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. 17, 1984
Filed:
Mar. 25, 1981
Reinoud J Gaymans, Enschede, NL;
Edmond H Bour, Limbricht, NL;
Stamicarbon B.V., Geleen, NL;
Abstract
A process is described for the preparation of high-molecular weight white polyamides, substantially consisting of units of --NH--(CH.sub.2).sub.4 --NH--CO(CH.sub.2).sub.4 --CO--, by the after-condensation of a corresponding low-molecular prepolymer, consisting substantially of a molecular chain of units of --NH--(CH.sub.2).sub.4 --NH--CO(CH.sub.2).sub.4 --CO--, in which process the prepolymer which is employed has been prepared in the presence of an excess of 0.5 to 15 moles-% of 1,4-diaminobutane with respect to the quantity stoichiometrically equivalent to the adipic acid applied. This prepolymer is thereafter subjected to the after-condensation reaction in the solid phase in an atmosphere containing water vapor.