JPH06100632A - Resin for pigment dispersion - Google Patents

Abstract

PURPOSE:To provide the resin which can give a pigment masterbatch used commonly for various coating resins. CONSTITUTION:The resin comprises a copolymer comprising a (meth)acrylate with a 1-4C alkyl group, a (meth)acrylate with a 6-30C alkyl group and a polymerizable monomer having a functional group.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a pigment dispersion resin. More specifically, it relates to a pigment dispersion resin for paints applicable to a very wide range of paint resins such as room temperature dry type alkyd, alkyd melamine, acrylic lacquer, acrylic melamine, acrylic urethane, vinyl acetate-acrylic, nitrified cotton lacquer. .

[0002]

2. Description of the Related Art Conventionally, a paint containing a pigment is prepared by mixing a pigment and a dispersion resin to prepare a pigment dispersion for a primary color paint (pigment masterbatch), and then using the same resin as that used for the dispersion. It is diluted and commercialized. This is because when the pigment dispersion resin used for each pigment masterbatch and the resin used for dilution are different from each other, the compatibility between the resins is generally poor, and there is a problem such as a decrease in gloss and hardness of the coating surface. Therefore, it has been desired to develop a pigment-dispersing resin that has excellent compatibility with many kinds of paint resins and can be commonly used in various resin paints. For this purpose, a method of using a urethane-modified polyester resin as a pigment-dispersing resin (JP-A-4-91)
115) or a method of using a copolymer of butyl methacrylate and a specific nitrogen-containing monomer as a resin for dispersing pigment (Japanese Patent Laid-Open No. 60-139713).

[0003]

However, in the above method, the urethane-modified polyester resin is compatible with a relatively wide range of resins, but since it has a urethane bond, the weather resistance is insufficient. There is a problem that it cannot be used for paints that require weather resistance (such as exterior paints). Further, the copolymer composed of butyl methacrylate and a specific nitrogen-containing monomer has a problem in that it cannot be used in a wide range of paints because the kinds of compatible resins are limited.

[0004]

Means for Solving the Problems The present inventors have found that they are compatible with a very wide range of paint resins and, when mixed with each resin, include the original weather resistance of each resin paint, including weather resistance. The present invention has been achieved as a result of intensive studies on a resin for dispersing a pigment that does not impair the performance.

That is, according to the present invention, a (meth) acrylate (a) having an alkyl group having 1 to 4 carbon atoms and 6 carbon atoms is used.
A resin for pigment dispersion comprising a copolymer (A) of (meth) acrylate (b) having 30 to 30 alkyl groups and a polymerizable monomer (c) having a functional group.

In the present invention, examples of the (meth) acrylate (a) having an alkyl group having 1 to 4 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, 1-propyl (meth) acrylate and isopropyl. (Meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate and a mixture of two or more of these.

Among these, in order to prevent the hardness of the paint from decreasing, one having a high glass transition point, that is, methyl (meth) acrylate, ethylmethacrylate,
Isobutyl methacrylate and t-butyl (meth)
Acrylate is preferred, and methyl methacrylate and t-butyl methacrylate are particularly preferred.

Examples of (b) include hexyl (meta)
Acrylate, cyclohexyl (meth) acrylate,
Octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate,
Decyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, 1-methyltridecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, eicosyl (meth) Acrylate, docosyl (meth) acrylate, tetracosyl (meth) acrylate, triacontyl (meth) acrylate and a mixture of two or more thereof may be mentioned.

Of these, hexyl (meth) acrylate, in order to be compatible with various coating resins and not to impair the original performance of each resin including weather resistance when mixed with each resin, Cyclohexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate and dodecyl (meth) acrylate are preferred.

Examples of the polymerizable monomer (c) having a functional group include a hydroxyl group-containing monomer (c1), a carboxylic acid group-containing monomer (c2) and a nitrogen-containing monomer (c3). Specific examples of (c1) include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2,
3-dihydroxypropyl (meth) acrylate, 3-
Examples include chloro-2-hydroxy (meth) acrylate and glycerol (meth) acrylate. Of these, particularly preferred is hydroxyethyl (meth) acrylate.

Specific examples of (c2) include (meth) acrylic acid, (anhydrous) maleic acid, fumaric acid, itaconic acid and the like, with (meth) acrylic acid being preferred.

Specific examples of (c3) include tertiary amino group-containing (meth) acrylates [dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth)].
Acrylate, dimethylaminopropyl (meth) acrylate, diethylaminoethyl (meth) acrylate and the like]; cyanoalkyl (meth) acrylates [cyanoethyl (meth) acrylate and the like]; acrylonitrile, (meth) acrylamides [(meth) acrylamide, methyl ( (Meth) acrylamide, cyclohexyl (meth) acrylamide, dimethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, etc.]; amineimide group-containing (meth) acrylates [trimethylamine (meth) acrylimide, dimethylethylamine (meth) acrylimide, Dimethylhydroxypropylamine (meth) acrylimide, dimethylphenylhydroxyethyl (meth) acrylimide, etc.]; quaternary ammonium Containing (meth) acrylates [(meth) acryloyloxyethyl trimethyl ammonium chloride, (meth) acryloyloxyethyl trimethyl ammonium methosulfate, etc.]; and the like. Among these, preferred are (meth) acrylamides and amine imide group-containing (meth) acrylates, and particularly preferred is (meth) acrylamide.

The copolymer (A) may optionally be copolymerized with other polymerizable monomer (d) other than the above-mentioned (a), (b) and (c).

There are no particular restrictions on (d) as long as it can be copolymerized with (a), (b) and (c), and specific examples are other than (a), (b) and (c). (Meth) acrylates [pentyl (meth) acrylate, benzyl (meth) acrylate, dibromopropyl (meth) acrylate, isobornyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, allyl methacrylate, dicyclopentenyl (meth) acrylate, Dicyclopentanyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acryloxyethyl phosphate, etc.]; vinyl aromatic compound (styrene, vinyltoluene, α-methylstyrene, etc.); vinyl chloride, vinyl acetate, butadiene, Dicyclopentadiene, vinylpyrrolidone, Isoprene, and the like.

The amount of (d) used is usually 30% by weight or less, preferably 20% by weight or less, based on the total amount of the monomers in the copolymer (A).

The weight ratio of (a) :( b) in the copolymer (A) is usually (30-95) :( 5-70), preferably (45-90) :( 10-55). . When the ratio of (a) is less than 30, the compatibility with an acrylic resin, particularly an acrylic resin containing vinyl acetate becomes insufficient, and 95
If it exceeds, the compatibility with the alkyd resin becomes extremely poor. The weight ratio of (a + b) :( c) is usually (40 to
98): (2-60), preferably (60-95):
(5-40). When the ratio of (c) is less than 2, the pigment dispersibility becomes insufficient, and when it exceeds 60, the compatibility of the alkyd resin becomes extremely poor.

As (c), usually (c1) to (c3)
The weight ratio may be at least one selected from the group below. However, in order to exhibit higher dispersibility for various pigments, as (c), (c1)-
It is preferable to include any of (c3). Further, (A) has a hydroxyl value of 3 to 120 mgKOH / g and an acid value of 0.005 to 50 mgKOH / g, and particularly preferably has a hydroxyl value of 5 to 100 mgKOH / g,
It has an acid value of 0.01 to 40 mgKOH / g.

The number average molecular weight of (A) by gel permeation chromatography (GPC) is usually 1,0.
00-10,000, preferably 1,500-8,000
It is 0. If it is less than 1,000, the coating film physical properties of the coating material are deteriorated, and if it exceeds 10,000, the compatibility with various coating resins is deteriorated.

The method for producing (A) is not particularly limited. For example, a monomer mixture comprising (a), (b), (c) and, if necessary, (d) is subjected to known thermal polymerization, photopolymerization or It can be produced by bulk or solution polymerization by a radical polymerization method such as radiation polymerization. A preferred polymerization method is a radical solution polymerization method using a radical initiator in an organic solvent.

In the case of solution polymerization, the organic solvent used is, for example, an aromatic hydrocarbon such as toluene or xylene,
Aliphatic hydrocarbons such as heptane and mineral spirits,
Esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ethers such as butyl cellosolve, butyl carbitol and ethylene glycol dimethyl ether, isopropanol,
Examples thereof include alcohols such as n-butanol and t-butanol, and a mixture of two or more thereof. Of these, preferred solvents are toluene, xylene, methyl isobutyl ketone and butyl acetate, alone or in a mixture thereof.

When a radical polymerization reaction is carried out, the radical initiator used is azobisisobutyronitrile,
Examples thereof include azo initiators such as azobisisovaleronitrile, t-butylperoxybenzoate, t-butylperoxyisobutyrate, di-t-butylperoxide, peroxides such as hydrogen peroxide. Preferred among these are azobisisobutyronitrile, t-butylperoxybenzoate and t-butylperoxyisobutyrate.

In the production method of (A), a known chain transfer agent such as lauryl mercaptan or dibenzyl ether may be used if necessary.

The polymerization temperature in the production of (A) is usually 50.
˜180 ° C., and the method of polymerization may be either batch or continuous polymerization.

The copolymer (A) in the present invention is particularly excellent in compatibility with an acrylic resin because the main chain skeleton is derived from an acrylic resin, and has an alkyd series because it has a long chain alkyl group in the side chain. Especially excellent compatibility with resin. That is, as a whole, the main chain and side chains have different SP values,
As it has a well-balanced comb structure, it has excellent compatibility with various paint resins. In addition, since it has a functional group in the side chain, it has excellent pigment dispersibility, and since it does not have a group that adversely affects weather resistance such as urethane group, it can be used as a pigment dispersion resin for almost all coating resins Is.

The pigment-dispersing resin of the present invention contains the copolymer (A) as an essential component, and if necessary, an organic solvent, another coating resin, or another known coating additive (surfactant, fluidity). (Adjusting agent, pigment dispersant, adhesion improver, etc.) and the like may be blended.

The high-concentration pigment dispersion (pigment masterbatch) using the pigment-dispersing resin of the present invention is a copolymer (A).
And pigments and, if necessary, organic solvents, other paint resins,
Alternatively, it can be obtained by blending various paint additives. The pigment concentration in this case varies depending on the type of pigment, but is usually 10 to 60% by weight.

As the organic solvent, those exemplified as the solvent for solution polymerization can be used.

Examples of the pigment include inorganic pigments (carbon black, iron oxide, titanium oxide, calcium carbonate, yellow lead, zinc white, navy blue, etc.), organic pigments (nitroso pigment, nitro pigment, azo pigment, phthalocyanine pigment, etc.) and These mixtures are mentioned.

The pigment-dispersing resin composition of the present invention or a pigment masterbatch for a paint using the same is a conventional disperser, for example, a roll mill disperser, a sand grind mill disperser, a planetary mixer, a high speed dispers disperser. It can be obtained by mixing and dispersing by a usual method using the above.

[0030]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. Parts in the examples are parts by weight.

Example 1 30 parts of butyl acetate and 70 parts of xylene were placed in a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introducing tube and a dropping pump, an inert gas was introduced, and butyl acetate was refluxed ( (Temperature: 125 to 128 ° C.), and then with stirring, 65 parts of methyl methacrylate, 10 parts of isobutyl methacrylate, 18 parts of dodecyl methacrylate, 1 part of methacrylic acid, 3 parts of hydroxyethyl methacrylate.
Part, 4 parts of acrylamide, 5 parts of azobisisobutyronitrile and 1 part of lauryl mercaptan were added dropwise over 3 hours, and after the addition was completed, 5 parts of azobisisobutyronitrile was added and the mixture was added at the same temperature for another 2 hours. The reaction was carried out to obtain a resin solution 1 having a nonvolatile content of 50% and a number average molecular weight of 4,500 (according to GPC; the same applies hereinafter).

Example 2 100 parts of xylene was placed in a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introducing pipe and a dropping pump, and an inert gas was introduced. After heating to 135 ° C., the mixture was stirred.
Methyl methacrylate 60 parts, t-butyl methacrylate 5 parts, octyl methacrylate 20 parts, acrylic acid 0.5 part, hydroxyethyl methacrylate 1
A mixture of 0.5 parts, 5 parts of methacrylamide and 8 parts of t-butylperoxybenzoate was added dropwise over 3 hours, and after completion of the addition, 4 parts of t-butylperoxybenzoate was added dropwise over 1.5 hours. Then, the mixture was further reacted at the same temperature for 1 hour to obtain a resin solution 2 having a nonvolatile content of 50% and a number average molecular weight of 3,300.

Example 3 A flask equipped with a stirrer, a condenser, a thermometer, an inert gas introducing tube and a dropping pump was charged with 30 parts of methyl isobutyl ketone and 70 parts of xylene, an inert gas was introduced, and methyl isobutyl ketone was added. Reflux (temperature; 114-
118 ° C.) and then, with stirring, methyl methacrylate 62.
5 parts, octyl methacrylate 15 parts, maleic anhydride 0.5 parts, hydroxyethyl acrylate 3 parts, trimethylamine (meth) acrylimide 5 parts, styrene 10 parts, cyclohexyl methacrylate 5 parts and t
A mixture of 5 parts of -butyl peroxyisobutyrate was added dropwise over 3 hours, 2.5 parts of t-butyl peroxyisobutyrate was additionally added over 1.5 hours after the completion of the addition, and the mixture was further added at the same temperature. The reaction was carried out for 1 hour to obtain a resin solution 3 having a nonvolatile content of 50% and a number average molecular weight of 5,600.

Comparative Example 1 Example 1 was repeated except that butyl methacrylate was used instead of dodecyl methacrylate in Example 1.
In the same manner as in, non-volatile content 50%, number average molecular weight 4,20
A resin solution 4 of 0 was obtained.

Comparative Example 2 60 parts of xylene was placed in a flask equipped with a stirrer, a condenser, a thermometer, an inert gas introducing tube, and a dropping pump. After introducing an inert gas and heating to 100 ° C., butyl was stirred under stirring. A mixture of 98 parts of methacrylate, 2 parts of t-butylaminoethyl methacrylate and 1 part of azobisisobutyronitrile was added dropwise over 4 hours, and after completion of the addition, azobisisobutyronitrile was appropriately added to the same temperature. Then, 40 parts of xylene was added thereto to obtain a resin solution 5 having a nonvolatile content of 50% and a number average molecular weight of 18,000.

Performance Test 1 Six types of coating varnishes shown in Table 1 and the resin solutions 1 to 5 obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were used, and the resin solid content weight ratio was 7/3. The mixture was mixed as described above, and the mixed liquid was applied onto a glass plate and dried, and the presence or absence of turbidity in the coating film obtained was visually observed. The transparent one was represented by ◯ (pass) and the turbid one was represented by x (fail). The results are shown in Table 1.

[0037]

[Table 1]

1) Oil length 60% Soybean oil-modified pentaerythritol phthalate varnish (nonvolatile content 60%) 2) Melamine resin varnish [Melan # 28 manufactured by Hitachi Chemical Co., Ltd.] and oil length 30
% Soybean oil-modified trimethylolpropane / phthalic varnish solids weight ratio 2
/ 8 mixed varnish (nonvolatile content 50%) 3) Melamine resin varnish [Melan # 28 manufactured by Hitachi Chemical Co., Ltd.] and acrylic resin A (60 parts methyl methacrylate, 28 parts butyl acrylate, 10 parts human hydroxyethyl acrylate and acrylic Copolymer with a monomer composition of acid 2 parts, number average molecular weight 15,000) and mixed varnish with a solid content weight ratio of 2/8 (nonvolatile content 50%) 4) Styrene 30 parts, methyl methacrylate 30 parts, butyl acrylate 40 parts Toluene solution of a copolymer (number average molecular weight 22,000) having a monomer composition of 5% (nonvolatile content) 5) Copolymer having a monomer composition of 60 parts of vinyl acetate, 39 parts of methyl methacrylate and 1 part of methacrylic acid (number average molecular weight) 18,000) toluene solution (50% non-volatile content) 6) 70 parts nitrified cotton liquor, castor oil / glycerin / varnish phthalate 27 parts, dibutyl phthalate 3 parts toluene / vinegar Ethyl (5/5) solution (nonvolatile content 50%)

Examples 4 to 6 and Comparative Examples 3 and 4 Resin solutions 1 to 1 obtained in Examples 1 to 3 and Comparative Examples 1 and 2
5 For each 20 parts, titanium oxide 60 parts, xylene 10
And 10 parts of propylene glycol monomethyl ether monoacetate (hereinafter abbreviated as MPA) are mixed and dispersed by a sand grind mill disperser until the particle size becomes 10 μm or less to prepare pigment master batches [1] to [5]. did.

Performance Test 2 Two kinds of melamine paint varnishes (melamine / alkyd varnish and melamine / acrylic varnish) used in Performance Test 1 and the pigment masterbatches obtained in Examples 4 to 6 and Comparative Examples 3 and 4. [1] to [5] were mixed so that the resin solid content weight ratio was 8/2 to obtain white paints A1 to A5 from melamine / alkyd varnish and white paints B1 to B5 from melamine / acrylic varnish. . After diluting each white paint with a mixing thinner, apply this paint to the treated steel sheet with a dry film thickness of 30μ.
The coating performance was evaluated by spray coating so as to obtain m and baking at 140 ° C. for 20 minutes. The results are shown in Table 2.

[0041]

[Table 2]

1) JIS K-5400 67; 60-degree specular reflectance 2) JIS K-5400 614; Mitsubishi Uni-Pencil is used 3) JIS K-5400 615; 100 mm square grids are engraved with a cellophane tape The number is shown by the number of squares remaining after pressure bonding and peeling.

[0043]

The pigment-dispersing resin of the present invention has excellent pigment dispersibility for various pigments, shows good compatibility with various coating resins, and has no problems such as weather resistance. It is possible to manufacture a pigment masterbatch that can be commonly used for various paint resins. The pigment masterbatch using the resin for pigment dispersion of the present invention is a very wide range of paints such as room temperature dry type alkyd paints, alkyd melamine paints, acrylic lacquer paints, acrylic melamine paints, vinyl acetate paints, and nitrified cotton lacquer paints. Can be used as an agent, resulting in a significant reduction in the types of pigment masterbatches,
It improves the productivity of the paint.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Komuta 1-11, Hitotsubashi Honmachi, Higashiyama-ku, Kyoto Sanyo Chemical Industry Co., Ltd.

Claims (7)

[Claims] 1. A (meth) acrylate (a) having an alkyl group having 1 to 4 carbon atoms, a (meth) acrylate (b) having an alkyl group having 6 to 30 carbon atoms, and a polymerizable monomer having a functional group. A pigment-dispersing resin comprising the copolymer (A) of the body (c). 2. The polymerizable monomer (c) is the following (c1) to
The pigment dispersion resin according to claim 1, which is at least one selected from the group (c3). (C1): Hydroxyl group-containing monomer (c2): Carboxylic acid group-containing monomer (c3): Nitrogen-containing monomer 3. A weight ratio of (a) :( b) is (30 to 9).
5) :( 5-70) and (a + b) :( c) is (40-98) :( 2-60).
The pigment dispersion resin described. 4. The number average molecular weight of (A) is 1,000 to 1.
The resin for pigment dispersion according to any one of claims 1 to 3, which is 10,000. 5. The pigment-dispersed resin according to claim 1, which contains any of (c1) to (c3) as (c). 6. A hydroxyl value of 5 to 100 mgKOH / g
And the acid value is 0.01 to 40 mgKOH / g, and the pigment dispersion resin according to any one of claims 1 to 5. 7. The pigment dispersion resin according to claim 1, which is used in a non-aqueous system.