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:
Sep. 13, 1977
Filed:
Sep. 09, 1975
Friedrich Engelhardt, Frankfurt am Main, DT;
Martin Hille, Bad Soden, Taunus, DT;
Dieter Ulmschneider, Konigstein, Taunus, DT;
Hoechst Aktiengesellschaft, Frankfurt am Main, DT;
Abstract
An aqueous clay base mud for deep drilling containing as a protective colloid a copolymer which is constituted by the formula I, II and III ##STR1## IN WHICH R.sub.1 and R.sub.2 each is hydrogen of --CH.sub.3 ; R.sub.3 is --CO--NH.sub.2, --CN or COOCH.sub.3 ; R.sub.4 is hydrogen, --CH.sub.3 or --C.sub.2 H.sub.5 ; R.sub.5 is --CH.sub.3 or --C.sub.2 H.sub.5 or R.sub.4 and R.sub.5 together represent a propylene group forming a pyrrolidone radical with the inclusion of the radical ##STR2## Me is ammonium, potassium, sodium or lithium and x is 5 to 50, y 25 to 92 and z 3 to 70, Or by the saponification products thereof and which contains the components in the parts by weight of the starting monomers indicated by the indices x, y and z.