Magnetic recording medium

• US 20050260459A1
• Filed: 05/19/2005
• Published: 11/24/2005
• Est. Priority Date: 05/19/2004
• Status: Abandoned Application

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Matsumoto, Ayako, Hanai, Kazuko
• Application Number:
  US11/132,406
• Publication Number:
  US 20050260459A1
• Time in Patent Office: Days
• US Class Current: 428/847.100
• CPC Class Codes: G11B 5/733 characterised by the addition of non-magnetic particles base layers having a non-magnetic layer under a soft magnetic layer G11B5/736; magnetic recording media substrates G11B5/739
• CPC Class Codes: G11B 5/7368 Non-polymeric layer under the lowermost magnetic recording layer base layers having a non-magnetic layer under a soft magnetic layer G11B5/736; magnetic recording media substrates G11B5/739
• CPC Class Codes: G11B 5/73929 comprising naphthalene ring compounds, e.g. polyethylene naphthalate substrates
• CPC Class Codes: G11B 5/73931 Two or more layers, at least one layer being polyester
• CPC Class Codes: G11B 5/73935 characterised by roughness or surface features, e.g. by added particles

Abstract

A magnetic recording medium comprising: a nonmagnetic support having a first surface and a second surface; and a magnetic layer containing ferromagnetic powder and a binder, so that the magnetic layer, the first surface and the second surface are in this order, wherein the nonmagnetic support contains polyester, a difference between largest ratio and smallest ratio among peak intensity ratios of gauche/trans on the first and second surfaces of the support in a machine direction and a transverse direction obtained by ATR-FT-IR method is 0.030 or less in an absolute value, and a shrinkage factor of the magnetic recording medium after preservation at 70° C. 5% RH for one week is 0.040% or less.

Claims

1. A magnetic recording medium comprising:

a nonmagnetic support having a first surface and a second surface; and

a magnetic layer containing ferromagnetic powder and a binder, so that the magnetic layer, the first surface and the second surface are in this order,

wherein the nonmagnetic support contains polyester, a difference between largest ratio and smallest ratio among peak intensity ratios of gauche/trans on the first and second surfaces of the support in a machine direction and a transverse direction obtained by ATR-FT-IR method is 0.030 or less in an absolute value, and a shrinkage factor of the magnetic recording medium after preservation at 70°

C. 5% RH for one week is 0.040% or less.

2. The magnetic recording medium according to claim 1, further comprising a substantially nonmagnetic lower layer between the nonmagnetic support and the magnetic layer.

3. The magnetic recording medium according to claim 1, wherein the substantially nonmagnetic lower layer contains a binder and nonmagnetic powder.

4. The magnetic recording medium according to claim 1, wherein the difference between largest ratio and smallest ratio among peak intensity ratios of gauche/trans on the first and second surfaces of the support in a machine direction and a transverse direction obtained by ATR-FT-IR method is 0.02 or less in an absolute value.

5. The magnetic recording medium according to claim 1, wherein the difference between largest ratio and smallest ratio among peak intensity ratios of gauche/trans on the first and second surfaces of the support in a machine direction and a transverse direction obtained by ATR-FT-IR method is 0.016 or less in an absolute value.

6. The magnetic recording medium according to claim 4, wherein the support contains polyethylene naphthalate.

7. The magnetic recording medium according to claim 5, wherein the support contains polyethylene naphthalate.

8. The magnetic recording medium according to claim 1, wherein the nonmagnetic support further contains a filler.

9. The magnetic recording medium according to claim 1, wherein the nonmagnetic support has a thickness of from 10 to 100 μ

m.

10. The magnetic recording medium according to claim 1, wherein the nonmagnetic support has a thickness of from 20 to 80 μ

m.

11. The magnetic recording medium according to claim 1, wherein the nonmagnetic support has a central line average surface roughness of 8 nm or less.

12. The magnetic recording medium according to claim 1, wherein the nonmagnetic support has a central line average surface roughness of 6 nm or less.