WO2005103146A1

WO2005103146A1 - Resin composition and process for producing the same

Info

Publication number: WO2005103146A1
Application number: PCT/JP2005/007169
Authority: WO
Inventors: Youkou Saito; Tadashi Utsunomiya; Naruhiko Mashita; Toshiki Takizawa
Original assignee: Bridgestone Corporation
Priority date: 2004-04-22
Filing date: 2005-04-13
Publication date: 2005-11-03

Abstract

A resin composition which comprises a (b)-(a)-(b) type isobutylene triblock copolymer comprising a polymer block (a) consisting mainly of isobutylene units and polymer blocks (b) consisting mainly of styrene units, an ethylene polymer and/or propylene polymer, and liquid polybutene, and has an air permeability of 200 cm3/(m2·24 hr·atm) or lower, a moisture permeability of 2.0 g/(m2·24 hr) or lower, a JIS-A hardness of 30-60 degrees, and a melt flow rate of 100 g/10 min or lower. It is rich in flexibility, excellent in air impermeability and moisture impermeability, and is satisfactory in injection moldability.

Description

Specification

Resin composition and method for producing the same

Technical field

The present invention relates to a resin composition and a method for producing the same. More specifically, the present invention includes a styrene-based polymer block, an isobutylene-based polymer block, a styrene-based polymer block, and an isobutylene-based triblock copolymer, which is also strong, and has high flexibility, air permeation resistance, and permeation resistance. A resin composition that has excellent wettability and good injection moldability, and is suitable for forming, for example, an insulator for a recording medium driving device, a gasket for an HDD, a shock absorber for an HDD, a tube for transporting a medical infusion, and the like. It is about.

Background art

[0002] Conventionally, as a polymer material having elasticity, a material obtained by blending a bridging agent, a reinforcing agent, or the like 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 time, and inevitably suffer from poor processability. Also, since crosslinked rubber does not show thermoplasticity, recycling molding like thermoplastic resin is generally impossible. For this reason, in recent years, there have been various thermoplastic elastomers 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. Is being developed. As such a thermoplastic elastomer, an olefin type, a urethane type, an ester type, a styrene type, a butyl chloride type and the like have been developed and are commercially available. Since these are easy to recycle, they have recently been used in a wide range of fields such as automobile parts, home electric parts, wire covering materials, medical parts, sundries, footwear and the like.

[0003] Among them, styrene-based thermoplastic elastomers are rich in flexibility and excellent in rubber elasticity at room temperature. Styrene-based thermoplastic elastomers include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), and hydrogenated styrene-ethylene-butylene-styrene block copolymers. Polymers (SEBS) and styrene ethylene propylene styrene block copolymers (SEPS) are known. While pressing, these block copolymers are compressed If the distortion characteristics are insufficient, there is a problem.

Among the styrene-based thermoplastic elastomers, isobutylene is one of the most flexible, excellent rubber elasticity at room temperature, and excellent thermal stability, weather resistance, vibration damping, gas noria, and sealing. An isobutylene-based block copolymer containing a polymer block mainly composed of a polymer block mainly composed of an aromatic vinyl-based compound is known. However, this isobutylene-based block copolymer was not always satisfactory in terms of compression set.

On the other hand, a technique of compounding a rubber and an organic polymer to improve the performance of a thermoplastic elastomer has been known for a long time. In particular, polyolefins such as polypropylene and polyolefins such as EPDM and IIR are known. Many studies have been made on a technique for complexing a crosslinked product of a styrene-based elastomer or a styrene-based elastomer such as SEBS.For example, in the case of an olefin-based thermoplastic elastomer, a crystalline olefin resin and an olefin-based resin are used. A technology for crosslinking a system rubber with an organic peroxide (for example, see Patent Document 1), or the use of a special structure of isobutylene rubber (for example, see Patent Document 2) is disclosed. However, these all use as the rubber component an olefin polymer such as EPDM or IIR in which a double bond is randomly present as a crosslinking point in the olefin polymer, and the crosslinking is not uniform. It was difficult to reduce the hardness.

In addition, the present inventors have developed a low-hardness thermoplastic resin having high gas-tightness that can be used for various applications (see Patent Document 3). Oil components are added, and depending on the application, the gas confidentiality of the material may decrease.

As described above, it is difficult to find a thermoplastic elastomer that has a well-balanced level of flexibility, air permeability, moisture permeability, compression set, injection moldability, etc. at a high level. This was the actual situation.

As for insulators for recording medium drive devices, gaskets for HDDs, shock absorbers for HDDs, etc., those composed of a resin composition using a thermoplastic elastomer have been proposed.Each has some problems. A resin composition suitable for constituting these members has been required. Patent Document 1: Japanese Patent Publication No. 53-21021

Patent Document 2: Japanese Patent Application Laid-Open No. 9-137007

Patent Document 3: International Publication Number WO03 / 027183

Disclosure of the invention

[0006] Under such circumstances, the present invention provides a resin composition which is rich in flexibility, excellent in air permeation resistance and moisture permeation resistance, has good injection moldability, and is capable of injection molding. It is intended to do so.

[0007] The present inventors have conducted intensive studies to develop a resin composition having the above-mentioned excellent functions, and as a result, a specific isobutylene-based triblock copolymer, an ethylene-based polymer and a Z or A resin composition containing a propylene polymer and liquid polybutene, and having specific values for air permeability, moisture permeability, hardness and melt flow rate [MFR], is suitable for the purpose. I found it.

It also contains two types of blends of styrene-based polymer blocks with different molecular weights, isobutylene-based polymer blocks, and styrene-based polymer block strength, and also has air permeability, moisture permeability, hardness, and melt flow rate. It has been found that a resin composition having a specific value for each of the rates [MFR] can meet its purpose.

Furthermore, at least one specific isobutylene-based triblock copolymer and, in some cases, an olefin polymer as a hard component or a soft component of the compound, and the ratio of all hard components to all soft components falls within a specific range. In addition, it has been found that a resin composition having specific values of air permeability, moisture permeability, hardness and melt flow rate [MFR] can be suitable for the purpose.

It has also been found that the above resin composition can be produced by melt-kneading the above-mentioned components under specific conditions. The present invention has been completed based on strong knowledge. Here, the hard component refers to a component having a softening temperature or a melting point higher than room temperature, while the soft component refers to a component that is liquid or rubbery at room temperature. In addition, one polymer molecule contains a hard component and a soft component! / For a polymer, the hard component is called a node segment and the soft component is called a soft segment. .

[0008] That is, the present invention provides: (A-l) (b)-(a)-(b) isobutylene type having (a) a polymer block mainly composed of isobutylene units and (b) a polymer block mainly composed of styrene units. A triblock copolymer, (B-1) an ethylene polymer and a Z or propylene polymer, and (C) liquid polybutene.

(1) Air permeability measured using a 0.5 mm thick sheet sample QilS K7126; A method (differential pressure method), 40 ° C] is less than 200 cm ³ Z (m ² · 24 hr · atm);

(2) Thickness 0. 5 mm moisture permeability was measured using a sheet sample (JIS Z0208; 40 ° C, 9 0% RH) is 2.0gZ (m ² - 24hr) or less,

(3) Hardness QilS 6253 (after 15 seconds)]

(4) Melt flow rate [MFR] (JIS K7210; 190.C, 52.185N (5.325Kgf)) Force OOgZlO component or less, a resin composition (hereinafter referred to as "first invention" There is.),

(A-2) (b) having a weight average molecular weight of 50,000 to 80,000 having (a) a polymer block mainly composed of isobutylene units and (b) a polymer block mainly composed of styrene units. (a) — (b) a type-isobutylene-based triblock copolymer, (B-2) (c) a polymer block mainly composed of isobutylene units, and (d) a polymer block mainly composed of styrene units. A weight-average molecular weight of 90,000 to 130,000 (d)-(c)-(d) -type isobutylene-based triblock copolymer is blended at a mass ratio of 20:80 to 60:40, (1) to (3), and

(4 ') Melt flow rate [MFR] (JIS K7210; 270.C, 98.0665N (10Kgf)) A resin composition characterized by having a force of 0 OOgZlO or less (hereinafter referred to as "second invention"). ), And

(A-3) (a) having a soft segment having a polymer blocking power mainly composed of isobutylene units and (b) a hard segment having a polymer blocking power mainly composed of styrene units, and (b)-(a) -(b) Ratio of total node components including at least one isobutylene-based triblock copolymer and including all hard segments and all soft components including the soft segments Total node components Z (all hard components + (All soft components) characterized by having a mass ratio in the range of 0.25 to 0.40, having the properties of the above (1) to (3), and having the properties of the above (4 ') Fat set Products (hereinafter sometimes referred to as "third invention"),

Is to provide.

According to the present invention, it is possible to provide a resin composition which is rich in flexibility, excellent in air permeability and moisture resistance, has good injection moldability, and is capable of injection molding. . BEST MODE FOR CARRYING OUT THE INVENTION

[0010] The resin composition of the first invention comprises (A-1) (a) a polymer block mainly composed of isobutylene units, and (b) a polymer block mainly composed of styrene units. A composition comprising (b)-(a)-(b) type isobutylene-based triblock copolymer, (B-1) ethylene-based polymer and Z or propylene-based polymer, and (C) liquid polybutene It is.

In the isobutylene-based triblock copolymer as the component (A-1), (a) a polymer block mainly composed of isobutylene units refers to a polymer block containing isobutylene units in an amount of 50% by mass or more, preferably 70% by mass or more. More preferably, it refers to a polymer block occupying 90% by mass or more. The monomer that forms a unit other than the isobutylene unit in the polymer block mainly composed of an isobutylene unit is not particularly limited as long as it is a monomer that can be cationically polymerized. Illustrative are aromatics, gens such as isoprene, butadiene, and dibutylbenzene, aryl ethers, and monomers such as β-pinene. These may be used alone or in combination of two or more.

[0011] Meanwhile, the polymer block composed mainly of a (b) styrene unit, styrene unit 50 mass ^_0/0 or more, preferably 70 mass% or more, more preferably polymer blocks that account for more than 90 wt% Means The monomer that forms a unit other than the styrene unit in the polymer block mainly composed of styrene units is not particularly limited as long as it is a monomer that can be cationically polymerized. Monomers such as aromatic butyls such as olestyrene, ρ-methynolestyrene, tert-butyl styrene, monochlorostyrene, dichlorostyrene, methoxystyrene and indene, aliphatic olefins, gens, aryl ethers and β-pinene Can be illustrated. These may be used alone or in combination of two or more.

The (A-1) component isobutylene-based triblock copolymer used at the time of compounding is (b)-(a) one (b) type, and (a) a polymer block mainly composed of isobutylene units and (b) ) Styrene Although there is no particular limitation on the content ratio of the polymer block mainly composed of units, from the viewpoint of the physical properties of the obtained resin composition, (a) the polymer block mainly composed of isobutylene units has a content of 60 to 60%. It is preferable that the content of (b) the polymer block mainly composed of styrene units is 40 to 15% by mass, and the content of the (a) polymer block is 65 to 80% by mass and the content of the (b) polymer block is 85% by mass. It is particularly preferred that the content of the block is 35 to 20% by mass.

[0012] The weight average molecular weight of the isobutylene-based triblock copolymer of the component (A-1) used at the time of compounding is not particularly limited, but the mechanical properties and moldability of the obtained resin composition are not limited. 50,000-200,000 force S preferred, especially 60,000-150,000 force S preferred. The weight average molecular weight is a value in terms of polystyrene measured by gel permeation chromatography (GPC method).

There is no particular limitation on the method for producing the isobutylene-based triblock copolymer. A conventionally known method can be used. For example, a monofunctional component such as α-chloro-isopropylbenzene, a bifunctional component such as 1,4-bis (α-chloro mouth isopropyl) benzene (also referred to as ρ dicum milk mouth ride) or a 1,3,5 tris (α-chloro mouth isopropyl) ) Trifunctional components such as benzene are used as initiators and chain transfer agents, and Lewis acids such as BC1 and TiCl are used as catalysts.

3 4

A polymer mainly composed of isobutylene units having a controlled molecular weight is formed by using a bifer method (for example, a method disclosed in US Pat. Subsequently, by adding and copolymerizing a monomer mainly composed of styrene, a desired isobutylene-based triblock copolymer can be obtained.

[0013] In the resin composition of the first invention, an ethylene polymer and a Z or propylene polymer are used as the component (B-1).

Examples of the ethylene-based polymer include high-, medium-, and low-density polyethylene, linear low-density polyethylene, ultrahigh-molecular-weight polyethylene, ethylene-vinyl acetate copolymer, and ethylene-ethyl acrylate copolymer. can do.

On the other hand, examples of the propylene-based polymer include a propylene homopolymer, a propylene-ethylene block copolymer, a random copolymer, and a propylene-ethylene-gen compound copolymer. Of these, crystalline polypropylene resins are preferred. Crystalline polypropylene resins include, for example, crystalline isotactic polymers. Tick propylene homopolymer, homopolymer part with low ethylene unit content, ethylene propylene random copolymer, propylene homopolymer power and copolymer part with relatively high ethylene-propylene random copolymer power with relatively high ethylene unit content And a homopolymer or copolymer component in the propylene block copolymer, and a crystalline propylene ethylene α-polymer obtained by copolymerizing an a-olefin such as butene 1. And olefin copolymers. By containing the (II-1) component, fluidity at high temperature is improved, and injection moldability and extrusion moldability are improved.

As the component (II-1), one or more of the above-mentioned ethylene polymers may be used, or one or more of a propylene polymer may be used. These may be used in combination with one or more propylene-based polymers.

[0014] In the resin composition of the first invention, the liquid polybutene used as the component (C) is preferably a liquid polybutene having a number average molecular weight of about 200 to 3,000 mainly containing isobutylene units. Such liquid polybutenes include, for example, butadiene from a C fraction produced by naphtha decomposition.

Four

A low polymer mainly composed of isobutylene obtained by copolymerizing a small amount of butene 1 obtained by using the remaining fraction obtained by extracting benzene as a raw material, or a low polymer of high purity isobutylene or isobutylene A liquid butyl rubber obtained by copolymerizing a small amount of isoprene with butyl rubber can be used. These may be used alone or in combination of two or more. By containing these liquid polybutenes, the resin composition has improved flexibility without deteriorating the steam barrier property.

[0015] The resin composition of the first invention has the following properties.

First, (l), based on the A method of JIS K7126 (differential pressure method), air permeability was measured using a sheet sample with a thickness of 0. 5mm QilS K7126; A method (differential pressure method), 40 ° C] is 200 cm ³ Z (m ² '24 hr 'atm) or less, and has excellent gas nori properties. The air permeability is preferably 180 cm ³ Z (m ² · 24 hr · atm) or less, and more preferably 160 cm V (m ² · 24 hr · atm) or less. The lower limit of the air permeability is not particularly limited, but is usually about 50 cm ³ Z (m ² · 24 hr · atm).

(2) Based on JIS Z0208, measured using a 0.5 mm thick sheet sample Moisture permeability (JIS Z0208; 40 ° C, 90% RH) is less than 2. OgZ (m ² '24hr), and it is excellent in noria against water vapor. The transparent humidity, preferably ^{1. 8g / (m 2 '24hr} ) or less, preferably to be al ^{1. 7g / (m 2' 24hr} ) or less, particularly preferably ^{1. 5g / (m 2 '24hr} ) or less It is. The lower limit of the moisture permeability is not particularly limited, but is usually about 0.5 gZ (m ² '24 hr).

Next, (3) hardness strength measured according to JIS K6253 (after 15 seconds) JIS-A hardness is 30 to 60 degrees. When the hardness is in the above range, the flexibility is good and the material has appropriate mechanical properties.

[0016] Further, (4) Menoleto flow rate [MFR] (JIS K7210; 190.C, 52.185N (5.325 Kgf)) is less than 100 gZlO. When the MFR is in the above range, good injection moldability and good mechanical properties are obtained. The preferred MFR is between 10 and 80 gZlO, more preferably between 10 and 60 gZlO.

Also, (5) Tensile strength and elongation (JIS K6251; dumbbell-shaped No. 3, 23 ° C) are preferably 5 MPa or more and 400% or more, respectively, preferably 6 MPa or more and 500% or more. Is more preferable.

[0017] The content ratio of the component (A-1), the component (B-1) and the component (C) in the resin composition of the first invention is as follows because the resin composition has the above-mentioned properties. The component (B-1) is preferably 1 to 50 parts by mass, more preferably 5 to 40 parts by mass, per 100 parts by mass of the component A-1). The component (C) is preferably 1 to 40 parts by mass, more preferably 5 to 40 parts by mass. In particular, it is preferable that the component (B-1) is 10 to 30 parts by mass and the component (C) is 15 to 35 parts by mass.

[0018] The resin composition of the second invention comprises (A-2) (a) a polymer block mainly composed of isobutylene units, and (b) a polymer block mainly composed of styrene units. A (b)-(a)-(b) -type isobutylene-based triblock copolymer having a weight average molecular weight of 50,000 to 80,000, and a polymer block mainly composed of (B-2) (c) isobutylene units; (d) a blend with a (d) (c) (d) type isobutylene triblock copolymer having a weight average molecular weight of 90,000 to 130,000 and a polymer block mainly composed of styrene units. .

The isobutylene-based triblock copolymers (A-2) and (B-2) The polymer blocks mainly composed of isobutylene units shown in (a) and (c) are the same as the polymer block mainly composed of (a) isobutylene units in the first invention.

The (b) and (d) polymer blocks mainly composed of styrene units are the same as the (b) polymer blocks mainly composed of styrene units in the first invention.

[0019] The isobutylene-based triblock copolymer of the component (A-2) and the isobutylene-based triblock copolymer of the component (B-2) are of the (b)-(a)-(b) type and (d)-(c)-(d) type, (a) the content ratio of a polymer block mainly composed of isobutylene units and (b) a polymer block mainly composed of styrene units, and (c) isobutylene units. There are no particular restrictions on the content ratio of the polymer block mainly composed of styrene units and the polymer block mainly composed of (d) styrene units, but from the viewpoint of the physical properties of the obtained resin composition, each of the polymer blocks mainly contains isobutylene units. It is preferable that the polymer block having 60 to 85% by mass and the polymer block mainly containing styrene units have a power of 0 to 15% by mass, and the polymer block mainly containing isobutylene units have 65 to 80% by mass. And the polymer block mainly composed of styrene units is 35 It is particularly preferred that the content is 20 to 20% by mass.

[0020] In the second invention, the content ratio of the polymer block mainly composed of isobutylene units and the polymer block mainly composed of styrene units is the same as that of the isobutylene triblock of the component (A-2). The coalesced and the isobutylene-based triblock copolymer of the component (B-2) may be the same or different.

In the second invention, the weight average molecular weight of the isobutylene-based triblock copolymer of the component (A-2) is selected from the range of 50,000 to 80,000, and the component (B-2) The weight average molecular weight of the isobutylene triblock copolymer is selected from the range of 90,000 to 130,000. When the number average molecular weight of the component (A-2) is less than 50,000, the obtained resin composition has too high a fluidity to cause burrs at the time of injection molding, and is stable in extrusion molding. A molded product cannot be obtained. On the other hand, when the number average molecular weight of the component (B-2) exceeds 130,000, moldability deteriorates and injection molding becomes difficult. The weight average molecular weight is a value in terms of polystyrene measured by a gel permeation chromatography method (GPC method). [0021] In the second invention, the mixing ratio of the isobutylene-based triblock copolymer of the component (A-2) and the isobutylene-based triblock copolymer of the component (B-2) is 20:80 by mass. 660: 40 is selected. When the mixing ratio is within the above range, a resin composition having predetermined properties can be obtained, and the object of the present invention can be achieved. A preferred compounding ratio is in the range of 25:75 to 45:55 by mass.

The method for producing the isobutylene-based triblock copolymer is the same as the method for producing the (A1) component isobutylene-based triblock copolymer of the first invention.

The resin composition of the second invention has the same properties as (1) air permeability, (2) moisture permeability, and (3) hardness as the resin composition of the first invention. In addition, it has the following properties.

(4) Melt flow rate [MFR] (JIS K7210; 270.C, 98.0665N (10Kgf)) is less than 5 OOOgZlO. When the MFR is within the above range, good injection moldability and good mechanical properties are obtained. A preferred MFR is 3000 gZlO or less, more preferably 2000 gZlO or less, particularly preferably lOOOOgZlO or less.

Furthermore, it is preferable that the (5 ') tensile strength and elongation (JIS K6251; dumbbell-shaped No. 3, 23 ° C) be 5 MPa or more and 300% or more, respectively, 6 MPa or more and 500% or less. More preferably, it is above.

[0023] The resin composition of the third invention comprises (A-3) (a) a soft segment having a polymer block strength mainly composed of isobutylene units, and (b) a polymer block mainly composed of styrene units. (B)-(a)-(b) -type isobutylene-based triblock copolymer having at least one kind having a hard component and a hard component. ) A composition containing an olefin polymer having 2 to 6 carbon atoms.

In the resin composition of the third invention, the ratio of the total node component to the total soft component in the composition is 0.25 to 0.2% by mass ratio of the total hard component Z (the total hard component + the total soft component). Selected within the range of 0.40. When this ratio is in the above range, it becomes possible to obtain a resin composition that satisfies predetermined physical properties described later. When the mass ratio is large, the flexibility is insufficient, and when it is small, the air permeability and the moisture permeability tend to be large. The preferable mass ratio of all hard components Z (all hard components + all soft components) is in the range of 0.28 to 0.37. [0024] In the isobutylene-based triblock copolymer as the component (A-3), the polymer block mainly composed of (a) isobutylene unit is mainly composed of the (a) isobutylene unit in the first invention. Same as for the polymer block.

The (b) polymer block mainly composed of styrene units is the same as the (b) polymer block mainly composed of styrene units in the first invention.

Further, the isobutylene-based triblock copolymer of the component (A-3) used at the time of compounding is of the (b)-(a)-(b) type, and (a) a polymer block mainly composed of isobutylene units. The content ratio of the polymer block mainly composed of (b) styrene units is the same as the content ratio of (a) and (b) in the first invention.

[0025] In the third invention, even if the mass ratio of all the node components Z (all the node components + all the soft components) is in the above range, the isobutylene-based triblock of the component (A-3) is When only one polymer is used, it is difficult to obtain a resin composition having predetermined physical properties described below. Therefore, in the present invention, as the component (A-3), the force of using two or more isobutylene-based triblock copolymers having different molecular weights in combination, or as the component (A-3), an isobutylene-based triblock copolymer Preferably, one or more copolymers are used, and as the component (B-3), a olefin-based polymer having 2 to 6 carbon atoms, which is a hard component and Z or a soft component, is preferably used.

In order to obtain a resin composition having predetermined physical properties without using the component (B-3), for example, the following method can be used.

[0026] As the component (A-3), (a-1) an isobutylene-based triblock copolymer having a weight average molecular weight in the range of 50,000 to 80,000, and (a-2) a weight average molecular weight An isobutylene-based triblock copolymer in the range of 90,000 to 130,000 is blended at a weight ratio of 20:80 to 60:40, and the hard segment Z (node segment + soft segment) mass A resin composition having specified physical properties can be obtained by using a resin having a specific gravity in the range of 0.25 to 0.40, preferably 0.28 to 0.37.

When the weight average molecular weight of the component (a-1) is 50,000 or more, the compression set becomes small, and the resilience at the time of heat molding becomes good. On the other hand, when the weight average molecular weight of the component (a-2) is 130,000 or less, the resin composition has good injection moldability. In addition, this weight flat The average molecular weight is a value in terms of polystyrene measured by gel permeation chromatography (GPC) in the same manner as described above.

When the mixing ratio of the components (a-1) and (a-2) is within the above range, a resin composition having predetermined properties can be obtained, and the object of the present invention can be achieved. A preferred blending ratio is in the range of 25:75 to 45:55 by mass.

[0027] Further, in the third invention, when a hard component and a olefin polymer having 2 to 6 carbon atoms as a soft component are used as the component (B-3), the hard component may be, for example, an ethylene polymer. Ability to use at least one selected polymer such as coalesce, propylene-based polymer, and methylpentene-based polymer Among these, ethylene-based polymer and Z or propylene-based polymer are preferable.

[0028] Examples of the ethylene polymer include high-, medium-, and low-density polyethylene, linear low-density polyethylene, ultra-high-molecular-weight polyethylene, ethylene-vinyl acetate copolymer, and ethylene-ethyl acrylate copolymer. And the like.

On the other hand, examples of the propylene-based polymer include a propylene homopolymer, a propylene-ethylene block copolymer, a random copolymer, and a propylene-ethylene-gen compound copolymer. Of these, crystalline polypropylene resin is preferred. Examples of the crystalline polypropylene resin include an isotactic propylene homopolymer having crystallinity, an ethylene propylene random copolymer having a small ethylene unit content, and the like. A propylene block copolymer comprising a homo part having an unified, propylene homopolymer power and a copolymer part having an ethylene-propylene random copolymer having a relatively large ethylene unit content, and further comprising the propylene block copolymer. And a crystalline propylene ethylene α-olefin copolymer comprising a copolymer of a-olefin such as butene 1 and the like.

[0029] As the soft component, liquid polybutene is preferably used. As the liquid polybutene, one having a number average molecular weight of 200 to 3,000 mainly containing isobutylene units is preferable, and one having a number average molecular weight of about 1,000 to 3,000 is more preferable. As such liquid polybutene, for example, the C fraction power generated by naphtha decomposition The remaining fraction obtained by extracting butadiene is

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Isobutylene obtained by copolymerizing some butene-11 obtained as it is as raw material Or a low-polymer of high-purity isobutylene or a liquid butyl rubber obtained by copolymerizing isobutylene with a small amount of isoprene. These may be used alone or in combination of two or more.

When the component (B-3) is used in the resin composition of the present invention, the ratio of the total hard component to the total soft component in the composition is determined by the ratio of the total hard component Z (the total hard component + the total soft component) to the mass. By using i: Dani so as to be in the range of 0.25 to 0.40, preferably 0.28 to 0.37, a resin composition having predetermined physical properties can be obtained. .

[0030] The resin composition of the third invention has the same properties as the resin composition of the first invention with respect to (1) air permeability, (2) moisture permeability, and (3) hardness, It has the same properties as 4 ′) MFR and (5 ′) tensile strength and elongation as the resin composition of the second invention.

In addition, (6) the compression set measured at 70 ° C for 22 hours based on JIS K6262 is preferably 95% or less, more preferably 90% or less, and Excellent permanent distortion properties. That is, it has good resilience in heat molding.

[0031] The resin composition of the present invention includes the component (A-1), the component (A-2), the component (A-3),

In addition to component 1), component (B-2), component (B-3), and component (C), if desired, for example, other thermoplastic elastomers and other components may be used as long as the object of the present invention is not impaired. Olefin resins, plasticizers, fillers, reinforcing agents, silane coupling agents, adhesion-imparting agents, radical crosslinking agents and crosslinking assistants, antioxidants (phenolic antioxidants, aromatic amines) Antioxidants, sulfur hydroperoxide decomposers, phosphorus hydroperoxide decomposers, benzotriazole UV absorbers, salicylate UV absorbers, benzophenone UV absorbers, hindered amine light stabilizers , Nickel-based light stabilizers), photo-curable resins, waxes, flow improvers, lubricants, surfactants, foaming agents, flame retardants, pigments, and other various additives.

[0032] The resin composition of the present invention can be efficiently produced according to the method of the present invention described below.

In the method of the present invention, the above-mentioned components and various optional components used as required are put into a melt-kneading apparatus, and melt-kneaded at a temperature of 140 to 230 ° C. Thus, a resin composition having the above-mentioned properties can be produced.

If the temperature during melt-kneading is within the above range, decomposition (block cutting) of the isobutylene-based triblock copolymer of the components (A-1), (A-2), and (A3) is suppressed. In addition, a resin composition having predetermined MFR and other physical properties can be obtained. Preferably the temperature is between 180 and 230 ° C, more preferably the temperature is between 200 and 220 ° C.

[0033] Examples of the melt kneading apparatus include a closed kneading apparatus such as Labo Plastomill, Brabender, Banbury mixer 1, kneader, and roll, or a batch kneading apparatus, a single screw extruder, and a twin screw extruder. And the like can be used.

The resin composition of the present invention thus obtained can be molded using a molding method and a molding apparatus generally used for a thermoplastic resin composition, and examples thereof include extrusion molding, injection molding, and the like. Melt molding can be performed by press molding, blow molding, or the like.

The resin composition of the present invention has a high level of balance of flexibility, air permeability resistance, moisture permeability resistance, injection moldability, etc., and is molded into a sheet, molded article, adhesive, foam, etc. Civil engineering sheets: sheets such as waterproof sheets, sealing materials such as packing materials, sealing materials, gaskets, plugs, damping materials for construction, damping materials for automobiles, vehicles and home appliances such as CD dampers, vibration damping materials, and It can be used for insulators for recording media drives, gaskets for HDDs, shock absorbers for HDDs, and tubes for transporting medical fluids. Example

[0034] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

In addition, the physical property evaluation in each example was performed by the following method.

(1) Hardness

The JIS-Α hardness was measured according to JIS K6253 (after 15 seconds).

(2) MFR

190 according to JIS K7210. C, 52.185N (5.325 Kgf) conditions (Condition A) or 270 ° C, 98.0665N (10 Kgf) conditions (Condition B).

(3) Tensile strength and elongation

According to JIS K6251, dumbbell shape No. 3 was measured at 23 ° C. (4) Air permeability

Measured on a 0.5 mm thick sheet according to JIS K7126 A method (differential pressure method) 40 ° C

(5) Moisture permeability

In accordance with JIS Z0208, a sheet having a thickness of 0.5 mm was measured at 40 ° C and 90% RH.

(6) Compression set

According to JIS K6262, it was measured at 70 ° C. for 22 hours.

Examples 1-3 and Comparative Examples 1-3

Each component of the kind and amount shown in Table 1 was put into a rubber kneading dough and melt-kneaded at 150 ° C. for 60 minutes to prepare a resin composition, and its performance was evaluated. The results are shown in Table 1. The ingredients used in each example are as follows.

Polymer A:. Styrene isobutylene styrene triblock copolymer, weight average molecular weight of about 65,000, a styrene polymer block content of 30 mass ^_0/0

Polymer B: Polypropylene [Novatech BC05B manufactured by Nippon Polychem Co., Ltd.]

Polymer C: liquid polybutene [Nisseki Chemical Co., Ltd., trademark “HV300”, number average molecular weight 1400] [0036] [Table 1]

Table 1

Examples 4 and 5 and Comparative Examples 4 to 7

Each component of the kind and amount shown in Table 2 was put into a single-shaft kneader, melt-kneaded at 200 ° C. for 60 minutes to prepare a resin composition, and its performance was evaluated. The results are shown in Table 2. Note that in each example As the compounding raw materials used, those described above and the following were used.

Polymer D: Styrene isobutylene styrene triblock copolymer, weight average molecular weight about 100,000, styrene polymer block content 30% by mass

[Table 2]

Table 2

* 1 Could not be extruded.

Examples 6 to: L1 and Comparative Examples 8, 9

Each component of the kind and amount shown in Table 3 was put into a rubber dough, melt-kneaded at 150 ° C. for 60 minutes to prepare a resin composition, and its performance was evaluated. Table 3 shows the results. In addition, as the compounding raw materials used in each example, those described above and the following were used.

Polymer E: styrene isobutylene styrene triblock copolymer, number average molecular weight Mn = 71,300, weight average molecular weight Mw = 113,000, Mw / Mn = l.55, styrene polymer block content 30% by mass

Polymer F: styrene isobutylene styrene triblock copolymer, number average molecular weight Mn = 45,700, weight average molecular weight Mw = 63,900, Mw / Mn = l.40, styrene polymer block content 30% by mass

[0040] [Table 3] Table 3

Industrial applicability

The resin composition of the present invention has a high level of balance of flexibility, air permeability resistance, moisture permeability resistance, compression set characteristics, injection moldability, extrusion moldability, and the like. It can be used for insulators, HDD gaskets, HDD shock absorbers, medical infusion transport tubes, and the like.

Claims

Claims [1] (A-1) (b)-(a)-(a) comprising (a) a polymer block mainly composed of isobutylene units and (b) a polymer block mainly composed of styrene units. b) Type isobutylene-based triblock copolymer, (B-1) ethylene-based polymer and Z or propylene-based polymer, and (C) liquid polybutene, (1) 0.5 mm thick sheet sample Air permeability measured by using QilS K7126; A method (differential pressure method), 40 ° C] is 200cm3Z (m2 · 24hr · atm) or less, (2) Measured using a 0.5mm thick sheet sample (JIS Z0208; 40 ° C, 90% RH) is less than 2.0gZ (m2'24hr). (3) Hardness QilS 6253 (after 15 seconds)] (4) Melt flow rate [MFR] (JIS K7210; 190.C, 52.185N (5.325Kgf)) Force of less than OOgZlO. [2] (A-2) (a) having a polymer block mainly composed of isobutylene units and (b) a polymer block mainly composed of styrene units, having a weight average molecular weight of 50,000 to 80,000 ( b) — (a) — (b) type isobutylene triblock copolymer, (B-2) (c) a polymer block mainly composed of isobutylene units, and (d) a polymer mainly composed of styrene units (D)-(c)-(d) -type isobutylene-based triblock copolymer having a weight average molecular weight of 90,000 to 130,000 and having a weight ratio of 20:80 to 60:40. (1) Air permeability measured using a 0.5 mm thick sheet sample QilS K7126; Method A (differential pressure method), 40 ° C] is less than 200cm3Z (m2 · 24hr · atm) (2) The moisture permeability (JIS Z0208; 40 ° C, 90% RH) measured using a 0.5 mm thick sheet sample is 2.0 gZ (m2 '24 hr) or less, and (3) Hardness QilS 6253 (after 15 seconds)] Ka ^ [13—eight hardness And (4 ') melt flow rate [MFR] (JIS K7210; 270.C, 98.0665N (10Kgf)) force 000 g / 10 min or less. Fat composition. [3] (A-3) having (a) a soft segment mainly composed of isobutylene units and also having a polymer blocking power, and (b) a hard segment mainly composed of styrene units and also having a polymer blocking ability. (B)- (a)-(b) Proportion of all node components including at least one type of isobutylene-based triblock copolymer and including hard segments and all soft components including soft segments Total node components Z (all (Hard component + all soft components) mass ratio in the range of 0.25 to 0.40,

(1) Air permeability measured using a 0.5 mm thick sheet sample QilS K7126; A method (differential pressure method), 40 ° C] is 200 cm ³ Z (m ² '24 hr'atm) or less ,

(2) Thickness 0. 5 mm moisture permeability was measured using a sheet sample (JIS Z0208; 40 ° C, 9 0% RH) is 2. OgZ (m ² - 24hr) or less,

(3) Hardness QilS 1: 6253 (after 15 seconds)]

(4,) Melt flow rate [MFR] (JIS K7210; 270.C, 98.0665N (10Kgf)) is 50

OOgZlO or less,

A fat composition characterized by the following.

[4] The resin composition according to claim 1, wherein the tensile strength and elongation (JIS K6251; dumbbell-shaped No. 3, 23 ° C) force are 5 MPa or more and 400% or more, respectively.

[5] Isobutylene triblock copolymer power of component (A-1) used during compounding (b) A polymer block mainly composed of styrene units containing 15 to 40% by mass and having a weight average molecular weight of 50

2. The resin composition according to claim 1, wherein the resin composition has a viscosity of from 2,000 to 200,000.

[6] Liquid polybutene force of component (C) Number average molecular weight of mainly isobutylene unit 200 to 3

2. The resin composition according to claim 1, wherein the resin composition is

[7] The resin composition according to claim 1, wherein the resin composition contains 1 to 50 parts by mass of the component (-1) and 100 parts by mass of the component (1) to 100 parts by mass of the component (A-1).

[8] (5) The resin composition according to claim 2, wherein the tensile strength and elongation (JIS K6251; dumbbell-shaped No. 3, 23 ° C) force are 5 MPa or more and 300% or more, respectively.

[9] Isobutylene-based triblock copolymer of component (A-2) and isobutylene-based triblock copolymer of component (B-2) used for compounding: (b) Polymer block mainly composed of styrene unit (D) a polymer block mainly composed of styrene units.

3. The resin composition according to claim 2, wherein the resin composition comprises about 40% by mass.

[10] (5) Tensile strength and elongation (JIS K6251; dumbbell-shaped No. 3, 23 ° C) Force 5MPa or more and 300% or more, respectively; and (6) Compression set (JIS K6262; 70 °) C, 22 hours 4. The resin composition according to claim 3, wherein the content is 95% or less.

[11] Isobutylene-based triblock copolymer power of component (A-3) used during compounding (b) A polymer segment mainly composed of styrene units, which contains 15 to 40% by mass of a hard segment and also has a weight average molecular weight The resin composition according to claim 3, wherein the resin composition has a molecular weight of 50,000 to 200,000.

12. The resin composition according to claim 3, comprising (B) an olefin polymer having 2 to 6 carbon atoms as a hard component and a Z or soft component in the whole formulation.

[13] The resin composition according to claim 12, which is a hard component power of the component (B-3), which is an ethylene polymer and a Z or propylene polymer.

14. The resin composition according to claim 12, wherein the soft component of the component (B) is liquid polybutene.

[15] The resin composition according to claim 14, wherein the liquid polybutene has a number average molecular weight of 200 to 3,000 mainly containing isobutylene units.

[16] The resin composition according to claim 3, which is a mixture of two or more isobutylene-based triblock copolymers having different molecular weights from each other.

[17] Component (A-1), component (A-2), or component (A-3), component (B-1) or component (B-2), and component (C) are charged to the melt kneading apparatus. The method for producing a resin composition according to any one of claims 1 to 16, wherein the mixture is melt-kneaded at a temperature of 140 to 230 ° C.