The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 09, 2026
Filed:
Oct. 13, 2021
Jsp Corporation, Tokyo, JP;
Tetsu Otsuka, Sapporo, JP;
JSP CORPORATION, Tokyo, JP;
Abstract
A method for producing polyamide-based resin multi-stage expanded beads includes an internal pressure applying step of placing polyamide-based resin expanded beads in a pressure-resistant container, impregnating the polyamide-based resin expanded beads with a physical blowing agent in the pressure-resistant container to apply internal pressure higher than atmospheric pressure; and a heating and foaming step of heating and expanding the polyamide-based resin expanded beads to which internal pressure is applied obtained in the internal pressure applying step to obtain polyamide-based resin multi-stage expanded beads having apparent density lower than that of polyamide-based resin expanded beads used in the internal pressure applying step, in the internal pressure applying step, polyamide-based resin expanded beads in a wet state having a water content of 1% or more being impregnated with the physical blowing agent at a temperature higher than change-point temperature of storage modulus of the polyamide-based resin expanded beads in a wet state.