摘要 |
PCT No. PCT/SE91/00798 Sec. 371 Date Jun. 3, 1993 Sec. 102(e) Date Jun. 3, 1993 PCT Filed Nov. 25, 1991 PCT Pub. No. WO92/09745 PCT Pub. Date Jun. 11, 1992.The present invention reduces the normally marked yellowing of paper which is at least partially based on lignin-containing pulps. The invention relates to paper produced from fibre material and other paper ingredients in the form of at least one chemical. The fibre material at least partially consists of pulp that contains lignin in an amount exceeding 0.5 percent by weight, and is characterized in that the paper includes a) an acid and/or a corresponding salt of the general formula (the acid form) <IMAGE> where R1=-CHOHCH2OH or -CHOHCOOH in an amount of at least 0.05 percent by weight, calculated on the fibre material; and b) a reduction agent in an amount of at least 0.05 percent by weight, calculated on the fibre material. |