JPS60260636A - Radiation-crosslinkable fluororesin composition - Google Patents

Abstract

PURPOSE:The titled resin composition which gives crosslinked moldings having a good appearance and excellent mechanical characteristics in a high-temperature atmosphere, obtained by incorporating Bi2O3, Sm2O3 or Dy2O3 and a crosslinking agent into an ethylene-fluoroolefin copolymer. CONSTITUTION:0.05-10pts.wt. at least one of bismuth oxide, samarium oxide, and dysprosium oxide, and at least 0.5pt.wt. crosslinking agent are incorporated into 100pts.wt. ethylene-fluoroolefin copolymer (e.g. an ethylene-tetrafluoroethylene copolymer or an ethylene-chlorotrifluoroethylene copolymer). Bismuth oxide, samarium oxide, and dysprosium oxide each have an activity of controlling chemical reaction, and can be used alone or as a mixture of at least two of them.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is directed to a fluorine resin crosslinkable product that can be crosslinked by irradiation with radiation such as an electron beam, thereby making it possible to obtain a fluororesin crosslinked molded product with excellent mechanical properties in a high-temperature atmosphere. This invention relates to a resin composition.

[Conventional technology]

Ethylene-fluoroolefin compound 1d is a well-balanced material that generally has excellent mechanical properties and processability among fluororesins, as well as excellent electrical properties, chemical resistance, and heat resistance.

For this reason, it is used in various fields, including as a material for covering electric wires, as well as in the form of films and tubes.

However, when placed in a high-temperature atmosphere that exceeds the melting point, it deforms due to external force, and there is a limit to its use at high temperatures.

In order to improve this, it is known to perform crosslinking by irradiating with radiation such as an electron beam, but crosslinking and collapse proceed 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 extrusion molded.

Due to extrusion at high temperatures, the crosslinking accelerator and fluororesin react with each other due to decomposition and local aggregation of the crosslinking accelerator.
There is a problem in that the appearance of the molded product becomes rough and a good product cannot be obtained.

[Problem that the invention seeks to solve]

The present invention has been made based on the above, and provides a fluorine-containing resin composition that makes it possible to obtain molded products with good appearance and excellent mechanical properties in high-temperature atmospheres. It is intended for the purpose of providing.

[Failure to solve the problem]

The fluororesin composition of the present invention contains bismuth oxide (
Bi 20B)% 0.051 to 10 parts by weight of at least one selected from malium oxide (Sm203) and dysprosium oxide CD'M 208), and 0.5 parts by weight or more of a crosslinking agent. That is.

[Effect]

In the present invention, examples of the ethylene-fluoroolefin copolymer include ethylene-tetrafluoroethylene copolymer and ethylene-chlorotrifluoroethylene copolymer, which may be used alone or in combination of two or more. Available for use.

Bismuth oxide, samarium oxide, and dysprosium oxide have the function of suppressing the chemical reaction between the ethylene-fluoroolefin copolymer and the crosslinking agent, and these can be used alone or in combination of two or more. The amount added is ethylene-
Fluoroolefin copolymer 10 [0 per 1 part by weight
．． It is necessary to set the amount to 0.05 to 10 parts by weight, and if it is less than 0.05 parts by weight, the function of suppressing the above chemical reaction will not be sufficient.
If the amount exceeds 10 parts by weight, the additives themselves tend to aggregate and form lumps.

Examples of crosslinking agents include allyl type compounds (compounds containing 11.1 allyl groups), such as triallylsia. ,
...nurate, triallyl isocyanurate, triallyl trimellitate, triallyl trimezate, and 6-titraallyl pyromellitate.

The amount of the crosslinking agent must be at least 0.5 parts by weight per 100 parts by weight of the ethylene-tetrafluoroethylene copolymer; if it is less than this, it is difficult to obtain a molded product with good mechanical properties in a high-temperature atmosphere. Can not. Usually 1~
The range is 20 parts by weight.

In the present invention, in addition to the above components, inorganic fillers,
A coloring agent, etc. may be added, and a tetrafluoroethylene-propylene copolymer, polyvinylidene butt, etc. may be blended.

〔Example〕

With the various ingredients in the proportions shown on each side of Table 1, the temperature in barrel zone 1 is 260°C, and the temperature in barrel zone 2 is 2.
Extruder (40 m 1 m, L/D
= 20, compression ratio = 3), extrusion coating was applied to the outer periphery of the conductor with an outer diameter of 0.8 W+ to a thickness of 0.2 m, and then 10 M
A cross-linked insulated wire was created by irradiating it with rad electron rays.

The evaluation results for the insulated wires on each side are shown in the lower column of Table 1.

The extruded appearance is the result of visually observing the number of lumps on the surface of the insulated wire after extrusion, and the heat deformation rate is based on JIS06.
These are the results measured at 300°C in accordance with 005.

6- Example 1 within the scope of the invention as evident from Table 1
- 5 had good extrusion appearance, 1, and 300
It is resistant to deformation even at high temperatures of ℃.

On the other hand, Comparative Example 1 in which the amount of added bismuth oxide, samarium oxide, dysprosium oxide, etc. is less than the amount stipulated in the present invention, Comparative Example 2 which exceeds the amount specified in the present invention, and Comparative Example 6 which does not contain any of the amounts has a large amount of lumps on the surface. The appearance of extrusion is poor. Comparative Example 4, which does not contain a crosslinking agent, melts at 600°C.

〔Effect of the invention〕

Claims (3)

[Claims] (1) Ethylene-fluoroolefin copolymer 100
Based on parts by weight, bismuth oxide (Bj208), samarium oxide (Sm20B), dysprosium oxide C'Dy
! 0.0 of at least one selected from 20 B)
A fluororesin composition capable of being crosslinked by radiation, comprising 5 to 10 parts by weight, and 0.5 parts by weight or more of a crosslinking agent. (2) Ethylene-fluoroolefin copolymer (c) The radiation-crosslinkable fluororesin composition according to claim 1, which is an ethylene-tetrafluoroethylene copolymer. (3) The radiation crosslinkable fluororesin composition according to claim 1 or 2, wherein the crosslinking agent is an allyl type compound.