Polyester composition, polyester film, and magnetic recording medium

Patent metadata

Field	Value
Publication number	US-11708488-B2
Application number	US-201917273889-A
Country	US
Kind code	B2
Filing date	Aug 29, 2019
Priority date	Sep 14, 2018
Publication date	Jul 25, 2023
Grant date	Jul 25, 2023

Abstract

The invention provides a polyester composition in which the primary repeating units contain an aromatic dicarboxylic acid component (Component A) and an ethylene glycol component (Component C) and a long-chain alkyl dicarboxylic acid component having not less than 6 carbons (Component B) or a long-chain alkyl diol component having not less than 6 carbons (Component D), wherein a sum (WB+WD) of a relative amount (WB) of Component B as calculated based on a total number of moles of Component A and Component B plus a relative amount (WD) of Component D as calculated based on a total number of moles of Component C and Component D are within a range of 2-13 mol %. The invention also provides a polyester film prepared from the polyester composition and having excellent dimensional stability, as well as a magnetic recording medium utilizing the polyester film.

First claim

The invention claimed is:

1. A polyester composition characterized in that primary repeating units therein comprise an aromatic dicarboxylic acid component (Component A) and an ethylene glycol component (Component C); a long-chain alkyl dicarboxylic acid component having from 6 to 14 carbons (Component B) or a long-chain alkyl diol component having from 6 to 14 carbons (Component D) is present therein; and a sum (WB+WD) of a relative amount (WB) of Component B as calculated based on a total number of moles of Component A and Component B plus a relative amount (WD) of Component D as calculated based on a total number of moles of Component C and Component D is within a range of 2 mol % to 13 mol %.

2. The polyester composition according to claim 1 , wherein at least one species selected from the group consisting of polyimide, polyether imide, polyether ketone, and polyether ether ketone is present in an amount within a range of 0.5 wt % to 25 wt % as calculated based on mass of the polyester composition.

3. A polyester film wherein the polyester composition according to claim 1 is employed in at least one layer thereof.

4. The polyester film according to claim 3 , having a Young's modulus in at least one surfacial direction of the film of not less than 4.5 GPa.

5. The polyester film according to claim 3 , having a percent elongation in a long direction of the film at 110° C. of not greater than 3.0%.

6. The polyester film according to claim 3 , having a coefficient of expansion due to humidity in at least one surfacial direction of the film of 1 ppm/% RH to 10.0 ppm/% RH, and a coefficient of expansion due to temperature in at least one direction of not greater than 14 ppm/° C.

7. The polyester film according to claim 3 that is capable of being used in a base film for a magnetic recording medium.

8. A magnetic recording medium comprising the polyester film according to claim 7 and a magnetic layer formed on one surface thereof.

9. A polyester film provided with a film layer comprising the polyester composition according to claim 1 .

10. The polyester film according to claim 9 , having a Young's modulus in at least one surfacial direction of the film of not less than 4.5 GPa.

11. The polyester film according to claim 9 , having a percent elongation in a long direction of the film at 110° C. of not greater than 3.0%.

12. The polyester film according to claim 9 , having a coefficient of expansion due to humidity in at least one surfacial direction of the film of 1 ppm/% RH to 10.0 ppm/% RH, and a coefficient of expansion due to temperature in at least one direction of not greater than 14 ppm/° C.

13. The polyester film according to claim 9 , wherein at least one species selected from the group consisting of polyimide, polyether imide, polyether ketone, and polyether ether ketone is present in the polyester composition in an amount within a range of 0.5 wt % to 25 wt % as calculated based on mass of the polyester composition.

14. The polyester film according to claim 9 , wherein the long-chain alkyl dicarboxylic acid component (Component B) has a structure that does not contain a branched chain.

15. A magnetic recording medium comprising the polyester film according to claim 9 and a magnetic layer formed on one surface thereof.

16. The polyester film according to claim 9 , wherein the long-chain alkyl diol component (Component D) has a structure that does not contain a branched chain.

17. A laminated film wherein the polyester composition according to claim 1 is employed in at least two layers thereof.

18. The laminated film according to claim 17 , having a Young's modulus in at least one surfacial direction of the laminated film of not less than 4.5 GPa.

19. The laminated film according to claim 17 , having a percent elongation in a long direction of the laminated film at 110° C. of not greater than 3.0%.

Assignees

• Toyobo Film Solutions Ltd
• Toyo Boseki

Inventors

• Hirose Amane
• Togasaki Junichi
• Handa Makoto
• Ogawa Tatsuya
• Watanabe Shigeyuki

Classifications

• C08L67/02 Primary

  Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence) · CPC title

• B32B27/36

  comprising polyesters · CPC title

• C08G63/189

  containing a naphthalene ring · CPC title

• G11B5/73927 Primary

  Polyester substrates, e.g. polyethylene terephthalate · CPC title

• B32B2307/208

  Magnetic, paramagnetic · CPC title