MANUFACTURING METHOD OF COPOLYMER LATEX, COPOLYMER LATEX AND COMPOSITION FOR PAPER COATING

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method of a copolymer latex giving a coated paper excellent in coating operability due to its excellent adhesive resistance and allowing good surface strength (dry strength) of a coated paper required in offset-printing and good surface strength (wet strength) in wetting.SOLUTION: A copolymer latex obtained by polymerizing 20 to 65 wt.% of an aliphatic conjugated diene-based monomer (a), 0.5 to 10 wt.% of an ethylenic unsaturated carboxylic acid monomer (b), and 25 to 79.5 wt.% of another monomer copolymerizable with these (the total of the monomers: 100 wt.%) is characterized in that when the point of starting continuous addition of the monomers is defined as 0 and the point of finishing addition of all the monomers is defined as 100, the method of adding (a) satisfies the following conditions (1) and (2). Condition (1): the time not to add the aliphatic conjugated diene-based monomer (a) exists within 30 to 80 from the above starting point. Condition (2): the width of the time not to add the above (a) is 0.7 to 35.