Nippon Shokubai Co., Ltd.

Noboru Sakamoto

Tsutomu Yuasa

Tsuyoshi Hirata

Hiromichi Tanaka

Yoshiyuki Onda

Toru Uno

Tomotaka Nishikawa

Tomiyasu Ueta

Hiroko Izukashi

Yuko Matsuda

Hiroshi Kawabata

Atsuro Yoneda

Takahiro Tsumori

Hiroko Okochi

Kaori Nakatani

Hidekazu Kozuki

Hideo Wakami

Hiroshi Osamura

Mari Otani

The present application relates to a production method for a polycarboxylic acid-based copolymer including a structural unit (I) derived from an unsaturated polyalkylene glycol ether-based monomer (a) and a structural unit (II) derived from an unsaturated carboxylic acid-based monomer (b), in which monomer components including the monomer (a) and the monomer (b) are polymerized using a peroxide and a reductant as polymerization initiators in combination while the pH during polymerization is controlled to 3 or less in the presence of a pH adjustor. The present application also relates to a polycarboxylic acid-based copolymer for a high-performance cement admixture including a structural unit (I) derived from an unsaturated polyalkylene glycol ether-based monomer (a) and a structural unit (II) derived from an unsaturated carboxylic acid-based monomer (b), and a nonpolymerizable organic sulfonic acid having a molecular weight of 300 or less and/or a salt thereof.

Method for producing polycarboxylic acid copolymer and copolymer composition for cement admixture

The present invention provides a multi-branched polyalkylene glycol polymer useful for various applications, especially for an admixture for cement, a dispersant, admixture for cement, and cement composition each comprising the same, a thiol compound having a polyalkylene glycol chain useful for materials and the like of the polymer, and a method for easily and effectively producing the multi-branched polyalkylene glycol polymer and the thiol compound having a polyalkylene glycol chain at low cost. The multi-branched polymer comprises: a polyalkylene glycol chain; a residue of a compound having three or more active hydrogen atoms; and a polymer portion having a constitutional unit derived from a vinyl monomer component, one end of the polyalkylene glycol chain bonding to the residue, and a terminal oxygen atom of at least one of the other ends of the polyalkylene glycol chain bonding to a main chain end of the polymer portion directly or via an organic residue.

Multi-branched polyalkylene glycol polymer, method for producing the same, and admixture for cement

The present invention provides a novel polymer, and a mixture and a cement admixture thereof. The cement admixture has higher dispersibility compared to the previous ones. The novel polymer of the present invention has a different structure from the conventional copolymers used for cement admixtures, using an unsaturated carboxylic acid monomer and an unsaturated polyalkylene glycol monomer as the monomer components. The novel polymer of the present invention basically contains a polyalkylene glycol chain and a polymer segment bonded to the chain. Another type of the novel polymer of the present invention contains two polyalkylene glycol chains and a polymer segment connecting the chains. In these polymers, at least one of unsaturated monomers constituting the polymer segment is an unsaturated carboxylic acid monomer or an unsaturated polyalkylene glycol monomer. The cement admixture of the present invention comprises a polymer, made from these monomers, or a mixture thereof.

Polymer and cement admixture using the same

To provide a polyalkylene glycol chain-containing thiol polymer which is excellent in various performances, particularly significantly excellent in cement dispersibility, and useful in various applications such as an admixture for cement; a thiol-modified monomer or a mixture thereof, which can produce such a polymer; production methods of the polymer and the monomer; and a dispersant and an admixture for cement, each including the polymer. The polyalkylene glycol chain-containing thiol polymer of the present invention is a polyalkylene glycol chain-containing thiol polymer, wherein the polymer comprises a polyalkylene glycol chain and a polymer segment bonded to at least one end of the polyalkylene glycol chain with a sulfur atom-containing group therebetween, the polymer segment includes a constitutional unit derived from an unsaturated monomer component, and the unsaturated monomer component includes an unsaturated carboxylic acid monomer and an unsaturated polyalkylene glycol monomer.

Polyalkylene glycol chain-containing thiol polymer, thiol-modified monomer, mixture thereof, and admixture for cement

To provide a continuous production method for producing a water-soluble polymer with a narrow molecular weight distribution with high efficiency. A continuous production method of a water-soluble polymer, comprising the steps of: circulating a circulation liquid containing a monomer having a polymerizable unsaturated bond through a reaction apparatus: having a tank and a circulation line comprising a piping circulating outside the tank, and thereby producing a water-soluble polymer continuously; and discharging part of the circulation liquid from a discharge line, wherein the circulation line is provided with a cooling device at least at one position.

Continuous production method of water-soluble polymer and water-soluble polymer

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

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&#x2212;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%.

Cement dispersant, its production process, and cement composition using the cement dispersant

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).

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Suita, Japan

Noboru Sakamoto