JP4354800B2 - Thermoplastic elastomer composition and molded article - Google Patents

Description

The present invention relates to a thermoplastic elastomer composition and a molded article excellent in gas barrier properties and compression set characteristics.

Conventionally, as a polymer material having elasticity, a material obtained by blending a rubber such as natural rubber or synthetic rubber with a crosslinking agent or a reinforcing agent and crosslinking under high temperature and high pressure has been widely used. However, such rubbers require a process of crosslinking and molding for a long time under high temperature and pressure, and are inferior in processability. Moreover, since the crosslinked rubber does not exhibit thermoplasticity, it is generally impossible to perform recycle molding like a thermoplastic resin. For this reason, various thermoplastic elastomers have been developed in recent years that can be easily produced using general-purpose melt molding techniques such as hot press molding, injection molding, and extrusion molding in the same way as ordinary thermoplastic resins. ing. As such thermoplastic elastomers, various types of polymers such as olefins, urethanes, esters, styrenes, and vinyl chlorides have been developed and are commercially available.

Of these, the styrene thermoplastic elastomer is rich in flexibility and excellent in rubber elasticity at room temperature. Styrenic thermoplastic elastomers include styrene-butadiene-styrene block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), and styrene-ethylenebutylene-styrene block copolymers obtained by hydrogenating them. (SEBS) and styrene-ethylenepropylene-styrene block copolymer (SEPS) have been developed. However, these block copolymers have insufficient compression set characteristics.

On the other hand, a polymer mainly composed of isobutylene as a thermoplastic elastomer that is flexible, has excellent rubber elasticity at room temperature, and has excellent vibration damping properties, gas barrier properties, and sealing properties that are characteristic of isobutylene polymers. An isobutylene block copolymer containing a block and a polymer block mainly composed of an aromatic vinyl compound is disclosed (see Patent Document 1). However, this isobutylene block copolymer also has a problem that its compression set characteristics are insufficient, like the styrene thermoplastic elastomer described above.

As a technique for improving compression set characteristics of this isobutylene block copolymer, a thermoplastic polymer composition comprising an isobutylene block copolymer containing a polymer block mainly composed of isobutylene and a crosslinked rubber (patent) Reference 2), a composition (see Patent Document 3) comprising an isobutylene block copolymer, a crystalline polyolefin and a plasticizer (softener) is disclosed. Although these compositions retain the characteristics of isobutylene polymers and have improved compression set characteristics, there is a need for thermoplastic elastomer compositions having better compression set characteristics.
Republished patent WO 93/14135 Republished patent WO98 / 14518 Japanese Patent Laid-Open No. 11-293083

In view of the above-mentioned problems of the prior art, the object of the present invention is excellent in vibration damping and gas barrier properties, which are characteristics of an isobutylene-based polymer, and has molding processability and rubber-like properties, and also has compression set properties. It is an object of the present invention to provide an improved thermoplastic elastomer composition.

As a result of intensive studies, the present inventors have completed the present invention. That is, the present invention provides (A) a hydrosilyl group-containing compound in the presence of at least one selected from the group consisting of an aromatic vinyl-based thermoplastic elastomer and an olefin-based resin as the isobutylene-based polymer having an alkenyl group at the terminal. It is related with the thermoplastic elastomer composition characterized by consisting of the composition bridge | crosslinked under melt-kneading by (B) and an ethylene-vinyl alcohol-type copolymer.
The present invention is described in detail below.

The isobutylene polymer having an alkenyl group at the terminal used for the component (A) of the present invention preferably contains 50% by weight or more of isobutylene units, more preferably 70% by weight or more, and still more preferably 90% by weight or more. Occupied polymer. The monomer other than isobutylene in the isobutylene polymer is not particularly limited as long as it is a monomer component that can be cationically polymerized, but aromatic vinyls, aliphatic olefins, isoprene, butadiene, divinylbenzene, etc. Examples thereof include monomers such as dienes, vinyl ethers, and β-pinene. These may be used alone or in combination of two or more.

The number average molecular weight of the isobutylene polymer is not particularly limited, but is preferably 1,000 to 500,000, more preferably a lower limit of 5,000, and a more preferable upper limit of 200,000. When the number average molecular weight is less than 1,000, the mechanical properties are not sufficiently exhibited, and when it exceeds 500,000, the moldability is greatly lowered. The number average molecular weight of the isobutylene polymer was measured by a gel permeation chromatography (GPC) method. More specifically, using a Waters 510 type GPC system, chloroform was used as the mobile phase, and the polymer concentration was 2 mg / ml and the column temperature was 35 ° C. The number average molecular weight was calculated using polystyrene as a standard sample.

The alkenyl group of the isobutylene polymer having an alkenyl group at the terminal is not particularly limited as long as it is a group containing an active carbon-carbon double bond with respect to a crosslinking reaction by a hydrosilyl group-containing compound. Specific examples include aliphatic unsaturated hydrocarbon groups such as vinyl group, allyl group, methylvinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group; cyclopropenyl group, cyclobutenyl group, cyclopentenyl group, cyclohexenyl group. And cyclic unsaturated hydrocarbon groups such as Preferably, it is an allyl group.

As a method for introducing an alkenyl group into the terminal of an isobutylene polymer, the polymer having a functional group such as a hydroxyl group is unsaturated as disclosed in JP-A-3-152164 and JP-A-7-304909. The method of reacting the compound which has group and introduce | transducing an unsaturated group into a polymer is mentioned. In order to introduce an unsaturated group into a polymer having a halogen atom, a method of performing a Friedel-Crafts reaction with alkenylphenyl ether, a method of performing a substitution reaction with allyltrimethylsilane in the presence of a Lewis acid, various phenols, etc. And a method of performing the above-mentioned alkenyl group introduction reaction after introducing a hydroxyl group by performing a Friedel-Crafts reaction. Further, as disclosed in U.S. Pat. No. 4,316,973, JP-A 63-105005, and JP-A 4-288309, an unsaturated group can be introduced during the polymerization of the monomer. Among these, those in which an allyl group is introduced at the terminal by a substitution reaction of allyltrimethylsilane and chlorine are preferable from the viewpoint of reactivity.

The amount of the alkenyl group at the end of the isobutylene polymer can be arbitrarily selected depending on the required properties, but is preferably at least 0.2 per molecule from the viewpoint of compression set properties after crosslinking. More preferably, the number is at least 0.5. If the number is less than 0.2, the effect of improving the compression set by crosslinking may not be sufficiently obtained.

The structure of the aromatic vinyl-based thermoplastic elastomer used in the component (A) of the present invention is not particularly limited, whether it is a random copolymer or a block copolymer, but is a heavy polymer mainly composed of an aromatic vinyl compound. A block copolymer composed of a combined block (a) and a polymer block (b) mainly composed of isobutylene is preferable. The aromatic vinyl-based thermoplastic elastomer includes a block copolymer composed of a polymer block (a) mainly composed of an aromatic vinyl-based compound and a polymer block (c) mainly composed of a conjugated diene compound, and hydrogen. A block copolymer (hydrogenated diene polymer) obtained by addition is preferable. From the viewpoint of high gas barrier properties and tensile strength, polymer block (a) mainly composed of aromatic vinyl compound-polymer block mainly composed of isobutylene (b) -mainly composed of aromatic vinyl compound. A triblock copolymer comprising the polymer block (a) is particularly preferred.

The polymer block (a) mainly composed of an aromatic vinyl compound is a block in which the aromatic vinyl compound unit occupies 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more. Say. Examples of aromatic vinyl compounds include styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, t-butylstyrene, monochlorostyrene, dichlorostyrene, methoxystyrene, indene, divinylbenzene, N, N-dimethyl- Examples include p-aminoethyl styrene, N, N-diethyl-p-aminoethyl styrene, and vinylpyridine. Among the above compounds, styrene, α-methylstyrene, p-methylstyrene, and indene are preferable from the balance of cost, physical properties, and productivity, and two or more of them may be selected.

The polymer block (b) mainly composed of isobutylene refers to a block in which isobutylene units occupy 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more. The monomer other than isobutylene in the polymer block mainly composed of isobutylene is not particularly limited as long as it is a monomer component capable of cationic polymerization, but aromatic vinyls, aliphatic olefins, isoprene, butadiene, divinyl. Examples include dienes such as benzene, vinyl ethers, and monomers such as β-pinene. These may be used alone or in combination of two or more.

The polymer block (c) mainly composed of the conjugated diene compound means a block in which the conjugated diene compound unit occupies 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more. Conjugated diene compounds include 1,3-butadiene, isoprene, 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. In order to obtain a hydrogenated diene polymer that can be used industrially and has excellent physical properties, 1,3-butadiene, isoprene, and 1,3-pentadiene are preferable, and 1,3-butadiene and isoprene are particularly preferable.

The ratio of the aromatic vinyl compound in the aromatic vinyl-based thermoplastic elastomer is not particularly limited, but from the balance between physical properties and processability, the aromatic vinyl compound is preferably 5 to 80% by weight, Particularly preferred is 40% by weight.

The number average molecular weight of the aromatic vinyl-based thermoplastic elastomer is not particularly limited, but is preferably 15,000 to 500,000, particularly preferably 40,000 to 200,000. When the number average molecular weight is less than 15,000, mechanical properties such as tensile properties tend to be insufficient, and when it exceeds 500,000, the moldability tends to decrease significantly. The number average molecular weight of the aromatic vinyl-based thermoplastic elastomer was measured by the GPC method. More specifically, using a Waters 510 type GPC system, chloroform was used as the mobile phase, and the polymer concentration was 2 mg / ml and the column temperature was 35 ° C. The number average molecular weight was calculated using polystyrene as a standard sample.

The olefin resin used in the component (A) of the present invention is a homopolymer or copolymer having as a main component a monomer unit selected from ethylene and an α-olefin having 3 to 20 carbon atoms. The homopolymer or copolymer mainly composed of a monomer unit selected from ethylene and an α-olefin having 3 to 20 carbon atoms is 50% by weight of the ethylene unit and the α-olefin unit having 3 to 20 carbon atoms. These are homopolymers and copolymers that account for 70% by weight or more, more preferably 90% by weight or more. Examples of such include polyethylene (high density polyethylene, low density polyethylene, linear low density polyethylene, etc.), polypropylene (isotactic-homopolypropylene, random polypropylene, block polypropylene, syndiotactic-homopolypropylene, etc.), Examples thereof include poly-1-butene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, and ethylene-1-octene copolymer. From the viewpoint of heat resistance, preferred are polypropylene and polyethylene having crystallinity. Furthermore, from the viewpoint of mechanical characteristics, random polypropylene is most preferable, and from the viewpoint of compression set characteristics, high-density polyethylene is most preferably exemplified.

In the present invention, the blending amount of at least one selected from the group consisting of the aromatic vinyl-based thermoplastic elastomer and the olefin-based resin in the component (A) is 100 parts by weight of the isobutylene-based polymer having an alkenyl group at the terminal. On the other hand, it is preferably 0.5 to 900 parts by weight, more preferably 5 to 100 parts by weight. If the blending amount exceeds 900 parts by weight, compression set characteristics tend to deteriorate. In the case of 100 parts by weight or less, the concentration of the alkenyl group is sufficiently high, so that the reaction rate of the crosslinking reaction is fast and preferable. On the other hand, if the amount is less than 0.5 parts by weight, the moldability tends to be significantly reduced.

In the present invention, the isobutylene polymer having an alkenyl group at the terminal is a hydrosilyl group (Si-H group) in the presence of at least one selected from the group consisting of an aromatic vinyl thermoplastic elastomer and an olefin resin. A composition formed by cross-linking under melt kneading is formed with the contained compound. Such a technique is generally called dynamic cross-linking, and unlike ordinary chemical cross-linking (static cross-linking), the cross-linking reaction proceeds under melt kneading, so that the generated polymer network is divided by shearing force, and cross-linking is performed. It is characteristic that it exhibits thermoplasticity later. Originally, the isobutylene-based polymer has no crosslinkable functional group, and the radical reaction generally used as a crosslinking reaction tends to cause a decomposition reaction. In the present invention, by introducing an alkenyl group at the end of the isobutylene polymer, a hydrosilylation reaction is possible, and a crosslinking reaction using a hydrosilyl group-containing compound as a crosslinking agent is possible. This hydrosilylation reaction has advantages such as no generation of by-products and no unnecessary side reactions.

In the present invention, the hydrosilyl group-containing compound used for obtaining a crosslinked product of an isobutylene polymer having an alkenyl group at the terminal is not particularly limited, and various compounds can be used. That is, a linear polysiloxane represented by the general formula (I) or (II);
^{_{R 1 3 SiO- [Si (R}} 1) 2 O] a - [Si (H) (R 2) O] b - [Si (R 2) (R 3) O] c -SiR 1 3 (I)
^{_{HR 1 2 SiO- [Si (R}} 1) 2 O] a - [Si (H) (R 2) O] b - [Si (R 2) (R 3) O] c -SiR 1 2 H (II)
Wherein R ¹ and R ² are the same or different and each represents an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R ³ is an alkyl group having 1 to 10 carbon atoms or an aralkyl having 7 to 12 carbon atoms. A represents 0 ≦ a ≦ 100, b represents an integer satisfying 2 ≦ b ≦ 100, and c represents an integer satisfying 0 ≦ c ≦ 100, and R ¹ , R ² and R ³ in the case where there are a plurality are the same. Or may be different.)
A cyclic siloxane represented by the general formula (III);

(In the formula, R ⁴ and R ⁵ are the same or different and each represents an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R ⁶ represents an alkyl group having 1 to 10 carbon atoms or an aralkyl having 7 to 12 carbon atoms. .d is 0 ≦ d ≦ 8, e indicating the group 2 ≦ e ≦ 10, f represents an integer of 0 ≦ f ≦ 8, and satisfy 3 ≦ d + e + f ≦ 10. R 4 when there are a plurality, R ⁵ and R ⁶ may be the same as or different from each other.

Further, among the above hydrosilyl group-containing compounds, those represented by the following general formula (IV) are particularly preferable from the viewpoint of good compatibility.

(In the formula, g and h are integers, and 2 ≦ g + h ≦ 50, 2 ≦ g, and 0 ≦ h. R ⁷ represents a hydrogen atom or a methyl group, and R ⁸ has 2 to 20 carbon atoms. The hydrocarbon group may have one or more aromatic rings, i is an integer of 0 ≦ i ≦ 5, and when there are a plurality of R ^{8 s} , they may be the same or different. May be.)

The isobutylene polymer having an alkenyl group at the terminal and the hydrosilyl group-containing compound can be mixed at an arbitrary ratio, but the molar ratio of the alkenyl group to the hydrosilyl group (alkenyl group / hydrosilyl group) is 0 from the viewpoint of reactivity. It is preferably in the range of 2 to 5, and more preferably 0.4 to 2.5. When the molar ratio exceeds 5, the crosslinking is insufficient and sticky, and the compression set tends to deteriorate. When the molar ratio is less than 0.2, a large amount of active hydrosilyl groups remain after crosslinking. Hydrogen gas is generated by hydrolysis, and a molded product obtained using the thermoplastic elastomer composition of the present invention tends to cause cracks and voids.

The cross-linking reaction between the isobutylene polymer and the hydrosilyl group-containing compound proceeds by mixing and heating the two components, but a hydrosilylation catalyst can be added to advance the reaction more rapidly. Such a hydrosilylation catalyst is not particularly limited, and examples thereof include radical initiators such as organic peroxides and azo compounds, transition metal catalysts, and the like.

The radical initiator is not particularly limited, and examples of the organic peroxide include di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, and 2,5-dimethyl. Dialkyl peroxides such as -2,5-di (t-butylperoxy) -3-hexyne, dicumyl peroxide, t-butylcumyl peroxide, α, α'-bis (t-butylperoxy) isopropylbenzene; benzoyl peroxide; Acyl peroxides such as p-chlorobenzoyl peroxide, m-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide; peroxyesters such as perbenzoic acid-t-butyl; diisopropyl percarbonate, di-percarbonate Peroxydicarbonates such as 2-ethylhexyl; 1 , 1-di (t-butylperoxy) cyclohexane, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, and the like. Examples of the azo compound include 2,2 '-Azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 1,1'-azobis-1-cyclohexanecarbonitrile, 2,2'-azobis (2,4-dimethylvaleronitrile ), 2,2'-azoisobutyrovaleronitrile and the like.

Also, the transition metal catalyst is not particularly limited. For example, platinum alone; platinum solid dispersed in a support such as alumina, silica, carbon black; chloroplatinic acid; chloroplatinic acid and alcohol, aldehyde, ketone, etc. A platinum-olefin complex; a platinum (0) -dialkenyltetramethyldisiloxane complex, and the like. Examples of transition metal catalysts other than platinum compounds include _{RhCl (PPh 3) 3, RhCl} 3, RuCl 3, IrCl 3, FeCl 3, AlCl 3, PdCl 2 · H 2 O, NiCl 2, TiCl 4 and the like .
These catalysts may be used alone or in combination of two or more. Of these, platinum vinyl siloxane is most preferred in terms of compatibility, crosslinking efficiency, and scorch stability.

Although there is no restriction | limiting in particular as a catalyst amount, It is good to use in the range of 10 ^<-8 > ^-10 < ^-1 > mol with respect to ¹ mol of alkenyl groups of an isobutylene type polymer, More preferably, 10 ^<-6 > ^-10 < ^-3 > mol. It is good to use in the range. When the amount is less than 10 ⁻⁸ mol, crosslinking tends not to proceed sufficiently. Moreover, since the clear effect is not seen even if it uses the quantity exceeding 10 ^<-1 > mol, it is preferable that it is less than 10 ^<-1 > mol from the surface of economical efficiency.

In the presence of at least one selected from the group consisting of an aromatic vinyl-based thermoplastic elastomer and an olefin resin, the isobutylene-based polymer having an alkenyl group at the terminal, which is the component (A) of the present invention, is a hydrosilyl group. The composition crosslinked by melt-kneading with the containing compound can be produced by the method exemplified below.

For example, when manufacturing using a closed or open batch type kneader such as a lab plast mill, Brabender, Banbury mixer, kneader, roll, etc., all components other than the premixed cross-linking agent are kneaded. And then kneading and kneading until uniform, then adding a cross-linking agent to the cross-linking reaction and then stopping the melt-kneading.
In addition, when producing using a continuous melt-kneading apparatus such as a single-screw extruder or a twin-screw extruder, all components other than the crosslinking agent are made uniform in advance by a melt-kneading apparatus such as an extruder. After melt-kneading and pelletizing, the pellet is dry-blended with a crosslinking agent, and then melt-kneaded with a melt-kneader such as an extruder or Banbury mixer to dynamically crosslink the isobutylene polymer having an alkenyl group at the terminal. And all components other than the crosslinking agent are melt-kneaded by a melt-kneading apparatus such as an extruder, and a cross-linking agent is added from the middle of the extruder cylinder to further melt-knead to have an alkenyl group at the end. Examples thereof include a method of dynamically crosslinking an isobutylene polymer.

In performing melt kneading, a temperature range of 140 to 210 ° C is preferable, and a temperature range of 150 to 200 ° C is more preferable. If the melt kneading temperature is lower than 140 ° C, the aromatic vinyl-based thermoplastic elastomer and the olefin-based resin do not melt and tend to be insufficiently mixed, and if higher than 210 ° C, the thermal decomposition of the isobutylene-based polymer Tends to occur.

In this invention, the point which mix | blends the ethylene-vinyl alcohol-type copolymer which is (B) component further to the dynamic crosslinking composition which is (A) component is the characteristics. Thus, by making it a two-stage process, in the stage of producing the component (A), the ratio of the isobutylene polymer having an alkenyl group at the terminal can be increased, and the reaction rate of the crosslinking reaction can be increased. There is. In particular, when a softening agent is added as the component (C), the merit is remarkable. Moreover, although the optimal point of reaction conditions changes with kinds and molecular weight of the aromatic vinyl-type thermoplastic elastomer and olefin resin in (A) component, (A) component is manufactured by setting it as a two-step process. Characteristics of the thermoplastic elastomer composition finally obtained by keeping constant the type and molecular weight of the aromatic vinyl-based thermoplastic elastomer and olefin resin used in the stage, and selecting the type and molecular weight of the component (B) Can be controlled in a wide range. Furthermore, it is also possible to mix | blend the component with a functional group which inhibits a crosslinking reaction.

The ethylene-vinyl alcohol copolymer (hereinafter also referred to as “EVOH”) which is the component (B) of the present invention is mainly composed of ethylene units (—CH ₂ CH ₂ —) and vinyl alcohol units (—CH ₂ —CH ( OH)-). The EVOH used in the present invention is not particularly limited, and examples thereof include known ones used in molding applications. However, the ethylene unit content of EVOH is preferably 10 to 99 mol%, more preferably 20 to 65 mol%, from the viewpoints of gas barrier properties, high moisture resistance and good moldability. It is preferably 25 to 60 mol%, more preferably 25 to 50 mol%.

As will be described later, EVOH is typically a saponified ethylene-fatty acid vinyl ester copolymer, but in the case of a saponified ethylene-fatty acid vinyl ester copolymer, the saponification degree of the fatty acid vinyl ester unit is From the viewpoint of gas barrier properties, moisture resistance and high thermal stability of the obtained EVOH, it is preferably 50 mol% or more, more preferably 90 mol% or more, and 95 mol% or more. Is more preferably 98 mol% or more.

The melt flow rate of EVOH (measured by the method described in ASTM D1238 under the conditions of a temperature of 210 ° C. and a load of 2.16 kg) is 0.1 to 100 g / 10 minutes from the viewpoint of good moldability. It is preferably 0.5 to 50 g / 10 min, more preferably 1 to 20 g / 10 min. The intrinsic viscosity of EVOH is preferably 0.1 to 5 dl / g, preferably 0.2 to 2 dl / g, at a temperature of 30 ° C. in a mixed solvent of 85% by weight of phenol and 15% by weight of water. It is more preferable.

In addition to the ethylene unit and the vinyl alcohol unit, EVOH may have other structural units as long as it is a small amount (preferably 10 mol% or less with respect to the total structural units). Other structural units include α-olefins such as propylene, isobutylene, 4-methylpentene-1, 1-hexene, 1-octene; vinyl acetate, vinyl propionate, vinyl vinyl versatate, vinyl pivalate, Carboxylic acid vinyl esters such as valeric acid vinyl ester, capric acid vinyl ester and benzoic acid vinyl ester; unsaturated carboxylic acids such as itaconic acid, methacrylic acid, acrylic acid and maleic anhydride, or derivatives thereof (eg, salts, esters, nitriles) , Amides, anhydrides, etc.); vinylsilane compounds such as vinyltrimethoxysilane; unsaturated sulfonic acids or salts thereof; units derived from N-methylpyrrolidone and the like. EVOH may have a functional group such as an alkylthio group at the terminal.

The production method of EVOH is not particularly limited. For example, EVOH can be produced by producing an ethylene-fatty acid vinyl ester copolymer according to a known method and then saponifying the ethylene-fatty acid vinyl ester copolymer. it can. The ethylene-fatty acid vinyl ester copolymer is prepared by, for example, treating a monomer mainly composed of ethylene and a fatty acid vinyl ester under pressure in an organic solvent such as methanol, t-butyl alcohol, dimethyl sulfoxide, or the like. It can be obtained by polymerization using a radical polymerization initiator such as isobutyronitrile. As the fatty acid vinyl ester, vinyl acetate vinyl ester, propionic acid vinyl ester, versatic acid vinyl ester, pivalic acid vinyl ester, valeric acid vinyl ester, capric acid vinyl ester and the like can be used. Among these, vinyl acetate vinyl ester Is preferred. In the saponification of the ethylene-fatty acid vinyl ester copolymer, an acid catalyst or an alkali catalyst can be used.

In this invention, it is preferable that the compounding quantity of the ethylene-vinyl alcohol-type copolymer which is (B) component is 5-200 weight part with respect to 100 weight part of total amounts of (A) component, 5-100 More preferred are parts by weight. When the blending amount of the component (B) exceeds 200 parts by weight, the compression set characteristic tends to be remarkably deteriorated, and when it is less than 5 parts by weight, the moldability and gas barrier property tend to be remarkably lowered.

In order to melt and knead the component (B) in the component (A) of the present invention, a known method may be employed, and the above-described batch kneader, continuous melt kneader or the like can be used. For example, after measuring (A) component and (B) component, after mixing with a tumbler, a Henschel mixer, a riboblender, etc., the method of melt-kneading with an extruder, a Banbury mixer, a roll, etc. is mentioned. Although the kneading | mixing temperature at this time does not have limitation in particular, the range of 100-250 degreeC is preferable, and the range of 150-220 degreeC is more preferable. When the kneading temperature is lower than 100 ° C., melting tends to be insufficient, and when it is higher than 250 ° C., deterioration due to heating tends to start.

In addition to the above components (A) and (B), a softener (C) can be further added to the composition of the present invention in order to improve moldability and flexibility. As the softening agent, mineral oil used in rubber processing, liquid or low molecular weight synthetic oil, and the like can be used. A softener and a plasticizer are often used in the same meaning, and are not particularly distinguished in the present invention.

Examples of mineral oils include paraffinic oils, naphthenic oils, and aromatic high-boiling petroleum components. Of these, paraffinic oil that does not inhibit the crosslinking reaction is preferred. Examples of liquid or low molecular weight synthetic oils include polybutene, hydrogenated polybutene, liquid polybutadiene, hydrogenated liquid polybutadiene, and liquid poly α-olefins. These softening agents may be used alone or in combination.

The blending amount of the softening agent (C) is preferably 1 to 300 parts by weight with respect to 100 parts by weight of the isobutylene polymer having an alkenyl group at the terminal. If the blending amount exceeds 300 parts by weight, stickiness or mechanical strength tends to decrease, and if it is less than 1 part by weight, moldability and flexibility tend to be lowered.

In addition, the composition of the present invention may further contain other thermoplastic resins, thermoplastic elastomers, rubbers, stabilizers, fillers, etc. within a range that does not impair the physical properties according to the required properties according to each application. An agent or the like can be appropriately blended.
Examples of the thermoplastic resin include polyolefin modified with maleic acid, maleic anhydride, glycidyl methacrylate, polymethylpentene, cyclic olefin (co) polymer, polystyrene, polyphenylene ether, polyamide, polyester, polyurethane, polycarbonate, ABS. Resins, polymethyl methacrylate, polyvinyl chloride and the like can be mentioned.

Examples of the thermoplastic elastomer include olefin, vinyl chloride, urethane, ester, and amide elastomers.
Examples of the rubber include natural rubber, butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, isoprene rubber, butyl rubber, ethylene-propylene rubber, acrylic rubber, silicone rubber, and fluorine rubber.

Examples of additives include hindered phenol-based, phosphorus-based, and sulfur-based antioxidants, hindered amine-based ultraviolet absorbers, light stabilizers, pigments, surfactants, flame retardants, anti-blocking agents, and antistatic agents. , Lubricants, silicone oils, fillers, reinforcing agents and the like can be appropriately blended.
Among the fillers, as inorganic fillers, light calcium carbonate, heavy calcium carbonate, other calcium fillers, hard clay, soft clay, kaolin clay, talc, wet silica, dry silica, amorphous silica, wollastonite, Synthetic zeolite, natural zeolite, diatomaceous earth, silica sand, pumice powder, slate powder, alumina, aluminum sulfate, barium sulfate, calcium sulfate, molybdenum disulfide, magnesium hydroxide, aluminum hydroxide, and those treated with silane Can be mentioned. The thermoplastic elastomer composition of the present invention can improve hardness and tensile strength, for example, by containing an inorganic filler. In addition, when a metal hydroxide such as magnesium hydroxide or aluminum hydroxide is used as the inorganic filler, it may be possible to impart excellent flame retardancy.

Further, as the anti-blocking agent, for example, silica, zeolite and the like are suitable, and these may be either natural or synthetic, and true spherical crosslinked particles such as crosslinked acrylic true spherical particles are also suitable.
As the antistatic agent, N, N-bis- (2-hydroxyethyl) -alkylamines and glycerin fatty acid esters having an alkyl group having 12 to 18 carbon atoms are preferable.
Furthermore, as the lubricant, fatty acid metal salt lubricants, fatty acid amide lubricants, fatty acid ester lubricants, fatty acid lubricants, aliphatic alcohol lubricants, partial esters of fatty acids and polyhydric alcohols, paraffin lubricants and the like are preferably used. Two or more of these may be selected and used.
These additives may be used alone or in combination of two or more.

The thermoplastic elastomer composition of the present invention is excellent in gas barrier properties and compression set properties, and also has flexibility, moisture resistance, etc., and can be used after being processed into a product that requires these properties.
The thermoplastic elastomer composition of the present invention can be molded using a molding method and molding apparatus generally employed for thermoplastic resins. For example, the thermoplastic elastomer composition is melted by extrusion molding, injection molding, press molding, blow molding, or the like. Can be molded.
In addition, the thermoplastic elastomer composition of the present invention can be used to produce a sheet or film by any molding method, and it further has a layer made of the thermoplastic elastomer composition and a layer made of another material. A laminated structure can also be manufactured.
Such a molded article, sheet, film, and laminated structure comprising the thermoplastic elastomer composition are also one aspect of the present invention.

The thermoplastic elastomer composition of the present invention has excellent gas barrier properties and compression set characteristics, and also has flexibility, moisture resistance, etc., and therefore, sealing materials such as packing materials, sealing materials, gaskets, plugs, optical drives, etc. Damper, hard disk drive drive insulator, civil / architecture damper, automotive damping material, railway vehicle damping material, household appliance damping material, damping material, automotive interior material, cushioning material, daily necessities, It can be effectively used as an electrical component, electronic component, sports member, grip, cushioning material, wire covering material, packaging material, various containers, stationery components, and the like.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited by these.
Prior to the examples, various measurement methods and evaluation methods will be described.
<Hardness>
In accordance with JIS K 6352, a 12.0 mm thick press sheet was used as a test piece.
<Tensile breaking strength>
In accordance with JIS K 6251, a 2 mm thick press sheet was used as a test piece by punching it into a No. 3 type with a dumbbell. The tensile speed was 500 mm / min.
<Tensile breaking elongation>
In accordance with JIS K 6251, a 2 mm thick press sheet was used as a test piece by punching it into a No. 3 type with a dumbbell. The tensile speed was 500 mm / min.
<Compression set>
In accordance with JIS K 6262, a 12.0 mm thick press sheet was used as a test piece. The measurement was performed at 100 ° C. for 22 hours under the conditions of 25% deformation.
<100% modulus>
In accordance with JIS K 6251, the test piece used was a 2 mm thick press sheet punched into No. 3 with a dumbbell. The tensile speed was 500 mm / min.
<Gas barrier properties (oxygen permeability)>
In accordance with JIS K 7126, the test piece was a 1 mm thick press sheet, the gas used was air, the measurement method was method A, and room temperature (23 ° C.).

Moreover, the symbol of the material used by the Example and the comparative example and the specific content are as follows.
APIB: Isobutylene polymer PP having an allyl group at the end PP: polypropylene (trade name: Grand Polypro J215W, manufactured by Grand Polymer Co., Ltd.)
OIL: Paraffinic process oil (trade name: P-500, manufactured by JOMO)
Crosslinker 1: Hydrosilyl group-containing polysiloxane (polysiloxane represented by the following chemical formula: (CH ₃ ) ₃ SiO— [Si (H) (CH ₃ ) O] ₄₈ —Si (CH ₃ ) ₃ )
Cross-linking catalyst: 1,1,3,3-tetramethyl-1,3-dialkenyldisiloxane complex of zerovalent platinum, 3% by weight xylene solution.
EVOH-1: ethylene-vinyl alcohol copolymer (vinyl alcohol content = 62 mol%) manufactured by Kuraray Co., Ltd. (trade name “EVAL EP-H101”)
EVOH-2: ethylene-vinyl alcohol copolymer (vinyl alcohol content = 56 mol%) manufactured by Kuraray Co., Ltd. (trade name “EVAL EP-E105”
SIBS: Styrene-isobutylene-styrene block copolymer

Production Example 1 Production of Isobutylene Copolymer (APIB) Having an Alkenyl Group at the Terminal A 2-L separable flask was equipped with a three-way cock, thermocouple, and stirring seal, and was purged with nitrogen. After nitrogen substitution, nitrogen was flowed using a three-way cock. To this, 785 ml of toluene and 265 ml of ethylcyclohexane were added using a syringe. After adding the solvent, the water content was measured with a Karl Fischer moisture meter. After the measurement, the mixture was cooled to about −70 ° C., and 277 ml (2933 mmol) of isobutylene monomer was added. After cooling to about −70 ° C. again, 0.85 g (3.7 mmol) of p-dicumulyl chloride and 0.68 g (7.4 mmol) of picoline were dissolved in 10 ml of toluene and added. When the internal temperature of the reaction system became -74 ° C and stabilized, 19.3 ml (175.6 mmol) of titanium tetrachloride was added to initiate polymerization. When the polymerization reaction was completed (90 minutes), 1.68 g (11.0 mmol) of a 75% allyltrimethylsilane / toluene solution was added, and the mixture was further reacted for 2 hours. Then, it deactivated with the pure water heated at about 50 degreeC, Furthermore, the organic layer was wash | cleaned 3 times with pure water (70 to 80 degreeC), the organic solvent was removed at 80 degreeC under pressure reduction, and APIB was obtained. About the obtained polymer, gel permeation chromatography (GPC) method (Waters 510 type GPC system, mobile phase: chloroform, polymer concentration: 2 mg / ml, column temperature: 35 ° C., standard sample: polystyrene), The number average molecular weight and the weight average molecular weight were measured. A polymer having a number average molecular weight (Mn) of 45500, a weight average molecular weight / number average molecular weight (Mw / Mn) of 1.10, and a content allyl group of 2.0 / mol was obtained.

(Comparative Production Example 1) Production of Styrene-Isobutylene-Styrene Block Copolymer (SIBS) After the inside of a 2 L separable flask was purged with nitrogen, n-hexane (dried with molecular sieves) was used with a syringe. ) 456.1 mL and 656.5 mL of butyl chloride (dried by molecular sieves) were added, the polymerization vessel was placed in a -70 ° C. dry ice / methanol bath and cooled, and then 232 mL (2871 mmol) of isobutylene monomer was contained. A Teflon (registered trademark) feeding tube was connected to a pressure-resistant glass liquefied sampling tube with a three-way cock, and isobutylene monomer was fed into the polymerization vessel by nitrogen pressure. 0.647 g (2.8 mmol) of p-dicumyl chloride and 1.22 g (14 mmol) of N, N-dimethylacetamide were added. Next, 8.67 mL (79.1 mmol) of titanium tetrachloride was further added to initiate polymerization. After stirring at the same temperature for 1.5 hours from the start of polymerization, about 1 mL of the polymerization solution was extracted from the polymerization solution for sampling. Subsequently, a mixed solution of 77.9 g (748 mmol) of styrene monomer, 23.9 mL of n-hexane and 34.3 mL of butyl chloride, which had been cooled to −70 ° C. in advance, was added to the polymerization vessel. 45 minutes after the addition of the mixed solution, about 40 mL of methanol was added to terminate the reaction.
After distilling off the solvent from the reaction solution, it was dissolved in toluene and washed twice with water. Further, the toluene solution was added to a large amount of methanol to precipitate a polymer, and the obtained polymer was vacuum-dried at 60 ° C. for 24 hours to obtain a target block copolymer. The obtained polymer was subjected to GPC method (Waters 510 type GPC system, mobile phase: chloroform, polymer concentration: 2 mg / ml, column temperature: 35 ° C., standard sample: polystyrene), number average molecular weight, weight average molecular weight. Was measured. The block copolymer in which Mn of the isobutylene polymer before styrene addition is 50,000 and Mw / Mn is 1.40, Mn of the block copolymer after styrene polymerization is 67,000 and Mw / Mn is 1.50. A polymer was obtained.

(Example 1)
[Step 1] (A) Components APIB, PP, and OIL were blended in the proportions shown in Table 1 to a total of 40 g, and melted for 3 minutes using Labo Plast Mill (Toyo Seiki Co., Ltd.) set at 170 ° C. After kneading, a cross-linking agent was added in the ratio shown in Table 1, and after adding 16 μl of the cross-linking catalyst, further melt kneading was performed at 170 ° C. until the torque value reached the maximum value, and dynamic cross-linking was performed. After showing the maximum value of torque, the composition was taken out after kneading for 5 minutes.
[Step 2] The composition obtained in Step 1 and (B) component EVOH-1 were blended in the proportions shown in Table 1 to a total of 40 g, and 10 minutes using a lab plast mill set at 170 ° C. It was melt-kneaded and taken out. The obtained thermoplastic elastomer composition could be easily formed into a sheet shape at 190 ° C. with a pressure press (manufactured by Shinfuji Metal Industry Co., Ltd.). The hardness, compression set characteristics, 100% modulus, tensile characteristics, and gas barrier properties of the obtained sheet were measured according to the above methods. Table 1 shows the physical properties of each sheet.

(Example 2)
(B) Except having changed the component into EVOH-2, the resin composition was shape | molded like Example 1 and the physical property was evaluated. The respective physical properties are shown in Table 1.

(Comparative Example 1)
(B) The resin composition was shape | molded similarly to Example 1 except having changed PP from 11 weight part to 25 weight part, without mix | blending component, and evaluated the physical property. The respective physical properties are shown in Table 1.

(Comparative Example 2)
(B) Component EVOH-1, SIBS, and OIL were blended in the proportions shown in Table 1 to a total of 40 g, and the torque value was set using a lab plast mill (manufactured by Toyo Seiki Co., Ltd.) set at 170 ° C. Melt kneading was performed until the maximum value was exhibited, and after the maximum value was exhibited, the mixture was kneaded for 5 minutes and then removed. The obtained thermoplastic elastomer composition could be molded into a sheet form at 190 ° C. with a pressure press (manufactured by Shinfuji Metal Industry Co., Ltd.). The hardness, compression set characteristics, 100% modulus, tensile characteristics, and gas barrier properties of the obtained sheet were measured according to the above methods. Table 1 shows the physical properties of each sheet.

(Comparative Example 3)
(B) Except having changed the component into EVOH-2, the resin composition was shape | molded similarly to the comparative example 2, and the physical property was evaluated. The respective physical properties are shown in Table 1.

(Comparative Example 4)
(B) Except having changed component into PP, the resin composition was shape | molded similarly to the comparative example 2, and the physical property was evaluated. The respective physical properties are shown in Table 1.

The thermoplastic elastomer composition of the present invention, that is, Examples 1 and 2, have the same hardness, 100% modulus, tensile breaking strength, tensile breaking elongation, and gas barrier properties (oxygen permeation) as compared with Comparative Examples 1 to 4. It was found that the compression set characteristic was 22-27% and a good value.

The thermoplastic elastomer composition of the present invention has excellent gas barrier properties and compression set characteristics, and also has flexibility, moisture resistance, etc., and therefore, sealing materials such as packing materials, sealing materials, gaskets, plugs, optical drives, etc. Damper, hard disk drive drive insulator, civil / architecture damper, automotive damping material, railway vehicle damping material, household appliance damping material, damping material, automotive interior material, cushioning material, daily necessities, It can be effectively used as an electrical component, electronic component, sports member, grip, cushioning material, wire covering material, packaging material, various containers, stationery components, and the like.

Claims (17)

(A) An isobutylene polymer having an alkenyl group at the terminal is melt-kneaded with a hydrosilyl group-containing compound in the presence of at least one selected from the group consisting of an aromatic vinyl thermoplastic elastomer and an olefin resin. A crosslinked composition,
(B) an ethylene-vinyl alcohol copolymer,
A thermoplastic elastomer composition comprising: In the component (A), the content of at least one selected from the group consisting of an aromatic vinyl-based thermoplastic elastomer and an olefin resin is 5 to 100 with respect to 100 parts by weight of the isobutylene-based polymer having an alkenyl group at the terminal. The thermoplastic elastomer composition according to claim 1, wherein the thermoplastic elastomer composition is part by weight. The thermoplastic elastomer composition according to claim 1, wherein the content of the component (B) is 5 to 100 parts by weight with respect to 100 parts by weight of the total amount of the component (A). . The softener (C) is further contained in an amount of 1 to 300 parts by weight per 100 parts by weight of the isobutylene polymer having an alkenyl group at the terminal in the component (A). The thermoplastic elastomer composition according to Item. The isobutylene polymer having an alkenyl group at the terminal in the component (A) is an allyl group introduced at the terminal by a substitution reaction of allyltrimethylsilane and chlorine. The thermoplastic elastomer composition according to any one of the above. The number average molecular weight of the isobutylene polymer having an alkenyl group at the end in the component (A) is 1,000 to 500,000, and the polymer has at least 0.2 alkenyl groups per end per molecule. The thermoplastic elastomer composition according to any one of claims 1 to 5, wherein the composition is a thermoplastic elastomer composition. The heat according to any one of claims 1 to 6, wherein the isobutylene polymer having an alkenyl group at the terminal in the component (A) is a polymer containing 50% by weight or more of isobutylene units. Plastic elastomer composition. The aromatic vinyl thermoplastic elastomer in component (A) is a block copolymer comprising a polymer block (a) mainly composed of an aromatic vinyl compound and a polymer block (b) mainly composed of isobutylene. The thermoplastic elastomer composition according to any one of claims 1 to 7, wherein The aromatic vinyl-based thermoplastic elastomer in the component (A) is a polymer block mainly composed of an aromatic vinyl compound (a) -a polymer block mainly composed of isobutylene (b) -mainly composed of an aromatic vinyl-based compound. The thermoplastic elastomer composition according to claim 8, wherein the thermoplastic elastomer composition is a triblock copolymer having a number average molecular weight of 40,000 to 200,000 indicating the structure of the polymer block (a). The thermoplastic elastomer composition according to any one of claims 1 to 9, wherein the olefin resin in the component (A) is polypropylene. The thermoplastic elastomer composition according to any one of claims 1 to 10, wherein the olefin resin in component (A) is polyethylene. The thermoplastic elastomer composition according to claim 10, wherein the olefin resin in component (A) is random polypropylene. The thermoplastic elastomer composition according to claim 11, wherein the olefin resin in component (A) is high-density polyethylene. The thermoplastic elastomer composition according to any one of claims 4 to 13, wherein the softening agent (C) is a paraffinic oil. A molded article comprising the thermoplastic elastomer composition according to any one of claims 1 to 14. The sheet | seat or film which consists of a thermoplastic-elastomer composition of any one of Claims 1-14. A laminated structure having a layer made of the thermoplastic elastomer composition according to any one of claims 1 to 14 and a layer made of another material.