Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA913088A
Inventor
Yao Shi-Kuang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GAF Corp
Original Assignee
GAF Corp
Publication date
Application grantedgrantedCritical
Publication of CA913088ApublicationCriticalpatent/CA913088A/en