JP2002361768A - Multilayer molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer molding having a foamed layer made of a specific thermoplastic resin and a thermoplastic elastomer composition containing a specific hydrogenated vinyl aromatic compound-conjugated diene copolymer, and also having excellent contact sense, light weight properties, impact resilience, appearance, heat resistance and flexibility. SOLUTION: The multilayer molding comprises the foamed layer made of the thermoplastic elastomer composition containing (A) a thermoplastic resin having a melt flow rate of a range of 0.001 to 100 g/10 min measured at 230 deg.C and 2.16 kg load and a die swell ratio of 1.7 to 5.0 (190 deg.C, a shearing speed of 122 sec<-1> , and L/D=10/1) according to a capillary rheometer; and (B) a specific 'hydrogenated vinyl aromatic compound-conjugated diene copolymer, in such a manner that a weight ratio of (A) the thermoplastic resin to (B) the specific hydrogenated vinyl aromatic compound-conjugated diene copolymer is 5/95 to 95/5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a multilayer molded article. More specifically, the present invention is a multilayer molded article having a foamed layer comprising a thermoplastic elastomer composition containing a specific thermoplastic resin and a specific hydrogenated vinyl aromatic compound-conjugated diene copolymer, The present invention relates to a multilayer molded article excellent in feel, lightness, resilience, appearance, heat resistance, and flexibility.

[0002]

2. Description of the Related Art Instrument panels, door trims,
Automobile interior parts such as console boxes, lids, pillar garnishes, and the like, for example, molded articles obtained by laminating a skin material made of polyvinyl chloride, various thermoplastic elastomers, and various foams including a polyurethane foam. It is used. In recent years, it has been demanded that the interior parts of automobiles have a more flexible feel in order to enhance a sense of quality.

[0003] For example, Japanese Patent Application Laid-Open No. 2000-177036 discloses an olefin-based thermoplastic elastomer for a flexible foaming material layer comprising a crystalline propylene-based copolymer, low-density polyethylene, ethylene-propylene copolymer rubber and a foaming agent. A composition is described, and a multilayer molded article produced by injection molding the same between a flexible skin material and a rigid substrate is described.

[0004]

However, the multilayer molded article is not sufficiently satisfactory in feel and lightness. Under such circumstances, the problem to be solved by the present invention is to provide a foamed layer made of a thermoplastic elastomer composition containing a specific thermoplastic resin and a specific hydrogenated vinyl aromatic compound-conjugated diene copolymer. An object of the present invention is to provide a multilayer molded article having excellent feel, lightness, resilience, appearance, heat resistance, and flexibility.

[0005]

That is, the present invention comprises the following component (A) and component (B), and the weight ratio of component (A) / component (B) is 5/95 to 95/5. The present invention relates to a multilayer molded article having a foamed layer made of a certain thermoplastic elastomer composition. (A): 230 ℃, the range the melt flow rate is from 0.001 to 100 g / 10 min as measured under a 2.16kg load, die swell ratio by capillary rheometer (190 ° C., a shear rate of 122 sec ^-1, L / D =
(B): a hydrogenated vinyl aromatic compound-conjugated diene copolymer satisfying all the conditions of the following formulas (i) to (iii): (I) The content of the vinyl aromatic compound unit is 50% by weight or less. (Ii) 2 carbon atoms based on the total number of hydrogenated conjugated diene units in the hydrogenated vinyl aromatic compound-conjugated diene copolymer. The ratio of the number of hydrogenated conjugated diene units having the above side chains is 60% or more (iii) 80 of the double bonds of the conjugated diene units in the hydrogenated vinyl aromatic compound-conjugated diene copolymer. % Must be hydrogenated

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The component (A) constituting the thermoplastic elastomer composition used in the multilayer molded article of the present invention comprises:
The melt flow rate measured under a load of 2.16 kg at 230 ° C. is in the range of 0.001 to 100 g / 10 minutes, and the die swell ratio by a capillary rheometer (190 ° C., shear rate 122 sec ⁻¹ , L / D = 10
/ 1) is a thermoplastic resin having a ratio of 1.7 to 5.0.

As the component (A), 230 ° C., 2.16
The melt flow rate measured under a kg load is 0.00
It is necessary to be in the range of 1 to 100 g / 10 min, preferably 0.01 to 50 g / 10 min, more preferably 0.1 to 20 g / 10 min. If the melt flow rate is too high, the resulting multilayer molded article may have poor appearance, feel, lightness, and rebound resilience.If the melt flow rate is too low, the resulting multilayer molded article may have an appearance, feel,
Lightweight, rebound resilience and strength may be poor. Here, the melt flow rate is in accordance with JIS-K-7210,
It is a value obtained by measuring at 230 ° C. under a load of 2.16 kg.

[0008] Component (A) is used in a capillary rheometer.
The die swell ratio must be 1.7 to 5.0.
And preferably 1.8 to 4.5, more preferably
2 to 4.0. If the die swell ratio is too small,
Multi-layer molded products are inferior in feel, light weight and rebound resilience.
There is. On the other hand, if the die swell ratio is too large,
Multi-layer molded body is inferior in feel, light weight and rebound resilience
There is. Also, the larger the die swell ratio, the more
Non-foamed thermoplastic elastomer composition
When used as a skin layer of a feature, the multilayer
The performance is improved. Here, the die swell ratio is JIS-K
According to -7199, barrel temperature 190 ° C, capillary
Diameter 1 mm, capillary length 10 mm, shear rate 1
22 sec ^-1Of the sample when the component (A) was extruded under the conditions of
It is the value obtained by dividing the diameter by the capillary diameter.

The component (A) can be selected from a wide variety of known thermoplastic resins. For example, high density polyethylene, medium density polyethylene, low density polyethylene,
Polyethylene resin such as linear low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer resin, ethylene-methyl methacrylate copolymer resin, ethylene-methacrylate copolymer resin, ethylene-acrylate copolymer Polymer resin, ethylene-methacrylic acid copolymer resin, ethylene-acrylic acid copolymer resin, ethylene-styrene copolymer resin, polypropylene resin, polybutene resin, poly-4-methyl-1-pentene resin, Examples include polystyrene resins, polyester resins, polyamide resins, polyphenylene ether resins, polyacetal resins, polycarbonate resins, cyclic olefin homopolymer resins, and cyclic olefin copolymer resins. Preferably, it is a polyolefin-based resin, more preferably a polyolefin-based resin having a unit composed of an aliphatic olefin having 2 or more carbon atoms as a main component, and still more preferably a unit composed of an aliphatic olefin having 3 or more carbon atoms. It is a polyolefin resin as a component, and particularly preferably a polypropylene resin.

As the polypropylene resin, a crystalline polypropylene mainly having an isotactic or syndiotactic structure and a wide variety of structures such as a homo-type or a random type containing a comonomer, or a block type by multi-stage polymerization can be used. It is.
The polypropylene-based resin may employ a multi-stage polymerization by a gas phase polymerization method, a bulk polymerization method, a solvent polymerization method, or any combination thereof.

The polypropylene resin has a melting point of 80 to 1 from the viewpoint of increasing the heat resistance of the obtained multilayer molded article.
A polypropylene resin having a heat of crystal fusion of 30 to 120 J / g at 76 ° C. is preferable, and a melting point of 120 to 176.
C. and a polypropylene resin having a heat of crystal fusion of 60 to 120 J / g are preferred. Here, the melting point and the heat of crystal fusion are JIS-K-7121 and JIS-K, respectively.
It is measured according to K-7122.

As a method for producing a polypropylene-based resin, generally, a Ziegler-type compound using a combination of a so-called titanium-containing solid transition metal component and an organic metal component is used.
A Natta-type catalyst, a catalyst essentially including a transition metal compound of Groups 4 to 6 of the periodic table, or a transition metal compound of Groups 4 to 6 of the periodic table having at least one cyclopentadienyl skeleton. Using a metallocene catalyst as an essential component, slurry polymerization, gas phase polymerization, bulk polymerization, solution polymerization or the like in one or multiple stages by a polymerization method or a combination thereof, to obtain a homopolymer by homopolymerizing propylene, Alternatively, there can be mentioned a method of obtaining a copolymer by copolymerizing propylene and one or more olefins selected from olefins having 2 to 12 carbon atoms in one or more stages. Further, a combination of homopolymerization and copolymerization in multiple stages is also possible. In addition, it is also possible to use a corresponding product on the market.

As a polypropylene resin satisfying the constitutional requirements of the component (A), for example, JP-A-11-228629
JP, JP-A-7-138430, WO 99/1
No. 6,797, the polypropylene resin.

The component (B) constituting the thermoplastic elastomer composition used for the multilayer molded article of the present invention of the present invention comprises:
A hydrogenated vinyl aromatic compound-conjugated diene copolymer which satisfies all of the following conditions (i) to (iii): (I) The content of the vinyl aromatic compound unit is 50% by weight or less. (Ii) 2 carbon atoms based on the total number of hydrogenated conjugated diene units in the hydrogenated vinyl aromatic compound-conjugated diene copolymer. The ratio of the number of hydrogenated conjugated diene units having the above side chains is 60% or more (iii) 80 of the double bonds of the conjugated diene units in the hydrogenated vinyl aromatic compound-conjugated diene copolymer. % Must be hydrogenated

The component (B) includes, for example, a block copolymer comprising a polymer block of a vinyl aromatic compound and a polymer block of a conjugated diene, and a polymer comprising a polymer block of a conjugated diene, a vinyl aromatic compound and a conjugated diene. Examples include hydrogenated products such as a block copolymer comprising a tapered block in which a vinyl aromatic compound is gradually increased. Although the number of polymer blocks in the block polymer is 2 or more, the strength of the multilayer molded article obtained to be 3 or 4 and the industrial productivity of the hydrogenated vinyl aromatic compound-conjugated diene copolymer are obtained. It is preferable from the viewpoint of. These may be used alone or in combination of two or more.

The component (B) may be modified with a functional group, and at least one functional group selected from an acid anhydride group, a carboxyl group, a hydroxyl group, an amino group, an isocyanate group, and an epoxy group. Can also be used as a modified functional group having

The conjugated diene used in the component (B) includes 1,3-butadiene, isoprene, 2,3
-Dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene,
Examples thereof include 3-butyl-1,3-octadiene and chloroprene. From the viewpoint of industrial productivity, 1,3-butadiene, isoprene and 1,3-pentadiene are preferable, and 1,3-butadiene and isoprene are particularly preferable. preferable.

The vinyl aromatic compounds include styrene, α-methylstyrene, p-methylstyrene, t-butylstyrene, divinylbenzene, N, N-dimethyl-
p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, vinylpyridine and the like.
From the viewpoint of industrial productivity, styrene and α-methylstyrene are preferred.

Among these components (B), hydrogenated styrene-butadiene-styrene block copolymer, styrene-
Hydrogenated isoprene-styrene block copolymer, hydrogenated styrene-butadiene / isoprene-styrene block copolymer, hydrogenated styrene-butadiene / styrene-styrene block copolymer and styrene-isoprene / styrene- Hydrogenated styrene block copolymer,
It is preferably used from the viewpoint of the strength and productivity of the obtained multilayer molded article. Here, “-” indicates the boundary of each polymer block, and “•” indicates that each monomer is copolymerized in the block.

The content of the vinyl aromatic compound unit in the component (B) must be 50% by weight or less.
To 25% by weight, more preferably 10 to 2% by weight.
It is preferably 0% by weight. If the content of the vinyl aromatic compound is too large, the obtained multilayer molded article may be inferior in flexibility, appearance, feel, lightness, and rebound resilience.
Further, when the content is within this range, when the non-foamed article comprising the thermoplastic elastomer composition of the present invention is used as a skin layer of a multilayer molded article, the multilayer molded article has improved scratch resistance.

The ratio of the number of hydrogenated conjugated diene units having a side chain having 2 or more carbon atoms to the total number of hydrogenated conjugated diene units in the component (B) must be 60% or more; It is preferably at least 70%, more preferably at least 80%.
% Is preferable. If the ratio is too small,
The multilayer molded article may be inferior in appearance, feel, lightness, rebound resilience and impact resistance. In addition, as the ratio increases, when the non-foamed body made of the thermoplastic elastomer composition of the present invention is used as a skin layer of a multilayer molded article, the multilayer molded article has improved scratch resistance.

It is necessary that at least 80% of the double bonds of the conjugated diene unit in the component (B) be hydrogenated.
% Or more, and more preferably 95% or more. If the value is too small, the multilayer molded article may be inferior in appearance, feel, lightness, rebound resilience and heat resistance. The value is the ratio of the total number of hydrogenated conjugated diene units to 100% of the total number of hydrogenated conjugated diene units and the unhydrogenated total number of conjugated diene units in component (B). is there.

Component (B) is described, for example, in JP-A-3-7251.
No. 2, JP-A-5-271325, JP-A-5-271325
It can be produced by a method described in, for example, Japanese Patent No. 271327. Particularly, the component (B) is described in JP-A-2001-49
In the case of satisfying the requirements described in Japanese Patent Publication No. 051
When heated to 0 to 120 ° C., there is no problem that gloss is generated on the surface, and scratch resistance and flexibility are excellent.

The thermoplastic elastomer composition used in the multilayer molded article of the present invention comprises the component (A) and the component (B),
5/95 to 95/5 by weight ratio of component (A) / component (B)
In a ratio of 1
5/85 to 85/15, more preferably 20/8
0/55/45, particularly preferably 20 / 80-4.
5/55. When the amount of the component (A) is too large, the flexibility of the multilayer molded body may be poor, while when the amount of the component (A) is too small, the heat resistance of the multilayer molded body may be poor.

The thermoplastic elastomer composition used in the multilayer molded article of the present invention may contain, if necessary, components (A) and (B) in addition to the essential components (A) and (B). A thermoplastic resin or other resin that does not satisfy the requirement of B) can be blended. For example, a thermoplastic resin not satisfying the requirement of the component (A), a hydrogenated vinyl aromatic compound-conjugated diene copolymer not satisfying the requirement of the component (B),
Vinyl aromatic compound-conjugated diene copolymer rubber, ethylene-α-olefin copolymer rubber, ethylene α-olefin-polyene copolymer rubber, propylene-α-olefin copolymer rubber, natural rubber, polybutadiene, liquid Polybutadiene, polyacrylonitrile rubber, acrylonitrile-butadiene copolymer rubber, hydrogenated acrylonitrile-butadiene copolymer rubber, butyl rubber, chloroprene rubber, fluorine rubber, chlorosulfonated polyethylene,
Silicone rubber, urethane rubber, isobutylene-isoprene copolymer rubber, halogenated isobutylene-isoprene copolymer rubber, polyolefin-based thermoplastic elastomer, polyurethane-based thermoplastic elastomer, polyester-based thermoplastic elastomer, polyamide-based thermoplastic elastomer, 1, 2-polybutadiene-based thermoplastic elastomer, polyvinyl chloride-based thermoplastic elastomer, trans-polyisoprene-based thermoplastic elastomer, chlorinated polyethylene-based thermoplastic elastomer, and the like.

The vinyl aromatic compound-conjugated diene copolymer is a copolymer obtained by copolymerizing the above-mentioned vinyl aromatic compound, conjugated diene and other components as required. Examples of the vinyl aromatic compound-conjugated diene copolymer include styrene-butadiene block copolymer, styrene-isoprene block copolymer, styrene-butadiene-styrene block copolymer, and styrene-
Examples include isoprene-styrene block copolymer, styrene / butadiene random copolymer, and styrene / isoprene random copolymer.

The thermoplastic elastomer composition used in the multilayer molded article of the present invention may contain the following components (C) and / or (D) in addition to the components (A) and (B). preferable. (C): a polyethylene resin having a die swell ratio of less than 1.7 (D): a hydrogenated vinyl aromatic compound-conjugated diene copolymer other than the component (B)

When the thermoplastic elastomer composition used in the multilayer molded article of the present invention contains the above-mentioned component (C) and / or component (D), the content thereof is the same as that of component (A) and component (B). 0.1 to 500 per 100 parts by weight of total amount
Parts by weight, more preferably 10 to 300 parts by weight, particularly preferably 20 to 200 parts by weight.

Component (C) includes high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer resin, and ethylene-methyl methacrylate copolymer resin. , Ethylene-methacrylate copolymer resin, ethylene-acrylate copolymer resin, ethylene-methacrylic acid copolymer resin, ethylene-acrylic acid copolymer resin, ethylene-styrene copolymer resin, etc. Can be. These may be used alone or in combination of two or more.

By containing the component (C) in the above range, the cold shock resistance of the multilayer molded article can be improved.

Component (D) is a hydrogenated vinyl aromatic compound-conjugated diene copolymer other than component (B). Here, as the vinyl aromatic compound, the conjugated diene, and the like, those similar to the above are used. The structure of the copolymer is the same as described above.

As the component (D), for example, a hydrogenated vinyl aromatic compound-conjugated diene copolymer which satisfies the conditions (i) and (ii) but does not satisfy the condition (iii), ) And (iii), but not (ii), a hydrogenated vinyl aromatic compound-conjugated diene copolymer, which satisfies the above conditions (ii) and (iii) but does not satisfy (i) Hydrogenated vinyl aromatic compound-conjugated diene copolymer which does not satisfy the condition (i), hydrogenated vinyl aromatic compound which satisfies the condition (i) but does not satisfy the conditions (ii) and (iii) -Based copolymer, and the above (i) to
Examples include hydrogenated vinyl aromatic compound-conjugated diene copolymers which do not satisfy all the conditions of (iii).

For example, when a hydrogenated vinyl aromatic compound-conjugated diene copolymer is used which satisfies the conditions (i) and (iii) but does not satisfy the condition (ii), the above range is not satisfied. By containing the component (D), various physical properties such as tensile strength and cold impact resistance of the obtained multilayer molded article can be improved.

The thermoplastic elastomer composition used in the multilayer molded article of the present invention may further comprise, if necessary, an adhesive resin component, in addition to the essential components (A) and (B). Various additional components and the like can be blended.

As the adhesive resin component, for example, a rosin resin, a polyterpene resin, a synthetic petroleum resin, a coumarone resin, a phenol resin, a xylene resin, a styrene resin, an isoprene resin, and the like are appropriately compounded. it can. Examples of the rosin-based resin include natural rosin; polymerized rosin; partially or completely hydrogenated rosin; glycerin ester, pentaerythritol ester of these various rosins,
Esterified products such as ethylene glycol ester and methyl ester; disproportionation, fumaration of these various rosins,
Rosin derivatives treated with lime or an appropriate combination of these are mentioned.

Examples of polyterpene resins include homopolymers or copolymers of cyclic terpenes such as α-pinene, β-pinene and dipentene; various terpenes such as α-pinene, β-pinene and dipentene, phenol and bisphenol. Terpene-phenolic resin (α-pinene-phenolic resin, dipentene-phenolic resin, terpene-bisphenolic resin, etc.) which is a copolymer with a phenolic compound of the formula (1): various terpenes such as α-pinene, β-pinene, dipentene An aromatic modified terpene resin which is a copolymer with an aromatic monomer is exemplified.

As the synthetic petroleum resin, naphtha cracked oil C
₅ fraction, C ₆ -C ₁₁ fraction and homopolymers or copolymers of other olefinic fraction; these polymers of hydrogenated products (aliphatic petroleum resin, aromatic petroleum resin, alicyclic Petroleum resin, aliphatic-alicyclic copolymer resin, etc.). Further, copolymers of each fraction of the above naphtha cracked oil and the above-mentioned various terpenes and copolymerized petroleum resins which are hydrogenated products thereof may also be mentioned. The C ₅ fraction here naphtha cracked oil, isoprene, cyclopentadiene, 1,3-pentadiene, 2-methyl-1-butene, 2-methyl-2-
Methylbutene such as butene, 1-pentene, pentene such as 2-pentene, preferably dicyclopentadiene, indene as C ₆ -C ₁₁ fraction, styrene,
Preferred are methylstyrenes such as o-, m-, p-vinyltoluene, α-, β-methylstyrene, methylindene, ethylindene, vinylxylene, propenylbenzene and the like.Other olefin-based fractions include butene,
Hexene, heptene, octene, butadiene, octadiene and the like are preferred.

Examples of the phenolic resin include an alkylphenol resin, an alkylphenol-acetylene resin obtained by condensation of an alkylphenol and acetylene, and modified products thereof. Here, the phenolic resin may be any of a novolak resin obtained by converting phenol to methylol with an acid catalyst, and a resol type resin obtained by converting phenol to methylol with an alkali catalyst.

Examples of the xylene resin include a xylene-formaldehyde resin composed of m-xylene and formaldehyde, and a modified resin obtained by adding and reacting a third component to the xylene-formaldehyde resin.

Examples of the styrene resin include low molecular weight polystyrene, copolymer resin of α-methylstyrene and vinyl toluene, and copolymer resin of styrene, acrylonitrile and indene.

[0041] As the isoprene-based resin, a resin obtained by copolymerization of C ₁₀ alicyclic compound is a dimer product of isoprene and C ₁₀ chain compound.

Among the above-mentioned adhesive resin components, rosin-based resins, polyterpene-based resins, synthetic petroleum resins, and the like are preferable, and among these, those having an aliphatic and / or alicyclic structure are the thermoplastic resins obtained. It is more preferable from the viewpoint of transparency of a molded article molded using the resin composition. Here, as a particularly preferable tackifying resin having an aliphatic and / or alicyclic structure, a rosin-based resin is a partially or completely hydrogenated rosin and a derivative thereof, and a polyterpene-based resin is a homopolymer of a cyclic terpene. Or a synthetic petroleum resin, such as an aliphatic petroleum resin, an alicyclic petroleum resin, an aliphatic-alicyclic copolymer resin, or a hydrogenated product of a copolymer of naphtha-decomposed oil and various terpenes. is there. These resin components are used alone or in combination of two or more. In addition, as the resin component, a corresponding commercially available product can be used.

As various additional components, for example, additives, fillers, softeners, flame retardants, high-frequency processing aids, glitter fillers, nucleating agents, plasticizers, antibacterial agents and the like can be appropriately compounded.

The additives include, for example, antioxidants,
Various stabilizers such as antioxidants, antiozonants, ultraviolet absorbers, and light stabilizers can be appropriately compounded. Also,
Examples include antistatic agents, slip agents, internal release agents, coloring agents, dispersants, antiblocking agents, lubricants, antifogging agents, and the like.
Examples of the filler include glass fiber, carbon fiber, metal fiber, glass beads, asbestos, mica, calcium carbonate, potassium titanate whisker, talc, aramid fiber, barium sulfate, glass flake, and fluororesin.

As the softener, for example, naphthenic oil,
Mineral oil-based softeners such as paraffin-based mineral oils.

Examples of the flame retardant include inorganic compounds such as antimony flame retardant, aluminum hydroxide, magnesium hydroxide, zinc borate, guanidine flame retardant, and zirconium flame retardant; ammonium polyphosphate, ethylene bistris (2 -Cyanoethyl) phosphonium chloride, tris (tribromophenyl) phosphate, tris (tribromophenyl) phosphate, tris (3-
Phosphoric esters and phosphorus compounds such as hydroxypropyl) phosphine oxide; chlorinated flame retardants such as chlorinated paraffins, chlorinated polyolefins and perchlorocyclopentadecane; hexabromobenzene, ethylenebisdibromonorbornanedicarboximide, ethylenebistetrabromophthalimide And brominated flame retardants such as tetrabromobisphenol A derivatives, tetrabromobisphenol S, and tetrabromodipentaerythritol, and mixtures thereof.

As a high frequency processing aid, for example, a polar polymer can be added. Specific examples of the polar polymer include acrylic acid, methacrylic acid, ethacrylic acid,
Unsaturated monocarboxylic acids such as crotonic acid; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid; unsaturated carboxylic acid esters such as methyl methacrylate, methyl acrylate and ethyl acrylate; ionomers of unsaturated carboxylic acids A copolymer of ethylene with one or more comonomers selected from vinyl esters of saturated carboxylic acids such as vinyl acetate and vinyl propionate.

The thermoplastic elastomer composition used in the multilayer molded article of the present invention comprises a component (A), a component (B) and, if necessary, other components, which are known in the art, such as a Banbury mixer and an extruder. And can be obtained by mixing. Further, the respective components can be mixed in a pellet state without melting, and used for molding. Further, as the thermoplastic elastomer composition, a partially crosslinked thermoplastic elastomer composition which has been subjected to a known crosslinking treatment, such as sulfur crosslinking or organic peroxide crosslinking, may be used as necessary. Among them, a dynamic crosslinking method using a crosslinking agent such as an organic peroxide or a crosslinking assistant such as bismaleimide or divinylbenzene is preferably used.

The multilayer molded article of the present invention is a multilayer molded article having a foamed layer comprising the thermoplastic elastomer composition of the present invention. Examples of the configuration of the multilayer molded body include a non-foamed layer-foamed layer, a non-foamed layer-foamed layer-non-foamed layer, a foamed layer-non-foamed layer-foamed layer, a non-foamed layer-foamed layer-non-foamed layer-foamed The configuration of layers and the like can be given. Here, the thermoplastic elastomer composition of the present invention can also be used for a non-foamed layer, and when there are two or more layers made of the thermoplastic elastomer composition of the present invention, the thermoplastic elastomer composition constitutes the thermoplastic elastomer composition. The contents of the component (A), the component (B) and other components selected as necessary may be the same or different. Further, the multilayer molded article of the present invention may include a layer made of various polymers other than the thermoplastic elastomer composition of the present invention. For example, a core material may be added to a foamed layer made of the thermoplastic elastomer composition of the present invention. Multi-layer molded body laminated, on the foam layer side of the multilayer molded body consisting of a non-foamed layer and a foamed layer made of the thermoplastic elastomer composition of the present invention,
Furthermore, a multilayer molded body obtained by laminating a core material can be given.

By using the thermoplastic elastomer composition of the present invention, the multilayer molded article of the present invention can increase the expansion ratio of the foamed layer, and is excellent in the feel such as cushioning and rebound resilience, and excellent in lightweight. A molded article can be obtained. In the case of a multilayer molded article having a non-foamed layer made of the thermoplastic elastomer composition of the present invention, a multilayer molded article excellent in various physical properties such as scratch resistance, abrasion resistance and impact resistance can be obtained. The surface of the non-foamed layer may be provided with a grain pattern, a stitch pattern, or the like. In this case, a multilayer molded article having excellent design properties can be produced.

The thickness of the foamed layer in the multilayer molded article of the present invention is preferably 1 to 10 mm, more preferably 2 mm, from the viewpoint of enhancing the feel, resilience and strength of the multilayer molded article.
８8 mm. In addition, the thickness of the non-foamed layer in the multilayer molded article of the present invention is preferably from 0.1 to 2 mm, more preferably from 0.5 to 1.2 mm, from the viewpoint of enhancing piercing strength and flexibility.

In the multilayer molded article of the present invention, the expansion ratio of the foamed layer comprising the thermoplastic elastomer composition of the present invention is preferably 2.7 to 6.0 from the viewpoints of tactile sensation, light weight, rebound resilience and strength. And more preferably 3.0 to 3.0
It is 5.5 times, and more preferably 3.5 to 5.0 times.

The multilayer molded article of the present invention is produced by a known molding method. For example, it can be manufactured by the following method.

(1) Production of Multilayer Molded Body Consisting of Non-foamed Layer-Foamed Layer The multilayered molded article constituted of non-foamed layer-foamed layer is produced by a method such as an adhesion or heat fusion method, an integrated production method, or the like. be able to.

Examples of the material used for the non-foamed layer include the thermoplastic elastomer composition of the present invention, and thermoplastic elastomers other than the thermoplastic elastomer composition of the present invention (polyolefin-based thermoplastic elastomer composition, polyurethane-based thermoplastic elastomer). And the like, and various polymers such as a polyvinyl chloride resin, the above-mentioned polyolefin resin or a crosslinked product thereof are usually used. Among these, when the non-foamed layer is used as the skin layer of the multilayer molded article, the thermoplastic elastomer composition of the present invention is preferable from the viewpoint of the scratch resistance of the multilayer molded article. When a polyolefin resin is used as the component (A), from the viewpoint of recycling and the like,
A polyolefin resin or a crosslinked product thereof, and a polyolefin thermoplastic elastomer composition are preferred. It should be noted that pigments, various stabilizers, fillers, and the like can be added to these polymers.

Adhesion or heat fusion method A method of molding the thermoplastic elastomer composition of the present invention into a foam having a desired shape, and then bonding a separately produced non-foam using a known adhesive, It is a method of integrating by a wearing method.

Examples of a method for molding the thermoplastic elastomer composition into a non-foamed body having a desired shape include an extrusion molding method, an injection molding method, a compression molding method, a powder molding method, and a vacuum molding method. When the non-foamed body is manufactured by a powder molding method, for example, JP-A-10-30036, JP-A-5-5050, and JP-A-2001-490.
An elastomer composition powder for powder molding described in JP-A-52-52, etc. is preferably used.

As a method for molding the thermoplastic elastomer composition of the present invention into a foam having a desired shape, extrusion molding and injection molding (low-pressure injection molding) may be carried out by mixing the thermoplastic elastomer composition of the present invention with a foaming agent. Molding, injection compression molding, etc.), powder molding, in-mold foam molding, and the like.

The foaming agent used for producing the foam is not particularly limited, and is a chemical foaming agent represented by baking soda, azodicarboxylic acid amide, and the like; a physical foaming agent represented by carbon dioxide, nitrogen gas, butane, and the like. Agents can be used, and these can be used in combination. In addition, an inorganic filler such as talc or silica may be added as a foam nucleating agent.

Examples of the chemical foaming agent include those of the thermal decomposition type which decomposes upon heating to generate gas, such as azodicarbonamide, p, p'-oxybis (benzenesulfonylhydrazide), azobisisobutyronitrile,
Barium azodicarboxylate, hydrazodicarbonamide and the like can be mentioned. Further, in order to obtain a foam having uniform cells, it is preferable that the decomposition temperature of the blowing agent is around the melting temperature of the thermoplastic elastomer composition, and a foaming aid for adjusting the decomposition temperature of the blowing agent is used. It may be added. Further, in order to prevent non-uniform bubbles from being generated due to heat generated during decomposition of the chemical foaming agent, a foaming agent exhibiting an endothermic decomposition behavior may be used in combination.

The amount of the chemical foaming agent to be added is not particularly limited as long as the required amount of gas is generated. From the viewpoints of rebound resilience, tactile sensation, lightness, appearance, flexibility and strength, thermoplastic elastomers are used. The amount is usually 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the composition.

The chemical foaming agent may be blended as long as the thermoplastic elastomer composition and the chemical foaming agent are uniformly blended, and examples thereof include a mechanical mixing method using a tumbler mixer or a Henschel mixer. The thermoplastic elastomer composition before blending the chemical foaming agent may be melt-kneaded using an extruder or the like in advance. When the component (A), the component (B), and the component to be added as necessary, which constitute the thermoplastic elastomer composition, are in the form of pellets or powder, these and the chemical foaming agent are mechanically combined by the above-described method. It is also possible to use a mixture which is mixed in a suitable manner. Further, it is also possible to use those obtained by melting and kneading the component (A), the component (B), the component added as required, and the chemical foaming agent at a temperature not higher than the decomposition temperature of the chemical foaming agent.

As the physical foaming agent used in the present invention, an inert gas such as nitrogen gas or carbon dioxide gas is usually used. Further, a physical foaming agent and a chemical foaming agent can be used in combination.

A foaming agent and a foaming auxiliary may be used in combination as necessary. Examples of the foaming aid include zinc oxide, zinc nitrate, basic zinc carbonate, zinc stearate, lead phthalate, lead carbonate, urea, and glycerin. It is also preferable to use a powder of calcium carbonate, talc, silica or the like as a foam nucleating agent in combination.

In particular, when a foam comprising the above thermoplastic elastomer composition is produced by an extrusion molding method and then the non-foam and foam are adhered with an adhesive to produce a multilayer molded article, It is preferable to use a mixed gas of nitrogen gas and carbon dioxide gas as a gas from the viewpoint of obtaining a foamed molded article having a fine cell diameter. In this case, for example, a mixed gas of nitrogen gas and carbon dioxide gas is directly extruded. It is also possible to use a method of injecting into a machine, or a combination of a pyrolytic foaming agent that mainly generates nitrogen gas by decomposition and a pyrolytic foaming agent that mainly generates carbon dioxide gas by decomposition.

Here, as the pyrolytic foaming agent mainly generating nitrogen gas, azodicarbonamide, azobisisobutyronitrile, dinitrosopentamethylenetetramine, p-toluenesulfonylhydrazide, p, p'-
Oxy-bis (benzenesulfonyl hydrazide) can be exemplified, and azodicarbonamide is preferably used. These foaming agents may be used in combination.

Examples of the pyrolytic foaming agent that mainly generates carbon dioxide gas include sodium bicarbonate, ammonium carbonate and ammonium bicarbonate, and sodium bicarbonate is preferably used. These foaming agents may be used in combination.

When a thermally decomposable organic foaming agent which mainly generates nitrogen gas and a thermally decomposable inorganic foaming agent which mainly generates carbon dioxide gas are used in combination, the weight ratio of the former foaming agent to the latter foaming agent is as follows: From the viewpoint that the bubble diameter is fine and uniform, 1 /
99-30 / 70, preferably 1 / 99-20 / 80,
More preferably, it is 1/99 to 10/90.

When a mixed gas of nitrogen gas and carbon dioxide is used as the foaming agent, the volume ratio of nitrogen gas to carbon dioxide is 1/99 to 30/70, preferably 1/99 to 20/8.
0, more preferably 1/99 to 10/90. In this case, it is preferable to use a powder of calcium carbonate, talc, silica or the like as a foam nucleating agent.

When a foam is produced by the extrusion molding method, a mixture of the above-mentioned thermoplastic elastomer composition and a foaming agent is charged into a raw material charging port, and the melting of the thermoplastic elastomer composition and the gas The mixture is thoroughly kneaded with the melt of the thermoplastic elastomer composition and the gas to homogenize the mixture, and after the homogenized mixture is cooled to a temperature suitable for foaming, the mixture is extruded from a die. Foamed and cooled by a take-off machine.

There is no particular limitation on the extruder used for the production of the foam by the extrusion molding method, and at least the thermoplastic elastomer composition and the foaming gas are sufficiently kneaded and mixed.
Any extruder that can be made uniform and cooled / adjusted to a temperature suitable for foaming may be used, and examples of such an extruder include a single screw extruder and a multi-screw extruder. Generally, a twin screw extruder is used as the multi-screw extruder, and the screw may be rotated in the same direction or in different directions. Regarding the type of the twin-screw extruder, a parallel twin-screw extruder in which the diameter of the screw is constant or an oblique twin-screw extruder in which the tip of the screw has a small diameter may be used. In the case of a twin-screw extruder, a sealing segment is preferably provided on the screw because the foaming gas easily escapes from the hopper. The single-screw extruder is preferably used from the viewpoint that the foaming gas hardly comes out of the hopper and the cost is low. It is also possible to use a tandem extruder in which a single-screw extruder and a multi-screw extruder are combined. As the die of the extruder, a flat die or a circular die can be used, and the thickness of the foam layer can be controlled by adjusting the lip gap at the tip of the die.

In the case of producing a foam using a pair of male and female molds by an injection molding method (such as a low pressure injection molding method or an injection compression molding method), the thermoplastic elastomer of the present invention can be produced in the same manner as in the extrusion molding method. The composition and the chemical and / or physical blowing agent are melt-kneaded in a supply cylinder to homogenize. The molten thermoplastic elastomer composition containing the foaming agent, which has been melt-kneaded and homogenized, is supplied into a mold cavity formed by a pair of male and female molds, and after shaping as necessary,
A foam can be manufactured by cooling and solidifying in a mold.

In the injection molding method (low-pressure injection molding method, injection compression molding method, etc.), supply into the mold cavity is performed.
Before the shaped foamed thermoplastic elastomer composition is cooled and solidified, the male mold and / or the female mold are opened by a predetermined amount, and by expanding the mold cavity volume, a foam having a higher expansion ratio is obtained. It can also be manufactured. (Hereinafter, it will be referred to as the mold slide method.)

Integral production method Non-foamed layer-A multilayer molded article comprising a foamed layer comprising the thermoplastic elastomer composition of the present invention is integrally produced by a coextrusion molding method, a two-layer injection molding method, a two-layer powder molding method and the like. It is also possible. In this case, the multilayer molded body is manufactured into a desired shape such as a sheet shape (a complicated shape can be formed by the two-layer powder molding method), a tubular shape, and the like.

Further, by forming the foam layer in a state where the non-foam is placed in the male mold or the female mold, it is possible to integrate the non-foam and the foam simultaneously with the molding of the foam. Can also be produced.

The multilayer molded body manufactured by such a method can be further processed into a desired shape by applying a vacuum forming method or the like or by bending.

(2) Production of Multilayer Molded Product Consisting of Non-foamed Layer-Foamed Layer-Core Material Layer Multilayered molding obtained by further laminating a core material on the foamed layer side of a multilayered molded product composed of a non-foamed layer-foamed layer The body can also be used. As a material constituting the core material, a resin having rigidity such as a known polypropylene resin, polyethylene resin, polystyrene resin, and acrylonitrile-butadiene-styrene copolymer is preferably used. The thickness of the core layer (core layer) is usually 1 to 20 mm, preferably 2 to 5 mm, from the viewpoint of increasing the strength of the multilayer molded body and the viewpoint of flexibility. The core material may be a preformed foam, and in this case, a multi-layer molded article with even better lightness can be obtained.

Examples of the method for producing a multilayer molded body composed of a non-foamed layer, a foamed layer, and a core material layer include an adhesive or heat fusion method, a method of supplying and molding a molten resin for a core material, and a laminating integrated molding method. can give.

Adhesion or heat fusion method After manufacturing a two-layer molded body composed of a non-foamed layer and a foamed layer,
It can be produced by laminating a core material with a known adhesive or heat fusion, or after producing a two-layer molded body composed of a foamed layer and a core material, laminating a non-foamed body by the same method. Alternatively, a non-foamed body, a foamed body, and a core material can be bonded using the present method.

A method for supplying and shaping the molten resin for the core material The melt for forming the core material is formed of a non-foamed layer and a foamed layer by a method such as an injection molding method (such as a low-pressure injection molding method or an injection compression molding method). It can also be manufactured by supplying the mixture to the foam layer side of the multilayer molded body and shaping it as necessary to integrate the core material simultaneously with the molding.

Laminate integral molding method The laminate integral molding method specifically uses an injection molding method (such as a low-pressure injection molding method or an injection compression molding method) or a compression molding method.
Male and female using a pair of molds, pre-shaped non-foam and pre-shaped core material are placed in the male mold and female mold respectively,
Next, a melt containing a foaming agent is supplied between the non-foamed material and the core material, and the foam is formed between the non-foamed material and the core material by shaping if necessary. At the same time that the non-foamed body, the foamed body and the core material are integrated.

Further, in the laminating and integral molding method, a melt containing a foaming agent is supplied between the non-foamed body and the core material, and is shaped as necessary. Opening the mold and / or female mold by a predetermined amount, and expanding the molding volume of the foam formed between the non-foamed body and the core material, thereby forming a multilayer molded body having a foamed layer with a higher expansion ratio. It can also be manufactured (mold slide method).

The expansion ratio of the foamed layer is adjusted mainly by the filling amount of the polymer containing a foaming agent between the non-foamed layer and the core material when a laminated integral molding method other than the mold slide method is used.
In the mold slide method, the expansion ratio can be arbitrarily adjusted also by the opening amount of the male mold and / or the female mold. As the foaming agent, the above-mentioned foaming agents can be used, and a foaming aid and a foam nucleating agent may be used in combination.

In these production methods, the bonding method uses a solvent and therefore has a problem in terms of working environment. In the method of supplying molten resin for the core material, the foaming layer is formed when the core material is formed. There is a problem that it is easily crushed under the influence of heat and pressure. Therefore, it is preferable to use a lamination integral molding method.

Hereinafter, a thermoplastic elastomer composition containing a foaming agent is supplied in a molten state between a non-foamed body and a core material using an injection compression molding method and foamed, and then a non-foamed layer—a foamed layer—
An example of a method of laminating and integrating a core material will be described.

FIG. 1 shows a female mold (1) used in the injection compression molding method and a male mold (2) having a molten resin passage (3). A pre-molded non-foamed body (4) is arranged in the female mold (1), and is also pre-molded in the male mold (2) at a location corresponding to the position of the resin passage (3). A core material (5) having a formed through hole (6) is arranged in advance.

As shown in FIG. 2, the male and female molds are brought close to predetermined positions, and a melt (8) of a thermoplastic elastomer composition containing a blowing agent melt-kneaded by an injection machine (not shown). ) Is passed through the resin passage (3) of the male mold (2) and the non-foamed body (4) and the core (5) through the through hole (6) of the core (5).
Into the cavity (7) formed by

The shape of the through-hole is not particularly limited as long as a melt of the thermoplastic elastomer composition containing a foaming agent can be supplied into the cavity (7).
Arbitrary hole shapes, such as a round hole and a square hole, can be applied. The size of the through-hole is not particularly limited, but if it is too large, the rigidity of the core material is reduced.

The melt-kneading temperature of the foaming agent and the thermoplastic elastomer composition in the injection machine is arbitrarily set depending on the foaming agent to be used, etc., and is usually in the range of 170 to 260 ° C.

Next, after the supply is completed or while the supply is being performed, the male mold (2) and / or the female mold (1) are movable-clamped to form a melt of the thermoplastic elastomer composition containing a foaming agent. (8) is filled in the cavity (7), shaped to foam the thermoplastic elastomer composition, and the non-foamed body (4) and the core material (5) are laminated and integrated (FIG. 3). The shaping pressure by this mold clamping is desirably as low as possible in order to make the foamed thermoplastic elastomer composition more easily foamed, and preferably 10 MPa or less.

After the lamination and integration, the resultant is cooled in a mold, then the mold is opened and the multilayer laminate is taken out to obtain a multilayer laminate (9) comprising a non-foamed layer, a foamed layer and a core material.

FIG. 4 shows an example of the mold slide method. The melt (8) of the thermoplastic elastomer composition containing the foaming agent containing the foaming agent shown in FIG. 7) Filling, shaping and foaming the inside, laminating and integrating the non-foamed body (4) and the core material (5), and then while the cooling of the foamed thermoplastic elastomer composition is not completed, the male mold ( 2) By expanding the cavity volume by opening the female mold (1) by a predetermined amount and / or, it becomes possible to obtain the multilayer laminate (10) having a higher foaming ratio of the foamed layer.

The timing for opening the mold by a predetermined amount may be any time as long as the thermoplastic elastomer composition can be foamed. However, if the cooling proceeds too much, the foaming ratio cannot be increased. It is desirable to do this.

In place of the above-mentioned core material, a sheet made of a material other than the core material is used to form a non-foamed layer—a foamed layer made of the thermoplastic elastomer composition of the present invention—a layer made of a material other than the core material. Can be produced. The sheet made of a material other than the core material may be made of the thermoplastic elastomer composition of the present invention,
It may be different.

Further, a grain or stitch pattern is formed on the surface of the multilayer molded article by previously applying a grain or stitch pattern to the product surface of the female mold or the male mold which forms the non-foamed layer. It is possible to impart a sense of quality to the multilayer molded article.

The multilayer molded article of the present invention utilizes its excellent features to produce vehicle parts, electric wires, building materials, agricultural / fishery / horticultural supplies, chemical industrial supplies, civil engineering materials, industrial / industrial materials, furniture, stationery. It can be used for daily and miscellaneous goods, clothing, containers and packaging supplies, toys, leisure goods and the like. Vehicle parts include, for example, automobile interior skins such as instrument panels, doors, pillars, airbag covers; over fenders, crowding panels, roof rails,
Automotive exterior parts such as side moldings; bicycle parts and the like. Examples of the electric wire include a plastic cable, an insulated electric wire, an electric wire protection material, and the like. Examples of building materials include wall and ceiling materials such as ribs, skirting boards, panels, and tarpaulins; roof materials such as corrugated sheets, gutters, and roof base materials; floor materials such as sill materials and tiles; Waterproofing applications such as rods and waterproof sheets, equipment and equipment parts applications such as ducts, cable ducts, prefabricated members and septic tanks; construction and construction materials such as building edges, architectural gaskets, carpet holders, angles and louvers; joiners, Industrial materials such as curing sheets can be used. Examples of the agricultural, marine and horticultural products include agricultural house applications. Industrial / industrial materials include, for example, machine covers, machine parts, packing, gaskets, hoses, tubes, flanges, leather canvas, metal protective films and the like. Examples of furniture include cabinets, stools, sofas, mats, curtains, tablecloths, and the like. Examples of stationery include card cases, writing implement cases, accessories, key cases, cash card cases, book covers, notebook covers, binders, notebooks, covers, files, holders, magazine trays, albums, and the like. Daily and sundry goods include, for example, bath lids, sunglasses, clothes covers, futon cases, western umbrellas,
Blinds, shelves, shelf holders, picture frames, trays, belts, bags,
Hoses, tubes, and the like. As clothes, raincoats, kappa, rain gear sheets, children's leather coats, shoes,
Shoe covers, footwear, gloves, ski wear, hats,
Secondary materials for hats and the like are given. Examples of containers and packaging supplies include food containers, clothing packages, packaging and packaging materials, cosmetic containers, containers, caps, food packs, and the like.

[0097]

The present invention will be described more specifically with reference to the following examples.

[I] Evaluation of Component (A) Thermoplastic Resin (1) Melt Flow Rate The melt flow rate at 230 ° C. was measured in accordance with JIS-K-7210 (load 2.16 kg). (2) Die swell ratio According to JIS-K-7199, a thermoplastic resin is extruded under the conditions of a barrel temperature of 190 ° C., a capillary diameter of 1 mm, a capillary length of 10 mm, and a shear rate of 122 sec ⁻¹ , and a die swell ratio (diameter of sample / capillary). diameter)
Was determined from the value measured using a caliper.

[0099] [II] Component (B) a hydrogenated vinyl aromatic compound - Evaluation of conjugated diene-based copolymer (1) using a carbon tetrachloride solution of content components of the vinyl aromatic compound unit (B), ¹ It was determined by an H-NMR measurement method (frequency: 90 MHz). (2) carbon number 2 based on the total number of hydrogenated conjugated diene units
The ratio of the number of hydrogenated conjugated diene units having the above side chains The component (B) was subjected to infrared analysis and determined by the Morero method. (3) Hydrogenation rate of double bond of conjugated diene unit The hydrogenation rate was determined by 1H-NMR measurement (frequency: 90 MHz) using the carbon tetrachloride solution of the component (B).

[III] Evaluation method of multilayer molded article Various properties of the multilayer molded article described in Examples and Comparative Examples were measured by the following methods. (1) Measurement of Foaming Ratio The thickness of the foamed layer of the obtained molded article was determined by measuring the thickness when the foamed layer was not foamed (Examples 1 and 2 and 2 m in Comparative Example 1).
The value divided by m) was taken as the expansion ratio. The higher the expansion ratio, the better the feel, lightness and resilience. (2) Flexibility According to JIS-K-6253, type A from the non-foamed layer side
The durometer hardness was measured. (3) Appearance (uniformity of foam cells) The foam layer was visually observed, and the case where the foam cells were uniform was evaluated as ○, and the case where the foam cells were non-uniform was evaluated as x.

Example 1 A non-foamed body made of a polyolefin-based thermoplastic elastomer composition (WT315, manufactured by Sumitomo Chemical Co., Ltd.) in a female mold of a disk mold having a diameter of 300 mm and made of polypropylene and ethylene / α-olefin rubber. (Thickness 0.5
mm) and a 4 mm thick polypropylene resin core material (a polypropylene resin AZ864E4 manufactured by Sumitomo Chemical Co., Ltd.) having a through hole with a diameter of 10 mm at a position corresponding to the position of the resin passage in the male mold. The distance between the male mold and the female mold was adjusted to 8.5 mm (the clearance between the non-foamed body and the core material was 4 mm). A polypropylene resin (melt flow rate = 4.0 g / 10 minutes, between the non-foamed body and the core material by the cavity slide method of the injection compression molding method,
30 parts by weight of a pellet having a die swell ratio of 2.3), a hydrogenated styrene-butadiene block copolymer (melt flow rate = 10 g / 10 min, a styrene unit content of 9% by weight, and the total number of hydrogenated butadiene units) Hydrogenated styrene-butadiene in which the ratio of the number of hydrogenated butadiene units having a side chain having 2 or more carbon atoms (in this example, an ethyl group) is 80% and the hydrogenation ratio of the double bond of the butadiene unit is 98% −
70 parts by weight of pellets of styrene block copolymer),
Using a thermoplastic elastomer composition mixed with 8 parts by weight of a powdery foaming agent master batch MB3074 (manufactured by Sankyo Kasei) containing 40% of an inorganic chemical foaming agent, a non-foaming layer
Laminate integrated molding of a multilayer molded body composed of a foam layer and a core material layer was performed. In this embodiment, a method of foaming at the time of mold slide was used.

The thermoplastic elastomer composition containing the foaming agent was charged into an injection machine and melted at a temperature of 200 ° C.
Kneaded. After the melt-kneading, an amount of the melt-kneaded material having a thickness of 2 mm in terms of an unfoamed state is placed between the core material and the non-foamed material in the unclosed male and female molds adjusted to a temperature of 50 ° C. (non-foamed material). And the core material has a clearance of 4 mm)
Close the mold with Pa, and make the distance between the male mold and the female mold 6.5m
m (the thickness of the melt-kneaded body was 2 mm), and the non-foamed body, the melt-kneaded body, and the core material were laminated and integrated.

Next, after pressurizing at 5 MPa for 1.5 seconds from the completion of shaping by mold clamping, the mold is opened until the distance between the male mold and the female mold becomes 13.5 mm. Foamed. After cooling in a mold for 60 seconds in this state, the mold was opened to take out a multilayer molded body composed of a non-foamed layer, a foamed layer, and a core material layer. Table 1 shows the evaluation results of the multilayer molded body.

Comparative Example 1 In Example 1, Tuftec H104 manufactured by Asahi Kasei Corporation was used instead of the hydrogenated styrene-butadiene copolymer.
2 (melt flow rate at 230 ° C., 2.16 kg load = 30 g / 10 min, styrene unit content 15% by weight, hydrogenated butadiene having a side chain having 2 or more carbon atoms based on the total number of hydrogenated butadiene units Multilayer molding in the same manner as in Example 1 except that the ratio of the number of units was 42% and the hydrogenation rate of the double bond of the butadiene unit was 98% (hydrogenated styrene-butadiene-styrene block copolymer). Body manufactured. Table 1 summarizes the evaluation results of the multilayer molded body.

Example 2 20 parts by weight of polypropylene resin pellets used in Example 1, 60 parts by weight of hydrogenated styrene-butadiene copolymer pellets used in Example 1, propylene-ethylene copolymer resin (ethylene Unit content 4% by weight, melt flow rate = 12 g / 10 min, die swell ratio = 3.5)
20 parts by weight of pellets, powdered foaming agent masterbatch M
A multilayer molded article was produced in the same manner as in Example 1 except that a thermoplastic elastomer composition mixed with 8 parts by weight of B3074 (manufactured by Sankyo Chemical) was used. Table 1 summarizes the evaluation results of the multilayer molded body.

In these examples, a non-foamed body made of a thermoplastic elastomer composition and a resin core material are integrally formed by lamination using the cab-slide method to obtain a multilayer molded body having a high expansion ratio, that is, excellent in lightness. Could be obtained.

[0107]

[Table 1] Evaluation results of multilayer molded products

[0108]

As described above, according to the present invention,
Specific thermoplastic resin and a specific hydrogenated vinyl aromatic compound-a multilayer molded article having a foamed layer comprising a thermoplastic elastomer composition containing a conjugated diene copolymer, feel, lightness, rebound resilience, A multilayer molded article having excellent appearance, heat resistance, and flexibility was provided. Since the multilayer molded body can be excellent in impact resistance, scratch resistance, abrasion resistance, strength, and cold resistance, vehicle parts, electric wires, building materials, agriculture / fisheries /
Gardening supplies, chemical industrial supplies, civil engineering materials, industrial and industrial materials,
It can be used for furniture, stationery, daily and miscellaneous goods, clothes, containers and packaging supplies, toys, leisure goods and the like.

[Brief description of the drawings]

FIG. 1 is a view showing that a non-foamed body and a core material are arranged in advance in an injection compression molding method.

FIG. 2 is a view showing that a melt of a thermoplastic elastomer composition is supplied into a cavity in an injection compression molding method.

FIG. 3 is a diagram showing a method of filling a melt of a thermoplastic elastomer composition into a cavity, shaping the foam, and laminating and integrating the melt in the injection compression molding method.

FIG. 4 is a diagram showing a mold slide method in the injection compression molding method.

[Explanation of symbols]

1: Female mold 2: Male mold 3: Resin passage 4: Non-foamed material 5: Core material 6: Through hole 7: Cavity 8: Melt of thermoplastic elastomer composition containing foaming agent 9: Non-foamed layer -Multilayer molded body consisting of foam layer-core material layer 10: Multilayer molded body

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 101/00 C08L 101/00 (72) Inventor Hidemi Hozumi 5-1, Anesaki Beach, Ichihara City, Chiba Prefecture Sumitomo Chemical 4F074 AA08 AA24 AA32. BB12W BB14W BP01X FD326 GF00

Claims (7)

[Claims] 1. A composition comprising the following components (A) and (B), wherein the weight ratio of component (A) / component (B) is 5/95 to 95.
/ 5 The multilayer molded article which has a foamed layer which consists of a thermoplastic elastomer composition which is / 5. (A): The melt flow rate measured at 230 ° C. under a load of 2.16 kg is in the range of 0.001 to 100 g / 10 minutes, and the die swell ratio by a capillary rheometer (190 ° C., shear rate 122 sec ⁻¹ , L / D =
(B): a hydrogenated vinyl aromatic compound-conjugated diene copolymer satisfying all the conditions of the following formulas (i) to (iii): (I) The content of the vinyl aromatic compound unit is 50% by weight or less. (Ii) 2 carbon atoms based on the total number of hydrogenated conjugated diene units in the hydrogenated vinyl aromatic compound-conjugated diene copolymer. The ratio of the number of hydrogenated conjugated diene units having the above side chains is 60% or more (iii) 80 of the double bonds of the conjugated diene units in the hydrogenated vinyl aromatic compound-conjugated diene copolymer. % Must be hydrogenated 2. The multilayer molded article according to claim 1, wherein the component (A) is a polypropylene resin. 3. The multilayer molded article according to claim 1, comprising a non-foamed layer and a foamed layer, wherein the non-foamed layer is a non-foamed layer comprising the thermoplastic elastomer composition according to claim 1. 4. A non-foamed layer comprising a non-foamed layer and at least one selected from the following components (a) to (c):
The multilayer molded article according to claim 1 or 2, which is a non-foamed layer containing various kinds of components. (A) Polyolefin-based thermoplastic elastomer composition (b) Polyolefin-based resin (c) Cross-linked polyolefin-based resin 5. The multilayer molded article according to claim 3, wherein a core material is laminated on the foam layer side. 6. The multilayer molded article according to claim 5, wherein the core material is a core material containing a polypropylene resin. 7. The foamed layer is formed by injection molding.
6. The multilayer molded article according to any one of 6.