JP2019069871A - Cement strength improver, cement additive and cement composition - Google Patents

Abstract

To provide a cement strength improver and a cement additive capable of remarkably improving the long-term strength of a hardened cement composition, and to provide a cement composition comprising such a cement strength improver.SOLUTION: A cement strength improver according to one embodiment of this present invention contains polysaccharides having gel-forming ability in alkaline water. A cement additive according to one embodiment of this invention has the above-mentioned cement strength improver and at least one materials selected from the group consisting of the following components A, B, and C: Component A: a compound having a structure in which 5 moles or more of alkylene oxide per mole of alcohol are added; Component B: an alkanolamine compound; Component C: at least one member selected from the group consisting of oxycarbonic acids or salts thereof, keto acids or salts thereof, sugars, and sugar alcohols.SELECTED DRAWING: None

Description

  The present invention relates to cement strength improvers, additives for cements, and cement compositions.

  Cement compositions generally include cement, aggregate, and water, and are generally required to improve fluidity and reduce water.

  Recently, there has been an increasing demand for improvement in the strength performance of a cured product of a cement composition relative to a cement composition. For example, depending on the application of the cement composition, early development of strength is desired, and various studies have been made (for example, Patent Document 1).

  On the other hand, depending on the application of the cement composition, it is required to improve the strength of the cured product of the cement composition over a long period of time (e.g., improve the strength at the 4-week level).

JP, 2011-84459, A

  An object of the present invention is to provide a cement strength improver and a cement additive which can significantly improve the strength of a cured product of a cement composition over a long period of time. Another object of the present invention is to provide a cement composition containing such a cement strength improver.

  The cement strength improver in one embodiment of the present invention comprises a polysaccharide having a gel-forming ability to gel in alkaline water.

  In one preferred embodiment, the polysaccharide is at least one selected from the group consisting of alginic acid or a salt thereof, an alginic acid ester and glucomannan.

The additive for cement in one embodiment of the present invention has the above-described cement strength improver and at least one selected from the group consisting of the following components A, B, and C.
Component A: A compound having a structure in which 5 moles or more of alkylene oxide is added to 1 mole of alcohol.
Component B: an alkanolamine compound.
Component C: at least one member selected from the group consisting of oxycarboxylic acids or salts thereof, keto acids or salts thereof, sugars, and sugar alcohols.

  In one preferred embodiment, the component A is polyethylene glycol, a copolymer having a structural unit derived from an alkylene oxide adduct of methacrylic acid, an alkylene oxide adduct of sorbitol, 3-methyl-3-butenyl alcohol It is at least one selected from the group consisting of a copolymer having a structural unit derived from an alkylene oxide adduct, and an alkylene oxide adduct to an active hydrogen bonded to an amino group of polyethyleneimine.

  In one preferred embodiment, the component B is at least one selected from the group consisting of triisopropanolamine, N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine, and diisopropanolethanolamine. It is.

  The cement composition in one embodiment of the present invention contains the above-described cement strength improver.

In one preferred embodiment, the cement composition further has at least one selected from the group consisting of the following components A, B, and C:
Component A: A compound having a structure in which 5 moles or more of alkylene oxide is added to 1 mole of alcohol.
Component B: an alkanolamine compound.
Component C: at least one member selected from the group consisting of oxycarboxylic acids or salts thereof, keto acids or salts thereof, sugars, and sugar alcohols.

  According to the present invention, it is possible to provide a cement strength improver and a cement additive which can significantly improve the strength of a cured product of a cement composition over a long period of time. It is also possible to provide a cement composition comprising such a cement strength improver.

  In the present specification, the expression "(meth) acrylic" means "acrylic and / or methacrylic", and the expression "(meth) acrylate" means "acrylate and / or methacrylate". When there is the expression “(meth) allyl”, it means “allyl and / or methallyl”, and when there is the expression “(meth) acrolein” it means “acrolein and / or methacroyl”. Means "Rain". Moreover, in the present specification, the expression “acid (salt)” means “acid and / or a salt thereof”. Examples of the salt include, for example, alkali metal salts and alkaline earth metal salts, and specific examples include sodium salt, potassium salt, calcium salt and the like.

<< 1. Cement strength improver »
Cement strength improvers include polysaccharides having gel forming ability to gel in alkaline water.

  The cement strength improver can significantly improve the strength of the cured product of the cement composition over a long period of time. That is, the cement strength improver is a specific agent intended to improve the strength of mortar and concrete containing cement, and exhibits an excellent effect of significantly improving the strength of a cured product of a cement composition over a long period of time sell.

  In the present specification, “gel-forming ability to gel in alkaline water” means, for example, gelation via metal ions in a liquid containing metal ions such as calcium ions to form a gel, etc. It refers to the ability to gel to form a gel.

  The content ratio of the polysaccharide having a gel-forming ability to gel in alkaline water in the cement strength improver is preferably 50% by mass to 100% by mass, and more preferably 70% by mass to 100% by mass. , More preferably 90 to 100% by mass, particularly preferably 95 to 100% by mass, and most preferably substantially 100% by mass. If the content ratio of the polysaccharide having a gel-forming ability to gel in alkaline water in the cement strength improver is within the above range, the strength of the cured product of the cement composition can be significantly improved over a long period of time.

  The cement strength improver may contain any suitable component other than polysaccharides having gel forming ability to gel in alkaline water, as long as the effects of the present invention are not impaired.

  Examples of polysaccharides having gel forming ability to gel in alkaline water include at least one selected from the group consisting of alginic acid or a salt thereof, alginic acid ester, and glucomannan.

  Alginic acid or a salt thereof preferably includes sodium alginate. Examples of alginic acid esters include propylene glycol alginate and lauroyl alginate, preferably propylene glycol alginate. Alginic acid or a salt thereof, an alginate ester is typically a polysaccharide having a gel-forming ability to gelate via calcium ions.

  Glucomannan is a polysaccharide having a gel-forming ability to gel in alkaline water.

  The cement strength improver may be used in any suitable embodiment. As such an embodiment, for example, an embodiment in which the cement strength improver is blended as it is into cement, or an embodiment in which the cement strength improver is blended with other components is blended into cement and used. It can be mentioned.

  The amount of the cement strength improver used is preferably 0.001% by mass to 0.5% by mass, more preferably 0.002% by mass to 0.1% by mass, based on cement, and more preferably Is 0.003% by mass to 0.05% by mass, particularly preferably 0.004% by mass to 0.02% by mass, and most preferably 0.005% by mass to 0.01% by mass. By adjusting the amount of the cement strength improver to be in the above range, the strength of the cured product of the cement composition can be significantly improved over a long period of time.

<< 2. One Embodiment of Additive for Cement >>
One embodiment of the cement additive comprises the cement strength improver and at least one selected from the group consisting of the following components A, B, and C.
Component A: A compound having a structure in which 5 moles or more of alkylene oxide is added to 1 mole of alcohol.
Component B: an alkanolamine compound.
Component C: at least one member selected from the group consisting of oxycarboxylic acids or salts thereof, keto acids or salts thereof, sugars, and sugar alcohols.

  The cement strength improver may be used alone or in combination of two or more.

  A component may be only 1 type and may be 2 or more types. The B component may be only one kind or two or more kinds. The C component may be only one type, or two or more types.

  The cement additive has the above-mentioned cement strength improver and at least one selected from the group consisting of A component, B component, and C component so that the strength of the cured product of the cement composition becomes remarkable over a long period of time. It produces an effect that it can be improved.

Specifically, the long-term strength improvement effect of the hardened material of the cement composition developed by the cement additive is
(I) To the effect expected from the sum of the long-term strength improvement effect of the hardened material of the cement composition attributed only to the cement strength improver and the long-term strength improvement effect of the hardened material of the cement composition attributed solely to the component A It shows a significantly higher synergy,
(Ii) To the effect expected from the sum of the long-term strength improvement effect of the hardened material of the cement composition attributed only to the cement strength improver and the long-term strength improvement effect of the hardened material of the cement composition attributed solely to the component B It shows a significantly higher synergy,
(Iii) An effect expected from the sum of the long-term strength improvement effect of the hardened material of the cement composition caused only by the cement strength improver and the long-term strength improvement effect of the hardened material of the cement composition caused only by the component C It exhibits a significantly higher synergy effect than.

  The content ratio of the total amount of the cement strength improver and at least one selected from the group consisting of A component, B component, and C component in the additive for cement is preferably 50 mass% to 100 mass%. More preferably, it is 70% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, particularly preferably 95% by mass to 100% by mass, and most preferably substantially 100% by mass. %. That is, most preferably, the additive for cement of the present invention comprises the above-described cement strength improver and at least one selected from the group consisting of the A component, the B component, and the C component.

  The content ratio of the cement strength improver in the cement additive is preferably 0.001% by mass to 0.5% by mass, and more preferably 0.002% by mass to 0.1% by mass with respect to the cement. %, More preferably 0.002% by mass to 0.05% by mass, particularly preferably 0.003% by mass to 0.02% by mass, most preferably 0.005% by mass to 0.01% It is mass%. By adjusting the content ratio of the cement strength improver in the cement additive to the above range, the strength of the cured product of the cement composition can be significantly improved over a long period of time.

  The content ratio of the component A in the cement additive is preferably 0.001% by mass to 0.5% by mass, and more preferably 0.002% by mass to 0.1% by mass with respect to the cement. More preferably, it is 0.002 mass% to 0.05 mass%, particularly preferably 0.005 mass% to 0.02 mass%, and most preferably 0.01 mass% to 0.02 mass%. is there. By adjusting the content ratio of the component A in the cement additive to the above range, the strength of the cured product of the cement composition can be significantly improved over a long period of time.

  The content ratio of the component B in the additive for cement is preferably 0.001% by mass to 0.5% by mass, and more preferably 0.002% by mass to 0.1% by mass with respect to the cement. More preferably, it is 0.002 mass% to 0.05 mass%, particularly preferably 0.005 mass% to 0.02 mass%, and most preferably 0.01 mass% to 0.02 mass%. is there. By adjusting the content ratio of the component B in the cement additive to the above range, the strength of the cured product of the cement composition can be significantly improved over a long period of time.

  The content ratio of the component C in the additive for cement is preferably 0.001% by mass to 0.5% by mass, and more preferably 0.002% by mass to 0.3% by mass with respect to the cement. More preferably, it is 0.003 mass% to 0.1 mass%, particularly preferably 0.005 mass% to 0.05 mass%, and most preferably 0.01 mass% to 0.05 mass%. is there. By adjusting the content of the component C in the cement additive to the above range, the strength of the cured product of the cement composition can be significantly improved over a long period of time.

  The ratio of at least one selected from the group consisting of A component, B component and C component to the cement strength improver in the cement additive (selected from the group consisting of A component, B component and C component) (Cement strength improver) is preferably 0.05 to 20, more preferably 0.1 to 15, still more preferably 0.1 to 10, particularly preferably 0. 1 to 5, most preferably 0.2 to 1. The ratio of at least one selected from the group consisting of A component, B component and C component to the cement strength improver in the cement additive (selected from the group consisting of A component, B component and C component) The strength of the cured product of the cement composition can be significantly improved over a long period of time by adjusting at least one of the above (cement strength improver) to the above range.

  The cement additive is not limited to any suitable cement strength improver and at least one member selected from the group consisting of A component, B component, and C component as long as the effects of the present invention are not impaired. May contain the components of

<2-1. A component>
The component A is a compound having a structure in which 5 moles or more of alkylene oxide is added to 1 mole of alcohol.

  The alkylene oxide is preferably an alkylene oxide having 2 to 10 carbon atoms, more preferably an alkylene oxide having 2 to 8 carbon atoms, from the viewpoint of achieving the effects of the present invention, and more preferably 2 It is an alkylene oxide of ̃6, particularly preferably an alkylene oxide having 2 to 4 carbon atoms, and most preferably an alkylene oxide having 2 to 3 carbon atoms (that is, ethylene oxide, propylene oxide). Moreover, only 1 type may be sufficient as an alkylene oxide, and 2 or more types may be sufficient as it.

  The lower limit value of the addition mole number of the alkylene oxide to 1 mole of alcohol is preferably 10 moles or more, more preferably 20 moles or more, still more preferably 30 moles or more, and still more preferably 40 moles or more. More preferably, it is 50 mol or more, more preferably 100 mol or more, particularly preferably 500 mol or more, most preferably 1000 mol or more, and the upper limit is preferably 100,000 mol or less. Preferably, it is 50000 mol or less, more preferably 40000 mol or less, further preferably 30000 mol or less, still more preferably 20000 mol or less, still more preferably 10000 mol or less, particularly preferably 7000 mol or less And most preferred It is 5000 mol or less. By adjusting the addition mole number of the alkylene oxide with respect to 1 mol of alcohol in the said range, the intensity | strength of the hardened | cured material of a cement composition can be improved more notably over the long term.

  The weight average molecular weight of the compound which is the component A is preferably 4000 or more, more preferably 5000 or more, still more preferably 10000 or more, particularly preferably 20000 or more, most preferably 100000 as a lower limit. The upper limit is preferably 10,000,000 or less, more preferably 5000000 or less, still more preferably 1,000,000 or less, particularly preferably 700000 or less, and most preferably 300000 or less. By adjusting the weight average molecular weight of the compound which is the component A within the above range, the strength of the cured product of the cement composition can be significantly improved over a long period of time. The measuring method of a weight average molecular weight is mentioned later.

  Examples of the alcohol include monohydric alcohols such as methanol, ethanol, propanol and butanol, and polyhydric alcohols may be compounds having two or more hydroxyl groups, and may be low molecular weight compounds or polymers. Any suitable polyhydric alcohol may be employed as long as the effects of the present invention are not impaired. The polyhydric alcohol is preferably a dihydric to 500-hydric alcohol, more preferably a dihydric to 100-hydric alcohol, and still more preferably a trihydric to 50-hydric alcohol. Examples of such polyhydric alcohols include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, pentanediol, butanediol, glycerin, sorbitol and the like.

  Examples of the alcohol include those obtained by polymerizing a monomer having a hydroxyl group. As a monomer having a hydroxyl group, for example, vinyl alcohol, allyl alcohol, methallyl alcohol, butenyl alcohol, 3-methyl-3-butenyl alcohol, 3-methyl-2-butenyl alcohol, 2-methyl-3-bu Tenyl alcohol etc. are mentioned. These may be polymerized alone or copolymerized with other polymerizable monomers.

  The compound which is the component A may have any appropriate functional group as long as the effects of the present invention are not impaired. However, it is preferable that the compound which is component A does not have a carboxyl group in that it can sufficiently exhibit the effects of the present invention.

  As a method of synthesizing the compound which is the component A, any appropriate method such as a known method can be adopted as long as the effects of the present invention are not impaired. Examples of such a method include a method of polymerizing a monomer having a hydroxyl group and then adding an alkylene oxide, and a method of adding an alkylene oxide to a monomer having a hydroxyl group first and then polymerizing.

  Specific examples of the compound which is the component A include, for example, polyethylene glycol, a copolymer having a structural unit derived from an alkylene oxide adduct of methacrylic acid, an alkylene oxide adduct of sorbitol, 3-methyl-3-butenyl A copolymer having a structural unit derived from an alkylene oxide adduct of alcohol, an alkylene oxide adduct to active hydrogen bonded to an amino group of polyethyleneimine, and the like can be mentioned. Here, “an alkylene oxide adduct to active hydrogen bonded to the amino group of polyethyleneimine” means that the alkylene oxide (such as ethylene oxide) is optionally selected from the active hydrogen bonded to the amino group possessed by polyethyleneimine. It refers to an adduct added with a certain number of moles.

  When the compound which is the component A is a copolymer having a structural unit derived from an alkylene oxide adduct of 3-methyl-3-butenyl alcohol, the copolymer has a carboxyl group in that the effect of the present invention can be more exhibited. It is preferable not to contain a group or a salt thereof (such as an alkali metal salt or an alkaline earth metal salt).

2-2. B component>
Any appropriate alkanolamine compound can be adopted as the alkanolamine compound as long as the effects of the present invention are not impaired. Examples of such alkanolamine compounds include low molecular weight alkanolamine compounds and high molecular weight alkanolamine compounds.

  Examples of low molecular weight alkanolamine compounds include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, methylisopropanolamine, methylethanolamine, methylisopropanolamine, methyldiethanolamine, methyldiisopropanolamine, Diethanolisopropanolamine, diisopropanolethanolamine, tetrahydroxyethylethylenediamine, N, N-bis (2-hydroxyethyl) 2-propanolamine, N, N-bis (2-hydroxypropyl) -N- (hydroxyethyl) amine, N, N-bis (2-hydroxyethyl) -N- (2-hydroxypropyl) amine, N, N, N ', N'-tetrakis (2- Mud hydroxypropyl) ethylenediamine, tris (2-hydroxybutyl) amine, and the like. Among these, preferable low molecular weight alkanolamine compounds include triisopropanolamine, N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine, and diisopropanolethanolamine. Other low molecular weight alkanolamine compounds also include, for example, monomers having a skeleton of triisopropanolamine.

  Examples of the polymer type alkanolamine compound include alkanolamines having a structure in which a part of the alkanolamine is bonded to the polymer. As such a high molecular weight type alkanolamine compound, for example, a polymer having a skeleton of triisopropanolamine can be mentioned.

<2-3. C component>
The component C is at least one selected from an oxycarboxylic acid or a salt thereof, a keto acid or a salt thereof, a sugar, and a sugar alcohol.

  Any appropriate oxycarboxylic acid can be adopted as the oxycarboxylic acid. As such an oxycarboxylic acid, for example, gluconic acid, tartaric acid, citric acid, malic acid, glucoheptonic acid, arabonic acid etc. may be mentioned, and gluconic acid is preferable in that the effects of the present invention can be further developed. It is at least one selected from tartaric acid, citric acid and malic acid.

  Examples of salts that can be adopted as salts of oxycarboxylic acids include inorganic salts or organic salts such as sodium salt, potassium salt, calcium salt, magnesium salt, ammonium salt, triethanolamine salt and the like.

  Any appropriate keto acid may be employed as the keto acid. As such a keto acid, for example, pyruvic acid, oxoglutaric acid and the like can be mentioned, and pyruvic acid is preferable in that the effect of the present invention can be more developed.

  As a salt which can be adopted as a salt of keto acid, for example, inorganic salts or organic salts such as sodium salt, potassium salt, calcium salt, magnesium salt, ammonium salt, triethanolamine salt and the like can be mentioned.

  Any appropriate sugar may be employed as the sugar. Such sugars include, for example, monosaccharides such as glucose, fructose, galactose, mannose, xylose, arabinose, ribose, isomerized sugars; disaccharides such as maltose, sucrose, lactose; trisaccharides such as raffinose; And the like, and glucose is preferable in that the effects of the present invention can be more developed.

  As sugar alcohol, any suitable sugar alcohol can be adopted. Such sugar alcohols are preferably sorbitol, mannitol, xylitol, galactitol in that the effects of the present invention can be more developed.

<< 3. Another Embodiment of Cement Additive >>
Another embodiment of the cement additive which can exhibit the effects of the present invention is a polysaccharide (X component) having a gel forming ability to gel in alkaline water, and the following components A, B, and C. And at least one selected from the group consisting of
Component A: A compound having a structure in which 5 moles or more of alkylene oxide is added to 1 mole of alcohol.
Component B: an alkanolamine compound.
Component C: at least one member selected from the group consisting of oxycarboxylic acids or salts thereof, keto acids or salts thereof, sugars, and sugar alcohols.

  The X component may be only one type or two or more types.

  A component may be only 1 type and may be 2 or more types. The B component may be only one kind or two or more kinds. The C component may be only one type, or two or more types.

  The cement additive can significantly improve the strength of the cured product of the cement composition over a long period of time by having the X component and at least one selected from the group consisting of the A component, the B component, and the C component. Express the effect.

Specifically, the long-term strength improvement effect of the hardened material of the cement composition developed by the cement additive is
(I) Compared to the effect expected from the sum of the long-term strength improvement effect of the cured product of the cement composition caused by only the X component and the long-term strength improvement effect of the cured product of the cement composition attributed only to the A component, Show a remarkably high synergy,
(Ii) Compared to the effect expected from the sum of the long-term strength improvement effect of the cured product of the cement composition caused by only the X component and the long-term strength improvement effect of the cured product of the cement composition attributed only to the B component, Show a remarkably high synergy,
(Iii) Compared to the effect expected from the sum of the long-term strength improvement effect of the hardened material of the cement composition caused by only the X component and the long-term strength improvement effect of the hardened material of the cement composition caused only by the C component Show a remarkably high synergy.

  The content ratio of the total amount of component X and at least one selected from the group consisting of component A, component B and component C in the additive for cement is preferably 50% by mass to 100% by mass, More preferably, it is 70% by mass to 100% by mass, still more preferably 90% by mass to 100% by mass, particularly preferably 95% by mass to 100% by mass, and most preferably substantially 100% by mass . That is, most preferably, the cement additive of the present invention comprises the X component and at least one selected from the group consisting of the A component, the B component, and the C component.

  The content ratio of the X component in the additive for cement is preferably 0.001% by mass to 0.5% by mass, more preferably 0.002% by mass to 0.1% by mass with respect to the cement. More preferably, it is 0.002 mass% to 0.05 mass%, particularly preferably 0.003 mass% to 0.02 mass%, and most preferably 0.005 mass% to 0.01 mass%. is there. By adjusting the content ratio of the X component in the cement additive to the above range, the strength of the cured product of the cement composition can be significantly improved over a long period of time.

  The content ratio of the component A in the cement additive is preferably 0.001% by mass to 0.5% by mass, and more preferably 0.002% by mass to 0.1% by mass with respect to the cement. More preferably, it is 0.002 mass% to 0.05 mass%, particularly preferably 0.005 mass% to 0.02 mass%, and most preferably 0.01 mass% to 0.02 mass%. is there. By adjusting the content ratio of the component A in the cement additive to the above range, the strength of the cured product of the cement composition can be significantly improved over a long period of time.

  The content ratio of the component B in the additive for cement is preferably 0.001% by mass to 0.5% by mass, and more preferably 0.002% by mass to 0.1% by mass with respect to the cement. More preferably, it is 0.002 mass% to 0.05 mass%, particularly preferably 0.005 mass% to 0.02 mass%, and most preferably 0.01 mass% to 0.02 mass%. is there. By adjusting the content ratio of the component B in the cement additive to the above range, the strength of the cured product of the cement composition can be significantly improved over a long period of time.

  The content ratio of the component C in the additive for cement is preferably 0.001% by mass to 0.5% by mass, and more preferably 0.002% by mass to 0.3% by mass with respect to the cement. More preferably, it is 0.003 mass% to 0.1 mass%, particularly preferably 0.005 mass% to 0.05 mass%, and most preferably 0.01 mass% to 0.05 mass%. is there. By adjusting the content of the component C in the cement additive to the above range, the strength of the cured product of the cement composition can be significantly improved over a long period of time.

  At least one ratio selected from the group consisting of component A, component B and component C to component X in the cement additive (at least one component selected from the group consisting of component A, component B and component C) The species / X component) is preferably 0.05 to 20, more preferably 0.1 to 15, still more preferably 0.1 to 10, and particularly preferably 0.1 to 5, Most preferably, it is 0.2-1. At least one ratio selected from the group consisting of component A, component B and component C to component X in the cement additive (at least one component selected from the group consisting of component A, component B and component C) The strength of the cured product of the cement composition can be more significantly improved over the long term by adjusting the species / X component) to the above range.

  In the cement additive, components other than any suitable components X and at least one selected from the group consisting of components A, B, and C, as long as the effects of the present invention are not impaired May be included.

<3-1. X component>
The X component is a polysaccharide having a gel-forming ability to gel in alkaline water.

  As such a component X, for example, at least one selected from the group consisting of alginic acid or a salt thereof, an alginate ester, and glucomannan can be mentioned.

  Alginic acid or a salt thereof preferably includes sodium alginate. Examples of alginic acid esters include propylene glycol alginate and lauroyl alginate, preferably propylene glycol alginate. Alginic acid or a salt thereof, an alginate ester is typically a polysaccharide having a gel-forming ability to gelate via calcium ions.

  Glucomannan is a polysaccharide having a gel-forming ability to gel in alkaline water.

<3-2. A component, B component, C component>
The components A, B, and C are described in << 2. <2-1. Item of Embodiment of Cement Additive><2-1. Description of A component in the item of A component>, <2-2. Description of B component in the item of B component>, <2-3. The description of the C component in the item of the C component> can be incorporated as it is.

<< 4. Cement composition »
The cement composition comprises at least a polysaccharide having a gel-forming ability to gel in cement, water and alkaline water. The polysaccharide having gel-forming ability to gel in alkaline water may be the cement strength improver.

  The cement composition may further have at least one selected from the group consisting of the component A, the component B, and the component C described above. With regard to the component A, the component B, and the component C, the description of the component A, the component B, and the component C in the item of «Cement Additive» can be used as it is.

  When the cement composition has a polysaccharide having a gel-forming ability to gel in alkaline water and at least one selected from the group consisting of the components A, B, and C described above, the combination of these components is Form in which a polysaccharide having gel forming ability to gel in alkaline water and at least one selected from the group consisting of the above-mentioned A component, B component and C component are blended as a form of a cement additive The cement additive may be a polysaccharide having a gel-forming ability to gelate in alkaline water, and at least one selected from the group consisting of the components A, B, and C described above. It may be a form which is blended without taking a form (for example, each is blended separately).

  The cement composition preferably contains an aggregate and a water reducing agent, in addition to at least one selected from polysaccharides having gel-forming ability to gel in alkaline water and the above-mentioned A component, B component and C component.

  The cement may be only one kind or two or more kinds. Any appropriate cement may be employed as the cement. As such cement, for example, Portland cement (usually, early strength, super early strength, moderate heat, sulfate resistance and respective low alkali types), various mixed cements (blast furnace cement, silica cement, fly ash cement), White portland cement, alumina cement, super rapid curing cement (1 clinker quick curing cement, 2 clinker quick curing cement, magnesium phosphate cement), cement for grout, oil well cement, low heat generation cement (low heat type blast furnace cement, fly ash mixed low Examples include heat-generating blast furnace cement, cement with high belite content, ultra-high strength cement, cement-based solidifying material, and eco-cement (cement manufactured from one or more of municipal waste incineration ash and sewage sludge incineration ash).

  The cement composition may contain fine powder or gypsum such as blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica powder, limestone powder and the like.

In the cement composition, unit water per Part 1 m ^3, it can be set to any appropriate value cement usage, and as a water / cement ratio. Such values, preferably, unit water is ^{100kg / m 3 ~185kg / m 3} , the amount of cement used is ^{250kg / m 3 ~800kg / m 3} , water / cement ratio (mass ratio) = is 0.1 to 0.7, more preferably, a unit water amount is ^{120kg / m 3 ~175kg / m 3} , the amount of cement used is ^{270kg / m 3 ~800kg / m 3} , water / cement ratio ( The mass ratio) is 0.12 to 0.65. Thus, the cement composition can be used widely from poor to rich mix, and is effective for both high strength concrete with a large amount of cement and poor mix with a unit cement amount of 300 kg / m ³ or less. .

  The aggregate may be only one type, or two or more types. As the aggregate, any appropriate aggregate such as fine aggregate (sand or the like) or coarse aggregate (crushed stone or the like) can be adopted. Examples of such aggregate include gravel, crushed stone, granulated slag, and regenerated aggregate. In addition, as such an aggregate, a refractory aggregate such as silicate, clay, zircon, high alumina, silicon carbide, graphitic, chromium, chromate, magnesia and the like can also be mentioned.

  The water reducing agent may be only one type or two or more types. The water reducing agent preferably includes a polycarboxylic acid-based dispersant having a polyoxyalkylene chain and a carboxyl group in the molecule, and a sulfonic acid-based dispersant having a sulfonic acid group in the molecule.

  As a polycarboxylic acid type dispersing agent, for example, a polyalkylene glycol mono (meth) acrylic acid ester type monomer having a polyoxyalkylene chain obtained by adding 2 to 300 in average addition mole number of an alkylene oxide having 2 to 18 carbon atoms Copolymer obtained by copolymerizing a monomer component containing as a main component and a (meth) acrylic acid type monomer; 2 to 300 additions of an alkylene oxide having 2 to 18 carbon atoms in average addition mole number Polyalkylene glycol mono (meth) acrylic acid ester monomer having polyoxyalkylene chain, (meth) acrylic acid monomer and (meth) acrylic acid alkyl ester as an essential component A copolymer obtained by copolymerizing a monomer component; a poly obtained by adding 2 to 300 in average addition mole number of alkylene oxide having 2 to 18 carbon atoms Polyalkylene glycol mono (meth) acrylic acid ester monomer having a xalkylene chain, (meth) acrylic acid monomer, (meth) allyl sulfonic acid (salt) (or vinyl sulfonic acid (salt), p- A copolymer obtained by copolymerizing a monomer component containing three kinds of monomers with (meth) allyloxybenzene sulfonic acid (salt) as an essential component; an alkylene having 2 to 18 carbon atoms Polyalkylene glycol mono (meth) acrylic acid ester monomer having a polyoxyalkylene chain having 2 to 300 additions of an oxide in an average added mole number, (meth) acrylic acid monomer and (meth) allyl sulfonic acid ( (Meth) acrylamide and / or 2- (meth) acic acid in the copolymer obtained by copolymerizing the monomer component which contains three types of monomers with (salt) as an essential component A copolymer obtained by graft polymerization of luamido-2-methylpropane sulfonic acid; a polyalkylene glycol mono (meth) acrylic acid having a polyoxyalkylene chain with 2 to 300 additions of an alkylene oxide having 2 to 18 carbon atoms in average addition mole number Polyalkylene glycol mono (meth) allyl ether monomer and (meth) acrylic acid having a polyoxyalkylene chain in which an ester monomer and an alkylene oxide having 2 to 18 carbon atoms are added by 2 to 300 in average addition mole number Copolymerizing a monomer component containing as main components four kinds of monomers of a system monomer and (meth) allyl sulfonic acid (salt) (or p- (meth) allyloxy benzene sulfonic acid (salt)) Copolymer obtained by esterification; polyoxyalkyl with 2 to 300 addition of alkylene oxide having 2 to 18 carbon atoms in average addition mole number A copolymer obtained by copolymerizing a monomer component containing, as an essential component, a polyalkylene glycol mono (meth) allyl ether monomer having a lene chain and a maleic acid monomer; Of a polyalkylene glycol mono (meth) allyl ether monomer having a polyoxyalkylene chain having 2 to 300 additions of an alkylene oxide of 2 to 3 in average addition mole number and a polyalkylene glycol ester monomer of maleic acid as essential components Copolymer obtained by copolymerizing monomer components containing: Polyalkylene glycol mono (meth) allyl ether having a polyoxyalkylene chain obtained by adding 2 to 300 in average addition mole number of alkylene oxide having 2 to 18 carbon atoms Of a copolymer of acrylic monomer and maleic anhydride and a polyoxyalkylene derivative having a hydroxyl group at the end Sterilization reaction product; a polyalkylene glycol mono (3-methyl-3-butenyl) ether monomer having a polyoxyalkylene chain in which an alkylene oxide of 2 to 18 carbon atoms is added in an average addition mole number of 2 to 300 and ( A copolymer obtained by copolymerizing a monomer component containing an acrylic acid type monomer as an essential component; a polyoxyalkylene obtained by adding 2 to 300 in average addition mole number of an alkylene oxide having 2 to 18 carbon atoms A copolymer obtained by copolymerizing a monomer component containing, as essential components, a polyalkylene glycol mono (3-methyl-3-butenyl) ether monomer having a chain and a maleic acid monomer; It can be mentioned.

  Examples of sulfonic acid-based dispersants include polyalkylaryl sulfonate-based sulfonic acid-based dispersants such as naphthalene sulfonic acid-formaldehyde condensate, methyl naphthalene sulfonic acid-formaldehyde condensate, anthracene sulfonic acid-formaldehyde condensate, etc .; melamine sulfonic acid Melamine formalin resin sulfonate-based sulfonic acid based dispersants such as formaldehyde condensates; aromatic amino sulfonate based sulfonic acid based dispersants such as aminoaryl sulfonic acid-phenol-formaldehyde condensates; lignin sulfonates, Lignin sulfonate-based sulfonic acid-based dispersants such as modified lignin sulfonates; polystyrene sulfonate-based sulfonic acid-based dispersants.

  When the cement composition contains a water reducing agent, any appropriate content ratio may be adopted as the content ratio of the water reducing agent in the cement composition depending on the purpose. Such content ratio is preferably 0.01% by mass to 10% by mass, more preferably 0.02% by mass to 5% by mass, and still more preferably 0.05% by mass with respect to cement. It is -3% by mass, particularly preferably 0.07% by mass to 1% by mass, and most preferably 0.1% by mass to 0.7% by mass. By adjusting the content ratio of the water reducing agent in the cement composition within the above range, various preferable effects such as reduction of unit water content, increase of strength, improvement of durability and the like are brought about.

  The cement composition may include any suitable additional components. Such additional components may be of only one type, or of two or more types. As such additional components, for example, water-soluble polymer substances, polymer emulsions, early strengthening agents / accelerators, AE agents, antifoaming agents, crack reducing agents, surfactants, waterproofing agents, rust inhibitors, swelling Materials, cement wetting agents, thickeners, separation reducing agents, flocculants, drying shrinkage reducing agents, strength enhancing agents, self-leveling agents, coloring agents, fungicides and the like.

  Examples of the water-soluble polymer substance include nonionic cellulose ethers such as methyl cellulose, ethyl cellulose and carboxymethyl cellulose; polysaccharides produced by microbial fermentation such as yeast glucan, xanthan gum and β-1.3 glucans; And polyoxyalkylene glycols, etc .; polyacrylamides.

  Examples of the polymer emulsion include copolymers of various vinyl monomers such as alkyl (meth) acrylate.

  Examples of early strengthening agents and accelerators include soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide, calcium iodide and the like; chlorides such as iron chloride and magnesium chloride; sulfate; potassium hydroxide Sodium hydroxide; carbonates; thiosulfates; formates such as formate and calcium formate;

  As the AE agent, for example, resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, ABS (alkyl benzene sulfonic acid), alkane sulfonate, polyoxyethylene alkyl (phenyl) ether, polyoxyethylene alkyl (phenyl) Ether sulfuric acid ester or salt thereof, polyoxyethylene alkyl (phenyl) ether phosphoric acid ester or salt thereof, protein material, alkenyl sulfosuccinic acid, α-olefin sulfonate can be mentioned.

  As an antifoamer, For example, an oxyalkylene type antifoamer, a mineral oil type antifoamer, a fat and oil type antifoamer, a fatty acid type antifoamer, a fatty acid ester type antifoamer, an alcohol type antifoamer, an amide type antifoaming agent Agents, phosphate ester antifoaming agents, metal soap antifoaming agents, silicone antifoaming agents. As an oxyalkylene type antifoamer, for example, polyoxyalkylene alkyl ethers such as diethylene glycol heptyl ether; polyoxyalkylene acetylene ethers; (poly) oxyalkylene fatty acid esters; polyoxyalkylene sorbitan fatty acid esters; polyoxy alkylene Alkyl (aryl) ether sulfuric acid ester salts; polyoxyalkylene alkyl phosphoric acid esters; polyoxypropylene polyoxyethylene laurylamine (addition of 1 to 20 moles of propylene oxide, addition of 1 to 20 moles of ethylene oxide, etc.), addition of alkylene oxide Fatty acid derived amines obtained from hardened beef tallow (1 to 20 moles of propylene oxide, 1 to 20 moles of ethylene oxide, etc. adducts), etc. Kiruamin like; polyoxyalkylene amides; and the like.

  As a crack reducing agent, polyoxyalkyl ether is mentioned, for example.

  Examples of the surfactant include various anionic surfactants; various cationic surfactants such as alkyltrimethyl ammonium chloride; various nonionic surfactants; and various amphoteric surfactants.

  Examples of the waterproofing agent include fatty acids (salts), fatty acid esters, fats and oils, silicones, paraffins, asphalts and waxes.

  Examples of the rust inhibitor include nitrite, phosphate and zinc oxide.

  Examples of the expansive material include ettringite-based expansive material and coal-based expansive material.

  The type, combination, blending amount and the like of the additional components can be appropriately set according to the purpose.

  The content ratio of the additional component in the cement composition is preferably 0% by mass to 50% by mass, more preferably 0% by mass to 10% by mass, and still more preferably 0% by mass to 1 as a solid content ratio. % By mass, particularly preferably 0% by mass to 0.1% by mass.

  The cement composition may be effective for ready mixed concrete, concrete for secondary concrete products, concrete for centrifugal molding, concrete for vibration compaction, steam cured concrete, shot concrete and the like.

  The cement composition is medium flow concrete (concrete with a slump value of 22 to 25 cm), high flow concrete (concrete with a slump value of 25 cm or more and a slump flow value of 50 to 70 cm), self-filling concrete, self-leveling material, etc. It can be effective for mortars and concretes that require high fluidity.

  The cement composition may be prepared by blending the components in any suitable manner. For example, the method etc. which knead | mix a component in a mixer are mentioned.

  Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. In addition, unless otherwise stated, when there is a part, it means a mass part, and when there is a%, it means a mass%.

<Weight-average molecular weight analysis conditions>
Used column: TSKguard column α + TSKgel α-5000 + TSKgel α-4000 + TSKgel α-3000, each manufactured by Tosoh Corp., were used by linking one by one.
Eluent: Sodium borohydride sodium 2H ₂ O: 62.4 g, disodium hydrogen phosphate 12 H ₂ O: 143.3 g, in ion exchange water: 7794.3 g acetonitrile: 2000 g Was used.
Detector: Triple Detector “Model 302 Light Scattering Detector” manufactured by Viscotek, 90 ° scattering angle as right angle light scattering, 7 ° scattering angle as low angle light scattering, 18 μL as cell capacity, 670 nm as wavelength.
Standard sample: using Tosoh Co., Ltd., polyethylene glycol SE-8 (Mw = 107000), the dn / dC was 0.135 ml / g, the refractive index of the eluent was 1.333, and the device constant was determined.
Load amount standard sample: 100 μL of a solution dissolved with the above eluent was injected so that the polymer concentration became 0.2 vol%.
Sample: 100 μL of a solution dissolved with the above-mentioned eluent was injected so that the polymer concentration became 1.0 vol%.
・ Flow rate: 0.8 ml / min
・ Column temperature: 40 ° C

<Concrete test>
(Manufacture of cement composition)
Ordinary portland cement (made by Pacific Cement Co., Ltd.) as cement, land sand from Oi River water system as fine aggregate, crushed gravel from Aokai as coarse aggregate, tap water as kneading water, cement: 382 kg / m ³ , water: 172 kg / m ³ , fine aggregate: 796 kg / m ³ , coarse aggregate: 930 kg / m ³ , water reducing agent: amount shown in Table 2, cement strength improver or additive for cement or comparison additive: amount shown in Table 2, fine A cement composition was prepared at a ratio of aggregate ratio (fine aggregate / fine aggregate + coarse aggregate) (volume ratio): 47%, water / cement ratio (mass ratio) = 0.45.
The materials used in the test, forced mixer, and measuring instruments are temperature-controlled under the above-mentioned test temperature atmosphere so that the temperature of the cement composition becomes the test temperature of 20 ° C., and the kneading and each measurement are as described above. It went under test temperature atmosphere.
In addition, in order to avoid the influence of air bubbles in the cement composition on the fluidity of the cement composition, if necessary, an oxyalkylene-based antifoaming agent is used so that the amount of air is 1.0 ± 0.5%. Adjusted to
Under the above conditions, a cement composition was manufactured using a forced kneading mixer for 90 seconds of kneading time, and the slump value, flow value, and air amount were measured. In addition, the measurement of the slump value, the flow value, and the air amount was performed based on Japanese-Industrial-Standards (JIS-A-1101, 1128). Moreover, the addition amount of a water reducing agent was made into the addition amount used as a flow value of 37.5-42.5 cm.

(Measurement of compressive strength)
After kneading, the flow value and the amount of air were measured to prepare a sample for compressive strength test, and the compressive strength after 28 days was measured under the following conditions.
Specimen preparation: 100 mm x 200 mm
Specimen curing (28 days): Temperature about 20 ° C, humidity 60%, constant temperature and humidity air curing for 24 hours, and then curing specimen curing in water for 27 days: Specimen surface polishing (using specimen polishing finisher)
Compressive strength measurement: Automatic compressive strength measuring instrument (Maekawa Works)

Production Example 1 Production of Copolymer (1) A Dimroth cooling pipe, a stirrer with a Teflon (registered trademark) stirring blade and a stirring seal with a stirring seal, a nitrogen introducing pipe, and a glass reaction vessel equipped with a temperature sensor. 80.0 parts of exchange water was charged, and heated to 70 ° C. while introducing nitrogen at 200 mL / min while stirring at 250 rpm. Next, a mixed solution of 133.4 parts of methoxypolyethylene glycol monomethacrylate (average addition mole number of ethylene oxide: 9), 26.6 parts of methacrylic acid, 1.53 parts of mercaptopropionic acid and 106.7 parts of ion exchange water Was added dropwise over 4 hours, and at the same time, a mixed solution of 1.19 parts of ammonium persulfate and 50.6 parts of ion-exchanged water was added dropwise over 5 hours. The polymerization reaction was completed by maintaining the temperature at 70 ° C. for 1 hour after the addition was completed. And it neutralized by sodium hydroxide aqueous solution, and obtained the aqueous solution of the copolymer (1) of the weight average molecular weight 100000.

Example 1
Sodium alginate (manufactured by Wako Pure Chemical Industries, Ltd.) was used as a cement strength improver (1). The results are shown in Table 1.

Example 2
Glucomannan (trade name "PROPOL A", manufactured by Shimizu Chemical Co., Ltd.) was used as a cement strength improver (2). The results are shown in Table 1.

[Example 3]
Sodium alginate (manufactured by Wako Pure Chemical Industries, Ltd.) and PEG 200,000 (polyethylene glycol, manufactured by Aldrich, weight average molecular weight: 200000) were blended at a mass ratio of 1: 1, and used as a cement additive (1). The results are shown in Table 1.

Example 4
A product obtained by adding 20 moles of ethylene oxide to 1 mole of active hydrogen of the amino group of sodium alginate (manufactured by Wako Pure Chemical Industries, Ltd.) and ESP (weight average molecular weight = 23000, polyethyleneimine (weight average molecular weight = 600) ) Was blended at a mass ratio of 1: 1 to obtain a cement additive (2). The results are shown in Table 1.

[Example 5]
Sodium alginate (manufactured by Wako Pure Chemical Industries, Ltd.) and EDIPA (hydroxyethyldiisopropanolamine, manufactured by Aldrich) were blended at a mass ratio of 1: 1, and used as a cement additive (3). The results are shown in Table 1.

[Example 6]
Sodium alginate (manufactured by Wako Pure Chemical Industries, Ltd.) and TIPA (triisopropanolamine, manufactured by Wako Pure Chemical Industries, Ltd.) were blended at a mass ratio of 1: 1 to prepare a cement additive (4). The results are shown in Table 1.

[Example 7]
Sodium alginate (manufactured by Wako Pure Chemical Industries, Ltd.) and sorbitol (manufactured by Wako Pure Chemical Industries, Ltd.) were blended at a mass ratio of 1: 5 to obtain a cement additive (5). The results are shown in Table 1.

Example 8
Sodium alginate (manufactured by Wako Pure Chemical Industries, Ltd.) and sodium gluconate (manufactured by Wako Pure Chemical Industries, Ltd.) were blended at a mass ratio of 1: 5 to prepare an additive (6) for cement. The results are shown in Table 1.

Comparative Example 1
PEG 200,000 (polyethylene glycol, manufactured by Aldrich, weight average molecular weight = 200000) was used as a comparative additive (C1). The results are shown in Table 1.

Comparative Example 2
ESP (The addition of 20 moles of ethylene oxide to 1 mole of active hydrogen of amino group of weight average molecular weight = 23000 and weight average molecular weight = 600, Nippon Shokubai Co., Ltd.) was used as a comparative additive (C2) . The results are shown in Table 1.

Comparative Example 3
EDIPA (hydroxyethyldiisopropanolamine, manufactured by Aldrich) was used as a comparative additive (C3). The results are shown in Table 1.

Comparative Example 4
TIPA (triisopropanolamine, manufactured by Wako Pure Chemical Industries, Ltd.) was used as a comparative additive (C4). The results are shown in Table 1.

Comparative Example 5
Sorbitol (manufactured by Wako Pure Chemical Industries, Ltd.) was used as a comparative additive (C5). The results are shown in Table 1.

Comparative Example 6
Sodium gluconate (manufactured by Wako Pure Chemical Industries, Ltd.) was used as a comparative additive (C6). The results are shown in Table 1.

[Example 9]
A cement composition (1) is prepared using the copolymer (1) obtained in Production Example 1 and the cement strength improver (1) obtained in Example 1 in the amounts shown in Table 2, and compression is performed. The intensity was measured. The results are shown in Table 2.

[Example 10]
Using the copolymer (1) obtained in Production Example 1 and the cement strength improver (1) obtained in Example 1 in the amounts shown in Table 2, a cement composition (2) is prepared and compressed. The intensity was measured. The results are shown in Table 2.

[Example 11]
A cement composition (3) is prepared using the copolymer (1) obtained in Production Example 1 and the cement strength improver (1) obtained in Example 1 in the amounts shown in Table 2, and compression is performed. The intensity was measured. The results are shown in Table 2.

[Example 12]
A cement composition (4) is prepared by using the copolymer (1) obtained in Production Example 1 and the cement strength improver (2) obtained in Example 2 in the amounts shown in Table 2, and compression is performed. The intensity was measured. The results are shown in Table 2.

[Example 13]
Using the copolymer (1) obtained in Production Example 1 and the additive for cement (1) obtained in Example 3 in the amounts shown in Table 2, a cement composition (5) is prepared. And the compressive strength was measured. The results are shown in Table 2.
In addition, in preparing the cement composition (5), instead of adding and using the additive (1) for cement obtained in Example 3, sodium alginate and PEG 200,000 with the compounding amounts shown in Table 2 Similar results were obtained when each was used independently.

Example 14
Using the copolymer (1) obtained in Production Example 1 and the additive for cement (2) obtained in Example 4 in the amounts shown in Table 2, a cement composition (6) is prepared. And the compressive strength was measured. The results are shown in Table 2.
In addition, in preparing the cement composition (6), instead of using the additive (2) for cement obtained in Example 4, sodium alginate and ESP were added at the amounts shown in Table 2 instead. Similar results were obtained when used independently.

[Example 15]
Using the copolymer (1) obtained in Production Example 1 and the additive for cement (3) obtained in Example 5 in the amounts shown in Table 2, a cement composition (7) is prepared. And the compressive strength was measured. The results are shown in Table 2.
In addition, in preparing the cement composition (7), instead of adding and using the additive (3) for cement obtained in Example 5, sodium alginate and EDIPA were compounded in the amounts shown in Table 2 respectively. Similar results were obtained when used independently.

[Example 16]
Using the copolymer (1) obtained in Production Example 1 and the additive for cement (4) obtained in Example 6 in the amounts shown in Table 2, a cement composition (8) is prepared. And the compressive strength was measured. The results are shown in Table 2.
In addition, in preparing the cement composition (8), instead of adding and using the additive (4) for cement obtained in Example 6, sodium alginate and TIPA were compounded in the amounts shown in Table 2 respectively. Similar results were obtained when used independently.

[Example 17]
A cement composition (9) is prepared by using the copolymer (1) obtained in Production Example 1 and the additive for cement (5) obtained in Example 7 in the amounts shown in Table 2. And the compressive strength was measured. The results are shown in Table 2.
In addition, in preparing cement composition (9), instead of adding and using the additive (5) for cement obtained in Example 7, sodium alginate and sorbitol are compounded in amounts shown in Table 2 respectively. Similar results were obtained when used independently.

[Example 18]
A cement composition (10) is prepared using the copolymer (1) obtained in Production Example 1 and the additive for cement (6) obtained in Example 8 in the amounts shown in Table 2. And the compressive strength was measured. The results are shown in Table 2.
In addition, in preparing the cement composition (10), instead of adding and using the cement additive (6) obtained in Example 8, sodium alginate and sodium gluconate were compounded in amounts shown in Table 2 Similar results were obtained when they were added independently.

Comparative Example 7
A cement composition (C1) was prepared using the copolymer (1) obtained in Production Example 1 in the amount shown in Table 2, and the compressive strength was measured. The results are shown in Table 2.

Comparative Example 8
A cement composition (C2) is prepared by using the copolymer (1) obtained in Production Example 1 and the comparative additive (C1) obtained in Comparative Example 1 in the amounts shown in Table 2, and the compressive strength is adjusted. Was measured. The results are shown in Table 2.

Comparative Example 9
A cement composition (C3) is prepared using the copolymer (1) obtained in Production Example 1 and the comparative additive (C2) obtained in Comparative Example 2 in the amounts shown in Table 2, and the compressive strength is adjusted. Was measured. The results are shown in Table 2.

Comparative Example 10
A cement composition (C4) is prepared using the copolymer (1) obtained in Production Example 1 and the comparative additive (C3) obtained in Comparative Example 3 in the amounts shown in Table 2, and the compressive strength is adjusted. Was measured. The results are shown in Table 2.

Comparative Example 11
A cement composition (C5) was prepared using the copolymer (1) obtained in Production Example 1 and the comparative additive (C4) obtained in Comparative Example 4 in the amounts shown in Table 2, and the compressive strength was adjusted. Was measured. The results are shown in Table 2.

Comparative Example 12
A cement composition (C6) is prepared by using the copolymer (1) obtained in Production Example 1 and the comparative additive (C5) obtained in Comparative Example 5 in the amounts shown in Table 2, and the compressive strength is adjusted. Was measured. The results are shown in Table 2.

Comparative Example 13
A cement composition (C7) is prepared using the copolymer (1) obtained in Production Example 1 and the comparative additive (C6) obtained in Comparative Example 6 in the amounts shown in Table 2, and the compressive strength is adjusted. Was measured. The results are shown in Table 2.

  In the technical field of the present invention, it is not easy to realize improvement of several% for 28-day compressive strength of concrete at present, and it is recognized to be significant long-term improvement if several% improvement can be realized .

  As shown in Table 2, Comparative Example 7 (Cement strength improvers (1) to (2), additives for cement (1) to (6), and comparative additives (C1) to (C6) are not added either Cement strength improver (2) obtained in Examples 9 to 11 and Example 2 to which the cement strength improver (1) obtained in Example 1 was added, assuming that the 28-day compressive strength of Example) is 100. The 28-day compressive strength of Example 12 to which was added was 101 to 105, and a remarkable strength improvement effect was observed.

  Example 13 is an embodiment in which sodium alginate (0.01% by mass / cement) and PEG 200,000 (0.01% by mass / cement) are used in combination, as shown in Table 2, 28 of Comparative Example 7 The 28-day compression strength of Example 13 is 110 (i.e., +10) when the daily compression strength is 100. On the other hand, as shown in Table 2, the 28-day compressive strength in Example 11 in which only sodium alginate (0.01% by mass / cement) is added is 105 when the 28-day compressive strength in Comparative Example 7 is 100. (Ie, +5), the 28-day compressive strength in Comparative Example 8 in which only PEG 200,000 (0.01 mass% / cement) is added is 102 (the 28-day compressive strength in Comparative Example 7 is 100). That is, +2), and their simple sum is +7 when the 28-day compression strength of Comparative Example 7 is 100. Therefore, as shown in Table 2, in Example 13 in which sodium alginate (0.01% by mass / cement) and PEG 200,000 (0.01% by mass / cement) were used in combination, sodium alginate (0.01% by mass) was used. (Cement) only + 3 compared to the simple sum of the long-term strength improvement effect in Example 11 in which only cement is added and the long-term strength improvement effect in Comparative Example 8 in which only PEG 200,000 (0.01 mass% / cement) is added The synergetic effect of (1) could be expressed, and a remarkable improvement in strength was observed.

  Example 14 is an embodiment in which sodium alginate (0.01% by mass / cement) and ESP (0.01% by mass / cement) are used in combination, as shown in Table 2, 28 days of Comparative Example 7 The 28-day compression strength of Example 14 is 111 (i.e., +11) when the compression strength is 100. On the other hand, as shown in Table 2, the 28-day compressive strength in Example 11 in which only sodium alginate (0.01% by mass / cement) is added is 105 when the 28-day compressive strength in Comparative Example 7 is 100. The 28-day compressive strength in Comparative Example 9 in which only the ESP (0.01% by mass / cement) is added is 103 (ie, when the 28-day compressive strength in Comparative Example 7 is 100). , +3), and their simple sum is +8, assuming that the 28-day compression strength of Comparative Example 7 is 100. Therefore, as shown in Table 2, in Example 14 in which sodium alginate (0.01 mass% / cement) and ESP (0.01 mass% / cement) were used in combination, sodium alginate (0.01 mass% / Compared with the simple sum of the long-term strength improvement effect in Example 11 in which only cement is added and the long-term strength improvement effect in Comparative Example 9 in which only ESP (0.01 mass% / cement) is added An effect was exhibited, and a remarkable strength improvement effect was observed.

  Example 15 is an embodiment in which sodium alginate (0.01 mass% / cement) and EDIPA (0.01 mass% / cement) are used in combination, as shown in Table 2, 28 days of Comparative Example 7 The 28-day compression strength of Example 15 is 112 (ie, +12) when the compression strength is 100. On the other hand, as shown in Table 2, the 28-day compressive strength in Example 11 in which only sodium alginate (0.01% by mass / cement) is added is 105 when the 28-day compressive strength in Comparative Example 7 is 100. The 28-day compressive strength in Comparative Example 10 in which only (ie, +5) and EDIPA (0.01 mass% / cement) are added is 105 (ie, the 28-day compressive strength in Comparative Example 7 is 100). , +5), and their simple sum is +10, assuming that the 28-day compression strength of Comparative Example 7 is 100. Therefore, as shown in Table 2, in Example 15 in which sodium alginate (0.01% by mass / cement) and EDIPA (0.01% by mass / cement) were used in combination, sodium alginate (0.01% by mass /%) was used. Compared with the simple sum of the long-term strength improvement effect in Example 11 in which only cement is added and the long-term strength improvement effect in Comparative Example 10 in which only EDIPA (0.01 mass% / cement) is added An effect was exhibited, and a remarkable strength improvement effect was observed.

  Example 16 is an embodiment in which sodium alginate (0.01% by mass / cement) and TIPA (0.01% by mass / cement) are used in combination, as shown in Table 2, 28 days of Comparative Example 7 The 28-day compression strength of Example 16 is 113 (ie, +13) when the compression strength is 100. On the other hand, as shown in Table 2, the 28-day compressive strength in Example 11 in which only sodium alginate (0.01% by mass / cement) is added is 105 when the 28-day compressive strength in Comparative Example 7 is 100. The 28-day compressive strength in Comparative Example 11 in which only (i.e., +5) and TIPA (0.01 mass% / cement) is added is 105 (i.e., assuming that the 28-day compressive strength in Comparative Example 7 is 100). , +5), and their simple sum is +10, assuming that the 28-day compression strength of Comparative Example 7 is 100. Therefore, as shown in Table 2, in Example 16 in which sodium alginate (0.01% by mass / cement) and EDIPA (0.01% by mass / cement) were used in combination, sodium alginate (0.01% by mass /%) was used. The synergy of +3 compared with the simple sum of the long-term strength improvement effect in Example 11 in which only cement is added and the long-term strength improvement effect in Comparative Example 11 in which only EDIPA (0.01 mass% / cement) is added An effect was exhibited, and a remarkable strength improvement effect was observed.

  Example 17 is an embodiment in which sodium alginate (0.01% by mass / cement) and sorbitol (0.05% by mass / cement) are used in combination, as shown in Table 2, 28 days of Comparative Example 7 The 28-day compression strength of Example 17 when the compression strength is 100 is 112 (that is, +12). On the other hand, as shown in Table 2, the 28-day compressive strength in Example 11 in which only sodium alginate (0.01% by mass / cement) is added is 105 when the 28-day compressive strength in Comparative Example 7 is 100. The 28-day compressive strength in Comparative Example 12 in which only (i.e., +5) and only sorbitol (0.05% by mass / cement) is added is 104 (i.e., when the 28-day compressive strength in Comparative Example 7 is 100). , +4), and their simple sum is +9 when the 28-day compression strength of Comparative Example 7 is 100. Therefore, as shown in Table 2, Example 17 in which sodium alginate (0.01% by mass / cement) and sorbitol (0.05% by mass / cement) are used in combination is sodium alginate (0.01% by mass / The synergy of +3 compared with the simple sum of the long-term strength improvement effect in Example 11 in which only cement is added and the long-term strength improvement effect in Comparative Example 12 in which only sorbitol (0.05 mass% / cement) is added An effect was exhibited, and a remarkable strength improvement effect was observed.

  Example 18 is an embodiment in which sodium alginate (0.01% by mass / cement) and sodium gluconate (0.05% by mass / cement) are used in combination, as shown in Table 2, Comparative Example 7 The 28-day compression strength of Example 18 is 112 (i.e., +12) when the 28-day compression strength is 100. On the other hand, as shown in Table 2, the 28-day compressive strength in Example 11 in which only sodium alginate (0.01% by mass / cement) is added is 105 when the 28-day compressive strength in Comparative Example 7 is 100. (Ie, +5), the 28-day compressive strength in Comparative Example 13 in which only sodium gluconate (0.05% by mass / cement) is added is 103 when the 28-day compressive strength in Comparative Example 7 is 100. (Ie, +3), and their simple sum is +8 when the 28-day compression strength of Comparative Example 7 is 100. Therefore, as shown in Table 2, in Example 18 in which sodium alginate (0.01% by mass / cement) and sodium gluconate (0.05% by mass / cement) were used in combination, sodium alginate (0.01% by mass) was used. % / Cement) in comparison with the simple sum of the long-term strength improvement effect in Example 11 and Comparative Example 13 in which only sodium gluconate (0.05 mass% / cement) is added. The synergetic effect of +4 was able to be expressed, and the remarkable strength improvement effect was seen.

  The cement strength improver and the cement additive of the present invention are suitably used in a cement composition.

Claims (7)

  A cement strength improver comprising a polysaccharide having a gel-forming ability to gel in alkaline water.   The cement strength improver according to claim 1, wherein the polysaccharide is at least one selected from the group consisting of alginic acid or a salt thereof, an alginate ester, and glucomannan. An additive for cement comprising the cement strength improver according to claim 1 and at least one selected from the group consisting of the following components A, B, and C:
Component A: A compound having a structure in which 5 moles or more of alkylene oxide is added to 1 mole of alcohol.
Component B: an alkanolamine compound.
Component C: at least one member selected from the group consisting of oxycarboxylic acids or salts thereof, keto acids or salts thereof, sugars, and sugar alcohols.   The component A is polyethylene glycol, a copolymer having a structural unit derived from an alkylene oxide adduct of methacrylic acid, an alkylene oxide adduct of sorbitol, a structural unit derived from an alkylene oxide adduct of 3-methyl-3-butenyl alcohol The cement additive according to claim 3, which is at least one selected from the group consisting of a copolymer having: and an alkylene oxide adduct to active hydrogen bonded to an amino group of polyethyleneimine.   The component B is at least one selected from the group consisting of triisopropanolamine, N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine, and diisopropanolethanolamine. Cement additive as described in.   A cement composition comprising the cement strength improver according to claim 1. Furthermore, the cement composition of Claim 6 which has at least 1 sort (s) chosen from the group which consists of the following A component, B component, and C component.
Component A: A compound having a structure in which 5 moles or more of alkylene oxide is added to 1 mole of alcohol.
Component B: an alkanolamine compound.
Component C: at least one member selected from the group consisting of oxycarboxylic acids or salts thereof, keto acids or salts thereof, sugars, and sugar alcohols.