Abstract: There are provided an admixture for cement which enhances water reducing property and flowability of a cement composition, and is excellent in slump retaining performance to retain the flowability with time, a polycarboxylic acid-based polymer for an admixture for cement suitable therefor, a producing method thereof, and a cement composition. One admixture for cement of the present invention contains copolymers (A) and (B) as an essential component, weight average molecular weights (AMw and BMw) of copolymers (A) and (B) are AMw>BMw, or peaktop molecular weights (AMp and BMp) of copolymers (A) and (B) are AMp>BMp. Another admixture for cement of the present invention contains a polycarboxylic acid-based polymer having a lower molecular weight side area ratio P of 50 to 87%.

Abstract: There are provided a cement admixture which enhances water reducing property and flowability of a cement composition, and is excellent in slump retaining performance to retain the flowability with time, a polycarboxylic acid-based polymer for a cement admixture suitable therefor, a producing method thereof, and a cement composition. One cement admixture of the present invention contains copolymers (A) and (B) as an essential component, weight average molecular weights (AMw and BMw) of copolymers (A) and (B) are AMw>BMw, or peaktop molecular weights (AMp and BMp) of copolymers (A) and (B) are AMp>BMp. Another cement admixture of the present invention contains a polycarboxylic acid-based polymer having a lower molecular weight side area ratio P of 50 to 87%.

Abstract: The present invention discloses a process for producing a dicyclopentadiene-modified unsaturated polyester. The process includes a first step of reacting a reaction mixture of maleic anhydride (MA) and water (H2O) with dicyclopentadiene (DCPD) and a second step of reacting the reaction product obtained in the first step with a polyhydric alcohol, or a polyhydric alcohol and a polybasic acid, to obtain an unsaturated polyester modified with dicyclopentadiene. In the first step of the process, (1) a molar ratio of water to dicyclopentadiene is greater than 1 and a molar ratio of maleic anhydride to dicyclopentadiene is 1.2 or more, (2) a molar ratio of water to maleic anhydride is 1 or less, or (3) both of the features (1) and (2) are satisfied. The present invention also discloses a polyester resin composition containing the modified unsaturated polyester and a radically polymerizable monomer, and a molding material containing the resin composition as a main component.

Abstract: A resin composition includes a dicyclopentenyl-group containing unsaturated polyester resin, a phenothiazine derivative (a) and an anion producing compound (b). On the other hand, resin composition includes a thermosetting resin, a phenothiazine derivative (a), an anion producing compound (b) and a phosphorous ester (c). A manufacturing method of resin composition includes the step of obtaining a dicyclopentenyl-group-containing unsaturated polyester by polycondensing unsaturated polyester material including a compound having a dicyclopentenyl group, and the step of mixing a cross-linking monomer with the obtained dicyclopentenyl-group-containing unsaturated polyester, wherein the phenothiazine (a) and the anion producing compound (b) are added in at least one of those steps.