A toy water ball includes a plurality of petals each having a first edge portion and a second edge portion. Each first edge portion is provided with first magnetic members, and each second edge portion is provided with second magnetic members. When all petals are closed to form a spherical shape, an attraction force is generated between the first magnetic members of each petal and the second magnetic members of the adjacent petal so that the first edge portion of the petal tightly fit the second edge portion of the adjacent petal and a water-carrying cavity is formed. The toy water ball can be closed or opened repeatedly and can be reused. Thus, it is environmentally friendly and clean. Furthermore, the toy water ball can be filled with water in a common water source without a specific pressure, so it can be used in many occasions, and has strong applicability.

An aqueous adhesive for rubber includes rubber latex and an ammonium-salt-based vulcanization acceleration aid. An amount of the ammonium-salt-based vulcanization acceleration aid contained in the aqueous adhesive is preferably not less than 0.01% by weight and not greater than 5.0% by weight in terms of solid content. An aqueous adhesive for a ball includes rubber latex as a main component. A content of an inorganic filler in the aqueous adhesive is not greater than 0.1% by weight in terms of solid content. A ball 2 includes a hollow core 4 obtained by crosslinking a rubber composition that contains a vulcanizing agent. The core 4 is formed of two hemispherical half cores. The two half cores are adhered to each other by using the aqueous adhesive for a ball.

An aqueous adhesive for rubber includes rubber latex and an ammonium-salt-based vulcanization acceleration aid. An amount of the ammonium-salt-based vulcanization acceleration aid contained in the aqueous adhesive is preferably not less than 0.01% by weight and not greater than 5.0% by weight in terms of solid content. An aqueous adhesive for a ball includes rubber latex as a main component. A content of an inorganic filler in the aqueous adhesive is not greater than 0.1% by weight in terms of solid content. A ball 2 includes a hollow core 4 obtained by crosslinking a rubber composition that contains a vulcanizing agent. The core 4 is formed of two hemispherical half cores. The two half cores are adhered to each other by using the aqueous adhesive for a ball.

The aqueous adhesive for a tennis ball includes rubber latex. The rubber latex is a mixture of liquid rubber latex and solid rubber latex. A ratio of liquid rubber to an entire rubber component contained in the rubber latex is greater than 20% by weight and less than 90% by weight in terms of solid content. The tennis ball includes a seam formed of the aqueous adhesive for a tennis ball.

The aqueous adhesive for a tennis ball includes rubber latex. The rubber latex is a mixture of liquid rubber latex and solid rubber latex. A ratio of liquid rubber to an entire rubber component contained in the rubber latex is greater than 20% by weight and less than 90% by weight in terms of solid content. The tennis ball includes a seam formed of the aqueous adhesive for a tennis ball.

The aqueous adhesive for a tennis ball includes rubber latex. The rubber latex is a mixture of liquid rubber latex and solid rubber latex. When a solid content in the aqueous adhesive is measured at a temperature of 140° C. by a curelastometer, a torque is not less than 0.26 N.Math.m after 10 minutes from start of heating. The tennis ball includes a seam portion formed of the aqueous adhesive for a tennis ball.

A toy ball which emits sounds as it is rolled and including a ball body and a plurality of mechanically-operated sound producing tubes carried within the ball body, each sound producing tube including a sound-producing device which moves by the force of gravity, and each sound producing tube lying along a longitudinal axis, in which the axes are transverse to one another so that the sound producing devices emit sound when the ball is rolled along various axes. The ends of the sound-producing tubes are held by sleeves that are molded as integral parts of the ball body.

A tennis ball including a spherical core. The spherical core including an outer surface and a raised wall integrally molded as part of the outer surface.

A tennis ball including a spherical core. The spherical core including an outer surface and a raised wall integrally molded as part of the outer surface.

A method for forming a tennis ball including the steps of providing a non-foamed thermoplastic core and providing a non-smooth textured surface on the core. The thermoplastic core including a thermoplastic material having a specific gravity of 0.86 to 1.38, a flexural modulus of 2.0 to 50.0 MPa, and a Shore D hardness of 10 to 70. The thermoplastic material having a thickness between 3.0 and 8.0 mm. The thickness of the thermoplastic material being configured to maintain dimensional stability at internal pressures of between zero and 15 psi.