JPH0770380A - Thermoplastic olefin elastomer - Google Patents

Abstract

PURPOSE:To obtain a molding which is lightweight, easily recyclable and excellent in scratch resistance by mixing a crystalline polyolefin resin with a specified block copolymer and an olefin rubber and partially crosslinking the mixture. CONSTITUTION:20-80 pts.wt. crystalline polyolefin resin (A) having a melt flow rate of 0.01-100g/10min and a degree of crystallinity of 20-80% is mixed with 15-75 pts.wt. block copolymer (B) which is composed of a block (a) of a polymer of styrene or its derivative and a block (b) of an isoprene polymer or of an isoprene/butadiene copolymer having a content of 1, 2 bonds and 3, 4 bonds in the isoprene polymer part of at least 40%, contains 95-50wt.% component (b) and may be hydrogenated, and 5-65 pts.wt. olefin rubber (C) having a Mooney viscosity of 30-150 in such amounts to give a total of components A, B and C of 100 pts.wt.. The obtained composition is melt-kneaded in the presence of an added organic peroxide and partially crosslinked to obtain a product used for molding.

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 excellent in scratch resistance, and have a crystalline polyolefin resin, a specific block copolymer and an olefin-based rubber in a specific ratio. It was found that, when compounded, an olefinic thermoplastic elastomer capable of providing a molded article having excellent scratch resistance can be obtained, and the present invention has been completed.

[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 The first olefinic thermoplastic elastomer according to the present invention comprises 20 to 80 parts by weight of [I] crystalline polyolefin resin (A), [II] styrene or its derivative polymer block (a). A polymer or copolymer block (b) which is 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. 15 to 75 parts by weight of an optionally hydrogenated block copolymer (B), and [III] an olefin rubber (C) 5 to 65 parts by weight [components (A), (B) and (C)] Is 100 parts by weight] and is partially crosslinked.

The second olefinic thermoplastic elastomer of the present invention comprises 100 parts by weight of the first olefinic thermoplastic elastomer of the present invention and 5 to 50 parts by weight of a crystalline polyolefin resin. Is characterized by.

[0009]

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 crystalline polyolefin resin (A) [I],
[II] An optionally hydrogenated block copolymer comprising a polymer block (a) of styrene or a derivative thereof and a specific isoprene polymer block or a specific isoprene-butadiene copolymer block (b) ( B) and [III] The olefinic rubber (C) is contained in a specific ratio and is partially crosslinked.

The olefinic thermoplastic elastomer according to the present invention comprises this partially crosslinked olefinic thermoplastic elastomer (hereinafter sometimes referred to as partially crosslinked thermoplastic elastomer) and a crystalline polyolefin resin. May be.

Crystalline Polyolefin Resin (A) Examples of the crystalline polyolefin resin (A) used in the present invention include homopolymers or copolymers of α-olefins having 2 to 20 carbon atoms.

Specific examples of the crystalline polyolefin resin (A) 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-olefins (5) Block copolymerization of propylene and 30 mol% or less of other α-olefins Combined (6) 1-butene homopolymer (7) Random copolymer of 1-butene and other α-olefin at 10 mol% or less (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, a propylene homopolymer and a propylene / α-olefin copolymer having a propylene content of 50 mol% or more are particularly preferable.

The crystalline polyolefin resin (A) as described above can be used alone or in combination. The crystalline polyolefin resin (A) 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 crystalline polyolefin resin (A)
Is usually 5 to 100% in crystallinity determined by X-ray method,
It is preferably in the range of 20 to 80%. In the present invention, the crystalline polyolefin resin (A) is based on 100 parts by weight of the total amount of the crystalline polyolefin resin (A), the block copolymer (B) and the olefin rubber (C).
It is used in a proportion of 20 to 80 parts by weight, preferably 30 to 70 parts by weight, more preferably 35 to 65 parts by weight.

When the crystalline polyolefin resin (A) is used in the above proportion, the scratch resistance is excellent and
A thermoplastic elastomer having excellent moldability capable of providing a molded product having excellent heat resistance is 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.

[0021]

[Chemical 1]

[0022]

[Chemical 2]

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 having excellent 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, for example, in 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 used in a total amount of 100 parts by weight of the crystalline polyolefin resin (A), the block copolymer (B) and the olefin rubber (C). 15 to 75 parts by weight, preferably 20 to 60 parts by weight, more preferably 25 to 55 parts by weight.
Used in proportions 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. Olefin-based rubber (C) As the olefin-based rubber (C) used in the present invention,
The content of α-olefin having 2 to 20 carbon atoms is 50 mol%
The above amorphous random elastic copolymer, which is an amorphous α-olefin copolymer composed of two or more α-olefins, and an α-olefin composed of two or more α-olefins and a non-conjugated diene -There are non-conjugated diene copolymers, and specific examples thereof include the following rubbers. (1) Ethylene / α-olefin copolymer rubber [ethylene / α-olefin (molar ratio) = about 90/10 to 50 /
50] (2) Ethylene / α-olefin / non-conjugated diene copolymer rubber [ethylene / α-olefin (molar ratio) = about 90
/ 10 to 50/50] (3) Propylene / α-olefin copolymer rubber [propylene / α-olefin (molar ratio) = about 90/10 to 5
0/50] (4) Butene / α-olefin copolymer rubber [butene /
α-olefin (molar ratio) = about 90/10 to 50/5
0] Specific examples of the α-olefin include the same α-olefins as the specific examples of the α-olefin constituting the crystalline polyolefin resin (A) 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 a non-conjugated diene is copolymerized is preferably 25 or less. Mooney viscosity [ML] of the copolymer rubber of the above (1) to (4)
_{1 + 4} (100 ° C)] is 10 to 250, especially 30
~ 150 is preferred.

In the present invention, the olefin rubber (C) is used in an amount of 100 parts by weight based on the total amount of the crystalline polyolefin resin (A), the block copolymer (B) and the olefin rubber (C). It is used in a proportion of 5 to 65 parts by weight, preferably 10 to 50 parts by weight, more preferably 10 to 40 parts by weight.

When the olefin rubber (C) is used in the above proportion, a thermoplastic elastomer capable of providing a molded article having excellent scratch resistance and flexibility is obtained. Further, the olefin rubber (C) and a rubber other than the olefin rubber (C) may be used in combination within a range not impairing the object of the present invention.

Examples of rubbers other than the olefin rubber (C) include styrene-butadiene rubber (S
BR), nitrile rubber (NBR), natural rubber (NR),
Examples thereof include diene rubbers such as butyl rubber (IIR) and polyisobutylene rubber.

Other Components In the present invention, the crystalline polyolefin resin (A), the block copolymer (B) and the olefin rubber (C) are used as the components of the partially crosslinked olefin thermoplastic elastomer. In addition, if necessary, a polymer block (c) of styrene or a derivative thereof and a specific isoprene polymer block or a specific isoprene-butadiene copolymer block (d) or a butadiene polymer block (e) An optionally hydrogenated block copolymer (D) consisting of

The polymer component constituting the block (c) of the block copolymer (D) is styrene or its derivative. Specific examples of the styrene derivative include the same compounds as those exemplified in the section of the block copolymer (B). As the polymer component constituting the block (c), styrene and α-methylstyrene are preferable.

The polymer or copolymer constituting the block (d) is an isoprene polymer or an isoprene-butadiene copolymer, and the content of 1,2 bonds and 3,4 bonds in the isoprene polymer portion is 30% or less,
It is preferably 25% or less.

In the present invention, when the content of 1,2 bonds and 3,4 bonds in the isoprene polymer part is 30% or less, it is possible to obtain a thermoplastic elastomer capable of providing a molded product having a good appearance. it can.

The block copolymer (D) used in the present invention may be composed of the block (c) and the block (d), or the block (e) composed of the block (c) and the butadiene polymer. ) And may consist of

The proportion of the polymer block (c) of styrene or its derivative in the block copolymer (D) is preferably 5 to 50% by weight, more preferably 10 to 45%.
It is in the range of% by weight. That is, the ratio of the isoprene polymer block or the isoprene-butadiene copolymer block (d) or the butadiene polymer block (e) is preferably 95 to 50% by weight, more preferably 90 to 55% by weight. Is.

In the present invention, the hydrogenated block copolymer (D) is preferred. When the hydrogenated block copolymer (D) 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 (D) used in the present invention.
238, 230 ℃, 2.16kg load, the same below)
It is preferably 0.01 to 100 g / 10 minutes, more preferably 0.01 to 50 g / 10 minutes. When the block copolymer (D) 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 (D) used in the present invention is most preferably block (c) -block (d) or (e) -block (c), but is not limited thereto. Not a thing.

The optionally hydrogenated block copolymer (D) can be produced, for example, by the same method as the method for producing the block copolymer (B) described above.

When the hydrogenated block copolymer is prepared, the hydrogenated block is an isoprene polymer block, an isoprene-butadiene copolymer block (d) or a butadiene polymer block (e). is there.

In the present invention, the block copolymer (D) is based on 100 parts by weight of the total amount of the crystalline polyolefin resin (A), the block copolymer (B) and the olefin rubber (C). , 1 to 40 parts by weight, preferably 3 to 35 parts by weight, and more preferably 5 to 30 parts by weight.

When the block copolymer (D) is used in the above proportion, a thermoplastic elastomer which is excellent in scratch resistance and can provide a molded article having an excellent appearance is obtained. In addition, in the present invention, in addition to the crystalline polyolefin resin (A), the block copolymer (B) and the olefin rubber (C), as a component of the partially crosslinked olefin thermoplastic elastomer, If necessary, a softening agent (E) can be added.

As the softening agent (E), 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 and the like. Coal tars such as coal tar and coal tar pitch; Fat 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, palmitin Acids, fatty acids such as stearic acid or metal salts thereof; synthetic polymers such as petroleum resin, coumarone indene resin, atactic polypropylene; ester plasticizers such as dioctyl phthalate, dioctyl adipate, dioctyl sebacate; other microcrystalline wax, Liquid polybutadiene or its modified products or hydrogenated products, liquid Call and the like.

In the present invention, the softening agent (E) is used in an amount of 1 part based on 100 parts by weight of the total amount of the crystalline polyolefin resin (A), the block copolymer (B) and the olefin rubber (C). -40 parts by weight, preferably 3-35 parts by weight, more preferably 5-30 parts by weight.

When the softening agent (E) is used in the above proportion, a thermoplastic elastomer having excellent fluidity during molding can be obtained. Molded products made of this thermoplastic elastomer are
Good scratch resistance.

Further, in the olefinic thermoplastic elastomer, if necessary, an inorganic filler, or a known heat stabilizer, antiaging agent, weathering stabilizer, antistatic agent, in an amount that does not impair the object of the present invention, Additives such as lubricants such as metal soap and wax can be added.

Specific examples of the inorganic fillers include calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth, mica powder, asbestos, barium sulfate, aluminum sulfate, calcium sulfate, magnesium carbonate and dicarbonate. Molybdenum sulfide, glass fiber, glass sphere,
Examples include shirasu balloon, graphite and alumina.

Examples of known heat stabilizers, antiaging agents and weathering stabilizers include phenol type, sulfite type, phenylalkane type, phosphite type and amine type stabilizers.

As described above, the olefin thermoplastic elastomer according to the present invention has a composition comprising at least the crystalline polyolefin resin (A), the block copolymer (B) and the olefin rubber (C), and at the Cross-linked.

The above-mentioned "partially crosslinked" means the gel content (cyclohexane insoluble matter) 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. When the gel content is in the above range, the obtained 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 (insoluble in cyclohexane)] About 100 mg of a sample of a thermoplastic elastomer was weighed and cut into a piece of 0.5 mm x 0.5 mm x 0.5 mm, which was 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, the value obtained by subtracting the weight of the cyclohexane-soluble component other than the polymer component (for example, the 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 olefin-based thermoplastic elastomer according to the present invention, a crystalline polyolefin resin is blended in a specific ratio with the above partially crosslinked thermoplastic elastomer. Good.

The crystalline polyolefin resin (A) described above is preferably used as such a crystalline polyolefin resin. In the present invention, the crystalline polyolefin resin is preferably 5 to 50 parts by weight, more preferably 5 to 40 parts by weight, based on 100 parts by weight of the partially crosslinked thermoplastic elastomer according to the present invention. Used in proportion.

In the present invention, when the crystalline polyolefin resin is used in the above proportion, it is possible to provide a molded article which is excellent in flexibility and scratch resistance as well as in secondary workability, and which is excellent in thermoplasticity in primary moldability. An elastomer is obtained.

The method for producing the olefinic thermoplastic elastomer according to the present invention will be described below. First, among the olefinic thermoplastic elastomers according to the present invention, a thermoplastic elastomer comprising the crystalline polyolefin resin (A), the block copolymer (B) and the olefin rubber (C), and a crystalline polyolefin resin. (A)
The thermoplastic elastomer comprising the block copolymer (B), the olefin rubber (C), the block copolymer (D) and / or the softening agent (E) is produced as follows.

That is, the olefinic thermoplastic elastomer according to the present invention as described above includes the crystalline polyolefin resin (A), the block copolymer (B) and the olefinic rubber (C), and further the block copolymer ( D) and / or the softening agent (E) are mixed in the above-mentioned proportions to obtain a blend, which is obtained by dynamically heat-treating in the presence of an organic peroxide to partially crosslink the blend. be able to.

Here, "dynamically heat treating" means kneading in a molten state. Specific examples of the organic peroxide used in the present invention include dicumyl peroxide and dicumyl peroxide.
-tert-Butyl peroxide, 2,5-dimethyl-2,5-di- (t
ert-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-dichloro Benzoyl peroxide, tert-butyl peroxybenzoate,
Examples thereof include tert-butyl perbenzoate, tert-butyl peroxyisopropyl carbonate, diacetyl peroxide, 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-in terms of odor and stability of scorch. (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 contained in an amount of 0.05 to 3% by weight, preferably 0.1% by weight, based on 100% by weight of the total amount of the crystalline polyolefin resin (A) and the olefin rubber (C). It is used in a proportion of 1 to 1% by weight.

In the present invention, in the partial crosslinking treatment with the above organic peroxide, sulfur, p-quinonedioxime, 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 compounds,
A uniform and mild crosslinking reaction can be expected. Particularly, divinylbenzene is most preferred in the present invention. Divinylbenzene is easy to handle and has good compatibility with the crystalline polyolefin resin (A), the olefin rubber (C) and rubbers other than the olefin rubber (C), which are the main components of the above-mentioned substance to be crosslinked. And, it has a function of solubilizing the organic peroxide, and acts as a dispersant for the organic peroxide,
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 whole 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 dynamic heat treatment is carried out using a kneading device such as a mixing roll, an intensive mixer such as a Banbury mixer, a kneader, a single-screw or twin-screw extruder, etc., but it is preferably carried out in a non-open type kneading device. . The dynamic heat treatment is preferably performed in an inert gas such as nitrogen. The heat treatment temperature is usually in the range from the melting point of the polyolefin resin to 300 ° C., and the kneading time is preferably 1 to 10 minutes. The shearing force applied at the time of kneading is 100 to 50,000 sec at a shearing rate.
A range of ^-1 is preferred.

The olefinic thermoplastic elastomer according to the present invention is obtained as described above. Further, as described above, the olefinic thermoplastic elastomer according to the present invention includes, in addition to the partially crosslinked thermoplastic elastomer obtained as described above, a thermoplastic resin comprising this partially crosslinked thermoplastic elastomer and a crystalline polyolefin. There is an elastomer.

Such a thermoplastic elastomer is preferably produced by subjecting 100 parts by weight of the above partially crosslinked thermoplastic elastomer and 5 to 50 parts by weight of a crystalline olefin resin to the above-mentioned dynamic heat treatment. However, the dynamic heat treatment is performed in the absence of organic peroxide.

[0075]

The olefinic thermoplastic elastomer according to the present invention comprises a crystalline polyolefin resin (A) [I],
[II] An optionally hydrogenated block copolymer comprising a polymer block (a) of styrene or a derivative thereof and a specific isoprene polymer block or a specific isoprene-butadiene copolymer block (b) ( B) and [III] have a composition containing the olefinic rubber (C) in a specific ratio and are partially crosslinked, so that they are lightweight and easy to recycle,
It is possible to provide a molded product that does not generate harmful gas even when incinerated and has excellent scratch resistance.

Another olefinic thermoplastic elastomer according to the present invention is composed of the above-mentioned thermoplastic elastomer and a crystalline polyolefin resin, is lightweight and easy to recycle, and does not generate harmful gas even when incinerated. ,
It is possible to provide a molded article having excellent scratch resistance, and further, the secondary workability of the molded article is excellent.

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

[0078]

Example 1 As a crystalline polyolefin resin (A), propylene homopolymer [melt flow rate (ASTM
D 1238, 230 ° C., 2.16 kg): 20 g / 1
0 minutes, crystallinity determined by X-ray method: 73%, below (A
1) and 40 parts by weight of pellets, and styrene / isoprene / styrene block copolymer as a block copolymer (B) [styrene content: 20% by weight, 1,2 bonds and 3 in the isoprene polymer portion]. , 4 bond content: 55%, melt flow rate (ASTM D 123
(8,230 ° C., 2.16 kg): 2.5 g / 10 min, 30 parts by weight of pellets of (B-1)] and ethylene / propylene / 5-ethylidene-2- as olefin rubber (C) Norbornene copolymer rubber [ethylene content: 70 mol%, iodine value: 14, Mooney viscosity ML
_{1 + 4} (100 ° C): 62, abbreviated as (C-1) below] 30
After kneading 5 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 square pellets.

Then, 100 parts by weight of the square pellets,
After 0.3 parts by weight of dicumyl peroxide and 0.5 parts by weight of divinylbenzene were mixed by stirring with a Henschel mixer, the resulting mixture was mixed with L / D = 30 and a screw diameter of 5
Using a 0 mm uniaxial extruder, the pellets of the thermoplastic elastomer were produced by extruding at 220 ° C. The gel content of the obtained thermoplastic elastomer was 79%.

Further, a square plate (150 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. Then, the appearance of the obtained rectangular plate was visually evaluated.

Further, a 20 mm square felt cloth was placed on the square plate, and a weight was placed thereon so that a pressure of 200 g / cm ² was applied, and the cloth was reciprocated 100 times on the square plate, and before and after the reciprocating operation. (JIS K 7105) was measured, and the scratch resistance was evaluated based on the degree of change in gloss.

The results are shown in Table 1.

[0083]

[Embodiment 2] In Embodiment 1, (A-1), (B-
22 parts by weight of each of 1) and (C-1),
33 parts by weight, 45 parts by weight, and 11 parts by weight of a mineral oil-based process oil [Idemitsu Kosan Co., Ltd., PW-380, hereinafter abbreviated as (E-1)] as a softening agent (E). To prepare a thermoplastic elastomer in the same manner as in 1.
I got a square plate. The obtained square plate was evaluated for appearance and scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0085]

Example 3 In Example 1, (A-1) and (C
The blending amount of -1) is 20 parts by weight and 15 parts by weight, respectively, and instead of (B-1), a block copolymer composed of a styrene polymer block, an isoprene-butadiene copolymer block and a styrene polymer block is used. Hydrogenated product [block copolymer (B), styrene content: 20% by weight, butadiene content in isoprene-butadiene copolymer block: 12% by weight, 1,2 bonds in isoprene-butadiene copolymer part and 3,4 bond content: 60%, melt flow rate (ASTM D 12
38,230 ° C., 2.16 kg): 2.1 g / 10 minutes,
Hereinafter, abbreviated as (B-2)], except that 65 parts by weight of pellets were 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 appearance and scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0087]

Fourth Embodiment In the first embodiment, (A-1), (B-
70 parts by weight of each of 1) and (C-1),
A thermoplastic elastomer was prepared in the same manner as in Example 1 except that 20 parts by weight and 10 parts by weight were used to obtain a square plate. The obtained square plate was evaluated for appearance and scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0089]

Example 5 In Example 1, the compounding amount of (C-1) was set to 22 parts by weight, and instead of (A-1), a propylene / ethylene copolymer [crystalline polyolefin resin (A), ethylene content: 3.2 mol%, melt flow rate (AS
TM D 1238, 230 ° C., 2.16 kg): 25 g
/ 10 minutes, crystallinity determined by X-ray method: 66%, 45 parts by weight of pellets of (A-2) hereinafter, (B-1)
33 parts by weight of (B-2) in place of the above, and a hydrogenated product of a block copolymer comprising a styrene polymer block, a butadiene polymer block and a styrene polymer block as the block copolymer (D) [ Styrene content:
40% by weight, melt flow rate (ASTM D 123
8,230 ° C., 2.16 kg): 15 g / 10 minutes, hereinafter abbreviated as (D-1)] 11 parts by weight of pellets were used to prepare a thermoplastic elastomer in the same manner as in Example 1. I got a square plate. The obtained square plate was evaluated for appearance and scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0091]

Example 6 In Example 1, 45 parts by weight of (A-2) in place of (A-1) and a linear low density polyethylene resin [crystalline polyolefin resin (A), comonomer:
1-butene, density: 0.920 g / cm ³ , melting point: 120
° C, melt flow rate (ASTM D 1238, 23
0 ° C., 2.16 kg): 31 g / 10 minutes, crystallinity determined by X-ray method: 52%, hereinafter abbreviated as (A-3)] 11
22 parts by weight of (B-2) instead of (B-1),
Instead of (C-1), ethylene / butene copolymer rubber [olefin rubber (C), ethylene content: 84 mol%, melt flow rate (ASTM D 1238, 23
0 ° C, 2.16 kg): 8.1 g / 10 minutes, the following (C-
2)] 22 parts by weight and (E-1) 11 parts by weight were used to prepare a thermoplastic elastomer in the same manner as in Example 1 to obtain a square plate. The obtained square plate was evaluated for appearance and scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0093]

[Comparative Example 1] In Example 1, except that the amount of (C-1) was 60 parts by weight and (B-1) was not added.
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 appearance and scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0095]

Comparative Example 2 In Example 1, (A-1) and (C
The same procedure as in Example 1 was performed except that the compounding amounts of -1) were 57 parts by weight and 43 parts by weight, respectively, and (D-1) was used in 43 parts by weight without using (B-1). Then, a thermoplastic elastomer was prepared to obtain a square plate. The obtained square plate was evaluated for appearance and scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0097]

Comparative Example 3 A square plate was obtained in the same manner as in Example 1 from the square pellets of the thermoplastic elastomer obtained in the step before using dicumyl peroxide and divinylbenzene in Example 1. The obtained square plate was evaluated for appearance and scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0099]

Comparative Example 4 (A-1), (B-1) and (C-1)
A thermoplastic elastomer was prepared in the same manner as in Example 1 except that the blending amounts of 60 parts by weight, 5 parts by weight, and 35 parts by weight were prepared to obtain a square plate. The obtained square plate was evaluated for appearance and scratch resistance in the same manner as in Example 1.

The results are shown in Table 1.

[0101]

[Table 1]

[0102]

Example 7 100 parts by weight of the thermoplastic elastomer obtained in Example 1 and (A-
3) After sufficiently stirring and mixing 30 parts by weight, thermoplastic elastomer pellets were obtained using a uniaxial extruder set at 200 ° C. Thereafter, a rectangular plate was obtained from this thermoplastic elastomer in the same manner as in Example 1. The obtained square plate was evaluated for appearance and scratch resistance in the same manner as in Example 1.

The results are shown in Table 2.

[0104]

Comparative Example 5 100 parts by weight of the thermoplastic elastomer obtained in Example 1 and (A-
3) After thoroughly mixing with 70 parts by weight of the mixture, pellets of the thermoplastic elastomer were obtained using a uniaxial extruder set at 200 ° C. Thereafter, a rectangular plate was obtained from this thermoplastic elastomer in the same manner as in Example 1. The obtained square plate was evaluated for appearance and scratch resistance in the same manner as in Example 1.

The results are shown in Table 2.

[0106]

[Table 2]

Claims (5)

[Claims] 1. [I] crystalline polyolefin resin (A) 2
0 to 80 parts by weight of a polymer block (a) of [II] styrene or a derivative thereof and an isoprene polymer block or an isoprene-butadiene copolymer block,
1,2 bond and 3,4 in isoprene polymer part
15 to 75 parts by weight of an optionally hydrogenated block copolymer (B) consisting of a polymer or a copolymer block (b) having a bond content of 40% or more, and [III]
5 to 65 parts by weight of the olefin rubber (C) [the total amount of the components (A), (B) and (C) is 100 parts by weight], and it is partially crosslinked. Characteristic olefinic thermoplastic elastomer. 2. The crystalline polyolefin resin (A),
Melt flow rate (ASTM D1238, 230
Propylene homopolymer or propylene / α-olefin copolymer having a crystallinity of 20 to 80% as determined by an X-ray method. The olefin-based thermoplastic elastomer according to claim 1, wherein 3. The olefinic thermoplastic resin according to claim 1 or 2, wherein the block copolymer (B) has a polymer block (a) of styrene or a derivative thereof in an amount of 5 to 50% by weight. Elastomer. 4. The olefinic heat according to claim 1, wherein the Mooney viscosity [ML _{1 + 4} (100 ° C.)] of the olefinic rubber (C) is 30 to 150. Plastic elastomer. 5. The thermoplastic elastomer 1 according to claim 1.
An olefin-based thermoplastic elastomer, which comprises 00 parts by weight and 5 to 50 parts by weight of a crystalline polyolefin resin.