JP2000154336A - Primer composition and bonding or coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a primer composition capable of improving adhesiveness and adhesion when bonding or coating a metal with a radically polymerizable curing resin by making the composition include a specific phosphoric ester (salt) and an acrylic monomer. SOLUTION: This composition is obtained by including (A) an acid phosphoric ester (salt) represented by the formula R is CH2=CR1CO(OR2)m [R1 is H or CH3; R2 is C2H4, C3H6, C4H8 or the like; (m) is 1-10]; (n) is 1 or 2} (e.g. acid phosphooxyethyl methacrylate) in an amount of preferably 0.1-30 pts.wt., more preferably 0.5-10 pts.wt. based on 100 pts.wt. of the sum total of the components A and B and (B) an acrylic monomer [e.g. methyl (meth)acrylate] in an amount of preferably 70-99.9 pts.wt., more preferably 90-99.5 pts.wt. based on 100 pts.wt. of the sum total of the components A and B preferably without including a volatile solvent or water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primer composition for surface treatment for improving the adhesive strength and adhesion when an adherend is adhered or coated using a radical polymerization curable resin. Particularly, it relates to a primer composition suitable for metal surface treatment.

[0002]

2. Description of the Related Art Vinyl compounds such as acrylate-based monomers and oligomers, unsaturated polyesters and styrene, and radical polymerization-curable resins containing polyene / polythiol as a main component are used as adhesives, paints, coating agents, potting agents and the like. Widely used in the field. The above-mentioned radical polymerization-curable resin is usually a liquid or paste-like one that is irradiated with active energy rays such as ultraviolet rays or electron beams or a room temperature-curable type using a redox polymerization initiator, and further a heat-curable type. Are known.

It has been known that the addition of an acidic phosphate having an unsaturated double bond to these radically polymerizable resins improves the adhesion and adhesion to metals (Japanese Patent Laid-Open No. 54-1979). No. 141826, JP-A-58-147777 and JP-A-59-84964).

[0004]

However, in the case of using an adhesive composition in which only an acidic phosphoric acid ester is added to a radical polymerization curable resin, for example, the effect of improving the adhesiveness is not sufficient, and the physical properties of the cured resin are not sufficient. (Tensile strength, hardness,
There is a problem that the resin may deteriorate the curing properties (curing rate, reaction rate, etc.) and storage stability of the resin.

It is also known that a primer prepared by dissolving an acidic phosphate ester in a volatile solvent is used (JP-A-1-297482, JP-A-6-9321).
No. 1).

However, since such a primer uses a volatile solvent, it has to wait for the solvent to evaporate, and there is a problem that a ventilation facility or the like is required in the working environment. In addition, it is becoming undesirable to release volatile solvents into the environment due to recent environmental destruction problems.

[0007] The present invention has been made in view of the above points, and is intended to adhere to or coat a metal using a radical polymerization curable resin without deteriorating the performance of the radical polymerization curable resin. An object of the present invention is to provide a primer composition for improving adhesion and adhesion.

[0008]

That is, the present invention provides the following a. And b. A. A primer composition comprising: a. Acidic phosphate ester represented by the following formula or a salt thereof

Embedded image b. Acrylic monomer This primer composition does not contain a volatile solvent. Then, when bonding or coating the adherend using a radical polymerizable resin, is a method for bonding or coating an adherend, which is characterized in that the adherend is previously coated with the primer composition, The bonding or coating method, wherein the adherend is a metal.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below.

[0010] a. The acidic phosphoric acid ester or a salt thereof (hereinafter, referred to as an acidic phosphoric acid ester) is a monoester, a diester, or a mixture of a monoester and a diester of phosphoric acid represented by the following general formula.

[0011]

Embedded image

A. Acid phosphooxyethyl methacrylate, (meth) acryloyloxypropyl acid phosphate, bis (2- (meth) acryloyloxyethyl) phosphate, acid phosphooxypolyethylene glycol (meth) acrylate,
Acid phosphooxypolypropylene glycol (meth) acrylate and amine salts thereof are preferred, but are not limited thereto, and these can be used alone or in combination of two or more.

A. Is used in a. And b. A total of 100
0.1 to 30 parts by weight, preferably 0.5 to 1 part by weight,
0 parts by weight is preferred. If the amount is less than 0.1 part by weight, the adhesiveness or adhesion may be small. If the amount is more than 30 parts by weight, the primer has a high viscosity and is difficult to use. Low adhesion,
It may not be economically favorable.

B. Used in the present invention. The acrylic monomer is an acrylic acid ester or a methacrylic acid ester (hereinafter referred to as (meth) acrylic acid ester), and is not particularly limited as long as it can dissolve or disperse the above-mentioned acidic phosphoric acid ester or a salt thereof. .

B. Examples include methyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentyl (meth) acrylate, dicyclopentenyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and methoxy. Phenoxyethyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, trimethylolpropane tri (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycerol (meth) acrylate, glycerol di (meth) acrylate, 2-hydroxyethyl (meth) ) Acrylate, 2-
Hydroxypropyl (meth) acrylate, ethoxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, phenoxydiethylene glycol (meth)
Acrylate, tripropylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 2,2-bis (4- (meth) acryloxyphenyl) propane, 2,2-bis (4- (meth) ) Acryloxyethoxyphenyl) propane, 2,2-bis (4
-(Meth) acryloxydiethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxypropoxyphenyl) propane, 2,2-bis (4- (meth) acryloxytetraethoxyphenyl) propane, tri Methylolpropane tri (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate and KAYARA
Examples thereof include, but are not limited to, DR-684 (manufactured by Nippon Kayaku), and these can be used alone or in combination of two or more. Among them, those having low odor and low viscosity are preferable in view of working environment.

B. Is used in a. And b. A total of 100
70 to 99.9 parts by weight, preferably 90 to 9 parts by weight, are preferred.
9.5 parts by weight is more preferred. If it is less than 70 parts by weight, the viscosity of the primer increases and it is difficult to use, the physical properties of the radical polymerization curable resin are reduced, the adhesiveness and adhesion are small,
If it exceeds 99.9 parts by weight, the adhesiveness and the adhesion may be small.

The primer composition of the present invention comprises methyl alcohol, ethyl alcohol, isopropyl alcohol,
Ethyl acetate, acetone, methyl ethyl ketone, toluene, xylene, methylene chloride, chloroform and 1,
It is preferable not to contain a volatile solvent such as 1,1-trichloroethane. Further, it is preferable that water is not contained. By not containing a volatile solvent, etc., it is not necessary to wait for the solvent to evaporate, so the working time is shortened,
This has the effect of eliminating the effect on the human body and the like.

Various additives can be added to the primer composition of the present invention according to the purpose. For example, in the case of bonding or coating a long time after applying the primer composition to the metal surface, a polymer soluble or dispersible in the acrylic monomer may be added.

Examples of such polymers include polystyrene, polymethyl methacrylate, polyvinyl chloride, polyvinyl acetate and saponified products thereof, polyvinyl acetal, polyvinyl butyral, vinyl chloride-vinyl acetate copolymers and saponified products thereof, and vinyl chloride- A vinyl acetate- (anhydride) maleic acid copolymer or a saponified product thereof, a methyl methacrylate-styrene copolymer, a methyl methacrylate- (meth) acrylic acid copolymer, and an acidic phosphate ester as a component of the present invention, Examples include, but are not limited to, copolymers with vinyl monomers such as methyl methacrylate, styrene, vinyl chloride and vinyl acetate.

By adding these polymers to the primer composition, it is possible to prevent deterioration of the acidic phosphate ester in the primer composition applied to the surface of the adherend, particularly to the metal surface, and to prevent rusting on the metal surface. Can be.

As additives other than polymers, antioxidants for improving storage stability, dyes and pigments for coloring, organic or inorganic fillers and the like are used within a range not to impair the object of the present invention. Can be.

The adherend of the present invention is preferably used for metals such as stainless steel and aluminum.

The primer composition of the present invention can be preferably used for bonding or coating using an adhesive or coating agent containing a radical polymerization curable resin, particularly an acrylate monomer or oligomer. It can be more preferably used.

[0024]

The present invention will be described in more detail with reference to the following examples. As the adhesive, a two-part type acrylic adhesive having the mixing ratio shown in Table 1 was used.

[0025]

[Table 1]

As the test piece, stainless steel (SUS
304, 100 mm × 25 mm × 0.3 mm) and aluminum (A5052P, 100 mm × 25 mm × 0.3 mm).
5 mm).

[Experimental Example 1] A primer composition having the compounding ratio shown in Table 2 was prepared, and this primer composition was impregnated into a waste cloth. The test piece was 100 mm x 25 mm in an environment of a temperature of 23 ° C and a humidity of 50%. Was coated with the primer composition. Next, an equal amount of a two-part type acrylic adhesive was mixed, applied to a test piece, immediately adhered and fixed, and heated to a temperature of 23.
A specimen that had been cured for 24 hours in an environment of 50 ° C. and a humidity of 50% was used as a test piece for a peel test, and a peel test was performed. Table 2 shows the results when stainless steel was used as the test piece, and Table 3 shows the results when aluminum was used.

(Measurement Method of Peeling Test) Peeling strength is 2
Under the environment of 3 ° C. and 30% humidity, JIS K-6854
A T-peel test was performed according to (tensile speed 50 mm / min, unit kgf / 25 mm), and the peel strength was measured. After the test, the state of destruction was observed. The percentage of the broken state was indicated by the ratio of the cohesive failure area to the bonding area.

[0029]

[Table 2]

[0030]

[Table 3]

[Experimental Example 2] The same procedure as in Experimental Example 1 was carried out except that the respective components were mixed at the mixing ratios shown in Table 4 to prepare respective primer compositions, and aluminum was used as a test piece. The results are shown in Table 4.

[0032]

[Table 4]

[Experimental Example 3] An experiment was conducted in the same manner as in Experimental Example 1 except that the primer composition having the mixing ratio shown in Table 5 was used. Table 5 shows the results when stainless steel was used as the test piece, and Table 6 shows the results when aluminum was used.

[0034]

[Table 5]

[0035]

[Table 6]

[0036]

Industrial Applicability The primer composition of the present invention has an extremely large industrial advantage, since the adhesion to metals, more preferably stainless steel and aluminum, is extremely improved. In addition, since it is a solventless primer composition that does not require the use of a volatile solvent, it is environmentally favorable without the influence of the human body and the like, and the drying step is unnecessary, so that the working time can be shortened, and its industrial benefits. Is extremely large.

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Claims (4)

[Claims] 1. The following a. And b. A primer composition comprising: a. An acidic phosphate ester represented by the following formula or a salt thereof: b. Acrylic monomer 2. The primer composition according to claim 1, which does not contain a volatile solvent. 3. A method for bonding or covering an adherend using a radical polymerizable resin, wherein the adherend is previously coated with the primer composition according to claim 1 or 2. A method of bonding or covering a body. 4. The method according to claim 3, wherein the adherend is a metal.