JP2003206388A - Thermoplastic elastomer composition, and its molded item and composite molded item - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition which is excellent in softness, (long-time and short-time) compression set, and oil resistance and does not allow a softener to bleed out; and its molded item and composite molded item. <P>SOLUTION: This thermoplastic elastomer composition contains (a) 100 pts.wt. polymer component which comprises a hydrogenated block copolymer prepared by hydrogenating a block copolymer comprising at least two polymer blocks A consisting mainly of an aromatic vinyl compound and a polymer block B consisting mainly a conjugated diene compound and/or a hydrogenation product of a conjugated diene compound block copolymer, (b) 30-150 pts.wt. nonaromatic softener for rubber, and (c) 3-100 pts.wt. petroleum hydrocarbon resin which has a softening point of 80-170°C and of which the temperature at which the melt viscosity is 10 P is 120-250°C. The molded item and composite molded item are prepared from the elastomer composition. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic elastomer composition, a molded article thereof and a composite molded article, and in particular,
The present invention relates to a thermoplastic elastomer composition which is excellent in flexibility, compression set (in short term and long term), molding processability, and suppresses bleeding out of a softening agent, a molded article thereof and a composite molded article.

[0002]

2. Description of the Related Art In recent years, a thermoplastic elastomer, which is a soft material having rubber elasticity and which does not require a vulcanization step and has the same moldability and recyclability as a thermoplastic resin, has been used in automobile parts, home electric appliance parts, It is widely used in the fields of wire coating, medical parts, footwear, and sundries.

Among thermoplastic elastomers, polystyrene-based heats such as styrene-butadiene block copolymer (SBS) and styrene-isoprene block copolymer (SIS), which are block copolymers of aromatic vinyl compound-conjugated diene compound. The thermoplastic elastomer is rich in flexibility and has good rubber elasticity at room temperature, and the thermoplastic elastomer composition obtained from them has excellent processability and is widely used as a substitute for vulcanized rubber. .

Further, the elastomer composition obtained by hydrogenating the intramolecular double bond of the block copolymer of styrene and the conjugated diene in these elastomers is an elastomer having improved heat aging resistance (heat stability) and weather resistance. Is widely used as a

However, thermoplastic elastomer compositions using these hydrogenated block copolymers still have rubber-like properties such as oil resistance, heat-pressurization deformation rate (compression set) and rubber elasticity at high temperatures. There is a problem, and in order to improve this point, a cross-linked product obtained by cross-linking the composition containing the hydrogenated derivative of the block copolymer has been proposed (see, for example, Patent Documents 1 to 5).

However, the crosslinked compositions of hydrogenated block copolymers disclosed in Patent Documents 1 to 5 are
In particular, there is a problem that the compression set at 100 ° C. is still insufficient and the mechanical strength is liable to be lowered, and the performance level conventionally required for vulcanized rubber applications has not yet been reached. Further, in extrusion molding, the melt tension at a high temperature is low, so that the shape retention is deteriorated, and in injection molding, the molding cycle becomes long, and there are many problems on the molding surface.

Further, all of the compositions disclosed in Patent Documents 1 to 5 have a Shore A hardness of 40 or more and are softened by increasing the addition amount of the softening agent.
In such a case, stickiness may occur on the surface of the molded product,
Under the present circumstances, there is a problem that bleeding out of the softening agent occurs under heating stress, which is not preferable in practical use.

[0008]

[Patent Document 1] JP-A-59-6236

[Patent Document 2] JP-A-63-57662

[Patent Document 3] Japanese Patent Publication No. 3-49927

[Patent Document 4] Japanese Patent Publication No. 3-11291

[Patent Document 5] Japanese Patent Publication No. 6-13628

[0009]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide flexibility, compression set (short and long term),
It is intended to provide a thermoplastic elastomer composition having excellent oil resistance and suppressing bleed-out of a softening agent.

[0010]

As a result of intensive studies to achieve the above object, the present inventors have found that a specific hydrogenated styrene elastomer is melted with a thermoplastic resin having a low melting point and a low melt viscosity. It was found that a thermoplastic elastomer composition having excellent flexibility, compression set, molding processability and suppressing bleeding out of a softening agent can be obtained by kneading, and completed the present invention.

That is, the first aspect of the present invention is (a)
Hydrogenated block obtained by hydrogenating a block copolymer consisting of at least two polymer blocks A mainly containing an aromatic vinyl compound and at least one polymer block B mainly containing a conjugated diene compound Copolymer (a-
1) and / or 100 parts by weight of a hydrogenated product of a conjugated diene compound block copolymer (a-2), (b) 30 to 150 parts by weight of a non-aromatic softening agent for rubber, and (c) a softening point of 8
Petroleum hydrocarbon resins 3 to 10 having a temperature of 120 to 250 ° C., and a temperature of 0 to 170 ° C. and a melt viscosity of 10 poises.
The thermoplastic elastomer composition is characterized by containing 0 part by weight.

The second invention of the present invention further comprises (d) 0.1 to 25 parts by weight of a peroxide-decomposable polyolefin resin, the thermoplastic elastomer composition according to the first invention. It is a thing.

The third invention of the present invention is the first or second invention.
A molded article comprising the thermoplastic elastomer composition according to the invention.

A fourth invention of the present invention is a medical elastic member, a food elastic member, or an inkjet recording device elastic member, characterized by comprising the molded body according to the third invention.

Further, a fifth invention of the present invention is characterized in that the molded product according to the third invention and the molded product made of polypropylene resin are heat-sealed together. Is.

Further, a sixth invention of the present invention comprises the heat-sealing composite molded article according to the fifth invention, which is an elastic member for medical use, an elastic member for food or an elastic member for an ink jet recording apparatus. Is.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The constituent components, production method, use and the like of the thermoplastic elastomer composition of the present invention will be described in detail below.

1. Constituent component of thermoplastic elastomer composition (1) Block copolymerization consisting of at least two polymer blocks A mainly containing an aromatic vinyl compound and at least one polymer block B mainly containing a conjugated diene compound Hydrogenated block copolymer (a-1) and / or hydrogenated product of conjugated diene compound block copolymer (a-2) obtained by hydrogenating the polymer (A-2) Aromatic vinyl in the thermoplastic elastomer composition of the present invention Hydrogenated block copolymer obtained by hydrogenating a block copolymer composed of at least two polymer blocks A containing a compound as a main component and at least one polymer block B containing a conjugated diene compound as a main component Component (a-1)
Is a polymer block A mainly composed of an aromatic vinyl compound
Is a polymer obtained by hydrogenating a block copolymer comprising at least two of the above and at least one of the polymer blocks B containing a conjugated diene compound as a main component. For example,
It is obtained by hydrogenating a block copolymer of an aromatic vinyl compound-conjugated diene compound having a structure of ABA, BABAA, ABABA, etc. is there.

The polymer block A containing an aromatic vinyl compound as a main component may be a polymer composed of only an aromatic vinyl compound or a copolymer of an aromatic vinyl compound and less than 50% by weight of a conjugated diene compound. Good. Further, the polymer block B containing a conjugated diene compound as a main component may be a polymer consisting only of the conjugated diene compound or a copolymer of the conjugated diene compound and an aromatic vinyl compound of less than 50% by weight.

It is obtained by hydrogenating a block copolymer comprising at least two polymer blocks A containing an aromatic vinyl compound as a main component and at least one polymer block B containing a conjugated diene compound as a main component. The hydrogenated block polymer component (a-1) is a polymer block B mainly composed of a conjugated diene compound, and its hydrogenation rate is arbitrary, but preferably 50% or more, more preferably 55% or more, It is preferably 60% or more. Further, its microstructure is arbitrary, and for example, when the block B is composed of butadiene alone, in the polybutadiene block, the 1,2-microstructure is preferably 20 to 50% by weight, and particularly preferably 25 to 45%. % By weight. Also,
It may be a product obtained by selectively hydrogenating the 1,2-bond. If block B is composed of a mixture of isoprene and butadiene, the 1,2-microstructure is preferably 50
%, More preferably less than 25%, even more preferably less than 15%.

When block B is composed of isoprene alone, in the polyisoprene block, preferably 70 to 100% by weight of isoprene has a 1,4-microstructure and isoprene-derived aliphatic double bond. Preferably, at least 90% is hydrogenated.

When a hydrogenated block copolymer is used depending on the application, the hydrogenated product can be preferably used as appropriate according to the application.

The polymer block A is preferably present in an amount of 5 to 70% by weight based on the total amount of the component (a-1). Furthermore, the weight average molecular weight of the entire component (a-1) is
It is preferably 50,000 to 550,000.

Specific examples of the hydrogenated block polymer component (a-1) include styrene-ethylene / butadiene / styrene copolymer (SEBS), styrene / ethylene / propylene / styrene copolymer (SEPS), styrene- Ethylene-ethylene-propylene-styrene copolymer (SE
EPS), styrene-butadiene / butylene-styrene copolymer (partially hydrogenated styrene-butadiene-styrene copolymer, SBBS) and the like.

A block copolymer composed of at least two polymer blocks A mainly containing the aromatic vinyl compound and at least one polymer block B mainly containing the conjugated diene compound is hydrogenated. Although many methods have been proposed as a method for producing the block copolymer obtained, a typical method is, for example, Japanese Patent Publication No. 40-
It can be obtained by block polymerization in an inert medium using a lithium catalyst or a Ziegler type catalyst according to the method described in JP-A-23798. The hydrogenation treatment of such a block copolymer can be carried out by a known method in an inert solvent in the presence of a hydrogenation catalyst.

The hydrogenated product (a-2) of the conjugated diene compound block copolymer used in the present invention is, for example, a crystalline ethylene block and an amorphous ethylene obtained by hydrogenating a block copolymer of butadiene. -A block copolymer having a butene block (CEBC) and the like can be mentioned. In the present invention, the hydrogenated product of the conjugated diene compound block copolymer may be used alone or in combination of two or more.

(2) Non-aromatic rubber softening agent component (b) The non-aromatic rubber softening agent component (b) in the thermoplastic elastomer composition of the present invention is a non-aromatic mineral oil or Liquid or low molecular weight synthetic softeners may be mentioned. Mineral oil softeners used for rubber are
A mixture in which an aromatic ring, a naphthene ring and a paraffin chain are combined, and a mixture of which the number of carbon atoms in the paraffin chain accounts for 50% or more of the total number of carbon atoms is a paraffin type and the number of carbon atoms in the naphthene ring is 30 to 40%. Those having a naphthene type are referred to as naphthenes, and those having an aromatic carbon number of 30% or more are called aromatic types.

The mineral oil type rubber softeners used as the component (b) of the present invention include paraffin type and naphthene type softeners, but the aromatic type softeners have the component (a) depending on their use. This is not preferable because it becomes soluble and the physical properties of the resulting composition cannot be improved. Component (b) of the present invention
Of these, paraffinic ones are preferable, and among paraffinic ones, those having less aromatic ring components are particularly suitable. Examples of liquid or low molecular weight synthetic softening agents include polybutene, hydrogenated polybutene, and low molecular weight polyisobutylene. Among these, polybutene or hydrogenated polybutene is preferable.

The properties of these non-aromatic softeners for rubber are such that the dynamic viscosity at 37.8 ° C. is 20 to 50,000 c.
St, dynamic viscosity at 100 ° C. is 5 to 1500 cS
t, pour point is −10 to −15 ° C., flash point (COC) is 1
It is preferably 70 to 300 ° C. Further, those having a weight average molecular weight of 100 to 2,000 are preferable.

When the component (a-1) is used as the component (a), the compounding amount of the component (b) is 100.
It is 30 to 150 parts by weight, preferably 50 to 120 parts by weight, based on parts by weight. If the blending amount is less than 30 parts by weight, the thermoplastic elastomer composition obtained will have poor moldability, and the hardness will be too high and the flexibility will be lost, so that a rubber-like product cannot be obtained. If it exceeds 150 parts by weight, the softening agent is likely to bleed out from the resulting thermoplastic elastomer composition, and peeling or deformation and flow marks are likely to occur in the molded product.

When the component (a-2) is used as the component (a), it is 30 to 100 parts by weight of the component (a-2).
170 parts by weight, preferably 50 to 160 parts by weight. If the blending amount is less than 30 parts by weight, the thermoplastic elastomer composition obtained will have poor moldability, and the hardness will be too high and the flexibility will be lost, so that a rubber-like product cannot be obtained. If it exceeds 170 parts by weight, the softening agent is likely to bleed out from the resulting thermoplastic elastomer composition, and peeling or deformation and flow marks are likely to occur in the molded product.

(3) Petroleum-based hydrocarbon resin component (c) The petroleum-based hydrocarbon resin component (c) in the thermoplastic elastomer composition of the present invention improves the rubber dispersion of the resulting thermoplastic elastomer composition, and It is effective in adjusting the hardness and shrinkage while improving the appearance of the molded product. The petroleum-based hydrocarbon resin includes an aliphatic petroleum resin mainly composed of a C ₅ fraction, which is a by-product of steam cracking of petroleum, an aromatic petroleum resin mainly composed of a C ₉ fraction, and both. There is a C ₅ C ₉ copolymer resin to be copolymerized, etc., but it is not particularly limited as long as it is a petroleum hydrocarbon resin having a softening point and a melt viscosity in the ranges described below, but a copolymer system containing aromatics It is preferably a resin.

The softening point of the component (c) is 80 to 170 ° C., preferably 110 to 160 ° C. When the softening point is outside the above range, the balance of flexibility, compression set and molding processability of the resulting elastomer composition deteriorates. The temperature at which the melt viscosity of the component (c) becomes 10 poise is 120 to 250 ° C., and preferably 1
It is 50-240 degreeC. When the temperature at which the melt viscosity becomes 10 poise is less than 120 ° C, the rubber elasticity of the obtained elastomer composition deteriorates, and when it exceeds 250 ° C, the moldability of the obtained elastomer composition decreases.

A commercially available product of the preferred example of the component (c) is an aromatic resin, particularly Endex 155 (Eastman C) which is a copolymer with an aromatic monomer.
Chemical Co., Ltd. or Kristalex 5140 (Eas, which is a copolymer of α-methylstyrene and styrene).
tman Chemical Co.).

The blending amount of the component (c) is 100 parts of the component (a).
It is 3 to 100 parts by weight, preferably 10 to 50 parts by weight, based on parts by weight. If the amount is less than 3 parts by weight,
Moldability of the obtained elastomer composition is deteriorated, and peeling, deformation, and flow marks are likely to occur in the molded product. 100
If it exceeds the weight part, the moldability of the obtained elastomer composition is deteriorated, and the hardness of the elastomer composition becomes too high and the flexibility is lost, so that a product having a rubber-like feel cannot be obtained.

(4) Peroxide-decomposable polyolefin resin component (d) In the thermoplastic elastomer composition of the present invention, a peroxide-decomposable polyolefin resin component (d) may be added, if necessary. The component (d) can remarkably improve the heat fusion property of the molded product made of the obtained thermoplastic elastomer composition to the molded product made of the peroxide-decomposable polyolefin resin.

The component is an olefin-based polymer or copolymer that is thermally decomposed by heat treatment in the presence of peroxide to reduce the molecular weight and increase the fluidity at the time of melting. For example, isotactic Polypropylene or propylene and other α-olefins such as ethylene, 1-
Butene, 1-hexene, 4-methyl-1-pentene, 1
Examples thereof include copolymers with octene and the like.

D of the homo portion of the above olefinic copolymer
The melting point measured by SC is preferably Tm of 150 to 1
67 ° C., ΔHm is in the range of 25 to 83 mJ / mg. The crystallinity can be estimated from Tm and ΔHm measured by DSC. When Tm and ΔHm are out of the above ranges, the oil resistance and rubber elasticity at 100 ° C. or higher of the obtained elastomer composition are not improved.

Further, the melt flow rate of component (d) (MFR, ASTM D-1238, L condition, 230
C) is preferably 0.1 to 200 g / 10 minutes, more preferably 0.5 to 100 g / 10 minutes. If the MFR is less than 0.1 g / 10 minutes, the moldability of the obtained elastomer composition will deteriorate, and if it exceeds 200 g / 10 minutes, the rubber elasticity of the obtained elastomer composition will deteriorate.

When compounding the component (d),
The amount is preferably 0.1 to 25 parts by weight, more preferably 1 to 20 parts by weight, based on 100 parts by weight of the component (a). Two
When it exceeds 5 parts by weight, the flexibility of the obtained elastomer composition deteriorates and the rubber elasticity decreases.

(5) Other components (e) In addition to the above components, the thermoplastic elastomer composition of the present invention may further contain various antiblocking agents, sealability improving agents, heat stability agents, if necessary. It is also possible to contain agents, antioxidants, light stabilizers, ultraviolet absorbers, lubricants, crystal nucleating agents, colorants and the like. Here, as the antioxidant,
For example, 2,6-di-tert-p-butyl-p-cresol, 2,6-di-tert-butylphenol,
2,4-dimethyl-6-tert-butylphenol,
Examples thereof include phenolic antioxidants such as 4,4-dihydroxydiphenyl and tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, phosphite antioxidants, and thioether antioxidants. Of these, phenol-based antioxidants and phosphite-based antioxidants are particularly preferable. The antioxidant is the above component (a).
To (d) are preferably 0 to 3.0 parts by weight, and particularly preferably 0.1 to 1.0 parts by weight, based on 100 parts by weight.

2. Production of Thermoplastic Elastomer Composition The thermoplastic elastomer composition of the present invention comprises the above components (a) to (c) or, if necessary, components (d) to (e).
, And each component is added simultaneously or in any order and melt-kneaded.

The melt-kneading method is not particularly limited, and a generally known method can be used. For example, a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer or various kneaders can be used. For example, a moderate L / D twin-screw extruder,
The above operation can be continuously performed by using a Banbury mixer, a pressure kneader or the like. Here, the temperature of the melt-kneading is preferably 160 to 220 ° C.

3. Uses of Thermoplastic Elastomer Composition The thermoplastic elastomer composition of the present invention has appropriate flexibility and is excellent in permanent compression strain, in particular, compression strain of 70 ° C. or less, and further, the obtained product is subjected to excessive stress deformation or Even if it is used under a load, it has a characteristic that it does not pollute the environment because there is little bleed-out of the softening agent. Therefore, the thermoplastic elastomer composition of the present invention is a multicolor molding with a medical sealing member, a food sealing member, an electrical component material, a bottle cap packing, an automotive sealing member, a polyolefin or a hard thermoplastic elastomer by a molding process. It can be used as a seal member or the like, and is particularly useful as an ink leak seal member or the like in an inkjet recording apparatus or the like.

Further, since the thermoplastic elastomer composition of the present invention is excellent in the heat fusion property with the polyolefin resin, especially with the polypropylene resin, the molded article from the thermoplastic elastomer composition and the molded article from the polypropylene resin are excellent. By heat-sealing and, the composite heat-sealing molded body can be easily molded.

Specific examples of the composite heat-sealed molded product include, for example, medical seal members, food seal members, electrical component materials, bottle cap packings, automobile seal members, and multicolor molded seal members. The body can be used, and particularly, it can be extremely usefully used as an ink leakage seal member in an inkjet recording apparatus or the like.

[0047]

EXAMPLES The present invention will be specifically described with reference to the following examples and comparative examples, but the present invention is not limited to these examples. The physical properties were measured by the following methods. (1) Specific gravity: Based on JIS K 7112, the test piece was measured using a 1 mm thick press sheet. (2) Hardness: According to JIS K 7215, the test piece uses a 6.3 mm thick press sheet, and the durometer hardness
It was measured with type A. (3) Tensile strength: In conformity with JIS K 6301, a test piece of 1 mm thick press sheet was punched into a No. 3 dumbbell mold for use. The pulling speed was 500 mm / min. (4) 100% elongation stress: In accordance with JIS K 6301, a test piece was a 1 mm thick press sheet punched out into a No. 3 dumbbell mold for use. The pulling speed was 500 mm / min. (5) Elongation at break: In accordance with JIS K 6301, a test piece of 1 mm thick press sheet was punched out into a No. 3 dumbbell mold for use. The pulling speed was 500 mm / min. (6) Compression set: In accordance with JIS K 6262,
The test piece used the 6.3 mm-thick press sheet. 25
It was measured at 70 ° C. for 22 hours under the condition of% deformation. (7) Bleed resistance: The presence or absence of bleeding and blooming of low molecular weight substances was visually observed for the molded product after compressing the molded product by 25% under the environment of 70 ° C. × 168 hours, and evaluated according to the following criteria. . ⊚: Good ∘: Slightly bad ×: Poor (8) Tack resistance: Two 1 mm thick press sheets were used as test pieces, two sheets were stacked, and a load of 500 g / cm ^{2 was} applied.
After standing for 4 hours, the degree of peeling of the press sheet was visually observed and evaluated according to the following criteria. ◎: Good ○: Slightly bad ×: Poor (9) Injection moldability: A 130 mm × 130 mm × 2 mm sheet was injection-molded, the appearance was visually observed, and flow marks and sink marks were evaluated according to the following criteria. did. ◎: Good ○: Somewhat bad ×: Bad

(10) Thermal fusion bondability: test pieces shown in FIGS.
1 is expressed in peel strength by 180 degree peel strength test
It was 1-3, length 150 mm, width 25 mm,
A polypropylene resin plate 3 with a thickness of 4 mm is injected with the following injection strip.
It was created by injection molding. Resin used to make the resin plate
Is as follows: Polypropylene resin: PP-BC8 (Japan Polychem stock
Made by the company), crystallinity; Tm 166 ° C, ΔHm; 82mJ
/ Mg, MFR; 1.8 g / 10 minutes (The injection condition of the resin plate is recommended by the resin manufacturer who used it.
It complied with the conditions. ) Injection molding machine: FS-120 manufactured by Nissei Plastic Industry Co., Ltd. Molding temperature: 180-220 ℃ Mold temperature: 40 ℃ Injection speed: 55 mm / sec Injection pressure: 1400kg / cm^Two Holding pressure: 400 kg / cm^Two Injection time: 6 seconds Cooling time: 45 seconds

Polypropylene resin plate 3 obtained above
After the paper 4 is attached to a part of the sheet with double-sided tape and inserted into the mold, the thermoplastic resin composition is injected under the following conditions so that the polypropylene resin plate 3 and the thermoplastic resin composition plate 2 are A test piece that was heat-bonded at the location was created.

[0050] Injection molding machine: FS-120 manufactured by Nissei Plastic Industry Co., Ltd. Molding temperature: 180-220 ℃ Mold temperature: 40 ℃ Injection speed: 55 mm / sec Injection pressure: 1400kg / cm^Two Holding pressure: 0 kg / cm^Two Injection time: 6 seconds Cooling time: 45 seconds

Next, with respect to the obtained test piece, the thermoplastic elastomer composition plate 2 was bent as shown in FIG. 3 and both ends of 2 and 3 were respectively pulled in the directions of the arrows.
The 180 degree peel strength was judged according to the following criteria. ◎: Material destruction Δ: Interface destruction ×: Peeling immediately after starting measurement

The components used in the examples and comparative examples are as follows. (1) Hydrogenated block copolymer component (a-1; SEP
S): Septon 4077 (trademark; manufactured by Kuraray Co., Ltd.),
Styrene content 30% by weight, number average molecular weight 260,00
0, weight average molecular weight 320,000, molecular weight distribution 1.2
3. Hydrogenation rate of 90% or more (2) Hydrogenated product of conjugated diene compound block copolymer (a-2; CEBC): Dynaron 6100P (trademark;
(JR Co., Ltd.) (3) Paraffin oil component (b): PW90 (trademark;
Idemitsu Petrochemical Co., Ltd.), number average molecular weight 980 (4) Petroleum-based hydrocarbon resin component (c): Endex15
5 (trademark; made by Eastman chemical),
Softening point: 151-155 ° C, specific gravity: 1.05, 235 ° C
Melt viscosity of 10 poise (5) peroxide-decomposable olefin resin component (d): PP-BC8 (polypropylene (PP); manufactured by Nippon Polychem Co., Ltd.), crystallinity; Tm 166 ° C., ΔH.
m; 82 mJ / mg, MFR; 1.8 g / 10 minutes

Examples 1 and 2 and Comparative Examples 1 to 8 Using the components in the amounts shown in Tables 1 and 2, the components were introduced into a twin-screw extruder having an L / D of 47, kneading temperature of 180 ° C., screw rotation. The mixture was melt-kneaded at several 350 rpm and pelletized.
Next, the obtained pellets were injection-molded to prepare test pieces, which were subjected to respective tests. The evaluation results are shown in Tables 1 and 2.

[0054]

[Table 1]

[0055]

[Table 2]

As is clear from Tables 1 and 2, Examples 1 and 2 are the thermoplastic elastomer compositions of the present invention. All the thermoplastic elastomer compositions showed good properties. In Example 1, resealability and safety required for medical components (Food Sanitation Law, food and additives, standard standards (Ministry of Health and Welfare Notification No. 370 of 1959) and polystyrene-based synthesis) It is especially excellent for resin instruments or containers and packaging (based on the Ministry of Health and Welfare Notification No. 20 of 1982). Further, in Example 1, PP was added to the component (a-1) SEPS.
The thermoplastic elastomer composition of the present invention obtained by adding 5 parts by weight to 100 parts by weight showed good heat fusion property with the PP molded body.

Instead of the component (a-1), the component (a-
2) Dynaron 6100, which is a block copolymer (CEBC) having a crystalline ethylene block and an amorphous ethylene-butene block obtained by hydrogenating a butadiene block copolymer as a hydrogenated product of a conjugated diene compound
Similarly good results were obtained using P (manufactured by JSR Co., Ltd.). Further, in Example 2, since PP was added, the obtained thermoplastic elastomer composition of the present invention showed good heat fusion property with the PP molded body.

On the other hand, in Comparative Examples 1-2 and 5-6, the compounding amount of the component (b) was out of the range of the present invention. When the amount of the component (b) is small, the hardness of the thermoplastic elastomer composition becomes too high, the flexibility is lost, a product having a rubber-like feel cannot be obtained, and the injection moldability is impaired. Not only becomes remarkable, but also tackiness and injection moldability are deteriorated, and the safety of the medical member is poor. In Comparative Examples 3 to 4 and 7 to 8, the compounding amount of the component (c) is outside the range of the present invention. When the amount of the component (c) is small, the injection moldability of the thermoplastic elastomer composition is deteriorated, and when the amount of the component (c) is large, not only the flexibility is lost and the rubber elasticity is lowered, but also the injection moldability is deteriorated. , The safety of medical parts is inferior.

[0059]

EFFECTS OF THE INVENTION The thermoplastic elastomer composition of the present invention suppresses bleeding out of the softening agent, is excellent in flexibility and compression set, and the molded article from the thermoplastic elastomer composition of the present invention is It does not cause contamination, especially when used as an elastic member of an inkjet recording device, does not deteriorate ink, and when used as a bottle cap packing or the like, it does not deteriorate the contents of the bottle and further When used in a composite molded body such as a seal member, a food seal member, and a multicolor molded seal member with a polyolefin or a hard thermoplastic elastomer, which is represented by an electric component material, etc., an excellent component that does not cause bleeding can be obtained. .

[Brief description of drawings]

FIG. 1 is a front view of a test piece for measuring peel strength.

FIG. 2 is a cross-sectional view of a test piece for measuring peel strength.

FIG. 3 is a diagram illustrating a measuring method for measuring peel strength.

[Explanation of symbols]

1 test piece 2 Plates made of thermoplastic elastomer composition 3 Polypropylene resin plate 4 paper A heat fusion part

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 57/02 C08L 57/02 F term (reference) 4F071 AA01 AA12X AA22X AA75 AE04 AF13 AH16 AH17 4F100 AK01A AK02A AK03A AK07B AK12A AK28A AL02A AL05A AL06A AL09A AN02A BA02 CA30A EH36 EH362 GB15 GB16 GB41 GB66 GB90 JA04A JA06A JB06 JB16A JK13 YY00A 4J002 AC02W AC08W BA01Y BB00Z BB11Z FD02X GB01 GM00 4J026 HA14 HA26 HA27 HA39 HB05 HB26 HB27 HB39 HB50 HE02

Claims (6)

[Claims] 1. A hydrogen-containing block copolymer comprising (a) at least two polymer blocks A mainly containing an aromatic vinyl compound and at least one polymer block B mainly containing a conjugated diene compound. 100 parts by weight of hydrogenated block copolymer (a-1) and / or hydrogenated product of conjugated diene compound block copolymer (a-2) obtained by addition, (b) softening agent for non-aromatic rubber 30 to 150 parts by weight, and (c) 3 to 100 parts by weight of a petroleum hydrocarbon resin having a softening point of 80 to 170 ° C. and a temperature of 120 poise to a melt viscosity of 10 poises of 120 to 250 ° C. And a thermoplastic elastomer composition. 2. The thermoplastic elastomer composition according to claim 1, further comprising (d) 0.1 to 25 parts by weight of a peroxide-decomposable polyolefin resin. 3. A molded article comprising the thermoplastic elastomer composition according to claim 1 or 2. 4. An elastic member for medical use, an elastic member for foodstuffs or an elastic member for an ink jet recording apparatus, comprising the molded body according to claim 3. 5. A heat-fusion composite molding, which is obtained by heat-sealing the molding according to claim 3 and a molding made of polypropylene resin. 6. An elastic member for medical use, an elastic member for foodstuffs or an elastic member for an ink jet recording apparatus, which comprises the heat fusion-bonded composite molded article according to claim 5.