Abstract: A coated magnetic recording medium includes a nonmagnetic support, a primer layer formed on the nonmagnetic support, and an upper magnetic layer formed on the primer layer. The primer layer and the upper magnetic layer contain, as a binder, a polyurethane resin and a polyvinyl chloride base resin, The weight ratio of the polyurethane resin to the polyvinyl chloride base resin in the primer layer is from 70:30 to 90:10, and the weight ratio of the polyurethane resin to the polyvinyl chloride base resin in the upper magnetic layer is from 20:80 to 40:60. A method for producing the coated magnetic recording medium is also described.

Abstract: A coated magnetic recording medium includes a nonmagnetic support, a primer layer formed on the nonmagnetic support, and an upper magnetic layer formed on the primer layer. The primer layer and the upper magnetic layer contain, as a binder, a polyurethane resin and a polyvinyl chloride base resin. The weight ratio of the polyurethane resin to the polyvinyl chloride base resin in the primer layer is from 70:30 to 90:10, and the weight ratio of the polyurethane resin to the polyvinyl chloride base resin in the upper magnetic layer is from 20:80 to 40:60. A method for producing the coated magnetic recording medium is also described.

Abstract: The present invention concerns magnetic recording media comprising fine, magnetizable pigment or particles dispersed within a binder and supported on a substrate. The invention particularly concerns the nature of the binder polymer and its preparation. The binder polymer is a curable polymer comprising a sulfonated, hydroxy-functional polyurethane polymer. A plurality of SO.sub.3 M groups are pendant from the polyurethane polymer backbone. The SO.sub.3 M groups have an equivalent weight of from about 2,000 to about 100,000. M is selected form the group consisting of H.sup.+, Li.sup.+, Na.sup.+, K.sup.+, NR.sub.4.sup.+ where R can be H.sup.+ or an alkyl group, and mixtures thereof. A plurality of hydrophobic polymer chain segments are incorporated into the polyurethane polymer that comprise residues of a polyol having a molecular weight of at least about 180. The hydrophobic chain segments have a carbon atom to polar functionality of at least about 60.

Abstract: The present invention relates to an iniferter compound of the formula I(T).sub.n wherein I represents the free radical initiator portion of the iniferter compound and wherein I comprises a hydroxy-functional polyurethane polymer which comprises: (i) a polyurethane backbone; (ii) a plurality of cross-linkable hydroxy groups pendant from the polyurethane backbone, wherein the polyurethane backbone has a hydroxy equivalent weight of from about 500 to about 10,000; (iii) at least n organic groups X which can be the same or different pendant from the polyurethane backbone wherein each organic group X is also bonded to a T group; T represents the terminator portion of the iniferter; and n is an integer of at least 1; wherein T and X are organic groups selected so that the T--X bond is capable of dissociating upon being subjected to an appropriate energy source of forming a terminator free radical of the formula nT.multidot. and an initiator free radical of the formula I(.multidot.).sub.n .

Abstract: The present invention concerns magnetic recording media comprising fine, magnetizable pigment for particles dispersed within a binder and supported on a substrate. The invention particularly concerns the nature of the binder polymer and its preparation. The binder polymer is a curable polymer comprising a sulfonated, hydroxy-functional polyurethane polymer. A plurality of SO.sub.3 M groups are pendant from the polyurethane polymer backbone. The SO.sub.3 M groups have an equivalent weight of from about 2,000 to about 100,000. M is selected from the group consisting of H.sup.+, Li.sup.+, Na.sup.+, K.sup.+, NR.sub.4.sup.+ where R can be H.sup.+ or an alkyl group, and mixtures thereof. A plurality of hydrophobic polymer chain segments are incorporated into the polyurethane polymer that comprise residues of a polyol having a molecular weight of at least about 180. The hydrophobic chain segments have a carbon atom to polar functionality of at least about 60.

Abstract: The present invention relates to an inferter compound of the formula I(T).sub.n wherein I represents the free radical initiator portion of the iniferter compound and wherein I comprises a hydroxy-functional polyurethane polymer which comprises: (i) a polyurethane backbone; (ii) a plurality of cross-linkable hydroxy groups pendant from the polyurethane backbone, wherein the polyurethane backbone has a hydroxy equivalent weight of from about 500 to about 10,000; (iii) at least n organic groups X which can be the same or different pendant from the polyurethane backbone wherein each organic group X is also bonded to a T group; T represents the terminator portion of the iniferter; and n is an integer of at least 1; wherein T and X are organic groups selected so that the T-X bond is capable of dissociating upon being subjected to an appropriate energy source of forming a terminator free radical of the formula nT. and an initiator free radical of the formula I(.).sub.n.

Abstract: The present invention concerns magnetic recording media comprising fine, magnetizable pigment or particles dispersed in a binder and supported on a substrate. The invention particularly concerns the nature of the binder. The binder comprises a sulfonated, hydroxy-functional polyurethane polymer having sulfonate and cross-linkable hydroxyl groups pendant from the polyurethane polymer backbone. The hydroxyl groups are pendant from the polyurethane polymer at locally hydrophobic sites. The binder also comprises a sulfonated, hydroxy-functional vinyl chloride copolymer having sulfonate and cross-linkable hydroxyl groups pendant from the vinyl chloride copolymer backbone.

Abstract: The present invention concerns magnetic recording media comprising fine, magnetizable pigment or particles dispersed within a binder and supported on a substrate. The invention particularly concerns the nature of the binder polymer and its preparation. The binder polymer is a curable polymer comprising a sulfonated, hydroxy-functional polyurethane polymer. A plurality of SO.sub.3 M groups are pendant from the polyurethane polymer backbone. The SO.sub.3 M groups have an equivalent weight of from about 2,000 to about 100,000. M is selected from the group consisting of H.sup.+, Li.sup.+, Na.sup.+, K.sup.+, NR.sub.4.sup.+ where R can be H.sup.+ or an alkyl group, and mixtures thereof. A plurality of hydrophobic polymer chain segments are incorporated into the polyurethane polymer that comprise residues of a polyol having a molecular weight of at least about 180. The hydrophobic chain segments have a carbon atom to polar functionality of at least about 60.

Abstract: The present invention concerns magnetic concerns magnetic recording media comprising fine, magnetizable pigment or particles dispersed in a binder and supported on a substrate. The invention particularly concerns the nature of the binder. The binder comprises a sulfonated, hydroxy-functional polyurethane polymer having sulfonate and cross-linkable hydroxyl groups pendant from the polyurethane polymer backbone. The hydroxyl groups are pendant from the polyurethane polymer at locally hydrophobic sites. The binder also comprises a sulfonated, hydroxy-functional vinyl chloride copolymer having sulfonate and cross-linkable hydroxyl groups pendant from the vinyl chloride copolymer backbone.