Abstract:
The invention relates to a papermaking agent system in liquid form, which comprises (i) cationic starch solution, prepared by cooking a starch mixture comprising a starch component and a water component, and (ii) polymer composition, which has anionic and cationic groups and a cationic net charge of >0.1 meq/g. The polymer composition comprises or originates from at least one of constituents a), b) or c). Constituent a) contains an amphoteric polymer, which is a copolymer comprising structural units derived from acrylamide and/or methacrylamide monomers, and anionic and cationic groups attached to the copolymer. Constituent b) contains a first polymer, which is a copolymer comprising structural units derived from acrylamide and/or methacrylamide monomers, and anionic or cationic groups attached to the copolymer, as well as a second polymer, which comprises groups with opposite charge than the first polymer. Constituent c) contains a third polymer, which comprises a copolymer comprising structural units derived from acrylamide and/or methacrylamide monomers, as well as hydrolytically unstable cationic groups attached to the copolymer. Constituent a), b) or c) is added to one of the components of the starch mixture or to the starch mixture before the cooking of the starch mixture, and/or constituent a) or b) is added to the cationic starch solution after cooking of the starch mixture. The invention relates also to the use of the papermaking agent system and to a method for its preparation.
Abstract:
The invention relates to a papermaking agent system in liquid form, which comprises (i) cationic starch solution, prepared by cooking a starch mixture comprising a starch component and a water component, and (ii) polymer composition, which has anionic and cationic groups and a cationic net charge of >0.1 meq/g. The polymer composition comprises or originates from at least one of constituents a), b) or c). Constituent a) contains an amphoteric polymer, which is a copolymer comprising structural units derived from acrylamide and/or methacrylamide monomers, and anionic and cationic groups attached to the copolymer. Constituent b) contains a first polymer, which is a copolymer comprising structural units derived from acrylamide and/or methacrylamide monomers, and anionic or cationic groups attached to the copolymer, as well as a second polymer, which comprises groups with opposite charge than the first polymer. Constituent c) contains a third polymer, which comprises a copolymer comprising structural units derived from acrylamide and/or methacrylamide monomers, as well as hydrolytically unstable cationic groups attached to the copolymer. Constituent a), b) or c) is added to one of the components of the starch mixture or to the starch mixture before the cooking of the starch mixture, and/or constituent a) or b) is added to the cationic starch solution after cooking of the starch mixture. The invention relates also to the use of the papermaking agent system and to a method for its preparation.
Abstract:
New polyvinylamide and/or acryl acid-based copolymers. The new structured block copolymers are based on the block copolymerization of N-vinyl formamide (NVF) with other monomers by using a bifunctional initiator. Further, a method of preparing the structured block copolymer is provided, and especially a method wherein the NVF-based block is at least partially hydrolyzed to obtain PVAm. Also the use of the new structured block copolymers in sludge dewatering and in papermaking processes is disclosed.
Abstract:
The invention relates to a papermaking agent composition, preferably in powder form, which comprises a water-soluble polymer, which comprises 21-30 mol-% of vinylamine units and has an average molecular weight of at least 1 000 000 Da. The invention relates also to a method for treating of fibre stock in manufacture of paper, board or the like, where a thick fibre stock is obtained, it is diluted to a thin fibre stock having a consistency
Abstract:
The invention relates to a papermaking agent composition, preferably in powder form, which comprises a water-soluble polymer, which comprises 21-30 mol-% of vinylamine units and has an average molecular weight of at least 1 000 000 Da. The invention relates also to a method for treating of fiber stock in manufacture of paper, board or the like, where a thick fiber stock is obtained, it is diluted to a thin fiber stock having a consistency