JPH0612923A - Electric wire / cable - Google Patents

Abstract

PURPOSE:To improve the tension property of a cover layer. CONSTITUTION:In an electric cable, which has a cove layer 3 on a conductor 1, the cover layer 3 is made of an object where a resin composition where the weight ratio of chlorinated polyethylene to vinyl chloride-ethylene copolymer is in the range of 95/5-20/80 and an organic silane composition are reacted upon each other under the existence of a free radical generator, and these reactants are crosslinked, being exposed to moisture under the existence of a silanol condensation catalyst.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electric wires and cables using a chlorinated polyethylene resin composition as a sheath material.

[0002]

2. Description of the Related Art Silane-crosslinked chlorinated polyethylene has been conventionally used as a sheath for electric wires and cables.
As means for cross-linking this chlorinated polyethylene, as disclosed in Japanese Patent Publication No. Sho 63-12486, chlorinated polyethylene and the general formula RR'SiY ₂ (wherein R is a monovalent olefinically unsaturated hydrocarbon or hydro) are disclosed. Is a carbonoxy group, Y is a hydrolyzable organic group, and R'is a group R or a group Y
(A) is reacted with silane represented by the formula (1) in the presence of peroxide, and then exposed to water in the presence of a silanol condensation catalyst to effect crosslinking.

[0003]

However, when a composition obtained by grafting silane onto the above-mentioned chlorinated polyethylene and crosslinking the same in the presence of a catalyst and water is applied to a sheath such as a cable, the tensile strength which is important for the cable is increased. May be inferior.

An object of the present invention is to solve the above problems and provide an electric wire / cable having excellent tensile properties.

[0005]

[Means for Solving the Problems] The present inventors have conducted various researches and developments in order to obtain a coating layer having excellent tensile properties based on the knowledge of coating a chlorinated polyethylene composition as a sheath of a cable or the like. As a result, the present invention has been completed, paying attention to a vinyl chloride-ethylene copolymer.

That is, according to the present invention, in an electric wire / cable having a coating layer on a conductor, the coating layer has a weight ratio of chlorinated polyethylene and vinyl chloride-ethylene copolymer.
Reacting a resin composition in the range of 95/5 to 20/80 with an organic silane compound in the presence of a free radical generator,
This reaction product is formed by crosslinking by exposing to water in the presence of a silanol condensation catalyst.

In the present invention, the chlorine content of chlorinated polyethylene is preferably 30 to 50% by weight. If the chlorine content is less than 30% by weight, the oil resistance, which is important as a sheath material, will be impaired, and 50% by weight or less. If it exceeds, heat deterioration resistance deteriorates.
Two or more kinds of this chlorinated polyethylene may be blended.

In the present invention, a vinyl chloride-ethylene copolymer is blended to improve the tensile properties.

The content ratio of the chlorinated polyethylene and the chlorinated vinyl-ethylene copolymer must be selected from the range of 95/5 to 20/80 by weight, and the content of the vinyl chloride-ethylene copolymer is If it is less than 5 parts by weight, the tensile strength will not be improved, and if it exceeds 80 parts by weight, the elongation and compression set will be poor.

The organic silane compound has a general formula RR '.
A silane represented by SiY ₂ may be mentioned. In the general formula of this silane, as R (monovalent olefinically unsaturated hydrocarbon or hydrocarbonoxy group), vinyl, allyl, budenyl, cyclohexanyl, cyclopentadienyl, cyclohexadienyl, formula CH ₂ = _{C (CH 3) COO (CH} 2) 3 -, wherein _{CH 2 = C (CH 3)} COOCH 2 CH 2 O (C
H ₂ ) ₃ −, and And vinyl radicals are preferred.

As Y (hydrolyzable organic group), 6
Alkoxy or alkoxy radicals having up to 6 carbon atoms (eg methoxy, ethoxy and butoxy radicals), acyloxy radicals containing up to 6 carbon atoms (eg formyloxy radicals, acetoxy radicals and propionoxy radicals) and 14 An oxime radical having the following carbon atoms (eg, formula-ON
= C (CH ₃₎ -, include those such as the formula -ON = CCH ₂ C ₂ H ₅ and the formula _{-ON = C (C 4 H 5} ) 3).

R'can be represented by either the radical R or the radical Y, but a monovalent hydrocarbon radical without aliphatic unsaturation,
It can also be represented, for example, by methyl, ethyl, propyl, tetradecyl, octadecyl, phenyl, benzyl or tolyl.

The preferred organic silane compound is one having _three hydrolyzable organic groups represented by the formula RSiY ₃ , and specifically, vinyltriethoxysilane and vinyltrimethoxysilane are most preferred. Conceivable. However, silanes having only two hydrolyzable groups, such as vinylmethyldiethoxysilane and vinylphenyldimethoxysilane, are also effective.

The amount of the organic silane compound used is preferably 0.1 to 20% by weight, preferably 1 to 8% by weight, based on 100 parts by weight of the total amount of chlorinated polyethylene and vinyl chloride-ethylene copolymer. Is good.

As the compound generating a free radical,
It is possible to use those capable of generating free radical sites in the chlorinated polyethylene under the above reaction conditions and having a half-life of 6 minutes or less, preferably 1 minute or less at the reaction temperature. Specifically, organic benzyl oxides and peresters [eg, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tertiary butyl peroxide, 2,5
-Dimethyl-2,5-di (peroquinobenzoate) hexyne-3,1.3-bis (t-butylperoxyisopropyl) benzene, lauroyl peroxide, tert-butyl peracetate, 2.5-dimethyl-2.5 -Di (t-butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (t-butylperoxy) hexane and tert-butylperbenzoate] and azo compounds (e.g. azobis-isoptyronitrile and dimethyl Azodiisobutyrate) and the addition amount thereof is preferably 0.2 to 1% by weight based on the amount of chlorinated polyethylene and vinyl chloride-ethylene copolymer.

Further, in addition to the above components, a filler, a stabilizer, a colorant, an antioxidant, a lubricant and the like may be appropriately added.

As the filler, any of white filler such as talc, clay, calcium carbonate, silicic acid anhydride, and carbon black can be used.
It is preferably 10 to 100 parts by weight. This is because if it is less than 10 parts by weight, the toughness such as abrasion resistance is poor, and if it exceeds 100 parts by weight, the viscosity of the compound becomes too high and extrusion processing becomes difficult.

As the stabilizer, a lead compound (eg, tribasic lead sulfate, dibasic lead phosphite, dibasic lead phthalate and lead white), an epoxy compound (eg, bisphenol A) can be used.
Diglycidyl ether, epoxidized soybean oil) and the like.

For the grafting reaction of the organic silane compound, any of kneader, Banbury, and extruder can be adopted.

Examples of silanol condensation catalysts include dibutyltin dilaurate, stannous acetate, stannous octoate, lead naphthenate, zinc octate, and iron-2.
Metal carboxylates such as ethylhexoate and cobalt naphthenate and organometallic compounds such as titanium esters and chelates such as tetrabutyl titanate, tetranonyl titanate and bis (acetylacetonyl) di-isopropyl titanate,
A compound comprising an organic base such as ethylamine, hexylamine, dibutylamine and viveridine and an acid such as a mineral acid and a fatty acid, preferably an organotin compound such as dibutyltin dilaurate, dibutyltin diacetate and dibutyltin dioctate. Can be mentioned.

The silanol condensation catalyst is usually prepared by adding 0.2 to 1 part by weight of chlorinated polyethylene to form a pellet of the catalyst masterbatch, which is used in the final cable extrusion in an amount of 2 to 10% by weight in the compound grafted with the organosilane compound.
Added by mixing.

Therefore, a resin composition having a weight ratio of chlorinated polyethylene and vinyl chloride-ethylene copolymer in the range of 95/5 to 20/80 and an organic silane compound are added in the presence of a free radical generator. By reacting and exposing this reaction product to moisture in the presence of a silanol condensation catalyst to crosslink, a coating layer having excellent tensile properties can be obtained.

[0023]

EXAMPLES Examples of the present invention will be described below.

Table 1 is a table showing the compounding ratios and characteristics of the examples according to the present invention and their comparative examples, and Table 2 is a table showing the composition of the pellets of the catalyst masterbatch.

First, Examples 1 to 4 and Comparative Example 1 in Table 1
Among the compounding agents shown in each column of 2, the compounding agents other than dicumyl peroxide and vinyltrimethoxysilane are used at a temperature of 120-
Knead for 15 minutes with a 150 mm diameter rubber roll set at 130 ° C to form a sheet. Then, this sheet is crushed by a crusher at room temperature, impregnated with dicumyl peroxide and vinyltrimethoxysilane in a closed system at a temperature of 60 ° C., head: 180 ° C., cylinder 1: 180 ° C., cylinder 2: 130 Set each temperature of ℃, screw rotation speed 10rpm
Grafting reaction was carried out using a 40 m / m extruder (L / D = 22) set to.

Next, 5% by weight of the pellets of the catalyst masterbatch having the composition shown in Table 2 was added to the pellets of the above-mentioned silane graft compound, and the pellets of the above-mentioned extruder were used.
As shown in Fig. 2, the cross-linked polyethylene layer 2 is attached to the cable conductor 1.
A cable was produced by coating a sheath (coating layer) 3 of silane water-crosslinked chlorinated polyethylene around four core wires coated with the conductive layer 4 interposed therebetween. The extrusion conditions were 180 ° C. for the head and cylinder 1, 130 ° C. for the cylinder 2, and the screw rotation speed was 20 rpm.

Next, the produced cable was exposed to saturated steam at a temperature of 80 ° C. for 1 day to be crosslinked.

The cables thus obtained were evaluated for tensile properties and compressive strain, and the results are shown in the lower column of Table 1.

Tensile properties are measured according to Japanese Industrial Standard JIS K 6
A sample punched out with dumbbell No. 3 was subjected to a tensile test at 500 mm / min using a Shopper type tensile tester in accordance with No. 301 to examine the tensile strength and elongation.

Regarding the compression set, pellets of the silane graft compound and the catalyst masterbatch were kneaded to form a right cylinder having a thickness of 12.7 mm and a diameter of 29.0 mm.
This was exposed to saturated steam at a temperature of 80 ° C. for 1 day and crosslinked to prepare a sample. And Japanese Industrial Standard JIS K
According to 6301, the sample was compressed by 25%, held at 70 ° C for 22 hours, released from the compression, and measured 30 minutes later. The calculation method is as follows.

Compression set (%) = [(original thickness of test piece (mm)
-Remove the test piece from the compression device, and the thickness after 30 minutes (mm)) /
Thickness of compressed part (mm)] × 100

[0032]

[Table 1]

[0033]

[Table 2]

From Table 1, it can be seen that Examples 1 to 4 according to the present invention all exhibit good tensile properties and compressive strain. On the other hand, Comparative Example 1 containing no vinyl chloride-ethylene copolymer is inferior in tensile strength. Further, it can be seen that Comparative Example 2 in which the content of the vinyl chloride-ethylene copolymer is larger than the specified value is inferior in the elongation property and the compression strain.

[0035]

In summary, according to the present invention, the weight ratio of chlorinated polyethylene and vinyl chloride-ethylene copolymer is
Reacting a resin composition in the range of 95/5 to 20/80 with an organic silane compound in the presence of a free radical generator,
Since this reaction product was exposed to water in the presence of a silanol condensation catalyst to crosslink it to form a coating layer, an electric wire / cable having a coating layer having excellent tensile properties can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a cable of the present invention.

[Explanation of symbols]

 1 conductor 3 coating layer

Claims (1)

[Claims] 1. An electric wire / cable having a coating layer on a conductor, wherein the coating layer has a resin composition in which the weight ratio of chlorinated polyethylene and vinyl chloride-ethylene copolymer is in the range of 95/5 to 20/80. An electric wire / cable which is formed by reacting an organic silane compound with an organic silane compound in the presence of a free radical generator and exposing the reaction product to moisture in the presence of a silanol condensation catalyst to crosslink the product.