Paper and a method of paper manufacture
AssigneeMo och Domsjo Aktiebolag
InventorArne R. Agnemo
Life of this patent
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Abstract
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) ##STR1## where R.sub.1 =--CHOHCH.sub.2 OH 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.
Claims14
A paper produced from fibre material which consists at least partially of pulp that contains lignin in a quantity which exceeds 0.5 percent by weight, and of at least one chemical, including retention agent and/or hydrophobizing agent and/or dry strength agent,
- wherein the paper includes
- a) an acid and/or corresponding salt of the general formula (the acid form) ##STR4## where
- R.sub.1 =--CHOHCH.sub.2 OH 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.
A method for manufacturing paper comprising fibre material, which at least partially consists of pulp containing lignin in an amount exceeding 0.5 percent by weight, and at least one chemical, including retention agent and/or hydrophobizing agent and/or dry strength agent, wherein there is introduced to the paper in any position whatsoever after forming said paper
- a) an acid and/or corresponding salt of the general formula (the acid form) ##STR5## where
- R.sub.1 =--CHOHCH.sub.2 OH 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.
Dependencies are inferred from the claim text.