Concrete surface impregnation material

Abstract

To provide a concrete surface impregnation material excellent in water absorption inhibiting properties, resistance to passage of water vapor, and weatherability.SOLUTION: A concrete surface impregnation material comprises: (a) alkyl alkoxysilane or partial hydrolytic condensation product thereof represented by R1aSi(OR2)4-a...(I) (in the formula (I), R1 is a 1-20C alkyl group, R2 is hydrogen or a1-6C alkyl group, and a is 1 or 2); (b) fibrillated fluoropolymer; (c) Fluorine-containing silane compound represented by [CF3(CF2)m(CH2)n]bSiR3cX4-b-c...(II) or a partially hydrolyzed condensation product thereof (in the formula (II), R3 is a 1-20C alkyl group, X is a1-6C alkoxy group, a hydroxyl group or a halogen, m is an integer from 0 to 19, n is an integer from 0 to 10, b is an integer from 1 to 3, c is an integer from 0 to 2, b+c is an integer from 1 to 3); and (d) an organic solvent.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a concrete surface impregnating material. Furthermore, it relates to a concrete product formed by applying and impregnating the concrete surface impregnating material and drying it, a method for protecting the concrete surface by applying and impregnating the concrete surface impregnating material to the concrete surface, and a method for producing the concrete surface impregnating material.

Background Art

[0002] Concrete is used in various structures because of its high durability. However, general concrete deteriorates over time, resulting in cracks, defects, etc. In order to prevent the deterioration of concrete and repair deteriorated concrete, it is effective to apply and impregnate a concrete surface impregnating material to prevent the intrusion of water and deterioration factors (halogen ions, halide ions, sulfide ions, sulfate ions, etc.) from the outside to the inside of the concrete.

[0003] As concrete surface treatment agents, for example, the following are known. Patent Document 1 describes a paint for imparting water and oil repellency to building materials such as cement-based joint materials, ALC boards, slate boards, cement-based molded bodies, cement mortars, and concrete bases, which contains a fluorine-containing silane compound having a specific structure. Patent Document 2 describes a water repellent composition for imparting water repellency to the surface of porous inorganic materials such as concrete building materials, which contains decyltrimethoxysilane, isoparaffin, and silica particles. Patent Document 3 describes a coating liquid applicable to concrete, etc., which is formed by dispersing hydrophobic fine particles having an average primary particle diameter of 100 nm or less and a surface treated with a fluorine-based water and oil repellent in an organic solvent containing 65% by mass or more of a hydrophobic solvent in all organic solvents. Patent Document 4 describes a water-repellent treatment composition for non-smooth surfaces that can impart sufficient water-repellent performance to non-smooth surfaces such as concrete blocks and tiles, wood, and cloth, and contains (1) fine particles with an average particle size of 100 nm or less and (2) an alkyl group-containing alkoxysilane. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2-107583 [Patent Document 2] Japanese Patent Publication No. 2016-50271 [Patent Document 3] Japanese Patent Publication No. 2010-155727 [Patent Document 4] Japanese Patent Publication No. 2010-121021 [Overview of the initiative] [Problems that the invention aims to solve]

[0005] The concrete surface impregnation materials described in Patent Documents 1 to 4 were not satisfactory in terms of water absorption inhibition (water absorption rate), water vapor permeability (moisture permeability), and weather resistance (water contact angle, surface moisture content after water absorption, water absorption rate, salt penetration resistance) of the coated / impregnated surface.

[0006] One of the problems that the present invention aims to solve is to provide a concrete surface impregnation material that can form a coated and impregnated surface of a concrete surface impregnation material that is excellent in water absorption suppression (water absorption rate), water vapor passage resistance (moisture permeability), and weather resistance (water contact angle, surface moisture content after water absorption, water absorption rate, salt penetration resistance). One of the problems that the present invention aims to solve is to provide a concrete product having a concrete surface coated and impregnated with the concrete surface impregnating material, which is formed by applying, impregnating, and drying the concrete surface impregnating material. One of the problems to be solved by the present invention is to provide a method for protecting a concrete surface by applying and impregnating the concrete surface impregnating material to the concrete surface. One of the problems to be solved by the present invention is to provide a method for producing the concrete surface impregnating material.

Means for Solving the Problems

[0007] The present inventor has conducted intensive studies to solve the above problems. As a result, it has been found that the above problems can be solved by a concrete surface impregnating material having a specific composition. That is, the present invention provides the following concrete surface impregnating material, concrete product, method for protecting a concrete surface, and method for producing a concrete surface impregnating material. [Item 1] (a) Formula (I); R n , , 4-b-c , , 3 , b , m , , , 3 , c a Si(OR 2 ) 4-a ···(I) (In formula (I), R 1 is an alkyl group having 1 to 20 carbon atoms, R 2 is hydrogen or an alkyl group having 1 to 6 carbon atoms, and a is 1 or 2.) An alkylalkoxysilane represented by or a partial hydrolysis condensate thereof, (b) A fibrillated fluororesin, and (c) Formula (II); [CF3(CF2) m (CH2) n b SiR 3 c X 4-b-c ···(II) (In formula (II), R 3 is an alkyl group having 1 to 20 carbon atoms, X is an alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, or a halogen, m is an integer of 0 to 19, n is an integer of 0 to 10, b is an integer of 1 to 3, c is an integer of 0 to 2, and b + c is an integer of 1 to 3.) A fluorine-containing silane compound represented by or a partial hydrolysis condensate thereof, (d) An organic solvent,​ A concrete surface impregnation material containing [specific ingredient]. [Section 2] The concrete surface impregnating material according to item 1, wherein the alkylalkoxysilane represented by formula (I) or a partially hydrolyzed condensate thereof is an alkyltrialkoxysilane or a partially hydrolyzed condensate thereof. [Section 3] A concrete product formed by applying, impregnating, and drying a concrete surface impregnation agent according to item 1 or 2. [Section 4] A method for protecting a concrete surface, comprising applying or impregnating the concrete surface impregnating material of item 1 or 2 onto the concrete surface. [Section 5] (a) Equation (I); R a Si(OR') 4-a ...(I) (In formula (I), R is an alkyl group having 1 to 20 carbon atoms, R' is hydrogen or an alkyl group having 1 to 6 carbon atoms, and a is 1 or 2.) Alkylalkoxysilanes represented by or partially hydrolyzed condensates thereof, (b) Fluoropolymers, and (c) Formula (II); [CF3(CF2)] m (CH2) n ] b SiR 3 c X 4-b-c ...(II) (In formula (II), R 3 (where is an alkyl group having 1 to 20 carbon atoms, X is an alkoxy group, hydroxyl group, or halogen having 1 to 6 carbon atoms, m is an integer from 0 to 19, n is an integer from 0 to 10, b is an integer from 1 to 3, c is an integer from 0 to 2, and b+c is an integer from 1 to 3.) A fluorine-containing silane compound represented by or a partially hydrolyzed condensate thereof, and (d) Organic solvents, The process of mixing, A step of fibrillating the fluororesin by applying a shear force and stirring (a) to (d), A method for manufacturing a concrete surface impregnation material, including the method described above. [Effects of the Invention]

[0008] The present invention provides a concrete surface impregnation material that can form a coated and impregnated surface of a concrete surface impregnation material that is excellent in water absorption suppression (water absorption rate), water vapor permeability (moisture permeability), and weather resistance (water contact angle, surface moisture content after water absorption, water absorption rate, salt penetration resistance). The present invention provides a concrete product having a surface coated and impregnated with the concrete surface impregnating material, which is formed by applying, impregnating, and drying the concrete surface impregnating material. The present invention provides a method for protecting a concrete surface, which involves applying and impregnating the concrete surface impregnation material onto the concrete surface. The present invention provides a method for producing the concrete surface impregnation material. [Brief explanation of the drawing]

[0009] [Figure 1] The images show photographs of the analytical surfaces of specimens SF and NF, cut from specimen SF and specimen NF, which were impregnated with the concrete surface impregnation material of Example 1 during the salt penetration depth test, as well as photographs showing the salt penetration status of the analytical surfaces of each specimen (specimen SF, specimen NF, and specimen without coating (specimen BL)). [Figure 2] This figure shows the chloride ion permeation concentration profiles after 13 cycles of accelerated testing for each test specimen (specimen SF, specimen NF, and specimen BL). [Modes for carrying out the invention]

[0010] The following describes the concrete surface impregnation material, concrete product, method for protecting concrete surfaces, and method for manufacturing the concrete surface impregnation material according to the present invention.

[0011] [Concrete surface impregnation material] The concrete surface impregnation material of the present invention is (a) Equation (I); R 1 aSi(OR 2 ) 4-a ...(I) (In formula (I), R 1 R is an alkyl group having 1 to 20 carbon atoms. 2 (where a is hydrogen or an alkyl group having 1 to 6 carbon atoms, and a is 1 or 2.) Alkylalkoxysilanes represented by or partially hydrolyzed condensates thereof, (b) Fibrillated fluororesins, and (c) Formula (II); [CF3(CF2)] m (CH2) n ] b SiR 3 c X 4-b-c ...(II) (In formula (II), R 3 (where is an alkyl group having 1 to 20 carbon atoms, X is an alkoxy group, hydroxyl group, or halogen having 1 to 6 carbon atoms, m is an integer from 0 to 19, n is an integer from 0 to 10, b is an integer from 1 to 3, c is an integer from 0 to 2, and b+c is an integer from 1 to 3.) A fluorine-containing silane compound represented by or a partially hydrolyzed condensate thereof, (d) Organic solvents, This is a concrete surface impregnation material containing [specific ingredient]. It will be explained in detail below.

[0012] <(a) Alkylalkoxysilanes represented by formula (I) or their partially hydrolyzed condensates> "(a) Alkylalkoxysilane or a partially hydrolyzed condensate thereof" (hereinafter sometimes referred to as "component (a)") is defined by formula (I); R 1 a Si(OR 2 ) 4-a ...(I) (In formula (I), R 1 R is an alkyl group having 1 to 20 carbon atoms. 2 (where a is hydrogen or an alkyl group having 1 to 6 carbon atoms, and a is 1 or 2.) It is one or more alkylalkoxysilanes represented by or their partially hydrolyzed condensates. In the present invention, the partially hydrolyzed condensate is obtained by hydrolyzing approximately 2 to 10 molecules of alkylalkoxysilane represented by formula (I).

[0013] R in equation (I) 1 This refers to alkyl groups having 1 to 20 carbon atoms. Examples include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, hexyl group (e.g., n-hexyl group), heptyl group (e.g., n-heptyl group), octyl group (e.g., n-octyl group, 2,2,4-trimethylpentyl group), nonyl group (e.g., n-nonyl group), decyl group (e.g., n-decyl group), and dodecyl group (e.g., n-dodecyl group), as well as cycloalkyl groups such as cyclopentyl group, cyclohexyl group, 4-ethylcyclohexyl group, cycloheptyl group, norbornyl group, and methylcyclohexyl group. 1 If there are multiple R in the molecule, 1 These may be the same or different from each other, independently of each other. In the present invention, preferred R 1 is an alkyl group having 4 to 12 carbon atoms, and more preferably an alkyl group having 4 to 10 carbon atoms.

[0014] R in equation (I) 2 This is an alkyl group having 1 to 6 carbon atoms. Examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, hexyl group (e.g., n-hexyl group), etc. 2 If there are multiple R in the molecule, 2 These may be the same or different from each other, independently of each other. In the present invention, preferred R 2 is an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group or an ethyl group.

[0015] In formula (I), a is either 1 or 2. In formula (I), if a is 1, it is an alkyltrialkoxysilane, and if a is 2, it is a dialkyldialkoxysilane. The substituents that R and R' may have include, for example, one or more species selected from the group consisting of halogen groups, vinyl groups, epoxy groups, methacryloxy groups, acryloxy groups, amino groups, aminoalkylamino groups, isocyanate groups, and the like.

[0016] Examples of such alkylalkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, nonyltrimethoxysilane, nonyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, undecyltrimethoxysilane, Undecyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, tridecyltrimethoxysilane, tridecyltriethoxysilane, tetradecyltrimethoxysilane, tetradecyltriethoxysilane, pentadecyltrimethoxysilane, pentadecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, heptadecyltrimethoxysilane, heptadecyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, dimethyldimethoxysilane, octylmethyldimethoxysilane, octadecylmethyldimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,One or more selected from the group consisting of 4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethoxysilane, N-2-(aminoethyl)-3-aminopropylethoxysilane, 3-aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3-isocyanatetopropyltriethoxysilane, etc. In the present invention, alkyltrialkoxysilanes in which a is 1 in formula (I) are preferred from the viewpoint of the hardening properties of the concrete surface impregnation material. More preferred alkyltrialkoxysilanes include, for example, one or more selected from the group consisting of hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, and the like.

[0017] The content of component (a) in the concrete surface impregnation material is not particularly limited. With the total amount of the concrete surface impregnation material as 100% by mass, it is, for example, 20% by mass or more, preferably 25% by mass or more, more preferably 30% by mass or more, and for example, 80% by mass or less, preferably 75% by mass or less, more preferably 70% by mass or less. (a) If the content of the component is less than 20% by mass, the viscosity of the concrete surface impregnating material may become too low, which may result in poor anti-sagging properties and poor water repellency. (a) If the content of the component exceeds 80% by mass, the viscosity of the concrete surface impregnating material may become too high, potentially resulting in poor application workability, appearance evaluation, and impregnation performance.

[0018] <(b) Fibrillated fluororesin> "(b) fibrillated fluororesin" (hereinafter sometimes referred to as "component (b)") is obtained by applying a shear force of an appropriate size to fluororesin particles, thereby making at least a portion of the shape of the fluororesin particles fibrous. The fibrillated fluororesin (b) in the present invention is different from that obtained by cutting fluororesin fibers. In the concrete surface impregnating material of the present invention, "(b) fibrillated fluororesin" functions as a thickening agent.

[0019] The fluororesin in this invention is a polymer containing repeating units derived from fluorine-containing monomers. The fluororesin is not particularly limited as long as it can be fibrillated. For example, one or more crystalline fluororesins such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropyrpyrene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF) can be used. Preferably, PTFE or PFA is preferred, and PTFE, which is easily fibrillated, is particularly preferred. Preferred commercially available fluororesins include, for example, one or more selected from the group consisting of Kitamura Co., Ltd.'s "KTL-8F", "KTL8FH", "KTL-500F", etc., and Daikin Industries, Ltd.'s "Polyflon T-104", "Polyflon F-201", etc. Fibrillated fluororesin exhibits suppressed re-coagulation in concrete surface impregnation materials, has excellent dispersibility, and can impart water repellency to the coated concrete surface.

[0020] The volume-average particle diameter (50% particle diameter) of the fluororesin particles is not particularly limited. For example, it may be 1.0 μm or more, preferably 1.5 μm or more, more preferably 2.0 μm or more, and for example, 20.0 μm or less, preferably 15.0 μm or less, and more preferably 10.0 μm or less. If the volume-average particle diameter of the fluororesin particles is between 1.0 μm and 20.0 μm, the fluororesin particles and the fibrillated fluororesin can be well dispersed in the solvent, and the fluororesin particles can be efficiently fibrillated. The aspect ratio (major axis / minor axis) of the fluororesin particles is not particularly limited. For example, it may be between 1 and 3.

[0021] The degree of crystallinity of the fluororesin particles is preferably 10% or more, more preferably 30% or more, preferably 80% or less, and more preferably 60% or less. The degree of crystallinity of the fluororesin particles can be measured, for example, by X-ray diffraction. If the degree of crystallinity of the fluororesin particles is within this range, the fluororesin particles are easily fibrillated by applying shear force.

[0022] Fibrillated fluororesins can be produced by applying a shear force to fluororesin particles to induce fibrillation. For example, one method involves mixing the materials constituting the concrete surface impregnating material and then applying a shear force to induce fibrillation of the fluororesin particles using a general dispersion method. Another example is mixing the fluororesin particles with a solvent and then applying a shear force to induce fibrillation of the fluororesin particles using a general dispersion method. Dispersion methods that apply shear force to induce fibrillation of fluororesin particles include, for example, dispersion methods using one or more selected from the group consisting of bead mills, ball mills, sand mills, jet mills, attritors, three-roll mills, mixers, homomixers, ultrasonic devices, ultradissolvers, high-pressure homogenizers, etc. However, even with these means, if sufficient shear force cannot be applied, fibrillation of the fluororesin particles cannot be achieved. In the present invention, a dispersion method using a wet media stirring pulverizer that applies shear force by stirring a media such as beads or balls in a solvent is preferred. When a wet media stirring pulverizer is used, collision and shear forces act on the fluororesin particles between the inner wall of the apparatus and the media, and between the media themselves, causing the fluororesin particles to fibrillate.

[0023] The shear force applied to the fluororesin particles to induce fibrillation can be appropriately adjusted depending on the amount, shape, and type of fluororesin used. When using a media mill, for example, shear force can be applied by stirring at 500 rpm or more, preferably 700 rpm or more, more preferably 800 rpm or more, for example, 1500 rpm or less, preferably 1300 rpm or less, and more preferably 1200 rpm or less for 10 to 120 minutes. In the present invention, confirmation of fibrillated fluororesin can be performed, for example, by transmission electron microscopy (TEM) observation (acceleration voltage 100kV, 1000x magnification).

[0024] The content of component (b) in the concrete surface impregnation material is not particularly limited. With the total amount of the concrete surface impregnation material as 100% by mass, for example, it is 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.10% by mass or more, and for example, 5.00% by mass or less, preferably 3.50% by mass or less, and more preferably 2.00% by mass or less. (b) If the content of component is less than 0.01% by mass, the viscosity of the concrete surface impregnating material may become too low, resulting in poor anti-sagging properties, poor water repellency of the applied and impregnated surface of the concrete surface impregnating material, and poor workability and appearance evaluation. (b) If the content of component exceeds 5.00% by mass, the viscosity of the concrete surface impregnating material may become too high, which may impair the workability of application and may result in poor appearance and impregnation depth.

[0025] <(c) Fluorine-containing silane compounds represented by formula (II) or partially hydrolyzed condensates thereof> "(c) A fluorine-containing silane compound represented by formula (II) or a partially hydrolyzed condensate thereof" (hereinafter sometimes referred to as "component (c)") is formula (II); [CF3(CF2)] m (CH2) n ] b SiR 3 c X 4-b-c ...(II) (In formula (II), R 3 (where is an alkyl group having 1 to 20 carbon atoms, X is an alkoxy group, hydroxyl group, or halogen having 1 to 6 carbon atoms, m is an integer from 0 to 19, n is an integer from 0 to 10, b is an integer from 1 to 3, c is an integer from 0 to 2, and b+c is an integer from 1 to 3.) It is one or more fluorine-containing silane compounds represented by [formula] or their partially hydrolyzed condensates. In the present invention, the partially hydrolyzed condensate is obtained by hydrolyzing approximately 2 to 10 molecules of a fluorine-containing silane compound represented by formula (II).

[0026] R in equation (II) 3This refers to alkyl groups having 1 to 20 carbon atoms. Examples include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, hexyl group (e.g., n-hexyl group), heptyl group (e.g., n-heptyl group), octyl group (e.g., n-octyl group, 2,2,4-trimethylpentyl group), nonyl group (e.g., n-nonyl group), decyl group (e.g., n-decyl group), and dodecyl group (e.g., n-dodecyl group), as well as cycloalkyl groups such as cyclopentyl group, cyclohexyl group, 4-ethylcyclohexyl group, cycloheptyl group, norbornyl group, and methylcyclohexyl group. In equation (II), R 3 If there are multiple, R 3 These may be the same or different from each other, independently of each other. In the present invention, preferred R 3 is an alkyl group having 1 to 12 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. R in formula (II) 3 c, which represents the number, is an integer between 0 and 2, and is preferably 0 from the viewpoint of the reactivity of the concrete surface impregnation material and the weather resistance of the applied and impregnated surface of the concrete surface impregnation material.

[0027] In equation (II) [CF3(CF2) m (CH2) n ] is a fluorine-containing alkyl group. In formula (II), m represents the number of fluorocarbon units (total number of CF3 and CF2). Increasing m improves the water repellency and weather resistance of the coated and impregnated surface of the concrete surface impregnation material. In the present invention, m is an integer from 0 to 19, preferably 1 or more, more preferably 2 or more, preferably 15 or less, and more preferably 10 or less. Fluoroalkylsilane compounds with a large number of m are difficult to obtain, and fluoroalkylsilane compounds with a small number of m have a small amount of fluoro atoms, which may result in insufficient water repellency and weather resistance of the coated and impregnated surface of the concrete surface impregnation material. In formula (II), n is an integer between 0 and 10, preferably 7 or less, and more preferably 5 or less. If the number of n is large, the amount of fluoro atoms will be relatively small, which may result in insufficient water repellency and weather resistance of the coated and impregnated surface of the concrete surface impregnation material. In equation (II), [CF3(CF2) m (CH2) n If there are multiple ], [CF3(CF2) m (CH2) n These elements may be identical or different from each other, independently of one another. In equation (II) [CF3(CF2) m (CH2) n The number b, which represents the number of ], is an integer from 1 to 3, and is preferably 1 or 2, and more preferably 1, from the viewpoint of the reactivity of the concrete surface impregnation material and the weather resistance of the applied and impregnated surface of the concrete surface impregnation material.

[0028] In formula (II), X can be a group selected from the group consisting of alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, and butoxy groups, as well as chloro and hydroxyl groups. If there are multiple X groups, they may be independent of each other and be identical or different. If the reactivity of X is too high, the handling of the concrete surface impregnating material during mixing will decrease, and the storage stability of the concrete surface impregnating material may decrease. On the other hand, if the reactivity of X is too low, the reaction will not proceed sufficiently, and the amount of silanol groups produced will not be sufficient, which may result in insufficient water repellency and weather resistance of the coated / impregnated surface of the concrete surface impregnating material. From the viewpoint of handling, storage stability, and water repellency and weather resistance of the coated / impregnated surface of the concrete surface impregnating material, X is preferably one or more alkoxy groups with 4 or fewer carbon atoms, and particularly preferably one or more methoxy groups or ethoxy groups. The number of X in formula (II) is between 1 and 3, and is 2 or more, more preferably 3, from the viewpoint of the reactivity of the concrete surface impregnating material, the water repellency of the coated and impregnated surface of the concrete surface impregnating material, and weather resistance.

[0029] Examples of fluorine-containing silane compounds represented by formula (II) include CF3(CF2)5CH2CH2Si(OCH3)3, CF3(CF2)5CH2CH2Si(OC2H5)3, CF3(CF2)5CH2CH2SiCH3(OCH3)2, CF3(CF2)5CH2CH2Si(CH3)2OCH3, CF3(CF2)3CH2CH2Si(OCH3)3, CF3(CF2)3CH2CH2SiCH3(OCH3)2, C One or more types selected from the group consisting of F3(CF2)3CH2CH2Si(CH3)2OCH3, CF3(CF2)5CH2CH2SiCl3, CF3(CF2)5CH2CH2SiCH3Cl2, CF3(CF2)5CH2CH2Si(CH3)2Cl, CF3(CF2)3CH2CH2SiCl3, CF3(CF2)3CH2CH2SiCH3Cl2, CF3(CF2)3CH2CH2Si(CH3)2Cl, etc. are selected. From the viewpoint of availability, storage stability of the concrete surface impregnating material, and water repellency and weather resistance of the coated and impregnated surface of the concrete surface impregnating material, in formula (II), [CF3(CF2) m (CH2) n ] is one or more of the bases where m is an integer between 3 and 7, and n is an integer between 1 and 3, R 3 A fluoroalkylsilane compound is preferred in which is an alkyl group having 1 to 10 carbon atoms, X is one or more alkoxy groups having 4 or fewer carbon atoms, b is an integer between 1 and 2, and c is 1 or 0.

[0030] The content of component (c) in the concrete surface impregnating material is not particularly limited. With the total amount of the concrete surface impregnating material as 100% by mass, for example, it is 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.10% by mass or more, for example, 5.00% by mass or less, preferably 3.50% by mass or less, more preferably 2.00% by mass or less. (c) If the content of component is less than 0.01% by mass, the water repellency and weather resistance of the coated and impregnated surface of the concrete surface impregnation material may decrease. (c) If the content of component exceeds 5.00% by mass, the handling and storage stability of the concrete surface impregnation material may decrease, and the cost of the concrete surface impregnation material will increase.

[0031] <(d) Organic solvents> The "(d) organic solvent" (hereinafter sometimes referred to as "component (d)") is not particularly limited as long as it can dissolve component (a), disperse component (b), and dissolve or disperse component (c). For example, one or more solvents selected from the group consisting of hydrocarbon solvents such as toluene, xylene, mineral spirits, cyclohexane, naphthenic solvents, and isoparaffinic solvents; alcoholic solvents such as methanol, ethanol, isopropanol, and butanol; ketoneic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and diacetone alcohol; amide solvents such as N-methyl-2-pyrrolidone, dimethylacetamide, and dimethylformamide; esteric solvents such as ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate; and etheric solvents such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monobutyl ether (butyl cellosolve), and propylene glycol monobutyl ether.

[0032] The content of component (d) in the concrete surface impregnation material is not particularly limited. With the total amount of the concrete surface impregnation material as 100% by mass, it is, for example, 20% by mass or more, preferably 25% by mass or more, more preferably 30% by mass or more, and for example, 75% by mass or less, preferably 65% ​​by mass or less, more preferably 60% by mass or less. (d) If the content of component is less than 20% by mass, the dispersibility of each component of the concrete surface impregnating material may be poor, the viscosity may become too high, and the application workability, appearance evaluation, and impregnation may be poor. (d) If the content of component exceeds 75% by mass, the viscosity of the concrete surface impregnating material may become too low, which may impair its ability to prevent sagging and reduce its water repellency.

[0033] <Thickening agent> The concrete surface impregnating material of the present invention may contain a thickening agent in addition to components (a) to (d). Examples of thickening agents include one or more organic thickening agents selected from the group consisting of amide-based, polyolefin-based, oxidized polyethylene-based, hydrogenated castor oil-based, sulfate ester-based, dimer acid ester-based, polycarboxylic acid-based, and vegetable oil polymer-based; and one or more inorganic thickening agents selected from the group consisting of bentonite, smectite, kaolinite, sepiolite, talc, silica fume, montmorillonite, hectorite, laponite, saponite, silica gel, and ultrafine calcium carbonate. In particular, amide-based thickening agents are preferred from the viewpoint of good compatibility with alkylalkoxysilane or its partially hydrolyzed condensates, easy swelling, and improvement of peeling and whitening.

[0034] Examples of the aforementioned organic thickeners include one or more selected from the group consisting of the following: Kyoeisha Chemical's "Talen" series (7200-20, 5400-25, 5500-25, etc.); Kyoeisha Chemical's "Flownon" series (SP-1000, SA-300, etc.); Kusumoto Chemical's "Disparon" series (6900-20X, FS-6010, 4300, 6820-20M, 4200-20, etc.); and Ito Oil's "ASA" series (T-20, T-1700, D-10A, etc.).

[0035] When a thickening agent is used in a concrete surface impregnation material, its content is not particularly limited. Taking the total amount of the concrete surface impregnation material as 100% by mass, the content can be, for example, 0.5% by mass or more, preferably 1.0% by mass or more, and can be, for example, 15.0% by mass or less, preferably 10.0% by mass or less. If the thickening agent content is less than 0.5% by mass, the effect of adding the thickening agent cannot be obtained. If it exceeds 15.0% by mass, the dispersibility of each component of the concrete surface impregnation material may deteriorate, the viscosity may become too high, and the application workability, appearance evaluation, and impregnation performance may deteriorate. Organic thickeners have a larger molecular weight compared to alkylalkoxysilanes or their partially hydrolyzed condensates, and when applied as a concrete surface impregnating agent, they tend to be unevenly distributed on the coating surface. Therefore, the volatilization of alkylalkoxysilanes or their partially hydrolyzed condensates is suppressed, increasing the amount that penetrates the coated / impregnated surface and improving the penetration depth. Furthermore, the volatilization of the impregnated alkylalkoxysilanes or their partially hydrolyzed condensates is less likely to occur, allowing for the maintenance of water repellency and other properties for a longer period.

[0036] <Other ingredients> The concrete surface impregnating material of the present invention may contain other components in addition to components (a) to (d) and a thickener. Examples of other components include one or more selected from the group consisting of surface modifiers, defoamers, light stabilizers, dispersants, curing catalysts, curing accelerators, hydrolysis inhibitors, antioxidants, film-forming aids, ultraviolet absorbers, plasticizers, dehydrators, leveling agents, adhesion promoters, stain-resistant agents such as alkoxysilicates, inorganic matting agents such as silica powder or organic matting agents such as acrylic beads, colorants, antifungal agents, antialgal agents, termite repellents, fillers, etc. When using the above-mentioned other components in a concrete surface impregnation material, their content is not particularly limited. Taking the total amount of the concrete surface impregnation material as 100% by mass, the content can be, for example, 0.1% or more by mass, or 3.0% or less by mass.

[0037] <Physical properties of concrete surface impregnation materials> (Impregnation depth) The impregnation depth of the concrete surface impregnation material of the present invention is not particularly limited, as long as it is deep enough to prevent deterioration factors (e.g., chloride ions, etc.) from penetrating into the concrete. For example, if the impregnation depth is 2.0 mm or more, preferably 3.0 mm or more, and more preferably 4.0 mm or more, the time it takes for deterioration factors to reach the reinforcing steel inside the concrete is extended, and the effect of suppressing concrete deterioration is enhanced. The impregnation depth can be measured, for example, based on "6.2 Impregnation Depth Test" in "17. Test Methods for Surface Impregnating Materials (JSCE-K 571-2013)" of the "2013 Standard Specifications for Concrete, Standards Section, Japan Society of Civil Engineers Standards and Related Standards". Furthermore, regarding the immersion depth of chloride ions, specimens can be prepared and immersed based on the Japan Society of Civil Engineers standard "Test method for apparent diffusion coefficient of chloride ions in concrete by immersion (draft) (JSCE-G 572-2018)," and the concentration distribution of salt penetration on the impregnated surface can be created based on the Japan Society of Civil Engineers standard "Surface analysis method for elements in concrete by EPMA method (JSCE-G 574-2018)."

[0038] (viscosity) The viscosity of the concrete surface impregnating material of the present invention is not particularly limited as long as it has excellent anti-sagging properties and can be easily applied to vertical and top surfaces. For example, it is 500 mPa·s or more, preferably 550 mPa·s or more, more preferably 600 mPa·s or more, and for example, 1200 mPa·s or less, preferably 1100 mPa·s or less, more preferably 1000 mPa·s or less. In the present invention, the viscosity can be adjusted, for example, by fibrillating the fluororesin by means of dispersion such as a wet media stirring and grinding machine, or by using an appropriate amount of thickener. By setting the viscosity range to such a range, it is possible to form a concrete surface impregnating material with excellent anti-sagging properties and applicability, and furthermore, it is possible to create a concrete surface impregnating material that has no problems with the appearance of the concrete surface after application and impregnation, has sufficient impregnation depth (impregnation performance), has a large water contact angle and excellent water repellency, and has excellent durability of the concrete after application and impregnation. Viscosity can be measured, for example, using a Type B viscometer at 25°C and with rotor No. 2 running at 30 rpm.

[0039] (water contact angle) The water contact angle on the coated / impregnated surface of a concrete test specimen formed by coating / impregnating it with the concrete surface impregnation material of the present invention is not particularly limited as long as it is within a range that exhibits sufficient water repellency. For example, it is greater than 135°, preferably 137° or more, and for example, 160° or less, preferably 150° or less. The water contact angle can be measured, for example, by the method described in the [Evaluation] section of the Examples.

[0040] <Applications of concrete surface impregnation materials, etc.> The concrete surface impregnation material of the present invention is used by applying or impregnating the concrete surface to protect the concrete surface, maintain its aesthetic appearance, and prevent the intrusion of deterioration factors (halogen ions, halide ions, sulfide ions, sulfate ions, etc.). The method of applying and impregnating the concrete surface impregnating material is not particularly limited. For example, methods such as rollers, brushes, spraying, and immersion can be used. The temperature during application and impregnation is not particularly limited and can be in the range of 0°C to 50°C. After application and impregnation, drying and curing can be carried out by methods such as leaving it at room temperature, sun drying, or heat drying. The amount of concrete surface impregnation material applied and impregnated in the present invention is not particularly limited. It can be adjusted as appropriate according to the condition of the concrete, for example, 50 g / m². 2 Preferably 100 g / m² 2 It can be greater than or equal to 500g / m², for example. 2 Preferably 300 g / m 2 The following is possible: The concrete surface impregnation material of the present invention can achieve sufficient effect with a single application and impregnation, but may be applied and impregnated two or more times if necessary. Furthermore, it can be applied and impregnated not only to newly constructed concrete surfaces, but also to surfaces that have been applied and impregnated several years later.

[0041] The concrete to which the concrete surface impregnation material of the present invention is applied and impregnated may be either existing concrete or newly constructed concrete. Furthermore, it includes not only on-site cast concrete but also precast concrete products and components manufactured in factories or yards. There are no particular restrictions on the type of concrete, and examples include ordinary concrete, high-strength concrete, mass concrete, expansive concrete, low-heat concrete, underwater non-segregating concrete, underwater concrete, factory-made concrete, marine concrete, sprayed concrete, pre-packed concrete, high-flow concrete, polymer concrete, lightweight (aggregate) concrete, cold-weather concrete, hot-weather concrete, steel-concrete composite structure, prestressed concrete, recycled aggregate concrete, exposed concrete, precast concrete, lightweight foamed concrete (ALC), pulp cement board, wood wool cement board, cement-based extruded board, fiber-reinforced concrete (steel fiber reinforced concrete, ultra-high-strength fiber-reinforced concrete (UFC), glass fiber cement board (GRC), carbon fiber cement board, etc.), fiber-reinforced cement board, concrete blocks, 3D printed concrete, etc. Admixtures such as fly ash, blast furnace slag powder, and silica fume may also be mixed into the concrete.

[0042] When the concrete surface impregnation material of the present invention is applied to or impregnates a concrete surface, the majority of alkylalkoxysilane or its partially hydrolyzed condensate impregnates to an appropriate depth, and a dense surface coating mainly composed of fluorine-containing silane compounds or their partially hydrolyzed condensates and fluororesin is formed on the surface of the applied or impregnated surface. This greatly improves the weather resistance of the applied or impregnated surface of the concrete surface impregnation material, and can prevent the occurrence of various water-related problems such as rainwater leakage due to heavy wind and rain, material deterioration due to acid rain, stain penetration, salt damage from seawater and de-icing agents, frost damage in cold regions, and efflorescence due to the leaching of salt in the material over a long period of time. Furthermore, the concrete surface impregnation material of the present invention can impart antifouling properties to the applied or impregnated surface of the concrete, thereby making it difficult for dirt to adhere to the concrete surface. For this reason, it can be used in concrete structures with heavy traffic, such as parking lots, logistics facilities, various factories, and loading docks. Furthermore, due to its high water repellency, it can also be used in bridge piers, dams, various waterways, etc.

[0043] [Concrete Products] The concrete product of the present invention is a concrete product formed by applying, impregnating, and drying the concrete surface impregnation material described above under [Concrete Surface Impregnation Material]. The application and impregnation method of the concrete surface impregnation material, the drying method, and the concrete itself are the same as those described in <Uses of Concrete Surface Impregnation Material> of the above-mentioned [Concrete Surface Impregnation Material].

[0044] [Methods for protecting concrete surfaces] The present invention provides a method for protecting the surface of concrete, which involves applying and impregnating the concrete surface impregnation material described above under [Concrete Surface Impregnation Material] to the concrete surface. The method of applying and impregnating the concrete surface impregnating material, the drying method, and the concrete itself are the same as those described in <Uses of Concrete Surface Impregnating Material> of the above-mentioned [Concrete Surface Impregnating Material].

[0045] [Method for manufacturing concrete surface impregnation material] The method for producing the concrete surface impregnation material of the present invention is as follows: (a) Equation (I); R a Si(OR') 4-a ...(I) (In formula (I), R is an alkyl group having 1 to 20 carbon atoms, R' is hydrogen or an alkyl group having 1 to 6 carbon atoms, and a is 1 or 2.) Alkylalkoxysilanes represented by or partially hydrolyzed condensates thereof, (b) Fluoropolymers, and (c) Formula (II); [CF3(CF2)] m (CH2) n ] b SiR 3 c X 4-b-c ...(II) (In formula (II), R 3(where is an alkyl group having 1 to 20 carbon atoms, X is an alkoxy group, hydroxyl group, or halogen having 1 to 6 carbon atoms, m is an integer from 0 to 19, n is an integer from 0 to 10, b is an integer from 1 to 3, c is an integer from 0 to 2, and b+c is an integer from 1 to 3.) A fluorine-containing silane compound represented by or a partially hydrolyzed condensate thereof, and (d) Organic solvents, The process of mixing, A step of fibrillating the fluororesin by applying a shear force and stirring (a) to (d), This is a method for manufacturing a concrete surface impregnation material, which includes [the specified ingredient].

[0046] In the method for producing the concrete surface impregnation material of the present invention, "(a) an alkylalkoxysilane represented by formula (I) or a partially hydrolyzed condensate thereof", "(b) a fibrillated fluororesin", "(c) a fluorine-containing silane compound represented by formula (II) or a partially hydrolyzed condensate thereof", and "(d) an organic solvent" are the same as those described in <(a) an alkylalkoxysilane represented by formula (I) or a partially hydrolyzed condensate thereof>, <(b) a fibrillated fluororesin>, <(c) a fluorine-containing silane compound represented by formula (II) or a partially hydrolyzed condensate thereof> and <(d) an organic solvent> of the above [concrete surface impregnation material]. The method of agitation by applying shear force is not particularly limited as long as it can fibrillate the fluororesin, and for example, a method similar to the one described in <(b) Fibrillated fluororesin> of the above [Concrete surface impregnation material] can be cited. [Examples]

[0047] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited in any way by these examples. Unless otherwise specified, "parts" means "parts by mass."

[0048] [Preparation of concrete surface impregnation material] <Example 1> 50.0 parts of decyltrimethoxysilane, 0.5 parts of tridecafluorooctyltriethoxysilane, 0.2 parts of uncalcined polytetrafluoroethylene (uncalcined PTFE), 44.3 parts of mineral spirits, and 5.0 parts of an amide wax-based thickener were mixed and dispersed by stirring at a rotation speed of 1000 rpm for 60 minutes using a bead mill filled with 2.0 mm diameter glass beads to fibrillate the uncalcined PTFE and obtain the concrete surface impregnation material according to Example 1.

[0049] <Comparative Example 1> A concrete surface impregnation material according to Comparative Example 1 was obtained by mixing 50.0 parts of decyltrimethoxysilane, 45.0 parts of mineral spirits, and 5.0 parts of an amide wax-based thickener, and dispersing the mixture by stirring at a rotation speed of 1000 rpm for 60 minutes using a bead mill filled with 2.0 mm diameter glass beads.

[0050] [evaluation] The obtained concrete surface impregnation material was evaluated as follows. <Fabrication of test substrates> A test substrate was prepared based on "5.1.1 Preparation of Mortar Substrate" in "17. Test Method for Surface Impregnating Materials (JSCE-K 571-2013)" of the "2013 Standard Specifications for Concrete, Standards Edition, Japan Society of Civil Engineers Standards and Related Standards". In accordance with JSCE-F 505, a mortar with a water-cement ratio of 50% and a sand-cement ratio of 3 was mixed using standard sand as specified in JIS R 5201 10.2 (standard sand), and molded into a 100 × 100 × 400 (mm) shape using a metal mold. After being left to stand for 24 hours at a temperature of 20±2℃ and a relative humidity of 80% or higher, it was demolded and then cured in water at 20±2℃ for 6 days. The molded mortar was cut to dimensions according to the type of evaluation test, cured at a temperature of 23±2°C and a relative humidity of (50±5)% for 28 days, and used as the test substrate. The mortar, which was molded to dimensions of 100 x 100 x 400 (mm), was cut according to the instructions in "5.1.1 Preparation of Mortar Substrate" above.

[0051] <Water absorption rate test> The test specimens were prepared in accordance with "5.2 Preparation of Test Specimens" in "17. Test Methods for Surface Impregnating Materials (JSCE-K 571-2013)" of the "2013 Standard Specifications for Concrete, Standards Edition, Japan Society of Civil Engineers Standards and Related Standards". The dimensions of the test specimens were 100 × 100 × 100 (mm), the impregnation surfaces of the test specimens were the two cut surfaces (100 × 100 (mm)), there were 3 test specimens, there were 3 original test specimens, and the test environment was a temperature of 23 ± 2°C and a relative humidity of (50 ± 5)%. The concrete surface impregnation material used was prepared by letting it stand for 24 hours at a temperature of 23±2℃ and a relative humidity of (50±5)%. The concrete surface impregnation agent was applied to the surface using a brush to impregnate it, and the specimens were cured for 14 days at a temperature of 23±2℃ and a relative humidity of (50±5)% to prepare the test specimens. Furthermore, the sealing surfaces other than the impregnated surface were sealed by applying an epoxy resin paint intermediate coating for concrete after polishing.

[0052] Based on "6.4 Water Absorption Test" in "17. Test Method for Surface Impregnating Materials (JSCE-K 571-2013)" mentioned above, water absorption tests were conducted on three types of test specimens after 7 and 28 days: a test specimen (SF) impregnated with the concrete surface impregnating material of Example 1, a test specimen (NF) impregnated with the concrete surface impregnating material of Comparative Example 1, and a test specimen (A) impregnated with a commercially available concrete surface impregnating material. A test substrate was left standing for 14 days under conditions of 23±2°C and (50±5)% relative humidity until the preparation of the test specimen was completed, without impregnation with a surface impregnation material. This was designated as the original test specimen (BL), and water absorption tests were performed after 7 and 28 days. The results are shown in Table 1.

[0053] [Table 1]

[0054] <Moisture Permeability Test> The test specimens were prepared in accordance with "5.2 Preparation of Test Specimens" in "17. Test Methods for Surface Impregnating Materials (JSCE-K 571-2013)" of the "2013 Standard Specifications for Concrete, Standards Edition, Japan Society of Civil Engineers Standards and Related Standards". The dimensions of the test specimens were 100 × 100 × 20 (mm), the impregnation surface of the test specimens was one side (100 × 20 (mm)) that was in contact with the mold, there were 3 test specimens, there were 3 original test specimens, and the environmental conditions for the test were a temperature of 23 ± 2°C and a relative humidity of (50 ± 5)%. The concrete surface impregnation material used was prepared by letting it stand for 24 hours at a temperature of 23±2℃ and a relative humidity of (50±5)%. The concrete surface impregnation agent was applied to the surface using a brush to impregnate it, and the specimens were cured for 14 days at a temperature of 23±2℃ and a relative humidity of (50±5)% to prepare the test specimens. Furthermore, the sealing surfaces other than the impregnated surface were sealed by applying an epoxy resin paint intermediate coating for concrete after polishing.

[0055] Based on "6.5 Water Permeability Test" in "17. Test Method for Surface Impregnating Materials (JSCE-K 571-2013)" mentioned above, water permeability tests were conducted on three types of test specimens: one impregnated with the concrete surface impregnating material of Example 1 (SF), one impregnated with the concrete surface impregnating material of Comparative Example 1 (NF), and one impregnated with a commercially available concrete surface impregnating material (A), after 7 and 28 days. A test substrate was left standing for 14 days under conditions of 23±2°C and (50±5)% relative humidity until the preparation of the test specimen was completed, without impregnation with a surface impregnation material. This was designated as the original test specimen (BL), and moisture permeability tests were performed after 7 and 28 days. The results are shown in Table 2.

[0056] [Table 2]

[0057] <Accelerated weathering resistance (water contact angle)> (Accelerated testing) An accelerated weathering test (accelerated degradation test) was conducted using a weathering tester (XER-W75, water-cooled, 7.5kW xenon arc lamp light source). The accelerated test conditions were: irradiation intensity (300-400nm, 60W / m²). 2 The black standard temperature (BST) was set at 65°C, the temperature at 38±3°C (referencing JIS K5600-7-7), and the relative humidity at 60% (referencing JIS A 1415). One cycle consisted of 120 minutes (2 hours), with a wetting time of 18 minutes and a drying time of 102 minutes.

[0058] (Correlation between accelerated testing and outdoor exposure) An absorbance ratio (carbonyl index value, hereinafter referred to as "CI value") of 1 under a xenon arc lamp corresponds to 90 hours of irradiation. Furthermore, the cumulative CI value for one year in Choshi, which is at approximately the same latitude as Tokyo, is 9.3, so this can be converted to xenon arc lamp irradiation time of 90 hours × 9.3 = 837 hours. Also, since 837 hours / 24 hours ≈ 35 (days), 35 days of irradiation in a weathering tester is equivalent to one year of exposure in Choshi or Tokyo. 500 hours of irradiation in a weathering tester is equivalent to approximately 0.6 years of exposure (calculation basis: Hidehiko Furuya et al., Evaluation of UV degradation of silane-based surface impregnating materials by water absorption test, Annual Proceedings of the Concrete Engineering Society, Vol. 31, No. 1, 2009).

[0059] (Measurement of water contact angle) The water contact angle was measured in accordance with JIS R 3257:1999 "Test method for wettability of substrate glass surfaces". The water contact angle was measured by measuring the static contact angle using an automatic contact angle meter (Kyowa Interface Science Co., Ltd., "DMo-701"). The volume of the water droplet to be dropped onto the surface of the test specimen was entered into the measurement software, and 15 consecutive measurements were specified. The entire process, from water droplet creation to contact angle measurement, was performed automatically.

[0060] A test specimen measuring 150 x 70 x 10 mm was cut from a test substrate. One side of the specimen (150 x 70 mm) was designated as the irradiation surface, and the remaining five sides were coated and sealed with epoxy resin. The specimen was impregnated with a concrete surface impregnation agent by applying it to the impregnation surface using a brush, and then cured for 14 days at a temperature of 23 ± 2°C and a relative humidity of (50 ± 5)% to obtain the test specimen. Accelerated testing was performed on test specimens (SF) obtained by applying and impregnating the concrete surface impregnating material of Example 1 onto the irradiated surface, and on test specimens (NF) obtained by applying and impregnating the concrete surface impregnating material of Comparative Example 1 onto the irradiated surface. The test specimens were removed every 500 hours of acceleration time, and the water contact angle of the impregnated surface was measured. The water contact angle was measured by dropping a water droplet onto the coated / impregnated surface of the test specimen and waiting 1 second. The measurement position was set to allow for 15 automatic measurements using a 6mm pinch in one direction, and the average of the 15 water contact angles was taken as the water contact angle for one test specimen. The water contact angle is shown as the average value of three test specimens. The results are shown in Table 3.

[0061] [Table 3]

[0062] <Accelerated weathering resistance (surface moisture content and water absorption rate after 24 hours of water absorption)> In the same manner as described above for accelerated weathering (water contact angle), test specimens (SF) obtained by applying and impregnating the concrete surface impregnating material of Example 1 onto the irradiated surface and test specimens (NF) obtained by applying and impregnating the concrete surface impregnating material of Comparative Example 1 onto the irradiated surface were prepared, and accelerated weathering tests were conducted. Every 500 hours of acceleration, the test specimens were removed and allowed to absorb distilled water for 24 hours. Immediately thereafter, the surface moisture content after 24 hours of water absorption and the mass of the test specimens were measured. Surface moisture content was measured using a high-frequency moisture meter manufactured by Kett. Furthermore, the 24-hour water absorption rate was calculated from the mass measurements before and after 24 hours of water absorption. The measurement results for surface moisture content after 24 hours of water absorption are shown in Table 4, and the 24-hour water absorption rate is shown in Table 5.

[0063] [Table 4]

[0064] [Table 5]

[0065] <Salt penetration depth test> Test specimens were prepared according to the "Draft Test Method for Apparent Diffusion Coefficient of Chloride Ions in Concrete by Immersion (JSCE-G 572-2018)". In this test, to avoid bleeding and the influence of the formwork surface, cylindrical test specimens measuring Φ100 × 200 mm were prepared by cutting 25 mm from both the top and bottom ends to Φ100 × 150 mm. One cut surface was left as the impregnation surface, and all other surfaces were coated with epoxy resin. The concrete surface impregnation material used was prepared by letting it stand for 24 hours at a temperature of 23±2℃ and a relative humidity of (50±5)%. Three types of specimens were prepared: one obtained by applying and impregnating the impregnated surface of the prepared specimen with the concrete surface impregnating material of Example 1 (Specimen SF), one obtained by applying and impregnating the concrete surface impregnating material of Comparative Example 1 (Specimen NF), and one in its original state (Specimen BL) which was left standing for 14 days under conditions of a temperature of 23±2℃ and a relative humidity of (50±5)% without applying or impregnating the surface impregnating material.

[0066] Samples SF, NF, and BL were immersed in a 10% saline solution. After immersion, test pieces were cut from samples SF, NF, and BL, with an immersion surface of 40 × 10 mm and a depth of 50 mm. The 50 × 40 mm surface of each test piece was used as the analysis surface, and the analysis surface was subjected to EPMA analysis according to "Method for Surface Analysis of Elements in Concrete by EPMA (JSCE-G 574-2013)" to determine the salt concentration distribution, and the depth of salt penetration was considered. EPMA analysis was performed using a JEOL JXA-iSP100. The electron beam diameter (probe diameter) irradiated onto each analysis surface was set to 100 μm, and the probe was moved at 100 μm (0.1 mm) intervals across the analysis surface to perform analysis at 500 × 400 locations (pixels) (surface analysis, stage scan method). The amount of the target element at each pixel was expressed as the characteristic X-ray intensity in counts, and the general change from count to concentration was calculated using a calibration curve prepared in advance with standard samples of known target element concentrations. In this study, analysis was performed on the analysis surface of each test specimen, and a concentration profile was created by averaging the chloride ion concentration values ​​of each pixel at the same chloride ion penetration depth. Figure 1 shows photographs of the analytical surfaces of specimens SF and NF, which were cut from the test specimens SF and NF, respectively, as well as the salt penetration status of the analytical surfaces of each specimen (specimen SF, specimen NF, and specimen BL). The analysis surfaces of the SF and NF test specimens were photographed after spraying water onto the cut surface before analysis. The impregnation of the concrete surface impregnation material of Example 1 and Comparative Example 1 can be seen. From the salt penetration status shown in Figure 1, it can be seen that salt has not penetrated the samples SF and NF, while salt has penetrated deeply into the sample BL.

[0067] Furthermore, to simulate a more severe saline environment, a wet-dry cycle salt penetration test was conducted to examine its resistance to salt penetration. In the wet-dry cycle salt penetration test, samples SF, NF, and BL were immersed in salt water at 20°C for 4 days, followed by drying in a constant temperature and humidity chamber at 40°C and 30%RH for 3 days. One cycle consisted of 13 accelerated cycles. From the samples SF, NF, and BL after the accelerated testing, test specimens were cut out with an immersion surface of 40 × 10 mm and a depth of 50 mm. The 50 × 40 mm surface of each specimen was used as the analysis surface, and the analysis surface was performed using EPMA according to "Method for Surface Analysis of Elements in Concrete by EPMA (JSCE-G 574-2013)". Figure 2 shows the chloride ion permeation concentration profile after 13 cycles of accelerated testing. Figure 2 shows that no chloride ions were observed in the depth direction or on the impregnation surface of specimens SF and NF. Figure 2 shows that specimen BL has a surface chloride ion concentration of approximately 1.0% and a penetration depth of approximately 30 mm. Figure 2 shows that, due to its water-repellent properties, the concrete surface impregnating material of the present invention makes it difficult for salt to adhere to the immersed surface, and the water absorption inhibiting layer formed by impregnation prevents the penetration of water and salt. From this, it can be seen that the concrete surface impregnation material containing the fluorine-containing silane compound or its partially hydrolyzed condensate has excellent resistance to salt penetration.

[0068] Test specimens coated with the concrete surface impregnation material of the present invention showed excellent results in all of the following tests: water absorption rate test, water vapor permeability test, accelerated weathering (water contact angle), accelerated weathering (surface moisture content after 24 hours of water absorption and 24-hour water absorption rate), and salt penetration depth test. From this, it can be seen that the concrete surface impregnation material of the present invention is useful for protecting the surface of concrete, maintaining the aesthetic appearance of the concrete surface, preventing the intrusion of deterioration factors from the concrete surface over a long period of time, and improving the weather resistance of the concrete surface.

Claims

1. (a) Equation (I); R １ ａ Si(OR ２ ) ４－ａ ・・・(I) (In formula (I), R １ R is an alkyl group having 1 to 20 carbon atoms. ２ (where a is hydrogen or an alkyl group having 1 to 6 carbon atoms, and a is 1 or 2.) Alkylalkoxysilanes represented by or partially hydrolyzed condensates thereof, (b) Fibrillated fluororesins, and (c) Formula (II); [CF ３ (CF ２ ) ｍ (CH ２ ) ｎ ] ｂ SiR ３ ｃ X ４－ｂ－ｃ ・・・(II) (In formula (II), R ３ (where is an alkyl group having 1 to 20 carbon atoms, X is an alkoxy group, hydroxyl group, or halogen having 1 to 6 carbon atoms, m is an integer from 0 to 19, n is an integer from 0 to 10, b is an integer from 1 to 3, c is an integer from 0 to 2, and b+c is an integer from 1 to 3.) A fluorine-containing silane compound represented by or a partially hydrolyzed condensate thereof, (d) Organic solvents, A concrete surface impregnation material containing [specific ingredient].

2. The concrete surface impregnating material according to claim 1, wherein the alkylalkoxysilane represented by formula (I) or a partially hydrolyzed condensate thereof is an alkyltrialkoxysilane or a partially hydrolyzed condensate thereof.

3. A concrete product formed by applying, impregnating, and drying the concrete surface impregnating material according to claim 1 or 2.

4. A method for protecting a concrete surface, comprising applying and impregnating the concrete surface impregnating material according to claim 1 or 2 onto the concrete surface.

5. (a) Equation (I); R ａ Si(OR’) ４－ａ ・・・(I) (In formula (I), R is an alkyl group having 1 to 20 carbon atoms, R' is hydrogen or an alkyl group having 1 to 6 carbon atoms, and a is 1 or 2.) Alkylalkoxysilanes represented by or partially hydrolyzed condensates thereof, (b) Fluororesins, and (c) Formula (II); [CF ３ (CF ２ ) ｍ (CH ２ ) ｎ ] ｂ SiR ３ ｃ X ４－ｂ－ｃ ・・・(II) (In formula (II), R ３ (where is an alkyl group having 1 to 20 carbon atoms, X is an alkoxy group, hydroxyl group, or halogen having 1 to 6 carbon atoms, m is an integer from 0 to 19, n is an integer from 0 to 10, b is an integer from 1 to 3, c is an integer from 0 to 2, and b+c is an integer from 1 to 3.) A fluorine-containing silane compound represented by or a partially hydrolyzed condensate thereof, and (d) Organic solvents, The process of mixing, A step of fibrillating the fluororesin by applying a shear force and stirring (a) to (d), A method for manufacturing a concrete surface impregnation material, including the method described above.

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