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:
Jul. 01, 1980
Filed:
Oct. 26, 1978
Josef Pfeifer, Therwil, CH;
Heinz Peter, Rheinfelden, CH;
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
The invention provides transparent polyamides which have a specific viscosity of at least 0.4 dl/g (0.5% in m-cresol at 25.degree. C.). They consist of recurring structural units of the formula I ##STR1## and, as the case may be, of recurring structural units of the formula II ##STR2## wherein X.sub.1 represents ##STR3## X.sub.2 represents ##STR4## R.sub.1 and R.sub.8 represent in general alkyl radicals. R.sub.1 to R.sub.3 can also represent hydrogen, and R.sub.5 and R.sub.6 and R.sub.7 and R.sub.8, together with the carbon atom to which they are attached, also represent cycloalkyl. The polyamides are derived in their structure from 100 to 25 mol % of terephthalic acid and from isophthalic acid. The polyamides may contain only up to 75 mol % of structural elements of the formula II. They are suitable for the manufacture of transparent moulded articles.