# US 12,006,375 B2 · Regioselectively substituted cellulose esters

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- Number: US 12,006,375 B2
- Document ID: US12006375B2
- Status: Granted
- Kind: B2
- Application number: 18/046,228
- Filed: 2022-10-13
- Published: 2023-04-13
- Granted: 2024-06-11
- Earliest claimed: 2017-03-29
- Assignees: Eastman Chemical Company
- Applicants: Eastman Chemical Company
- Inventors: Casey Lynn Elkins; Robert Jacks Sharpe; Bin Wang
- Web page: https://patentgrep.com/patent/US12006375B2

## CPC

- C08B 3/16: Preparation of mixed organic cellulose esters {, e.g. cellulose aceto-formate or cellulose aceto-propionate}
- C08B 3/06: Cellulose acetate {, e.g. mono-acetate, di-acetate or tri-acetate}
- C08B 3/08: of monobasic organic acids with three or more carbon atoms, {e.g. propionate or butyrate}
- C08J 5/18: Manufacture of films or sheets
- C08L 1/14: Mixed esters, e.g. cellulose acetate-butyrate
- C08J 2301/10: Esters of organic acids
- C08J 2301/12: Cellulose acetate
- C08J 2301/14: Mixed esters
- C08B: POLYSACCHARIDES; DERIVATIVES THEREOF (polysaccharides containing less than six saccharide radicals attached to each other by glycosidic linkages C07H; fermentation or enzyme-using processes C12P19/00; sugar industry C13; production of cellulose D21)
- 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)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

The present application discloses regioselectively substituted cellulose esters, films made from the regioselectively substituted cellulose esters and methods for making the same. The regioselectively substituted cellulose esters are synthesized using trifluoroacetic anhydride and cellulose with various acyl donors or acyl donor precursors.

## Claims

### Claim 1

A film comprising a regioselectively substituted cellulose ester comprising:
(i) a plurality of R1—CO— substituents;
(ii) a plurality of R4—CO— substituents;
(iii) a plurality of hydroxyl substituents,
wherein the degree of substitution of R1—CO— at the C2 position (“C2DSR1-CO”) is in the range of from about 0.2 to about 1.0,
wherein the degree of substitution of R1—CO— at the C3 position (“C3DSR1-CO”) is in the range of from about 0.2 to about 1.0,
wherein the degree of substitution of R1—CO— at the C6 position (“C6DSR1-CO”) is less than 0.1, wherein the degree of substitution of R4—CO— at the C6 position (“C6DSR4-CO”) is in the range of from about 0.1 to about 1.0,
wherein the degree of substitution of hydroxyl is in the range of from about 0 to about 2.6,
wherein R1 is (C6-20)aryl, wherein the aryl is unsubstituted or substituted by 1 to 6 R2 groups,
wherein R2 is chosen from (C1-6)alkyl, halo(C1-6)alkyl, (C1-6)alkoxy, halo(Ci-6)alkoxy, halo, (C3-7)cycloalkyl, (C6-10)aryl, or nitro,
wherein R4 is chosen from (C1-20)alkyl; halo(C1-5)alkyl; (C2-20)alkenyl, or (C3-7)cycloalkyl,
wherein the film is a uniaxially, biaxially, or 45 degree stretched film.

### Claim 2 (depends on 1)

The film of claim 1, wherein R1—CO— is chosen from benzoyl, naphthoyl, 3,4,5-trimethoxybenzoyl, biphenyl-CO—, benzoyl-benzoyl-; and wherein R4—CO— is chosen from acetyl, propionyl, butyryl, or acetyl.

### Claim 3 (depends on 1)

The film of claim 1, wherein R4—CO— is (C1-6)alkyl-CO—.

### Claim 4 (depends on 3)

The film of claim 3, wherein R4—CO— is propionyl.

### Claim 5 (depends on 1)

The film of claim 1, wherein the weight average molecular weight (“Mw”) is in the range from about 50,000 Da to about 500,000 Da.

### Claim 6 (depends on 1)

The film of claim 1, wherein the film is a C+ film, a C− film, a reverse A film, or a NRZ film.

### Claim 7 (depends on 1)

The film of claim 1, wherein the film has an out-of-plane retardation (“Rth”) as measured at a wavelength of 589 nm divided by the thickness of the film (“d”) is in the range of from −20 to 0.

### Claim 8 (depends on 1)

The film of claim 1, wherein the film has an out-of-plane retardation (“Rth”) as measured at a wavelength of 589 nm divided by the thickness of the film (“d”) is in the range of from −1 to 1.

### Claim 9 (depends on 1)

The film of claim 1, wherein the in-plane retardation (“Re”) of the film as measured at the wavelength of 589 nm is in the range of from about 100 nm to about 300 nm.

### Claim 10 (depends on 1)

A multilayer film comprising the film of claim 1.

### Claim 11 (depends on 1)

The film of claim 1, wherein the film is prepared by solvent casting, melt extrusion, or lamination.

### Claim 12 (depends on 1)

The film of claim 1, further comprising a UV absorber.

### Claim 13 (depends on 1)

The film of claim 1, further comprising a plasticizer.

### Claim 14 (depends on 1)

The film of claim 1, further comprising a stabilizer.