JPS5937034B2 - Adhesive composition for PVC/steel plates - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an adhesive composition for soft PVC/steel plates, and more particularly to an adhesive composition that is capable of lowering the pressure bonding temperature during PVC film lamination.

The conventional method for producing PVC/steel plate composites is to heat-fuse PVC resin directly onto the steel plate.
There is a method of laminating PVC resin and a method of laminating PVC resin through a certain type of adhesive (for example, one mainly composed of nitrile-butadiene rubber and phenol), but in most cases, high temperature treatment (2o0°C or higher) is used. ), there is a risk that the appearance (beauty) of the product may be impaired, the laminate body may become discolored, and a large amount of energy is consumed.

Furthermore, most cases involving adhesives require a large amount of solvent, which poses problems in terms of the working environment. The object of the present invention is to develop an adhesive suitable for lowering the temperature of heat treatment conditions during the production of PVC/steel plate composites.

The present inventors have conducted extensive research aimed at developing adhesives for soft PVC/steel sheet composites, particularly adhesives that exhibit good adhesion under low-temperature processing conditions. The present invention has been completed by discovering that a composition comprising an epoxy resin and an amine compound satisfies the above-mentioned objects.That is, the present invention provides a composition comprising a bisphenol A type epoxy resin per 100 parts by weight of an acrylic polymer. , bisphenol F type epoxy resin, novolak type epoxy resin, glycidyl ester ether type epoxy resin of oxybenzoic acid, and glycidyl ether type epoxy resin of diaminophenylmethane. and as a curing agent for epoxy resin, two or more l in the l molecule.
A solvent-based adhesive consisting of an amine compound having primary and/or secondary amino groups in an amount capable of curing the epoxy resin is interposed between the soft PVC and the steel plate, and thermocompression bonded at a temperature of about 150°C. It is characterized by this.

Here, to describe the basic idea of the present invention, taking into consideration the affinity for soft PVC resin and wettability and adhesion to steel plates, acrylic resin is suitable for the former, epoxy resin is suitable for the latter, and It is believed that when these two components have suitably good compatibility, the adhesive layer exhibits toughness and exhibits excellent adhesive properties.

In the present invention, as mentioned above, the amount of epoxy resin blended is 20 parts by weight per 100 parts by weight of the specific acrylic polymer.
~100 parts by weight, preferably 40 to 70 parts by weight.

If the amount of epoxy resin is less than 20 parts by weight, the adhesive strength with the steel plate side will be unstable, and if it exceeds 100 parts by weight, the adhesive strength with the steel plate side will improve, but the adhesive strength with PVC will be unstable. decreases dramatically. The acrylic polymer used in the present invention is a polymer of arylic acid ester represented by the general formula H2C=CH (R1 is an alkyl group having 6 or less carbon atoms) or a polymer of the general formula H2C=C (R2 is a carbon number\ester polymer, Alternatively, it is a polymer obtained by copolymerizing 10 mol% or less of a vinyl monomer copolymerizable with the above-mentioned styl acrylate or methacrylate, and a mixture thereof.

The copolymerizable monomers that have a vinyl group, an allyl group, or an unsaturated bond in the molecule include acrylonitrile, methacrylonitrile, acrolein, vinyl acetate, vinyl chloride, allyl chloride, These include vinylidene, vinyl isocyanate, glycidyl methacrylate (GMA), and the above-mentioned acrylic esters, methacrylic esters, etc.
A copolymer formed by using one or more of these can be used.

In addition, the number of carbon atoms for R,,R2 in the above general formula is 6
It is preferably 4 or less, more preferably 4 or less. This is true even when considering compatibility, for example, and furthermore, as the number of carbons increases, the modulus of the adhesive itself decreases, making it no longer commensurate with the modulus of steel plates and PVC resin. , not appropriate. The average molecular weight of the acrylic polymer is preferably 50,000 or more.

If it is less than 50,000, it lacks toughness and is not useful as an adhesive.

The epoxy resin used in the present invention is a compound having two or more epoxy groups in one molecule, and specifically includes bisphenol A epoxy resin, bisphenol F epoxy resin, novolak epoxy resin, and oxybenzoic epoxy resin. These are glycidyl ester ether type epoxy resin of acid and glycidyl ether type epoxy resin of diaminodiphenylmethane. Of course, these epoxy resins may be used alone or in combination of two or more. In the present invention, the amine compound used as a curing agent for epoxy resin has two or more primary and/or secondary amino groups in one molecule, and specifically includes aliphatic polyamines such as ethylenediamine and triethylenetetramine. , tetraethylenepentamine, etc., or aromatic amines such as m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylmethane, and the like.

Further mention may be made of heterocyclic diamines, such as oxaspiro ring-containing diamines. These amine compounds can be used alone or in combination of two or more. In the present invention, in addition to acrylic polymers, copoxy resins, and curing agents, phenolic resins, plasticizers such as dioctyl phthalate (DOP), and tricresyl phosphate (TCP), and fillers such as Talukyu silica and potassium carbonate may also be added. It is possible.

The above blended resin and additives are dissolved in a suitable organic solvent to form a liquid adhesive.

The solvent to be used here is preferably a mixed solvent system with a high boiling point and a low boiling point, taking into account the coatability of the adhesive and the increased wetting effect during lamination of the soft vinyl chloride resin after heat treatment.
High boiling point solvents include toluene, xylene, cyclohexanone, etc. with a boiling point of 100°C or higher, and low boiling point solvents have a boiling point of 8°C or higher.
Examples include methylene chloride, ethyl acetate, and methyl ethyl ketone (MEK) at temperatures below 0°C. In order to firmly adhere the soft PVC resin and the steel plate, the amount of adhesive applied is preferably 3 to 309/Rrl2 as a dry resin amount, and if it is less than 39/M2, sufficient adhesiveness will not be developed, and if it exceeds 309/M2, Problems occur when the solvent evaporates, resulting in poor coating surface conditions.

The adhesive composition of the present invention is mainly used for adhering a soft PVC resin to a phosphate-treated steel plate or a chromate-treated steel plate as a base metal plate. It is desirable to perform surface cleaning in order to ensure stronger adhesion. Hereinafter, the present invention will be specifically explained with reference to Examples.

In the table, all numerical values for formulation examples are parts by weight. Example 1 A degreased zinc phosphate treated steel sheet and a soft PVC sheet were used as adherends, and 95 parts by weight (98 mol (F) of methyl methacrylate (MMA) was added as an acrylic polymer.
t)) 5 parts by weight of glycidyl methacrylate (GMA) (
4 mol %) of a polymer with an average molecular weight of 60,000, Sumiepoxy E
LAl28 (epoxy equivalent: 185; manufactured by Sumitomo Chemical Co., Ltd.) 50
Part by weight, Epomate B-002 (3
,9bis(3-aminopropyl)3,4,8,10-tetooxaspiro[5,5]undecane; manufactured by Mitsubishi Yuka) 1
Dissolve 0 parts by weight in 100 parts by weight of methyl ethyl ketone (MEK) and 100 parts by weight of cyclohexanone. After thorough mixing and stirring, apply the dried adhesive on the steel plate to a thickness of about 10 mm and 2 mm, and leave at room temperature. After being left for 30 minutes, it was heat-treated at 150° C. for 1 minute, a vinyl chloride sheet was pressed onto it using a roller, and after cooling, the peel strength was measured, and the results are shown in Table 1.

Comparative Example 1 To 100 parts by weight of the acrylic polymer in Example 1, epoxy resin ELAl28 (epoxy equivalent: 185,
Bisphenol A type epoxy resin; manufactured by Sumitomo Chemical Co., Ltd.)
10 parts by weight (Comparative Example 1-a) and 150 parts by weight (Comparative Example 1-b), respectively, and B-
002 was added to 5 parts by weight (Comparative Example 1-a) and 30 parts by weight (Comparative Example 1-b), respectively, and methyl ethyl ketone (MEK
) and 100 parts by weight of cyclohexanone, and after thorough mixing and stirring, samples were prepared according to the method of Example 1, and the peel strength was measured. The results are shown in Table 1.

In the peel test, Example 1 showed good adhesion and material failure of PVC occurred, but in Comparative Example 1-a, in which the amount of epoxy resin added was small, peeling occurred between the steel plate and the adhesive layer.
In addition, in Comparative Example 11b in which the amount added was large, peeling occurred between the vinyl chloride and the adhesive layer.

Example 2 100 parts by weight of the acrylic polymer in Example 1 was mixed with various epoxy resins (novolac type, oxybenzoic styrene ether type, nitrogen-containing epoxy resin) and B-002 as a curing agent. Table 2 shows formulation examples and peel strengths of the adhesives.

Even when the type of epoxy resin was changed, each exhibited good adhesion, and material failure of PVC occurred in the peel test.

Example 3 An amine compound such as tetraethylenepentamine (TEPA) or diaminodiphenylmethane (D
Table 3 shows formulation examples and peel strengths of adhesives obtained by blending DM).

"5" showed good adhesion even when used, and material failure of PVC occurred in the peel test.

Example 4 Polymethyl methacrylate (/
V), n-butyl polyacrylate 13), n-hexyl polyacrylate 0, and 2-ethylhexyl polyacrylate (auto), these acrylic polymers 1
00 parts by weight of epoxy resin ELAl285O and epoxy resin curing agent B-00210 parts by weight of MEK.
The mixture was thoroughly mixed and stirred in a mixed solvent of /toluene, and then the solvent was evaporated to form a film and the compatibility was evaluated. The results are shown in Table 4.

Claims (1)

[Claims] 1 General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ General formula of an acrylic ester polymer represented by (R_1: an alkyl group with 6 or less carbon atoms) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ A polymer of methacrylic ester represented by (R_2: alkyl group having 6 or less carbon atoms), and 10 mol% or less of a vinyl monomer copolymerizable with the acrylic ester and/or the methacrylic ester are copolymerized. At least one acrylic polymer having an average molecular weight of 50,000 or more selected from the group of polymers 10
0 parts by weight, bisphenol A type epoxy resin,
20 to 100 parts by weight of an epoxy resin selected from one or more of bisphenol F type epoxy resin, novolac type epoxy resin, glycidyl ester ether type epoxy resin of oxybenzoic acid, and glycidyl ether type epoxy resin of diaminodiphenylmethane; As a curing agent, an amount of an amino compound having two or more primary and/or secondary amino groups in one molecule that can cure the epoxy resin is added to a mixed solvent of a low boiling point solvent and a high boiling point solvent at 80°C or less. An adhesive composition for PVC/steel plates made by melting.