Patent GB-721052-A (GB)
Title: Improvements in acetylation of wood pulp
IPC: C08B3/06
Filed: 1952-03-06
Abstract: An aqueous solution of a water-soluble nonionic surface-active agent containing a multiplicity of alkenoxy groups is used to treat at least the surfaces of wood-pulp sheets prior to completion of drying. The treated wood pulp possesses improved activity towards acetylation.  Suitable surface-active agents include: (1) polyethylene oxides of freezing point of at least 34 DEG  C.; (2) polypropylene oxides of specific viscosity of about 0.065-0.138 measured in a 4 per cent benzene solution at 18 DEG  C.; (3) mixed ethers of aliphatic alcohols containing a polyethylene oxide radical and an aliphatic hydrocarbon radical having more than 7 carbon atoms (preferably those ethers containing 8-50 ethenoxy groups and a normal primary aliphatic hydrocarbon radical with from 8-20 carbon atoms); (4) mixed ethers of substituted phenols of formula R-O(CHR1,CH2O)xH where R is an aryl radical substituted by at least one aliphatic alkyl or acyl radical having more than 2 carbon atoms or by at least one cycloaliphatic radical, where R1 is H or methyl and x is a whole number greater than 1; (5) mixed thio-ethers containing a polyethylene oxide radical and an aliphatic hydrocarbon radical containing more than 7 carbon atoms (preferably those ethers containing 8 to 50 ethenoxy groups and a normal primary aliphatic hydrocarbon radical with from 12 to 18 carbon atoms), and (6) mixed ethers formed by reacting ethylene oxide with a rosin alcohol such as dihydroabietyl, dehydroabietyl, tetrahydroabiethyl or abietyl alcohol or the commercial mixture known as hydroabietyl alcohol.  Compounds specified include mixed ethers of polyethylene oxide and p-n-butyl phenol, p-tert.-butyl phenol, p-1 : 1 : 3 : 3-tetramethyl butyl phenol, decyl phenol, dodecyl phenol, cetyl phenol, octadecyl phenol, (2-ethyl hexyl) phenol, 9 : 10-octadecenyl phenol, di- and trioctyl phenols, amyl cresol, dodecyl cresol, isopropyl naphthol, isobutyl naphthol, dodecyl naphthol, p-cyclohexyl phenol, cyclohexyl-cyclohexyl phenol, bornyl phenol, butyryl, valeryl, lauroyl and stearoyl phenols and the corresponding cresols, naphthols and xylenols, and with the mixture of mercaptans derived from technical lauryl alcohol.  In order to achieve satisfactory solutions, non-ionic dispersing agents such as mixed ethers of aliphatic alcohols containing a higher proportion of ethenoxy groups may be mixed with those surface active agents of limited water-solubility. From 0.015 to 0.5 per cent of the surface active agents, based on the weight of the bone dry pulp may be employed. The compounds may be incorporated in the bulk prior to sheet formation or in the sheet (as by sprays or rollers) at any stage prior to completion of drying.  The results are reported of acetylation trails of p  pulps treated with polyethylene oxide of freezing point 49.5 DEG  C., polypropylene oxide of specific viscosity 0.131, pentadecaethenoxy ether of dibutyl phenol, octaethoxy ether of lauryl mercaptan, polyethenoxy (160) ether of hydroabietyl alcohol, dodecaethenoxy ether of lauryl alcohol, nonadecaethenoxy ether of oleyl alcohol and other similar compounds. Specifications 601,783, 718,188, 721,053 and U.S.A.  Specifications 2,362,217, 2,392,103, 2,393,817, 2,423,469 and 2,481,693 are referred to.