公开(公告)号：JPH0676275A

公开(公告)日：1994-03-18

申请号：JP14930093

申请日：1993-06-21

Applicant: BASF MAGNETICS GMBH

Inventor： URURITSUHI IEEGAA ,  MIHIYAERU BOBURITSUHI ,  HERUMUUTO KOPUKE ,  RAINAA EDAA ,  HANSUUPEETAA SHIRUTOBERUKU ,  KURAUSU DEIITAA SHIYOOMAN ,  HAARARUTO KERAA

IPC: C09D5/23 ,  C09D175/00 ,  C09D175/04 ,  G11B5/64 ,  G11B5/72

Abstract: PURPOSE: To improve wear resistance and corrosion resistance by forming a protective layer comprising a specified polyurethane having specified mol.wt. obtd. by specified reaction on a ferromagnetic metal layer. CONSTITUTION: A protective layer formed on a metal layer consists of a polyurethane having 500 to 10000 average mol.wt. This polyurethane is obtd. by the following reaction. An isocyanate expressed by formula Q-(NCO)z is made to react with a compd. expressed by formula Rf -A-B and/or a compd. expressed by formula X-RH-B. In formulae, Q is an alkyl, cycloalkyl or heterocycloalkyl group, (z) is an integer 1 to 5, Rf is a perfluoro (cyclo) alkyl or perfluoroalkyl aryl group having 3 to 30 carbon atoms, A is -(CH2 )n -, wherein(n)= 1 to 10, B is -OH, =NK, -NH2 or -(COOH), RH is an alkyl or cycloalkyl group having 1 to 30 carbon atoms, and X is -H, -OH, =NH, -NH2 , -SO3 H or -SO3 Na.