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: 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: To provide a polymer having a specific parameter value with a very narrow molecular weight distribution different from the conventional copolymers despite of a polymer having a polyoxyalkylene chain, and an excellent dispersant for inorganic powders, particularly a cement addmixture. The polymer (P) in the present invention is containing a constitutional unit derived from a polyoxyalkylene chain, and satisfying a range of PD value defined as the following mathematical formula 1: 1<PD<MD??(Formula 1) wherein PD=Mw/Mn, MD=G(n)×Mw+H(n).

Abstract: 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.

Abstract: 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.

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: An object of the present invention is to provide a polycarboxylic acid polymer for blending in cement for a cement composition superior both in dispersion and dispersibility-retention.

Abstract: A workpiece cradle and a clamp arm is provided, and an arm opening/closing cylinder 15 for opening and closing the clamp arm and the workpiece cradle are attached to a moving block 13. To a workpiece-cradle driving cylinder 23 provided with a piston rod 25 for driving the moving block 13, fluid is supplied from workpiece-cradle driving supply/discharge ports 27a and 27b formed in a manifold block 21. To the moving block 13, guide rods 33a and 33b are fixed and, to the arm opening/closing cylinder 15, fluid is supplied, from arm driving supply/discharge ports 34a and 34b formed in the manifold block 21, via hollow holes 36a and 36b in the guide rods 33a and 33b and via fluid supply/discharge paths 43a and 43b in the moving block 13.

Abstract: A workpiece cradle and a clamp arm is provided, and an arm opening/closing cylinder 15 for opening and closing the clamp arm and the workpiece cradle are attached to a moving block 13. To a workpiece-cradle driving cylinder 23 provided with a piston rod 25 for driving the moving block 13, fluid is supplied from workpiece-cradle driving supply/discharge ports 27a and 27b formed in a manifold block 21. To the moving block 13, guide rods 33a and 33b are fixed and, to the arm opening/closing cylinder 15, fluid is supplied, from arm driving supply/discharge ports 34a and 34b formed in the manifold block 21, via hollow holes 36a and 36b in the guide rods 33a and 33b and via fluid supply/discharge paths 43a and 43b in the moving block 13.

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: 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: 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: 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: 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: An improved engine emission control for controlling both nitrous oxide emissions through an exhaust gas recirculation system and evaporative fuel emissions. These gases (exhaust and evaporated fuel) are mixed with the intake charge in a mixing chamber that surrounds the intake passage so as to insure good mixing at an upstream point removed from the combustion chambers so that a uniform mixture will be delivered to each chamber and there will be uniformity in the added mixture between the chambers.

Abstract: A number of embodiments of cylinder head constructions wherein the cylinder head is comprised of a main cylinder head member that slidably supports the valves for the engine, and which has an upper peripheral edge that defines a cam chamber. At least one camshaft and the tappets associated thereby are supported by a separate cam and tappet carrier member that is affixed to the main cylinder head member. Various arrangements are shown wherein one or both camshafts and the tappets associated therewith may be carried by the cam and tappet carrier member and lubricating and fastening variations are also disclosed.

Abstract: A method for recovering zinc oxide comprises the steps of: agglomerating a dust; charging the agglomerate to a molten iron in a melting furnace; collecting a dust generated from the melting furnace; recycling a part of the collected dust and recovering another part of the collected dust. An apparatus for recovering zinc oxide comprises: an agglomeration unit for agglomerating a dust containing iron oxide and zinc oxide; a melting furnace for accepting the agglomerate and for holding the molten iron for reducing the dust; and at least two units of dust collector for collecting the dust containing zinc oxide generated from the melting furnace.

Abstract: A standby redundancy system comprising a control CPU unit for controlling controlled machines and a standby CPU unit capable of controlling the controlled machines instead of the control CPU unit, characterized by tracking unit for temporarily storing a command consisting of a statement and data entered from a peripheral machine, processing the data based on the statement in the command, and transferring the temporarily stored command to the associated CPU unit.