JP2011132292A - Thermoplastic elastomer resin composition for substrate storage container gasket and gasket molded product for substrate storage container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer resin composition for a substrate storage container gasket, which has excellent injection moldability and flexibility and has a small amount of organic substances attached to the surface of a substrate due to a small amount of volatile gas generated and a gasket molded product for substrate storage container. <P>SOLUTION: The thermoplastic elastomer resin composition for a substrate storage container gasket includes 50-98 wt.% of a polyether ester block copolymer (A) having a modulus of elongation of <30 MPa, 2-50 wt.% of one or more thermoplastic elastomer (B) selected from a hydrogenated styrene-based elastomer (b1) and/or an olefin-based elastomer (b2) in which the thermoplastic elastomer (B) is a dispersion phase, and has a modulus of elongation of ≤15 MPa and an amount of volatile gas measured by a static headspace method under heating conditions at 80°C for two hours based on weight of ≤5 ppm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermoplastic elastomer resin composition for a substrate storage container gasket and a gasket molded body for a substrate storage container, which is excellent in injection moldability and flexibility, and has less organic matter adhering to the substrate surface due to a small amount of volatile gas generated. Is.

  Conventionally, in applications represented by substrate storage containers and jigs associated therewith, low-contamination thermoplastic resins that do not contaminate substrates stored in containers have been demanded. Lower ones are being sought. This is because the yield is greatly reduced due to contamination of the substrate as the diameter of the substrate is increased and the circuit formed on the substrate is reduced in diameter. In particular, the gasket used for the substrate storage container is required to be made of a material having flexibility in order to maintain low air-contamination and hermeticity to prevent entry of contaminants from the outside. However, a more flexible material for increasing the airtightness has a problem that a large amount of volatile gas is generated and the substrate is easily contaminated.

  NBR, isoprene rubber, EPDM, SBR, silicone rubber, fluororubber, and thermoplastic polyolefin-based elastomers have been proposed as gasket materials used for substrate storage containers (see, for example, Patent Documents 1, 2, 3, and 4). ). In addition, thermoplastic polyester elastomers that define the surface hardness and the amount of generated volatile gas have been proposed (see, for example, Patent Documents 5 and 6).

  However, the materials disclosed in the above-mentioned documents 1, 2, 3, and 4 have high airtightness because they are flexible, but they generate a large amount of volatile gas, so that the substrate is contaminated by the volatile gas. As a result, it was insufficient as a gasket for storing a substrate.

  In addition, the materials disclosed in the above-mentioned documents 5 and 6 are suitable as a gasket for a substrate storage container because they are flexible and maintain high airtightness and generate little volatile gas. However, since it is a single thermoplastic polyester elastomer resin that does not contain any softening material, there is a problem in that the mounting property of the gasket to the substrate storage container is lowered due to a decrease in moldability and an increase in adhesiveness. It was.

Japanese Patent Laid-Open No. 2003-60021 JP 2004-119427 A JP 2005-353898 A Japanese Patent Laid-Open No. 2003-118776 JP 2006-303261 A

  The present invention is intended to solve the above-described problems in the prior art, and the object of the present invention is to provide excellent injection moldability and flexibility on the surface of the substrate due to low volatile gas generation. It is an object of the present invention to provide a thermoplastic elastomer resin composition for a substrate storage container gasket and a molded article for a substrate storage container with less organic matter adhering thereto.

As a result of intensive studies to achieve the above object, the present inventors have found that a polyether ester block copolymer having a tensile modulus of elasticity of less than 30 MPa measured at 23 ° C. according to the method described in JIS K7113, and hydrogen A thermoplastic elastomer resin composition having an added styrene-based elastomer and / or olefin-based elastomer as a dispersed phase, the tensile elastic modulus measured at 23 ° C. according to the method described in JIS K7113 is 15 MPa or less, and It has been found that the above-mentioned object is effectively achieved by a thermoplastic elastomer resin composition having a volatile gas amount of 5 ppm or less per weight measured at 80 ° C. for 2 hours under the static headspace method, The present invention has been reached.

  That is, in order to achieve the above object, according to the present invention, the high-melting crystalline polymer segment (a1) mainly composed of a crystalline aromatic polyester, and mainly composed of an aliphatic polyether unit and / or an aliphatic polyester unit. A polyether ester block copolymer (A) 50 to 98 having a low melting point polymer segment (a 2) as a main constituent and a tensile modulus measured at 23 ° C. of less than 30 MPa according to the method described in JIS K7113. And 2 to 50% by weight of one or more thermoplastic elastomers (B) selected from hydrogenated styrene elastomers (b1) and / or olefin elastomers (b2). A thermoplastic elastomer resin composition having (B) as a dispersed phase, wherein JIS The tensile modulus measured at 23 ° C. according to the method described in No. 7113 is 15 MPa or less, and the amount of volatile gas measured at 80 ° C. for 2 hours under the static headspace method is 5 ppm or less per weight. There is provided a thermoplastic elastomer resin composition for a substrate storage container gasket.

In the thermoplastic elastomer resin composition for a substrate storage container gasket of the present invention,
The high melting crystalline polymer segment (a1) of the polyetherester block copolymer (A) is composed of a polybutylene terephthalate unit, or a polybutylene terephthalate unit and a polybutylene isophthalate unit,
The low melting point polymer segment (a2) of the polyether ester block copolymer (A) comprises poly (tetramethylene oxide) glycol, poly (propylene oxide) glycol ethylene oxide adduct, and ethylene oxide / tetrahydrofuran copolymer glycol. Composed of at least one selected from
The hydrogenated styrene elastomer (b1) is a hydrogenated styrene-butadiene block copolymer, a hydrogenated styrene-isoprene block copolymer, a hydrogenated styrene-isoprene / butadiene block copolymer, or a hydrogenated styrene butadiene rubber. Composed of at least one selected from
The olefin elastomer (b2) is composed of an ethylene / α-olefin copolymer obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms,
However, both are preferable conditions, and by applying these conditions, it can be expected to obtain a more excellent effect.

  In addition, a molded article for a substrate storage container gasket according to the present invention is formed by injection molding the thermoplastic elastomer resin composition.

  The thermoplastic elastomer resin composition for a substrate storage container gasket of the present invention is excellent in injection moldability, flexibility, and the amount of volatile gas that contaminates the substrate is suppressed to a low level. The body exhibits the excellent property that the contamination of the substrate is very low.

It is the top view (I) and side view (B) which show the outline of an adhesive test.

  Hereinafter, the present invention will be described in detail.

  The high-melting crystalline polymer segment (a1) of the polyetherester block copolymer (A) having a tensile modulus of less than 30 MPa measured at 23 ° C. according to the method described in JIS K7113 used in the present invention is mainly A polyester formed from an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2, 6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, anthracene dicarboxylic acid, diphenyl-4,4′-dicarboxylic acid, diphenoxyethanedicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 5-sulfoisophthalic acid, and Sodium 3-sulfoisophthalate, etc. And the like. Although aromatic dicarboxylic acid is mainly used, if necessary, a part of the aromatic dicarboxylic acid may be converted to alicyclic dicarboxylic acid such as 1,4-cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, 4,4′-dicyclohexyldicarboxylic acid. Or an aliphatic dicarboxylic acid such as adipic acid, succinic acid, oxalic acid, sebacic acid, dodecanedioic acid, and dimer acid. Of course, ester-forming derivatives of dicarboxylic acids such as lower alkyl esters, aryl esters, carbonates, and acid halides can be used equally. Examples of the diol include diols having a molecular weight of 400 or less, such as 1,4-butanediol, aliphatic diols such as ethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, decamethylene glycol, 1,1- Cycloaliphatic diols such as cyclohexanedimethanol, 1,4-dicyclohexanedimethanol, tricyclodecane dimethanol, xylylene glycol, bis (p-hydroxy) diphenyl, bis (p-hydroxyphenyl) propane, 2,2- Bis [4- (2-hydroxyethoxy) phenyl] propane, bis [4- (2-hydroxy) phenyl] sulfone, 1,1-bis [4- (2-hydroxyethoxy) phenyl] cyclohexane, 4,4′- Dihydroxy - terphenyl, an aromatic diol such as 4,4'-dihydroxy -p- Quarter phenyl preferably, such diols also ester-forming derivatives, for example acetyl form, it may be used in the form such as an alkali metal salt.

  Two or more of these dicarboxylic acids and their derivatives or diol components may be used in combination. An example of the most preferable high melting crystalline polymer segment (a1) is polybutylene terephthalate derived from terephthalic acid and / or dimethyl terephthalate and 1,4-butanediol.

  The low-melting-point polymer segment (a2) of the polyether ester block copolymer (A) used in the present invention is an aliphatic polyether and / or an aliphatic polyester. As the aliphatic polyether, poly (ethylene oxide) is used. Glycol, poly (propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, copolymer of ethylene oxide and propylene oxide, ethylene oxide adduct of poly (propylene oxide) glycol, copolymer of ethylene oxide and tetrahydrofuran A polymer etc. are mentioned. Examples of the aliphatic polyester include poly (ε-caprolactone), polyenantlactone, polycaprylolactone, and polybutylene adipate. Poly (tetramethylene oxide) glycol, poly (propylene oxide) glycol ethylene oxide adduct, poly (ε-caprolactone) from the elastic properties of polyester block copolymers obtained from these aliphatic polyethers and / or aliphatic polyesters ), Polybutylene adipate and the like are preferable, and among these, an ethylene oxide adduct of poly (propylene oxide) glycol is particularly preferable.

  The tensile modulus measured at 23 ° C. according to the method described in JIS K7113 of the polyether ester block copolymer (A) used in the present invention is 30 MPa or less, preferably 25 MPa or less. If the tensile modulus is 30 MPa or more, the desired flexibility cannot be obtained, and the airtightness is lowered, which is not preferable.

  The copolymerization amount of the low-melting-point polymer segment (a2) of the polyether ester block copolymer (A) having a tensile modulus of less than 30 MPa measured at 23 ° C. according to the method described in JIS K7113 used in the present invention is Usually, it is 50 to 90% by weight, preferably 55 to 85% by weight. In particular, if it is 50% by weight or less, the flexibility is insufficient, and if it is 90% by weight or more, the crystallinity is low and the moldability is poor.

  Two or more kinds of polyetherester block copolymers having different compositions may be used in combination.

  The polyether ester block copolymer (A) used in the present invention can be produced by a known method. For example, a method in which a lower alcohol diester of dicarboxylic acid, an excessive amount of low molecular weight glycol, and a low melting point polymer segment component are transesterified in the presence of a catalyst and the resulting reaction product is polycondensed, or an excess amount of dicarboxylic acid This method involves esterifying the glycol and low melting polymer segment components in the presence of a catalyst and then polycondensing the resulting reaction product, or preparing a high melting crystalline segment in advance and adding the low melting segment component to this. And a method of randomizing by transesterification, a method of connecting a high melting crystalline segment and a low melting polymer segment with a chain linking agent, and a poly (ε-caprolactone) for the low melting polymer segment. Do not add ε-caprolactone monomer to the crystalline segment. Any method may be taken.

  The hydrogenated styrene elastomer (b1) used in the present invention includes a styrene block copolymer formed from a block composed of an aromatic vinyl monomer and a block composed of a conjugated diene, and an aromatic vinyl series. It is obtained by hydrogenating a styrene butadiene rubber composed of a monomer and a conjugated diene.

  Specific examples of the aromatic vinyl monomer include styrene, α-methylstyrene, vinyltoluene, p-methylstyrene, pt-butylstyrene, o-ethylstyrene, and o, p-dichlorostyrene. Is mentioned.

  Specific examples of the conjugated diene include butadiene, isoprene, butadiene / isoprene copolymer, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1 , 3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, chloroprene, and the like.

  Among these, at least one selected from a hydrogenated styrene-butadiene block copolymer, a hydrogenated styrene-isoprene block copolymer, a hydrogenated styrene-isoprene / butadiene block copolymer, and a hydrogenated styrene butadiene rubber. Species are preferred.

  The hydrogenated styrene elastomer (b1) used in the present invention may be modified. The modification is performed with a carboxyl group-containing unsaturated compound, an acid anhydride-containing unsaturated compound, or an epoxy group-containing monomer. Specific examples of the carboxyl group-containing unsaturated compound include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid, and maleic acid. Specific examples of the acid anhydride-containing unsaturated compound include maleic anhydride, itaconic anhydride, chloromaleic anhydride, citraconic anhydride, butenyl succinic anhydride, and tetrahydrophthalic anhydride. Specific examples of the epoxy group-containing monomer include glycidyl methacrylate, glycidyl acrylate, vinyl glycidyl ether, and glycidyl ether of hydroxyalkyl (meth) acrylate. Among modified hydrogenated styrene block copolymers, modified hydrogenated styrene-butadiene block copolymers, modified hydrogenated styrene-isoprene block copolymers, modified hydrogenated styrene-isoprene / butadiene. Copolymers and hydrogenated styrene butadiene rubber are preferred.

  The olefin elastomer (b2) used in the present invention is an ethylene / α-olefin copolymer obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms, and ethylene and α, β-unsaturated. At least one selected from ethylene / unsaturated carboxylic acid copolymers obtained by copolymerizing alkyl esters of carboxylic acids is preferred.

  The olefin elastomer (b2) used in the present invention is preferably an ethylene / α-olefin copolymer obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms.

  The ethylene / α-olefin copolymer is a copolymer comprising ethylene and at least one α-olefin having 3 to 20 carbon atoms as a constituent component, and is an α-olefin having 3 to 20 carbon atoms. Specific examples include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene. 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicocene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4 -Methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl- - hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene and combinations thereof. Among these α-olefins, copolymers using α-olefins having 6 to 12 carbon atoms are preferred.

  Further, the olefin elastomer (b2) used in the present invention may be modified. Modification is effected with an unsaturated carboxylic acid or derivative thereof. Specific examples of unsaturated carboxylic acids or derivatives thereof include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methyl fumaric acid, citraconic acid, glutaconic acid and metal salts of these carboxylic acids. , Methyl hydrogen maleate, methyl hydrogen itaconate, methyl acrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, hydroxyethyl methacrylate, diethyl maleate, dimethyl itaconate, maleic anhydride, anhydrous Itaconic acid, citraconic anhydride, maleimide, N-ethylmaleimide, N-butylmaleimide, N-phenylmaleimide, glycidyl acrylate, glycidyl methacrylate, glycidyl itaconate, glycidyl citraconic acid, etc.Among the modified olefin-based elastomers, an α-olefin copolymer having 6 to 12 carbon atoms modified with an unsaturated carboxylic acid and an acid anhydride thereof is preferable.

  In the present invention, the hydrogenated styrene elastomer and / or olefin elastomer (B) is 2 to 50% by weight, preferably 5 to 45%, based on 50 to 98% by weight of the polyetherester block copolymer (A). What is blended as a dispersed phase by weight%, more preferably 10 to 40% by weight is the main constituent. If the blended amount of the hydrogenated styrene-based elastomer and / or olefin-based elastomer (B) is less than the above range, the flexibility is insufficient and the airtightness is lowered, so that it is not suitable as a gasket for a substrate storage container. On the other hand, if the above range is exceeded, the moldability is inferior, a large amount of volatile gas is generated, and the adhesiveness of the gasket molded body itself increases. .

  The thermoplastic elastomer resin composition of the present invention has a tensile elastic modulus of 15 MPa or less, more preferably 13 MPa or less, measured at 23 ° C. according to the method described in JIS K7113. A tensile modulus of 15 MPa or more is not preferable because airtightness is lowered.

  The thermoplastic elastomer composition of the present invention preferably has a volatile gas amount of 5 ppm or less per weight measured by a static headspace method at 80 ° C. for 2 hours. When the amount of volatile gas measured by the static headspace method at 80 ° C. for 2 hours under heating is 5 ppm or more per weight, an undesired tendency of increasing the amount of organic components adhering to the substrate is caused.

  The method for producing the thermoplastic elastomer resin composition for gaskets used in the substrate storage container of the present invention is not particularly limited, but includes a polyetherester block copolymer, a hydrogenated styrene elastomer and / or an olefin. A method in which a raw material mixed with an elastomer is supplied to a screw extruder and melt-kneaded, and a polyetherester block copolymer is first supplied to the screw extruder, and then hydrogenated from another supply port. A method of supplying and kneading the system elastomer and / or olefin elastomer can be appropriately employed.

  The substrate storage container gasket of the present invention is manufactured by injection-molding the above thermoplastic elastomer resin composition according to a conventional method. In this case, in particular, when melt-kneading, the vent of the cylinder portion of the extruder is used. Preferred conditions include vacuum degassing from the mouth and degassing of the resin composition at a temperature of 80 ° C. to 140 ° C. at which substantially solid phase polymerization does not occur.

  When the thermoplastic elastomer resin composition for a gasket for a substrate storage container according to the present invention is injection-molded, a gasket molded body that is flexible and generates less volatile gas is provided.

  The effects of the present invention will be described below with reference to examples. In the examples,% and parts are based on weight unless otherwise specified. The physical properties shown in the examples were measured as follows.

[Melt viscosity index (MFR)]
Measurement was performed at a temperature of 220 ° C. and a load of 2160 g in accordance with ASTM D-1238.

[Mechanical properties]
According to JIS K7113, the tensile breaking strength and tensile breaking elongation at 23 ° C. were measured.

[Tensile modulus]
The measurement was performed at 23 ° C. according to JIS K7113.

[Adhesion index]
A strip test piece having a width of 25 mm and a length of 125 mm was punched out from a plate having a length of 125 mm, a width of 75 mm, and a thickness of 2 mm, which had been injection-molded under conditions of a cylinder temperature of 200 ° C. and a mold temperature of 30 ° C. Next, as shown in FIG. 1, two strip test pieces (1) and (1 ′) are overlapped by 50 mm, pressed with a 2 kg weight for 1 minute, and then subjected to an adhesive shear load under the conditions of a 23 ° C. tensile speed of 50 mm / min. It was measured.

[Volume of volatile gas]
(1) Pretreatment A 4L glass container in which a background of a 125 mm long, 75 mm wide, 2 mm thick plate in which a thermoplastic elastomer resin composition was injection molded under conditions of a cylinder temperature of 220 ° C. and a mold temperature of 30 ° C. And sealed at 80 ° C. for 2 hours. Thereafter, a collecting agent (Tenax-GR: 100 mg) was immediately connected, and air was vented by a pump in order to sample the air in the container. Sampling was performed in a clean room, and the amount of sampled gas was 8 L, which is twice the volume of the glass container.

(2) Measurement The scavenger (Tenax-GR) was thermally desorbed under the following conditions and subjected to GC / MS analysis.
・ Thermal desorption device: TDSA + CIS4 (Gerstel)
Desorption temperature x time: 280 ° C x 15 minutes Trap temperature: -150 ° C
GC / MS: GC6890 + MSD5973 (Agilent)
Column: SPB-1 Sulfur (30 m × 0.32 mm ID film thickness 4.0 μm)
-Oven temperature: 40 ° C to 300 ° C (10 ° C / min)
Scan range: m / z 29-600.

(3) Quantification A calibration curve was prepared using normal hexadecane as a standard substance, and quantification was performed.

[Reference example]
[Production of Polyether Ester Block Copolymer (A-1)]
320 parts of dimethyl terephthalate, 93 parts of dimethyl isophthalate, 345 parts of 1,4-butanediol, and 550 parts of poly (propylene oxide) glycol capped with ethylene oxide (number average molecular weight 2200, EO content 26.8%) Charge a reaction vessel equipped with a helical ribbon type stirring blade together with 2 parts of titanium tetrabutoxide and 3 parts of trimellitic anhydride and heat at 210 ° C. for 2 hours and 30 minutes to bring out 95% of the theoretical amount of methanol out of the system. Distilled. After adding 0.75 part of “Irganox” 1010 to the reaction mixture, the temperature was raised to 245 ° C., and then the pressure in the system was reduced to 27 Pa over 50 minutes, and polymerization was carried out for 1 hour and 50 minutes under these conditions. I did it. The obtained polymer was discharged into water in the form of strands and pelletized by cutting.

  The tensile modulus of the polyetherester block copolymer (A-1) thus obtained was 21 MPa.

[Polyether ester block copolymer (A-2)]
Helical ribbon type stirring of 273 parts of dimethyl terephthalate, 120 parts of 1,4-butanediol and 723 parts of poly (tetramethylene oxide) glycol having a number average molecular weight of about 2000 together with 3 parts of titanium tetrabutoxide and 3 parts of trimellitic anhydride The reaction vessel equipped with a blade was charged and heated at 210 ° C. for 2 hours and 30 minutes, and 95% of the theoretical methanol amount was distilled out of the system. After adding 0.5 parts of “Irganox” 1330 (Hindered Phenolic Antioxidant manufactured by Ciba Geigy) to the reaction mixture, the temperature was raised to 245 ° C., and then the pressure in the system was increased to 27 Pa over 50 minutes. The polymerization was carried out for 1 hour and 50 minutes under the reduced pressure. The obtained polymer was discharged into water in the form of strands and pelletized by cutting.

  The tensile modulus of the polyetherester block copolymer (A-2) thus obtained was 18 MPa.

[Polyether ester block copolymer (A-3)]
348 parts of terephthalic acid, 340 parts of 1,4-butanediol and 645 parts of poly (tetramethylene oxide) glycol having a number average molecular weight of about 1400 are placed in a reaction vessel equipped with a helical ribbon stirring blade together with 0.2 part of titanium tetrabutoxide. The esterification reaction was carried out while charging the reaction water at 190 to 225 ° C. for 3 hours and distilling the reaction water out of the system. After adding 0.5 parts of “Irganox” 1098 (Hindered Phenolic Antioxidant manufactured by Ciba Geigy) to the reaction mixture, the temperature was raised to 245 ° C., and then the pressure in the system was changed to 27 Pa over 50 minutes. The pressure was reduced and polymerization was carried out for 2 hours and 45 minutes under the conditions. The obtained polymer was discharged into water as a strand and cut into pellets.

  The tensile modulus of the polyether ester block copolymer (A-3) thus obtained was 42 MPa.

[Examples 1 to 8]
As a styrene-based elastomer and / or an olefin-based elastomer hydrogenated to the polyetherester block copolymer (A-1) or (A-2) obtained in the Reference Example, “Tuftec” H1221 (manufactured by Asahi Kasei Corporation) Hydrogenated SEBS) (B-1),
“Tough Tech” H1052 (hydrogenated SEBS) (B-2), manufactured by Asahi Kasei Corporation
“Tuftec” M1943 (modified hydrogenated SEBS) (B-3), manufactured by Asahi Kasei Corporation
“Tuffmer” A4050S (ethylene / 1-butene copolymer) (B-4) manufactured by Mitsui Chemicals,
“Tuffmer” MH7020 (modified ethylene / 1-butene copolymer) (B-5) manufactured by Mitsui Chemicals,
Were dry blended at the blending ratios shown in Table 1 and using a twin screw extruder having a cylinder diameter of 26 mmφ, while vacuum deaeration treatment was performed from the central part of the cylinder and the two vent ports close to the discharge port. The mixture was melt-kneaded at 200 ° C. and pelletized. The obtained pellets were charged into a shelf-type hot air dryer and dried at 100 ° C. for 10 hours to obtain a thermoplastic elastomer composition for a substrate storage container gasket. Next, using an injection molding machine, molding was performed under conditions of a cylinder temperature of 220 ° C. and a mold temperature of 30 ° C. The evaluation results are shown in Table 2.

[Comparative Examples 1-6]
Each component was dry blended at the blending ratio shown in Table 1 and pelletized in the same manner as in Examples 1-8. The results evaluated in the same manner as in Examples 1 to 8 are shown in Table 2.

  The thermoplastic elastomer resin composition of the present invention is extremely useful as a gasket material for a substrate storage container because it is excellent in injection moldability, has high airtightness, and can keep the amount of volatile gas low.

1,1 '... strip specimen

Claims (6)

  Main components are a high-melting-point crystalline polymer segment (a1) mainly composed of a crystalline aromatic polyester and a low-melting-point polymer segment (a2) mainly composed of an aliphatic polyether unit and / or an aliphatic polyester unit. A polyether ester block copolymer (A) having a tensile modulus measured at 23 ° C. of less than 30 MPa according to the method described in JIS K7113, and a hydrogenated styrenic elastomer (b1) and A thermoplastic elastomer resin composition comprising 2 to 50% by weight of one or more thermoplastic elastomers (B) selected from olefin-based elastomers (b2) and having the thermoplastic elastomer (B) as a dispersed phase. And measured at 23 ° C. according to the method described in JIS K7113. Heat for a substrate storage container gasket having a tensile elastic modulus of 15 MPa or less and a volatile gas amount measured by a static headspace method at 80 ° C. for 2 hours under a heating condition of 5 ppm or less per weight A plastic elastomer resin composition.   The high-melting crystalline polymer segment (a1) of the polyetherester block copolymer (A) comprises a polybutylene terephthalate unit, or a polybutylene terephthalate unit and a polybutylene isophthalate unit. 2. The thermoplastic elastomer resin composition for a substrate storage container gasket according to 1.   The low melting point polymer segment (a2) of the polyether ester block copolymer (A) comprises poly (tetramethylene oxide) glycol, poly (propylene oxide) glycol ethylene oxide adduct, and ethylene oxide / tetrahydrofuran copolymer glycol. The thermoplastic elastomer resin composition for a substrate storage container gasket according to claim 1 or 2, comprising at least one selected from the group consisting of:   The hydrogenated styrene elastomer (b1) is a hydrogenated styrene-butadiene block copolymer, a hydrogenated styrene-isoprene block copolymer, a hydrogenated styrene-isoprene / butadiene block copolymer, and a hydrogenated styrene butadiene. The thermoplastic elastomer resin composition for a substrate storage container gasket according to any one of claims 1 to 3, wherein the thermoplastic elastomer resin composition is one or more selected from rubber.   The olefin elastomer (b2) is an ethylene / α-olefin copolymer obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms. The thermoplastic elastomer resin composition for a substrate storage container gasket according to any one of the above.   A gasket molded body for a substrate storage container, which is formed by injection molding the thermoplastic elastomer resin composition according to any one of claims 1 to 5.

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