JP2002348479A - Radiation crosslinkable polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation crosslinkable polymer composition having excellent thermal resistance, high flexibility and superior handling ability at the processing because a liquid substance does not bleed out, which is useful, particularly, as a coating material for electric wires. SOLUTION: The radiation crosslinkable polymer composition containing (A) from 1 to 30 parts by weight of 1,2-polybutadiene and (B) from 99 to 70 parts by weight of thermoplastic polymers exclusive of the (A) component [provided that (A)+(B)=100 parts by weight].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-crosslinkable polymer composition containing 1,2-polybutadiene, which is particularly excellent in heat resistance and is useful as a covering material for electric wires.

[0002]

2. Description of the Related Art Urethane resins have excellent mechanical properties such as abrasion resistance, are flexible even at low temperatures, and have excellent chemical resistance. Used as an insulating coating material in a sensor cable for use. However, when extruding a multi-core insulated wire formed by twisting two or more insulated wires using this urethane resin, the insulating layer of each insulated wire may be deformed by the pressure of the urethane resin during extrusion. Is easy to occur.

A multi-core insulated wire having an insulated wire whose insulation layer is deformed as described above has a remarkable decrease in end workability, or causes insulation breakdown due to the deformed insulation layer being thinned due to wear or the like. As a result, a short circuit accident may occur between the insulated wires. In order to solve such a problem, the outer periphery of the multi-core insulated wire is extrusion-coated with a thermoplastic resin having a low molding pressure at the time of extrusion coating to form an inner layer once, and then the outer periphery of the inner layer is formed of urethane resin. A coated electric wire having a structure coated with a crosslinked body layer by electron beam irradiation has been proposed (see Japanese Utility Model Publication No. 4-52888). In the above-described coated electric wire, since a melt index of 0.2 or more is used as the thermoplastic resin for the inner layer, the insulating layer of the multi-core insulated electric wire is not deformed at the time of extrusion coating, so that the terminal workability is low. It is said to be excellent. However, there is a problem that the coated electric wire described in Japanese Utility Model Publication No. 4-52888 is not always suitable as an electric wire used in a high-temperature atmosphere environment.
For example, a cable for a vehicle such as an automobile must always be thermally affected by heat radiation from an engine or a brake disk. Therefore, electric wires used in these fields are stipulated by the Japanese automobile standard JASO D608. It is required to pass a heat test.

[0004]

DISCLOSURE OF THE INVENTION The present invention is excellent in heat resistance and flexibility, without causing bleed out of a liquid substance.
An object of the present invention is to provide a radiation-crosslinkable polymer composition which is excellent in handling properties at the time of processing and the like, and is particularly useful as a covering material for electric wires.

[0005]

The present invention provides (A) 1, 2
-A radiation-crosslinkable polymer composition containing 1 to 30 parts by weight of polybutadiene and (B) 99 to 70 parts by weight of a thermoplastic polymer other than the component (A) (provided that (A) + (B) = 100 parts by weight). About things.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION (A) 1,2-Polybutadiene The 1,2-polybutadiene used in the present invention has a 1,2-bond content of 70% or more, for example.
Any 1,2-polybutadiene may be used, but it is preferably obtained by polymerizing butadiene in the presence of a catalyst containing a cobalt compound and aluminoxane.

The 1,2-polybutadiene of the present invention has a 1,2-bond content of 70% or more, preferably 80% or more, and more preferably 90% or more, in the butadiene-binding unit. When the 1,2-bond content is 70% by weight or more, 1,2-polybutadiene of the present invention exhibits good properties as a thermoplastic elastomer.

The 1,2-polybutadiene of the present invention is preferably 1,2-polybutadiene having a crystallinity of 5% or more, preferably 10 to 40%, and its melting point is preferably 50 to 50%. 130 ° C, more preferably in the range of 60 to 120 ° C. When the crystallinity / melting point is in this range, the result is an excellent balance between mechanical strength such as tensile strength and tear strength and flexibility.

The 1,2-polybutadiene of the present invention may contain a small amount of a conjugated diene other than butadiene.
Examples of the conjugated diene other than butadiene include 1,3-pentadiene, 1,3-butadiene derivatives substituted with a higher alkyl group, and 2-alkyl-substituted-1,3-butadiene. Among them, 1,3-butadiene derivatives substituted with higher alkyl groups include 1-pentyl-
Examples thereof include 1,3-butadiene, 1-hexyl-1,3-butadiene, 1-heptyl-1,3-butadiene, and 1-octyl 1,3-butadiene.

Here, typical examples of the 2-alkyl-substituted-1,3-butadiene include 2-methyl-1,3-butadiene (isoprene), 2-ethyl-1,3-butadiene, and 2-propyl-butadiene. 1,3-butadiene, 2-isopropyl-1,3-butadiene, 2-butyl-1,3-butadiene, 2-isobutyl-1,3-butadiene, 2-amyl-1,3-butadiene, 2-isoamyl- 1,3-
Butadiene, 2-hexyl-1,3-butadiene, 2-
Cyclohexyl-1,3-butadiene, 2-isohexyl-1,3-butadiene, 2-heptyl-1,3-butadiene, 2-isoheptyl-1,3-butadiene, 2-
Octyl-1,3-butadiene, 2-isooctyl-
1,3-butadiene and the like can be mentioned. Among these conjugated dienes, preferred conjugated dienes copolymerized with butadiene include isoprene and 1,3-pentadiene. The content of butadiene in the monomer component used for the polymerization is preferably at least 50 mol%, particularly preferably at least 70 mol%.

As described above, the 1,2-polybutadiene of the present invention is preferably obtained by polymerizing butadiene in the presence of a catalyst containing a cobalt compound and an aluminoxane. As the cobalt compound, preferably, an organic acid salt of cobalt having 4 or more carbon atoms can be exemplified. Specific examples of the organic acid salts of cobalt include octylates such as butyrate, hexanoate, heptylate and 2-ethyl-hexyl acid, decanoates, and higher grades such as stearic acid, oleic acid and erucic acid. Examples thereof include fatty acid salts, benzoates, tolylates, xylates, alkyls such as ethylbenzoic acid, aralkyls, allyl-substituted benzoates and naphthoates, and alkyl, aralkyl or allyl-substituted naphthoates. Of these, two
The so-called octylates, stearates and benzoates of ethylhexylic acid are preferred for their excellent solubility in hydrocarbon solvents.

Examples of the aluminoxane include those represented by the following general formula (I) or (II).

[0013]

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In the aluminoxane represented by the general formula (I) or (II), R is a hydrocarbon group such as a methyl group, an ethyl group, a propyl group and a butyl group, preferably a methyl group, an ethyl group. And particularly preferably a methyl group. M is an integer of 2 or more, preferably 5 or more, and more preferably 10 to 100. Specific examples of aluminoxane include methylaluminoxane, ethylaluminoxane, propylaluminoxane, butylaluminoxane, and the like.
Methylaluminoxane is particularly preferred.

It is extremely preferable that the polymerization catalyst contains a phosphine compound in addition to the above-mentioned cobalt compound and aluminoxane. The phosphine compound is a component effective for activating the polymerization catalyst, controlling the vinyl bond structure and crystallinity, and preferably includes an organic phosphorus compound represented by the following general formula (III).

P (Ar) _n (R ′) _3-n (III) In the general formula (III), Ar represents a group shown below.

[0017]

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(In the above groups, R ¹ , R ² and R ³ are the same or different and each have a hydrogen atom and a carbon number of preferably 1 to 1.
6 alkyl groups, halogen atoms, and preferably 1 carbon atom
And preferably 6 to 12 alkoxy groups or 6 to 12 carbon atoms.
Represents an aryl group. In the general formula (III), R ′ represents a cycloalkyl group or an alkyl-substituted cycloalkyl group, and n is an integer of 0 to 3.

Specific examples of the phosphine compound represented by the general formula (III) include tri- (3-methylphenyl)
Phosphine, tri- (3-ethylphenyl) phosphine, tri- (3,5-dimethylphenyl) phosphine,
Tri- (3,4-dimethylphenyl) phosphine, tri- (3-isopropylphenyl) phosphine, tri-
(3-t-butylphenyl) phosphine, tri- (3,
5-diethylphenyl) phosphine, tri- (3-methyl-5-ethylphenyl) phosphine), tri- (3-
Phenylphenyl) phosphine, tri- (3,4,5-
Trimethylphenyl) phosphine, tri- (4-methoxy-3,5-dimethylphenyl) phosphine, tri-
(4-ethoxy-3,5-diethylphenyl) phosphine, tri- (4-butoxy-3,5-dibutylphenyl) phosphine, tri (p-methoxyphenylphosphine), tricyclohexylphosphine, dicyclohexylphenylphosphine, tribenzylphosphine , Tri (4-methylphenylphosphine), tri (4-ethylphenylphosphine) and the like. Of these, particularly preferred are triphenylphosphine, tri- (3-methylphenyl) phosphine,
Tri- (4-methoxy-3,5-dimethylphenyl) phosphine and the like.

Further, as the cobalt compound, a compound represented by the following general formula (IV) can be used.

[0021]

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The compound represented by the general formula (IV) is a complex having, as a ligand, a phosphine compound in which n is 3 in the general formula (III) with respect to cobalt chloride. When using this cobalt compound, a compound synthesized in advance may be used, or a method in which cobalt chloride and a phosphine compound are brought into contact in a polymerization system may be used. By selecting various phosphine compounds in the complex, it is possible to control the amount of 1,2-bonds and crystallinity of the obtained 1,2-polybutadiene.

Specific examples of the cobalt compound represented by the above general formula (IV) include cobalt bis (triphenylphosphine) dichloride, cobalt bis [tris (3-methylphenylphosphine)] dichloride, cobalt bis [tris (3 -Ethylphenylphosphine)] dichloride, cobalt bis [tris (4-methylphenylphosphine)] dichloride, cobalt bis [tris (3,5-dimethylphenylphosphine)] dichloride, cobalt bis [tris (3,4-dimethylphenylphosphine) )] Dichloride, cobalt bis [tris (3-isopropylphenylphosphine)] dichloride, cobalt bis [tris (3-t-butylphenylphosphine)] dichloride, cobalt bis [tris (3,5-diethylphenyl) Sphine)] dichloride, cobalt bis [tris (3-methyl-5-ethylphenylphosphine)] dichloride, cobalt bis [tris (3-phenylphenylphosphine)] dichloride, cobalt bis [tris (3,4,5-trimethylphenyl) Phosphine)] dichloride, cobalt bis [tris (4-methoxy-3,5-dimethylphenylphosphine)] dichloride, cobalt bis [tris (4-ethoxy-3,5-diethylphenylphosphine)] dichloride, cobalt bis [tris ( 4-butoxy-3,
5-dibutylphenylphosphine)] dichloride, cobalt bis [tris (4-methoxyphenylphosphine)] dichloride, cobalt bis [tris (3-methoxyphenylphosphine)] dichloride, cobalt bis [tris (4-dodecylphenylphosphine)] dichloride And cobalt bis [tris (4-ethylphenylphosphine)] dichloride.

Of these, cobalt bis (triphenylphosphine) dichloride, cobalt bis [tris (3-methylphenylphosphine)] dichloride, cobalt bis [tris (3,3)
5-dimethylphenylphosphine)] dichloride, cobalt bis [tris (4-methoxy-3,5-dimethylphenylphosphine)] dichloride and the like.

The amount of the catalyst used is as follows: in the case of homopolymerization of butadiene, per mole of butadiene;
Total amount of butadiene and conjugated diene other than butadiene 1
The amount of the cobalt compound per mole is 0.001 to 1 mmol, preferably 0.01 to 0.5 in terms of cobalt atom.
Use about millimoles. The amount of the phosphine compound used is determined by the ratio of the phosphorus atom to the cobalt atom (P / Co).
As 0.1 to 50, preferably 0.5 to 2
0, more preferably 1 to 20. Further, the amount of aluminoxane used is expressed as a ratio of aluminum atoms to cobalt atoms of the cobalt compound (Al / Co):
Usually, it is 4 to 10 ⁷ , preferably 10 to 10 ⁶ . When the complex represented by the general formula (IV) is used, the amount of the phosphine compound used is such that the ratio of the phosphorus atom to the cobalt atom (P / Co) is 2, and the amount of the aluminoxane is as described above. Follow the description in

Examples of the inert organic solvent used as the polymerization solvent include aromatic hydrocarbon solvents such as benzene, toluene, xylene and cumene; aliphatic hydrocarbon solvents such as n-pentane, n-hexane and n-butane; Examples include alicyclic hydrocarbon solvents such as cyclopentane, methylcyclopentane, and cyclohexane, and mixtures thereof.

The polymerization temperature is usually -50 to 120 ° C.
Preferably it is -20 to 100 ° C. The polymerization reaction may be a batch type or a continuous type. The concentration of the monomer in the solvent is usually 5 to 50% by weight, preferably 10 to 35% by weight. In addition, in order to prevent the deactivation of the catalyst and the polymer of the present invention in producing the polymer, consideration must be given to minimizing the incorporation of a compound having a deactivating effect such as oxygen, water or carbon dioxide gas into the polymerization system. is necessary. When the polymerization reaction has progressed to the desired stage, the reaction mixture is added with an alcohol, other polymerization terminators, an antioxidant, an antioxidant, an ultraviolet absorber, and the like, and then the produced polymer is separated, washed, and dried according to a conventional method. 1,2- used in the present invention
Polybutadiene can be obtained.

The weight average molecular weight of (A) 1,2-polybutadiene used in the present invention is preferably 10,000 to 500.
10,000, more preferably 10,000 to 1.5 million, particularly preferably 50,000 to 1,000,000. If the weight average molecular weight is less than 10,000, the fluidity is extremely high, processing becomes extremely difficult, and the molded product is not sticky, and if it exceeds 5,000,000, the fluidity is extremely low, and the processing is extremely difficult. Is not preferred.

(B) Thermoplastic Polymer (B) The thermoplastic polymer includes a thermoplastic resin and / or a thermoplastic elastomer other than the component (A). (B) As the thermoplastic polymer, polyethylene, polypropylene, ethylene-based copolymer such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polyolefin such as polybutene-1, ionomer, polystyrene, polyester, polyamide And thermoplastic polyurethane.

The amount of the component (B) is 70 to 99 parts by weight, preferably 80 to 95 parts by weight, per 100 parts by weight of the total of the components (A) and (B). If it is less than 70 parts by weight,
On the other hand, if the molding productivity exceeds 99 parts by weight, the use ratio of the component (A) decreases, radiation crosslinking does not proceed, and the heat deformation resistance is poor.

(C) Polyfunctional Monomer The radiation-crosslinkable polymer composition of the present invention may contain (C) a polyfunctional monomer. (C) Examples of the polyfunctional monomer include trimethylolpropane triacrylate (TMPTA), tromethylolpropane trimethacrylate (TMPT), triallyl cyanurate (TAC), and triallyl isocyanurate (TAI).
Compounds such as C) that can function as a crosslinking aid for the above-mentioned components (A) and (B) can be mentioned. These (C) polyfunctional monomers may be used alone, or two or more may be appropriately selected and used.

The compounding amount of the polyfunctional monomer (C) is usually 0.3 to 3 parts by weight, preferably 1 to 2 parts by weight, based on 100 parts by weight of the total of the components (A) and (B). It is. If the amount is less than 0.3 parts by weight, the effect as a crosslinking aid may not be sufficiently exhibited, and the degree of crosslinking after the crosslinking treatment may not be sufficient. Is not preferred because not only does the effect of improving the degree of crosslinking reach saturation, but the bleeding of these polyfunctional monomers starts to occur after the crosslinking treatment.

(D) Thermally Decomposable Foaming Agent The radiation-crosslinkable polymer composition of the present invention may contain (D) a thermally decomposable foaming agent. (D) The thermally decomposable blowing agent is usually heated at 150 to 230 ° C. to generate fine bubbles by decomposition, and azodicarbonamide (decomposition temperature about 200 to 210 ° C.), dinitrosopentamethylene Tetramine (about 200-205 ° C), 4,
4'-oxybis (benzenesulfonyl hydrazide)
(About 150 to 160 ° C.) and decomposed at lower temperatures, such as p-toluenesulfonyl hydrazide (about 100 to 110 ° C.) and azobisbutyronitrile (about 1 to about 100 ° C.).
00 ° C.). One or two or more of these, considering the expansion ratio after foaming, determine the blending ratio,
Is added.

(D) The amount of the thermally decomposable foaming agent is usually 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the total of the components (A) and (B). Parts by weight. If the amount is less than 0.5 parts by weight,
When the expansion ratio is not sufficient, and on the other hand, when it exceeds 20 parts by weight,
The foam molding appearance is poor and not preferable.

The radiation-crosslinkable polymer composition of the present invention can also contain a coloring agent, so that a molded article can be colored in a desired color. As the coloring agent, titanium oxide or carbon black can be used. Further, in order to impart durability and weather resistance to the molded product, an antioxidant and an ultraviolet absorber can be added. If necessary, an inorganic filler such as calcium carbonate and a flame retardant such as magnesium hydroxide and aluminum hydroxide may be added. Here, examples of the magnesium hydroxide include natural magnesium hydroxide (manufactured by Kamishima Chemical Co., Ltd., N-1 etc.) and synthetic magnesium hydroxide (manufactured by Kyowa Chemical Co., Ltd., Kisuma 5A etc.).

The composition of the present invention is obtained by adding the above components (A) and (B) and, if necessary, the above components (C) and / or (D) and softening by heating. Knead and mold. The kneading and molding are carried out in a temperature range below the decomposition temperature of the above-mentioned thermally decomposable foaming agent and in the moldability favorable temperature range above the softening temperature or melting temperature of 1,2-polybutadiene,
Make a homogeneous molded body without bubbles. Therefore, the molding temperature is preferably about 90 to 170 ° C. In order to obtain a molded product, press molding, extrusion molding, injection molding, blow molding, deformed extrusion molding, T-die film molding, inflation molding, powder slush molding, rotational molding and the like are used.

The molded article obtained from the radiation-crosslinkable polymer composition of the present invention can be subsequently irradiated with radiation and crosslinked. Here, examples of the radiation include an electron beam, an ultraviolet ray, and a γ-ray, and preferably an electron beam. When irradiated with an electron beam, a three-dimensional crosslinked structure is formed by radical polymerization of vinyl groups of 1,2-polybutadiene, and the molded product is cured. The electron beam is permeable to the synthetic resin, and the degree of transmission depends on the thickness of the molded product and the kinetic energy of the electron beam. If the energy of the electron beam is adjusted so that it can be transmitted uniformly in the thickness direction according to the irradiation thickness, a molded article having a uniform degree of crosslinking in the thickness direction can be obtained.

The energy of the electron beam is 50 to 3,000 keV, preferably 300 to 3,000 keV with respect to the above-mentioned molded product.
2,000 keV, but if less than 50 keV,
Since the ratio of electrons captured and absorbed in the surface layer portion is relatively increased, the number of electron beams transmitted through the sheet is reduced, and internal crosslinking is delayed as compared with the surface layer portion, and a difference in the degree of crosslinking occurs. Absent. On the other hand, if it is larger than 3,000 keV, the degree of crosslinking becomes too large and becomes hard. Therefore, even when this is heated and foamed, it is difficult to soften at the foaming heating temperature, the generation of bubbles is small, and the tensile strength is low. Although it is large, it is not preferable as a foam because its elasticity and elongation are small.

The irradiation amount of the electron beam at this time is preferably 1 to 100 Mrad (10 to 1, 0 in SI unit system).
00 kGy), more preferably 1 to 50 M
Irradiation is performed in the range of rad to cure by crosslinking. If it is less than 1 Mrad, the degree of crosslinking of 1,2-polybutadiene is small, and the strength of the sheet is small. If this is foamed, even if the cell structure is uniform, the cell structure becomes coarse and the tensile strength of the sheet becomes small, which is not preferable. . If it exceeds 100Mrad,
Since the degree of cross-linking becomes too large and becomes hard, even if this is heated and foamed, at the foaming heating temperature, it is difficult to soften, the generation of bubbles is small, and the tensile strength is large, but the foam has elasticity. It is not preferable because the properties and elongation are small.

When heated above the decomposition temperature of the thermally decomposable foaming agent (D) after the electron beam irradiation, the moderately cross-linked molded product releases gas components due to the decomposition of the foaming agent inside to generate many bubbles, It becomes a dense and uniform foam. The heating method has good heat transfer to the molded product, such as a method of contacting and passing the surface of a molten salt bath of a salt bath or nitrate, and a method of placing the molded product on the upper surface of a heating plate and slidingly moving the molded product. It is sufficient because the temperature control is easy. As other methods, infrared irradiation of an infrared lamp, electric heating or high-frequency heating can be used.

The Vicat softening point of the thus obtained polymer composition of the present invention after radiation crosslinking is determined by the above (B)
It is preferably at least 5 ° C., more preferably 10 to 30 ° C. higher than the Vicat softening point of the thermoplastic polymer alone. As a result, the heat resistance of the molded product is improved, and the molded product can be used at high temperatures. In addition, the Vicat softening point of the polymer composition after radiation crosslinking of the present invention can be easily adjusted by adjusting the composition ratio, the kind of the components, and the like.

The molded article produced in this way is excellent in heat resistance, flexibility, bleed resistance and handling properties, and is useful not only as a covering material for electric wires but also in tensile strength and tear strength. It has excellent bonding strength and peeling strength with adhesives and adhesives, so it can be used as a base material for adhesive tapes, as a vibration-absorbing material, as a soundproofing and vibration-proofing material, and as a heat insulating material, footwear sole material,
It is suitable for use as a backing material for carpet flooring, a shrink film when formed into a film, and a water pipe when formed into a pipe.

[0043]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples. In the examples, parts and% are by weight unless otherwise specified. Various measurements in the examples were performed as follows.

Heat deformation resistance (Vicat softening point) Evaluated according to JIS K7206. After leaving the bleeding molded product at 23 ° C. and 50% RH for 24 hours, it was evaluated visually and by a finger using the following criteria. ：: No bleed-out was observed visually and by touch. ×: Bleed out is confirmed by visual and tactile evaluation. Flexibility Evaluated according to JIS K6253. Handleability ○: easy to handle during processing. ×: difficult to handle during processing. For example, TMPT
Since MA is a liquid at room temperature, the composition containing it is poor in handling properties.

In addition, (A)-
The content of the component (B) is as follows. LDPE: Nippon Polychem Corp., LDPE, Novatec LD ZF33 EVA: Tosoh Corp., EVA, Ultracene 510
F RB1: JSR Corporation, 1,2-polybutadiene, R
B810 RB2: JSR Corporation, 1,2-polybutadiene, trial product (vinyl bond content 90%, crystallinity 15%, weight average molecular weight 150,000) EOM: Dupont Dow Elastomer Co., Ltd., ethylene / octene Polymer, Engage 8150 TMPTMA: manufactured by Nippon Yupika Co., Ltd., TMPTMA

Examples 1 to 4 and Comparative Examples 1 to 4 According to the formulation shown in Table 1, each component was kneaded with a roll at 120.degree. C. and then press-molded at 170.degree.
A test piece of 0 × 1 mm was obtained. The irradiation method is 1,0
A test sample was obtained by irradiating an electron beam using a 00 keV electron beam irradiation apparatus. Table 1 shows the results.

[0047]

[Table 1]

[0048]

The radiation-crosslinkable polymer composition of the present invention is excellent in heat resistance and flexibility, and has excellent handling properties during processing without bleeding out of a liquid substance. It is also useful as a base material for adhesive tapes, as a soundproofing / vibration-proof material, as a heat insulating material, a sole material for footwear, a backing material for carpet flooring, and a shrink film or pipe by being formed into a film. It can be used as a water pipe by molding.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 9/06 C08J 9/06 H01B 3/30 H01B 3/30 BC 3/42 3/42 E 3 / 44 3/44 FGM // (C08L 101/00 C08L 47:00 47:00) (72) Inventor Koji Okada 2-11-24 Tsukiji, Chuo-ku, Tokyo JSR Co., Ltd. (72) Invention Person Katsuaki Morino 2-11-24 Tsukiji, Chuo-ku, Tokyo FSR in JSR Co., Ltd. (reference) 4F071 AA02 AA15 AA15X AA20 AA21 AA22 AA28X AA32X AA33X AA39 AA43 AA45 AA53 AA54 AE01 BA02A03 A01 A02 A03 A06 BC05 4F074 AA10 AA17 AA17A AA24 AA26 AA31 AA32 AA41A AA48A AA65 AA71 AA78 AC19 AC20 AC26 AC37 AG01 AG10 AG20 BA13 BA14 BA16 BA17 BA18 BB25 BB28 CA21 CC04Y CC06X CC45 CC49 CC53 CC54 DA32 DA40 D A45 DA57 DA58 4J002 AA011 BB021 BB041 BB061 BB111 BB171 BB231 BC021 BF031 BG041 BL012 CF001 CK021 CL001 FD018 FD139 FD146 FD156 FD327 GC00 GF00 GG02 GJ00 GL00 GQ01 4J026 AABB01BA02 GA02 DBA CA08 CA11 CA12 CA18 CA20 CB30 CD01 CD09 CD13 DA12

Claims (11)

[Claims] (A) 1,2-polybutadiene 1 to 30
Parts by weight, and (B) 99 to 70 parts by weight of a thermoplastic polymer other than the component (A) [where (A) + (B) = 1
00 parts by weight]. 2. The radiation-crosslinkable polymer composition according to claim 1, wherein (A) 1,2-polybutadiene has a vinyl bond content of 70% or more and a crystallinity of 5% or more. 3. The radiation-crosslinkable polymer composition according to claim 1, wherein (B) the thermoplastic polymer is at least one selected from the group consisting of polyolefin, polystyrene, polyester, polyamide and thermoplastic polyurethane. 4. An ethylene (co) polymer in which the polyolefin is polyethylene, ethylene-vinyl acetate copolymer or ethylene-ethyl acrylate copolymer,
4. The radiation-crosslinkable polymer composition according to claim 3, which is polypropylene. 5. The method of claim 1, wherein (C) the polyfunctional monomer is
0.1 parts by weight based on 100 parts by weight of the total amount of the components (A) and (B).
The radiation-crosslinkable polymer composition according to any one of claims 1 to 4, wherein 5 to 3 parts by weight is blended. 6. The composition according to claim 1, further comprising (D) a thermally decomposable blowing agent.
0.1 parts by weight based on 100 parts by weight of the total amount of the components (A) and (B).
The radiation-crosslinkable polymer composition according to any one of claims 1 to 5, which is blended in an amount of 5 to 20 parts by weight. 7. The radiation-crosslinkable polymer composition according to any one of claims 1 to 6, wherein the Vicat softening point of the polymer composition after radiation crosslinking is 5 ° C. or more higher than the Vicat softening point of the thermoplastic polymer alone. object. 8. A radiation crosslinking method, comprising irradiating the radiation-crosslinkable polymer composition according to claim 1 with an electron beam of 50 to 3,000 keV. 9. A coating material for electric wires obtained by molding the radiation-crosslinkable polymer composition according to claim 1 and crosslinking the radiation-crosslinkable polymer composition. 10. A shrink film obtained by molding and radiation-crosslinking the radiation-crosslinkable polymer composition according to claim 1. 11. A water supply pipe formed by molding and radiation-crosslinking the radiation-crosslinkable polymer composition according to claim 1.