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. 20, 2005
Filed:
Apr. 30, 2004
Yoshinori Nakahara, Kashima-gun, JP;
Masatsugu Takano, Tsuchiura, JP;
Yasuhiro Takahashi, Kashima-gun, JP;
Tadashi Amano, Kashima-gun, JP;
Yoshinori Nakahara, Kashima-gun, JP;
Masatsugu Takano, Tsuchiura, JP;
Yasuhiro Takahashi, Kashima-gun, JP;
Tadashi Amano, Kashima-gun, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
A production process for a vinyl chloride polymer is proposed in which either vinyl chloride, or a monomer mixture comprising vinyl chloride, is polymerized in an aqueous medium inside a polymerization vessel, while heat removal is conducted using a reflux condenser. In this process, the liquid level of the contents inside the polymerization vessel is monitored using an electric wave liquid level gauge, which is disposed on the polymerization vessel and radiates microwaves with a frequency of 4 to 20 GHz. The operating efficiency of the reflux condenser can be improved, and the quantity of heat removed by the reflux condenser can be increased. Furthermore, the time required to complete the process, including the raw material addition step and/or the washing step conducted following completion of the polymerization, can be shortened.