Water-soluble emulsion used in concrete or mortar

Abstract

To provide a water-soluble emulsion that suppresses the generation of efflorescence in concrete and mortar for a long period of time.SOLUTION: A water-soluble emulsion used for concrete or mortar, comprising component (A): a fatty acid having 12 to 22 carbon atoms, and component (B): a hydrophobic component other than fatty acids.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a water-soluble emulsion used for concrete or mortar. Background Art

[0002] It has been conventionally known that efflorescence occurs in concrete. "Efflorescence" refers to a phenomenon in which white crystals (efflorescence) form on the surface of concrete blocks and the like. Specifically, when cement, which is a raw material of concrete, reacts with water, calcium hydroxide is produced as a by-product. When this calcium hydroxide dissolves in water inside the concrete, it migrates to the surface as calcium ions. When the calcium ions that have migrated to the surface react with carbon dioxide in the atmosphere, poorly soluble calcium carbonate is produced. This calcium carbonate is observed as efflorescence. Such efflorescence impairs the commercial value of concrete in terms of appearance.

[0003] In the case of an immediate demolding concrete product obtained by charging ultra-stiff-mixed concrete with an extremely low unit water content into a mold, performing pressure vibration compaction, and then demolding, a concrete product with suppressed plastic deformation immediately after demolding can be obtained, but the void content is higher than that of ordinary concrete. Therefore, part of the mixing water and moisture derived from rainwater penetrating from the outside easily move inside the concrete, and soluble efflorescence components migrate to the concrete surface along with the movement of moisture. For this reason, immediate demolding concrete products are particularly prone to efflorescence.

[0004] In recent years, the commercial value of concrete blocks imparted with design properties has been on an upward trend, so there is a demand for technologies that suppress efflorescence that impairs the appearance of concrete. However, under the current circumstances, although there are agents that suppress initial efflorescence, no agent that suppresses efflorescence over the long term has been developed, which remains one of the major problems. It should be noted that such efflorescence also occurs similarly in mortar.

[0005] In a conventional technology proposal, Patent Document 1 proposes a penetrating waterproofing composition for imparting waterproofing properties to concrete or mortar. By using this penetrating waterproofing composition to prevent moisture from penetrating into the concrete or mortar, the occurrence of efflorescence is also suppressed. The penetrating waterproofing composition of Patent Document 1 consists of an epoxy resin emulsion, an amide polyamine compound, a higher fatty acid or a salt thereof. However, because epoxy resin is used, there are concerns about adverse effects on the human body.

[0006] Patent Document 2 discloses a curing agent for cement structures that suppresses moisture evaporation when applied to the surface of cement. It is conceivable that the curing agent for cement structures described in Patent Document 2 could also suppress the occurrence of efflorescence. Similarly, Patent Document 3 discloses a curing agent for mortar or concrete that suppresses the occurrence of efflorescence when applied to the surface of mortar or concrete. However, since the curing agents in Patent Documents 2 and 3 are applied to the surface of concrete or mortar, they have the problem of being easily removed by wind and rain. In other words, they cannot be expected to suppress the occurrence of efflorescence over a long period of time.

[0007] Furthermore, Patent Document 4 discloses a technique for using a cement admixture containing alkali salts of fatty acids to suppress efflorescence. Similarly, Patent Document 5 discloses a waterproofing agent for cement containing a salt of fatty acids and sodium. The waterproofing agent for cement described in Patent Document 5 is also expected to be used to suppress efflorescence. However, the techniques in Patent Documents 4 and 5 have the problem that the function of suppressing efflorescence decreases over time because the amount of alkali salts of fatty acids or salts of fatty acids and sodium on the concrete surface decreases.

[0008] Furthermore, Patent Document 6 proposes a technique for suppressing efflorescence by applying an efflorescence inhibitor, which is a mixture of water and oil, to the surface of concrete. However, Patent Document 6 has room for improvement in terms of suppressing efflorescence over a long period of time. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 53-132030 [Patent Document 2] Japanese Patent Publication No. 2010-18490 [Patent Document 3] Japanese Patent Publication No. 2018-171748 [Patent Document 4] Japanese Patent Application Publication No. 11-60301 [Patent Document 5] Japanese Patent Publication No. 2016-210671 [Patent Document 6] Japanese Patent Publication No. 2018-43928 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] Considering the above circumstances, the object of the present invention is to provide a water-soluble emulsion that can suppress the occurrence of efflorescence in concrete and mortar over a long period of time. [Means for solving the problem]

[0011] To solve the above problems, the water-soluble emulsion of the present invention is a water-soluble emulsion used in concrete or mortar, and comprises the following components: (A) Fatty acids with 12 to 22 carbon atoms (B) Hydrophobic components other than fatty acids It is characterized by containing [something]. [Effects of the Invention]

[0012] According to the present invention, the occurrence of efflorescence in concrete and mortar can be suppressed over a long period of time. [Modes for carrying out the invention]

[0013] The present invention will be described in detail below.

[0014] The water-soluble emulsion of the present invention is used as an admixture to be mixed into concrete or mortar for suppressing the occurrence of efflorescence. In the following description, the function of suppressing the occurrence of efflorescence is referred to as efflorescence suppressing ability. In addition, the water-soluble emulsion according to the present invention is also used for improving the waterproofness of concrete or mortar. Improving waterproofness consequently further suppresses the occurrence of efflorescence.

[0015] Specifically, the water-soluble emulsion contains component (A) and component (B). Component (A) is a fatty acid having 12 to 22 carbon atoms. Component (B) is a hydrophobic component other than fatty acids.

[0016] As the fatty acid having 12 to 22 carbon atoms for component (A), it may be a saturated fatty acid or an unsaturated fatty acid, and the aliphatic group may be linear or branched, with linear being preferred.

[0017] Examples of saturated fatty acids having 12 to 22 carbon atoms include lauric acid (C12), myristic acid (C14), palmitic acid (C16), stearic acid (C18), arachidic acid (C20), behenic acid (C22), and the like.

[0018] Examples of unsaturated fatty acids having 12 to 22 carbon atoms used as component (A) include myristoleic acid (C14:1), palmitoleic acid (C16:1), oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3), erucic acid (C22:1), and the like. Note that the above numerical notation represents the number of carbon atoms and the number of double bonds of the fatty acid. These may be used alone, or two or more of them may be used in combination.

[0019] The number of carbon atoms of the fatty acid in component (A) is 12 to 22; however, in consideration of waterproofness and efflorescence suppressing ability, 20 or less is preferred, 14 to 20 is more preferred, and 14 to 18 is even more preferred.

[0020] In the water-soluble emulsion of the present invention, the hydrophobic components other than fatty acids in component (B) are not particularly limited, and examples thereof include hydrocarbons, oils and fats, fatty acid esters, fatty acid metal salts, fatty acids other than those having 12 to 22 carbon atoms, higher alcohols, silicone oils, waxes, steroids, etc., and these may be liquid, paste or solid at normal temperature. Among these, in consideration of the initial efflorescence suppression ability, hydrocarbons, oils and fats, fatty acid esters, and fatty acid metal salts are preferred, and hydrocarbons and oils and fats are more preferred. These may be used alone singly, or may be used in combination of two or more kinds.

[0021] Examples of the hydrocarbon used as component (B) include mineral oil, liquid paraffin, paraffin, solid paraffin, light isoparaffin, light liquid isoparaffin, liquid isoparaffin, ceresin, microcrystalline wax, petrolatum, squalane, polyethylene wax, polypropylene wax, hydrogenated isopolybutene, ethylene / α-olefin co-oligomer, ethylene propylene polymer, and the like. Among these, solid paraffin and hydrocarbons are preferred in consideration of the initial efflorescence suppression ability.

[0022] Examples of the oil and fat used as component (B) include avocado oil, almond oil, linseed oil, olive oil, cacao oil, perilla oil, camellia oil, castor oil, coconut oil, sesame oil, wheat germ oil, rice germ oil, rice bran oil, sasanqua oil, safflower oil, soybean oil, evening primrose oil, camellia oil, corn oil, rapeseed oil, persic oil, palm kernel oil, coconut oil, palm oil, shea butter, cacao butter, perselin oil, castor oil, sunflower oil, jojoba oil, grape seed oil, macadamia nut oil, cottonseed oil, meadowfoam seed oil, coconut oil, vegetable oils such as peanut oil, and animal oils such as cod liver oil, turtle oil, mink oil, egg yolk oil, beef tallow, milk fat, lard, horse fat, sheep fat, hardened beef tallow, extremely hardened beef tallow, hardened castor oil, extremely hardened palm oil, and the like. Among these, vegetable oils are preferred in consideration of the initial efflorescence suppression ability.

[0023] Examples of fatty acid esters used as component (B) include alkyl stearate, alkyl palmitate, alkyl myristate, alkyl laurate, alkyl behenate, alkyl oleate, alkyl isostearate, alkyl 12-hydroxystearate, alkyl undecylenate, alkyl lanolin fatty acid, alkyl erucate, alkyl coconut oil fatty acid, alkyl stearoyloxystearate, alkyl isononanoate, alkyl dimethyloctanoate, alkyl octanoate, alkyl lactate, alkyl ethylhexanoate, alkyl neopentanoate, alkyl malate, alkyl phthalate, alkyl citrate, alkyl malonate, alkyl adipate, ethylene glycol fatty acid ester, propanediol fatty acid ester, butanediol fatty acid ester, trimethylolpropane fatty acid ester, pentaerythritol fatty acid ester, polyglycerin fatty acid ester, trehalose fatty acid ester, and pentylene glycol fatty acid ester. Among these, alkyl stearate is preferred, considering its ability to suppress initial efflorescence.

[0024] The fatty acid metal salt used as component (B) is not particularly limited, but the number of carbon atoms is preferably 8 to 22, and more preferably 12 to 18. The aliphatic group of the fatty acid metal salt may be a saturated or unsaturated fatty acid, and may be linear or branched, but saturated fatty acids and linear structures are preferred. Examples of saturated fatty acids corresponding to fatty acid metal salts include caprylic acid (C8), capric acid (C10), lauric acid (C12), myristic acid (C14), palmitic acid (C16), stearic acid (C18), arachidic acid (C20), and behenic acid (C22). Examples of unsaturated fatty acids with 12 to 22 carbon atoms include myristoleic acid (C14:1), palmitoleic acid (C16:1), oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3), and erucic acid (C22:1). Examples of fatty acid metal salts include calcium, magnesium, zinc, aluminum, barium, and lithium. These may be used individually or in combination of two or more. Among these, calcium salts, magnesium salts, and aluminum salts are preferred considering water resistance and suppression of initial efflorescence.

[0025] Examples of fatty acids other than those with 12 to 22 carbon atoms that can be used as component (B) include butyric acid (4), caproic acid (6), heptanoic acid (7), caprylic acid (8), capric acid (10), undecylenic acid (11:1), and lignoceric acid (24).

[0026] Examples of higher alcohols used as component (B) include lauryl alcohol, cetyl alcohol, cetostearyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, lanolin alcohol, hexyldecanol, myristyl alcohol, arachidodecanol, phytosterol, isostearyl alcohol, and octyldodecanol.

[0027] Examples of silicone oils used as component (B) include amino-modified silicone oil, epoxy-modified silicone oil, carboxyl-modified silicone oil, polyether-modified oil, polyglycerin-modified silicone oil, dimethylpolysiloxane, dimethyl silicone, polyether-modified silicone, methylphenyl silicone, alkyl-modified silicone, higher fatty acid-modified silicone, methyl hydrogen silicone, fluorine-modified silicone, epoxy-modified silicone, carboxyl-modified silicone, carbinol-modified silicone, amino-modified silicone, methylpolysiloxane, methylphenylpolysiloxane, silicone resin, dimethicone, methyl hydrogenpolysiloxane, methylcyclopolysiloxane, octamethyltrisiloxane, tetramethylhexasiloxane, and highly polymerized methylpolysiloxane.

[0028] Examples of waxes used as component (B) include Japanese wax, beeswax, laurel wax, lacquer wax, sugarcane wax, palm wax, montan wax, carnauba wax, candelilla wax, rice bran wax, lanolin, whale wax, reduced lanolin, liquid lanolin, hard lanolin, ceresin, and ozokerite.

[0029] Examples of steroids used as component (B) include cholesterol, dihydrocholesterol, and cholesterol fatty acid esters.

[0030] Here, component (A) gradually exhibits water-resistant properties over time. In other words, component (A) has good water-resistant properties in the medium and long term, but its initial water-resistant properties are insufficient. Therefore, when only fatty acids with 12 to 22 carbon atoms of component (A) are contained in a water-soluble emulsion, the ability to suppress efflorescence, especially in the initial stages, is insufficient.

[0031] On the other hand, component (B) contributes particularly to initial water resistance. In other words, component (B) provides good initial water resistance, but is insufficient for medium- to long-term water resistance. Therefore, if only oily components other than the fatty acid component (B) are included in a water-soluble emulsion, the sustained effect of efflorescence suppression is particularly insufficient.

[0032] In contrast, the water-soluble emulsion according to the present invention, when using components (A) and (B) in combination, exhibits waterproofing properties in concrete and mortar continuously from the initial stage to the long term, compared to when they are used individually. As a result, the efflorescence suppression ability can also be improved over a long period of time.

[0033] As can be understood from the above explanation, in the present invention, by using component (A) and component (B) in combination, the efflorescence suppression ability and waterproofing ability are synergistically and significantly improved compared to when they are used individually.

[0034] The mass content ratio of component (A) to the total of component (B) (A / (A+B)) is preferably 0.05 to 0.99, and more preferably 0.15 to 0.85.

[0035] The total amount of component (A) and component (B) in the water-soluble emulsion is, for example, 1 to 50% by mass, and more preferably 1 to 30% by mass.

[0036] The water-soluble emulsion of the present invention may be in two formulations, each containing a separate agent with component (A) and an agent with component (B). However, a single formulation, where component (A) and component (B) are emulsified with water to form a single agent, is most preferable from the viewpoint of workability. Here, the single formulation may be a ready-to-use mixing type, where component (A) and component (B) are contained in separate containers and mixed immediately before use. In the case of a single-component formulation, the total amount of component (A) and component (B) in the water-soluble emulsion of the present invention is preferably 1 to 50% by mass, and more preferably 5 to 30% by mass, from the viewpoint of a suitable concentration for use.

[0037] Furthermore, in the water-soluble emulsion of the present invention, it is preferable to include a surfactant component (C) in addition to the above-mentioned components (A) and (B). Including a surfactant component (C) results in particularly good long-term stability of the water-soluble emulsion. Here, long-term stability means that no separation is observed in the water-soluble emulsion when stored for a long period of time. Note that component (C) may be used alone or in combination of two or more types.

[0038] The surfactant component (C) is not particularly limited, but examples include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. Among these, nonionic surfactants and anionic surfactants are preferred, and anionic surfactants are more preferred from the viewpoint of improving the low-temperature stability of the water-soluble emulsion. Low-temperature stability here means that the water-soluble emulsion does not solidify or separate when stored for a long period of time in a low-temperature environment (-5°C).

[0039] Examples of nonionic surfactants used as component (C) include fatty acid alkanolamides (e.g., coconut oil fatty acid mono or diethanolamide, lauric acid mono or diethanolamide, palmitic acid mono or diethanolamide, myristic acid mono or diethanolamide, stearic acid mono or diethanolamide, oleic acid mono or diethanolamide, palm oil fatty acid mono or diethanolamide, etc., especially fatty acid alkanolamides with 8 to 18 carbon atoms), polyoxyalkylene glycols (e.g., polyethylene glycol, polypropylene glycol, polypropylene glycol ethylene oxide adduct, etc.), polyoxyethylene alkylamines (e.g., 2 to 20 molar adducts of aliphatic primary amines (linear or branched with 12 to 18 carbon atoms), sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyalkylene alkyl ethers, polyoxy Examples include ethylene alkylphenyl ethers, polyoxyethylene styrene-phenyl ethers, polyoxyethylene (hydrogenated) castor oil, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil fatty acid esters, castor oil fatty acid esters, hydrogenated castor oil fatty acid esters, ethylene glycol fatty acid esters, sucrose fatty acid esters, glycerin fatty acid esters, diglycerin fatty acid esters, polyglycerin fatty acid esters, organic acid monoglycerides, polyethylene glycol fatty acid monoethanolamide, propylene glycol fatty acid esters, polyoxyethylene lanolin alcohol ethers, polyoxyethylene alkyl ethers, lauric acid alkanolamide, polyoxyethylene glycerin fatty acid esters, polyoxyethylene hydrogenated castor oil pyroglutamic acid fatty acid diesters, pyroglutamic acid fatty acid glyceryl, polyoxyethylene glyceryl pyroglutamic acid fatty acid diesters, and polyether-modified silicones. Among these, polyoxyethylene sorbitan fatty acid esters and polyoxyalkylene alkyl ethers are preferred.

[0040] Examples of anionic surfactants used as component (C) include sulfonate type, phosphate ester type, sulfate ester type, and carboxylate type. Examples of sulfonate type include alkanesulfonate, α-olefin sulfonate, α-sulfo fatty acid methyl ester salt, acyl isethionate, alkyl glycidyl ether sulfonate, alkyl sulfosuccinate, polyoxyalkylene alkyl sulfosuccinate, alkylbenzene sulfonate, alkyl naphthalene sulfonate, N-acyl methyl taurate, formalin condensate sulfonate, paraffin sulfonate, alkylamide sulfonate, alkenylamide sulfonate, alkyl glyceryl ether sulfonate, and alkylaryl ether sulfonate. Examples of phosphate ester type include alkyl phosphate, alkylaryl ether phosphate, fatty acid amide ether phosphate, and polyoxyalkylene alkyl ether phosphate. Examples of sulfate ester salts include alkyl sulfates, alkenyl sulfates, alkyl ether sulfates, alkenyl ether sulfates, polyoxyalkylene alkyl ether sulfates, alkylaryl ether sulfates, fatty acid alkanolamide sulfates, fatty acid monoglyceride sulfates, polyoxyalkylene aliphatic amide ether sulfates, alkylglyceryl ether sulfates, and sulfated fatty acid alkyl esters. Examples of carboxylate salts include alkyl ether carboxylates, alkylene alkyl ether carboxylates, fatty acid amide ether carboxylates, acyl lactates, N-acyl glutamates, N-acyl alanines, N-acyl sarcosines, N-acyl-ω-amino acids, alkyl sulfoacetates, alkenyl sulfoacetates, alkenyl succinates, rosinates, and naphthenates. Among these, α-olefin sulfonates and polyoxyalkylene alkyl ether phosphates are preferred.

[0041] Examples of cationic surfactants used as component (C) include quaternary ammonium salts such as monoalkyltrimethylammonium salt, dialkyldimethylammonium salt, N,N-dialkylyloxyethyl-N-methyl,N-hydroxyethylammonium salt, and stearyldimethylbenzylammonium salt, as well as alkylpyridinium salts and alkylamine salts. Among these, alkylamine salts are preferred.

[0042] Examples of amphoteric surfactants used as component (C) include alkyl betaine, fatty acid amidopropyl betaine, lauryl hydroxysulfobetaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lecithin, hydrogenated lecithin, alkyloxyhydroxypropylarginine hydrochloride, lauryl hydroxysultaine, sodium lauriminodipropionate, sodium undecylhydroxyethylimidazolinium betaine, sodium laurylaminodiacetate, lauryldimethylaminoacetate betaine, N-[3-alkyloxy-2-hydroxypropyl]-L-arginine hydrochloride, alkylhydroxysulfobetaine, alkyldimethylamine oxide, sodium alkylaminodipropionate, dihydroxyalkylmethylglycine, and sodium lauryldiaminoethylglycine. Among these, alkyldimethylamine oxide is preferred.

[0043] Component (C) is added, in particular, to improve the long-term stability when components (A) and (B) are combined into a single dosage form. From the viewpoint of improving long-term stability, the content of component (C) in the water-soluble emulsion is preferably 1 to 50% by mass, and more preferably 10 to 30% by mass, relative to the total amount of components (A) and (B).

[0044] In the water-soluble emulsion of the present invention, it is preferable to further contain a chelating agent which is component (D).

[0045] When component (A), a fatty acid with 12 to 22 carbon atoms, reacts with calcium in concrete (or mortar), metal soaps (salts of the fatty acid (A) and calcium) may precipitate. As a result, the amount of component (A) in the concrete decreases, which may reduce its efflorescence-inhibiting ability. This point should be considered in particular when using well water containing a high amount of calcium as the mixing water for concrete, etc.

[0046] On the other hand, chelating agents have the function of adsorbing calcium. Therefore, in this invention, in such cases, it is considered to include component (D) in the water-soluble emulsion. Since the calcium in the concrete is adsorbed by the chelating agent component (D), it is possible to suppress the reaction of component (A) with the calcium in the concrete. Consequently, it is possible to prevent a decrease in efflorescence suppression ability. Furthermore, by using component (D), the long-term stability of the water-soluble emulsion can be improved.

[0047] The chelating agent for component (D) is not particularly limited, but examples include aminocarboxylic acid-based chelating agents and phosphonic acid-based chelating agents, and among these, aminocarboxylic acid-based chelating agents are preferred. Examples of aminocarboxylic acid-based chelating agents include tetrasodium ethylenediaminetetraacetate, disodium ethylenediaminetetraacetate, trisodium nitrilotriacetate, pentasodium diethylenetriaminopentaacetate, and trisodium hydroxyethylethylenediaminetriacetate.

[0048] The content of component (D) in the water-soluble emulsion is preferably 0.01 to 30% by mass, and more preferably 0.1 to 20% by mass, relative to the total amount of components (A) and (B). In particular, it is suitable for suppressing efflorescence when the calcium concentration of the kneading water is 100 ppm or higher.

[0049] Other components besides components (A) to (D) may be added to the water-soluble emulsion of the present invention, as long as they do not impair the effects of the present invention. Examples of such other components include air-entraining agents (air-entraining components), defoaming agents (defoaming components, antifoaming components), water-reducing agents (standard type, retarding type, accelerating type), high-performance AE water-reducing agents (standard type, retarding type), high-performance water-reducing agents, hardening accelerators, fluidizing agents (standard type, retarding type), shrinkage reducing agents, AE water-reducing agents, setting retarders, accelerators, rapid setting agents, foaming agents, rust inhibitors, cold-resistance accelerators, adhesive mortar stabilizers, blackening inhibitors, thickeners, separation reducing agents, flocculants, self-leveling agents, blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, gypsum, and expanding agents.

[0050] The water-soluble emulsion of the present invention is used in concrete or mortar. The type of concrete or mortar is not particularly limited and may be one used in pouring methods, etc. However, it is preferably used in immediate demolding concrete, which uses ultra-hard concrete obtained by mixing cement and aggregate with only the water necessary to hydrate the cement added.

[0051] The concrete and mortar to which the water-soluble emulsion of the present invention is added contain water, cement, and aggregate in addition to the water-soluble emulsion. The aggregate contained in the mortar is fine aggregate, and examples of fine aggregate include river sand, mountain sand, sea sand, and crushed sand. The aggregate contained in the concrete includes coarse aggregate in addition to fine aggregate. Examples of coarse aggregate include river gravel, crushed stone, and lightweight aggregate. Note that the examples described later refer to mortar.

[0052] Examples of cements include ordinary Portland cement, rapid-hardening Portland cement, ultra-rapid-hardening Portland cement, sulfate-resistant Portland cement, moderate-heat Portland cement, low-heat Portland cement, blast furnace cement, fly ash cement, silica fume cement, and alumina cement.

[0053] In addition to fine aggregate, coarse aggregate is also used in concrete. Examples of fine aggregate include river sand, land sand, sea sand, crushed sand, and blast furnace slag fine aggregate, while examples of coarse aggregate include gravel, crushed stone, and blast furnace slag coarse aggregate.

[0054] In addition, concrete and mortar require the water-soluble emulsion of the present invention as an essential component, and other admixtures that have been conventionally used to improve the properties and performance of concrete and mortar, such as AE water-reducing agents, high-performance AE water-reducing agents, plasticizers, setting retarders, setting accelerators, defoamers, thickeners, waterproofing agents, dispersants, and expansive agents, can be used in combination as needed. Furthermore, inorganic admixtures such as blast furnace slag powder, fly ash, silica fume, and limestone powder can be added.

[0055] In manufacturing an immediate demolding concrete product using the water-soluble emulsion of the present invention, for example, cement and aggregate are mixed, and water and the water-soluble emulsion are added and mixed to prepare concrete. Next, the concrete is placed in a mold, compacted by applying external vibrations and pressure molding, immediately demolded after molding, and cured to obtain an immediate demolding concrete product.

[0056] The amount of the water-soluble emulsion of the present invention added is not particularly limited, but from the standpoint of obtaining the desired effect, 0.001 to 5.0% by mass relative to the cement is preferred, 0.005 to 3.0% by mass is more preferred, and 0.01 to 2.0% is even more preferred. Furthermore, the water-soluble emulsion of the present invention may be used after being diluted in mixing water or the like beforehand, or may be added mixed with other admixtures as needed. [Examples]

[0057] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0058] 1. Preparation of water-soluble emulsions The water-soluble emulsion was obtained by placing the various components shown in Table 1 into a beaker, raising the temperature to 80-90°C, adding the amount of water (80-90°C) listed in Table 1, and mixing and stirring for 1 hour. 2. Sample preparation and evaluation Mortar was prepared using 450g of ordinary Portland cement (manufactured by Taiheiyo Cement), 1,350g of standard sand (manufactured by the Cement Association), and 157.5g of tap water (containing water-soluble emulsion) (water / cement ratio = 35%, sand / cement = 3), in accordance with JIS R 5201 using a Shinagawa-type multi-purpose mixer (manufactured by San-ei Seisakusho). This mortar was filled into the formwork using a table vibrator and steam-cured at 70°C for 3 hours.

[0059] [Efflorescence suppression ability] Mortar samples were left outdoors, and the state of efflorescence was visually observed at initial (1 month), medium (3 months), and long (6 months) stages. The state of efflorescence was evaluated on the following five-point scale. 5: Very good 4: Good 3: Fairly good 2: Slightly poor 1: Defective

[0060] [Waterproofness (water absorption rate)] Mortar samples were left outdoors, and their waterproofing performance was evaluated over initial (1 month), medium (3 months), and long-term (6 months) periods. The test involved submerging the entire mortar sample in water for 1 minute, and calculating the water absorption rate using the following formula. Water absorption rate (%) = Weight of mortar after water absorption [g] / Weight of mortar before water absorption [g] × 100

[0061] Regarding waterproofness, we evaluated it using the water absorption rate as an indicator, on a five-point scale as follows. 5: Less than 1% 4: 1% or more but less than 3% 3: 3% or more but less than 5% 2: 5% or more but less than 10% 1:10% or more

[0062] [Temporal stability of water-soluble emulsions] The long-term stability of the water-soluble emulsion (one month after manufacturing) was observed visually, and the degree of separation between the water layer and the oil layer was used to determine the stability in the following four stages. 4: Separation less than 5% 3: Separation less than 10% 2: Separation less than 20% 1: Separation 30% or more

[0063] The evaluation results are shown in Table 1. For the five-level evaluation of efflorescence suppression and waterproofing, a score of "2" or lower indicates that the problem was not resolved, "3" indicates that the problem was resolved, "4" indicates that the problem was significantly resolved, and "5" indicates that the problem was even more significantly resolved. The amounts of each component in Tables 1 and 2 are shown in parts by mass.

[0064] [Table 1]

[0065] Table 1 shows that Examples 1-17, which combine component (A), a fatty acid with 12-22 carbon atoms, with component (B), a hydrophobic component other than a fatty acid, all exhibit good efflorescence suppression ability ("3" or higher) in the initial, medium, and long term. In other words, it can be seen that efflorescence can be suppressed over a long period of time.

[0066] Furthermore, in Examples 1 to 17, it was found that the waterproofing performance was good ("3" or higher) in the initial, medium, and long term. As described above, it was confirmed that the problem can be solved in Examples 1 to 17. In addition, Examples 1 to 17 also showed good stability over time.

[0067] Regarding component (A), a comparison of Examples 1-5 shows that a higher number of carbon atoms results in higher efflorescence suppression ability. Furthermore, comparing Example 2 (C18 saturated fatty acid: stearic acid) and Example 3 (C18 unsaturated fatty acid: oleic acid), the inclusion of saturated fatty acids shows an improved effect in efflorescence suppression ability.

[0068] Regarding component (B), a comparison of Examples 2, 7-10 shows that incorporating solid paraffin (Example 2), rapeseed oil (Example 7), or mineral oil (Example 8) further improves efflorescence suppression and waterproofing.

[0069] Regarding the component ratio (A / (A+B)), from Examples 12 (0.10), 13 (0.17), 14 (0.47), 15 (0.83), and 16 (0.90), it can be seen that when the component ratio (A / (A+B)) is within the range of 0.05 to 0.99, the efflorescence suppression ability and waterproofing ability are good.

[0070] Furthermore, a comparison between Example 2 and Example 11 reveals that the presence of a chelating agent as component (D) improves the long-term stability of the water-soluble emulsion. Additionally, from Examples 2 and 17, it can be seen that the long-term stability of the water-soluble emulsion improves regardless of the type of chelating agent included as component (D).

[0071] In contrast, in Comparative Examples 1-3, which contain only one of component (A) or component (B), it is found that it is difficult to continuously maintain efflorescence suppression and waterproofing ability from the initial stage to the long term. Specifically, in Comparative Examples 1-3, the efflorescence suppression ability and waterproofing ability each become "2" at the initial, medium, and long term stages.

[0072] As can be understood from the above explanation, Examples 1 to 17, which incorporated both component (A) and component (B), not only showed a synergistic improvement in efflorescence suppression ability compared to Comparative Examples 1 to 3, which incorporated either component (A) or component (B) alone, but also demonstrated good waterproofing properties.

[0073] Next, we evaluated the low-temperature stability of the water-soluble emulsion.

[0074] [Low temperature stability] The water-soluble emulsions of Examples 1 to 10 were evaluated in the following three stages after being stored at -5°C for 1 day, 1 month, and 3 months. ◎: No change in state ○: Fluid but thickened ×: Solidification or separation

[0075] The evaluation results are shown in Table 2.

[0076] [Table 2]

[0077] A comparison of Examples 1-10 shows that incorporating at least one anionic surfactant into component (C) improves long-term stability during storage at low temperatures (-5°C). Examples 7 and 10, which contain both sodium tetradecenesulfonate and potassium polyoxyethylene alkyl ether phosphate, show particularly good results.

Claims

1. A water-soluble emulsion used in concrete or mortar, The following ingredients: (A) Fatty acids with 12 to 22 carbon atoms (B) At least one hydrophobic component selected from mineral oil, solid paraffin, liquid paraffin, oils and fats, linear saturated fatty acid metal salts having 12 to 18 carbon atoms, lauryl alcohol, cetyl alcohol, cetostearyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, and arachidyl alcohol. (C) Surfactants (excluding soap) including, Water-soluble emulsion.

2. The water-soluble emulsion according to claim 1, wherein the mass content ratio of component (A) to the total of component (B) is (A) / (A+B) = 0.05 to 0.

99.

3. The water-soluble emulsion according to claim 1 or 2, characterized in that the component (A) is a saturated fatty acid having 14 to 20 carbon atoms.

4. The water-soluble emulsion according to any one of claims 1 to 3, characterized in that the saturated fatty acid metal salt of component (B) is calcium stearate.

5. A water-soluble emulsion according to any one of claims 1 to 4, used for immediately demolded concrete.

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