Abstract: Disclosed is a pitch control agent including a (meth)acrylamide-based amphoteric polymer. The (meth)acrylamide-based amphoteric polymer contains 50 mol % or more of (meth)acrylamide, 0.5 to 20 mol % of a diallyldialkylammonium salt; and 0.1 to 14 mol % of an anionic monomer, as copolymerizable monomer components. This pitch control agent is less likely to be affected by a change in a surrounding environment, and therefore can exhibit excellent pitch controllability under various environments in paper production process.

Abstract: Disclosed is a pitch control agent including a (meth)acrylamide-based amphoteric polymer. The (meth)acrylamide-based amphoteric polymer contains 50 mol % or more of (meth)acrylamide, 0.5 to 20 mol % of a diallyldialkylammonium salt; and 0.1 to 14 mol % of an anionic monomer, as copolymerizable monomer components. This pitch control agent is less likely to be affected by a change in a surrounding environment, and therefore can exhibit excellent pitch controllability under various environments in paper production process.

Abstract: The present invention relates to a method for producing a cationic surface sizing agent, and contains a first step of obtaining a copolymer (A) by solution-polymerizing a monomer mixture which contains a monomer having a tertiary amino group (a) in the amount of 15 to 45% by weight, a (meth)acrylic acid ester (b) in the amount of 15 to 85% by weight, and styrenes (c) in the amount of 0 to 70% by weight in the presence of a chain transfer agent; a second step of obtaining a copolymer (B) by polymerizing the copolymer (A) and a nonionic hydrophilic monomer (d); a third step of obtaining a copolymer (C) by polymerizing the copolymer (B) and a hydrophobic monomer (e) in the absence of a surfactant; and a fourth step of obtaining a quaternary ammonium salt of the copolymer (C) by quaternizing a tertiary amino group present in the copolymer (C).

Abstract: The present invention relates to a method for producing a cationic surface sizing agent, and contains a first step of obtaining a copolymer (A) by solution-polymerizing a monomer mixture containing a monomer having a tertiary amino group (a), a specific (meth)acrylic acid ester (b) and styrenes (c) in the specific proportion in the presence of a chain transfer agent; a second step of obtaining a copolymer (B) by polymerizing the copolymer (A) and a hydrophobic monomer (d), in order to have a specific proportion of the copolymer (A), in an oxidation-reduction system using a water-soluble free-radical initiator and a heavy metal salt in the absence of a surfactant; and a third step of obtaining a quaternary ammonium salt of the copolymer (B) by quaternizing a tertiary amino group present in the copolymer (B).

Abstract: The present invention relates to a method for producing a cationic surface sizing agent, and contains a first step of obtaining a copolymer (A) by solution-polymerizing a monomer mixture which contains a monomer having a tertiary amino group (a) in the amount of 15 to 45% by weight, a (meth)acrylic acid ester (b) in the amount of 15 to 85% by weight, and styrenes (c) in the amount of 0 to 70% by weight in the presence of a chain transfer agent; a second step of obtaining a copolymer (B) by polymerizing the copolymer (A) and a nonionic hydrophilic monomer (d); a third step of obtaining a copolymer (C) by polymerizing the copolymer (B) and a hydrophobic monomer (e) in the absence of a surfactant; and a fourth step of obtaining a quaternary ammonium salt of the copolymer (C) by quaternizing a tertiary amino group present in the copolymer (C).