JPH0796529A - Thermoplastic elastomer rotational molded object - Google Patents

Abstract

PURPOSE:To enhance mechanical and physical properties and scratch resistance by forming a molded object from a crystalline polyolefinic resin (A) and a block bopolymer (B) consisting of a polymer block of styrene or a derivative thereof and an isoprene copolymer block or an isoprene/butadiene copolymer block. CONSTITUTION:A molded object is formed from 20-85 pts.wt. of a crystalline polyolefin resin (A) [I] and 15-80 pts.wt. of a block copolymer (B) [II] which may be hydrogenated consisting of a polymer block (a) of styrene or a derivative thereof and a polymer or copolymer block (b) being an isoprene polymer block or an isoprene/butadiene copolymer block and characterized by that the content of the 1,2-bond and 3,4-bond in an isoprene polymer is 40% or more. The total amt. of the components (A), (B) is set to 100 pts.wt. The crystalline polylefin resin (A) is a homopolymer of 2-20C alpha-olefin or a copolymer thereof.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic elastomer rotomolded article, and more specifically, a thermoplastic elastomer rotomolded article having excellent mechanical properties and scratch resistance, a grain pattern mainly having fine irregularities on the surface, Particularly, the present invention relates to a thermoplastic elastomer rotomolded product having a deep grain pattern and excellent in mechanical properties and scratch resistance.

[0002]

BACKGROUND OF THE INVENTION Conventionally, an automobile dashboard,
Vinyl chloride resin (PVC) is widely used for molded articles such as dolls. In particular, car dashboards, which have a textured pattern, are in great demand because of their strong high-class image.

By the way, as a method for producing the above-mentioned vinyl chloride resin molded product having an embossed pattern for automobile dashboards, dolls, etc., vinyl chloride resin powder for plastisol to which a plasticizer such as dioctyl phthalate is added is used. Injection into a mold or dipping the mold in the powder to deposit the powder on the mold surface and heating for molding, so-called slush molding method, vacuum molding of vinyl chloride resin sheet (PVC sheet) The method is known.

However, the vinyl chloride resin has a problem that it is inferior in heat resistance, heat aging resistance, cold resistance and light resistance. Moreover, vinyl chloride resin is said to generate harmful substances such as dioxins when incinerated, and environmental pollution due to such harmful substances poses a problem. Further, even if a slush molding or vacuum molding is performed using a vinyl chloride resin to manufacture a molded article having a grain pattern, the grain depth is limited to about 90 μm.

Therefore, the inventors of the present invention have disclosed in Japanese Patent Laid-Open No. 2-573.
No. 09 (Japanese Patent Application No. 63-208635),
We proposed a textured thermoplastic elastomer molded product obtained by rotational molding of a powder of a thermoplastic elastomer containing a polyolefin resin and an ethylene / α-olefin copolymer rubber. This thermoplastic elastomer molded product is superior in mechanical properties, heat resistance, heat aging resistance, cold resistance and light resistance to the vinyl chloride resin molded product, and
It is possible to form deep wrinkles of 50 μm or more.

However, since the thermoplastic elastomer molded article with a grain pattern does not always have sufficient scratch resistance, it is the fact that it is often used after being surface-treated in applications such as automobile dashboards.

Therefore, the inventors of the present invention have conducted extensive studies to solve the above problems, and rotationally mold a thermoplastic elastomer powder containing a crystalline polyolefin resin and a specific block copolymer in a specific ratio. As a result, it has a deep wrinkle that is almost the same as that of the embossed thermoplastic elastomer molding, and is excellent in the transferability of the embossed pattern and more excellent in scratch resistance than the embossed thermoplastic elastomer molding. The inventors have found that a molded product can be obtained, and completed the present invention.

[0008]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, and is more excellent in scratch resistance as compared with the conventional embossed thermoplastic elastomer moldings described above. The object is to provide a thermoplastic elastomer rotomolded article.

In particular, the present invention is capable of forming a deep grain pattern almost equivalent to that of a conventional embossed thermoplastic elastomer molded article, and is more resistant to scratching than a conventional grain embossed thermoplastic elastomer molded article. The object is to provide a more excellent thermoplastic elastomer rotomolded article.

[0010]

SUMMARY OF THE INVENTION The first thermoplastic elastomer rotomolded article according to the present invention comprises 20 to 85 parts by weight of [I] crystalline polyolefin resin (A) and [II] polymer block (a) of styrene or its derivative. ) 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 (b). A thermoplastic elastomer containing 15 to 80 parts by weight of an optionally hydrogenated block copolymer (B) [the total amount of components (A) and (B) is 100 parts by weight]. It is characterized by that.

The second thermoplastic elastomer rotational molding product according to the present invention comprises 20 to 85 parts by weight of [I] crystalline polyolefin resin (A), [II] polymer block (a) of styrene or its derivative. 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 part is 40% or more (b). 12 to 79 parts by weight of an optionally hydrogenated block copolymer (B), and [III] a polymer block (c) of styrene or a derivative thereof, and an isoprene polymer block or isoprene-butadiene copolymer Polymerization in which the isoprene polymer portion has 1,2 bond and 3,4 bond content of 30% or less Or a copolymer block (d), or butadiene polymer block (e) because comprising hydrogenated which may be block copolymer (C)
It is characterized by comprising a thermoplastic elastomer containing 1 to 30 parts by weight [the total amount of components (A), (B) and (C) is 100 parts by weight].

The olefin rubber (D) and the softening agent (E) can be added to the above-mentioned thermoplastic elastomer within a range that does not impair the object of the present invention. For example, in the thermoplastic elastomer containing the crystalline polyolefin resin (A), the block copolymer (B) and the block copolymer (C), the crystalline polyolefin resin (A), the block copolymer (B) and 1 to 40 parts by weight of an olefin rubber (D) and / or a softening agent (E) based on 100 parts by weight of the total amount of the block copolymer (C).
1 to 40 parts by weight can be blended.

The thermoplastic elastomer rotomolded product according to the present invention may or may not have a grain pattern on the surface.

[0014]

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

The thermoplastic elastomer forming the thermoplastic elastomer rotationally molded product according to the present invention comprises a crystalline polyolefin resin (A) and a specific block copolymer (B) in a specific ratio. A thermoplastic elastomer [1], a crystalline polyolefin resin (A), a specific block copolymer (B), and a specific block copolymer (C) in specific proportions [ 2].

If desired, an olefinic rubber (D) and a softening agent (E) may be added to these thermoplastic elastomers. These thermoplastic elastomers may be non-crosslinked thermoplastic elastomers,
It may be a partially crosslinked thermoplastic elastomer.

In producing the thermoplastic elastomer rotomolded article according to the present invention, the above-mentioned thermoplastic elastomer powder is used. Crystalline Polyolefin Resin (A) Examples of the crystalline polyolefin resin (A) used in the present invention include α-olefin homopolymers or copolymers 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 containing propylene as a main component 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, 23).
0 ° C., 2.16 kg load, the same applies hereinafter) is preferably 0.
01 to 100 g / 10 minutes, more preferably 0.3 to 7
It is in the range of 0 g / 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 thermoplastic elastomers [1] and [2] described above, the crystalline polyolefin resin (A) is added to the crystalline polyolefin resin (A) and the block copolymer (B) in a total amount of 100 parts by weight, or in the form of crystals. 20 to 85 parts by weight, preferably 30 to 80 parts by weight, and more preferably 35 to 100 parts by weight of the total amount of the polymerizable polyolefin resin (A), the block copolymer (B) and the block copolymer (C). It is used in a proportion of 75 parts by weight.

When the crystalline polyolefin resin (A) is used in the above proportion, it has excellent scratch resistance and
A thermoplastic elastomer having excellent moldability, which can provide a rotomolded product having excellent heat 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.

[0026]

[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, a thermoplastic elastomer capable of providing a rotomolded article excellent in scratch resistance is obtained. be able to.

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 rotomolded product excellent in 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 rotomolded 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, the block copolymer (B) obtained by the above method
If hydrogenation treatment is carried out, the 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 above-mentioned thermoplastic elastomer [1], the block copolymer (B) is 15 parts by weight per 100 parts by weight of the total amount of the crystalline polyolefin resin (A) and the block copolymer (B). ˜80 parts by weight, preferably 20 to 70 parts by weight, more preferably 25 to 65 parts by weight.

The above-mentioned thermoplastic elastomer [2]
In the above, the block copolymer (B) is 12 to 79 parts by weight based on 100 parts by weight of the total amount of the crystalline polyolefin resin (A), the block copolymer (B) and the block copolymer (C). Parts, preferably 17-67 parts by weight,
It is more preferably used in a proportion of 20 to 60 parts by weight.

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

Block Copolymer (C) The block copolymer (C) optionally used in the present invention includes a polymer block (c) of styrene or a derivative thereof and a specific isoprene polymer or a specific isoprene. A block (b) made of a butadiene copolymer,
Alternatively, it may be hydrogenated with the butadiene polymer block (e).

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

The polymer or copolymer constituting the block (d) is an isoprene polymer block or an isoprene-butadiene copolymer block, which contains 1,2 bonds and 3,4 bonds in the isoprene polymer part. The amount is 30% or less, preferably 25% or less.

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

The block copolymer (C) 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 (C) 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 (C) is preferred. When the hydrogenated block copolymer (C) is used, a thermoplastic elastomer capable of providing a rotomolded product having excellent weather resistance and heat resistance can be obtained.

The melt flow rate (MFR; ASTM D 1) of the block copolymer (C) 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 (C) having a melt flow rate in the above range is used, a thermoplastic elastomer capable of providing a rotomolded article having excellent scratch resistance can be obtained.

The block form of the block copolymer (C) 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 (C) 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 above-mentioned thermoplastic elastomer [2], the block copolymer (C) is the total amount of the above crystalline polyolefin resin (A), block copolymer (B) and block copolymer (C). For 100 parts by weight,
It is used in a proportion of 1 to 30 parts by weight, preferably 3 to 25 parts by weight, more preferably 5 to 20 parts by weight.

When the block copolymer (C) is used in the above proportion, a thermoplastic elastomer which is excellent in scratch resistance and can provide a rotomolded product having an excellent appearance is obtained.

Olefin-based rubber (D) The olefin-based rubber (D) optionally used in the present invention is an amorphous random elastic copolymer mainly composed of an α-olefin having 2 to 20 carbon atoms. And an amorphous α-olefin copolymer composed of two or more α-olefins, an α-olefin / nonconjugated diene copolymer composed of two or more α-olefins and a non-conjugated diene, and the like. Specifically, the following rubbers are included. (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
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 (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 to 15
0 is preferred.

The olefin rubber (D) as described above is
If necessary, the above-mentioned thermoplastic elastomer [1] or [2] can be compounded within a range that does not impair the object of the present invention. For example, in the above-mentioned thermoplastic elastomer [2], the total amount of the olefin rubber (D) of the crystalline polyolefin resin (A), the block copolymer (B) and the block copolymer (C) is 100.
1 to 40 parts by weight, preferably 3 to 35 parts by weight
It is used in parts by weight, more preferably 5 to 30 parts by weight.

When the olefinic rubber (D) is used in the above proportion, a thermoplastic elastomer which is excellent in flexibility and can provide a rotomolded article excellent in scratch resistance is obtained.

Further, in the present invention, an olefin rubber (D) and a rubber other than the olefin rubber (D) may be used in combination within a range not impairing the object of the present invention.

Examples of the rubber other than the olefin rubber (D) 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.

Softener (E) As the softener (E) optionally used in the present invention, a softener usually used for rubber is suitable, and specifically, a process oil, a lubricating oil, and a paraffin. Petroleum-based substances such as liquid paraffin, petroleum asphalt, and petrolatum; coal tars such as coal tar and coal tar pitch; fatty oils such as castor oil, linseed oil, rapeseed oil, soybean oil, and coconut oil; tall oil, beeswax , Waxes such as carnauba wax and lanolin, fatty acids such as ricinoleic acid, palmitic acid and stearic acid or metal salts thereof; synthetic polymers such as petroleum resin, coumarone indene resin and atactic polypropylene; dioctyl phthalate, dioctyl adipate, dioctyl seba Ester plasticizers such as silicates; Other microcrystalline wax, liquid polybuta Ene or its modified product or hydrogenated product, and liquid Thiokol and the like.

The above-mentioned softening agent (E) may be added to the above-mentioned thermoplastic elastomer [1] or [2], if necessary.
It may be incorporated therein in a range not impairing the object of the present invention. For example, in the above-mentioned thermoplastic elastomer [2], the softening agent (E) is 100 parts by weight in total of the crystalline polyolefin resin (A), the block copolymer (B) and the block copolymer (C). Against
It is used in a proportion of 1 to 40 parts by weight, preferably 3 to 35 parts by weight, more preferably 5 to 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. The rotational molded body made of this thermoplastic elastomer has excellent scratch resistance.

Other Components In the present invention, if necessary, an inorganic filler may be added to the thermoplastic elastomer within a range not impairing the object of the present invention.
Or known heat-resistant stabilizers such as phenol-based, sulfite-based, phenylalkane-based, phosphite-based, amine-based stabilizers, antiaging agents, weathering stabilizers, antistatic agents,
Additives such as lubricants such as metal soap and wax 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. Examples thereof include magnesium, molybdenum disulfide, glass fiber, glass spheres, shirasu balloon graphite, alumina and the like.

The thermoplastic elastomer rotomolding product according to the present invention is manufactured from the above-mentioned thermoplastic elastomer by the rotomolding method, and a powdery thermoplastic elastomer is used in the rotomolding. The size of this powder is preferably 20 to 120 mesh, more preferably 40 to 100 mesh, and particularly preferably 60.
~ 80 mesh. In the present invention, a powder of a thermoplastic elastomer which does not have a sticky feeling, such as soft vinyl chloride containing a plasticizer, is used.

Method for Preparing Thermoplastic Elastomer Powder The above-mentioned thermoplastic elastomer powder can be prepared as follows.

First, the crystalline polyolefin resin (A), the block copolymer (B), and, if necessary, the block copolymer (C), the olefin rubber (D), the softening agent (E). , Other additives, and then dynamically heat-treated in the presence or absence of organic peroxide, and then granulated and partially crosslinked thermoplastic elastomer or non-crosslinked thermoplastic elastomer To obtain a pellet of. Then, a powder of the thermoplastic elastomer is prepared by, for example, crushing the pellets obtained as described above.

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 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 a crystalline polyolefin resin (A) or a block copolymer (B).
And an olefin rubber (D) used as necessary
Of 100% by weight or the total amount of the crystalline polyolefin resin (A), the block copolymer (B), the block copolymer (C) and the olefinic rubber (D) used as necessary. 0.0 to 100% by weight
It is used in a proportion of 5 to 3% by weight, preferably 0.1 to 1% by weight.

In the present invention, during 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 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 block copolymer (B) and the block copolymer (C), which are the main components of the above-mentioned substance to be crosslinked, Moreover, since 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 well-balanced fluidity and physical properties can be obtained. .

In the present invention, the above-mentioned crosslinking aid or polyfunctional vinyl monomer is used in an amount of 0.1 to 2% by weight, and 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 blending ratio of the crosslinking aid or the polyfunctional vinyl monomer exceeds 2% by weight, when the blending amount of the organic peroxide is large, the crosslinking reaction proceeds too fast. Inferior, on the other hand, when the blending amount of the organic peroxide is small, the crosslinking aid and the polyfunctional vinyl monomer remain as unreacted monomers in the thermoplastic elastomer. Physical properties may change due to heat history. Therefore, the cross-linking aid and the polyfunctional vinyl monomer should not be blended in excess.

The above-mentioned "dynamically heat-treating" means kneading each of the above components in a molten state. As the kneading device, a conventionally known kneading device, for example, an open type mixing roll, a non-open type Banbury mixer, an extruder, a kneader, a continuous mixer or the like is used. Among these, a non-open type kneading device is preferable. The kneading is preferably performed in an atmosphere of an inert gas such as nitrogen gas or carbon dioxide gas.

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 170
˜240 ° C., and the kneading time is 1 to 20 minutes, preferably 1 to 5 minutes. The shearing force applied is usually 10 to 10 ⁴ sec ⁻¹ , preferably 10 at the shearing rate.
It is determined within the range of ² to 10 ⁴ sec ^-1 .

As described above, a partially crosslinked thermoplastic elastomer or an uncrosslinked thermoplastic elastomer 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, especially 2%.
It refers to the case of 0% or more and less than 98%. In the present invention, the gel content is preferably 30% or more.

[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 thermoplastic elastomer rotomolded article The thermoplastic elastomer rotomolded article according to the present invention is formed of the thermoplastic elastomer as described above, and has a grain pattern on the surface of the molded article. It may or may not have. The grain-patterned thermoplastic elastomer rotomolded article according to the present invention has excellent scratch resistance and can have a grain depth of 150 μm or more. As described above, the conventional vinyl chloride resin has a grain depth of 90 μm.
The limit was to obtain a molded product with a texture.

Method for Producing Thermoplastic Elastomer Rotomolded Product Next, a method for producing the thermoplastic elastomer rotomolded product according to the present invention will be described with reference to the drawings by taking a textured thermoplastic elastomer rotomolded product as an example.

FIG. 1 is a schematic cross-sectional view of a rotomolding apparatus used for producing a textured thermoplastic elastomer rotomolding product according to the present invention. First, the powder of the thermoplastic elastomer obtained as described above is put into the mold 1 for grain pattern transfer, and the mold 1 is sealed.

In the present invention, since the powder of the thermoplastic elastomer containing the crystalline polyolefin resin (A) and the specific block copolymer (B) in a specific ratio is used,
The shape of the mold is not particularly limited, and molds of various shapes can be used, and a deep-drawn molded product can also be manufactured.

Next, the die 1 for transferring the embossed pattern is heated while being rotated, for example, by the heater 2, so that the powder of the thermoplastic elastomer is brought into close contact with the inner surface of the die in a fluid plastic state and melted.

The heating temperature is usually not lower than the melting point of the crystalline polyolefin resin (A) and not higher than 250 ° C. In the present invention, since the mold 1 for grain pattern transfer is heated while being rotated using the powder of the thermoplastic elastomer, the powder of the thermoplastic elastomer in the mold 1 is fluidized to be plasticized to the inside of the mold 1. It penetrates deeply into the inside of the grain on the surface, adheres to the inner surface of the mold 1 and melts. Therefore, in the present invention, it is possible to obtain a thermoplastic elastomer rotomolded product having a deep grain pattern.

Next, the mold 1 for transferring the embossed pattern is cooled to obtain a thermoplastic elastomer rotomolded product having an embossed pattern on the surface. Examples of the cooling method include an air cooling method and a water cooling method.

The textured thermoplastic elastomer rotomolded product obtained as described above is excellent in scratch resistance, appearance and texture. By applying the surface treatment described in Japanese Patent Application No. 62-331718 filed by the applicant of the present application to the surface of this textured thermoplastic elastomer rotationally molded product, it is possible to obtain further excellent scratch resistance and appearance. A thermoplastic elastomer rotomolded product having a texture and having a texture is obtained.

That is, as the surface treatment, first, at least one selected from a saturated polyester and a chlorinated polyolefin is formed on the surface of the thermoplastic elastomer rotary molding.
A primer layer containing one kind of compound is formed, and a top coat layer containing at least one kind of compound selected from saturated polyester, acrylic ester resin and isocyanate resin is further formed on this primer layer. However, when the primer layer contains only saturated polyester among at least one compound selected from saturated polyester and chlorinated polyolefin, the topcoat layer must contain at least acrylic ester resin. I won't.

To form a primer layer on the surface of a thermoplastic elastomer rotomolded product, at least one compound selected from saturated polyester and chlorinated polyolefin is dissolved in an organic solvent to obtain a primer layer. The coating solution may be applied on the surface of the molded body according to a conventional method.

In order to form the topcoat layer on the primer layer, at least one compound selected from saturated polyester, acrylic ester resin and isocyanate resin is dissolved in an organic solvent to obtain the topcoat layer. The coating solution for formation may be applied on the primer layer by a conventional method.

The texture-free thermoplastic elastomer rotational molding according to the present invention uses the above-mentioned grain-patterned thermoplastic elastomer rotational molding using a mold other than the texture-pattern transfer mold as the rotational molding die. It can be manufactured by the same method as the manufacturing method of. The thermoplastic elastomer rotomolded article having no grain pattern according to the present invention is excellent in scratch resistance, appearance, and texture, like the above-described thermoplastic elastomer rotomolded article with grain pattern according to the present invention. Also,
By subjecting the surface of the thermoplastic elastomer rotomolded article having no grain pattern to the above-mentioned surface treatment, a thermoplastic elastomer rotomoulded article having more excellent scratch resistance, appearance and texture can be obtained. .

[0089]

The thermoplastic elastomer rotational molding product according to the present invention comprises a crystalline polyolefin resin (A), a specific block copolymer (B), a specific block copolymer (C), and an olefin rubber. (D), softener (E)
Since it is formed of a thermoplastic elastomer containing a specific ratio, compared with a vinyl chloride resin molded body, mechanical properties such as tensile strength, heat resistance, heat aging resistance, cold resistance, and light resistance are excellent, It is more excellent in scratch resistance as compared with the above-mentioned conventional thermoplastic elastomer molded article having a grain pattern.

Further, according to the present invention, it is possible to form an embossed pattern having a grain depth of 150 μm or more as in the conventional embossed thermoplastic elastomer molding described above. It is possible to obtain a thermoplastic elastomer rotomolded product having a textured pattern, which is more excellent in scratch resistance than the product.

Since the thermoplastic elastomer rotationally molded product according to the present invention is particularly excellent in scratch resistance, when it is used for applications such as automobile dashboards, console boxes, door trim skins, etc. It is not necessary to apply such surface treatment.

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

[0093]

Example 1 [Preparation of Powder of Thermoplastic Elastomer] Propylene homopolymer as crystalline polyolefin resin (A) [melt flow rate: 60 g / 10 min, crystallinity determined by X-ray method: 70%, A-1)] pellets 62.5 parts by weight, and a block copolymer (B) styrene / isoprene / styrene block copolymer [styrene content: 30% by weight, 1,2 in the isoprene polymer portion] Bond and 3,4 bond content: 55%,
Melt flow rate: 5 g / 10 minutes, 37.5 parts by weight of pellets (hereinafter abbreviated as (B-1)], and a paraffin-based process oil as a softening agent (E) [Idemitsu Kosan PW-
380, hereinafter abbreviated as (E-1)] 25 parts by weight using a Banbury mixer under nitrogen atmosphere at 180 ° C. for 5
After kneading for a minute, the obtained kneaded product was passed through an open roll to form a sheet, which was cut with a sheet cutter to form a square pellet.

Further, the square pellets were passed through a uniaxial extruder set at 220 ° C. to produce thermoplastic elastomer pellets. The thermoplastic elastomer pellets thus obtained were crushed under an atmosphere of -60 ° C to obtain 4
0-80 mesh thermoplastic elastomer [hereinafter, TP
E- (1)]] was obtained.

[Manufacture of Rotational Molded Product] First, a mold for taking two automobile dashboards, which has a textured pattern with a textured depth of 150 μm on its inner surface, is used for a textured pattern transfer mold.
After a predetermined amount of the TPE- (1) powder was added, the air in the mold was replaced with nitrogen to prevent the TPE- (1) from being oxidized and deteriorated.

Then, while rotating the mold, the mold was heated to 210 ° C. from the outside of the mold by a heater to fluidize and plasticize the TPE- (1) powder in the mold to melt it. During this, heating was performed at 180 ° C. for 5 minutes and 210 ° C. for 15 minutes.

Finally, this mold was water-cooled for 10 minutes to room temperature to obtain a grain-patterned thermoplastic elastomer rotationally molded product. The size of the obtained embossed thermoplastic elastomer rotomolded article was 1200 mm in length, 500 mm in width, and 1.0 mm in thickness.

With respect to the obtained embossed thermoplastic elastomer rotomolded article, the tensile properties, heat aging properties, embossing depth, and scratch resistance were evaluated by the following methods. The sample for evaluation was punched out from the obtained rotomoulded body. [Evaluation method] (1) Tensile property Tensile strength of the sample according to the method of JIS K-6301,
Tensile elongation was measured. (2) Heat aging characteristics After the sample was left in an air oven at 120 ° C for 1000 hours, the sample was taken out and JIS K-63 was used.
Tensile elongation was measured by the No. 01 tensile test method. (3) Texture depth The distance from the crest to the valley bottom of the emboss transferred to the surface of the molded body was measured. (4) Scratch resistance A 20 mm square felt cloth is placed on the surface of a square plate taken from a molded body, and a weight is placed thereon so that a pressure of 200 g / cm ² is applied, and the square plate surface is reciprocated 100 times. ,
The glossiness (JIS K 7105) was measured before and after the reciprocating operation. The gloss retention was obtained from the following formula, and the scratch resistance was evaluated based on this gloss retention.

Gloss retention (%) = (Gloss after reciprocating felt cloth) / (Gloss before reciprocating felt cloth) × 100 The results are shown in Table 1.

[0100]

Example 2 In Example 1, the amounts of the pellets (A-1), the pellets (B-1) and the compound (E-1) were 47.06 parts by weight, 35.29 parts by weight and 17.
65 parts by weight, and as the block copolymer (C), styrene / isoprene / styrene block copolymer [styrene content: 30% by weight, 1,2 bond and 3,4 bond content in the isoprene polymer part: 7 %, Melt flow rate: 8 g / 10 minutes, hereinafter abbreviated as (C-1)]
Of the thermoplastic elastomer [hereinafter referred to as TPE
-(2) abbreviated] was prepared, and then a thermoplastic elastomer rotomolded product with a grain pattern was obtained in the same manner as in Example 1.

The resulting embossed thermoplastic elastomer rotomolded article was evaluated for tensile properties, heat aging properties, embossed depth, and scratch resistance in the same manner as in Example 1. The results are shown in Table 1.

[0102]

Example 3 Propylene-Ethylene Copolymer [Crystalline Polyolefin Resin (A), Ethylene Content: 3.2 Mol%, Melt Flow Rate: 50 g / 10 Minutes, Crystallinity Determined by X-Ray Method: 65%, Hereinafter abbreviated as (A-2)]
68.75 parts by weight of pellets of (B-1), 18.75 parts by weight of pellets of (B-1), 12.5 parts by weight of pellets of (C-1), and ethylene / butene co-weight as olefin rubber (D). Combined [ethylene content: 84 mol%, melt flow rate: 29 g / 10 minutes, hereinafter abbreviated as (D-1)]
A powder of a thermoplastic elastomer [hereinafter abbreviated as TPE- (3)] was prepared in the same manner as in Example 1 from 12.5 parts by weight of the pellets of [1] and 12.5 parts by weight of [E-1].
Then, in the same manner as in Example 1, a grain-patterned thermoplastic elastomer rotomolded product was obtained.

The obtained embossed thermoplastic elastomer rotomolded article was evaluated for tensile properties, heat aging properties, embossed depth, and scratch resistance in the same manner as in Example 1. The results are shown in Table 1.

[0104]

[Example 4] In Example 3, T before powdering
To 125 parts by weight of PE- (3) square pellets, 0.3 parts by weight of dicumyl peroxide and 0.4 parts by weight of divinylbenzene were added and thoroughly mixed with a Henschel mixer, and the resulting mixture was used in Example 1. In the same manner as above, square pellets of partially crosslinked thermoplastic elastomer were prepared by passing through a single screw extruder.

Then, the square pellets were pulverized in the same manner as in Example 1 to obtain a thermoplastic elastomer [hereinafter referred to as TPE-
A powder abbreviated as (4)] was prepared and a grain-patterned thermoplastic elastomer rotomolded product was obtained in the same manner as in Example 1. The gel content of the obtained TPE- (4) was 66.
% By weight.

The resulting embossed thermoplastic elastomer rotomolded product was evaluated for tensile properties, heat aging properties, embossed depth, and scratch resistance in the same manner as in Example 1. The results are shown in Table 1.

[0107]

Comparative Example 1 47.06 parts by weight of (A-1) pellets, 52.94 parts by weight of (C-1) pellets, and (E-
1) From 17.65 parts by weight, a powder of a thermoplastic elastomer [hereinafter abbreviated as TPE- (5)] was prepared in the same manner as in Example 1, and then, in the same manner as in Example 1, a textured thermoplastic resin. An elastomer rotomolded product was obtained.

The obtained embossed thermoplastic elastomer rotomolded product was evaluated for tensile properties, heat aging properties, embossed depth, and scratch resistance in the same manner as in Example 1. The results are shown in Table 1.

[0109]

[Table 1]

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a rotomolding apparatus used for producing a textured thermoplastic elastomer rotomolding product according to the present invention.

[Explanation of symbols]

 1 ... Mold for transferring grain pattern 2 ... Heater

Claims (4)

[Claims] 1. [I] crystalline polyolefin resin (A) 2
0 to 85 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 bonds in the isoprene polymer part are included. , Copolymer block having a 4 bond content of 40% or more (b)
A thermoplastic elastomer containing 15 to 80 parts by weight of an optionally hydrogenated block copolymer (B) [the total amount of components (A) and (B) is 100 parts by weight]. A thermoplastic elastomer rotomolded product characterized by: 2. [I] crystalline polyolefin resin (A) 2
0 to 85 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, wherein 1,2 bonds and 3,3 in the isoprene polymer part are included. Polymer or copolymer block (b) having a 4-bond content of 40% or more
12 to 79 parts by weight of an optionally hydrogenated block copolymer (B), and [III] a polymer block (c) of styrene or a derivative thereof, and an isoprene polymer block or isoprene-butadiene copolymer A polymer block or a copolymer block (d) having a 1,2 bond or 3,4 bond content of 30% or less in the isoprene polymer portion, or a butadiene polymer block (e) Block copolymer which may be hydrogenated (C)
A thermoplastic elastomer rotational molding comprising a thermoplastic elastomer containing 1 to 30 parts by weight [the total amount of components (A), (B) and (C) is 100 parts by weight]. 3. Olefin-based rubber (D) 1 to 100 parts by weight of the total amount of crystalline polyolefin resin (A), block copolymer (B) and block copolymer (C).
The thermoplastic elastomer rotomolded article according to claim 2, which is composed of a thermoplastic elastomer containing 40 parts by weight and / or 1 to 40 parts by weight of a softening agent (E). 4. The thermoplastic elastomer rotomolded article according to claim 1, which has a texture pattern on the surface.