JPH06240218A - Adhesive for ball-game racket, ball-game racket rubber coated with the adhesive, and ball-game packet - Google Patents

Abstract

PURPOSE:To provide an adhesive for ball-game racket with which a rubber can be tenaciously and easily bonded to a paddle base to give a racket in which the rubber can easily be peeled off for renewal without marring the base and which adhesive is safe and has no fear of causing an environmental problem; and to provide a ball-game racket rubber coated with the adhesive and a ball- game racket. CONSTITUTION:The adhesive comprises an aqueous medium and a polymer which is made up mainly of monomer units derived from an alkyl acrylate and/or an alkyl methacrylate each having a 4-12C alkyl and which has a glass transition temp. (Tg) of -20 deg.C or lower. The rubber and racket are made using the adhesive.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive for a ball game racket such as table tennis, a rubber for a ball game racket and a ball game racket using the adhesive.

[0002]

2. Description of the Related Art A racquet for ball game represented by table tennis and the like (hereinafter also simply referred to as a racket) has a structure in which a racket body and a rubber or a rubber with a sponge (hereinafter simply referred to as a rubber) are bonded together. Since the rubber can hit the ball quickly and rotate the ball quickly, the athletes frequently re-rubber the rubber in order to play under more favorable conditions.

Conventionally, an adhesive obtained by dissolving natural rubber or synthetic rubber in an organic solvent has been used as an adhesive for bonding the racket main body and the rubber, and athletes use this adhesive as the adhesive. The racket was applied to the competition after being applied to both sides of the and dried.

However, in the rubber refilling work,
Due to harmful organic solvents such as toluene and chlorine contained in the above adhesives, the audience in the gymnasium may fall down, and problems such as health problems to athletes may occur. There are voices that threaten the use of drugs.

A water-based adhesive such as vinyl acetate was also examined, but it was not practical because the adhesive strength was so strong that the rubber could not be peeled off cleanly or the racket could be damaged.

[0006] Therefore, there has been a strong demand for an adhesive having no environmental problems, excellent adhesiveness, and capable of easily replacing rubber.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have no environmental problems and are excellent in the adhesiveness between the racket body and the rubber and the workability of sticking, and when the rubber is peeled off, the racket is damaged. The present invention has been completed as a result of earnest studies on an adhesive that can be easily peeled off without using the adhesive.

[0008]

The present invention has 4 to 12 carbon atoms.
Of an alkyl acrylate and / or methacrylic acid alkyl ester having an alkyl group of (hereinafter referred to as (meth) acrylic acid alkyl ester) as a main constituent monomer unit and having a glass transition temperature (hereinafter abbreviated as Tg point). The present invention relates to an adhesive for a ball game racket comprising a polymer having a temperature of -20 ° C or lower and an aqueous medium, and a rubber coated with the adhesive or a ball game racket using the adhesive.

The (meth) acrylic acid alkyl ester having 4 to 12 alkyl groups, which is the main constituent monomer unit in the adhesive of the present invention, includes (meth) acrylic acid n-butyl and (meth) acrylic acid isobutyl. , (Meta)
Hexyl acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
Examples thereof include n-octyl acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, and lauryl (meth) acrylate. Is 4
(Meth) acrylic acid alkyl esters having -9 alkyl groups are preferred.

The polymer in the adhesive of the present invention may be a homopolymer consisting of the above-mentioned monomer unit or a copolymer consisting of the above-mentioned monomer unit and another vinyl monomer unit.

Preferred copolymerizable vinyl monomers are (meth) acryl such as methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, and n-propyl (meth) acrylate. Alkyl acid,
Vinyl aromatic monomers such as styrene, α-methylstyrene and vinyltoluene, unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, cinnamic acid, itaconic acid, fumaric acid and maleic acid, itaconic acid mono Monoalkyl ester monomers of unsaturated dicarboxylic acids such as ethyl ester, fumaric acid monobutyl ester, maleic acid monobutyl ester, 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meth ) 2-Hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, glycerol (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate and polyethylene glycol-
Hydroxyl group-containing vinyl monomers such as polypropylene glycol mono (meth) acrylate, ethylenically unsaturated carboxylic acid amide monomers such as acrylamide, methacrylamide, N-methylol acrylamide, N-substituted compound monomers, and allyl alcohol Examples thereof include cyano group-containing vinyl monomers such as saturated alcohol monomers, acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile, and glycidyl methacrylate, vinyl acetate, vinyl chloride, vinylidene chloride monomers, and the like.

In the copolymer, the copolymerization ratio of the (meth) acrylic acid alkyl ester monomer unit having 4 to 12 alkyl groups is preferably 50% by weight or more, more preferably 70% by weight.

The Tg point of the polymer of the present invention is -20 ° C or lower, preferably -30 ° C to -75 ° C. When the Tg point is higher than -20 ° C, the adhesiveness is lowered and it is not practical.

The Tg point of the polymer can be actually measured by measuring the thermal expansion or the dynamic viscoelasticity. However, for the sake of simplicity, since the Tg point of a homopolymer of individual monomers constituting the copolymer is known, the Tg point can be determined by the following calculation formula. The Tg point is a value calculated by this calculation formula. 1 / Tg = CA / TgA + CB / TgB + CC
/ Tgc + ···· CA: Weight fraction of component A CB: Weight fraction of component B CC: Weight fraction of component C TgA: Tg point of component A homopolymer (K) TgB: component B homopolymer Tg point (K) TgC: component C homopolymer Tg point (K) where CA + CB + CC + ... = 1.

The Tg points of typical monomer homopolymers are as follows. Homopolymer Tg point Polymethyl acrylate 8 ° C Polymethylmethacrylate 105 ° C Polyethyl acrylate -23 ° C Poly (n-butyl acrylate) -54 ° C Poly (i-butyl acrylate) -24 ° C Cyclohexyl polyacrylate 16 ° C Polyacrylic Acid 2-ethylhexyl-85 ° C Polymethacrylic acid 144 ° C Acrylic acid 106 ° C Polystyrene 100 ° C Polyvinyl acetate 30 ° C Polyacrylonitrile 96 ° C

The polymer in the adhesive of the present invention can be produced by radical polymerization using an aqueous medium and a known emulsion polymerization method. In the polymerization, conventionally known anionic emulsifiers, nonionic emulsifiers,
Emulsion polymerization can be carried out by using a polymeric emulsifier alone or in combination. Further, a known protective colloid can be used in combination.

Examples of emulsifiers that can be used include long-chain alkyl sulfates, long-chain alkylbenzene sulfonates, polyoxyethylene alkylphenyl ether sulfates, and alkyldiphenyl ether disulfonates as anionic emulsifiers, with long-chain alkyls being preferred. Sodium sulphate, long-chain alkyl ammonium sulphate, long-chain sodium alkylbenzene sulphonate, long-chain ammonium benzene sulphonate, sodium polyoxyethylene alkylphenyl ether sulphate and ammonium polyoxyethylene alkyl sulphate. Examples of the nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, pluronic type emulsifier, and the like, and polyoxyethylene alkylphenyl ether is preferable. Examples of the polymeric emulsifier include polyvinyl alcohol, poly (meth) acrylic acid salt, polyhydroxyalkylene (meth) acrylate and the like.

If necessary, a chain transfer agent and a plasticizer may be added during the polymerization, and after the polymerization, a tackifier, a cross-linking agent, a preservative, a rust preventive, a filler, an antifreezing agent, A boiling point solvent, a surfactant, and an antifoaming agent may be added as appropriate. Further, from the viewpoint of safety, it is desirable to neutralize this polymer with aqueous ammonia or an alkaline solution such as caustic soda aqueous solution.

The solid content (nonvolatile content) of the adhesive of the present invention is
40% by weight or more is preferable, and 60% by weight is particularly preferable.
That is all. If it is less than 40% by weight, it takes time to dry,
It cannot be said that workability is good.

The adhesive of the present invention may be adjusted in viscosity with a thickener in order to improve workability when applying the adhesive to a rubber or a racket. Viscosity is 50 cps to 50,000
0 cps is preferable, especially 1,000 cps to 20,0
00 cps is preferred. If it exceeds 50,000 cps, the elongation may not be good when applied and it may be difficult to apply it uniformly. If it is less than 50 cps, it may easily sag, and it may be difficult to apply an amount sufficient for adhesion.

The adhesive of the present invention may be used as it is in an emulsion form, or may be applied to a release paper or the like and then dried.
You may use it as an adhesive film form. A preferable coating amount is 5 g / m ^{2 to} 100 g in terms of solid content of the adhesive.
/ M ^2, more preferably a ^{10g / m 2 ~80g / m 2} .

The present invention also provides a rubber in which the adhesive is applied to the surface of the rubber (sponge in the case of a rubber with sponge) that is to be attached to the racket body.

Regarding the rubber material in the present invention,
The material is not particularly limited, and examples thereof include known materials such as natural rubber and isoprene rubber, and may be surface-treated with a thermoplastic elastomer, modified nylon, curable polyurethane or the like as necessary.

In the case of the rubber with sponge, known materials such as natural rubber and isoprene can be used as the material of the sponge.

Examples of the rubber manufacturing method in the present invention include the following methods. A method for producing by transferring an adhesive film, which is produced by applying an adhesive agent on a paper that has been treated with silicon such as release paper in advance, and drying the adhesive film, on the surface of the rubber that is attached to the racket body. A method in which an adhesive is directly applied to the surface of the rubber that is attached to the racket body, and the adhesive is dried. In any of the above cases, the surface of the adhesive may be covered with release paper or the like, if necessary.

The present invention also provides a ball game racket in which the racket body and the rubber are adhered by the above adhesive.

The racket of the present invention is not particularly limited as long as the surface of the hitting portion of the racket body is a flat surface. For example, table tennis and free tennis (tenipon).
Rackets for indoor and outdoor ball games such as.

The outermost layer constituting the surface of the hitting portion of the racket body may be fiber-reinforced plastic or the like, not to mention wood. The fiber reinforced plastic is not particularly limited, for example, epoxy resin, unsaturated polyester resin, thermosetting resin such as phenol resin,
Known thermoplastic resins such as nylon, polyethylene terephthalate resin, polybutylene terephthalate resin, etc.,
Examples include those formed by a known method using various known fibers such as carbon fibers and glass fibers.

Examples of the method for manufacturing the racket of the present invention include the following methods.

A rubber obtained by applying an adhesive agent to a silicon-treated paper such as a release paper in advance and drying the adhesive film to transfer it to the surface of the rubber to be attached to the racket body. And a racket body are attached to each other for manufacturing. A method in which an adhesive is directly applied to the surface of the rubber that is attached to the racket body, dried, and then the rubber and the racket body are attached. A method in which the adhesive is directly applied to the surface of the racket body where the rubber is attached, dried, and then the racket body and the rubber are attached. A method in which an adhesive is directly applied to the bonding surfaces of both the racket body and the rubber, dried, and then the racket body and the rubber are bonded together.

Among the above-mentioned manufacturing methods, the application of the adhesive is required on only one side, and after adhesion, the rubber can be easily peeled off without damaging the racket body, and the rubber can be immediately bonded. In consideration of the above, the above methods are more preferable from the viewpoint that the adhesive is absorbed on the rubber side and the rubber is bonded to the racket main body side with the minimum necessary amount of the adhesive. Also when bonding
A known primer may be applied to rubber or a racket.

[0032]

EXAMPLES The present invention will be described more specifically below with reference to Examples and Comparative Examples. In the following examples, parts mean parts by weight, and% means% by weight.

The adhesive force and the peeling test were measured by the following methods. Adhesive strength: A: An adhesive is applied to release paper so as to have a solid content of 20 g / m ^2, and dried at 100 ° C. for 2 minutes to prepare an adhesive film. This film was transferred onto a sponge surface of a commercially available rubber for table tennis (with sponge), and this rubber was attached to a commercially available racket body. B: The adhesive was directly applied to the surface of a commercially available rubber sponge similar to A using a spatula while being thinly spread in the same amount as A, dried at room temperature, and then applied to the commercially available racket body. Wearing. C: An adhesive was directly applied to a commercially available racket body using a spatula while being thinly and uniformly spread in the same amount as A, dried at room temperature, and then a commercially available rubber similar to A was applied. . D: Apply the adhesive on a commercially available racket body and on a commercially available rubber (sponge surface) similar to A, using a spatula, while uniformly thinly spreading so that the total amount is the same as A. After drying at room temperature, the racket body and the rubber were attached. The state of adhesion between the racket body and the rubber adhered by the above-mentioned methods A to D was observed. Peeling test: The rubber of the racket laminated by the above-mentioned laminating methods A to D was peeled by hand, and the peeling manner was observed.

(Example) Example 1 A 3 liter flask equipped with a stirrer, a thermometer, a cooler and two dropping funnels was charged with 30 parts of water and heated to 80 ° C. 2-ethylhexyl acrylate (hereinafter "H
50 parts, butyl acrylate (hereinafter "BA")
40 parts, styrene (hereinafter referred to as "St") 10 parts
Part, methacrylic acid (hereinafter referred to as "MAA") 3 parts, to a monomer mixture, 2 parts of sodium polyoxyethylene nonylphenyl ether sulfonate and 19 parts of water were added and emulsified to obtain an emulsion and 5%. 8 parts of the ammonium persulfate aqueous solution was continuously dropped into the flask from the dropping funnel over 4 hours to carry out polymerization. The obtained copolymer emulsion has a solid content of 65.0.
%, The viscosity was 600 cps, and the Tg point was −59.6 ° C. Neutralize this emulsion with 5% aqueous ammonia,
A thickener was added to obtain an adhesive having a viscosity of 2,000 cps. The solid content of this adhesive is as shown in Table 1. Using this adhesive, the racket body and the rubber were attached by the above-mentioned four attachment methods A to D. The results of the adhesive force and the peeling test are shown in Table 1.

[0035]

[Table 1]

Example 2 76 parts HA, 15 parts BA, 9 parts methyl methacrylate (hereinafter referred to as "MMA"), 2 parts acrylic acid (hereinafter referred to as "AA"), N-methylol acrylamide (hereinafter referred to as "N").
-MAM ") to a monomer mixture consisting of 0.3 parts,
1 part of ammonium polyoxyethylene alkylphenyl ether sulfonate, 1 part of sodium dodecylbenzene sulfonate and 19 parts of water were added to emulsify, and polymerization was carried out in the same manner as in Example 1. The obtained emulsion had a solid content of 65.2%, a viscosity of 550 cps, and a Tg of 69.7 ° C. This emulsion was neutralized as in Example 1,
The viscosity was increased to obtain an adhesive having a viscosity of 5,000 cps. The solid content of this adhesive was as shown in Table 1. Using this adhesive, the racket body and the rubber were bonded together as in Example 1. The results of the adhesive strength and the peel test are shown in Table 1.

Example 3 95 parts BA, 3 parts MAA, vinyl acetate (hereinafter referred to as "VAC")
5 parts of a monomer mixture was added with 3 parts of polyoxyethylene lauryl ether succinate disodium and 19 parts of water to emulsify and polymerize in the same manner as in Example 1. This copolymer emulsion has a solid content of 65.2%,
The viscosity was 2,300 cps and Tg-47.9 ° C. This emulsion was neutralized and thickened in the same manner as in Example 1 to obtain an adhesive having a viscosity of 15,000 cps. The solid content of this adhesive was as shown in Table 1. Using this adhesive, the racket body and the rubber were bonded together as in Example 1. The results of the adhesive strength and the peel test are shown in Table 1.

Example 4 28 parts of water was charged in the same flask as in Example 1 and heated to 80 ° C.
After the temperature was raised to 0.5, 0.5 part of ammonium persulfate was dissolved. H
A mixture of 90 parts of A, 10 parts of MMA, 0.5 part of MAA, 1 part of sodium polyoxyethylene nonylphenyl ether sulfate and 20 parts of water was added to emulsify, and the emulsion was treated with a dropping funnel over 4 hours to give Example 1 In the same manner, it was continuously added dropwise to carry out polymerization. The obtained copolymer emulsion had a solid content of 69%, a viscosity of 7,000 cps and a Tg-
It was 74.5 ° C. This emulsion was neutralized in the same manner as in Example 1 to obtain an adhesive. The solid content of this adhesive was as shown in Table 1. Using this adhesive, the racket body and the rubber were bonded together as in Example 1. The results of the adhesive strength and the peel test are shown in Table 1.

Example 5 A flask was charged with 38 parts of water, and HA of 50 parts and BA of 25 were used.
Part, St 25 parts, MAA 3 parts monomer mixture, sodium polyoxyethylene nonylphenyl ether sulfate 1.
5 parts, polyoxyethylene nonyl phenyl ether 1.
5 parts and 30 parts of water were added and emulsified and polymerized in the same manner as in Example 1. The obtained copolymer emulsion had a solid content of 58%, a viscosity of 300 cps, and a Tg of 46.3 ° C. This emulsion was neutralized and thickened in the same manner as in Example 1 to obtain an adhesive having a viscosity of 12,000 cps. The solid content of this adhesive was as shown in Table 1. With this adhesive,
The racket body and the rubber were stuck together as in Example 1.
The results of the adhesive strength and the peel test are shown in Table 1.

Example 6 38 parts of water was charged in a flask, BA 100 parts, N-MA
M 0.5 parts of the monomer mixture, 2 parts of sodium polyoxyethylene nonylphenyl ether sulfonate, 1 part of polyoxyethylene nonyl phenyl ether and 30 parts of water were added and emulsified, followed by polymerization in the same manner as in Example 1. The obtained copolymer emulsion had a solid content of 57.8%, a viscosity of 200 cps and a Tg of 54.0 ° C. This emulsion was neutralized and thickened in the same manner as in Example 1 to obtain an adhesive having a viscosity of 8,000 cps. The solid content of this adhesive was as shown in Table 1. Using this adhesive, the racket body and the rubber were bonded together as in Example 1. The results of the adhesive strength and the peel test are shown in Table 1.

Example 7 A flask was charged with 48 parts of water, 100 parts of BA, 2 parts of sodium lauryl sulfate and 36 parts of water were added to emulsify and polymerized in the same manner as in Example 1 to obtain a polymer emulsion. An emulsion having a solid content of 52.5%, a viscosity of 300 cps, and a Tg point of −54 ° C. was obtained. This emulsion was neutralized and thickened in the same manner as in Example 1 to obtain an adhesive having a viscosity of 3,000 cps. The solid content of this adhesive was as shown in Table 1. Using this adhesive, the racket body and the rubber were bonded together as in Example 1. The results of the adhesive strength and the peel test are shown in Table 1.

Example 8 A flask was charged with 38 parts of water, BA 78 parts, MMA 20
Parts, 2 parts MAA monomer mixture, 1 part sodium polyoxyethylene phenyl ether sulfonate and 30 parts water
Parts were added and emulsified and polymerized in the same manner as in Example 1. The obtained copolymer emulsion had a solid content of 57.6%, a viscosity of 240 cps, and a Tg point of -31.4 ° C. This emulsion was neutralized and thickened in the same manner as in Example 1 to obtain an adhesive having a viscosity of 2,000 cps. The solid content of this adhesive was as shown in Table 1. With this adhesive,
The racket body and the rubber were stuck together as in Example 1.
The results of the adhesive strength and the peel test are shown in Table 1.

Example 9 The same monomer composition as in Example 1 and 0.1 part of n-dodecyl mercaptan as a chain transfer agent were added to the emulsifier, and the mixture was emulsified and polymerized in the same manner as in Example 1. The obtained copolymer emulsion has a solid content of 65.0% and a viscosity of 620 cp.
An emulsion polymer having an s and Tg point of -59.6 was obtained. The emulsion was neutralized with 5% aqueous ammonia and a thickener was added to obtain an adhesive having a viscosity of 1,000 cps. The solid content of this adhesive was as shown in Table 1. Using this adhesive, the racket body and the rubber were bonded together as in Example 1. The results of the adhesive strength and the peel test are shown in Table 1.

Example 10 A copolymer emulsion obtained by polymerization in the same manner as in Example 1 was neutralized, 1.0 part of polyoxyethylene nonylphenyl ether was added, and then the viscosity was increased to a viscosity of 20. , 00
An adhesive of 0 cps was obtained. The solid content of this adhesive was as shown in Table 1. Using this adhesive, the racket body and the rubber were bonded together as in Example 1. The results of the adhesive strength and the peel test are shown in Table 1.

Example 11 A copolymer emulsion obtained by polymerization in the same manner as in Example 1 was neutralized, and a commercially available rosin ester tackifier emulsion (softening point 100 ° C., active ingredient 50%).
Add 10 parts then thicken to a viscosity of 5,000 cps
The adhesive of was obtained. The solid content of this adhesive was as shown in Table 1. Using this adhesive, the racket body and the rubber were bonded together as in Example 1. The results of the adhesive strength and the peel test are shown in Table 1.

Comparative Example 1 A commercially available table tennis rubber adhesive consisting of 15% natural rubber and 85% organic solvent (normal hexane, xylene) was used.
The racket body and the rubber were stuck together as in Example 1.
The results of the adhesive strength and the peel test are shown in Table 1.

Comparative Example 2 Polymerization was carried out in the same manner as in Example 8 except that BA, 67 parts, MMA, 31 parts, and MAA, 2 parts were used as the monomers, and solid content was 57.6%, viscosity was 440 cps, and Tg-1.
A copolymer emulsion having a temperature of 8.3 ° C. was obtained. This emulsion was neutralized and thickened in the same manner as in Example 1 to obtain a viscosity of 2,000.
An adhesive of 0 cps was obtained. The solid content of this adhesive was as shown in Table 1. Using this adhesive, the racket body and the rubber were bonded together as in Example 1. The results of the adhesive strength are shown in Table 1.

Comparative Example 3 Polymerization was carried out in the same manner as in Example 8 except that 48 parts of HA, 50 parts of St, and 2 parts of MAA were used as the monomers, and solid content was 57.6%, viscosity was 440 cps, and Tg-1.
An 9.3 ° C. emulsion was obtained. This emulsion was neutralized and thickened in the same manner as in Example 1 to give a viscosity of 2,000 cps.
The adhesive of was obtained. The solid content of this adhesive was as shown in Table 1. Using this adhesive, the racket body and the rubber were bonded together as in Example 1. The results of the adhesive strength are shown in Table 1.

[0049]

According to the present invention, the adhesion between the racket body and the rubber and the workability of the attachment are excellent, and the rubber can be easily peeled off without damaging the racket body when the rubber is reattached. It is possible to provide an adhesive for a ball game racket, which is safe in an aqueous system and has no environmental problem, a rubber for a ball game racket and a ball game racket using the adhesive.

Claims (3)

[Claims] 1. A polymer having an alkyl acrylate and / or methacrylic acid alkyl ester having an alkyl group having 4 to 12 carbon atoms as a main constituent monomer unit and having a glass transition temperature of -20 ° C. or lower. An adhesive for a ball game racket, which is composed of an aqueous medium. 2. A rubber for a ball game racket or a rubber with a sponge, which is obtained by applying the adhesive according to claim 1 to a surface to be bonded to a ball game racket body. 3. A racket for ball game, comprising a racket main body for ball game, a rubber for racket for ball game and a rubber with sponge bonded by the adhesive according to claim 1.