JP3184720B2 - Ethylene / propylene rubber composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention relates to reduction of a process oil to improve the moldability such as injection molding or extrusion molding, ethylene used in the cable connection and the terminal portions for molding rubber material of the dressing or the like of electric cables The present invention relates to a propylene rubber composition.

[0002]

2. Description of the Related Art Conventionally, process oil is frequently used as an ethylene / propylene-based rubber composition used as a rubber for electric insulation molding, a covering material of electric wires and cables in an injection molding system, a transfer molding system, an extrusion molding system, and the like. It has been known that the fluidity at the time of molding is increased. The usage of the process oil typically amounts to more than 30% by weight of the total filler.

[0003] However, due to the frequent use of the process oil, the tackiness of the composition increases and the workability such as handleability decreases, and even the resulting molded product has poor physical properties such as strength, hardness and stress relaxation. And there were problems such as transfer of process oil to other products.

[0004]

SUMMARY OF THE INVENTION The present invention does not require the use of a large amount of process oil, so that the workability such as handleability is reduced due to the increase in tackiness, the physical properties of the obtained molded product are reduced, and An object of the present invention is to develop an ethylene / propylene rubber composition having excellent moldability by injection molding, transfer molding, extrusion molding, or the like without causing the problem of transfer of process oil.

[0005]

Means for Solving the Problems The present invention provides an ethylene
Propylene rubber per 100 parts by weight of two or more fillers will be blended 15-200 weight parts comprising calcium carbonate, Ri proportion 10-50 wt% der calcium carbonate relative to the total amount of the filler, And the end of the electric cable
Or for the formation of a rubber molded product for electrical insulation at the connection
There is provided a ethylene-propylene-based rubber composition characterized der Rukoto intended for use.

[0006]

The above composition makes it possible to obtain an ethylene / propylene rubber composition having excellent moldability by injection molding or extrusion molding without using a large amount of process oil. The use of calcium carbonate alone improves moldability and tackiness, thereby improving workability such as handleability and process oil migration, but the resulting molded products have poor strength and large stress relaxation, and physical properties Is not improved.

[0007]

Illustrative constituents of the invention The ethylene / propylene rubber composition of the present invention comprises an ethylene / propylene rubber 10
0 parts by weight per state, and are not blended 15-200 parts by weight of 2 or more fillers including calcium carbonate as the percentage of calcium carbonate relative to the total amount of filler is 10 to 50 wt%, and the wire At the terminal or connection part of the cable
For forming rubber molded products for electrical insulation
Nodea Ru.

As the ethylene / propylene rubber, any suitable rubber can be used without any particular limitation. Any of known materials such as an ethylene / propylene copolymer and an ethylene / propylene / diene copolymer can be used. Ethylene / propylene rubbers that can be preferably used from the viewpoint of moldability and the like are those having a low Mooney viscosity, especially ML _{1 + 4} (100
° C). One or more ethylene-propylene rubbers may be used.

As the filler, in addition to calcium carbonate,
For example, appropriate materials such as calcined clay, talc, silica, zinc white, magnesia, and carbon can be used. Also, fatty acids, process oils, coupling agents, crosslinking agents, crosslinking aids,
Additives such as an anti-aging agent may be appropriately used depending on the purpose of use. Therefore, any of known fillers and additives can be used for the covering material of the electric cable.

[0010] Incidentally, the above-mentioned calcined clay is advantageous for improving the electrical insulation properties, and talc, silica, zinc white and the like are also useful as white colorants. Also carbon is
It can be used as a conductivity-imparting agent or a reinforcing agent.

[0011] As for the calcium carbonate, it is possible to use an appropriate type such as a heavy substance or a light substance. Calcium carbonate, which can be preferably used from the viewpoint of dispersibility, extrudability, non-hygroscopicity or electrical properties after immersion, is surface-treated with fatty acids, high molecular weight alcohol derivatives or the like.

As described above, in the present invention, two or more fillers containing calcium carbonate are used in an appropriate combination. In this case, in the present invention, the total amount per 100 parts by weight of the ethylene / propylene rubber is used. 15 based on
200 parts by weight of filler are used, and the proportion of calcium carbonate in the total amount of filler is 10 to 50% by weight.

When the total amount of the filler is out of the above range, it is difficult to provide necessary physical properties such as appearance, physical properties, and electrical properties.
If the proportion of calcium carbonate is less than 10% by weight, the effect of improving the moldability is poor, and if it exceeds 50% by weight, physical properties such as strength tend to decrease. The preferred total amount of filler is 20 to 180 parts by weight, especially 30 to 150 parts by weight. The preferred ratio of calcium carbonate is 1
It is 2 to 48% by weight, especially 15 to 45% by weight.

The ethylene / propylene rubber composition of the present invention can be prepared in a state excellent in moldability in injection molding and extrusion molding without using a large amount of processing oil. It can be up to 25% by weight, especially up to 20% by weight of the total amount of the agent. The above good moldability is exhibited also in molding methods other than injection molding and extrusion molding, such as compression molding and transfer molding.

The compositions of the present invention has a good moldability electrically insulating rubber molded product of the terminal portion or the connection portion of the process oil required Ru conductive cables that no transition on the basis of, for example, stress cone , T-type and Y-type, Ru is used for the formation of such connection of the π-shaped.

[0016]

According to the present invention, a terminal portion of an electric cable having a composition having a low content of process oil and exhibiting excellent moldability in various molding methods such as injection molding, extrusion molding, compression molding and transfer molding. Or electrical interruption at the connection
It is possible to obtain an ethylene / propylene rubber composition for forming an edge rubber molded product . Therefore, it has low tackiness, is not sticky, and is excellent in workability such as handleability. Further, the obtained molded product is excellent in physical properties such as strength, hardness and low stress relaxation property, and does not cause a problem of transfer of process oil.

[0017]

【Example】

Example 1 100 parts (parts by weight, hereinafter the same) of ethylene / propylene / diene rubber (EPT4045, manufactured by Mitsui Petrochemical Industries, Ltd.), calcined clay (Satinton W / Whitetex, the same hereinafter, manufactured by Engelhard Co.) 90 parts, process oil (Nippon Sun Oil, Sansen 4240, the same applies hereinafter), 11 parts, calcium carbonate A (manufactured by Bihoku Powder Chemical Industry Co., Ltd., Ryton BK; surface-treated product with a polymer derivative of a polyhydric higher alcohol, the same applies hereinafter) 10 Parts, Zinc Hua (Hakusui Chemical Co., Ltd., No. 3, the same applies hereinafter), 5 parts, carbon black (Mitsubishi Kasei Co., Diamond Black H, the same applies hereinafter), 5 parts, an antioxidant (Ouchi Shinko Chemical Co., Ltd., Nocrack MB (hereinafter the same) 2 parts, stearic acid (manufactured by Asahi Denka Kogyo Co., Ltd., ADEKA fatty acid SA-200, the same applies hereinafter) 1 part, silane coupling agent (Shin-Etsu Chemical Co., Ltd.) KR-219, manufactured by Gaku Kogyo Co., Ltd.)
Parts, 2.7 parts of dicumyl peroxide (crosslinking agent; manufactured by Mitsui Petrochemical Industries, Ltd .; the same applies hereinafter), and 1 part of triallyl isocyanurate (crosslinking aid; manufactured by Nippon Kasei Co., Ltd., TAIC; the same applies hereinafter) by a roll mill. The compound was prepared by kneading.

Example 2 100 parts of ethylene / propylene / diene rubber, 70 parts of calcined clay, 11 parts of process oil, calcium carbonate A30
Parts, zinc white 5 parts, carbon black 5 parts, antioxidant 2
Parts, stearic acid 1 part, silane coupling agent 1 part,
2.7 parts of dicumyl peroxide and 1 part of triallyl isocyanurate were kneaded with a roll mill to prepare a compound.

Example 3 100 parts of ethylene / propylene / diene rubber, 50 parts of calcined clay, 11 parts of process oil, calcium carbonate A50
Parts, zinc white 5 parts, carbon black 5 parts, antioxidant 2
Parts, stearic acid 1 part, silane coupling agent 1 part,
2.7 parts of dicumyl peroxide and 1 part of triallyl isocyanurate were kneaded with a roll mill to prepare a compound.

Example 4 100 parts of ethylene / propylene / diene rubber, 90 parts of calcined clay, 11 parts of process oil, 10 parts of calcium carbonate B (Shiraishi Calcium Co., Ltd., white luster cc; surface treated with fatty acid, the same applies hereinafter) 5 parts of zinc white, 5 parts of carbon black, 2 parts of antioxidant, 1 part of stearic acid, 1 part of silane coupling agent, 2.7 parts of dicumyl peroxide,
And 1 part of triallylisocyanurate were kneaded with a roll mill to prepare a compound.

Example 5 100 parts of ethylene / propylene / diene rubber, 11 parts of process oil, 5 parts of calcium carbonate A, 5 parts of zinc white, 20 parts of conductive carbon black (Ketjen Black EC, manufactured by Mitsubishi Yuka Co., Ltd.) Antioxidant 2 parts, stearic acid 1 part,
2.7 parts of dicumyl peroxide and 1 part of triallyl isocyanurate were kneaded with a roll mill to prepare a compound.

Example 6 100 parts of ethylene / propylene / diene rubber, 20 parts of process oil, 10 parts of calcium carbonate A, 5 parts of zinc white, conductive carbon black (acetylene black; Denka Black granules, manufactured by Denki Kagaku Kogyo KK) 60 Part, anti-aging agent 2
Parts, stearic acid 1 part, dicumyl peroxide 2.7
And 1 part of triallylisocyanurate were kneaded with a roll mill to prepare a compound.

Comparative Example 1 100 parts of ethylene / propylene / diene rubber, 100 parts of calcined clay, 11 parts of process oil, 5 parts of zinc white, 5 parts of carbon black, 2 parts of antioxidant, 1 part of stearic acid,
A compound was prepared by kneading 1 part of a silane coupling agent, 2.7 parts of dicumyl peroxide, and 1 part of triallylisocyanurate with a roll mill.

Comparative Example 2 100 parts of ethylene / propylene / diene rubber, 40 parts of calcined clay, 11 parts of process oil, calcium carbonate A60
Parts, zinc white 5 parts, carbon black 5 parts, antioxidant 2
Parts, stearic acid 1 part, silane coupling agent 1 part,
2.7 parts of dicumyl peroxide and 1 part of triallyl isocyanurate were kneaded with a roll mill to prepare a compound.

Comparative Example 3 100 parts of ethylene / propylene / diene rubber, 11 parts of process oil, 5 parts of zinc white, Ketjen Black EC20
Parts, an antioxidant 2 parts, stearic acid 1 part, dicumyl peroxide 2.7 parts, and triallyl isocyanurate 1 part were kneaded with a roll mill to prepare a compound.

Comparative Example 4 100 parts of ethylene / propylene / diene rubber, 20 parts of process oil, 5 parts of zinc white, 60 parts of denka black granules,
A compound was prepared by kneading 2 parts of an antioxidant, 1 part of stearic acid, 2.7 parts of dicumyl peroxide, and 1 part of triallylisocyanurate in a roll mill.

Evaluation Test The compounds obtained in Examples and Comparative Examples were examined for the following characteristics. Moldability In accordance with JIS K 7210, the melt flow rate (extrusion moldability) was examined under the conditions of a temperature of 125 ° C. and a load of 18.9 kg.
Those with less than 4 cc / 10 minutes were evaluated as x.

According to M ₂₀₀ JIS K 6301, a compound press-vulcanized at 160 ° C. for 30 minutes was measured for tensile stress at 200% elongation (200% modulus: M ₂₀₀ ), and the value was 3.0 MPa or more. Was evaluated as ○, and those less than 3.0 MPa were evaluated as ×.

The above results are shown in Table 1.

[Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 23/00-23/36 C08K 3/00-13/08 H01B 3/28

Claims (1)

(57) [Claims] 1. One or more fillers containing calcium carbonate are added per 100 parts by weight of ethylene / propylene rubber.
5-200 will be parts by weight blended, Ri ratio is 10 to 50 wt% der calcium carbonate relative to the total amount of the filler,
And electrical insulation at the end or connection of the cable
Ethylene-propylene-based rubber composition characterized der Rukoto intended for use in the formation of use rubber molded part.