JPS5933633B2 - Adhesive for mold inserts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to adhesives for molding inserts, and more specifically, in moldings made of polyvinyl chloride (hereinafter referred to as "PvC"), adhesives for adhesives for inserts made of aluminum and PV
This invention relates to an adhesive suitable for bonding C and O.

3 In this specification, "parts" refers to "parts by weight."

Synthetic resin side moldings attached to the bodies of automobiles and other vehicles are often directly affected by the outside temperature, and undergo large temperature changes during the summer and winter, as well as during the day and night, causing them to expand and contract repeatedly. As a result, the molding itself becomes curved, and due to the difference in expansion and contraction between the sheet metal part of the car body and the molding itself, the molding tends to separate from the car body. For this reason, modern side moldings have metal inserts buried within the molding to suppress expansion and contraction of the molding due to outside temperature. Then, an adhesive such as urethane-based, chloroprene-based, acrylonitrile-butadiene-based adhesive, etc. is applied to the insert in order to bond it to the resin forming the molding. However, these adhesives do not have very strong adhesion strength and do not have the adhesive strength to overcome the difference in expansion and contraction between the resin and the insert. Expansion and contraction due to temperature changes could no longer be suppressed, resulting in the above-mentioned problems.

Furthermore, after long-term use, plasticizers, stabilizers, and low-molecular compounds in the molding resin volatilize, causing the molding to shrink, causing the insert to protrude from the end of the molding, which may impair its appearance. At present, there is no adhesive suitable for bonding aluminum and PVC, and the above-mentioned problems are particularly likely to occur in PVC moldings in which aluminum inserts are embedded.

In view of the above, the present invention has been made to improve the adhesive strength that can overcome the expansion and contraction difference between resin and metal, and the adhesive for molding inserts that occurs between PVC and inserts in PVC moldings in which aluminum inserts are embedded. The purpose is to provide.

The gist of this invention is a PVC copolymer 1 in which ethyl methacrylate and methyl methacrylate are copolymerized with PVC.
00 parts and 5 to 20 parts of a methacrylic copolymer obtained by copolymerizing methyl methacrylate, styrene, acrylic acid, or methacrylic acid and maleic acid, diluted with an organic solvent, and is a Pv adhesive with an embedded aluminum insert.
It is used by applying it to the insert when molding a C molding. The adhesive of the present invention will be explained in more detail below.

The adhesive of this invention is made of the following PVC copolymer (A) 100
part and 5 to 20 parts of the following methacrylic copolymer (B) diluted with an organic solvent.

Here, if the methacrylic copolymer (B) is 5 parts or less, the adhesive force with the insert side (aluminum side) is reduced, and if it is 20 parts or more, the adhesive force with the PVC side is reduced.

The above-mentioned organic solvent is usually added and used to dissolve each compound when synthesizing a PVC copolymer and a methacrylic copolymer by a polymerization reaction.

Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene, and xylene, and ketones such as acetone, methyl ethyl ketone (hereinafter referred to as "MEK"), and methyl isobutyl ketone (hereinafter referred to as "MIBK"). . Also, when adjusting the adhesive, fillers such as carbon black and pigments are added if necessary.

CA) PVC copolymer This PVC copolymer contains 40 to 60 ethyl methacrylate (hereinafter abbreviated as "EMA") to the PVClOO part.
and methyl methacrylate (hereinafter abbreviated as "MMA")
Dissolve 100 to 140 parts in the above-mentioned organic solvent and mix,
A peroxide catalyst such as benzoyl peroxide (hereinafter abbreviated as "BPO") is added, and the mixture is reacted at 80 to 85° C. for about 5 hours with stirring to synthesize.

Here, if the amount is less than 40 parts of EMA and less than 40 parts of MMAlOO, the adhesive force with the insert side is low, and if it is more than 60 parts of EMA and less than 40 parts of MMAl, the adhesive force with the PVC side is reduced.

Furthermore, PVC refers to commonly used PVC for extrusion and injection molding, and vinyl chloride copolymerized with one or more monomers such as propylene, ethylene, and vinyl acetate.

The amount of pinyl chloride is preferably 70% or more, and in the case of a vinyl chloride/vinyl acetate copolymer, it may be used after being saponified. (B) Methacrylate copolymer This methacrylate copolymer is prepared by adding parts of MMA lOO, 2 to 7 parts of styrene, 1 to 10 parts of acrylic acid or 1 to 8 parts of methacrylic acid, and 1 to 10 parts of maleic acid in the above-mentioned organic solvent. The mixture is dissolved and mixed, a peroxide catalyst such as BPO is added, and the mixture is reacted at 80 to 85° C. with stirring for about 5 hours to synthesize.

Here, if the content is 2 parts or less of styrene, 1 part or less of acrylic acid or methacrylic acid, or 1 part or less of maleic acid, the adhesive strength with the insert side will decrease. 8 parts or more, 1 maleic acid
If the amount is 0 parts or more, the adhesive strength with the PVC side will decrease.

Next, a method of using the adhesive having the above structure will be explained.

First, after cleaning the surface of the aluminum insert, the viscosity (80 to 2000
The adhesive of this invention diluted with CP) has a dry film thickness of 80~2
Coat to a thickness of 00 μm. Examples of the coating method include spray coating, brush coating, knife coating, roll coating, etc., but these are not specified. Next, the adhesive layer on the surface of the insert is dried at a temperature ranging from room temperature to 300° C. for several tens of minutes to several seconds.

Preferably it is 200°C or less. If the temperature exceeds 300°C, the adhesive and insert may deteriorate.

Next, by embedding the above-mentioned insert at the same time as extruding the PVC, a PVC molding containing the required insert can be obtained.

When the PVC molding obtained in this way is used as a side molding for an automobile, etc., the adhesive strength between the insert and the PVC is high, and even if the molding is subjected to a large temperature change, the molding in the PVC Even if plasticizers, stabilizers, etc. volatilize, the insert will not peel off from the PvC.

Therefore, the molding will not bend or the insert will not protrude from the end of the molding. Examples of the present invention will be listed below along with comparative examples to confirm the effects of the present invention.

The adhesives of Examples 1 to 13 and Comparative Examples 1 to 4 were prepared by using mixtures having the compositions in the vinyl chloride copolymer (A) column and methacrylic copolymer (B) column in Table 1, respectively. Each copolymer was obtained by stirring for about 8" CX for 5 hours, and each copolymer (
5) and (B) were mixed in the ratio shown in the table.

In addition, in Comparative Example 5, NBR adhesive (“Bond GlO3
'' (trade name, produced by Konishi Co., Ltd.) and Comparative Example 6 used a CR adhesive (trade name: "Bond Gl7", produced by Konishi Co., Ltd.), respectively.

Test 5 test pieces were aluminum inserts obtained by applying adhesive in each example and comparative example and air-drying them for 30 hours.
Width 18m77! ) A side molding obtained by extruding the following PVC compound onto soil was pressed at 190° C. x 5 mm.

The film thickness of the adhesive is 60 to 70 μm. The test method was to test the above test piece using a tensile tester (“Tensilon UTM-1-5
000W” manufactured by Toyo Port Win Co., Ltd.).
A 180° peel test was conducted.

The heat resistance test is a 1800 peel test at room temperature after placing the test piece in a thermostat at 80°C for 200 hours.
The weather resistance test was a 180 peel test at room temperature after being exposed for 200 hours using a Sunshine Weathermeter (trade name: manufactured by Toyo Rika Kogyo Co., Ltd.) using two carbon arc lamps.

The above test results are shown in Table 2.

Claims (1)

[Scope of Claims] 1. An adhesive for molding inserts comprising 100 parts of the following polyvinyl chloride copolymer (A) and 5 to 20 parts of the following methacrylic copolymer (B) diluted with an organic solvent. (A) 40 to 60 parts of ethyl methacrylate and 100 parts of methyl methacrylate to 100 parts of polyvinyl chloride
A polyvinyl chloride copolymer obtained by copolymerizing ~140 parts. (
B) A methacrylic copolymer prepared by copolymerizing 100 parts of methyl methacrylate, 2 to 7 parts of styrene, 1 to 10 parts of acrylic acid, or 1 to 8 parts of methacrylic acid, and 1 to 10 parts of maleic acid.