JP2001002736A - Resin for dispersing pigment and pigment-dispersing paste composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject resin useful for production of a coating material composition excellent in coating film performance, having good disperse stability of a pigment and capable of making the concentration of the pigment high by copolymerizing specific three kinds of unsaturated monomers in a specific amount with a specific amount of a specific (meth)acrylic acid ester monomer in a specific amount. SOLUTION: This resin having 10,000-100,000 weight average molecular weight is obtained by copolymerizing a monomer mixture of (A) 0.1-10 pts.wt. polymerizable unsaturated monomer comprising at least one kind of hydrophilic functional group selected from amino group, a quaternary ammonium base and sulfonic acid group with (B) 2-30 pts.wt. hydroxyl group-containing polymerizable unsaturated monomer, (C) 5-50 pts.wt. (meth)acrylic acid ester monomer having an 8-24C branched alkyl group having a part represented by the formula (R1 and R2 are each a 1-6C alkyl; R3 is H or a 1-6C alkyl) and (D) 10-92.9 pts.wt. of the other polymerizable unsaturated monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel acrylic resin for dispersing a pigment, which is particularly excellent in pigment dispersibility and letdown stability, a pigment-dispersed paste composition using this resin, and a pigment-dispersed paste composition using the resin. Colored coating compositions.

[0002]

2. Description of the Related Art In general, organic and inorganic pigments are widely used in paints, inks and the like for the purpose of light emission, light shielding, aesthetics, rust prevention and the like. When dispersing these pigments in paints and inks, the dispersion stability of the pigments is insufficient and the pigments re-aggregate, the fluidity is poor, and the hue when formed into a coating film is insufficient or the gloss is insufficient. . In order to solve such a problem, various proposals have been made so far.

For example, JP-A-59-96175, JP-A-Hei02
-36252, JP-A-10-81849 and the like, there is a proposal to add a pigment derivative having the same skeleton as the pigment dispersed at the time of pigment dispersion, or to use a pigment treated with those pigment derivatives. However, all of the methods according to these proposals not only have an insufficient pigment dispersing effect, but also have poor versatility because many kinds of pigment derivatives are required, and are disadvantageous in that they are expensive in production. There is.

Various pigment dispersants such as acrylic resin, polyester resin, urethane resin, and polyester-modified urethane resin are commercially available and widely used. There is a problem that it causes a decrease in coating film performance such as physical performance, and especially when a large amount is incorporated into the coating material, the coating film performance becomes remarkably reduced, which is not always satisfactory.

[0005] In recent years, in the automotive paint industry and the like, not only the coating properties such as weather resistance and physical properties, but also pigment dispersing resins and auxiliaries generally used today are not satisfactory. Such high definition, transparency,
There is a demand for a high-grade coating film appearance such as high color development. In addition, the required appearance of the coating film is expected to become more and more diverse in the future, and accordingly, pigment dispersing performance for various color materials is required.

In recent years, there has been an urgent need in the coatings industry to reduce the amount of organic solvents in coatings and to achieve high solidification from the viewpoint of global environmental protection. As a technique for high solid differentiation, studies are generally being made in the direction of lowering the viscosity by reducing the molecular weight of the coating resin. However, when the molecular weight of the resin is reduced, problems such as deterioration of curability and deterioration of coating film performance are caused.

As a technique for achieving high solid differentiation of paint, in addition to reducing the molecular weight of the paint resin, increasing the pigment concentration of the paint (reducing the amount of resin used to disperse the same amount of pigment).
Are also mentioned. However, in general, when an attempt is made to increase the pigment concentration of a paint, the viscosity of the pigment paste, the aggregation of the pigments in the pigment paste or the paint, and the lack of letdown stability when forming the paint are likely to occur. There was a problem that it was difficult to obtain a paste or paint.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pigment paste having greatly improved pigment dispersibility, pigment coloring property and let-down stability, and a finished appearance and weather resistance of a coating film. Another object of the present invention is to provide an acrylic resin for dispersing a pigment without impairing the properties of a coating film such as physical properties.

Another object of the present invention is to provide a pigment dispersing resin capable of obtaining a stable pigment paste even when the pigment concentration is increased.

[0010] Furthermore, an object of the present invention is to provide a pigment having a coloring property,
An object of the present invention is to provide a coating composition which is excellent in the finished appearance of the coating film and the coating film performance such as weather resistance and physical properties, has good pigment dispersion stability, and can be made to have a high pigment concentration.

[0011]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above object, and as a result, have found that a polymerizable unsaturated monomer having a specific hydrophilic functional group, a polymerizable unsaturated monomer having a hydroxyl group and a specific polymerizable monomer. The present inventors have found that the above object can be achieved by a pigment dispersing acrylic resin obtained by copolymerizing a monomer mixture having a (meth) acrylic acid ester monomer having a branched alkyl group, and have completed the present invention.

That is, the present invention relates to (a) 0.1 to 10 parts by weight of a polymerizable unsaturated monomer containing at least one hydrophilic functional group selected from an amino group, a quaternary ammonium base and a sulfonic acid group. (B) 2 to 30 parts by weight of a hydroxyl group-containing polymerizable unsaturated monomer, (c) the following formula (I)

[0013]

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Wherein R ¹ and R ² are the same or different and each represents an alkyl group having 1 to 6 carbon atoms, and R ³ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. 5 to 50 parts by weight of a (meth) acrylate monomer having a branched alkyl group having 8 to 24 carbon atoms having a portion and (d) another polymerizable unsaturated monomer 10 to 9
An object of the present invention is to provide a pigment dispersing acrylic resin having a weight average molecular weight in the range of 10,000 to 100,000 obtained by copolymerizing 2.9 parts by weight of a monomer mixture.

The present invention also provides a pigment-dispersed paste composition characterized by containing an acrylic resin for pigment dispersion, a pigment and, if necessary, a solvent.

Further, the present invention provides a colored coating composition comprising the above-mentioned pigment-dispersing paste and a coating binder resin.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. First, the acrylic resin for pigment dispersion of the present invention will be described.

The pigment-dispersing acrylic resin of the present invention (hereinafter referred to as “the acrylic resin”)
"Acrylic resin (A)" may be a polymerizable unsaturated monomer containing a specific hydrophilic functional group (a), a polymerizable unsaturated monomer containing a hydroxyl group (b), a specific number of carbon atoms. An acrylic resin obtained by copolymerizing a monomer mixture comprising a (meth) acrylate monomer (c) having 10 to 24 branched alkyl groups and another polymerizable unsaturated monomer (d). In this specification,
“(Meth) acrylate” shall mean “acrylate or methacrylate”.

The hydrophilic functional group in the monomer (a) is a group selected from an amino group, a quaternary ammonium salt group and a sulfonic acid group.
It is a monomer having one polymerizable unsaturated group and one or more hydrophilic functional groups, and may be abbreviated as “monomer (a)” below.

Specific examples of the monomer (a) include, for example, N, N-dimethylaminoethyl (meth) acrylate,
N, N-diethylaminoethyl (meth) acrylate,
Aminoalkyl (meth) containing a tertiary amino group such as N, N-dimethylaminopropyl (meth) acrylate
Acrylates; quaternary ammonium base-containing monomers such as methacryloyloxyethyltrimethylammonium chloride; and sulfonic acid group-containing polymerizable unsaturated monomers such as 2-acrylamido-2-methylpropanesulfonic acid. These compounds can be used alone or in combination of two or more.

In the above monomer (a), particularly for acidic pigments and neutral pigments, tertiary amino group-containing aminoalkyl (meth) acrylate monomers and / or quaternary ammonium base-containing polymerizable unsaturated monomers; The acrylic resin (A) having good pigment dispersibility for each pigment can be obtained by copolymerizing the hydrophilic pigment with a sulfonic acid group-containing polymerizable unsaturated monomer.

The hydroxyl group-containing polymerizable unsaturated monomer (b) is a polymerizable unsaturated monomer containing one or more hydroxyl groups in one molecule, and may be abbreviated as "monomer (b)" hereinafter. .

Specific examples of the monomer (b) include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2,3-dihydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. And monoesterified product of polyhydric alcohol and acrylic acid or methacrylic acid such as polyethylene glycol mono (meth) acrylate; and ring-opening polymerization of ε-caprolactone to the monoesterified product of polyhydric alcohol and acrylic acid or methacrylic acid. And the like. These can be used alone or in combination of two or more.

The (meth) acrylate monomer (c) having a branched alkyl group having 10 to 24 carbon atoms (hereinafter sometimes abbreviated as "monomer (c)") has a specific structure. In 24 branched alkyl groups,
The following formula (I)

[0025]

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(Wherein R ¹ and R ² are the same or different and each represents a methyl group or an ethyl group, and R ³ represents a hydrogen atom, a methyl group or an ethyl group).

Specific examples of the monomer (c) include, for example, the following formula (II)

[0028]

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(Wherein R ⁴ represents a hydrogen atom or a methyl group); Cardura (Cardura)
E10 (manufactured by Shell Chemical Company, registered trademark, carbon number 9)
To 11 branched higher fatty acids) and an equimolar ester of acrylic acid or methacrylic acid. These compounds may be used alone or
More than one species can be used in combination.

Other polymerizable unsaturated monomers (d) include:
It is a polymerizable unsaturated monomer other than the above-mentioned monomers (a), (b) and (c), and is a monomer appropriately used depending on the required properties of the resin. May be abbreviated.

Specific examples of the monomer (d) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, C such as isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate
_1-9 alkyl (meth) acrylate; styrene, o-
Benzene ring-containing polymerizable unsaturated monomers such as methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, phenyl (meth) acrylate; glycidyl (meth) acrylate, methylglycidyl (meth)
Epoxy group-containing polymerizable unsaturated monomers such as acrylate, 3,4-epoxycyclohexyl (meth) acrylate, allyl glycidyl ether and vinyl glycidyl ether; acrylonitrile, methacrylonitrile and the like. These compounds may be used alone or
More than one species can be used in combination.

The above monomers (a), (b), (c) and (d) for producing the acrylic resin for pigment dispersion of the present invention.
Is suitably within the following range with respect to the total amount of all the monomer components constituting the acrylic resin (A).

Monomer (a): 0.1 to 10% by weight, preferably 0.2 to 8% by weight, Monomer (b): 2 to 30% by weight, preferably 4 to 25%
% By weight, monomer (c): 5 to 50% by weight, preferably 10 to 4%
0% by weight, monomer (d): 10 to 92.9% by weight, preferably 3%
0-70% by weight.

The amount of the monomer (b) is usually 10 to 200 mgKOH / g, preferably 20 to 15 mg.
The range is 0 mgKOH / g.

When the monomer compounding ratio in the production of the acrylic resin (A) of the present invention is within the above range, the dispersion stability of pigments and inorganic powders, the physical properties of the coating film, the finished appearance, and the like are reduced. It is suitable. Here, the amount of the monomer (a) can be appropriately selected according to the type of the pigment, the specific surface area and the particle diameter of the pigment particles, the presence or absence or properties of the pigment surface treating agent, the polarity of the dispersion medium, and the like. The monomer (b) contains a hydroxyl group that is a cross-linking reactive group, and the above range is preferable from the viewpoint of the curability, weather resistance, physical performance, and the like of the coating film. Since the monomer (c) has a long-chain alkyl group having a portion represented by the formula (I), when the monomer (c) is within the above-mentioned quantitative range, a steric repulsion layer is formed, and Since aggregation is prevented and the let-down stability is excellent, high pigment concentration (high solid differentiation) is also possible.

As a method for obtaining an acrylic resin (A) by copolymerizing a monomer mixture comprising the above-mentioned monomers (a), (b), (c) and (d), a bulk polymerization which is a known polymerization method is used. Examples include a batch method, a solution polymerization method, and a bulk-suspension two-stage polymerization method in which suspension polymerization is performed after bulk polymerization.

When the acrylic resin (A) of the present invention is obtained by copolymerization, a polymerization initiator generally used in a process for producing an acrylic polymer or the like is used as a polymerization initiator, and the amount thereof is usually , Monomers (a), (b),
0.1 to 8% by weight based on the total amount of (c) and (d)
Within the range.

As the above-mentioned polymerization initiator, for example, 2,2 '
Azo polymerization initiators such as azobisisobutylnitrile, azobis-2-methylbutyronitrile, azobisdivaleronitrile, etc .; t-butylperoxyisobutyrate, t
-Butylperoxy-2-ethylhexanoate, t-
Amyl peroxy 3,5,5-trimethylhexanoate, t-butyl peroxyisopropyl carbonate,
Organic peroxide-based polymerization initiators such as 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane and the like can be mentioned.

As a method for obtaining the acrylic resin (A) of the present invention, a solution polymerization method is particularly preferable. Examples of the solution polymerization method include a method in which the monomer mixture is dissolved or decomposed in an organic solvent, and the mixture is heated with stirring at a temperature of usually about 80 ° C to 200 ° C in the presence of a radical polymerization initiator. it can. Reaction time is usually 1
About 10 to about 10 hours is appropriate.

Examples of the organic solvent include hydrocarbon solvents such as heptane, toluene, xylene, octane, and mineral spirit; esters such as ethyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, and diethylene glycol monobutyl ether acetate. Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone and cyclohexanone; alcohol solvents such as methanol, ethanol, isopropanol, n-butanol, sec-butanol and isobutanol; n-butyl ether, dioxane, ethylene glycol monomethyl Ether solvents such as ether and ethylene glycol monoethyl ether; Swazole 310, Swazole 1000, Swazo manufactured by Cosmo Oil Co., Ltd. And aromatic petroleum solvents such as C.I. These organic solvents can be used alone or in combination of two or more. At the time of copolymerization, the organic solvent is a monomer (a),
The total amount of (b), (c) and (d) is usually 4
It is used in a range of not more than 00% by weight.

In the copolymerization reaction for obtaining the acrylic resin (A) of the present invention, the method of adding the monomer component and the polymerization initiator is not particularly limited, but the polymerization initiator is used rather than being charged all at once in the initial stage of polymerization. From the initial stage to the late stage of the polymerization, it is preferable to divide the solution into several portions and to drop it, for example, from the viewpoint of suppressing the formation of defective crosslinked products.

The pigment dispersing acrylic resin (A) of the present invention, which can be obtained by the above copolymerization, is a so-called comb resin having a branched alkyl group in a side chain. The acrylic resin (A) has a weight average molecular weight of 10,000 to 100,0.
And preferably in the range of 15,000 to 50,000, the pigment dispersibility, various properties of the coating film (for example, weather resistance, acid resistance, scratch resistance), and ease of handling of the resin (resin not significantly high) Viscosity) and the finished appearance of the coating film.

Next, the pigment-dispersed paste composition of the present invention will be described.

The pigment-dispersed paste composition of the present invention contains the above-mentioned acrylic resin (A) for dispersing pigment and pigment (B), and if necessary, an organic solvent.

Examples of the pigment (B) include aluminum powder, copper powder, nickel powder, stainless steel powder, chromium powder,
Bright pigments such as mica-like iron oxide, acid value titanium-coated mica powder, iron oxide-coated mica powder, and bright graphite; organic red pigments such as pink EB, cyanine blue, cyanine green, azo and quinacridone, benzimidazo Organic yellow pigments such as lon-based, isoindolinone-based, isoindoline-based, and quinophthalone-based; and inorganic color pigments such as titanium white, titanium yellow, red iron black, carbon black, graphite, and various calcined pigments.

The organic solvent used if necessary can be used without any particular limitation as long as it is an organic solvent capable of dissolving the acrylic resin (A) for pigment dispersion. Specific examples include toluene, xylene, mineral spirit and the like. Hydrocarbon solvents; ester solvents such as ethyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate and butyl carbitol acetate; ether solvents such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether and diethylene glycol , Methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and other ketone solvents; methanol, ethanol, isopropanol, n-butanol, sec-butanol, isobutanol, and other alcohol solvents; Ether, dioxane, ethylene glycol monomethyl ether, ethers such as ethylene glycol monoethyl ether, Cosmo Oil Co. Swasol 310, Swasol 1000, SWASOL 15
And an aromatic petroleum solvent such as 00. The organic solvents can be used alone or in combination of two or more.

The above-mentioned pigment-dispersed paste composition comprises a binder resin for a coating material and, if necessary, an organic solvent, polymer fine particles, a curing catalyst, an ultraviolet absorber, an ultraviolet stabilizer, a coating surface adjuster, an antioxidant, A coating composition can be obtained by blending with additives such as a regulator and a silane coupling agent.

The above-mentioned binder resin for paints includes a base resin and a curing agent which can be used for paints, such as a hydroxyl-containing acrylic resin, a hydroxyl-containing polyester resin, and the like.
Epoxy resin, epoxy group-containing acrylic resin, amino resin, polyisocyanate compound which may be blocked, carboxyl group-containing high acid value polyester resin, carboxyl group-containing high acid value acrylic resin, and the like. They can be used alone or in combination of two or more. The polyisocyanate compound which may be blocked includes both a blocked polyisocyanate compound in which isocyanato groups are blocked and a non-blocked polyisocyanate compound.

As the binder resin for paint, at least one base resin selected from a hydroxyl group-containing acrylic resin and a hydroxyl group-containing polyester resin, and at least one selected from an amino resin and a polyisocyanate compound which may be blocked. A combination with one curing agent; at least one resin selected from an epoxy resin and an epoxy group-containing acrylic resin, and at least one resin selected from a high acid value polyester resin and a high acid value acrylic resin
Combinations with different carboxyl group-containing resins can be suitably used.

As the organic solvent used as required, various organic solvents similar to those exemplified as the organic solvent which can be contained in the pigment dispersion paste composition can be used.

The above polymer fine particles are polymers which are not dissolved in the coating composition of the present invention and are dispersed as fine particles, and usually those having an average particle diameter in the range of 0.01 to 1 μm are preferred. The polymer particles may or may not be cross-linked inside the particles, but preferably are internally cross-linked. The fine particles are known per se, and can be appropriately selected from these and used.

When the curing agent is a polyisocyanate compound which may be blocked, examples of the curing catalyst include dibutyltin diacetate, dibutyltin dioctate, dibutyltin dilaurate, triethylamine and diethanolamine. Is an amino resin such as a melamine resin, sulfonic acid compounds such as paratoluenesulfonic acid, dodecylbenzenesulfonic acid, and dinonylnaphthalenesulfonic acid, and amine-neutralized products of these sulfonic acid compounds. .

Examples of the ultraviolet absorber include benzophenone-based, benzotriazole-based, cyanoacrylate-based, salicylate-based, and oxalic anilide-based compounds. Examples of the ultraviolet stabilizer include a hindered amine compound.

[0054]

EXAMPLES The present invention will be further clarified with reference to Production Examples, Examples and Comparative Examples. Unless otherwise specified, “parts” and “%” mean “parts by weight” and “% by weight”, respectively.

Production of Acrylic Resin Solution for Dispersing Pigment Example 1 50 parts of xylol and n-butyl alcohol 20 were placed in an acrylic resin reaction tank equipped with a stirrer, thermometer, reflux condenser and the like.
The mixture was heated and stirred, and after the temperature reached 115 ° C., a mixture of the following monomers and the like was added dropwise over 3 hours.

Methyl methacrylate 48.5 parts Praxel FM-3X (Note 1) 20 parts Isostearyl acrylate (Note 2) 30 parts Dimethylaminoethyl methacrylate 1.5 parts 2,2′-azobisisobutyronitrile 1 part n -Butyl alcohol 5 parts After the dropping of the mixture of the above monomers is completed, 115
After the temperature was kept at 0 ° C., an additional catalyst solution, which was a mixture of 0.5 part of 2,2′-azobisisobutyronitrile and 5 parts of xylol, was added dropwise over 1 hour. After further stirring at 115 ° C. for 1 hour, the mixture was cooled. This was diluted with n-butyl alcohol to obtain a pigment dispersion acrylic resin solution (A-1) having a solid content of 50%. The weight average molecular weight (Mw) of the obtained acrylic resin was 28,000, and the hydroxyl value was 24 mgKOH / g.

(Note 1) Praxel FM-3X: manufactured by Daicel Chemical Industries, Ltd., a trade name, methacrylic acid ester having a polyester chain with ε-caprolactone opened. (Note 2) Isostearyl acrylate: a product of Osaka Organic Chemical Industry Co., Ltd., an acrylic ester compound in which R ⁴ is a hydrogen atom in the above formula (II).

(Note 3) Isostearyl methacrylate:
In the above formula (II), a methacrylate compound wherein R ⁴ is a methyl group.

Examples 2 to 9 and Comparative Examples 1 to 4 The same procedures as in Example 1 were carried out except that the composition of the mixture of monomers and the like dropped during the production of the acrylic resin solution was changed to the composition shown in Table 1 below. Reaction was carried out in the same manner as in Example 1. In Examples 2, 8 and 9, and Comparative Examples 1, 3 and 4, after the reaction, cooling was carried out in the same manner as in Example 1, and diluted by adding n-butyl alcohol to disperse each pigment having a solid content of 50%. An acrylic resin solution was obtained. In Examples 3 to 7 and Comparative Example 2, after the reaction and before cooling, the temperature was raised and the water in the system was removed by azeotropic distillation. When the amount of the distillate reached 5 parts, the temperature was stopped and the system was cooled. Then this thing is n
-Dilute with butyl alcohol, solid concentration 50%
Acrylic resin solution for pigment dispersion was obtained. The special values of the obtained acrylic resin are listed in Table 1 below.

[0060]

[Table 1]

Examples 10 to 18 and Comparative Examples 5 to 8 Each of the acrylic resin solutions, pigments and mixed solvents produced in the above Examples and Comparative Examples were mixed in the composition shown in Table 2 below.
Disperse for 4 hours with a paint shaker (225cc capacity)
Using a wide-mouthed glass bottle having a diameter of about 1.3 mmφ glass beads) to obtain each pigment dispersion paste.

A performance test was performed on each of the obtained pigment dispersion pastes according to the following test method. The test results are shown in Table 2 below.

Test Method Appearance of coating film: Each pigment-dispersed paste was 100 × 200 mm
Was applied by a bar coater so as to have a dry film thickness of 15 μm, and baked at 140 ° C. for 30 minutes. The degree of turbidity of the coating film formed on the film was visually evaluated according to the following criteria.

：: uniform and no turbidity Δ: slight turbidity X: considerable turbidity

Gloss: JIS K5400 7.6 (19
90), the 60 ° specular reflectance of each coating film was measured.

Transparency: Using a turbidimeter (COH-300), the light transmittance (%) was measured according to the following equation.

Light transmittance (%) = 100 × [1− (scattered light intensity / irradiation light intensity)] Viscoelastic property: Viscosity (Pa · ・) using a viscoelasticity analyzer “MR-300” (manufactured by Rheology). s) and the yield value (dy)
n / cm ² ).

[0068]

[Table 2]

(Note) in Table 2 has the following meanings.

(Note 4) MONARCH1300: Cab
OT Corporation, trade name of carbon black pigment, Monarch 1
300.

(Note 5) HOSTAPERM PINK
EB TRANSPARENT: a brand name of organic red pigment, Hostaperm Pink EB Transparent, manufactured by Clariant.

(Note 6) Cyanine blue 5206: trade name of copper phthalocyanine blue pigment manufactured by Dainichi Seika Co., Ltd.

Production Example 1 of Resin for Paint Production Example 1 30 parts of Swazole 1000 (Cosmo Oil, aromatic hydrocarbon solvent) in an acrylic resin reaction tank equipped with a stirrer, thermometer, reflux condenser, etc., n-butyl 5 parts of alcohol was charged, heated and stirred, and after the temperature reached 130 ° C., a mixture of the following monomers and the like was added dropwise over 3 hours.

Styrene 20 parts Methyl methacrylate 50 parts n-butyl acrylate 15 parts 2-hydroxyethyl methacrylate 15 parts 2,2′-azobisisobutyronitrile 5 parts n-butyl alcohol 5 parts The above monomers and the like After the addition of the mixture of
After maintaining at 30 ° C., an additional catalyst solution, which was a mixture of 0.5 part of 2,2′-azobisisobutyronitrile and 8 parts of swazole 1000, was added dropwise over 1 hour. One more
After stirring at 30 ° C. for 1 hour, the mixture was cooled. This was diluted with 8 parts of n-butyl alcohol to obtain an acrylic polymer solution (AP-1) having a solid content of 60%.

Production Example 2 An acrylic polymer solution (solid content: 60%) was prepared in the same manner as in Production Example 1 except that the composition of the mixture of monomers and the like to be dropped was changed as shown in Table 3 below. AP-
2) was synthesized.

Production Example 3 In Production Example 1, the composition of the mixture of monomers and the like to be dropped was as shown in Table 3 below, and the reaction temperature and the aging temperature were 1
A glycidyl group-containing acrylic polymer solution (GP-1) having a solid content of 60% was synthesized in the same manner as in Production Example 1 except that the temperature was changed from 30 ° C to 120 ° C.

Production Example 4 40 parts of xylene and 15 parts of 3-methoxybutyl acetate were charged into an acrylic resin reaction tank equipped with a stirrer, a thermometer, a reflux condenser, etc., heated and stirred. A mixture of monomers and the like was added dropwise over 4 hours.

Styrene 5 parts n-butyl methacrylate 30 parts isobutyl methacrylate 24 parts lauryl methacrylate 25 parts methacrylic acid 6 parts acrylic acid 10 parts 2,2′-azobisisobutyronitrile 5 parts After dropping the mixture, add 1 minute for 30 minutes.
After maintaining at 25 ° C., an additional catalyst solution, which is a mixture of 0.5 part of 2,2′-azobisisobutyronitrile and 15 parts of 3-methoxybutyl acetate, was added dropwise over 1 hour. After further stirring at 125 ° C. for 1 hour, the mixture was cooled and a high acid value acrylic polymer solution (CP
-1) was obtained. Table 3 below shows the resin properties of the acrylic polymers obtained in Production Examples 1 to 4.

[0079]

[Table 3]

Production Example 5 2.4 mol of isophthalic acid, 4.8 mol of hexahydrophthalic acid, and 2 parts of adipic acid were placed in a reaction vessel equipped with a stirrer, thermometer, rectification tower, nitrogen inlet tube, reflux condenser and the like. 5.7 mol, 5.1 mol of neopentyl glycol, 3.3 mol of 1,6-hexanediol, and 2.5 mol of trimethylolpropane, and heated and stirred to reach 160 ° C., and then to 240 ° C. over 3 hours. The temperature rose. After aging for 1.5 hours after raising the temperature, the rectification column was switched to a reflux condenser, and 1.4 mol of xylene was introduced to carry out the reaction under reflux. 240 ° C as it is
The reaction was carried out for 12 hours, followed by the addition of Swarsol 1000, and a polyester polymer solution (PP-
1) was obtained.

Production Example 6 A solid content of 60 was prepared in the same manner as in Production Example 3 except that the raw materials used were changed as shown in Table 4 below.
% Polyester polymer solution (PP-2) was synthesized. Table 4 below shows resin special values of the polyester polymers obtained in Production Examples 5 and 6 above.

[0082]

[Table 4]

Production of Colored Paint Composition Example 19 The pigment dispersion paste (B-1) obtained in Example 10 was
Parts (solids content: 80 parts), 300 parts of the acrylic polymer solution (AP-2) obtained in Production Example 1 (solids content: 180 parts)
Parts), 85.7 parts (60 parts by solid content), Nicarac MS25 (manufactured by Sanwa Chemical Co., Ltd., trade name, butyl etherified melamine resin solution having a solid content of about 70%), Nacure
5225 (Nailure 5225, manufactured by King Industries, USA, trade name, curing catalyst solution as amine neutralized solution of sulfonic acid compound, active ingredient 25%) 1.1
Section and Dispalon LC-955 (manufactured by Kusumoto Kasei Co., Ltd.
(Trade name, surface conditioner) (1.4 parts) was mixed to obtain a colored coating composition.

Examples 20 to 29 and Comparative Examples 9 to 12 Each of the colored coating compositions was obtained in the same manner as in Example 19, except that the composition was changed as shown in Table 5 below.

(Note) in Table 5 has the following meanings.

(Note 7) Desmodur N3500: trade name, block isocyanate compound manufactured by Sumitomo Bayer Urethane Co., Ltd.

(Note 8) TBAB: tetrabutylammonium bromide.

Using the colored coating compositions obtained in Examples 19 to 29 and Comparative Examples 9 to 12, each test coated plate was prepared according to the following method for preparing test coated plates.

Preparation of Test Coated Plate Electrodeposited with an epoxy resin-based cationic electrodeposition paint on a 0.8 mm thick cold-rolled dull steel plate that had been subjected to zinc phosphate chemical conversion treatment so that the dry film thickness was about 20 μm. On the baked electrodeposition coating film, a polyester resin intermediate coating for automobiles was applied so as to have a dry film thickness of about 20 μm and baked. This coated plate is water-dried with # 400 sandpaper, drained and dried,
Degreasing with petroleum benzine. Then, on the degreased plate, each of the colored coating compositions was coated with a coating having a coating viscosity of 25 seconds (Ford Cup #
(4, 25 ° C.), paint to a dry film thickness of about 40 μm, leave it at room temperature for about 3 minutes, set it, and bake it at 140 ° C. for 30 minutes with an electric hot air dryer to make each test coated plate It was created.

Various tests were carried out on these test coated plates based on the following test methods. Table 5 below shows the test results.
Shown in

Test Method Appearance of Coating Film: The finished appearance of the coating film was comprehensively investigated from the sense of luster and the feeling of holding, and evaluated according to the following criteria. ：: good, △: bad, ×: extremely poor.

Adhesion: JIS K-5400 8.5.
2 (1990) According to the crosscut-tape method, 11 parallel vertical and horizontal straight lines are drawn at 1 mm intervals on the surface of the coating film of the test plate so as to reach the substrate with a cutter knife, and the distance is 1 mm. 100 × 1 mm squares were created. A cellophane adhesive tape was adhered to the surface, and the degree of peeling of the squares when the tape was abruptly peeled was observed and evaluated according to the following criteria. ：: 90 or more squares of the coating film remained, Δ: the coating film was peeled, and the number of remaining squares was 50 or more and 90
Less than, ×: The coating film peeled off, and the number of remaining squares was less than 50.

Acid resistance: 0.5 cc of artificial rain having the following composition was dropped on the coating film of the test plate, heated for 30 minutes on a hot plate heated to 80 ° C., washed with water, and the coated surface was visually observed. Then, the following criteria were used for evaluation. ：: No change was observed on the painted surface, Δ: Whitening and swelling were not observed on the painted surface, but a step was observed at the boundary, ×: Whitening or swelling was observed on the painted surface, 1 mg / g NaNO ₃ aqueous solution 1
9.6 g, 1 mg / g KNO ₃ aqueous solution 5.2 g, 1 m
3.7 g of 1 g / g CaCl ₂ .2H ₂ O aqueous solution, 1 mg
/ G MgSO ₄ .7H ₂ O aqueous solution 8.2 g, 1 mg / g
g of (NH ₄ ) ₂ SO ₄ aqueous solution, 73.3 g, 0.1 N H ₂ SO ₄ aqueous solution, 30.0 g, 0.1 N HNO ₃ aqueous solution, 20.0 g, 0.05 N HCl aqueous solution, 10.0 g and 1 mg / g g of an aqueous NaF solution (4.7 g), and the pH was adjusted to 1.0 with H ₂ SO ₄ .

Solvent resistance: In a room at 20 ° C., about 1 kg was applied to the painted surface with gauze impregnated with methyl ethyl ketone.
After applying a load of / cm ² and reciprocating 50 times over a length of about 5 cm, the state of the coated surface was visually evaluated according to the following criteria. ：: no change is observed on the coated surface, Δ: scratch is recognized on the coated surface, ×: whitening or swelling of the coated film is recognized.

Impact resistance: JIS K-5400
According to 3.2 (1990) Dupont impact resistance test,
With the coating surface of the test coated plate facing upward, the test is performed under the conditions of a drop weight of 500 g and a tip diameter of the hammer of 1/2 inch, and the maximum drop weight height that does not cause damage to the coating film is indicated. The maximum value is 50 cm.

[0096]

[Table 5]

[0097]

By using the pigment dispersing resin of the present invention, it is possible to obtain a pigment dispersing paste composition in which the pigment dispersibility, the pigment coloring property and the let-down stability are greatly improved.

Further, the use of the pigment dispersing resin of the present invention does not impair the finish appearance, weather resistance, physical properties, etc. of the coating film in the coating composition, and reduces the pigment dispersibility in the coating composition. Has been improved.

Further, by using the pigment dispersing resin of the present invention, a stable pigment paste can be obtained even when the pigment concentration is increased. Therefore, it is possible to obtain a coating composition which is excellent in the coloring properties of the pigment, the finished appearance of the coating film, and the coating properties such as weather resistance and physical properties, and has a good pigment dispersion stability and a high pigment concentration. it can.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Isao Jinmori 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa F-term in Kansai Paint Co., Ltd. 4J002 BC04W BC08W BC09W BE04W BG04W BG05W BG07W BG07X BG10W BG11W BG13W CC13X CD00X CD19W CF00X CH05W CK02X DA027 DA037 DA077 DA087 DA097 DA117 DC007 DE117 DE137 DE157 DJ057 EQ017 ER006 EU027 EU037 EU117 FB077 FD050 FD097 FD140 FD150 GH01 HA05 HA08 4J038 CB001 CC022 CC072 GA083 DG141 CG141 CG141 DD08 KA06 KA08 MA14 NA01 4J100 AB02P AB03P AB04P AE09P AE18P AL03P AL04P AL04Q AL05Q AL08P AL08R AL08S AL09R AL10P AL11P AM02P AM21S BA03R BA09R BA15R BA16R BA31S BA32S BA56S BC54P CA06 DA01 JA01

Claims (6)

[Claims] 1. A polymerizable unsaturated monomer containing at least one hydrophilic functional group selected from (a) an amino group, a quaternary ammonium base and a sulfonic acid group.
Parts by weight, (b) 2 to 30 parts by weight of a hydroxyl group-containing polymerizable unsaturated monomer, (c) the following formula (I): (Wherein R ¹ and R ² are the same or different and each have 1 carbon atom)
It represents 6 alkyl group, R ³ is (meth) acrylic acid ester having a branched alkyl group having 8 to 24 carbon atoms having a portion indicated by a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) 5 to 50 parts by weight of monomer and (d) other polymerizable unsaturated monomer 10 to 92.9
Weight average molecular weight 1 obtained by copolymerizing parts by weight of a monomer mixture
Acrylic resin for pigment dispersion in the range of 000 to 100,000. 2. The (meth) acrylate monomer (c) is represented by the following formula (II): (Wherein, R ⁴ represents a hydrogen atom or a methyl group) according to claim 1, wherein the acrylic resin is a compound represented by. 3. A pigment-dispersed paste composition comprising the pigment-dispersed acrylic resin according to claim 1, a pigment, and, if necessary, a solvent. 4. A colored coating composition comprising the pigment dispersion paste according to claim 3 and a binder resin for a coating. 5. The coating binder resin comprises at least one base resin selected from a hydroxyl group-containing acrylic resin and a hydroxyl group-containing polyester resin, and at least one type selected from an amino resin and an optionally blocked polyisocyanate compound. 5. The coating composition according to claim 4, comprising a curing agent. 6. The binder resin for a coating material contains at least one resin selected from an epoxy resin and an epoxy group-containing acrylic resin, and at least one carboxyl group-containing resin selected from a high acid value polyester resin and a high acid value acrylic resin. The coating composition according to claim 4, comprising a resin.