Abstract: The present invention provides a rubber-based resin closed-cell foam sheet with its sealing capability being unlikely to be lowered even for a prolonged period of use, and with its excellent waterproofing capability. The inventive rubber-based resin closed-cell foam sheet is characterized in that the foam sheet includes a rubber-based resin containing a nitrile group, and exhibits an excellent adhesion. When used as a waterproof sealing material, the foam sheet can adhere, in a tightly close contact, to the interface of a portion to be sealed. Therefore, the inventive rubber-based resin closed-cell foam sheet can be advantageously used as a waterproof sealing material having high sealing capability and excellent waterproofing capability.

Abstract: The present invention provides a rubber-based resin closed-cell foam sheet with its sealing capability being unlikely to be lowered even for a prolonged period of use, and with its excellent waterproofing capability. The inventive rubber-based resin closed-cell foam sheet is characterized in that the foam sheet includes a rubber-based resin containing a nitrile group, and exhibits an excellent adhesion. When used as a waterproof sealing material, the foam sheet can adhere, in a tightly close contact, to the interface of a portion to be sealed. Therefore, the inventive rubber-based resin closed-cell foam sheet can be advantageously used as a waterproof sealing material having high sealing capability and excellent waterproofing capability.

Abstract: The present invention provides a closed-cell foamed rubber sheet whose sealability is less likely to decrease even after long-time use and which has excellent water resistance. The closed-cell foamed rubber sheet of the present invention comprises a rubber-based resin, and is provided by the steps of: providing a foamable resin composition containing the rubber-based resin and a foaming agent; irradiating the foamable resin composition with ionizing radiation to cross-link the foamable resin composition; and foaming the cross-linked foamable resin composition. In the case where the foamable resin composition further contains 0.5 parts by weight or more of a powdery additive other than the foaming agent per 100 parts by weight of the rubber-based resin, the rubber-based resin preferably contains a rubber-based resin ingredient which is in a liquid state at normal temperature.

Abstract: The present invention provides a closed-cell foamed rubber sheet whose sealability is less likely to decrease even after long-time use and which has excellent water resistance. The closed-cell foamed rubber sheet of the present invention comprises a rubber-based resin, and is provided by the steps of: providing a foamable resin composition containing the rubber-based resin and a foaming agent; irradiating the foamable resin composition with ionizing radiation to cross-link the foamable resin composition; and foaming the cross-linked foamable resin composition. In the case where the foamable resin composition further contains 0.5 parts by weight or more of a powdery additive other than the foaming agent per 100 parts by weight of the rubber-based resin, the rubber-based resin preferably contains a rubber-based resin ingredient which is in a liquid state at normal temperature.