JPH0143787B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a resin composition that is an excellent pigment dispersant. Conventionally, paints in which pigments are dispersed using vinyl resin or acrylic resin as a color vehicle are known, but when two or more paints of different colors are mixed and painted, the surface of the paint film is Pigment separation and floating (due to the specific gravity of the pigment itself and other factors, when a rubbing test is performed on a paint film, there will be a difference in color between the rubbed test area and other areas)
Such phenomena occurred. This phenomenon is considered to be due to homoaggregation and heteroaggregation of pigments. This heteroaggregation can be prevented to some extent by adding various additives such as surfactants and alcohols during pigment dispersion. However, when a large amount of additives are present in a paint, it brings about unfavorable results in terms of paint film performance, such as repellency and a decrease in water resistance. On the other hand, as a method to prevent homoaggregation, a solution has been found by changing the combination of the conventionally used vehicle and pigment. This method was not universal because it relied on the experience and intuition of paint manufacturers. In order to prevent the agglomeration of pigments as described above, synthetic resins with dispersibility comparable to that of nitrified cotton and oils and fats have been developed, but a sufficient amount has not yet been obtained. The present invention has been made in view of the above-mentioned current situation, and it is an object of the present invention to provide a resin composition mainly aimed at improving the homoaggregation of pigments and improving the dispersibility of pigments. That is, the present invention comprises (a) acrylic acid or methacrylic acid alkyl ester...46.0-99.9% by weight, (b) triallylamine...0.1-4.0% by weight, and (c) other vinyl monomers...0-99.9% by weight. The present invention relates to a pigment-dispersing resin composition comprising a copolymer having a molecular weight of 60,000 to 120,000 obtained from 50% by weight and a solvent. In other words, one feature of the present invention is that it uses a resin copolymerized with a small amount of a polyfunctional polar monomer. The alkyl esters of acrylic acid or methacrylic acid [component (a)] used in the present invention include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and (meth)acrylic acid. Butyl, octyl (meth)acrylate, lauryl (meth)acrylate, (meth)acrylic acid 2
-Ethylhexyl and the like, which may be used singly or as a mixture of two or more. This component is used in a proportion of 46.0 to 99.9% by weight in the copolymer. If the content of this component exceeds 99.9% by weight, the amount of component (b) described below will inevitably decrease, making it impossible to achieve the effects of the present invention. In addition, if the above-mentioned (a) component does not account for 96.0% by weight, in addition to the (b) component, the following (c) may be added.
Use ingredients together. However, considering the purpose of the present invention and coating film performance, the amount of the component (a) to be used should be at least
46.0% by weight is required. Moreover, the triallylamine used in the present invention [(b)
component] has the following structural formula. Component (b) is used in a proportion of 0.1 to 4.0% by weight in the copolymer. If component (b) is less than 0.1% by weight within the above range, it will be difficult to obtain the effect of preventing pigment homoaggregation, which is the objective of the present invention, and conversely, if it is used in an amount exceeding 4% by weight, the copolymer will Both are undesirable as there is a risk of gelation during production. Due to the presence of a small amount of the component (b) in the copolymer, when the polar group of the component (b) in the copolymer is adsorbed to the pigment surface, the polymeric resin layer that prevents the pigments from coagulating together is formed. It is thought that it is formed on the surface of the pigment, and as a result, homoaggregation of the pigment is prevented. Furthermore, in the present invention, other vinyl monomers [component (c)] may be used in combination in a proportion of 50% by weight or less in the copolymer, if necessary. The (c) component includes (meth)acrylic acid, maleic anhydride, cyclohexyl (meth)acrylate,
Examples include styrene, vinyltoluene, α-methylstyrene, divinylbenzene, vinyl acetate, (meth)acrylonitrile, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, etc. These may be used alone or in a mixture of two or more. used as. In particular, in the copolymer of the present invention, a vinyl monomer containing a carboxyl group or an acid anhydride group, such as (meth)acrylic acid or maleic anhydride, is added to the copolymer to improve adhesion to the coated object. It is preferable to use it in a proportion of 0.1 to 1% by weight in the polymer. If the amount of the vinyl monomer exceeds 1% by weight, it is not preferable because the water resistance, alkali resistance, etc. of the film decrease. The pigment dispersible resin composition of the present invention includes a monomer mixture consisting of component (a), component (b), and optionally component (c), and a polymerization initiator in an amount of 0.1 to 5% by weight based on the mixture. and 50~400% by weight, preferably 60~
Add 150% by weight of solvent, 60-150℃, 3-12
It can be obtained by a copolymerization reaction using a conventional method under conditions of approximately 100 hrs. At this time, monomers, polymerization initiators, etc. may be used separately. Examples of the polymerization initiator include organic peroxides such as benzoyl peroxide, di-tert-butyl peroxide, and methyl isobutyl ketone peroxide; azobisisobutyronitrile;
Examples include azo compounds such as azobisvaleronitrile and azobis2-methylbutyronitrile. The solvents include aromatic hydrocarbon solvents such as benzene, toluene, and xylene; aliphatic hydrocarbon solvents such as mineral turpentine; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; methyl acetate, and ethyl acetate. , ester solvents such as butyl acetate; and ether alcohol solvents such as ethylene glycol ethyl ether and diethylene glycol ethyl ether, and these may be used alone or as a mixture of two or more. The molecular weight of the copolymer obtained by the above production method is preferably about 60,000 to 120,000. The resin composition thus obtained is further diluted with a solvent if necessary, and then mixed with a pigment in a conventional manner. Therefore, the resin composition of the present invention mixed with each pigment does not cause any agglomeration of pigments even when two or more types are mixed together, and can be used as a coating composition for metals and other base materials by conventional methods. Even when applied by a painting method, the performance of the film is as good as, if not better than, conventional ones. Furthermore, the pigment-dispersible resin composition of the present invention can be used as a coating composition by blending various additives, plasticizers, extender pigments, and other resins as necessary. Furthermore, the pigment dispersible resin composition of the present invention includes:
(c) Select the components appropriately ((meth)acrylic acid 2-
By using vinyl monomers containing hydroxyl groups such as hydroxyethyl, etc., they can be used in combination with polyisocyanate compounds or amino resins as coating compositions for cold-curing or heat-curing paints, respectively. Hereinafter, the details of the present invention will be explained with reference to Examples.
"Part" or "%" indicates "part by weight" or "% by weight". Example 1 70 parts of methyl methacrylate, 10 parts of ethyl acrylate
part, butyl acrylate 20 parts, maleic anhydride 0.4 parts
parts, triallylamine 1.5 parts, azobisisobutyronitrile 0.8 parts, toluene 40 parts, butyl acetate 10 parts
The mixture consisting of 50% of
After the reaction was completed, 50 parts of toluene was added to dilute the mixture to obtain a resin composition of the present invention. The obtained resin composition was light brown and transparent, and had a color number of 2.
(Gardner), nonvolatile content was 50%, and viscosity was 30 Stoke Poise (hereinafter referred to as sp). Examples 2 to 4 and Comparative Example 1 Resin compositions of the present invention and comparative examples were obtained in the same manner as in Example 1 using the formulations shown in Table 1. Solution state, number of colors, non-volatile content,
The viscosity is also shown in Table 1.

[Table] Comparative Test 1 Using each of the resin compositions obtained in Examples 1 to 4 and Comparative Example 1, the compositions shown in Table 2 were mixed in a sand grinder to produce white, rust-red, yellow-brown,
Black and red primary color paints were created. Next, as shown in Table 3, paints were mixed at a ratio of 1 part of each primary color to 10 parts of white paint, and white/rust red/yellow/black = 1/1/2/1 (parts).
Create paints mixed at the ratio of (the viscosity of each paint is
90 to 120 KU, /20℃), diluted each with 60 to 80% thinner, air sprayed the entire surface of the slate board, dried for 5 minutes, then flow-painted on half of the air spray coating. did. After drying for 2 minutes, the flow-coated area was rubbed with a finger and the difference in color was observed. The results are shown in Table 3. In the table, ◎ indicates that there is no difference in color between the air spray area, flow coating area, and rubbing area, △ indicates that the color is slightly different, × indicates that the color is different, and XX indicates that the color is significantly different.

【table】

[Table] It is clear from the test results table in Table 3 that the paint obtained from the resin composition of the present invention shows no difference in color, whereas the comparative composition shows no difference in color between the spray-painted area and the sink. Differences in color from the painted areas were observed, particularly in the mixed colors of white/black and white/red rust/yellow/black. Comparative Test 2 A white paint obtained using each of the resin compositions described above was applied onto a glass plate using a 4 mil applicator, and drying properties were observed. After drying for a week, JIS
Comparative tests were conducted on the alkali resistance, water resistance, weather resistance (Sunshine Weather-Ometer), and adhesion of -K-5654. The results are shown in Table 4.

【table】

[Table] It is clear from the comparative test table in Table 4 that the film performance of the paint obtained from the resin composition of the present invention was superior to, if not inferior to, other similar acrylic resin paints. .

Claims (1)

[Scope of Claims] 1 (a) Acrylic acid or methacrylic acid alkyl ester...46.0 to 99.9% by weight, (b) Triallylamine...0.1 to 4.0% by weight, and (c) Other vinyl monomers... A pigment-dispersible resin composition comprising a copolymer having a molecular weight of 60,000 to 120,000 obtained from 0 to 50.0% by weight, and a solvent.