Abstract: Anionic, water-soluble cellulose ethers which are treated with a mixture of glyoxal and a sodium borate, preferably borax, readily disperse in aqueous solutions without clumping or agglomerating. These treated compounds can be formed by contacting an organic slurry of an anionic, water-soluble cellulose ether with an aqueous solution of glyoxal and a sodium borate, recovering the product and then drying it.
Abstract: A process for purification and working-up of cellulose or starch ethers using a solid-jacket sieve centrifuge for removing the suspension agent extraction with purifying agent and isolation of the purified ether product.
Abstract: Plasticized cellulose polymers comprise a base polymer having a chain of .beta.-anhydroglucose units joined by ether linkages and having ether substituents, with at least one of the units being additionally substituted, by esterification of at least one hydroxyl group, by at least one ester group, which contains at least two carbon atoms and is chemically unreactive.Preferably the ester group contains four or more, most preferably five, carbon atoms. The carbon chains of the ester groups may be straight or branched.These internally plasticized celluloses may be prepared by, for example, reacting the base polymer with a carboxylic acid in xylene or with an acid chloride or anhydride in pyridine. They are useful in particular as inhibitor coatings for rocket motor propellants and in general wherever cellulose polymers are employed.
Type:
Grant
Filed:
September 19, 1980
Date of Patent:
December 7, 1982
Assignee:
The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britian and Northern Ireland
Inventors:
Michael Burnup, Gerard F. Hayes, Norman C. Paul
Abstract: A carrier base material adapted to be combined with a therapeutically active medicament and shaped and compressed to form a sustained release therapeutic composition having a long-lasting, slow and regular incremental release of the medicament upon administration, the carrier base material being hydroxypropylmethylcellulose or a mixture of hydroxypropylmethylcellulose and either up to 30% ethylcellulose or 30% sodium carboxymethylcellulose or both, and wherein the carrier base material has been subjected to hydrolysis and oxidation successively or concurrently until the carbonyl content ranges from 0.2-3.0 grams/100 grams, the carboxyl content ranges from 0.60-2.60 grams/100 grams and the moisture content is in the range of 0.5-3.9%.
Abstract: This invention relates to a process for reducing the viscosity of cellulose ethers by reacting a water-soluble cellulose ether with ozone in the presence of water, wherein said cellulose ether which is moist with water and has a dry content of from 20 to 95% by weight is reacted with an ozone/oxygen mixture or with an ozone/air mixture at a temperature of about 0.degree. to 60.degree. C.
Abstract: Easily dispersible anionic water-soluble polymers are disclosed which are prepared by lightly treating particulate water-soluble polymer with a water-soluble aluminum salt and an aluminum chelant. Rate of hydration is retarded when the particles are added to aqueous media, allowing the particles to be dispersed completely before their surfaces hydrate sufficiently to gel and prevent complete dissolution.
Abstract: A process for the purification of cold-water soluble cellulose ethers containing alkali metal halides consisting essentially of suspending a cold-water-soluble cellulose ether crude reaction product containing 25% by weight or more of alkali metal halides, based on the dry weight, in an aqueous solution containing from 4% to about 25% by weight of one or more water-soluble salts of acids selected from the group consisting of polybasic inorganic acids and organic polycarboxylic acids with agitation at a temperature of from 10.degree. C. to 50.degree. C., separating the purified cellulose ether solids and optionally repeating the suspending and separating steps one or more times. The resulting material can be employed in washing and cleansing composition slurries for spray-drying. The process is especially suitable for the treatment of methyl cellulose or water-soluble mixed ethers of methyl or ethyl cellulose with a sodium sulfate solution.
Abstract: A process for preparing a derivative of an hydroxyl bearing substrate by reacting an hydroxyl bearing substrate with oxirane bearing molecules to produce an oxirane ring bearing substrate; and reacting the oxirane ring with a substituted primary aromatic amine selected from primary aromatic amine alcohols and primary aromatic amine thiols. Among the compositions so produced is a stable modified hydroxyl bearing substrate or hydroxyl bearing sheet having covalently bonded thereto primary aromatic amines which can be diazotized. The diazotized substrate selectively, covalently binds proteins, polypeptides, peptides, nucleic acids, RNA, single stranded DNA, and nucleic acid hybrids.
Abstract: A process for preparing a cellulose ether which comprises reacting celluloses untreated or treated with an aqueous solution of alkali hydroxide with an etherifying agent in the presence of an aqueous solution of alkali hydroxide, an organic solvent being substantially immiscible with water and capable of dissolving the etherifying agent and a quaternary salt having the following general formula: ##STR1## wherein M is nitrogen atom or phosphorus atom, R.sup.1, R.sup.2, R.sub.3 and R.sub.4 are independently an organic group and X.sup.- is an anion. According to the process, the etherification is carried out uniformly to give a cellulose ether of a high quality in which the substituents are uniformly distributed.
Abstract: This invention relates to a process for preparing swellable cross-linked carboxyalkylcelluloses by reacting cellulose, a carboxyalkylating etherifying agent, and a cross-linking agent in an aqueous alkaline medium, comprising effecting alkalizing, etherifying, and cross-linking simultaneously in one reaction step using fibers, textile sheet materials containing these fibers, or sheet materials of other kinds, having a base of cellulose hydrate or of natural cellulose, by contacting said fibers or sheet materials with an ample quantity of an aqueous alkaline reaction mixture, removing part of the reaction mixture from the fibers or sheet materials contacted therewith, so that at least the quantity required for reaction is still present, and treating the fibers or sheet materials containing the remainder of the aqueous alkaline reaction mixture with heat energy. The invention also relates to equipment for performing the process.
Type:
Grant
Filed:
May 29, 1979
Date of Patent:
February 10, 1981
Assignee:
Hoechst Aktiengesellschaft
Inventors:
Helmut Lask, Arno Holst, Ehrenfried Nischwitz, Hans Sommer
Abstract: Polymers from the group consisting of cellulose and its ester and ether derivatives, of polyvinyl alcohol and its ester derivatives, polymers with vinyl esters and homopolymers and copolymers of acrylates and methacrylates are modified with monofunctional or difunctional cyclic .beta.-ketonic acids or their esters, in particular with succinylsuccinic acid or its ester derivatives. The modified polymers are particularly suitable for obtaining semi-permeable membranes for osmotic separation methods.
Abstract: Biocompatible articles are obtained by treating a polymeric material with a hydrolyzing agent on its surface and covalently binding thereon a biological agent, such as an anti-platelet-aggregation agent.
Type:
Grant
Filed:
June 21, 1978
Date of Patent:
January 6, 1981
Assignee:
Snamprogetti S.p.A.
Inventors:
Walter Marconi, Francesco Pittalis, Francesco Bartoli, Franco Morisi
Abstract: In the preparation of organosoluble cellulose ethers, the content of alkali metal (hydroxides and the salts thereof) in the resulting cellulose ether is reduced by forming a solution of the cellulose ether and an organic solvent, converting the alkali metal hydroxide therein to an alkali metal salt and heating the resulting solution at conditions sufficient to (1) increase the size of the alkali metal salt particles and (2) remove any water therefrom. Filtering the resulting mixture and drying the filtrate yields a cellulose ether containing a very small percentage of alkali metal salt, e.g., often less than about 500 ppm.
Abstract: Hydrophilic films, fibers and spongy articles of a water-insoluble polymer selected from the group consisting of regenerated cellulose, cellulose ether, cellulose ester and polyalkylene, and capable of forming fibers and films, are produced by distributing in a mass of the polymer up to 50% of pulverulent or granular amorphous particles of an originally water-soluble cellulose ether prepared from natural cellulose and rendered by chemical modification at least partly water-insoluble while remaining water-absorbent. The resulting mixture is then processed by conventional methods into the desired article.
Type:
Grant
Filed:
May 8, 1978
Date of Patent:
April 29, 1980
Assignee:
Hoechst Aktiengesellschaft
Inventors:
Arno Holst, Michael Kostrzewa, Helmut Lask
Abstract: A composition of matter for use in a visual-type instrument which includes a polarizer for a light beam and an analyzer for a light beam, the chemical composition being birefringent at a first relative humidity and nonbirefringent at a second relative humidity.
Abstract: A polysaccharide or polyvinyl alcohol containing a mixture of nitrite ester groups with sulfate or nitrate ester groups with the mixture of ester groups being substantially uniformly distributed among the polymer units of the polysaccharide or polyvinyl alcohol.A nitrite ester of a polysaccharide alcohol having a degree of substitution of less than about 2.0. A nitrite ester of polyvinyl alcohol having a degree of substitution of 1.0 or less.
Abstract: In the process for the preparation of low-substituted cellulose ethers comprising the successive steps of etherification of alkali cellulose, neutralization of the crude cellulose ether, washing, drying and pulverization, the neutralization step is carried out in two stages, i.e., by first employing 5 to 80% of an acid stoichiometrically required and then adding an additional amount of the acid to complete neutralization. The cellulose ethers thus prepared can readily be pulverized into fine powder having a very good flowing property and yet an excellent binding force, and work as a suitable disintegrator in tablets.
Abstract: A process for the synthesis of hydroxyethyl cellulose having improved resistance of enzyme catalyzed hydrolysis is provided by employment of a controlled, optimum amount of available water for swelling the cellulose in aqueous caustic reaction medium in hydroxy ethoxylation sequences of first high and then low ratios of caustic:cellulose.
Type:
Grant
Filed:
November 18, 1976
Date of Patent:
April 11, 1978
Assignee:
Union Carbide Corporation
Inventors:
Joseph Edward Glass, Jr., Roy Gale Lowther
Abstract: The invention relates to a new substance, namely 2,3-di-(2,3-diiodopropoxy)-propyl cellulose and to the production of the same by the action of a dihalogenopropyl ether of cellulose with an alkali metal allylate with iodine addition to the resulting 2,3-di-allyloxy propyl cellulose.
Abstract: A compound of the formula, wherein R.sub.1 is hydrogen or a halogen atom, R.sub.2 is ##STR1## R.sub.3 is hydrogen, an alkyl group, a cycloalkyl group or an aralkyl group, and n is an integer of 1 or 2, which is useful as ultraviolet absorber.
Type:
Grant
Filed:
August 15, 1975
Date of Patent:
March 7, 1978
Assignees:
Sumitomo Chemical Company, Limited, Kyodo Chemical Company, Ltd.
Abstract: There is disclosed the preparation of a gradable polymeric composition by the chemical modification of a polymeric material such as a polymer or copolymer. The preparation comprises reacting in the presence of free radicals the polymeric material with a non-polymeric organic reagent having a structure which contains both a hydrocarbon residue and a polymeric material-degradation-sensitizing group.
Abstract: A novel aldehyde-containing polymer (ACP) is prepared by reaction of a polysaccharide with periodate to introduce aldehyde groups onto the C.sub.2 - C.sub.3 carbon atoms and by introduction of ether and ester groups onto the pendant primary hydroxyl to modify solubility characteristics. The ACP is utilized to absorb nitrogen bases such as urea in vitro or in vivo.
Type:
Grant
Filed:
March 15, 1976
Date of Patent:
August 9, 1977
Inventors:
James C. Administrator of the National Aeronautics and Space Administration, with respect to an invention of Fletcher, William A. Mueller, George C. Hsu, Harold E. Marsh, Jr.
Abstract: Preparation of partially substituted nitrate and sulfate esters of polysaccharides or polyvinylalcohol, their esters containing a mixture of nitrite with sulfate or nitrate groups, aqueous media thickened with such esters, the simultaneous preparation of such esters and alkyl nitrites or such esters and inorganic nitrites or nitrates and resulting products, useful as thickeners, films, fibers and in many other applications.
Abstract: A reactive matrix comprises a co-enzyme chemically attached to a water insoluble organic polymeric support material. The reactive matrix may be used in a process for the separation of mixtures containing a plurality of enzymes.
Type:
Grant
Filed:
September 2, 1975
Date of Patent:
March 8, 1977
Inventors:
Peter Duncan Goodearl Dean, Christopher Robin Lowe
Abstract: The invention relates to diethylaminohydroxypropyl derivatives of cellulose I or II having maximum weight percentage of nitrogen of 1.6 and 6.3 respectively, and having the power to sorb 7.5 - 14 and 11.5 - 36 per cent of water, respectively, at a temperature of 20.degree.C and a relative humidity of 63 per cent. The invention relates also to the method for preparing these cellulose derivatives which consists in treating diethylaminohydroxypropyl derivatives of cellulose I or II having maximum weight percentage of nitrogen of 1.6 and 6.3 respectively and having the power to sorb a maximum of 7.3 or 11 per cent of water respectively, at a temperature of 20.degree.C and relative humidity of 63 percent, with acetic acid or with its aqueous solutions, taking not less than 0.1 mole of acetic acid per mole of diethylaminohydroxypropyl groups. The proposed derivatives of cellulose have highly accessible structure, increased reactivity and lowered chromacity.
Abstract: Disclosed are epoxy-azido compounds of the formula ##EQU1## WHERE R is a polyvalent organic radical, R' is a hydrogen, alkyl, cycloalkyl, aryl, or aralkyl radical, A is ##EQU2## and n and m are integers from 1 to 100. Also disclosed is the use of said epoxy-azido compounds in modifying polymers, cross-linking polymers, and adhering polymers to certain substrates, e.g. glass and other polymers.
Abstract: Disclosed are epoxy-azido compounds of the formula ##EQU1## WHERE R is a polyvalent organic radical, R' is a hydrogen, alkyl, cycloalkyl, aryl, or aralkyl radical, A is ##EQU2## and n and m are integers from 1 to 100. Also disclosed is the use of said epoxy-azido compounds in modifying polymers, cross-linking polymers, and adhering polymers to certain substrates, e.g. glass and other polymers.
Abstract: A polysaccharide or polyvinyl alcohol containing a mixture of nitrite ester groups with sulfate or nitrate ester groups with the mixture of ester groups being substantially uniformly distributed among the polymer units of the polysaccharide or polyvinyl alcohol.A nitrite ester of a polysaccharide alcohol having a degree of substitution of less than about 2.0. A nitrite ester of polyvinyl alcohol having a degree of substitution of 1.0 or less.