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
GB22794/24A
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.)
RIBLU RECORD AG
Original Assignee
RIBLU RECORD AG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by RIBLU RECORD AGfiledCriticalRIBLU RECORD AG
Publication of GB222503ApublicationCriticalpatent/GB222503A/en
In a process for making sound-records, a mixture of naphthol, resorcin or other phenol, and formaldehyde with a catalyst such as sodium sulphite, copper sulphate, caustic soda, or benzoic acid, is heated to about 65 DEG or 70 DEG C., and then rapidly cooled to about 25 DEG or 30 DEG C. It is then mixed with a filling material and colouring matter.
GB22794/24A1923-09-261924-09-26Improvements in the manufacture of record plates for reproducing sound
ExpiredGB222503A
(en)