# US 9,040,683 B2 · Cellulose interpolymers and method of oxidation

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- Number: US 9,040,683 B2
- Document ID: US9040683B2
- Status: Granted
- Kind: B2
- Application number: 13/728,187
- Filed: 2012-12-27
- Published: 2013-08-08
- Granted: 2015-05-26
- Earliest claimed: 2003-11-28
- Assignees: Eastman Chemical Company
- Applicants: Eastman Chemical Company
- Inventors: Charles Michael Buchanan; Norma Lindsey Buchanan; Susan Northrop Carty; Chung-Ming Kuo; Juanelle Little Lambert; Michael Orlando Malcolm; Jessica Dee Posey-Dowty; Thelma Lee Watterson; Matthew Davie Wood; Margaretha Soderqvist Lindblad
- Web page: https://patentgrep.com/patent/US9040683B2

## CPC

- C08B 3/06: Cellulose acetate {, e.g. mono-acetate, di-acetate or tri-acetate}
- A61K 9/2054: {Cellulose; Cellulose derivatives, e.g. hydroxypropyl methylcellulose}
- A61K 9/4891: {Coated capsules; Multilayered drug free capsule shells (with drug coating for immediate release A61K9/4808; osmotic devices A61K9/0004)}
- A61K 47/38: Cellulose; Derivatives thereof
- C08B 3/04: Cellulose formate
- C08B 3/08: of monobasic organic acids with three or more carbon atoms, {e.g. propionate or butyrate}
- C08B 3/16: Preparation of mixed organic cellulose esters {, e.g. cellulose aceto-formate or cellulose aceto-propionate}
- C08B 3/22: Post-esterification treatments, including purification
- C08B 3/24: Hydrolysis or ripening
- C08B 15/02: Oxycellulose; Hydrocellulose; {Cellulosehydrate, e.g. microcrystalline cellulose}
- C08B 15/04: Carboxycellulose, e.g. prepared by oxidation with nitrogen dioxide
- C08L 1/10: Esters of organic acids {, i.e. acylates}
- C08L 1/12: Cellulose acetate
- C08L 1/14: Mixed esters, e.g. cellulose acetate-butyrate
- C09D 17/00: Pigment pastes, e.g. for mixing in paints (artists' paints C09D5/06)
- A61K 9/19: lyophilised {, i.e. freeze-dried, solutions or dispersions (lyophilised products with subsequent particle size reduction A61K9/14; granules or pellets made by lyphilisation A61K9/1682; solid oral dosage forms made by lyophilisation A61K9/2095; lyophilisation additives A61K47/00)}
- A61K 9/2866: {Cellulose; Cellulose derivatives, e.g. hydroxypropyl methylcellulose}
- 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)
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)

## Abstract

This invention provides cellulose ester interpolymers, and methods of oxidizing cellulose interpolymers and cellulose ester interpolymers. The invention also provides routes to access carboxylated cellulose ester derivatives with high acid numbers wherein the carboxyl group is attached directly to the cellulose backbone by a carbon-carbon bond. Through functionalization of an intermediate aldehyde, the corresponding cationic or zwitterionic cellulose ester derivatives can also be accessed. The interpolymers of the present invention have a number of end-use applications, for example, as binder resins in various types of coating compositions and as drug delivery agents.

## Claims

### Claim 1

A method for converting a C6 hydroxyl of an anhydroglucose unit of a cellulose ester interpolymer to a formyl group or a carboxyl group comprising:
adding an amino substituted cyclic nitroxyl compound, a primary oxidant, and a terminal oxidant to a homogeneous solution having a pH of less than 4 to form a reaction mixture, wherein the homogeneous solution comprises a C2-C12 alkyl acid, water, and a cellulose ester interpolymer comprising anhydroglucose units having C6 hydroxyl groups; and
passing of a reaction period sufficient to affect conversion of a C6 hydroxyl to a formyl group or a carboxy group and produce an oxidized cellulose ester interpolymer, wherein the oxidized cellulose ester interpolymer consists of anhydroglucose units:
as the non-terminal monomer units of the oxidized cellulose ester interpolymer,
wherein R1, R2, R3, R4, and R5 are independently selected from the group consisting of hydrogen and C2-C12 acyl groups, and X is formyl or carboxy.

### Claim 2 (depends on 1)

The method of claim 1, wherein the cellulose ester interpolymer has a degree of substitution per anhydroglucose unit of C2-C12 acyl of at least 0.5.

### Claim 3 (depends on 1)

The method of claim 1, wherein the pH of the homogeneous solution is from about 1.5 to about 3.

### Claim 4 (depends on 1)

The method of claim 1, wherein the amino substituted cyclic nitroxyl compound is a 4-amino substituted 2,2,6,6-tetramethyl piperidin-1-oxyl derivative.

### Claim 5 (depends on 1)

The method of claim 1, wherein the amino substituted cyclic nitroxyl compound is 4-amino 2,2,6,6-tetramethyl piperidin-1-oxyl.

### Claim 6 (depends on 1)

The method of claim 1, wherein the amino substituted cyclic nitroxyl compound is a 4-(C1-C4 acylamido)-2,2,6,6-tetramethylpiperidin-1-oxyl.

### Claim 7 (depends on 1)

The method of claim 1, wherein the amino substituted cyclic nitroxyl compound is 4-acetamido-2,2,6,6-tetramethylpiperidin-1-oxyl.

### Claim 8 (depends on 1)

The method of claim 1, wherein the amount of amino substituted cyclic nitroxyl compound ranges from about 0.0025 to about 0.1 molar equivalents per mole of anhydroglucose unit monomer in the cellulose ester interpolymer.

### Claim 9 (depends on 1)

The method of claim 1, wherein the primary oxidant comprises a salt of Na, K, Mn, Mg, Fe, or Cu, or mixtures thereof.

### Claim 10 (depends on 1)

The method of claim 1, wherein the primary oxidant comprises KCl, KBr, NaCl, NaBr, NaI, NaOCl, NaOBr, Oxone, Mn(NO3)2, Mn(OAc)3, KMnO4, Mn2O3, MnO2, Mg(NO3)2, FeCl3, Cu(NO3)2, or mixtures thereof.

### Claim 11 (depends on 1)

The method of claim 1, wherein the primary oxidant is manganese triacetate.

### Claim 12 (depends on 11)

The method of claim 11, wherein the terminal oxidant is peracetic acid.

### Claim 13 (depends on 1)

The method of claim 1, wherein the primary oxidant is KMnO4.

### Claim 14 (depends on 1)

The method of claim 1, wherein the amount of primary oxidant ranges from about 0.0001 to about 0.1 molar equivalents per mole of anhydroglucose unit monomer in the cellulose ester interpolymer.

### Claim 15 (depends on 1)

The method of claim 1, wherein the terminal oxidant comprises O2, ozone, NaOCl, NaOBr, H2O2, or CH3CO3H.

### Claim 16 (depends on 1)

The method of claim 1, wherein the terminal oxidant is CH3CO3H.

### Claim 17 (depends on 1)

The method of claim 1, wherein the amount of terminal oxidant ranges from about 0.1 to about 10 molar equivalents per mole of anhydroglucose unit monomer in the cellulose ester interpolymer.

### Claim 18 (depends on 1)

The method of claim 1, wherein the temperature of the reaction mixture is greater than 40° C. and less than 60° C.

### Claim 19 (depends on 1)

The method of claim 1, wherein the contact time is of a duration operable to provide an oxidized cellulose ester interpolymer having a degree of polymerization of greater than 10.

### Claim 20 (depends on 1)

The method of claim 1, wherein water is present in an amount ranging from 1 to 60 weight percent based on total weight of the reaction mixture.

### Claim 21 (depends on 1)

The method of claim 1, wherein the oxidized cellulose ester interpolymer has an acid number greater than 10.

### Claim 22 (depends on 1)

The method of claim 1, wherein the oxidized cellulose ester interpolymer has an acid number greater than 30.

### Claim 23 (depends on 1)

The method of claim 1, further comprising the step of isolating the oxidized cellulose ester interpolymer.