JP2001131357A - Rubber for coating electric wire and rubber for water- stop sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire-coating rubber and a rubber for a water-stop sheet having excellent external damage resistance low-temperature flexibility and collapse resistance. SOLUTION: The objective wire-coating rubber and water-stop sheet rubber is made of a rubber composition containing (A) a random copolymer rubber composed of ethylene, a 3-20C α-olefin and a structural unit derived from a specific triene compound, (B) a vulcanizing agent and (C) a filler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric wire covering rubber and a rubber for a waterproof sheet, and more particularly, to an electric wire covering rubber excellent in trauma resistance, crush resistance and low temperature flexibility, and trauma resistance and low temperature flexibility. The present invention relates to a rubber for a waterproof sheet having excellent properties.

[0002]

BACKGROUND OF THE INVENTION Ethylene / propylene / non-conjugated diene copolymer rubber (hereinafter sometimes referred to as EPT)
Utilizing its excellent weather resistance, low-temperature flexibility, heat aging resistance, and electric insulation, is used for electric insulation parts such as rubber covering electric wires. In a commonly used electric wire, an insulating layer is provided around a conducting wire, and a sheath is provided on the outer periphery of the insulating layer. Such an electric wire is usually formed by continuously vulcanizing rubber forming an insulating layer and rubber forming a sheath. In such a molding method, it is desirable to continuously vulcanize the rubber that forms the sheath immediately after vulcanizing the rubber that forms the insulating layer and efficiently produce electric wires in a short time. There is a problem that the wire coating rubber cannot be molded at a high speed due to a low vulcanization rate. In addition, in the case of an electric wire that is not covered with a sheath and has an exposed insulating layer, the insulating layer is particularly problematic in terms of resistance to trauma and crushing.

[0003] Therefore, by increasing the vulcanization density of EPT, E
It is conceivable to increase the modulus of PT and use this EPT for rubber covering electric wires. If such an EPT is used, the wire covering rubber can be formed at a high speed, and it is possible to improve the trauma resistance and the crush resistance of the wire covering rubber without lowering the productivity of the wire.

[0004] However, in order to increase the vulcanization density of the conventional EPT to increase the modulus, only a method of increasing the non-conjugated diene content of the EPT can be considered. When the non-conjugated diene content of the EPT increases, the flexibility of the EPT at low temperatures deteriorates, and the rubber elasticity, which is indispensable as an electric wire, becomes poor in low-temperature atmospheres such as winter and cold regions. However, there is a problem that it is very difficult to improve the crush resistance.

On the other hand, vulcanized sheets of butyl rubber suitable for waterproofing sheets such as roofing sheets used for construction and civil engineering have appeared in the 1950's, but these vulcanized sheets have weather resistance, heat resistance and heat aging. Sex is not always enough. Thereafter, a vulcanized sheet made of a blend of butyl rubber and EPT has been used as a vulcanized sheet having improved weather resistance, heat aging resistance and the like. Initially, the proportion of EPT used in this blend was small, but eventually increased, and in order to improve the performance as a waterproof sheet such as a roofing sheet, recently, the proportion of EPT used was larger than that of butyl rubber. Production of plain waterproof sheets is also being carried out.

[0006] In producing a waterproof sheet such as a roofing sheet made of vulcanized rubber, how to continuously extrude a vulcanized rubber sheet having a good surface skin at a high speed, and weather resistance required as a waterproof sheet The problem is how to end the vulcanization in a short time to increase the productivity while maintaining physical properties such as heat aging resistance, trauma resistance and low-temperature flexibility.

Considering the productivity of the water-stop sheet, the vulcanization rate of the conventional EPT can be somewhat increased by increasing the iodine value of the EPT, as in the case of the wire covering rubber. However, with this method, the desired vulcanization rate cannot be obtained, so that there is a limit in improving the productivity of the waterproof sheet. In addition, considering the physical properties of the water-stop sheet, the conventional EPT can slightly improve the trauma resistance strongly required of the water-stop sheet by increasing the iodine value of the EPT. However, when the non-conjugated diene content of the EPT increases, the flexibility of the EPT at low temperatures deteriorates, and at low temperatures such as winter and cold regions,
There is a problem that the rubber elasticity, which is indispensable as a water-stop sheet, is poor, so that it is very difficult to improve the scratch resistance.

[0008] Therefore, the appearance of wire covering rubber excellent in trauma resistance, crush resistance, low-temperature flexibility and the like, and rubber for waterproof sheets excellent in trauma resistance, low-temperature flexibility and the like have been conventionally desired. .

[0009]

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems associated with the prior art as described above, and to provide an electric wire covering rubber excellent in trauma resistance, crush resistance, low temperature flexibility and the like. It is an object.

[0010] Another object of the present invention is to provide a rubber for a water-stop sheet having excellent scratch resistance and low-temperature flexibility.

[0011]

SUMMARY OF THE INVENTION A wire covering rubber according to the present invention has a random copolymer comprising ethylene, an α-olefin having 3 to 20 carbon atoms, and a structural unit derived from a triene compound represented by the following general formula [1]. The random copolymer rubber (A) is formed of a rubber composition containing a polymer rubber (A), a vulcanizing agent (B), and a filler (C).
The molar ratio of ethylene to α-olefin having 3 to 20 carbon atoms (ethylene / α-olefin) is 99/1 to 30 /
70, (ii) the content of the structural unit derived from the triene compound is 0.1 to 30 mol%, and (ii)
i) The intrinsic viscosity [η] measured in decalin at 135 ° C. is in the range of 0.1 to 10 dl / g.

[0012]

Embedded image [In the formula [1], R ¹ and R ² are each independently a hydrogen atom, a methyl group or an ethyl group, and R ³ and R ⁴ are each independently a methyl group or an ethyl group. ]

The rubber for a water-stop sheet according to the present invention has a random copolymer comprising ethylene, an α-olefin having 3 to 20 carbon atoms, and a structural unit derived from a triene compound represented by the following general formula [1]. The random copolymer rubber (A) is formed of a rubber composition containing a polymer rubber (A), a vulcanizing agent (B), and a filler (C).
The molar ratio of ethylene to α-olefin having 3 to 20 carbon atoms (ethylene / α-olefin) is 99/1 to 30 /
70, (ii) the content of the structural unit derived from the triene compound is 0.1 to 30 mol%, and (ii)
i) The intrinsic viscosity [η] measured in decalin at 135 ° C. is in the range of 0.1 to 10 dl / g.

[0014]

Embedded image

[In the formula [1], R ¹ and R ² are each independently a hydrogen atom, a methyl group or an ethyl group, and R ³ and R ⁴ are each independently a methyl group or an ethyl group. ] Is characterized.

[0016]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the rubber for covering electric wires and the rubber for a waterproof sheet according to the present invention will be specifically described.

The rubber for covering electric wires and the rubber for water-stop sheets according to the present invention are compositions comprising a specific random copolymer rubber (A), a vulcanizing agent (B) and a filler (C). Is formed.

Random copolymer rubber (A) The ethylene copolymer rubber (A) used in the present invention comprises:
Ethylene, an α-olefin having 3 to 20 carbon atoms,
And a branched polyene compound.

As the α-olefin having 3 to 20 carbon atoms, specifically, propylene, 1-butene,
1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-
Pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene,
Examples thereof include 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Among them, propylene, 1-butene, 1-hexene and 1-octene are preferably used.

These α-olefins can be used alone or in combination of two or more. The structural unit derived from the triene compound is represented by the following general formula [1].

[0021]

Embedded image

[In the formula [1], R ¹ and R ² are each independently a hydrogen atom, a methyl group or an ethyl group, and R ³ and R ⁴ are each independently a methyl group or an ethyl group. ]

Among the triene compounds represented by the above formula [1], a compound in which R ³ and R ⁴ are both methyl groups is preferred. A random copolymer rubber obtained by using such a triene compound as a monomer material is It is particularly excellent in the balance between vulcanization rate and scorch characteristics.

Specific examples of the triene compound represented by the above formula [1] include the following compounds.

Embedded image These triene compounds are disclosed in Japanese Patent Application No. 11-146429.
It can be manufactured by the method described in the above item.

Among the above triene compounds, 4,8-dimethyl-1,4,8-decatriene (hereinafter abbreviated as DMDT), which is the first exemplified, is preferable. The triene compound represented by the formula [1] may be a mixture of a trans form and a cis form, or may be a trans form alone or a cis form alone.

The triene compound represented by the formula [1] is obtained by reacting a compound having a conjugated diene represented by the following formula [2] with ethylene in the presence of a catalyst comprising a transition metal compound and an organoaluminum compound. Can be manufactured.

[0027]

Embedded image

[0028] (wherein ^{[2], R 1, R} 2, R 1 in R ³ and R ⁴ in general formula described above, respectively ^{[1], R 2, R} 3
And R ⁴ are the same. In the random copolymer rubber (A) used in the present invention, the structural units derived from the monomers of the ethylene, α-olefin and triene compounds as described above are randomly arranged and bonded to form a triene rubber. It has a branched structure due to the compound, and the main chain has a substantially linear structure.

The fact that the copolymer rubber has a substantially linear structure and does not substantially contain a gel-like crosslinked polymer means that the copolymer rubber is dissolved in an organic solvent and the insoluble content is substantially reduced. It can be confirmed by not including it. For example, when the intrinsic viscosity [η] is measured, it can be confirmed that the copolymer rubber is completely dissolved in decalin at 135 ° C.

In such a random copolymer rubber (A), the structural unit derived from the triene compound has a structure substantially represented by the following formula [3].

[0031]

Embedded image

[0032] (wherein ^{[2], R 1, R} 2, R 1 in R ³ and R ⁴ in general formula described above, respectively ^{[1], R 2, R} 3
And R ⁴ are the same. The fact that the structural unit derived from the triene compound has the above structure can be confirmed by measuring the ¹³ C-NMR spectrum of the copolymer.

The random copolymer rubber (A) used in the present invention has the following composition and properties. (I) The random copolymer rubber (A) that constitutes the composition for a wire covering rubber is composed of ethylene and α- having 3 to 20 carbon atoms.
The molar ratio with the olefin (ethylene / α-olefin) is 40/60 to 95/5, preferably 50/50 to 90 /
10, more preferably in the range of 60/40 to 85/15.

The use of the random copolymer rubber (A) in which the molar ratio of ethylene to the α-olefin having 3 to 20 carbon atoms is in the above-mentioned range provides excellent mechanical strength and low temperature. A composition capable of providing an electric wire covering rubber having excellent rubber elasticity is obtained.

The random copolymer rubber (A) constituting the rubber composition for a water-stop sheet has a molar ratio of ethylene to an α-olefin having 3 to 20 carbon atoms (ethylene / α-olefin).
Olefin) is 40/60 to 85/15, preferably 5
0/50 to 80/20, more preferably 60/40 to
It is in the range of 80/20.

The use of the random copolymer rubber (A) in which the molar ratio of ethylene to the α-olefin having 3 to 20 carbon atoms is within the above range provides excellent mechanical strength and low temperature. A rubber composition capable of providing a waterproof sheet excellent in rubber elasticity is obtained.

(Ii) The content of the triene processed product of the random copolymer rubber (A) constituting the composition for the electric wire covering rubber is as follows:
It is in the range of 0.1 to 30 mol%, preferably 0.3 to 8 mol%, more preferably 0.5 to 5 mol%. Random copolymer rubber (A) having an iodine value in the above range
The use of E.g. provides a composition which is excellent in trauma resistance and can provide a wire covering rubber which retains the excellent heat aging resistance inherent in EPT.

The random copolymer rubber (A) constituting the rubber for the water-stop sheet has an iodine value of 5 to 40, preferably 7 to 25. When a random copolymer rubber (A) having an iodine value within the above range is used, a rubber for water-stop sheets having excellent heat resistance and excellent heat aging resistance, which is inherent in EPT, is obtained. A composition that can be provided is obtained. Further, the triene compound of the compound 1 in the random copolymer rubber (A) is 0.1%.
-30 mol%, preferably 0.3-8 mol%, particularly preferably 0.5-5 mol%.

EPT in which the third component is 4,8-dimethyl-1,4,8-decatriene (hereinafter sometimes abbreviated as DMDT) (hereinafter sometimes abbreviated as DMDT-EPT)
And the third component is 5-ethylidene-2-norbornene (hereinafter, referred to as
EPT (hereinafter sometimes referred to as ENB)
Compared with B-EPT (sometimes abbreviated as B-EPT) at the same iodine value, DMDT-EPT has a vulcanization rate more than twice as fast.

The third component is 4-ethylidene-8-methyl
-1,7- Nonadiene (EMND) EPT is also DM
It shows the same vulcanization rate as DT-EPT, but DMDT-EP
T has a longer t ₅ than EMND-EPT, and has higher scorch stability.

It should be noted that ENB-EPT has a polyene content of more than 4 mol% even if its polyene content is increased.
The effect of improving the vulcanization rate is lost. On the other hand, DMDT-EP
T can increase the vulcanization rate in proportion to the polyene content until its polyene content is 7 mol%.

Further, when the iodine value of ENB-EPT is increased in order to increase the vulcanization rate, the low-temperature flexibility deteriorates proportionately. On the other hand, DMDT-EPT has excellent low-temperature flexibility regardless of its iodine value.

(Iii) The random copolymer rubber (A) that constitutes the composition for a wire covering rubber has an intrinsic viscosity [η] of 0.8 dl / g <[η] <5 measured in decalin at 135 ° C. d
l / g, preferably 1.0 dl / g <[η] <3.5 dl / g
In the range represented by When a random copolymer rubber (A) having an intrinsic viscosity [η] in the above range is used,
A composition excellent in extrusion processability, which can provide a wire covering rubber excellent in damage resistance, is obtained.

The random copolymer (A) constituting the rubber composition for a waterproof sheet has an intrinsic viscosity [η] of 0.8 dl / g <[η] <5 dl measured in decalin at 135 ° C. / g
, Preferably 1.5 dl / g <[η] <3.0 dl / g. Using a random copolymer rubber (A) having an intrinsic viscosity [η] in the above range, it is possible to provide a rubber for a water-blocking sheet having excellent trauma resistance and excellent extrudability. Is obtained.

The above random copolymer rubber (A)
Can be obtained by copolymerizing ethylene, an α-olefin having 3 to 20 carbon atoms, and a structural unit derived from the triene compound represented by the general formula [1] in the presence of a catalyst.

As such a catalyst, a Ziegler catalyst comprising a transition metal compound such as vanadium (V), zirconium (Zr), or titanium (Ti) and an organic aluminum compound (organic aluminum oxy compound) can be used.

In the present invention, [a] a catalyst comprising a soluble vanadium compound and an organoaluminum compound, or [b] a metallocene compound of a transition metal selected from Group IVB of the periodic table, and an organoaluminum oxy compound or an ionized ionic compound A catalyst comprising a compound is particularly preferably used.

In the present invention, the catalyst [a] (a catalyst comprising a soluble vanadium compound and an organoaluminum compound) or the catalyst [b] (a metallocene compound of a transition metal selected from Group IV of the periodic table) and an organic Ethylene in the presence of an aluminum oxy compound or a catalyst comprising an ionized ionic compound) and ethylene having an α of 3 to 20 carbon atoms.
-An olefin and a structural unit derived from a triene compound are usually copolymerized in a liquid phase.

In this case, a hydrocarbon solvent is generally used, but an α-olefin such as propylene may be used as the solvent. Specific examples of such hydrocarbon solvents include pentane, hexane, heptane, octane, decane, dodecane, aliphatic hydrocarbons such as kerosene and halogen derivatives thereof, cyclohexane, methylcyclopentane,
Alicyclic hydrocarbons such as methylcyclohexane and halogen derivatives thereof, aromatic hydrocarbons such as benzene, toluene and xylene, and halogen derivatives such as chlorobenzene are used.

These solvents may be used in combination.
The copolymerization of ethylene, an α-olefin having 3 to 20 carbon atoms and a structural unit derived from a triene compound may be carried out by either a batch method or a continuous method. When the copolymerization is carried out by a continuous method, the above-mentioned catalyst is used in the following concentration.

In the present invention, when the above-mentioned catalyst [a], that is, a catalyst comprising a soluble vanadium compound and an organoaluminum compound, is used, the concentration of the soluble vanadium compound in the polymerization system is usually from 0.01 to 5%. Mmol / liter (polymerization volume), preferably 0.05 to 3 mmol / liter. This soluble vanadium compound is desirably supplied at a concentration of 10 times or less, preferably 1 to 7 times, more preferably 1 to 5 times the concentration of the soluble vanadium compound present in the polymerization system.

The organoaluminum compound has a ratio of aluminum atoms to vanadium atoms in the polymerization system (A
1 / V), and is supplied in an amount of 2 or more, preferably 2 to 50, more preferably 3 to 20.

The catalyst [a] comprising a soluble vanadium compound and an organoaluminum compound is usually diluted with the above-mentioned hydrocarbon solvent and / or a liquid α-olefin having 3 to 20 carbon atoms and a branched polyene compound. Supplied. At this time, the soluble vanadium compound is desirably diluted to the concentration described above, and the organoaluminum compound is diluted to, for example, 50% of the concentration in the polymerization system.
It is desirable to adjust the concentration to an arbitrary concentration of 2 times or less and supply it to the polymerization system.

In the present invention, when a catalyst [b] comprising a metallocene compound and an organic aluminum oxy compound or an ionized ionic compound (also referred to as an ionic ionized compound or ionic compound) is used, a polymerization system The concentration of the metallocene compound in is usually 0.1.
0.0005-0.1 mmol / liter (polymerization volume),
Preferably it is 0.0001-0.05 mmol / l.

The organic aluminum oxy compound is
It is supplied in an amount of 1 to 10,000, preferably 10 to 5,000 in terms of the ratio of aluminum atoms to the metallocene compound in the polymerization system (Al / transition metal).

In the case of the ionized ionic compound, the molar ratio of the ionized ionic compound to the metallocene compound in the polymerization system (ionized ionic compound / metallocene compound) is 0.5 to 20, preferably 1 to 10. Supplied.

When an organoaluminum compound is used, it is generally used in an amount of about 0 to 5 mmol / l (polymerization degree), preferably about 0 to 2 mmol / l.

In the present invention, ethylene, an α-olefin having 3 to 20 carbon atoms and a structural unit derived from a triene compound are copolymerized in the presence of a catalyst [a] comprising a soluble vanadium compound and an organoaluminum compound. When it is carried out, the copolymerization reaction is usually carried out at a temperature of -50C to 10C.
The reaction is carried out at 0 ° C., preferably at −30 ° C. to 80 ° C., more preferably at −20 ° C. to 60 ° C., and at a pressure of 5 MPa or less, preferably 2 MPa or less.

In the present invention, ethylene, an α-olefin having 3 to 20 carbon atoms and a triene compound are derived in the presence of a catalyst [b] comprising a metallocene compound and an organic aluminum oxy compound or an ionized ionic compound. When copolymerizing with a structural unit, the temperature of the copolymerization reaction is usually from -20 ° C to 150 ° C, preferably 0 ° C.
C. to 120.degree. C., more preferably 0.degree. C. to 100.degree. C., and a pressure of 8 MPa or less, preferably 5 MPa or less.

The reaction time (average residence time when copolymerization is carried out by a continuous method) varies depending on conditions such as the catalyst concentration and the polymerization temperature, but is usually 5 minutes to 5 hours, preferably 10 minutes. ~ 3 hours.

In the present invention, ethylene, C 3 -C 2
The structural unit derived from the α-olefin and the triene compound of 0 is supplied to the polymerization system in such an amount as to obtain the random copolymer rubber having the above specific composition. Further, upon copolymerization, a molecular weight regulator such as hydrogen may be used.

As described above, ethylene and carbon atom 3
When structural units derived from α-olefins and triene compounds of from 20 to 20 are copolymerized, a random copolymer rubber is usually obtained as a polymerization liquid containing the same. This polymerization liquid is
It is processed by a conventional method to obtain a random copolymer rubber.

The method for preparing the random copolymer rubber (A) [unsaturated ethylenic copolymer] as described above is described in detail in Japanese Patent Application No. 7-69986.

Vulcanizing Agent (B) Examples of the vulcanizing agent (B) used in the present invention include sulfur, sulfur compounds, and organic peroxides.

Examples of the sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, and insoluble sulfur. As sulfur compounds,
Specific examples include sulfur chloride, sulfur dichloride, polymer polysulfide, and the like. Sulfur compounds that release active sulfur at the vulcanization temperature and vulcanize, such as morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide, and the like can also be used.

In the present invention, the sulfur or the sulfur compound is used in an amount of 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the random copolymer rubber (A). Can be

When sulfur or a sulfur compound is used as the vulcanizing agent (B), it is preferable to use a vulcanization accelerator in combination. Specific examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazolesulfenamide,
N-oxydiethylene-2-benzothiazolesulfenamide, N, N-diisopropyl-2-benzothiazolesulfenamide, 2-mercaptobenzothiazole, 2- (2,4-
Dinitrophenyl) mercaptobenzothiazole, 2-
(2,6-Diethyl-4-morpholinothio) thiazole compounds such as benzothiazole and dibenzothiazyldisulfide; guanidine compounds such as diphenylguanidine, triphenylguanidine, diorsonitrileguanidine, orthonitrile biguanide, diphenylguanidine phthalate Acetaldehyde-aniline reactants, butyraldehyde-aniline condensates, aldehyde amines such as hexamethylenetetramine, acetaldehyde ammonia or aldehyde-ammonia compounds; imidazoline compounds such as 2-mercaptoimidazoline; thiocarbanilide, diethylthiourea, dibutylthiourea ,
Thiourea compounds such as trimethylthiourea and diortho tolyl thiourea; thiuram compounds such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, pentamethylenethiuram tetrasulfide; zinc dimethyldithiocarbamate ,
Dithioxanthogen compounds such as zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate and tellurium dimethyldithiocarbamate; dibutylxanthogen Xanthate compounds such as zinc acid; and compounds such as zinc white.

In the present invention, the vulcanization accelerator is used in an amount of from 0.1 to 100 parts by weight of the random copolymer rubber (A).
It is used in a proportion of 20 parts by weight, preferably 0.2 to 10 parts by weight.

The organic peroxide may be any compound which is usually used for peroxide vulcanization of rubber. For example, dicumyl peroxide, di-t-butyl peroxide,
Di-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butyl hydroperoxide, t-butylcumyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-di (t-butyl Peroxin) hexyne-3,2,
5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-mono (t-butylperoxy)-
Hexane, α, α′-bis (t-butylperoxy-m-isopropyl) benzene and the like can be mentioned. Among them, dicumyl peroxide, di-t-butyl peroxide,
Di-t-butylperoxy-3,3,5-trimethylcyclohexane is preferably used. These organic peroxides
One type or a combination of two or more types is used.

In the present invention, the organic peroxide is 3 × 1 based on 100 parts by weight of the random copolymer rubber (A).
It is used in a proportion of 0-4 to 5 * 10 <-2> mol, but it is desirable to determine the optimum amount appropriately according to the required physical properties.

When an organic peroxide is used as the vulcanizing agent (B), it is preferable to use a vulcanizing aid in combination. Specific examples of the vulcanization aid include sulfur; quinone dioxime compounds such as p-quinone dioxime; methacrylate compounds such as polyethylene glycol dimethacrylate; allyl compounds such as diallyl phthalate and triallyl cyanurate; Other maleimide compounds include divinylbenzene.

In the rubber composition for covering electric wires, the vulcanizing agent (B)
It is preferable to use an organic peroxide. In the rubber composition for a water-stop sheet, it is preferable to use sulfur or a sulfur compound as the vulcanizing agent (B).

Filler (C) The filler (C) used in the present invention includes a filler having a reinforcing property and a filler having no reinforcing property.

The reinforcing filler has an effect of improving mechanical properties such as tensile strength, tear strength and abrasion resistance of the vulcanized rubber. As such a filler, specifically,
Examples thereof include carbon black, silica, activated calcium carbonate, and fine talc, which may be subjected to a surface treatment with a silane coupling agent. In the present invention, any type of carbon black that is commonly used for rubber can be used regardless of its type.

Further, the filler having no reinforcing property can increase the hardness of the rubber product without significantly affecting the physical properties,
Used to reduce costs. As such a filler, specifically, talc, clay,
Calcium carbonate and the like.

In the present invention, the filler (C) is used in an amount of 20 to 100 parts by weight of the random copolymer rubber (A).
It is used in a proportion of 200 parts by weight, preferably 50 to 150 parts by weight.

Other Ingredients The above-mentioned random copolymer rubber (A), vulcanizing agent (B) and filler (C) are contained in the rubber composition for electric wire covering rubber or the waterproofing sheet used in the present invention. ), Vulcanization accelerators and vulcanization auxiliaries can be compounded as described above, and in addition, softeners, processing auxiliaries, foaming agents and other compounding agents for rubber are used in the present invention. Can be blended in a range that does not impair.

Examples of the softener include softeners usually used for rubber, that is, various mineral oils, synthetic oils, ester plasticizers and the like. Specifically, various mineral oils usually used as rubber process oils, for example, paraffinic, naphthenic, aroma mineral oils, butene oligomers, synthetic hydrocarbon oils such as ethylene / α-olefin cooligomers, polyglycol oils, Examples include polyphenyl ether oil, ester oil, phosphate ester oil, polychlorotrifluoroethylene oil, fluoroester oil, chlorinated biphenyl oil, and silicone oil.

The softener is a random copolymer rubber (A) 1
It is used in an amount of 10 to 120 parts by weight, preferably 30 to 80 parts by weight, based on 00 parts by weight. As the processing aid, a processing aid usually used for rubber is used in an amount of 10 parts by weight or less based on 100 parts by weight of the random copolymer rubber (A).
Preferably, it is used in a proportion of 1 to 5 parts by weight.

Preparation of Composition The composition for rubber for covering electric wires and the rubber composition for waterproof sheet used in the present invention can be prepared, for example, by the following method.

That is, the composition for the wire-covered rubber and the rubber composition for the water-stop sheet used in the present invention are prepared by using a random copolymer rubber (A), a filler (C), and a mixer such as a Banbury mixer. After kneading necessary additives such as a softener at a temperature of 80 to 170 ° C. for about 3 to 10 minutes, using rolls such as an open roll,
It can be prepared by additionally mixing the vulcanizing agent (B), a vulcanization accelerator or a vulcanization aid as required, kneading the mixture at a roll temperature of 40 to 80 ° C. for 5 to 30 minutes, and then dispensing. . The rubber composition thus obtained is a ribbon-shaped or sheet-shaped rubber compound.

The rubber composition for electric wire covering rubber and the rubber composition for water-stop sheet used in the present invention are composed of a random copolymer rubber (A), a vulcanizing agent (B), a filler (C) and the above-mentioned filler. The additives can be fed directly to an extruder heated to about 80 to 100 ° C., granulated with a residence time of about 0.5 to 5 minutes, and prepared into pellets.

Electric Wire Coating Rubber The electric wire coating rubber according to the present invention comprises the above-mentioned random copolymer rubber (A), vulcanizing agent (B), filler (C), and if necessary, a softener and a processing agent. It is formed of a rubber composition comprising a rubber compounding agent such as an auxiliary agent and a foaming agent, and is usually vulcanized.

The rubber covering the electric wire according to the present invention is
For example, immediately after providing an insulating layer around the conducting wire, it can be prepared by extrusion-coating the surrounding of the insulating layer with the vulcanizable compounded rubber prepared by the above-described method and vulcanizing. The wire covering rubber according to the present invention may be a so-called wire protection cover prepared from the above-described composition for wire covering rubber according to the present invention.

Rubber for Water-Stopping Sheet The rubber for water-stopping sheet according to the present invention comprises the above-mentioned random copolymer rubber (A), vulcanizing agent (B), filler (C), and, if necessary, It is formed of a rubber composition comprising a rubber compounding agent such as a softener and a processing aid, and is usually vulcanized.

The rubber for a water-stop sheet according to the present invention can be prepared, for example, by using a rubber composition as described above, for example, a conventionally known T-
It can be obtained by a die extrusion method or a calendar method.

[0087]

According to the present invention, the random copolymer rubber (A) comprising ethylene, an α-olefin having 3 to 20 carbon atoms and a structural unit derived from the above-mentioned triene compound is ethylene, α-olefin. , Iodine value and intrinsic viscosity [η] are in the specific ranges, so that it is possible to provide a vulcanized rubber having excellent resistance to trauma, crushing and low-temperature flexibility. And high speed molding is possible. Further, this random copolymer rubber (A)
Excellent properties such as weather resistance, ozone resistance and heat aging resistance.

Since the wire covering rubber according to the present invention is formed of a composition containing the above random copolymer rubber (A), vulcanizing agent (B) and filler (C), it is resistant to electric resistance. Excellent in trauma, crush resistance and low temperature flexibility.

Further, the rubber for a waterproof sheet according to the present invention comprises:
The random copolymer rubber (A), a vulcanizing agent (B),
Since it is formed of a composition containing the filler (C), it has excellent scratch resistance and low-temperature flexibility.

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited to these examples. The evaluation test methods for the ethylene / α-olefin / polyene copolymer rubber and the vulcanized rubber in Examples and Comparative Examples are as follows.

[1] Physical property test of unvulcanized rubber The physical property test of the unvulcanized rubber was performed according to JIS K6300. The scorch stability was measured using a Mooney viscometer (model SMV-202) manufactured by Shimadzu Corporation at 125 ° C. and the change in Mooney viscosity was measured at t ₅ [min].
As a guide. The t ₅ indicates the longer scorch that stability is good. The vulcanization rate, using a Monsanto rotor-less rheometer (model MDR 2000), to measure the change in torque at 160 ° C., t _c (9
0) was obtained and used as a guide. The shorter the t _c (90), the faster the vulcanization rate.

[2] Tensile test A vulcanized rubber sheet was punched out and JIS K6251 (199)
No. 3 dumbbell test piece described in (3 years), and using this test piece, a measurement temperature of 25 ° C. and a tensile speed of 50 were applied in accordance with the method specified in JIS K 6251, Paragraph 3.
A tensile test was performed under the conditions of 0 mm / min, 100% modulus (M100), 200% modulus (M200),
100% modulus (M300), tensile stress at break T _B and tensile elongation at break E _B were measured.

[3] Hardness Test The hardness test was performed according to JIS K 6253 (1993), and the spring hardness H _A (Shore A hardness) was measured.

[4] Compression set test The compression set test was performed according to JIS K 6262 (1993).
And the compression set (C _S ) was determined.

[5] Heat Deformation Test The heat deformation test was performed in accordance with JIS C 3005 (1993), and the reduction rate [%] of the thickness after the heat deformation was determined. This reduction rate is an index of the crush resistance of the vulcanized rubber. (Test conditions) Heating temperature: 90 ° C, 120 ° C, 150 ° C Load: 10.5kg

[6] Dyeing and Abrasion Test The dyeing and abrasion test was performed in accordance with JIS L 0849 (1996), and the weight change rate [%] before and after the test was determined. This rate of change in weight is an indicator of the scratch resistance of the vulcanized rubber. (Test conditions) Test load: 200 g Friction surface: 20 × 20 mm Size of test piece: 25 × 210 mm Friction piece: Cloth of size 20 × 20 mm (Kanakin No. 3) Number of times of friction: 500 times

[5] Low-temperature torsion test (Gehman torsion test) The low-temperature torsion test was performed according to JIS K 6261 (1993), and t ₂ [° C.] and freezing temperature [° C.] were determined.
These temperatures are indicators of the low temperature flexibility of the vulcanized rubber.
as t ₂ is low, the low temperature flexibility is good.

The random copolymer rubbers used in Examples and Comparative Examples are as shown in Table 1.

[0099]

[Table 1] (Note) DMDT-EPT: Ethylene propylene 4,8-dimethyl-1,4,8-decatriene copolymer rubber ENB-EPT: Ethylene propylene 5 -ethylidene-2
-Norbornene copolymer rubber

[Examples and Comparative Examples of Wire Covering Rubber]

[0101]

Example 1 The above-mentioned ethylene / propylene / 4,8-dimethyl-1,4,8-decatriene copolymer rubber (DMDT-EPT-1) 100 was used as the random copolymer rubber (A).
Parts by weight, 5 parts by weight of zinc white, 1 part by weight of stearic acid, 100 parts by weight of Mythrone vapor talc [filler], and 20 parts by weight of paraffinic oil, a 4.3 liter Banbury mixer [ ) Made by Kobe Steel].

To the kneaded material thus obtained, 6.8 parts by weight of dicumyl peroxide and 3.5 parts by weight of p- (p-dibenzoylquinone) dioxime [vulcanization aid] were added, and the mixture was added to 8 inches. Roll (temperature of front roll and rear roll 50
C.), kneaded at 160.degree.
Press vulcanization was performed for 0 minutes to prepare a vulcanized sheet having a thickness of 2 mm.

The obtained vulcanized sheet was subjected to the above-mentioned physical properties test and the like according to the above-mentioned method. Further, for the unvulcanized rubber composition before performing the above vulcanization, according to the above method,
Mooney viscosity [ML (1 + 4) 130 ° C], t ₅ , t _c (9
0) was determined.

Table 2 shows the results.

[0105]

Comparative Examples 1 and 2 In Example 1, DMDT-EPT was used.
ENB-EPT-1, EN shown in Table 1 instead of -1
The procedure was performed in the same manner as in Example 1 except that B-EPT-2 was used.

Table 2 shows the results.

[0107]

[Table 2]

Table 2 shows the following. Comparing Comparative Example 1 using ENB-EPT-1 having a low iodine value with Comparative Example 2 using ENB-EPT-2 having a high iodine value, it was found that both crush resistance and trauma resistance were improved. The higher the iodine value of the polymer, that is, the higher the ENB content, the lower the flexibility at low temperatures.

On the other hand, comparing Example 1 with Comparative Example 2, it is found that DMDT-EPT-1 used in Example 1 has the same iodine value as ENB-EPT-2 used in Comparative Example 2. Nevertheless, Example 1 shows better low-temperature flexibility than Comparative Example 2 and also has very good trauma resistance.

Further, although the copolymer having the same iodine value is used in Example 1 and Comparative Example 2, the vulcanization rate of Example 1 is much higher than that of Comparative Example 2.

[Examples and Comparative Examples of Rubber for Water-Stop Sheet]

Example 2 The above-mentioned ethylene / propylene / 4,8-dimethyl-1,4,8-decatriene copolymer rubber (DMDT-EPT-2) 100 was used as the random copolymer rubber (A).
4.3 parts by weight of 4.3 parts by weight of 5 parts by weight of zinc white, 1 part by weight of stearic acid, 75 parts by weight of HAF carbon black, 40 parts by weight of heavy calcium carbonate, and 40 parts by weight of paraffinic oil Mixer [Co., Ltd.
Made by Kobe Steel].

To the kneaded product thus obtained, 1.0 part by weight of sulfur and 0.75 part of 2-mercaptobenzothiazole were added.
Parts by weight, 0.75 parts by weight of dibenzothiazyl disulfide and 0.5 parts by weight of tetramethylthiuram disulfide were added, kneaded with an 8-inch roll (the temperature of the front roll and the rear roll was 50 ° C.), and the mixture was separated into sheets. , 160
Press vulcanization was performed at 10 ° C. for 10 minutes to prepare a vulcanized sheet having a thickness of 2 mm.

The obtained vulcanized sheet was subjected to the above-mentioned physical properties test and the like according to the above-mentioned method. Further, for the unvulcanized rubber composition before performing the above vulcanization, according to the above method,
Mooney viscosity [ML (1 + 4) 130 ° C], t ₅ , t _c (9
0) was determined.

Table 3 shows the results.

[0115]

Comparative Examples 3 and 4 In Example 2, DMDT-EPT was used.
ENB-EPT-3, EN shown in Table 1 in place of -2
The procedure was performed in the same manner as in Example 2 except that B-EPT-4 was used.

Table 3 shows the results.

[0117]

[Table 3]

Table 3 shows the following. A comparison between Comparative Example 3 using ENB-EPT-3 having a low iodine value and Comparative Example 4 using ENB-EPT-4 having a high iodine value shows that in order to improve the trauma resistance, the copolymer iodine was used. The higher the value, that is, the higher the ENB content, the lower the flexibility at low temperature.

On the other hand, comparing Example 2 with Comparative Example 4, the DMDT-EPT-2 used in Example 2 had an iodine value almost the same as the iodine value of ENB-EPT-4 used in Comparative Example 4. Despite having the following, Example 2 shows better low-temperature flexibility than Comparative Example 4, and also has extremely excellent trauma resistance.

Further, in Example 2 and Comparative Example 4, although copolymers having almost the same iodine value were used,
The vulcanization rate of Example 2 is much higher than that of Comparative Example 4.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) C08K 5/36 C08K 5/36 C08L 23/16 C08L 23/16 C09K 3/10 C09K 3/10 Z H01B 7/282 H01B 7/28 EF term (reference) 4F071 AA15 AA88 AE02 AH03 AH12 BB06 BC01 BC07 4H017 AA03 AB07 AC04 AC19 AD06 AE05 4J002 BB051 BB101 BB151 CC152 CH052 DA038 DA046 DA047 DD006 DE107 DE238 DG016 EN017 E0 017 017 017 EU107 EU197 EV027 EV047 EV057 EV066 EV076 EV117 EV127 EV157 EV166 EV167 EV277 FD018 FD020 FD146 FD152 FD157 GQ01 5G313 AB01 AB02 AE02 FA01 FD04

Claims (2)

[Claims] 1. A random copolymer rubber (A) comprising ethylene, an α-olefin having 3 to 20 carbon atoms and a structural unit derived from a triene compound represented by the following general formula [1]: The random copolymer rubber (A) is formed of a rubber composition containing an agent (B) and a filler (C), and (i) ethylene and an α-olefin having 3 to 20 carbon atoms. Is in the range of 99/1 to 30/70, (ii) the content of the structural unit derived from the triene compound is 0.1 to 30 mol%, and (iii) ) 135 ° C
Intrinsic viscosity [η] measured in decalin is 0.1 to 10 d
1 / g; a wire covering rubber characterized by being in the range of 1 / g; [In the formula [1], R ¹ and R ² are each independently a hydrogen atom, a methyl group or an ethyl group, and R ³ and R ⁴ are each independently a methyl group or an ethyl group. ] 2. A random copolymer rubber (A) comprising ethylene, an α-olefin having 3 to 20 carbon atoms and a structural unit derived from a triene compound represented by the following general formula [1]: The random copolymer rubber (A) is formed of a rubber composition containing an agent (B) and a filler (C), and (i) ethylene and an α-olefin having 3 to 20 carbon atoms. Is in the range of 99/1 to 30/70, (ii) the content of the structural unit derived from the triene compound is 0.1 to 30 mol%, and (iii) ) 135 ° C
Intrinsic viscosity [η] measured in decalin is 0.1 to 10 d
1 / g; rubber for a waterproof sheet, characterized by being in the range of 1 / g; [In the formula [1], R ¹ and R ² are each independently a hydrogen atom, a methyl group or an ethyl group, and R ³ and R ⁴ are each independently a methyl group or an ethyl group. ]