JPH06306237A - Fluororubber composition having improved mechanical characteristic - Google Patents

Abstract

PURPOSE:To obtain the composition useful as automotive parts, having a low modulus, excellent mechanical characteristics, heat resistance and vulcanizing properties, comprising specific fluororubber, a specific quaternary ammonium salt, a polyhydroxy compound, a metal oxide, etc., in a specific ratio. CONSTITUTION:The objective composition comprises (A) 100 pts.wt. of fluororubber obtained by copolymerizing vinylidene fluoride with hexafluoropropylene or vinylidene fluoride with hexafluoropropylene and tetrafluoroethylene, (B) 0.05-2 pts.wt. of an organic quaternary ammonium salt of the formula R<1>R<2>R<3>R<4>NX (R<1> is aryl; R<2> is R<1> or 1-20C hydrocarbon; R<3> and R<4> are 1-20C hydrocarbon, etc.; X is monovalent anion) such as phenyltrimethylammonium chloride, (C) 0.1-10 pts.wt. of a polyhydroxy compound such as bisphenol AF and (D) 0.5-30 pts.wt. of a metal (hydroxide) oxide such as magnesium oxide or its mixture.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a fluororubber composition, and more particularly to a novel fluororubber composition having improved mechanical properties.

[0002]

2. Description of the Related Art Fluorine rubber is widely used in various industrial fields such as automobile parts because it has excellent heat resistance, oil resistance and chemical resistance. However, the mechanical properties of the vulcanizates obtained by any of the vulcanization methods were relatively high in hardness and modulus and low in elongation. In order to lower the modulus and increase the elongation, it is necessary to reduce the amount of vulcanizing agent and vulcanization accelerator, in which case the crosslinking density will decrease, and compression set and heat resistance will decrease. was there.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluororubber composition having a low modulus and a large elongation without impairing the excellent properties of fluororubber.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a specific organic quaternary ammonium salt is effective as a vulcanization accelerator. The present invention has been completed based on this finding.

That is, the present invention provides (A) a fluororubber obtained by copolymerizing vinylidene fluoride and hexafluoropropylene, or a fluororubber obtained by copolymerizing vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene. 100 parts by weight, (B) general formula R ¹ R ² R ³ R ⁴ NX (R ¹ is an aryl group, R ² is R ¹
Aryl groups the same as or different from each other, or having 1 carbon atom
20 hydrocarbon group, R ^3, R ⁴ are carbon atoms different identical or different further R ¹ the same or mutually from each other 1-2
Hydrocarbon group of 0, X is monovalent anion) Organic quaternary ammonium salt represented by 0.05 to 2 parts by weight, (C) Polyhydroxy compound 0.1 to 10 parts by weight, (D) Metal oxide Or metal hydroxide or a mixture thereof.
The present invention provides a fluororubber composition having 5 to 30 parts by weight and improved mechanical properties.

The fluororubber used as the component (A) in the present invention is a fluororubber obtained by copolymerizing vinylidene fluoride and hexafluoropropylene in a weight ratio of 40/60 to 80/20, or in the above-mentioned proportion. A fluororubber obtained by copolymerizing vinylidene fluoride and hexafluoropropylene with tetrafluoroethylene at a ratio of 35% by weight or less based on the total weight of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene. Used alone or as a mixture of two or more kinds.

Further, the molecular weight and molecular weight distribution of these fluororubbers are not particularly limited, and may be appropriately selected according to the application and molding conditions. For producing these fluororubbers, conventionally known polymerization methods such as emulsion polymerization, suspension polymerization, solution polymerization and bulk polymerization are preferably adopted.

The organic quaternary ammonium salt used as the component (B) in the present invention has a vulcanizability equivalent to that of an ammonium salt or a phosphonium salt generally used as a conventional vulcanization accelerator, and Has the effect of lowering the hardness and modulus of the obtained vulcanizate and increasing the elongation. Further, the compression set of the obtained vulcanized product is not impaired.

Specific examples of the component (B) include phenyltrimethylammonium chloride, phenyltrimethylammonium bromide, phenyltrimethylammonium hydrogen sulfate, phenyltriethylammonium chloride, phenyltrioctylammonium bromide and the like.

These compounds are used alone or as a mixture of two or more kinds. In addition, these compounds are
You may use together with the vulcanization accelerator generally used conventionally. The amount of the component (B) used relative to 100 parts by weight of the component (A) is 0.05 to 2 parts by weight, preferably 0.1 to 1 part by weight, and particularly preferably 0.1 to 0.6 part by weight. .

The polyhydroxy compound as the component (C) used in the present invention serves as a vulcanizing agent for fluororubber, and any conventionally known compound can be used. (C)
Examples of the component include bisphenol AF, bisphenol A, hydroquinone, catechol, and fluorine-containing aliphatic polyhydroxy compound, and bisphenol AF is particularly preferably used. The amount of the component (C) used with respect to 100 parts by weight of the component (A) is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight.

The metal oxide or metal hydroxide or the mixture thereof as the component (D) used in the present invention is used as an acid acceptor during the vulcanization of fluororubber. All are available. Specific examples of the component (D) include magnesium oxide,
Examples thereof include calcium oxide, zinc oxide, lead oxide, calcium hydroxide and magnesium hydroxide. (A) ingredient 1
The amount of component (D) used is 0.5 to 30 parts by weight per 100 parts by weight.
Parts by weight, preferably in the range of 1 to 25 parts by weight.

In the fluororubber composition of the present invention, if necessary, other components such as fillers and reinforcing agents such as carbon black, silica, clay, diatomaceous earth, calcium carbonate, calcium fluoride, barium sulfate, etc., Processing aids,
It is possible to add an internal release agent, an adhesion promoter, a plasticizer, a coloring agent and the like.

It is also possible to blend with natural rubber, other synthetic rubber, thermoplastic resin, thermosetting resin and the like. The fluororubber composition of the present invention can be obtained by uniformly mixing the above-mentioned respective components with an ordinary rubber kneading device such as a roll or a kneader.

The fluororubber composition thus obtained is vulcanized and molded by a usual rubber molding method such as press molding, injection molding, extrusion molding, calender molding, coating after dissolving in a solvent or dip molding. It
The vulcanization conditions are appropriately determined depending on the shape and conditions of the product to be molded, but generally, 100 ° C to 4 ° C.
It is in the range of several seconds to 24 hours at 00 ° C. Further, secondary vulcanization may be performed in order to stabilize the properties of the obtained vulcanizate. In that case, the conditions are generally 150 ° C ~
It is about 30 minutes to 48 hours at 300 ° C.

[0016]

EXAMPLES Next, the present invention will be described in more detail by way of examples. In addition, in Table 1, actually, the examples and the ratios indicate comparative examples. According to the composition shown in Table 1, the respective components were uniformly mixed with two rolls to obtain a fluororubber composition. This was subjected to press vulcanization at 170 ° C. for 10 minutes and secondary vulcanization at 230 ° C. for 24 hours, and then physical properties were measured according to JIS K6301. The vulcanizability was measured at 170 ° C. for 24 minutes using ODR manufactured by Toyo Seiki.

[0017]

[Table 1]

[0018]

INDUSTRIAL APPLICABILITY The fluororubber composition of the present invention has the same excellent properties as conventional fluororubbers and is excellent in vulcanizability, and therefore has an extremely high industrial value. Based on its excellent properties, the fluororubber composition of the present invention is used for O-rings, oil seals, gaskets, sealing materials, hoses, tubes, diaphragms, etc. of vehicles such as automobiles and aircraft, as well as chemical plants and foods. Widely used for similar parts such as plants and general industrial parts.

Continued Front Page (72) Inventor Hiroyuki Hirai 10 Goi Kaigan, Ichihara City, Chiba Asahi Glass Co., Ltd. Chiba Factory

Claims (1)

[Claims] 1. A fluororubber obtained by copolymerizing (A) vinylidene fluoride and hexafluoropropylene or a fluororubber obtained by copolymerizing vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene, 100 parts by weight, (B) General formula R ¹ R ² R ³ R ⁴ NX (R ¹ is an aryl group, R ² is the same or different aryl group as R ¹ ,
Or a hydrocarbon group having 1 to 20 carbon atoms, R ³ and R ⁴ are the same or different from each other, and are hydrocarbon groups having 1 to 20 carbon atoms which are the same as or different from R ^1, and X is a monovalent anion)
0.05 to 2 parts by weight of (C) polyhydroxy compound 0.1 to 10 parts by weight, (D) metal oxide or metal hydroxide or a mixture thereof 0.5 to 30 A fluororubber composition having improved mechanical properties, which comprises 1 part by weight.