JPH0786178B2 - Matte paint composition - Google Patents

Description

The present invention relates to a curable fluorine-containing copolymer having a hydroxy group in the molecule, a vinylidene fluoride-based copolymer or a fluorine-containing acrylic-based copolymer. The present invention relates to a resin composition for a matte coating, which uses a blended resin composition with a polymer as a main component and utilizes a phase separation phenomenon between both copolymers.

(Prior Art) Conventionally, fluorine-containing copolymers are excellent in heat resistance, mechanical properties, chemical resistance, weather resistance, etc., and various applications have been studied.
Among them, attempts to use fluorine-containing polymers as paints have been made in the old days, starting with tetrafluoroethylene polymers and chlorotrifluoroethylene polymers, and recently using vinylidene fluoride polymers and even fluorine-based copolymers. Modified fluorine resin paints that have been modified by addition to other synthetic resin paints are on the market, and are mainly used in the chemical industry, food, construction, instruments, etc. It is used. In particular, weather-resistant paints using solvent-type fluorine resin have recently been put into practical use.

These are curable paints that have increased solubility in organic solvents and can be dissolved in general paint solvents.The construction can be performed on-site as with ordinary hydrocarbon solvent-based paints. As a long-term maintenance-free paint that takes advantage of weather resistance and chemical resistance, it is expanding for building civil engineering and mechanical metals.

As an attempt to apply the fluorine-based resin as described above to a solvent type coating, JP-A-57-34107, 57-34108 and 60-
There is an example found in −147415.

On the other hand, not only fluorocarbon resin-based paints, but also interior and exterior walls of buildings, etc. have attracted attention for their weather resistance, aesthetics, and calmness, and various matte-type paints have been devised. It has been put to practical use. However, since these are fine powders of inorganic substances such as silica and calcium carbonate, and fine powders of organic substances such as epoxy resin, dispersed as a matting agent, in the case of fluorine resin-based paint, the matting agent itself has weather resistance. It has a drawback that it causes a decrease. In order to eliminate these drawbacks, a dispersion of a vinylidene fluoride, a tetrafluoroethylene polymer, etc. as a matting agent has been proposed (JP-A-59).
-204667).

(Means for Solving Problems) As a result of various studies on matte coatings having an aesthetic appearance while maintaining weather resistance, the present invention provides a curable fluorine-containing copolymer having a hydroxy group in the molecule. The inventors have found a weather-resistant matte-type resin composition for coating, which is prepared by blending another solvent-soluble fluorine-containing resin and applying light scattering caused by a microphase separation phenomenon.

The curable fluorine-containing copolymer having a hydroxy group used in the present invention is a multi-component system containing at least a fluoroolefin-based fluorine-containing monomer and a hydroxy-containing ether unsaturated compound or a hydroxy-containing ester unsaturated compound. It is a copolymer of monomers.
Examples of such fluoroolefin monomers include chlorotrifluoroethylene, tetrafluoroethylene, trifluoroethylene, vinylidene fluoride, and the like.
Chlorotrifluoroethylene is preferable, and the content thereof is 25 to 80 mol%.

Further, as the hydroxy-containing monomer, ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, hydroxyalkyl vinyl ether,
Examples thereof include hydroxyalkyl (meth) acrylate, and the content thereof is 5 to 40 mol%.

Other monomers include vinyl ester-based monomers,
It is also possible to use an olefin-based general-purpose monomer in an amount of 10 to 70 mol%.

Thus, the present invention provides a curable fluorine-containing copolymer,
It has a hydroxy group in the molecule and is further plasticized internally by disturbing the crystallinity by copolymerization containing a fluorine-containing monomer.

As the fluorine-containing polymer for the purpose of phase separation, a vinylidene fluoride-based copolymer which is an amorphous type and is easily dissolved in a solvent, which has a reduced crystallinity and is easily dissolved in a solvent, is used. That is, vinylidene fluoride-hexafluoroacetone copolymer, vinylidene fluoride-hexafluoropropene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, vinylidene fluoride. -A vinyl fluoride copolymer or the like is used. In particular, when a vinylidene fluoride-based polymer is used, it becomes difficult to dissolve in a solvent depending on the copolymer composition or the degree of polymerization, so it is necessary to select a soluble range.

As the solvent, tetrahydrofuran, cyclic ethers such as dioxane, benzene, aromatic hydrocarbons such as toluene,
Esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, as well as nitrogen-containing solvents and halogen-containing solvents, may be used alone or as a mixed solvent.

As the curing agent used for causing the curing reaction, paraphenylene diisocyanate, 2.4-tolylene diisocyanate, 2.6-tolylene diisocyanate, hexamethylene diisocyanate monomer and trimer, triphenylmethane triisocyanate, A polyvalent reactive curing agent represented by polyvalent isocyanates such as isophorone diisocyanate is desirable. At this time, the amount of the curing agent added is 100 parts by weight of the curable fluorine-containing copolymer,
It is 0.1 to 100 parts by weight, preferably 0.2 to 20 parts by weight. Furthermore, in order to accelerate curing, dibutyltin dilaurate,
A curing catalyst such as dimethyltin dichloride, trimethyltin hydroxide, tin chloride or cobalt naphthenate can also be added.

In the present invention, the proportion of the fluorine-containing copolymer having a curable hydroxy group and the vinylidene fluoride copolymer is 40 to 40, which is a curable fluorine-containing copolymer having a hydroxy group in the molecule. With respect to 99 parts by weight, the amount of the other vinylidene fluoride copolymer is 60 to 1 part by weight. If the mixing ratios deviate from the above ranges, respectively, it is not preferable because matte curing cannot be obtained and the durability of weather resistance is deteriorated. As a mixing method, powder mixing, roll mixing, or the like may be performed in advance, or both may be blended by dissolving them in a solvent and stirring.

The surface of the coating film formed by mixing the two undergoes microphase separation while maintaining smoothness. That is, 2 having different refractive indices
Since they are separated into phases, light scattering occurs on the surface, which causes a matte effect.

Further, the matte coating material according to the present invention may be used in combination with coloring pigments such as calcium carbonate, titanium oxide, iron oxide, and other additives used in the coating material.

The present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1 As a fluorine-containing copolymer having a hydroxy group, chlorotrifluoroethylene, vinyl acetate, and ethylene glycol monoallyl ether copolymer were polymerized by radical polymerization. The polymerization composition is (molar ratio) 50/30/20.

As a solvent-soluble fluorine-containing copolymer, radical copolymerization was carried out with vinylidene fluoride-hexafluoroacetone at a molar composition of 91/9. Toluene / methyl isobutyl ketone / acetic acid butyl ester 50/2 for each 100 parts
100 parts of mixed solvent consisting of 5/25 weight composition, titanium oxide 80
Parts and a polyvalent isocyanate curing agent Coronate EH (manufactured by Nippon Polyurethane Co.) were added and mixed to prepare a coating solution. Then, the mixed weight composition of the hydroxy group-containing fluorine-based copolymer and vinylidene fluoride-hexafluoroacetone copolymer was set to 50/50, 80/20, 90/10, 95/5, 100/0, and each of them was used as a sample. It was set to 1, 2, 3, 4, and 5.

These were coated on an aluminum plate and the gloss due to 60 degree specular reflection was measured according to JIS-K5400, which was 20, 20, 18, 2
It was 8 and 85.

Example 2 Using the chlorotrifluoroethylene-vinyl acetate-ethylene glycol monoallyl ether copolymer used in Example 1, as a solvent-soluble fluorine-containing copolymer, vinylidene fluoride-hexafluoropropene copolymer ( Molar ratio 90/1
The low molecular weight compounds of 0) were synthesized by radical polymerization. Then, a coating solution having the same composition as in Example 1 was prepared.
The mixed weight composition of the hydroxy group-containing fluorine-based copolymer and the vinylidene fluoride-hexafluoropropene copolymer was 50/50, 80/20, 90/10, 95/5. It was set to 7, 8, and 9.

When these were coated on an aluminum plate and the glossiness due to specular reflection at 60 degrees was measured, the results were 45, 50, 52 and 58.

Reference Example 1 Using the chlorotrifluoroethylene-vinyl acetate-ethylene glycol monoallyl ether copolymer used in Example 1, as a solvent-soluble fluorine-containing acrylic polymer,
Trifluoroethyl acrylate polymer was synthesized in radical polymerization. Then, a coating solution was prepared with the same composition as in Example 1. The mixed weight composition of the hydroxy group-containing fluorine-based copolymer and trifluoroethyl acrylate was 50/50, 80/20, 90/10, and 95/5, and the samples 10, 11, 12, and 13 were used. .

These were coated on an aluminum plate, and the gloss due to specular reflection at 60 degrees was measured. The result was 35, 35, 35, 45.

Reference Example 2 As a hydroxy group-containing fluorine-based copolymer coating, Newgarmet # 2000 (clear; manufactured by Toa Paint Co., Ltd.) 10
0 part of vinylidene fluoride-hexafluoroacetone copolymer synthesized in Example 1 was added to toluene / methyl isobutyl ketone / acetic acid butyl ester (weight ratio 50/25/25) to give 25 parts by weight.
% Solution, 50 parts titanium oxide, and 7 parts coronate EH were added and mixed to prepare a coating solution. Further, 7 parts of Coronate EH was added to 100 parts of New Gamet # 2000 (white) and mixed to prepare a coating solution. Sample 14 for the former and sample 15 for the latter
And

These were coated on an aluminum plate and the gloss due to specular reflection at 60 degrees was measured, and the results were 30 and 80.

Weather resistance test Samples 3, 8, 12, and 14 were coated on an aluminum plate, and an accelerated weather resistance test was carried out with a Sunshear in weather meter. No change was observed in any of the samples after 2,000 hours had elapsed. Also, 10% caustic soda, 10%
When immersed in a sulfuric acid solution at room temperature for 10 days, no change was observed in any of the samples.

 ─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP 59-204667 (JP, A) JP 59-189108 (JP, A) JP 61-51045 (JP, A) JP 61- 12760 (JP, A) JP-A-59-197471 (JP, A)

Claims (1)

[Claims] 1. A curable solvent-soluble fluorine-containing copolymer having a hydroxy group in the molecule, 40 to 99 parts by weight, and a vinylidene fluoride copolymer 60 to 1 part by weight, which is soluble in a solvent. A solution in which a blended body containing an appropriate amount of a curing agent is dissolved in a solvent, and a matte which forms a coating film having a gloss of 60 or less by 60 degree specular reflection measured according to JIS-5400 by coating on an aluminum plate. Coating composition.