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:
Dec. 25, 1990
Filed:
Mar. 24, 1989
Junichi Nakada, Kamisu, JP;
Toshiaki Yamamoto, Kamisu, JP;
Minoru Tada, Kamisu, JP;
Kyoichi Nakamura, Kamisu, JP;
Kanegafuchi Kagaku Kogyo Kabushiki Kaisha, Osaka, JP;
Abstract
This invention provides a process for coloring expandable beads of polystyrene resins which comprises suspending expandable beads of a polystyrene resin and a dye in water in a closed vessel and heating this aqueous suspension at a temperature above the softening point of the expandable beads, wherein the closed vessel is filled up almost completely with the aqueous suspension and heating is conducted without further addition of any blowing agent, whereby the expandable beads are impregnated uniformly with the dye. According to this process, uniformly colored expandable beads of polystyrene resins are obtained at a high efficiency of dye impregnation without using any impregnation aid or the like, the expandable beads being capable of forming beautiful molded foams of uniform color.