Nippon Shokubai Co., Ltd.

Elf Atochem S.a.

Tomiyasu Ueta

Hiromichi Tanaka

Tsuyoshi Hirata

Tsutomu Yuasa

Toru Uno

Yoshiyuki Onda

Hiroko Izukashi

Hiroshi Yamazaki

Hideyuki Nishibayashi

Daijo Tomihisa

Shogo Iwai

Tomotaka Nishikawa

Noboru Sakamoto

Akio Naka

Yoshitomo Nakata

Toshiaki Kuriyama

Thierry Aubert

Yoshihiro Arita

Toshio Hayashiya

Minoru Miyagawa

Hirokazu Yamamoto

Yukiko Nishikawa

A cement admixture object of the present invention can make slump-retaining ability excellent to retain fluidity and, at the same time, can realize a viscosity of cement compositions so that work becomes easy at a field handling them, can make the state of a cement composition better. The present invention relates to a cement admixture

Cement admixture

It is an object of the present invention, which has been made in view of the above-mentioned state of the art, to provide a cement admixture capable of improving the water-reducing ability of cement compositions and the like and enhancing the strength and durability of hardened products produced therefrom and further capable of adjusting the viscosity of such compositions so as to facilitate the works at the sites of handling the same, as well as a method of producing such cement additive. A cement admixture comprising a polycarboxylic acid polymer and a nitrogen atom-containing compound having non-amide bond, wherein the mass ratio (A/B) between the mass (A) of said polycarboxylic acid polymer and the mass (B) of said nitrogen atom-containing compound having non-amide bond satisfies the relation 200&#x3e;(A/B)&#x3e;1.

Cement admixture and production method thereof

The polycarboxylic acid concrete admixture of the present invention exhibits properties such as decreasing the concrete viscosity, improving the slump-retaining ability, and suppressing bleeding water, and is improved in the ability to cement compositions or the like. The above-mentioned polycarboxylic acid concrete admixture comprises a polycarboxylic acid polymer containing a polyalkylene glycol in the side chain, wherein the polycarboxylic acid polymer is obtained by polymerizing monomer components containing an alkyl (meth)acrylate monomer and a specific polyalkylene glycol unsaturated monomer and unsaturated carboxylic acid (salt) monomer, and it has a specific weight average molecular weight.

Polycarboxylic acid concrete admixture

It is an object of the present invention to provide a polycarboxylic acid polpolymer which improves the water reducing capacity and workability of cement compositions and the like and making them easier to handle when the fluidity and water reducing capacity are at the same levels, a method of producing the copolymer, and a cement additive and a cement composition comprising the copolymer. The present invention is further to provide a polycarboxylic acid copolymer and a cement additive which are capable of improving the strength and durability of hardening products of cement compositions, hence can advantageously be used in ultrahigh strength concrete. The present invention is polycarboxylic acid copolymers having high water reducing capacity, reducing the viscosity of cement compositions and improving the workability in applying cement. The present invention is directed to a polycarboxylic acid copolymer which is obtained by copolymerization of monomer components comprising a polyalkyleneimine unsaturated monomer (A1) and an unsaturated carboxylic acid monomer (B).

Polycarboxylic acid copolymer, production method and use thereof

The cement admixture and the cement admixture composite of the present invention can improve the water-reducing ability of cement compositions and the like and enhance the strength and durability of hardening products produced therefrom and further can adjust the viscosity of such compositions so as to facilitate the works at the sites of handling the same. The above-mentioned cement admixture is a cement admixture comprising a polycarboxylic acid polymer containing a specific site, and the above-mentioned cement admixture composite comprises two or more species of cement admixtures, wherein at least one of them is said cement admixture.

Cement admixture and cement admixture composite

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&#x3e;BMw, or peaktop molecular weights (AMp and BMp) of copolymers (A) and (B) are AMp&#x3e;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%.

Admixture for cement

It is an object of the present invention to provide a polycarboxylic acid copolymer which improves the water reducing capacity and workability of cement compositions and the like and making them easier to handle when the fluidity and water reducing capacity are at the same levels, a method of producing the copolymer, and a cement additive and a cement composition comprising the copolymer. The present invention is further to provide a polycarboxylic acid copolymer and a cement additive which are capable of improving the strength and durability of hardening products of cement compositions, hence can advantageously be used in ultrahigh strength concrete. The present invention is still further to provide a method of producing polycarboxylic acid copolymers having high water reducing capacity, reducing the viscosity of cement compositions and improving the workability in applying cement. The present invention is directed to a polycarboxylic acid copolymer which is obtained by copolymerization of monomer components comprising a polyalkyleneimine unsaturated monomer (A1) and an unsaturated carboxylic acid monomer (B).

The present invention provides: a vinylpyrrolidone polymer which exhibits good heat resistance and storage stability; a composition containing the vinylpyrrolidone polymer; a stabilization process for the vinylpyrrolidone polymer, and a preservation process for a vinylpyrrolidone polymer by which: even when the vinylpyrrolidone polymer is preserved for a long time or at high temperature, the physical properties such as molecular weight (K value) of the vinylpyrrolidone polymer can be prevented from changing, therefore the vinylpyrrolidone polymer can stably be preserved. To enhance the heat resistance and the storage stability, a vinylpyrrolidone polymer is mixed with a certain amount of antioxidant, and the oxygen concentration is suppressed to not higher than 50,000 ppm in a gas phase that contacts with the vinylpyrrolidone polymer when preserving.

Vinylpyrrolidone polymer and its stabilization and preservation processes

This invention concerns a method for the production of an ethylene sulfide/sulfur copolymer which comprises copolymerizing ethylene sulfide with sulfur. This method permits an ethylene sulfide/sulfur copolymer as a novel copolymer.

Growing community of inventors

Osaka, Japan

Tomiyasu Ueta