Abstract: The present invention aims to provide a polycarboxylic acid copolymer which is excellent in various properties, in particular dispersibility, and is useful in various uses such as dispersants and admixtures for cement. The present invention also aims to provide a dispersant for cement, an admixture for cement, and a cement composition each containing the above polycarboxylic acid copolymer. The polycarboxylic acid copolymer of the present invention includes a structural unit (I) derived from an unsaturated polyalkylene glycol monomer (a) and a structural unit (II) derived from an unsaturated carboxylic acid monomer (b). The copolymer has a weight average molecular weight (Mw) of 5000 to 25000. The copolymer includes a dimer including two units of the unsaturated polyalkylene glycol monomer (a) bonded to each other, and has an area percentage of the dimer of 7% or higher.

Abstract: The present invention aims to provide a polycarboxylic acid copolymer which is excellent in various properties, in particular dispersibility, and is useful in various uses such as dispersants and admixtures for cement. The present invention also aims to provide a dispersant for cement, an admixture for cement, and a cement composition each containing the above polycarboxylic acid copolymer. The polycarboxylic acid copolymer of the present invention includes a structural unit (I) derived from an unsaturated polyalkylene glycol monomer (a) and a structural unit (II) derived from an unsaturated carboxylic acid monomer (b). The copolymer has a weight average molecular weight (Mw) of 5000 to 25000. The copolymer includes a dimer including two units of the unsaturated polyalkylene glycol monomer (a) bonded to each other, and has an area percentage of the dimer of 7% or higher.

Abstract: The present invention has an object to provide a polymer-containing composition for dispersants for cement which exhibits higher cement dispersibility even when used in a small amount, and can provide high flowability to a cement composition such as mortar and concrete and stably maintain this high flowability for a certain period, and to provide a production method thereof. The polymer-containing composition for dispersants for cement includes a polymer including a repeating unit derived from an unsaturated polyalkylene glycol ether monomer (I) having a specific structure and a repeating unit derived from an unsaturated carboxylic acid monomer (II) having a specific structure, and is prepared by polymerizing an unsaturated polyalkylene glycol ether monomer (I)-containing composition that includes specific amounts of specific components.

Abstract: The present invention has an object to provide a polymer-containing composition for dispersants for cement which exhibits higher cement dispersibility even when used in a small amount, and can provide high flowability to a cement composition such as mortar and concrete and stably maintain this high flowability for a certain period, and to provide a production method thereof. The polymer-containing composition for dispersants for cement includes a polymer including a repeating unit derived from an unsaturated polyalkylene glycol ether monomer (I) having a specific structure and a repeating unit derived from an unsaturated carboxylic acid monomer (II) having a specific structure, and is prepared by polymerizing an unsaturated polyalkylene glycol ether monomer (I)-containing composition that includes specific amounts of specific components.

Abstract: To provide an ultrarapid hardening cement composition with high strength, the composition having: excellent fluidity; excellent usable time; and excellent initial strength under low temperature atmosphere as well as under general temperature atmosphere, and improving strength and durability of a hardening product of the composition. An ultrarapid cement hardening composition comprising: an ultrarapid hardening cement (A) comprising a calcium aluminate; and a cement dispersant (B), wherein the cement dispersant (B) comprises a copolymer having: a repeating unit derived from a monomer represented by the following formula (1) and formula (2) as defined in the specification.

Abstract: To provide an ultrafine particle grouting composition which is excellent in dispersibility and dispersion retainability and can be easily injected into minute spaces between particles of grounds, rock cracks, and the like.

Abstract: To provide an ultrarapid hardening cement composition with high strength, the composition having: excellent fluidity; excellent usable time; and excellent initial strength under low temperature atmosphere as well as under general temperature atmosphere, and improving strength and durability of a hardening product of the composition.

Abstract: The efficiency of production of the polycarboxylic acid type cement dispersant is exalted. Photo-polymerization is adopted in the production of the polycarboxylic acid type cement dispersant by polymerizing at least one kind of monomer represented by the chemical formula 1 and at least one kind of monomer represented by the chemical formula 2. A polymer composition having a small solvent content is obtained by causing the polymerization reaction to proceed under the condition of containing the monomers at a high concentration. Specifically, this invention is directed toward a method for producing a powdered polycarboxylic acid type cement dispersant, which method comprises a step of polymerizing the monomers under the condition of containing the monomers at a concentration of 50-100 mass % based on the total mss of the monomers and the solvent, a step of cooling the formed polymer thereby solidifying the polymer, and a step of pulverizing the solidified polymer.

Abstract: The objective of the present invention is to provide a concrete composition in which the amount of air entrained can be maintained stably and which is excellent in strength and durability, a concrete composition which is excellent in freeze-thaw durability owing to the good quality of foams and is excellent in air content stability with time and which can form curing products excellent in strength and durability, a method of producing such concrete composition, and a cement admixture.

Abstract: To provide an ultrafine particle grouting composition which is excellent in dispersibility and dispersion retainability and can be easily injected into minute spaces between particles of grounds, rock cracks, and the like.

Abstract: A polycarboxylic acid cement dispersant that can exhibit high dispersing ability and allow deforming in early stages in the case of producing concrete products, whereby the turnover of a formwork is increased so as to improve productivity, and the method of producing such as concrete product are provided. The polycarboxylic acid cement dispersant which provides a cement composition having a penetration resistance value exponent of 55 MPa or more and a slump retention exponent of 80% or more, and the method of producing a concrete product which makes use of a copolymer derived by using monomer components comprising the monomer (A) as polyalkylene glycol unsaturated monomer, the monomer (B) as unsaturated carboxylic monomer, and the monomer (C) as sulfonic acid group-containing monomer.

Abstract: The present invention provides a means to express superior dispersibility and to be easily pulverized in the polycarboxylic acid type cement dispersant. The purpose is attained by a powdery cement dispersant having, as a main component, a polycarboxylic acid type copolymer having a repeating unit (I) derived from an unsaturated polyalkyleneglycol type monomer, a repeating unit (II) derived from an unsaturated carboxylic acid type monomer and a repeating unit (III) derived from a branched compound having a branched structure containing 3 or more polyalkyleneimine chains or polyoxyalkylene chains in a molecule, or a powdery cement dispersant comprising a polycarboxylic acid type copolymer (A) having a repeating unit (IV) derived from an unsaturated polyalkyleneglycol type monomer and a repeating unit (V) derived from an unsaturated carboxylic acid type monomer and a branched compound (B) with a branched structure containing 3 or more polyalkyleneimine chains or polyoxyalkylene chains in a molecule.

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: There is provided: a (meth)acrylic acid (salt) polymer which has high properties and is little colored; and a process which can produce this polymer with a high polymerization conversion without causing the corrosion of the reaction vessel.

Abstract: The polycarboxylic acid cement dispersant of the present invention can exhibit high dispersing ability and allow deforming in early stages in the case of producing concrete products, whereby the turnover of a formwork is increased so as to improve productivity, and the method of producing a concrete product of the present invention can allow deforming in early stages, whereby the turnover of a formwork is increased so as to improve productivity.

Abstract: The objective of the present invention is to provide a concrete composition in which the amount of air entrained can be maintained stably and which is excellent in strength and durability, a concrete composition which is excellent in freeze-thaw durability owing to the good quality of foams and is excellent in air content stability with time and which can form curing products excellent in strength and durability, a method of producing such concrete composition, and a cement admixture.

Abstract: There is provided: a (meth)acrylic acid (salt) polymer which has high properties and is little colored; and a process which can produce this polymer with a high polymerization conversion without causing the corrosion of the reaction vessel.

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 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.