples of acid anhydride groups and hydroxyl groups include maleic anhydride and β-hydroxyethyl (meth) acrylate. , An example of an isocyanate group and a hydroxyl group is β-
Isocyanate ethyl (meth) acrylate and β-hydroxyethyl (meth) acrylate, for example, isocyanate group and amino group, β-isocyanate ethyl (meth) acrylate and allylamine, hydroxyl group and methylol group or alkyl etherified methylol Examples of groups are β-hydroxyethyl (meth) acrylate and n-butyl ether of N-methylol (meth) acrylamide, and examples of hydrolyzable silyl groups and hydroxyl groups are γ- (meth) acryloyloxypropyl. Examples of hydrolyzable silyl groups and carboxyl groups of trimethoxysilane and β-hydroxyethyl (meth) acrylate include combinations of γ- (meth) acryloyloxypropyltrimethoxysilane and (meth) acrylic acid. Yes, also hydrolyzable silyl Examples of between .gamma. (meth)
Acryloyloxypropyltrimethoxysilane may be used alone, or two types may be appropriately selected from the above-mentioned various hydrolyzable silyl group-containing monomers.

These two kinds of monomers forming a pair are reacted as a part of the core monomers at the same time as the non-aqueous dispersion polymerization, or are heated at the end of the non-aqueous dispersion polymerization to be reacted.
Further, in order to promote such a reaction, intramolecular crosslinking may be carried out by allowing a known and commonly used catalyst to coexist and react.

On the other hand, in the case of the latter intramolecular cross-linking method in which the polyfunctional vinyl-based monomer is used in combination with the core monomer, the polyfunctional vinyl-based monomer as shown below is used as the core monomer in the same manner as the former method. By polymerizing as a part, a non-aqueous dispersion type polymer can have a cross-linking structure. Typical examples of such polyfunctional vinyl-based monomers are ethylene glycol di (meth) acrylate or trimethylol. Examples include propane tri (meth) acrylate.

As the fine particle polymers (C) used in the present invention, the same functional group capable of reacting with the component (B), that is, a hydroxyl group is introduced into both the dispersion stabilizer and the core monomers. The use of water-dispersible polymers is especially preferred.

This is because when the composition of the present invention forms a cured coating film, both the dispersion stabilizer portion and the core portion of the non-aqueous dispersion type polymer react with the curing agent (curing resin). This is because a uniform and highly transparent coating film can be obtained.

As described above, in order to prepare such a non-aqueous polymer dispersion, it is sufficient to polymerize the dispersion stabilizer and the core monomers in the presence of the solvents as described above. For example, the radical polymerization initiator as described above and, if necessary, the above chain transfer agent can be used.

The amount of the fine particle polymers (C) used as described above is appropriately in the range of 0.1 to 100 parts by weight based on 100 parts by weight of the total amount of the components (A) and (B). Is.

Further, as the above-mentioned solvents (D), the solvents already used in the preparation of the component (A) or the component (C) can be applied as they are or in the form of a combination, and the types and the combinations thereof can be used. It goes without saying that the composition and the like in the case of mixing should be determined according to the type of coating method and baking conditions.

The amount of the solvent (D) used in that case should be kept as small as possible. In order to meet the purpose of the present invention, 50% by weight or less, preferably 5 to 30% by weight. It should be within the range.

As described above, the high solid content coating composition of the present invention can be obtained. In the composition of the present invention, if necessary, pigments, various resins, and known conventional flow control agents, color components Antioxidants, antioxidants or UV absorbers, silane coupling agents and curing catalysts can be added.

Among them, typical examples of pigments include titanium oxide, inorganic pigments such as carbon black, or organic pigments such as quinacridone, azo, and phthalocyanine, and various types such as aluminum powder, copper powder, and zinc powder. Metal powder and the like, typical resins include nitrocellulose, cellulose acetate butyrate such as fibrin resin, ketone resin, petroleum resin, etc., and typical silane coupling agents. Include γ-aminopropyltrimethoxysilane, γ-glycidoxypropylmethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane and γ-mercaptopropyltrimethoxysilane.

Typical examples of the above curing catalyst include paratoluene sulfonic acid, or "Betcamine P-198" (produced by Dainippon Ink and Chemicals, Inc.), "Nakeyour 155,25".
00X, X49-110,5225 or 3525 "(made by US King Company). The amount of the catalysts used may be appropriately selected depending on the baking temperature and the baking time.

The coating composition of the present invention is applied by a conventional method such as spray coating, brush coating, roll coater coating, and the like.
A cured coating film can be obtained by baking at a temperature range of 60 to 180 ° C. for 10 to 40 minutes.

[Use of the present invention]

Thus, the high solid content coating resin composition of the present invention can be applied especially for general baking of home electric appliances and the like, or for automobiles, more specifically, as an enamel paint for automobiles, as a metallic base paint. , Or can be used as a clear paint, respectively.

Next, the present invention will be described in detail with reference to Reference Examples, Examples and Comparative Examples. In the following, all parts and% are based on weight unless otherwise specified.

Reference Example 1 [Preparation example of hydroxyl group-containing polymers (A)] 160 parts of xylene and 1 part of n-butyl acetate were placed in a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser.
60 parts were charged and heated to 125 ° C. under a nitrogen atmosphere to obtain 120 parts of styrene, 180 parts of n-butyl acrylate, 120 parts of n-butyl methacrylate, 108 parts of β-hydroxypropyl acrylate and β-hydroxy. 66 parts of propyl methacrylate and 6 parts of acrylic acid, 80 parts of n-butanol, 48 parts of tert-butyl peroxyoctate
Part, 3 parts of di-tert-butyl peroxide and 12 parts of azobisisobutyronitrile were added dropwise over 8 hours, and after the addition was completed, the mixture was kept at the same temperature for 15 hours to give a nonvolatile content ( NV) is 60%, Gardner color (G.
A solution of a hydroxyl group-containing vinyl polymer (A) having a C.) of 1 or less, a Gardner viscosity at 25 ° C. (the same applies below) of E, and a ▼ of 3,000 was obtained. Hereinafter, this will be abbreviated as polymers (A-1).
The OHV was 109.

Reference Example 2 (Same as above) In a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reaction product water distiller, 215 parts of adipic acid and 63.8 mol% of all polybasic acid components, hexahydrophthalic anhydride. Of 400
Parts, 44.6 parts of trimethylolpropane, 50 parts of ethylene glycol and 390.2 parts of neopentyl glycol corresponding to 76.7 mol% of all alcohol components, and gradually heated to 230 ° C over 5 hours under a nitrogen atmosphere. Then, it was kept at the same temperature until the acid value became 10, and an oil-free alkyd resin having OHV of 111 and ▲ ▼ of 1,010 was obtained.

Then, the resin is cooled to 100 ° C. or lower, and xylene 250
Parts were added to obtain an oil-free alkyd resin solution having an NV of 80%. Hereinafter, this is abbreviated as polymers (A-2).

Reference Example 3 (Same as above) 83.2 parts of adipic acid, 400 parts of hexahydrophthalic anhydride corresponding to 82 mol% of all polybasic acid components, 61.1 parts of trimethylolpropane and 90 mol% of all alcohol components
The same procedure as in Reference Example 2 was repeated except that 423 parts of neopentyl glycol was charged to obtain an oil-free alkyd resin.

Then, the resin is cooled to 100 ° C. or lower and 250 g of xylene is added.
Part and 0.1 part of dibutyltin dilaurate are added, and the temperature is 65 ° C.
While maintaining the same temperature, 100 parts of hexamethylene diisocyanate was gradually added dropwise over 2 hours while paying attention to heat generation, and after the addition was completed, the temperature was increased to the same temperature for 2 hours and then to 80 ° C. Then, the solution was kept for 1 hour to obtain a solution of a partially urethanized oil-free alkyd resin having an NV of 80%. Hereinafter, this is abbreviated as a polymer (A-3). The OHV of the solid component of this is 118, and ▲ ▼ is
It was 1,070.

Reference Example 4 (same as above) 157.4 parts of adipic acid, 64.4 mol% in all polybasic acid components
Hexahydrophthalic anhydride corresponding to 300 parts, trimethylolpropane 203.8 parts, neopentyl glycol corresponding to 59 mol% of the total alcohol components 230 parts and 200 parts except that palm oil fatty acid was charged, Reference example 2
In the same manner as above, react until the acid value reaches 10
An 80% solution was obtained. Hereinafter, this is abbreviated as a polymer (A-4), but the OHV of the solid component of this is 125, and ▲ ▼ is 1,140.

Reference Example 5 (Same as above) A reactor similar to that of Reference Example 1 was charged with trimethylolpropane.
134 parts (1 mol) and 684 parts of ε-caprolactone (6
Mol) and 0.04 part of tetrabutyl titanate.
The temperature was raised to 180 ° C. and the temperature was kept for 10 hours to obtain a lactone-added polyester resin. Hereinafter, these are abbreviated as polymers (A-5), but these have a NV of 100%, a Gardner viscosity of X, an OHV of 206, and a ▲ ▼ of 82.
It was 0.

Reference Example 6 (Same as above) NV was 60 in the same manner as in Reference Example 1 except that 320 parts of "LAWS" (product of Ciel, Netherlands) was used instead of xylene and n-butyl acetate. %, GC is 1
Below, a solution of a hydroxyl group-containing vinyl polymer (A) having a Gardner viscosity of F was obtained. Hereinafter, this will be abbreviated as polymers (A-6).
OHV was 109 and ▲ ▼ was 3,100.

Reference Example 7 [Preparation Example of Fine Particle Polymers (C)] In a reactor equipped with a stirrer, a thermometer and a cooling tube, 12-
Esterification was carried out by charging 1,800 parts of hydroxystearic acid and raising the temperature to 220 ° C. At that time, during the temperature rise
Since it melts at 72 ° C or higher, start stirring at the same time as this melting.

Dehydration was started at about 190 ° C, and esterification was allowed to proceed until the acid value reached about 38.

After the reaction for about 7 hours in this way, the self-condensing polyester obtained by cooling and then taking out had NV
At 100%, the Gardner viscosity (G.Vis.) At 25 ° C is Z ₁
It was a viscous polymer with a Gardner color (GC) of 15 and an acid value of 38. Hereinafter, this is an intermediate (m-
Abbreviated as 1).

Separately, in a reactor similar to that of Reference Example 1, 45 of the intermediate (m-1) was added.
0 part, 330.5 parts of -n-butyl acetate, and this intermediate (m
-1) 46 parts of glycidyl methacrylate equivalent to the carboxyl group in 1), 1.0 part of 2-methylimidazole and 1.0 part of hydroquinone were charged and heated to 130 ° C, and the reaction was continued at the same temperature for 6 hours. Then, glycidyl methacrylate was added to the intermediate (m-1). The reaction at this time may be carried out while tracing the acid value.

The polyester containing the terminal unsaturated bond thus obtained is NV
Was 60%, G.Vis. Was A ₁ , GC was 15, and the acid value was 1 or less. Hereinafter, this is abbreviated as an intermediate (m-2).

Separately, “Isopar E” was added to the same reactor as in Reference Example 1.
(American exon aliphatic hydrocarbon mixture; bp = 115
˜142 ° C.), 207 parts of which was heated to 105 ° C., 167 parts of the intermediate (m-2), and 47.5% of methyl methacrylate.
Part, 2.5 parts of acrylic acid, 30.5 parts of toluene, 4.5 parts of tert-butyl peroxyoctoate, 0.8 parts of tert-butyl peroxybenzoate and 0.9 parts of azobis-iso-butyronitrile over 4 hours. After dropping, raise the temperature to 110 ° C immediately after the dropping and
After holding for 0 hour, a dispersion stabilizer was obtained. Hereinafter, this is abbreviated as a dispersion stabilizer (S-1), but this is NV
Was 35%, G.Vis. Was A ₂ , and GC was 10.

Separately, 200.2 parts of "Isopar E" was charged in the same reactor as in Reference Example 1 and heated to 100 ° C, and 167.7 parts of methyl methacrylate and 1 part of ethyl acrylate were added at the same temperature.
04.8 parts, β-hydroxyethyl methacrylate 69.9
Parts, 3.3 parts of glycidyl methacrylate, 3.7 parts of methacrylic acid, 3.4 parts of azobis-iso-butyronitrile and 69.5 parts of dispersion stabilizer (S-1), 0.7 parts of 2-methylimidazole and "Isopar E". A mixture consisting of 331.7 parts was added dropwise over 8 hours, and after the completion of the addition, the mixture was kept at the same temperature for 10 hours for reaction to obtain a dispersion liquid of fine particle polymers (C). Hereinafter, the polymer (C-
It is abbreviated as 1), but this is a milky white dispersion liquid having NV of 45% and G.Vis. Of A ₅ .

Reference Example 8 (same as above) A reactor similar to that of Reference Example 1 was charged with 170 parts of “Isopar E” and 67.5 parts of n-butanol and heated to 105 ° C., and at the same temperature, 465 of 2-ethylhexyl acrylate was added.
Parts, 10 parts of β-hydroxypropyl acrylate and 25 parts of γ-methacryloyloxypropyltrimethoxysilane and 5 parts of tert-butyl peroxyoctoate.
Part, 2 parts of tert-butylperoxybenzoate and 100 parts of "Isopar E" were added dropwise over 4 hours, and after the addition was completed, the mixture was reacted at the same temperature for 10 hours to give a dispersion stabilizer ( S-2) was obtained.

This was a polymer solution having an NV of 60%, G.Vis. Of A ₁ , and GC of 1 or less.

Separately, in a reactor similar to that of Reference Example 1, a dispersion stabilizer (S-
166.7 parts of 2) and 400 parts of "Isopar E" were charged and heated to 90 ° C in a nitrogen stream, then while maintaining the same temperature, 360 parts of methyl methacrylate, 360 parts of ethyl acrylate, β-hydroxyethyl Acrylic 153
Part, 9 parts of glycidyl methacrylate, 18 parts of acrylic acid
Part, 3 parts of tetrabutyl titanate, 1 part of 2-methylimidazole, 200 parts of "Isopar E" and tert-
A mixture of 13.5 parts of butyl peroxy octoate was added dropwise over 4 hours, and after the completion of the addition, the mixture was kept at the same temperature for 10 hours and reacted to obtain a dispersion liquid of fine particle polymers (C). Hereinafter, abbreviated this polymer compound and (C-2), this compound NV is 60%, and G.Vis. Is Atsuta opalescent dispersion comprising A _3.

Reference Example 9 (same as above) 166.7 parts of the dispersion stabilizer (S-2) was used as it was, and 400 parts of methyl methacrylate was added as a mixture for dropping.
Parts, 322 parts of ethyl acrylate, 160 parts of β-hydroxyethyl acrylate, 3 parts of tetrabutyl titanate
Parts, "isopar E" 200 parts and tert-butyl peroxyoctoate 13.5 parts were used in the same manner as in Reference Example 8 except that the mixture was changed to obtain a target fine particle polymer (C). . Hereinafter, the polymer (C-
3), this has 60% NV and G.Vis.
Was obtained as a milky white dispersion liquid of A ₄ .

Reference Example 10 [Preparation Example of Methylated Methylol Melamine] In a two-necked three-necked flask equipped with a stirrer, a thermometer, and a deintegrator trap, 126 parts (1 mol) of melamine and 337.5 parts of 9% of 80% paraformaldehyde (9 Mol) and adjust the pH to 8 with a 10% aqueous sodium hydroxide solution.
Adjust to 5-9.5, react at 70 ℃ for 2-3 hours, add 640 parts (20 mol) of methanol, and add 90% sulfuric acid to pH.
Was adjusted to 1.6-2.0, reacted at 40 ℃ for 4 hours, then
A viscous target liquid substance with NV of 98.3% and G.Vis. Of X, adjusted to a slightly alkaline pH of 7.0 to 8.0 with a 50% aqueous sodium hydroxide solution, and then filtered and concentrated under reduced pressure. Got

It was confirmed from the result of gas chromatographic analysis of a phosphoric acid decomposition product that this product had 5.5 methyl groups per melamine nucleus and was methylated methylolmelamine with almost no free methylol groups. . Hereinafter, this is abbreviated as melamine resin (B'-1).

Reference Example 11 [Preparation example of methylbutyl mixed alkylated methylol melamine (B)] In a flask similar to Reference Example 10, 390 parts (1 mol) of the melamine resin (B'-1) obtained in Reference Example 10 (1 mol), n 8 charged with 296 parts (4 moles) of butanol and 0.37 parts of phosphoric acid
The reaction was carried out by heating at 0 ° C. for 3 hours, and after the reaction was completed, 3.8 parts of quick lime was added to neutralize and then allowed to pass.

Next, the excess is concentrated under reduced pressure at a bath temperature of 70 ° C or lower, and the NV
Was 96.7% and G.Vis. Was Z to give a colorless and transparent viscous target concentrate.

From the result of gas chromatographic analysis of the phosphoric acid decomposition product, it was confirmed that this was a methylbutyl-mixed alkylated methylolmelamine having 0.33 n-butyl groups per methyl group. Hereinafter, this is abbreviated as melamine resin (B-1).

Examples 1-12 and Comparative Examples 1-9 Polymers (A-1)-(A- obtained in Reference Examples 1-6
6) each of the hydroxyl group-containing polymers (A), the melamine resin (B'-1) or (B-1) obtained in Reference Example 10 or 11, and the weight obtained in Reference Examples 7 to 9 Union (C
-1) to (C-3) fine particle polymers (C) are mixed with a pigment and a curing catalyst, if necessary, in a composition as shown in Table 1 to form a paint, and then "Solvetsuso". Ten
0 "(Aromatic hydrocarbon mixture manufactured by Exxon, USA) / n-
Various paint solutions were obtained by adjusting the spray viscosity with a diluted thinner of butanol / cellosolve acetate = 60/20/20 (volume ratio).

Then, each of the paints was separately coated on a 0.8 mm thick mild steel plate so that the dry film thickness was about 35 μm, set for 30 minutes, and then baked at 140 ° C. for 30 minutes.

The results of the performance evaluation of each cured coating film thus obtained are summarized in the same table.

As is clear from the results shown in Table 1, the composition of the present invention can achieve high solidification, and the cured coating film obtained from the composition of the present invention is particularly excellent in hot water resistance and acid resistance. It is known to be a thing.

Claims (10)

[Claims] 1. (A) 90 to 30 parts by weight of hydroxyl group-containing polymers, (B) 10 to 70 parts by weight of methylbutyl mixed alkylated methylol melamine, (C) a mixture of the above hydroxyl group-containing polymers (A) and methylbutyl. A high solid content coating composition comprising 0.1 to 100 parts by weight of fine particle polymers and (D) an appropriate amount of solvents as essential components to 100 parts by weight of the total amount of alkylated methylol melamine (B). object. 2. The hydroxyl group-containing polymer (A) is 50
The composition according to claim 1, which is a vinyl polymer having a number average molecular weight of 0 to 8,000 and a hydroxyl value of 40 to 250. 3. The hydroxyl group-containing polymer (A) is 20
It is at least one (condensed) polymer selected from the group consisting of alkyd resins, oil-free alkyd resins and urethane resins having a number average molecular weight of 0 to 3,000 and a hydroxyl value of 40 to 600. The composition according to claim 1, wherein 4. The hydroxyl group-containing polymer (A) is a polybasic acid component containing one or more of hexahydrophthalic acid, methylhexahydrophthalic acid, hexahydroterephthalic acid or their reactive derivatives. As obtained by using 50 mol% or more of all the acid components as the alkyd resin having a number average molecular weight of 200 to 3,000 and having a hydroxyl group of 40 to 600, selected from the group consisting of oil-free alkyd resins and urethane resins. At least one (curly)
The composition according to claim 1 or 3, which is a polymer. 5. The hydroxyl group-containing polymer (A) is 50
A vinyl polymer having a number average molecular weight of 0 to 8,000 and a hydroxyl value of 40 to 250, an alkyd resin having a number average molecular weight of 200 to 3,000, and a hydroxyl value of 40 to 600, and an oil. The composition according to claim 1 or 3, which is a mixture with at least one (condensed) polymer selected from the group consisting of a free alkyd resin and a urethane resin. 6. The methylbutyl-mixed alkylated methylolmelamine (B) as described above is used in an amount of 0.1 to 1 methyl group.
Characterized in that it is an alkylated methylol melamine containing mixed alkyl in a proportion of ~ 10 butyl groups,
The composition according to claim 1. 7. The above-mentioned fine particle polymer (C) is a non-aqueous dispersion type polymer having both a segment soluble in an aliphatic or alicyclic hydrocarbon solvent and a segment insoluble in it. The composition according to claim 1, wherein 8. The above-mentioned fine particle polymer (C) is a non-aqueous dispersion type polymer having both a segment soluble in an aliphatic or alicyclic hydrocarbon solvent and a segment insoluble in the aliphatic or alicyclic hydrocarbon solvent. Each of the segments contains a hydroxyl group capable of reacting with the methylbutyl-mixed alkylated methylolmelamine (B),
The composition according to claim 1. 9. The fine particle polymer (C) is a non-aqueous dispersion type polymer having an intramolecular crosslinked structure in the segment as a segment insoluble in an aliphatic or alicyclic hydrocarbon solvent. The composition according to claim 1, characterized in that 10. The hydrolyzable silyl group and the silyl group of the fine particle polymer (C) as a bond between a segment soluble in an aliphatic or alicyclic hydrocarbon solvent and a segment insoluble in the solvent. The composition according to claim 1, which is a non-aqueous dispersion type polymer having a bond formed by a reaction between a group and a group capable of reacting with the group.