Method of manufacture of paper and products based on paper having a high rate of absorption of the liquid and increased opacity and novel products thus obtained

摘要

Paper pulps and formed paper webs are treated with liquid ammonia or an alkylamine, and the treating agent is removed by washing with a solvent, e.g. water, for the ammonia or alkylamine or by evaporation. The alkylamine may have up to four carbon atoms in the molecule. The ammonia or amine may be anhydrous or may be in a mixture with not more than 75% of water, including any water present in the paper or pulp to be treated. Mixtures of two or more of these substances may be used. If the material treated is in sheet or web form and is not to be subsequently reslurried, it must be held against shrinkage during the treatment. The treatment increases the rate of absorption of liquids and the opacity of the material. Part of the treating liquid may be pressed out before the remainder is washed out or evaporated. The treatment may be applied to 90% - dry pulp which is then dispersed in water, may be beaten and formed into paper, with or without the addition of a wet-strength agent, e.g. a urea-formaldehyde condensation product, or of untreated pulp.