Nippon Shokubai Co., Ltd.

Other

Yoshiyuki Onda

Tsuyoshi Hirata

Hiromichi Tanaka

Toru Uno

Hideaki Tsuneki

Yukio Kadono

Masaru Kirishiki

Akihiko Yamashita

Tsutomu Yuasa

Kenichi Watanabe

Toru Inaoka

Kenji Rakutani

Hiroshi Yoshida

Tomotaka Nishikawa

Noboru Sakamoto

Tomiyasu Ueta

Atusi Moriya

Masaya Yamamoto

Hiroko Izukashi

Kunihiko Kimata

Seiichi Suzuki

Koichiro Nagare

Isao Satoh

Hiroki Wakayama

Hideyuki Tahara

Yasuhiko Sato

Yoshiaki Urano

Toshio Tamura

Tomoki Gomi

Hiroko Okochi

Naoko Hirano

Fumiaki Morishita

Isamu Maeda

Minoru Miyagawa

Yasuhiko Satoh

Masato Nishiue

Hisamoto Kawano

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

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 present invention provides: a production process for an alkylene oxide addition product, by which a high-molecular alkylene oxide addition product can be obtained with ordinary production facilities while the formation of by-products is suppressed; and production processes for derivatives from the alkylene oxide addition product. The present invention production process for an alkylene oxide addition product comprises the step of carrying out an addition reaction of an alkylene oxide to a hydroxyl-group-containing saturated compound in order to obtain the alkylene oxide addition product; with the production process being characterized by further comprising: the initial step of causing the alkylene oxide to add to the hydroxyl-group-containing saturated compound in an amount of not larger than 20 mols on average of the alkylene oxide per 1 mol of the hydroxyl-group-containing saturated compound to thereby obtain an alkylene oxide low-mol-addition product; and the molar-degree-of-polyaddition-adjusting step of causing the alkylene oxide to further add to the alkylene oxide low-mol-addition product as obtained in the initial step; wherein a portion of the entirety of the alkylene oxide low-mol-addition product as obtained in the initial step is used in the molar-degree-of-polyaddition-adjusting step.

Production processes for alkylene oxide addition product and its derivatives

The cement admixture of the present invention can provide viscosity decreasing ability as well as a high dispersing ability and slump loss preventing ability even in a high water reducing ratio range. The above-mentioned cement admixture comprises three components of a copolymer (A) containing a constituent unit (I) derived from the unsaturated (poly)alkylene glycol ether monomer (a) and a constituent unit (II) derived from a maleic acid monomer (b), a specific unsaturated (poly)alkylene glycol ether monomer (a) and a non-polymerizable (poly)alkylene glycol (B) having no alkenyl group.

Cement admixture, cement composition and method for laying work the same, and method for producing cement hardened product

The cement admixture of the present invention can improve the workability by displaying sufficient viscosity decreasing ability and initial dispersing ability even under a low temperature environment as well as high dispersing ability and dispersion retaining ability even in a high water reducing ratio range. The above-mentioned cement admixture comprises four components of a copolymer (A) containing a constituent unit (I) derived from the unsaturated (poly)alkylene glycol ether monomer (a) and a constituent unit (II) derived from a maleic acid monomer (b), a specific unsaturated (poly)alkylene glycol ether monomer (a), a non-polymerizable (poly)alkylene glycol (B) having no alkenyl group, and a polymer (C) having an oxyalkylene group or a polyoxyalkylene group and a carboxyl group, which is different from the copolymer (A).

Cement admixture and cement composition

It is an object of the present invention to provide a cement admixture capable of exhibiting high cement dispersing ability at low addition levels, in particular capable of displaying excellent initial dispersing ability and dispersion retaining ability even in a high water reducing ratio range, and a cement composition in which this admixture is used. A cement admixture comprising

It is an object of the present invention to provide a production method of a dehydration reaction product by which the occurrence of troubles in the production step or the degradation in performance characteristics or quality of various chemical products can be suppressed to a satisfactory extent. A production method of a dehydration reaction product

Production process for product of dehydration reaction and apparatus used for the production

It is an object of the present invention to provide a cement admixture which can show not only a high dispersing ability and a slump loss preventing effect but also a viscosity reducing effect and can show these characteristics even in the high water reduction ratio range, and a cement composition in which this admixture is used. A cement admixture comprising,

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).

Method for producing chemical reactive substance and polycarboxylic acid produced thereby

Method for production of alkoxylated compound

The present invention provides: a copolymer for cement admixtures which displays high dispersibility with a small adding amount and excellent dispersibility particularly even in a high water reducing ratio area, a cement admixture utilizing the copolymer, and a cement composition, and further, a production process for the copolymer. The copolymer for cement admixtures comprises: constitutional unit (I) derived from unsaturated polyalkylene glycol ether monomer (a) having an alkenyl group having 5 carbon atoms and an oxyalkylene group having 2 to 18 carbon atoms with an average addition number of moles of the oxyalkylene groups to be in the range of 10 to 300; and constitutional unit (II) derived from unsaturated monocarboxylic acid monomer (b). The cement admixture includes the copolymer for cement admixtures as an essential component, and may further include a defoaming agent. The cement composition includes the copolymer for cement admixtures, and cement as essential components. The production process for the copolymer comprises: copolymerizing comonomers including unsaturated polyalkylene glycol ether monomer (a) and unsaturated monocarboxylic monomer (b) as essential components by use of a chain-transfer agent, and/or adjusting pH of a resultant reaction mixture to not less than 5 after the copolymerization.

Copolymer for cement admixtures and its production process and use

A cement dispersant which displays high dispersibility with a small addition amount and excellent dispersibility particularly even in a high water-reducing ratio area, and a cement composition comprising this. A first cement dispersant includes a copolymer having a first constitutional unit derived from an unsaturated (poly)alkylene glycol ether monomer; and a second constitutional unit derived from an unsaturated monocarboxylic acid monomer, wherein the second constitutional unit includes at least one structure derived from an acrylic acid (salt).

Cement dispersant and cement composition comprising this

Provided are processes by which an ethylenimine polymer and an aqueous solution thereof can advantageously be produced at low costs in an industrial scale. The ethylenimine polymer can be produced by polymerizing crude ethylenimine obtained by a simple distilling operation from an ethylenimine-containing reaction mixture produced by subjecting ethanolamine to intermolecular dehydration reaction, preferably crude ethylenimine having impurity contents which are controlled in the specific ranges. When the above crude ethylenimine is polymerized in an aqueous medium, capable of being obtained is an aqueous solution of an ethylenimine polymer having a higher molecular weight than that produced by non-solvent polymerization. The ethylenimine polymer can be purified by, for example, adding water thereto, mixing them and then vaporizing and removing water under heating. The aqueous solution of an ethylenimine polymer can be purified by heating and condensing it.

Ethylenimine polymer, aqueous solution of ethylenimine polymer, production process for the same and purifying process therefor

Provided is a process for producing an ethylenimine polymer aqueous solution which has a high concentration (high resin content) and is less changeable with the passage of time, that is, has a stabilized quality. The above process comprises polymerizing ethylenimine in a water based medium at a temperature of 80&deg; C. or lower and then ripening it at a temperature of 100 to 150&deg; C.

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Tokyo, Japan

Yoshiyuki Onda