Abstract: Disclosed are the following: a cement dispersant which is excellent in initial dispersibility and further in flow retainability of cement, because of using a polymer having a proper molecular weight distribution; a process for producing this cement dispersant; and a cement composition using this cement dispersant. The cement dispersant comprises a water-soluble polymer (P) as a main component, and is characterized by displaying an area proportion (a value (A?B) given by subtracting an area ratio B of a lower molecular weight side portion from an area ratio A of a higher molecular weight side portion) in the range of 13 to 60%.

Abstract: A tetraalkoxy silane type additive for hydraulic material and/or a tetraalkoxy silane hydrolyzate type additive for hydraulic material are used as admixtures. The additive at a small amount efficiently improves the shrinkage reducing property, represses infliction of a crack, and imparts durability to the concrete structure.

Abstract: 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.

Abstract: The present invention provids an admixture composition for hydraulic material that is capable of enabling minute air to be entrained into a hydraulic material composition and imparting an excellent the freeze/thaw durability to the hydraulic material. The object of the present invention is accomplished by an admixture composition for hydraulic material which contains component (A) and component (B) as essential components. The component (A) is a polyoxyalkylene polymer possessing a side chain containing a carboxyl group and the component (B) is a compound which is represented by the general formula (B-1) or (B-2).

Abstract: Disclosed are the following: a cement dispersant which is excellent in initial dispersibility and further in flow retainability of cement, because of using a polymer having a proper molecular weight distribution; a process for producing this cement dispersant; and a cement composition using this cement dispersant. The cement dispersant comprises a water-soluble polymer (P) as a main component, and is characterized by displaying an area proportion (a value (A?B) given by subtracting an area ratio B of a lower molecular weight side portion from an area ratio A of a higher molecular weight side portion) in the range of 13 to 60%.

Abstract: Disclosed are the following: a cement dispersant which is excellent in initial dispersibility and further in flow retainability of cement, because of using a polymer having a proper molecular weight distribution; a process for producing this cement dispersant; and a cement composition using this cement dispersant. The cement dispersant comprises a water-soluble polymer (P) as a main component, and is characterized by displaying an area proportion (a value (A?B) given by subtracting an area ratio B of a lower molecular weight side portion from an area ratio A of a higher molecular weight side portion) in the range of 13 to 60%.

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 admixtures for a cementitious composition of the invention, which have the above-mentioned constitutions, can suitably be used in cement pastes, mortar, concrete and like cement compositions and can stabilize the amount of air entrained with the lapse of time and thus facilitate the quality control of cement compositions and, further, can improve the workability of cement compositions owing to their excellent dispersing capacities. The cement compositions of the invention which comprise such admixture for a cementitious composition are excellent in water-reducing ability and workability and can give hardened products excellent in strength and durability and, further, can stably maintain the amount of air entrained without allowing increases in the amount of air even when the time of kneading is prolonged in the production.

Abstract: 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.

Abstract: 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.

Abstract: An object of the present invention is to provide a polymer which is suitable as a detergent builder in that it exerts an excellent detergency and it has no adverse effect on the environment, and is suitable as a cement admixture in that it is excellent in cement dispersibility, and workability is better.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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).

Abstract: 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.

Abstract: The present invention provides: an acrylic acid (salt) polymer, which has a low molecular weight and a narrow molecular weight distribution and can display excellent dispersibility, or which has a high molecular weight and a high water solubility; a production process that enables easy production of this polymer; and an acrylic acid (salt) polymer composition comprising this polymer. The acrylic acid (salt) polymer is an acrylic acid (salt) polymer of which not less than 1 weight % of the entirety is accounted for by an acrylic acid (salt) polymer having a specific terminal structure. In addition, the production process for an acrylic acid (salt) polymer comprises the step of carrying out polymerization of a monomer component including an acrylic acid (salt), wherein an acrylic acid (salt) having a furfural content of 200 to 400 weight ppm is used as at least a portion of the acrylic acid (salt) in an amount of not smaller than 10 weight % of the entire monomer component.

Abstract: When the reaction solution formed during the addition of an alkylene oxide to an active hydrogen-containing compound has viscosity of not less than 10 mPa·s, this invention provides a method for stirring the reaction solution by the rotation of a vane or vanes continuously disposed in the vertical direction within an agitating reaction vessel in such a manner that the numerical value C represented by the following formula (1): C=A/(h2−h1)  (1) (wherein A denotes the length (m) of the vane or the vanes newly immersed by the supply of alkylene oxide, h1 denotes the height (m) of the liquid level before the supply of alkylene oxide, and h2 denotes the height (m) of the liquid level after the supply of alkylene oxide) may be not less than 0.5. By employing the method of this invention, it is made possible to effect addition of an alkylene oxide to the active hydrogen-containing compound with high efficiency.

Abstract: 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.

Abstract: A method for the production of an esterified product which can prevent the occurrence of a gel-like substance during the separation and removal of the water formed by the reaction in the esterification reaction or during the expulsion of a dehydrating solvent by distillation after the esterification reaction by causing an antigelling agent to act on the distillate and consequently permits efficient production of the esterified product of high quality, and an apparatus therefor are to be provided.