Curing agent for cement structure and method for producing cement structure

Abstract

To provide a curing agent for a cement structure, which has excellent performance in preventing moisture evaporation from the cement structure and can improve the appearance of the cement structure, and to provide a method for producing the cement structure.SOLUTION: A curing agent for a cement structure contains (A) a saturated alcohol compound and (B) a saturated fatty acid salt, wherein the saturated alcohol compound (A) is a 18-22C linear higher alcohol, and the saturated fatty acid salt (B) is a 16-22C linear saturated fatty acid salt.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curing agent for cement structures and a method for producing a cement structure. [Background technology]

[0002] To maximize the performance of cement structures such as mortar and concrete, curing methods have been used to prevent water loss from the cement surface. Common curing methods include water spray curing, coating curing, and sheet curing.

[0003] The problem with water spray curing is that it requires more frequent water spraying during periods of high temperature and rapid evaporation, making it a tedious process. Sheet curing requires more sheets as the construction area increases, making it difficult to apply to large areas and difficult to handle increasingly complex shapes.

[0004] In contrast, film curing involves applying a curing agent to the surface of a cement structure to form a film that suppresses water loss from the cement structure. This method is known to be less susceptible to the above problems, and various types of curing agents for use in film curing are currently being investigated.

[0005] Resin-based coating curing agents such as epoxy, acrylic, and urethane have traditionally been used as curing materials. However, these resin-containing curing agents contain solvents, and some are two-component, making their application complicated. Furthermore, the coating film they produce is relatively hard, making it difficult for them to adapt to deformations in cement structures. To address these issues, for example, Patent Document 1 discloses a coating curing agent made of an aqueous solution containing cellulose, and Patent Document 2 discloses a concrete surface finishing agent containing a specific alcohol compound. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-244255 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-111683 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in recent years, cement structures have been required to further suppress water loss (evaporation), and naturally, curing agents are also required to have an even greater effect in suppressing water loss. From this perspective, there was an urgent need to develop a curing agent that can form a film with excellent performance in suppressing water evaporation from cement structures.

[0008] The present invention has been made in view of the above, and an object of the present invention is to provide a curing agent for cement structures that has excellent performance in suppressing water evaporation from cement structures and can improve the appearance of cement structures, and a method for manufacturing cement structures. [Means for solving the problem]

[0009] As a result of extensive research into achieving the above-mentioned object, the present inventors discovered that the above-mentioned object can be achieved by using a saturated alcohol compound having a specific structure in combination with a saturated fatty acid salt having a specific structure, and thus completed the present invention.

[0010] That is, the present invention includes, for example, the subject matter described in the following sections. Item 1 (A) a saturated alcohol compound and (B) a saturated fatty acid salt, The (A) saturated alcohol compound is a linear higher alcohol having 18 or more and 22 or less carbon atoms, The (B) saturated fatty acid salt is a linear saturated fatty acid salt having 16 or more and 22 or less carbon atoms. Curing agent for cement structures. Section 2 Item 2. The curing agent for cement structures according to Item 1, wherein the total content of the (A) saturated alcohol compound and the (B) saturated fatty acid salt is 1% by mass or more and 10% by mass or less. Section 3 When the content of the (A) saturated alcohol compound is A (parts by mass) and the content of the (B) saturated fatty acid salt is B (parts by mass), Item 3. The curing agent for cement structures according to Item 1 or 2, wherein the A / B value is 2 or more and 5 or less. Section 4 Item 4. A method for producing a cement structure, comprising a step of forming a coating on a cement structure using the curing agent for a cement structure according to any one of Items 1 to 3. [Effects of the Invention]

[0011] The curing agent for cement structures of the present invention has excellent performance in suppressing water evaporation from cement structures, and can improve the appearance of cement structures. DETAILED DESCRIPTION OF THE INVENTION

[0012]

[0023] In the present specification, the terms "contain" and "comprise" include the concepts of "contain," "comprise," "consist essentially of," and "consist only of."

[0013] The curing agent for cement structures of the present invention contains (A) a saturated alcohol compound and (B) a saturated fatty acid salt. The (A) saturated alcohol compound is a linear higher alcohol having 18 to 22 carbon atoms, and the (B) saturated fatty acid salt is a linear saturated fatty acid salt having 16 to 22 carbon atoms.

[0014] The curing agent for cement structures of the present invention has excellent performance in suppressing water evaporation (also known as water loss) from a cement structure, and can improve the appearance of the cement structure. That is, by coating a cement structure with the curing agent for cement structures of the present invention, a film can be formed on the cement structure, and this film suppresses water evaporation from the cement structure (that is, the film formed from the curing agent for cement structures of the present invention has excellent water retention properties). Furthermore, suppressing water evaporation from the cement structure also suppresses the occurrence of darkening on the cement structure, making it possible to form a cement structure with a good appearance.

[0015] The curing agent for cement structures of the present invention will be described below. In this specification, the curing agent for cement structures of the present invention will be abbreviated simply as "curing agent" or "curing agent of the present invention."

[0016] <(A) Saturated alcohol compound> The curing agent of the present invention contains (A) a saturated alcohol compound as an essential component. (A) The saturated alcohol compound is an alcohol compound derived from a saturated hydrocarbon group, and in particular, a linear alkyl alcohol (i.e., a higher alcohol) having 18 to 22 carbon atoms.

[0017] The curing agent of the present invention contains (A) a saturated alcohol compound, which allows it to form a film that can inhibit water evaporation from a cement structure. If the number of carbon atoms in the (A) saturated alcohol compound is less than 18, the film formed from the curing agent will be less able to inhibit water evaporation from a cement structure. If the number of carbon atoms in the (A) saturated alcohol compound is more than 22, the film formed from the curing agent will be less able to inhibit water evaporation from a cement structure. In addition, the curing agent is more likely to emulsify poorly, making it difficult to use as a curing agent.

[0018] (A) saturated alcohol compound has a saturated hydrocarbon group (alkyl group) but does not have an unsaturated hydrocarbon group. If an unsaturated alcohol compound is used in place of (A) saturated alcohol compound in a curing agent, the film formed from the curing agent will have difficulty suppressing water evaporation from the cement structure.

[0019] The (A) saturated alcohol compound is linear. That is, the (A) saturated alcohol compound is an alcohol compound having a linear alkyl group, and the alkyl group does not have a branched structure. This allows the curing agent of the present invention to form a film that can suppress water evaporation from a cement structure. If a saturated alcohol compound having a branched structure is used in place of the (A) saturated alcohol compound in the curing agent, the film formed from the curing agent will have difficulty suppressing water evaporation from the cement structure.

[0020] Specific examples of the (A) saturated alcohol compound include stearyl alcohol, arachidyl alcohol, and behenyl alcohol.

[0021] The (A) saturated alcohol compound contained in the curing agent of the present invention may be one or more types.

[0022] <(B) Saturated fatty acid salt> The health-promoting agent of the present invention contains (B) a saturated fatty acid salt as an essential component. (B) The saturated fatty acid salt is a linear saturated fatty acid salt having 16 to 22 carbon atoms, i.e., a linear alkyl carboxylate having 16 to 22 carbon atoms.

[0023] The curing agent of the present invention contains (B) a saturated fatty acid salt, which allows the formation of a film that can inhibit water evaporation from a cement structure. If the carbon number of the (B) saturated fatty acid salt is less than 16, the film formed from the curing agent will be less able to inhibit water evaporation from a cement structure. If the carbon number of the (B) saturated fatty acid salt is more than 22, the film formed from the curing agent will be less able to inhibit water evaporation from a cement structure. In addition, poor emulsification of the curing agent will occur, making it difficult to use as a curing agent. It is preferable that the carbon number of the (B) saturated fatty acid salt is 18 or more.

[0024] (B) saturated fatty acid salts have saturated hydrocarbon groups (alkyl groups) but do not have unsaturated hydrocarbon groups. If unsaturated fatty acid salts are used in place of (B) saturated fatty acid salts in a curing agent, the film formed by the curing agent will have difficulty suppressing water evaporation from the cement structure.

[0025] The (B) saturated fatty acid salt is linear. That is, the (B) saturated fatty acid salt is an alkyl carboxylate having a linear alkyl group, and the alkyl group does not have a branched structure. This allows the curing agent of the present invention to form a film that can suppress water evaporation from a cement structure. If a saturated fatty acid salt having a branched structure is used in place of the (B) saturated fatty acid salt in the curing agent, the film formed from the curing agent will have difficulty suppressing water evaporation from the cement structure.

[0026] (B) The saturated fatty acid salt is, for example, an alkali metal salt. The alkali metal is not particularly limited, and examples thereof include sodium and potassium.

[0027] Specific examples of (B) saturated fatty acid salts include sodium palmitate, potassium palmitate, sodium stearate, potassium stearate, sodium arachidate, potassium arachidate, sodium behenate, potassium behenate, etc.

[0028] The (B) saturated fatty acid salt contained in the health-promoting agent of the present invention may be one type or two or more types.

[0029] <Curing agent> The curing agent of the present invention may contain, in addition to (A) the saturated alcohol compound and (B) the saturated fatty acid salt, for example, a solvent.

[0030] As the solvent, for example, a wide range of solvents used in conventional curing agents can be used in the present invention, with water being preferred. Thus, a preferred embodiment of the curing agent of the present invention is a curing agent containing (A) a saturated alcohol compound, (B) a saturated fatty acid salt, and water.

[0031] When the curing agent of the present invention contains a solvent such as water in addition to (A) a saturated alcohol compound and (B) a saturated fatty acid salt, the curing agent becomes, for example, an emulsified dispersion or a solution, preferably an emulsified dispersion. In the emulsified dispersion, the (B) saturated fatty acid salt contained in the curing agent can provide an emulsifying effect.

[0032] The curing agent of the present invention preferably has a total content of the (A) saturated alcohol compound and the (B) saturated fatty acid salt of 1% by mass or more and 10% by mass or less. In this case, the curing agent of the present invention has a higher effect of suppressing water evaporation from cement structures, and the viscosity of the curing agent of the present invention is less likely to increase more than necessary, which also tends to improve the coatability (i.e., applicability) of the curing agent of the present invention. The total content of the (A) saturated alcohol compound and the (B) saturated fatty acid salt of the present invention is more preferably 8% by mass or less, even more preferably 6% by mass or less, and particularly preferably 4% by mass or less, more preferably 1.2% by mass or more, even more preferably 1.5% by mass or more, and particularly preferably 2% by mass or more.

[0033] When the curing agent of the present invention is a solution or dispersion containing (A) a saturated alcohol compound and (B) a saturated fatty acid salt as well as a solvent such as water, the solids concentration is not particularly limited and can be, for example, the same as that of known curing agents. The solids concentration of the curing agent here refers to the concentration of components other than volatile components such as the solvent, and particularly refers to the concentration of components dispersed or dissolved in the solvent. Therefore, the solids concentration of the curing agent of the present invention refers to the ratio of the mass of components other than volatile components (solvent) to the total mass of the curing agent. The solids concentration of the curing agent of the present invention is, for example, 1% by mass or more and 10% by mass or less.

[0034] The respective content ratios of (A) saturated alcohol compound and (B) saturated fatty acid salt contained in the health-promoting agent of the present invention can be adjusted within a range that does not impair the effects of the present invention.

[0035] Specifically, when the content of the (A) saturated alcohol compound contained in the curing agent of the present invention is A (parts by mass) and the content of the (B) saturated fatty acid salt is B (parts by mass), the A / B value is preferably 2 or more and 5 or less. An A / B value of 2 or more improves the emulsion stability of the curing agent, and an A / B value of 5 or less enhances the effect of the curing agent of the present invention in suppressing water evaporation from cement structures. The A / B value is preferably 4.8 or less, and more preferably 4.6 or less.

[0036] The curing agent of the present invention may contain other components in addition to (A) the saturated alcohol compound, (B) the saturated fatty acid salt, and the solvent. Examples of other components include additives that can be contained in known curing agents, such as antifoaming agents, mildew inhibitors, light stabilizers, early strengthening agents, retarders, water retention agents, preservatives, and colorants.

[0037] Furthermore, the curing agent of the present invention contains (A) a saturated alcohol compound and (B) a saturated fatty acid salt, and may contain other alcohol compounds as long as the effects of the present invention are not impaired. Furthermore, the curing agent of the present invention may also be used in combination with other fatty acid salts.

[0038] The total content of (A) saturated alcohol compound and (B) saturated fatty acid salt relative to the total solid content (excluding the solvent) in the curing agent of the present invention is preferably 60 mass% or more, more preferably 80 mass% or more, even more preferably 90 mass% or more, and particularly preferably 95 mass% or more. The solid content in the curing agent of the present invention may consist solely of (A) saturated alcohol compound and (B) saturated fatty acid salt.

[0039] The method for preparing the curing agent of the present invention is not particularly limited. For example, the curing agent of the present invention can be prepared by mixing (A) a saturated alcohol compound, (B) a saturated fatty acid salt, and a solvent in a predetermined mixing ratio. The mixing method is also not particularly limited, and for example, a wide variety of known mixing means can be used in the present invention. It is particularly preferable to prepare the curing agent of the present invention using an emulsifying means such as an emulsifying disperser. Specifically, the curing agent of the present invention can be obtained by mixing (A) a saturated alcohol compound, (B) a saturated fatty acid salt, and a solvent in predetermined amounts, and then emulsifying the mixture obtained using an emulsifying disperser or the like. This allows the curing agent to be obtained in a state in which (A) a saturated alcohol compound and (B) a saturated fatty acid salt are emulsified in the solvent (water).

[0040] The curing agent of the present invention can be used to form a coating on a cement structure. The method for forming the coating is not particularly limited, and examples thereof include a method of applying the curing agent of the present invention to a cement structure, a method of spraying (dispersing) the curing agent of the present invention onto a cement structure, and a method of immersing the cement structure in the curing agent of the present invention. By these methods, a coating of the curing agent of the present invention can be formed on a cement structure.

[0041] When applying the curing agent of the present invention to a cement structure, a known application means can be used, for example, such as a brush or roller. When spraying the curing agent of the present invention onto a cement structure, a hand pump type sprayer, a mechanical sprayer, or the like can be used.

[0042] When the curing agent of the present invention is applied or sprayed on a cement structure, the amount is not particularly limited, and for example, it may be applied in the range of 50 to 500 g / m 2 After the curing agent of the present invention has been applied to the cement structure, a coating can be formed on the cement structure by, for example, heat treatment or natural drying, as needed.

[0043] The coating formed from the curing agent of the present invention may be formed on a part of the surface of the cement structure, or may be formed on the entire surface.

[0044] The type of cement structure is not particularly limited, and for example, a wide range of known cement structures can be applied to the present invention. Materials for forming the cement structure include concrete, mortar, etc. The shape of the cement structure is also not particularly limited.

[0045] By providing a film formed by the curing agent of the present invention on a cement structure, the cement structure is prevented from evaporating water, and the water retention is excellent. Furthermore, the suppression of water evaporation also prevents the cement structure from darkening, resulting in a good appearance.

[0046] Therefore, the curing agent of the present invention can be suitably used for producing the above-mentioned cement structure. In particular, the cement structure can be produced by a simple process that includes a step of forming a film on the cement structure using the curing agent of the present invention, and the cement structure has excellent water retention and appearance. For example, the method for producing a cement structure can include a step of forming a film on the cement structure using the curing agent for cement structures of the present invention.

[0047] In specifying the inventions included in the present disclosure, the components (properties, structures, functions, etc.) described in each embodiment of the present disclosure may be combined in any manner. In other words, the present disclosure includes all subject matter consisting of all combinations of the components that can be combined as described in this specification. [Example]

[0048] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0049] (raw materials) Appropriate raw materials were selected from the raw materials shown below to prepare curing agents.

[0050] <(A) Saturated alcohol compound> Stearyl alcohol (carbon number 18) Behenyl alcohol (carbon number 22)

[0051] <Other alcohol compounds> 1-Octacosanol (carbon number 28) Cetyl alcohol (carbon number 16) Oleyl alcohol (18 carbon atoms, unsaturated alcohol) Isostearyl alcohol (18 carbon atoms, branched structure)

[0052] <Ether compounds> Polyoxyethylene stearyl ether (Nippon Emulsion Co., Ltd. "EMALEX608")

[0053] <(B) Saturated fatty acid salt> Sodium stearate (carbon number 18) Sodium behenate (carbon number 22) Sodium palmitate (carbon number 16) Potassium stearate (carbon number 18)

[0054] <Other fatty acid salts> Sodium montanate (carbon number 28) Sodium myristate (carbon number 14) Sodium laurate (carbon number 12) Sodium oleate (18 carbon atoms, unsaturated fatty acid)

[0055] <Oils> White petrolatum

[0056] <Solvent> ·water

[0057] Example 1 A curing agent was prepared by blending the raw materials shown in Example 1 of the formulation table in Table 1 in the prescribed blending amounts. Specifically, 2.00 parts by mass of stearyl alcohol as (A) a saturated alcohol compound, 0.50 parts by mass of sodium stearate as (B) a saturated fatty acid salt, and 97.50 parts by mass of water were mixed and emulsified / dispersed to prepare a curing agent (solid concentration 2.5% by mass).

[0058] Examples 2 to 11 As shown in Table 1, curing agents were prepared in the same manner as in Example 1, except that the types and amounts of raw materials were changed.

[0059] (Comparative Examples 1 to 9) As shown in Table 2, curing agents were prepared in the same manner as in Example 1, except that the types and amounts of raw materials were changed.

[0060] (Evaluation method) [Evaluation of film formation and water loss] The mixed mortar (cement / sand = 1 / 2.5, W / C = 40%) was molded using a simple formwork 120 mm square and 20 mm deep, and then cured for 3 hours in a constant temperature and humidity chamber at 37.8±1.1°C and 32±2% RH to obtain a cement structure in the simple formwork. After measuring the mass M1 of the obtained cement structure (including the simple formwork), 200 g / m of the curing agent obtained in each of the above examples and comparative examples was applied to the surface of the cement structure. 2 The curing agent was applied with a brush in an amount of 100g, and then dried for 72 hours in a constant temperature and humidity chamber at 37.8±1.1°C and 32±2% RH. This allowed a film of the curing agent to be formed on the cement structure. The mass M2 of the cement structure (including the simple formwork) on which this film had been formed was measured.

[0061] Next, the amount of water loss was calculated based on the measured values ​​of the mass M1 and mass M2. The amount of water loss of the cement structure was calculated using the following formula (1) in accordance with ASTM C156-20. Water loss (kg / m 2 )=1000×(M1+NV×MA-M2) / A (1) (In equation (1), M1 is the mass (g) of the cement structure (including simple formwork) before applying the curing agent, M2 is the mass (g) of the cement structure (including simple formwork) after drying, NV is the proportion of non-volatile matter in the curing agent (mass%), MA is the mass (g) of the applied curing agent, and A is the area of ​​the coating (mm 2 ) Based on the calculation results of the amount of water loss, the water retention (effect of inhibiting water evaporation) was evaluated according to the following criteria. ≪Judgment criteria≫ A: The water loss is 0.3 (kg / m 2 ) and was extremely effective in inhibiting water evaporation. B: Water loss is 0.3 (kg / m 2 ) or more 0.55 (kg / m 2 ) and was excellent in the effect of suppressing water evaporation. C: Water loss is 0.55 (kg / m 2 ) or more, and the effect of suppressing water evaporation was extremely poor.

[0062] [Appearance evaluation of cement structures] The appearance of the cement structure was visually observed and evaluated according to the following criteria. ≪Judgment criteria≫ ○: No darkening was observed on the surface of the cement structure. ×: Darkening was clearly observed on the surface of the cement structure.

[0063] Table 1 shows the blending conditions of the curing agents prepared in each example, and the evaluation results (evaluation of water loss amount, evaluation of appearance) of the cement structures on which the curing agent films were formed.

[0064] Table 2 shows the blending conditions of the curing agents prepared in each comparative example, and the evaluation results (evaluation of water loss amount, evaluation of appearance) using the curing agents.

[0065] Note that blank spaces in Tables 1 and 2 mean that the raw material was not used.

[0066] As can be seen from Table 1, the curing agents prepared in the examples contained a linear higher alcohol ((A) saturated alcohol compound) having a carbon number of 18 or more and 22 or less and a linear saturated fatty acid salt ((B) saturated fatty acid salt) having a carbon number of 16 or more and 22 or less, and therefore reduced the amount of water loss. Therefore, the curing agents prepared in the examples were excellent in their ability to reduce water evaporation from cement structures and were able to improve the appearance of the cement structures.

[0067] In contrast, the curing agent prepared in the comparative example did not contain (A) saturated alcohol compound and (B) saturated fatty acid salt, and therefore was inferior in its ability to inhibit water evaporation from cement structures.

[0068] [Table 1]

[0069] [Table 2]

Claims

1. (A) a saturated alcohol compound and (B) a saturated fatty acid salt, The saturated alcohol compound (A) is a linear higher alcohol having 18 to 22 carbon atoms, The (B) saturated fatty acid salt is a linear saturated fatty acid salt having 16 or more and 22 or less carbon atoms. Curing agent for cement structures.

2. 2. The curing agent for cement structures according to claim 1, wherein the total content of the (A) saturated alcohol compound and the (B) saturated fatty acid salt is 1% by mass or more and 10% by mass or less.

3. When the content of the (A) saturated alcohol compound is A (parts by mass) and the content of the (B) saturated fatty acid salt is B (parts by mass), 2. The curing agent for cement structures according to claim 1, wherein the value of A / B is 2 or more and 5 or less.

4. A method for manufacturing a cement structure, comprising a step of forming a coating on a cement structure using the curing agent for cement structures according to any one of claims 1 to 3.

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