JPS649336B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a fluororesin composition that can be crosslinked by irradiation with radiation such as an electron beam, which can yield a fluororesin crosslinked molded product with excellent mechanical properties in a high-temperature atmosphere. It is related to. [Prior art] Ethylene-fluoroolefin copolymers generally have particularly excellent mechanical properties and processability among fluororesins, as well as excellent electrical properties, chemical resistance, and heat resistance, and are well-balanced. The material is
For this reason, it is used in various fields, including as a material for covering electric wires, and 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 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 agent such as an allyl type compound. [Problems to be Solved by the Invention] However, if a crosslinking agent is simply added and extrusion molded, the crosslinking agent and fluororesin will decompose and locally aggregate due to extrusion at high temperatures. There is a problem in that the molded product has a rough appearance due to a reaction with the molded product, making it impossible to obtain a good product. [Means for Solving the Invention] The present invention has been made using the above, and provides a molded product that can obtain a molded product that has a good appearance and has excellent mechanical properties in a high-temperature atmosphere. The object of the present invention is to provide a sulfur-containing resin composition that can be obtained. The fluororesin composition of the present invention contains 0.05 to 10 parts by weight of neodymium oxide and a crosslinking agent to 100 parts by weight of the ethylene-fluoroolefin copolymer.
It is characterized by containing 0.5 parts by weight or more. [Function] 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 types. It is also possible to use the above mixtures. Neodymium oxide has the function of suppressing the chemical reaction between the ethylene-fluoroolefin copolymer and the crosslinking agent, and the amount added is per 100 parts by weight of the ethylene-fluoroolefin copolymer.
It is necessary to make it 0.05 to 10 parts by weight, especially 0.2 to 2 parts by weight.
Parts by weight ranges are preferred. If it is less than 0.05 parts by weight, the effect of suppressing the above chemical reaction will not be sufficient, and the extruded appearance cannot be improved, and if it is more than 10 parts by weight, it will be easy to form lumps due to agglomeration of neodymium oxide. Examples of the crosslinking agent include allyl type compounds (compounds containing an allyl group) such as triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, triallyl trimesate,
Examples include tetraallyl pyromellitate. The amount of the crosslinking agent must be 0.5 parts by weight or more based on 100 parts by weight of the ethylene-tetrafluoroethylene copolymer, and if it is less than this, it will not be possible to obtain a molded article with good mechanical properties in a high-temperature atmosphere. It is usually in the range of 1 to 20 parts by weight. In the present invention, in addition to the above-mentioned components, inorganic fillers, colorants, etc. may be added as appropriate, and tetrafluoroethylene-propylene copolymers, polyvinylidene fluoride, etc. may be blended. [Example] Even when the various ingredients were mixed in the proportions shown in the examples in Tables 1 and 2, the temperature in barrel zone 1 was 260°C.
The extruder (40 m/m, L/D= 20, compression ratio = 3), extrusion coating was applied to the outer periphery of a conductor with an outer diameter of 0.8 mm to a thickness of 0.2 mm, and then 10 Mrad electron beam was irradiated to create a crosslinked insulated wire. The reputation results for the insulated wires of each example are shown in the lower columns of Tables 1 and 2. The appearance after extrusion is the result of visual observation of the appearance of the insulated wire, and the heat deformation rate is
These are the results measured at 300℃ in accordance with JISC3005.

【table】

[Table] As is clear from Table 1, all of Examples 1 to 4 within the scope of the present invention had a good extrusion appearance and were resistant to deformation even at a high temperature of 300°C. On the other hand, in Comparative Example 1 in which the amount of neodymium oxide added was less than the amount specified in the present invention, Comparative Example 2 in which it exceeded the specified amount, and Comparative Example 3 in which it was not added at all, there were many lumps on the surface and the extruded appearance was poor. Comparative Example 4, which does not contain a crosslinking agent, melts at 300°C. Comparative Examples 5 to 10 are cases in which a metal oxide other than neodymium oxide was added, and in all cases, many particles were generated on the surface and the appearance was poor. In the case of magnesium oxide, grains were generated and the insulator deteriorated severely, resulting in black discoloration. [Effects of the Invention] As explained above, the present invention provides a composition containing neodymium oxide and a crosslinking agent in an ethylene-fluoroolefin copolymer, which improves mechanical properties at high temperatures. excellent,
Moreover, it becomes possible to obtain crosslinked molded products with good appearance, and the fields of use of fluororesins will be further expanded.

Claims (1)

[Claims] 1. Ethylene-fluoroolefin copolymer 100
A fluororesin composition capable of crosslinking by radiation irradiation, comprising 0.05 to 10 parts by weight of neodymium oxide and 0.5 parts by weight or more of a crosslinking agent. 2 Ethylene-fluoroolefin copolymer is
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 material is an allyl type compound.