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SELECT DISTINCT patent.*, YEAR(date) as year FROM patent LEFT JOIN category ON category.patent = patent.patent AND category.type = patent.type WHERE (category.class = '523') AND (category.subclass = '328') ORDER BY date ASC, patent, type

Total of 1 patents found where: Class is '523'; Subclass is '328';

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T / S Patent Date Description Patentee Category Assigned To
 1939
U 2,146,597 February 7, 1939 Process of Treating Rubber
Rubber treating process		 SCHWARTZ, Emil W.
CROASDALE, Evan T.
 Rubber General Electric Co.

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