JPS61247717A - Production of graft copolymer - Google Patents

Abstract

PURPOSE:To obtain the titled copolymer excellent in weatherability and pigment dispersibility, by polymerizing an ethylenically unsaturated monomer copolymerizable with a carbon-carbon double bond in the presence of a specified fluorine-containing resin having carbon-carbon double bonds. CONSTITUTION:A graft copolymer suitable as a material for paints is obtained by polymerizing 50-0.5wt% ethylenically unsaturated monomer (B) copolymerizable with the double bonds in component A (e.g., methyl methacrylate) in the presence of 50-95.5wt% alkoxy or cyclohexyloxy group- containing fluorine-containing resin (A) having 0.001-0.025mol, per 100g of the resin, reactive carbon-carbon double bonds. Component A can be produced by, for example, a method in which a fluoroolefin/hydroxyalyl vinyl ehter/alkyl vinyl ether copolymer with an alpha,beta-unsaturated carboxylic acid (e.g., maleic anhydride).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing a graft copolymer in which a fluorine-containing resin is reacted with an ethylenically unsaturated monomer.

(Prior Art) In recent years, there has been a strong demand in the coating industry for maintenance-free coatings, that is, coatings that are weather resistant, from the viewpoint of saving resources and energy. Conventionally, acrylic resins have been commonly used for applications that require weather resistance, but there is a desire for further improvements.

In addition, acrylic resins generally have poor compatibility with pigments that have high oil absorption, and are particularly poor in pigment dispersion with pigments such as carbon black, requiring a long time for uniform dispersion, or during storage. It has the disadvantage of causing pigment separation. Therefore.

In order to improve pigment dispersibility, methods of synthesizing acrylic resins in the presence of alkyd resins having unsaturated carbon-carbon double bonds have been reported and practiced.

On the other hand, fluorine-containing copolymers containing essential components of fluoroolefins, hydroxyalkyl vinyl ethers, alkyl vinyl ethers, and cyclohexyl vinyl ethers are known.

Furthermore, a reactive carbon-carbon double bond is added to the fluorine-containing copolymer, and an ethylenically unsaturated monomer is polymerized in the presence of 0.5 to 50% by weight of this to form a graft copolymer. A manufacturing method is known (Japanese Patent Application Laid-Open No. 59-413
Publication No. 15).

(Problems to be Solved by the Invention) Although the resin obtained by synthesizing acrylic resin in the presence of the above-mentioned nine-alkyd resin has improved pigment dispersibility, it has poor weather resistance compared to the original performance of acrylic resin. The above-mentioned fluorine-containing copolymers have excellent weather resistance, but are inferior in pigment dispersibility, initial gloss, etc. Therefore, the above-mentioned graft copolymer was proposed.

Resins with excellent weather resistance, pigment dispersibility, initial gloss, etc. have been obtained.

However, this graft copolymer still has insufficient weather resistance, and improvement thereof is desired.

(Means for solving problems) The present invention is.

100g of resin contains reactive carbon-carbon double bonds! 7
K in the presence of 0.001 to 0.025 mol and >50% to 99.5% by weight of a fluorine-containing resin having alkoxy or cyclohexyloxy groups.

(B) This invention relates to a method for producing a graft copolymer, which comprises polymerizing less than 50% by weight and 0.5% by weight or more of an ethylenically unsaturated monomer copolymerizable with the double bonds of component (A).

The fluorine-containing resin that is the captive component of the present invention includes the resin xo,
og 2 reactive carbon-carbon double bond from 0.001 to
It has 0.025% h, preferably 0.003 to 0.015 mol. If the amount is less than 0.001 mol, graph polymerization will be difficult when polymerizing with component (B);
If the amount exceeds 5 moles, gelation tends to occur during polymerization.

Moreover, the fluorine-containing resin.

It has an alkoxy group or a cyclohexyloxy group.

This makes it possible to make it soluble in organic solvents such as xylene, toluene, butyl acetate, and methyl isobutyl ketone. Furthermore, by containing fluorine, the paint film using the graft copolymer obtained by the present invention has excellent weather resistance.

1 molecular weight of the fluorine-containing resin component is approximately 1,
Preferably, the range is OOO to 2oo, ooo.

Particularly preferred is about 10,000 to 100,000. If the molecular weight is too low, weather resistance and chemical resistance tend to decrease, while if it is too high, gelation tends to occur when component (B) is polymerized in the presence of component (3).

The fluorine-containing resin as the component (3) consists of the following copolymer (a) having a hydroxyl group, maleic anhydride, and acrylic acid.

It can be obtained by reacting an α,β-unsaturated carboxylic acid such as methacrylic acid, acrylic anhydride, methacrylic anhydride, or their acid chloride, or a reactive derivative thereof with a hydroxyl group.

In this case, the α,β-unsaturated carboxylic acid or its hydroxyl group-reactive derivative is a copolymer frame having a hydroxyl group) 10
0.001 to 0.025 mol is reacted with respect to 0.09.

The above copolymer (a) is chlorotrifluoroethylene,
Fluoroolefins such as trifluoroethylene and tetrafluoroethylene, hydroxyethyl vinyl ether,
Hydroxy alkyl vinyl ethers and ethyl vinyl ethers such as hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxyhexyl vinyl ether.

Propyl vinyl ether, butyl vinyl ether.

It is a copolymer obtained by copolymerizing alkyl vinyl ethers or cyclohexyl vinyl ethers such as hexyl vinyl ethers, such as those in which hydrogen of these alkyl groups or vinyl groups is replaced with fluorine, and other components include ethylene, propylene, imbutylene, vinyl chloride,
Vinylidene chloride.

It may also contain vinyl acetate, vinyl n-butyrate, methyl methacrylate, etc. as a copolymer component.

In the copolymer (a), the fluoroolefin has a hydroxyl group of 4 to 60 mole, and the hydroxyalkyl vinyl ether has a hydroxyl group of 0.57 to 100 mole. In particular, it is preferably used so that the number is 3 to 70. If the amount of fluoroolefin is too small, the effect of improving weather resistance tends to decrease, and it is difficult to introduce a large amount in production.

The copolymer (a) has a hydroxyl value of 0.57 to 100.

Preferably it is 3-70. If the hydroxyl value is less than 0.57, the required amount of α,β-unsaturated carboxylic acid or its hydroxyl-reactive derivative will not react completely.

If it exceeds 100, the amount of hydroxyalkyl vinyl ether used increases, and solubility in organic solvents tends to be limited. From the viewpoint of solubility in organic solvents, the hydroxyalkyl vinyl ether is preferably used in an amount of 15 molar or less.

cyclohexyl vinyl ether and alkyl vinyl ether are present in the copolymer (a) in a total of 5 to 60%.
It is preferable to use it so that it becomes morchi. If the amount of cyclohexyl vinyl ether and alkyl vinyl ether is too small, the copolymer (a) will be difficult to dissolve in an organic solvent, and if it is too large, the amount of fluoroolefin or hydroxyalkyl vinyl ether used will be reduced. Moreover, it is preferable in terms of characteristics that cyclohexyl vinyl ether and alkyl vinyl ether are used in an amount of 5 to 45 mol each. It is preferred that other components are used in the copolymer (a) in an amount of 30 molar or less.

(Bl components include alkyl acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, inopropyl acrylate, and 2-ethylhexyl acrylate, similar alkyl methacrylates, styrene, or vinyltoluene.

Substituted styrenes such as α-methylstyrene and chlorostyrene, acrylonitrile, and methacrylatetrile.

Vinyl chloride, vinyl acetate, maleic acid dialkyl esters can be used, as well as hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate, 2-hydroxyalkyl acrylate, 2-hydroxybutyl acrylate.

Ethylenically unsaturated monomers having hydroxyl groups such as similar hydroxyalkyl methacrylates, glycerin, monoacrylates or monomethacrylates of polyhydric alcohols such as trimethylolpropane, N-methylolacrylamide, N-methylolmethacrylamide, etc. can be used. . Also.

If necessary, unsaturated amides such as acrylamide and methacrylamide, unsaturated monomers having an oxirane group such as glycidyl methacrylate and glycidyl acrylate, and α, β-unsaturated carboxylates such as acrylic acid, methacrylic acid, and maleic acid monoalkyl esters. Acids can be used. Too much unsaturated monomer containing unsaturated amide and oxirane groups tends to reduce the water resistance of the coating film and limit the number of reaction solvents. It is preferable to use 30% by weight or less of α,β-unsaturated carboxylic acid, as too much α,β-unsaturated carboxylic acid tends to reduce the water resistance of the coating film.

It is preferred to use less than 10% by weight.

In the present invention, the above (3) component and (B) component are (5)
) / (B) is 9 weight ratio, exceeds 50150, 99.5
Used within the range of 70.5 or less. This ratio is 50150
Exceeding the above results in excellent weather resistance, especially during long-term use, and also results in an excess of component (A).

Pigment dispersibility is sufficiently improved. If the above weight ratio exceeds 99.570.5, pigment dispersibility and initial gloss will be poor. (Al/(Bl is preferably 60/40 to 9
515 is preferred.

In addition, the hydroxyl group of the graft copolymer can be adjusted by the hydroxyl value of the prisoner component, its usage amount, and the usage amount of the ethylenically unsaturated monomer having a hydroxyl group (of the Bl component); It can be adjusted by adjusting the amount of α,β-unsaturated carboxylic acid used.

The graft copolymer obtained by the present invention can be dissolved in an organic solvent to form a lunker paint, and can also be appropriately combined with a curing agent known as a curing agent for acrylic resin paints to form a curable paint. . in this way,
When used as a paint, inorganic pigments such as titanium white, cadmium yellow, and silicone black, and organic pigments such as 7-talocyanine and azo pigments can be added as necessary. It is preferable to use such a pigment by thoroughly kneading it with a kraft copolymer in advance. The above-mentioned paints are particularly suitable as paints for building materials such as wood, metal, slate, and roof tiles.

In the polymerization of component (B) in the presence of a captive component, toluene, xylene, methyl isobutyl ketone, butyl acetate, ethyl acetate, cellosolve acetate is used as necessary.

Butylselonorp, 1-butanol, 2-butanol,
Using organic solvents such as 1-propertool and 2-propertool as reaction solvents, peroxides such as benzoyl peroxide, ditertiary-butyl peroxide, and cumene hydroperoxide, and azobisisobutyronitrile and the like are used as bipolymerization catalysts. 1 to 1 at 50 to 200°C using an azobis compound
It is also possible to conduct the reaction by heating for 0 hours.

The reaction is preferably carried out in an atmosphere or stream of an inert gas such as nitrogen gas, and peroxides are preferred as the nine-polymerization catalyst in terms of improving the grafting rate.

In order to reduce the amount of residual monomer, it is preferable to use a peroxide and an azobis-based compound in combination. Polymerization can be carried out not only by bulk polymerization and solution polymerization, but also by suspension polymerization, emulsion polymerization, etc., if necessary.

Next, synthesis examples and examples related to the present invention will be shown. Hereinafter, "part" means "part by weight".

Synthesis Example 1 Fluorine-containing copolymer with hydroxyl group [hydroxyl value 52, molecular weight approximately go, ooo (gel permeation analysis: calibrated with standard polystyrene), copolymer of trifluoroethylene, hydroxyalkyl vinyl ether, and alkyl vinyl ether. Ashi.

A mixed solvent solution of xylene and methylinobutylketone containing about 50 mol of trifluoroethylene [solid content 501%, Lumiflon LP-200D.

(Asahi Glass ■Product name) Used: 100 parts, Malay anhydride/acid 0
．． 3 parts and 0.3 parts of xylene into a flask equipped with a thermometer, stirrer, and reflux condenser.

The reaction was carried out at 50°C for 1 hour and at 120'C for 72 hours to form a single polymerizable carbon-carbon double bond of 0.0 in 100g of resin.
Synthesize a fluorine-containing resin having 0.6 moles.

A resin solution (solid content 50%) containing it was obtained. This resin solution is! ! The monovalence was 1.5 and the hydroxyl value was 25.

Examples 1 to 3 and Comparative Examples 1 to 3 The formulations shown in Table 1 were charged into a flask equipped with a thermometer, a stirrer, a nitrogen gas blowing tube, and a reflux condenser, and heated at 110°C under a nitrogen stream for 6 hours with stirring. After heating, 0.5 part of azobisisobutyronitrile was added, and the mixture was heated at 100° C. for 2 hours to react, thereby obtaining a copolymer. After this, butyl acetate was added.

The solid content was adjusted to an appropriate level. Table 1 shows the solid content and acid value of the obtained copolymer solution.

Solutions of the copolymers obtained in Examples 1 to 3 and Comparative Examples 1 to 3, and the above-mentioned Lumiflor LF-200D [a xylene-isoptyl ketone mixed solvent solution of a fluorine-containing copolymer having a hydroxyl group (solid content so Accelerated weathering test and pigment dispersion test were conducted using %):). The results are shown in Table 2.

<Test condition> (1) Accelerated weathering test 1) Each solution has a solid content of more than 30%.

Adjust the solid content to 30 cm with toluene and add Bonderite toner 14
The coating was applied to a 4-treated mild steel plate (manufactured by Nippon Test Panel Co., Ltd.) using a bar coater 60 to a film thickness of 30 μm, and after setting for 20 minutes, it was dried at 80° C. for 20 minutes to prepare a test plate.

11) Using a Q-UV accelerated weathering tester (manufactured by Q-Pane 1, USA), the prepared test plate was exposed to ultraviolet rays for 50 minutes.
The 60 degree specular reflectance was measured after exposure for a predetermined period of time under cycling conditions of 4 hours at 50 DEG C. and 4 hours with condensation.

(2) Pigment dispersibility test 50 parts of each solution (solid content) and 3 parts of carbon black were mixed and kneaded with three rolls until the particle size was 10 μm as measured by a grain gauge.
The number of times of crosstalk was measured until the following occurred. Subsequently, the prepared paint was allowed to stand at room temperature for 3 days, and the separation (sedimentation) property of the pigment was examined.

The graft copolymer obtained (according to the present invention) can be used as a raw material for paints, provides a coating film with excellent weather resistance, and itself has excellent pigment dispersibility.

Claims (1)

[Claims] 1. (A) Reactive carbon-carbon double bond in 100g of resin
(B) copolymerizes with the double bond of component (A) in the presence of more than 50% by weight and not more than 95.5% by weight of a fluorine-containing resin having 0.0001 to 0.025 mol and an alkoxy group or cyclohexyloxy group. A method for producing a graft copolymer, characterized in that less than 50% by weight of possible ethylenically unsaturated monomers are polymerized and 0.5% by weight or more is polymerized. 2. The fluorine-containing resin of component (A) contains 40 to 60 mol% of fluoroolefin, hydroxyalkyl vinyl ether and cyclohexyl vinyl ether or alkyl vinyl ether as components, and has a hydroxyl value of 0.57.
-100, and 0.001 to 0.025 mole of an α,β-unsaturated carboxylic acid or a derivative reactive with its hydroxyl group per 100 g of the copolymer. A method for producing a graft copolymer according to claim 1.