JPH07278394A - Cross-linkable resin composition containing fluorine - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing a cross-linking accelerator in a tetrafluoroethylene/ethylene/propylene copolymer capable of providing moldings capable of keeping the flexibility, good in appearance and excellent in mechanical characteristics at high temperatures. CONSTITUTION:This composition contains a cross-linking accelerator (preferably a polyallylic type compound such as triallyl cyanurate or triallyl isocyanurate) and preferably further an elastomer containing fluorine (preferably a tetrafluoroethylene/propylene-based copolymer) in a tetrafluoroethylene/ethylene/ propylene copolymer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a crosslinkable fluorine-containing resin composition.

[0002]

2. Description of the Related Art Tetrafluoroethylene / ethylene / propylene copolymers have excellent heat resistance and electrical properties,
Further, since it can be molded by heating, it can be used as a material for various molded products, electric wire coatings, linings and the like. In particular, due to its high flexibility, it can be applied to more complicated wiring, piping, and places with intense movement for wire and tube applications. However, when it is placed in a high temperature atmosphere, it is deformed by an external force, so that there is a limit to its use at a high temperature.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a fluorine-containing resin composition capable of giving a molded article which retains the flexibility of a tetrafluoroethylene / ethylene / propylene copolymer and is less likely to be deformed by an external force at a high temperature. It is provided.

[0004]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that a tetrafluoroethylene / ethylene / propylene copolymer contains a crosslinking accelerator and is crosslinked. It was found that the purpose can be achieved by. That is, the present invention is a crosslinkable fluorine-containing resin composition obtained by adding a crosslinking accelerator to a tetrafluoroethylene / ethylene / propylene copolymer.

In the present invention, the content of tetrafluoroethylene / ethylene / propylene polymer units in the tetrafluoroethylene / ethylene / propylene copolymer is 40.
-65 / 10-40 / 25-45 (mol%) is preferable. When the content of the tetrafluoroethylene polymerized unit is less than 40 mol%, the decomposition temperature is lowered and the moldability is likely to be impaired. When the content of the ethylene polymer units is less than 10 mol%, the flexibility tends to decrease, and when it exceeds 40 mol%, the heat resistance tends to be impaired. The content of propylene polymer units is 2
When it is less than 5 mol%, both transparency and flexibility tend to be lowered.

Further, in the present invention, a mixture of a tetrafluoroethylene / ethylene / propylene copolymer and a fluorine-containing elastomer can also be used.

The fluorine-containing elastomer is not particularly limited, and tetrafluoroethylene / propylene copolymer, vinylidene fluoride / hexafluoropropylene copolymer, vinylidene fluoride / chlorotrifluoroethylene copolymer, Vinylidene fluoride / pentafluoropropylene copolymer, polyfluoroalkyl group-containing acrylate polymer, polyfluoroalkyl group-containing polysiloxane polymer, tetrafluoroethylene / vinylidene fluoride / propylene copolymer, tetrafluoroethylene / Ethylene / isobutylene-based copolymer, ethylene / hexafluoropropylene-based copolymer, tetrafluoroethylene / 1-butene-based copolymer, tetrafluoroethylene / ethyl vinyl ether-based copolymer, fluorine-containing phosphonitrile Coalescence, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer.

Of these, a tetrafluoroethylene / propylene copolymer is particularly preferable, and the content of the tetrafluoroethylene / propylene polymerization unit is 95 to 30.
It is preferable to select from the range of / 5 to 70, especially 90 to 45/10 to 55 (mol%).

In the present invention, the crosslinking accelerator is preferably a polyallyl type compound such as triallyl cyanurate or triallyl isocyanurate. Further, a prepolymer of triallyl isocyanurate (2-200 mer) and a prepolymer of diallyl phthalate (5-200 mer) are also suitable. The amount added is tetrafluoroethylene /
1 per 100 parts by weight of an ethylene / propylene copolymer or a mixture of the copolymer and a fluorine-containing elastomer.
A range of -20 parts by weight is common. Crosslinking methods include peroxide crosslinking and polyol crosslinking,
Radiation crosslinking is particularly preferred.

In the present invention, in addition to the above components, stabilizers, fillers (carbon black, silicic acid fillers such as silica, etc.), colorants, antioxidants, lubricants, etc. may be added as appropriate. Examples of the stabilizer include lead oxide, magnesium oxide, calcium oxide, aluminum oxide, titanium oxide, antimony oxide, phosphorus pentoxide and the like.

Molded products obtained by introducing the above-mentioned various components into the extruder in predetermined amounts and extruding while melt-kneading had a smooth appearance. In particular, a fluorine-containing elastomer and a crosslinking accelerator are uniformly mixed in advance, and this mixture is introduced into an extruder together with a tetrafluoroethylene / ethylene / propylene copolymer, whereby a molded article having a particularly excellent appearance can be obtained.

[0012]

EXAMPLES Example 1 100 parts by weight of a tetrafluoroethylene / ethylene / propylene copolymer (42/23/35 mol%) and a triallyl isocyanurate prepolymer (5
4 parts by weight, fine particle silica (Nippon Aerosil Co., Ltd.)
Aerosil R972) 2 parts by weight and titanium oxide 3 parts by weight were added to prepare a mixture having a barrel zone 1 temperature of 200 ° C.
Barrel zone 2 temperature 210 ° C, barrel zone 3 temperature 22
0 ℃, cross head temperature 260 ℃, die temperature 260
Extruder (4 ° C, screw rotation speed 15 rpm)
0 mm, L / D = 20, compression ratio = 3), and then extruded and coated on the outer circumference of a copper wire with an outer diameter of 0.8 mm to a thickness of 0.2 mm, followed by irradiation with an electron beam of 10 Mrad to crosslink insulation I created an electric wire. The cross-linking accelerator did not evaporate during molding, the molded product retained the flexibility of the tetrafluoroethylene / ethylene / propylene copolymer, had a good appearance, and had a heating change rate (JIS C3005, 250 ° C) of 27%. It was

[Example 2] 80 parts by weight of tetrafluoroethylene / ethylene / propylene copolymer (42/23/35 mol%), 20 parts by weight of tetrafluoroethylene / propylene copolymer (55/45), 4 parts by weight of prepolymer (pentamer) of triallyl isocyanurate, fine particle silica (Aerosil R97, Nippon Aerosil Co., Ltd.)
2) A crosslinked insulated electric wire was prepared in the same manner as in Example 1 using a mixture prepared by mixing 2 parts by weight and 3 parts by weight of titanium oxide. There is no volatilization of the cross-linking accelerator during molding, and the molded product retains the flexibility of the tetrafluoroethylene / ethylene / propylene copolymer, has a good appearance, and has a heating change rate (JIS
C3005, 250 ° C) was 25%.

Comparative Example 1 100 parts by weight of tetrafluoroethylene / ethylene / propylene copolymer (42/23/35 mol%), 2 parts by weight of fine particle silica (Aerosil R972 of Nippon Aerosil Co., Ltd.), titanium oxide 3 A crosslinked insulated electric wire was prepared in the same manner as in Example 1 using a composition prepared by mixing parts by weight. Heating change rate (JIS
C3005, 250 ° C.) was 80% or more.

[0015]

EFFECT OF THE INVENTION It is possible to obtain a fluororesin molded product which retains flexibility of a tetrafluoroethylene / ethylene / propylene copolymer, has a good appearance, and has excellent mechanical properties at high temperatures.

Claims (4)

[Claims] 1. A crosslinkable fluorine-containing resin composition comprising a tetrafluoroethylene / ethylene / propylene copolymer containing a crosslinking accelerator. 2. The fluororesin composition according to claim 1, which further comprises a fluoroelastomer. 3. The fluorine-containing resin composition according to claim 2, wherein the fluorine-containing elastomer is a tetrafluoroethylene / propylene-based copolymer. 4. The fluorine-containing resin composition according to claim 1, wherein the crosslinking accelerator is a polyallyl type compound or a prepolymer thereof.