JP2020152787A - Thermoplastic elastomer composition and its compact - Google Patents

Abstract

To provide a thermoplastic elastomer composition that has excellent injection moldability and is difficult for a softener for hydrocarbon-based rubber to bleed at the time of high compression and its compact.SOLUTION: There are provided: a thermoplastic elastomer composition containing the following components (A) to (D), and preferably furthermore the following component (E); and its compact. Component (A): a hydrogenation product of a block copolymer having at least two polymer blocks P mainly made of an aromatic vinyl compound unit, and at least one polymer block Q mainly made of a conjugated diene compound unit. Component (B): a softener for hydrocarbon-based rubber. Component (C): a polypropylene-based resin. Component (D): diallyl orthophthalate and/or diallyl isophthalate. Component (E): an organic peroxide.SELECTED DRAWING: None

Description

The present invention relates to a thermoplastic elastomer composition and a molded product thereof, and more particularly to a thermoplastic elastomer composition and a molded product thereof, which are excellent in injection moldability and in which oil does not easily bleed even in a highly compressive environment.

Thermoplastic elastomers are excellent in rubber elasticity, colorability, and design, and can be applied to various molding methods such as injection molding, extrusion molding, blow molding, and vacuum molding in the same way as ordinary thermoplastics, so they are used for automobiles and building materials. It is used in various fields such as packing for automobiles, interior and exterior materials for automobiles, parts for building materials, and daily miscellaneous goods. Styrene-based thermoplastic elastomers, which are typical thermoplastic elastomers, are widely used from low hardness regions to high hardness regions in the JIS-A hardness region such as rubber, but are highly compressed in products with relatively high hardness. If left in this state, the hydrocarbon-based oil in the formulation tends to bleed to the surface for the following reasons.

Most styrene-based thermoplastic elastomers are block copolymers having at least two polymer blocks mainly composed of aromatic vinyl compound units and at least one polymer block mainly composed of conjugated diene compound units. And / or a system in which a predetermined amount of a polypropylene-based resin and a hydrocarbon-based softening agent for rubber (hereinafter, referred to as "softening agent") are blended with the hydrogenated additive thereof. The hardness of such a system is adjusted by the content ratio of the polypropylene resin, the vinyl aromatic compound polymer block of the block copolymer, the conjugated diene polymer block, and the softening agent in the entire system, and the ratio of the polypropylene resin. The higher the value, the higher the hardness, and the higher the softening agent ratio, the lower the hardness tends to be. On the other hand, in terms of injection moldability, it is better that the fluidity is high, and the softener contributes as the most effective material for increasing the fluidity. However, when the ratio of the softener is high, most of the softeners are aromatic vinyl compounds. Since it is present in a polymer block mainly composed of a unit or a polymer block mainly composed of a conjugated diene compound unit, the ratio of polypropylene-based resin is high and the ratio of softener is high at the same time, especially in a region of high hardness. As a result, the ratio of the polymer block mainly composed of the aromatic vinyl compound unit and the polymer block mainly composed of the conjugated diene compound unit decreases, and the polymer block mainly composed of the aromatic vinyl compound unit and the conjugated diene compound unit become smaller. The main polymer block exceeds the holding capacity of the softener. As a result, the molded product sticks or the softening agent exudes to the surface of the molded product, causing a bleeding phenomenon.

Patent Document 1 proposes a system using a petroleum resin or a terpene resin and having less oil bleeding than a styrene-based thermoplastic elastomer in a low hardness region.

Japanese Unexamined Patent Publication No. 2006-225580

The above-mentioned Patent Document 1 suppresses oil bleeding in a low hardness region, and has not confirmed oil bleeding in a state where a high compression load is applied in a high hardness region.
Ratio of polypropylene resin with the ratio of softener to vinyl aromatic compound polymer block and conjugated diene copolymer block that can be retained without bleeding in a relatively low hardness region such as DULO A hardness of 60 or less. When the hardness is increased by increasing the hardness, bleeding rarely occurs statically, but when the compression is high, a bleeding phenomenon occurs, which causes a problem in practicality. Therefore, there has been a demand for a product that can be practically used without bleeding of the softener even in a highly compressed environment while maintaining injection moldability, that is, fluidity.

The present invention has been made in view of the above-mentioned conventional conditions, and provides a thermoplastic elastomer composition and a molded product thereof, which are excellent in injection moldability and in which the hydrocarbon softener for rubber does not easily bleed even at high compression. The purpose is to provide.

As a result of diligent studies to solve the above problems, the present inventor has found a block copolymer having a polymer block mainly composed of an aromatic vinyl compound unit and a polymer block mainly composed of a conjugated diene compound unit. By blending diallyl phthalate with hydrogen additives, polypropylene resins and hydrocarbon softeners, hydrocarbon rubber softeners that are oils even under high hardness regions, that is, under highly compressive loads, can be obtained. We have found that it is possible to obtain a thermoplastic elastomer composition that is difficult to bleed, and have arrived at the present invention.
That is, the gist of the present invention is as follows.

[1] A thermoplastic elastomer composition containing the following components (A) to (D).
Component (A): Hydrogen in a block copolymer having at least two polymer blocks P mainly composed of aromatic vinyl compound units and at least one polymer block Q mainly composed of conjugated diene compound units. Additives Component (B): Hydrocarbon-based rubber softener Component (C): Polypropylene-based resin Component (D): Diallyl orthophthalate represented by the following structural formula (1A) and / or represented by the following structural formula (1B) Dialyl isophthalate

[2] The content of the component (A) is 20 to 30 parts by mass, and the content of the component (B) is 100 parts by mass in total of the component (A), the component (B), and the component (C). The thermoplastic elastomer composition according to [1], wherein the content of the component (C) is 30 to 40 parts by mass and the content is 30 to 40 parts by mass.

[3] The thermoplastic elastomer composition according to [1] or [2], which further comprises the following component (E).
Component (E): Organic peroxide

[4] The thermoplastic elastomer composition according to any one of [1] to [3], wherein the component (C) is a homopolypropylene and / or a propylene / α-olefin copolymer.

[5] The thermoplastic elastomer composition according to any one of [1] to [4], which has a DULO A hardness (JIS K6253) of 40 to 95.

[6] A molded product made of the thermoplastic elastomer composition according to any one of [1] to [5].

The thermoplastic elastomer composition of the present invention is excellent in injection moldability, and can provide a molded product in which oil does not bleed even when a high load is applied.

The present invention will be described in detail below, but the following description is an example of an embodiment of the present invention, and the present invention is not limited to the following description as long as the gist of the present invention is not exceeded. It can be arbitrarily modified and carried out without departing from the gist of the invention.
In addition, in this invention, 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 is characterized by containing the following components (A) to (D).
Component (A): Hydrogen in a block copolymer having at least two polymer blocks P mainly composed of aromatic vinyl compound units and at least one polymer block Q mainly composed of conjugated diene compound units. Additives Component (B): Hydrocarbon-based rubber softener Component (C): Polypropylene-based resin Component (D): Diallyl orthophthalate represented by the following structural formula (1A) and / or represented by the following structural formula (1B) Dialyl isophthalate

Hereinafter, each component will be described in detail.

<Ingredient (A)>
The component (A) used in the present invention includes at least two polymer blocks P mainly composed of aromatic vinyl compound units (hereinafter, may be simply referred to as “block P”) and at least one component (A). , A hydrogenated additive of a block copolymer having a polymer block Q mainly composed of a conjugated diene compound unit (hereinafter, may be simply referred to as "block Q") (hereinafter, "hydrogenated block copolymer (A)". ) ”). Here,“ main body ”means that the target monomer unit is contained in the target polymer block in an amount of 50 mol% or more.

The aromatic vinyl compound constituting the block P is not particularly limited, and for example, styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N, N-dimethyl-p-amino. Aromatic vinyl compounds such as ethylstyrene, N, N-diethyl-p-aminoethylstyrene and the like can be mentioned. Among these, styrene, α-methylstyrene, and 4-methylstyrene are preferably used from the viewpoint of availability and productivity. Styrene is particularly preferable.
The block P may be composed of one type of aromatic vinyl compound unit, or may be composed of two or more types of aromatic vinyl compound units. Further, the block P may contain a monomer unit other than the vinyl aromatic compound unit.

The conjugated diene compound constituting the block Q is a diolefin having a pair of conjugated double bonds, and is not limited to, for example, 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene). ), 2,3-Dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene and the like. Among these, 1,3-butadiene and isoprene are preferably used from the viewpoint of availability and productivity. Particularly preferred is 1,3-butadiene.
The block Q may be composed of one kind of conjugated diene compound unit, or may be composed of two or more kinds of conjugated diene compound units. Further, the block Q may contain a monomer unit other than the conjugated diene compound unit.

The block polymer before hydrogenation having at least two blocks P and at least one block Q may be linear, branched, radial or the like, and may have the following formula (1) or ( It is preferably a block copolymer represented by 2).
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. ..

The component (A) used in the present invention is more preferably a hydrogenated block copolymer represented by the formula (1) having m of 3 or less, and the formula (1) having m of 2 or less. It is more preferably a hydrogenated block copolymer represented by the block copolymer, and most preferably a hydrogenated block copolymer represented by the formula (1) in which m is 1.

The content of the total aromatic vinyl compound unit in the component (A) is preferably 8 to 25% by mass, more preferably 9 to 21% by mass, and 10 to 20% by mass. It is more preferable, and it is particularly preferable that it is 10 to 19% by mass.

The content of block P in the hydrogenated block copolymer (A) shall be 8 to 25% by mass from the viewpoint of the hardness of the obtained thermoplastic elastomer composition and the molded product using the same and the suppression of oil bleeding. Is more preferable, 10 to 20% by mass is more preferable, and 10 to 18% by mass is further preferable. The content of block Q in the hydrogenated block copolymer (A) is preferably 75 to 92% by mass, more preferably 80 to 90% by mass, and 82 to 90% by mass. Is even more preferable.

The hydrogenation rate of all conjugated diene compound units contained in the hydrogenated block copolymer (A) (hereinafter, this hydrogenation rate may be simply referred to as "hydrogenation rate"), that is, carbon of the conjugated diene compound unit. The hydrogenation rate of the -carbon double bond 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 with the polypropylene-based resin (C) described later approaches, and the dispersion becomes good, so that the oil bleeding tends to be further reduced. 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 weight average molecular weight of the component (A) used in the present invention is preferably 80,000 to 1,000,000, more preferably 80,000 to 600,000, still more preferably 8 as the polystyrene-equivalent molecular weight measured by gel permission chromatography. It is 10,000 to 400,000. When the weight average molecular weight is 80,000 or more, the rubber elasticity and mechanical strength are good, and bleeding of the hydrocarbon-based rubber softening agent of the component (B) described later is less likely to occur. On the other hand, when the weight average molecular weight is 1 million or less, the fluidity is good and the moldability is excellent.

The method for producing 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. The block copolymer before hydrogenation can be obtained, for example, by performing block polymerization in an inert solvent using a lithium catalyst or the like by the method described in Japanese Patent Publication No. 40-23798. Further, hydrogenation of block copolymers is described in, for example, JP-A-42-8704, JP-A-43-6636, JP-A-59-133203, JP-A-60-79005 and the like. This method can be carried out in the presence of a hydrogenation catalyst in an inert solvent.

Commercially available products of such hydrogenated block copolymer (A) include "KRATON-G" (Kraton Polymer Co., Ltd.), "Septon" (Kuraray Co., Ltd.), "Tough Tech" (Asahi Kasei Co., Ltd.), and "TAIPOL" (. Examples of products such as TSRC).

As the hydrogenated block copolymer (A), only one type may be used, or two or more types having different block configurations, physical properties, etc. may be mixed and used.

<Ingredient (B)>
The component (B) used in the present invention is a hydrocarbon-based rubber softener.

As the hydrocarbon-based rubber softener (B), a hydrocarbon having a weight average molecular weight of usually 300 to 2,000, preferably 500 to 1,500 is used, and a mineral oil-based hydrocarbon or a synthetic resin-based hydrocarbon is used. Suitable. Here, the weight average molecular weight is a polystyrene-equivalent molecular weight measured by gel permission chromatography.

Generally, the softener for mineral oil-based rubber is a mixture of aromatic hydrocarbons, naphthenic hydrocarbons, and paraffinic hydrocarbons. Aromatic oils have a carbon content of 35% by mass or more, and naphthenic oils and paraffinic hydrocarbons have a naphthenic hydrocarbon content of 30 to 45% by mass based on the total carbon content. Those having a carbon content of 50% by mass or more are called paraffinic oils. In the present invention, paraffinic oil is preferably used.

The paraffin-based oil is not particularly limited, but has a kinematic viscosity at 40 ° C. of usually 20 cSt (centimeter Stokes) or more, preferably 50 cSt or more, and usually 800 cSt or less, preferably 600 cSt or less. The pour point is usually −40 ° C. or higher, preferably −30 ° C. or higher, and 0 ° C. or lower is preferably used. Further, a flash point (COC) of usually 200 ° C. or higher, preferably 250 ° C. or higher, and usually 400 ° C. or lower, preferably 350 ° C. or lower is preferably used.

As the hydrocarbon-based rubber softener of the component (B), only one type may be used, or two or more types may be mixed and used.

<Component (C)>
The polypropylene-based resin of the component (C) is a crystalline polymer containing a repeating unit derived from propylene.
Examples of the polypropylene-based resin of the component (C) include a homopolymer of propylene or a copolymer of propylene and an α-olefin.

The α-olefin in the propylene / α-olefin copolymer refers to an α-olefin in a broad sense including ethylene, for example, ethylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-. 1-Pentene, 4,4-dimethyl-1-pentene, 1-hexene, 4-methyl-1-hexene, 1-hexene, 1-octene, 1-decene, 1-octadecene, etc. have 2 to 20 carbon atoms (carbon). Examples thereof include α-olefins having 2 to 8 carbon atoms (excluding propylene having 3 carbon atoms), more preferably α-olefins having 2 to 8 carbon atoms (excluding propylene having 3 carbon atoms), but are not particularly limited thereto. Among these, ethylene, 1-butene, 1-hexene, 1-octene and the like are preferable from the viewpoint of easy availability.
As the α-olefin, only one type can be used alone, or two or more types can be used in any combination and ratio.

Among polypropylene-based resins, homopolypropylene, propylene / α-olefin random copolymer, and propylene / α-olefin block copolymer are preferable.
Here, homopolypropylene is a homopolymer of propylene. The propylene / α-olefin random copolymer is a copolymer in which propylene and α-olefin are randomly polymerized. The propylene / α-olefin block copolymer consists of a first segment and a second segment. The first segment is a homopolypropylene portion of propylene homopolymerization, and the second segment is a propylene / α-olefin random copolymer portion. It has a structure in which a dispersed phase is formed as a certain block copolymer. The first segment of the propylene / α-olefin block copolymer may be a propylene / α-olefin random copolymer portion having a different α-olefin content from the second segment.

The propylene unit content (content of repeating units derived from propylene) in the propylene / α-olefin random copolymer is preferably 55 mol% or more. In the propylene / α-olefin block copolymer, the content of the dispersed phase component of the second segment is preferably 5 to 30% by mass in the propylene / α-olefin block copolymer.
The content of each structural unit in the component (C) can be determined by infrared spectroscopy.

The melt flow rate (JIS K7210 (1999), 230 ° C., 21.2 N load) of the polypropylene-based resin of the component (C) is usually 0.05 to 200 g / 10 minutes, preferably 0.1 to 100 g / 10 minutes. is there. When a melt flow rate of less than 0.05 g / 10 minutes is used, the moldability of the obtained thermoplastic elastomer composition deteriorates and appearance defects are likely to occur, and when a melt flow rate of more than 200 g / 10 minutes is used. Tends to reduce the mechanical properties of the resulting thermoplastic elastomer composition, especially the tensile strength.

Only one kind of polypropylene-based resin of component (C) may be used, or two or more kinds of polypropylene resins having different types, compositions, physical properties, etc. of constituent units may be used.

<Component (D)>
The component (D) in the present invention is diallyl orthophthalate represented by the following structural formula (1A) and / or diallyl isophthalate represented by the following structural formula (1B).

The two vinyl groups contained in the component (D) are components that promote denaturation by the component (E) described later. When the thermoplastic elastomer composition of the present invention contains the above-mentioned components (A) to (C) together with the component (D) diallyl orthophthalate and / or diallyl isophthalate, oil bleeding in a high hardness region is suppressed. The details of the mechanism are not clear, but it is presumed as follows.
Dialyl phthalate has a double bond in its chemical structure that contributes to the reaction, and the phthalate structure has a property of having high affinity and easy migration in aromatic vinyl compounds such as polystyrene. For example, polymers such as DEHP (bis (2-ethylhexyl phthalate)) and DINP (diisononyl phthalate) used in vinyl chloride resins can easily be transferred to polystyrene resins, and the aromatic vinyl compound unit which is also a component (A). A block copolymer having a polymer block P mainly composed of thalate and a polymer block Q mainly composed of a conjugated diene compound unit can easily migrate, and the skeleton that easily migrates is an aromatic vinyl compound unit. Since diallyl phthalate has a structure similar to that of these phthalate plasticizers, it is considered that it has a high affinity for the polymer block P mainly composed of aromatic vinyl compound units, and organic peroxides and the like are considered to be high. It is considered that diallyl phthalate reacts in the polymer block P mainly composed of the aromatic vinyl compound unit when the polymer block P mainly composed of the aromatic vinyl compound unit is cleaved.

There are three types of diallyl phthalates, ortho, iso, and tele, but in the present invention, the ortho and / or iso is used. From the viewpoint of reactivity, the iso form is suitable from the viewpoint of steric hindrance.

The method for producing diallyl orthophthalate and diallyl isophthalate is not particularly limited. For example, a method of directly esterifying ortho-form or iso-form phthalic anhydride with allyl alcohol in the presence of an acid catalyst (direct esterification method) or , Ortho-form and iso-form phthalic anhydride are reacted with an aqueous solution of sodium hydroxide to obtain sodium phthalate, and then allyl chloride is continuously reacted under pressure (allyl chloride method).

As the component (D), one obtained by the above-mentioned production method may be used, or a commercially available product may be used. Examples of commercially available products include "Daiso Dap Monomer" and "Daiso Dap 100 Monomer" manufactured by Osaka Soda Co., Ltd.

As the diallyl phthalate of the component (D), only one type having the above structure may be used alone, or two types may be used in combination.

<Mixing ratio of ingredients (A) to (D)>
In the thermoplastic elastomer composition of the present invention, the component (A) is 20 to 30 parts by mass and the component (B) is 30 to 30 parts by mass with respect to a total of 100 parts by mass of the component (A), the component (B) and the component (C). It is preferable to contain 40 parts by mass and 30 to 40 parts by mass of the component (C).

The content of diallyl phthalate of the component (D) in the thermoplastic elastomer composition of the present invention is preferably 0.05 to 3 parts by mass with respect to a total of 100 parts by mass of the components (A) to (C). , More preferably 0.1 to 2 parts by mass. If the content of the component (D) is 0.05 parts by mass or more, the effect of suppressing oil bleeding by blending the component (D) can be sufficiently obtained, and if it is 3 parts by mass or less, the addition amount can be increased. It is possible to obtain a matching effect of suppressing oil bleeding.

<Ingredient (E)>
The thermoplastic elastomer composition of the present invention preferably contains the organic peroxide of the component (E) in addition to the above-mentioned components (A) to (D). By containing the component (E), a part of the component (A) can be denatured and oil bleeding can be suppressed more effectively. As the organic peroxide, only one type can be used alone, or two or more types can be used in any combination and ratio.

As the organic peroxide, either an aromatic type or an aliphatic type can be used, and it may be a single peroxide or a mixture of two or more kinds of peroxides. Specifically, di-t-butylperoxide, t-butylcumylperoxide, dicumylperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl. -2,5-di (t-butylperoxy) hexin-3,1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-di (t-butylperoxy) -3,3,5 Dialkyl peroxides such as -trimethylcyclohexane, t-butylperoxybenzoate, t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2 , 5-Di (benzoylperoxy) Peroxyesters such as hex-3, acetyl peroxide, lauroyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, hydroper such as 2,4-dichlorobenzoyl peroxide Oxides and the like are used. Of these, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane is particularly preferable.

When the thermoplastic elastomer composition of the present invention contains the organic peroxide of the component (E), the content thereof is based on 100 parts by mass of the total amount of the component (A), the component (B) and the component (C). , It is preferably 0.05 to 2.0 parts by mass, and more preferably 0.07 to 1.5 parts by mass. When the content of the component (E) is at least the above lower limit, the effect of modification by the component (E) can be sufficiently obtained, and when it is at least the above upper limit, the modification reaction can be easily controlled.

<Other ingredients>
The thermoplastic elastomer composition of the present invention contains, as necessary, a stabilizer, a lubricant, an antioxidant, an ultraviolet absorber, a foaming agent, a flame retardant, a colorant, and a filler, as long as the object of the present invention is not impaired. It may contain various additives such as, and thermoplastic resins and rubbers other than essential components.

In particular, the thermoplastic elastomer composition of the present invention preferably contains an antioxidant as a stabilizer.
Examples of the antioxidant include monophenols, bisphenols, polyphenols of birds and above, thiobisphenols, naphthylamines, diphenylamines, and phenylenediamines. Among these, monophenol-based, bisphenol-based, polyphenol-based triphenols and thiobisphenol-based antioxidants are preferable. When an antioxidant is contained, the content thereof is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, based on 100 parts by mass of the total amount of the components (A) to (C). It is a department. When the content of the antioxidant is 0.01 parts by mass or more, the effect of adding the antioxidant can be sufficiently obtained, and when the content is 5 parts by mass or less, an improvement effect commensurate with the increase in the amount of the antioxidant can be obtained. Can be done.

Examples of the filler include glass fiber, hollow glass ball, carbon fiber, talc, calcium carbonate, mica, potassium titanate fiber, silica, metal soap, titanium dioxide, carbon black and the like. Only one type of these can be used alone, or two or more types can be used in any combination and ratio.

Examples of the thermoplastic resin other than the essential components include polyphenylene ether resin, polyamide resin such as nylon 6 and nylon 66, polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polyoxymethylene homopolymer, and polyoxymethylene copolymer. Polyoxymethylene resin, polymethylmethacrylate resin, polystyrene resin, biodegradable resin, plant-derived raw material resin and the like can be mentioned.
Examples of the optional rubber include ethylene propylene rubber and polybutadiene rubber.

<Manufacturing method of thermoplastic elastomer composition>
The thermoplastic elastomer composition of the present invention contains the above components (A), (B), (C), (D), preferably each component (E), and other resin components and various additives. , It can be produced by mixing, kneading or melt-kneading by a conventional method using an ordinary extruder, a Banbury mixer, a mixing roll, a roll, a thermoplastic plastograph, a kneader lavender or the like. Among these, it is preferable to use an extruder, particularly a twin-screw extruder.

When the thermoplastic elastomer of the present invention is kneaded and produced by an extruder or the like, it is preferable to perform a dynamic heat treatment in which the thermoplastic elastomer of the present invention is melt-kneaded while being heated to usually 80 to 300 ° C., preferably 100 to 250 ° C. The treatment time for performing the dynamic heat treatment is not particularly limited, but is usually 0.1 to 30 minutes in consideration of productivity and the like.

This dynamic heat treatment is preferably performed by melt-kneading as described above, and when a twin-screw extruder is used, each component is supplied to the raw material supply ports (hoppers) of the twin-screw extruder having a plurality of raw material supply ports. It is more preferable to perform dynamic heat treatment.

<DULO A hardness>
The thermoplastic elastomer composition of the present invention preferably has a DULO A hardness (JIS K6253) of 40 to 95 as measured by the method described in the section of Examples described later.
That is, the Duro A hardness of the thermoplastic elastomer composition of the present invention is preferably 40 or more because the thermoplastic elastomer composition of the present invention can suppress oil bleeding in a high hardness region. On the other hand, when the DULO A hardness is larger than 95, the elastomer is inflexible and the rubber-like properties are inferior. Therefore, from the viewpoint of a practical range of use, the DULO A hardness of the thermoplastic elastomer composition of the present invention is 95 or less. Is preferable. A more preferred Dulo A hardness of the thermoplastic elastomer composition of the present invention is 40-95.

[Molded product]
The molded product of the present invention is obtained by molding the thermoplastic elastomer composition of the present invention with a molding machine such as an injection molding machine, a single-screw extrusion molding machine, a twin-screw extrusion molding machine, a compression molding machine, or a calendar processing machine. Can be done.

The molded body of the present invention can be applied to many automobile members, building members, miscellaneous goods members, distribution materials, etc., but is particularly suitable as a non-slip member, especially for pallet grommets of distribution materials. , The effect of the present invention is fully exhibited.

Hereinafter, 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 thereof 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 range is the above-mentioned upper limit or lower limit value. , The range specified by the combination of the values of the following examples or the values of the examples may be used.

[raw materials]
The following raw materials were used in the following examples.

<Component (A): Hydrogenated block copolymer>
A-1: Hydrogenated product of styrene block, butadiene block, styrene block copolymer (TSRC "TAIPOL 6151")
Styrene unit content: 33% by mass
Hydrogenation rate: 98% or more Weight average molecular weight: Approximately 260,000

<Component (B): Softener for hydrocarbon rubber>
B-1: Softening agent for paraffin rubber ("Diana (registered trademark) process oil PW90" manufactured by Idemitsu Kosan Co., Ltd.)
40 ° C kinematic viscosity: 95.5 cSt
Pour point: -15 ° C
Flash point: 272 ° C

<Component (C): Polypropylene resin>
C-1: Propylene homopolymer (commercially available)
MFR: 2.5 g / 10 minutes (230 ° C, 21.2 N load)
C-2: Propylene / ethylene random copolymer (commercially available)
Propene unit content: 97% by mass
MFR: 1.3 g / 10 minutes (230 ° C, 21.2 N load)
C-3: Propylene / ethylene random copolymer (commercially available)
MFR: 30 g / 10 minutes (230 ° C, 21.2 N load)
Propene unit content: 98% by mass
C-4: Propylene / ethylene block copolymer (commercially available)
MFR: 0.7 g / 10 minutes (230 ° C, 21.2 N)
Propene unit content: 79% by mass

<Component (D): Dialyl phthalate>
D-1: Dialyl Isophthalate ("Daiso Dap 100 Monomer" manufactured by Osaka Soda Co., Ltd.)

<Component (E): Organic peroxide>
E-1: A mixture of 40% by mass of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and 60% by mass of calcium carbonate ("AD40C" manufactured by Kayaku Akzo Corporation)

<Component (X): Other reaction aids>
X-1: Divinylbenzene (mixture of 55% by mass of divinylbenzene manufactured by Wako Pure Chemical Industries, Ltd. and 45% by mass of ethylvinylbenzene)

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

(1) Measurement of melt flow rate (MFR) The measurement was performed at a measurement temperature of 230 ° C. and a measurement load of 21.2 N by a method conforming to the JIS K7210 standard. MFR is an index of injection moldability, and is preferably in the range of 5 to 50 g / 10 minutes.

(2) Evaluation of physical properties In the measurement of the following physical properties, an in-line screw type injection molding machine (manufactured by Toshiba Machine Co., Ltd., product number: IS130) is used, and the injection pressure is 50 MPa, the cylinder temperature is 220 ° C, and the mold temperature is 40 ° C. Under the conditions, each thermoplastic elastomer composition was injection-molded to form a sheet having a thickness of 2 mm, a width of 120 mm, and a length of 80 mm.
In the tensile test of (2-2), a sheet (thickness 2 mm × width 120 mm × length 80 mm) obtained by using a test piece punching blade (JIS No. 3 type dumbbell shape) in accordance with JIS K6251 was used. A dumbbell-shaped test piece was punched out from the material, and measurement was performed using this test piece.

(2-1) Dulo A Hardness The hardness (after 15 seconds) was measured according to JIS K6253 (JIS-A).

(2-2) Tensile strength during cutting / Elongation during cutting (tensile test)
The test speed was measured at 500 mm / min according to JIS K6251.

(2-3) Bleed test Using a jig according to JIS K6262, the state of the sample surface touching the metal surface immediately after compression at 70 ° C. and a compression rate of 25% for 68 hours was observed, and evaluation was performed according to the following criteria. ..
<Bleed judgment criteria>
○: No oil is observed on the surface △: Oil is observed on the surface slightly ×: Oil is observed on the surface severely

[Examples 1 to 7, Comparative Example 1]
Tetrakiss [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (Ciba Special Tee Chemicals) as an antioxidant with respect to the blending amount shown in Table-1. "Irganox 1010" manufactured by Japan Steel Works, Ltd.) Add 0.1 parts by mass, mix with a Henschel mixer, and use a JSW twin-screw extruder "TEX30" with a heavy-duty feeder to a cylinder temperature of 200 ° C. and screw rotation speed. Extrusion was performed at 400 rpm to obtain a thermoplastic elastomer composition.

The obtained thermoplastic elastomer was evaluated as described above, and the results are shown in Table-1.

From Table 1, it can be seen that the thermoplastic elastomer composition of the present invention containing the diallyl phthalate component (D) can significantly improve oil bleeding.

On the other hand, with respect to Example 1 and Example 3, Comparative Example 1 containing no component (D) had oil bleed and contained divinylbenzene as a reaction aid instead of component (D). In 2 and Comparative Example 3, bleeding is rather worse.

Claims (6)

A thermoplastic elastomer composition containing the following components (A) to (D).
Component (A): Hydrogen in a block copolymer having at least two polymer blocks P mainly composed of aromatic vinyl compound units and at least one polymer block Q mainly composed of conjugated diene compound units. Additives Component (B): Hydrocarbon-based rubber softener Component (C): Polypropylene-based resin Component (D): Diallyl orthophthalate represented by the following structural formula (1A) and / or represented by the following structural formula (1B) Dialyl isophthalate

The content of the component (A) is 20 to 30 parts by mass, and the content of the component (B) is 30 to 40 with respect to a total of 100 parts by mass of the component (A), the component (B), and the component (C). The thermoplastic elastomer composition according to claim 1, wherein the content of the component (C) is 30 to 40 parts by mass. The thermoplastic elastomer composition according to claim 1 or 2, further comprising the following component (E).
Component (E): Organic peroxide The thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the component (C) is a homopolypropylene and / or a propylene / α-olefin copolymer. The thermoplastic elastomer composition according to any one of claims 1 to 4, wherein the DULO A hardness (JIS K6253) is 40 to 95. A molded product comprising the thermoplastic elastomer composition according to any one of claims 1 to 5.