JP2003201372A - Thermoplastic elastomer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition which is a material useful for all applications where an elastomer is used and which is excellent in flexibility, mechanical characteristics, heat resistance and marring resistance. <P>SOLUTION: The thermoplastic elastomer composition consists of (A) 25-95 pts.wt. of a partially or completely crosslinked rubbery polymer and (B) 5-75 pts.wt. of a thermoplastic resin comprising essentially a crystalline styrene polymer, preferably a styrene polymer having a syndiotactic structure, with the total of the component (A) and the component (B) being 100 pts.wt. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic elastomer composition comprising a partially or completely crosslinked rubbery polymer and a crystalline styrenic polymer. More specifically, a partially or completely crosslinked rubber-like polymer and a crystalline styrene-based polymer, preferably a thermoplastic resin containing a styrene-based polymer having a syndiotactic structure as an essential component, that is, syndyne A styrene-based polymer having an tactic structure or a mixture of a styrene-based polymer having a syndiotactic structure and a thermoplastic resin other than the styrene-based polymer having a syndiotactic structure, which has flexibility and mechanical properties In particular, it relates to a thermoplastic elastomer composition having excellent heat resistance and coatability.

[0002]

2. Description of the Related Art Conventionally, as a thermoplastic elastomer,
Olefin-based, styrene-based, vinyl chloride-based, urethane-based, polyester-based, polyamide-based, etc. are typically known. Among them, in recent years, olefin-based thermoplastic elastomers, which are relatively low in cost and have excellent physical property balance, are used in automobile interior and exterior materials, home appliances, building furniture, sports equipment, toys,
Widely used for daily goods.

This olefinic thermoplastic elastomer is mainly composed of an olefinic rubbery polymer represented by ethylene / propylene / diene copolymer (EPDM) and polypropylene (PP) in the extruder in the presence of a radical initiator. Mainly products that have undergone a so-called dynamic cross-linking process, in which they are cross-linked while being melt-kneaded, and the market is currently expanding as a substitute for vulcanized rubber and polyvinyl chloride. However, since these olefin-based dynamically crosslinkable thermoplastic elastomers use polypropylene as a matrix, they are inferior in printability and paintability to molded articles and adhesiveness to adhesives, and their applications are limited.

Focusing on these printability and paintability, what we have been working on in recent years is that some or all of the polypropylene used in the above-mentioned olefinic dynamically crosslinkable elastomer is made of polystyrene or the like. It is a styrene type dynamically crosslinkable thermoplastic elastomer replaced with a styrene type resin (Japanese Patent Application No. 2001-46944, Japanese Patent Application No. 20).
01-46945, Japanese Patent Application No. 2001-51392). Since these thermoplastic elastomers use a styrene-based resin as the matrix phase, the properties such as printability, paintability, and adhesiveness, which are the drawbacks of conventional olefin-based resins, have been dramatically improved, and they are wide-ranging. Market expansion is expected. However, compared with the conventional olefin-based cross-linking type thermoplastic elastomer, its use is limited because it is inferior in practical heat resistance, oil resistance and solvent resistance, and its heat resistance, oil resistance and solvent resistance are limited. Improvement was a major issue.

[0005]

DISCLOSURE OF THE INVENTION The present invention has improved properties such as printability, paintability, and adhesiveness, which were the drawbacks of conventional olefinic crosslinked thermoplastic elastomers, and further improved heat resistance, scratch resistance, and oil resistance. The present invention relates to a thermoplastic elastomer composition having properties and solvent resistance equivalent to or higher than those of conventional olefins.

[0006]

Means for Solving the Problems In view of the above-mentioned problems, the present inventors have conducted extensive studies, and as a result, found that the thermoplastic elastomer composition shown below solves the above problems, and completed the present invention. I arrived. That is, the present invention includes: 1) (A) 25 to 95 parts by weight of a partially or completely crosslinked rubbery polymer, and (B) 5 to 75 parts by weight of a thermoplastic resin containing a crystalline styrene polymer as an essential component. Department (total 100
Part by weight).

2) The thermoplastic elastomer composition according to 1), wherein the crystalline styrene polymer is a styrene polymer having a syndiotactic structure. 3) The composition has a total of 100 components (A) and (B).
The thermoplastic elastomer composition according to claim 1, which comprises less than 50 parts by weight of the compatibilizing agent (C) with respect to parts by weight. 4) The thermoplastic elastomer composition according to 1) to 3), wherein the rubber-like polymer is an ethylene-based polymer and / or a conjugated diene-based polymer.

5) The ethylene polymer is an ethylene monomer, an α-olefin having 3 to 20 carbon atoms, an aromatic vinyl,
It is a copolymer with a monomer selected from the group of vinyl acetate, acrylic acid ester and methacrylic acid ester 4).
The thermoplastic elastomer composition described. 6) The thermoplastic elastomer according to 4), wherein the conjugated diene-based polymer is a conjugated diene polymer, an aromatic vinyl compound / block or random copolymer of conjugated diene and / or a partial or complete hydrogenation product thereof. Composition.

7) The thermoplastic resin containing the crystalline styrene polymer (B) as an essential component is a styrene polymer having a syndiotactic structure, or a styrene polymer having a syndiotactic structure and syndiotactic. The thermoplastic elastomer composition according to 1) to 6), which is a mixture with a thermoplastic resin other than a styrene polymer having a tick structure. 8) The thermoplastic elastomer composition according to 1) to 7), wherein the compatibilizing agent (C) is a styrene block copolymer. Related to.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. First, each component of the present invention will be described in detail. The thermoplastic elastomer composition of the present invention comprises at least (A) a partially or completely crosslinked rubbery polymer,
(B) A composition comprising two components of a crystalline styrene polymer, preferably a thermoplastic resin containing a styrene polymer having a syndiotactic structure as an essential component. Here, it is preferable that the rubber-like polymer component (A) partially or completely crosslinked in the “sea” of (B) is present as “islands”. By taking this form, it becomes possible to maximize the mechanical properties and heat resistance of the composition.

The rubbery polymer which is the base of the partially or completely crosslinked rubbery polymer used as the component (A) of the present invention will be explained. The rubber-like polymer in the present invention is not particularly limited as long as it is a polymer showing rubber elasticity, but preferably an ethylene-based polymer and / or a conjugated diene-based polymer can be mentioned. The reason for this is
By using these rubber-like polymers, it becomes possible to finally obtain a thermoplastic elastomer composition having low hardness and high strength.

The ethylene polymer described here is at least one of monomers selected from the group consisting of ethylene and α-olefins having 3 to 20 carbon atoms, aromatic vinyl compounds, vinyl acetate, acrylic acid esters and methacrylic acid esters. A preferable example is a copolymer containing 1 to 60% by weight of the seed. On the other hand, the conjugated diene-based polymer described here is a conjugated diene polymer derived from a conjugated diene-based compound, and a copolymer (block, random, or aromatic vinyl-based compound / conjugated diene-based compound).
Tapered, any combination thereof, and hydrogenated products thereof can be mentioned as preferable examples. The hydrogenation rate of the hydrogenated product can be set arbitrarily.

Specific examples of the α-olefin having 3 to 20 carbon atoms, which is a copolymerization component with ethylene, include propylene, butene-1, pentene-1, 4-methylpentene-1, and hexene-1. , Heptene-1, octene-
1, nonene-1, decene-1, undecene-1, dodecene-1 and the like, among which butene-1 and hexene-
1, octene-1 are preferably used. In addition, containing a small amount of non-conjugated diene components such as ethylidene norbornene,
An ethylene / α-olefin / diene terpolymer represented by EPDM is also included in the concept of the copolymer.

The above ethylene / α-olefin copolymer is preferably produced by a known Ziegler type or metallocene type catalyst, and among them, the polymer produced by a metallocene type catalyst is more preferably used. Generally, a metallocene catalyst is composed of a cyclopentadienyl derivative of a group IV metal such as titanium and zirconium and a cocatalyst, and is not only highly active as a polymerization catalyst, but also has a higher weight than the Ziegler catalyst. The molecular weight distribution of the coalesced product is narrow, the distribution of the α-olefin having 3 to 20 carbon atoms, which is a comonomer in the copolymer, is uniform, and the thermoplastic elastomer of the present invention using this rubber-like polymer as a rubber component has a high It becomes strength.

Further, specific examples of the aromatic vinyl compound which is a copolymerization component with ethylene include styrene, p-methylstyrene, p-ethylstyrene, pt-butylstyrene and α-methylstyrene. Among them, styrene and α-methylstyrene are preferably used. In fact, an ethylene / styrene random copolymer (trade name: Index) marketed by The Dow Chemical Company in the United States is a typical example, and a random copolymer of an aromatic vinyl compound such as ethylene and styrene is a constituent monomer unit. It is a polymer. Since it is used as a rubbery polymer, it is preferable to use a polymer having a low styrene content.

Further, specific examples of acrylic acid ester and methacrylic acid ester which can be mentioned as a copolymerization component with ethylene include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, stearyl acrylate and acrylic acid. There are glycidyl acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, stearyl methacrylate, glycidyl methacrylate, and the like. Among them, methyl acrylate and methyl methacrylate are preferably used.

Here, the copolymerization ratio of the comonomer which is a component other than ethylene in the ethylene-based polymer is 1 to 60.
It is preferably 10% by weight, more preferably 10-5.
It is 0% by weight, most preferably 20 to 45% by weight. When the copolymerization ratio of the comonomer exceeds 60% by weight, the mechanical strength and heat resistance of the composition are greatly deteriorated, which is not preferable. On the other hand, if the amount is less than 1% by weight, the ethylenic crystallinity is high and the hardness of the composition is high, resulting in lack of flexibility as an elastomer material, which is not preferable.

Further, the conjugated diene polymer preferably used as the rubber-like polymer of the present invention will be described. The conjugated diene-based polymer is a conjugated diene polymer derived from a conjugated diene-based compound as described above, and an aromatic vinyl compound / conjugated diene-based compound and hydrogenated products thereof are preferably used. The diene compound is a general term for butadiene, isoprene, cyclohexadiene and the like, and polybutadiene, polybutadiene,
A conjugated diene polymer such as polyisoprene is formed.

On the other hand, the aromatic vinyl compound is as described above.
A compound typified by styrene, which can be copolymerized with butadiene, isoprene and the like by a known polymerization method to obtain an aromatic vinyl / conjugated diene copolymer. At this time, the order of the aromatic vinyl monomer and the conjugated diene-based monomer is not limited at all, and includes any structure such as random, tapered, block, and any combination thereof. As for the polymerization method, any known production method such as solution polymerization or emulsion polymerization may be used. Further, any polymerization method such as continuous polymerization or batch polymerization may be used.

In the present invention, a conjugated diene polymer and / or
Or about the aromatic vinyl / conjugated diene copolymer,
Although it may be used as a rubbery polymer as it is, it is preferable to hydrogenate the unsaturated bond in the molecular chain from the viewpoint of heat resistance, weather resistance and the like. The use of titanium-based hydrogenation catalysts is recommended as a technique for hydrogenation.
Japanese Patent Laid-Open No. 60-220147 discloses the technical contents. The hydrogenation rate can be arbitrarily set in consideration of required characteristics and productivity.

The number average molecular weight of the rubber-like polymer before crosslinking is preferably in the range of 30,000 to 1,000,000. By using the polymer in this range, the processability in producing a thermoplastic elastomer composition and the balance of mechanical properties of the thermoplastic elastomer composition of the present invention are excellent. In addition, the molecular weight distribution of the polymer [weight average molecular weight (M
The ratio (w / Mn) of w) to the number average molecular weight (Mn)] is preferably 10 or less, more preferably 5 or less, and most preferably 3 or less. When the molecular weight distribution is more than 10, the cross-linking property is significantly deteriorated, and the mechanical properties of the obtained thermoplastic elastomer composition are significantly decreased, which is not preferable.

These number average molecular weights and molecular weight distributions can be easily determined by gel permeation chromatography using standard polystyrene. An example of a specific measurement method is as follows: Apparatus: PL-GPC-210 manufactured by Polymer Laboratory Co., Ltd. Column: PL gel 10 μm MIXED-B 300 × 7.5 mm 2 PL gel 10 μm GUARD 10 × 7.5 mm 1 column Temperature: 140 ° C Solvent: 1,2,4-trichlorobenzene Sample concentration: 0.1% by weight After dissolution, filtration is performed with a filter. By using the high temperature gel permeation chromatography described above, a conjugated diene polymer or an aromatic vinyl / conjugate is used. It is possible to measure the molecular weight of not only the diene copolymer but also the crystallinity of the ethylene polymer which is hardly soluble at room temperature.

The rubber-like polymer of the present invention may be used in combination with rubber-like polymers having different copolymerization compositions and hydrogenation rates. Further, the rubbery polymer of the present invention needs to be partially or completely crosslinked. As a result, the desired sea-island structure can be expressed, and it is possible to bring out the high heat resistance originally possessed by the composition. The degree of crosslinking is 30% or more, preferably 50% or more.

Next, the crystalline styrene polymer which is the component (B) of the present invention will be explained. Examples of the crystalline styrene polymer include a styrene polymer having a syndiotactic structure and a styrene polymer having an isotactic structure. Among these, a styrene-based polymer having a syndiotactic structure is more preferable because it has high heat resistance and is easily crystallized. The styrene-based polymer having a syndiotactic structure preferably used in the present invention is different from the styrene-based polymer having an atactic structure produced by a usual radical polymerization, and is produced, for example, by a catalyst of a titanium-based compound and an alkylaluminoxane. Is a crystalline polymer. In the case of styrene homopolymer, this melting point is 270 ° C.

The monomer component which constitutes the crystalline styrene polymer in the present invention is preferably styrene or substituted styrene, and may be a homopolymer or copolymer thereof, or It may be a mixture. Examples of the substituted styrene include α-methylstyrene, paramethylstyrene, orthoparadimethylstyrene, paratertiarybutylstyrene and the like. The syndiotactic structure means that the steric structure has a steric structure in which the phenyl groups, which are side chains, are alternately located in opposite directions with respect to the polymer main chain formed from carbon-carbon bonds, The tacticity is quantified by NMR, and a plurality of consecutive constitutional units, for example, two diads, three triads, 5
Individual cases are indicated by Pendad.

On the other hand, the atactic structure possessed by conventional polystyrene having no crystallinity means that the phenyl group, which is a side difference with respect to the polymer main chain, has no regularity and is randomly located. Means The syndiotactic polystyrene used in the present invention is
It is preferable that the dyad is 75% or more and the pendad is 30% or more. The crystalline styrene polymer used in the present invention preferably has a number average molecular weight of 10,000 to 1,000,000, more preferably 50,000 to 400,000. As the method for measuring the molecular weight, high temperature gel permeation chromatography is used as in the method for measuring the rubber-like polymer described above.

The component (B) of the thermoplastic elastomer composition of the present invention comprises a thermoplastic resin containing a crystalline styrene polymer as an essential component.
Means that the thermoplastic resin as the component (B) contains a crystalline styrene polymer, preferably 10% by weight or more, more preferably 25% by weight or more, and further preferably 40% by weight. % Or more, most preferably 60
It is more than weight%. If it is less than 10% by weight, it will be difficult to obtain the thermoplastic elastomer composition intended and intended by the present invention.

Next, the compatibilizing agent which is the component (C) of the present invention will be described. The role of the compatibilizing agent used as the component (C) of the present invention is that the crosslinked rubber-like polymer as the component (A) is a crystalline styrenic polymer as the component (B),
Preferably, the styrene-based polymer having a syndiotactic structure is finely dispersed in a thermoplastic resin as an essential component, and the interface between these is strongly reinforced to improve the mechanical properties. Therefore, when (A) is finely dispersed and the mechanical properties are improved as compared with a system in which the (A) component and the (B) component are simply mixed, they serve as a compatibilizer. And if it plays this role,
It is useful in the present invention.

Here, (A) the rubber-like polymer itself is compatible with a styrene polymer having a syndiotactic structure, for example, the rubber-like polymer is an aromatic vinyl compound /
In the case of a block or random copolymer of a conjugated diene or a hydrogenated product thereof, not only the amount of the (C) compatibilizer added can be reduced but, in some cases, the addition of the (C) compatibilizer It may not be necessary. In general, those that serve as the above-mentioned compatibilizer tend to have a structure. In particular, polymer-based ones are generally used, and among them, block copolymers and graft copolymers are preferably used as the compatibilizing agent.

In the present invention, the styrenic block copolymer is the most suitable compatibilizer. The styrene-based block copolymer described here is a block copolymer of an aromatic vinyl compound typified by styrene and butadiene, or a conjugated diene compound typified by isoprene, or its Refers to hydrogenated products.

The block structure means that when the aromatic vinyl compound block is A and the conjugated diene block is B,
A-B, A-B-A, A-B-A-B, (A-B-) ₄
Si etc. can be illustrated. By adding the block copolymer to the thermoplastic elastomer composition of the present invention,
The crosslinked rubbery polymer is preferably finely dispersed, (A)
Since the interface between the component and the component (B) is strongly reinforced, the mechanical properties are improved and the smoothness of the skin is exhibited in the case of an extruded product, the effect is extremely large. It is strongly recommended to add a styrenic block copolymer as an agent.

It is strongly recommended to select a hydrogenated product in which the conjugated diene block is saturated as the block copolymer. The reason is also good compatibility with the rubber-like polymer, but is particularly excellent in heat deterioration resistance during processing as compared with the non-hydrogenated block copolymer, and physical properties as a product over time. There is little change. As an aromatic vinyl monomer, styrene, α
-Methylstyrene is preferably used. Particularly preferred is styrene. The conjugated diene monomer is preferably butadiene or isoprene, or may be a mixture of both.

When butadiene is used as a monomer, 1,2- in the microstructure of the polybutadiene block is used.
A block copolymer obtained by hydrogenating an addition structure of 20 to 80% is preferable, and a 1,2-addition structure of 30 to 60% is particularly preferable. The molecular structure of the block copolymer may be linear, branched, radial, or a combination thereof. The block copolymer may be produced by any production method. For example, it can be obtained by block copolymerization in an inert solvent using a lithium-based polymerization initiator or the like by the method described in JP-B-40-23798.

Further, the hydrogenation treatment of such a block copolymer is carried out, for example, in Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, or JP-A-59-1332.
It can be carried out in the presence of a hydrogenation catalyst in an inert solvent according to the method described in JP-A No. 03 and JP-A-60-79005. In this hydrogenation process,
At least 50%, preferably 80%, most preferably 9% of the olefinic double bonds in the unhydrogenated block copolymer.
0% or more is hydrogenated. The styrene content in the styrene block copolymer is 30 to 70% by weight.
Those of are preferably used.

In order to improve the compatibility between the crosslinked rubber-like polymer which is the component (A) and the crystalline styrenic polymer which is contained in the component (B), the above block copolymer may be used in some cases. It is possible to use those obtained by copolymerizing a monomer having a polar group. Specific examples of the polar group-containing monomer include acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, maleic anhydride, maleic acid, butyl acrylate, methacrylonitrile, and N.
-Phenylmaleimide, glycidyl methacrylate, etc. are mentioned.

Commercially available products of such hydrogenated block copolymers include "Tuftec" (Asahi Kasei), "Kraton G" (Kraton polymer), "Septon", "High Blur" (Kuraray) and the like. The amount of the styrenic block copolymer contained in the composition of the present invention is 50% by weight based on 100 parts by weight of the total of the components (A) and (B).
Less than 25% by weight, more preferably less than 25% by weight
Is less than. When it is 50% by weight or more, the gist of the present invention is different, which is not preferable.

The styrene block copolymer preferably used as the compatibilizing agent which is the component (C) is also the component (A) of the present invention as long as it exhibits rubber elasticity. In this case, in the present invention, those which are crosslinked are counted as the component (A), and those which are not crosslinked are counted as the component (B). As described above, the component (B) of the present invention may optionally contain other thermoplastic resin in addition to the crystalline styrene polymer. There is no limitation on the structure or type of this thermoplastic resin. Here, preferable specific examples of the thermoplastic resin include an amorphous styrene resin (such as atactic polystyrene), polyphenylene ether, and an olefin resin.

The amorphous styrenic resin can be produced by a known polymerization method (radical polymerization, living polymerization, etc.). It is also possible to contain an arbitrary monomer component copolymerizable with the aromatic vinyl compound or a graftable polymer component. Specific examples thereof include (meth) acrylic acid alkyl esters represented by methyl acrylate, methyl methacrylate, butyl acrylate, etc., and unsaturated nitrile compounds represented by acrylonitrile, etc., as copolymerizable monomer components. Kind,
Examples thereof include conjugated diene compounds represented by butadiene and isoprene. The order of the monomers in these copolymers is not limited, and random copolymers, block copolymers, tapered, etc. are typical examples. Also,
In the case of a copolymer with a conjugated diene compound, a diene portion hydrogenated at an arbitrary ratio may be used.

On the other hand, the graftable polymer components include polybutadiene, polyisoprene, styrene / butadiene copolymers, styrene / isoprene copolymers, and hydrogenated products having any of these hydrogenation ratios, ethylene / methyl. Ethylene / methacrylate copolymer /
(Meth) acrylic acid alkyl ester copolymer, ethylene / α-olefin copolymer such as ethylene / propylene copolymer, ethylene / α-olefin / diene copolymer such as ethylene / propylene / ethylidene norbornene copolymer Etc.

Among them, the amorphous styrenic resin includes polystyrene homopolymer (GPPS), rubber-reinforced polystyrene (HIPS; usually polybutadiene, styrene / butadiene copolymer, and reinforcement by selective hydrogenation of these). Most preferably used. Specific examples of these amorphous styrenic resins include GPPS, HIPS,
Examples thereof include a styrene-acrylonitrile copolymer, a rubber-reinforced styrene-acrylonitrile copolymer, a styrene-butyl acrylate copolymer, a styrene-methylmethacrylate copolymer, and a rubber-reinforced styrene-methylmethacrylate copolymer.

The thermoplastic elastomer composition of the present invention comprises
Polyphenylene ether can be contained as a part of the component (B). The polyphenylene ether used here is an effective component for the purpose of improving the mechanical properties of the resulting thermoplastic elastomer composition. The binding unit of polyphenylene ether is represented by the following formula (1) and has a reduced viscosity (0.5 g / dl chloroform solution, 30
C. measurement) is 0.15 to 0.70, preferably 0.20
Those in the range of 0.60 are used.

[0042]

[Chemical 1]

(Here, R1, R2, R3, and R4 are each selected from the group consisting of hydrogen, hydrocarbons, and substituted hydrocarbon groups, and may be the same or different from each other.
n is an integer of 1 or more) As this polyphenylene ether, known ones are used. Specific examples include poly (2,6-dimethyl-1,4-phenylene ether) and poly (2-methyl-
6-ethyl-1,4-phenylene ether), poly (2,6-diphenyl-1,4-phenylene ether), poly (2-methyl-6-phenyl-1,4-phenylene ether) and the like, In addition, 2,6-dimethylphenol and other phenols (for example, 2,3,6-
Also included are polyphenylene ether copolymers such as copolymers with trimethylphenol and 2-methyl-6-butylphenol. Among them, poly (2,6-dimethyl-1,4-phenylene ether), 2,6-dimethylphenol and 2,3,6-trimethylphenol are preferable, and poly (2,6-dimethyl-1,4-phenylene) is more preferable. Ether) is preferred.

Further, examples of the olefin resin include polyethylene (high density, low density, linear low density), polypropylene (homo, block, random), polybutene and the like. In addition, examples of other thermoplastic polymers that can be optionally added to the composition include polymethylmethacrylate, polycarbonate, polyester, polyamide,
Examples thereof include polyacetal, polyphenylene sulfide, polysulfone, and polyether ether ketone.

Thermoplastic resins other than these crystalline styrene polymers are preferably used in the component (B) of the present invention, preferably 9
It is less than 0% by weight, more preferably less than 75% by weight, even more preferably 60% by weight and most preferably less than 40% by weight. When it exceeds 90% by weight, various characteristics of the crystalline styrene resin, which is the object of the present invention, cannot be utilized, which is not preferable. Further, to the thermoplastic elastomer composition of the present invention, a softening agent for rubber such as mineral oil can be preferably added mainly for the purpose of lowering hardness and lowering elastic modulus.

The kind of the softening agent for rubber is not particularly limited, but paraffin oil, naphthene oil and ester oil are recommended from the viewpoint of compatibility with the rubber-like polymer. However, the amount of these added is 100 parts by weight or less, preferably 60 parts by weight or less, based on 100 parts by weight of the crosslinked rubbery polymer as the component (A), from the viewpoint of mechanical properties and touch. It is preferable. Also,
The method of adding the softening agent for rubber to the thermoplastic elastomer composition is not limited in the present invention. The most common method is to attach or absorb the raw material polymer, or to add liquid from the middle of the extruder.

In the production of the thermoplastic elastomer composition of the present invention, there is no particular limitation on the method of melt-kneading the respective components constituting the composition, and a single-screw extruder, a twin-screw extruder, a Banbury mixer, pressurization Known methods such as kneader and mixing roll can be used. The rubber-like polymer which is the component (A) of the thermoplastic elastomer composition of the present invention needs to be partially or completely crosslinked. In order to efficiently crosslink a rubber-like polymer to obtain a partially or completely crosslinked rubber-like polymer (A),
The dynamic crosslinking method is preferably used, and therefore the twin-screw extruder is preferably used. The twin-screw extruder uniformly and finely disperses an uncrosslinked rubber-like polymer, a crystalline polymer component, and an arbitrary thermoplastic resin component, and causes a crosslinking reaction of the rubber-like polymer to produce a desired heat. It is most suitable for continuously producing a plastic elastomer composition. In the present invention, there is no regulation on the means for partially or completely crosslinking the rubber-like polymer, but it is possible to use a radical initiator such as an organic peroxide or a combination of an organic peroxide and a crosslinking aid as a crosslinking agent. The method of cross-linking is most recommended.

Specific examples of the organic peroxides preferably used here are 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,
1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 1 , 1-bis (t-butylperoxy) cyclohexane, 2,2-bis (t-
Butylperoxy) octane, n-butyl-4,4-bis (t-butylperoxy) butane, n-butyl-4,
Peroxyketals such as 4-bis (t-butylperoxy) valerate; di-t-butylperoxide, dicumylperoxide, t-butylcumylperoxide, α, α′-bis (t-butylperoxy) -M-isopropyl) benzene, α, α'-bis (t-butylperoxy) diisopropylbenzene, 2,5-dimethyl-
Dialkyl peroxides such as 2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3;

Acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,
Diacyl peroxides such as 5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide and m-trioyl peroxide; t-butyl peroxyacetate, t-butyl peroxyisobutyrate Rate, t-butylperoxy-2-ethylhexanoate, t-butylperoxylaurylate, t-butylperoxybenzoate, di-t-butylperoxyisophthalate,
2,5-Dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-
Butyl peroxy isopropyl carbonate, and peroxy esters such as cumyl peroxy octate;
And t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,
5-dihydroperoxide and 1,1,3,3-
Hydroperoxides such as tetramethylbutyl peroxide; non-peroxides such as 2,3-dimethyl-2,3-diphenylbutane can be mentioned.

Among these compounds, when a crystalline polymer having a relatively low melting point is used, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane and di-t-butylperoxide are used. Oxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5
-Bis (t-butylperoxy) hexyne-3 is particularly preferably used. These organic peroxides are used in an amount of 0.02 to 3 parts by weight, preferably 0.05 to 1.5 parts by weight, based on 100 parts by weight of the rubber-like polymer. 0.02
If the amount is less than 1 part by weight, the crosslinking reaction is insufficient. On the other hand, even if the amount is more than 3 parts by weight, the degree of crosslinking of the thermoplastic elastomer composition reaches a ceiling and the physical properties are not improved. Become.

Further, as a crosslinking aid, divinylbenzene, triallyl isocyanurate, triallyl cyanurate, diacetone diacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate. , Ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diisopropenylbenzene, P-quinonedioxime, P, P'-dibenzoylquinonedioxime, phenylmaleimide, allyl methacrylate, N, N'-
m-phenylene bismaleimide, diallyl phthalate,
Tetraallyloxyethane, 1,2-polybutadiene and the like are preferably used. Of these, divinylbenzene and triallyl isocyanurate are preferable. Moreover, these crosslinking aids may be used alone or in combination of two or more.

These cross-linking aids are used as the rubber-like polymer 100.
0.05 to 5 parts by weight, preferably 0.5 to 5 parts by weight
Used in an amount of 3 parts by weight. If it is less than 0.05 parts by weight, the role as a crosslinking aid is insufficient, and if it is added in an amount of more than 5 parts by weight, the physical properties such as mechanical strength of the composition are not improved. Results in remaining in the composition,
Poor quality. The degree of crosslinking is defined as a measure of the crosslinkability of the composition. About 5 g of the thermoplastic elastomer composition according to the present invention was weighed to obtain 2-butanone (MEK) 200 m.
Soxhlet extraction is carried out for 16 hours using 1. By this operation, the uncrosslinked rubbery polymer, the styrene block copolymer, and the softening agent for rubber such as paraffin oil are extracted and removed. Here, when a 2-butanone-insoluble rubber-like polymer such as an ethylene polymer having microcrystallinity is used as the rubber-like polymer, Soxhlet extraction is further performed using 200 ml of n-heptane for 16 hours. The uncrosslinked rubbery polymer is extracted and removed. After these series of operations, the residue in the cylindrical filter paper was quantified after heating and vacuum drying, and the ratio of the residue to the weight of the entire rubber-like polymer in the composition, that is, the weight ratio of the cross-linked rubbery polymer, that is, Calculate the degree of crosslinking (%).

At this time, the weight corresponding to the amount of the styrene-based polymer having the insoluble syndiotactic structure is, of course, calculated by subtracting the weight. This number also includes the weight of grafted chains and occluded polymer. In addition, when insoluble polymers such as other crystalline resins or insoluble graft rubber components contained in the rubber-reinforced polystyrene are contained, or when an insoluble filler is added to the composition, these are also included in the calculation. Subtract the corresponding amount to determine the degree of crosslinking.

The thermoplastic elastomer composition of the present invention comprises
It can be manufactured via a manufacturing process such as the following example. (Example 1) The rubber-like polymer before cross-linking, the crystalline styrenic polymer component, and optionally each thermoplastic resin pellet, crumb, etc. are well dry-blended and charged into the hopper of the extruder. The radical initiator and the crosslinking aid may be added together with the rubbery polymer or the like from the beginning or may be added in the middle of the extruder. Furthermore, a part of the rubber-like polymer and / or a part (or all) of the crystalline styrenic polymer component and / or a part (or all) of any other thermoplastic resin are added from the middle of the extruder. You may. When the rubber-like polymer, the radical initiator and the crosslinking aid undergo a crosslinking reaction when heated and melted and kneaded in the extruder, and further sufficiently kneaded and dispersed, the product is taken out from the extruder. Finally, pelletizing can be performed to obtain pellets of the desired thermoplastic elastomer composition.

Example 2 Pelletizing was first carried out by the above-mentioned method without adding a radical initiator and a crosslinking aid, and then,
The pellets of the desired thermoplastic elastomer composition can be obtained by adhering the radical initiator and the crosslinking aid to the obtained pellets and kneading and dispersing again through an extruder. (Example 3) Pellets, crumbs and the like of the rubber-like polymer before cross-linking and any thermoplastic resin contained in the component (B) are well dry-blended and put into a hopper of an extruder. The radical initiator and the crosslinking aid may be added together with the rubbery polymer or the like from the beginning or may be added in the middle of the extruder. Further, a part of the rubber-like polymer and / or a part (or the whole) of any other thermoplastic resin may be added in the middle of the extruder. When the rubber-like polymer, the radical initiator and the crosslinking aid undergo a crosslinking reaction when heated and melted and kneaded in the extruder, and further sufficiently kneaded and dispersed, the product is taken out from the extruder. Then pelletize,
It is possible to obtain pellets of a thermoplastic elastomer that does not contain the crystalline styrene polymer, which is an essential component in the component (B). Then, the pellets of the thermoplastic elastomer and the pellets of the crystalline styrene polymer, and further, if necessary, the pellets of the thermoplastic resin of an arbitrary component are dry blended, and the mixture is put into the hopper of the extruder, and the extruder is used. The pellets of the desired thermoplastic elastomer composition can be obtained by pelletizing after kneading.

Among them, the specific production method carried out by the present inventors is as follows. First, a rubber-like polymer and a crystalline styrene-based polymer,
Specifically, syndiotactic polystyrene, a styrene block copolymer as a compatibilizer, and optionally another thermoplastic polymer are charged into a hopper, and melt-kneaded with a twin-screw extruder. At this time, half of the predetermined amount of the softening agent for rubber is added by liquid. The pellets obtained are put into the same twin-screw extruder again, and this time, the remaining half of the softening agent for rubber mixed with a crosslinking agent and a crosslinking aid is liquid-added to perform dynamic crosslinking, and a predetermined thermoplastic elastomer composition is obtained. Get things. All the examples and comparative examples described below were manufactured by this manufacturing method. The thermoplastic elastomer composition of the present invention can be used after foaming. The method of foaming is not particularly limited, but, for example, a conventionally known method such as a method of blending a pyrolytic foaming agent, a method of blending water under pressure as a foaming agent, and a method of injecting high-pressure gas during injection molding are available. It is available.

The thermoplastic elastomer composition of the present invention comprises
The following compounding agents and additives can be compounded as necessary. There is no limitation on the amount that can be blended, but it is premised that the amount is blended within the range consistent with the gist of the present invention. Examples include antioxidants, weathering agents, metal deactivators, UV absorbers, light stabilizers, anti-bleeding / blooming agents, sealability improving agents, crystal nucleating agents, flame retardants, antibacterial / antifungal agents. Agent, dispersant, silicone oil, viscosity modifier, anti-coloring agent, foaming agent, foaming aid, organic dye / pigment, inorganic dye / pigment, titanium oxide, carbon black, metal powder such as ferrite,
Inorganic fibers such as glass fibers and metal fibers, carbon fibers, organic fibers such as aramid fibers, composite fibers, inorganic whiskers such as potassium titanate whiskers, glass beads, glass balloons, glass flakes, silicate compounds such as mica, calcium carbonate Examples include fillers such as talc, silica, calcium silicate, hydrotalcite, kaolin, diatomaceous earth, graphite, pumice, evo powder, cotton flock, cork powder, barium sulfate, fluororesin, polymer beads, and mixtures thereof. It Above all,
Antioxidants help prevent thermal oxidative degradation during processing and their use is especially recommended.

The thermoplastic elastomer composition of the present invention comprises
It can be used for various moldings such as extrusion, injection, blow, and compression molding. Especially excellent in injection molding and extrusion molding, 2
It is widely applicable to extrusion molding applications such as color injection molding, insert injection molding, gas-assisted injection molding, profile extrusion, sheet extrusion, and multilayer extrusion. As applications, building materials such as automobile interior and exterior materials, OA equipment parts, building materials, for example,
Examples of various applications include wood opening materials, door doors, sillboards, sashes, gratings, table edges, handrails, anti-slip, etc. Hereinafter, the present invention will be described in more detail with reference to Examples. In addition, in these Examples and Comparative Examples, the test methods used for various evaluation methods are as follows.

(1) Crosslinking Degree [%] Each composition was formed into a film by compression molding, and the crosslinking degree of the rubber-like polymer was determined by the method described in the text. (2) Hardness Each composition is compression molded into a sheet having a thickness of 2 mm,
Four of them were stacked and the hardness (A or D) was measured according to JIS K6253. (3) Tensile Strength [MPa] and Tensile Elongation at Break [%] Based on JIS K6251, a dumbbell test piece of JIS No. 3 was punched out from the above 2 mm thick sheet under the condition of a tensile speed of 500 mm / sec and measured.

(4) Compression set [%] In accordance with JIS K6262, evaluation was carried out under the conditions of 100 ° C. and 22 hours. (5) Coating test 10 cm square flat plate was used with lacquer spray A red made by Campehapio, which was sprayed for about 5 seconds, and then left for a day and night, and then cut into squares at 1 mm intervals (100 sections), made by Nichiban. Cellotape (registered trademark) was attached from above, and then peeled off to confirm the presence or absence of peeling of the coating film. The mark "○" was given when no peeling occurred even at one place, and the mark "X" was marked when the coating film peeled. In addition, even when no peeling occurred at one place, when the background was visible from the lines of the squares, it was marked with "△".

(6) Scratch resistance test tester Using a Taber type scratch tester manufactured by Sangyo, a test was conducted with a load of 300 g and a reverse blade (counterclockwise rotation). Regarding the part to which the blade was applied, a mark with a shallow scratch was marked with "○", and a mark with a large scratch and a large scratch was marked with "x". (7) Oil resistance test Each thermoplastic elastomer composition was subjected to compression molding by compression molding.
A test piece of 5 mm thickness x 20 mm x 50 mm was molded and placed in a light liquid paraffin oil (manufactured by Nacalai Tesque, Inc.)
It was immersed at 0 ° C. for 24 hours, and the weight change rate (%) was determined. However, when some of the samples were dissolved and the measurement became impossible, it was described as “partially dissolved”. (8) Each thermoplastic elastomer composition was prepared by heat-resistant compression molding, 2.
The test piece was molded into a 0 mm thick test piece, and the temperature at which the needle penetrated to a depth of 0.1 mm was measured with a TMA tester (TMA100 manufactured by Seiko Denshi Kogyo) under a load condition of 20 g.
Various components used in the formulation of Examples and Comparative Examples are shown below.

Component (A-1) ethylene / vinyl acetate copolymer; NUC3810 manufactured by Nippon Unicar, vinyl acetate content 27
% By weight, MFR13 (190 ° C., 2.16 kgf) Component (A-2) ethylene / octene-1 copolymer; DuPont Dow Elastomers Engage 8150, octene content 25% by weight MFR0.5 (190 ° C. 2.16 kgf) ) Component (A-3) ethylene / propylene / diene copolymer: DuPont Dow Elastomers Nodel IP 3745P ethylene / propylene / ethylidene norbornene = 69
/30.5/0.5 number average molecular weight 114,000, Mooney viscosity 45 (125 ° C)

Component (A-4) hydrogenated product of polybutadiene; synthesized by a continuous solution polymerization method and having a number average molecular weight of 1
A hydrogenated product of polybutadiene having a molecular weight distribution of 20,000, a polybutadiene portion before hydrogenation of 40% by weight of 1,2-vinyl bond and a hydrogenation ratio of 97% is disclosed in JP-A-6-242.
The component (A-4) was obtained by synthesizing by the method described in JP-A No. 0-220147. Component (A-5) Hydrogenated product of styrene / butadiene copolymer; synthesized by a batch-type solution polymerization method, having a number average molecular weight of 145,000, a molecular weight distribution of 1.20, and having a styrene block chain at one end, 20% by weight of bound styrene, 12% by weight of styrene in the block part, 35% by weight of 1,2-vinyl bond in the polybutadiene part before hydrogenation,
A hydrogenated product of a styrene / butadiene block random copolymer having a hydrogenation rate of 99% in the polybutadiene portion was synthesized by the method described in JP-A-60-220147 to obtain a component (A-5). Component (A-6) ethylene / aromatic vinyl-based compound random copolymer; styrene amount of 10% by weight, MF polymerized by a known catalyst using styrene as an aromatic vinyl compound
R = 0.5 (190 ° C, 2.16 kgf) ethylene /
A styrene random copolymer was used.

Component (B) Crystalline (syndiotactic) polystyrene; Kurimoto Takusho KRC (internal volume 8.6 L, blade diameter 100 mm, cylinder effective length 1000 mm, paddle number 44 pairs, cylinder inner wall and paddle) as a reactor The clearance 1 mm) was inclined 5 degrees, the internal temperature was controlled at 80 ° C., and the rotation speed was 60 rpm. Styrene monomer was supplied to this reactor at a rate of 1 L / hr, and methylaluminoxane was used as a catalyst at 75 m.
Polymerization was carried out for 5 hours while supplying mol / hr and pentamethylcyclopentadienyl titanium trimethoxide at a ratio of 0.15 mmol / hr. The amount of polymer obtained was 2950 g. The polymer had a syndiotactic structure, and the syndiotacticity in racemic pentad was 97%. The number average molecular weight of the polymer was 300,000. The melting point was measured and found to be 270 ° C. Component (C) Hydrogenated block copolymer; Asahi Kasei Corp., Tuftec H1043 Hydrogenated product of styrene butadiene block copolymer Styrene content 67% by weight, hydrogenation rate 98%

Component (D-1) Amorphous (Atactic)
Polystyrene A & M Styrene's A & M polystyrene G9305 Rubber non-reinforced type, MFR1.5 (200 ° C, 5kg
f) Component (D-2) polyphenylene ether resin; Poly (2,6-dimethyl-1,4-phenylene) ether (reduced viscosity: 0.56) was synthesized. Ingredient (D-3) Polypropylene Sun Allomer PM900A homotype, MFR30 (230 ° C, 2.16 kgf)

Component (E) Softening agent for rubber; Diana Process Oil PW-380 manufactured by Idemitsu Kosan (paraffin type process oil, kinematic viscosity; 381.6c
st (40 ° C.), 30.1 cst (100 ° C.), ring analysis; CN = 27%, CP = 73%) Crosslinking agent (radical initiator); manufactured by NOF Corporation, Perhexa 25B [2,5-dimethyl-
2,5-bis (t-butylperoxy) hexane] (P
ox) Cross-linking aid (1); Nippon Kasei Co., Ltd. (Tyryl isocyanurate) (described as cross-linking aid 1) Cross-linking aid (2); Shin-Nakamura Chemical, NK ester 3G (triethylene glycol di) Methacrylate) (described as crosslinking aid 2)

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Examples 1 to 13 and Comparative Examples 1 to 3 The compositions shown in Table 1 and the method described in the text were used to obtain thermoplastic elastomer compositions. The results are shown in Table 1. As is clear from these results, the thermoplastic elastomer composition of the present invention has excellent heat resistance, scratch resistance and oil resistance as well as flexibility and mechanical properties.

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[Table 1]

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EFFECTS OF THE INVENTION The thermoplastic elastomer composition of the present invention has improved properties such as printability, paintability and adhesiveness, which are the drawbacks of the conventional olefin-based cross-linking type thermoplastic elastomers, and further has heat resistance and scratch resistance. A thermoplastic elastomer composition having oil resistance and solvent resistance equivalent to or better than those of conventional olefins, is a completely new material, and is a useful material for all applications in which an elastomer material is used. The industrial value is extremely high.

Continued front page    F-term (reference) 4J002 AC03W AC08W BB05W BB06W                       BB07W BB10W BB15W BC03X                       BC04W BC04X BC08X BC09X                       BP01W BP01Y FD010 FD146                       FD157 GC00 GL00 GN00

Claims (9)

[Claims] 1. A partially or completely cross-linked rubbery polymer 25 to 95 parts by weight, and a thermoplastic resin (B) a crystalline styrene polymer as an essential component 5 to 75 parts by weight (total). 100 parts by weight). 2. The thermoplastic elastomer composition according to claim 1, wherein the crystalline styrene-based polymer is a styrene-based polymer having a syndiotactic structure. 3. The thermoplastic composition according to claim 1, wherein the composition contains less than 50 parts by weight of the compatibilizing agent (C) with respect to 100 parts by weight of the total of the components (A) and (B). Elastomer composition. 4. The thermoplastic elastomer composition according to claim 1, wherein the rubber-like polymer is an ethylene-based polymer and / or a conjugated diene-based polymer. 5. The ethylene-based polymer comprises an ethylene monomer and a monomer selected from the group consisting of α-olefins having 3 to 20 carbon atoms, aromatic vinyl, vinyl acetate, acrylic acid ester and methacrylic acid ester. The thermoplastic elastomer composition according to claim 4, which is a copolymer of 6. The conjugated diene polymer is a conjugated diene polymer, a block or random copolymer of an aromatic vinyl compound / conjugated diene, and / or a partially or fully hydrogenated product thereof. The thermoplastic elastomer composition. 7. The thermoplastic resin containing the crystalline styrene polymer (B) as an essential component is a styrene polymer having a syndiotactic structure, or a styrene polymer having a syndiotactic structure and syndiotactic. The thermoplastic elastomer composition according to claim 1, which is a mixture with a thermoplastic resin other than the styrene-based polymer having a tick structure. 8. The thermoplastic elastomer composition according to claim 1, wherein the compatibilizing agent (C) is a styrene block copolymer. 9. The thermoplastic elastomer composition according to claim 1, wherein the composition is produced by a dynamic crosslinking method.