专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

2. 发明专利

GB699027A Improvements in and relating to the production of cellulose triesters 未知
公开(公告)号：GB699027A
公开(公告)日：1953-10-28
申请号：GB32151
申请日：1951-01-04
申请人： COURTAULDS LTD
发明人： CAVE GODFREY JOHN , HAMPSON HENRY , STONEMAN JOHN PHILIP
IPC分类号： C08B17/02
摘要： In the production of cellulose triesters (particularly the triacetate) by circulating a fatty acid anhydride in an inert solvent through a static bed of cellulose so as to maintain its fibrous form, said cellulose having been pre-treated with the fatty acid corresponding to the anhydride, the esterification liquid is initially free from an esterification catalyst or contains part only of the catalyst to be used, and is circulated until the water present as moisture in the cellulose has reacted with the anhydride substantially before any esterification of the cellulose has taken place, whereupon all or the remaining quantity of catalyst is added and liquid is circulated until esterification is complete. When the circulating liquid contains no catalyst initially, the catalyst may be added to the liquid at a point removed from the cellulose bed and the liquid circulated through a heat exchanger so as to by-pass the cellulose bed, whereby the heat of the reaction between the water and anhydride, initiated by the catalyst, is removed before the esterification liquid, containing the catalyst, is recirculated through the cellulose bed to effect esterification. Alternatively, the catalyst may be added gradually while the esterification liquid is being circulated through the bed of cellulose. In another form of the invention the esterification liquid may contain initially from 10 to 30 per cent, preferably 20 to 25 per cent, of the total catalyst to be used, and this liquid is circulated through the bed of cellulose until the water-anhydride reaction is complete. Then the remainder of the catalyst is added and circulation is continued to effect esterification of the cellulose. Suitable catalysts are sulphuric and perchloric acids or mixtures of these. The inert solvent may be carbon tetrachloride, benzene or toluene. The cellulosic material may be in the form of flat wood pulp chips as described in Specification 699,026. The pretreatment of the cellulose with fatty acid may be effected by circulating the acid through the preformed bed of cellulose, or the cellulose may be treated before being formed into a bed, e.g. by steeping it in the acid and then draining off the excess. Specifications 207,562, 332,607, 332,608, [all in Class 2 (ii)], 387,533, 407,355, 412,710, 439,245, 464,843, 684,975 and 19210/46 (as open to inspection under Sect. 91, and corresponding to French Specification 929,968) also are referred to. The Provisional Specification refers also to Specification 280,493, [Class 15 (ii)], and to U.S.A. Specification 2,033,716.

IPRDB

热门服务

关于我们

友情链接

联系方式