# US 11,299,621 B2 · Anti-blush and chemical resistant polyester film

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- Number: US 11,299,621 B2
- Document ID: US11299621B2
- Status: Granted
- Kind: B2
- Application number: 16/223,144
- Filed: 2018-12-18
- Published: 2020-06-18
- Granted: 2022-04-12
- Earliest claimed: 2018-12-18
- Assignees: Toray Plastics (America), Inc.
- Applicants: Toray Plastics (America), Inc.
- Inventors: Jan Moritz; Robert Ervolino
- Web page: https://patentgrep.com/patent/US11299621B2

## CPC

- B32B 15/18: comprising iron or steel {(B32B15/011, B32B15/012 and B32B15/013 take precedence)}
- C08L 67/02: Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence)
- B32B 15/08: of synthetic resin
- B32B 15/09: comprising polyesters
- B32B 27/08: of synthetic resin
- B32B 27/36: comprising polyesters
- C08K 5/527: Cyclic esters
- B32B 2307/40: having particular optical properties
- B32B 2307/518: bi-axially
- B32B 2307/714: Inert, i.e. inert to chemical degradation, corrosion
- B32B 2307/732: Dimensional properties
- B32B 2439/62: Boxes, cartons, cases
- B32B 2439/70: Food packaging
- C08K 5/52: Phosphorus bound to oxygen only
- C08L 67/03: the dicarboxylic acids and dihydroxy compounds having the carboxyl- and the hydroxy groups directly linked to aromatic rings
- 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
- Y10T 428/31681: Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
- Y10T 428/31786: Of polyester [e.g., alkyd, etc.]
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Embodiments herein relate to a polymer film comprising an anti-blushing composition in a blend comprising polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); wherein the blend contains at least 50 wt. % of PBT; wherein the anti-blushing composition comprises a phosphorus containing compound but excludes certain phosphorus compounds; and wherein the anti-blushing composition is configured to prevent blushing in the polymer film laminated directly to a metal substrate sheet and exposed to steam at a temperature of 260° F. for 90 minutes.

## Claims

### Claim 1

A method of reducing blushing on a film laminated to a metal, comprising:
a. exposing the film to a retort process, and
b. obtaining a blush-free film after the retort process;
c. wherein the film comprises a polyethylene terephthalate (PET), a polybutylene terephthalate (PBT) and a derivative of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, and
d. wherein the derivative comprises a phosphate and has a higher molecular weight than that of the bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite.

### Claim 2 (depends on 1)

The method of claim 1, wherein the derivative has a molecular weight greater than 604.

### Claim 3 (depends on 1)

The method of claim 1, wherein the derivative has a molecular weight in the range of about 605 to 700.

### Claim 4 (depends on 1)

The method of claim 1, wherein the derivative has a molecular weight in the range of about 610 to 660.

### Claim 5 (depends on 1)

The method of claim 1, wherein the derivative has a molecular weight in the range of about 620 to 640.

### Claim 6 (depends on 1)

The method of claim 1, wherein the derivative comprises a monophosphate and a diphosphate.

### Claim 7 (depends on 6)

The method of claim 6, wherein the monophosphate comprises bis(2,4-di-tert-butylphenyl) pentaerythritol monophosphate.

### Claim 8 (depends on 6)

The method of claim 6, wherein the diphosphate comprises bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphate.

### Claim 9 (depends on 1)

The method of claim 1, wherein derivative comprises an orthophosphate.

### Claim 10 (depends on 1)

The method of claim 1, wherein the PBT is at least about 40% by weight in the film.

### Claim 11 (depends on 10)

The method of claim 10, wherein the PBT is about 40% to about 80% by weight in the film.

### Claim 12 (depends on 11)

The method of claim 11, wherein the PBT is about 50% weight to about 70% in the film.

### Claim 13 (depends on 1)

The method of claim 1, wherein the film is laminated on an exterior surface of a container.

### Claim 14 (depends on 1)

The method of claim 1, wherein an average melting point of the PET in the film as measured by a differential scanning colorimeter (DSC) ranged from about 244.0° C. to about 250.0° C.

### Claim 15 (depends on 14)

The method of claim 14, wherein the average melting point of the PET in the film ranged from 244.0° C. to 248.5° C.

### Claim 16 (depends on 1)

The method of claim 1, wherein the film is laminated on an interior surface of a container.

### Claim 17 (depends on 1)

The method of claim 1, wherein the film comprises a single layer.

### Claim 18 (depends on 1)

The method of claim 1, wherein the film comprises at least a two layer.

### Claim 19 (depends on 1)

The method of claim 1, wherein a thickness of the film is in a range of about 1 μm to about 80 μm.