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: 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: 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: 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).

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: The objective of the present invention is to provide a cement additive which causes no increase in the amount of air and can thus stably maintain the amount of air entrained even when the time of kneading is prolonged in the production of cement compositions. A further object is to provide a cement admixture having such air entraining properties and having a high level of water-reducing capacity as well as a cement composition.

Abstract: The present invention is thus directed to a cement additive which comprises a copolymer (A) obtained by polymerizing a monomer mixture (K), wherein; said monomer mixture (K) comprises a polyalkylene glycol ester monomer (I) represented by the general formula (1):  a polyalkylene glycol ester monomer (II) represented by the general formula (2):  and a carboxylic acid monomer (III) represented by the general formula (3):

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.

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: The present invention has for its object to provide an economical cement additive capable of reducing the amount of water to be added to cement compositions and still capable of providing cement compositions with high fluidity, good processability, and a proper level of air-entraining ability resulting from sufficient foaming prevention, at low addition levels, a cement composition in which the above cement additive is used, and a polycarboxylic acid polymer excellent in dispersing effects on cement particles or inorganic powders or pigments and capable of being used with advantage as a cement additive or a dispersant for various uses.

Abstract: The present invention provides: a cement admixture which displays excellent cracking inhibition effect and brings about good fluidity even if the quantity of the cement admixture as added is small; and a cement composition comprising this cement admixture. The cement admixture comprises a polyalkylene glycol (A) and a polyalkylene glycol mono(meth)acrylate/unsaturated carboxylic acid-based copolymer (B), wherein: the average molecular weight (X) of the (A) is in the range of 400 to 10,000; the average molecular weight (X) of the (A) and the average molecular weight (Y) of a polyalkylene glycol chain portion of the (B) satisfy 0.9<(X/Y)<1.1; and the weight ratio of the (A) to the (B) is in the range of (A)/(B)=0.02 to 0.3. The cement composition at least comprises the above cement admixture, water, and cement.

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.

Abstract: The present invention provides a method for producing a cement dispersant having high percentage in water reduction rate and appropriate air-entraining property. This method for producing a polycarboxylic acid for a cement dispersant is characterized in that alkylene oxide is added at a specific temperature range.

Abstract: The present invention is related to a shrinkage reducing agent for hydraulic materials which comprises at least one polymer selected from the group consisting of (a) a polymer having a structure derived from the residue of a compound containing 2 to 30 carbon atoms and one active hydrogen atom by the binding thereto of one oxyalkylene chain having a carboxyl-containing side chain, (b) a polymer having a structure derived from the residue of a compound containing 4 to 30 carbon atoms and two active hydrogen atoms by the binding thereto of at least one oxyalkylene chain having a carboxyl-containing side chain, (c) a polymer having a structure derived from the residue of a compound containing 1 to 30 carbon atoms and at least three active hydrogen atoms by the binding thereto of at least one oxyalkylene chain having a carboxyl-containing side chain and (d) a polymer having a structure derived from the residue of an amine by the binding thereto one oxyalkylene chain having a carboxyl-containing side chain.

Abstract: The present invention provides: 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.

Abstract: 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.

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.

Abstract: The present invention is related to a shrinkage reducing agent for hydraulic materials