Patent GB-846515-A (GB)
Title: Improvements in or relating to agglomerating agents
IPC: C08C1/14
Filed: 1958-01-28
Abstract: 70% by weight of methacrylic acid and 30% by weight of methacrylamide were polymerized in a 20% aqueous solution with 0,5% by weight of potassium persulphate.  The white granular copolymer was washed with water and dried in vacuo to constant weight at 50 DEG C.  The product was then heated dry for 4 hours to 180 DEG C. and the ammonia split off.  The resulting product corresponds in composition to a copolymer of methacrylic acid, methacrylamide and dimethacryloylimide.  An alkali metal or ammonium salt of the product is soluble in water. Specifications 730,464, 764,004 and 818,249 are referred to.ALSO:The process of Specification 818,249 provides derivatives, for settling calcium carbonate from raw sugar juices comprising of methyl methacrylic polymers and copolymers in which said polymers or copolymers are subjected to hydrolysis and/or alcoholysis in the presence of ammonia and/or amines at temperatures above 180 DEG C. to give a derivative containing recurring units of dimethacryloylimide as well as recurring units of methacrylic acid wherein the copolymers/comprise at least 25 mol per cent of methacrylic acid units and at least 10 mol per cent of dimethacryloylimide units. These substances and/or their alkali metal or alkaline earth metal salts thereof may be used for the sedimenting of solid particles in aqueous suspensions.  When treating aqueous suspensions a concentration of less than 4 grams and preferably less than 1 gram need be applied for every 1000 litres of the aqueous suspension being treated.  Specifications 730,464 and 764,004 also are referred to.ALSO:The process of Specification 818,249 provides derivatives, of methyl methacrylic polymers and copolymers in which said polymers or copolymers are subjected to hydrolysis and/or alcoholysis in the presence of ammonia and/or amines at temperatures above 180 DEG C. to give a deriaative containing recurring units of dimethacryloylimide as well as recurring units of methacrylic acid wherein the copolymers comprise at least 25 mol. per cent. of methacrylic acid units and at least 10 mol per cent. of dimethacryloylimide units.  These substances and/or their alkali metal or alkaline earth metal salts thereof may be used as p  agglomerating agents for the improvement of soil.  For soil treatment the substance may be diluted with an inert substance such as clay or chalk or a fertilizer.  Specification 730,464 and 764,004 are also referred to.ALSO:The derivatives of Specification 818,249 [Group IV(a)] comprising methyl methacrylic polymers and copolymers in which said polymers or copolymers are subjected to hydrolyis and/or alcoholysis in the presence of ammonia and/or amines at temperatures above 180 DEG C. to give a derivative containing recurring units of dimethylacryloylimide as well as recurring units of methacrylic acid, wherein the copolymers comprise at least 25 mol. per cent. of methacrylic acid units and at least 10 mol per cent. of dimethacryloylimide units, and/or their alkali metal or alkaline earth metal salts, may be used as agglomerating agents, e.g. for settling calcium carbonate from raw sugar juices, by addition of 3 grams of the copolymer to each 1,000 litres of juice. Specifications 730,464 and 764,004 also are referred to.