Cationic surface sizing agent and base paper for newspaper

Abstract

Disclosed is a cationic surface sizing agent intended to be coated on a base paper for a newspaper, which can improve a sizing property and scumming resistance during offset printing. The cationic surface sizing agent is produced by quaternizing a copolymer having a weight average molecular weight of 30,000 to 60,000, wherein the copolymer is produced by polymerizing (a) 20 to 40% by weight of a monomer having a tertiary amino group, (b) 10 to 80% by weight of a C4-C18 alkyl ester of (meth)acrylic acid and (c) 0 to 70% by weight of styrene or a derivative thereof with an azo-type polymerization initiator in the presence of a chain transfer agent. The cationic surface sizing agent has an improved sizing property without causing the decrease in the level of hydrophobicity of the copolymer and can prevent the sensitization of a plate to be printed (e.g., a PS plate) by specifying the composition of the monomers, using an azo-type polymerization initiator and also specifying the molecularweight of the copolymer.

Description

technical field The present invention relates to a cationic sizing agent having both sizing properties and plate contamination resistance adaptability in offset printing. Background technique In the offset printing of newsprint, the improvement of the quality of the paper proposed in response to the recent demand for high-speed and multi-color printing, the environmental response of the offset ink proposed in consideration of the environment during printing, and the printing process The conversion of dampening alkaline etching solution to fresh water or the reduction of dampening solution, etc. On the other hand, since newsprint requires ultra-light weight, neutralization, high-speed printing, and high quality, it needs further high water resistance. Therefore, when making base paper, not only internal sizing agent but also surface sizing agent and For starches, apply on machine. Especially recently, in order to improve the workability during papermaking, or to reduce th...

AI Technical Summary

Problems solved by technology

Due to such a situation, the effect of the conventional anionic surface sizing agent is reduced, so especially in the case of neutral paper, a cationic surface sizing agent is applied

Images