Table tennis ball and table tennis ball-use thermoplastic resin composition

Patent metadata

Field	Value
Publication number	US-9623288-B2
Application number	US-201414787028-A
Country	US
Kind code	B2
Filing date	Apr 16, 2014
Priority date	Apr 26, 2013
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A table tennis ball faithfully reproduces the playing characteristics of celluloid table tennis balls without using celluloid, and a thermoplastic resin composition for table tennis balls provides a table tennis ball having an excellent balance of elastic modulus, impact resistance, and density. The table tennis ball is composed of a celluloid-free thermoplastic resin or thermoplastic resin composition having a flexural modulus according to ISO 178 of 1650 MPa or more, a Charpy impact strength according to ISO 179 of 20 kJ/m 2 or more, and a density according to ISO 1183 of less than 1.20 g/cm 3 , has a diameter of 39.0 mm or more, and weighs 2.0 to 3.5 g.

First claim

The invention claimed is:

1. A table tennis ball having a diameter of 39.0 mm or more and a weight of 2.0 to 3.5 g, and composed of a celluloid-free thermoplastic resin composition having a flexural modulus according to ISO 178 of 1650 MPa or more, a Charpy impact strength according to ISO 179 of 20 kJ/m 2 or more, and a density according to ISO 1183 of less than 1.20 g/cm 3 , wherein the thermoplastic resin composition comprises a rubber-reinforced thermoplastic resin (A) containing a rubbery polymer (a), and an ethylene-carbon monoxide-(meth) acrylic ester copolymer (C); the rubbery polymer (a) contains poly(butadiene-styrene); the component (A) and the component (C) are contained in an amount of 94 to 97 parts by weight and 3 to 6 parts by weight, respectively, based on 100 parts by weight of the total amount of (A) and (C); and the weight percentages of the respective components based on 100% by weight of the total amount of (A) and (C) satisfy Expressions (1) and (2); and wherein the rubber-reinforced thermoplastic resin (A) comprises a rubber-containing graft copolymer (I) obtained by copolymerization of a monomer mixture containing a vinyl cyanide monomer and an aromatic vinyl monomer in the presence of the rubbery polymer (a) containing poly(butadiene-styrene); and a vinyl copolymer (II) obtained by copolymerization of a monomer mixture containing a vinyl cyanide monomer and an aromatic vinyl monomer;
11.2≦[Weight percentage of ( a )/{Weight percentage of ( A )+Weight percentage of ( C )}]×100<14.5   (1); and

[{Weight percentage of ( a )+Weight percentage of ( C )}/{Weight percentage of ( A )+Weight percentage of ( C )}]×100<18.5   (2).

2. The table tennis ball according to claim 1 , wherein the thermoplastic resin composition comprises a rubber-reinforced thermoplastic resin (A) containing a rubbery polymer (a), and a polycarbonate resin (B).

3. A table tennis ball composed of a celluloid-free thermoplastic resin composition, the thermoplastic resin composition comprising:
a rubber-reinforced thermoplastic resin (A) containing a rubbery polymer (a); and
an ethylene-carbon monoxide-(meth) acrylic ester copolymer (C),
wherein
the rubbery polymer (a) contains poly(butadiene-styrene);
the rubber-reinforced thermoplastic resin (A) comprises a rubber-containing graft copolymer (I) obtained by copolymerization of a monomer mixture containing a vinyl cyanide monomer and an aromatic vinyl monomer in the presence of the rubbery polymer (a) containing poly(butadiene-styrene); and a vinyl copolymer (II) obtained by copolymerization of a monomer mixture containing a vinyl cyanide monomer and an aromatic vinyl monomer; and
the component (A) and the component (C) are contained in an amount of 94 to 97 parts by weight and 3 to 6 parts by weight, respectively, based on 100 parts by weight of the total amount of (A) and (C); and the weight percentages of the components based on 100% by weight of the total amount of (A) and (C) satisfy Expressions (1) and (2):
11.2<[Weight percentage of ( a )/{Weight percentage of ( A )+Weight percentage of ( C )}]×100<14.5  (1); and

[{Weight percentage of ( a )+Weight percentage of ( C )}/{Weight percentage of ( A )+Weight percentage of ( C )}]×100<18.5  (2).

4. The table tennis ball according to claim 3 , wherein the vinyl copolymer (II) has an intrinsic viscosity of 0.5 to 0.9 dl/g.

5. The table tennis ball according to claim 1 , formed by joining hollow hemispheres molded by injection molding.

6. The table tennis ball according to claim 1 , formed by injection blow molding.

7. A celluloid-free thermoplastic resin composition for table tennis balls, comprising:
a rubber-reinforced thermoplastic resin (A) containing a rubbery polymer (a); and
an ethylene-carbon monoxide-(meth) acrylic ester copolymer (C);
wherein
the rubbery polymer (a) contains poly(butadiene-styrene);
the rubber-reinforced thermoplastic resin (A) comprises a rubber-containing graft copolymer (I) obtained by copolymerization of a monomer mixture containing a vinyl cyanide monomer and an aromatic vinyl monomer in the presence of the rubbery polymer (a) containing poly(butadiene-styrene); and a vinyl copolymer (II) obtained by copolymerization of a monomer mixture containing a vinyl cyanide monomer and an aromatic vinyl monomer; and
the component (A) and the component (C) are contained in an amount of 94 to 97 parts by weight and 3 to 6 parts by weight, respectively, based on 100 parts by weight of the total amount of (A) and (C); and the weight percentages of the components based on 100% by weight of the total amount of (A) and (C) satisfy Expressions (1) and (2):
11.2<[Weight percentage of ( a )/{Weight percentage of ( A )+Weight percentage of ( C )}]×100<14.5   (1); and

[{Weight percentage of ( a )+Weight percentage of ( C )}{Weight percentage of ( A )+Weight percentage of ( C )}]×100 <18.5   (2).

8. The thermoplastic resin composition for table tennis balls according to claim 7 , wherein the vinyl copolymer (II) has an intrinsic viscosity of 0.5 to 0.9 dl/g.

9. A method of manufacturing a table tennis ball, the method comprising injection molding the thermoplastic resin composition for table tennis balls according to claim 7 to form hollow hemispheres, and joining the hollow hemispheres to form a hollow sphere.

10. A method of manufacturing a table tennis ball, the method comprising injection blow molding the thermoplastic resin composition for table tennis balls according to claim 7 to form a hollow sphere.

11. The table tennis ball according to claim 3 , formed by joining hollow hemispheres molded by injection molding.

12. The table tennis ball according to claim 3 , formed by injection blow molding.

Assignees

• Nippon Takkyu Co Ltd
• Toray Industries

Inventors

• Mochizuki Hidenori
• Egawa Hitoshi
• Sato Tetsu
• Takasaki Tadakatsu
• Toki Satoshi

Classifications

• A63B39/08

  made of two halves · CPC title

• C08L51/00

  Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds (for ABS polymers C08L55/02); Compositions of derivatives of such polymers · CPC title

• A63B39/00 Primary

  Hollow non-inflatable balls {, i.e. having no valves (rigid balls A63B37/00)} · CPC title

• C08L2205/03

  containing three or more polymers in a blend · CPC title

• A63B2209/00

  Characteristics of used materials · CPC title