Hitachi Maxell, Limited

Yoshiyuki Nagataki

Kazushi Miyata

Kenji Kohno

Hiroshi Higashi

Mitsuru Ito

Yuichi Sakurai

Hideki Nagano

Kouji Takazawa

Takuya Hayashi

Optical recording medium

A lubricating composition having an affinity for synthetic resins comprising a silicone oil and a fatty acid-modified silicone and a fatty acid ester. The lubricating coating composition is utilized in the preparation of a magnetic recording medium.

Lubricating composition and recording medium using the same

A polycarbonate polyol having a main chain of the formula: ##STR1## wherein R is an aliphatic or alicyclic hydrocarbon group having 4 to 10 carbon atoms, and n is a number of 2.00 to 20.00, and having an aliphatic OH group at the terminal; an aromatic polycarbonate polyurethane resin prepared from the polycarbonate polyol as set forth above and a polyisocyanate compound having two or more isocyanate groups in the molecule and optionally other components, particularly a chain extender having a polar group; a coating agent comprising the polycarbonate polyol and/or aromatic polycarbonate polyurethane resin as set forth above and optionally a polyisocyanate compound as set forth above and a solvent; a cast film comprising a coating film formed from the polycarbonate polyol and/or aromatic polycarbonate polyurethane resin as set forth above and a base film; and a magnetic recording medium comprising a magnetic layer formed from the aromatic polycarbonate polyurethane resin as set forth above and optionally the polyisocyanate compound as set forth above, and a base film.

Magnetic recording medium having a magnetic layer formed from an

A polycarbonate polyol having a main chain of the formula: ##STR1## wherein R is an aliphatic or alicyclic hydrcarbon group having 4 to 10 carbon atoms, and n is a number of 2.00 to 20.00, and having an aliphatic OH group at the terminal; an aromatic polycarbonate polyurethane resin prepared from the polycarbonate polyol as set forth above and a polyisocyanate compound having two or more isocyanate groups in the molecule and optionally other components, particularly a chain extender having a polar group; a coating agent comprising the polycarbonate polyol and/or aromatic polycarbonate polyurethane resin as set forth above and optionally a polyisocyanate compound as set forth above and a solvent; a cast film comprising a coating film formed from the polycarbonate polyol and/or aromatic polycarbonate polyurethane resin as set forth above and a base film; and a magnetic recording medium compriisng a magnetic layer formed from the aromatic polycarbonate polyurethane resin as set forth above and optionally the polyisocyanate compound as set forth above, and a base film.

Polycarbonate polyol, aromatic polycarbonate polyurethane resin, coating

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Osaka, Japan

Yoshiyuki Nagataki