JPH01268771A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing a copolymer prepared by copolymerizing a component containing a basic monomer with an acidic monomer, unsaturated alkyd resin, vinyl acetate and alkyl (meth)acrylate and excellent in pigment dispersibility and glossiness. CONSTITUTION:The objective composition containing a copolymer obtained by copolymerizing a component containing (A) 0.01-10wt.%, preferably 0.1-2wt.% basic monomer [preferably dimethylaminoethyl (meth)acrylate], (B) 0.01-3wt.%, preferably 0.1-1wt.% acidic monomer (preferably maleic anhydride), (C) 0.01-5wt.%, preferably 1-3wt.% unsaturated alkyd resin, (D) 20-70wt.%, preferably 50-60wt.% vinyl acetate and (E) 20-70wt.% alkyl (meth)acrylate [preferably methyl (meth)acrylate] having a 1-8C alkyl group.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a coating composition with excellent pigment dispersibility.

(Prior art) In recent years, organic M-containing materials such as carbon black and cyanine blue have been
Various coating compositions have been proposed that contain either singly or in part and have excellent pigment dispersibility and pigment miscibility (color separation properties).

For example, vinyl acetate 80-30% by weight, methyl methacrylate 2
A copolymer consisting of 0 to 70% by weight and 0.1 to 1% by weight of an unsaturated carboxylic acid (JP-A-54-I30630), and vinyl acetate, methyl methacrylate and maleic anhydride in a weight ratio of 6 to 5/ A copolymer composed of 4 to 3/1 ratio (Japanese Patent Publication No. 48-39215), 80 to 30% by weight of vinyl acetate, and 20 to 70% of alkyl acrylate or alkyl methacrylate having an alkyl group having 1 to 8 carbon atoms. Weight%, basicity 0.0
1-10% by weight and 0.05-3% acidic monomer
Paint for mortar based on a copolymer consisting of
Coating compositions (Japanese Patent Publication No. 58-50647), etc., whose main ingredient is a copolymer consisting of vinyl acetate/metal methacrylate/unsaturated carboxylic acid monomer = 80-35/20-6510.05-3 double bases, etc. Disclosed.

(Problems to be Solved by the Invention) The above paints are all known as inexpensive paints for mortar, but they have the following drawbacks. In other words, paints using the above copolymer as a vehicle (vehicle) have good pigment dispersibility when the pigment component is a general-purpose pigment such as titanium oxide, clay, kaolin, or calcium carbonate, and are free from color separation during storage. Although the painted surface does not become glossy, when carbon black or cyanine blue is used, or a mixed pigment containing some of them is used, the pigment dispersibility is poor and it takes a long time for uniform dispersion. It takes.

In addition, even if the paint composition is stirred, if it is left for a long time, the pigments will settle, making workability worse, and
After drying, the paint film exhibits a mottled surface with poor gloss due to recondensation of pigment particles.

On the other hand, in construction sites, color-matching paints from different paint manufacturers are often used, and even in such cases, a paint that does not cause color separation or fading of the painted surface is desired.

Therefore, attempts have been made to improve the above problems by adding dispersants such as cationic surfactants, but the pigment dispersibility improvement effect is insufficient and foaming may occur.
There are problems such as decreased water resistance, thinner selectivity, and easy gelation during storage.

In view of the above problems, the present invention has excellent pigment dispersibility, shortens the time required for uniform mixing, maintains uniformity for a long time, and has excellent gloss without causing browning or fading. The purpose of the present invention is to provide a coating composition that has the following properties.

(Means for Solving the Problems) The present invention provides (a) 0.01 to 10% by weight of a basic monomer.
, (b) acidic monomer o, oi~3% by weight, (c) unsaturated alkyd resin 0.01~5% by weight, (d>vinyl acetate 20~70% by weight, and (e) carbon number of alkyl group is 20 The present invention relates to a coating composition containing a copolymer obtained by copolymerizing a component containing 1 to 8 alkyl acrylate or alkyl methacrylate in an amount of 70% by weight.

Examples of the alkyl acrylate or alkyl methacrylate (hereinafter referred to as alkyl (meth)acrylate) whose alkyl group has 1 to 8 carbon atoms used in the present invention include methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate. , amyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, and the like. Methyl (meth)acrylate is preferred.

In addition, as basic additives, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, butylaminoethyl (meth)acrylate,
Vinylpyridine, 4vinylpyridine, 2-methyl-5-
Vinylpyridine, 2-ethyl-5-vinylpyridine, N
-vinylimidazole, 2-methyl-N-vinylimidazole, dimethylallylamine, diallylamine, vinylpyrroline, vinylquinoline, vinylisoquinoline, N
, N-dimethylaminoethyl vinyl ether, 2-(
N,N-dimethylamino)-4-vinylpyrimidine, trans-1,2-dipyridylethylene, 3-cinnamoylpyridine, 2-methyl-5-cinnamoylpyridine,
Examples include 4,6-diamitu-2-vinyl-5-triazine.

Dimethylaminoethyl (meth)acrylate and diethylamino (meth)acrylate are preferred.

As acidic monomers, maleic anhydride, maleic acid,
Examples include monoalkyl maleate, fumaric acid, monoalkyl fumarate, itaconic anhydride, itaconic acid, monoalkyl itaconic acid, citraconic anhydride, citraconic acid, acrylic acid, methacrylic acid, crotonic acid, and the like. Maleic anhydride is preferred.

In addition, considering copolymerizability with the above monomers, as long as the copolymer is not cloudy, 2hydroxy (meth)acrylate,
A 2-hydroxypropyl (meth) aβ-ethylenically unsaturated compound may be used as part of the acrylic monomer.

The alkyd resin to be grafted to the copolymer of the present invention contains an unsaturated group and is not particularly limited as long as it does not cause "turbidity" in the copolymer when copolymerized.

The proportion of vinyl acetate is preferably 20 to 70% by weight. If the proportion of vinyl acetate is less than 20% by weight, the flexibility of the coating film will decrease and cracks will easily occur in the coating film.
Also, the gloss tends to be lower. On the other hand, if it is 70% by weight or more, the water resistance and alkali resistance of the coating film tend to decrease. A more preferable range is 50 to 60% by weight.

The ratio of the above alkyl (meth)acrylate is 50 to 60
Preferably, it is % by weight. Outside this range, the toughness, weather resistance, and other properties of the coating film tend to be unbalanced.

The proportion of basic additives is 0.01 to 10% by weight. If the proportion of the basic additive is less than 0.01% by weight, the effect of improving pigment dispersibility will be insufficient, and if it exceeds 10% by weight, the coloring or water resistance of the resin will deteriorate. The preferred range is 0.1 to 2%.

The proportion of acidic monomer is 0.01 to 3% by weight. When the proportion of acidic additives is less than 0.01% by weight, the effect of improving pigment dispersibility is insufficient, and when it exceeds 3% by weight, a gelation phenomenon occurs. A more preferable range is 0.1 to 1% by weight.

The proportion of the unsaturated group-containing alkyd resin is 0.01 to 5% by weight. When the unsaturated group-containing alkyd resin is less than 0.01% by weight, the effect of improving pigment dispersibility is insufficient, and when it exceeds 5% by weight, the alkali resistance and weather resistance are poor. A more preferred range is 1 to 3% by weight.

As a reaction method for the above-mentioned substances, a polymer chain equipped with a cooling condenser, a thermometer, a nitrogen gas filling port, and a seven-point dripping port can be used. A continuous reaction method can also be used.

As the polymerization initiator, azo compounds such as azobisisobutyronitrile, peroxides such as benzoyl peroxide or di-1-butyl peroxide, and mercaptans such as octyl thioglycolate are used. A chain transfer agent such as the following may be used in combination. Also,
In the case of solution polymerization, the polymerization solvent includes aromatic hydrocarbons such as xylene or toluene, alcohols such as isopropanol and butanol (n, 1so),
Examples include esters such as ethyl acetate or 11-n-butyl acid, ketones such as methyl ethyl ketone or methyl-1-butyl ketone, and the like.

The coating composition of the present invention can be used as an adhesive and for lamination, but is particularly applicable to the various coatings mentioned above.

(Example) The present invention will be explained by examples.

In addition, in the following, the term "department" shall mean "Mold Science Department J" unless otherwise specified.

(1) Production of unsaturated group-containing alkyd resin Safflower oil 5
00 parts, dehydrated castor oil 510 parts, glycerin 130 parts,
200 parts of trimethylolpropane, 6 parts of lithium naphthenate, and 6 parts of Kizilol are charged into a 3000 ml four-bottle flask, heated to 230°C, and saturated to a methanol tolerance of 3.0 or more in about 3 hours. The revenge, 100'C
Cool until cool. Next, 110 parts of glycerin, 25 parts of xylene, 0.2 parts of antifoaming agent, and 15 parts of trimethylolpropane.
0 parts, 20 parts of maleic anhydride, and 710 parts of phthalic acid were charged, and the temperature was raised to 210°C. and acid value 3. O (things in the pot/
Toluene - Keep warm until the temperature drops below 70/30). Cool to 1120'C, add 140 parts of malein and keep warm for 1.5 hours.

Then, it was diluted with toluene to give a non-volatile content of 65% and a viscosity of
An alkyd resin of Y was obtained.

(2) Example 1 60 parts of vinyl acetate and 40 parts of methyl methacrylate in a polymerization can
1 part, 0.5 parts of dimethylaminoethyl methacrylate, 0.8 parts of maleic anhydride, 2.5 parts of the unsaturated group-containing alkyd resin obtained in (1) above, 40 parts of toluene, and 1 part of azobisisobutyrronitrile. Prepare the temperature 80-100
The reaction was carried out at ℃ for 10 hours.

After the polymerization was completed, 60 parts of toluene was added to obtain a resin solution with a solid content of 50% and a viscosity of 4500 CpS.

Add 3 parts of titanium oxide to 100 parts of the resin liquid obtained as above.
0 parts and 15 parts of toluene were added, and 150 parts of glass powder having a particle size of 1 mm was added to the colander, followed by dispersion for 1 hour using a paint shaker. This will be used as white enamel.

Separately, 5 parts of carbon black and 15 parts of toluene were added to 100 parts of the above resin liquid, and 150 parts of coarse glass beads having a particle size of 1 mm were added, followed by dispersion in a paint shaker for 1 hour. This is called black enamel.

Separately, 90 parts of the above white enamel, 10 parts of black enamel, and 50 parts of toluene were mixed and stirred using a disper.

This is called mixed color enamel.

Dispersibility (dispersion time, gloss, rubbing test, overcoat color separation) and storage stability tests were conducted using the three types of paints, white enamel, black enamel, and mixed color enamel, obtained as described above. The coating was performed using a tin plate. The above test results are shown in Table 1.

In the above test, the dispersion time was determined by measuring the change in particle size of carbon black over time using a particle gauge, and was expressed as the time required for the maximum particle size to become 20 μm or less.

Gloss is measured at an angle of incidence of 60'.

In addition, in the rubbing test, 90 parts of white enamel, 10 parts of black enamel, and 50 parts of toluene were dispersed with a disperser for 5 hours, then poured onto a tin plate, and after 60 seconds, the painted surface was lightly rubbed with a finger, and the surface was left to stand. This was done by comparing the colors.

Next, the color separation property of overcoating was determined by pouring the blended paint used in the rubbing test onto a tinplate plate, and after 60 seconds, roughly overlapping a part of the tinplate and pourcoating. The difference in color was compared.

Furthermore, storage stability can be improved by adding toluene to the resulting paint.
Total paint height A (cm
) to the precipitated pigment height B (cm).

That is, storage stability was set as B/AX100 (%).

(3) Comparative example Next, a comparative example will be explained, and the test results are also shown in Table 1.

Comparative Example 1 A 50% toluene solution of a copolymer consisting of 60 parts of vinyl acetate and 40 parts of methyl methacrylate (viscosity 3000C)
I) Three types of paints were prepared in the same manner as in Example 1 above, except that S) was used, and various tests were conducted in the same manner as in the above Example. The same applies to the following comparative examples.

Comparative Example 2 60 parts of vinyl acetate, 39° 2 parts of methyl methacrylate,
Three types of paints were prepared in the same manner as in Example 1 above, except that a 50% toluene solution (viscosity: 3000 CpS) of a copolymer containing 0.8 parts of maleic anhydride was used.

Comparative Example 3 60 parts of vinyl acetate, 39°5 parts of methyl methacrylate,
50% toluene solution of copolymer consisting of 0.5 parts of dimethylaminoethyl methacrylate (viscosity 30,000 pS)
Three types of paints were prepared in the same manner as in Example 1 above, except that .

Comparative Example 4 60 parts of vinyl acetate, 38.9 parts of methyl methacrylate,
Example 1 above except that a 50% toluene solution (viscosity 3000 cps) of a copolymer consisting of 0.5 parts of dimethylaminoethyl methacrylate and 0.8 parts of maleic anhydride was used.
Three types of paint were prepared in the same manner.

Comparative Example 5 60 parts of vinyl acetate, 37°5 parts of methyl methacrylate,
Three types of paints were prepared in the same manner as in Example 1 above, except that a 50% toluene solution (viscosity 3500 cps) of a copolymer consisting of 2.5 parts of an unsaturated group-containing alkyd resin was used.

Comparative Example 6 60 parts of vinyl acetate, 36.7 parts of methyl methacrylate,
0.8 parts of maleic anhydride, unsaturated group-containing alkyd resin 2
．． A 50% toluene solution of a copolymer consisting of 5 parts (viscosity 3
Three types of paints were prepared in the same manner as in Example 1 above, except that 500CpS) was used.

Comparative Example 7 A 50% toluene solution (viscosity 35,000 pS) of a copolymer consisting of 60 parts of vinyl acetate, 3 parts of methyl methacrylate, 0.5 parts of dimethylaminoethyl methacrylate, and 2.5 parts of an unsaturated group-containing alkyd resin was used. Other than that, three types of paints were prepared in the same manner as in Example 1 above.

(4) In Table 2, 90 parts of the white enamel of each comparative example was taken against 10 parts of the black enamel of Example 1, diluted appropriately with toluene, and the test results of color separation properties are shown.

Further, Table 3 shows the test results of color separating properties obtained by taking 90 parts of the mixed color enamel of each comparative example against 10 parts of the black enamel of Example 1 and diluting them with toluene.

Table 2 (Effects of the Invention) The coating composition according to the present invention has excellent pigment dispersibility, and can maintain uniformity for a long period of time by performing high-degree dispersion. This has the effect of producing a coating composition that does not cause any blemishes and also has excellent gloss.

Claims (1)

[Claims] 1. (a) 0.01 to 10% by weight of basic monomer, (b) 0.01 to 3% by weight of acidic monomer, (c) 0.01 to 5% by weight of unsaturated alkyd resin, (d)
A coating composition containing a copolymer of a component containing 20 to 70% by weight of vinyl acetate and (e) an alkyl acrylate or alkyl methacrylate having an alkyl group having 20 to 70% by weight of 1 to 8 carbon atoms.