Claims
- 1. A biaxially oriented, polyethylene-2,6-naphthalate film having a longer length in the longitudinal direction than width in the transverse direction, and
- (A) having a Young's modulus of at least 550 kg/mm.sup.2 in the longitudinal direction and a Young's modulus of at least 800 kg/mm.sup.2 in the transverse direction, the Young's modulus in the transverse direction being greater than the Young's modulus in the longitudinal direction by more than 200 kg/mm.sup.2,
- (B) containing 0.005 to 2.0% by weight of fine particles having a volume shape factor of 0.3 to .pi./6, a relative standard deviation of 0.5 or less and an average particle diameter of 0.2 to 2.5 .mu.m,
- (C) having a heat shrinkage in the longitudinal direction, after heat treatment at 70.degree. C. for 1 hour under no load, of 0.1% or less, and
- (D) having a surface roughness, Ra of 1 to 12 nm.
- 2. A biaxially oriented film according to claim 1, wherein the fine particles are at least one type of particles selected from the group consisting of monodisperse silica particles, silicone resin particles and crosslinked polystyrene particles.
- 3. A biaxially oriented film according to claim 1, wherein in addition to said fine particles, the film further contains other inert particles.
- 4. A magnetic tape comprising a magnetic layer on one surface of the biaxially oriented polyethylene-2,6-naphthalate film recited in claim 1.
- 5. A biaxially oriented film according to claim 1, having a film thickness of from 2 to 12 .mu.m.
- 6. A biaxially oriented, polyethylene-2,6-naphthalate film having a longer length in the longitudinal direction than width in the transverse direction, and
- (A) having a Young's modulus of at least 600 kg/mm.sup.2 in the longitudinal direction and a Young's modulus of at least 800 kg/mm.sup.2 in the transverse direction, the Young's modulus in the transverse direction being greater than the Young's modulus in the longitudinal direction by more than 200 kg/mm.sup.2,
- (B) having a heat shrinkage, after heat treatment at 70.degree. C. for 1 hour under no load, of 0.1% or less, and
- (C) having a surface roughness, Ra of 12 nm or less,
- (D) containing 0.01 to 2.0% by weight of fine particles having an average particle diameter of 0.2 to 2.5 .mu.m, a volume shape factor of 0.3 to .pi./6, and a relative standard deviation of 0.5 or less, and
- (E) having a film thickness of 2 to 19 .mu.m.
- 7. A biaxially oriented film according to claim 6, having a film thickness of 2 to 12 .mu.m.
- 8. A biaxially oriented film according to claim 6, wherein the fine particles are at least one type of particles selected from the group consisting of monodisperse silica particles, silicone resin particles and crosslinked polystyrene particles.
- 9. A magnetic tape comprising a magnetic layer on one surface of the biaxially oriented polyethylene-2,6-naphthalate film recited in claim 6.
- 10. A biaxially oriented polyethylene-2,6-naphthalate film having a longer length in the longitudinal direction than width in the transverse direction, and
- (A) having a Young's modulus of at least 550 kg/mm.sup.2 in the longitudinal direction and a Young's modulus at least 800 kg/mm.sup.2 in the transverse direction, the Young's modulus in the transverse direction being greater than the Young's modulus in the longitudinal direction by more than 200 kg/mm.sup.2,
- (B) containing 0.005 to 2.0% by weight of fine particles having a volume shape factor of 0.3 to .pi./6, a relative standard deviation of 0.5 or less and an average particle diameter of 0.2 to 2.5 .mu.m,
- (C) having a heat shrinkage in the longitudinal direction, after heat treatment at 70.degree. C. for 1 hour under no load, of 0.1% or less,
- (D) having a surface roughness, Ra of 1-12 nm, and
- (E) having a film thickness of 2 to 12 .mu.m.
- 11. A magnetic tape comprising a magnetic layer on one surface of biaxially oriented polyethylene-2,6-naphthalate film having a longer length in the longitudinal direction than width in the transverse direction, and
- (A) having a Young's modulus of at least 600 kg/mm.sup.2 in the longitudinal direction and a Young's modulus at least 800 kg/mm.sup.2 in the transverse direction, the Young's modulus in the transverse direction being greater than the Young's modulus in the longitudinal direction by more than 200 kg/mm.sup.2,
- (B) having a heat shrinkage in the longitudinal direction, after heat treatment at 70.degree. C. for 1 hour under no load, of 0.08% or less,
- (C) having a surface roughness, Ra of 1-12 nm,
- (D) containing 0.01 to 2.0% by weight of fine particles having an average particle diameter of 0.2 to 1.0 .mu.m, a volume shape factor of 0.3 to .pi./6, and a relative standard deviation of 0.5 or less, and
- (E) having a film thickness of 2 to 19 .mu.m.
- 12. A magnetic tape comprising a magnetic layer on one surface of biaxially oriented polyethylene-2,6-naphthalate film having a longer length in the longitudinal direction than width in the transverse direction, and
- (A) having a Young's modulus of at least 550 kg/mm.sup.2 in the longitudinal direction and a Young's modulus at least 800 kg/mm.sup.2 in the transverse direction, the Young's modulus in the transverse direction being greater than the Young's modulus in the longitudinal direction by more than 200 kg/mm.sup.2,
- (B) containing 0.12 to 0.20% by weight of fine particles having a volume shape factor of 0.47-0.50, a relative standard deviation of 0.09 to 0.10 and an average particle diameter of 0.26 to 0.27 .mu.m, said fine particles being selected from the group consisting of mono dispersed silica particles, silicone resin particles and crosslinked polystyrene particles,
- (C) having a heat shrinkage in the longitudinal direction, after heat treatment at 70.degree. C. for 1 hour under no load, of 0.08% or less,
- (D) having a surface roughness, Ra of 1-12 nm, and
- (E) having a film thickness of 2 to 12 .mu.m.
Priority Claims (2)
Number |
Date |
Country |
Kind |
3-81103 |
Mar 1991 |
JPX |
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PCT/JP92/00338 |
Mar 1992 |
WOX |
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Parent Case Info
This is a divisional of application Ser. No. 08/308,203 filed Sep. 19, 1994, U.S. Pat. No. 5,665,454, which is a continuation of application Ser. No. 07/949,854 filed Nov. 20, 1992, abandoned.
US Referenced Citations (7)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0381213 |
Feb 1990 |
EPX |
0381212 |
Feb 1990 |
EPX |
50-45877 |
Apr 1975 |
JPX |
62-143938 |
Jun 1987 |
JPX |
Non-Patent Literature Citations (1)
Entry |
Database WPI Week 7647, Derwent Publications Ltd., London GB; AN 76-87405X & JP-A-50 081 325 (Teijin) Jul. 2, 1975. |
Divisions (1)
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Number |
Date |
Country |
Parent |
308203 |
Sep 1994 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
949854 |
Nov 1992 |
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