JPS59217769A - Coating material composition - Google Patents

Abstract

PURPOSE:A coating material composition, containing a specific acrylic based graft copolymer in a specific proportion, having improved dispersion stability and storage stability, and useful for varnishes, etc. CONSTITUTION:A coating material composition obtained by incorporating (A) a resin component with (B) 5% or more, based on the resin component (A), acrylic based graft copolymer consisting of (i) a monomer, constituting a graft chain, and containing 30% or more basic monomer, e.g. dimethylaminomethyl acrylate, and (ii) a monomer constituting the main chain, e.g. acrylic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating composition, and more particularly to a coating composition having particularly good pigment dispersibility.

Since the color pigments used in coatings range from acidic, neutral, and basic, attempts have already been made in JP-A-58-21468 to make the resin for pigment dispersion amphoteric and obtain paints with excellent pigment dispersibility.
It is well known as seen in M. et al.

As a method of imparting basicity to acidic resins such as acrylic resins, a method of random copolymerization of basic monomers is generally adopted. However, in this case, the basic groups are widely distributed in the main chain. Therefore, when adsorbing acidic pigments, it is thought that the resin adsorbs to pigment particles in such a way that the intermolecular distance between basic groups becomes short; however, the thickness of the adsorption layer inevitably increases. As the paste became thinner, a sufficient pigment dispersion stabilizing effect could not be exhibited, and in fact, the dispersion paste 1 made of such a resin had a problem in terms of stability over time.

In addition, since the basic group is present in close proximity to the main chain, steric hindrance and other issues arise during contact with pigments, resulting in poor adsorption efficiency and a need for improvement in terms of dispersion speed.

In view of this, the present invention has developed a coating composition with excellent dispersion stability and storage stability by discovering an amphoteric resin that efficiently adsorbs pigment particles and forms a thick adsorption layer around the particles. This was done for the purpose of 1q. The present inventors have discovered that among α,β-ethylenically unsaturated monomers, those having no oxirane ring and carfoyacyl group, such as esters such as acrylic acid and methacrylic acid, acid amides, acid nitrile acids, etc. When fatty acid vinyl esters, aromatic monoolefins, etc. are polymerized in an organic solvent in the presence of an azo initiator having a carboxyl group and a tertiary amine, the molecular weight ranges from about 600 to about 2 at a high polymerization rate.
An acrylic oligomer having a terminal carboxyl group with a controlled molecular weight of up to about 0,000 is obtained, and by reacting this with a compound having an oxirane ring and a polymerizable unsaturated group such as glycidyl (meth)acrylate, They have discovered that a reactive acrylic oligomer, that is, a macromer solution can be obtained, and that a grafted acrylic resin composition can be obtained by copolymerizing the macromer with an α,β-edylenically unsaturated monomer. The patent application was filed on the same date as the present application. According to the method for producing the graft copolymer resin (hereinafter referred to as the macromer method), a basic supermer is added to the heptadylamine-1 constituting the graft chain, that is, the α,β-ethylenically unsaturated monomer used in the production of the macromer. By arranging ~ and an acidic monomer in the monomers constituting the main chain, it is possible to obtain a grafted amphoteric resin in which basic groups are omnipresent or concentrated in the graft chain, and moreover, It is possible to control the molecular weight of the chain and freely design the concentration of basic groups.

The present inventors have obtained an acrylic graft copolymer in which basic groups are concentrated in the graft chains using this macromer method, and when this is used as a resin vehicle for dispersing pigments, for example, the base of the graft chains can be used for acidic pigments. The functional groups are adsorbed with high adsorption efficiency without steric hindrance caused by the main chain, while the main chain portion acts as an effective barrier against contact between pigments, resulting in coating compositions with excellent dispersion stability and stability over time. The present inventors discovered that the present invention can be obtained and completed the present invention.

That is, according to the present invention, at least 5% of the resin component contains an acrylic graft copolymer consisting of a graft chain and a main chain in which at least 30% of the monomers constituting the graft chain are basic monomers. A coating composition with good pigment dispersibility is provided.

As mentioned above, it is convenient and preferable for the acrylic graft copolymer used in the present invention to be produced by the macromer method discovered by the present inventors. However, it is also possible to manufacture it by other methods if desired. As the basic monomer constituting the graft chain, any basic monomer used in the production of acrylic or vinyl resins can be used. Typical examples thereof include dimethylaminomethyl acrylate, diethylaminomethyl acrylate, dibutylaminomethyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, di(t-butyl)aminoethyl acrylate, diisohexyl A4-acrylates such as aminoethyl acrylate, diethylaminoethyl acrylate, di(-butyl)aminohexyl acrylate; corresponding methacrylates 1 to 4; 4-vinylpyridine, 2-vinylpyridine, 2-methyl-5- Examples include vinylpyridines such as vinylpyridine.

The monomers constituting the graft chain may be composed only of these basic monomers, but in the present invention, it is essential that at least 30% of the monomers be composed of basic monomers. If the amount of basic monomer in the graft chain is less than 30%, the pigment adsorption efficiency will not be sufficiently high, and the purpose of the invention, which is to obtain a coating composition with particularly excellent pigment dispersibility, will not be fully achieved. .

The heptamer constituting the main chain of the graft copolymer may be any α,β-ethylenically unsaturated monomer used in the production of acrylic polymers, including the above-mentioned basic hepatomer.

However, in order to make the resin an amphoteric resin, a part of the heptamers constituting the main chain must be an acidic monomer, for example, a polymerizable unsaturated monomer having a carboxyl group. This R
+1. - Typical E-sumers include acrylic acid, methacrylic acid, maleic anhydride, maleic acid,
Examples include fumaric acid, itaconic acid, and crotonic acid, but of course the compound is not limited to these, and any compound can be used as long as it has a polymerizable unsaturated bond and an acidic group. For the purpose of obtaining a coating composition containing not only an amphoteric resin but also an amino resin or a curing agent, for example, the acidic monomer aλ in the main chain should be set so that the acid value of the final resin is 5, based on the solid content of the resin. - It is preferable to set it as sufficient amount to become -50.

Similarly, the monomers constituting the main chain contain hydroxyl group-containing monomers, whose hydroxyl value is 4 in the resin solid content.
It has also been found that it is preferable to have a sufficient amount of 0 to 150.

In the present invention, the above acrylic graft copolymer is
It is preferably used as a resin component for pigment dispersion, making up at least 5% of the resin component.

The coating composition of the present invention contains a resin vehicle, a solvent, a pigment, and their respective additives, but it is essential that at least 5% of the resin component is the graft copolymer. Jru. Normally, when making a paint, a pigment paste is prepared by dispersing a pigment in a resin composition, and other resins for film formation and other additives are uniformly mixed. In a particularly preferred embodiment of the invention, the graft copolymer composition described above is used to prepare a pigment paste and then other resins are incorporated. However, when a part of the graft copolymer and a part of other resin are used to prepare a pigment paste,
You can add the remaining graft copolymer later, or
It is also possible to add a graft copolymer to the lifting platform afterwards. In any case, the grafted copolymer must be used in an amount of at least 5% of the resin component, and if it is less than 5%, the purpose of the present invention cannot be fully achieved. One of the characteristics of the present invention is that since the grafted copolymer is an amphoteric resin, it has extremely good compatibility with other resins.

The resin, pigment, solvent, etc. for forming the coating are not special at all and can be arbitrarily selected from a wide range of commonly used ones, and the means for forming the coating or the means for applying the coating are also conventional.

In the present invention, a specific grafted acrylic copolymer resin is
When used in a specific proportion in the resin component, a coating composition with particularly improved pigment dispersion stability can be provided. In order to make it easier to understand, we have explained the combination with acidic pigment, but since the copolymer from Graph 1 is an amphoteric resin, it does not matter whether the pigment is neutral or basic. It shows excellent pigment dispersion stability.

The present invention will be explained below with reference to Examples.

Macromer synthesis example 1 Dripping funnel A, 82 pieces, cooling pipe, nitrogen introduction pipe, temperature t1
400 parts of methylisobutylkene and 400 parts of xylene were charged into a reaction vessel equipped with a stirring bar and the temperature was raised to 120°C. 400 parts of styrene and 400 parts of 2-ethylhexyl methacrylate were charged into dropping funnel A, and a solution of 80 parts of 4,4'-azobis(4-cyan)valeric acid, 320 parts of butanol, and 58 parts of triethylamine was charged into dropping funnel B. The contents of dropping funnels A and B were mixed at 120°C under a nitrogen atmosphere at 3:08 p.m.
− Drop at a constant speed between After dropping, maintain at 120°C for 30 minutes,
A solution of 8 parts of 4,4'-azobis(4-cyanovaleric acid), 32 parts of butanol, and 5.8 parts of triethylamine was charged into dropping funnel B and added dropwise over 30 minutes. 120 minutes after completion of dripping
After aging at 100°C for 1 hour, the solvent was removed at 100°C under reduced pressure, 945 parts of xylene was added to make a xylene solution of O1 oligomer, and 10% of methylglycidyl methacrylate was added.
484 parts and 1.1 parts of hydroquinone were added, and the mixture was back-warmed to 150°C and reacted at 150°C for 1 hour. After cooling, the contents were taken out to obtain a macromer solution.

Macromer Synthesis Examples 2 to 7 Macromer solutions were obtained in the same manner as in Synthesis Example 1 using the monomer formulations shown in Table 1. The special values are shown in Table 2.

(Leaving space below) Table 1 -11- Varnish synthesis example 1 35 parts of toluene and 10 parts of n-butanol were placed in a reaction vessel equipped with a stirring bar, cooling tube, thermometer, nitrogen introduction tube, and dropping funnel 1.
The temperature was raised to 105°C. Into the dropping funnel, 50 parts of methyl methacrylate, 30.0 parts of n-7dyl acrylate,
4.6 parts of n-butyl methacrylate, 14.0 parts of 2hydro-4-nidiethyl methacrylate, 11.4 parts of acrylic, 10 parts of the macromer solution obtained in Macromer Synthesis Example 1,
2 parts of azobisisobutyronitrile was charged and added dropwise at a constant rate at 105°C over 3 hours. 30 minutes after completion of dropping, add tert-butylperoxy 2-ethylhexanoate 0.2
After adding 5 parts of toluene to the reaction vessel and aging for 2 hours, 45 parts of toluene was added, and after cooling, it was taken out from the reaction vessel, non-volatile content 50%, viscosity (Toshiba bubble viscosity reduction) Y-7, acid value 11, O (mqKOH/g solid content), number average molecule 1
7,800, and a weight average molecular weight ff of 129,000 was obtained.

Varnish Synthesis Examples 2 to 10 Varnishes were obtained using the same method as Synthesis Example 1 and the monomer formulations shown in Table 3. Special values are shown at the bottom.

Table 3 - Varnish Comparative Synthesis Example 1 In Production Example 1, 8110 parts of varnish obtained in Synthesis Example 1 was added to 1 volume of dimethylaminoconitylbutylene methacrylate, and 1 to 2 parts of dimethylaminoconityl methacrylate was added to Varnish A was obtained by carrying out the same operation as in Production Example 1 except that the amount was changed to 1.8 parts. The special values are shown in Table 4.

Varnish Comparative Synthesis Examples 2 to 10 Varnishes were obtained in the same manner as in Production Example 1 using the formulations shown in Table 4. Varnish special values are shown below.

(Left below) Example 1 Grafted acrylic resin solution obtained in varnish synthesis example 1
A black dispersion paste was prepared by dispersing pigments using the following dispersion blending method, and then a black primary color paint was prepared by melt blending.

Table 5 (Dispersion blend) Carbon black (Note 1> 3.3 parts Graft acrylic resin solution I 15.6 parts Kijiroru 15.1 parts 34
．． 0 parts (dissolved blend) Black dispersion paste 1 to 34.0 parts Graft acrylic resin solution I 102.0 parts Melamine resin (Note 2) 28.0 parts Kijirol 8.6 parts Butanol 4.7 parts 177.3 parts
Department (Note 1) Columbia Industries Neo Spectra AG Peas (Note 2) Mitsui Toatsu Co., Ltd. Knee Pants 20S
E-60-17- Pour the obtained black primary color paint onto a glass plate, 1
It was baked for 30 minutes in a hot air dryer set at a temperature of 40°C. 20° mirror gloss of this coating (Murakami type gloss system GM-3
H type) was measured to evaluate pigment dispersibility. Table 7 shows the specular gloss results.

In addition, this coating film was measured in the visible region (400 nm) using a spectrophotometer (Macbeth Automatic Color Eye KC8-18).
The color was measured by reflectance measurement (up to 700 nm), and the Y value was determined to evaluate the degree of jet blackness. The results are shown in Table 1. In addition, in order to evaluate the dispersion stability of the paste, the viscosity was measured after storage at 40° for one month, and the viscosity increase rate (40°C x 1
Viscosity after months (CEIS)/Initial viscosity (CIIS)
) was evaluated. The results are shown in Table 1.

Example 2 Grafted acrylic resin solution obtained in varnish synthesis example 2
A red primary color paint was prepared by dispersing and dissolving the following.

Table-6 (Dispersion blend) Kijiroru 30.0 parts 10
0.0 (Dissolved blend) Red dispersion paste 100. On-
Buknor 5.0167
．． 0 (Note 3) DuPont Shinka Shared RT-759D
The red primary color paint obtained in the same manner as in Example 1 was flow-coated onto a glass plate, and the 20' specular gloss was measured. The result is second
Shown in the table. Further, the dispersion stability of the paste was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Examples 3 to 5 In Example 1, the graft acrylic resin solution (1) was changed to m, rv, and v, respectively, and 19-18-ri black primary color paints were obtained and evaluated in the same manner. The evaluation results are shown in Table 1.

Examples 6 to 8 Red primary color paints were obtained and evaluated in the same manner as in Example 2 except that the graft acrylic resin solution TI was changed to Vl, VW, and ■, respectively. The evaluation results are shown in Table 2.

Comparative Example 1 In Example 1, the graft acrylic resin solution ■ was used as A and B.
A black primary color paint was obtained and evaluated in the same manner as in Example 1, except for the following changes. The evaluation results are shown in Table 1.

Comparative Example 2 A red primary color paint was obtained and evaluated in the same manner as in Example 2 except that the graft acrylic resin solution I was changed to C and D. The evaluation results are shown in Table 2.

Comparative Examples 3 to 5 In Example 1, the graft acrylic resin solution
, G, black primary color coating 11 was obtained and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

Comparative Examples 6 to 8 In Example 2, graph 1 to acrylic resin solution ■ to 11
, I, and J, and the red primary color paint was evaluated at 19 by the same method as in Example 2. The evaluation results are shown in Table 2.

(Space below) 21- Table 1 Black paint evaluation results Table 2 Red paint evaluation results 491- Name Relationship with the person making amendments to the coating composition 3 Patent applicant address 2-1-2 Oyodokita, Oyodo-ku, Osaka-shi, Osaka Name Nippon Pain 1-Co., Ltd. Representative Masao Suzuki 4 Agent address 540 Osaka Prefecture 3-57 Kyobashi, Higashi-ku, Osaka Number of inventions to be increased by the amendment 6 - 7 Subject of the amendment Contents of the amendment in column 8 of detailed explanation of the specification Vinylpyridines, etc. J such as vinylpyridine should be corrected to "Vinylpyridines such as 5-vinylpyridine, dimethylaminopropylacrylamide, etc. J.

2. Delete the entire text between page 9, line 11 and page 10, line 11, and insert the following.

"Macromer synthesis example 1 dropping funnel A, 82 pieces, cooling pipe, nitrogen introduction pipe, thermometer,
A reaction vessel equipped with a stirring bar was charged with 590 parts of butyl acetate and heated to 120°C.

Add 200 parts of dimethylaminoethyl methacrylate to dropping funnel A, and add 40 parts of 4,4'-azobis(4-cyanovaleric acid).
A mixed solution of 200 parts of n-butanol and 24 parts of triethylamine was charged into dropping funnel B, and heated at 120°C for 3 hours.
It was dropped at a uniform rate over time.

After the dropwise addition was completed, the mixture was kept at 120°C for 30 minutes, and then 37 parts of glycidyl methacrylate and 2.6 parts of hydroquinone were added, followed by reaction at 120°C for 60 minutes. After cooling, the contents were taken out to obtain macromer solution 1. The special values are shown in Table 2. 3. In Table 1 on page 11, the entry for methyl methacrylate in Macromer 4 has been corrected to read "r180J" as "80".

Claims (2)

[Claims] (1) At least 30 of the hepatomers constituting the graft chain
A coating composition with good pigment dispersibility, characterized in that it contains at least 5% of the resin component of an acrylic graft copolymer consisting of a graft chain and a main chain, of which % is a basic monomer. (2) The composition according to claim 1, wherein the acrylic graft copolymer is used as a base for pigment dispersion.