JPS59204647A - Fluorine-containing elastomer composition - Google Patents

Abstract

PURPOSE:To provide the titled composition having excellent tear resistance, by adding a hydroxyaromatic compound and a cyanoethyl-substituted imidazole as crosslinking agents to a tetrafluoroethylene-propylene-glycidyl vinyl ether terpolymer. CONSTITUTION:A hydroxyaromatic compound containing hydroxyl group in the molecule and a cyanoethyl-substituted imidazole compound (e.g. 1-cyanoethyl-2- methylimidazole) are added as crosslinking agents to a tetrafluoroethylene- propylene-glycidyl vinyl ether terpolymer. The molar ratio of tetrafluoroethylene/ propylene in the terpolymer is 90/10-55/45, preferably 60/40-50/50, and the content of glycidyl vinyl ether is 0.1-10mol%, preferably 1-5mol%. The amount of the components of the crosslinking agent is 0.1-10pts.wt. each per 100pts.wt. of the terpolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluorine-containing elastomer composition from which a molded article having excellent tear resistance can be obtained.

Tetrafluoroethylene-propylene-glycidyl vinyl ether terpolymer has the excellent heat resistance, oil resistance, chemical resistance, steam resistance, and flame retardancy of Fuji Rubber, and is used for hoses, tubes, etc. It is expected to be used as an industrial coating material for rings, gaskets, etc.

When producing a crosslinked molded article using such a copolymer, conventional crosslinking agents include triethylnoamine, hexamethylenediamine carbamate, ammonium benzoate, and metal salts of dialkyldithiocarbamic acid, as well as JP-A-53-1999-1.
As disclosed in Japanese Patent Application No. 75290, tertiary amines such as benzyldimethylamine, α-methylbenzyltrimethylamine, dimethylaminemethylphenol, and N-aminoethylpiperazine are removed. Combinations of these tertiary amines and hydroxy compounds are used. ing.

However, the tear strength of the molded product obtained is insufficient, which is a major obstacle to its practical application.

The present invention is intended to improve the drawbacks of the prior art described above, and aims to provide a fluorine-containing elastomer composition that can significantly improve the tear strength of the resulting molded product.

That is, the fluorine-containing elastomer composition of the present invention comprises tetrafluoroethylene-propylene-gly7ylvinyl-
It is made by adding a hydroxy aromatic compound having a hydrophilic group in the molecule and an anoethyl-converted imidazole to a tertiary copolymer as a crosslinking agent.

In the above copolymer, it is preferable to select a molar ratio of tetrafluoroethylene/propylene from the range of 90/10 to 55/45, preferably from '6 o/40 to 50,150 in terms of heat resistance, moldability, etc. However, glycidyl vinyl ether is preferably selected from a range of 01 to 10 molar ratios, and < is preferably selected from a range of 1 to 5 molar ratios; if the content is too small, the tear strength of the molded product will be insufficient;
If it is too large, heat resistance will be impaired.

In addition to the main components of tetrafluoroethylene, propylene, and glycinol vinyl ether, there are also components copolymerizable with these, such as ethylene, imbutylene, vinyl fluoride, vinylidene fluoride, fluoropylene hexafluoride, fluorovinyl ether, and alkyl vinyl ether. 1. Chlorotrifluoroethylene or the like may be copolymerized, and the content thereof is preferably selected from a range of 15 molti or less.

The number average molecular weight of such a copolymer is preferably selected from the range of 3 to 100,000; if it is too thick, the molded product may crack or lose surface smoothness, and if it is too small, the molded product may tear. strength is insufficient.

In the present invention, as a crosslinking agent for the above copolymer, (a)
It is important to use both a hydroxy aromatic compound containing a hydroxyl group in the molecule and a (b) cyanoethyl group-substituted imidazole, as this can significantly improve the tear strength of the molded article.

The amount of crosslinking agent added is 7 parts by weight per 100 parts by weight of the copolymer.
A) and (b) each should be 01 parts by weight or more, and (a) + (
b) is appropriately selected from a range with an upper limit of 10 parts by weight.

Specific examples of the crosslinking agent (a) include phenol, hypoquinone, catechol, resorcinol, 1,3.5-trihydroxybenzene, dihydroxynaphthalene, 2-methylresorcinol, trimethylolallylic 7-phenol, and the like. .

Specific examples of the crosslinking agent (b) include 1-one anoethyl=2
-Ethyl-4-methyl-esterol, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-15decylimidazole, etc.

The ingredients of the above rig include fillers such as carbon blank and fine silica, and lubricants such as stearic acid, and fine dispersants, processing aids, stabilizers, etc. may be added as long as the properties are not deteriorated. .

Examples of the present invention will be described below along with comparative examples.

Tetrafluoroethylene-propylene-glycidyl vinyl ether ternary copolymer 100 in which the molar ratio of tetrafluoroethylene/propylene/glycidyl vinyl ether is 55/43/2 and the number average molecular weight is 50,000
Parts by weight, 20 parts by weight of MT Karsho, 1 part by weight of stearic acid, and predetermined amounts of various components shown in Table 1 as a crosslinking agent were kneaded using a 6-inch roll set at 60°C, and then , lO in a press set at 150°C.
1 by holding for 30 minutes at a pressure of OI<g/cJ.
A sheet with a thickness of 2wn was molded using 5 an x 12 cn+.

The tear strength of the thus obtained /-t was measured based on ASTM D470, and the results are shown in the lower column of Table 1.

(The following is a blank space) As is clear from Table 1, Examples 1 to 5 in which two types of crosslinking agents defined in the present invention were used in combination all have high tear strength.

On the other hand, in Comparative Example 1 in which only one of the crosslinking agents specified in the present invention was used, and in Comparative Examples 2 and 3 in which a combination with a conventionally known crosslinking agent was used, almost no crosslinking occurred.
Even if crosslinking occurs, only very low tear strengths are obtained.

As explained above, the present invention takes advantage of the various properties of the tetrafluoroethylene-zolobylene-cricidyl vinyl ether terpolymer, such as heat resistance, oil resistance, and chemical resistance, and also has excellent tear strength. A molded body will be obtained.

It can be said that the fluorine-containing elastomer composition of the present invention is extremely useful for tubes, hoses, O-rings, gaskets, heat rollers for copying machines, etc.

Claims (2)

[Claims] (1) A fluorine-containing product made by adding a hydroxy aromatic compound having a hydroxyl group in the molecule and a cyanethyl group-substituted imidazole as a crosslinking agent to a tetrafluoroethylene-propylene-glycidyl vinyl ether ternary copolymer. Elastomeric composition. (2) The above copolymer is characterized in that the molar ratio of tetrafluoroethylene/propylene is 90/10 to 55/45, and that the glycynorvinyl ether is contained in a molar ratio of 0.1 to 10. A fluorine-containing elastomer composition according to claim 1.