Transparent cellulosic paper and method for making the same
AssigneeMitsubishi Paper Mills Limited
InventorsTakashi Koike, Masahiro Amano
Life of this patent
Estimating the term…
Abstract
A transparent cellulosic paper is produced by coating or impregnating a cellulosic paper with an organic solvent solution containing a compound having a weight-average molecular weight of 200 to 2,000 and having at least two isocyanate groups in a molecule or with an organic solvent solution containing, in addition to said compound, at least one compound selected from the group consisting of an aliphatic monohydric alcohol having 6 to 18 carbon atoms and a nonionic surface active agent to the polyethylene glycol type having one hydroxyl group in a molecule, the ratio OH/NCO in the solution being less than 1; removing said organic solvent; and allowing the coated or impregnated paper to harden by aging.
Claims7
A method for producing a transparent cellulosic paper which consists essentially of coating or impregnating a cellulosic paper with an organic solvent solution consisting essentially of the organic solvent and a compound having a weight-average molecular weight of 200 to 2,000 and having at least two isocyanate groups in the molecule;
- removing said organic solvent;
- and allowing the resulting coated or impregnated cellulosic paper to harden by aging, the amount of said compound being sufficient to make the cellulosic paper transparent by filling the pores of the cellulosic paper.
A method for producing a transparent cellulosic paper which consists essentially of coating or impregnating a cellulosic paper with an organic solvent solution consisting essentially of the organic solvent and (a) a compound having a weight-average molecular weight of 200 to 2,000 and having at least two isocyanate groups in the molecule and (b) at least one compound selected from the group consisting of an aliphatic monohydric alcohol having 6 to 18 carbon atoms and a nonionic surface active agent of the polyethylene glycol type having one hydroxyl group in the molecule, said compounds (a) and (b) being contained in a ratio of OH/NCO <
- 1;
- removing said organic solvent;
- and allowing the resulting coated or impregnated cellulosic paper to harden by aging, the amount of said compounds (a) and (b) being sufficient to make the cellulosic paper transparent by filling the pores of the cellulosic paper.
Dependencies are inferred from the claim text.