US 12,344,770 B2
Adhesive for tennis ball
Takehiko Hyodo, Kobe (JP); Yuko Kujirai, Kobe (JP); and Kazuyoshi Shiga, Kobe (JP)
Assigned to SUMITOMO RUBBER INDUSTRIES, LTD., Kobe (JP)
Filed by SUMITOMO RUBBER INDUSTRIES, LTD., Kobe (JP)
Filed on Jun. 24, 2022, as Appl. No. 17/849,436.
Claims priority of application No. 2021-116340 (JP), filed on Jul. 14, 2021.
Prior Publication US 2023/0027197 A1, Jan. 26, 2023
Int. Cl. C09J 109/00 (2006.01); A63B 39/00 (2006.01); A63B 102/02 (2015.01)
CPC C09J 109/00 (2013.01) [A63B 39/00 (2013.01); A63B 2102/02 (2015.10)] 5 Claims
OG exemplary drawing
 
1. A tennis ball comprising a hollow core made of a rubber material, wherein
the core includes two hemispherical half cores, and
the two half cores are adhered to each other by using an adhesive,
the adhesive comprises a base rubber containing, as a main component thereof, a liquid rubber having a number average molecular weight of not less than 10,000,
the ratio of the liquid rubber to the base rubber is not less than 90% by mass, and
the adhesive has a shear viscosity of not less than 80 Pa·s and not greater than 2,000 Pa·s.