JPS6069143A - Chloroprene rubber composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition having high abrasion resistance and high insulating property and suitable as a sheath material for wires and cables, by mixing chloroprene rubber with furnace carbon or thermal carbon at a specified mixing ratio and vulcanizing the mixture. CONSTITUTION:Chloroprene rubber is mixed with furnace carbon and/or thermal carbon in amounts satisfying the relationship of the formula [wherein phi is the amount of carbon filled (wt%) and d is a diameter of carbon particle (mmu)], and the mixture is vulcanized. Unlike a material for car trims, a sheath material for wires and cables must have both abrasion resistance and insulating property, and the above composition has both high abrasion resistance and high insulating property, so that it is possible to produce a high-performance wires and cables by using the composition as a sheath material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Background and Objectives of the Invention] The present invention relates to a chloroprene rubber composition, and particularly to a chloroprene rubber composition suitable as a sheath material for electric wires and cables.

Chloroprene rubber has well-balanced and excellent properties when compared with other synthetic rubbers, such as mechanical properties, aging resistance, chemical resistance, and flame retardance.

1- Therefore, it is widely used as a sheath material for electric wires and cables.

Sheath materials are required to have toughness in order to protect electric wires and cables, and abrasion resistance is particularly important for cables.

Generally, a reinforcing filler is mixed in to impart wear resistance to the sheath material. Carbon black is the most effective of these. For example, large amounts of carbon black are mixed into automobile tires that require a high degree of wear resistance. However, these rubber compositions mixed with carbon black have the drawback of low volume resistivity and electrical conductivity.

Furthermore, rubber compositions mixed with insulating inorganic fillers have a drawback of poor abrasion resistance.

Cable sheath materials, unlike automobile tires, need to have both abrasion resistance and insulation properties; 1. From the viewpoint of safety, it has been desired to improve the above drawbacks.

An object of the present invention is to provide a chloroprene rubber composition that has been made to satisfy the above-mentioned needs and has both high abrasion resistance and insulation properties.

[Summary of the invention]

In the present invention, furnace carbon or thermal carbon, or furnace carbon and thermal carbon are mixed into chloroprene rubber in the following range: It is characterized by being vulcanized.

That is, as a conventional filler, it has been known that carbon black with a small particle size has good wear resistance, but has a low volume resistivity and high conductivity. Therefore, it has been difficult to satisfy high levels of wear resistance and insulation. As a result of repeated experiments and detailed studies by the present inventors, we found that various carbon blacks can be mixed with chloroprene rubber within a specific range for each particle size. It has been found that a product that satisfies a high degree of abrasion resistance and insulation properties can be obtained. The present invention was made based on the results of these studies.

〔Example〕

The present invention will be explained in detail below. FIG. 1 is a schematic diagram of a JISC6004 wear test apparatus used for testing the amount of wear of chloropre/rubber compositions of Examples and Comparative Examples of the present invention, (a) is an elevational view of the test apparatus, (b) ) is a perspective view of the sample, (1) is a partial detailed view showing the sample mounting state, and 1
is the sample, 2 is the pipe to which the sample is attached, 3 is the chain that supports the pipe 2, 4 is the 1K hanging from the lower end of the pipe 2
The load in g, 5 is a grinder rotating at 60 rpm, and in this test, the wear amount of sample 1 is shown when the grinder is rotated 100 times.

In this example, chloroprene rubber having the basic composition shown in Table 1 was mixed with a predetermined amount of filler as shown in Table 2, and then pressed and vulcanized at 145° C. for 40 minutes. The measurement results of the volume resistivity and wear amount of the chloroprene rubber thus obtained are shown in Tables 6 and 4. In addition, conductive paint (Dotite D-550; Fujikura Kasei Co., Ltd.) was applied to both ends of a sheet with volume resistivity high i 00 m x 50 m 1 shows the weight loss values obtained using the wear test device shown in FIG. 1.

Table 1 5- Table 2 6- Here, Table 3 shows the measurement results of the amount of wear and volume resistivity when the filling rate of the filler is kept almost constant.
If the abrasion amount is 0.15 mA or less, it is not practical, and as a sheath material, 0.12 mt or less is preferable. The volume resistivity needs to be 1060α or more, and more preferably 1060 or more. In this embodiment, the pupil IZf
10.292 Pupil d+0.889 value is 0.95 to 1.0
5, the results show that the wear resistance is good and the volume resistivity is high. In the case of the comparative example, either the abrasion resistance or the volume resistivity is inferior, and therefore, it is not practical.

In addition, Table 4 shows the wear amount and volume resistivity when the amount of carbon black filled is changed, and the results are similar to those above, and the examples are not practical.
It is clear that the comparative example is not practical.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to obtain a chloroprene composition that has both high wear resistance and insulation properties, and this can be used as a sheath material to manufacture high-performance electric wires and cables. It can produce industrial effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an abrasion test apparatus used to test the amount of wear of chloroprene rubber compositions of Examples and Comparative Examples of the present invention. 1; Sample, 2; Pipe to attach the sample, 3; Cheno,
4; Load; 5; Grinder. 10-

Claims (1)

[Claims] (1) Mix furnace carbon, thermal carbon, or furnace carbon and thermal carbon with chloroprene rubber in the following range: A chloroprene rubber composition characterized by being formed by sulfurization.