摘要:
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. The production process for the copolymer comprises: copolymerizing comonomers including unsaturated polyalkylene glycol ether monomer (a) and unsaturated monocarboxylic monomer (b) as essential components by use of a chain-transfer agent, and/or adjusting pH of a resultant reaction mixture to not less than 5 after the copolymerization.
摘要:
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).
摘要:
The cement admixture of the present invention can provide viscosity decreasing ability as well as a high dispersing ability and slump loss preventing ability even in a high water reducing ratio range. The above-mentioned cement admixture comprises three components of a copolymer (A) containing a constituent unit (I) derived from the unsaturated (poly)alkylene glycol ether monomer (a) and a constituent unit (II) derived from a maleic acid monomer (b), a specific unsaturated (poly)alkylene glycol ether monomer (a) and a non-polymerizable (poly)alkylene glycol (B) having no alkenyl group.
摘要:
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.A cement admixture comprising two polymers, namely a polymer (A) and a polymer (B), as essential constituents in a ratio of polymer (A) to polymer (B) between 1 to 99/99 to 1% by mass, wherein the polymer (A) is a polymer comprising, as essential constituent units, a constituent unit (I) derived from an unsaturated (poly)alkylene glycol ether monomer (a) and a constituent unit (II) derived from an unsaturated monocarboxylic acid monomer (b) and wherein the constituent units (I) and (II) each accounts for not less than 1% by mass relative to all constituent units but the constituent unit (I) accounts for not more than 50 mole percent relative to all constituent units and, wherein the polymer (B) is an oxyalkylene group- or polyoxyalkylene group- and carboxyl group-containing polymer.
摘要:
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.A cement admixture comprising, as three essential constituents, a copolymer (A), an unsaturated (poly)alkylene glycol ether monomer (a) and an unpolymerizable (poly)alkylene glycol (B) not containing an alkenyl group, wherein the content of the unsaturated (poly)alkylene glycol ether monomer (a) is 1 to 100% by mass relative to the copolymer (A) and the content of the unpolymerizable (poly)alkylene glycol (B) not containing an alkenyl group is 1 to 50% by mass relative to the copolymer (A), the copolymer (A) comprising, as essential constituent units, a constituent unit (I) derived from the unsaturated (poly)alkylene glycol ether monomer (a) and a constituent unit (II) derived from an unsaturated carboxylic acid monomer (b), with the constituent unit (I) and constituent unit (II) each accounting for not less than 1% by mass based on all the constituent units, and the unsaturated carboxylic acid monomer (b) being an unsaturated monocarboxylic acid monomer.
摘要:
The cement admixture of the present invention can improve the workability by displaying sufficient viscosity decreasing ability and initial dispersing ability even under a low temperature environment as well as high dispersing ability and dispersion retaining ability even in a high water reducing ratio range. The above-mentioned cement admixture comprises four components of a copolymer (A) containing a constituent unit (I) derived from the unsaturated (poly)alkylene glycol ether monomer (a) and a constituent unit (II) derived from a maleic acid monomer (b), a specific unsaturated (poly)alkylene glycol ether monomer (a), a non-polymerizable (poly)alkylene glycol (B) having no alkenyl group, and a polymer (C) having an oxyalkylene group or a polyoxyalkylene group and a carboxyl group, which is different from the copolymer (A).
摘要:
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
摘要:
The present invention provides a cement admixture and a cement composition, both of which displays little dependence of the water-reducibility upon temperature in that these cement admixture and cement composition involve little slump loss at high temperature and little increase in the amount of addition at low temperature. The cement admixture comprises either or both of the following components: copolymer (A) which includes constitutional unit (I) of general formula (1) below and constitutional unit (II) of general formula (2) below as essential constitutional units and may further include constitutional unit (III) of general formula (3) below, wherein the content of constitutional unit (III) is 45 weight % or less of copolymer (A); and copolymer salt (B) which is obtained by further neutralizing copolymer (A) with an alkaline substance.
摘要:
The present invention aims at providing a cement admixture having superior water-reducing performance, along with no decrease in slump and slump flow caused by decrease in fluidity of a cement composition over time. A cement admixture is to be provided, which cement admixture comprises two or more members of polycarboxylic acid-based polymers, wherein said cement admixture comprises at least one polycarboxylic acid-based polymer (A) having a constitutional unit represented by the following formula (1): wherein R1 and R2 independently represent a hydrogen atom, an alkyl group with carbon atoms of 1 to 30, an alkenyl group with carbon atoms of 1 to 30, an aryl group with carbon atoms of 6 to 12; A represents an alkylene group with carbon atoms of 1 to 30 or an arylene group with carbon atoms of 6 to 12; a is 0 or 1; OR3 represents an oxyalkylene group with carbon atoms of 2 to 18, wherein each OR3 may be the same or different each other, provided that when OR3 is in a mixed form of two or more members, each OR3 may be added in a block or random form; R4 represents a hydrogen atom or a hydrocarbon group with carbon atoms of 1 to 30; and m represents an average mole number of oxyalkylene groups added and is in the range of 1 to 300; and at least one polycarboxylic acid-based polymer (B) having a constitutional unit represented by the following formula (2): wherein R5 and R6 independently represent a hydrogen atom, a methyl group; x is an integer in the range of 0 to 2 and y is 0 or 1, provided that x and y are not 0 at the same time; OR7 represents an oxyalkylene group with carbon atoms of 2 to 18, wherein each OR7 may be the same or different each other, provided that when OR7 is in a mixed form of two or more members, each OR7 may be added in a block or random form; R8 represents a hydrogen atom or a hydrocarbon group with carbon atoms of 1 to 30; and n represents an average mole number of oxyalkylene groups added and is in the range of 1 to 300; and the weight ratio of said polycarboxylic acid-based polymer (A) and said polycarboxylic acid-based polymer (B) [weight ratio of (A)/(B)] is in the range of 1/99 to 99/1.
摘要:
The present invention provides a cement admixture and a cement composition, both of which displays little dependence of the water-reducibility upon temperature in that these cement admixture and cement composition involve little slump loss at high temperature and little increase in the amount of addition at low temperature. The cement admixture comprises the following essential components: either or both of polymer (A) and polymer salt (AA), wherein polymer (A) includes constitutional unit (I) of general formula (1) below as an essential constitutional unit, and polymer salt (AA) is obtained by further neutralizing polymer (A) with an alkaline substance; and either or both of polymer (B) and polymer salt (BB), wherein polymer (B) includes constitutional unit (II) of general formula (2) below as an essential constitutional unit, and polymer salt (BB) is obtained by further neutralizing polymer (B) with an alkaline substance. ##STR1##