Magnetic recording medium with backside coating containing polymeric particles
AssigneeMinnesota Mining and Manufacturing Company
InventorsJames A. Greczyna, Chi-Ming Tseng
Life of this patent
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Abstract
Magnetic media having a backside coating containing polymeric acrylate particles are provided. The polymeric acrylate particles are prepared from about 50-98 parts by weight of at least one kind of polymerizable di(meth)acrylate monomer of the formula: CH.sub.2 .dbd.CR.sup.1 C(O)O--X--O(O)CCR.sup.1 .dbd.CH.sub.2 wherein each R.sup.1 is independently H (for diacrylates) or CH.sub.3 (for dimethacrylates) and X is a divalent branched or unbranched aliphatic or aromatic linking group; and about 2-50 parts by weight of at least one kind of polymerizable hydroxyl-containing monomer.
Claims19
A magnetic recording medium comprising a support having two major surfaces, a magnetic layer provided on one major surface of the support, and a backside coating provided on the other major surface of the support, wherein the backside coating comprises nonmagnetic particles dispersed in a polymeric binder;
- the particles having a mean particle size of 0.5 to 5.0 .mu.m and comprising a copolymer of:
- (a) about 50-98 parts by weight of at least one polymerizable di(meth)acrylate monomer of the formula:
- CH.sub.2 .dbd.CR.sup.1 C(O)O--X--O(O)CCR.sup.1 .dbd.CH.sub.2
- wherein each R.sup.1 is independently H or CH.sub.3 and X is a divalent branched or unbranched aliphatic or aromatic linking group;
- and
- (b) about 2-50 parts by weight of at least one polymerizable hydroxyl-containing monomer.
A magnetic recording medium comprising a support having two major surfaces, a magnetic layer provided on one major surface of the support, and a backside coating provided on the other major surface of the support, wherein the backside coating comprises nonmagnetic particles dispersed in a polymeric binder;
- the particles having a mean particle size of 0.5 to 5.0 .mu.m and comprising a copolymer of:
- (a) about 50-98 parts by weight of at least one polymerizable di(meth)acrylate monomer of the formula:
- CH.sub.2 .dbd.CR.sup.1 C(O)OC.sub.n H.sub.2n O(O)CCR.sup.1 .dbd.CH.sub.2
- wherein R.sup.1 is H or CH.sub.3, and n is an integer from 4 to 18;
- and
- (b) about 2-50 parts by weight of at least one polymerizable hydroxyl-containing monomer selected from the group consisting of a hydroxyl-containing alkyl acrylate, hydroxyl-containing alkyl methacrylate, caprolactone acrylate, caprolactone methacrylate, hydroxyl-containing acrylamide, hydroxyl-containing methacrylamide, hydroxyl-containing styrene derivative, hydroxyl-containing vinyl ether, hydroxyl-containing allyl ether, poly(alkylene glycol) acrylate, poly(alkylene glycol) methacrylate, allyl alcohol, and mixtures thereof.
A magnetic recording medium comprising a support having two major surfaces, a magnetic layer provided on one major surface of the support, and a backside coating provided on the other major surface of the support, wherein the backside coating comprises nonmagnetic particles dispersed in a polymeric binder;
- the particles having a mean particle size of 0.5 to 5.0 .mu.m and comprising a copolymer of:
- (a) about 50-98 parts by weight of at least one polymerizable di(meth)acrylate of the formula:
- CH.sub.2 .dbd.CR.sup.1 C(O)OC.sub.n H.sub.2n O(O)CCR.sup.1 .dbd.CH.sub.2
- wherein R.sup.1 is H or CH.sub.3, and n is an integer from 4 to 18;
- and
- (b) about 2-50 parts by weight of at least one hydroxyl-containing (meth)acrylate monomer of the formula CH.sub.2 .dbd.CR.sup.2 C(O)OR.sup.3, wherein R.sup.2 is H or CH.sub.3, and R.sup.3 is a hydroxyl-containing moiety.
Dependencies are inferred from the claim text.