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:
Apr. 08, 1997
Filed:
May. 16, 1995
Yoshiaki Okuhama, Kobe, JP;
Seishi Masaki, Kobe, JP;
Takao Takeuchi, Kobe, JP;
Yoshiharu Matsuda, Ube, JP;
Masakazu Yoshimoto, Kobe, JP;
Daiwa Fine Chemicals Co., Ltd., Hyogo-ken, JP;
Abstract
An electrolytic process for producing lead and tin sulfonates which comprises applying a DC voltage to an anode and a plurality of cathodes in an electrolytic cell and thereby dissolving lead or tin in an electrolytic solution. The electrolytic cell is partitioned by cation- and anion-exchange membranes into anode and cathode chambers. The electrolytic solution is a solution of an organic sulfonic acid, and the anode is lead or tin. The process reduces contents of radioisotopes such as uranium and thorium to a level of less than 50 ppb, and therefore the coatings formed by solder plating using the lead and tin salts in accordance with the invention show radioactive .alpha. particle counts of less than 0.1 CPH/cm.sup.2.