Verfahren zur Herstellung von geleimtem Papier

摘要

In the production of paper sized with a hydrophobic organic acid anhydride, an aqueous suspension of papermaking fibres or an undried web is treated with an aqueous dispersion of the anhydride (as a solid or liquid) containing a water-soluble cellulose-substantive monomeric or polymeric cationic compound in an amount sufficient to render the anhydride cellulose-substantive. A large proportion of the sizing properties is thereby developed during the paper drying stage (at a temperature of 190-250 DEG C.). The anhydride and cationic compound may be added together or separately to the suspension of papermaking fibres. The anhydride may be added at the beater or stock chest and the cationic agent may be added at the head box. The pH of the papermaking fibres after treatment is preferably 5-8. 0.1-5% of size based on the dry fibres may be employed. The anhydride may be formed from myristic, palmitic, oleic, stearic, naphthenic, or 1, 12-dodecanedicarboxylic acid, or from a mixture of acetic and stearic acid. The monomeric cationic compound may be octadecylpyridinium chloride, octadecylamine acetate, N-(2-aminoethyl) stearamide acetate, tetraethylenepentaminestearic acid, stearamidotrimethylene dimethyl 2-hydroxyethyl ammonium dihydrogen phosphate. The polymeric cationic compound may be polyethylenamine, tetraethylenepentamine-epychlorohydrin, urea-formaldehyde-triethylenetetramine, diethylenetriamineadipic acid-epichlorohydrin, acrylamide-diallyl dimethyl ammonium chloride, casein, glue, acrylamide-acrylic acid treated with alum, or cationic starch. The polymeric compound preferably has a molecular weight of more than 1,000. Up to 5% of alum based on the fibres may also be employed. Polyoxyethylene sorbitol oleate laurate, sodium lignosulphonate, or formaldehyde-naphthalenesulphonic acid may be used as nonionic emulsifying agent. A dispersion of anhydride and cationic compound may contain 0.5-5% of solid. Its pH may be 4-6. A solid dispersion is formed by rapidly cooling a fine emulsion. The cationic agent may be added before, during, or after emulsification, and before or after cooling. A dry blend of all the non-aqueous constituents may be formed before emulsification. The blend may comprise a colloid protector, a hydrophobic pigment such as titanium dioxide or ultramarine, and a perfume. Specifications 451,300 and 804,504 are referred to.