JPS61111377A - Fluororesin primer - Google Patents

Abstract

PURPOSE:To provide a primer which has excellent adhesion and impart excellent appearance to the surface of a resin, consisting of a vinylidene fluoride/ tetrafluoroethylene copolymer, a liquid medium capable of dissolving or dispersing said copolymer and an aluminosilicate powder. CONSTITUTION:100pts.wt. vinylidene fluoride/tetrafluoroethylene copolymer (A), 95-50pts.wt. (per 5-50pts.wt. of the combined quantity of components A and C) liquid medium (B) (e.g. ethyl acetate) capable of dissolving or dispersing component A, 15-50pts.wt. aluminosilicate powder (C) having an average particle size of 0.01-10mu and an Al2O3 content of 10-60wt% and optionally additives (D) such as dispersant (e.g. polyoxyethylene alkyl ether), viscosity modifier, colorant, etc. are blended together.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a method for imparting adhesiveness between a base material and a fluororesin when adhering a fluororesin (hereinafter referred to as fluororesin) to a base material. The present invention relates to a fluororesin ply i-.

<Conventional technology> Fluororesin is stable against chemicals, has a small coefficient of friction, and has excellent properties such as dimensional stability, non-adhesiveness, heat resistance, and weather resistance, so it is used for coating and lining various parts and plate materials. There is.

<Problems to be solved by the invention> However, due to its excellent non-adhesive properties, metals, glass,
Alternatively, there is a problem in that the adhesion to a base material such as ceramics is poor, and the fluororesin layer peels off from the base material when used for a long time.

Many studies have been conducted to improve the adhesion between fluororesin and substrates. For example, the adhesive surface of fluororesin has been treated with sodium or ammonium complex salts to defluorinate it, or A method of firmly adhering the base material by applying polar groups to the surface by corona discharge treatment, etc., and a method of hardening the surface of the base material by physical or chemical means to create an anchor effect. do not have.

<Means for solving the problems> The present invention was made based on the discovery that the above problems can be solved by incorporating a specific aluminosilicate without adversely affecting the appearance. It is.

That is, the present invention provides [(4) a copolymer of vinylidene fluoride and tetrafluoroethylene, ω) a liquid medium capable of dispersing or dissolving the copolymer, and (C) an average particle size of 0.
A fluororesin primer comprising an aluminosilicate powder having a particle size of 1 to 10μ and an aluminum oxide content of 15 to 60% by weight, characterized in that the weight ratio of (4) to C) is 100 to 15 to 50. ”.

<Function> The copolymer of vinylidene fluoride and tetrafluoroethylene used in the present invention may be copolymerized with a small amount of other components without any problem. Hereinafter, this copolymer may also be referred to as a fluorine-containing copolymer.

! Further, as the liquid medium used in the present invention, a wide range of solvents that can disperse or dissolve the above-mentioned fluorine-containing copolymer can be used. Specific examples include esters such as ethyl acetate and dimethyl phthalate; polyhydric alcohols or derivatives thereof such as methyl cellosolve, ethyl seron rub acetate, diethyl cellosolve, and ethylene glycol; hydrocarbons such as heptane and toluene; methyl ethyl ketone; Ketones such as methyl isobutyl ketone; alcohols such as isopropanol and octatool; ethers such as methyl phenyl ether and tetrahydrofuran; and water.

The liquid medium may be used alone or in combination, but the selection, liquid state, and boiling point are carefully selected depending on the composition of the primer and the method of coating and drying. The amount of liquid medium to be used is selected depending on the composition of the primer and the application method - although it cannot be determined generally, it is usually the amount of liquid medium relative to the sum of the above fluorine-containing copolymer and aluminosilicate powder. The weight ratio is between 5:95 and 50:50.

Furthermore, the aluminosilicate powder used in the present invention has an average particle size of 0.01 to 10μ (preferably o, i to 7μ),
The content of aluminum oxide is 15 to 60% by weight (preferably 15 to 45% by weight).

Specifically, for example, mica such as progovite and muscovite, clay, and kaolin can be used in combination. Among these, mica is most preferred.

If the average particle size is less than 0.01 μm, the adhesion to the substrate will be reduced, while if it exceeds 10 μm, the surface of the primer layer will become rougher, resulting in poor appearance and reduced adhesion.

Furthermore, if the aluminum oxide content is outside the above range, the effects of the invention will not be exhibited in terms of adhesiveness.

This aluminosilicate naturally contains small amounts of other components, such as
There is no problem even if it contains alkali metals, etc.

The primer of the present invention can be obtained by various known methods. That is, it can be obtained, for example, by preparing a dispersion of each of the above components using a high-speed shear stirring mixer. Furthermore, if necessary, wet pulverization using a ball mill, sand mill, attritor, etc. may be carried out in order to finely grind or uniformly disperse the fluorine-containing copolymer and /l or aluminosilicate powder.

The thus obtained primer contains the fluorine-containing copolymer and the aluminum silicate powder in a weight ratio of io.

The ratio is 15 to 50 to 100, preferably 20 to 45 to 100.

If it is outside this range, the adhesion between the base material and the primer will not be good.

Furthermore, the primer of the present invention may contain various known additives. Examples of such additives include polyoxyethylene alkyl ether, nonionic activators having fluoroalkyl groups; gluing agents; methyl cellulose,
Viscosity modifiers such as wax; pigments as coloring agents, and the like.

Substrates targeted by the primer of the present invention include, for example, iron,
It can be made of any material or shape, such as metals such as aluminum or stainless steel, glass, or ceramics. Also, to improve adhesion with the primer, the base material may be sandblasted, shot blasted, grid blasted, wire scratched, hairline treated, or chemically treated. A treatment such as etching may also be applied.

Further, as the fluororesin to be bonded to the base material by the primer of the present invention, it is preferable to use the fluorine-containing copolymer described above for use in the present invention, but a different resin may be used if necessary. In addition, if necessary, this fluororesin may be mixed with (meth)acrylic resin, which is a polymer or copolymer of methyl methacrylate, methyl methacrylate, methyl acrylate, etc., or as a coloring agent. Pigments, etc. may also be blended.

The form of the fluororesin to be adhered may be any form such as powder, granules, film, sheet, aqueous or organic dispersion, organosol, and emulsion of organosol in water.

<Example> Example 1 Vinyritine fluoride and tetrafluoroethylene 1'
38,□O. . , Oh, □. -3 parts by weight and 170 parts by weight of ethylene glycol diethyl ether to produce a primer using a high-speed shear stirring mixer (Disilver).

This composition was applied to various metal plates (dry film thickness: 10μ).
, and baked at 280°C for 3 minutes. Further, a polyvinylidene fluoride resin film (thickness: 1.20 .mu.m) was thermocompression bonded in a hot compression molding device at 180.degree. C. and zooh/- for 3 minutes.

Using this test piece, 150 m was measured using an automatic tensile tester.
Peel off the welded film in the direction of 180 degrees at a speed of / min.
Adhesive strength was measured. The results are shown in Table 1.

(Space below) Example 2 30 parts by weight of clay powder with an average particle size of 20μ and an aluminum oxide content of 18% by weight and 170 parts by weight of ethyl acetate were blended and pulverized in a sand mill to obtain dispersions with each average particle size. .

100 parts by weight of vinylian fluoride-atrafluoroethylene copolymer resin powder was added to 200 parts by weight of this dispersion, and a primer was produced using a high-speed shear stirring mixer.

Next, the adhesive strength was evaluated in the same manner as in Example 1.

However, the metal plate to be coated was an iron plate treated with zinc phosphate. The results are shown in Table 2.

Table 2 Example 3 Vinylidene fluoride-tetrofluoroethylene copolymer resin powder and muscovite having an aluminum oxide content of 35 μm and an average particle size of 3 μm were blended in the prescribed amounts shown in Table 3, and further,
To these 45-heavy portions, 5-heavy portions of methoxyk=thylketone were added, and a primer was produced using a high-speed shear stirring mixer.

This composition was coated on an iron plate whose surface had been roughened by sandblasting (dry film thickness: 10 μm), and baked at 280° C. for 3 minutes. Further, an organosol of polyvinylidene fluoride resin powder (dimethyl phthalate and methyl ethyl ketone solvent) was coated (dry film thickness: 200 μm) and baked at 250° C. for 30 minutes to obtain a test piece.

Using this test piece, the adhesive strength was measured in the same manner as in Example 1. The results are shown in Table 3.

(Margin below) Table 3 Amount based on parts by weight of the present fluorine-containing copolymer Zoo.

<Effects of the Invention> As shown in the Examples, the primer of the present invention exhibits excellent adhesive strength and has a remarkable effect of not changing the appearance of the surface resin.

Claims (1)

[Claims] (A) a copolymer of vinylidene fluoride and tetrafluoroethylene; (B) a liquid medium capable of dispersing or dissolving the copolymer; and (C) an average particle size of 0.01 to 10 μ and an aluminum oxide content. 15 to 60% by weight of aluminosilicate powder, with a weight ratio of (A) to (C) of 100
A fluororesin primer characterized by having a ratio of 15 to 50.