JP3445314B2 - Olefin-based thermoplastic elastomer composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an olefin-based thermoplastic elastomer, and more particularly to an olefin-based thermoplastic elastomer capable of providing a molded article having excellent scratch resistance.

[0002]

BACKGROUND OF THE INVENTION Olefin-based thermoplastic elastomers are lightweight and easy to recycle, so they are used as energy-saving and resource-saving type elastomers, especially as substitutes for vulcanized rubber for automobile parts, industrial machinery parts, electric
Widely used in electronic parts and building materials.

In recent years, from the viewpoint of protecting the global environment, in place of vinyl chloride resin, which emits harmful gas when incinerated,
Olefin-based thermoplastic elastomers that do not generate harmful gas have been used.

However, the conventional molded article made of an olefinic thermoplastic elastomer has a drawback that it is inferior in scratch resistance as compared with a molded article made of a vinyl chloride resin, and its improvement is strongly desired.

Therefore, the inventors of the present invention have conducted diligent research to obtain an olefin-based thermoplastic elastomer having excellent scratch resistance, and partially or completely crosslinked the crystalline polyolefin resin and the olefin-based rubber. By blending the thermoplastic elastomer and a specific block copolymer in a specific ratio, it was found that an olefinic thermoplastic elastomer capable of providing a molded article having excellent scratch resistance can be obtained, and the present invention It came to completion.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, is lightweight, is easy to recycle, and does not generate harmful gas even when incinerated. It is an object of the present invention to provide an olefin-based thermoplastic elastomer capable of imparting a molded article having excellent stickiness.

[0007]

SUMMARY OF THE INVENTION An olefin-based thermoplastic elastomer composition according to the present invention contains [I] a crystalline polyolefin resin and an olefin-based rubber, and a partially or completely crosslinked thermoplastic elastomer (A) 10 to 80 parts by weight, and a polymer block (a) of [II] styrene or a derivative thereof, and an isoprene polymer block or an isoprene-butadiene copolymer block, wherein 1,2 bonds and 3,4 in the isoprene polymer portion are included. Polymer or copolymer block (b) having a bond content of 40% or more
20 to 90 parts by weight of the block copolymer (B) which may be hydrogenated [the total amount of the components (A) and (B) is 100 parts by weight].

[0008]

DETAILED DESCRIPTION OF THE INVENTION The olefinic thermoplastic elastomer according to the present invention will be specifically described below.

The olefinic thermoplastic elastomer according to the present invention comprises a specific thermoplastic elastomer (A) and a specific block copolymer (B) in a specific ratio. In the olefinic thermoplastic elastomer according to the present invention, in addition to the thermoplastic elastomer (A) and the block copolymer (B), a crystalline polyolefin resin, an olefinic rubber, and a softening agent are each added, if necessary. It may be present in a specific proportion.

Thermoplastic Elastomer (A) The thermoplastic elastomer (A) used in the present invention comprises a crystalline polyolefin resin and an olefin rubber.

As the above crystalline polyolefin resin,
Examples thereof include homopolymers or copolymers of α-olefins having 2 to 20 carbon atoms. Specific examples of the crystalline polyolefin resin include the following polymers or copolymers. (1) Ethylene homopolymer (manufacturing method may be either low pressure method or high pressure method) (2) Copolymerization of ethylene with 10 mol% or less of other α-olefin or vinyl monomer such as vinyl acetate or ethyl acrylate Polymer (3) Propylene homopolymer (4) Random copolymer of propylene and 10 mol% or less of other α-olefin (5) Block copolymerization of propylene and 30 mol% or less of other α-olefin Copolymer (6) 1-butene homopolymer (7) Random copolymer of 1-butene and 10 mol% or less of other α-olefin (8) 4-Methyl-1-pentene homopolymer (9) 4 -Methyl-1-pentene and other α up to 20 mol%
-Random copolymer with olefin As the above α-olefin, specifically, ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-
Examples include hexene and 1-octene.

Among the above crystalline polyolefin resins, propylene homopolymer and propylene / α-olefin copolymer containing propylene as a main component are particularly preferable.
The above crystalline polyolefin resins can be used alone or in combination.

The crystalline polyolefin resin has a melt flow rate (MFR; ASTM D 1238, 230 ° C.,
2.16 kg load, the same hereinafter) is preferably 0.01 to
100 g / 10 minutes, more preferably 0.3 to 70 g /
It is in the range of 10 minutes.

The crystallinity of the crystalline polyolefin resin is usually 5 to 100%, preferably 20 to 80% as determined by the X-ray method. In the present invention, the crystalline polyolefin resin is 10 to 90 parts by weight, preferably 10 to 80 parts by weight, and more preferably 20 to 10 parts by weight based on 100 parts by weight of the total amount of the above crystalline polyolefin resin and olefin rubber. It is used in a proportion of 70 parts by weight.

When the crystalline polyolefin resin is used in the above proportion, a thermoplastic elastomer having excellent moldability which can provide a molded article having excellent scratch resistance and heat resistance can be obtained.

The above-mentioned olefin rubber is an amorphous random elastic copolymer whose main component is an α-olefin having 2 to 20 carbon atoms, and an α-olefin copolymer composed of two or more kinds of α-olefins. There are polymers, α-olefin / non-conjugated diene copolymers composed of two or more kinds of α-olefins and non-conjugated dienes, and specific examples thereof include the following rubbers. (1) Ethylene / α-olefin copolymer rubber [ethylene / α-olefin (molar ratio) = about 90/10
50/50] (2) Ethylene / α-olefin / non-conjugated diene copolymer rubber [ethylene / α-olefin (molar ratio) = about 90/10
-50/50] (3) Propylene / α-olefin copolymer rubber [propylene / α-olefin (molar ratio) = about 90/1
0-50 / 50] (4) Butene / α-olefin copolymer rubber [butene / α-olefin (molar ratio) = about 90/10
50/50] Specific examples of the α-olefin include the same α-olefins as the specific examples of the α-olefin constituting the crystalline polyolefin resin described above.

Specific examples of the non-conjugated diene include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene and ethylidene norbornene.

The iodine value of the ethylene / α-olefin / non-conjugated diene copolymer rubber of the above (2) in which such non-conjugated diene is copolymerized is preferably 25 or less. Mooney viscosity ML _{1 + 4 of the} above-mentioned copolymer rubbers (1) to (4)
(100 ° C.) is preferably 10 to 250, particularly preferably 30 to 150.

The above-mentioned olefin rubber is in a partially crosslinked state in the thermoplastic elastomer (A),
Or, it exists in a completely crosslinked state. In the present invention, it is preferable that the olefin rubber is in a partially crosslinked state.

Further, in the present invention, an olefin-based rubber and a rubber other than the olefin-based rubber may be used in combination as long as the object of the present invention is not impaired. Examples of rubbers other than such olefin rubbers include styrene-butadiene rubber (SBR), nitrile rubber (NBR), natural rubber (NR) and butyl rubber (IIR).
And the like, such as diene rubber and polyisobutylene rubber.

In the present invention, the olefin rubber is
10 to 90 parts by weight based on 100 parts by weight of the total amount of the crystalline polyolefin resin and the olefin rubber,
Preferably 20 to 90 parts by weight, more preferably 30 to 90 parts by weight.
Used in a proportion of 80 parts by weight.

When the olefin rubber and the rubber other than the olefin rubber are used in combination, the rubber other than the olefin rubber is 100 parts by weight of the total amount of the crystalline polyolefin resin and the olefin rubber. Four
It is used in an amount of 0 parts by weight or less, preferably 5 to 20 parts by weight.

When the olefinic rubber, or the olefinic rubber and the rubber other than the olefinic rubber are used in the above proportions, a thermoplastic elastomer capable of providing a molded article having excellent scratch resistance and flexibility is obtained. To be

In the thermoplastic elastomer (A) used in the present invention, if necessary, a mineral oil softener, a heat resistance stabilizer, an antistatic agent, a weather resistance stabilizer, an antiaging agent, a filler, a colorant, Additives such as lubricants can be added within a range that does not impair the object of the present invention.

The thermoplastic elastomer (A) preferably used in the present invention is a crystalline polypropylene resin and an ethylene / α-olefin copolymer rubber or ethylene / α.
-Consisting of olefin / non-conjugated diene copolymer rubber,
In the thermoplastic elastomer (A), these components are present in a partially crosslinked state, and the weight blending ratio of the crystalline polypropylene resin and the olefin rubber (crystalline polypropylene resin / olefin rubber) is 70 / Thirty
Within the range of 10/90.

More specific examples of the thermoplastic elastomer (A) preferably used in the present invention include 60 to 10 parts by weight of a crystalline polypropylene resin and an ethylene / propylene copolymer rubber or ethylene / propylene as an olefin rubber. 40 to 90 parts by weight of diene copolymer rubber [total amount of crystalline polypropylene resin and olefin rubber is 100 parts by weight], and 5 to 100 parts by weight of rubber other than olefin rubber and / or mineral oil The thermoplastic elastomer is composed of 5 to 100 parts by weight of a softening agent, and the olefin rubber is partially crosslinked.

The thermoplastic elastomer (A) used in the present invention can be obtained by dynamically heat treating a blend containing a crystalline polyolefin resin and an olefin rubber in the presence of an organic peroxide. it can.

Specific examples of the organic peroxide include:
Dicumyl peroxide, di-tert-butyl peroxide,
2,5-Dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-Dimethyl-2,5-di- (tert-butylperoxy) hexyne-3,1,3-bis (tert- Butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-
4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, tert-butylperbenzoate, tert-butylperoxyisopropyl carbonate, diacetyl Examples thereof include peroxides, lauroyl peroxide, and tert-butyl cumyl peroxide.

Among these, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane and 2,5-dimethyl-2,5-di-from the viewpoint of odor and scorch stability. (Tert-Butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4 1,4-bis (tert-butylperoxy) valerate is preferred, and among them, 1,3-bis (tert-butylperoxyisopropyl) benzene is most preferred.

In the present invention, the organic peroxide is 0.05 to 3% by weight, preferably 0.1 to 1% by weight, based on 100% by weight of the total amount of the crystalline polyolefin resin and the olefinic rubber. Used in proportion.

In the present invention, in the partial cross-linking treatment with the above organic peroxide, sulfur, p-quinone dioxime, p,
Peroxy crosslinking aids such as p'-dibenzoylquinone dioxime, N-methyl-N-4-dinitrosoaniline, nitrosobenzene, diphenylguanidine, trimethylolpropane-N, N'-m-phenylenedimaleimide, Or polyfunctional methacrylate monomers such as divinylbenzene, triallyl cyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate, vinyl butyrate, vinyl stearate. Polyfunctional vinyl monomers can be included.

By using the above compound,
A uniform and mild crosslinking reaction can be expected. Particularly, divinylbenzene is most preferred in the present invention. Divinylbenzene is easy to handle, has good compatibility with the crystalline polyolefin resin and the olefinic rubber system which are the main components of the above-mentioned substance to be crosslinked, and has the action of solubilizing the organic peroxide. Since it functions as a dispersant for organic peroxides, a thermoplastic elastomer having a uniform cross-linking effect by heat treatment and a good balance of fluidity and physical properties can be obtained.

In the present invention, the above-mentioned crosslinking aid or polyfunctional vinyl monomer is contained in an amount of 0.1 to 2% by weight, particularly 0.3 to 1% by weight, based on the total amount of the above-mentioned object to be crosslinked. It is preferable to use it in a ratio of. When the mixing ratio of the crosslinking aid or the polyfunctional vinyl monomer is within the above range,
In the obtained thermoplastic elastomer, since the crosslinking aid and the polyfunctional vinyl monomer do not remain as unreacted monomers in the elastomer, there is no change in physical properties due to heat history during processing and molding, and It has excellent fluidity.

The above-mentioned "dynamically heat-treating" means kneading each of the above components in a molten state. Dynamic heat treatment includes mixing rolls, intensive mixers,
For example, a kneading device such as a Banbury mixer, a kneader, or a single-screw or twin-screw extruder is used, but it is preferably carried out in a non-open kneading device. The dynamic heat treatment is preferably performed in an inert gas such as nitrogen.

The kneading is preferably carried out at a temperature at which the half-life of the organic peroxide used is less than 1 minute.
The kneading temperature is usually 150 to 280 ° C., preferably 17
The temperature is 0 to 240 ° C., and the kneading time is 1 to 20 minutes, preferably 1 to 5 minutes. The shearing force applied during kneading is usually 10 to 10 ⁴ sec ^-1 , preferably 1
It is determined within the range of 0 ² to 10 ⁴ sec ⁻¹ .

As described above, the thermoplastic elastomer (A) in which the olefinic rubber is partially or completely crosslinked can be obtained. Here, "partially crosslinked" means that the gel content (cyclohexane insoluble content) measured by the following method is, for example, 10% or more, and particularly 20% or more and less than 98%. In the present invention, the gel content is preferably 30% or more. In addition, "completely crosslinked" means that the gel content (cyclohexane insoluble content) measured by the following method is 98% or more and 100%. When the thermoplastic elastomer (A) in the above range is used, the obtained olefinic thermoplastic elastomer has good fluidity at the time of molding and can provide a molded article excellent in mechanical strength and heat resistance.

[Measurement method of gel content (cyclohexane insoluble content)] A sample of a thermoplastic elastomer was weighed in an amount of about 100 mg, cut into 0.5 mm × 0.5 mm × 0.5 mm strips, and then obtained. 30m in a closed container
Immerse in 1 liter of cyclohexane at 23 ° C. for 48 hours.

Next, this sample is taken out on a filter paper and dried at room temperature for 72 hours or more until a constant weight is obtained. The value obtained by subtracting the weight of the cyclohexane-insoluble component (fibrous filler, filler, pigment, etc.) other than the polymer component from the weight of the dry residue is defined as "corrected final weight (Y)".

On the other hand, a value obtained by subtracting the weight of the cyclohexane-soluble component other than the polymer component (for example, a softening agent) and the weight of the cyclohexane-insoluble component other than the polymer component (fibrous filler, filler, pigment, etc.) from the weight of the sample,
The corrected initial weight (X) is used.

Here, the gel content (cyclohexane insoluble content) is calculated by the following equation. Gel content [% by weight] = [corrected final weight (Y)] ÷
[Corrected initial weight (X)] × 100 In the present invention, the thermoplastic elastomer (A) is 10 per 100 parts by weight of the total amount of the thermoplastic elastomer (A) and the block copolymer (B). To 80 parts by weight, preferably 20 to 70 parts by weight, more preferably 3
It is used in a proportion of 0 to 70 parts by weight.

When the thermoplastic elastomer (A) is used in the above proportion, a thermoplastic elastomer capable of providing a molded article having excellent heat resistance and scratch resistance can be obtained.

Block Copolymer (B) The block copolymer (B) used in the present invention comprises a polymer block (a) of styrene or a derivative thereof and a specific isoprene polymer or a specific isoprene-butadiene copolymer. It is composed of a block (b) composed of a united body and may be hydrogenated.

The polymer component constituting the block (a) is styrene or its derivative. As the styrene derivative, specifically, α-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene,
4-dodecylstyrene, 2-ethyl-4-benzylstyrene,
4- (phenylbutyl) styrene and the like can be mentioned. As the polymer component constituting the block (a), styrene,
α-Methylstyrene is preferred.

The polymer or copolymer constituting the block (b) is an isoprene polymer or an isoprene-butadiene copolymer, and the 1,2 bond and the 3,4 bond in the isoprene polymer portion shown below are used. Content is 4
It is 0% or more, preferably 45% or more.

[0045]

[Chemical 1]

In the present invention, when the content of 1,2 bonds and 3,4 bonds in the isoprene polymer portion is 40% or more, it is possible to obtain a thermoplastic elastomer capable of providing a molded product excellent in scratch resistance. You can

The proportion of the polymer block (a) of styrene or its derivative in the block copolymer (B) is preferably 5 to 50% by weight, more preferably 10 to 45.
It is in the range of% by weight. That is, the proportion of the above isoprene polymer block or isoprene-butadiene copolymer block (b) is preferably in the range of 95 to 50% by weight, more preferably 90 to 55% by weight.

In the present invention, the hydrogenated block copolymer (B) is preferred. When the hydrogenated block copolymer (B) is used, a thermoplastic elastomer capable of providing a molded article having more excellent weather resistance and heat resistance can be obtained.

The melt flow rate (MFR; ASTM D 1) of the block copolymer (B) used in the present invention.
238, 230 ℃, 2.16kg load, the same below)
It is preferably in the range of 0.01 to 30 g / 10 minutes, more preferably 0.01 to 10 g / 10 minutes. When the block copolymer (B) having a melt flow rate in the above range is used, a thermoplastic elastomer capable of providing a molded article having excellent scratch resistance can be obtained.

The block form of the block copolymer (B) used in the present invention is most preferably block (a) -block (b) -block (a).
It is not limited to this.

Such a block copolymer (B) can be produced, for example, by the following method. (1) A method of sequentially polymerizing styrene or a derivative thereof, isoprene, or an isoprene-butadiene mixture using an alkyllithium compound as an initiator. (2) A method in which styrene or a derivative thereof, and then isoprene or a mixture of isoprene and butadiene are polymerized, and this is coupled with a coupling agent. (3) A method of sequentially polymerizing isoprene or an isoprene-butadiene mixture, and then styrene or a derivative thereof using a dilithium compound as an initiator.

Details of the method for producing the block copolymer (B) are described in, for example, JP-A-2-300250 and JP-A-3-45646. Further, when the block copolymer (B) obtained by the above method is subjected to hydrogenation treatment, a hydrogenated block copolymer (B) can be obtained. The block to be hydrogenated is an isoprene polymer block or an isoprene-butadiene copolymer block (b).

In the present invention, the block copolymer (B) is based on 100 parts by weight of the total amount of the thermoplastic elastomer (A) and the block copolymer (B).
It is used in a proportion of 20 to 90 parts by weight, preferably 30 to 80 parts by weight, more preferably 30 to 70 parts by weight.

When the block copolymer (B) is used in the above proportion, a thermoplastic elastomer capable of providing a molded article having excellent heat resistance and scratch resistance can be obtained. In addition to the thermoplastic elastomer (A) and the block copolymer (B), a crystalline polyolefin resin can be added to the olefin-based thermoplastic elastomer according to the present invention, if necessary. This crystalline polyolefin resin is the same as the crystalline polyolefin resin that constitutes the thermoplastic elastomer (A) described above.

In the present invention, the crystalline polyolefin resin is preferably 5 to 100 parts by weight, and more preferably 5 to 100 parts by weight, based on 100 parts by weight of the total amount of the thermoplastic elastomer (A) and the block copolymer (B). It is preferably used in a proportion of 5 to 70 parts by weight.

When the crystalline polyolefin resin is used in the above proportion, it is possible to provide a molded product which is excellent in secondary processability as well as in flexibility and scratch resistance, and is a thermoplastic elastomer excellent in primary moldability. Is obtained.

Further, the olefinic thermoplastic elastomer according to the present invention includes the above-mentioned thermoplastic elastomer (A).
In addition to the block copolymer (B) and, if necessary, an olefin rubber can be blended. This olefin rubber is the same as the olefin rubber constituting the thermoplastic elastomer (A) described above.

Further, instead of the above-mentioned olefin rubber, rubber other than olefin rubber, for example, styrene.
Butadiene rubber (SBR), nitrile rubber (NBR),
A diene rubber such as natural rubber (NR) or butyl rubber (IIR), polyisobutylene, or the like can also be used. A rubber other than such an olefin rubber can be used in combination with the above olefin rubber.

In the present invention, the olefin rubber is
The total amount of the thermoplastic elastomer (A) and the block copolymer (B) is 100 parts by weight, preferably 5
It is used in an amount of about 100 to 100 parts by weight, more preferably 5 to 70 parts by weight.

The rubber other than the olefin rubber is preferably 5 to 100 parts by weight of the total amount of the thermoplastic elastomer (A) and the block copolymer (B).
It is used in an amount of 100 parts by weight, more preferably 5 to 70 parts by weight.

When a rubber other than the olefin-based rubber is used in combination with the olefin-based rubber, the rubber other than the olefin-based rubber is 100 wt% of the total amount of the thermoplastic elastomer (A) and the block copolymer (B). To the department
Preferably 5 to 70 parts by weight, more preferably 5 to 5 parts
Used in a proportion of 0 parts by weight.

When the olefin-based rubber and / or the rubber other than the olefin-based rubber are used in the above proportions, a thermoplastic elastomer capable of providing a molded article excellent in flexibility and scratch resistance can be obtained. In addition to the thermoplastic elastomer (A) and the block copolymer (B), a softener may be added to the olefin-based thermoplastic elastomer according to the present invention, if necessary. As such a softening agent, a softening agent usually used for rubber is suitable, and specifically, a petroleum-based substance such as process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, petrolatum; coal tar, Coal tars such as coal tar pitch; fatty oils such as castor oil, linseed oil, rapeseed oil, soybean oil and coconut oil; tall oil, beeswax, carnauba wax, lanolin and other waxes, ricinoleic acid, palmitic acid, stearic acid Fatty acids such as and the like or metal salts thereof; synthetic polymers such as petroleum resin, coumarone indene resin, atactic polypropylene; ester-based plasticizers such as dioctyl phthalate, dioctyl adipate, dioctyl sebacate; other microcrystalline wax, liquid polybutadiene or the like Modified products, hydrogenated products, liquid thiochol, etc. And the like.

In the present invention, the softening agent is used in an amount of 3 to 100 parts by weight, preferably 5 to 70 parts by weight, based on 100 parts by weight of the total amount of the thermoplastic elastomer (A) and the block copolymer (B). Used in proportion.

When the softening agent is used in the above proportion, a thermoplastic elastomer having excellent fluidity during molding can be obtained. The molded article made of this thermoplastic elastomer has good scratch resistance.

In the present invention, in the olefinic thermoplastic elastomer, to the extent that the object of the present invention is not impaired,
Inorganic fillers as required, phenolic, sulfite-based, phenylalkane-based, phosphite-based,
Known heat stabilizers such as amine stabilizers, antioxidants,
Additives such as weather resistance stabilizers, antistatic agents, metal soaps, and lubricants such as waxes can be added.

Specific examples of such an inorganic filler include calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica powder, asbestos, barium sulfate, aluminum sulfate, calcium sulfate and carbonic acid. Magnesium, molybdenum disulfide, glass fiber, glass sphere, shirasu balloon, graphite, alumina and the like can be mentioned.

The thermoplastic elastomer (A), the block copolymer (B), the crystalline polyolefin resin optionally used, the olefin rubber, and the softening agent may be mixed by a thermoplastic method. The method of performing the dynamic heat treatment described above in the production of the elastomer (A) is desirable.
However, this dynamic heat treatment is performed in the absence of organic peroxide.

[0068]

The olefinic thermoplastic elastomer according to the present invention contains [I] a crystalline polyolefin resin and an olefinic rubber, and is a partially or completely crosslinked thermoplastic elastomer (A), and [II] ] A polymer block (a) of styrene or a derivative thereof and an isoprene polymer block or an isoprene-butadiene copolymer block, wherein 1, in the isoprene polymer part
20 to 90 parts by weight of an optionally hydrogenated block copolymer (B) consisting of a polymer or copolymer block (b) having a content of 2 bonds and 3,4 bonds of 40% or more [component ( The total amount of A) and (B) is 100 parts by weight.] Further, if necessary, a crystalline polyolefin resin, an olefinic rubber and a softening agent are contained in a specific ratio, so that they are lightweight and easy to recycle. Thus, it is possible to provide a molded article which does not generate harmful gas even when incinerated and has excellent scratch resistance.

The present invention will be described below with reference to examples.
The invention is not limited to these examples.

[0070]

Example 1 Polypropylene [melt flow rate (ASTM D 1238-
65T, 230 ° C., 2.16 kg): 13 g / 10 minutes,
Density: 0.91 g / cm ³ , 20% by weight of crystallinity determined by X-ray method: 72%, and ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber [ethylene content as olefin rubber] : 70 mol%, iodine value:
12, Mooney viscosity ML _{1 + 4} (100 ℃): 120] 8
After kneading 0 parts by weight with a Banbury mixer in a nitrogen atmosphere at 180 ° C. for 5 minutes, the obtained kneaded product was passed through a roll to form a sheet, which was cut with a sheet cutter to produce a square pellet.

Then, 100 parts by weight of the square pellets,
After 0.3 parts by weight of 1,3-bis (tert-butylperoxyisopropyl) benzene and 0.5 parts by weight of divinylbenzene were mixed with stirring with a Henschel mixer, the resulting mixture was mixed with L / D = 30, screw. Using a uniaxial extruder having a diameter of 50 mm, it was extruded at 220 ° C. in a nitrogen atmosphere to produce pellets of a thermoplastic elastomer [hereinafter, abbreviated as TPE- (1)]. The gel content of the obtained TPE- (1) was 84%.

Then, the pellet 7 of this TPE- (1)
0 parts by weight and styrene / isoprene / styrene block copolymer as the block copolymer (B) [styrene content: 20% by weight, 1,2 in the isoprene polymer part
Bond and 3,4 bond content: 55%, melt flow rate (ASTM D 1238, 230 ° C, 2.16k)
g): 2.5 g / 10 minutes, 30 parts by weight of pellets of the following (B-1) will be agitated and mixed sufficiently, and then the resulting mixture will be mixed with L / D = 30, screw diameter 50 mm uniaxial Using an extruder, the pellets of the thermoplastic elastomer were manufactured by extruding at 220 ° C.

Further, a square plate (120 mm × 150 mm) was formed from the pellets of the thermoplastic elastomer by using an injection molding machine.
mm × 3 mm) was molded at 220 ° C. Place a 20mm square felt cloth on the obtained square plate, and further 2 on it.
Place a weight on it so that a pressure of 00g / cm ² is applied.
The square plate was reciprocated 0 times, the glossiness (JIS K 7105) before and after the reciprocating operation was measured, and the scratch resistance was evaluated based on the change in glossiness.

The results are shown in Table 1.

[0075]

Example 2 In Example 1, the amount of TPE- (1) was 20 parts by weight, and instead of (B-1), a styrene polymer block, an isoprene-butadiene copolymer block and a styrene polymer block were used. Hydrogenated product of polymer [block copolymer (B), styrene content: 20% by weight,
Butadiene content in the isoprene-butadiene copolymer block: 12% by weight, 1,2 bond and 3,4 bond content in the isoprene polymer part: 60%, melt flow rate (ASTM D 1238, 230 ° C,
2.16 kg): 2.1 g / 10 minutes, hereinafter abbreviated as (B-2)] A thermoplastic elastomer was prepared in the same manner as in Example 1 except that 80 parts by weight was used to obtain a square plate. . The obtained square plate was evaluated for scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0077]

Example 3 In Example 1, the blending amount of TPE- (1) was 50 parts by weight, and (B-2) was used instead of (B-1).
50 parts by weight of propylene / ethylene random copolymer [ethylene content: 3 mol%, melt flow rate (ASTM D
1238, 230 ° C, 2.16 kg): 15 g / 10
Min, crystallinity determined by X-ray method: 67%, below (C-
Abbreviated to 1)] A thermoplastic elastomer was prepared in the same manner as in Example 1 except that 50 parts by weight was used to obtain a square plate. The obtained square plate was evaluated for scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0079]

Example 4 In Example 1, the blending amount of TPE- (1) was 50 parts by weight, and (B-2) was used instead of (B-1).
50 parts by weight of polybutene-1 [melt flow rate (ASTM
D 1238, 230 ° C., 2.16 kg): 11 g / 1
0 minutes, crystallinity determined by X-ray method: 53%, below (C
-2)] A thermoplastic elastomer was prepared in the same manner as in Example 1 except that 50 parts by weight was used to obtain a square plate. The obtained square plate was evaluated for scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0081]

Example 5 In Example 1, the blending amount of TPE- (1) was 50 parts by weight, and (B-2) was used instead of (B-1).
And 50 parts by weight of ethylene / propylene copolymer [ethylene content: 78 mol%, Mooney viscosity ML _{1 + 4} (100 ° C.): 14, hereinafter (D-1)) 50 parts by weight as an olefin rubber. A thermoplastic elastomer was prepared in the same manner as in Example 1 except that the square plate was obtained. The obtained square plate was evaluated for scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0083]

Example 6 In Example 1, the blending amount of TPE- (1) is 50 parts by weight, and (B-2) is used instead of (B-1).
50 parts by weight of (C-1) and 30 parts by weight of (C-1) and an ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber as an olefinic rubber [ethylene content: 82 mol%, iodine value: 8, Mooney Viscosity ML _{1 + 4}
(100 ° C.): 72, hereinafter abbreviated as (D-2)] A thermoplastic elastomer was prepared in the same manner as in Example 1 except that 20 parts by weight was used to obtain a square plate. The obtained square plate was evaluated for scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0085]

Example 7 In Example 1, the blending amount of TPE- (1) was 50 parts by weight, and (B-2) was used instead of (B-1).
50 parts by weight, (C-1) 30 parts by weight, and (D
-1) 20 parts by weight and a mineral oil-based process oil as a softening agent [made by Idemitsu Kosan Co., Ltd., PW-380, hereinafter (E-1)
A thermoplastic elastomer was prepared in the same manner as in Example 1 except that 20 parts by weight was used to obtain a square plate.
The obtained square plate was evaluated for scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0087]

[Comparative Example 1] In Example 1, the amount of TPE- (1) was 20 parts by weight, and styrene was used instead of (B-1).
Hydrogenated butadiene / styrene block copolymer [styrene content: 20% by weight, melt flow rate (ASTM D 1238, 230 ° C, 2.16 kg):
2.8 g / 10 minutes] A thermoplastic elastomer was prepared in the same manner as in Example 1 except that 80 parts by weight was used to obtain a square plate. The obtained square plate was evaluated for scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0089]

Comparative Example 2 Example 2 was repeated except that TPE- (1) and (B-1) were mixed in amounts of 20 parts by weight and 0 parts by weight, respectively, and 80 parts by weight of (D-1) was used. A thermoplastic elastomer was prepared in the same manner as in Example 1 to obtain a square plate. The obtained square plate was evaluated for scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0091]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Uchiyama 3 Chikusaigan, Ichihara-shi, Chiba Mitsui Petrochemical Industrial Co., Ltd. (56) Reference JP-A-7-48484 (JP, A) Areas (Int.Cl. ⁷ , DB name) C08L 53/00 C08L 23/02

Claims (4)

(57) [Claims] 1. A partially or completely crosslinked thermoplastic elastomer (A) containing 10 to 80 parts by weight of [I] a crystalline polyolefin resin and an olefin rubber, and [II] styrene or a derivative thereof. The polymer block (a) and an isoprene polymer block or an isoprene-butadiene copolymer block, wherein the content of 1,2 bonds and 3,4 bonds in the isoprene polymer portion is 40% or more. Polymer block (b)
An olefinic system characterized by comprising 20 to 90 parts by weight of an optionally hydrogenated block copolymer (B) consisting of [the total amount of components (A) and (B) is 100 parts by weight]. Thermoplastic elastomer composition . 2. A total amount of 100 parts by weight of the thermoplastic elastomer (A) and the block copolymer (B),
The olefinic thermoplastic elastomer composition according to claim 1, wherein the crystalline polyolefin resin is blended in an amount of 5 to 100 parts by weight. 3. A total amount of 100 parts by weight of the thermoplastic elastomer (A) and the block copolymer (B),
The olefin-based thermoplastic elastomer composition according to claim 1 or 2, wherein the olefin-based rubber is compounded in an amount of 5 to 100 parts by weight. 4. A total amount of 100 parts by weight of the thermoplastic elastomer (A) and the block copolymer (B),
The olefin-based thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the softening agent is blended in an amount of 3 to 100 parts by weight.