Patent GB-349984-A (GB)
Title: Improvements in and relating to the manufacture of nitrocellulose products
IPC: D06N3/02
Filed: 1929-11-28
Abstract: Nitrocellulose plastics, particularly for floor coverings, are prepared by gelatinizing with a non-volatile gelatinizer, a nitro-cellulose having a viscosity of 1-100 c.g.s. units in a solution of 20 gm. in 100 c.c. of 95 per cent acetone at 20 DEG  C. and which has been prepared by nitrating cellulose with at least 40 times its weight of mixed acid to a nitrogen content of between about 11,5 and 12,5 per cent and, if necessary, treated to bring the viscosity within the above range; and incorporating filling-material with the gelatinized plastic mass in an amount of 1 1/2 -2\ba1/3 times the weight of the plastic.  In an example, cotton is nitrated with 50 times its weight of mixed acid comprising 21,5 per cent nitric and 61,1 per cent sulphuric acids with a trace of nitrous acid in a mechanical dipper plant until a nitrogen content of 12,2 per cent is obtained.  This nitrocellulose is then kiered at 30 DEG  C. under a pressure of 30 lbs. per sq. inch for 1 3/4 hours to attain a viscosity of 37 c.g.s. units.  The kiered product is then mixed by compressed air with 6 times its weight of water and tricresyl phosphate and castor oil are added and mixed for half an hour, the amounts of nitrocellulose, castor oil and tricresyl phosphate being in the ratio 35 : 15 : 50.  Water is removed in a centrifuge and the mass is rolled thinly and dried, after which cork dust and yellow ochre are incorporated therewith on heated rolls.  The amount of dried plastic, cork dust, and ochre are in the ratio 33 : 50 : 17. Alternatively, the filling-material may be incorporated with the plastic after removal of the bulk of the water, the mass being rolled into a sheet and dried.  The product is suitable for floor coverings. The mixing of the nitrocellulose and gelatinizer may be carried out in the absence of any substantial amount of water.ALSO:Nitrocellulose plastics, particularly for floor coverings, are prepared by gelatinizing with a non-volatile gelatinizer, a nitrocellulose having a viscosity of 1-100 c.g.s. units in a solution of 20 gm. in 100 c.c. of 95 per cent acetone at 20 DEG  C. and which has been prepared by nitrating cellulose with at least 40 times its weight of mixed acid to a nitrogen content of between about 11,5 and 12,5 per cent and, if necessary, treated to bring the viscosity within the above range; and incorporating fillingmaterial with the gelatinized plastic mass in an amount of 1 1/2 -2\ba1/3 times the weight of the plastic.  In an example, cotton is nitrated until a nitrogen content of 12,2 per cent is obtained.  This nitrocellulose is then kiered to attain a viscosity of 37 c.g.s. units, and is then mixed by compressed air with 6 times its weight of water and tricresyl phosphate and castor oil are added and mixed for half an hour, the amounts of nitrocellulose, castor oil and tricresyl phosphate being in the ratio 35 : 15 : 50.  Water is removed in a centrifuge and the mass is rolled thinly and dried after which cork dust and yellow ochre are incorporated therewith on heated rolls.  The amounts of dried plastic, cork dust, and ochre are in the ratio 33 : 50 : 17. Alternatively, the filling material may be incorporated with the plastic after removal of the bulk of the water, the mass being rolled into a sheet and dried.  The product is suitable for floor coverings. The mixing of the nitrocellulose and gelatinizer may be carried out in the absence of any substantial amount of water.