摘要 |
Novel sizing comprising an aqueous mixture of ammonia, an ammonium salt of formic acid, 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 formic acid. A method of making the sizing compositions and paper which is sized with the sizing compositions are also provided. |