JPH10204249A - Damping material and damping member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a damping thermoplastic material, excellent in damping properties of a lightweight material, especially creep characteristics, having a low hardness and low in compression set at high temperatures and capable of suppressing the bleeding of a compounded low-molecular weight component and a damping member using the material. SOLUTION: This damping thermoplastic material comprises a styrene- vinylisoprene-styrene copolymer cross-linked with an organic peroxide, a thermoplastic material and a softener and has preferably 0-25 deg. JIS A hardness. The amount of the compounded cross-linked styrene-isoprene-styrene copolymer is preferably 5-25wt.%. The copolymer is preferably contained in a solid dispersed state in a matrix comprising the thermoplastic material and the softener.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping material made of a thermoplastic material, and more particularly, to a portable CD, a CD-ROM.
The present invention relates to an anti-vibration material suitably used for anti-vibration of small and light-weight objects such as ROMs and optical disks.

[0002]

2. Description of the Related Art In recent years, disks on which information such as CD-ROMs are written are widely used, and these are mechanically vulnerable to external and internal vibrations. For this reason, an insulator such as a synthetic rubber is attached for the purpose of vibration isolation.
In addition, small and lightweight mechanical devices such as mini-discs, optical discs such as DVDs, and small high-performance microphones for small videos and micro tape recorders are also provided.
The issue of vibration isolation is becoming more important.

Conventionally, as a vibration damping material for lightweight objects such as small microphones and CD-ROMs, synthetic rubbers such as silicone rubber, general vulcanized rubbers such as butyl rubber, gels, oil dampers and the like have been used. When the hardness of the rubber material is designed to be about 20 ° to 30 ° on the JIS-A scale, the softener contained in the rubber bleeds, and the workability deteriorates. When used as a vibration isolating member, there has been a problem that the vibration isolating performance such as creep characteristics deteriorates when used for a long time.

[0004] For this reason, low-frequency vibration isolation, which cannot be achieved by the characteristics of the material, has been achieved by molding the rubber, which is the vibration-isolating material, into a complicated shape such as thin molding. However, when a rubber material is molded into such a shape, if the thickness is reduced, the strength is reduced, the material is easily damaged during molding, and it is difficult to increase the productivity. Further, in the vulcanized rubber, there is a concern that sulfur as a vulcanizing agent may remain and affect electronic components. In the case of a silicone rubber, there is a problem that a low molecular weight silicone may cause contact failure.

[0005] Further, it is conceivable to select a softer material, for example, a gel, in order to achieve vibration isolation in a low frequency range. However, a material having a low hardness is easily deformed by compression.
There is a concern that the anti-vibration property will decrease over time, or that low molecular components in the material will bleed and adversely affect precision disks that require anti-vibration.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and is intended to reduce the weight of a light-weight material by using a material having a low hardness and capable of suppressing the bleeding of the compounded low-molecular component. An object of the present invention is to provide a vibration-proof material having excellent vibration-proof properties, particularly, a creep characteristic, and a vibration-proof member having excellent vibration-proof properties and durability using the material.

[0007]

According to the present invention, there is provided a vibration damping material comprising:
Styrene-vinyl isoprene-styrene block copolymer cross-linked by an organic peroxide, a thermoplastic material,
And a softener.

Here, styrene-vinyl isoprene cross-linked by an organic peroxide contained in the vibration damping material is used.
It is preferable that the content of the styrene block copolymer is 5 to 25% by weight.

Further, a vibration isolating member of the present invention is characterized by using the above-mentioned vibration isolating material. In the anti-vibration material of the present invention, a low-hardness material is obtained by combining a thermoplastic material and a softener, and further comprises a styrene-vinyl isoprene-styrene block copolymer and a thermoplastic material. By adding an organic peroxide to the thermoplastic material, the vinyl group portion of the styrene-vinyl isoprene-styrene block copolymer can be selectively crosslinked, so that an unprecedented improvement in creep characteristics can be achieved.

[0010] In addition, since the vibration-proof material has good releasability, even if it is formed into a sheet and laminated and stored, the materials do not stick to each other and can be smoothly peeled off. After that, the productivity of the vibration damping material does not decrease.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The vibration damping material of the present invention is a material having thermoplasticity comprising a styrene-vinyl isoprene-styrene block copolymer crosslinked with an organic peroxide, a thermoplastic material, and a softener. However, what is contained in the anti-vibration material of the present invention is not limited to the above three components, and may contain various additives and improvers as long as the effects of the present invention are not impaired.

The styrene-vinyl isoprene-styrene block copolymer used in the present invention is not particularly limited, as long as it contains a styrene block and an isoprene block having a vinyl group and can be crosslinked with an organic peroxide. Can be used arbitrarily. The weight ratio of styrene block / isoprene block having a vinyl group is 10
It is preferably about / 90 to 90/10. Examples of commercially available products suitably used in the present invention include, for example, Hibler VS-1 (trade name) manufactured by Kuraray Co., Ltd.

In the vibration damping material of the present invention, the amount of the copolymer is preferably 5 to 50% by weight.
Further, the content is preferably 5 to 25% by weight. If the amount is less than 5% by weight, the creep properties are not sufficiently improved, and if it exceeds 50% by weight, the fluidity during molding deteriorates.

The organic peroxide used as a crosslinking agent is not particularly limited as long as it is an organic peroxide capable of crosslinking a vinyl group. Specifically, for example, t-butylcumyl peroxide is used. , 2,5-dimethyl-2,5-
Di (t-butylperoxy) -hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) -hexane, t-butylperoxybenzoate, dicumyl peroxide, diisopropylbenzohydroperoxide, 1, 3-bis- (t-butylperoxyisopropyl) -benzene, benzoyl peroxide, 1,1
-Di (t-butylperoxy) -3,3,5-trimethylcyclohexane and the like, and preferable commercial products include Kayabutyl C (trade name) manufactured by Kayaku Akzo.

In order to promote a crosslinking reaction by a crosslinking agent,
A crosslinking aid can be added. As a crosslinking aid,
Examples include divinylbenzene, trimethylolpropane triacrylate, ethylene dimethacrylate, diallyl phthalate, quinone dioxime, phenylene bismaleimide, polyethylene glycol dimethacrylate, and unsaturated silane compounds. These organic peroxides and crosslinking aids are 0.1% by weight based on 100 parts by weight of the whole compounding material.
In the range of from 5 to 5 parts by weight, the degree of crosslinking can be adjusted arbitrarily. These organic peroxides and crosslinking assistants may be used in combination of two or more, if necessary.
When an unsaturated silane compound is used as a crosslinking aid, crosslinking can be further advanced by contact with moisture in the presence of a silanol condensation catalyst.

In the present invention, as the thermoplastic material,
Number average molecular weight of 20,000 or more, especially 30,000
Above all, especially 40,000 or more thermoplastic thermoplastic materials are preferable, for example, various thermoplastic elastomers such as styrene (butadiene styrene, isoprene styrene, etc.), ester, amide, urethane, etc. Hydrogenated, other modified products, styrene (ethylene styrene, propylene styrene, etc.),
ABS type, olefin type (ethylene type, propylene type,
Ethylene propylene type), vinyl chloride type, acrylate type (methyl acrylate type, etc.), methacrylate type (methyl methacrylate type, etc.), carbonate type, acetal type, nylon type, halogenated polyether type (chlorinated) Polyether type), halogenated olefin type (tetrafluoroethylene type, fluorinated ethylene chloride type, fluoroethylene propylene type etc.), cellulose type (acetylcellulose type, ethylcellulose type etc.),
Examples thereof include thermoplastic resins such as vinylidene-based, vinyl butyral-based, and alkylene oxide-based (such as propylene oxide-based), and rubber-modified products of these resins.

As a specific thermoplastic material, it is particularly preferable to use a thermoplastic material having both a portion where a hard block such as a crystal structure and a cohesive structure is easily formed and a soft block such as an amorphous structure. Specifically, the following may be mentioned.

A block copolymer of crystalline polyethylene and an ethylene / butylene-styrene random copolymer obtained by hydrogenating a block copolymer of polybutadiene and a butadiene-styrene random copolymer.

It is obtained by hydrogenating a block copolymer of polybutadiene and polystyrene, a block copolymer of polyisoprene and polystyrene, or a block copolymer of polybutadiene or a random copolymer of ethylene-butadiene and polystyrene. For example, a styrene-ethylene / butylene-styrene block copolymer, such as a diblock copolymer of crystalline polyethylene and polystyrene, and a triblock copolymer of styrene-ethylene / butylene-styrene.

A block copolymer in which crystalline polyethylene is linked to one or both ends of an ethylene / butylene copolymer.

Ethylene-propylene rubber. A hydrogenated block copolymer obtained by hydrogenating a styrene-vinyl isoprene-styrene block copolymer.

Among these, the block copolymers composed of at least one polymer block mainly composed of a vinyl aromatic compound and at least one polymer block mainly composed of a conjugated diene compound are particularly preferred. A hydrogenated block copolymer obtained by the addition and having an average molecular weight of 150,000 to 400,000 is preferred.

That is, at least one (one segment) polymer block mainly composed of a vinyl aromatic compound is used.
And those obtained by hydrogenating a block copolymer composed of at least one polymer block mainly composed of a conjugated diene compound, and preferably at least two polymer blocks mainly composed of a vinyl aromatic compound. A block copolymer having at least one polymer block mainly composed of a conjugated diene compound (for example, a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, etc.) is hydrogenated. The resulting hydrogenated block copolymer is more preferred.

Further, as a hydrogenated block copolymer similar to the hydrogenated block copolymer, a modified vinyl aromatic compound to which a molecular unit containing a carboxylic acid group, a maleic anhydride group or a derivative group thereof is bonded is used. A hydrogenated block copolymer obtained by hydrogenating a block copolymer containing at least one of a main polymer block or a main conjugated diene compound polymer block is also preferable.

The hydrogenated block copolymer represented by the styrene-ethylene / butylene-styrene block copolymer and the styrene-ethylene / propylene-styrene block copolymer has an average molecular weight of 150,
If it is less than 000, the compression set is deteriorated and the durability of the vibration damping effect is reduced. If it exceeds 400,000, the fluidity of the material is reduced and the moldability is deteriorated. Preferably, there is.

The content of the amorphous styrene block in the block copolymer is 10 to 70% by weight, preferably 15% by weight.
It is desirable that the amount is in the range of -60% by weight. The glass transition temperature (Tg) of the amorphous styrene block is 60 ° C.
The temperature is preferably 80 ° C. or higher. As the polymer of the portion connecting the amorphous styrene blocks at both ends, an amorphous polymer is also preferable, for example, an ethylene-butylene copolymer, a butadiene polymer,
Examples include isoprene polymers, and these blocks or random copolymers may be used.

These various thermoplastic materials are mainly used alone, but two or more kinds may be blended and used.

As the softening agent used in the present invention, it is preferable to use a low molecular weight material having a number average molecular weight of less than 20,000, and as a physical property, the viscosity at 100 ° C. is 5 × 10 ⁵ centipoise. Hereinafter, especially 1 × 10
It is preferably ⁵ centipoise or less, and from the viewpoint of molecular weight, the number average molecular weight is preferably less than 20,000, especially 10,000 or less, particularly preferably 5,000 or less. Usually, a liquid or liquid material at room temperature is suitably used as such a softener. Further, either a hydrophilic or hydrophobic softener can be used. The softener is not particularly limited, but the following are suitable. Various types of rubber or resin softeners such as mineral oils, vegetable oils, and synthetic oils, and examples of mineral oils include naphthenic and paraffinic process oils. Vegetable oils include castor oil, cottonseed oil, syrup oil, rapeseed oil, soybean oil,
Palm oil, palm oil, peanut oil, wood wax, pine oil,
Olive oil and the like. Among them, one or more selected from paraffinic oil, naphthenic oil, and polyisobutylene oil of mineral oils, and those having an average molecular weight of 450 to 5,000 are preferable. In the oil preferably used as the softening agent, if the average molecular weight is less than 450, the compression set is deteriorated, and the durability of the vibration damping effect is reduced.
If it exceeds 000, stickiness occurs on the surface of the obtained vibration damping material, so that the average molecular weight is preferably in the above range.

One of these softeners may be used alone, or two or more thereof may be used in combination as long as they have good compatibility with each other.

The amount of these softeners is 50 to 500 parts by weight, especially 30 to 300 parts by weight, based on 100 parts by weight of the total of the styrene-vinylisoprene-styrene block copolymer and the thermoplastic material. Is preferred.
If the compounding amount is less than 50 parts by weight, a sufficiently low hardness cannot be achieved, and the flexibility of the material becomes insufficient. If the compounding amount exceeds 500 parts by weight, bleeding of the softening agent is liable to occur. Any of these methods is not preferable from the viewpoint of the anti-vibration effect.

The vibration-proof material of the present invention may contain a polyphenylene ether resin for the purpose of improving the compression set of the material, the durability of the vibration-proof effect and the durability of the vibration-proof material. Can be. The polyphenylene ether resin used here is a homopolymer composed of a bonding unit represented by the following formula or a copolymer containing the bonding unit.

[0033]

Embedded image

In the formula, R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom or a hydrocarbon group.

As the polyphenylene ether resin, known resins can be used. Specifically, for example, poly (2,2)
6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), poly (2,6-diphenyl-1,4-phenylene ether), poly (2- Methyl-6-phenylene-1,
4-phenylene ether), poly (2,6-dichloro-)
1,4-phenylene ether) and the like.
A polyphenylene ether copolymer such as a copolymer of 2,6-dimethylphenol and a monovalent phenol (for example, 2,3,6-trimethylphenol or 2-methyl-6-butylphenol) can also be used. Among them, poly (2,6-dimethyl-1,4-phenylene ether) and a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol are preferable, and further,
Poly (2,6-dimethyl-1,4-phenylene ether) is preferred.

The blending amount of the polyphenylene ether resin is as follows:
It can be suitably selected in the range of 10 to 250 parts by weight based on the total amount of the styrene-vinyl isoprene-styrene block copolymer and the thermoplastic material. If the amount exceeds 250 parts by weight, the hardness of the thermoplastic material is increased, the flexibility is lost, and there is a possibility that the vibration-proofing property of a light-weight material is deteriorated. Are not preferable because of insufficient.

[0037] The anti-vibration material according to the present invention may further contain the following fillers, if necessary.
In other words, clay, diatomaceous earth, silica, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxide, mica, graphite, flaky inorganic fillers such as aluminum hydroxide, various metal powders, wood chips, glass powder, ceramics Granular or powdery solid fillers such as powder, granular or powdery polymer, and other various natural or artificial short fibers and long fibers (eg, straw, wool, glass fiber, metal fiber, various other polymer fibers, etc.) Can be blended.

The weight can be reduced by blending a hollow filler, for example, an inorganic hollow filler such as a glass balloon or a silica balloon, or an organic hollow filler made of polyvinylidene fluoride or a polyvinylidene fluoride copolymer. Furthermore, it is also possible to mix various foaming agents to improve various physical properties such as weight reduction.
It is also possible to mechanically mix gas during mixing or the like.

In addition to the above-mentioned components, known additives such as resin components can be used in combination with the above-mentioned components for improving various properties.

As the resin component, for example, a polyolefin resin or a polystyrene resin can be used in combination. By adding these, the workability of the anti-vibration material,
Heat resistance can be improved. Examples of the polyolefin resin include polyethylene, isotactic polypropylene, and a copolymer of propylene with a small amount of other α-olefin (eg, a propylene-ethylene copolymer and a propylene / 4-methyl-1pentene copolymer). ,
Examples thereof include poly (4-methyl-1pentene) and polybutene-1. When isotactic polypropylene or its copolymer is used as the polyolefin resin, its MFR (JIS K7210) is 0.1 to 5
A range of 0 g / 10 min, particularly 0.5 to 30 g / 10 min can be suitably used.

As the polystyrene resin, any one obtained by a radical polymerization method or an ionic polymerization method can be suitably used as long as it can be obtained by a known production method. The number average molecular weight of the polystyrene resin is 5,000-5
00,000, preferably 10,000-200,00
0 and a molecular weight distribution [ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw / M
n)] is preferably 5 or less.

Examples of the styrene resin include polystyrene and styrene having a styrene content of 60% by weight or more.
Butadiene block copolymer, rubber reinforced polystyrene,
Examples thereof include poly-α-methylstyrene and poly-p-tert-butylstyrene, and these may be used alone or in combination of two or more. Further, a copolymer obtained by polymerizing a mixture of monomers constituting these polymers can also be used.

Further, the polyolefin resin and the polystyrene resin can be used in combination. When these resins are added to the anti-vibration material of the present invention, the hardness of the resulting material tends to be higher when a polystyrene resin is used in combination than when only a polyolefin resin is added. Therefore, the hardness of the obtained anti-vibration material can be adjusted by selecting these compounding ratios. In this case, the ratio of polyolefin resin / polystyrene resin is 9
It is preferable to select from the range of 5/5 to 5/95 (weight ratio).

When these resin components are used in combination, they should be used within a range that does not impair the effects of the present invention, and the amount is preferably about 0 to 100 parts by weight based on 100 parts by weight of the thermoplastic material. . The amount of the resin component is 1
If the amount is more than 00 parts by weight, the hardness of the obtained vibration isolating material becomes too high, the flexibility is lost, and the vibration isolating property is undesirably reduced.

As other additives, if necessary,
Flame retardants, antibacterial agents, hindered amine light stabilizers, ultraviolet absorbers, antioxidants, inorganic fillers, coloring agents, silicone oils, coumarone resins, coumarone-indene resins, phenol terpene resins, petroleum hydrocarbons, rosin derivatives, etc. Various tackifiers (tack fire), various adhesives such as rheosomer (trade name: manufactured by Riken Vinyl Co., Ltd.), high blur (trade name: manufactured by Kuraray Co., Ltd., a block in which polystyrene blocks are connected to both ends of a vinyl-polyisoprene block) A thermoplastic elastomer or resin such as a copolymer) or Norex (trade name: polynorbornene obtained by ring-opening polymerization of norbornene manufactured by Zeon Corporation) can be used in combination.

The method for producing the vibration damping material of the present invention is not particularly limited, and a known method can be applied. For example, the above-mentioned materials and, if desired, additive components are melt-kneaded using a heat kneader, for example, a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, a Brabender, a kneader, a high-shear mixer, or the like. Further, if desired, a cross-linking agent such as an organic peroxide, a cross-linking aid, or the like is added, or these necessary components are mixed at the same time, and the mixture is heated and melt-kneaded, so that it can be easily produced.

A matrix material in which a thermoplastic material and a softening agent are kneaded is prepared in advance, and a styrene-vinylisoprene-styrene block copolymer cross-linked with an organic peroxide prepared in advance into particles is prepared. It can also be manufactured by dispersing the coalesced solid in this matrix.

The anti-vibration material of the present invention thus obtained is
Since it is thermoplastic, it can be molded into a desired shape by a known method for molding a thermoplastic material, for example, injection molding, and used as a vibration isolating member.

The anti-vibration material of the present invention can be suitably used for audio equipment, information-related equipment, information transmission equipment, game-related equipment, and the like. Insulators for CD players and car-mounted CDs; Microphone holders for vibration isolation of home video, boombox, karaoke, various handy microphones, etc .; Cone edges of speakers;
Holders for portable mini-discs; optical disc holders for digital video discs, etc .; information-related devices include hard disk drive insulators; HD
Insulators for various motors such as spindle motors and stepping motors for D; Insulators for floppy disk drives; CD-Rs for various personal computer devices
OM insulators; optical disk holders such as MO, etc., and information transmission devices such as small high-performance microphone holders and speaker holders for various mobile phones, pagers, PHS, etc .; microphone holders for wireless devices; portable electronic notebooks, etc. Disc holders, etc., as game-related devices, CD-ROM insulators for home-use game devices; small high-performance microphone holders; cone edges of speakers, etc. Other application fields include various word processors, personal computer printers, compact・ Vibration isolator for print head of printers such as medium-sized handy type printing equipment and various name printing equipment; C used for various measuring instruments
D-ROM insulators and the like can be mentioned.

[0050]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

The physical properties of these examples were evaluated by the following methods. (1) Hardness of material The test method was based on JIS K6301 A type evaluation method.

(2) Creep Performance A sheet having a diameter of 10 mm and a thickness of 3 mm was subjected to a load of 70 g and the amount of settlement (mm) after 48 hours at 70 ° C. was measured. 0.
20 mm or less is preferable, and if it exceeds this value, practically,
Problems arise.

(3) tan δ The tan δ was measured by a viscoelasticity measuring device (manufactured by Toyo Seiki Co., Ltd.) under the conditions of a measurement temperature of 25 ° C., a measurement frequency of 10 Hz and a strain of 1%.
0.3 or more was considered suitable.

(4) Workability At an environmental temperature of 180 ° C., a strand was prepared by a flow tester (manufactured by Shimadzu Corporation). Those were evaluated as "x".

[Example 1] (1) Adjustment of anti-vibration material An anti-vibration material was prepared using the following raw materials.

Styrene-vinyl isoprene-styrene block copolymer in which vinyl portion is crosslinked: (Styrene block / vinyl isoprene block ratio = 20/80: Hibler VS-1, manufactured by Kuraray Co., Ltd.) 20 parts by weight Thermoplastic Material 80 parts by weight (hydrogenated product of styrene-vinyl isoprene-styrene block copolymer: Hybler HVS-3, manufactured by Kuraray Co.) Softener: 100 parts by weight of paraffinic oil (PW380, manufactured by Idemitsu Kosan Co., Ltd.) Crosslinking agent: t -Butyl cumyl peroxide 1 part by weight (Kayabutyl C, manufactured by Kayaku Akzo Co., Ltd.) Each of the above raw materials was mixed well with a Henschel mixer, and the mixture was melt-kneaded with a 50 mm diameter twin screw extruder at 240 ° C. Thus, pellets of the vibration-proof material were obtained.

When this vibration-proof material was evaluated in accordance with the above evaluation method, the hardness was 10 ° according to JIS-A, the creep performance was 0.20, the tan δ was 0.34, and the workability was “〇 (good). "Met. The results are shown in Table 1 below. (2) Molding of anti-vibration member This material is molded by an injection molding machine at a temperature of 200 to 250 ° C., and a portable CD having a shape as shown in the sectional view of FIG.
As a floating rubber. The weight of the floating part of the portable CD used here is 30g
Met.

When the thus obtained anti-vibration member was used, excellent anti-vibration properties were exhibited, and it was confirmed that the anti-vibration properties were maintained after use for 30 days.

In this embodiment, the floating rubber having the shape as shown in the sectional view of FIG. 1 is manufactured. However, the shape of the vibration isolating member can be arbitrarily selected so as to be suitable for a portion to which the rubber is applied. FIG. 2 is a cross-sectional view showing another example of the shape of the floating rubber. This floating rubber can also provide the same effects as those of the first embodiment. Example 2 (1) Adjustment of Vibration Isolating Material A vibration isolating material was prepared in the same manner as in Example 1 except that the blending amount of paraffin oil as a softener was 40 parts by weight.

The anti-vibration material was evaluated in the same manner as in Example 1. The results are shown in Table 1 below. (2) Molding of anti-vibration member This material was molded by an injection molding machine at a temperature of 200 to 250 ° C. to obtain an anti-vibration member as a floating rubber for CD-ROM as in Example 1. .

When the thus obtained anti-vibration member was used, it was confirmed that the anti-vibration property was excellent and the anti-vibration property was maintained after use for 30 days. [Example 3] (1) Adjustment of anti-vibration material An anti-vibration material was prepared in the same manner as in Example 1 using the following raw materials.

Styrene-vinyl isoprene-styrene block copolymer in which vinyl portion is crosslinked: (Hybler VS-1, manufactured by Kuraray Co., Ltd.) 20 parts by weight Thermoplastic material 40 parts by weight (styrene-vinyl isoprene-styrene block copolymer) Hydrogenated product: Hybler HVS-3, manufactured by Kuraray Co., Ltd. Thermoplastic material 40 parts by weight (styrene-ethylene / butylene-styrene block copolymer: Tuftec S2244 (manufactured by Asahi Kasei Corporation)) Softener: 100 parts by weight of paraffin-based oil ( PW380, manufactured by Idemitsu Kosan Co., Ltd. Crosslinking agent: 1 part by weight of t-butylcumyl peroxide (Kayabutyl C, manufactured by Kayaku Akzo Co., Ltd.) The anti-vibration material was evaluated in the same manner as in Example 1. The results are shown in Table 1 below. (2) Molding of anti-vibration member This material is molded by an injection molding machine at a temperature of 200 to 250 ° C. , In the same manner as in Example 1, a floating rubber CD-ROM, or to obtain a vibration isolating member.

When the thus obtained vibration-proofing member was used, it was confirmed that the vibration-proofing property was excellent and the vibration-proofing property was maintained after 30 days of use. [Comparative Example 1] (1) Adjustment of anti-vibration material An anti-vibration material was prepared in the same manner as in Example 1 using the following raw materials.

Styrene-vinyl isoprene-styrene block copolymer in which vinyl portion is crosslinked: (HIBLER VS-1, manufactured by Kuraray Co., Ltd.) 100 parts by weight Softener: paraffin-based oil 100 parts by weight (PW380, manufactured by Idemitsu Kosan Co., Ltd.) This anti-vibration material was evaluated in the same manner as in Example 1. The results are shown in Table 1 below. (2) Molding of anti-vibration member This material was molded by an injection molding machine at a temperature of 200 to 250 ° C. to obtain an anti-vibration member as a floating rubber for CD-ROM as in Example 1. .

When the thus obtained anti-vibration member was used, it was confirmed that the anti-vibration property was satisfied at an early stage, but after 30 days, the creep property was deteriorated and it could not be used. (Comparative Example 2) (1) Adjustment of anti-vibration material An anti-vibration material was prepared in the same manner as in Example 1 using the following raw materials.

Styrene-vinyl isoprene-styrene block copolymer in which vinyl portion is crosslinked: (HIBLER VS-1, manufactured by Kuraray Co., Ltd.) 100 parts by weight Softener: paraffin-based oil 100 parts by weight (PW380, manufactured by Idemitsu Kosan Co., Ltd.) Crosslinking agent: 1 part by weight of t-butylcumyl peroxide (Kayabutyl C, manufactured by Kayaku Akzo) This vibration-proof material was evaluated in the same manner as in Example 1. The results are shown in Table 1 below. (2) Molding of anti-vibration member This material was molded with an injection molding machine in the same manner as in Example 1 for 200 to 200 hours.
When trying to mold as a floating rubber at a temperature condition of 250 ° C., workability was poor and uniform molding was difficult.

[0067]

[Table 1]

As is clear from the above examples, the vibration damping material of the present invention has low hardness, excellent creep properties,
The bleeding of the low molecular material was suppressed, and the workability was excellent. The vibration isolator obtained from this material is
It was excellent in durability and durability of anti-vibration effect.

On the other hand, Comparative Example 1 comprising only a styrene-vinyl isoprene-styrene block copolymer and a softening agent and not adding a crosslinking agent had low hardness, but was inferior in crepe characteristics. Floating rubber deforms due to settling in the vibration isolating member molded from this vibration isolating material,
The anti-vibration property deteriorated with time, and was unsuitable as an anti-vibration material. Comparative Example 2 obtained by adding a cross-linking agent thereto had good creep properties but high hardness,
The workability was poor.

[0070]

As described above, the anti-vibration material of the present invention has a low hardness and can suppress the bleeding of the compounded low-molecular component. In particular, it has an effect of being excellent in creep characteristics.
In addition, a vibration isolating member using the vibration isolating material is excellent in vibration isolation and durability.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a floating rubber according to a first embodiment.

FIG. 2 is a cross-sectional view showing another embodiment of the floating rubber as the vibration damping material of the present invention.

Claims (3)

[Claims] 1. A vibration damping material comprising a styrene-vinyl isoprene-styrene block copolymer crosslinked with an organic peroxide, a thermoplastic material, and a softener. 2. The method according to claim 1, wherein the content of the styrene-vinyl isoprene-styrene block copolymer crosslinked by the organic peroxide contained in the vibration damping material is 5 to 25% by weight. The anti-vibration material described. 3. An anti-vibration member using the anti-vibration material according to claim 1 or 2.