JPH09206408A - Materials for sports - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To use a thermoplastic material, which has a remarkably good impact absorption property and can be manufactured at a high productivity at a low cost, has an excellent impact absorption property, and the impact absorption property decreases with time. Provided is a sports member having excellent durability that does not occur. SOLUTION: A high molecular organic material and a softening agent are included, and
The ISA hardness is 0 ° to 25 °, the compression set at 100 ° C is 50% or less, and the M at 230 ° C is M.
A thermoplastic material having an FR of 10 g / 10 minutes or more is used as the shock absorber. 50 to 500 parts by weight of the softening agent is included in 100 parts by weight of the high molecular weight organic material, the difference in solubility parameter between the high molecular weight organic material and the softening agent is 3.0 or less, and 10 to 250 parts by weight of polyphenylene ether is added. It is preferable that the polymer organic material contained is a polymer obtained by hydrogenating a copolymer containing polystyrene and polybutadiene, and the softening agent is selected from naphthene-based, paraffin-based, and polyisobutylene-based oils.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sports member, and more particularly to a sports member having a shock absorbing portion or a shock absorbing member provided at a shock transmitting portion. The present invention relates to a sports member in which the shock absorbing property of the shock absorbing material is significantly improved.

[0002]

2. Description of the Related Art Golf clubs, tennis, badminton, squash, rackets such as racket balls, sports members for hitting balls such as baseball bats are conventionally provided with a grip portion in order to reduce the impact of hitting. Materials such as leather, rubber, and resin are used.

Also, in other sports equipment such as ski poles and oars for boats, the same materials as those mentioned above are generally used for the grip portion or the inside thereof in order to easily fit in the hand and prevent slipping. Has been done.

Since the grip for sports equipment is a portion where the impact is transmitted to the hand when hitting the ball when it is gripped and used by the hand, the grip material is sufficient so that a large impact is not transmitted to the human body. It is desired to have shock absorbing performance.

Similarly, baseball glove catching parts, boxing gloves, headgear, various sports helmets, supporters, baseball fields, fence components such as skating rinks, floor exercise mats, kendo armor (face), karate practice table. Further improved impact absorption performance of various other sports materials such as (practice materials for kicking and pushing), tackle machines for rugby, protectors for American football, etc. to reduce the impact on the human body. Is currently desired.

However, in the conventional materials, for example, laser and synthetic leather are excellent in touch, but shock absorption is insufficient, and known resins and rubbers increase flexibility in order to increase shock absorption. However, there has been a problem that the stress absorbs and deforms, and the shock absorbency decreases with time. A gel-like impact absorbing member has been proposed to solve this problem, but its use range has been limited due to the physical properties that it needs to be enclosed in a covering member before use.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and is a moldable material, which has a remarkably good impact absorption property and is manufactured at a high productivity and at a low cost. It is an object of the present invention to provide a sports member using a shock absorbing material having excellent durability, which is possible and whose shock absorbing property does not decrease with time.

[0008]

According to a first aspect of the present invention, there is provided a sports member comprising a shock absorbing material at a shock generating portion or a shock transmitting portion, wherein the shock absorbing material is a polymer organic material and a softened material. A thermoplastic material including an agent,
Hardness is 0 to 25 on JIS K6301 standard A scale
And the compression set at 100 ° C is JIS K
It is characterized by being constituted by using a thermoplastic material having a characteristic of being 50% or less in 6301 standard and having an MFR at 230 ° C. of 10 g / 10 min or more in JIS K7210 standard.

That is, the inventors of the present invention have conducted extensive studies on shock absorbing materials having excellent shock absorbing performance, and as a result, the thermoplastic material according to the present invention has various properties such as shock absorbing characteristics and hardness. The present invention has been completed based on the finding that it has excellent properties as a shock absorbing material for sports members, and that by using this thermoplastic material as a shock absorbing material, a very excellent sports member can be obtained.

Here, the impact generating portion refers to a portion to which an impact force is directly applied, such as the surface of the floor exercise mat, and the impact transmitting portion refers to the impact generating portion (for example, a hitting point) and the sports like a grip of a bat. It refers to a part that is located somewhere between the body of a member that uses the member and that transmits the impact to the body.

The thermoplastic material contains 100 parts by weight of a high molecular weight organic material and 50 to 500 parts by weight of a softening agent, and the difference in solubility parameter between the high molecular weight organic material and the softening agent is 3.0. The following is preferable.

The thermoplastic material preferably contains 10 to 250 parts by weight of polyphenylene ether.

The polymer organic material used in the thermoplastic material constituting the shock absorber of the sports member of the present invention contains at least one polymer block containing a vinyl aromatic compound as a main component and a conjugated diene compound as a main component. Is a hydrogenated block copolymer obtained by hydrogenating a block copolymer consisting of at least one polymer block having the formula (1) and having an average molecular weight of 150,000 to 400,000.

Further, the softening agent is one or more selected from naphthenic oils, paraffinic oils or polyisobutylene oils, and has an average molecular weight of 450 to 5,000. .

The thermoplastic material has a loss tangent (tan δ) of 0.05 to 1.0 at 25 ° C. and 5 Hz, and a shear modulus of 0.0005 to 25 ° C.
It is preferably 0.1 kgf / mm ² .

The thermoplastic material having impact absorbing ability according to the present invention is a material having a low hardness obtained by combining a high molecular weight organic material and a softening agent, and has good shape following property and adhesiveness, and By setting the difference in solubility parameter between the high molecular weight organic material and the softening agent to 3.0 or less, the compatibility of the materials is improved, and the bleeding of low molecular weight components can be prevented, which is excellent. It can achieve shock absorption and its durability.

[0017]

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

In the present invention, the high molecular weight organic material has a number average molecular weight of 20,000 or more, particularly 30,0.
00 or more, especially 40,000 or more of thermoplastic polymer organic materials are preferable, and for example, various thermoplastic elastomers such as styrene (butadiene styrene, isoprene styrene, etc.), ester, amide, urethane, etc., and Hydrogenated or other modified products thereof, styrene type, ABS type, olefin type (ethylene type, propylene type, ethylene propylene type, ethylene styrene type, propylene styrene type, etc.), vinyl chloride type, acrylic acid ester type (acrylic acid Methyl type, etc., Methacrylic acid ester type (methyl methacrylate type, etc.) Carbonate type, acetal type, nylon type, halogenated polyether type (chlorinated polyether type, etc.), halogenated olefin type (tetrafluoroethylene type, Fluorinated-ethylene chloride type, fluorinated ethylene Propylene type), cellulose type (acetyl cellulose type, ethyl cellulose type, etc.), vinylidene type, vinyl butyral type, alkylene oxide type (propylene oxide type, etc.) and other thermoplastic resins, and rubber modified products of these resins, etc. To be

As a concrete thermoplastic polymer organic material, a material having a hard block such as a crystal structure or an agglomerate structure and a soft block such as an amorphous structure together is particularly preferable. Preferably, specifically, the following are mentioned.

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

Obtained by hydrogenating a block copolymer of polybutadiene and polystyrene, or a block copolymer of polybutadiene or ethylene-butadiene random copolymer and polystyrene, for example, diethylene of crystalline polyethylene and polystyrene Among them, block copolymers, styrene-ethylene / butylene-styrene triblock copolymers, and the like, among them, styrene-ethylene / butylene-styrene block copolymers.

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

Ethylene-propylene rubber. Among these, obtained by hydrogenating a block copolymer, which is specifically mentioned, consisting of at least one polymer block mainly containing a vinyl aromatic compound and at least one polymer block mainly containing a conjugated diene compound. Hydrogenated block copolymer having an average molecular weight of 150,000 to 40
Those of 10,000 are preferred. That is, at least one of polymer blocks mainly composed of vinyl aromatic compounds
One (1 segment) and at least one polymer block mainly composed of a conjugated diene compound are preferably obtained by hydrogenating a block copolymer, but a polymer block mainly composed of a vinyl aromatic compound is preferable. At least 2
And a block copolymer having at least one polymer block mainly composed of a conjugated diene compound (for example,
(Styrene-butadiene-styrene block copolymer etc.)
A hydrogenated block copolymer obtained by hydrogenating is more preferable. In the hydrogenated block copolymer represented by this styrene-ethylene / butylene-styrene block copolymer, when the average molecular weight is less than 150,000, the compression set is deteriorated and the vibration damping effect is not sustained. Decreased to 40
When it exceeds 10,000, the fluidity of the material is lowered and the moldability is deteriorated. Therefore, the average molecular weight is preferably in the above range.

The content of the amorphous styrene block in the block copolymer is 10 to 70% by weight, preferably 15
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 polymer organic 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. Physically, the viscosity at 100 ° C. is 5 × 10 ⁵ centipoise. Below, in particular, 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. As such a softening agent, usually, a liquid or liquid material at room temperature is preferably used. 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, the surface of the obtained thermoplastic material becomes sticky, so that the average molecular weight is preferably within the above range.

These softening agents may be used alone or in combination of two or more as long as they have good compatibility with each other.

The blending amount of these softening agents is 50 to 500 parts by weight, and particularly preferably 50 to 300 parts by weight, based on 100 parts by weight of the high molecular weight organic material. The amount is 5
If it is less than 0 parts by weight, a sufficiently low hardness cannot be achieved, and the flexibility of the material becomes insufficient, and if it exceeds 500 parts by weight, bleeding of the softening agent tends to occur, and the mechanical strength of the material is Any of them is not preferable from the viewpoint of impact absorption effect.

In order for the thermoplastic material according to the present invention to exhibit preferable flexibility, impact absorption and durability, the physical properties are such that the hardness is 0 ° to JIS K6301 standard A scale.
25 ° and compression set at 100 ° C is JIS
K6301 standard is 50% or less and 230 ° C
MFR in JIS K7210 standard is 10g / 1
It should be 0 minutes or more.

The hardness of the thermoplastic material according to the present invention is JIS
If the hardness exceeds 25 ° on the K6301 standard A scale, the hardness of the material becomes high and it is difficult to fit the body, and further, the preferable shock absorption cannot be obtained, and if the compression set at 100 ° C exceeds 50% according to JIS K6301 standard. The material may be deformed over time, and shock absorption may be reduced.
MFR at ℃ 10g / JIS K7210 standard
If it is less than 10 minutes, the workability is deteriorated and the productivity is deteriorated.

The test methods for these physical properties are all JIS
It can be measured according to the K6301 and K7210 standards.

Furthermore, it is preferable that the thermoplastic material constituting the shock absorbing material of the sports member of the present invention has the following characteristics.

(A) Loss tangent (tan δ, 25 ° C., 5H
z): 0.05 to 1.0 (B) Shear elastic modulus (25 ° C.): 0.0005 to 0.1 k
gf / mm ^{2 The} loss tangent (tan δ) is a value measured by a shear dynamic viscoelasticity tester (manufactured by Toyo Seiki Co., Ltd.) under the conditions of 25 ° C. and 5 Hz, and the loss tangent is 0.05 as described above. ~ 1.
0, preferably 0.1 to 1.0, and more preferably 0.3 to 1.0 from the viewpoint of effect. Loss tangent is 0.
If it is less than 05, it is difficult to obtain the desired impact absorbency, and if the loss tangent exceeds 1.0, the temperature dependence of various physical properties such as elastic modulus becomes large, which is not preferable.

The shear modulus of elasticity is 0 when measured with a shear type dynamic viscoelasticity tester (manufactured by Toyo Seiki Co., Ltd.) at 25 ° C.
0005 to 0.1 kgf / mm ² , and preferably
It is 0.001 to 0.009 kgf / mm ² . Shear modulus results in fatigue, etc. and lowered shape retention is less than 0.0005kgf / mm ^2, there is a possibility that shock absorption is reduced, with stiffened exceeds 0.1 kgf / mm ^2, the body It is not preferable because it is difficult to fit in and the impact absorption is lowered.

In order to have each of the above properties, the polymer organic material constituting the thermoplastic material of the present invention preferably has a three-dimensional continuous network skeleton structure, and the formed three-dimensional continuous network skeleton structure is formed. Has an average diameter of its skeleton of 50 μm
Or less, preferably 30 μm or less, the average diameter of the cells (mesh) is 500 μm or less, preferably 300 μm or less, and the volume fraction of the high molecular weight organic material is [volume of high molecular weight organic material / (volume of high molecular weight organic material) + Volume of softener)] × 10
When it is defined as 0 (%), the volume fraction of the high-molecular organic material is preferably 50% or less, particularly preferably 33% or less.

Further, in order to obtain a thermoplastic material containing a large amount of a softening agent and a smaller amount of a polymeric organic material, the solubility parameter value δ of each of the softening agent and the polymeric organic material used.
= (ΔE / V) ^1/2 (ΔE = molar evaporation energy, V =
It is preferable to select both materials so that the difference in molar volume) is 3.0 or less, preferably 2.5 or less. If this difference exceeds 3.0, from the viewpoint of the compatibility of both materials, it is difficult to retain a large amount of the softening agent, which is an obstacle to lowering the elasticity of the obtained thermoplastic material, and bleeding of the softening agent is likely to occur. Therefore, it is not preferable because there is a risk that the shock absorbability will decrease.

The thermoplastic material for impact absorbing material according to the present invention includes a polyphenylene ether resin for the purpose of improving the compression set of the material, sustaining the impact absorbing effect and improving the durability of the impact absorbing material. Can be blended. 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.

[0038]

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 within the range of 10 to 250 parts by weight with respect to the thermoplastic material. If it exceeds 250 parts by weight, the hardness of the thermoplastic material becomes high, the flexibility is lost, it is hard to fit into the body, and further, the shock absorption may be deteriorated.
If the amount is less than 10 parts by weight, the effect of improving the compression set obtained by blending is insufficient, and thus both are not preferable.

If necessary, the thermoplastic material for impact absorbing material according to the present invention may further contain the following fillers. That is, clay, diatomaceous earth, silica, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxides, mica, graphite, flaky inorganic fillers such as aluminum hydroxide, various metal powders, wood chips,
Granular or powdered solid fillers such as glass powder, ceramics powder, granular or powdered polymer, and other various natural or artificial short fibers, long fibers (for example, straws, hairs, glass fibers, metal fibers, other various polymers) (Such as fiber) can be blended.

Weight reduction can be achieved 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 components, known additives such as resin components may be used in combination with the thermoplastic material according to the present invention in order to improve 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 and heat resistance of the thermoplastic material can be improved. Examples of the polyolefin resin include polyethylene, isotactic polypropylene, and a copolymer of propylene and a small amount of other α-olefin (for example, propylene-ethylene copolymer, propylene / 4-methyl-1pentene copolymer). , Poly (4-methyl-1 pentene), polybutene-
1 and the like. When isotactic polypropylene or its copolymer is used as the polyolefin resin, its MFR (JIS K7210) is 0.
Those having a range of 1 to 50 g / 10 minutes, particularly 0.5 to 30 g / 10 minutes can be preferably used.

As the polystyrene resin, those obtained by either radical polymerization method or ionic polymerization method can be preferably used as long as they are 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-methyl styrene and poly p-tertiary butyl styrene, 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.

The polyolefin resin and polystyrene resin may be used in combination. When these resins are added to the thermoplastic material for impact absorbing material of the present invention, the hardness of the obtained material tends to be higher when the polystyrene resin is used in combination as compared with the case where only the polyolefin resin is added. Therefore, the hardness of the obtained thermoplastic material can be adjusted by selecting these compounding ratios. In this case, the ratio of polyolefin resin / polystyrene resin is preferably selected from the range of 95/5 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 blending amount is 0 to 100 relative to 100 parts by weight of the polymer organic material.
It is preferred that the amount is about parts by weight. If the blending amount of the resin component exceeds 100 parts by weight, the hardness of the thermoplastic material for an impact absorbing material obtained becomes too high, the flexibility is lost, it is hard to fit into the body, and the impact absorbing property is deteriorated, which is not preferable. .

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 thermoplastic material according to the present invention is not particularly limited, and known methods 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.

Further, a thermoplastic material prepared by kneading a high molecular weight organic material and a low molecular weight material is prepared in advance, and one or more high molecular weight organic materials which are the same as or different from the material used here are used. It can also be manufactured by further mixing.

Further, in the thermoplastic material according to the present invention, it is possible to crosslink by adding a crosslinking agent such as organic peroxide, a crosslinking aid and the like.

Here, as the cross-linking agent which can be added for the partial cross-linking, organic peroxide is preferably mentioned, and specifically, for example, 2,5-dimethyl-2,5-di (t
-Butylperoxy) -hexane, 2,5-dimethyl-
2,5-di (benzoylperoxy) -hexane, t-
Butyl peroxybenzoate, dicumyl peroxide, t-butyl cumyl peroxide, diisopropyl benzohydroperoxide, 1,3-bis- (t-
Butylperoxyisopropyl) -benzene, benzoyl peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane and the like, and useful crosslinking aids include, for example, Divinylbenzene, trimethylolpropane triacrylate, ethylene dimethacrylate, diallyl phthalate,
Examples include quinone dioxime, phenylene bismaleimide, polyethylene glycol dimethacrylate, and unsaturated silane compounds. These organic peroxides and crosslinking aids are used in an amount of 0.1% based on 100 parts by weight of the whole compounding material.
The degree of crosslinking can be adjusted arbitrarily in the range of 1 to 5 parts by weight. These organic peroxides and crosslinking assistants can 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.

The thus obtained thermoplastic material for shock absorbing material according to the present invention is molded into a shock absorbing material having a desired shape by a known molding method, for example, injection molding, molding or the like, and used for various sports members. It can be applied and used.

For example, concretely, a sport in which an impact absorbing material is arranged in a grip portion of a golf club, tennis, badminton, squash, racket such as racket ball, baseball bat, ski stock, boat oar, etc. Members, baseball glove and catcher mitt (the impact absorbing material according to the present invention is placed in the ball catching part), boxing gloves, headgear, various sports helmets, supporters, kendo armor (face), protectors for American football, etc. Examples of sports equipment to be applied to, and further, karate practice tables (practice materials for kicking and pushing), rugby tackle machines, baseball fields, fence components such as skating rinks, floor exercise mats, etc. It can be applied to equipment and equipment to reduce the impact on the human body. Further, by utilizing this excellent shock absorbing property, it can be suitably used as a shock absorbing material for bulletproof vest.

[0057]

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) Compression set In accordance with JIS K6301, 100 ° C. × 22 hours, 2
It was evaluated by the residual strain rate after 5% deformation.

(3) MFR Evaluation was carried out at 230 ° C. in accordance with the flow test method for thermoplastics of JIS K7210.

(4) Measurement of tan δ For the measurement of tan δ, a shearing type dynamic viscoelasticity tester (manufactured by Toyo Seiki Co., Ltd.) was used, temperature 25 ° C, strain 10%, frequency 5
It was performed at Hz.

(5) Measurement of Shear Elastic Modulus The shear elastic modulus was measured at 25 ° C. using a shear dynamic viscoelasticity tester (manufactured by Toyo Seiki Co., Ltd.).

The solubility parameter is measured by a conventional method, and the number average molecular weight is measured by gel permeation chromatography [GPC; Tosoh GMH-XL (2
Main series)] and using the differential refractive index (RI),
It was carried out in terms of polystyrene using monodisperse polystyrene as a standard. Example 1 (1) Preparation of Thermoplastic Material for Impact Absorber A thermoplastic material for impact absorber was prepared using the following raw materials.

Polymer organic material 100 parts by weight (styrene-ethylene / butylene-styrene block copolymer: molecular weight 200,000, SP value 8.5) Softener: paraffin oil 58 parts by weight (molecular weight 1,500, SP value 7.8 ) Softener: Paraffin oil 170 parts by weight (molecular weight 750, SP value 7.8) Polyphenylene ether resin 10 parts by weight [Poly (2,6-dimethyl-1,4-phenylene ether)] Polypropylene resin 13.1 parts by weight (iso Tactic polypropylene M-1300, manufactured by Asahi Polypro) Higher fatty acid amide 3.0 parts by weight (Armoslip E, manufactured by Lion) The above raw materials were well mixed with a Henschel mixer, and the mixture was a twin screw extruder with a diameter of 50 mm. Melt-kneaded at 240 ° C. to obtain thermoplastic material pellets.

The hardness of this thermoplastic material was 0 ° according to JIS-A, the permanent compression strain was 45%, and the MFR was 300 g / min. Furthermore, the tan δ value was 0.15, and the shear modulus was 0.005 kgf / mm ² . (2) Molding of thermoplastic material for impact absorbing material This material was poured into a mold while being kept at a temperature of 200 to 250 ° C., cooled, and molded into a sheet having a thickness of 2 mm,
After that, it was cut into a width of 25 mm to obtain a sheet-shaped impact absorbing material. (3) Production of sports member As shown in FIGS. 1A and 1B, the obtained sheet-shaped impact absorbing material 14 is arranged on the grip portion 12A of the frame 12 of the tennis racket 10 and the surface thereof is made of leather. Tennis racket (sports member) 1 having a shock absorbing material 14 according to the present invention on the grip portion 12A by taping with the tape 16
0 was obtained.

FIG. 1A shows a tennis racket 1 of this embodiment.
0 is a front view of the tennis racket 10 shown in FIG.
12A is a cross-sectional view of the grip portion 12A at AA.

When the tennis racket 10 thus obtained was used for a panelist, the grip feeling was good, the shot feeling was excellent, and the impact absorbing property of the grip portion 12A was excellent. It was evaluated that it was significantly reduced compared to the above. Further, it was confirmed that the impact on the elbow and the wrist was significantly reduced because the impact on the ball was extremely small, and the burden on the elbow during the ball was significantly reduced. (Example 2) (1) Preparation of thermoplastic material for impact absorbing material A thermoplastic material for impact absorbing material was prepared in the same manner as in Example 1 using the following raw materials.

Polymer organic material 100 parts by weight (styrene-ethylene / butylene-styrene block copolymer: molecular weight 200,000, SP value 8.5) Softening agent: paraffin oil 58 parts by weight (molecular weight 1,500, SP value 7.8 ) Softener: Paraffin oil 73 parts by weight (molecular weight 750, SP value 7.8) Polyphenylene ether resin 10 parts by weight [Poly (2,6-dimethyl-1,4-phenylene ether)] Polypropylene resin 13.1 parts by weight (iso Tactic polypropylene M-1300, manufactured by Asahi Polypro) The hardness of this thermoplastic material was 10 ° in JIS-A, the permanent compression strain was 30%, and the MFR was 119 g / min. Further, the tan δ value is 0.10 and the shear modulus is 0.
It was 01 kgf / mm ² . (2) Manufacture of sports member A material having a thickness of 2 m was used in the mold as in Example 1.
The sheet was molded into a sheet of m and cut to obtain a shock absorbing material.

A tennis racket in which the shock absorbing material thus obtained was placed in the grip portion in the same manner as in Example 1 was produced.

When this tennis racket was evaluated in the same manner as in Example 1, the grip comfort was good, the shot feeling was excellent, the impact at the time of hitting was reduced, and even if the number of hits was increased, the elbow, It was confirmed that fatigue of the wrist was low. Comparative Example 1 (1) Preparation of Thermoplastic Material for Impact Absorber A thermoplastic material for impact absorber was prepared in the same manner as in Example 1 using the following raw materials.

Polymer organic material 100 parts by weight (styrene-ethylene / butylene-styrene block copolymer: molecular weight 30,000, SP value 8.5) Softener: paraffin oil 58 parts by weight (molecular weight 1,500, SP value 7.8 ) Softener: Paraffin oil 73 parts by weight (molecular weight 750, SP value 7.8) Polyphenylene ether resin 15 parts by weight [Poly (2,6-dimethyl-1,4-phenylene ether)] Polypropylene resin 12 parts by weight (isotactic) Polypropylene M-1300, manufactured by Asahi Polypro) The hardness of this thermoplastic material was 5 ° in JIS-A, the permanent compression strain was 90%, and the MFR was 300 g / min. Furthermore, the tan δ value shows 0.10, and the shear modulus is 0.0
It was 01 kgf / mm ² . (2) Manufacture of sports member A material having a thickness of 2 m was used in the mold as in Example 1.
The sheet was molded into a sheet of m and cut to obtain a shock absorbing material.

A tennis racket in which the shock absorbing material thus obtained was placed in the grip portion in the same manner as in Example 1 was produced.

When this tennis racket was evaluated in the same manner as in Example 1, it was found that the grip feeling was good at first,
The shot feel was excellent, and the impact at the time of hitting was reduced, but as the number of hits was piled up, the material got worn out, the grip part deformed according to the shape of the finger, and the shock absorption began to decline. It was confirmed that the burden on the elbows and wrists would be the same as the conventional one. Comparative Example 2 (1) Preparation of Thermoplastic Material for Impact Absorber A thermoplastic material for impact absorber was prepared in the same manner as in Example 1 using the following raw materials.

Polymer organic material 100 parts by weight (styrene-ethylene / butylene-styrene block copolymer: molecular weight 200,000, SP value 8.5) Softener: paraffin oil 58 parts by weight (molecular weight 1,500, SP value 7.8) ) Softener: Paraffin oil 73 parts by weight (molecular weight 400, SP value 7.8) Polyphenylene ether resin 15 parts by weight [Poly (2,6-dimethyl-1,4-phenylene ether)] Polypropylene resin 12 parts by weight (isotactic) Polypropylene M-1300, manufactured by Asahi Polypro) The hardness of this thermoplastic material was 8 ° according to JIS-A, the permanent compression strain was 100%, and the MFR was 200 g / min. Further, the tan δ value is 0.10 and the shear modulus is 0.
It was 003 kgf / mm ² . (2) Manufacture of sports member A material having a thickness of 2 m was used in the mold as in Example 1.
The sheet was molded into a sheet of m and cut to obtain a shock absorbing material.

The impact absorbing material thus obtained was placed in the grip portion in the same manner as in Example 1 to produce a tennis racket.

When this tennis racket was evaluated in the same manner as in Example 1, it was found that the grip feeling was good at first and
The shot feel was excellent, and the impact at the time of hitting was reduced, but as the number of hits was piled up, the material got worn out, the grip part deformed according to the shape of the finger, and the shock absorption began to decline. It was confirmed that the burden on the elbows and wrists would be the same as the conventional one.

As is clear from the above examples, the thermoplastic material for shock absorbers according to the present invention is a moldable material, has a low hardness, and has a low compression set at high temperatures.
Since the bleeding of the low molecular weight material can be suppressed, the sports member of the present invention to which this is applied has a remarkably good impact absorption property, can be manufactured at a low cost with high productivity, and the impact absorption property thereof can be reduced. Was not deteriorated with time and was excellent in durability.

On the other hand, Comparative Example 1 obtained by using a hydrogenated block copolymer having a low molecular weight as the high molecular weight organic material and Comparative Example 2 obtained by using a low molecular weight paraffinic oil as a softening agent to be added are , All have low hardness,
The compression set was high, which was outside the scope of the present invention. The sports member to which this shock absorbing material is applied is unsuitable as a sports member because the shock absorbing material is deformed due to the settling of the thermoplastic material and the shock absorbing property is deteriorated with time.

[0079]

As described above, the sports member of the present invention has low hardness, low compression set at high temperature,
Since it uses a thermoplastic material for shock absorbers that can suppress bleeding of low molecular weight materials, it has extremely good shock absorbency, and its shock absorbency does not decrease over time and has high durability. It has an excellent effect. Further, since this material is a thermoplastic material, it can be molded and can be manufactured at high cost with low productivity.

[Brief description of drawings]

FIG. 1A is a front view of a tennis racket of Example 1, and FIG. 1B is a sectional view of a grip portion of the tennis racket.

[Explanation of symbols]

 10 Tennis Racket (Sports Material) 12A Grip Part 14 Shock Absorber

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08L 101/00 LTB C08L 101/00 LTB

Claims (6)

[Claims] 1. A sports member having an impact absorbing portion or an impact transmitting portion provided with an impact absorbing material, wherein the impact absorbing material is a thermoplastic material containing a high molecular weight organic material and a softening agent, and has a hardness. JIS K6301 standard A scale is 0 ° to 25 °, and compression set at 100 ° C. is 50% or less in JIS K6301 standard.
Further, a sports member characterized by comprising a thermoplastic material having a characteristic that the MFR at 230 ° C. is 10 g / 10 min or more in accordance with JIS K7210 standard. 2. The thermoplastic material is a high molecular weight organic material 1.
100 parts by weight and 50 to 500 parts by weight of a softening agent are included, and the difference in solubility parameter between each of the high molecular weight organic material and the softening agent is 3.0 or less. Materials for sports. 3. The sports member according to claim 1, wherein the thermoplastic material contains 10 to 250 parts by weight of polyphenylene ether. 4. The polymer organic material comprises at least one polymer block containing a vinyl aromatic compound as a main component,
A hydrogenated block copolymer obtained by hydrogenating a block copolymer composed of at least one polymer block mainly composed of a conjugated diene compound, having an average molecular weight of 15
The member for sports according to any one of claims 1 to 3, wherein the member has a size of from 10,000 to 400,000. 5. The softening agent is one or more selected from naphthenic oils, paraffinic oils and polyisobutylene oils, and has an average molecular weight of 45.
It is 0-5,000, It is characterized by the above-mentioned.
Described sports member. 6. The loss tangent (tan δ) of the thermoplastic material at 25 ° C. and 5 Hz is 0.05 to 1.0, and the shear modulus of elasticity at 25 ° C. is 0.0005.
The laminated structure according to any one of claims 1 to 5, wherein the laminated structure has a thickness of 0.1 kgf / mm ² .