JP2002226667A - Thermoplastic elastomer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new thermoplastic elastomer composition rich in flexibility, and excellent in molding processability, rubber properties, mechanical strengths, gas barrier properties, sealing properties, and permanent compression strain properties. SOLUTION: The thermoplastic elastomer composition includes an isobutylene block copolymer (A) consisting of a polymer block (a) composed almost exclusively of isobutylene and a polymer block (b) composed almost exclusively of an aromatic vinyl compound, and an isobutylene block copolymer modified object (B) to which an unsaturated bond is added.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel thermoplastic elastomer composition having excellent flexibility, excellent moldability, rubbery properties, mechanical strength, gas barrier properties and sealing properties, and excellent compression set properties. It is about things.

[0002]

2. Description of the Related Art Conventionally, as a polymer material having elasticity, a material obtained by blending a crosslinking agent or a reinforcing agent with rubbers such as natural rubber or synthetic rubber and crosslinking under high temperature and high pressure has been widely used. However, such rubbers require a process of performing crosslinking and molding under a high temperature and a high pressure for a long period of time, resulting in poor processability. In addition, since the crosslinked rubber does not show thermoplasticity, recycling molding is generally impossible like thermoplastic resins. Therefore, in recent years, various types of thermoplastic elastomers have been developed that can easily produce molded articles by using general-purpose melt molding techniques such as hot press molding, injection molding, and extrusion molding, like ordinary thermoplastic resins. ing. As such thermoplastic elastomers, various types of polymers such as olefin-based, urethane-based, ester-based, styrene-based, and vinyl chloride-based polymers have been developed and are commercially available.

[0003] Of these, styrene-based thermoplastic elastomers are rich in flexibility and excellent in rubber elasticity at room temperature. As a styrene-based thermoplastic elastomer,
Styrene-butadiene-styrene block copolymer (S
BS), styrene-isoprene-styrene block copolymer (SIS), and hydrogenated styrene-
Ethylene butylene-styrene block copolymer (SEB
S) and styrene-ethylene propylene-styrene block copolymer (SEPS) have been proposed. However, since these block copolymers do not have sufficient gas barrier properties, sealing properties, and stickiness of the material itself,
It cannot be used effectively as a sealing material such as a packing material, a sealing material, a gasket, or a plug.

On the other hand, thermoplastic elastomers having high flexibility, good rubber elasticity at room temperature, and excellent gas barrier properties and sealing properties include a polymer block mainly composed of isobutylene and an aromatic vinyl compound. An isobutylene-based block copolymer containing a polymer block mainly composed of However, this isobutylene-based block copolymer has a problem in the pressure deformation rate (compression set) during heating and rubber elasticity at high temperatures.

[0005] A thermoplastic polymer composition comprising a crosslinked product of an isobutylene-based block copolymer containing a polymer block mainly composed of isobutylene and a rubber is also known (Republished Patent WO98 / 14518). Although this composition is excellent in gas barrier properties, sealing properties and compression set properties, it has a problem that its hardness and strength are low because rubber is used as a crosslinked product.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a high flexibility, moldability,
An object of the present invention is to provide a thermoplastic elastomer composition having excellent rubber properties, mechanical strength, gas barrier properties and sealing properties, and particularly excellent compression set properties.

[0007]

That is, the present invention provides an isobutylene block copolymer comprising a polymer block (a) mainly composed of isobutylene and a polymer block (b) mainly composed of an aromatic vinyl compound. A thermoplastic elastomer composition containing (A) and a modified isobutylene-based block copolymer (B) having an unsaturated bond, wherein the modified isobutylene-based block copolymer (B) is used.
Is an acid chloride having an unsaturated bond between an isobutylene-based block copolymer (A) containing a polymer block (a) mainly composed of isobutylene and a polymer block (b) mainly composed of an aromatic vinyl compound. And / or those modified with acid anhydrides are preferred.

The modified isobutylene block copolymer (B) is preferably a modified polymer block (b) mainly composed of an aromatic vinyl compound.

In the thermoplastic elastomer composition, when the isobutylene-based block copolymer (A) and the modified isobutylene-based block copolymer (B) are melt-kneaded, the (B) is dynamically crosslinked. Alternatively, the modified isobutylene-based block copolymer (B) may be cross-linked before being mixed with the isobutylene-based block copolymer (A).

In addition to the above (A) and (B), a plasticizer (C)
Can also be contained. As the acid chloride, methacrylic acid chloride is preferable, and as the acid anhydride, acetic anhydride is preferable.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic elastomer composition of the present invention comprises an isobutylene-based block comprising a polymer block (a) mainly composed of isobutylene and a polymer block (b) mainly composed of an aromatic vinyl compound. A thermoplastic elastomer composition containing a copolymer (A) and a modified isobutylene-based block copolymer (B) having an unsaturated bond, wherein the (B) is obtained by converting the (A) into an unsaturated bond. Those modified with acid chlorides and acid anhydrides having a bond are preferred.

The isobutylene-based polymer block (a) of the isobutylene-based block copolymer (A) of the present invention refers to a polymer block containing isobutylene as a main component in an amount of 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight. The block that occupies the above. The monomer other than isobutylene in the polymer block mainly composed of isobutylene is not particularly limited as long as it is a cationically polymerizable monomer component.Aromatic vinyls, aliphatic olefins, dienes,
Examples thereof include monomers such as vinyl ethers and β-pinene. These may be used alone or in combination of two or more.

The polymer block (b) mainly composed of an aromatic vinyl compound of the isobutylene block copolymer (A) is defined as a polymer block containing at least 50% by weight of an aromatic vinyl compound.
Preferably 70% by weight or more, more preferably 90% by weight
The block that occupies the above. The monomer other than the aromatic vinyl compound in the polymer block mainly composed of an aromatic vinyl compound is not particularly limited as long as it is a monomer that can be cationically polymerized, but may be an aliphatic olefin, a diene, or a vinyl ether. And monomers such as β-pinene.

The aromatic vinyl compound of the polymer block (b) includes styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, t-butylstyrene, monochlorostyrene, dichlorostyrene, methoxystyrene, indene And the like. Among the above compounds, styrene, α from the balance of cost, physical properties and productivity
-Methylstyrene, p-methylstyrene, and indene are preferred, and two or more of them may be selected.

The ratio of the polymer block (a) mainly composed of isobutylene and the polymer block (b) mainly composed of an aromatic vinyl compound in the isobutylene-based block copolymer (A) is not particularly limited. From the balance between physical properties and processability, the polymer block (a) mainly composed of isobutylene is 95 to 20 parts by weight, and the polymer block (b) mainly composed of an aromatic vinyl compound is 5 to 80 parts by weight. It is particularly preferable that the polymer block (a) mainly composed of isobutylene is 90 to 60 parts by weight, and the polymer block (b) mainly composed of an aromatic vinyl compound is 10 to 40 parts by weight.

The preferred structure of the isobutylene-based block copolymer (A) of the present invention is at least one of the polymer blocks (a) mainly composed of isobutylene in view of the physical properties and processability of the obtained composition. And at least two polymer blocks (b) mainly composed of an aromatic vinyl compound. The structure is not particularly limited. For example, a triblock copolymer formed from (b)-(a)-(b), ｛(b)-
At least one selected from (a) a multi-block copolymer having repeating 繰 り 返 し units, and a star-shaped polymer having a di-block copolymer (b)-(a) as an arm can be used. . Further, in the isobutylene-based block copolymer (A), in addition to the above structure, a polymer mainly composed of isobutylene, a polymer mainly composed of an aromatic vinyl compound, and a dimer composed of (a)-(b) At least one of block copolymers may be included. However, from the viewpoint of physical properties and processability, at least one of the isobutylene-based polymer block (a) contained in the isobutylene-based block copolymer (A) and the polymer mainly containing an aromatic vinyl-based compound Preferably, the structure having at least two blocks (b) accounts for 50% by weight or more.

The number average molecular weight of the isobutylene block copolymer (A) is not particularly limited, but is preferably from 30,000 to 500,000, more preferably from 40,000 to 400,000.
000 is particularly preferred. When the number average molecular weight is less than 30,000, mechanical properties and the like are not sufficiently exhibited.
If it exceeds 000, the decrease in moldability and the like is large.

The modified isobutylene-based block copolymer (B) referred to in the present invention is obtained by converting the above-mentioned isobutylene-based block copolymer (A) into an acid chloride having an unsaturated bond and / or
Alternatively, it is modified with an acid anhydride.

Specifically, the polymer block (b) comprising the aromatic vinyl compound as the main component constituting the above (A)
Is 1% in an acid chloride and an acid anhydride having an unsaturated bond.
Above, preferably those modified by 5% or more are preferable.

The acid chloride having an unsaturated bond used for modification in the present invention includes methacrylic acid chloride, methacrylic acid bromide, methacrylic acid iodide, acrylic acid chloride, acrylic acid bromide, acrylic acid iodide, crotonyl chloride, crotonyl chloride. Examples thereof include acid bromide and crotonyl iodide, and methacrylic acid chloride is preferred from the viewpoint of industrial availability. Examples of the acid anhydride include acetic anhydride, maleic anhydride, and phthalic anhydride, and acetic anhydride is preferable from the viewpoint of solubility in the reaction solvent. These may be used alone or in combination of two or more. By the above-mentioned acid chloride and / or acid anhydride, the polymer block mainly composed of an aromatic vinyl compound can have at least one unit represented by the following formula (I).

[0021]

Embedded image [Wherein R ₁ is a monovalent organic group having a functional group] By this modification, a functional group which can be cross-linked by using various cross-linking agents can be introduced.

The compounding amount of the modified isobutylene-based block copolymer (B) modified with an acid chloride having an unsaturated bond and an acid anhydride is based on 100 parts by weight of the isobutylene-based block copolymer (A). The amount is preferably from 10 to 220 parts by weight, more preferably from 20 to 400 parts by weight. Crosslinked product of non-isobutylene-based block copolymer (B)
If the compounding amount is less than 10 parts by weight, the compression set characteristic tends to be poorly improved. On the other hand, if it exceeds 500 parts by weight, there is a tendency that problems occur in the moldability.

The modified isobutylene-based block copolymer (B) modified with an acid chloride having an unsaturated bond and an acid anhydride according to the present invention (B) has an unsaturated bond with the isobutylene-based block copolymer (A). It is preferred that the modified isobutylene-based block copolymer modified with an acid chloride and an acid anhydride be dynamically crosslinked at the time of melt-kneading.

It is also preferable that the resin is crosslinked before mixing with the isobutylene-based block copolymer (A).

As described above, a known method can be used to crosslink the modified isobutylene-based block copolymer modified with an acid chloride having an unsaturated bond and an acid anhydride. However, for example, thermal crosslinking by heating and crosslinking by a crosslinking agent can be performed.

As the crosslinking agent for obtaining the crosslinked product (B) of the non-isobutylene block copolymer of the present invention, it is preferable to use an organic peroxide. Examples of the organic peroxide include dicumyl peroxide, di-t
tert-butyl peroxide, 2,5-dimethyl-
2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3, 1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (te
rt-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide,
2,4-dichlorobenzoyl peroxide, tert
-Butylperoxybenzoate, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, tert-butylcumyl peroxide and the like.

Of these, 2,5-dimethyl 2,5-di- (ter) is preferable in terms of odor, coloring, and scorch stability.
Most preferred are t-butylperoxy) hexane and 2,5-dimethyl2,5-di- (tert-butylperoxy) hexyne-3.

The compounding amount of the organic peroxide is preferably in the range of 0.5 to 3.5 parts by weight based on 100 parts by weight of the non-isobutylene block copolymer at the time of adding the organic peroxide.

When the composition of the present invention is crosslinked with an organic peroxide, a polyfunctional vinyl monomer such as divinylbenzene or triallyl cyanurate, or ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, Polyethylene glycol dimethacrylate,
It can be produced by blending a polyfunctional methacrylate monomer such as trimethylolpropane trimethacrylate or allyl methacrylate as a crosslinking aid. With such a compound, a uniform and efficient crosslinking reaction can be expected.

In particular, ethylene glycol dimethacrylate and triethylene glycol dimethacrylate are easy to handle and have a peroxide solubilizing effect,
Since it acts as a peroxide dispersing agent, the crosslinking effect by heat treatment is uniform and effective, and a crosslinked thermoplastic elastomer having a good balance between hardness and rubber elasticity is obtained, which is preferable.

The amount of the crosslinking aid to be added is 0.9 to 8 parts by weight based on 100 parts by weight of the modified isobutylene-based block copolymer modified with an acid chloride having an unsaturated bond and an acid anhydride at the time of addition. A range of 0.0 parts by weight is preferred.

The composition of the present invention comprises, in addition to the isobutylene-based block copolymer (A), an acid chloride having an unsaturated bond and a modified isobutylene-based block copolymer (B) modified with an acid anhydride. In order to further improve moldability and flexibility, it is preferable to further add a plasticizer (C).
As the plasticizer (C), mineral oil used in processing rubber or a liquid or low molecular weight synthetic softener can be used. Examples of the mineral oil include paraffinic, naphthenic, and aromatic high-boiling petroleum components, and paraffinic and naphthenic types that do not inhibit the crosslinking reaction are preferred. The liquid or low molecular weight synthetic softener is not particularly limited, but includes polybutene, hydrogenated polybutene,
Liquid polybutadiene, hydrogenated liquid polybutadiene, poly α
Olefins and the like. One or more of these plasticizers (C) can be used. The blending amount of the plasticizer (C) is preferably 10 to 200 parts by weight based on 100 parts by weight of the isobutylene-based block copolymer (A).
If the amount is more than 200 parts by weight, problems arise in mechanical strength and moldability.

The composition of the present invention may further contain, in addition to a reinforcing agent and a filler, a hindered phenol-based or hindered amine-based antioxidant or an ultraviolet absorber, depending on the required characteristics for each application. A light stabilizer, a pigment, a surfactant and the like can be appropriately compounded.

As the most preferred composition of the thermoplastic elastomer composition of the present invention, 100 parts by weight of an isobutylene-based block copolymer (A) is modified with an acid chloride having an unsaturated bond and an acid anhydride. 20 to 200 parts by weight of a crosslinked product of the modified isobutylene-based block copolymer (B) and 10 to 200 parts by weight of a plasticizer (C). In this case, the modified isobutylene-based block copolymer (B) 1 modified with an acid chloride having an unsaturated bond and an acid anhydride
The crosslinking agent is 0.1 to 7 parts by weight, and the crosslinking aid is 0.45 to 16 parts by weight with respect to 00 parts by weight.

The method for producing the thermoplastic elastomer composition of the present invention is not particularly limited, and is an isobutylene-based block copolymer (A), an isobutylene-based acid chloride having an unsaturated bond and an acid-butyl-modified isobutylene-based acid copolymer. Any method can be adopted as long as the modified block copolymer (B) and the above-mentioned components optionally used can be uniformly mixed.

When melt-mixing the isobutylene-based block copolymer (A) with the acid chloride having an unsaturated bond and the modified isobutylene-based block copolymer modified with an acid anhydride, the acid chloride having an unsaturated bond And a crosslinked product of a modified isobutylene-based block copolymer modified with an acid anhydride and an acid chloride having an unsaturated bond by dynamically crosslinking the modified isobutylene-based block copolymer with an acid anhydride The production of the thermoplastic elastomer composition of the present invention can be preferably carried out by the method exemplified below.

For example, in the case of using a closed kneading apparatus or a batch kneading apparatus such as Labo Plastomill, Brabender, Banbury mixer, kneader, roll, etc., all components other than the crosslinking agent and the crosslinking aid are used. May be mixed in advance and melt-kneaded until uniform, and then a crosslinking agent and a crosslinking aid may be added to the mixture to stop the melt-kneading sufficiently in the crosslinking reaction.

In the case of using a continuous melt kneading apparatus such as a single screw extruder or a twin screw extruder, all components other than the crosslinking agent and the crosslinking auxiliary are melted in advance by an extruder or the like. The mixture is melt-kneaded by a kneading device, pelletized, and then the pellets are dry-blended with a crosslinking agent and a crosslinking aid.Then, the mixture is melt-kneaded with a melt-kneading device such as an extruder to form a non-isobutylene block copolymer. Dynamically crosslinked, isobutylene-based block copolymer (A) of the present invention,
A method for producing a thermoplastic elastomer composition comprising a crosslinked product of a modified isobutylene-based block copolymer (B) modified with an acid chloride having an unsaturated bond and an acid anhydride.
Alternatively, all components other than the cross-linking agent and the cross-linking aid are melt-kneaded by a melt-kneading device such as an extruder, and the cross-linking agent and the cross-linking auxiliary are added from the middle of the extruder cylinder and further melt-kneaded, Modification of non-isobutylene block copolymer dynamically with isobutylene block copolymer (A) of the present invention, isobutylene block copolymer modified with acid chloride having unsaturated bond and acid anhydride A method for producing a thermoplastic elastomer composition comprising a crosslinked product of the product (B) can be employed.

In performing the above-mentioned method of performing dynamic crosslinking simultaneously with melt kneading, a temperature of 150 to 210 ° C. is preferred. In this case, the isobutylene-based block copolymer (A) does not cause a cross-linking reaction, and only the modified isobutylene-based block copolymer modified with an acid chloride having an unsaturated bond and an acid anhydride can be cross-linked. it can.

A crosslinked product of the modified isobutylene-based block copolymer (B) modified with an acid chloride having an unsaturated bond and an acid anhydride is prepared in advance, and the crosslinked product is used as the isobutylene-based block copolymer. When mixing with (A) to prepare the thermoplastic elastomer composition of the present invention, the following exemplified methods are preferably employed.

For example, a crosslinking agent and a crosslinking aid are added to the above-mentioned non-isobutylene-based block copolymer, and the mixture is sufficiently kneaded at an appropriate temperature using a kneader or the like usually used for producing a rubber cross-linked product. The obtained kneaded product is subjected to a crosslinking reaction using a suitable crosslinking temperature and crosslinking time using a press machine or the like, and then cooled and pulverized to obtain an acid chloride and an acid anhydride having an unsaturated bond. A thermoplastic elastomer composition of the present invention is produced by obtaining a crosslinked product of the modified isobutylene-based block copolymer (B) and melt-mixing the crosslinked product with the isobutylene-based block copolymer (A). be able to.

At this time, the melt-mixing of the crosslinked product of the modified isobutylene-based block copolymer (B) and the isobutylene-based block copolymer (A) modified with an acid chloride having an unsaturated bond and an acid anhydride. As the method, any of the known methods conventionally used for the production of a thermoplastic resin or a thermoplastic elastomer composition can be adopted, for example, Labo Plast Mill, Banbury Mixer, Single Screw Extruder, Twin Screw Extruder,
The melting and kneading can be carried out by using another melting and kneading apparatus, and the melting and kneading temperature is preferably from 150 to 210C.

The thermoplastic elastomer composition of the present invention comprises:
The thermoplastic resin composition can be molded using a molding method and a molding apparatus generally adopted, and for example, can be melt-molded by extrusion molding, injection molding, press molding, blow molding, or the like. Further, the thermoplastic elastomer composition of the present invention is excellent in moldability, gas barrier properties, and compression set characteristics, and thus can be effectively used as a sealing material such as a packing material, a sealing material, a gasket, and a plug. it can.

[0044]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Prior to the examples, various measuring methods, evaluation methods,
An example will be described.

(Hardness) According to JIS K 6352, a test piece used was a 12.0 mm pressure press sheet.

(Tensile breaking strength) According to JIS K6251, the test piece was a 2 mm-thick pressed sheet, and 3 dumbbells were used.
It was used by punching it into a model. The tensile speed was 500 mm / min.

(Tensile elongation at break) In accordance with JIS K6251, the test piece was a 2 mm-thick pressed sheet, and 3 dumbbells were used.
It was used by punching it into a model. The tensile speed was 500 mm / min.

(Compression Set) According to JIS K 6262, a test piece used was a 12.0 mm thick press sheet. It was measured under the conditions of 100 ° C. × 22 hours and 25% deformation. The abbreviations of the materials used in the examples and comparative examples and their specific contents are as follows. SIBS: polystyrene-polyisobutylene-polystyrene triblock copolymer f-SIBS: polystyrene-polyisobutylene-polystyrene triblock copolymer acid chloride and acid anhydride modified product. IIR: butyl rubber, manufactured by JSR (trade name “Butyl
065 ") Plasticizer: paraffinic process oil, manufactured by Idemitsu Petrochemical Co., Ltd. (trade name" Diana Process Oil PW-90 ") Crosslinking agent 1: 2,5-dimethyl-2,5-di (tert)
-Butylperoxy) hexane, manufactured by NOF Corporation (trade name "Perhexa 25B") Crosslinking agent 2: Reactive brominated alkylphenol formaldehyde compound, manufactured by Taoka Chemical Industry Co., Ltd. (trade name "Tacchirol 250-1") Crosslinking aid 1 : Ethylene glycol dimethacrylate, manufactured by Kanto Chemical Co., Ltd. Crosslinking aid 2: Triethylene glycol dimethacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd. (trade name “NK ester 3G”) Crosslinking aid 3: Zinc oxide Crosslinking aid 4: Stearic acid ( Production Example 1) [Production of Styrene-Isobutylene-Styrene Block Copolymer (SIBS)] After the inside of the polymerization vessel of a 2 L separable flask was replaced with nitrogen, n-hexane (dried with molecular sieves) using a syringe. ) 456.1 mL and butyl chloride (dried by molecular sieves) 65 .5m
L, and the polymerization vessel was placed in a dry ice / methanol bath at −70 ° C. and cooled. The liquid sending tube was connected, and the isobutylene monomer was sent into the polymerization vessel under 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 of titanium tetrachloride (79.1 m
mol) was added to initiate polymerization. 1.5 from the start of polymerization
After stirring at the same temperature for a period of time, about 1 mL of the polymerization solution was withdrawn from the polymerization solution for sampling. continue,
77.9 g (748 mmol) of a styrene monomer previously cooled to -70 ° C, 23.9 n-hexane
A mixed solution of mL and 34.3 mL of butyl chloride was added to the polymerization vessel. Forty-five minutes after the addition of the mixed solution, about 40 mL of methanol was added to terminate the reaction.

After the solvent and the like were distilled off from the reaction solution, it was dissolved in toluene and washed twice with water. Further, a 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 molecular weight of the obtained polymer was measured by gel permeation chromatography (GPC). The Mn of the isobutylene polymer before styrene addition was 50,000 and Mw / Mn was 1.40, and the Mn of the block copolymer after styrene polymerization was 67,00.
0, and a block copolymer having Mw / Mn of 1.50 was obtained.

(Production Example 2) [Styrene-isobutylene-
Production of Modified Styrene Block Copolymer (f-SIBS)] 75 g of styrene-isobutylene block copolymer (styrene content: 30%, mole number of styrene unit: 0.216 mol) was placed in a 2 L separable flask, followed by polymerization. The inside of the container was replaced with nitrogen. Using a syringe, 1200 mL of n-hexane (dried with molecular sieves)
And 1800 mL of normal butyl chloride (dried by molecular sieves) were added. Next, using a syringe, 30 g of methacrylic acid chloride (0.291 mol
l) was added. Finally, the reaction was started by adding 39.4 g (0.295 mol) of aluminum trichloride while stirring the solution. 30 minutes after the start of the reaction, about 10
The reaction was terminated by adding 00 mL of water and stirring vigorously.

The reaction solution was washed with a large amount of water five times or more. A larger amount of a mixed solvent of methanol and acetone (1:
1 vt / vt), and the polymer was precipitated by dripping slowly, and the obtained polymer was vacuum-dried at 60 ° C. for 24 hours to obtain a target block copolymer.

(Example 1) SIB manufactured in Production Example 1
S, f-SIBS produced in Production Example 2, and a plasticizer were melt-kneaded at a ratio shown in Table 1 for 5 minutes using a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.) set at 180 ° C., and then a crosslinking agent 1 and crosslinking aid 1 were added at the ratios shown in Table 1, and the mixture was further melt-kneaded at 180 ° C. until the torque value reached the maximum value (3 to 7 minutes) to perform dynamic crosslinking. The obtained thermoplastic elastomer composition could be easily formed into a sheet at 180 ° C. The hardness, tensile rupture strength, tensile rupture elongation, and compression set of the obtained sheet were measured according to the above methods. Table 1 shows the physical properties of each sheet.

Example 2 f-SI manufactured in Production Example 2
Using a Labo Plastomill with BS set at 180 ° C, 5
For 1 minute, then crosslinker 1 and crosslinker 1
The mixture was further melt-kneaded at 180 ° C. until the torque value reached the maximum value (3 to 7 minutes) to effect crosslinking. The obtained resin and SIBS were further melt-kneaded for 5 minutes using a Labo Plastomill set at 180 ° C. to form a sheet. Table 1 shows the physical properties of the obtained sheet.

Example 3 A resin composition was molded in the same manner as in Example 1 except that the amount of SIBS was changed to 25 parts, and the physical properties were evaluated. Table 1 shows the respective physical properties.
(Comparative Example 1) The SIBS produced in Production Example 1 was melt-kneaded for 10 minutes using a Labo Plastomill set at 180 ° C, and then formed into a sheet at 180 ° C. The hardness, tensile strength at break, tensile elongation at break, and compression set of the obtained sheet were measured in accordance with the above methods. Table 1 shows the physical properties of each sheet.

(Comparative Example 2) SIBS produced in Production Example 1
The IIR was melted and kneaded at a ratio shown in Table 1 for 5 minutes using a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.) set at 180 ° C. The mixture was added at the ratio shown in FIG. 1, and further melt-kneaded at 180 ° C. until the torque value reached the maximum value (3 to 7 minutes) to perform dynamic crosslinking. The resulting thermoplastic elastomer composition is 180
It could be easily formed into a sheet at ℃. The hardness, tensile strength at break, tensile elongation at break, and compression set of the obtained sheet were measured in accordance with the above methods. Table 1 shows the physical properties of each sheet.

[0056]

[Table 1] The thermoplastic elastomer composition of the present invention, that is, Example 1 has a hardness equal to or higher than the hardness (JIS A: 47) of SIBS alone which is the isobutylene-based block copolymer shown in Comparative Example 1, The value of the compression set is lower than that of the SIBS alone, and the compression set is excellent while maintaining the properties of the isobutylene-based block copolymer. Then, II was added to the crosslinked product shown in Comparative Example 2.
Compared with the case where R is used, it is apparent that the hardness maintains the value of the SIBS alone and is easy to handle, and is excellent in the values of tensile strength, tensile elongation at break and compression set.

[0057]

As described above, the thermoplastic elastomer composition has high flexibility, moldability, rubber-like properties, mechanical strength, gas barrier properties and the like while maintaining the properties of the isobutylene-based block copolymer. It is a novel thermoplastic elastomer composition having excellent sealing properties, particularly excellent compression set characteristics.

Continued on the front page F-term (reference) 4F070 AA12 AA17 AB03 AB08 AB09 AC32 GA05 GA06 GA08 GA10 4J002 AE053 BP03W BP03X EA047 EH107 EK036 EK046 EK056 EK066 EU197 FD123 FD146 FD157 4J011 AA05 PA02 PC02 PA02 PA02 PA02 DB02 NA01 CB03 CC02 CD01 4J100 HA01 HA53 HC27 HC29 HD01 HE17 HG01

Claims (8)

[Claims] 1. An isobutylene-based block copolymer (A) comprising a polymer block (a) mainly composed of isobutylene and a polymer block (b) mainly composed of an aromatic vinyl compound, and an unsaturated bond. Thermoplastic elastomer composition containing the modified isobutylene-based block copolymer (B) 2. An isobutylene-based modified block copolymer (B) comprising a polymer block (a) mainly composed of isobutylene and a polymer block (b) mainly composed of an aromatic vinyl compound. The thermoplastic elastomer composition according to claim 1, wherein the block copolymer (A) is modified with an acid chloride and / or an acid anhydride having an unsaturated bond. 3. The thermoplastic elastomer composition according to claim 2, wherein the modified isobutylene block copolymer (B) is obtained by modifying a polymer block (b) mainly composed of an aromatic vinyl compound. 4. The thermoplastic elastomer composition dynamically crosslinks the isobutylene-based block copolymer (A) and the modified isobutylene-based block copolymer (B) during melt-kneading. Claim 1, 2 or 3
5. The thermoplastic elastomer composition according to item 1. 5. The heat according to claim 1, wherein the modified isobutylene-based block copolymer (B) is cross-linked before being mixed with the isobutylene-based block copolymer (A). Plastic elastomer composition. 6. The method according to claim 1, further comprising a plasticizer (C).
4. The thermoplastic elastomer composition according to 2 or 3. 7. The thermoplastic elastomer composition according to claim 2, wherein the acid chloride is methacrylic acid chloride. 8. The thermoplastic elastomer composition according to claim 2, wherein the acid anhydride is acetic anhydride.