# US 12,006,376 B2 · Regioselectively substituted cellulose esters and films made therefrom > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,006,376 B2 - Document ID: US12006376B2 - Status: Granted - Kind: B2 - Application number: 18/190,415 - Filed: 2023-03-27 - Published: 2023-07-27 - Granted: 2024-06-11 - Earliest claimed: 2016-04-22 - Assignees: Eastman Chemical Company - Applicants: Eastman Chemical Company - Inventors: Matthew Allen Boone; Christopher Harlan Burk; Peter Borden Mackenzie; Jennifer A. Fish; Eduardo Gallas Cervo; Elaine Beatrice Mackenzie; Robert Joseph Maleski; Wesley Wayne McConnell; David William Norman; Tabatha Stearns; Bin Wang - Web page: https://patentgrep.com/patent/US12006376B2 ## CPC - C08B 3/16: Preparation of mixed organic cellulose esters {, e.g. cellulose aceto-formate or cellulose aceto-propionate} - B32B 7/12: using interposed adhesives or interposed materials with bonding properties - B32B 23/08: of synthetic resin - B32B 27/06: as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08)} - B32B 27/08: of synthetic resin - B32B 27/18: characterised by the use of special additives - B32B 27/22: using plasticisers - B32B 27/24: using solvents or swelling agents - B32B 27/281: {comprising polyimides} - B32B 27/325: {comprising polycycloolefins} - B32B 27/36: comprising polyesters - B32B 27/365: {comprising polycarbonates} - C08L 1/14: Mixed esters, e.g. cellulose acetate-butyrate - G02B 5/3033: {in the form of a thin sheet or foil, e.g. Polaroid} - G02B 5/305: {including organic materials, e.g. polymeric layers} - G02B 5/3083: {Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001)} - G02F 1/13363: Birefringent elements, e.g. for optical compensation - H10K 59/8791: {Arrangements for improving contrast, e.g. preventing reflection of ambient light} - B32B 2307/40: having particular optical properties - B32B 2307/516: mono-axially - B32B 2307/518: bi-axially - B32B 2307/546: Flexural strength; Flexion stiffness - B32B 2307/732: Dimensional properties - B32B 2309/105: Thickness - B32B 2457/202: LCD, i.e. liquid crystal displays - B32B 2457/206: Organic displays, e.g. OLED - C08L 1/08: Cellulose derivatives - C08L 1/10: Esters of organic acids {, i.e. acylates} - C09K 2323/03: Viewing layer characterised by chemical composition - C09K 2323/035: Ester polymer, e.g. polycarbonate, polyacrylate or polyester - G02F 1/133638: {Waveplates, i.e. plates with a retardation value of lambda/n} - G02F 2413/13: Positive birefingence - 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) - 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) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE ## Abstract Regioselectively substituted cellulose esters having a plurality of pivaloyl substituents and a plurality of aryl-acyl substituents are disclosed along with methods for making the same. Such cellulose esters may be suitable for use in films, such as +A optical films, and/or +C optical films. Optical films prepared employing such cellulose esters have a variety of commercial applications, such as, for example, as compensation films in liquid crystal displays and/or waveplates in creating circular polarized light used in 3-D technology. ## Claims ### Claim 1 A regioselectively substituted cellulose ester comprising: (a) a plurality of chromophore-acyl substituents; and (b) a plurality of pivaloyl substituents, (c) a plurality of (C1-6)alkyl-acyl substituents, wherein the cellulose ester has a hydroxyl degree of substitution (“DSOH”) in the range of from 0 to 0.9, wherein the cellulose ester has a pivaloyl degree of substitution (“DSPv”) in the range of from 0.1 to 1.2, wherein the cellulose ester has a chromophore-acyl degree of substitution (“DSCh”) in the range of from 0.4 to 1.6, and wherein the regioselectivity is such that the sum of the chromophore-acyl degree of substitution at C2 and C3 (“C2DSCh” and “C3DSCh”) minus the chromophore-acyl degree of substitution at C6 (“C6DSCh”) is between 0.1 and 1.6, wherein the chromophore-acyl is chosen from a heteroaryl-acyl, wherein the heteroaryl is a 5- to 10-membered ring having 1- to 4- heteroatoms chosen from N, O, or S, and wherein the heteroaryl is unsubstituted or substituted by 1-5 R1; wherein each R1 is independently chosen from nitro, cyano, (C1-6)alkyl; halo(C1-6)alkyl; (C6-20)aryl-CO2-; (C6-20)aryl; (C1-6)alkoxy; halo(C1-6)alkoxy; halo; 5- to 10-membered heteroaryl having 1-4 heteroatoms chosen from N, O, or S; or ### Claim 2 (depends on 1) The regioselectively substituted cellulose ester of claim 1, wherein C2DSCh minus C3DSCh is greater than or equal to 0.1. ### Claim 3 (depends on 1) The regioselectively substituted cellulose ester of claim 1, wherein at least one (C1-6)alkyl-acyl substituent is acetyl. ### Claim 4 (depends on 1) The regioselectively substituted cellulose ester of claim 1, wherein at least one (C1-6)alkyl-acyl substituent is propionyl. ### Claim 5 (depends on 1) The regioselectively substituted cellulose ester of claim 1, wherein at least one (C1-6)alkyl-acyl substituent is butyryl. ### Claim 6 (depends on 1) A film comprising regioselectively substituted cellulose ester of claim 1. ### Claim 7 (depends on 6) The film of claim 6, wherein the film has a birefringence (“Δn”) between 0.001 and 0.020 as measured at a wavelength of 589 nm. ### Claim 8 (depends on 6) The film of claim 6, wherein the thickness of the film is in the range of from 1 μm to 20 μm. ### Claim 9 (depends on 6) The film of claim 6, wherein the film is a +C, −C, +A, or −A film. ### Claim 10 (depends on 6) The film of claim 6, wherein the film is 45 degree, uniaxially, or biaxially stretched. ### Claim 11 (depends on 6) A multilayer film comprising the film of claim 6. ### Claim 12 (depends on 11) The multilayer film of claim 11, further comprising another film comprising a cellulose ester, a polycarbonate, a polyester, a polyimide, a cycloolefin polymer, a cycloolefin copolymer, or combinations thereof. ### Claim 13 (depends on 11) The multilayer film of claim 11, wherein the multilayer film has a thickness in the range of 20 μm to 140 μm. ### Claim 14 (depends on 11) The multilayer film of claim 11, wherein the multilayer film is 45 degree, uniaxially, or biaxially stretched. ### Claim 15 (depends on 11) The multilayer film of claim 11, wherein the multilayer film has a positive in-plane retardation that satisfies the relations of 0.7