Film curing agent for hydraulic composition

Abstract

To provide a film curing agent for a hydraulic composition capable of suppressing moisture loss with time. The film curing agent for a hydraulic composition contains (A) a polyester containing a structural unit derived from a polyalkylene glycol.

Description

Film curing agent for hydraulic compositions

[0001] The present invention relates to a coating curing agent for hydraulic compositions and a curing method using the same.

[0002] BACKGROUND ART Curing methods for cement concrete pavements generally include water spray curing, mat curing, and film curing. These curing methods serve to prevent drying shrinkage cracking and a decrease in surface strength caused by water evaporation from the pavement surface. However, water spray curing, which must be repeated depending on the degree of water evaporation, and mat curing, which requires a large amount of matting to cover the pavement surface and is risky to handle in windy conditions, are both cumbersome tasks. To reduce this work, progress is being made in the development of film curing agents, which form a coating on the pavement surface to retain moisture.

[0003] Japanese Patent Application Laid-Open No. 2014-28729 discloses a coating curing agent for preventing initial drying during concrete curing, which is a material containing a water-dispersible polyester as its main component and is applied to the exposed surface of poured concrete after a predetermined curing period and after the concrete has been removed from the formwork.Japanese Patent Application Laid-Open No. 2006-248868 discloses a coating curing agent for cement-based materials that is applied or sprayed on the cement-based material before it hardens, which is characterized by containing a polymer emulsion and a lithium salt.

[0004] Summary of the Invention A coating curing agent for a hydraulic composition is required to exhibit excellent water retention properties for the period until the cement material reaches a predetermined strength. For example, in cement concrete pavement, a coating curing agent that has high water retention properties for about one week is required, and conventional coating curing agents have room for improvement in terms of long-term water retention properties.

[0005] The present invention provides a coating curing agent for hydraulic compositions that can suppress moisture loss over time over a long period of time when curing a hydraulic composition.

[0006] In one embodiment, the present invention provides a coating curing agent for hydraulic compositions, which comprises (A) a polyester containing structural units derived from polyalkylene glycol [hereinafter referred to as component (A)].

[0007] In another embodiment, there is provided a method for curing a hydraulic composition containing hydraulic powder and water, which comprises applying a treatment liquid containing (A) a polyester containing a structural unit derived from polyalkylene glycol [hereinafter referred to as component (A)] and water to the surface of the hydraulic composition, and then curing the hydraulic composition.

[0008] The coating curing agent for hydraulic compositions of the present invention can suppress moisture loss over time when curing a hydraulic composition. As a result, it is expected that the curing work can be labor-saving compared to conventional water sprinkling curing or mat curing, and that it will also have an effect of suppressing surface cracking. Furthermore, the coating curing agent for hydraulic compositions of the present invention can be applied when there is floating water on the surface of the hydraulic composition, and the timing of application of the coating curing agent is also highly versatile, so it is expected that work efficiency will be shortened.

[0009] Although the mechanism by which the effects of the present invention are achieved is unclear, it is believed to be as follows. The polyester of the present invention has structural units derived from polyalkylene glycol in the backbone of its molecular structure, and these structural units are derived from polyalkylene glycols of a certain length, resulting in excellent stability in water. Therefore, the polyester of the present invention can exist in water as uniform and fine particles, and has excellent stability against metal ions and other substances derived from hydraulic compositions. Therefore, it is unlikely to undergo changes in state, such as aggregation, even when it comes into contact with the surface of a hydraulic composition material. Therefore, it is believed that when applied to the surface of a hydraulic composition material, a uniform polymer coating can be formed on the surface of the hydraulic composition material. Furthermore, from the perspective of molecular structure, the highly polar ester structure in the main chain enhances adhesion to cement and aggregates, making it possible to form a dense coating without gaps on the surface of a cement-containing hydraulic composition. As a result, the uniform and dense polymer coating effectively blocks the evaporation pathways of water, thereby suppressing water evaporation from the cement-containing hydraulic composition for a long period of time.

[0010] 1 is a photograph showing the results of crack evaluation in Comparative Example 3. 2 is a photograph showing the results of crack evaluation in Example 8. 3 is a photograph showing the results of crack evaluation in Example 1. 4 is a graph showing the change in the amount of water loss over time.

[0011] MODE FOR CARRYING OUT THE INVENTION [Coating Curing Agent for Hydraulic Composition] In one embodiment, the coating curing agent for hydraulic composition of the present invention contains (A) a polyester containing a structural unit derived from polyalkylene glycol.

[0012] Examples of the structural units constituting the polyester of component (A) include structural units derived from polyhydric alcohols including polyalkylene glycols, and structural units derived from polybasic acids. The term "structural unit" as used herein refers to a structure corresponding to 1 mole of the raw material monomer of the polyester. For structural units derived from polyalkylene glycols, the polyalkylene glycol is also considered to be the raw material monomer. The molar ratio of the structural units of the raw material monomers in all structural units of the polyester of component (A) can be calculated from the amount (molar ratio) of the raw material monomers charged. The acid value of the polyester can be adjusted, for example, by changing the ratio of structural units derived from polyhydric alcohols and structural units derived from polybasic acids, using a carboxylic acid ester, or blocking the acid value with a monohydric alcohol.

[0013] <Structural Units Derived from Polyalkylene Glycol> As the structural unit derived from polyalkylene glycol, for example, one or more selected from polyethylene glycol (or polyethylene oxide), poly(ethylene / propylene) glycol (or poly(ethylene / propylene) oxide), and polypropylene glycol (or polypropylene oxide) can be used as the raw material monomer, and polyethylene glycol (or polyethylene oxide) can be preferably used. Hereinafter, polyalkylene glycol may be replaced with polyalkylene oxide.

[0014] From the viewpoint of stability in water, the weight average molecular weight of the polyalkylene glycol raw material monomer may be, for example, preferably 500 or more, more preferably 1000 or more, and preferably 20000 or less, more preferably 10000 or less. The weight average molecular weight and number average molecular weight can be determined by gel permeation chromatography (GPC) described later.

[0015] The polyalkylene glycol-derived constituent unit may be a combination of two or more different types as long as the weight-average molecular weight is within the above-mentioned range. For example, from the viewpoint of film formation, as the two or more raw material monomers having different weight-average molecular weights, for example, two or more polyalkylene glycols having different weight-average molecular weights of preferably 500 or more and preferably 2000 or less may be combined, and for example, two or more polyethylene glycols having different weight-average molecular weights of preferably 500 or more and preferably 2000 or less may be combined.

[0016] In addition, instead of the structural unit derived from polyalkylene glycol, for example, a structural unit derived from polyvinyl alcohol may be used, and for example, a structural unit derived from polyalkylene glycol and a structural unit derived from polyvinyl alcohol may be used in combination.

[0017] Of all the structural units constituting component (A), the proportion of structural units derived from polyalkylene glycol may be, for example, preferably 1 mol% or more, more preferably 1.5 mol% or more, even more preferably 2 mol% or more, and preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 10 mol% or less, and still more preferably 6 mol% or less. The content may be a value based on the amount of polyalkylene glycol used when preparing component (A).

[0018] <Constituent Units Derived from Polyhydric Alcohols Other than Polyalkylene Glycols> The component (A) may also contain, for example, constituent units derived from polyhydric alcohols other than polyalkylene glycols. As constituent units derived from polyhydric alcohols (excluding polyalkylene glycols), for example, one or more selected from dihydric alcohols and trihydric or higher polyhydric alcohols can be used as raw material monomers, and preferably one or more selected from aromatic polyhydric alcohols and aliphatic polyhydric alcohols (excluding polyalkylene glycols), more preferably aromatic polyhydric alcohols.

[0019] Examples of constituent units derived from polyhydric alcohols (excluding polyalkylene glycols) include, as raw material monomers, aliphatic dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, and 1,4-cyclohexanedimethanol; alkylene oxide adducts of bisphenol A (2,2-bis(4-hydroxyphenyl)propane); hydrogenated bisphenol A; Examples of suitable structural units include aromatic dihydric alcohols such as bisphenol A and alkylene oxide adducts of hydrogenated bisphenol A; trihydric alcohols such as 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene; and trihydric or higher polyhydric alcohols such as dipentaerythritol, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, and tripentaerythritol. The structural units derived from the polyhydric alcohols (excluding polyalkylene glycols) may also include structural units of component (A) derived from alkylene glycols of polyalkylene glycols.

[0020] From the viewpoint of film formation, the constituent unit derived from a polyhydric alcohol (excluding polyalkylene glycol), and further the constituent unit derived from an aromatic polyhydric alcohol, may be, for example, preferably a constituent unit derived from one or more selected from an alkylene oxide adduct of bisphenol A such as a propylene oxide adduct of bisphenol A or an ethylene oxide adduct of bisphenol A, 1,4-butanediol, 1,6-hexanediol, hydrogenated bisphenol A, and an alkylene oxide adduct of hydrogenated bisphenol A, and more preferably a constituent unit derived from an alkylene oxide adduct of bisphenol A.

[0021] Examples of the alkylene oxide adduct of bisphenol A include alkylene oxide adducts of bisphenol A represented by the following formula (I).

[0022]

[0023] [In the formula, OR 1 and R 1 O is an alkylene oxide, and R 1 represents an alkylene group having 2 or 3 carbon atoms, and x and y each represent a positive number indicating the average number of moles of alkylene oxide added.

[0024] In the formula (I), R 1 may be, for example, an alkylene group preferably having 3 carbon atoms. In the formula (I), the sum of x and y may be, for example, preferably 1 or more, more preferably 1.5 or more, and preferably 16 or less, more preferably 8 or less, and even more preferably 4 or less. The alkylene oxide adduct of bisphenol A represented by the formula (I) may be, for example, 1 is, for example, an alkylene group preferably having 3 carbon atoms, and the sum of x and y is preferably 1.5 or more and preferably 4 or less.

[0025] Of all the structural units constituting component (A), the total proportion of structural units derived from polyalkylene glycol and structural units derived from any polyhydric alcohol (excluding polyalkylene glycol) may be, for example, preferably 50 mol% or more, and preferably 70 mol% or less, more preferably 65 mol% or less, and even more preferably 60 mol% or less. The content may be a value based on the amount of polyalkylene glycol and any polyhydric alcohol (excluding polyalkylene glycol) used when preparing component (A).

[0026] Of all the structural units constituting component (A), the proportion of structural units derived from aromatic polyhydric alcohols and structural units derived from alkylene oxide adducts of bisphenol A may be, for example, preferably 30 mol% or more, more preferably 40 mol% or more, even more preferably 50 mol% or more, and preferably 65 mol% or less, more preferably 60 mol% or less, even more preferably 55 mol% or less. The above-mentioned contents may be values ​​based on the amounts of aromatic polyhydric alcohols and alkylene oxide adducts of bisphenol A used when preparing component (A).

[0027] From the viewpoint of production efficiency of component (A), the proportion of the aromatic polyhydric alcohol-derived structural units and the alkylene oxide adduct of bisphenol A in all structural units derived from the polyhydric alcohol may be, for example, preferably 80 mol% or more, more preferably 90 mol% or more, and preferably 97 mol% or less, more preferably 95 mol% or less, with the remainder being the proportion of structural units derived from an aliphatic polyhydric alcohol containing polyalkylene glycol. The above-mentioned content may be a value based on the amount of the aromatic polyhydric alcohol and the alkylene oxide adduct of bisphenol A used when preparing component (A).

[0028] From the viewpoint of the moisture retention performance of the coating, the proportion of the polyalkylene glycol-derived structural units among all structural units derived from aliphatic polyhydric alcohols including polyalkylene glycol may be preferably 60 mol% or more, more preferably 70 mol% or more, and preferably 100 mol% or less, more preferably 97 mol% or less, and even more preferably 95 mol% or less.

[0029] Component (A) preferably contains a small amount of structural units derived from a trihydric or higher polyhydric alcohol. In component (A), the proportion of structural units derived from a trihydric or higher polyhydric alcohol among all structural units derived from a polyhydric alcohol may be, for example, preferably 0 mol % or more and preferably 10 mol % or less. The content may be a value based on the amount of trihydric or higher polyhydric alcohol used when preparing component (A).

[0030] <Constituent Units Derived from Polybasic Acids> Examples of polybasic acids that can be used as constituent units derived from polybasic acids include, for example, polycarboxylic acids as raw material monomers. Examples of polycarboxylic acids include aromatic polycarboxylic acids and aliphatic polycarboxylic acids. Furthermore, examples of the polycarboxylic acids include dicarboxylic acids, their acid anhydrides, or lower alkyl esters, and tricarboxylic or higher carboxylic acids, their acid anhydrides, or lower alkyl esters.

[0031] Examples of divalent carboxylic acids, acid anhydrides thereof, and lower alkyl esters thereof include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octenylsuccinic acid, n-octylsuccinic acid, isooctenylsuccinic acid, isooctylsuccinic acid, and acid anhydrides or lower alkyl esters thereof.

[0032] Examples of trivalent or higher carboxylic acids, acid anhydrides thereof, or lower alkyl esters thereof include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra(methylenecarboxyl)methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empol trimer acid, and anhydrides or lower alkyl esters of these acids.

[0033] The component (A) may contain, for example, structural units derived from one or more raw material monomers selected from the above-mentioned acids. From the viewpoint of film formation, the raw material monomer may preferably be, for example, one or more selected from terephthalic acid, isophthalic acid, fumaric acid, succinic acid, adipic acid, n-dodecenylsuccinic acid, and isododecenylsuccinic acid, and more preferably terephthalic acid or fumaric acid.

[0034] The component (A) preferably has a structural unit derived from, for example, a dicarboxylic acid, and more preferably from an aromatic dicarboxylic acid.

[0035] Of all the structural units constituting component (A), the proportion of structural units derived from dibasic carboxylic acid and aromatic dibasic carboxylic acid may be, for example, preferably 30 mol% or more, more preferably 35 mol% or more, even more preferably 40 mol% or more, and preferably 50 mol% or less. The content may be a value based on the amount of polybasic acid, dibasic carboxylic acid, and aromatic dibasic carboxylic acid used when preparing component (A).

[0036] Of all the structural units derived from polycarboxylic acids, the proportion of structural units derived from dicarboxylic acids and aromatic dicarboxylic acids may be, for example, preferably 40 mol% or more, more preferably 60 mol% or more, even more preferably 80 mol% or more, and preferably 100 mol% or less. The content may be a value based on the amount of dicarboxylic acids and aromatic dicarboxylic acids used when preparing component (A).

[0037] Component (A) preferably contains a small amount of structural units derived from a trivalent or higher polycarboxylic acid, its acid anhydride, or its lower alkyl ester. From the viewpoint of stability in water, component (A) may, for example, preferably have a proportion of structural units derived from a trivalent or higher polycarboxylic acid, its acid anhydride, or its lower alkyl ester of, among all structural units derived from the polycarboxylic acid, of 0 mol% or more and preferably 10 mol% or less. The content may be a value based on the amount of trivalent or higher polycarboxylic acid, its acid anhydride, or its lower alkyl ester used when preparing component (A).

[0038] In the (A) component, the content of structural units derived from polybasic acid, polycarboxylic acid, and dicarboxylic acid relative to a total of 100 moles of polyhydric alcohol including polyalkylene glycol may be, for example, preferably 50 moles or more, more preferably 60 moles or more, and preferably 90 moles or less, more preferably 80 moles or less, from the viewpoint of stability in water and film formation.

[0039] The component (A) may contain, for example, structural units other than structural units derived from polyhydric alcohols including polyalkylene glycols and structural units derived from polybasic acids, as long as the effects of the present invention are not impaired.

[0040] Component (A) can be obtained, for example, by co-polycondensation of the above-mentioned raw material monomers, i.e., polyalkylene glycol, polyhydric alcohol (excluding polyalkylene glycol), polybasic acid, and optionally other raw material monomers. The method of co-polycondensation is not particularly limited, but for example, the method for producing an oil-in-water emulsion of polyester described in JP-A-50-3480 can be used. The amount of polyalkylene glycol charged as a raw material monomer may be preferably 10% by mass or more and preferably 30% by mass or less of the total amount of all raw material monomers charged for component (A).

[0041] The acid value (according to JIS K 0070) of the polyester in component (A) may be, for example, preferably 5 mgKOH / g or more, more preferably 8 mgKOH / g or more, from the viewpoint of stability in water, and preferably 18 mgKOH / g or less, more preferably 12 mgKOH / g or less, even more preferably 11.5 mgKOH / g or less, and still more preferably 11 mgKOH / g or less, from the viewpoint of film formation.

[0042] From the viewpoint of uniformity of the curing coating, the glass transition temperature of the polyester of component (A), as measured by DSC (differential scanning calorimetry), may be, for example, preferably −30° C. or higher, more preferably −15° C. or higher, and preferably 20° C. or lower, more preferably 10° C. or lower. The glass transition temperature can be adjusted by changing the composition ratio of the raw material monomers.

[0043] From the viewpoint of film formation, the number average molecular weight of the polyester in component (A) may be, for example, preferably 500 or more, more preferably 800 or more, and preferably 5,000 or less, more preferably 3,000 or less.

[0044] From the viewpoint of film formation, the weight average molecular weight of the polyester in component (A) may be, for example, preferably 2,000 or more, more preferably 4,000 or more, and preferably 15,000 or less, more preferably 10,000 or less.

[0045] In the present invention, the weight average molecular weight and the number average molecular weight can be determined by the following gel permeation chromatography (GPC) method.

[0046] (i) Preparation of sample solution The sample is dissolved in tetrahydrofuran at 40°C to a concentration of 0.5 g / 100 mL. Next, this solution is filtered using a PTFE-type membrane filter "DISMIC-25JP" (manufactured by Toyo Roshi Kaisha, Ltd.) with a pore size of 0.20 μm to remove insoluble components, and the resulting solution is used as a sample solution. (ii) Molecular weight measurement Using the following measurement device and analytical column, tetrahydrofuran is passed as an eluent at a flow rate of 1 mL per minute, and the column is stabilized in a thermostatic bath at 40°C. 100 μL of the sample solution is injected into the column and measurement is performed. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. The calibration curve used here is a sample containing several types of monodisperse polystyrene (A-500 (5.0 x 10) manufactured by Tosoh Corporation). 2 ), A-1000 (1.01×10 3 ), A-2500 (2.63×10 3 ), A-5000 (5.97×10 3 ), F-1 (1.02×10 4 ), F-2 (1.81×10 4 ), F-4 (3.97×10 4 ), F-10 (9.64×10 4 ), F-20 (1.90×10 5 ), F-40 (4.27×10 5 ), F-80 (7.06×10 5 ), F-128 (1.09×10 6 )) was used as a standard sample. The molecular weight is shown in parentheses.

[0047] Measuring device: "HLC-8220GPC" (manufactured by Tosoh Corporation) Analytical column: "TSKgel GMHXL" + "TSKgel G3000HXL" (manufactured by Tosoh Corporation)

[0048] The coating curing agent for hydraulic compositions of the present invention contains, for example, component (A) and water, and preferably further contains component (B) described below. The coating curing agent of the present invention in a water-containing form can be obtained by mixing water with component (A) obtained by reacting the raw material monomers. When component (A) is produced using an aqueous medium, a reaction product containing component (A) and water is obtained, and this can be used as is as the coating curing agent for hydraulic compositions of the present invention, for example. The coating curing agent for hydraulic compositions of the present invention may be, for example, an aqueous dispersion of component (A).

[0049] Component (A) may be, for example, in particulate form. The coating curing agent for hydraulic compositions of the present invention preferably contains, for example, particles of component (A). The coating curing agent for hydraulic compositions of the present invention may be, for example, in a form in which particles of component (A) are dispersed in water, i.e., an aqueous dispersion of component (A). When component (A) is particulate, the average particle size of component (A) may be, for example, preferably 20 nm or more, more preferably 40 nm or more, and preferably 400 nm or less, more preferably 200 nm or less, from the viewpoints of stability in water and the water retention performance of the coating. The average particle size is measured using a laser diffraction particle size analyzer "LA-920" (manufactured by Horiba, Ltd.).

[0050] Preferred examples of component (A) include polyesters containing, for example, 1 mol % to 30 mol % of structural units derived from polyalkylene glycol, 30 mol % to 65 mol % of structural units derived from aromatic dihydric alcohols and / or alkylene oxide adducts of bisphenol A, and 30 mol % to 50 mol % of structural units derived from dicarboxylic acids, aromatic dicarboxylic acids, and / or terephthalic acid.

[0051] The coating curing agent for hydraulic compositions of the present invention may contain a thermoplastic resin (B) [hereinafter referred to as "component (B)"] in addition to the component (A). The thermoplastic resin of component (B) excludes the polyester of component (A).

[0052] The component (B) may be, for example, one or more selected from poly(meth)acrylic acid, poly(meth)acrylic acid ester, styrene-acrylic copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, styrene-butadiene rubber, isoprene rubber, chloroprene rubber, and natural rubber (hereinafter, referred to as component (B1)), and preferably one or more selected from styrene-acrylic copolymer and styrene-butadiene rubber.

[0053] The component (B) may be two or more types selected from the thermoplastic resins listed as the component (B1). When the component (B) is two or more types of thermoplastic resins listed as the component (B1), the component (B) may be a combination of a styrene-acrylic copolymer and a styrene-butadiene rubber. In this case, the content of the styrene-acrylic copolymer in the total of the styrene-acrylic copolymer and the styrene-butadiene rubber may be, for example, preferably 40% by mass or more, more preferably 50% by mass or more, and, for example, preferably 100% by mass or less, more preferably 80% by mass or less.

[0054] From the viewpoint of the moisture retention performance of the coating, the glass transition temperature of the thermoplastic resin of component (B), as measured by DSC (differential scanning calorimetry), may be, for example, preferably −30° C. or higher, more preferably −20° C. or higher, and preferably 5° C. or lower, more preferably 0° C. or lower.

[0055] In terms of the moisture retention performance of the coating, the number average molecular weight of the thermoplastic resin in component (B) may be, for example, preferably 100 or more, more preferably 500 or more, and preferably 30,000 or less, more preferably 20,000 or less.

[0056] In terms of the moisture retention performance of the coating, the weight average molecular weight of the thermoplastic resin in component (B) may be preferably 1,000 or more, more preferably 2,000 or more, and preferably 200,000 or less, more preferably 100,000 or less.

[0057] Component (B) may be, for example, in a particulate form. The coating curing agent for hydraulic compositions of the present invention preferably contains, for example, particles of component (B). The coating curing agent for hydraulic compositions of the present invention may be, for example, in a form in which particles of component (B) are dispersed in water.

[0058] When component (B) is in the form of particles, the average particle size of component (B) may be, for example, preferably 20 nm or more, more preferably 50 nm or more, and preferably 400 nm or less, more preferably 200 nm or less. The average particle size of component (B) is calculated using the same measurement method as for the average particle size of component (A).

[0059] When the coating curing agent for hydraulic compositions of the present invention contains component (B) and further component (B1), the mass ratio of the content of component (B) to the content of component (A) [(B) / (A)], and the mass ratio of the content of component (B1) to the content of component (A) [(B1) / (A)], may be, from the viewpoint of the moisture retention performance of the coating, for example, preferably 0.3 or more, more preferably 0.35 or more, even more preferably 0.45 or more, still more preferably 0.7 or more, and preferably 5 or less, more preferably 3.75 or less, and even more preferably 3 or less. When the coating curing agent for hydraulic compositions of the present invention contains component (B), for example, a polyester having an acid value of more than 18 mgKOH / g (hereinafter referred to as (B2), excluding component (A)) can be used as component (B), and the mass ratio of the content of component (B2) to the content of component (A) [(B2) / (A)] may be, from the viewpoint of coating formation, preferably less than 0.1.

[0060] The coating curing agent for hydraulic compositions of the present invention may further contain, for example, water. The water may be deionized water, ion-exchanged water, or tap water. The coating curing agent for hydraulic compositions of the present invention preferably contains particles of component (A), particles of component (B), and water. For example, the coating curing agent for hydraulic compositions of the present invention may be an aqueous dispersion of component (A) and component (B).

[0061] The coating curing agent for hydraulic compositions of the present invention may contain component (A) in an amount of, for example, preferably 10% by mass or more, more preferably 20% by mass or more, from the viewpoint of stability in water, and in an amount of, for example, preferably 60% by mass or less, more preferably 50% by mass or less, from the viewpoint of viscosity suitable for application to hydraulic composition materials. The content of component (A) is preferred when the coating curing agent for hydraulic compositions of the present invention contains water.

[0062] When the coating curing agent for hydraulic compositions of the present invention contains component (B), the total content of components (A) and (B) in the coating curing agent for hydraulic compositions may be, for example, preferably 20% by mass or more, more preferably 30% by mass or more, and preferably 60% by mass or less, more preferably 50% by mass or less, in view of suitability for application to hydraulic composition materials and the moisture retention performance of the coating. This total content of components (A) and (B) is preferred when the coating curing agent for hydraulic compositions of the present invention contains water.

[0063] In addition to component (A) and, if necessary, component (B), the coating curing agent for hydraulic compositions of the present invention may contain, for example, an antifoaming agent, a stabilizer, a pigment, a preservative, an antioxidant, etc.

[0064] The coating curing agent for hydraulic compositions of the present invention is not particularly limited in the method of mixing component (A) and component (B) which is blended as needed, and is prepared by mixing them in any desired ratio using a conventional stirring device such as a homomixer. Preferably, it is prepared by mixing an aqueous dispersion of component (A) and an aqueous dispersion of component (B) in any desired ratio using the stirring device.

[0065] The hydraulic composition to be treated with the coating curing agent for hydraulic compositions of the present invention may contain, for example, hydraulic powder and water.

[0066] Examples of the hydraulic powder include cement such as ordinary Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, sulfate-resistant Portland cement, low-heat Portland cement, white Portland cement, and ecocement (e.g., JIS R5214). From the viewpoint of pavement strength and casting ease, ordinary Portland cement and early-strength Portland cement are preferred.

[0067] The hydraulic powder may include, for example, blast furnace slag, fly ash, silica fume, anhydrous gypsum, etc., or may include non-hydraulic limestone fine powder, etc. As the hydraulic powder, for example, blast furnace cement, fly ash cement, or silica fume cement, which is a mixture of cement with blast furnace slag, fly ash, silica fume, etc., may be used. Clay such as bentonite may also be included within a range that does not impair the effects of the present invention.

[0068] The hydraulic composition that is the target of the coating curing agent for hydraulic compositions of the present invention may have a mass percentage of the water content and the hydraulic powder content in the hydraulic composition [water / hydraulic powder] of, for example, preferably 25 mass % or more, more preferably 35 mass % or more, from the viewpoint of uniform application of the curing agent, and may have a mass percentage of preferably 50 mass % or less, more preferably 45 mass % or less, from the viewpoint of strength.

[0069] The hydraulic composition to which the coating curing agent for hydraulic compositions of the present invention is applied may contain, for example, any component other than the hydraulic powder.

[0070] [Method for Curing Hydraulic Compositions] In one embodiment, the coating curing agent for hydraulic compositions of the present invention can be applied to the surface of a hydraulic composition to be cured to form a resin coating, and the resin coating can suppress moisture loss from the hydraulic composition during curing. That is, the present invention provides a method for curing a hydraulic composition containing hydraulic powder and water, which comprises applying a treatment solution containing (A) a polyester containing a structural unit derived from polyalkylene glycol (hereinafter, component (A)) and water to the surface of the hydraulic composition, and then curing the hydraulic composition. The treatment solution preferably contains, for example, the aforementioned component (B). Specific examples and preferred examples of the component (A) and the optional component (B) used in the curing method of the present invention may be the same as those of the coating curing agent for hydraulic compositions of the present invention described above. Furthermore, the hydraulic composition used in the curing method of the present invention may contain, for example, the hydraulic powder and water, and specific examples and preferred examples of the hydraulic powder may be the same as those described above. Furthermore, the matters described in relation to the coating curing agent for hydraulic compositions of the present invention and the matters described in relation to the curing method of the present invention can be mutually applied.

[0071] The treatment liquid can be prepared, for example, by mixing the component (A), water, and optionally the component (B).

[0072] When the coating curing agent for hydraulic compositions of the present invention contains component (A), water, and optionally component (B), it can be used as the treatment liquid as is, as long as the contents of components (A) and (B) are suitable for application to hydraulic compositions. Therefore, the coating curing agent for hydraulic compositions of the present invention may also be the treatment liquid.

[0073] In another embodiment of the curing method of the present invention, the treatment liquid, for example, a treatment liquid containing the coating curing agent for hydraulic compositions of the present invention and water, is applied to the surface of the hydraulic composition during curing. After the preparation of the hydraulic composition, the treatment liquid can be applied to the surface of the hydraulic composition within, for example, 8 hours, but preferably within, for example, 60 minutes from the time when the hydraulic powder and mixing water first come into contact with each other during the preparation of the hydraulic composition. In the present invention, the mixing water may be water, or may contain water and other components, for example, the coating curing agent for hydraulic compositions of the present invention and other components used in the hydraulic composition.

[0074] In the curing method of the present invention, in order to suppress the loss of moisture from the hydraulic composition during curing, the treatment liquid can be applied after the preparation of the hydraulic composition, for example, preferably within 60 minutes from the time when the hydraulic powder and mixing water first come into contact when the hydraulic composition is prepared, from the viewpoint of improving work efficiency.

[0075] In the curing method of the present invention, the treatment liquid may be, for example, a treatment liquid containing the coating curing agent for hydraulic compositions of the present invention and water. That is, the treatment liquid may contain, for example, component (A), water, and, if necessary, component (B). The treatment liquid can be applied to the surface of the hydraulic composition during curing, for example, by coating or spraying.

[0076] The treatment liquid can be applied to the surface of the hydraulic composition by, for example, coating using a brush, a roller, or a known spray or pump sprayer.

[0077] The treatment liquid can be applied to the surface of the hydraulic composition by spraying, for example, using a sprayer, a watering can, a hand pump sprayer, or the like.

[0078] From the viewpoint of moisture retention, the treatment liquid is preferably 100 g / m 2 More preferably, 150 g / m 2 From the viewpoint of uniformity of the application surface, it is preferable to use a coating weight of 300 g / m 2 or less, more preferably 250 g / m 2The following can be applied to the surface of the hydraulic composition.

[0079] In the curing method of the present invention, the amount of component (A) applied to the surface of the hydraulic composition is, for example, preferably 10 g / m from the viewpoint of moisture retention performance. 2 More preferably, 20 g / m 2 From the viewpoint of film formation, it is preferably 110 g / m 2 or less, more preferably 60 g / m 2 It is preferable to adjust the concentration of the component (A) in the treatment liquid and the amount of the treatment liquid applied to the surface of the hydraulic composition so that the amount of the component (A) applied falls within this range.

[0080] In the curing method of the present invention, a water layer is formed on the surface of the hydraulic composition, and the treatment liquid is applied to the water layer, after which the hydraulic composition is cured. The water layer may be, for example, separated water (floating water, bleeding water) generated on the surface of the hydraulic composition after casting, or a water layer formed by water supplied to the surface of the hydraulic composition after casting. Separated water can be formed by physical means, such as vibrating the hydraulic composition after casting. Separated water may also be generated naturally during the casting operation. When separated water is generated naturally, it has conventionally been necessary to wait for the separated water to disappear before applying a film curing agent. However, the film curing agent of the present invention can be applied while the separated water remains, thereby improving work efficiency.

[0081] In the curing method of the present invention, when the treatment liquid is applied to the water layer, the thickness of the water layer may be, for example, preferably 0.1 mm or more and preferably 1 mm or less.

[0082] In the curing method of the present invention, when the treatment liquid is applied to the aqueous layer, the amount of component (A) applied per unit area (g / m ２ ) is preferably in the above range.

[0083] The curing method of the present invention can form a coating, specifically a curing coating, on the surface of a hydraulic composition. The coating formed by the coating curing agent for hydraulic compositions of the present invention depends on the environment, such as temperature and humidity, but for example, in an environment of a temperature of 20°C and a humidity of 60% RH, is formed, for example, preferably after 1 hour or more, more preferably after 2 hours or more have elapsed since application to the surface of the hydraulic composition.

[0084] In the curing method of the present invention, the treatment liquid may be applied to a hydraulic composition in which the mass percentage of the water content to the hydraulic powder content [water / hydraulic powder] in the hydraulic composition is, for example, preferably 25 mass% or more, more preferably 35 mass% or more, from the viewpoint of uniform application of the curing agent, and preferably 50 mass% or less, more preferably 45 mass% or less, from the viewpoint of strength.

[0085] The coating curing agent and curing method for hydraulic compositions of the present invention can also be used as a coating curing agent and curing method for, for example, concrete pavement, concrete materials for road peripheral structures, concrete blocks, tunnel lining concrete, 3D printer molded bodies for building materials, cement boards, etc.

[0086] The present invention discloses the following coating curing agent for hydraulic compositions and a curing method using the coating curing agent for hydraulic compositions.

[0087] <1> A coating curing agent for a hydraulic composition, comprising (A) a polyester containing a structural unit derived from polyalkylene glycol.

[0088] <2> The coating curing agent for hydraulic compositions according to the above <1>, wherein the acid value of the polyester in the component (A) is 5 mgKOH / g or more, further 8 mgKOH / g or more, and 18 mgKOH / g or less, further 12 mgKOH / g or less, further 11.5 mgKOH / g or less, further 11 mgKOH / g or less.

[0089] <3> The coating curing agent for hydraulic compositions according to the above <1> or <2>, wherein the content of the component (A) is 10% by mass or more, further 20% by mass or more, and 60% by mass or less, further 50% by mass or less.

[0090] <4> The coating curing agent for hydraulic compositions according to any one of the above <1> to <3>, wherein the proportion of structural units derived from polyalkylene glycol in all structural units of the polyester (A) is 1 mol% or more, further 1.5 mol% or more, further 2 mol% or more, and 30 mol% or less, further 20 mol% or less, further 10 mol% or less, further 6 mol% or less.

[0091] <5> The coating curing agent for hydraulic compositions according to any one of <1> to <4> above, wherein the weight average molecular weight of the polyester in the component (A) is 2,000 or more, preferably 4,000 or more, and 15,000 or less, preferably 10,000 or less.

[0092] <6> The coating curing agent for hydraulic compositions according to any one of the above <1> to <5>, wherein the component (A) has a structural unit derived from an aromatic polyhydric alcohol and further has an alkylene oxide adduct of bisphenol A.

[0093] <7> The coating curing agent for a hydraulic composition according to any one of <1> to <6> above, which contains (B) a thermoplastic resin.

[0094] <8> The coating curing agent for a hydraulic composition according to the above <7>, wherein the component (B) is at least one selected from poly(meth)acrylic acid, poly(meth)acrylic acid ester, styrene-acrylic copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, styrene-butadiene rubber, isoprene rubber, chloroprene rubber, and natural rubber.

[0095] <9> The coating curing agent for hydraulic compositions according to <7> or <8>, wherein the total content of the components (A) and (B) is 20% by mass or more, further 30% by mass or more, and further 60% by mass or less, further 50% by mass or less.

[0096] <10> The coating curing agent for hydraulic compositions according to any one of the above <7> to <9>, wherein the mass ratio of the content of the component (B) to the content of the component (A) [(B) / (A)] is 0.3 or more, further 0.35 or more, further 0.45 or more, further 0.7 or more, and is 5 or less, further 3.75 or less, further 3 or less.

[0097] <11> A method for producing a coating curing agent for hydraulic compositions, comprising (A) a polyester containing a structural unit derived from polyalkylene glycol, wherein the amount of polyalkylene glycol charged relative to the total amount of all raw material monomers charged of component (A) is 10 mass% or more and 30 mass% or less. <12> A method for curing a hydraulic composition containing hydraulic powder and water, comprising applying a treatment liquid containing the polyester according to any one of <1> to <6> above and water to the surface of the hydraulic composition, and then curing the hydraulic composition.

[0098] <13> The method for curing a hydraulic composition according to the above <12>, wherein the treatment liquid is applied to the surface of the hydraulic composition within 8 hours from the time when the hydraulic powder and mixing water first come into contact with each other during preparation of the hydraulic composition.

[0099] <14> The method for curing a hydraulic composition according to the above <12> or <13>, wherein the time for applying the treatment liquid to the surface of the hydraulic composition is 60 minutes or less.

[0100] <15> The method for curing a hydraulic composition according to any one of the above items <12> to <14>, wherein a water layer is formed on a surface of the hydraulic composition, the treatment liquid is applied to the water layer, and then the hydraulic composition is cured.

[0101] <16> The method for curing a hydraulic composition according to any one of the above items <12> to <15>, wherein the treatment liquid is applied by coating or spraying.

[0102] <17> The method for curing a hydraulic composition according to any one of the above items <12> to <16>, wherein the mass percentage of the water content and the hydraulic powder content in the hydraulic composition [water / hydraulic powder] is 25 mass% or more, further 35 mass% or more, and 50 mass% or less, further 45 mass% or less.

[0103] Examples Various physical properties were measured and evaluated by the following methods.

[0104] Component (A) (a1): Polyester described in Production Example 1 (a2): Polyester described in Production Example 2 Comparative (A): Polyester described in Production Example 3 Component (B): (b1) Styrene-acrylic copolymer: "PEGAL 809" manufactured by Koatsu Gas Kogyo Co., Ltd. (anionic emulsion with a solid content of 52.5% by mass, pH=8, Tg=-16°C) (b2) Styrene-acrylic copolymer: "JONCRYL PDX-7182" manufactured by BASF (emulsion with a solid content of 36.5% by mass, pH=8.0, Tg=5°C) (b3) Styrene-acrylic copolymer: emulsion with a solid content of 50% by mass, pH=10

[0105] Production Example 1 (Method for producing polyester (a1)) 5086.7 g (91 mol) of a polyoxypropylene (2.2 mol) adduct of bisphenol A and 45 g of tin(II) di(2-ethylhexanoate) were placed in a reaction vessel equipped with a stirrer, thermometer, stainless steel stirring rod, nitrogen gas inlet, and dehydration tube, and 1967.1 g (74.2 mol) of terephthalic acid, 495.1 g (3.1 mol) of polyethylene glycol having an average molecular weight of 1000, and 1451.1 g (5.9 mol) of polyethylene glycol having an average molecular weight of 1540 were added. The mixture was stirred in a nitrogen gas stream at 160 to 220°C for 8 hours, and the reaction was terminated when the acid value of the polyester reached 13 or less, yielding polyester (a1). The reaction product was cooled to 100°C and gradually poured into water at 76 to 80°C with stirring to obtain a uniform emulsion (solids content 28% by mass) containing polyester (a1). This emulsion was used to prepare a coating curing agent for hydraulic compositions. The resulting (a1) had a glass transition temperature Tg of -10.1°C, an acid value of 11.9 mg KOH / g, and a weight average molecular weight of 4632. The various physical properties of component (A) were evaluated by the following methods.

[0106] Production Example 2 (Production Method of Polyester (a2)) Except for changing the monomer composition of the raw material monomers to the formulation shown in (a2) in Table 1, the reaction was carried out in the same manner as in Production Example 1 to obtain an emulsion (solid content 28% by mass) containing polyester (a2). This emulsion was used to prepare a coating curing agent for hydraulic compositions. The obtained (a2) had a glass transition temperature Tg of -5.4°C, an acid value of 10.5 mg KOH / g, and a weight average molecular weight of 6,044.

[0107] Production Example 3 (Production Method of Polyester (Comparative (A))) The components shown in Table 1 for Comparative (A) were placed in a 5-liter four-neck flask equipped with a thermometer, thermocouple, stainless steel stirring rod, downflow condenser, and nitrogen inlet tube. An esterification catalyst (25 g of tin(II) di(2-ethylhexanoate)) was added under a nitrogen atmosphere. The mixture was heated to 215°C over 3 hours and maintained at 215°C for 5 hours. The reaction was then carried out under reduced pressure at 8.0 kPa for 1 hour, until the softening point (101.2°C) was reached, producing Comparative (A) polyester. The reaction product was cooled to 100°C and gradually poured into water at 76-80°C with stirring to obtain a uniform emulsion (solids content 35% by mass) containing the polyester Comparative (A). This emulsion was used to prepare a coating curing agent for hydraulic compositions. The obtained comparative (A) had a glass transition temperature Tg of 60.0°C, an acid value of 19.8 mgKOH / g and a weight average molecular weight of 14,299.

[0108] [Glass transition point (Tg) of polyester] Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of a polyester sample, calculated as solid content, was weighed into an aluminum pan, heated to 200°C, and cooled from that temperature to 0°C at a rate of 10°C / min. Measurement was then performed while raising the temperature to 150°C at a rate of 10°C / min. The glass transition point of the polyester was determined as the temperature at the intersection of an extension of the baseline below the maximum endothermic peak temperature and a tangent line showing the maximum slope from the rise of the peak to the peak apex.

[0109] [Acid Value of Polyester] The acid value of the polyester was measured according to the method of JIS K0070: 1992. However, the measurement solvent was changed from the mixed solvent of ethanol and ether specified in JIS K0070: 1992 to a mixed solvent of acetone and toluene (acetone:toluene = 1:1 (volume ratio)).

[0110] Examples 1 to 11 and Comparative Examples 1 to 3: Coating curing agents for hydraulic compositions were produced by mixing an emulsion of component (A), an emulsion of component (B), and an emulsion of comparative (A) for 1 minute using a stirring blade at 20°C to 25°C so that the mass ratio [(B) / (A)] and the total content [(A)+(B)] of components (A) and (B) were as shown in Table 2. In Example 7, (b1) and (b3) were used as component (B) in a mass ratio [(b1) / (b3)] of 67.7 / 32.3. These coating curing agents for hydraulic compositions are also the treatment liquid in the curing method of the present invention.

[0111] [Evaluation of moisture loss] A formwork (length 30 cm x width 21 cm x height 3.7 cm, area viewed from above 0.063 m) was used. ２ ) and prepared cement mortar to prepare a cement mortar specimen. The total weight of the specimen, including the mass of the formwork, was 2500 g. After casting, the specimen was vibrated for 90 seconds using a table vibrator to compact it. The surface of the specimen was then leveled with a trowel. When the surface of the specimen was observed, it was confirmed that a water layer (floating water) of about 0.1 mm to 0.5 mm had formed on the surface of the cement mortar specimen.

[0112] The water to cement mass ratio (W / C) was 42% (42 parts by mass of water per 100 parts by mass of cement). The amount of fine aggregate was 300 parts by mass per 100 parts by mass of cement. The amount of AE water reducing agent was 1 part by mass per 100 parts by mass of cement. The components used were as follows:

[0113] W: Mixing water (tap water (Wakayama City tap water)) C: Ordinary Portland cement (a mixture of Taiheiyo Cement Corporation and Sumitomo Osaka Cement Co., Ltd. in a mass ratio of 50 / 50, specific gravity 3.16 g / cm ３ ) S: Fine aggregate (mountain sand, Joyo, specific gravity 2.50 g / cm ３ ) AE water reducing agent (Mighty 1000S, manufactured by Kao Corporation)

[0114] Twenty-five minutes after compaction (0.5 hours after the cement powder and water first came into contact), the hydraulic composition coating curing agent shown in Table 2 was sprayed in mist form using a sprayer at the application amount shown in Table 2. From 24 to 120 hours after spraying the coating curing agent, the mass of the cement mortar specimen was measured every 24 hours under an environment of 20°C and 60% RH. The difference between this mass and the mass of the cement mortar specimen immediately after pouring (2,500 g) was used as the moisture loss amount, and the moisture loss suppression effect of the hydraulic composition coating curing agent was evaluated. Table 2 shows the moisture loss amounts after 24 and 120 hours. Each moisture loss amount is also shown as a relative value, with Comparative Example 1 set to 100. The relationship between the moisture loss amount and elapsed time is shown in a graph for some Examples and Comparative Examples.

[0115] [Evaluation of cracking] In the evaluation of moisture loss, cracking on the surface of the cement mortar specimen 120 hours after application of the coating curing agent for hydraulic compositions was visually observed and evaluated according to the following criteria.

[0116] ◯: No cracks, or four or fewer minute cracks with a width of 0.1 mm to 0.5 mm. △: Five or more cracks have occurred, but all of them are minute cracks with a width of 0.1 mm to 0.5 mm. ×: Ten or more cracks with a width of 0.5 mm or more have occurred.

[0117] Fig. 1 shows a photograph of the surface of the hydraulic composition 120 hours after application of the coating curing agent for hydraulic compositions of Comparative Example 3. In Comparative Example 3, cracks were formed on the surface to which the coating curing agent for hydraulic compositions was applied. Fig. 2 shows a whole photograph (a) and a partially enlarged photograph (b) of the surface of the hydraulic composition 120 hours after application of the coating curing agent for hydraulic compositions of Example 8. Fig. 3 shows a whole photograph (a) and a partially enlarged photograph (b) of the surface of the hydraulic composition 120 hours after application of the coating curing agent for hydraulic compositions of Example 1.

[0118] Figure 4 shows a graph of the amount of water loss over time. In Figure 4, the vertical axis represents the amount of water loss (kg / m ２4, (i) indicates the amount of water loss of the cement specimen of Comparative Example 1, (ii) indicates the amount of water loss of the cement specimen of Comparative Example 2, and (iii) indicates the amount of water loss of the cement specimen of Example 1.

[0119]

[0120]

Claims

1. (A) A coating curing agent for hydraulic compositions comprising a polyester containing a structural unit derived from a polyalkylene glycol [hereinafter referred to as component (A)].

2. The coating curing agent for hydraulic compositions according to claim 1, wherein the acid value of component (A) is 18 mg KOH / g or less.

3. A coating curing agent for hydraulic compositions according to claim 1 or 2, wherein the content of component (A) is 10% by mass or more and 60% by mass or less.

4. A coating curing agent for hydraulic compositions according to claim 1 or 2, in which the proportion of structural units derived from polyalkylene glycol among all structural units of component (A) is 1 mol % or more and 30 mol % or less.

5. The coating curing agent for hydraulic compositions according to claim 1 or 2, further comprising (B) a thermoplastic resin [hereinafter referred to as (B) component] (excluding (A) component).

6. The coating curing agent for hydraulic compositions according to claim 5, wherein component (B) is at least one selected from the group consisting of poly(meth)acrylic acid, poly(meth)acrylic acid ester, styrene-acrylic copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, styrene-butadiene rubber, isoprene rubber, chloroprene rubber, and natural rubber.

7. A coating curing agent for hydraulic compositions according to claim 5, wherein the total content of components (A) and (B) is 20% by mass or more and 60% by mass or less.

8. A coating curing agent for hydraulic compositions according to claim 5, wherein the mass ratio [(B) / (A)] of the content of the (B) component to the content of the (A) component is 0.3 or more and 5 or less.

9. A method for curing a hydraulic composition containing hydraulic powder and water, comprising applying a treatment liquid containing (A) a polyester containing a structural unit derived from polyalkylene glycol [hereinafter referred to as (A) component] and water to a surface of the hydraulic composition, and then curing the hydraulic composition.

10. The method for curing a hydraulic composition according to claim 9, wherein the treatment liquid is applied to the surface of the hydraulic composition within 60 minutes from the time when the hydraulic powder and mixing water first come into contact with each other during preparation of the hydraulic composition.

11. The curing method according to claim 9 or 10, further comprising forming a water layer on the surface of the hydraulic composition, applying the treatment liquid to the water layer, and then curing the hydraulic composition.

12. A curing method according to claim 9 or 10, wherein the mass percentage of the water content and the hydraulic powder content in the hydraulic composition [water / hydraulic powder] is 25 mass% or more and 50 mass% or less.

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