JPS6099137A - Bonding of molded resin article - Google Patents

Abstract

PURPOSE:To enable sufficiently firm bonding of an adherend having a releasing agent layer, without removing the releasing agent, by using an adhesive obtained by adding benzyl alcohol to an epoxy-resin-polyamide resin. CONSTITUTION:An adhesive composed mainly of an epoxy resin-polyamide resin (100pts.wt.) and added with 1-20pts.wt. of benzyl alcohol (solid basis) is used in the bonding of a molded resin article having a releasing agent layer. The epoxy resin is preferably an epibis-type resin, and the polyamide resin is preferably a low molecular weight polyamide amine having an amine value of >=600.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adhering resin molded articles to which a mold release agent is attached. The surface of resin molded products, including elastic materials and low-foam materials made by injecting thermosetting resins and liquid rubbers that are liquid at room temperature such as urethane and epoxy resins into molds, and hardening them, is coated with molds in advance during molding. Usually, 5 to 201 d of a silicone-based or wax-based mold release agent applied to the surface is attached. Conventionally, in order to adhesively process resin molded products with a mold release agent attached, the mold release agent was removed by cleaning with a solvent, sanding, or cutting, as ordinary adhesives would not adhere. This method involves applying adhesive to the resin surface.

An object of the present invention is to develop an adhesive that can adhere even if a mold release agent is attached to the surface of a resin molded product, and to provide a method for bonding resin molded products that can omit the step of removing the mold release agent.

The present invention is a method for bonding resin molded articles using an adhesive containing an epoxy resin-polyamide resin as a main component and 1 to 20 parts of benzyl alcohol added in terms of solid content weight.

The epoxy resin used in the present invention refers to highly reactive three-membered epoxy groups such as glycidyl ether type, glycidyl ester type, glycidyl amine type, linear aliphatic epoxide type, and alicyclic epoxide type in one molecule. It refers to single substances such as L, copolymers with urethane resins, copolymers of acrylic resins, etc., and mixtures thereof, which are cured by crosslinking with amines. Among these, epibis type is the best. Next, polyamide resin is obtained by condensing daimer acid obtained by thermal polymerization of drying oil, semi-drying oil, tall oil, etc. and alkylene polyamine such as ethylenediamine, diethylenetriamine, triethylenetetramine, etc. It is a resin that has been conventionally used as a curing agent for epoxy resins, and among these, polyamide amine having an amine value of 600 or more and having a low molecular weight is most suitable. Next, benzyl alcohol is an industrial product used as a raw material for the production of volatilization retaining agents, paints, solvents, and esthetics.In the present invention, the amount of benzyl alcohol added is 10%
1 to 20 parts are effective for 0 parts. That is, if it is more than 1 part, no adhesive effect is observed, and if it is more than 20 parts, the M concentration of the adhesive layer is weak (and sufficient adhesive strength cannot be obtained). It also includes adhesive compositions modified by adding known compounding agents such as fillers depending on the purpose.

In the present invention, the polyamide resin, which is a curing agent component of the epoxy resin, in particular a low molecular weight polyamide amine with an amine value of 0 or more, and benzyl alcohol dissolve the mold release agent attached to the surface of the resin molded product. It is thought that it is absorbed and dispersed in the adhesive layer and exerts the inherent adhesion of epoxy resin at the adhesive interface, and this effect is exhibited in the coexistence of polyamide resin and Benji7/L'coal. As applicable mold release agents for resin molding, both silicone-based and wax-based release agents are found to be effective.

As described above, in the present invention, d: By using a special adhesive, it is possible to bond resin molded products to which a mold release agent is attached.
7. Removing the mold release agent (this step can be omitted. Therefore, it is of great engineering value because it simplifies the process of combining the resin molded product with other adherends such as metals, galanus, and water conduits through adhesion processing. .

Next, the present invention will be explained by examples. Parts indicate parts by weight.

Examples 2 and 3. /) Mubihi Soft A Row/.

A bispheno-/VA type epoxy resin with an epoxy equivalent of about 190, a polyamide resin with an amine value of about 900, benzyl alcohol, and heavy calcium carbonate were mixed together to prepare an adhesive as shown in Table 1. Example 1.2 .3 and the adhesive of Comparative Example 1.

Next, the hard urethane resin moldings coated with about 10ν of a silicone mold release agent and about 30gβ of a wax mold release agent and a galvanized iron plate with a thickness of 0.3 fl. Paste them together with a spacer in between, and heat at 60℃.
Table 2 shows the results of measuring the tensile shear adhesive strength at room temperature after curing for 20 minutes.

Claims (1)

[Claims] 1. When bonding a resin molded product to which a mold release agent is attached, 1 to 20 parts of benzyl alcohol (calculated as solid weight) is added to an epoxy resin-polyamide resin as the main component. A method for bonding resin molded articles, characterized by using an adhesive. 2. The method for bonding resin molded articles according to claim 1, wherein the polyamide resin is a low molecular weight polyamide amine having an amine value of 600 or more.