摘要:
Disclosed are polymers of hydroxypropyl methyl cellulose acetate succinate (HPMCAS) and hydroxypropyl methyl cellulose acetate (HPMCA) with unique degrees of substitution of hydroxypropoxy, methoxy, acetyl, and succinoyl groups. When used in making compositions comprising a low-solubility drug and such polymers, the polymers provide enhanced aqueous concentrations and/or improved physical stability.
摘要:
A method for improving holdout on a coated, cellulosic substrate, such as a man-made fiber board. The process comprises the steps of applying an aqueous carboxymethyl cellulose acetate butyrate size composition to a man-made fiber substrate, forming a sized substrate. The sized substrate is then dried. Next, an aqueous coating composition is applied to form a coated, sized substrate. The coated, size substrate is then dried. According to the invention, the aqueous carboxymethyl cellulose acetate butyrate size composition used in the process comprises carboxymethyl cellulose acetate butyrate, water, and an organic solvent. The invention also relates to a sized, man-made fiber substrate comprising a man-made fiber substrate and a carboxymethyl cellulose acetate butyrate size. The carboxymethyl cellulose acetate butyrate may be either an internal sizing agent, or an an external sizing agent.
摘要:
A process for producing a cellulose ether acetate succinate comprises the step of reacting a cellulose ether with acetic anhydride, succinic anhydride and an depolymerizing agent, wherein the cellulose ether has an initial viscosity of at least 50 mPa-s, measured as a 2 weight-% solution in water at 20° C., and the reaction of the cellulose ether with acetic anhydride, succinic anhydride and the depolymerizing agent is conducted simultaneously or in sequence in one reaction device.
摘要:
A process for producing an esterified cellulose ether can be efficiently be produced by reacting a moist cellulose ether having a water content of at least 10 percent, based on the weight of the moist cellulose ether, with an aliphatic monocarboxylic acid anhydride, a dicarboxylic acid anhydride or a combination thereof. Further improvements in efficiency and reduction in process steps are achieved in a process for producing an esterified cellulose ether which comprises the steps of a) reacting cellulose with an alkaline material to produce alkali cellulose, b) reacting the produced alkali cellulose with one or more etherifying agents and washing the produced cellulose ether to obtain a moist cellulose ether having a water content of at least 10 weight percent, and c) reacting the moist cellulose ether with an aliphatic monocarboxylic acid anhydride and/or a dicarboxylic acid anhydride and with a depolymerizing agent.
摘要:
The present invention relates to a cellulose composite that makes separation and aggregation less likely to occur, and, more specifically, relates to a cellulose composite comprising cellulose and one or more types of water-soluble carboxymethyl cellulose wherein tan ´ of an aqueous dispersion obtained by dispersing 1 mass% of the cellulose composite in ion-exchanged water is 0.6 or lower.
摘要:
There is provided is a hydroxyalkyl alkyl cellulose exhibiting good flowability and high compressibility. More specifically, provided are a hydroxyalkyl alkyl cellulose having a volume-based average particle diameter, determined by dry laser diffractometry, of 50 to 100 µm, and having, on a basis of a dynamic image analysis to divide all particles into fine particles, spherical particles and fibrous particles, a volume fraction of the fibrous particles consisting of long and short fibrous particles relative to all of the particles of 45 to 70%, and a volume fraction of the fine particles relative to all of the particles of less than 2.0%; a solid preparation including the hydroxyalkyl alkyl cellulose; and others.
摘要:
There are provided low-substituted hydroxypropyl cellulose (L-HPC) having good compressibility and capping-prevention performance, and others. Specifically, provided are L-HPC having a hydroxypropoxy content of 5 to 16% by weight, a volume fraction of long fibrous particles of 20 to 40% and a volume fraction of short fibrous particles of 26 to 60% with the proviso that the latter is greater than the former; and a solid preparation containing the L-HPC. Also provided is a method for producing the L-HPC including the steps of: bringing powdery pulp having a length-weighted mean width of 10 to 25 µm into contact with an alkali metal hydroxide solution, reacting the alkali cellulose with propylene oxide, and neutralizing the alkali metal hydroxide present in the reaction product with an acid to precipitate crude low-substituted hydroxypropyl cellulose in the absence of a step of dissolving a portion or all of the reaction product.
摘要:
Provided are a composition for hot-melt extrusion which can be hot-melt extruded at a temperature lower than a conventional temperature and therefore free of heat-induced deactivation of a drug; and a method for producing a hot-melt extrusion product which is simpler than a spray-drying method. More specifically, provided is a composition for hot-melt extrusion comprising a drug and hypromellose acetate succinate (HPMCAS) having a hydroxypropoxy molar substitution of 0.40 or more. Also provided is a method for producing a hot-melt extrusion product comprising a step of hot-melt extruding a composition for hot-melt extrusion comprising a drug and hypromellose acetate succinate having a hydroxypropoxy molar substitution of 0.40 or more at a hot-melt temperature of melting temperature of the hypromellose acetate succinate or higher, or at a hot-melt temperature equal to or higher than a temperature at which both the hypromellose acetate succinate and the drug become melted.
摘要:
A hair fixative composition includes at least one carboxylated cellulose ether based polyglucose polymer, an alcohol based solvent system, and a cosmetically acceptable additive, wherein the polyglucose polymer is soluble in the alcohol based solvent system. The polyglucose polymer is obtained by reacting at least one cellulose ether with at least one anhydride.