To provide a method for producing a mixture comprising two or more kinds of esterification products in an arbitrary composition at a low cost in a good productivity, to provide a method for producing a polycarboxylic acid-based polymer at a low cost in a good productivity by employing two or more kinds of esterification products as raw materials thus obtained, and to provide a method for producing an additive for cement at a low cost in a good productivity by including the polycarboxylic acid-based polymer as an essential ingredient.
A mixture comprising two or more kinds of esterification products is produced by feeding raw materials (carboxylic acid-based compound and alcohol) in a divided state into two or more stages to perform reaction and by making the composition of raw materials fed at least one stage different from the composition of raw materials fed at other stage. A polycarboxylic acid-based polymer is produced by polymerizing the reaction product containing two or more kinds of esterification products, if necessary, after adding a comonomer so as to form a monomer mixture. An additive for cement is produced by including the obtained polycarboxylic acid-based polymer as an essential ingredient.
TANAKA HIROMICHI
YUASA TSUTOMU
HIRATA TAKESHI
MAEDA ERIKO
