JP2020143232A - Thermoplastic elastomer composition, molded body, and seal member for automobile - Google Patents

Abstract

To provide a thermoplastic elastomer composition which is excellent in mechanical strength and compressive permanent set at high temperature, and has a low content of a volatile organic compound.SOLUTION: A thermoplastic elastomer composition contains the following components (A), (B), (C) and (D), and 1-200 pts.mass of the component (B), 1-300 pts.mass of the component (C) and 0.1-300 pts.mass of the component (D) with respect to 100 pts.mass of the component (A). Preferably, the thermoplastic elastomer composition further contains the following component (E). Component (A): hydrogenerated product of a block copolymer having at least two polymer blocks mainly containing a vinyl aromatic compound unit and at least one polymer block mainly containing a conjugated diene compound unit. Component (B): polypropylene-based resin. Component (C): polyphenylene ether-based resin. Component (D): hydrotalcite component. Component (E): softening agent for hydrocarbon-based rubber.SELECTED DRAWING: None

Description

The present invention relates to a thermoplastic elastomer composition and an automobile interior member comprising the thermoplastic elastomer composition. More specifically, the present invention relates to a thermoplastic elastomer composition having excellent mechanical strength and compression set at high temperature and having a small amount of volatile organic compounds, an automobile seal member and an automobile interior member made of this thermoplastic elastomer composition.

The thermoplastic elastomer composition obtained by dynamically heat-treating a polypropylene-based resin and a styrene-butadiene block copolymer has characteristics as a rubber-like soft material, but does not require a vulcanization step, and is a thermoplastic resin. It has the same molding processability. For this reason, such thermoplastic elastomer compositions have attracted attention from the viewpoints of rationalization of manufacturing processes and recyclability, and are widely used in the fields of automobile parts, home appliances, medical equipment parts, electric wires, miscellaneous goods, and the like. .. In particular, this thermoplastic elastomer composition has been widely used in applications such as a sealing material for automobiles and a sealing material for building materials.

In such applications, the thermoplastic elastomer composition may be used in a high temperature environment, and therefore technical development has been made to improve the compression set at high temperature.
For example, Patent Document 1 describes a thermoplastic elastomer composition obtained by adding a polyphenylene ether resin and a softening agent for non-aromatic rubber to a styrene-butadiene hydrogenated block copolymer in order to improve compression set at high temperature. The technology related to is disclosed.

Further, Patent Document 2 discloses a technique relating to a thermoplastic elastomer composition in which a polyphenylene ether resin having a specific molecular weight is added to a styrene-butadiene hydrogenated block copolymer in order to improve molding processability.

Japanese Unexamined Patent Publication No. 3-174463 Japanese Unexamined Patent Publication No. 9-87483

In recent years, automobile seal members and automobile interior members made of thermoplastic elastomer compositions have excellent mechanical strength and compressive permanent strain at high temperatures, and have few volatile organic compounds, that is, volatilization of organic components. It is required that there is no problem.

The molded product made of the thermoplastic elastomer composition described in Patent Document 1 and Patent Document 2 is excellent in compression set at high temperature, but mentions reduction of volatile organic compounds required for automobile interior materials. Absent. In fact, the thermoplastic elastomer composition containing the styrene-butadiene hydrogenated block copolymer and the polyphenylene ether-based resin described in Patent Documents 1 and 2 tends to have a large amount of volatile organic compounds derived from the polyphenylene ether-based resin. is there.

For this reason, conventionally, there has been no provision of a thermoplastic elastomer composition having excellent mechanical strength, compression set at high temperature, and a small amount of volatile organic compounds.

The present invention has been made in view of the above problems, and is an automobile comprising a thermoplastic elastomer composition having excellent mechanical strength, compression set at high temperature, and a small amount of volatile organic compounds, and the thermoplastic elastomer composition. An object of the present invention is to provide seal members for automobiles, interior members for automobiles, and the like.

By using a specific molecular weight styrene-butadiene hydrogenated block copolymer, polypropylene resin, polyphenylene ether resin and hydrotalcite in a specific ratio, the present inventor has excellent mechanical strength and is permanently compressed at high temperature. The present invention has been completed by finding that not only the strain is improved but also the amount of volatile organic compounds can be reduced and the above-mentioned problems can be solved.

That is, the gist of the present invention is as follows.

[1] Containing the following components (A), (B), (C) and (D), 1 to 200 parts by mass of the component (B) and 1 part of the component (C) with respect to 100 parts by mass of the component (A). A thermoplastic elastomer composition containing ~ 300 parts by mass and 0.1 to 300 parts by mass of the component (D).
Component (A): A hydrogenated component of a block copolymer having at least two polymer blocks mainly composed of a vinyl aromatic compound unit and at least one polymer block mainly composed of a conjugated diene compound unit. (B): Polypropylene resin component (C): Polyphenylene ether resin component (D): Hydrotalcite

[2] The thermoplastic elastomer composition according to [1], wherein the thermoplastic elastomer composition further contains the following component (E) in an amount of 1 to 300 parts by mass per 100 parts by mass of the component (A).
Component (E): Hydrocarbon-based rubber softener

[3] The thermoplastic elastomer composition according to [1] or [2], wherein the weight average molecular weight of the component (A) is 150,000 or more.

[4] The thermoplastic elastomer composition according to any one of [1] to [3], which has a Dulo A hardness of 20 to 90 as measured according to JIS K6253.

[5] An automobile interior member comprising the thermoplastic elastomer composition according to any one of [1] to [4].

[6] A sealing member for automobiles, which comprises the thermoplastic elastomer composition according to any one of [1] to [4].

[7] A molded product using the thermoplastic elastomer composition according to any one of [1] to [4].

[8] A sealing material for automobiles using the molded product according to [7].

The thermoplastic elastomer composition of the present invention has excellent mechanical strength, good compression set at high temperature, and few volatile organic compounds. Therefore, by using the thermoplastic elastomer composition of the present invention, it is possible to obtain a molded product having excellent mechanical strength, good compression set at high temperature, and few volatile organic compounds.
The molded product made of the thermoplastic elastomer composition of the present invention has excellent mechanical strength, compression set at high temperature, and a small amount of volatile organic compounds. Therefore, the material for automobile interiors, the seal material for automobiles, and the seal material for building materials. It is particularly useful as a seal around windows of automobile glass run channels and as a seal member for automobile interiors such as seat rail covers.

Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following description, and can be arbitrarily modified and carried out without departing from the gist of the present invention. In addition, in this specification, when a numerical value or a physical property value is put before and after using "~", it is used as including the value before and after that.

[Thermoplastic Elastomer Composition]
The thermoplastic elastomer composition of the present invention contains at least the following components (A) to (D) in a predetermined ratio, and preferably further contains the following components (E).
Component (A): Hydrocarbon additive component of a block copolymer having at least two polymer blocks mainly composed of a vinyl aromatic compound unit and at least one polymer block mainly composed of a conjugated diene compound unit. (B): Polypropylene resin component (C): Polyphenylene ether resin component (D): Hydrotalcite component (E): Hydrocarbon rubber softener

[mechanism]
The thermoplastic elastomer composition of the present invention has the effects of being excellent in mechanical strength and compression set at high temperature, and having a small amount of volatile organic compounds.
Here, "there is little volatile organic compound" means that the amount of volatile organic compound volatilized from the thermoplastic elastomer composition or its molded product is small.

The mechanism by which the thermoplastic elastomer composition of the present invention exerts such an effect is considered as follows.
It is considered that by adding the component (C) to the component (A), the glass transition temperature of the aromatic block portion of the component (A) can be raised, and the rubber elasticity at high temperature, that is, the compression set is improved. The component (C) is effective in improving the compression set at a high temperature, but the by-products and the catalyst residue contained in the component (C) are factors of the volatile organic compound. However, in the thermoplastic elastomer composition of the present invention, since the component (D) is present, the by-products and the catalyst residue in the component (C) are adsorbed by the component (D), so that the volatile organic compound It is thought that can be reduced.

Conventionally, as in Patent Documents 1 and 2 described above, a method for improving compression set at high temperature by using a thermoplastic elastomer composition composed of a styrene-butadiene-based hydrogenated block copolymer, a polypropylene-based resin, and a polyphenylene ether-based resin. Is generally well known, but a technique for further reducing the amount of volatile organic compounds while sufficiently increasing the mechanical strength and compression set at high temperature by adding hydrotalcite is the present invention. It was first established by.
The component (D) also contributes to the improvement of tensile stress during cutting, as shown in Examples described later.

[Component (A)]
The component (A) used in the thermoplastic elastomer composition of the present invention includes at least two polymer blocks (hereinafter, may be referred to as "block P") mainly composed of vinyl aromatic compound units and conjugated diene. A hydrogenated product of a block copolymer having at least one polymer block mainly composed of a compound unit (hereinafter, may be referred to as "block Q") (hereinafter, "hydrogenated block copolymer"). It may be called.).

Here, the "polymer mainly composed of a vinyl aromatic compound unit" means a polymer obtained by polymerizing a monomer mainly composed of a vinyl aromatic compound, and the term "mainly composed of a vinyl aromatic compound" means. , It means that it contains 50 mol% or more of vinyl aromatic compounds.
Similarly, "a polymer mainly composed of a conjugated diene compound unit" means a polymer obtained by polymerizing a monomer mainly composed of a conjugated diene compound, and "mainly composed of a conjugated diene compound" means a conjugated diene. It means that the compound is contained in an amount of 50 mol% or more.

The weight average molecular weight of the component (A) is preferably 150,000 or more, preferably 180,000 or more, as a polystyrene-equivalent value measured by gel permeation chromatography (hereinafter, may be abbreviated as GPC). More preferably, it is more preferably 200,000 or more. On the other hand, the upper limit of the weight average molecular weight of the component (A) is usually 600,000 or less, preferably 580,000 or less, and more preferably 560,000 or less.
If the weight average molecular weight of the component (A) is within the above range, sufficient compression set can be obtained.

The vinyl aromatic compound of the monomer constituting the block P of the hydrogenated block copolymer of the component (A) is not limited, but a styrene derivative such as styrene and / or α-methylstyrene is preferable. Above all, it is preferable to mainly use styrene. The block P may contain a monomer unit other than the vinyl aromatic compound.

The conjugated diene compound constituting the block Q is preferably butadiene or isoprene, and may be a mixture of both, but it is more preferable that butadiene is the main component, and it is further preferable that it is composed of only butadiene units. When the block Q is composed of only butadiene units, it is preferable that the 1,2-addition structure in the microstructure of this block is 20 to 50% in order to maintain the properties as an elastomer after hydrogenation. .. A more preferred proportion of 1,2-additional structures is 35-45%.

The weight ratio of the block P in the hydrogenated block copolymer of the component (A) is not limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, and 55% by mass or less. It is preferably 50% by mass or less, and more preferably 45% by mass or less. When the weight ratio of the block P is in the above range, the compression set tends to be good.

The chemical structure of the hydrogenated block copolymer of the component (A) may be linear, branched, radial, etc., but the hydrogenated block represented by the following formula (1) or (2) may be used. It is preferably a polymer, and more preferably has the structure of the following formula (1) from the viewpoint of improving mechanical strength.

P- (QP) m (1)
(PQ) n (2)
(In the equation, P represents block P, Q represents block Q, m represents an integer of 1 to 5, and n represents an integer of 2 to 5).

In the formula (1) or (2), m and n should be large in terms of lowering the order-disorder transition temperature as a rubber polymer, but should be small in terms of ease of manufacture and cost. .. In the present invention, m and n are preferably 2 to 4.

Since the hydrogenated block copolymer of the component (A) is excellent in rubber elasticity, the hydrogenated block copolymer represented by the formula (1) is more weight than the hydrogenated block copolymer represented by the formula (2). The coalescence is preferable, the block copolymer represented by the formula (1) in which m is 3 or less is more preferable, and the hydrogenated block copolymer represented by the formula (1) in which m is 2 or less is further preferable. preferable.

Hydrogenation rate of all conjugated diene compound units contained in the hydrogenated block copolymer of component (A) (hereinafter, this hydrogenation rate may be simply referred to as "hydrogenation rate"), that is, a conjugated diene compound unit. The hydrogenation rate of the carbon-carbon double bond of the above is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more.
When the hydrogenation rate is 80% or more, the solubility parameter value of the component (B) described later with the polypropylene resin approaches, and the dispersion becomes good, so that the mechanical strength tends to improve. In addition, since unsaturated bonds are reduced, heat resistance and weather resistance are improved. The hydrogenation ratio can be determined by proton nuclear magnetic resonance ^(H 1 -NMR) method.
In the present specification, the conjugated diene compound unit is referred to as "conjugated diene compound unit" regardless of before and after hydrogenation.

The method for producing the hydrogenated block copolymer of the component (A) in the present invention may be any method as long as the above-mentioned structure and physical properties can be obtained, and is not particularly limited. Specifically, for example, it can be obtained by performing block polymerization using a lithium catalyst or the like by the method described in JP-A-7-97493. Further, hydrogenation (hydrogenation) of the block copolymer can be carried out in the presence of a hydrogenation catalyst in an inert solvent, for example, by the method described in JP-A-59-133203.

Commercially available products of the hydrogenated block copolymer of component (A) include "TAIPOL-6151" and "TAIPOL-6159" manufactured by Taiwan Synthetic Rubber (TSRC), and "G1651" and "G1633" manufactured by Kraton Polymer Japan Co., Ltd. , "Septon 4099" manufactured by Kralet Co., Ltd. and the like.

As the hydrogenated block copolymer of the above component (A), only one type may be used, or two or more types having different compositions and physical properties may be used in combination.

[Component (B)]
The polypropylene-based resin of the component (B) used in the present invention is a polyolefin-based resin in which the content of propylene units with respect to all monomer units is more than 50% by mass. In the thermoplastic elastomer composition of the present invention, the component (B) contributes to moldability.

The type of the polypropylene-based resin of the component (B) is not particularly limited, and any of propylene homopolymer, propylene random copolymer, propylene block copolymer and the like can be used. Further, one of these may be used, or two or more thereof may be used in combination.

When the component (B) is a propylene random copolymer, the monomers copolymerizing with propylene include ethylene, 1-butene, 2-methylpropylene, 1-pentene, 3-methyl-1-butene, 1-. Hexene, 4-methyl-1-pentene, 1-octene and the like can be exemplified. When the component (B) is a propylene block copolymer, a propylene block copolymer obtained by polymerizing in multiple steps can be mentioned. More specifically, polypropylene is polymerized in the first step and the second Examples thereof include a propylene block copolymer obtained by polymerizing a propylene / ethylene copolymer in a step.

The content of the propylene unit in the polypropylene-based resin of the component (B) is preferably 60% by mass or more, more preferably 75% by mass or more, and further preferably 90% by mass or more. When the content of the propylene unit is at least the above lower limit value, the heat resistance and the rigidity tend to be good. On the other hand, the upper limit of the content of the propylene unit is not particularly limited and is usually 100% by mass. The content of propylene units in the polypropylene resin can be determined by infrared spectroscopy.

The melt flow rate (MFR: JIS K7210) of the component (B) at 230 ° C. and a load of 21.2 N is usually 0.05 g / 10 minutes or more, preferably 0.1 g / 10 minutes or more from the viewpoint of fluidity. More preferably, it is 0.5 g / 10 minutes or more. On the other hand, the MFR of the component (B) is usually 100 g / 10 minutes or less, preferably 90 g / 10 minutes or less, and more preferably 80 g / 10 minutes or less from the viewpoint of moldability.

As a method for producing the propylene-based resin of the component (B), a known polymerization method using a known catalyst for olefin polymerization is used. For example, a multi-stage polymerization method using a Ziegler-Natta catalyst can be mentioned. For this multi-stage polymerization method, a slurry polymerization method, a solution polymerization method, a massive polymerization method, a gas phase polymerization method and the like can be used, and two or more of these may be combined for production.

Further, as the propylene resin of the component (B), a commercially available applicable product can be used. Commercially available polypropylene-based resins can be procured from the manufacturers listed below, and can be appropriately selected and used.
Available commercial products include Prime Polypro® from Prime Polymer, Sumitomo Noblen® from Sumitomo Chemical, polypropylene block copolymers from Sun Aroma, Novatec® PP from Polypro Japan, and Lyondell Basell. Moplen®, ExxonMobile PP, Formosa Plastics Formolene®, Borearis Borearis PP, LG Chemical SEETEC PP, A.M. Schulman's ASI POLYPROPYLENE, INEOS Olefins & Polymers, Inc. of INEOS PP, Braskem's Braskem PP, SAMSUNG TOTAL PETROCHEMICALS's Sumsung Total, Sabic's Sabic (registered trademark) PP, TOTAL PETROCHEMICALS company of TOTAL PETROCHEMICALS Polypropylene, SK Corporation of YUPLENE ( Registered trademark), etc.

The lower limit of the content of the component (B) in the thermoplastic elastomer composition of the present invention is usually 1 part by mass or more and 5 parts by mass with respect to 100 parts by mass of the component (A) from the viewpoint of improving moldability. The above is preferable, 10 parts by mass or more is more preferable, and 20 parts by mass or more is further preferable. On the other hand, the upper limit of the content of the component (B) is usually 200 parts by mass or less and 100 parts by mass or less from the viewpoint of obtaining the flexibility required for sealing applications with respect to 100 parts by mass of the component (A). Is preferable, and 80 parts by mass or less is more preferable.

[Component (C)]
The polyphenylene ether-based resin of the component (C) used in the present invention has a repeating unit represented by the following formula (I).

(Here, R ¹ , R ² , R ³ , and R ⁴ represent a hydrocarbon group which may have a hydrogen atom, a halogen atom, or a substituent, and may be the same or different from each other.)

The polyphenylene ether-based resin used in the present invention preferably has an intrinsic viscosity of 0.1 to 0.8 dl / g at 30 ° C. as measured in chloroform. The intrinsic viscosity of the polyphenylene ether-based resin is more preferably 0.2 to 0.7 dl / g, still more preferably 0.25 to 0.6 dl / g. When the intrinsic viscosity of the polyphenylene ether resin is 0.1 dl / g or more, the effect of improving the compression set at high temperature can be easily obtained, and when it is 0.8 dl / g or less, the moldability can be sufficiently satisfied. ..

Known polyphenylene ether-based resins can be used. Specific examples include poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), and poly (2,6-diphenyl-1). , 4-Phenylene ether), poly (2-methyl-6-phenyl-1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether), etc., and 2,6 Polyphenylene ether copolymers such as copolymers of -dimethylphenol with other phenols (eg, 2,3,6-trimethylphenol and 2-methyl-6-butylphenol) can also be used. Of these, poly (2,6-dimethyl-1,4-phenylene ether) and a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol are preferable, and poly (2) is particularly preferable. , 6-Dimethyl-1,4-phenylene ether).

As these polyphenylene ether-based resins, one type may be used alone, or two or more types may be mixed and used.

The lower limit of the content of the component (C) in the thermoplastic elastomer composition of the present invention is usually 1 part by mass or more with respect to 100 parts by mass of the component (A) from the viewpoint of improving the compression set at high temperature. It is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 15 parts by mass or more. On the other hand, the upper limit of the content of the component (C) is usually 300 parts by mass or less, and 200 parts by mass or less from the viewpoint of obtaining a hardness sufficiently flexible as a molded product with respect to 100 parts by mass of the component (A). It is more preferably 150 parts by mass or less, and further preferably 100 parts by mass or less.

[Component (D)]
The component (D) used in the present invention is hydrotalcite.
The hydrotalcite, is a designation of the natural mineral having the formula _{Mg 6 Al 2 (OH) 16} CO 3 · 4H 2 O, more recently, the following formula having the natural mineral basically the approximate structure It is also generally used as a general term for the double hydroxide represented by (1).
[M 2 ⁺ _1-x M ³⁺ _x (OH) ₂ ] (A _{x / y} · zH ₂ O) ・ ・ ・ (1)
In the formula (1), M ²⁺ represents a divalent metal ion such as Mg, Fe, Zn, Ca, Cu, Co, and is preferably Mg, Zn or Ca, and more preferably Mg. Further, M ³⁺ represents a trivalent metal ion such as Al, Ce, Fe, Mn, In, Cr, etc., and is preferably Al, Ce, and more preferably Al. x is a number from 0.2 to 0.33, and z is a real number greater than 0, which varies depending on the degree of dehydration, but is generally an integer of 0 to 2. A is a carbonate ion (CO ₃ ^2- ), HPO ₃ ^2- , a saturated aliphatic monocarboxylic acid, and is preferably a carbonate ion. In addition, y is a valence of A.

A particularly preferable hydrotalcite is one represented by the following formula (2).
Mg _1-x Al _x (OH) ₂ (CO ₃ ) _{x / 2} · zH ₂ O ・ ・ ・ (2)
In the formula (2), the definitions of x and z are the same as the definitions in the formula (1).

In the present invention, commercially available hydrotalcite can be used. Examples of commercially available products include DHT-4A manufactured by Kyowa Chemical Industry Co., Ltd. and HT-1 manufactured by Sakai Chemical Industry Co., Ltd.

The lower limit of the content of the component (D) in the thermoplastic elastomer composition of the present invention is usually 0.1 part by mass or more with respect to 100 parts by mass of the component (A) from the viewpoint of reducing volatile organic compounds. It is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and further preferably 10 parts by mass or more. On the other hand, the upper limit of the content of the component (C) is usually 300 parts by mass or less, and 200 parts by mass or less from the viewpoint of obtaining a hardness sufficiently flexible as a molded product with respect to 100 parts by mass of the component (A). It is preferably 100 parts by mass or less, and more preferably 100 parts by mass or less.

[Component (E)]
In the thermoplastic elastomer composition of the present invention, from the viewpoint of improving moldability, the hydrocarbon softener of the component (E) is added in an amount of 1 part by mass or more and 300 parts by mass with respect to 100 parts by mass of the component (A). It is preferable to include the following.

The lower limit of the content of the component (E) in the thermoplastic elastomer composition of the present invention is not particularly limited, but is usually 1 part by mass or more with respect to 100 parts by mass of the component (A) from the viewpoint of moldability. It is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, and further preferably 50 parts by mass or more. The upper limit of the content of the component (E) is not particularly limited, but is usually 300 parts by mass or less, preferably 250 parts by mass or less, with respect to 100 parts by mass of the component (A) from the viewpoint of softening agent retention. It is more preferably 200 parts by mass or less.

Examples of the hydrocarbon-based rubber softener of the component (E) include mineral oil-based softeners and synthetic resin-based softeners, but mineral oil-based softeners are preferable from the viewpoint of compatibility with other components. Mineral oil-based softeners are generally a mixture of aromatic hydrocarbons, naphthenic hydrocarbons and paraffinic hydrocarbons, and paraffinic oils in which 50% or more of all carbon atoms are paraffinic hydrocarbons. Those in which 30 to 45% of all carbon atoms are naphthenic hydrocarbons are called naphthenic oils, and those in which 35% or more of all carbon atoms are aromatic hydrocarbons are called aromatic oils. Among these, in the present invention, it is preferable to use paraffin oil.

The kinematic viscosity of the hydrocarbon softener for the hydrocarbon component (E) at 40 ° C. is not particularly limited, but is preferably 20 cSt or more, more preferably 50 cSt or more, and preferably 800 cSt or less, more preferably 600 cSt or less. is there. The flash point (COC method) of the hydrocarbon-based rubber softener is preferably 200 ° C. or higher, more preferably 250 ° C. or higher.

The hydrocarbon softener for component (E) can be obtained as a commercially available product. Examples of applicable commercial products include the "Nisseki Polybutene (registered trademark) HV" series manufactured by JX Nippon Oil Energy Co., Ltd. and the "Diana (registered trademark) process oil PW" series manufactured by Idemitsu Kosan Co., Ltd. Applicable products can be selected and used as appropriate.

As the hydrocarbon-based rubber softener of the component (E), only one type may be used, or two or more types may be used in any combination and ratio.

[Other ingredients]
In the production of the thermoplastic elastomer composition of the present invention, other components other than the components (A) to (E) can be used as raw materials as needed, as long as the effects of the present invention are not impaired.
However, in order to effectively obtain the effect of the present invention by further containing the components (A) to (D), preferably the component (E), the thermoplastic elastomer composition of the present invention has the thermoplastic elastomer composition of the present invention. It is preferable that the components (A) to (E) are contained in the product in a total amount of 90% by mass or more.

Examples of other components include resins other than the component (A), the component (B) and the component (C), a resin such as an elastomer, an antioxidant, a filler, a heat stabilizer, a light stabilizer, and ultraviolet absorption. Agents, neutralizers, lubricants, antifogging agents, antiblocking agents, slip agents, dispersants, colorants, flame retardants, antistatic agents, conductivity-imparting agents, metal inactivating agents, molecular weight modifiers, antibacterial agents , Various additives such as antifungal materials and fluorescent whitening agents can be mentioned. Any of these can be used alone or in combination.

Examples of the thermoplastic resin other than the components (A) to (C) include polyamide resins such as nylon 6 and nylon 66; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyoxymethylene homopolymers and polyoxymethylene. Polyoxymethylene-based resins such as copolymers; polymethylmethacrylate-based resins, polyolefin resins (excluding those corresponding to component (B)) and the like can be mentioned. Examples of the elastomer other than the components (A) to (C) include styrene-based elastomers (excluding those corresponding to the component (A)); polyester-based elastomers; polybutadiene and the like.

Examples of the antioxidant (hereinafter, may be referred to as “component (F)”) include a phenol-based antioxidant, a sulfide-based antioxidant, a thioether-based antioxidant, and the like. When an antioxidant is used, the antioxidant is usually used in the range of 0.01 to 3.0 parts by mass, preferably 0.15 to 0.6 parts by mass with respect to 100 parts by mass of the component (A). Be done. If it is within the above range, good thermal stability can be obtained.

Examples of the filler (hereinafter, may be referred to as “component (G)”) include glass fiber, hollow glass ball, carbon fiber, talc, calcium carbonate, mica, potassium titanate fiber, silica, and metal soap. Examples thereof include titanium dioxide and carbon black. When a filler is used, the filler is usually used in the range of 0.3 to 100 parts by mass with respect to 100 parts by mass of the component (A).

[Manufacturing method of thermoplastic elastomer composition]
The thermoplastic elastomer composition of the present invention preferably contains a predetermined amount of the component (A), the component (B), the component (C), the component (D), the component (E), and other components. Is obtained by dynamic heat treatment.

In the present invention, "dynamic heat treatment" means kneading in a molten state or a semi-molten state. This dynamic heat treatment is preferably performed by melt-kneading, and as a mixing and kneading device for that purpose, for example, a non-open type Banbury mixer, a mixing roll, a kneader, a twin-screw extruder and the like are used. Among these, it is preferable to use a twin-screw extruder. A preferred embodiment of the manufacturing method using this twin-screw extruder is to supply each component to a raw material supply port (hopper) of a twin-screw extruder having a plurality of raw material supply ports to perform dynamic heat treatment.

The temperature at which the dynamic heat treatment is performed is usually 80 to 300 ° C, preferably 100 to 250 ° C. The time for performing the dynamic heat treatment is usually 0.1 to 30 minutes.

[Physical properties of thermoplastic elastomer composition]
The thermoplastic elastomer composition of the present invention preferably has a DULO A hardness measured in accordance with JIS K6253 of 10 or more from the viewpoint of heat resistance, and preferably 95 or less from the viewpoint of flexibility for sealing applications. .. The Dulo A hardness of the thermoplastic elastomer composition of the present invention is more preferably 20 to 90.

The thermoplastic elastomer composition of the present invention has a compression set of 55% or less from the viewpoint of rubber elasticity at high temperature, as measured under the conditions of 70 ° C., 22 hours, and 25% compression in accordance with JIS K6262. It is preferably 50% or less, and more preferably 50% or less.
Further, in the thermoplastic elastomer composition of the present invention, the compression set measured under the conditions of 100 ° C., 22 hours and 25% compression according to JIS K6262 is 70% or less from the viewpoint of rubber elasticity at high temperature. It is preferably 65% or less, and more preferably 65% or less.

Further, the thermoplastic elastomer composition of the present invention preferably has a tensile stress at the time of cutting of 10 MPa or more as measured in accordance with JIS K6251.
Further, the thermoplastic elastomer composition of the present invention preferably has a volatile organic compound (VOC) value of 200 μg / g or less, preferably 150 μg / g, measured in accordance with VDA278 of the German Automobile Manufacturers Association (VDA) standard. The following is more preferable.

[Molded body / application]
The thermoplastic elastomer composition of the present invention can be made into a molded product by various molding methods usually used for the thermoplastic elastomer composition, for example, injection molding, extrusion molding, hollow molding, compression molding and the like. Of these, injection molding is preferable. Further, it is also possible to obtain a molded product obtained by performing secondary processing such as laminating molding and thermoforming after performing these moldings.

The molded body made of the thermoplastic elastomer composition of the present invention is an automobile part such as a skin, a weather strip, a ceiling material, an interior sheet, a bumper molding, a side molding, an air spoiler, an air duct hose, and a sealing material; a water blocking material and a joint material. Civil engineering and building material parts such as window frames and sealing materials; Sporting goods such as golf club grips and tennis racket grips; Industrial parts such as hose tubes and gaskets; Home appliances parts such as hoses and packings; It can be applied to a wide range of fields such as medical parts such as containers, gaskets and packings; food parts such as containers and packings; medical equipment parts; electric wires; miscellaneous goods and the like.

Among those listed above, the molded body made of the thermoplastic elastomer composition of the present invention is suitable as an interior member for automobiles, a sealing material for automobiles, and a sealing material for building materials, and is suitable for sealing materials for automobiles, particularly glass run channels for automobiles. It is suitable as a seal member for automobile interiors such as a window seal and a seat rail cover.

Hereinafter, the content of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded. The values of various production conditions and evaluation results in the following examples have meanings as preferable values of the upper limit or the lower limit in the embodiment of the present invention, and the preferable ranges are the above-mentioned upper limit or lower limit values and the following. It may be in the range specified by the value of Examples or the combination of the values of Examples.

〔raw materials〕
The raw materials used in the following examples and comparative examples are as follows.

[Component (A)]
Styrene-butadiene-styrene hydrogenated block copolymer (having the structure (m = 1) of the above formula (1). Styrene (block P) content: 32% by mass, hydrogenation rate: 100%, weight average molecular weight: 250,000) / "G1651HU" manufactured by Clayton Polymer Japan Co., Ltd.

[Component (B)]
Propylene homopolymer (MFR (JIS K7210): 1.9 g / 10 minutes (230 ° C, 21.2 N)) / "Novatec (registered trademark) PP FY6H" manufactured by Japan Polypropylene Corporation

[Component (C)]
Poly (2,6-dimethyl-1,4-phenylene) ether (intrinsic viscosity at 30 ° C. measured in chloroform: 0.38 dl / g) / "Iupital (registered trademark) PX100F" manufactured by Mitsubishi Engineering Plastics Co., Ltd.

[Component (D)]
Hydrotalcite / Kyowa Chemical Industry Co., Ltd. "DHT-4A"

[Component (E)]
Softener for paraffin rubber (kinematic viscosity at 40 ° C: 95.5 cSt, pour point: -15 ° C, flash point: 272 ° C) / "Diana (registered trademark) process oil PW90" manufactured by Idemitsu Kosan Co., Ltd.

[Component (F)]
Phenolic antioxidant / BASF Japan's "Irganox (registered trademark) 1010"

[Component (G)]
Carbon Black Masterbatch / Dainichiseika Co., Ltd. "PC40C"

[Evaluation method]
The evaluation method of the thermoplastic elastomer composition in the following Examples and Comparative Examples is as follows.

For the following measurements (2) to (7), each thermoplastic elastomer composition was used, and an injection pressure of 50 MPa and a cylinder temperature of 220 were used in an in-line screw type injection molding machine (“IS130” manufactured by Toshiba Machine Co., Ltd.). A sheet (width 120 mm, length 80 mm, wall thickness 2 mm) obtained by injection molding under the conditions of ° C. and a mold temperature of 40 ° C. was used.

(1) MFR: Measured at a measurement temperature of 230 ° C. and a measurement load of 21.2 N by a method conforming to the JIS K7210 standard.

(2) Dulo A hardness: In accordance with JIS K6253 (JIS-A), the value 15 seconds after the needle was pressed against the test piece was measured.

(3) Tensile stress during cutting: The procedure was performed in accordance with the method for measuring tensile stress during cutting of JIS K6251.

(4) Elongation during cutting: The procedure was performed in accordance with the measurement method of elongation during cutting of JIS K6251.

(5) Permanent compression strain: Measured according to JIS K6262 under the conditions of 70 ° C., 22 hours, and 25% compression.

(6) Compressive permanent strain at high temperature: Measured according to JIS K6262 under the conditions of 100 ° C., 22 hours, and 25% compression.

(7) Volatile organic compound (VOC): Measured according to the German Automobile Manufacturers Association standard VDA278.

[Example / Comparative example]
<Example 1>
Component (A): 100 parts by mass, component (B): 57 parts by mass, component (C): 29 parts by mass, component (D): 29 parts by mass, component (E): 129 parts by mass, component (F): 0.3 parts by mass, component (G): 3 parts by mass were blended with a Henschel mixer for 1 minute to obtain a mixture. This mixture is charged into the supply section of a twin-screw extruder in the same direction (“TEM26SS” manufactured by Toshiba Machine Co., Ltd., L / D = 48.5) at a total speed of 16 kg / h and rises in the range of 220 to 260 ° C. It was warmed and melt-kneaded, and pelletized to produce a thermoplastic elastomer composition.
The obtained thermoplastic elastomer composition was evaluated in the above-mentioned (1) to (7). The evaluation results are shown in Table-1.

<Comparative Examples 1-2>
The same procedure as in Example 1 was carried out except that the compounding composition was changed as shown in Table 1, to obtain pellets of the thermoplastic elastomer composition. The obtained thermoplastic elastomer composition was evaluated in the same manner as in Example 1. The results are shown in Table-1.

<Evaluation result>
As shown in Table 1, Example 1 is excellent in tensile stress during cutting and compressive permanent strain at high temperature, and is good with few volatile organic compounds.

Comparative Example 1 is an example in which the component (C) and the component (D) are not contained, but the evaluation of the tensile stress at the time of cutting and the compression set at a high temperature is inferior.
Comparative Example 2 is an example in which the component (D) is not contained, but the evaluation of tensile stress during cutting and volatile organic compounds is inferior.

The thermoplastic elastomer composition of the present invention is used for automobile parts such as skins, weather strips, ceiling materials, interior sheets, bumper moldings, side moldings, air spoilers, air duct hoses, sealing materials; water blocking materials, joint materials, window frames, etc. Civil and building material parts such as sealing materials; Sporting goods such as golf club grips and tennis racket grips; Industrial parts such as hose tubes and gaskets; Home appliances parts such as hoses and packings; Medical containers, gaskets, etc. It can be used in a wide range of fields such as medical parts such as packings; food parts such as containers and packings; medical equipment parts; electric wires; and miscellaneous goods. Among those listed above, the thermoplastic elastomer composition of the present invention is suitable as an automobile interior member, an automobile sealing material, and a building material sealing material, and is suitable for an automobile sealing material, particularly an automobile glass run channel, a window sealing material, and the like. It is suitable as a seat rail cover material.

Claims (8)

It contains the following components (A), (B), (C) and (D), and the component (B) is 1 to 200 parts by mass and the component (C) is 1 to 300 parts by mass with respect to 100 parts by mass of the component (A). A thermoplastic elastomer composition containing 0.1 to 300 parts by mass of the component (D).
Component (A): A hydrogenated component of a block copolymer having at least two polymer blocks mainly composed of a vinyl aromatic compound unit and at least one polymer block mainly composed of a conjugated diene compound unit. (B): Polypropylene resin component (C): Polyphenylene ether resin component (D): Hydrotalcite The thermoplastic elastomer composition according to claim 1, wherein the thermoplastic elastomer composition further contains the following component (E) in an amount of 1 to 300 parts by mass per 100 parts by mass of the component (A).
Component (E): Hydrocarbon-based rubber softener The thermoplastic elastomer composition according to claim 1 or 2, wherein the component (A) has a weight average molecular weight of 150,000 or more. The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the DULO A hardness measured according to JIS K6253 is 20 to 90. An automobile interior member comprising the thermoplastic elastomer composition according to any one of claims 1 to 4. An automobile sealing member comprising the thermoplastic elastomer composition according to any one of claims 1 to 4. A molded product using the thermoplastic elastomer composition according to any one of claims 1 to 4. A sealing material for automobiles using the molded product according to claim 7.