US5001232A
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Carboxymethylsulphoethyl celluloses and a process for their preparation
Assignee: Dow Produktions und Vertriebs GmbH and Co OHG
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Filing: 1988-12-09
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Granted: 1991-03-19
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Expires: 2008-12-09
Abstract
Abstract Improved water soluble carboxymethylsulphoethyl celluloses may be obtained by suspending cellulose, adding compounds which transfer sulphoalkyl and carboxymethyl and then etherifying after alkalization.
Inventors
- 👤 Dieter Herzog
- 👤 Klaus Balser
- 👤 Klaus Szablikowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:34
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/84; C09K8/86; C09K8/88; C09K8/90; A; A61; A61K; A61K8/00; A61K8/18; A61K8/72; A61K8/73; A61K8/731; A61Q; A61Q19/00; C08; C08B; C08B11/00; C08B11/193; C09K3/00
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
93 words
Carboxymethylsulphoethyl cellulose (CMSEC) having 1. a degree of substitution DS sulphoethyl of 0.1 to 1 and a degree of substitution DS carboxymethyl of 0.3 to 1.2, the degrees of substitution satisfying the following equation: 0.5≦DS.sub.sulphoethyl +DS.sub.carboxymethyl ≦1.6, 2. a viscosity as measured on a 2% by weight solution of 5 mPa.s to 60,000 mPa.s (determined at a shear rate γ of 2.5 s -1 and 20° C.) and 3. a transmission in 2% by weight aqueous solution of T>95% (wave length of the light used: λ=550 nm, optical path length of cell=10 mm).
Claim 2
Dependent Claim
93 words
Carboxymethylsulphoethyl cellulose (CMSEC) having 1. a degree of substitution DS sulphoethyl of 0.1 to 1 and a degree of substitution DS carboxymethyl of 0.3 to 1.2, the degrees of substitution satisfying the following equation: 0.5≦DS.sub.sulphoethyl +DS.sub.carboxymethyl ≦1.6, 2. a viscosity as measured on a 2% by weight solution of 5 mPa.s to 60,000 mPa.s (determined at a shear rate γ of 2.5 s -1 and 20° C.) and 3. a transmission in 2% by weight aqueous solution of T>95% (wave length of the light used: λ=550 nm, optical path length of cell=10 mm).
Claim 3
Dependent Claim
28 words
Carboxymethylsulphoethyl cellulose according to claim 1, wherein the degree of substitution DS sulphoethyl is 0.3 to 1.0 and the degree of substitution DS carboxymethyl is 0.3 to 1.2.
Claim 4
Dependent Claim
75 words
Process for the preparation of a carboxymethylsulphoethyl cellulose by etherification of cellulose in alkaline solution with at least one compound SA which transfers a sulpho alkyl group and at least one compound CM which transfers a carboxymethyl group, wherein (a) cellulose is suspended, (b) the suspension is combined with compound SA and/ or CM, (c) the reaction mixture is then made alkaline, (d) etherification is carried out, (e) compound CM and/or SA is then added,
Claim 5
Dependent Claim
75 words
Process for the preparation of a carboxymethylsulphoethyl cellulose by etherification of cellulose in alkaline solution with at least one compound SA which transfers a sulpho alkyl group and at least one compound CM which transfers a carboxymethyl group, wherein (a) cellulose is suspended, (b) the suspension is combined with compound SA and/ or CM, (c) the reaction mixture is then made alkaline, (d) etherification is carried out, (e) compound CM and/or SA is then added,
Claim 6
Dependent Claim
32 words
Process for the preparation of a carboxymethylsulphoethyl cellulose according to claim 3, wherein in reaction step (b) only compound SA is added and in reaction step (e) only compound CM is added.
Claim 7
Dependent Claim
23 words
Process according to claim 3, wherein in reaction step (b) only CM is added and in reaction step (e) only SA is added.
Claim 8
Dependent Claim
63 words
Process for the preparation of a carboxymethylsulphoethyl cellulose CMSEC by the etherIfication of carboxymethyl cellulose CMC in alkaline solution with at least one compound SA which transfers a sulpho alkyl group, wherein (a) CMC is suspended, (b) the suspension is combined with compound SA, (c) the reaction mixture is made alkaline, and (d) etherification is carried out, with the formation of a CMSEC.
Claim 9
Dependent Claim
63 words
Process for the preparation of a carboxymethylsulphoethyl cellulose CMSEC by the etherIfication of carboxymethyl cellulose CMC in alkaline solution with at least one compound SA which transfers a sulpho alkyl group, wherein (a) CMC is suspended, (b) the suspension is combined with compound SA, (c) the reaction mixture is made alkaline, and (d) etherification is carried out, with the formation of a CMSEC.
Claim 10
Dependent Claim
101 words
Carboxymethylsulphoethyl cellulose having 1. a degree of substitution DS sulphoethyl of 0.1 to 1 and a degree of substitution DS carboxymethyl of 0.3 to 1.2, the degrees of substitution satisfying the following equation: 0.5≦DS.sub.sulphoethyl +DS.sub.carboxymethyl ≦1.6, 2. a viscosity as measured on a 2% by weight solution of 5 mPa.s to 60,000 mPa.s (determined at a shear rate of 2.5 s -1 and 20° C.) and 3. a transmission in a 2% by weight aqueous solution of T>95% (wave length of the light used: λ=550 nm, optical pathlength of cell=10 mm), obtainable according to the process of claim 3 or 6.
Claim 11
Dependent Claim
18 words
A process according to claim 3 wherein in (a) the cellulose is in the form of a pulp.
Claim 12
Dependent Claim
19 words
A process according to claim 3 wherein in (a) the cellulose is suspended in a secondary or tertiary alcohol.
Claim 13
Dependent Claim
26 words
A process according to claim 3 wherein in (b) the combination of the suspension and SA and/or CM results in a pH of 0 to 9.
Claim 14
Dependent Claim
20 words
A process according to claim 3 wherein in (c) the reaction mixture is made alkaline to pH 13 to 14.
Claim 15
Dependent Claim
23 words
A process according to claim 11 wherein the reaction mixture is made alkaline to pH 13 to 14 by the addition of alkali.
Claim 16
Dependent Claim
22 words
A process according to claim 3 wherein in (d) the etherification is carried out at a temperature of 55° to 100° C.
Claim 17
Dependent Claim
30 words
A process according to claim 3 wherein in (e) the compound CM and/or SA is added at temperatures from 15° to 100° C. and at a pH 10 to 14.
Claim 18
Dependent Claim
18 words
A process according to claim 6 wherein in (a) CMC is suspended in a secondary or tertiary alcohol.
Claim 19
Dependent Claim
25 words
A process according to claim 6 wherein in (b) the suspension is combined with compound SA to result in a pH of 0 to 9.
Claim 20
Dependent Claim
21 words
A process according to claim 6 wherein in (c) the reaction mixture is made alkaline to a pH 13 to 14.
Claim 21
Dependent Claim
24 words
A process according to claim 17 wherein the reaction mixture is made alkaline to a pH 13 to 14 by the addition of alkali.
Claim 22
Dependent Claim
23 words
A process according to claim 6 wherein in (d) the etherification is carried out at a temperature of from 55° to 100° C.
Claim 23
Dependent Claim
36 words
Carboxymethylsulphoethyl cellulose having 1. a degree of substitution DS sulphoethyl of 0.1 to 1 and a degree of substitution DS carboxymethyl of 0.3 to 1.2, the degrees of substitution satisfying the following equation: 0.5≦DS.sub.sulphoethyl +DS.sub.carboxymethyl ≦1.6,
Claim 24
Dependent Claim
36 words
Carboxymethylsulphoethyl cellulose having 1. a degree of substitution DS sulphoethyl of 0.1 to 1 and a degree of substitution DS carboxymethyl of 0.3 to 1.2, the degrees of substitution satisfying the following equation: 0.5≦DS.sub.sulphoethyl +DS.sub.carboxymethyl ≦1.6,
Claim 25
Dependent Claim
61 words
a viscosity as measured on a 2% by weight solution of 5 mPa.s to 60,000 mPa.s (determined at a shear rate of 2.5 s -1 and 20° C.) and 3. a transmission in a 2% by weight aqueous solution of T>95% (wave length of the light used:=550 nm, optical pathlength of cell=10 mm), obtainable according to the process of claim 6.
References Cited (Backward Citations)
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