JPS60262845A - Fluororesin composition crosslinkable by irradiation - Google Patents

Abstract

PURPOSE:To provide the titled resin compsn. capable of yielding moldings having fine appearance, by incorporating hydrogen-contg. fluororesins, crosslinkers, and silica. CONSTITUTION:100pts.wt. hydrogen-contg. fluororesin (e.g., vinylidene fluoride polymer, ethylene/tetrafluoroethylene copolymer) (fluorine-contg. elastomers such as tetrafluoroethylene/propylene copolymer may be used in combination), about 1-20pts.wt. crosslinker (pref. compds. contg. an allyl group, e.g., triallyl cyanurate), and about 0.01-20pts.wt. silica (pref. highly pure anhydrous silica powder prepd. by burning refined silicon tetrachloride) are mixed. The resulting fluororesin compsn. is extruded while melt-kneading by the use of extruders, etc. and crosslinked by irradiation, yielding moldings.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application 1) The present invention relates to a fluororesin composition that can be crosslinked by irradiation with radiation such as an electron beam.

[Prior art] Fluororesins containing hydrogen atoms generally have particularly excellent mechanical properties and processability among fluororesins, and also have excellent electrical properties, chemical resistance, and heat resistance, and have a well-balanced It is a material. For this reason, it is used in various fields, including as a material for covering electric wires, as well as in the form of film Yabucove.

However, in a high temperature atmosphere that exceeds the melting point, J3
If it is bent, it will deform due to external force, and there is a limit to its use at high temperatures.

In order to improve this problem, it is known to cause crosslinking by irradiating with radiation such as electron beams, but crosslinking and disintegration occur simultaneously due to radiation irradiation, making it impossible to achieve sufficient crosslinking efficiency.

Therefore, attempts have been made to improve the crosslinking efficiency by adding a crosslinking accelerator such as an allyl type compound, but if the crosslinking accelerator is simply added and extruded, the crosslinking accelerator is There is a problem in that the crosslinking accelerator and the fluororesin react with each other due to decomposition and local aggregation, resulting in a rough appearance of the molded product, making it impossible to obtain a good product.

[Problems to be Solved by the Invention] The present invention has been made based on the above, and an object of the present invention is to provide a fluororesin composition with which a molded article having a good appearance can be obtained.

[Means for Solving the Problems] The fluororesin composition of the present invention contains a crosslinking accelerator and silica in a fluororesin containing hydrogen atoms or a mixture of a fluororesin containing hydrogen atoms and a fluorine-containing elastomer. It is what it is.

[Function] In the present invention, the fluororesin containing a hydrogen atom is a vinylidene butylene polymer, a vinylidene butylene polymer, an ethylene-detrafluoroethylene copolymer, or an ethylene-chlorotrifluoroE [from a tyrene copolymer]. These can be used alone or in combination of two or more.

Further, in the present invention, it is also possible to use a mixture of the above-mentioned hydrogen atom-containing silicone resin and fluorine-containing elastomer.

The fluorine-containing elastomer is not particularly limited;
Tetrafluoroethylene-propylene copolymer, vinylidene butthorate-hexafluoro[]propene copolymer,
vinyletine fluoride-chlorotrifluor-A ethylene copolymer, vinylidene fluoride-pentafluoro-propylene copolymer, polyfluoroalkyne group-containing acrylate elastomer, polyfluoroalkyne group-containing polysiloxane elastomer, De1 ~Lafluoroethylene-vinylidene fluoride-propylene copolymer, tetrafluoroni[dylene-ethylene-butylene copolymer, ethylene-hexafluorobrobene copolymer, tetrafluoroethylene-butene-1 copolymer, tetrafluoroethylene-ethyl vinyl ether copolymer, fluorine-containing phosphonitrile elastomer, tetrafluoroethylene-
Examples include fluorovinyl needle-based co-combination.

Among these, De1herafluoro ethylene-propylene copolymer is particularly suitable, and the molar ratio of tetrafluoroethylene/propylene is 9515 to 30/70.
In particular, it is preferable to select from the knots of 90/10 to 45155.

In addition, tetrafluoroethylene polymer, tetrafluoroethylene-hexafluoropropylene copolymer, Te1
~Lafluoroethylene-perfluoroalkylvinyl■
Fluororesins that do not contain hydrogen atoms, such as a -chill type co-unit, are excluded from the present invention because they are radiation-degradable.

As a crosslinking accelerator, a compound containing an allyl group is used.
Suitable examples include triallyl cyanure-1~, triallyl isocyanure-1~, triallyl-1-rimezate, triallyl-rimesate, tetraallyl viromelidate, and the like.

The amount added is 1 to 1 to 11 parts of fluororesin or a mixture of fluororesin and fluorine-containing elastomer.
A range of 20 feet is common.

Silica (J) refers to silicic acid and silicon MW, and is called Tsutomi White Carbon (C).

Among these, those with small particle size and low moisture content are suitable, and in particular, J,
Anhydrous silica with a purity of 10% is effective. Also,
It is also effective to have the surface hydrophobically treated with a methyl-based j'-alkyl group.

Addition amount of A: 1 U, 0.00 for 100 parts of a mixture of fluororesin or S, fluorine-containing resin and fluorine-containing lastomer.
01 to 20 parts, preferably 0.05 to 5Φ all
range is common.

In the present invention, metal oxides, inorganic fillers, shield coloring agents, etc. may be appropriately added in addition to the above-mentioned components.

Put a predetermined amount of various ingredients into an extruder, melt and knead them.
The inventor's experiments have confirmed that the molded product obtained by extrusion has an extremely smooth appearance.

In particular, it has been confirmed that a molded product with a particularly excellent appearance can be obtained by uniformly mixing the fluorine-containing elastomer, the crosslinking accelerator, and silica in advance, and introducing the mixed portion together with the fluororesin into an extruder.

[Example 1] The various components listed in Table 1 were introduced into an extruder in the proportions shown on each side, and melt-kneaded at a temperature of 280 to 310°C to form pellets.

This barrel belt is I @! 1 temperature ffj260℃
, barrel zone 2 temperature v270℃, barrel zone 3 temperature 2
80℃, crosshead temperature 320℃, die temperature 32
0℃, screw rotation speed 15 r, I), ltl at 11
, 411tl output Ia (40m 7m, L, /D=2
0. The conductor was introduced at a compression ratio of -3), extrusion coated on the outer periphery of a conductor having an outer diameter of 0.8# to a thickness of 0.2 m, and then irradiated with an electron beam of 10 Mrad to create a crosslinked insulated wire.

The results of visually inspecting the appearance of the insulated wires on each side are as follows:
As shown in the bottom column of the table.

Table 1 *1. Kureha Chemical Co., Ltd. KF1000 *5 Nippon Aerosil Co., Ltd. Ayorisil R972 As is clear from Table 1, all of Examples 1 to 5 within the scope of the present invention had a good extrusion appearance.

(Effects of the Invention) As explained above, the present invention provides a composition in which a fluororesin containing a hydrogen atom or a fluororesin containing a hydrogen atom and a fluorine-containing trastomer contain a crosslinking accelerator and silica. This makes it possible to obtain a crosslinked molded product that has excellent mechanical properties at high temperatures and also has a good appearance.

=285

Claims (4)

[Claims] (1) A mixture of a fluororesin containing hydrogen atoms or a fluororesin containing hydrogen atoms and a fluorine-containing lath]
A fluororesin composition capable of crosslinking by radiation, characterized in that it contains a crosslinking accelerator and silica. (2) The fluororesin containing a hydrogen atom is selected from vinylidene butylene polymer, vinylidene butylene polymer, ethylene-tetrafluoroethylene copolymer, or J-thylene-chlorotrifluorΔroethylene copolymer. The tllll focal ray irradiation crosslinkable fluororesin composition according to claim 1, which is characterized by: (3) The radiation-crosslinkable fluororesin composition according to claim 1, wherein the elastomer is a te-1-nnororoethylene-propylene copolymer. (4) The fluororesin composition capable of being crosslinked by radiation as set forth in item ii', wherein the crosslinking accelerator is a compound containing an allyl group.