Hollow particle-containing elastomer composition and method for production thereof

A hollow particle-containing elastomer composition comprising at least a base material elastomer and hollow particles,

• wherein the hollow particles have a shell and a hollow portion surrounded by the shell, the shell comprising a resin which is a polymer containing 50 parts by mass or more of a crosslinkable monomer unit in 100 parts by mass of all monomer units;
• wherein the hollow particle-containing elastomer composition has a storage elastic modulus G′ at 60° C. of 2.5 MPa or less, which is obtained by dynamic viscoelasticity measurement;
• and
• wherein the hollow particle-containing elastomer composition has a residual void ratio of 80% or more, which is obtained by forming a sheet-shaped molded body using the composition and measuring the residual void ratio in accordance with the following method:
• [method for measuring the residual void ratio of the hollow particle-containing elastomer molded body]
• a sheet-shaped, hollow particle-containing elastomer molded body is produced by press-molding the hollow particle-containing elastomer composition at a pressure of 1 MPa or less by a hot press machine at 120° C.;
• a specific gravity of the obtained elastomer molded body is measured;
• and the residual void ratio of the hollow particles in the elastomer molded body is calculated by the following formula (D):
• residual
• ⁢
• void
• ⁢
• ratio
• ⁢
• (
• %
• )
• =
• {
• (
• c
• -
• a
• )
• /
• (
• c
• -
• b
• )
• }
• ×
• 100
• Formula
• ⁢
• (
• D
• )
• a:
• the specific gravity of the sheet-shaped molded body after the pressing
• b:
• the specific gravity (a calculated value) of the molded body with the premise that the voids were maintained
• c:
• the specific gravity (a calculated value) of the molded body with the premise that all the hollow particles collapsed.