Nippon Shokubai Co., Ltd.

Nippon Shokubai Kagaku Kogyo Co., Ltd.

Mbt Holding Ag

Other

Toru Uno

Tsuyoshi Hirata

Yoshiyuki Onda

Hiromichi Tanaka

Tsutomu Yuasa

Akihiko Yamashita

Tomiyasu Ueta

Hideyuki Tahara

Koichiro Nagare

Noboru Sakamoto

Masaya Yamamoto

Hiroko Izukashi

Yoshio Tanaka

Toru Inaoka

Kenji Rakutani

Tomoki Gomi

Yoshiyuki Hozumi

Shogo Iwai

Tomotaka Nishikawa

Akira Ohta

Takakiyo Goto

Naoko Hirano

Minoru Miyagawa

Hirokazu Yamamoto

Hisamoto Kawano

Masato Nishiue

Yukiko Nishikawa

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 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

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

A cement dispersant having excellent ability to prevent slump loss and high water-reducing property which comprises a polycarboxylic acid type polymer having a specific molecular weight distribution, a method for the production thereof, and a cement composition using the dispersant are provided. The cement dispersant comprises as a main component thereof a polycarboxylic acid type polymer (A), having a weight average molecular weight in the range of 10,000 to 500,000 in terms of polyethylene glycol determined by gel permeation chromatography, and having a value determined by subtracting the peak top molecular weight from the weight average molecular weight in the range of 0 to 8,000.

Cement dispersant, method for production thereof, and cement composition using the dispersant

Cement composition using the dispersant of (meth)acrylic esters, (metha)acrylic acids polymers

A cement composition excelling in the slump retaining property which comprises at least cement admixture comprising as a main ingredient thereof (I) a copolymer (A) of short-chain polyalkylene glycol (meth)acrylate (a), a long-chain polyalkylene glycol (meth)acrylate (b), a carboxylic acid monomer (c), and a monomer copolymerizable with the monomers mentioned above or a salt of the copolymer (B), (II) a copolymer (A.sub.1) of the monomers (a), (c), and (d) mentioned above or a salt thereof, (III) a mixture of a copolymer (A.sub.1) of the monomers (a), (c), and (d) mentioned above or a salt (B.sub.1) of thereof with a known cement admixture, or (IV) a polycarboxylic acid based polymer (A.sub.3) manifesting to a calcium sulfoaluminate based expansive additive an adsorption ratio of not less than 90% in 5 minutes at room temperature when added in an amount of 0.1% by weight as solids or a salt (B.sub.3) thereof, or (V) a mixture of said polycarboxylic acid polymer with a known cement dispersant; cement; and water.

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Yokohama, Japan

Toru Uno