摘要:
Cellulose ethers, wherein at least a part of the hydroxyl groups of the cellulose backbone are substituted by methoxy groups and hydroxyalkoxy groups, and optionally alkoxy groups being different from methoxy groups, having an unconventional distribution of methoxy substituents at the 2-, 3- and 6-positions of the anhydroglucose units are described. Such cellulose ethers exhibit significantly higher thermoreversible gel strengths than any known hydroxyalkyl methyl celluloses of comparable viscosity and kind and level of substitution rendering them useful as additives for building compositions such as cement based tile adhesives. In particular, such cellulose ethers can be used to improve the attainable adhesion strength after heat storage conditioning and the temporal setting characteristics of a building composition.
摘要:
Cellulose ethers, wherein at least a part of the hydroxyl groups of the cellulose backbone are substituted by methoxy groups and hydroxyalkoxy groups, and optionally alkoxy groups being different from methoxy groups, having an unconventional distribution of methoxy substituents at the 2-, 3- and 6-positions of the anhydroglucose units are described. Such cellulose ethers exhibit significantly higher thermoreversible gel strengths than any known hydroxyalkyl methyl celluloses of comparable viscosity and kind and level of substitution rendering them useful as additives for building compositions such as cement based tile adhesives. In particular, such cellulose ethers can be used to improve the attainable adhesion strength after heat storage conditioning and the temporal setting characteristics of a building composition.
摘要:
Cellulose ethers are described herein which are useful in capsules or in coatings for dosage forms. In these cellulose ethers the ether substituents are methyl groups, hydroxyalkyl groups, and optionally alkyl groups being different from methyl, the cellulose ether has an MS (hydroxyalkyl) of 0.05 to 1.00, and hydroxy groups of anhydroglucose units are substituted with methyl groups such that [s23/s26−0.2*MS(hydroxyalkyl)] is 0.35 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 3-positions of the anhydroglucose unit are substituted with methyl groups and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 6-positions of the anhydroglucose unit are substituted with methyl groups.
摘要:
Cellulose ethers are described herein which are useful in food compositions. In these cellulose ethers the ether substituents are methyl groups, hydroxyalkyl groups, and optionally alkyl groups being different from methyl, the cellulose ether has a DS(methyl) of from 1.65 to 2.20, an MS(hydroxyalkyl) of from 0.10 to 1.00, and hydroxy groups of anhydroglucose units are substituted with methyl groups such that [s23/s26−0.2*MS(hydroxyalkyl)] is 0.35 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 3-positions of the anhydroglucose unit are substituted with methyl groups and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 6-positions of the anhydroglucose unit are substituted with methyl groups.
摘要:
Cellulose ethers are described which are useful in compositions for extrusion-molded bodies. In these cellulose ethers the ether substituents are methyl groups, hydroxyalkyl groups, and optionally alkyl groups being different from methyl, the cellulose ether has an MS (hydroxyalkyl) of 0.11 to 1.00, and hydroxy groups of anhydroglucose units are substituted with methyl groups such that [s23/s26−0.2*MS (hydroxyalkyl)] is 0.35 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 3-positions of the anhydroglucose unit are substituted with methyl groups and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 6-positions of the anhydroglucose unit are substituted with methyl groups.
摘要:
Cellulose ethers are described herein which are useful in food compositions. In these cellulose ethers the ether substituents are methyl groups, hydroxyalkyl groups, and optionally alkyl groups being different from methyl, the cellulose ether has a DS(methyl) of from 1.65 to 2.20, an MS(hydroxyalkyl) of from 0.10 to 1.00, and hydroxy groups of anhydroglucose units are substituted with methyl groups such that [s23/s26−0.2*MS(hydroxyalkyl)] is 0.35 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 3-positions of the anhydroglucose unit are substituted with methyl groups and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 6-positions of the anhydroglucose unit are substituted with methyl groups.
摘要:
Cellulose ethers are described herein which are useful in capsules or in coatings for dosage forms. In these cellulose ethers the ether substituents are methyl groups, hydroxyalkyl groups, and optionally alkyl groups being different from methyl, the cellulose ether has an MS (hydroxyalkyl) of 0.05 to 1.00, and hydroxy groups of anhydroglucose units are substituted with methyl groups such that [s23/s26−0.2*MS(hydroxyalkyl)] is 0.35 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 3-positions of the anhydroglucose unit are substituted with methyl groups and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 6-positions of the anhydroglucose unit are substituted with methyl groups.
摘要:
Cellulose ethers are described which are useful in compositions for extrusion-molded bodies. In these cellulose ethers the ether substituents are methyl groups, hydroxyalkyl groups, and optionally alkyl groups being different from methyl, the cellulose ether has an MS (hydroxyalkyl) of 0.11 to 1.00, and hydroxy groups of anhydroglucose units are substituted with methyl groups such that [s23/s26−0.2*MS (hydroxyalkyl)] is 0.35 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 3-positions of the anhydroglucose unit are substituted with methyl groups and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxy groups in the 2- and 6-positions of the anhydroglucose unit are substituted with methyl groups.
摘要:
The present invention relates to the preparation of methylhydroxypropylcellulose (MHPC) and the use thereof in mineral-bound building material systems, preferably in gypsum-bound building material systems, particularly preferably in gypsum machine plaster.
摘要:
The invention is directed to a process of preparing carboxymethyl cellulose comprising the steps of (a) reacting non-regenerated cellulose with an alkalization agent in the presence of water and isopropyl alcohol and (b) reacting the alkalized cellulose with monohaloacetic acid or a salt thereof, wherein 1.0 to 1.6 mol of the alkalization agent and 15 to 30 mol of water are used in step (a) and 0.5 to 0.8 mol of monohaloacetic acid or a salt thereof are used in step (b), each based on 1 mol of anhydroglucose unit of the cellulose. The invention also relates to carboxymethyl cellulose prepared by that process.