JPH0751696B2 - Adhesive composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electron beam curable adhesive composition suitable for laminating vinyl chloride films having excellent adhesive strength and flexibility of a cured product.

(Prior Art) To manufacture a vinyl chloride film laminate represented by a vinyl chloride steel plate,
Although an adhesive is used, conventionally, as the adhesive, a thermosetting type adhesive containing an organic solvent such as ethyl acetate, methyl ethyl ketone, toluene, xylene is generally used.
Since the working environment is contaminated by the organic solvent and the curing is performed by heating, the embossed pattern on the film disappears, and it is difficult to laminate a thin PVC film.

In recent years, as a solution to the above-mentioned problems of the adhesive, an electric wire-curable adhesive which is solventless and does not require heating (a room temperature curable type) has been proposed.

For example, JP-A-57-172969 and JP-A-58-174475 disclose electron beam curable adhesives containing a polyacrylate such as urethane polyacrylate or polyol polyacrylate as a main component. JP-A-56-127674 discloses an electron beam curable adhesive composition comprising a radically polymerizable prepolymer, a vinyl acetate polymer and a plasticizer, respectively.

(Problems to be Solved by the Invention) However, the electron beam curable adhesives of the above-mentioned conventional techniques are not sufficiently flexible or have insufficient adhesion to a vinyl chloride film, and therefore are bent. The vinyl chloride film may peel off during post-processing such as processing and drawing. Further, in an adhesive using a plasticizer, bleed-out of the plasticizer may cause deterioration of the vinyl chloride film.

(Means for Solving Problems) The present invention is an improvement over the above-mentioned drawbacks of the prior art,
It is intended to provide an electron beam curable adhesive composition having improved flexibility of a cured product after curing and adhesion to a vinyl chloride film.

That is, the present invention includes: 1. (A) at least one of an acrylic acid ester monomer and a methacrylic acid ester monomer, and 100 parts by weight (B) a vinyl chloride copolymer 1 soluble in the above monomer
-60 parts by weight (C) Linear polyurethane resin soluble in the above-mentioned monomer and obtained by addition reaction of diisocyanate and diol 0.5-40 parts by weight Above (A), (B) and (C) are essential components. An electron beam-curable adhesive composition containing the same.

It is about.

In the following description, (meth) acrylate is a general term for acrylic acid ester monomers or methacrylic acid ester monomers, and the contents in parentheses in the substance name are treated in the same manner as this (meth).

Examples of the (meth) acrylate used in the adhesive composition of the present invention include alkyl (meth) acrylate,
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, phenoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxy- 3-phenyloxypropyl (meth) acrylate,
Isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol Di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, neopentyl glycol di (meth) ) Acrylate, various urethane (meth)
Examples thereof include acrylates, epoxy (meth) acrylates, polyester (meth) acrylates, and the like, but are not limited to these, and one type or a combination of two or more types is used. Also, if necessary, the above (meta)
Vinyl monomers other than acrylates such as (meth) acrylic acid, maleic acid, (meth) acrylamide and its derivatives, styrene, divinylbenzene, and N-vinylpyrrolidone may be used, but these monomers are used in the adhesive composition. It is preferably 50 parts by weight or less with respect to 100 parts by weight of the monomer used, and the use of more than 50 parts by weight may impair the object of the present invention.

The vinyl chloride-based copolymer used in the adhesive composition of the present invention is not particularly limited as long as it is a vinyl chloride-based polymer that is soluble in the monomer used in the adhesive composition. Examples thereof include vinyl chloride-vinyl acetate copolymers, copolymers of vinyl chloride-vinyl acetate- and other modified monomers, and saponified products thereof. As the above-mentioned modified monomer, (anhydrous)
Acidic monomers such as maleic acid, (anhydrous) itaconic acid, (meth) acrylic acid, (meth) acryloyloxyethyl acid phosphate are common, and when one of the adherends is a metal, these modified monomers are used. It is advisable to use a polymer copolymerized in a small amount.

The linear polyurethane resin used in the adhesive composition of the present invention is generally obtained by an addition reaction of diisocyanate and diol, and is soluble in the (meth) acrylate used in the adhesive composition. If so, there is no particular limitation. Examples of the diisocyanate include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 1,5-naphthalene diisocyanate, xylene diisocyanate, and prepolymers of these diisocyanates. Examples of the diol include (poly) ethylene glycol, (poly) propylene glycol, copolymers of ethylene oxide and propylene oxide, glycols such as 1,4-butanediol and 1,6-hexanediol, and adipic acid. A polyester type polyol obtained by an esterification reaction of a dicarboxylic acid such as phthalic acid or isophthalic acid with a glycol, a liquid polybutadiene resin having hydroxyl groups at both ends,
Castor oil and the like can be mentioned.

The amounts of the vinyl chloride copolymer and the linear polyurethane resin used in the adhesive composition are preferably 1 to 60 parts by weight and 0.5 to 0 parts by weight based on 100 parts by weight of the monomer used in the adhesive composition. When the amount of the vinyl chloride-based copolymer and the linear polyurethane resin used is less than the above range, the flexibility of the cured product and the adhesiveness to the vinyl chloride film are reduced, and the post-workability of the vinyl chloride film laminate is reduced,
On the contrary, when the content exceeds the above range, the viscosity of the composition becomes too high, and the workability of coating is deteriorated.

In the case of the adhesive composition of the present invention, in addition to the components described above within a range that does not impair the object of the invention, various additives, for example, a polymerization inhibitor for improving the storage stability of the composition, for increasing the amount. Organic or inorganic filler, thixotropic agent for improving workability at the time of applying an adhesive, leveling agent, defoaming agent,
A colorant or the like may be added.

As one of the uses of the adhesive composition of the present invention, it can be preferably used for an adhesive for forming a vinyl chloride film laminate. As a method for producing a vinyl chloride film laminate, either one of a vinyl chloride film, or a plate material, or after applying the adhesive composition of the present invention to both adherend surfaces, a vinyl chloride film and a plate material are bonded together, It suffices to irradiate the vinyl chloride film side with an electron beam in an amount sufficient to cure the adhesive composition to cure the adhesive composition and bond the vinyl chloride film and the plate material.

The vinyl chloride film used for the vinyl chloride film laminate generally has a thickness of about 10 μm to several hundreds μm (including a relatively thick film called a vinyl chloride sheet).

On the other hand, as the plate material used for the PVC film laminate, cold rolled steel plates, hot rolled steel plates, and various surface-treated steel plates (plated steel plates, coated steel plates, chemical conversion treated steel plates, primer-treated steel plates, etc.) are generally used. However, it may be a metal plate other than steel, such as an aluminum plate, or various plastic or wood plates.

Further, during the production of a vinyl chloride film laminate, the irradiation dose of the electron beam for curing the adhesive varies depending on the thickness of the vinyl chloride film, the type of monomer used in the adhesive composition, etc. It is 1 Mrad to several tens Mrad. If the amount of electron beam irradiation is too small, the curing of the adhesive will be insufficient, and if it is too large, the PVC film may deteriorate.

(Examples) Hereinafter, the present invention will be described with reference to Examples, but all parts in the specification are on a weight basis.

Example-1 and Comparative Example-1 According to Table 1, the adhesive compositions a-1 to a-4 of the present invention were used.
And the adhesive composition b-1 of a comparative example-b-3 was prepared.
Then, these compositions were applied on a steel plate treated with a polyester resin-based primer, and after a 0.1 mm thick PVC film was attached, an electron beam of 7 Mrad was irradiated from the PVC film side (acceleration voltage; 200 KeV), The adhesive was cured to produce a vinyl chloride film laminate.

Using this vinyl chloride film laminate, a peeling test and an Erichsen test stipulated in JIS K 6744 were performed, and the results shown in Table 2 were obtained.

Example 2 Table 3 shows 10 parts of a partially saponified vinyl chloride-vinyl acetate-maleic acid copolymer (copolymerization ratio; 85: 14: 1, average degree of polymerization: 400) and 10 parts of "Dismocole 400". It was dissolved in a mixture of acrylate monomers to prepare an electron beam curable adhesive composition of the present invention. Then, a vinyl chloride film laminate was prepared and tested in the same manner as in Example-1. The test results are shown in Table 4.

(Effects of the Invention) As described above, the adhesive composition of the present invention eliminates the drawbacks of the conventional electron beam-curable adhesives for laminating vinyl chloride films, and has excellent adhesion to vinyl chloride films, and Since the cured product has an appropriate degree of flexibility, the resulting PVC film laminate can sufficiently withstand post-processing such as bending and drawing, and is extremely useful in fields such as PVC steel sheets. It is a thing.

Claims (1)

[Claims] 1. At least one of (A) an acrylic acid ester monomer and a methacrylic acid ester monomer, 100
Parts by weight (B) Vinyl chloride copolymer 1 soluble in the above monomers
-60 parts by weight (C) Linear polyurethane resin soluble in the above-mentioned monomer and obtained by addition reaction of diisocyanate and diol 0.5-40 parts by weight Above (A), (B) and (C) are essential components. An electron beam-curable adhesive composition containing the same.