Abstract: 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 which comprises a dehydration reaction step of subjecting a reaction solution containing a polymerizable compound to the dehydration reaction, said dehydration reaction step comprising using a dehydration reaction apparatus, said dehydration reaction apparatus comprising a reaction vessel, a condenser and a connecting pipe joining said reaction vessel with said condenser and satisfying the requirement: 0.05<(B3/A)<35 where A is a capacity (m3) of said reaction vessel and B is a total length (m) of said connecting pipe on the horizontal basis.

Abstract: It is an object of the present invention to provide a storing and/or transferring method of polyalkylene glycol monomers by which the gel-like matter formation and/or decomposition reaction can be satisfactorily inhibited and, as a result, troubles can be prevented from occurring in the production process and the performance characteristics or quality of various chemical products can be satisfactorily prevented from being deteriorated. A storing and/or transferring method of a polyalkylene glycol monomer which comprises storing and/or transferring a polyalkylene glycol monomer in the form of an aqueous solution.

Abstract: A storing and/or transferring method of an alkoxy(poly)alkylene glycol-containing material for cement additive polymer which comprises a step of filling a vessel, a step of storing and/or transferring and a step of drawing out, in that order, said alkoxy(poly)alkylene glycol being represented by the following general formula (1); R1O(R2O)nH??(1) in the formula, R1 represents a hydrocarbon group containing 1 to 30 carbon atoms, R2O group represents an oxyalkylene group containing 2 to 18 carbon atoms and each R2O group may be the same or different and n represents the average number of moles of the oxyalkylene groups represented by R2O as added and is a number of 0 to 300, and said step of storage and/or transfer being carried out at a temperature not higher than the solidifying point of the material for cement additive polymer.

Abstract: The present invention is to provide a production method of chemical reactive substances with stable quality by which solidification, gel formation, and the resulting blockade within material injection nozzles are prevented, and contamination of a reaction system with the gelled matter is prevented, as well as occurrence of problems on a production process due to the gelled matter is suppressed, when the chemical reactive substances are produced by injecting the liquid materials containing reactive substances having unsaturated double bonds into the reaction vessel through the material injection nozzles of the reaction vessel. The present invention is a production method of a chemical reactive substance which comprises injecting a liquid material containing a reactive substance having an unsaturated double bond into a reaction vessel through a material injection nozzle of said reaction vessel and causing a reaction at a reaction temperature of not less than 50° C.

Abstract: The present invention is to provide a production method of chemical reactive substances with stable quality by which solidification, gel formation, and the resulting blockade within material injection nozzles are prevented, and contamination of a reaction system with the gelled matter is prevented, as well as occurrence of problems on a production process due to the gelled matter is suppressed, when the chemical reactive substances are produced by injecting the liquid materials containing reactive substances having unsaturated double bonds into the reaction vessel through the material injection nozzles of the reaction vessel.

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: A storing and/or transferring method of an alkoxy(poly)alkylene glycol-containing material for cement additive polymer

Abstract: It is an object of the present invention to provide a storing and/or transferring method of polyalkylene glycol monomers by which the gel-like matter formation and/or decomposition reaction can be satisfactorily inhibited and, as a result, troubles can be prevented from occurring in the production process and the performance characteristics or quality of various chemical products can be satisfactorily prevented from being deteriorated.

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 is related to a shrinkage reducing agent for hydraulic materials

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 invention provides: a cement admixture which has excellent cement dispersibility and can afford high slump retainability; and a cement composition which has excellent cement dispersibility and high slump retainability. The cement admixture comprises a polycarboxylic acid as an effective component, wherein the polycarboxylic acid is obtained by a process including the steps of: charging "a" parts by weight of a polyalkylene glycol (A) and "b" parts by weight of a (meth)acrylic acid monomer (B) into a reactor in the range of {(a/n.sup.1/2)/b}.times.100.ltoreq.200, wherein n is an average molar number of the added oxyalkylene groups in the polyalkylene glycol (A) and is a number of 1 to 300; carrying out an esterification reaction of the resultant mixture in the reactor, thus obtaining a polyalkylene glycol (meth)acrylate (C); and copolymerizing the resultant polyalkylene glycol (meth)acrylate (C) and the (meth)acrylic acid monomer (B), thus obtaining the polycarboxylic acid.

Abstract: A method for the dispersion of cement, which comprises incorporating in a cement composition consisting at least of cement and water a cement dispersing agent formed of a polymer obtained by polymerizing a monomer component containing an alkoxy polyalkylene glycol mono(meth)acrylic ester monomer produced by the interesterification of an alkoxy polyalkylene glycol and a (meth)acrylic ester. A cement composition comprising the cement dispersing agent, cement and water.

Abstract: 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.

Abstract: The present invention provides a cement additive its production process and cement composition achieving excellent slump loss prevention capability. As a cement additive, there can be a copolymer (A-1) comprising an unsaturated polyalkylene glycol ether-based monomer (I), maleic acid-based monomer (II) and other monomer (III) copolymerizable with these monomers, the monomer (I)/monomer (II)/monomer (III) weight ratio being 50-99/50-1/0-49 and the weight average molecular weight of the copolymer (A) being 10,000 to 100,000 in terms of polyethylene glycol measured by gel permeation chromatography, or a copolymer (A) with an antifoaming agent (B), wherein the copolymer (A) comprises polyalkylene glycol ether-based units and dicarboxylic acid-based units as repeating units.

Abstract: A novel acrylic ester which is represented by general formula (2) ##STR1## wherein R.sub.1 and R.sub.2 independently represent a hydrogen atom or an organic residue, R.sub.3 represents an organic residue, n is a positive number among 1 to 3, and m is a positive number among 1 to 100 and which is applicable to various uses, is obtained by reacting an acrylic ester of general formula (3) ##STR2## wherein R.sub.1 represents a hydrogen atom or an organic residue, and R.sub.3 represents an organic residue, with a cyclic ether compound of general formula (4) ##STR3## wherein R.sub.2 represents a hydrogen atom or an organic residue, and n is a positive number among 1 to 3. Moreover, a novel acrylic acid derivative whose use is even wider is obtained by hydrolyzing the acrylic acid derivative.