JPS5948072B2 - Adhesive for mold inserts - Google Patents

Description

[Detailed description of the invention] The present invention relates to an adhesive for molding inserts.

More specifically, the present invention relates to an adhesive suitable for bonding an iron insert to PVC in a polyvinyl chloride (hereinafter referred to as "PVC") molding. In this specification, "part"
, 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 is curved, and due to the difference in expansion and contraction between the sheet metal part of the vehicle body and the molding itself, the molding is likely to separate from the vehicle body. For this reason, Sakuima's side moldings have metal inserts buried in the molding to suppress expansion and contraction due to outside temperature. In order to bond with the resin that forms the molding, the insert is made of urethane,
Adhesives such as chloroprene type and acrylonitrile ptadiene type are applied. 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. As a result, 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 steel and PVC, and the above-mentioned problems are particularly likely to occur in PVC moldings with embedded iron inserts.

In view of the above, this invention has a PVC molding in which a steel insert is embedded, and has adhesive strength that can overcome the expansion and contraction of the resin and metal, and an adhesive for the molding insert that is generated between the PVC and the insert. The purpose is to provide.

The gist of the present invention is to provide a PVC copolymer and a chlorinated rubber copolymer in which PVC and chlorinated rubber are copolymerized with one or more types of acrylic mortar selected from lower alkyl esters of methacrylic acid or acrylic acid. But the former 1
It is an adhesive that is dissolved in an organic solvent and mixed at a ratio of 50 parts or less to 00 parts of the latter, and is used by applying it to the insert when forming a PVC molding in which the iron insert is embedded. be.

The adhesive of this invention is made of the following PVC copolymer (4) 100
and 50 parts or less of the following chlorinated rubber copolymer (B) are dissolved in an organic solvent.

If the chlorinated rubber copolymer (B) contains O parts, the adhesion to the insert (iron) side will decrease, and if it exceeds 50 parts, the PV
Adhesion to the C side decreases. The above organic solvent is usually P
When synthesizing a VC copolymer and a methacrylic copolymer by polymerization reaction, it is added and used to dissolve each compound.

Examples of this organic solvent include aromatic hydrocarbons such as benzene, toluene, and xylene, as well as acetone, methyl ethyl ketone (hereinafter referred to as "MEK"), methyl isopropyl ketone, methyl isobutyl ketone (hereinafter referred to as "MIBK"), and cyclohexanone. Examples of ketones include:
Also, when adjusting the adhesive, add fillers such as carbon black and slope if necessary.

(A) PVC copolymer This PVC copolymer is prepared by dissolving and mixing PVClOO part and 150 to 250 parts of an acrylic monomer selected from lower alkyl esters of methacrylic acid or acrylic acid in the above-mentioned organic solvent. Synthesis is carried out by adding a peroxide catalyst such as penzoyl peroxide (hereinafter abbreviated as "BPO") to react.

Here, if the acrylic monomer is less than 150 parts, the adhesion to the insert side will be reduced, and if the acrylic monomer is more than 250 parts, the adhesion to the PVC side will be reduced.

In addition, the PVC used here includes commonly used PVC for extrusion/injection molding, and polyvinyl chloride monomers copolymerized with one or more monomers such as propylene, ethylene, and vinyl acetate. Can be mentioned.

The amount of pinyl chloride monomer is preferably 70 vt% or more, and in the case of a vinyl chloride/vinyl acetate copolymer, it may be used after being saponified. The above-mentioned lower alkyl ester is an acrylic monomer having an alkyl group having 1 to 4 carbon atoms, and examples thereof include methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate.

(B) Chlorinated rubber copolymer This chlorinated rubber copolymer consists of 100 parts of chlorinated rubber, and
Acrylic monomer 50 to 15 similar to that used in (4) above
0 part is dissolved in an organic solvent and mixed, and a peroxide catalyst similar to that used in (4) above is added to react and synthesize.

Here, if the acrylic monomer is less than 50 parts, the adhesion to the insert side will be reduced, and if it exceeds 150 parts, the adhesion to the PVC side will be reduced.

The chlorinated rubber mentioned above is Adeka Chlorinated Rubber CR-5 manufactured by Asahi Denka Co., Ltd.・CR-10-CR-20・CR-20
Examples include S-CR-40 and CR-90 (product name).Next, we will explain how to use the adhesive with the above structure.
After cleaning the surface of the iron insert, the adhesive of the present invention diluted with the above-mentioned organic solvent to a suitable viscosity (8.042,000 cp) is coated to a dry film thickness of 80 to 200 um.

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 isosade at the same time as PVC extrusion, a molding made of Hill C with a 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, there is no possibility that the molding will curve or the insert will 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.

In preparing the adhesives of Examples 1 to 10 and Comparative Examples 1 to 6, each mixture having the composition shown in Tables 1 and 2 was heated to 80'
PVC copolymer 6 and chlorinated rubber copolymer 8 were synthesized by stirring CX for 5 hours, and each copolymer (A) and 8 were mixed in the combinations and ratios shown in Table 3.

The chlorinated rubber is the aforementioned “ADEKA Chlorinated Rubber, CR-2”.
0S" was used. Comparative Example 7 used an NBR adhesive (trade name "Bond GlO3l", manufactured by Konishi Co., Ltd.), and Comparative Example 8 used a CR adhesive (trade name "Bond Gl7", manufactured by Konishi Co., Ltd.). .

In Comparative Example 9, a PVC copolymer^ and a methacrylate copolymer O were synthesized by stirring a mixture having the composition in A8 of Table 1 and a mixture having the composition shown below at 80°C for 5 hours, and (A)/( The adhesive was prepared by mixing C)=100/10.

Methacrylate copolymer 0 MMAI 00 parts, BPOO. 5 parts of O, 3.5 parts of styrene, 5.8 parts of acrylic acid, 5.8 parts of maleic acid, 100 parts of toluene, 69 parts of MlBKl.

The test pieces were iron inserts (width: 18 m) obtained by applying adhesive by tapping and air-drying for 30 minutes.
A side molding obtained by extruding the following PVC compound on top of the mold was pressed at 190° C. for 5 minutes.

The film thickness of the adhesive was 60 to 70 μm.
W” manufactured by Toyo Port Win Co., Ltd.), 180
A peel test was conducted. The above test results are shown in Table 3.

Claims (1)

[Claims] 1. An adhesive for molding inserts comprising a mixture of 100 parts of the following polyvinyl chloride copolymer (A) and 50 parts or less of the following chlorinated rubber copolymer (B) dissolved in an organic solvent. . (A) 1 selected from lower alkyl esters of methacrylic acid or acrylic acid per 100 parts of polyvinyl chloride
A vinyl chloride copolymer obtained by copolymerizing 150 to 250 parts of a species or two or more acrylic monomers. (B) A chlorinated rubber copolymer prepared by copolymerizing 100 parts of chlorinated rubber with 50 to 150 parts of one or more acrylic monomers selected from lower alkyl esters of methacrylic acid or acrylic acid.