Abstract: Novel sizing compositions comprising an aqueous mixture of ammonia, an ammonium salt, and a rosin that is modified with from about 5 to 50 percent based on the weight of the rosin, of an organic acidic compound selected from the group consisting of an .alpha.,.beta.-unsaturated organic acid, an anhydride thereof, and their mixtures. In one embodiment, the ammonia and ammonium salt are produced as the reaction product of urea and an acid selected from the group consisting of sulfamic acid, phosphoric acid, oxalic acid, methane-sulfonic acid, trichloracetic acid, nitric acid, sulfuric acid, hydrochloric acid, stearic acid, and acetic acid. The method of making the sizing compositions and paper which is sized with the sizing compositions are also provided.

Abstract: This invention is directed to novel sizing agent compositions containing urea which is chemically modified and/or combined with other materials which produce desirable sizing properties. These novel agents are used as beater additives in pulp refining for the manufacture of cellulosic products or are applied to finished cellulosic products as surface sizes. The invention is also directed to methods of making the sizing agents. In one preferred embodiment, urea is reacted with sulfamic acid and the resulting reaction product is combined with rosin and further reacted to produce a novel sizing agent.

Abstract: Novel sizing compositions comprising an aqueous mixture of ammonia, an ammonium salt, and a rosin that is modified with from about 5 to 50 percent based on the weight of the rosin, of an organic acidic compound selected from the group consisting of an .alpha., .beta.-unsaturated organic acid, an anhydride thereof, and their mixtures. In one embodiment, the ammonia and ammonium salt are produced as the reaction product of urea and an acid selected from the group consisting of sulfamic acid, phosphoric acid, oxalic acid, methane-sulfonic acid, trichloracetic acid, nitric acid, sulfuric acid, hydrochloric acid, stearic acid, and acetic acid. The method of making the sizing compositions and paper which is sized with the sizing compositions are also provided.