| 摘要 |
Water soluble ionic cellulose ethers from the hydroxyalkylcellulose group, substituted by 0.001-1.0, preferably 0.001-0.2 alkyl groups, per anhydroglucose unit and which carry 0.01-0.1 sulfoalkyl groups per anhydroglucose unit are new, and are outstandingly useful as protective colloids in emulsion polymerization. New water soluble ionic cellulose ethers from the hydroxyalkylcellulose group, substituted by 0.001-1.0, preferably 0.001-0.2, alkyl groups per anhydroglucose unit carry 0.01-0.1 sulfoalkyl groups per anhydroglucose unit. The cellulose ethers have the formula (I): where: C6H7O2 = an anhydroglucose unit, m = 50-3000, preferably 100-1000, and R<1>-R<3> = a polyalkylene oxide chain of formula (II): where X = H, CnH(2n+1)O, CH2-CH2-SO3Y, CH2CHOH-CH2SO3Y, where: n = 4-20; Y = H, Na, K, p,q, and r can have the values = 0-4 in R<1>-R<3>; The sum of (p+q+r) added to R<1>-R<3> per anhydroglucoise unit exceeds 1.3 and is less than 4.5, and is preferably 1.5-3.0, the series of oxyalkyl units in the polyalkylene oxide chain is random, the mean number of hydrophobically modified groups per anhydroglucose unit (DS HM) is 0.001-0.2, preferably 0.01-0.04, the mean number of sulfoalkyl groups per anhydroglucose unit is 0.01-0.1, preferably 0.01-0.01. Independent claims are included for: (1) preparation of cellulose ether by etherification of cellulose with an alkylene oxide etherification agent, and etherification with an alkyl halogenide or an alkylglycidyl ether and a sulfonate under base catalysis conditions; (2) an aqueous polymer dispersion obtained by radical initiated polymerization of ethylenically unsaturated monomers in aqueous emulsion in the presence of 0.2-5.0 wt.%, on the total wt.% monomers of water soluble ionic cellulose ethers selected from hydroxyalkyl cellulose, substituted with 0.001-1.0 alkyl groups per anhydroglucose unit and 0.01-0.4 sulfoalkyl groups per anhydroglucose unit.
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