# US 2021/0332233 A1 · Polyester composition, polyester film, and magnetic recording medium

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- Number: US 2021/0332233 A1
- Document ID: US20210332233A1
- Status: Published application
- Kind: A1
- Application number: 17/273,889
- Filed: 2019-08-29
- Published: 2021-10-28
- Earliest claimed: 2018-09-14
- Assignees: Toyobo Co., Ltd.
- Applicants: Toyobo Film Solutions Limited
- Inventors: Amane HIROSE; Junichi TOGASAKI; Makoto HANDA; Tatsuya OGAWA; Shigeyuki WATANABE
- Web page: https://patentgrep.com/patent/US20210332233A1

## CPC

- C08L 67/02: Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence)
- B32B 27/08: of synthetic resin
- B32B 27/281: {comprising polyimides}
- B32B 27/285: {comprising polyethers}
- B32B 27/288: {comprising polyketones}
- B32B 27/36: comprising polyesters
- C08G 63/183: Terephthalic acids
- C08G 63/189: containing a naphthalene ring
- C08J 5/18: Manufacture of films or sheets
- C08L 71/00: Compositions of polyethers obtained by reactions forming an ether link in the main chain (of polyacetals C08L59/00; of epoxy resins C08L63/00; of polythioether-ethers C08L81/02; of polyether-sulfones C08L81/06); Compositions of derivatives of such polymers
- G11B 5/73927: {Polyester substrates, e.g. polyethylene terephthalate}
- B32B 2255/10: on synthetic resin layer or on natural or synthetic rubber layer
- B32B 2255/20: Inorganic coating
- B32B 2255/205: Metallic coating
- B32B 2255/26: Polymeric coating
- B32B 2270/00: Resin or rubber layer containing a blend of at least two different polymers
- B32B 2307/208: Magnetic, paramagnetic
- B32B 2307/306: Resistant to heat
- B32B 2307/518: bi-axially
- B32B 2307/538: Roughness
- B32B 2307/54: Yield strength; Tensile strength
- B32B 2307/732: Dimensional properties
- B32B 2307/734: Dimensional stability
- C08J 2367/02: Polyesters derived from dicarboxylic acids and dihydroxy compounds; (C08J2367/06 takes precedence)
- C08J 2479/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08L 79/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08L 2203/16: used for films
- C08L 2205/025: containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
- C08L 2205/03: containing three or more polymers in a blend
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## 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.

## Claims

### Claim 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 not less than 6 carbons (Component B) or a long-chain alkyl diol component having not less than 6 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 that is 2 mol % to 13 mol %.

### Claim 2 (depends on 1)

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

### Claim 3 (depends on 1)

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

### Claim 4 (depends on 3)

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

### Claim 5 (depends on 3)

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

### Claim 6 (depends on 3)

The polyester film according to claim 3 wherein coefficient of expansion due to humidity in at least one surfacial direction of the film is 1 ppm/% RH to 10.0 ppm/% RH; and coefficient of expansion due to temperature in at least one direction is within a range that is not greater than 14 ppm/° C.

### Claim 7 (depends on 3)

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

### Claim 8 (depends on 7)

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

### Claim 9 (depends on 1)

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

### Claim 10 (depends on 9)

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

### Claim 11 (depends on 9)

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

### Claim 12 (depends on 9)

The polyester film according to claim 9 wherein coefficient of expansion due to humidity in at least one surfacial direction of the film is 1 ppm/% RH to 10.0 ppm/% RH; and coefficient of expansion due to temperature in at least one direction is within a range that is not greater than 14 ppm/° C.

### Claim 13 (depends on 9)

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

### Claim 14 (depends on 9)

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.

### Claim 15 (depends on 9)

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

### Claim 16 (depends on 1)

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

### Claim 17 (depends on 16)

The laminated film according to claim 16 wherein Young's modulus in at least one surfacial direction of the laminated film is not less than 4.5 GPa.

### Claim 18 (depends on 16)

The laminated film according to claim 16 wherein percent elongation in a long direction of the laminated film at 110° C. is not greater than 3.0%.