Magnetic recording medium comprising a syndiotactic styrene-based polymer substrate, a magnetic layer and a backcoat lubricating layer each layer containing a curable phosphazine compound

• US 5,273,830 A
• Filed: 10/02/1991
• Issued: 12/28/1993
• Est. Priority Date: 12/16/1988
• Status: Expired due to Fees

• Current Assignee: Idemitsu Petrochemical Co., Ltd. (Idemitsu Kosan Company Limited)
• Original Assignee: Idemitsu Petrochemical Co., Ltd. (Idemitsu Kosan Company Limited)
• Inventors: Funaki, Keisuke, Yaguchi, Atsunori
• Primary Examiner(s): Resan, Stevan A.
• Application Number:
  US07/770,171
• Time in Patent Office: 818 Days
• Field of Search: 428/694, 428/695, 428/900, 428/704, 428/523
• US Class Current: 428/523
• CPC Class Codes: C07F 9/65814 n = 3 or 4
• CPC Class Codes: C08J 2325/06 Polystyrene
• CPC Class Codes: C08J 2485/00 Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing atoms other than silicon, sulfur, nitrogen, oxygen, and carbon; Derivatives of such polymers
• CPC Class Codes: C08J 7/0427 with only one layer of a composition containing a polymer binder with more layers C08J7/042
• CPC Class Codes: C08J 7/043 Improving the adhesiveness of the coatings per se, e.g. forming primers adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50
• CPC Class Codes: C08J 7/046 Forming abrasion-resistant coatings; Forming surface-hardening coatings
• CPC Class Codes: G11B 5/702 characterised by the bonding agent
• CPC Class Codes: G11B 5/7023 containing polyesters, polyethers, silicones, polyvinyl resins, polyacrylresins or epoxy resins G11B5/7022 takes precedence
• CPC Class Codes: G11B 5/7026 Radiation curable polymers
• CPC Class Codes: G11B 5/725 containing a lubricant , e.g. organic compounds inorganic carbon protective coating G11B5/727
• CPC Class Codes: G11B 5/735 characterised by the back layer magnetic recording media substrates G11B5/739
• CPC Class Codes: G11B 5/73937 Substrates having an organic polymer comprising a ring structure
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10T 428/31938 Polymer of monoethylenically unsaturated hydrocarbon

Abstract

Disclosed are a styrene-based resin composite material in which a layer composed mainly of a curable phosphazene compound is formed on the surface of a molding material of a styrene-based polymer having a mainly syndiotactic configuration or a composition thereof, and also a magnetic recording medium characterized in that a magnetic layer containing the curable phosphazene compound as a binder on a support composed of the above polymer or a composition thereof, an over coated layer of a magnetic recording medium which contains the curable phosphazene compound and a lubricating layer of a magnetic recording medium which contains the curable phosphazene compound.

Claims

1. A magnetic recording medium which comprises a support of a styrene-based polymer having a syndiotactic configuration or a composition thereof, a magnetic layer containing a curable phosphazene compound as a binder formed on the support and a lubricating layer containing a curable phosphazene compound formed on the support at the opposite side of the magnetic layer.

2. A magnetic recording medium according to claim 1, wherein the phosphazene compound is a chain compound having a recurring unit represented by the formula:

##STR28## wherein a and b each represent a real number satisfying a>

0, b≧

0 and a+b=2, A represents a group that can be cured by polymerization, and B represents a group that cannot be cured by polymerization and having a polymerization degree of 3 or more.

3. A magnetic recording medium according to claim 1 wherein the phosphazene compound is a cyclic compound having a recurring unit represented by the formula:

##STR29## wherein a and b each represent a real number satisfying a>

0, b≧

0 and a+b=2, A represents a group that can be cured by polymerization, and B represents a group that cannot be cured by polymerization.

4. A magnetic recording medium according to claim 1, wherein the phosphazene compound is a cyclic compound represented by the formula ##STR30##

5. A magnetic recording medium according to claim 1, wherein the phosphazene compound is a cyclic compound represented by the formula ##STR31##

6. A magnetic recording medium which comprises a support of a styrene-based polymer having a syndiotactic configuration or a composition thereof, a magnetic layer containing a curable phosphazene compound as a binder formed on the support, a lubricating layer containing a curable phosphazene compound formed on the support at the opposite side of the magnetic layer and a magnetic over coated layer containing a curable phosphazene compound on the magnetic layer.

7. A magnetic recording medium according to claim 6, wherein the phosphazene compound is a chain compound having a recurring unit represented by the formula:

##STR32## wherein a and b each represent a real number satisfying a>

0, b≧

0 and a+b=2, A represents a group that can be cured by polymerization, and B represents a group that cannot be cured by polymerization and having a polymerization degree of 3 or more.

8. A magnetic recording medium according to claim 6 wherein the phosphazene compound is a cyclic compound having a recurring unit represented by the formula:

##STR33## wherein a and b each represent a real number satisfying a>

0, b≧

0 and a+b=2, A represents a group that can be cured by polymerization, and B represents a group that cannot be cured by polymerization.

9. A magnetic recording medium according to claim 6, wherein the phosphazene compound is a cyclic compound represented by the formula ##STR34##

10. A magnetic recording medium according to claim 6, wherein the phosphazene compound is a cyclic compound represented by the formula ##STR35##