JP2001191456A - Molded object and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded object excellent in cushioning properties consisting of a skin layer comprising a thermoplastic elastomer composition containing a polyolefinic resin and a hydrogenated diene copolymer having a specific structure as essential components and a foamed layer comprising a thermoplastic elastomer composition containing a polyolefinic resin and a rubbery polymer having a specific structure and a method of manufacturing the same. SOLUTION: A two-layered molded object consists of an (A) layer being a skin layer comprising a thermoplastic elastomer composition containing (A-1) a polyolefinic resin and (A-2) a hydrogenated diene copolymer and a (B) layer being a foamed layer comprising a thermoplastic elastomer composition containing (B-1) a polyolefinic resin and (B-2) a rubbery polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article and a method for producing the molded article. More specifically, the present invention relates to a skin layer comprising a thermoplastic elastomer composition containing a polyolefin resin and a hydrogenated diene copolymer having a specific structure as essential components, and a rubber material having a specific structure and a polyolefin resin. A foam layer made of a thermoplastic elastomer composition containing a polymer as an essential component, which has excellent moldability, does not emit gloss even when heated to a temperature lower than the melting point of the polyolefin resin from about 80 ° C, The present invention relates to a molded article having excellent cushioning properties and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, vinyl chloride resins have been widely used for interior and exterior parts of automobiles, household appliances, stationery, office automation equipment, packaging containers, sports goods and the like. However, due to global environmental problems and the like, replacement of vinyl chloride resin has been promoted, and as an alternative, a thermoplastic elastomer composition containing an olefin-based thermoplastic elastomer or a polyolefin-based resin and a styrene-based thermoplastic elastomer has been used. Proposed.

For example, Japanese Patent Application Laid-Open No. 5-5050 proposes a molded product obtained by powder molding an olefin-based thermoplastic elastomer. Since the molded article made of the composition does not contain a vinyl chloride-based resin, it is excellent in that no harmful gas or the like is generated even when incinerated. However, there was a problem that the whitening was remarkable.

[0004] Japanese Patent Application Laid-Open No. 3-72512 discloses that
It describes a thermoplastic elastomer composition comprising a non-polar resin such as polypropylene and a hydrogenated diene copolymer having a specific structure. Since the molded article made of the composition is excellent in flexibility, it is excellent in moldability (for example, even if the molded article is bent at an acute angle, it does not cause poor appearance such as whitening in a bent portion), but about 80 ° C. Because it emits gloss when heated at a temperature lower than the melting point of the polyolefin-based resin, there has been a problem that when used outdoors, the appearance is poor (for example, when used outdoors, the temperature of the surface of the molded product may be reduced). It is known that the temperature rises to about 80 to 120 ° C.).

For automobile interior parts such as instrument panels, console boxes and door trims, a two-layer molded body composed of a skin layer made of a vinyl chloride resin and a foam layer made of a polyurethane material is widely used. Have been. In recent years, from the viewpoint of recycling and the like, there has been a movement to unify the skin layer and the foam layer into a material made of a thermoplastic elastomer composition, but both the skin layer and the foam layer are made of the thermoplastic elastomer composition, A two-layer molded article which does not emit gloss when heated at a temperature of about 80 ° C. to less than the melting point of the polyolefin resin and has excellent cushioning properties is not known.

[0006]

Under these circumstances, an object of the present invention is to provide a thermoplastic elastomer composition containing a polyolefin resin and a hydrogenated diene copolymer having a specific structure as essential components. A skin layer made of a product and a foamed layer made of a thermoplastic elastomer composition containing a polyolefin resin and a rubbery polymer having a specific structure as essential components. An object of the present invention is to provide a molded article which does not emit gloss even when heated to a temperature lower than the melting point of the resin and has excellent cushioning properties, and a method for producing the same.

[0007]

That is, the first invention of the present invention relates to a two-layer molded article comprising the following layers (A) and (B). (A) layer: 100 parts by weight of the following (A-1) and (A-2)
A skin layer comprising a thermoplastic elastomer composition containing 10 to 1000 parts by weight (A-1): a polyolefin-based resin (A-2): a hydrogenated diene-based copolymer satisfying all of the following conditions: water The added diene copolymer contains the following structural units (i) and (ii): (i): vinyl aromatic compound polymer block (ii): (ii-1), (ii-2) and (Ii-3) at least one block selected from (ii-1): a block obtained by hydrogenating a random copolymer block of a vinyl aromatic compound and a conjugated diene (ii-2): a vinyl aromatic compound A block comprising a conjugated diene and a hydrogenated tapered block in which a vinyl aromatic compound is gradually increased. (Ii-3): A block which is hydrogenated with a conjugated diene polymer: included in a hydrogenated diene copolymer Including all vinyl aromatic compound units The content is 8 to 20% by weight: the ratio of the content of the vinyl aromatic compound unit of (i) to the total content of the vinyl aromatic compound unit in the hydrogenated diene copolymer (S: percentage) Is 3% or more: ratio of the number of hydrogenated conjugated diene units having side chains having 2 or more carbon atoms to the total number of hydrogenated conjugated diene units in the hydrogenated diene-based copolymer (V: percentage ) Exceeds 60%: The relationship between the above (S) and the above (V) in the hydrogenated diene copolymer is represented by the relational expression (1): V ≦ 0.375 × S + 62.5 (1): 80% or more of the double bond of the conjugated diene unit in the hydrogenated diene copolymer is hydrogenated: the number average molecular weight of the hydrogenated diene copolymer is 50,000 to 60
(B) layer: 100 parts by weight of the following (B-1) and (B-2)
Foamed layer made of a thermoplastic elastomer composition containing 10 to 1000 parts by weight (B-1): polyolefin resin (B-2): rubbery polymer, obtained by kneading with (B-1) T obtained by solid viscoelasticity measurement of the resulting composition
In the an δ-temperature dependence curve, the tan δ peak temperature of (B-1) and (B-
2) A rubbery polymer that gives a new single tan δ peak at a temperature different from any of the tan δ peak temperatures. The second invention of the present invention is a molding of the first invention, which is produced by a powder molding method. It concerns the body. Further, the third invention of the present invention relates to a multilayer molded article in which a thermoplastic core material is laminated on the (B) layer side of a two-layer molded article, and a method for producing the same.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Among the two-layer molded articles of the present invention,
The component (A-1) of the thermoplastic elastomer composition constituting the layer (A) is a polyolefin resin, and is at least one selected from homopolymers or copolymers of olefins having high crystallinity. As the olefin,
Ethylene and propylene, 1-butene, 1-hexene,
Α-olefins having 3 to 8 carbon atoms, such as 1-octene. Examples of (A-1) include polyethylene, polypropylene, poly (1-butene), and copolymers of propylene with other α-olefins (eg, 1-butene). When (A-1) is a propylene-ethylene copolymer resin or a propylene-1-butene copolymer resin, it is preferable in that the layer (A) has excellent heat resistance and feel. From the viewpoint of heat resistance,
The crystallinity of (A-1) needs to be 50% or more, and preferably 60% or more. Here, the crystallinity refers to the ratio of the heat of fusion of (A-1) to the heat of fusion of a crystalline polyolefin homopolymer composed of only the olefin unit having the highest weight content in the resin used.
The heat of fusion is determined by the DSC method.

Further, a copolymer obtained by copolymerizing two or more monomers selected from ethylene and an α-olefin having 3 to 8 carbon atoms in two or more steps can also be used. For example, a copolymer obtained by homopolymerizing propylene in the first step and copolymerizing propylene with ethylene or an α-olefin other than propylene in the second step can be used.

From the viewpoint of the strength of the layer (A), (A-
1) The melt flow rate (MF) measured at 230 ° C. under a load of 2.16 kgf according to JIS K-7210.
R) is usually in the range of 0.1 to 500 g / 10 min, preferably 1 to 300 g / 10 min.

The component (A-2) of the thermoplastic elastomer composition constituting the layer (A) is a hydrogenated diene copolymer which satisfies all of the above conditions.

Examples of the conjugated diene used in the production of (A-2) include, for example, 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 1,3-pentadiene, 2,3- Dimethyl-1,3-butadiene, 2
4 to 4 carbon atoms such as -methyl-1,3-pentadiene
8 conjugated dienes. Among them, 1,3-butadiene and isoprene are preferably used from an industrial viewpoint.

The vinyl aromatic compound has one of the vinyl groups.
The 2- or 3-position may be substituted with an alkyl group such as a methyl group. Examples of vinyl aromatic compounds include styrene, p-methylstyrene, α-methylstyrene, t-
Examples thereof include vinyl aromatic compounds having 8 to 12 carbon atoms, such as butylstyrene, divinylbenzene, and vinylpyridine. Among them, styrene is preferably used from an industrial viewpoint.

(A-2) is usually represented by the general formula [(i)-
(Ii)] n, [(i)-(ii)] n- (i), [(ii)
-(I)] n- (ii) (where n is an integer of 1 or more and repeating units (i) and (ii) may be the same or different). Among them, (i)
The hydrogenated diene copolymer represented by-(ii-1)-(i), (i)-(ii-2)-(i) or (i)-(ii-3)-(i) is It is preferable because it can be industrially manufactured. Among them, hydrogenated styrene-butadiene-styrene-styrene copolymer, hydrogenated styrene-butadiene-styrene copolymer, hydrogenated styrene-isoprene / styrene-styrene copolymer, styrene-isoprene-styrene Hydrogenated copolymers are preferred in that they can be easily produced industrially. Note that "-" indicates a boundary between blocks, and "-" indicates that two or more compounds are used in combination in one block.

The total content of the vinyl aromatic compound unit in (A-2) must be in the range of 8 to 20% by weight (condition), and preferably in the range of 10 to 18% by weight. . Total vinyl aromatic compound unit content is 20
%, The feel of the layer (A) tends to be inferior. Further, when the total content of the vinyl aromatic compound units is less than 8%, there is a problem that the layer (A) has tackiness. In addition,
The total vinyl aromatic compound unit content can be determined by ¹ H-NMR measurement at a frequency of 90 MHz or more using a solution of (A-2) such as carbon tetrachloride.

(A-2) Ratio of the content of the vinyl aromatic compound unit of the vinyl aromatic compound polymer block to the total content of the vinyl aromatic compound unit (S: percentage)
Is required to be 3% or more (condition) and 30%
To 100%, more preferably 50 to 100%.
%. When the ratio is less than 3%,
There is a problem that the layer (A) has tackiness. As the ratio is higher, the (A) layer having excellent stab resistance and strength can be obtained. Incidentally, the ratio is ¹ in carbon tetrachloride solution was used to frequencies above 90MHz of (A-2)
It can be determined by 1 H-NMR measurement.

In (A-2), the number of carbon atoms relative to the number of all hydrogenated conjugated diene units in the conjugated diene copolymer is 2
The ratio (V: percentage) of the number of hydrogenated conjugated diene units having the above side chains must be 60% or more (conditions), and is preferably 70% to 95%. When the proportion is less than 60%, there is a problem that the feeling of the obtained layer (A) is reduced and the scratch resistance is poor. In addition, such a ratio can be obtained by a Morello method using infrared analysis.

The ratio (S: percentage) of the vinyl aromatic compound unit content of (i) the vinyl aromatic compound polymer block to the total vinyl aromatic compound unit content in (A-2) and the hydrogenated diene type The relationship between the ratio of the number of hydrogenated conjugated diene units having side chains having 2 or more carbon atoms to the number of hydrogenated conjugated diene units of the polymer (V: percentage) is represented by the following formula (1). It needs to be expressed (conditions). V ≦ 0.375 × S + 62.5 (1) In equation (1), when the value on the left side exceeds the value on the right side,
When the obtained two-layer molded body is heated at a temperature of about 80 ° C. to less than the melting point of the polyolefin-based resin, there is a problem that the layer (A) emits gloss.

It is necessary that at least 80% of the double bonds of the conjugated diene unit in (A-2) be hydrogenated (conditions), and it is preferable that at least 90% be hydrogenated. If the degree of hydrogenation is less than 80%, the light resistance of the layer (A) may decrease.

It is necessary that the number average molecular weight of (A-2) is from 50,000 to 600,000 (conditions) in order to obtain a molded article having excellent appearance and strength, and the range is from 100,000 to 500,000. Is preferred. When the number average molecular weight is less than 50,000, the obtained layer (A) tends to have tackiness and insufficient heat resistance and light resistance. When the number average molecular weight exceeds 600,000, the meltability of the thermoplastic elastomer composition is inferior, so that the (A) layer having sufficient appearance and strength cannot be obtained. Number average molecular weight is GP
It is measured by the C method.

The melt flow rate (MFR) measured at 230 ° C. under a load of 2.16 kgf according to JIS K-7210 of (A-2) is preferably from 0.1 to 200 g / 10 min. It is preferably from 100 g / 10 min, particularly preferably from 3 to 80 g / 10 min, from the viewpoint of sufficient appearance and strength.

(A-2) of the present invention 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.

Such hydrogenated diene copolymers are disclosed, for example, in JP-A-3-72512 and JP-A-5-2713.
No. 25, JP-A-5-271327, JP-A-6-271327
It can be produced by a method described in -287365 or the like.

The thermoplastic elastomer composition constituting the layer (A) of the present invention comprises, in addition to the essential components (A-1) and (A-2), (A-3): ethylene-α- An olefin copolymer may be contained. When (A-3) is contained, the moldability at the time of molding the (A) layer and 80
Even if heated to a temperature lower than the melting point of the polyolefin resin from about ℃, without lowering the property that gloss does not occur,
The cold shock resistance of the layer (A) is improved.

(A-3) Ethylene-α-olefin copolymer is a copolymer of ethylene and α-olefin,
A polymer having little crystallinity or a polymer having a crystallinity of less than 50%, such as a copolymer of ethylene, an α-olefin and a non-conjugated diene. Here, the degree of crystallinity indicates the ratio of the heat of fusion of the copolymer to the heat of fusion of the crystalline polyethylene homopolymer. The heat of fusion is DS
It is determined by the C method. Here, the α-olefin is an α-olefin having 3 to 10 carbon atoms such as propylene, 1-butene, and 3-methyl-1-butene, and the non-conjugated diene is dicyclopentadiene, 2-5-ethylidene norbornene, Examples thereof include non-conjugated dienes having 5 to 15 carbon atoms such as 1,4-hexadiene, 1,5-cyclooctadiene, and 2-methylene-5-norbornene. Examples of the ethylene-α-olefin-based copolymer include ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, and ethylene-propylene- Ethylidene norbornene copolymer (hereinafter, referred to as
Called "EPDM". ). Such an ethylene-α-olefin-based copolymer may be crosslinked.

The content of the α-olefin unit in (A-3) is preferably 5 to 40% by weight, more preferably 10 to 40% by weight.
It is in the range of 35% by weight, and the ethylene unit content is usually 60 to 95% by weight, preferably 65 to 90% by weight. The α-olefin unit content and the ethylene unit content can be determined by ¹³ C-NMR method, infrared absorption spectroscopy, or the like. In addition, from the viewpoint of the strength of a molded article obtained by molding the thermoplastic elastomer composition of the present invention, the ethylene-α-olefin-based copolymer may have an AS
The Mooney viscosity {ML _{1 + 4} (100 ° C.)} measured at 100 ° C. according to TM D-927-57T is preferably 1
It is in the range of 0 to 350, more preferably 15 to 300.

When (A-3) is used, the amount of (A-3) is 250 parts by weight or less, preferably 20 to 200 parts by weight, per 100 parts by weight of (A-1). (A-
If 3) is excessive, the layer (A) obtained may have a sticky feeling.

The thermoplastic elastomer composition constituting the layer (A) of the present invention is an essential component (A-1).
(A-4): In addition to (A-2), (A-4): the above-mentioned (A-2) as long as it is heated to a temperature from about 80 ° C. to a temperature lower than the melting point of the polyolefin-based resin, so that the property that gloss does not occur is not reduced. ) Other styrenic thermoplastic elastomers,
May be contained. Examples of (A-4) include, for example, a hydrogenated diene copolymer containing the same structural units (i) and (ii) as described in (A-2) above, and a vinyl aromatic compound-conjugated diene random copolymer. And the combined hydrogenated product.
(A-4) a hydrogenated diene containing the same structural units (i) and (ii) as described in the above (A-2) and not satisfying at least one of the conditions described in the above (A-2). System copolymers.

For example, when the conditions are not satisfied and a hydrogenated diene copolymer satisfying and is used (when the relational expression of V> 0.375 × S + 62.5 is satisfied), the scratch resistance is improved. Gives a more excellent layer (A).

When a hydrogenated diene copolymer which does not satisfy the conditions is used (water having a side chain having 2 or more carbon atoms with respect to the total number of hydrogenated conjugated diene units in the hydrogenated diene copolymer) is used. When a hydrogenated diene-based copolymer in which the ratio of the number of added conjugated diene units (V: percentage) is 60% or less is used, a layer (A) having more excellent cold impact resistance is provided.

When (A-4) is used, the amount of (A-4) is 250 parts by weight or less, preferably 20 to 200 parts by weight, per 100 parts by weight of (A-1). (A-
If 4) is excessive, the resulting layer (A) may have a sticky feeling.

The thermoplastic elastomer composition constituting the layer (A) of the present invention comprises (A-5): a conjugated diene polymer in addition to the essential components (A-1) and (A-2). May be contained. Examples of (A-5) include hydrogenated polybutadiene and hydrogenated polyisoprene. When the ratio (V: percentage) 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 (A-5) exceeds 60%, powder Although it is preferable from the viewpoint of the flexibility of the molded product obtained by molding, the ratio differs in the hydrogenated diene polymer.
It may be composed of the above blocks. Examples of such a hydrogenated diene polymer include a polymer described in JP-A-3-74409 and CEBC62 manufactured by JSR Corporation.
00 and the like. When (A-5) was added to the thermoplastic elastomer composition of the present invention, the obtained (A) was obtained.
The strength of the layer, especially the thermoplastic elastomer composition is (A-
It improves when 3) is contained.

When (A-5) is used, the amount of (A-5) is 250 parts by weight or less, preferably 2 to 200 parts by weight, per 100 parts by weight of (A-1). (A-
If the content of (5) is excessive, the obtained molded product may have a sticky feeling.

The thermoplastic elastomer composition constituting the layer (A) of the present invention includes polymers such as natural rubber, butyl rubber, chloroprene rubber, epichlorohydrin rubber, and acrylic rubber; ethylene-acrylic acid copolymer; It contains other polymer components such as a vinyl acetate copolymer and a saponified product thereof, an ethylene-methyl methacrylate copolymer, an ethylene-glycidyl methacrylate-vinyl acetate copolymer, and an ethylene-glycidyl methacrylate-vinyl acetate copolymer. May be.

The thermoplastic elastomer composition constituting the layer (A) of the present invention may be, for example, a mineral oil-based softening agent, a phenol-based, sulfite-based, phenylalkane-based, phosphite-based, amine-based, amide-based or the like. It may contain various additives such as heat stabilizers, weather stabilizers, antistatic agents, pigments, metallic soaps, waxes, fungicides, antibacterial agents, and fillers.

When the thermoplastic elastomer composition constituting the layer (A) of the present invention contains a mineral oil-based softening agent, the layer (A) comprising the thermoplastic elastomer composition having excellent melting properties and flexibility is obtained. be able to.

The thermoplastic elastomer composition constituting the layer (A) of the present invention contains the above (A-1) and (A-2) as essential components, and optionally comprises (A-3) and (A-3). A-
It contains at least one of 4) and (A-5). The content of (A-2) is required to contain 10 to 1000 parts by weight of (A-2) based on 100 parts by weight of (A-1), and may be 40 to 200 parts by weight. preferable. When the content of (A-2) relative to 100 parts by weight of (A-1) is less than 10 parts by weight, the obtained (A) was obtained.
When the feel and scratch resistance of the layer are inferior and exceed 1000 parts by weight, the obtained layer (A) becomes tacky,
Heat resistance and light resistance become insufficient.

The MFR of the thermoplastic elastomer composition constituting the layer (A) of the present invention is determined from the viewpoint of the moldability of the thermoplastic elastomer composition and the appearance of the obtained layer (A).
It is preferably 0.1 to 200 g / 10 min, and more preferably 0.5 to 100 g / 10 min.

As a method for obtaining the thermoplastic elastomer composition constituting the layer (A) of the present invention, for example, the following method can be mentioned. That is, (A-1) and (A
-A) and (A-3), (A-3)
-4) and (A-5) may be melt-kneaded. Alternatively, it can be produced by kneading or dynamically cross-linking all or some of the above-mentioned components and then kneading and kneading the unselected components. For example, (A-1), (A-2), (A-
3) containing (A-4) and (A-5), and (A-1)
The thermoplastic elastomer composition of the present invention in which (A-3) is intramolecularly and / or intermolecularly crosslinked, usually (A-1) and (A-3) are dynamically crosslinked. Thereafter, (A-2), (A-4) and (A-5) are further added and kneaded, whereby the compound can be produced. For kneading, a single-screw extruder, a twin-screw extruder, a kneader, a roll, or the like can be used. The above-mentioned various additives and various polymers are compounded, for example, by adding these additives in advance (A
-1), (A-2), (A-3), (A-4) or (A
-5) or by mixing the above components during kneading or dynamic crosslinking.

The dynamic crosslinking of the kneaded mixture can be carried out, for example, by kneading the kneaded mixture and a crosslinking agent under heating. As the crosslinking agent, usually, 2,5-dimethyl-2,5-di (tert-butylperoxyno) is used.
Organic peroxides such as hexane and dicumyl peroxide are used. The cross-linking agent is (A-1) and (A-2) to be cross-linked, and is compounded if necessary (A-
3), usually at most 1 part by weight per 100 parts by weight of at least one of (A-4) and (A-5);
Preferably 0.1 to 0.8 parts by weight, more preferably 0.1 to 0.8 parts by weight.
It is used in the range of 2 to 0.6 parts by weight. When using an organic peroxide as a cross-linking agent, when performing dynamic cross-linking in the presence of a cross-linking auxiliary agent such as a bismaleimide compound, a thermoplastic elastomer composition that gives a molded article having excellent heat resistance can be obtained. Can be. In this case, the amount of the organic peroxide used is (A-1), (A-2) to be subjected to crosslinking, and (A-3), (A-4) and ( A-
5) At least 0.8 part by weight, preferably 0.2 to 0.8 part by weight, more preferably 0.4 part by weight, per 100 parts by weight of the total of the components to be crosslinked among at least one of 5). It is in the range of 0.6 parts by weight.

The amount of the crosslinking aid used is determined by the crosslinking (A
-1) and (A-2), and if necessary, at least one of (A-3), (A-4) and (A-5), usually 100 0.5 parts by weight or less, preferably 0.2 to 1 part by weight, more preferably 0.4 to 0.8 part by weight. The crosslinking aid is preferably added before the addition of the crosslinking agent, and is usually added when the components to be crosslinked are preliminarily kneaded. Crosslinking can be performed by kneading under heating using, for example, a single-screw extruder or a twin-screw extruder in a temperature range of 150 to 250 ° C. It is also possible to carry out crosslinking by a method such as sulfur crosslinking.

The aforementioned additives and other polymer components are represented by (A-
1) and (A-2) and optionally used (A
-3), at least one of (A-4) and (A-5) may be used beforehand, or may be compounded by kneading or the like at the time of the above-mentioned kneading or dynamic crosslinking or thereafter. Is also good.

When a mineral oil-based softening agent is used, if the oil-extended ethylene-α-olefin-based copolymer in which the mineral oil-based softening agent is contained in advance in (A-3) is used, the above-mentioned kneading and mixing can be performed. Crosslinking can be easily performed.

In order to produce the thermoplastic elastomer composition constituting the layer (A) of the present invention, the degree of the above-mentioned kneading and dynamic crosslinking and the type of each component constituting the thermoplastic elastomer composition are described. And the amount thereof, the type and amount of the cross-linking agent and the cross-linking aid in the dynamic cross-linking, the type of the additive and the amount thereof are appropriately selected. Among them, the shear rate in kneading and dynamic crosslinking greatly affects the above physical property values,
It is preferable to knead or dynamically crosslink at a shear rate of 1 × 10 ³ seconds ^{- 1} or more.

The component (B-1) of the thermoplastic elastomer composition constituting the layer (B) in the two-layer molded article of the present invention.
Is a polyolefin resin, and the polyolefin resin described in the above (A-1) is used.

The component (B-2) contained in the thermoplastic elastomer composition constituting the layer (B) of the present invention is the following rubbery polymer. (B-2): t is a rubbery polymer obtained by a solid viscoelasticity measurement of a composition obtained by kneading with (B-1).
In the an δ-temperature dependence curve, the tan δ peak temperature of (B-1) and (B-
A rubbery polymer that gives a new single tan δ peak at a temperature different from any of the tan δ peak temperatures in 2). In addition,
This is a behavior that does not depend on the weight ratio of the kneading compositions (B-1) and (B-2).

(B-2) used in the present invention includes:
Examples include conjugated diene rubbery polymers and hydrogenated conjugated diene rubbery polymers.

The conjugated diene rubbery polymer is a conjugated diene polymer rubber or a conjugated diene copolymer rubber.

The conjugated diene polymer rubber includes at least one
It is a polymer rubber obtained by polymerizing or copolymerizing a kind of conjugated diene. Examples of conjugated dienes include, for example, 1,3-
Examples thereof include conjugated dienes having 4 to 8 carbon atoms, such as butadiene, isoprene (2-methyl-1,3-isoprene), 1,3-pentadiene, and 2,3-dimethylbutadiene. Among them, 1,3-butadiene and isoprene are preferable because they can be easily used industrially and a conjugated diene polymer rubber having excellent physical properties can be obtained. Examples of the conjugated diene polymer include polybutadiene, polyisoprene, polypentadiene, butadiene-isoprene copolymer, and the like.

The conjugated diene copolymer rubber is a copolymer rubber of a conjugated diene and a monomer other than the conjugated diene as described above. Examples of the monomer other than the conjugated diene include a vinyl aromatic compound, a vinyl ester compound, an ethylenically unsaturated carboxylic acid ester compound, and a vinyl nitrile compound. Is preferred because it can be easily pelletized, for example, it can be easily industrially used.

The vinyl aromatic compound has one of the vinyl groups
The 2- or 3-position may be substituted with an alkyl group such as a methyl group. Examples of vinyl aromatic compounds include styrene, p-methylstyrene, α-methylstyrene, t-
Examples thereof include vinyl aromatic compounds having 8 to 12 carbon atoms such as butylstyrene. Among them, styrene is preferred because it is most easily industrially available.

Examples of the vinyl ester compound include vinyl acetate.

Examples of the ethylenically unsaturated carboxylic acid ester compound include methyl methacrylate, ethyl methacrylate, methyl acrylate, butyl acrylate and the like.

Examples of the vinyl nitrile compound include acrylonitrile and methacrylonitrile.

Examples of the conjugated diene copolymer rubber include butadiene-styrene copolymer rubber and isoprene-
Styrene copolymer rubber, conjugated diene-vinyl aromatic compound copolymer rubber such as butadiene-p-methylstyrene copolymer rubber, conjugated diene-vinyl ester compound copolymer rubber such as butadiene-vinyl acetate copolymer, Conjugated diene-ethylenically unsaturated carboxylic acid ester copolymer rubber such as butadiene-methacrylic acid copolymer rubber, butadiene-methyl acrylate copolymer, and conjugated diene-vinyl nitrile compound copolymer such as butadiene-acrylonitrile copolymer And polymer rubber.

The structure of such a conjugated diene copolymer rubber includes a random copolymer of a monomer other than a conjugated diene and a conjugated diene, and a monomer polymer block other than a conjugated diene and a conjugated diene polymer. And block copolymers comprising a conjugated diene polymer block, a conjugated diene polymer block and a monomer other than the conjugated diene and a conjugated diene. Above all, a block copolymer is preferably used from the viewpoint of the cushioning property and the piercing strength of the layer (B). The number of blocks constituting these block copolymers is 2 or more, but is preferably 2 to 4 from the viewpoint that it can be easily produced industrially.

The hydrogenated conjugated diene rubber is a hydrogenated conjugated diene polymer rubber or a hydrogenated conjugated diene copolymer rubber obtained by hydrogenating the above conjugated diene polymer rubber or conjugated diene copolymer rubber. Examples of the hydrogenated conjugated diene rubber include hydrogenated conjugated diene rubbers described above. Preferably, 80% or more of the double bonds of the conjugated diene unit are hydrogenated. Preferably, 90% or more is hydrogenated. If the hydrogenation rate is less than 80%,
The light fastness of the (B) layer may decrease.

The conjugated diene copolymer rubber or hydrogenated conjugated diene copolymer rubber may have a monomer unit content other than conjugated diene of 50% by weight or less, preferably 20% by weight or less. This is preferable in that a layer (B) having excellent flexibility can be obtained. When the content exceeds 50% by weight, the flexibility of the layer (B) is reduced, and the cushioning property of the two-layer molded body is reduced.

When a hydrogenated conjugated diene rubber is used as (B-2), (B-2) is a hydrogenated conjugated diene rubber having a side chain having 2 or more carbon atoms based on the number of all hydrogenated conjugated diene units. The ratio of the number of the conjugated diene units differs depending on the type of the conjugated diene monomer used in the polymerization.
From the viewpoint of the cushion feeling of the layer, it is necessary to be 50% or more, preferably 60% to 95%, more preferably 70%.
It is preferably about 90%. The ratio is
It can be determined by the Morero method using infrared spectroscopy.

The melt flow rate (MFR) measured at 230 ° C. under a load of 2.16 kgf according to JIS K-7210 of (B-2) is preferably 0.1 to 200 g / 10 min, and more preferably 1 to 200 g / 10 min. 100 g / 10 min, particularly preferably 3 to 80 g / 10 min, is preferable in that a layer (B) having sufficient appearance and cushioning properties can be obtained.

The (B-2) of the present invention 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. A modified functional group having the formula (1) can also be used.

Such rubbery polymers are disclosed, for example, in JP-A-2-36244, JP-A-3-72512, JP-A-7-118335, and JP-A-56-38.
It can be easily produced by the method described in Japanese Patent Application Laid-Open No. 338, JP-A-61-60739 and the like.

As (B-2), JP-A-11-23
No. 6,468, propylene-1-butene copolymer rubber or propylene-α-olefin-ethylene copolymer rubber can also be used.

The thermoplastic elastomer composition constituting the layer (B) of the present invention comprises the following components (B-3) and / or (B-2) in addition to the essential components (B-1) and (B-2). B-
4) may be contained. (B-3): t is a rubbery polymer obtained by measuring the solid viscoelasticity of the composition obtained by kneading with (B-1).
A rubbery polymer that gives two tan δ peaks in a temperature range of −70 to 30 ° C. in an an δ-temperature dependency curve. (B-4): ethylene-α-olefin copolymer

(B-3) is a rubbery polymer composed of the same monomers as described in (B-2), but having low affinity for (B-1).

As (B-4), the ethylene-α-olefin copolymer described in (A-3) is used.

When (B-3) and / or (B-4) are contained, the cold shock resistance of the (B) layer can be improved without lowering the cushioning properties of the (B) layer.

When (B-3) and / or (B-4) is used, the amount used is based on 100 parts by weight of (B-1).
The total of (B-3) and / or (B-4) is 250 parts by weight or less, preferably 20 to 200 parts by weight.
If the content of (B-3) and / or (B-4) is excessive, the durability of the obtained (B) layer may decrease.

The thermoplastic elastomer composition constituting the layer (B) of the present invention can be made of natural rubber, butyl rubber, chloroprene rubber, epichlorohydrin rubber, or the like, similarly to the above-mentioned thermoplastic elastomer composition constituting the layer (A). Polymers such as acrylic rubber, ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer and saponified product thereof, ethylene-
It may contain other polymer components such as a methyl methacrylate copolymer, an ethylene-glycidyl methacrylate-vinyl acetate copolymer, and an ethylene-glycidyl methacrylate-vinyl acetate copolymer.

The thermoplastic elastomer composition constituting the layer (B) of the present invention may be, for example, a mineral oil-based softener, a phenol-based or a sulfite-based, similar to the above-mentioned thermoplastic elastomer composition constituting the layer (A). , Phenyl alkane, phosphite, amine and amide heat stabilizers, light stabilizers, antistatic agents, pigments, metallic soaps, waxes, fungicides, antibacterial agents, various additives such as fillers, etc. May be contained.

When the thermoplastic elastomer composition constituting the layer (B) of the present invention contains a mineral oil-based softening agent, the thermoplastic elastomer composition comprises the obtained thermoplastic elastomer composition having excellent melting properties and flexibility. ) Layer can be obtained, and the molding processability of the layer (B) can be improved.

The thermoplastic elastomer composition constituting the layer (B) of the present invention contains the above (B-1) and (B-2) as essential components, and if necessary, (B-3) and / or (B-3). Or (B-4) is contained. The content of (B-2) is (B-
1) (B-2) is 10 to 100 with respect to 100 parts by weight.
It is necessary to contain 0 parts by weight, preferably 40 to 200 parts by weight. When the content of (B-2) is less than 10 parts by weight per 100 parts by weight of (B-1), the cushioning property of the layer (B) is inferior, and when it exceeds 1000 parts by weight, the obtained molded article is obtained. In addition to the occurrence of stickiness, the cushion of the layer (B) may decrease when the molded article is stored for a long period of time.

The MFR of the thermoplastic elastomer composition constituting the layer (B) of the present invention is 0.1 from the viewpoint of the moldability of the thermoplastic elastomer composition and the appearance and cushioning property of the obtained layer (B). ２００200 g / 10 min, and more preferably 0.5-100 g / 10 min.

In order to obtain the thermoplastic elastomer composition constituting the layer (B) of the present invention, (B-1) and (B-
2) and (B-3) and / or (B-4) blended as necessary may be melt-kneaded. Alternatively, it can be produced by kneading or dynamically cross-linking all or some of the above-mentioned components and then kneading and kneading the unselected components. Regarding the method of melt-kneading and dynamic crosslinking (including the types and amounts of the crosslinking agent and the crosslinking aid), the same method as the method for producing the thermoplastic elastomer composition constituting the layer (A) described above is used. Is used.

The two-layer molded product of the present invention comprises the layer (A) and the layer (B)
The two-layer molded body is manufactured by separately manufacturing the (A) layer and the (B) layer, and then integrating the (A) layer and the (B) layer. There is a method of manufacturing at the same time.

In the case where the layers (A) and (B) are separately manufactured and then integrally manufactured, a method such as an injection molding method, an extrusion molding method, a vacuum molding method, a compression molding method, or a powder molding method is used in advance. The obtained layer (A) and layer (B) are integrated. Examples of the integration method include a heat fusion method and a bonding method.

In this case, the layer (B) can be produced by foaming the thermoplastic elastomer constituting the layer (B) of the present invention containing a foaming agent. in this case,
It is preferable that the foaming agent is previously contained in the thermoplastic elastomer composition. As the foaming agent, a pyrolytic foaming agent is usually used. Examples of such a thermal decomposition type foaming agent include azo compounds such as azodicarbonamide, 2,2′-azobisisobutyronitrile and diazodiaminobenzene, benzenesulfonylhydrazide, benzene-1,3.
Sulfonyl hydrazide compounds such as -sulfonyl hydrazide, p-toluenesulfonyl hydrazide, N, N'-
Nitroso compounds such as dinitrosopentamethylenetetramine, N, N'-dinitroso-N, N'-dimethylterephthalamide, azide compounds such as terephthalazide;
Carbonates such as sodium bicarbonate, ammonium bicarbonate and ammonium carbonate are included. Among them, azodicarbonamide is preferably used. The compounding of the foaming agent
Usually, it is carried out at a temperature lower than the decomposition temperature of the foaming agent. Also,
A foaming aid and a cell conditioner may be contained together with the foaming agent. The foam molding temperature is not problematic as long as it is a temperature equal to or higher than the melting point of the thermoplastic elastomer composition constituting the layer (B), but is usually 160 to 320 ° C, preferably 180 to 300 ° C.
It is in the range of ° C. As the foaming method, a molded article made of a thermoplastic elastomer composition constituting a layer (B) previously molded by blending a foaming agent in a mold at a temperature not higher than its decomposition temperature,
A method of foaming by heating the foaming agent to a temperature higher than the decomposition temperature of the foaming agent after putting it in a desired mold, a method of foaming in a furnace heated to a temperature higher than the decomposition temperature of the foaming agent without entering the mold, and the like. .

The heat fusion method refers to (A) layer and / or (B)
This is a production method in which, after heating to a melting temperature or higher of the thermoplastic elastomer composition constituting the layer, pressure is applied to the (A) layer and / or (B) layer as necessary. The bonding method is a manufacturing method in which a known adhesive is applied to the (A) layer and / or the (B) layer, and then pressure is applied to the (A) layer and / or the (B) layer as necessary. is there.

Examples of the method for producing the layers (A) and (B) at the same time include a coextrusion method and a powder molding method.
Among them, the powder molding method is preferable because a two-layer molded body having a complicated shape such as a convex portion or a corner portion can be easily produced. Examples of the powder molding method include a powder slush molding method, a fluid immersion method, an electrostatic coating method, a powder spraying method, a powder rotational molding method, and the like. Is preferred because it can be easily produced.

For example, the powder slush molding method is performed as follows. First step: a step of applying a fluorine-based and / or silicon-based release agent on the molding surface of the mold as required. Second step: (A) a step of supplying a powder of the thermoplastic elastomer composition constituting the layer onto a molding surface of a mold heated to a temperature higher than its melting temperature. A) The heating temperature is usually from 160 to 320C, preferably from 210 to 300C, depending on the type of the thermoplastic elastomer composition constituting the layer. In this method, the mold is heated by, for example, a gas heating furnace method, a heat medium oil circulation method, a dipping method in heat medium oil or hot fluidized sand, a high-frequency induction heating method, or the like. The supply time for heat-sealing the powder is appropriately selected according to the size and thickness of the target compact. Third step: heating the powder on the molding surface of the second step for a predetermined time, and fusing powders having at least their surfaces fused to each other. Fourth step: after a lapse of a predetermined time in the third step,
Step of recovering the unfused powder Fifth step: If necessary, further heating the mold on which the molten thermoplastic elastomer composition powder is placed Sixth step: Then, layer (B) The step of further supplying the powder of the thermoplastic elastomer composition constituting the above onto the molding surface of the mold.The supply time for heat-sealing the powder depends on the size, thickness, expansion ratio, etc. of the target molded article. It is appropriately selected according to the situation. Seventh step: a step of heating the thermoplastic elastomer composition powder constituting the layer (B) on the molding surface of the sixth step for a predetermined time, and fusing the powders having at least their surfaces fused together eighth step: After the elapse of the predetermined time in the seven steps,
Step of Recovering Non-fused Powder Ninth Step: If necessary, further heat the mold on which the molten powder is placed, so that the thermoplastic elastomer composition constituting the (B) layer is formed. Step of foaming Tenth step: After the ninth step, the mold is cooled, and the two-layer molded body formed thereon is removed from the mold.

In addition, when the thermoplastic elastomer composition constituting the layer (A) is produced, an internal release agent is blended to reduce the load required for removing the molded article in the tenth step. effective. In this case, the first step described above can be omitted. The addition amount of the internal release agent is usually 5 parts by weight or less, preferably 0.1 to 2 parts by weight, per 100 parts by weight of the thermoplastic elastomer composition. When the amount of the internal release agent exceeds 5 parts by weight, problems such as a decrease in the strength of the obtained molded article and contamination of the mold surface may occur.

As a method for powdering the thermoplastic elastomer composition constituting the layer (A) or the layer (B), there is a freeze-pulverization method. The freeze-pulverization method cools the thermoplastic elastomer composition below its glass transition temperature, preferably below -70 ° C, more preferably below -90 ° C,
This is a method of pulverizing while maintaining the cooling state. It is also possible to pulverize the thermoplastic elastomer composition at a temperature higher than its glass transition temperature, but the resulting pulverized product has an irregular particle size, and powder powder obtained by adding a fine powder is added. Molding tends to be difficult.

In order to pulverize the thermoplastic elastomer composition while keeping it in a cooled state, it is preferable that the pulverization be carried out by a method having good pulverization efficiency and low heat generation. For example, a machine using an impact type pulverizer such as a ball mill can be used. Crushing method is used. The powder of the thermoplastic elastomer composition in this method is usually sized to pass through a Tyler standard sieve 24 mesh (mesh size 700 μm × 700 μm), preferably 28 mesh (mesh size 590 μm ×
590 μm), more preferably 32 mesh (500 μm × 500 μm), particularly preferably 42 mesh (355 μm × 355 μm).
m).

The thermoplastic elastomer composition powder constituting the layer (A) or the layer (B) can also be produced by the following method.

Freezing-pulverization-solvent treatment: The thermoplastic elastomer composition is heated to a temperature lower than its glass transition temperature (usually -70
℃, preferably -90 ℃ or less) and pulverized. Then, the powder produced by the above-mentioned freeze-milling method, in a solvent having poor compatibility with the thermoplastic elastomer composition, in the presence of a dispersant and an emulsifier, the melting temperature of the thermoplastic elastomer composition or more, Preferably, after stirring at a temperature 30 to 50 ° C. higher than the melting temperature, the mixture is cooled (for example, see JP-A-62-280226).

Strand cutting method: The molten thermoplastic elastomer composition is extruded from a die into air to form a strand, which is cooled and cut (see, for example, JP-A-50-149747).

Die face cutting method: The molten thermoplastic elastomer composition is cut while being extruded from a die into water.

In the above-mentioned solvent treatment method, as the solvent, for example, ethylene glycol, polyethylene glycol, polypropylene glycol or the like is usually 300 to 300 parts by weight per 100 parts by weight of the thermoplastic elastomer composition.
It is used in an amount of 1000 parts by weight, preferably 400 to 800 parts by weight. As the dispersant, for example, ethylene-
Acrylic acid copolymer, silicic anhydride, titanium oxide, etc.,
It is used in an amount of usually 5 to 20 parts by weight, preferably 10 to 15 parts by weight, per 100 parts by weight of the thermoplastic elastomer composition. As the emulsifier, for example, polyoxyethylene sorbitan monolaurate, polyethylene glycol monolaurate, sorbitan tristearate and the like are usually 3 to 15 parts by weight, preferably 5 to 10 parts by weight, per 100 parts by weight of the thermoplastic elastomer composition. Used in parts by weight.

In the above-mentioned strand cutting method, the discharge opening diameter of the die is usually in the range of 0.1 to 3 mm, preferably 0.2 to 2 mm. The discharge speed of the thermoplastic elastomer composition per discharge port of the die is usually in the range of 0.1 to 5 kg / hour, preferably 0.5 to 3 kg / hour. Strand take-off speed is usually 1 to 1
00 m / min, preferably in the range of 5 to 50 m / min.
The cooled strand is usually cut to 1.4 mm or less, preferably 0.3 to 1.2 mm.

In the above die face cutting method,
The discharge diameter of the die is usually in the range of 0.1 to 3 mm, preferably 0.2 to 2 mm. The discharge rate of the thermoplastic elastomer composition per discharge port of a die is usually 0.1 to 5 kg / hour, preferably 0.5 to 3 kg / hour.
In the range of time. The temperature of the water is usually in the range from 30 to 70C, preferably from 40 to 60C.

When the thermoplastic elastomer compositions constituting the layers (A) and (B) are powder-molded, the complex dynamic viscosity η ^* (1) at 250 ° C. of each composition is 1.5 × Must be less than 10 ⁵ poise, 1
It is preferably in the range of × 10 ² to 8 × 10 ³ poise,
It is preferably in the range of × 10 ^{2 to} 5 × 10 ³ poise.

Here, the complex dynamic viscosity η ^* (ω) is the storage elastic modulus G ′ (ω) at a temperature of 250 ° C. and a vibration frequency ω.
And the elastic modulus of loss G ″ (ω), the following equation (2)
Complex dynamic viscosity η ^* (1)
Is the complex dynamic viscosity at ω = 1 radian / second. η ^* (ω) = ｛[G ′ (ω)] ² + [G ″ (ω)] ² ｝ ^1/2 / ω (2)

If η ^* (1) exceeds the above upper limit, the melt fluidity of the thermoplastic elastomer composition is inferior, and the shear rate at the time of molding such as a powder molding method is usually as low as 1 second ^-1 or less. It tends to be difficult to produce a molded article by the molding method described above.

The Newton viscosity index n of each composition must be 0.67 or less, preferably in the range of 0.01 to 0.35, and more preferably 0.03.
It is preferably in the range of ~ 0.25. Here, the Newton's viscosity index n is defined as follows using the complex dynamic viscosity η ^* (1) and the complex dynamic viscosity η ^* (100) measured at a temperature of 250 ° C. and an oscillation frequency ω = 100 radians / sec. This is a value calculated by calculation formula (3). n = {log [eta] ^* (1) -log [eta] ^* (100)} / 2 (3) When the Newton's viscosity index n exceeds the above-mentioned upper limit, the mechanical strength of the obtained molded body becomes low.

When the thermoplastic elastomer composition constituting the layer (B) is powder-molded, the blowing agent is melted and kneaded at a temperature lower than the decomposition temperature of the blowing agent (the process for producing the thermoplastic elastomer composition). ), Or after powdering. When compounding after powdering, a powdery foaming agent is preferably used. As the foaming agent, those described above are usually used.

In the case where the thermoplastic elastomer composition constituting the layers (A) and (B) is powder-formed, the powder obtained is mixed with a fine powder having a primary particle size of 10 μm or less. By improving the fluidity of a molded article, a molded article free of underfill, pinholes, and the like can be obtained. Here, the primary particle size means a transmission electron microscope (TEM).
The photograph of (d) is taken, and about 1,000 particles are arbitrarily selected, the diameter of the particles is measured, and the diameter of these particles is divided by the number of particles.

Examples of the fine powder used in the present invention include inorganic oxides, powder pigments, vinyl chloride resins for pastes, and metal salts of fatty acids. These can be used alone or in combination of two or more. Examples of the inorganic oxide include alumina, silica, and alumina silica.

Almost all aluminas have the chemical formula Al ₂
It is a fine powder composed of O ₃ units. Alumina has various crystal forms, and any of the crystal forms can be used. These are called α-alumina, β-alumina, γ-alumina, etc. depending on the crystal form. Alumina C (γ-alumina) manufactured by Degussa, AKP-G008 (α-alumina) manufactured by Sumitomo Chemical Co., Ltd.
And so on.

Most of silica has a chemical formula of SiO ₂
It is a fine powder composed of units. Crushing natural diatomaceous earth,
It is produced by a method such as decomposition of sodium silicate. OX50 manufactured by Degussa Corporation and the like can be mentioned. Alumina silica is an inorganic oxide containing the aforementioned alumina and silica as main components.

The surface of these inorganic oxides may be coated with dimethyl silicone oil or the like, or may be surface-treated with a trimethylsilyl group or the like.

Examples of the powder pigments include organic pigments such as azo, phthalocyanine, sulene, and dye lakes, oxides such as titanium oxide, molybdic acid chromate, selenium sulfide compounds, ferrocyan compounds, and carbon black. Are used.

The addition amount of the fine powder is 0.1 to 5 parts by weight, preferably 0.2 to 3 parts by weight, based on 100 parts by weight of the powder of the thermoplastic elastomer. If the amount is less than 0.1 part by weight, good powder flow characteristics and powder moldability cannot be obtained. When the amount exceeds 5 parts by weight, the heat fusion between the pulverized particles is reduced, and the strength of the obtained molded body tends to be poor.

The primary particle size of the fine powder needs to be 10 μm or less. When one type is used alone, the primary particle size is 200 nm or less, and more preferably 5 nm to 150 nm. It is preferable in that a powder having excellent fluidity can be obtained. When two types are used in combination, (I) 2
When a powder having (II) of 1 to 10 μm is used in addition to the powder having a diameter of not more than 00 nm, a powder having more excellent powder flow characteristics and powder moldability can be obtained. In this case, (I) and (II)
Is preferably 1:10 to 10: 1.

The method of blending the fine powder with the powder of the thermoplastic elastomer is not particularly limited as long as the fine powder uniformly adheres to the powder of the thermoplastic elastomer. For example, a method of blending using a blender with a jacket, a high-speed rotary mixer, or the like can be used. Among them, a method of uniformly dispersing the powder by applying a shearing force to prevent cohesion of the powders, such as a Henschel mixer or a super mixer, is preferred. The compounding is usually performed at room temperature.

When the two-layered molded product of the present invention is produced by a powder molding method, the (B) layer is further provided on the side opposite to the (A) layer,
It is also possible to form a third layer. In this case, the third layer has an effect of blocking heat given to the layer (B) when the multilayer molded body in which the thermoplastic core material is laminated is manufactured by a method described later, so that the layer (B) is not easily crushed. Become. The third layer has a thermoplastic elastomer composition constituting the layer (A), a thermoplastic elastomer composition constituting the layer (B),
Examples include polypropylene resins, olefin-based thermoplastic elastomers composed of polyolefin-based resins and ethylene / α-olefin-based rubber. The third layer may be non-foamed or foamed.

The two-layer laminate of the present invention can be produced as a multilayer molded product by laminating a thermoplastic core material on the layer (B) side of the two-layer molded product.

As the thermoplastic resin in the thermoplastic resin core material, for example, a polyolefin such as polypropylene or polyethylene, or a thermoplastic resin such as an ABS (acrylonitrile-butadiene-styrene copolymer) resin is used. Above all, when a polyolefin such as polypropylene is used, the (A) layer and (B) constituting the two-layer molded body
The layer and the thermoplastic resin core material are preferably used because they are polyolefin-based.

Such a multilayer molded article is prepared by, for example, supplying a thermoplastic resin melt to the (B) layer side of the two-layer molded article and pressurizing it, or supplying a thermoplastic resin melt to the foam layer side of the two-layer molded article. It can be easily produced by a method of applying pressure, a method of applying a bonding agent after applying an adhesive on the bonding surface of the layer (B) or a previously molded thermoplastic resin core layer, and the like.

The thermoplastic resin melt is a thermoplastic resin which is heated to a temperature higher than its melting temperature and is in a molten state. The supply of the thermoplastic resin melt may be before the pressurization or may be simultaneous with the pressurization. The pressurization may be performed by using a mold or the like, or may be performed by the supply pressure of the thermoplastic resin melt. Examples of such a molding method include an injection molding method, a low-pressure injection molding method, and a low-pressure compression molding method.

Specifically, between a pair of opened molds,
The two-layer molded body may be placed so that the (B) layer side is in contact with the thermoplastic resin melt, and then the two molds may be clamped after or while supplying the thermoplastic resin melt. here,
The opening and closing directions of the two dies are not particularly limited, and may be a vertical direction or a horizontal direction.

When a two-layer molded product produced using the above-mentioned powder molding die is used as the skin material, the powder molding die is held on the molding surface while the two-layer molded product is held. It can also be used as one of the molds in the production of the multilayer molded article. According to this method, the two-layer molded body on which the pattern of the mold has been transferred is supplied between the molds without being separated from the mold. Can be obtained.

The thermoplastic resin melt may be supplied after the clamping of the two dies is completed. However, the two-layer molded product is less likely to be displaced, and a multi-layer molded product having improved pattern transfer is obtained. It is preferred that both dies be clamped during or after feeding while the dies are not closed. The method for supplying the thermoplastic resin melt is not particularly limited. For example, the thermoplastic resin melt can be supplied from a resin passage provided in one mold facing the two-layer molded body. Alternatively, the supply nose of the molten resin may be inserted between the two dies to supply the molten resin, and thereafter, the supply nose may be retracted outside the system to close both the dies.

As the pair of dies, a pair of male and female dies in which the outer peripheral surface of one die and the inner peripheral surface of the other die can slide can be used. In this case, by making the clearance between the sliding surfaces of the two dies approximately equal to the thickness of the two-layer molded body, a multilayer molded body having an extra skin material at its end can be obtained. By folding the skin material on the back surface of the multilayer molded body, a multilayer molded body whose end is covered with the skin material layer can be obtained.

When the thermoplastic resin melt is supplied directly to the layer (B) side of the two-layer molded product, the thickness of the layer (B) may be slightly reduced by heat and pressure. In such a case,
After inserting a barrier layer between the (B) layer of the two-layer molded product and the preformed thermoplastic resin core material layer, by supplying a thermoplastic resin melt on the barrier layer,
(B) A decrease in thickness of the layer due to heat and pressure can be suppressed. The thickness of the barrier layer is preferably about 0.2 to 1 mm. The barrier layer may have a shape substantially equal to the shape of the two-layer molded body in advance, or may have a flat plate shape (because it is shaped by the pressure at the time of supplying the thermoplastic resin melt).

[0115]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. The evaluation of the characteristic values of the components of the thermoplastic elastomer constituting the layers (A) and (B) used in the two-layer molded article of the present invention and the evaluation of the two-layer molded article were performed by the following methods. [1] Using a carbon tetrachloride solution of (A-2) or (B-2) in (A-2) or (B-2),
^{It was determined by a 1} H-NMR measurement method (frequency: 90 MHz). [2] The ratio of the number of hydrogenated conjugated diene units having a side chain having 2 or more carbon atoms to the number of hydrogenated conjugated diene units in (A-2) or (B-2) (V: percentage). Using the carbon tetrachloride solution of (A-2), it was determined by ¹ H-NMR measurement (frequency: 90 MHz). [3] Ratio of vinyl aromatic compound unit content of vinyl aromatic compound polymer block (i) to total vinyl aromatic compound content in (A-2) (S: percentage) Morero method using infrared analysis Determined by [4] Hydrogenation rate of double bond of conjugated diene unit in hydrogenated diene copolymer was determined by ¹ H-NMR measurement (frequency: 90 MHz) using a carbon tetrachloride solution of (b). [5] Number average molecular weight of (A-2) or (B-2) Using a tetrahydrofuran solution of (A-2) or (B-2), a gel permeation chromatography (GPC) method at 38 ° C is used. It was determined as a polystyrene equivalent. [6] Solid viscoelasticity of a two-component composition composed of (B-1) and (B-2) Using a solid viscoelasticity measurement device Leo Vibron (DDV-II-EA type) of Orientec Kogyo Co., Ltd. Used mode. 2cm x 5cm (3.5mm between chucks)
cm) × 0.1 mm thick sample was prepared by press molding, and the temperature was raised at a rate of 2 ° C. within a range of −150 ° C. to 130 ° C.
/ Min, the sample was vibrated at an excitation frequency of 110 Hz and an excitation amplitude of 16 μm, and the peak temperature and intensity of the tan δ peak were determined. [7] Complex dynamic viscosity η ^* (1) and Newton viscosity index n Dynamic analyzer (RD) manufactured by Rheometrics
S-7700), the storage elastic modulus G ′ (ω) and the loss elastic modulus G ″ (ω) were measured at the vibration frequency ω = 1 radian / sec or 100 radian / sec, and the above equation (2) was used. ) Was used to calculate the complex dynamic viscosity η ^* (1) and η ^* (100). The measurement was performed in a parallel plate mode, an applied strain of 5%, and a sample temperature of 250 ° C. Also, η ^* (1) and η
^{* Using} (100), the Newtonian viscosity index n was determined by the above-mentioned equation (3). [8] Change in appearance when the two-layered molded body is heated The two-layered molded body obtained by the powder slush molding method described below is converted into a gear oven (Yamato Scientific Co., Ltd .; For 24 hours, and the change in gloss value (gloss) before and after heating was determined based on the following criteria. The gloss value was measured using a digital gloss meter (GM-26D, manufactured by Murakami Color Research Laboratory, reflection angle 60 °). ：: Difference in gloss value is less than 1.0 △: Difference in gloss value is 1.0 or more and less than 2.5 ×: Difference in gloss value is 2.5 or more

[9] Change in appearance when the two-layer molded body is bent (formability) After the two-layer molded body obtained by the powder slush molding method described below is bent for 1 minute so that a load of 200 g / cm is applied, The state change of that part was determined based on the following criteria. ：: The bent portion did not whiten. ×: The bent portion was significantly whitened. [10] Cushioning Property of Two-Layer Molded Body The hardness of the two-layer molded body obtained by the powder slush molding method described below (measured based on JIS K-6253) was measured as an index.

[(B-2) Rubbery polymer used] (B-
2) is a hydrogenated butadiene-styrene copolymer [a styrene unit content of 10% by weight, a hydrogenation ratio of 99%, and a hydrogenated hydrogen having a side chain having 2 or more carbon atoms with respect to all hydrogenated conjugated diene units] Is 80%, the number average molecular weight is 160,000, and the peak temperature of the tan δ peak is -17.
° C and a strength of 1.5]. Further, as the polyolefin resin (B-1), a propylene-ethylene random copolymer resin (the peak temperature of the tan δ peak is −7)
° C, strength is 0.12, ethylene unit content = 5% by weight,
(MFR = 228 g / 10 min).

These were mixed at a ratio shown in Table 1 with a Labo Plastomill (Model 30C150, manufactured by Toyo Seiki Co., Ltd.) for 180 minutes.
The composition was kneaded at 50 ° C. for 10 minutes at a temperature of 50 ° C. to obtain a composition (the amount charged into the mill was 84 g in total). The composition obtained is -70 to 30
A new single tan δ peak was given at a temperature different from both the tan δ peak temperature of (B-1) and the tan δ peak temperature of (B-2) in the temperature range of ° C. Table 1 shows the peak temperature and intensity of the tan δ peak of these compositions.

[0118]

Table 1 t of the composition comprising (B-1) and (B-2)
Temperature and intensity of anδ peak

Reference Example 1 Propylene-ethylene copolymer resin [manufactured by Sumitomo Chemical Co., Ltd., ethylene unit content 5% by weight, MFR = 220]
g / 10 minutes], 100 parts by weight, hydrogenated styrene-butadiene-styrene-styrene copolymer [(i)-(ii-
1) Corresponds to-(i) structure, total styrene unit content 16% by weight, vinyl aromatic compound unit content of part (i) 85% based on total styrene unit content, MFR = 10 g / 10
The ratio of the hydrogenated conjugated diene unit having a side chain having 2 or more carbon atoms to the total hydrogenated conjugated diene unit is 75%.
%, Hydrogenation rate 98%, number average molecular weight 130,000] 100 parts by weight, ethylene-propylene copolymer rubber [Supreto Chemical Industry Co., Ltd., Esplen V0141, propylene content 27% by weight] 50 parts by weight, and black pigment carbon One part by weight of black was kneaded at a temperature of 170 ° C. using a single-axis kneader (VS40 mm extruder manufactured by Tanabe Plastic Machinery Co., Ltd.) to obtain a composition, which was cut using a cutting machine to obtain pellets. Obtained [η * (1) = 2.5 × 10
³ poise, n = 0.12]. The pellets were cooled to −120 ° C. using liquid nitrogen, and then pulverized while maintaining the cooling state, to obtain a powder of the thermoplastic elastomer composition for producing the layer (A) [Tyler Standard Sieve 42 mesh (mesh size 3).
55 μm × 355 μm).

Reference Example 2 Propylene-ethylene copolymer resin [manufactured by Sumitomo Chemical Co., Ltd., ethylene unit content 5% by weight, MFR = 220]
g / 10 min], 100 parts by weight, 100 parts by weight of the hydrogenated butadiene-styrene copolymer (B-2) described above, ethylene-propylene copolymer rubber [Esprene V0141, manufactured by Sumitomo Chemical Co., Ltd., propylene] Content: 27% by weight] 50 parts by weight and 1 part by weight of black pigment carbon black were mixed with a single-axis kneader [VS, manufactured by Tanabe Plastic Machinery Co., Ltd.
40mm extruder] at a temperature of 170 ° C
To obtain a composition, which was cut using a cutting machine to obtain a pellet [η * (1) = 2.7 × 10 ³ poise,
n = 0.07].
After cooling to 20 ° C., the mixture was pulverized while maintaining the cooling state [Tyler Standard Sieve 42 mesh (opening: 355 μm × 3)
55 μm)].

100 parts by weight of the pulverized product was mixed with a powder blowing agent (azodicarbonamide (CAP-50, manufactured by Sankyo Chemical Co., Ltd.)
0, decomposition temperature 150 ° C.) and 3 parts by weight of a supermixer (Kawada Seisakusho Co., Ltd., 5 L supermixer SVM-
Using 5), mixing was performed at 23 ° C. and 1500 rpm for 5 minutes to obtain a thermoplastic elastomer composition containing a foaming agent for producing a layer (B).

Reference Example 3 Oil-extended EPDM (ethylene-propylene-5-ethylidene-2-norbornene copolymer rubber: propylene unit content = 28% by weight, iodine value = 12) (provided that a mineral oil-based softener (Idemitsu) Diana Process Oil PW-3 manufactured by Kosan
80), 100 parts by weight), 100 parts by weight of a propylene-ethylene copolymer resin (ethylene unit content: 5% by weight, MFR = 90 g / 10 min) and a cross-linking aid (Sumitomo Chemical Co., Ltd. Fine BM, bismaleimide) (0.4 parts by weight) was kneaded using a Banbury mixer for 10 minutes, and then processed into pellets using an extruder to obtain a master batch. Next, the master batch 10
To 0 parts by weight, 0.1 part by weight of an organic peroxide (Sanperok APO, 2,5-dimethyl-di (t-butylperoxyno) hexane, manufactured by Sanken Kako Co., Ltd.) was added, and a biaxial kneader ( Dynamic cross-linking was performed at 220 ° C. using Nippon Steel Works, TEX-44) to obtain a composition (η * (1) = 5.2 × 10 ³ poise, n = 0.31). To obtain pellets. The pellets were cooled to −120 ° C. using liquid nitrogen, and then pulverized while keeping the cooling state, to obtain a powder of the thermoplastic elastomer composition for producing the layer (A) [Tyler standard sieve 42 mesh (mesh size 355 μm)].
mx 355 µm).

Example 1 The powder obtained in Reference Example 1 was supplied onto a molding surface of a mold (30 cm square) having a grain pattern heated to 280 ° C.
Next, 8 seconds after the start of the supply, excess powder was washed off. Next, 20 seconds after the powder was removed, the powder obtained in Reference Example 2 was supplied onto a mold on which the powder obtained in Reference Example 1 was attached. Excessive powder was brushed off 20 seconds after the start of the supply. Thereafter, the mold was stored in an oven at 280 ° C. for 1 minute, the mold was water-cooled (shower cooling from the mold surface), and the mold was removed to obtain a two-layer molded body. Table 2 shows the evaluation results of the two-layered molded product.

Comparative Example 1 In Example 1, instead of the hydrogenated product of the styrene-butadiene-styrene-styrene copolymer described in Reference Example 1,
The following hydrogenated product of styrene-butadiene-styrene-styrene copolymer [corresponding to the structure of (i)-(ii-1)-(i), the total styrene unit content being 10% by weight, i) Part of vinyl aromatic compound unit content 48
%, MFR = 10 g / 10 min, ratio of hydrogenated conjugated diene unit having a side chain having 2 or more carbon atoms to hydrogenated conjugated diene unit is 80%, hydrogenation rate 98%, number average molecular weight 13 A two-layered molded article was obtained in the same manner as in Example 1 except that the above-mentioned was used. Table 2 shows the evaluation results.

Comparative Example 2 In Example 1, the following hydrogenated product of a butadiene-styrene copolymer was used in place of the hydrogenated product of the butadiene-styrene copolymer described in Reference Example 2 (total styrene unit content). The amount of the hydrogenated conjugated diene unit having a side chain having 2 or more carbon atoms is 75%, the hydrogenation rate is 98%, and the number average molecular weight is 160,000. However, the composition obtained by kneading with the propylene-ethylene copolymer resin described above has a temperature range of −70 to 30 ° C.
Tan δ peak temperature of (B-1) and ta of (B-2)
A new single t at a temperature different from any of the nδ peak temperatures
An an δ peak was not given, and the same peak was given at each temperature). Table 2 shows the evaluation results.

Comparative Example 3 The procedure of Example 1 was repeated, except that the powder described in Reference Example 3 was used instead of the powder described in Reference Example 1.
To obtain a two-layered molded article. Table 2 shows the evaluation results.

[0127]

[Table 2]

[0128]

As described above, according to the present invention, a skin layer and a polyolefin resin comprising a thermoplastic elastomer composition containing a polyolefin resin and a hydrogenated diene copolymer having a specific structure as essential components are provided. A foamed layer made of a thermoplastic elastomer composition containing a rubbery polymer having a specific structure as an essential component, and having excellent moldability, heated to a temperature of about 80 ° C. to less than the melting point of the polyolefin resin. A molded article which does not emit gloss and has excellent cushioning properties and a method for producing the same can be provided.

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[Procedure amendment]

[Submission date] February 9, 2001 (2001.2.9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0061

[Correction method] Change

[Correction contents]

The compound (B-2) of the present invention 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. A modified functional group having the formula (1) can also be used.

[Procedure amendment 2]

[Document name to be amended] Statement

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[0115]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. The evaluation of the characteristic values of the components of the thermoplastic elastomer constituting the layers (A) and (B) used in the two-layer molded article of the present invention and the evaluation of the two-layer molded article were performed by the following methods. [1] Using a carbon tetrachloride solution of (A-2) or (B-2) in (A-2) or (B-2),
^{It was determined by a 1} H-NMR measurement method (frequency: 90 MHz). [2] The ratio of the number of hydrogenated conjugated diene units having a side chain having 2 or more carbon atoms to the number of hydrogenated conjugated diene units in (A-2) or (B-2) (V: percentage). Using the carbon tetrachloride solution of (A-2), it was determined by ¹ H-NMR measurement (frequency: 90 MHz). [3] Ratio of vinyl aromatic compound unit content of vinyl aromatic compound polymer block (i) to total vinyl aromatic compound content in (A-2) (S: percentage) (b) Carbon tetrachloride solution Using ¹ H-NMR measurement method
(Frequency 90 MHz). [4] Hydrogenation rate of double bond of conjugated diene unit in hydrogenated diene copolymer was determined by Morero method using infrared analysis. [5] Number average molecular weight of (A-2) or (B-2) Using a tetrahydrofuran solution of (A-2) or (B-2), a gel permeation chromatography (GPC) method at 38 ° C is used. It was determined as a polystyrene equivalent. [6] Solid viscoelasticity of a two-component composition composed of (B-1) and (B-2) Using a solid viscoelasticity measurement device Leo Vibron (DDV-II-EA type) of Orientec Kogyo Co., Ltd. Used mode. 2cm x 5cm (3.5mm between chucks)
cm) × 0.1 mm thick sample was prepared by press molding, and the temperature was raised at a rate of 2 ° C. within a range of −150 ° C. to 130 ° C.
/ Min, the sample was vibrated at an excitation frequency of 110 Hz and an excitation amplitude of 16 μm, and the peak temperature and intensity of the tan δ peak were determined. [7] Complex dynamic viscosity η ^* (1) and Newton viscosity index n Dynamic analyzer (RD) manufactured by Rheometrics
S-7700), the storage elastic modulus G ′ (ω) and the loss elastic modulus G ″ (ω) were measured at the vibration frequency ω = 1 radian / sec or 100 radian / sec, and the above equation (2) was used. ) Was used to calculate the complex dynamic viscosity η ^* (1) and η ^* (100). The measurement was performed in a parallel plate mode, an applied strain of 5%, and a sample temperature of 250 ° C. Also, η ^* (1) and η
^{* Using} (100), the Newtonian viscosity index n was determined by the above-mentioned equation (3). [8] Change in appearance when the two-layered molded body is heated The two-layered molded body obtained by the powder slush molding method described below is converted into a gear oven (Yamato Scientific Co., Ltd .; For 24 hours, and the change in gloss value (gloss) before and after heating was determined based on the following criteria. The gloss value was measured using a digital gloss meter (GM-26D, manufactured by Murakami Color Research Laboratory, reflection angle 60 °). ：: Difference in gloss value is less than 1.0 △: Difference in gloss value is 1.0 or more and less than 2.5 ×: Difference in gloss value is 2.5 or more

[9] Change in appearance when the two-layer molded body is bent (formability) After the two-layer molded body obtained by the powder slush molding method described below is bent for 1 minute so that a load of 200 g / cm is applied, The state change of that part was determined based on the following criteria. ：: The bent portion did not whiten. ×: The bent portion was significantly whitened. [10] Cushioning Property of Two-Layer Molded Body The hardness of the two-layer molded body obtained by the powder slush molding method described below (measured based on JIS K-6253) was measured as an index.

[Procedure amendment 3]

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[0118]

Table 1 t of the composition comprising (B-1) and (B-2)
Temperature and intensity of anδ peak

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08L 53/02 C08L 53/02 F-term (Reference) 4F100 AK00C AK03A AK03B AK11A AK28A AL01A AL03A AL09B AN00B AR00D BA02 BA03 BA04 BA07 BA10A BA10C CB00 GB16 GB48 GB90 JA06B JA07A JB16B JB16C JD01D YY00A 4J002 AC02X AC07X AC08X BB03W BB12W BB14W BB15W BB17W BC05X BF02X BG04X BP01X DE206 EQ016 EQ026 EQ036 ES006

Claims (6)

[Claims] 1. A two-layer molded article comprising the following layers (A) and (B). (A) layer: 100 parts by weight of the following (A-1) and (A-2)
A skin layer comprising a thermoplastic elastomer composition containing 10 to 1000 parts by weight (A-1): a polyolefin-based resin (A-2): a hydrogenated diene-based copolymer satisfying all of the following conditions: water The added diene copolymer contains the following structural units (i) and (ii): (i): vinyl aromatic compound polymer block (ii): (ii-1), (ii-2) and (Ii-3) at least one block selected from (ii-1): a block obtained by hydrogenating a random copolymer block of a vinyl aromatic compound and a conjugated diene (ii-2): a vinyl aromatic compound A block comprising a conjugated diene and a hydrogenated tapered block in which a vinyl aromatic compound is gradually increased. (Ii-3): A block which is hydrogenated with a conjugated diene polymer: included in a hydrogenated diene copolymer Including all vinyl aromatic compound units The content is 8 to 20% by weight: the ratio of the content of the vinyl aromatic compound unit of (i) to the total content of the vinyl aromatic compound unit in the hydrogenated diene copolymer (S: percentage) Is 3% or more: ratio of the number of hydrogenated conjugated diene units having side chains having 2 or more carbon atoms to the total number of hydrogenated conjugated diene units in the hydrogenated diene-based copolymer (V: percentage ) Exceeds 60%: The relationship between the above (S) and the above (V) in the hydrogenated diene copolymer is represented by the relational expression (1): V ≦ 0.375 × S + 62.5 (1): 80% or more of the double bond of the conjugated diene unit in the hydrogenated diene copolymer is hydrogenated: the number average molecular weight of the hydrogenated diene copolymer is 50,000 to 60
(B) layer: 100 parts by weight of the following (B-1) and (B-2)
Foamed layer made of a thermoplastic elastomer composition containing 10 to 1000 parts by weight (B-1): polyolefin resin (B-2): rubbery polymer, obtained by kneading with (B-1) T obtained by solid viscoelasticity measurement of the resulting composition
In the an δ-temperature dependency curve, the tan δ peak temperature of (B-1) and the (B-2) in the temperature range of -70 to 30 ° C.
Polymer giving a new single tan δ peak at a temperature different from any of the tan δ peak temperatures of 2. The two-layer molded product according to claim 1, which is produced by a powder molding method. 3. A multilayer molded article comprising the two-layer molded article according to claim 1 and a thermoplastic core material laminated on the (B) layer side. 4. The method for producing a multilayer molded article according to claim 3, wherein a thermoplastic resin melt is supplied to the (B) layer side of the two-layer molded article according to claim 1 and pressurized. 5. The thermoplastic resin core layer after applying an adhesive to the (B) layer side of the two-layer molded article according to claim 1 or to the bonding surface of the thermoplastic resin core layer preformed. The method for producing a multilayer molded article according to claim 3, wherein 6. After a barrier layer is inserted between the layer (B) side of the two-layer molded article according to claim 1 and a thermoplastic resin core material which has been preliminarily formed, a thermoplastic layer is formed on the barrier layer. The method for producing a multilayer molded article according to claim 3, wherein the resin melt is supplied and pressurized.