Concrete mold release agent

Abstract

To provide a concrete mold release agent that is durable for repetitive use.SOLUTION: The concrete mold release agent contains a wax derived from plants or animals that is solid at room temperature and a dispersing medium for dispersing the wax or a solvent for dissolving the wax.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a concrete release agent.

Background Art

[0002] Conventionally, when obtaining a concrete molded body, uncured concrete (also referred to as fresh concrete) is filled into a mold in which the target concrete molded body can be obtained, and in this state, the concrete is dried and cured until it reaches an appropriate strength, and then the mold is removed.

[0003] This mold may be discarded after being used once, but it is generally reused multiple times. In particular, when mass-producing standardized molded bodies of the same shape, it is common to be repeatedly reused multiple times.

[0004] As molds for concrete molding, wood, plastic, metal, etc. are used. In particular, as reusable molds, those using metal materials such as iron, aluminum, stainless steel, and copper are widely used due to their usefulness in terms of strength, durability, cost, etc.

[0005] When filling uncured concrete into these molds, in order to facilitate the demolding of the hardened concrete from the molding mold, or to prevent the adhesion of the hardened concrete, or to facilitate the removal or washing of the adhered concrete, etc., a release agent mainly composed of mineral oil or mineral oil (hereinafter referred to as "mineral oil-based release agent") is applied to the surface of the molding surface of the mold.

[0006] Mineral oil-based release agents have been widely adopted conventionally because they are preferable in terms of cost and ease of application at the manufacturing site of concrete molded bodies. However, since mineral oil-based release agents have poor durability of the release effect, in fact, they usually have only the durability for about one concrete molding. For this reason, every time concrete molding (also referred to as casting) is performed, a mineral oil-based release agent is applied to the formwork surface.

[0007] Needless to say, applying a mineral oil-based release agent every time concrete molding is performed is disadvantageous in terms of work efficiency and cost.

[0008] Furthermore, in the process of curing concrete, steam curing (about 50 to 70 °C) is generally performed. During such steam curing, the mineral oil-based release agent applied to the molding formwork is discharged together with moisture (liquefaction of steam), which has an adverse impact on the water quality environment, so reduction of environmental load is required.

[0009] In addition, the mineral oil-based release agent may contaminate the surface of the concrete molded body and cause coloring or stains, and it has been hard to say that it is always satisfactory depending on the application.

[0010] Furthermore, in recent years, in order to improve workability and shorten the construction period at the construction site, it has become widely adopted to transport precast concrete members molded in the factory in advance to the construction site and join them together. This construction method is generally called the precast method.

[0011] In such a precast method, it is particularly important that each concrete molded body has no chips or molding defects and has the dimensions as designed. And in recent years, the requirement for the appearance of the surface of the concrete molded body (for example, no coloring or stains) has also been increasing.

[0012] Patent Document 1 relates to a concrete release agent with excellent concrete release properties, and discloses a concrete release agent composed of 95 to 99.9% by weight of liquid polybutene with an average molecular weight of 150 to 400 and 0.1 to 5% by weight of liquid polybutene with an average molecular weight of 700 to 2000.

[0013] Although the above-mentioned document discloses a concrete release agent with excellent concrete release properties, there is no description regarding the durability of repeated use.

Prior Art Documents

Patent Documents

[0014]

Patent Document 1

Summary of the Invention

[0015] The present inventors have now found that by using wax that is solid at room temperature and derived from plants or animals as a concrete release agent, the durability of repeated use can be improved. The present invention is based on such findings.

[0016] One object of the present invention is to provide a new technical means for improving the durability of repeated use in a concrete release agent applied to the surface of a formwork for concrete molding.

[0017] And the present invention includes the following inventions. (1) A concrete release agent comprising wax that is solid at room temperature and derived from plants or animals, and a dispersion medium for dispersing the wax or a solvent for dissolving the wax. (2) The concrete release agent according to (1), wherein the plant or animal is at least one selected from the group consisting of plants or animals of the Poaceae, Urticaceae, Arecaceae, Cyperaceae, Apidae, and Scarabaeidae families. (3) The concrete release agent according to (1) or (2), wherein the wax that is solid at normal temperature and derived from plants or animals is at least one selected from the group consisting of rice bran wax, wood wax, Chinese wood wax, carnauba wax, candelilla wax, beeswax, and spermaceti wax. (4) The concrete release agent according to any one of (1) to (3), which is a colloidal dispersion type concrete release agent containing wax that is solid at normal temperature and derived from plants or animals, water, and an emulsifier. (5) The concrete release agent according to (4), wherein the colloidal dispersion type concrete release agent is an O / W emulsion type or a solid wax in water dispersion type concrete release agent. (6) The concrete release agent according to any one of (1) to (5), which is for application to a metal concrete forming frame. (7) The concrete release agent according to any one of (1) to (6), having a viscosity of 5 to 40 mPa·s. (8) The concrete release agent according to any one of (1) to (7), which forms a solid coating film on the surface of the frame by drying after being applied to a metal concrete forming frame. (9) A method of applying the concrete release agent according to any one of (1) to (8) to the surface of a concrete forming frame, comprising: spraying the concrete release agent, or applying the concrete release agent using a sponge that is difficult to soak with the concrete release agent. (10) A concrete forming frame having a release property cured coating film on the surface, which contains the dried product of the concrete release agent according to any one of (1) to (9).

[0018] ​According to the present invention, there is provided a concrete release agent with improved durability for repeated use. Further, the present invention is advantageous in reducing the environmental load (e.g., adverse effects on the water quality environment) in the concrete release agent. Also, the present invention is advantageous in improving the appearance of the surface of the concrete molded body (e.g., suppressing coloring and the occurrence of stains) in the concrete release agent. Specific description of the invention

[0019] The concrete release agent of the present invention is a release agent applied to the surface of a concrete molding form, and is characterized in that it comprises a wax that is solid at normal temperature and derived from a plant or an animal, and a dispersion medium for dispersing the wax or a solvent for dissolving the wax. As shown in Test Examples 1, 2, 4, and 5 described later, it is an unexpected fact that such a concrete release agent can significantly improve the durability for repeated use.

[0020] <Wax that is solid at normal temperature and derived from a plant or an animal> The wax that is solid at normal temperature and derived from a plant or an animal used in the present invention is not particularly limited and can be appropriately selected according to the purpose. In the present invention, normal temperature refers to 15 to 25°C. Here, the solid may include semi-solids. Further, the wax may include waxes.

[0021] The plant in the wax that is solid at normal temperature and derived from a plant is not particularly limited, and examples include Gramineae plants, Anacardiaceae plants, Palmae plants, and Euphorbiaceae plants. Preferably, they are rice, sumac, lacquer tree, carnauba palm, coconut palm, and candelilla grass, and more preferably, rice and candelilla grass.

[0022] The animal in the wax that is solid at normal temperature and derived from an animal is not particularly limited, and examples include insects of the family Apidae and insects of the family Coccidae. Preferably, they are honeybees and scale insects, and more preferably, honeybees.

[0023] According to a preferred embodiment of the present invention, examples of the solid wax at room temperature derived from plants or animals used in the present invention include rice bran wax, wood wax, Chinese wood wax, carnauba wax, candelilla wax, beeswax, and spermaceti wax (also called snow wax), etc. More preferably, they are rice bran wax, candelilla wax, and beeswax. These may be used alone or in combination of two or more.

[0024] Plant or animal-derived waxes that are solid at room temperature usually mainly consist of fatty acid esters formed by the combination of fatty acids and monovalent or divalent fatty alcohols (higher alcohols). Therefore, according to one embodiment of the present invention, the concrete release agent of the present invention comprises a fatty acid ester of a fatty acid and a higher alcohol. As the fatty acid ester of the fatty acid and the higher alcohol, it is preferably a monoester of the fatty acid and the higher alcohol. From the viewpoint of forming a wax that is solid at room temperature, examples of the fatty acid include fatty acids having 14 or more carbon atoms or fatty acids having 16 or more carbon atoms, preferably fatty acids having 14 to 40 carbon atoms or fatty acids having 16 to 40 carbon atoms, more preferably fatty acids having 14 to 24 carbon atoms or fatty acids having 20 to 30 carbon atoms. The fatty acid includes saturated or unsaturated fatty acids, preferably saturated fatty acids. Specifically, examples of the fatty acid include myristic acid (C14), palmitic acid (C16), heneicosanoic acid (C21), behenic acid (C22), lignoceric acid (C24), etc. Also, from the viewpoint of forming a wax that is solid at room temperature, examples of the higher alcohol include higher alcohols having 16 or more carbon atoms, preferably higher alcohols having 16 to 40 carbon atoms, more preferably higher alcohols having 20 to 36 carbon atoms. The higher alcohol includes saturated or unsaturated aliphatic alcohols, preferably saturated aliphatic alcohols. Specifically, examples of the higher alcohol include 1-tetracosanol (C24), 1-hexacosanol (C26), 1-octacosanol (C28), triacontanol (C30), 1-dotriacontanol (C32), 1-tetratriacontanol (C34), hexatriacontanol (C36), etc. Also, the total number of carbon atoms of the ester of the fatty acid and the higher alcohol is, for example, 30 or more, preferably 30 to 60, more preferably 38 to 58, and even more preferably 40 to 56. The fatty acid ester is preferably CH3(CH2) 22 COO(CH2) 29 CH3, CH3(CH2) 14 COOCH2(CH2) 28 CH3.

[0025] According to one embodiment of the present invention, the content of the solid wax derived from plants or animals at normal temperature is not particularly limited, but for example, it is 10 to 80% by mass, preferably 20 to 60% by mass, based on the total amount of the concrete release agent.

[0026] <Rice bran wax> According to a preferred embodiment of the present invention, the concrete release agent of the present invention comprises rice bran wax. The above rice bran wax is produced mainly from rice bran and can be produced by various methods without particular limitation. Examples of the production method of rice bran wax include a method of producing crude wax obtained in the process of refining rice bran oil extracted from rice bran by deoiling and refining treatment. Further, the above rice bran wax may be modified. Such modification includes increasing the polarity of rice bran wax by a hydrolysis reaction. Commercially available products may be used for the above rice bran wax, for example, XECO-0002B, ECOSOLE-1500 manufactured by Nippon Seiro Co., Ltd., NC-1720, NC-1740F manufactured by Serica Noda Co., Ltd., highly deodorized rice bran wax true sphere powder, and the like.

[0027] The above rice bran wax is mainly composed of an ester component, specifically, a fatty acid ester such as an ester of a fatty acid and a higher alcohol, preferably a monoester. Examples of the above fatty acid include palmitic acid (C16), behenic acid (C22), lignoceric acid (C24), and the like. Examples of the above higher alcohol include 1-tetracosanol (C24), 1-hexacosanol (C26), 1-octacosanol (C28), triacontanol (C30), 1-dotriacontanol (C32), 1-tetratriacontanol (C34), and the like. Preferably, the main component of the above rice bran wax is CH3(CH2) 22 COO(CH2) 29 CH3.

[0028] <Beeswax> According to another preferred embodiment of the present invention, the concrete release agent of the present invention comprises beeswax. The above beeswax is the wax secreted by worker bees of honeybees and is used as a nest construction material. Since the raw wax contains pollen, propolis, etc., as beeswax, refined beeswax obtained by performing purification such as a decolorization and deodorization process is preferable. The above beeswax (especially refined beeswax) has a melting point of about 55 to 67 °C. Among the above beeswax, the acid value of beeswax obtained from European honeybees is, for example, as high as 17 to 24 (hereinafter also referred to as high-acid beeswax), and the acid value of beeswax obtained from Asian honeybees is, for example, as low as 5 to 9 (hereinafter also referred to as low-acid beeswax). As the beeswax of the present invention, either high-acid beeswax or low-acid beeswax may be used. As the above beeswax, commercially available products may be used. For example, deodorized and refined honey wax (high acid), deodorized and refined honey wax (low acid), NC-1450, etc. manufactured by Serica Noda Co., Ltd., and Gardner No. 5 manufactured by Miki Chemical Industry Co., Ltd. etc. may be mentioned.

[0029] The above beeswax has an ester component as the main component. Specifically, it is a fatty acid ester such as an ester of a fatty acid and a higher alcohol, and preferably a monoester. Examples of the above fatty acid include myristic acid (C14), palmitic acid (C16), heneicosanoic acid (C21), etc. Examples of the above higher alcohol include 1-tetracosanol (C24), 1-hexacosanol (C26), 1-octacosanol (C28), triacontanol (C30), 1-dotriacontanol (C32), 1-tetratriacontanol (C34), hexatriacontanol (C36), etc. Preferably, the main component of the above ester is myristyl palmitate CH3(CH2) 14 COOCH2(CH2) 28 CH3. Beeswax further contains cerotic acid CH3(CH2) 24 COOH.

[0030] <Dispersion medium for dispersing wax that is solid at room temperature and derived from plants or animals> According to one embodiment of the present invention, the dispersion medium used in the present invention is not particularly limited as long as it can disperse a wax that is solid at room temperature and derived from plants or animals, and can be appropriately selected according to the purpose. The dispersion medium of the present invention is not particularly limited, and examples include dispersion media in which a wax that is solid at room temperature and derived from plants or animals is insoluble or hardly soluble, and solvents corresponding to "difficult to dissolve", "extremely difficult to dissolve", and "hardly soluble" described in the 17th revised Japanese Pharmacopoeia for the above wax. Examples of the dispersion medium in the present invention include dispersion media in which the solubility (wax derived from plants or animals at room temperature / dispersion medium) of a wax that is solid at room temperature and derived from plants or animals is 10 mg / mL or less at 20 ± 5°C. The dispersion medium of the present invention depends on the type of wax that is solid at room temperature and derived from plants or animals, but preferably includes water, ethanol, methanol, or a combination thereof, and more preferably water, ethanol, or a combination thereof.

[0031] <Solvent for dissolving wax that is solid at room temperature and derived from plants or animals> According to one embodiment of the present invention, the solvent (i.e., good solvent) used in the present invention is not particularly limited as long as it can dissolve a wax that is solid at room temperature and derived from plants or animals, and can be appropriately selected according to the purpose. The solvent of the present invention is not particularly limited, but it is necessary that the solubility of a wax that is solid at room temperature and derived from plants or animals is greater than that of the above dispersion medium. Examples of the solvent in the present invention depend on the type of the above wax, and include, for example, solvents in which the solubility (the above wax / solvent) of the above wax is greater than 10 mg / mL at 20 ± 5°C, preferably solvents in which the solubility of the above wax is 20 mg / mL or more, and more preferably solvents in which the solubility of the above wax is 30 mg / mL or more. Such good solvents include organic solvents such as toluene, benzene, turpentine oil, and naphtha, and preferably toluene, benzene, etc.

[0032] According to a preferred embodiment of the present invention, the concrete release agent of the present invention contains water and further an emulsifier in addition to the above-mentioned wax which is solid at room temperature and derived from plants or animals. The concrete release agent of the present invention may further contain an emulsion stabilizer in addition to the above-mentioned wax which is solid at room temperature and derived from plants or animals, water, and an emulsifier.

[0033] <Water> The concrete release agent according to the present invention can contain water. When the concrete release agent of the present invention contains water, the water content is, for example, 1.0 to 99.0% by mass, preferably 10.0 to 95.0% by mass, more preferably 20.0 to 90.0% by mass, based on the total amount of the concrete release agent at the stage of applying the concrete release agent. The water is not particularly limited, and examples thereof include ion-exchanged water, distilled water, and alkaline electrolyzed water such as strongly alkaline electrolyzed water. From the viewpoint of improving the dispersibility of the wax by the ions contained in the strongly alkaline electrolyzed water, strongly alkaline electrolyzed water is preferably used. In particular, when beeswax is used as the wax, it is preferable to use strongly alkaline electrolyzed water as the water from the viewpoint of improving the dispersibility of beeswax (particularly, improving the dispersibility of beeswax during preliminary emulsification). The pH of the above-mentioned strongly alkaline electrolyzed water is 9.5 or more, preferably 11 to 14. The method for producing strongly alkaline electrolyzed water is not particularly limited. For example, it is a method of electrolyzing an aqueous solution in which sodium chloride is mixed with water to obtain strongly alkaline electrolyzed water. More precisely, it is a method of electrolyzing an aqueous solution in which sodium chloride is mixed with water and obtaining the strongly alkaline electrolyzed water generated on the cathode side through a diaphragm from the aqueous solution.

[0034] <Emulsifier> Examples of the emulsifier include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and combinations thereof. From the viewpoints of adhesion to metals and mold release properties from concrete, nonionic surfactants and anionic surfactants are preferably used. Examples of the nonionic surfactant include sorbitan fatty acid esters, fatty alcohol ethoxylates (FAE), polyoxyethylene fatty acid esters, polyoxyethylene hydroxy fatty acid esters, poloxamers (polyoxyethylene-polyoxypropylene block copolymers), polyoxyethylene castor oil, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene hydrogenated castor oil, polyethylene glycol, and combinations thereof. Sorbitan fatty acid esters, fatty alcohol ethoxylates, polyethylene glycol, and combinations thereof are preferably used. Examples of the anionic surfactant include sulfonate esters, sulfate esters, phosphate esters, and combinations thereof. Examples of the fatty acid component of the sorbitan fatty acid ester include saturated or unsaturated fatty acids having 8 to 22 carbon atoms, preferably saturated or unsaturated fatty acids having 12 to 20 carbon atoms, more preferably saturated or unsaturated fatty acids having 16 to 20 carbon atoms. Specific examples of the sorbitan fatty acid ester are preferably sorbitan oleate and sorbitan palmitate. Sorbitan oleate is preferably sorbitan monooleate, sorbitan sesquioleate, or sorbitan trioleate, more preferably sorbitan monooleate or sorbitan sesquioleate. Sorbitan palmitate is preferably sorbitan monopalmitate. Commercially available sorbitan fatty acid esters may be used. Examples of commercially available products of sorbitan monooleate include Sorbon S-80 (biomass content 38%) (manufactured by Toho Chemical Industry Co., Ltd.), Ionet S-80 (manufactured by Sanyo Chemical Industries, Ltd.), etc. Examples of commercially available products of sorbitan sesquioleate include Nonion OP-83RAT (manufactured by NOF Corporation), etc. Examples of commercially available products of sorbitan trioleate include Nonion OP-85R (manufactured by NOF Corporation), etc.The above fatty alcohol ethoxylate is not particularly limited. For example, it is an ethoxylated C having ethoxylation of 1 to 40. 12 -C 22 Examples of the fatty alcohol include fatty alcohol ethoxylates. As the fatty alcohol ethoxylate, commercially available products may be used. For example, Genapol (Genapol) manufactured by Clariant Japan Co., Ltd., Adeka Tol manufactured by ADEKA Corporation, etc. may be mentioned. Preferably, Genapol LA 030 SG Vita (biomass content 100%) (Clariant Japan Co., Ltd.), Adeka Tol LA775 (ADEKA Corporation), etc. are used. Further, the biomass content of the above emulsifier is not particularly limited, but from the viewpoint of reducing environmental load, it may be 10% or more, preferably 25% or more, and more preferably 50% or more.

[0035] The content of the emulsifier is not particularly limited, but for example, it may be 1 to 10% by mass based on the whole concrete release agent.

[0036] <Emulsion stabilizer> Examples of the above emulsion stabilizer include cellulose nanofibers and polyvinyl alcohol. From the viewpoint of strengthening the solid coating film, cellulose nanofibers are preferably used. Cellulose nanofibers are nanocellulose extracted from cellulose raw materials (for example, wood). Examples of the extraction method of cellulose nanofibers include mechanical treatment (for example, grinding treatment by a bead mill) and chemical treatment (for example, TEMPO (2,2,6,6-tetramethyl-1-piperidine-oxyradical) catalytic oxidation treatment, carboxymethylation treatment, cationization treatment, etc.). As the cellulose nanofibers, commercially available products may be used. For example, "Celenia" (registered trademark) manufactured by Nippon Paper Industries Co., Ltd., "Reocrista" (registered trademark) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., "ELLEX" manufactured by Oji Paper Co., Ltd., "Auro·Visko" (registered trademark) manufactured by Oji Holdings Corporation, etc. may be mentioned.

[0037] The content of the emulsion stabilizer is not particularly limited, and for example, it may be 0.05 to 5% by mass based on the whole concrete release agent.

[0038] <Colloidal dispersion type concrete release agent> The concrete release agent of the present invention is preferably in the form of a colloidal dispersion containing a wax that is solid at room temperature and derived from plants or animals and water. The concrete release agent in the form of such a colloidal dispersion is also referred to as a colloidal dispersion type concrete release agent. The above colloidal dispersion type concrete release agent is preferably in the form of an O / W emulsion (oil-in-water emulsion) or a solid wax dispersion in water (which may also be referred to as a solid wax dispersion in water or a water dispersion of solid wax). The concrete release agents in such forms are also referred to as O / W emulsion type or solid wax dispersion in water type concrete release agents, respectively. Here, specific examples of the solid wax dispersion in water include a wax dispersion in which the wax is solid (including semi-solid) and dispersed in water, and preferably a fine wax dispersion in which the wax is solid (including semi-solid) and finely dispersed in water. According to a preferred embodiment of the present invention, the concrete release agent of the present invention is a colloidal dispersion type (preferably O / W emulsion type or solid wax dispersion in water type) concrete release agent containing a wax that is solid at room temperature and derived from plants or animals (preferably rice bran wax or beeswax), an emulsifier, and water. Here, by forming the concrete release agent of the present invention in the form of a colloidal dispersion (preferably an O / W emulsion or a solid wax dispersion in water) containing a wax that is solid at room temperature and derived from plants or animals, the concrete release agent can be applied to the surface of the formwork for concrete molding, and further, by drying, a solid coating film (preferably a release solid coating film) can be formed on the surface, which is advantageous. The mixing ratios of the wax that is solid at room temperature and derived from plants or animals, the emulsifier, and water for forming the colloidal dispersion (preferably an O / W emulsion or a solid wax dispersion in water) can be appropriately set by those skilled in the art based on common general knowledge, taking into account the volatilization of water after the application of the concrete release agent, the adhesion and retention of the concrete release agent to the steel plate, etc., or referring to commercially available concrete release agents. Further, as will be described later, the mixing ratios of the wax, the emulsifier, and water for forming the above colloidal dispersion (preferably an O / W emulsion or a solid wax dispersion in water) can be appropriately adjusted according to the application means.For example, when applying the concrete release agent of the present invention by spraying, the spray pattern, spray distance, discharge amount, particle size, etc. can be appropriately set to be in the preferred embodiments described later. When using a sponge, for example, a sponge that is difficult to soak can be used and appropriately set to facilitate application. The colloidal dispersion containing the above-mentioned rice bran wax, emulsifier, and water (preferably an O / W emulsion or a solid wax dispersion in water) may be a commercially available product. For example, XAQUASPROUT-0009, XAQUASPROUT-0010, XAQUASPROUT-0011, etc. manufactured by Nippon Seiro Co., Ltd. can be mentioned.

[0039] According to a preferred embodiment regarding the combination of wax, emulsifier, and water in the above-mentioned colloidal dispersion containing wax, emulsifier, and water (preferably an O / W emulsion or a solid wax dispersion in water), the wax is beeswax, the emulsifier is sorbitan fatty acid ester or fatty alcohol ethoxylate, and the water is strongly alkaline electrolyzed water. According to another preferred embodiment regarding the combination of wax, emulsifier, and water in the above-mentioned colloidal dispersion containing wax, emulsifier, and water (preferably an O / W emulsion or a solid wax dispersion in water), the wax is beeswax, the emulsifier is sorbitan fatty acid ester or fatty alcohol ethoxylate, the water is strongly alkaline electrolyzed water, and preferably further contains cellulose nanofibers as an emulsion stabilizer.

[0040] According to one embodiment of the present invention, the viscosity of the concrete release agent of the present invention at 20°C is, for example, 5 to 40 mPa·s, preferably 8 to 20 mPa·s. The viscosity of the concrete release agent can be easily measured using a commercially available rotational viscometer. As the above-mentioned concrete release agent, a colloidal dispersion type (preferably an emulsion type or a solid wax dispersion type in water) concrete release agent containing rice bran wax or beeswax, an emulsifier, and water is preferred.

[0041] According to one embodiment of the present invention, the concrete release agent of the present invention can adjust the pH at 25°C to, for example, 3 to 12, preferably 4 to 11. The pH of the concrete release agent can be easily measured using a commercially available pH meter. As the above concrete release agent, a colloidal dispersion type (preferably, emulsion type or solid wax in water dispersion type) concrete release agent containing rice bran wax or beeswax, an emulsifier and water is preferred.

[0042] According to one embodiment of the present invention, the concrete release agent according to the present invention can contain components other than the above, if necessary. Examples of such components that can be contained as necessary include polyethylene glycol, PVP (polyvinylpyrrolidone), PVB (polyvinyl butyral), PVA (polyvinyl alcohol), citric acid, hydrochloric acid, acetic acid, and the like.

[0043] According to one embodiment of the present invention, when the concrete release agent of the present invention is a solution comprising a solid wax at room temperature derived from a plant or an animal and a solvent for dissolving the wax, it can be easily prepared by a normal dissolution method. Specifically, each of the above components can be easily obtained by dissolving and mixing them, for example, at a temperature of 10 to 80°C for 10 minutes to 3 hours by mechanical stirring such as a stirrer or an ultrasonic disperser.

[0044] According to another embodiment of the present invention, when the concrete release agent of the present invention is in the form of a colloidal dispersion (preferably an O / W emulsion or a solid wax dispersion in water) containing a solid wax at room temperature derived from plants or animals and water, such a colloidal dispersion (preferably an O / W emulsion or a solid wax dispersion in water) can be easily prepared by ordinary emulsification methods. For example, a solid wax at room temperature derived from plants or animals is dissolved by heating, water is added thereto, and emulsification is carried out using a propeller stirrer, a homogenizer, etc. to prepare it. Alternatively, for example, to heated water (e.g., strongly alkaline electrolyzed water), a solid wax at room temperature derived from plants or animals dissolved by heating or the like is added, preliminary emulsification is carried out using a dispersion stirrer such as a propeller mixer or a disperser mixer, and then an emulsifier is added, and emulsification and dispersion treatment are carried out using an emulsifying disperser to prepare a colloidal dispersion type (preferably an O / W emulsion type or a solid wax dispersion in water type) concrete release agent. Examples of the emulsifying disperser include general emulsifying dispersers such as a high-speed rotating centrifugal spraying type stirrer such as a homodisper, a high-speed rotating shearing type stirrer such as a homomixer, a high-pressure jet type emulsifying disperser such as a homogenizer, a colloid mill, and an ultrasonic emulsifier. The release agent of the colloidal dispersion type (preferably the emulsion type or the solid wax dispersion in water type) thus prepared is diluted with water, for example, 1 to 50 times according to the application and used.

[0045] According to one embodiment of the present invention, since the "concrete release agent" of the present invention is a mixture of multiple components, it may also be referred to as a "composition for concrete release".

[0046] <Formwork for concrete molding> According to another aspect of the present invention, there is provided a formwork for concrete molding having a coating film containing a dried product of the above concrete release agent on its surface.

[0047] Here, the formwork for concrete molding refers to a formwork or a part of the formwork (for example, a member constituting the formwork) that holds fresh concrete in a certain shape for a predetermined time and cures it. Its shape, size, etc. can be determined according to the intended concrete molded body. Also, the material of the formwork for concrete molding can be appropriately determined.

[0048] According to a preferred embodiment of the present invention, examples of the formwork for concrete molding include formworks for concrete molding made of various metal materials, preferably metal. Examples of the metal material include iron (including steel), stainless steel, aluminum, copper, etc., preferably iron, stainless steel, and aluminum, and more preferably iron.

[0049] According to one embodiment of the present invention, the concrete release agent according to the present invention can form a solid coating film on the surface of the formwork by drying after being applied to a metal formwork for concrete molding. Here, the solid state includes the semi-solid state. The semi-solid state refers to, for example, a hard molasses state that deforms when pressed with a finger. The thickness of such a solid coating film, after drying and in a state where concrete can be poured, is not particularly limited, but examples include 20.0 μm or less, preferably 0.1 to 20.0 μm, more preferably 0.2 to 15.0 μm, and even more preferably 0.2 to 10.0 μm. The thickness of the above solid coating film can be measured using a surface roughness and surface shape measuring instrument (SURFCOM NEX 241 SD2-13, Tokyo Seimitsu Co., Ltd.).

[0050] The thickness of the solid coating film after drying does not have to be uniform over the entire surface of the concrete forming frame and can be partially different. For example, when forming concrete, a thicker solid coating film can be formed in parts where the contact opportunity and contact pressure with the concrete are high compared to other parts, and the thickness of the solid coating film can be reduced in parts where there is substantially no contact opportunity with the concrete. The application of the concrete release agent and the formation of the solid coating film do not have to be carried out over the entire surface of the concrete forming frame and can be carried out on parts or regions where the concrete comes into contact (or may come into contact).

[0051] <Method for applying concrete release agent> According to one embodiment of the present invention, a method for applying the concrete release agent of the present invention to the surface of the above-mentioned concrete forming frame is provided. Such an application method can be set as appropriate, but the concrete release agent of the present invention can be applied as it is, or after being diluted with a dispersion medium or a solvent, by any method such as a spray method, a dipping method, a bar coating method, a roll coating method, a brush coating method, a sponge coating method, and a combination of these methods. Among them, the spray method or the method of applying using a sponge in which the concrete release agent of the present invention is difficult to penetrate is preferable. In the above spray method, the spray pattern is not particularly limited, and any of a flat pattern, a straight pattern, a full cone pattern, and a hollow cone pattern can be adopted. From the viewpoint of spraying over a wide range, the full cone pattern is preferably used. Also, the distance between the spray discharge port and the surface of the object (for example, the concrete forming frame or the concrete forming mold) (that is, the spray distance) is not particularly limited, but is preferably 5 to 50 cm, more preferably 8 to 30 cm. In the above spray method, the discharge amount of the concrete release agent is not particularly limited, and examples thereof include 0.05 to 5 mL, preferably 0.1 to 3 mL. In the above spray method, the particle diameter of the concrete release agent after spray injection is not particularly limited, and examples thereof include 0.05 to 100 μm, preferably 0.07 to 50 μm. In addition, in the application method using the above sponge, by applying using a sponge that is difficult to penetrate, the active ingredient of the release agent in a brush or a single-layer sponge is prevented from being sucked into the brush or the inside of the sponge, reducing waste of the release agent, making it more economical, and also preferable in reducing the risk of the wax solidifying and clogging in the middle of the spray nozzle, unlike spray coating. Examples of the sponge that is difficult to penetrate for the concrete release agent of the present invention include a two-layer structure in which a coating layer and a back plate are adhered, the thickness of the coating layer is reduced, and there is no penetration above the adhesion interface with the back plate. Here, examples of the material of the coating layer include polyester-based urethane foam and non-woven fabric, and examples of the material of the back plate include foamed polyethylene and EVA (ethylene vinyl acetate) foam. Examples of such a sponge include a sponge for coating application (a sponge for glass coating, a headlight coating, CarCarePit Co., Ltd., back plate: foamed polyethylene (about 20 mm) (A-8 manufactured by Inoac Corporation), coating layer: polyester-based urethane foam (about 5 mm) (MF-50 manufactured by Inoac Corporation)).

[0052] When diluting with a dispersion medium or a solvent, the addition amount of the dispersion medium or the solvent is arbitrary and can be appropriately determined in consideration of, for example, the specific application method, application apparatus or instrument, coatability, drying speed, liquid stability, film strength, etc.

[0053] <Drying of the Concrete Release Agent> The temperature for drying the concrete release agent of the present invention is, for example, a temperature exceeding 0°C and less than 45°C, preferably 5 to 40°C, and more preferably 10 to 35°C. The temperature for drying the concrete release agent does not necessarily have to be constantly maintained at a specific temperature within the above temperature range and can vary within the above temperature range.

[0054] The drying time of the concrete release agent of the present invention is not particularly limited. However, when the concrete release agent comprises a wax that is solid at normal temperature and derived from plants or animals and a dispersion medium for dispersing the wax, examples thereof include 10 minutes to 72 hours, preferably 30 minutes to 60 hours, more preferably 1 to 48 hours or 16 to 48 hours. When the concrete release agent comprises a wax that is solid at normal temperature and derived from plants or animals and a solvent for dissolving the wax, examples thereof include 10 minutes to 96 hours, preferably 30 minutes to 72 hours, more preferably 1 to 48 hours.

[0055] Regarding the temperature conditions when drying the concrete release agent of the present invention, for example, in an indoor place such as a factory or an outdoor place such as a concrete molding site, it is usually already sufficient without actively heating or cooling from the outside.

[0056] Since the concrete release agent of the present invention can form a cured coating film by being left in an atmosphere above 0°C and below 45°C, it can be formed easily, efficiently, and at low cost.

Examples

[0057] The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples.

[0058] Release agent In the following Test Examples 1 to 3, the following were used as release agents 1 to 4.

[0059] Release agent 1: Rice bran wax aqueous emulsion (ionic: anionic, viscosity (20°C): 11 mPa·s, pH (25°C): 9) (product name: XAQUASPROUT-0009, Nippon Seiro Co., Ltd.) Release agent 2: Rice bran wax aqueous emulsion (ionic: nonionic, viscosity (20°C): 12 mPa·s, pH (25°C): 6) (product name: XAQUASPROUT-0010, Nippon Seiro Co., Ltd.) Release agent 3: Modified rice bran wax aqueous emulsion (ionic: nonionic, viscosity (20 °C): 12 mPa·s, pH (25 °C): 6) (Product name: XAQUASPROUT-0011, Nippon Seiro Co., Ltd.) Release agent 4: Mineral oil-based release agent (a release agent based on mineral oil derived from crude oil) (low coat, Fukoku Oil Co., Ltd.) The rice bran wax aqueous emulsions of release agents 1 to 3 are products in which the wax component extracted and refined from rice bran is dispersed in water together with an emulsifier.

[0060] Furthermore, in Test Examples 4 to 6 below, release agents 5 and 6 prepared by the following method were used.

[0061] Preparation of Release Agent 5 (Colloidal Dispersion Type Concrete Release Agent) The emulsifying tank was filled with strongly alkaline electrolyzed water (pH: 12.5) heated, and beeswax (product name: deodorized refined honey wax (high acid), Serika Noda Co., Ltd.) dissolved in the dissolution tank was added with stirring for preliminary emulsification. Then, a nonionic surfactant (product name: Solvon S-80, Toho Chemical Industry Co., Ltd.) was added as an emulsifier, and emulsification and dispersion treatment were performed using an emulsifying and dispersing machine to obtain an aqueous dispersion of solid wax (pH (25 °C): 7) as release agent 5.

[0062] Preparation of Release Agent 6 (Colloidal Dispersion Type Concrete Release Agent) The emulsifying tank was filled with strongly alkaline electrolyzed water heated, and beeswax (product name: deodorized refined honey wax (high acid), Serika Noda Co., Ltd.) dissolved in the dissolution tank was added with stirring for preliminary emulsification. Then, a nonionic surfactant (product name: Genapol LA 030 SG Vita, Clariant Japan K.K.) and cellulose nanofiber (product name: Celenpia TC-01A, Nippon Paper Industries Co., Ltd.) were added as emulsifiers, and emulsification and dispersion treatment were performed using an emulsifying and dispersing machine to obtain an aqueous dispersion of solid wax (pH (25 °C): 7) as release agent 6.

[0063] Test Example 1 Table test of release agents 1 to 3 (1) On a steel plate (formwork for concrete molding) measuring 30 mm × 30 mm, release agents 1 to 3 were applied using a sponge for coating application (a sponge headlight coating for glass coating, manufactured by CarCarePit Co., Ltd.). Thereafter, it was left to dry at room temperature (25°C) for 24 hours to obtain concrete release test samples 1 to 3. (Note that the steel plate coated with release agent 1 was designated as concrete release test sample 1. The same applies to concrete release test samples 2 and 3.) Here, the above-mentioned sponge for coating application is a sponge into which the chemical agent hardly penetrates. Also, it was confirmed that solid coating films were formed on concrete release test samples 1 to 3 by the fingertip touch method based on the following criteria. · When the fingertip touched the concrete release test sample and no release agent adhered to the fingertip, it was judged that a solid coating film was formed. · When the fingertip touched the concrete release test sample and the release agent adhered to the fingertip, it was judged that a solid coating film was not formed. (2) Concrete release test samples 1 to 3 were placed flat on the bottom surface of a formwork for concrete release test (diameter 100 mm × height 200 mm) (HitOne #100, manufactured by Daiya Reform Co., Ltd.), and fresh concrete was poured in and cured in 72 hours. (3) Concrete release test samples 1 to 3 were taken out from the cured concrete, and the releasability from the concrete and the surface appearance (coloring and stains) of the concrete molded body were observed. The evaluation criteria for "releasability" are as follows. A: No concrete adhesion to the steel plate can be confirmed visually. B: The total area of concrete adhesion is less than 3% of the entire steel plate. C: The total area of concrete adhesion is 3% or more of the entire steel plate. D: The total area of concrete adhesion is 50% or more of the entire steel plate. (4) After the observation in (3), when the "releasability" was A or B, the steps in (2) and (3) were repeated to confirm the durability of repeated use (n = 1). Also, in the releasability evaluation, the number of times when the criteria were "A" or "B" (the total adhesion area was less than 3% of the entire steel plate) was counted as the continuous durability times. The results of the releasability for each time and the results of the coloring and spotting of the first concrete molded body are shown in Table 1.

[0064] Table test of release agent 4 (comparative example) (1) A mold release agent 4 was spray-coated on a 30 mm × 30 mm steel plate (formwork for concrete molding) to obtain a concrete mold release test sample 4. Also, in the same way as the finger touch method in (1) of the table test of the mold release agents 1 to 3 in Test Example 1 above, the finger touch method was also performed on the concrete mold release test sample 4. As a result, it was confirmed that no solid coating film was formed on the concrete mold release test sample 4. (2) The above concrete mold release test sample 4 was placed still in a concrete mold release test mold (diameter 100 mm × height 200 mm) (HitOne #100, manufactured by Daiya Lifoam Co., Ltd.), and fresh concrete was poured in and cured in 72 hours. (3) The concrete mold release test sample 4 was taken out from the cured concrete, and the releasability from the concrete and the coloring and spotting conditions of the concrete molded body were observed. The evaluation criteria for "releasability" are the same as those in the table test of the mold release agents 1 to 3. (4) After the observation in (3), when the "releasability" was A or B, the steps in (2) and (3) were repeated to confirm the durability of repeated use (n = 1). Also, in the releasability evaluation, the number of times when the criteria were "A" or "B" (the total adhesion area was less than 3% of the entire steel plate) was counted as the continuous durability times. The results of the releasability for each time and the results of the coloring and spotting of the first concrete molded body are shown in Table 1.

[0065]

Table 1

[0066] Test Example 2 Field test of release agent 3 (1) On the forming mold for field test (a drainage box lid steel mold of 270 mm × 270 mm × 30 mm), the mold release agent 3 was applied using a sponge for coating application. Then, it was left to dry at room temperature (25°C) for 24 hours to produce the forming mold 3 for field test. (2) Fresh concrete was poured into the forming mold 3 for field test and placed in a moist heat environment at 70°C for 4 hours to cure the concrete. (3) The cured concrete was demolded from the forming mold 3 for field test, and the mold release property from the mold and the state of concrete adhesion to the mold were observed. (4) After the observation in (3), the steps in (2) and (3) were repeated to confirm the durability of repeated use (n = 1). The determination of whether continuous use was possible was based on the presence or absence of defects (such as chipping of the formed body due to deteriorated mold release property) that made the concrete formed body removed from the mold unusable as a product, and whether the concrete formed body could be smoothly demolded from the mold. The results are shown in Table 2.

[0067]

Table 2

[0068] Test Example 3 Measurement of the thickness of the solid coating film formed on the surface of the formwork of concrete release test sample 3 The thickness of the solid coating film formed on the frame surface of the concrete mold release test sample 3 obtained in (1) of Test Example 1 was measured (n = 4) using a surface roughness and surface shape measuring machine (SURFCOM NEX 241 SD2 - 13, Tokyo Seimitsu Co., Ltd.). The measurement conditions were a measurement length of 20 mm and a measurement speed of 0.15 mm / second. As a result, the thicknesses of the solid coating film were 0.31 μm, 0.409 μm, 0.695 μm, and 1.341 μm (average 0.689 μm). For the concrete mold release test sample 4 of Test Example 1, since no solid coating film was formed, measurement with the surface roughness and surface shape measuring machine was not performed.

[0069] Test Example 4 Table test of release agents 5 and 6 (1) The release agent 5 was spray-coated on a 30 mm × 30 mm steel plate (formwork for concrete molding) at a spray distance of approximately 10 cm. Thereafter, it was left to dry at room temperature (25°C) for 24 hours to obtain a concrete release test sample 5. Also, a concrete release test sample 6 was obtained in the same manner as the concrete release test sample 5, except that the release agent 6 was used instead of the release agent 5. Also, in the same manner as the finger-touch method in (1) of the table test of the release agents 1 to 3 in Test Example 1 above, the finger-touch method was also performed on the concrete release test samples 5 and 6. As a result, it was confirmed that solid coating films were formed on the concrete release test samples 5 and 6. (2) The above concrete release test samples 5 and 6 were placed in a formwork for concrete release test (diameter 100 mm × height 200 mm) (HitOne #100, manufactured by Daiya Reform Co., Ltd.), and fresh concrete was poured in and cured in 72 hours. (3) The concrete release test samples 5 and 6 were taken out from the cured concrete, and the mold release property from the concrete and the coloring and staining conditions of the concrete molded body were observed. The evaluation criteria for "mold release property" were the same as those in the table test of the release agents 1 to 3 in Test Example 1. (4) After the observation in (3), when the "mold release property" was A or B, the steps in (2) and (3) were repeated to confirm the durability of repeated use (n = 1). Also, in the mold release property evaluation, the number of times when the criteria were "A" and "B" (the total adhesion area was less than 3% of the entire steel plate) was counted as the continuous durable number of times. The results of the mold release property for each time and the results of the coloring and staining of the concrete molded body for the first time are shown in Table 3.

[0070]

Table 3

[0071] Test Example 5 Field test of release agent 5 (1) A mold release agent 5 was applied using a spray onto a forming mold for field test (a drain lid steel mold of 270 mm × 270 mm × 30 mm). Then, it was left to dry at room temperature (25°C) for 24 hours to produce a forming mold 5 for field test. (2) Fresh concrete was poured into the forming mold 5 for field test and placed in a humid heat environment at 70°C for 4 hours to cure the concrete. (3) The cured concrete was demolded from the forming mold 5 for field test, and the mold release property from the mold and the state of concrete adhesion to the mold were observed. (4) After the observation in (3), the steps in (2) and (3) were repeated to confirm the durability of repeated use (n = 1). The determination of whether continuous use was possible was based on the presence or absence of defects (such as chipping of the formed body due to deterioration of mold release property) that made the concrete formed body removed from the mold unusable as a product, and whether the concrete formed body could be smoothly demolded from the mold. The results are shown in Table 4.

[0072]

Table 4

[0073] Test Example 6 Measurement of the thickness of the solid coating film formed on the surface of the formwork of concrete release test sample 5 The thickness of the solid coating film formed on the frame surface of the concrete mold release test sample 5 obtained in (1) of Test Example 4 was measured using a surface roughness and surface shape measuring machine (SURFCOM NEX 241 SD2 - 13, Tokyo Seimitsu Co., Ltd.) (n = 5). The measurement conditions were a measurement length of 20 mm and a measurement speed of 0.15 mm / second. As a result, the thicknesses of the solid coating film were 3 μm, 6 μm, 2 μm, 6 μm, 6 μm (average 4.6 μm). Also, the thickness of the solid coating film formed on the frame surface of the concrete mold release test sample 6 obtained in (1) of Test Example 4 was measured in the same manner as the thickness of the solid coating film formed on the frame surface of the concrete mold release test sample 5 (n = 5). As a result, the thicknesses of the solid coating film were 5 μm, 5 μm, 5 μm, 3 μm, 6 μm (average 4.8 μm).

Claims

1. A concrete release agent comprising a wax that is solid at normal temperature and derived from a plant or an animal, and a dispersion medium for dispersing the wax or a solvent for dissolving the wax.

2. The concrete release agent according to claim 1, wherein the plant or animal is at least one selected from the group consisting of plants or animals of the Poaceae, Urticaceae, Arecaceae, Cyperaceae, Apidae, and Tenebrionidae families.

3. The concrete release agent according to claim 1 or 2, wherein the wax that is solid at normal temperature and derived from the plant or animal is at least one selected from the group consisting of rice bran wax, wood wax, Chinese wood wax, carnauba wax, candelilla wax, beeswax, and spermaceti wax.

4. The concrete release agent according to claim 1 or 2, which is a colloidal dispersion type concrete release agent containing a wax that is solid at normal temperature and derived from a plant or an animal, water, and an emulsifier.

5. The concrete release agent according to claim 1 or 2, for application to a metal concrete forming frame.

6. The concrete release agent according to claim 1 or 2, having a viscosity of 5 to 40 mPa·s.

7. The concrete release agent according to claim 1 or 2, which forms a solid coating film on the surface of the frame by drying after being applied to a metal concrete forming frame.

8. A method of applying the concrete release agent according to claim 1 to the surface of a concrete forming frame, comprising: spraying the concrete release agent, or applying the concrete release agent using a sponge that is difficult for the concrete release agent to penetrate. The method comprising the above.

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