JPH03246817A - Chlorinated ethylene-propylene rubber sheathed cable - Google Patents

Abstract

PURPOSE:To enable obtaining good rubber elasticity and extrusion appearance by providing a cover layer wherein a specific amount of an epoxy stabilizer and an inorganic filler is added to specific ethylene-propylene and each component is bridged under exposure to moisture in the existence of a silanol condensing solvent. CONSTITUTION:A composition is composed of 1 to 50 weight parts of an epoxy stabilizer and 10 to 100 weight pats of an inorganic filler added to 100 weight parts of chlorinated ethylene-propylene rubber containing 20 to 50 weight parts of chlorine. This composite is made to react with silane generally expressed as RR'SiY2 in the presence of a free radical generating agent. The sheathed cable in the titIe has a cover layer available from bridging the reactant under exposure to moisture in the presence of a silanol condensing solvent. In the formula, R stands for a univalent olefine unsaturated hydrocarbon radical or hydrocarbon-oxy radical, Y for a hydrolyzable organic radical, and R' for a radical R or Y. According to the aforesaid construction, a cable of high flexibility and abrasion resistance can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to electric wires and cables having a chlorinated ethylene-propylene rubber composition capable of crosslinking at low temperature and normal pressure as a coating layer.

[Prior art] Chlorinated polyethylene and the general formula RR' S I Y* (in this formula, R is a monovalent olefinic unsaturated hydrocarbon group or a hydrocarbonoxy group, and Y is a hydrolyzable organic group) and R' is a group R or a group Y) (hereinafter simply referred to as silane) in the presence of peroxide, and then crosslinked by exposing to moisture in the presence of a silanol condensation catalyst. This is already known.

[Problem to be solved by the invention] However, since chlorinated ethylene-polyethylene has poor reactivity with peroxide, the silane grafting reaction does not proceed smoothly, and when applied to electric wires or cable sheaths, There is a problem in that the rubber elasticity, which is important as a material, is inferior.

An object of the present invention is to solve the above-mentioned problems and provide electric wires and cables with excellent rubber elasticity.

[Means for Solving the Problems] This invention provides 1 to 50 parts by weight of an epoxy stabilizer and 10 parts by weight of an inorganic filler to 100 parts by weight of chlorinated ethylene-propylene rubber having a chlorine content of 20 to 50% by weight. The composition containing ~100 parts by weight was added to the cereal formula RR'SIYx (
In the formula, R is a monovalent olefinically unsaturated hydrocarbon group or a hydrocarbonoxy group, Y is a hydrolyzable organic group, and R' is a group R or a group Y. This cable has a coating layer formed by reacting in the presence of a radical generator and exposing the reaction product to moisture in the presence of a silanol condensation catalyst to crosslink it.

[Example] In this invention, the amount of chlorine in the chlorinated ethylene-propylene rubber was specified as 20 to 50% by weight.
This is because if it is less than 0% by weight, oil resistance, which is important for a sheath material, will be impaired, and if it exceeds 50% by weight, thermal stability will deteriorate. Chlorinated monotyrene-brobylene may be used alone or in combination of two or more.

The epoxy stabilizer has a remarkable effect on preventing the crosslinking reaction of chlorinated ethylene-propylene rubber that occurs during the graft reaction of silane, and glycidyl vinyl ether, epoxidized soybean oil, etc. are employed. These are usually 1 to 5 parts by weight per 100 parts by weight of chlorinated ethylene-propylene.
0 parts by weight is added.

In the general formula of the silane used in the method of this invention,
R represents a monovalent olefinically unsaturated radical consisting of carbon, hydrogen and optionally oxygen. Examples of such radicals are vinyl, allyl, pudenyl, cyclohexenyl, cyclopentagenyl, cyclohexagenyl, CH,=CfcH,1cOO(CH,1,-CH2=C
, fCH,1COOCH2CH20fcH213- and CH,=C(CH,1COOCH2CH,O.
A vinyl radical is preferred; the Y substituent is an alkoxy or alkoxyalkoxy radical having up to 6 carbon atoms, such as methoxy.

Ethoxy and butoxy radicals and acyloxy radicals with up to 6 carbon atoms, such as pormyroxy. acetoxy or propiotoxy diradicals and oxime radicals having up to 14 carbon atoms, such as -0N=C
fcH, +2-10N=CCH, cx H, and -0
N=C(C4H,), and so on. The R' radical can represent a monovalent hydrocarbon radical free of aliphatic unsaturation, such as methyl, ethyl, propyl, tetradecyl, octadecyl, phenyl, benzyl or tolyl. R'
The group can also be represented by an R group or a Y group. Preferably the silane has the formula RS i ym and contains three hydrolyzable organic groups; the most preferred silanes are vinyltriethoxysilane and vinyltrimethoxysilane. However, silanes with only two hydrolysable groups, such as vinylmethyljethoxysilane and vinylphenyldimethoxysilane, are also effective.

The proportion of silane used depends in part on the reaction conditions and in part on the degree of modification desired in the chlorinated polyethylene. The actual proportions can vary widely, from 0.1 to 20% by weight, based on the weight of the chlorinated ethylene-propylene rubber. However, it is generally preferred to use 1 to 8% by weight, based on the weight of the chlorinated ethylene-propylene rubber.

The compound that generates free radicals is one that can generate free radical sites in chlorinated ethylene-propylene rubber under the above reaction conditions and has a half-life of 6 minutes or less, preferably 1 minute or less at the above reaction temperature. Any compound that has can be used. The best known and preferred radical generating compounds for use in this invention are organic peroxides and bersesters such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl- 2,5-di(beloquine benzoate) 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-butylberbenzoate and azo compounds such as azobis-isobutyronitrile and dimethylazodiisobutyrate, the amount of which is chlorine It is preferable to use 0.2 to 1% by weight based on the weight of the polyethylene.

Silane grafting reactions are Nieda and Panbari.

Any extruder can be used.

Any of a wide variety of materials that act as silanol condensation catalysts can be used in the process of this invention.

Such substances include, for example, dibutyltin dilaurate,
Group 11!2 carboxylates and titanium esters and chelates, such as stannous acetate, stannous ctate, lead naphthinate, zinc oftate, iron-2-ethylhexoate and cobalt naphthinate, such as tetrabutyl titanate, These include organometallic compounds such as tetranonyl titanate and bis(acetylacetonyl) di-isopropyl titanate, organic bases such as ethylamine, hexylamine, dibutylamine and piperidine, and acids such as mineral acids and fatty acids. Preferred catalysts are organotin compounds such as dibutyltin dilaurate, dibutyltin diacetate and dibutyltin diacetate.

The silanol condensation catalyst is usually added to chlorinated ethylene-propylene rubber in an amount of 0.2 to 1 part by weight to make catalyst masterbatch pellets, and this is mixed in 2 to 10% by weight with the silane grafted powder during final cable extrusion. It is sometimes added.

As the inorganic filler, any of white fillers such as talc, clay, calcium carbonate, and carbon black can be used, but carbon black, especially fine thermal furnace black (FT carbon), has good rubber elasticity and toughness. granted and most preferred.

These are added in an amount of 10 to 100 parts by weight. If the amount is less than 10 parts by weight, the toughness such as abrasion resistance will be poor;
If it exceeds 0.00 parts by weight, the viscosity of the compound will increase too much, making extrusion processing difficult. Preferably it is in the range of 30 to 60 parts by weight.

Next, the present invention will be explained in more detail with reference to Examples, but it goes without saying that this invention is not to be construed as being limited by such explanations.

Compounding ingredients other than dicumyl peroxide and vinyltrimethoxysilane shown in Table 1 are kneaded for 15 minutes using a 150 mm diameter rubber roll set at a temperature of 120 to 130°C. Next, this sheet was pulverized with a pulverizer at room temperature, and
After impregnation with dicumyl peroxide and vinyltrimethoxysilane in a closed system at ℃, head: 180 ℃, cylinder 1: 180 ℃, Schilling - 2: 40 m set at each temperature of 130 ℃ and screw rotation speed 10 rpm. / m
The graft reaction was carried out using an extruder (L/D=22).

Next, pellets of a catalyst masterbatch having the composition shown in Table 2 (Pellet-1 for Example 1, Pellet-2 for Examples 2 to 4 and Comparative Example 2, and Pellet-3 for Comparative Example 1)
was added in an amount of 5% by weight to the pellets of the above-mentioned Silane Craft compound, and as shown in FIG. A cable having a structure covered with a sheath 3 of silane water-crosslinked ethylene-propylene rubber was manufactured. The extrusion conditions are head = cylinder 1 = 150°C, cylinder 2 = 130°C, and screw rotation speed =
Each sample was then cross-linked by exposing it to saturated steam at 80° C. for one day at 20 rpm. The extrusion appearance and rubber elasticity evaluation results of these sample cables are also shown in the lower column of Table 1.

The compositions of Examples 1 to 4 are within the range defined by the present invention, and it can be seen that they all have good rubber elasticity and extruded appearance.

On the other hand, Comparative Example 1 uses conventional chlorinated polyethylene and is found to have poor rubber elasticity. In addition, Comparative Example 2 is a system that does not contain an epoxy stabilizer, but the silane grafting reaction does not proceed smoothly.
Extrusion appearance deteriorates.

(The following is a blank space) Table [Effects of the Invention] As explained above, the chlorinated ethylene-propylene sheathed cable of the present invention has excellent flexibility and abrasion resistance.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a cable having a coating layer made of the composition of the present invention. 1... Cable conductor 2... Crosslinked polyethylene layer 3... Sheath 4... Conductive layer

Claims (1)

[Claims] 1 to 5 parts by weight of epoxy stabilizer to 100 parts by weight of chlorinated ethylene propylene rubber with a chlorine content of 20 to 50% by weight.
0 parts by weight and 10 to 100 parts by weight of an inorganic filler were added to the composition with the general formula RR'SiY_2 (where R is a monovalent olefinic unsaturated hydrocarbon group or a hydrocarbonoxy group, and Y is a hydrated It is an organic group that can be decomposed, and R
' is a group R or a group Y) is reacted in the presence of a free radical generator, and the reaction product is crosslinked by exposing it to moisture in the presence of a silanol condensation catalyst. A chlorinated ethylene-propylene rubber sheathed cable featuring: