	US 12,215,057 B2
	Cement additive, cement admixture, cement composition, molded body, and method for improving strength of molded body
Takeshi Takayama, Osaka (JP); Kunihiko Ishizaki, Hyogo (JP); and Shigeru Sakamoto, Hyogo (JP)
Assigned to NIPPON SHOKUBAI CO., LTD., Osaka (JP)
Appl. No. 17/602,081
Filed by Nippon Shokubai Co., Ltd., Osaka (JP)
PCT Filed Mar. 24, 2020, PCT No. PCT/JP2020/013157 § 371(c)(1), (2) Date Oct. 7, 2021, PCT Pub. No. WO2020/209057, PCT Pub. Date Oct. 15, 2020.
Claims priority of application No. 2019-074148 (JP), filed on Apr. 9, 2019.
Prior Publication US 2022/0212995 A1, Jul. 7, 2022
Int. Cl. C04B 24/26 (2006.01); C04B 24/04 (2006.01); C04B 28/02 (2006.01); C04B 40/00 (2006.01); C04B 103/00 (2006.01); C04B 103/40 (2006.01); C08F 220/20 (2006.01); C08F 220/28 (2006.01); C08F 220/56 (2006.01); C08L 33/26 (2006.01)

CPC C04B 24/2652 (2013.01) [C04B 24/04 (2013.01); C04B 24/2641 (2013.01); C04B 28/02 (2013.01); C04B 40/0039 (2013.01); C08F 220/20 (2013.01); C08F 220/286 (2020.02); C08F 220/56 (2013.01); C08L 33/26 (2013.01); C04B 24/2647 (2013.01); C04B 2103/0046 (2013.01); C04B 2103/0051 (2013.01); C04B 2103/0062 (2013.01); C04B 2103/408 (2013.01)]

11 Claims

1. A cement admixture comprising a cement additive and a cement dispersant,

wherein the cement dispersant is a polycarboxylic acid-based dispersant,

the cement additive comprises a water-absorbent resin,

the water-absorbent resin is formed by polymerizing a monomer mixture containing no less than 50 mol % of a nonionic non-crosslinkable monomer and no less than 0.1 mol % of a nonionic crosslinkable monomer,

a content of an anionic monomer in the monomer mixture is no more than 4 mol %,

the nonionic non-crosslinkable monomer is not N-vinylacylamides, and

a water absorption ratio when the water-absorbent resin is immersed in an aqueous solution having a pH of 12.9 (here, the aqueous solution having a pH of 12.9 is an aqueous solution obtained by mixing 1.72 g of CaSO₄·2H₂O, 6.96 g of Na₂SO₄, 4.76 g of K₂SO₄, 7.12 g of KOH, and 979.4 g of deionized water) at 25° C. for 2 hours is less than 20 g/g.