JPH0152424B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a curable resin composition for coating with excellent pigment dispersibility. More specifically, double bond-containing addition reaction products,
A copolymer obtained by polymerizing an unsaturated oil-free alkyd and a copolymerizable polymerizable monomer,
The present invention also relates to a novel resin composition containing a crosslinking component. A coating composition that combines a vinyl copolymer and a crosslinking component is characterized in that when the vinyl copolymer mainly consists of styrene and methyl methacrylate, the resulting coating film has good weather resistance, quick drying properties, durability, and resistance to yellowing. , has excellent performance in terms of solvent resistance and physical properties, and has excellent performance in terms of solvent resistance and physical properties.
It is already widely used for finishing aluminum sash, wood, plastic, slate, etc. However, due to its molecular structure, vinyl copolymers generally have poor compatibility with pigments when compared to algide resins, resulting in color separation during coating and pigment separation during storage, and therefore from a practical point of view. Therefore, there was a demand for improved pigment dispersibility. In order to improve the pigment dispersibility, for example, (a) an unsaturated dicarboxylic acid diester obtained by the reaction of an unsaturated dicarboxylic acid with a glycidyl ester of a tertiary aliphatic carboxylic acid, (b) an unsaturated oil Attempts have been made to use copolymers with free alkyds and (c) polymerizable monomers. (Japanese Patent Publication No. 53-766) To further explain this, the diester of unsaturated dicarboxylic acid as component (a) is It can be obtained as follows. In addition, as another method for improving the above-mentioned drawbacks, an oil- or fatty acid-containing unsaturated polyester,
It has also been proposed to use it in combination with an unsaturated trialkoxysilane monomer. (Japanese Unexamined Patent Publication No. 53-61694) However, even in a resin composition characterized by using an unsaturated dicarboxylic acid diester or an unsaturated trialkoxysilane monomer as described above, the coating film performance is sufficient for practical use. Pigment dispersibility could not be obtained. The present invention has been made to improve the drawbacks of the prior art as described above. That is, the present invention aims to provide a curable resin composition for coating that has excellent pigment dispersibility and excellent coating film performance. That is, the present invention provides A(a) obtained as a result of the reaction of (i) glycidyl ester of tertiary fatty acid carboxylic acid, (ii) saturated polycarboxylic acid anhydride, and (iii) hydroxyl group-containing unsaturated compound. Addition reaction product having one double bond in the molecule 5 to 95% by weight [However, the ratio of each of the above compounds is (i) epoxy group: (ii) acid anhydride group: (iii) hydroxyl Base=
0.8-1.2:1.0:0.8-1.2 (molar ratio)] (B) Mixture consisting of 95-5% by weight of unsaturated oil-free alkyd......5-45% by weight B. Copolymerizable polymer At least one type of sexual monomer...
This invention relates to a curable resin composition for coating with excellent pigment dispersibility, which is obtained by further blending a crosslinking agent component with a copolymer obtained by reaction with 95 to 55% by weight. One of the characteristics of the present invention is that 1
The purpose is to use an addition reaction product (a) containing double bonds. The reaction product (a) is synthesized by the following one-step reaction or two-step reaction. The production of the addition reaction product (a) containing one double bond in the molecule is preferably carried out in the presence of air in order to prevent ring opening of the double bond due to oxygen. The reaction temperature is 180°C or lower. Preferably
A range of 90 to 135°C is suitable. In the case of synthesis by the general reaction described above, the progress of the reaction can be confirmed by acid value measurement. Therefore, in the present invention, the acid value is set to 40 or less, preferably 20 or less. If the acid value exceeds 40, unreacted substances will remain and this will cause a decrease in the performance of the final coating film, which is not preferable. In addition, in the first step of the two-step reaction, the acid anhydride group of the acid anhydride

[Formula] and the hydroxyl group-containing unsaturated compound are reacted at 140°C or lower. That is, a ring-opening reaction of an acid anhydride group and an addition reaction (half-esterification) of a hydroxyl group are performed under conditions in which the formation of water is not observed, to obtain an esterified product containing a terminal carboxyl group. Then, in a second reaction, the esterified product is reacted with a glycidyl ester of a tertiary aliphatic carboxylic acid to obtain a double bond-containing addition reaction product. The end point of the first and second stage reactions can be determined by confirming the disappearance of the acid anhydride group in the first stage. However, since it is generally difficult to confirm by chemical analysis, it is desirable to use an infrared spectrophotometer. In the method using an infrared spectrophotometer, absorption due to acid anhydride groups appears sharply around about 1770 cm ^-1 and about 1850 cm ^-1 although it differs somewhat depending on the type of acid anhydride. Therefore, the progress of the first stage reaction can be determined by tracing these two absorptions, and can be quickly confirmed using this method. Next, the second stage reaction is carried out in the same temperature range as the first stage reaction. The end point of the reaction is when the acid value becomes 40 or less. Water may be produced in the one-stage or two-stage reaction. However, reactions under reaction conditions that produce water should be avoided in the present invention. This is because when water is produced, the acid anhydride and water react to open the acid anhydride group, thereby inhibiting the addition reaction of the hydroxyl group-containing unsaturated compound. The glycidyl ester of tertiary aliphatic carboxylic acid used to obtain the addition reaction product (a) containing one double bond in the molecule of the present invention includes:
Examples include compounds such as Cardiula E (trade name: Versatric acid glycidyl ester), neopentanoic acid glycidyl ester, neodecanoic acid glycidyl ester, neotridecanoic acid glycidyl ester, and the like. These may be used alone or as a mixture of two or more. In addition, as an anhydride of saturated polyhydric carboxylic acid,
Examples include phthalic anhydride, hexahydrophthalic anhydride, hexic anhydride, succinic anhydride, etc.
Trimellitic anhydride, pyromellitic anhydride, etc. can be used as necessary. These can be used alone or as a mixture. Furthermore, examples of unsaturated compounds containing hydroxyl groups include β-hydroxyethyl (meth)acrylate, β-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, or polyhydric alcohol and (meth)acrylic acid. Examples include monoesters of trimethylolpropane and acrylic acid, monoesters of glycerin and methacrylic acid, and monoesters of ethylene glycol and acrylic acid. These can be used alone or as a mixture. In the reaction to obtain the addition reaction product (a) containing one double bond in the molecule in the present invention, both the one-step reaction and the two-step reaction can be carried out without a catalyst. The following reaction catalysts may be used as necessary. For example, secondary and tertiary amines or their inorganic or organic acid salts such as dimethylamine hydrochloride, triethylamine, benzinedimethylamine 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethyl (aminomethyl)phenol, etc. Also organic acid salts, such as metal salts of naphthenic acid, octylic acid, linoleic acid, such as sodium phthalate, zirconium naphthenate, chromium naphthenate, lithium naphthenate, zinc octylate, chromium linoleate, etc. can.
Also, Lewis acids and their organic adducts such as boron trifluoride, boron trifluoride monoethylamine, metal halides such as lithium chloride, lithium bromide, tin chloride, etc., or metal hydroxides such as sodium hydroxide. , lithium hydroxide, etc., hydrogen halides such as hydrobromic acid, and alkyl titanates such as butyl titanate. Furthermore, sulfonic acids and sulfonium salts such as para-toluenesulfonic acid, triphenylsulfonium chloride, etc., phosphonic acids and phosphonium salts such as benzenephosphonic acid, triphenylmethylphosphonium, iodite, etc., and quaternary ammonium salts. is trimethylbenzyl ammonium chloride, etc. Also, imidazoles or their inorganic or organic adducts, such as 2-methyl-4-imidazole, 2-naphthyl-4,5-diphenylimidazole, and adducts such as 2- Examples include a cyanoethylene type obtained by reacting methylimidazole and acrylonitrile, an adduct of 2-methylimidazole and trimellitic acid, and others such as triphenylphosphine and triphenylantimony. These may be used alone or in mixtures. When using such a reaction catalyst, the reactant 100
About 0.01 to 10 parts by weight of catalyst are used. The optimum amount is preferably about 0.1 to 3.0 parts by weight. In the one-step reaction (i) in the present invention, the epoxy group of the glycidyl ester of a tertiary aliphatic carboxylic acid is parallel to the carboxyl group generated by the ring-opening reaction between the acid anhydride and the hydroxyl group-containing unsaturated compound. It follows the process of reacting. Therefore, the ring-opening reaction of the acid anhydride group proceeds with the hydroxyl group-containing unsaturated compound and also with the secondary alcohol produced by the reaction between the epoxy group and the carboxyl group. Therefore, in the case of a one-step reaction, in order to completely open the ring of the acid anhydride group, the ratio of hydroxyl group to 1 mol of acid anhydride group is required to be 0.8 to 1.2 mol, preferably 0.9 to 1.1 mol. be. If the amount of hydroxyl groups is less than 0.8 mole, acid anhydride groups may remain, and the
The reaction between component B and component B increases the viscosity of the system or deteriorates the performance of the final product, which is undesirable. Also, when the amount of epoxy groups in the glycidyl ester of tertiary aliphatic carboxylic acid is less than 0.8 mole, the remaining carboxyl groups increase;
If the amount exceeds 1.2 moles, the glycidyl ester remains, which deteriorates the pigment dispersibility and the water resistance of the final coating film, which is not preferable. In addition, when using a two-step reaction to obtain the addition reaction product (a), in order to improve the ring-opening reaction rate of the acid anhydride group, 1.0 mol or more of hydroxyl group is used per 1.0 mol of the acid anhydride group. It is preferable. Next, the unsaturated oil-free alkyd (b) used in the present invention is obtained from a polyhydric alcohol and a polyhydric carboxylic acid or its anhydride by a known esterification reaction. The polyhydric alcohol and polyhydric carboxylic acid are preferably combined so that the hydroxyl value of the unsaturated oil-free alkyd is 50 to 200 (solid content). The unsaturated oil-free alkyd in the present invention contains an unsaturated dicarboxylic acid in its raw material composition in order to exhibit excellent performance by copolymerizing with a double bond-containing addition reaction product and a polymerizable monomer. There is a need. The unsaturated dicarboxylic acid ranges from 0.3 to 10% by weight, preferably from 0.5 to 5.0% by weight. The reaction temperature during the production of unsaturated oil-free alkyd is set at 150 to 280°C, and the reaction is carried out while the produced water is successively removed. The end point of the reaction is determined by measuring the amount of water produced by the esterification reaction or the acid value. From the viewpoint of coating film performance, the acid value at the end of the reaction is preferably 50 or less. Examples of the polyhydric alcohol used in the production of the unsaturated oil-free alkyd of the present invention include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butanediol 1,3, butanediol 1,4, and butanediol. diol 2,3, pentanediol 1,5, hexanediol-1,
6, neopentyl glycol, 2,2,4-trimethylpentanediol-1,3, hydrogenated bisphenol A, 2,2-di(4-hydroxypropoxyphenyl)propane, glycerin, pentaerythritol diallyl ether, trimethylene Glycol, 2-ethyl-1,3 hexanediol, trimethylolpropane, cyclohexanedimethanol-1,4,2,2,4-tetramethylcyclobutanediol-1,3,1,4-bis(2-oxyethoxy) benzene, 2,2,4,
4-tetramethylcyclobutanediol-1,
3, etc., and these may be used alone or as a mixture. Saturated or unsaturated polycarboxylic acids or their acid anhydrides used in the production of unsaturated oil-free alkyds include maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, maleic anhydride, and phthalic anhydride. , isophthalic acid, terephthalic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, hettic acid, 3,6-endomethylenetetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, Examples include methylnadic acid, succinic acid, adipic acid, sepacic acid, azelaic acid, anthracene-maleic anhydride adduct, rosin-maleic anhydride adduct, and the like, and these may be used alone or as a mixture. Although the reaction of the unsaturated oil-free alkyd in the present invention can proceed without a catalyst, it is also possible to use a known reaction catalyst as necessary to shorten the industrial time. For example, tetrabutyl zirconate, zirconium naphthenate, tetrabutyl titanate, tetraoctyl titanate, tinn oxalate-sodium acetate mixture. Stannous oxalate-sodium acetate zinc acetate mixture,
Examples include tetraphenyltin, and the amount used is approximately 0.001 to 1.0 parts by weight per 100 parts by weight of the total formulation.
Parts by weight are used. Furthermore, the copolymerizable polymerizable monomer used in the composition of the present invention includes a monomer having a functional group such as a hydroxyl group, a carboxyl group, an amino group, an epoxy group, or a monomer having a functional group. At least one type of monomer. The polymerizable monomers used in the present invention include 0.3 to 35% by weight of a monoethylenically unsaturated monomer having a hydroxyl group and 0.3 to 35% by weight of a monoethylenically unsaturated monomer having a carboxyl group in terms of pigment dispersibility, curing speed, degree of curing, etc. The mixture is preferably 0.1 to 5.0% by weight, with the remainder consisting of other copolymerizable polymerizable monomers (total of 100 parts by weight). Examples of the polymerizable monomer include styrene, methylstyrene, chlorstyrene, tertiarybutylstyrene, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate.
Acrylate, lauryl (meth)acrylate,
β-Hydroxyethyl (meth)acrylate, β
-Hydroxypropyl (meth)acrylate, 4
-Hydroxybutyl (meth)acrylate, monoester of (meth)acrylic acid of glycerol trimethylolpropane, glycidyl (meth)acrylate, N-butoxymethyl (meth)acrylamide, N-tertiarybutyl (meth)acrylamide, dimethyl Aminoethyl (meth)acrylate, diacetone acrylamide, vinylpyrrolidone, N-methylolacrylamide, acrylamide, (meth)acrylic acid, crotonic acid,
Examples include vinyl acetate, (meth)acrylonitrile, ethylene glycol mono(meth)acrylate, and derivatives thereof. In the present invention, the components (a) and (b) are 5 to 5.
It is necessary to use it in a proportion of 95/95 to 5% by weight, preferably 10 to 90/90 to 10% by weight. These weight range limitations are determined from the viewpoint of pigment dispersibility. That is, 5% by weight of any component
If it does not meet the above criteria, the pigment dispersibility of the composition tends to decrease. Further, component (A) and component (B) are used in a ratio of 5 to 45/95 to 55% by weight, preferably 10 to 35/90 to 65% by weight. Component (A) is less than 5% by weight or 45% by weight
If it exceeds % by weight, the compatibility with the crosslinking agent, the gasoline resistance, water resistance, gloss, weather resistance, flexibility, hardness, etc. of the coating film, the pigment dispersibility of the composition, the painting workability, etc. This is not desirable as it will upset the balance. The copolymer obtained by copolymerizing components (A) and (B) in the present invention preferably has a hydroxyl value (solid content) in the range of 10 to 150. This range is preferable in terms of reactivity with the crosslinking agent and coating film performance. The hydroxyl value can be adjusted as appropriate, for example, during the reaction of component (A), by selecting raw materials for component (B), or by using a hydroxyl group-containing monomer in component (B). A crosslinking agent component is further added to the copolymer. As the crosslinking agent component used in the present invention, any compound that can react with the functional group in the copolymer, such as polyisocyanates, epoxy resins, and amino resins, can be used. Examples of the crosslinking agent components include Desmodyur N, Desmodyur L, Desmodyur 1L, Desmodyur HL (trade name manufactured by Bayer), Takenate D-110N, Takenate D-202 [trade name manufactured by Takeda Pharmaceutical Company Limited], and Burnok D. −750, Burnotsk
Polyisocyanates such as DN-950 [trade name manufactured by Dainippon Ink and Chemicals Co., Ltd.], or blocked isocyanates obtained by blocking these isocyanates with a known blocking agent; Epicoat
Epoxy resins such as 1001, Epicort 1004 (trade name manufactured by Ciel Corporation), Araldite 6071, Araldite 6084 (trade name manufactured by Ciba Corporation), Epiclon 1050, Epiclon 4050 [trade name manufactured by Dainippon Ink and Chemicals Co., Ltd.];
Other examples include alkoxylated melamine resins, alkoxylated urea resins, and alkoxylated guanamine resins. These crosslinking agent components can be used alone or as a mixture, and the amount used is customary depending on the type of copolymer, the curability of the composition, the performance of the final coating film, etc. Further, depending on the type of crosslinking agent component used, the resin composition can be a one-pack type or a two-pack type resin composition. The composition of the present invention thus obtained has a low viscosity,
In order to use component (a) with low hue,
A composition having a lower viscosity and a lower hue can be obtained compared to known compositions such as those disclosed in JP-A No. 766 and JP-A-53-61694. Therefore, it is very advantageous when a clear finish is required or when increasing the nonvolatile content of the copolymer. Furthermore, the coating composition of the present invention may contain known coloring pigments, extender pigments, dyes, various paint additives, modifiers, curing accelerators, reinforcing agents, etc., as necessary, within a range suitable for the application. Can be added. The coating resin composition of the present invention thus obtained can be applied by a known coating method such as brush, roller, dipping, or spray coating. The paint film after painting is kept at room temperature,
It is formed into a film using far infrared rays or baking drying. In the case of baking drying, a temperature of 50 to 200°C for 10 to 60 minutes is appropriate. The coating resin composition of the present invention can be applied not only to all fields in which acrylic resin compositions have conventionally been used, but also to other coating fields. Therefore, it has great industrial value. Hereinafter, the details of the present invention will be explained with reference to Examples.
"Parts" or "%" are expressed as "parts by weight" or "% by weight." Synthesis Example 1 Synthesis of double bond-containing addition reaction product by one-step reaction 350.2 parts of succinic anhydride (acid anhydride group) was added to two flasks equipped with a stirrer, condenser, thermometer, and air inlet.

[Formula] 3.5 moles), 468.5 parts of β-hydroxyethyl methacrylate (hydroxyl group, 3.6 moles), 875.0 parts of Cardiura E (trade name of Ciel Co., Ltd., 3.5 moles of epoxy group), and 1.6 parts of hydroquinone as a polymerization inhibitor, and air The reaction was carried out in an atmosphere at 125 to 130 ℃ for 3 hours to obtain 1695.3 parts of double bond-containing addition reaction product [A-1]. The double bond-containing addition reaction product had a color number of 1 or less, a viscosity (at 20° C.) of 120.5 Stokes poise, an acid value of 10.4, and a hydroxyl value of 117. Synthesis Example 2 Synthesis of double bond-containing addition reaction product by two-step reaction In the same flask as Synthesis Example 1, in the first stage, 350.2 parts of succinic anhydride (3.5 moles of acid anhydride group) and 468.5 parts of β-hydroxyethyl methacrylate were used. (3.6 moles of hydroxyl groups) and 1.5 parts of hydroquinone as a polymerization inhibitor, and
After carrying out the reaction for a time, approximately
When the amount of acid anhydride groups remaining around 1770 cm ^-1 and about 1850 cm ^-1 was measured, the reaction rate was 92%. Next, as a second-stage reaction, 875.0 parts of Cardiura E (3.5 moles of epoxy groups) and 0.5 parts of hydroquinone were added to the first-stage reaction product, and the reaction was carried out at 125°C for 2 hours to produce a double bond-containing addition reaction product [ A-2〕1695
I got the department. The reaction product had a color number of 1 or less, an acid value of 12.0, a hydroxyl value of 117, and a viscosity (at 20° C.) of 122.0 Stokes poise. Synthesis Example 3 Synthesis of unsaturated oil-free alkyd In a flask using a partial condenser instead of the condenser in Synthesis Example 1, 370.1 parts of neopentyl glycol (7.1 moles of hydroxyl group),
236.2 parts of trimethylolpropane (5.3 moles of hydroxyl group), 442.8 parts of isophthalic acid (5.3 moles of carboxyl group) and 207.7 parts of adipic acid (2.8 moles of carboxyl group) were charged and heated under a nitrogen gas atmosphere.
The reaction was carried out at 200°C for 2 hours and then at 210°C for 2 hours to obtain an esterified product with an acid value of 30.6. Next, 41.2 parts of fumaric acid (carboxyl group 0.7 mol, raw material composition
3.2%) and reacted at 210°C for 2.5 hours to obtain an unsaturated oil-free alkyd with an acid value of 14.5 and a hydroxyl value of 158. The alkyd was diluted with toluene to a nonvolatile content of 60% to obtain an unsaturated oil-free alkyd solution [B-1] having a viscosity (20° C.) of 5.0 stokes, an acid value of 8.7, and a hydroxyl value of 98. Example 1 73.5 parts of triol and 119.0 parts of isobutyl acetate were placed in flask 1 equipped with a stirrer, condenser, thermometer, and dropping device, and after raising the temperature to 110°C, the double bond-containing mixture obtained in Synthesis Example 1 was charged. Addition reaction product [A-1] 42.0 parts, unsaturated oil-free alkyd obtained in Synthesis Example 3 [B-1] 105.0 parts, styrene
A mixture consisting of 85.8 parts of methyl methacrylate, 80.9 parts of isobutyl acrylate, 27.7 parts of β-hydroxyethyl methacrylate, 1.8 parts of methacrylic acid, 80.5 parts of triol, 35.0 parts of isobutyl acetate, and 12.3 parts of benzoyl peroxide was added to the flask over 3 hours. The polymerization reaction was carried out while dropping into the solution, and after the completion of the dropping, the reaction was further carried out for 5 hours. The obtained copolymer solution [C-1] had a viscosity (20°C) of 4.8 Stokes, an acid value of 5.5, a hydroxyl value of 39,
The non-volatile content was 53.5%. Example 2 In Example 1, the double bond-containing addition reaction product [A-2] obtained in Synthesis Example 2 was used instead of the double bond-containing addition reaction product [A-1]. A polymerization reaction was carried out in the same manner. The obtained copolymer solution [C-2] had a viscosity (20
°C) 5.8 Stoke poison, acid value 5.5, hydroxyl value 38, and non-volatile content 53.0%. Comparative Example 1 Xylol 119.0 in the same flask as Example 1
After charging 175.0 parts of butyl acetate and raising the temperature to 100°C, 140.0 parts of styrene, 81.2 parts of β-hydroxylethyl methacrylate, and butyl acrylate were added.
A mixture consisting of 98.0 parts of methyl methacrylate, 23.8 parts of methyl methacrylate, 7.0 parts of methacrylic acid, 0.7 parts of benzoyl peroxide, and 21.0 parts of xylol was added dropwise into the flask over 3 hours. After the dropwise addition, the polymerization reaction was further carried out at 100℃ for 6 hours, and the xylol was 35.0
part was added to dilute. The obtained copolymer solution [D-1] had a viscosity (20°C) of 5.1 Stokes, an acid value of 6.1, a hydroxyl value of 50, and a nonvolatile content of 51.5.
It was %. 97.0 parts of the copolymer solution obtained in Examples 1 and 2 and Comparative Example 1 and 3.0 parts of carbon black were mixed and kneaded using three rollers, and the pigment dispersibility after kneading was compared twice and five times. and display the results.
Shown in 1.

[Table] Example 3 Copolymer solution obtained in Example 1 [C-1] 70
30 parts of titanium oxide was mixed with the mixture and dispersed by roller kneading to obtain a paint. Example 4 Copolymer solution obtained in Example 1 [C-1]
A coating material was obtained by dispersing 30.0 parts of titanium oxide and 20.0 parts of butylated melamine resin (trade name: Super Betsucomin J-820, manufactured by Dainippon Ink & Chemicals Co., Ltd.) into 50.0 parts by roller kneading. Example 5 50.0 parts of the above copolymer solution [C-1], epoxy resin solution (70% of Ciel Co., Ltd. trade name Epicote 1001)
A coating material was obtained by dispersing 2.0 parts of xylol solution, 18.0 parts of butylated melamine resin (same as in Example 4), and 30.0 parts of titanium oxide by roller kneading. Example 6 A black pigment (trade name: Laben 14, manufactured by Columbia Carbon) was added to 94.0 parts of the copolymer solution [C-1].
6.0 parts were added and kneaded with a roller to obtain a paint. Example 7 7.0 parts of an orange pigment (trade name: Hostapalm Orange GR manufactured by Hoechst) was added to 93.0 parts of the copolymer solution [C-1] and kneaded with a roller to obtain a paint. Comparative Example 2 A coating material was obtained in the same manner as in Example 3 using the copolymer solution [D-1]. Comparative Example 3 A coating material was obtained in the same manner as in Example 4 using the copolymer solution [D-1]. Comparative Example 4 A coating material was obtained in the same manner as in Example 5 using the copolymer solution [D-1]. Comparative Example 5 A coating material was obtained in the same manner as in Example 6 using the copolymer solution [D-1]. Comparative Example 6 A coating material was obtained in the same manner as in Example 7 using the copolymer solution [D-1]. Pigment dispersibility was measured for the paints obtained in Examples 3, 6, and 7 and Comparative Examples 2, 5, and 6,
The results are shown in Table-2. The above pigment dispersibility is paint (white) / paint (black) =
Mix well just before use at a mixing ratio of 9/1 (weight ratio) or paint (white)/paint (orange) = 9/1 (weight ratio), and add polyisocyanate as a crosslinking agent [Bayer's product name Desmodyur N]. -75: Biuret structure of hexamethylene diisocyanate] was added at an equivalent ratio of OH/NCO = 1.0, and after stirring,
Toluol/isobutyl acetate = 60/40 (weight ratio)
The viscosity of the composition (Food Cup #4) was adjusted to about 20 seconds using mixed thinner, and then sprayed and flow coated onto a tin plate, dried at room temperature, and measured for the color difference (△E) of the paint film. It was determined by

[Table] Note 1 Coating film obtained by spray painting and
Color difference in paint films obtained by flow coating It is clear from Table 2 above that the paint mixtures obtained in the examples of the present invention had very good pigment dispersibility (△E). In the comparative sample, the pigment dispersibility was significantly inferior. Next, the coating film performance obtained in Examples 3 to 5 and Comparative Examples 2 to 4 was evaluated, and the results are shown in Table 3.

[Table] From the results shown in Table 3 above, it is clear that the coating resin composition of the present invention has significantly improved pigment dispersibility as compared to the comparative example composition, and also has extremely excellent coating film performance. Ta.

Claims (1)

[Scope of Claims] 1 A(a)(i) A glycidyl ester of a tertiary aliphatic carboxylic acid, (ii) a saturated polyhydric carboxylic acid anhydride, and (iii) a product obtained as a result of the reaction of an unsaturated compound containing a hydroxyl group. 5 to 95% by weight of an addition reaction product having one double bond in the molecule [however, the proportion of each compound is (i) epoxy group: (ii)
Acid anhydride group: (iii) hydroxy group = 0.8 ~
1.2:1.0:0.8 to 1.2 (molar ratio)] (B) Mixture consisting of 95 to 5% by weight of unsaturated oil-free alkyd......15 to 45% by weight B. Polymerizability capable of copolymerization At least one type of monomer...
A curable resin composition for coating with excellent pigment dispersibility, which is obtained by further blending a crosslinking agent component with a copolymer obtained by reaction with 95 to 55% by weight.