A fibrous structure to which the composition and additives are attached, an uncured body containing the fibrous structure, and a cured body of the uncured body.

Abstract

To provide a fibrous structure that exhibits improved water-repellent, hydrophobic, and / or rust-preventive effects in a hardened unhardened body comprising a fibrous structure and a hydraulic composition, wherein the fibrous structure is embedded in the hydraulic composition. [Solution] A fiber structure to which a composition containing a silane compound and an additive are attached, wherein the additive contains a polyvinyl alcohol-based compound, the amount of the composition attached is 10 to 300 parts by mass per 100 parts by mass of a fiber structure to which the composition and the additive are not attached, and the amount of the additive attached is 0.05 to 35 parts by mass per 100 parts by mass of a fiber structure to which the composition and the additive are not attached.

Description

Technical Field

[0001] The present invention relates to a fiber structure to which a silane compound-containing composition and a polyvinyl alcohol-based compound-containing additive are attached, an uncured product containing the fiber structure, and a cured product of the uncured product.

Background Art

[0002] In order to delay or prevent the corrosion of a metal material (for example, a reinforcing bar) embedded in a cement-containing structure, it is known to use a corrosion inhibitor such as an organosilicon compound, a nitrite-based compound, or an amine-based compound. For example, Patent Document 1 discloses protecting a metal in an inorganic building material from corrosion by adding a mixture containing an organosilicon compound during the production of an inorganic building material such as mortar and / or concrete. However, according to the study by the present inventors, it is difficult to sufficiently obtain the effect of protecting metal corrosion by the method of adding an organosilicon compound to an inorganic building material as in Patent Document 1.

[0003] As a technique for solving such problems, Patent Document 2 discloses an uncured product including a fiber structure to which a composition containing a silane compound is attached and a cement-containing hydraulic composition, wherein the fiber structure is embedded in the hydraulic composition. The same document describes that the silane compound released from the fiber structure in the hydraulic composition diffuses in the vicinity of the fiber structure, and there, the polymeric silane compound forms something like a water-repellent film, so that the cured product of the hydraulic composition can exhibit a water-repellent, hydrophobic, and / or rust-preventive effect against moisture from the outside.

[0004] On the other hand, it is known that polyvinyl alcohol-based compounds can be used as fiber consolidators. Specifically, Patent Document 3 discloses a consolidated yarn produced by a method including coating multiple fibers with a modified polyvinyl alcohol-containing consolidator and integrating the fibers. It is disclosed that when this consolidated yarn is kneaded with a hydraulic material, the fibers are defibrated in the hydraulic material, and the hardened body of the hydraulic material is reinforced by the defibrated fibers. However, the same document does not describe corrosion inhibitors such as silane compounds, nor does it describe the water-repellent, hydrophobic, and / or rust-preventive properties of the hardened body. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Special Publication No. 2010-525157 [Patent Document 2] Specification of Japanese Patent Application No. 2024-115843 [Patent Document 3] International Publication No. 2020 / 137466 [Overview of the project] [Problems that the invention aims to solve]

[0006] There has always been a demand for materials that can provide higher water-repellent, hydrophobic, and / or rust-preventive effects to the cured bodies of hydraulic compositions. In view of the above, the problem that the present invention aims to solve is to provide a fiber structure that exhibits improved water-repellent, hydrophobic and / or rust-preventive effects in a hardened unhardened body comprising a fiber structure and a hydraulic composition, wherein the fiber structure is embedded in the hydraulic composition. [Means for solving the problem]

[0007] In order to solve the aforementioned problems, the inventors conducted detailed studies on fiber structures and have now completed the present invention. That is, the present invention encompasses the following preferred embodiments. [1] A fibrous structure to which a composition containing a silane compound and an additive are attached, The aforementioned additive includes a polyvinyl alcohol-based compound. The amount of the composition to be attached is 10 to 300 parts by mass per 100 parts by mass of the fibrous structure to which the composition and the additive are not attached. A fiber structure in which the amount of the additive attached is 0.05 to 35 parts by mass per 100 parts by mass of the fiber structure that does not have the composition and the additive attached. [2] The fiber structure according to [1], wherein the total release rate of the composition and the additive into the water when the fiber structure is immersed in water at 20-25°C for 240 minutes is 68% by mass or more. [3] The fiber structure according to [1] or [2], wherein the total release rate of the composition and the additive into the water when the fiber structure is immersed in water at 20-25°C for 5 minutes is 50% by mass or less. [4] The fiber structure according to any one of [1] to [3], wherein the fibers constituting the fiber structure are polyvinyl alcohol fibers. [5] The additive is water-soluble, and the fiber structure is as described in any of [1] to [4]. [6] The polyvinyl alcohol compound is one or more selected from the group consisting of modified polyvinyl alcohol and unmodified polyvinyl alcohol, according to any one of [1] to [5]. [7] The fiber structure according to any one of [1] to [6], wherein the viscosity-average degree of polymerization of the polyvinyl alcohol-based compound is 100 to 2,400. [8] The fibrous structure according to any one of [1] to [7], wherein the degree of saponification of the polyvinyl alcohol-based compound is 75 to 100 mol%. [9] The fiber structure according to any one of [1] to [8], wherein the ratio of the amount of the additive to the total amount of the composition and the additive is 0.1 to 15% by mass.

[10] The modified polyvinyl alcohol has structural units derived from an unsaturated carboxylic acid or a derivative thereof, as described in [6].

[11] The fiber structure according to

[10] , wherein the unsaturated carboxylic acid or its derivative is at least one selected from the group consisting of (meth)acrylic acid, alkyl (meth)acrylic acid esters, and metal salts of (meth)acrylic acid.

[12] The fibrous structure according to any one of [6],

[10] , and

[11] , wherein the degree of saponification of the modified polyvinyl alcohol is 88 mol% or more.

[13] The fiber structure according to any one of [6] and

[10] to

[12] , wherein the amount of modification of the modified polyvinyl alcohol is 0.1 to 10 mol%. An unhardened body comprising a fibrous structure described in any of

[14] [1] to

[13] and a hydraulic composition containing cement, wherein the fibrous structure is embedded in the hydraulic composition. The cured uncured material described in

[15]

[14] . [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a fiber structure that exhibits improved water-repellent, hydrophobic, and / or rust-preventive effects in a hardened unhardened body comprising a fiber structure and a hydraulic composition, wherein the fiber structure is embedded in the hydraulic composition. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic cross-sectional view of one embodiment of the uncured material of the present invention. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described in detail below. However, the scope of the present invention is not limited to the embodiments described herein, and various modifications can be made without impairing the spirit of the invention.

[0011] [Fiber structures to which compositions, etc., are attached] The fiber structure of the present invention has adhered thereto a composition containing a silane compound (hereinafter also referred to as "silane compound-containing composition") and an additive containing a polyvinyl alcohol-based compound (hereinafter also referred to as "polyvinyl alcohol-based compound-containing additive"). In this specification, unless otherwise specified, the fiber structure to which the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive are adhered may be referred to as "fiber structure with composition etc. adhered thereto" or "fiber structure with composition etc. adhered".

[0012] In this specification, "adhesion" means a state in which the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive cover at least a part of the surface of the fiber structure and / or are present in at least a part of the gaps (the surface of the fibers constituting the fiber structure, or the surface and the inside) of the fiber structure, and in order to achieve the effects of the present invention, in the presence of water, for example, in a hydraulic composition, the silane compound and the polyvinyl alcohol-based compound can be released (emitted) from the fiber structure. That is, the state in which the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive are "adhered" to the fiber structure does not include a state in which the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive are fixed or set to the fiber structure by high temperature and pH conditions, etc. The silane compound and the polyvinyl alcohol-based compound-containing additive fixed or set to the fiber structure are not released from the fiber structure in the presence of water. Therefore, even if such a fiber structure is embedded in a hydraulic composition, the effects of the present invention cannot be obtained. The silane compound adhered to the fiber structure and released from the fiber structure in the presence of water includes a polymerizable silane compound, or a monomeric silane compound and / or an oligomeric silane compound (in this specification, may be collectively referred to as "non-polymeric silane compound"), and preferably consists of a polymerizable silane compound or a non-polymeric silane compound. On the one hand, a silane compound-containing composition that is fixed or set usually contains a polymeric silane compound as the silane compound. Therefore, for example, even if the silane compound has fallen off from the fibrous structure due to physical action or the like in water or a hydraulic composition, the fallen silane compound will not hydrolyze or polymerize to form something like the water-repellent film described later.

[0013] The inventors have found that when the fibrous structure to which the composition of the present invention is attached is embedded in a hydraulic composition, the cured body obtained after the curing of the hydraulic composition has an improved water-repellent, hydrophobic and / or rust-preventive effect. Although the reason is not clear, the following non-limiting mechanism of action is conceivable.

[0014] He silane compound released from the fibrous structure in the hydraulic composition diffuses near the fibrous structure, where it hydrolyzes and polymerizes, and it is considered that a polymeric silane compound forms something like a water-repellent film (hereinafter sometimes referred to as a "film-like substance"). As a result, in the vicinity of the fibrous structure in the cured body, the polymeric silane compound is present at a higher concentration (locally) than in other places, and it is considered that the cured body can exhibit a water-repellent, hydrophobic and / or rust-preventive effect against moisture from the outside. Due to this local presence, it is considered that a sufficient water-repellent, hydrophobic and / or rust-preventive effect can be exhibited even if the amount of the silane compound incorporated is significantly less than when the silane compound-containing composition is incorporated throughout the cured body. In addition, by arranging the fibrous structure to which the composition or the like is attached at an appropriate position in the hydraulic composition, a film-like substance can be formed without unevenness or non-uniform distribution of the silane compound that causes insufficient water-repellent, hydrophobic and / or rust-preventive effects. By allowing a larger amount of silane compound-containing composition to adhere to the fiber structure, a larger amount of silane compound-containing composition can be released from the fiber structure in the hydraulic composition, resulting in an improved water-repellent, hydrophobic, and / or rust-preventive effect on the hardened body. On the other hand, while it is preferable for the silane compound-containing composition adhering to the fiber structure to be released from the fiber structure in the hydraulic composition, it is undesirable for it to detach (wash away) from the fiber structure by rain, for example, before burial in the hydraulic composition. Furthermore, even if a larger amount of silane compound-containing composition adheres to the fiber structure, it is undesirable for it not to be released from the fiber structure after burial in the hydraulic composition. Therefore, it is preferable that a larger amount of silane compound-containing composition is well retained on the fiber structure until burial in the hydraulic composition, and that a larger amount of silane compound-containing composition is well released from the fiber structure after burial in the hydraulic composition. The inventors have found that this combination of good retention and good release can be achieved by having a fibrous structure to which the composition is attached possess a specific configuration in the present invention, and in particular by having a specific amount of the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive attached to the fibrous structure.

[0015] The amount of silane compound-containing composition attached is 10 to 300 parts by mass, preferably 20 to 270 parts by mass, more preferably 40 to 240 parts by mass, and particularly preferably 50 to 220 parts by mass, per 100 parts by mass of a fiber structure that does not have the silane compound-containing composition and polyvinyl alcohol-based compound-containing additive attached. When the amount of silane compound-containing composition attached is within the above range, when the fiber structure to which the composition is attached is embedded in the hydraulic composition, the silane compound in the silane compound-containing composition can be released into the hydraulic composition in a sufficient amount and diffuse well. Furthermore, the possibility of problems caused by an excess amount of silane compound contained in the hydraulic composition (for example, a decrease in the strength of the hardened body of the unhardened body containing the hydraulic composition) can be reduced. The amount of silane compound-containing composition attached to the fiber structure can be determined by the method described in the examples below.

[0016] The amount of polyvinyl alcohol-based compound-containing additive attached is 0.05 to 35 parts by mass per 100 parts by mass of a fiber structure that does not have the silane compound-containing composition or the polyvinyl alcohol-based compound-containing additive attached. When the additive contains a polyvinyl alcohol-based compound and the amount of the additive attached to the fiber structure is within the above range, a larger amount of the silane compound-containing composition can be attached to and retained on the fiber structure. On the other hand, when the fiber structure to which the composition is attached is embedded in the hydraulic composition, a larger amount of the silane compound-containing composition can be suitably released into the hydraulic composition. Such release of the silane compound-containing composition makes it possible to obtain a cured body with improved water-repellent, hydrophobic, and / or rust-preventive effects. From the viewpoint of obtaining a fibrous structure to which a composition, etc., is attached, which results in a cured body having improved water-repellent, hydrophobic, and / or rust-preventive effects, the amount of polyvinyl alcohol-based compound-containing additive attached is preferably 0.1 to 25 parts by mass, more preferably 0.15 to 20 parts by mass, and particularly preferably 0.2 to 15 parts by mass, per 100 parts by mass of a fibrous structure to which the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive are not attached. The amount of polyvinyl alcohol-based compound-containing additive attached to the fiber structure can be determined by the method described in the examples below.

[0017] In a preferred embodiment, the ratio of the amount of polyvinyl alcohol-based compound-containing additive to the total amount of silane compound-containing composition and polyvinyl alcohol-based compound-containing additive is preferably 0.1 to 15% by mass, more preferably 0.15 to 14% by mass, even more preferably 0.2 to 13% by mass, even more preferably 0.25 to 12% by mass, and particularly preferably 0.3 to 11% by mass. When the ratio is within the above range, a larger amount of silane compound-containing composition is suitably retained on the fiber structure, and when the fiber structure to which the composition is attached is embedded in the hydraulic composition, it can be suitably released from the fiber structure in the hydraulic composition. The ratio can be determined by the method described in the examples below.

[0018] In a preferred embodiment, when a fibrous structure to which the composition is attached is immersed in water at 20-25°C for 240 minutes, the total release rate of the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive into the water is preferably 68% by mass or more, more preferably 70% by mass or more, even more preferably 72% by mass or more, and particularly preferably 74% by mass or more. A high total release rate indicates that, after some time has passed since the fibrous structure to which the composition is attached was embedded in the hydraulic composition, the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive are released more highly from the fibrous structure. Therefore, if the total release rate is above the lower limit, an improved water-repellent, hydrophobic, and / or rust-preventive effect can be obtained in the hardened body when the fibrous structure to which the composition is attached is embedded in the hydraulic composition. The upper limit of the total release rate is not limited, but may be 100% by mass. The total release rate can be adjusted to be above the lower limit by, for example, employing a method for manufacturing a fiber structure to which the composition described later is attached, preferably by employing an embodiment described as preferred in the method for manufacturing a fiber structure to which the composition described later is attached.

[0019] In one preferred embodiment, when a fibrous structure to which the composition is attached is immersed in water at 20-25°C for 5 minutes, the total release rate of the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive into the water is preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 35% by mass or less. A low total release rate indicates that the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive are less likely to detach (leak) from the fibrous structure when embedded in a hydraulic composition. For example, in the manufacturing process of an unhardened body containing a hydraulic composition, a fibrous structure to which the composition is attached, and reinforcing bars, when the fibrous structure to which the composition is attached is wrapped around multiple reinforcing bars arranged vertically at intervals, it indicates that the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive are less likely to detach from the fibrous structure due to rain or the like. Therefore, if the total release rate is below the upper limit, an improved water-repellent, hydrophobic, and / or rust-preventive effect may be brought to the hardened body when a fibrous structure to which the composition is attached is embedded in the hydraulic composition. The lower limit of the total release rate is not limited, but is usually 25% by mass or more, preferably 30% by mass or more. The total release rate can be adjusted to be below the upper limit and above the lower limit by, for example, employing a method for manufacturing a fiber structure to which the composition described later is attached, preferably by employing an embodiment described as preferred in the method for manufacturing a fiber structure to which the composition described later is attached. The total release rate after immersion for 240 minutes or 5 minutes, as described above, can be measured by the method described in the examples below.

[0020] <Fiber structure> In a preferred embodiment, the fiber structure is one or more selected from the group consisting of filamentous fibers, woven fabrics, knitted fabrics, nets, meshes, nonwoven fabrics, unidirectional fiber bundles, spun yarns, ropes, and braided cords. As will be described later, the uncured material in the present invention may optionally contain synthetic staple fibers. However, synthetic staple fibers are not included in the fiber structure. When the fiber structure is a filamentous fiber, unidirectional fiber bundle, spun yarn, or braided cord, its longitudinal length is preferably 100 mm or more, more preferably 500 mm or more. Examples of woven fabrics include plain weave, twill weave, satin weave, triaxial weave, quadriaxial weave, twist weave, and leno weave. Examples of knitted fabrics include tricot, raschel, and Milanese. Examples of meshes include knotted meshes such as rib nets, frog-toe nets, and double frog-toe nets, as well as knotless meshes such as raschel nets, twist nets, woven nets, and meteric fiber nets. Furthermore, the mesh of the net can be shaped in various ways, such as diamond, tortoise, square, staggered, or hexagonal. Of these, knotless nets, which have no knots and flat connecting sections, are preferred from the viewpoint of ease of handling and installation.

[0021] The shape and mesh size of woven, knitted, and nonwoven fabrics, as well as the spacing or mesh size when forming a fiber structure by arranging multiple long fibers in a specific shape (e.g., a spaced arrangement or a grid), are determined appropriately depending on the application. Typically, the mesh size of woven, knitted, and nonwoven fabrics, as well as the spacing or mesh size when forming a fiber structure by arranging multiple long fibers in a specific shape, is between 20 and 120 mm.

[0022] The average fiber diameter of the fibers constituting the fibrous structure is preferably 1 to 50 μm, more preferably 2.5 to 45 μm, and even more preferably 5 to 40 μm. When the average fiber diameter is within the above range, the retention of silane compounds and polyvinyl alcohol-based compounds can be improved. The average fiber diameter can be determined in accordance with JIS L 1015 "Test Method for Chemical Fiber Staples (8.5.1)".

[0023] The average diameter of the braided cord is preferably 0.5 to 10 mm, more preferably 1 to 7 mm, and even more preferably 1.5 to 5 mm. When the average diameter is within the above range, the retention of silane compounds and polyvinyl alcohol-based compounds is improved, and handling during installation is also improved. The average diameter can be determined by measuring the diameter of any number of points (e.g., 10 points) using a scanning electron microscope or optical microscope and calculating the average value.

[0024] In a preferred embodiment, the fibers constituting the fibrous structure are organic or inorganic fibers. Examples of organic fibers include polyvinyl alcohol fibers, aramid fibers, polypropylene fibers, cellulose fibers, polyester fibers, and polyamide fibers, while examples of inorganic fibers include glass fibers and carbon fibers. If reinforcing and crack suppression effects are desired, high-strength fibers that do not decrease in strength in the presence of alkali, such as polyvinyl alcohol fibers, aramid fibers, polypropylene fibers, glass fibers, and carbon fibers, can be suitably used.

[0025] In another preferred embodiment, the fibers constituting the fibrous structure do not have acidic or basic functional groups, but rather hydrophilic functional groups. Because the fibers do not have acidic or basic functional groups, polymerization of silane compounds is less likely to occur on or near the fiber surface, enabling good release and diffusion of nonpolymer silane compounds into the cement-containing hydraulic composition. Furthermore, because the fibers have hydrophilic functional groups, a sufficient amount of the silane compound-containing composition can adhere to the fibrous structure, and a sufficient amount of nonpolymer silane compounds can be released and diffused into the cement-containing hydraulic composition. In other words, fibers that do not have acidic or basic functional groups, but have hydrophilic functional groups, can possess both the ability to retain a large amount of silane compounds as nonpolymer silane compounds and the ability to release a large amount of nonpolymer silane compounds.

[0026] The fiber structure may be composed of a combination of two or more fibers that differ in one or more aspects, such as average fiber diameter, composition, and degree of saponification of the polyvinyl alcohol fibers described later, or it may be composed solely of the same fibers.

[0027] An example of a fiber that does not have acidic or basic functional groups but has hydrophilic functional groups is polyvinyl alcohol fiber. Therefore, in one embodiment, it is preferable that the fibers constituting the fiber structure are polyvinyl alcohol fibers. Note that polyvinyl alcohol fibers as fibers constituting the fiber structure are not water-soluble. The fact that polyvinyl alcohol fibers are not water-soluble can be confirmed by the method described in the examples below.

[0028] Polyvinyl alcohol fibers are fibers containing a vinyl alcohol-based polymer. From the viewpoint of mechanical strength, alkali resistance, and hydrophilicity, the content of the vinyl alcohol-based polymer in polyvinyl alcohol fibers is preferably 30% by mass or more, more preferably 60% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 100% by mass.

[0029] The polyvinyl alcohol fiber may be a composite fiber with other polymers or a sea-island fiber, as long as it does not impair the effects of the present invention. The vinyl alcohol polymer is mainly composed of polyvinyl alcohol, and may be copolymerized with other monomers other than vinyl alcohol, or modified, as long as it does not impair the effects of the present invention. From the viewpoint of the mechanical strength and alkali resistance of the fiber, the ratio of modified units in the vinyl alcohol polymer is preferably 30 mol% or less, more preferably 10 mol% or less. Also from the viewpoint of the mechanical strength and alkali resistance of the fiber, the average degree of polymerization (viscosity-average degree of polymerization) of the vinyl alcohol polymer determined by the viscosity method in an aqueous solution at 30°C is preferably 1000 or more, more preferably 1500 or more, and from the viewpoint of manufacturing cost, it is preferably 10000 or less, more preferably 5000 or less, and even more preferably 3000 or less. Also from the viewpoint of heat resistance, durability, dimensional stability, and retention of nonpolymer silane compounds, the degree of saponification is preferably 99 mol% or more, more preferably 99.8 mol% or more.

[0030] Polyvinyl alcohol fibers can be prepared, for example, by the following method. The vinyl alcohol polymer described above is made into a hydrated chip with a concentration of 40-60% by mass, heated and dissolved in an extruder, and then degassed. Next, a crosslinking agent is added to this aqueous solution of vinyl alcohol polymer to obtain a spinning solution. Examples of crosslinking agents include ammonium sulfate, sulfuric acid, ammonium phosphate, phosphoric acid, hydrochloric acid, nitric acid, acetic acid, and oxalic acid. Ammonium sulfate is preferred from the viewpoint of not corroding pipes, not producing a foul odor, and not causing foaming of the fibers. The amount of crosslinking agent added is preferably 0.5-10% by mass relative to the mass of the vinyl alcohol polymer. The temperature of the spinning solution is preferably 90-140°C. Subsequently, the spinning solution is pressurized and discharged into the air from a nozzle hole for dry spinning. The nozzle hole may be circular, or it may be an irregular shape other than circular, such as flat, cross-shaped, T-shaped, Y-shaped, L-shaped, triangular, square, or star-shaped. The spinning method may be wet, wet-dry, or dry.

[0031] Next, the polyvinyl alcohol fibers obtained by spinning are dried. The drying temperature is usually 100°C or lower, and it is preferable to dry them completely at a temperature of 100°C or higher after they have dried to a certain extent.

[0032] After drying, the fibers are stretched. Stretching is usually carried out at a temperature of 200-250°C, preferably 220-240°C. The stretch ratio is usually 5 times or more, preferably 6 times or more. During stretching, the crosslinking agent added to the spinning solution reacts with the OH groups of polyvinyl alcohol, forming crosslink bonds. Stretching is carried out in a hot-air stretching furnace for approximately 20 seconds to 3 minutes. The stretched fibers are then heat-treated as needed to achieve a specific length or shrinkage.

[0033] Commercially available fibers may be used as the fibers that make up the fibrous structure. The method for producing fiber structures from fibers is not particularly limited, and known methods can be used.

[0034] <Additives containing polyvinyl alcohol-based compounds> The additives attached to the fiber structure include one or more polyvinyl alcohol-based compounds. From the viewpoint of the release of silane compound-containing compositions in hydraulic compositions, it is preferable that the additives be water-soluble. Therefore, it is also preferable that the polyvinyl alcohol-based compounds are water-soluble. The water solubility of the additives and polyvinyl alcohol-based compounds can be confirmed by the methods described in the examples below.

[0035] The viscosity-average degree of polymerization of polyvinyl alcohol compounds is preferably 100 to 2,400, more preferably 300 to 2,100, and particularly preferably 500 to 1,800, from the viewpoint of retention of a larger amount of silane compound-containing composition to the fiber structure and release from the fiber structure into the hydraulic composition. The viscosity-average degree of polymerization of polyvinyl alcohol compounds can be measured by the method described in the examples below. If the additive contains two or more polyvinyl alcohol compounds, the viscosity-average degree of polymerization corresponding to their composition ratio may be adopted as the viscosity-average degree of polymerization of the polyvinyl alcohol compounds contained in the additive.

[0036] The degree of saponification of the polyvinyl alcohol compound is preferably 75 to 100 mol%, more preferably 88 to 99 mol%, from the viewpoint of the solubility of the polyvinyl alcohol compound-containing additive in water. The degree of saponification of the polyvinyl alcohol compound can be measured by the method described in the examples below. If the additive contains two or more polyvinyl alcohol compounds, the degree of saponification corresponding to their composition ratio may be adopted as the degree of saponification of the polyvinyl alcohol compound contained in the additive. When the polyvinyl alcohol compound is modified polyvinyl alcohol, the degree of saponification of the modified polyvinyl alcohol is preferably 88 to 100 mol%, more preferably 90 to 99.9 mol%, from the viewpoint of the solubility of the polyvinyl alcohol compound-containing additive in water.

[0037] The polyvinyl alcohol-based compound is preferably one or more selected from the group consisting of modified polyvinyl alcohol and unmodified polyvinyl alcohol. From the viewpoint of retention of a larger amount of silane compound-containing composition to the fiber structure and release from the fiber structure into the hydraulic composition, it is preferable that the additive contains one or more modified polyvinyl alcohols, and more preferably that the polyvinyl alcohol-based compound contained in the additive consists of one or more modified polyvinyl alcohols.

[0038] The degree of modification of the modified polyvinyl alcohol is preferably 0.1 to 10 mol%, more preferably 0.5 to 9.5 mol%, even more preferably 1 to 9.0 mol%, and particularly preferably 1.5 to 8.5 mol%, from the viewpoint of retention of a larger amount of silane compound-containing composition to the fibrous structure and release from the fibrous structure into the hydraulic composition. The degree of modification of the modified polyvinyl alcohol is the amount of structural units derived from the modified monomer when the total structural units of the modified polyvinyl alcohol are set to 100 mol%. The degree of modification of the modified polyvinyl alcohol, as well as the types and proportions of structural units contained in the modified polyvinyl alcohol, as described later, are, for example, solid 1 The degree of modification can be measured using 1H-NMR (nuclear magnetic resonance spectroscopy), more specifically by the method described in the examples below. The degree of modification of modified polyvinyl alcohol can also be determined from the monomer charging ratio when preparing the modified polyvinyl alcohol.

[0039] The modified polyvinyl alcohol preferably has structural units derived from an unsaturated carboxylic acid or a derivative thereof. The unsaturated carboxylic acid or a derivative thereof is preferably at least one selected from the group consisting of (meth)acrylic acid, alkyl (meth)acrylate, and metal salts of (meth)acrylic acid. When the modified polyvinyl alcohol contained in the additive has these structural units, the additive can adhere to and retain a larger amount of the silane compound-containing composition on the fiber structure, and when the fiber structure to which the composition is attached is embedded in a hydraulic composition, the release of the silane compound-containing composition from the fiber structure cannot be inhibited or suppressed. In this specification, the term "(meth)acrylic" means "acrylic and / or methacrylic".

[0040] Examples of alkyl (meth)acrylate esters include esters of (meth)acrylic acid with linear or branched alcohols having 1 to 5 carbon atoms. Specific examples include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and pentyl (meth)acrylate. Examples of metal salts of (meth)acrylic acid include alkali metal salts of (meth)acrylic acid. Examples of alkali metal elements include lithium, sodium, and potassium.

[0041] When modified polyvinyl alcohol has structural units derived from an unsaturated carboxylic acid or its derivative (hereinafter also referred to as "structural unit (X)"), and the modification amount is 0.1 to 10 mol%, it is considered that most of the structural units (X) exist adjacent to the vinyl alcohol structural units. In this case, structural units (X) and vinyl alcohol structural units may exist as separate structural units (monomer units), but at least some of the multiple structural units (X) may be included in a ring-closed structural unit (hereinafter also referred to as "ring-closed structural unit") formed with the hydroxyl group contained in the adjacent vinyl alcohol structural unit. Although such ring-closed structural units are also included in structural unit (X), when calculating the above modification amount, the ring-closed structural unit is not considered as a single structural unit, but rather the pre-ring-closed structural unit (X) and the vinyl alcohol structural unit, which are structural units corresponding to monomers, are considered as separate structural units.

[0042] When modified polyvinyl alcohol has the above-mentioned ring-closed structural units, its solubility in water is low due to these units. Therefore, if the polyvinyl alcohol-based compound-containing additive attached to the fiber structure contains such modified polyvinyl alcohol, the possibility of the polyvinyl alcohol-based compound-containing additive detaching (leaching) from the fiber structure by rain, for example, before burying in the hydraulic composition can be reduced, and as a result, the possibility of the silane compound-containing composition detaching from the fiber structure can be reduced. The above-mentioned ring-closed structural unit exhibits very high ring-opening properties, especially when in contact with water under alkaline conditions. Modified polyvinyl alcohol having the ring-opened structural unit (X) has high solubility in water. Therefore, in a hydraulic composition that is normally alkaline, the above-mentioned ring-closed structural unit can rapidly open its ring. Thus, if a polyvinyl alcohol-based compound-containing additive attached to a fiber structure contains modified polyvinyl alcohol having the above-mentioned ring-closed structural unit, the polyvinyl alcohol-based compound-containing additive can rapidly dissolve in the hydraulic composition after the fiber structure to which the composition is attached is embedded, and the silane compound-containing composition can be rapidly released and diffused from the fiber structure.

[0043] In a preferred embodiment of the present invention, the modified polyvinyl alcohol is used as a structural unit (X) derived from an unsaturated carboxylic acid or its derivative, with respect to the retention of a larger amount of silane compound-containing composition to the fibrous structure and its release from the fibrous structure into the hydraulic composition, using formula (X1): [ka] [In formula (X1), X is either a hydrogen atom or a methyl group.] A structural unit represented by and / or formula (X2): [ka] [In formula (X2), X is a hydrogen atom or a methyl group, and Y is a hydrogen atom, an alkali metal atom, or an alkyl group having 1 to 5 carbon atoms.] It includes structural units represented by .

[0044] The structural unit represented by formula (X2) is derived from at least one selected from the group consisting of (meth)acrylic acid, alkyl (meth)acrylic acid esters, and metal salts of (meth)acrylic acid, and when structural unit (X2) undergoes ring closure with an adjacent vinyl alcohol structural unit, it becomes structural unit (X1).

[0045] The modified polyvinyl alcohol may contain one structural unit represented by formula (X1), or two structural units represented by formula (X1). Furthermore, the modified polyvinyl alcohol may contain one structural unit represented by formula (X2), or two or more structural units represented by formula (X2). In addition to one or more structural units represented by formula (X1) and / or one or more structural units represented by formula (X2), the modified polyvinyl alcohol may have further structural units.

[0046] When the modified polyvinyl alcohol contains structural units represented by formula (X1) and / or structural units represented by formula (X2), the ratio of the molar amount of the structural units represented by formula (X1) to the total molar amount of the structural units represented by formula (X1) and formula (X2) (X1 / (X1+X2)) is preferably 0.65 to 1.0, more preferably 0.70 to 0.99, even more preferably 0.85 to 0.99, and particularly preferably 0.90 to 0.99. If the content ratio of the structural units represented by formula (X1) is above the lower limit, the possibility of the polyvinyl alcohol-based compound-containing additive detaching (leaching) from the fiber structure by, for example, rain, before burying in the hydraulic composition can be reduced, and as a result, the possibility of the silane compound-containing composition detaching from the fiber structure can be reduced. As a result, a larger amount of silane compound can be released into the hydraulic composition, and the cured body of the hydraulic composition can have improved water-repellent, hydrophobic, and / or rust-preventive effects.

[0047] In a preferred embodiment of the present invention, the modified polyvinyl alcohol contains at least structural units represented by formula (X1). In this embodiment, the amount of structural units represented by formula (X1) is preferably 0.1 to 10 mol%, more preferably 0.5 to 10 mol%, more preferably 1 to 9.5 mol%, and particularly preferably 2 to 9 mol%, when the total amount of structural units of the modified polyvinyl alcohol is 100 mol%. When the amount of structural units represented by formula (X1) is within the above range, the possibility of the polyvinyl alcohol-based compound-containing additive detaching (leaching) from the fiber structure by, for example, rain, before burial in the hydraulic composition can be reduced, and as a result, the possibility of the silane compound-containing composition detaching from the fiber structure can be reduced. As a result, a larger amount of silane compound can be released into the hydraulic composition, and the cured body of the hydraulic composition can have improved water-repellent, hydrophobic, and / or rust-preventive effects.

[0048] The polyvinyl alcohol compound-containing additive may optionally contain conventionally known additive components in addition to the polyvinyl alcohol compound. Examples of such additive components include thickeners, pH buffers, pH adjusters, silica sols, alumina sols, ceria sols, ultraviolet absorbers, water-soluble polymers other than water-soluble polyvinyl alcohol compounds, organic emulsion polymers, fungicides, algaecides, and termite repellents. These additive components may be included in the polyvinyl alcohol compound-containing additive individually or in combination of two or more, and if included, their amounts may be appropriately selected.

[0049] <Method for preparing unmodified polyvinyl alcohol and modified polyvinyl alcohol> Unmodified polyvinyl alcohol can be prepared by polymerizing vinyl ester monomers by known methods, saponifying the resulting polymer by known methods, and then subjecting it to washing and heat treatment. To improve efficiency, the polymer may be neutralized by acid treatment after saponification, followed by washing and heat treatment. Modified polyvinyl alcohol can be prepared in the same manner as unmodified polyvinyl alcohol, except that during polymerization, a monomer having a carbonyl group (an unsaturated carboxylic acid or its derivative) is used in addition to vinyl ester monomers, and these monomers are copolymerized.

[0050] Examples of vinyl ester monomers used in the preparation of unmodified and modified polyvinyl alcohol include vinyl acetate, vinyl propionate, and vinyl formate. From an economic standpoint, vinyl acetate is preferred. Examples of monomers having a carbonyl group that can be used in the preparation of modified polyvinyl alcohol include acrylic acid, methacrylic acid, and alkyl esters of these carboxylic acids. Methyl esters and ethyl esters are preferably used as the alkyl esters. Carboxylate salts obtained by partially or completely neutralizing these carboxylic acids and esters are also preferably used. Furthermore, vinyl monomers containing a lactone ring in the side chain may also be used.

[0051] It is important to perform heat treatment in order for at least some of the multiple structural units (X) to form ring-closed structural units with hydroxyl groups contained in adjacent vinyl ester monomer-derived structural units (vinyl alcohol structural units). The method of heat treatment is not particularly limited, but it is preferable to use, for example, a hot air dryer or a rotary dryer. The heating temperature is preferably 60 to 150°C, more preferably 80 to 150°C. The heating time is preferably 1 to 10 hours, more preferably 2 to 8 hours. Through the above heat treatment, for example, the ratio of structural units (X1) to the total amount of structural units (X2) can be adjusted to the above-mentioned preferred range.

[0052] <Compositions containing silane compounds> The composition attached to the fiber structure contains one or more silane compounds. A silane compound is a compound having a silane group in its molecule. The silane compound preferably includes a polymerizable silane compound, and more preferably consists of polymerizable silane compounds. A polymerizable silane compound is a silane compound having two or more polymerizable groups. The polymerizable groups are preferably hydrolyzable polymerizable groups, and examples include alkoxy groups having 1 to 10 carbon atoms, such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentyloxy, and hexyloxy groups. The hydrolyzable polymerizable groups are preferably alkoxy groups having 1 to 4 carbon atoms, and more preferably methoxy, ethoxy, and propoxy groups. The two or more polymerizable groups contained in the polymerizable silane compound may be the same group or different groups.

[0053] The silane compound preferably includes a nonpolymer silane compound, and more preferably consists of a nonpolymer silane compound. The silane compound preferably includes a monomeric silane compound. The silane compound may also include a polymeric silane compound.

[0054] Non-polymer silane compounds adhering to a fiber structure readily leach out of the fiber structure in the presence of water (e.g., by washing). On the other hand, polymer silane compounds that may adhere to a fiber structure do not leach out of the fiber structure in the presence of water (although some polymer silane compounds may detach from the fiber structure by washing). Therefore, if the uncured material includes a fiber structure to which a composition containing a silane compound including a non-polymer silane compound is adhering, the non-polymer silane compound will readily be released from the fiber structure. The proportion of non-polymer silane compounds and, if present, polymer silane compounds in the silane compounds attached to the fiber structure can be adjusted, for example, by the temperature or time in the heat treatment process for attaching the silane compounds to the fiber structure, and / or by the material of the fibers constituting the fiber structure or the type of coating, attachment, or covering component on the fiber surface, and / or the amount of polyvinyl alcohol-based compound-containing additive.

[0055] As described above, nonpolymer silane compounds adhering to fiber structures readily leach out of the fiber structure in the presence of water. However, this leaching can be suitably suppressed by the fiber structure to which the composition is attached having a specific configuration according to the present invention, and in particular by the fiber structure being adhering to a specific amount of polyvinyl alcohol-based compound-containing additive.

[0056] In one embodiment, the silane compound is one or more compounds selected from the group consisting of organosilanes and organosiloxanes. Organosilanes preferably include alkylalkoxysilanes and aminosilanes. Organosilanes and organosiloxanes may be alone or in combination of two or more.

[0057] Examples of alkylalkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, nonyltrimethoxysilane, nonyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, cyclohexyltriethoxysilane, cyclohexyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and methyloctyldimethoxysilane and methyloctyldiethoxysilane.

[0058] Examples of aminosilanes include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, aminobutyltrimethoxysilane, aminobutyltriethoxysilane, aminopropylmethyldiethoxysilane, and n-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

[0059] Examples of organosiloxanes include oligomers or polymers of the organosilanes mentioned above. From the viewpoint of good release from the fibrous structure, the organosiloxane is preferably an oligomer of an organosilane.

[0060] The silane compound-containing composition to be attached to the fiber structure may be a commercially available product. Examples of such commercially available products include Protectosil® WA CIT from Evonik Industries, Protectosil® WS670 from Evonik Industries, and MasterProtect H400 from Pozzolith Solutions Inc.

[0061] The silane compound-containing composition attached to the fiber structure is preferably derived from an emulsion. That is, it is preferable to attach a silane compound-containing composition in emulsion form to the fiber structure. According to the inventors' studies, it has been found that in uncured structures containing a polyvinyl alcohol-based compound-containing additive and the silane compound itself (not the silane compound-containing composition), and a cement-containing hydraulic composition, the silane compound may not be released well from the fiber structure into the cement-containing hydraulic composition. The reason for this is not clear, and it is not intended to be limited to the reasons below, but when the polyvinyl alcohol-based compound-containing additive and the silane compound itself are attached to the fiber structure, the silane compound polymerizes on or near the surface of the fiber structure and cannot diffuse from the fiber structure into the cement-containing hydraulic composition. On the other hand, when a silane compound-containing composition (preferably an emulsion) is attached to the fiber structure, the silane compound-containing composition does not polymerize or polymerizes very little on or near the surface of the fiber structure and can diffuse from the fiber structure into the cement-containing hydraulic composition. When the silane compound-containing composition to be attached to the fiber structure is an emulsion, the nonpolymer silane compound present in the oil droplets of the emulsion adheres to the fiber structure, and it is thought that the nonpolymer silane compound is readily released into the cement-containing hydraulic composition and can diffuse near the fiber structure.

[0062] The concentration of the silane compound in the silane compound-containing composition to be attached to the fiber structure is preferably 10 to 90% by mass, more preferably 30 to 70% by mass, and even more preferably 40 to 60% by mass, relative to the mass of the silane compound-containing composition. When the concentration of the silane compound in the silane compound-containing composition is within the above range, polymerization is less likely to occur on or near the surface of the fiber structure, and good release and diffusion of the nonpolymer silane compound into the cement-containing hydraulic composition can be achieved.

[0063] A silane compound-containing composition to be attached to a fiber structure preferably contains an emulsifier. In particular, if the silane compound-containing composition is an emulsion, the composition usually further contains an emulsifier in addition to the silane compound and water. Known emulsifiers can be used as such, and specific examples include nonionic emulsifiers such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene fatty acid esters, dimethylsiloxane copolymers in which the side chain or terminal of dimethylsiloxane is modified with polyalkylene oxide, and celluloses; anionic emulsifiers such as alkylbenzene sulfonates, higher alcohol sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylphenyl ether sulfates, and alkylnaphthylates; and cationic emulsifiers such as alkylamine salts and quaternary ammonium salts. These emulsifiers may be included in silane compound-containing compositions individually or in combination of two or more.

[0064] The concentration of the emulsifier in the silane compound-containing composition as an emulsion can be selected as appropriate, and is usually 0.1% to 20% by mass, preferably 0.5% to 15% by mass, and more preferably 1.0% to 10% by mass, relative to the mass of the emulsion.

[0065] The silane compound-containing composition to be attached to the fibrous structure may optionally contain conventionally known additives. Examples of such additives include thickeners, pH buffers, pH adjusters, silica sols, alumina sols, ceria sols, ultraviolet absorbers, water-soluble polymers, organic emulsion polymers, fungicides, algaecides, and termite repellents. These additives may be included in the silane compound-containing composition individually or in combination of two or more, and if included, their amounts may be appropriately selected.

[0066] [Method for manufacturing a fibrous structure to which a composition or other substance is attached] A fibrous structure to which a composition is attached can be produced, for example, by attaching a silane compound-containing composition and a polyvinyl alcohol-based compound-containing additive to a fibrous structure using a common method such as immersion, spraying, or coating, and then extracting and / or drying the liquid as necessary. Alternatively, if the fibrous structure is a woven fabric, knitted fabric, nonwoven fabric, unidirectional fiber bundle, or braided cord, the fibrous structure may be produced using fibers to which a silane compound-containing composition and a polyvinyl alcohol-based compound-containing additive is attached, and then extracted and / or dried as necessary. From the viewpoint of uniform adhesion, it is preferable that both the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive to be attached are in liquid form, such as a solution or dispersion.

[0067] The silane compounds that can be incorporated into the silane compound-containing composition to be attached, and the silane compound-containing composition to be attached, are subject to the descriptions given in the preceding section <Compositions Containing Silane Compounds>. The polyvinyl alcohol compounds that can be incorporated into the polyvinyl alcohol compound-containing additive to be attached, and the polyvinyl alcohol compound-containing additive to be attached, must conform to the descriptions given in the previous section <Additives containing polyvinyl alcohol compounds>.

[0068] When the silane compound-containing composition to be attached is an emulsion, general mixing and emulsification methods can be used to prepare the emulsion. For example, an emulsion can be prepared by stirring with a stirrer, homomixer, ultradisperser, high-pressure homogenizer, etc., and adding the silane compound, usually an emulsifier, and optionally an additive separately or pre-mixed, to water little by little or all at once, or by adding the silane compound little by little or all at once to a mixture of water, usually an emulsifier, and optionally an additive.

[0069] When the polyvinyl alcohol-based compound-containing additive to be attached is in liquid form (e.g., aqueous solution), a general mixing method can be used for its preparation. For example, a liquid polyvinyl alcohol-based compound-containing additive can be prepared by stirring with a stirrer, homomixer, ultradisperser, high-pressure homogenizer, etc., and adding the polyvinyl alcohol-based compound and any additive separately or pre-mixed and then gradually or all at once to water, or by adding the polyvinyl alcohol-based compound gradually or all at once to a mixture of water and any additive.

[0070] When the polyvinyl alcohol-based compound-containing additive to be attached is an aqueous solution, the concentration of the polyvinyl alcohol-based compound-containing additive in the aqueous solution is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, and particularly preferably 10 to 20% by mass. When the concentration is within the above range, uniform attachment to the fiber structure or fibers, as well as efficient water removal, can be achieved.

[0071] Next, the liquid silane compound-containing composition and the liquid polyvinyl alcohol-based compound-containing additive may be applied to the fiber structure or fibers one or more times in any order. Alternatively, a mixture containing the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive may be prepared, and this mixture may be applied to the fiber structure or fibers. This mixture may be prepared by mixing the liquid silane compound-containing composition and the liquid polyvinyl alcohol-based compound-containing additive prepared as described above in a general manner, or by mixing the silane compound-containing, polyvinyl alcohol-based compound-containing additive, and optionally emulsifiers and additives in a general manner.

[0072] The fiber structure or fibers to which the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive are attached are subjected to liquid extraction and / or drying as necessary. Liquid extraction and drying can be carried out by general methods, but the temperature at which they are performed is preferably less than 130°C, more preferably 100°C or less, even more preferably 80°C or less, and particularly preferably 60°C or less, from the viewpoint of avoiding the silane compound-containing composition adhering to or setting on the fiber structure or fibers. Examples of general methods for liquid extraction include centrifugal dehydration and nip dehydration. Reduced pressure may also be applied during drying. The degree of drying can be selected as appropriate, and drying may be continued until a constant weight is reached.

[0073] [Uncured body] The present invention also applies to an unhardened body comprising the fibrous structure of the present invention and a cement-containing hydraulic composition (which may be referred to herein as "cement-containing hydraulic composition" or "hydraulic composition"), wherein the fibrous structure is embedded in the hydraulic composition. In this specification, "uncured body" refers to a stage in which a fibrous structure to which a composition is attached has been embedded in a cement-containing hydraulic composition, or a stage in which the hydraulic composition to which the fibrous structure to which the composition is attached has hardened to some extent but is not yet complete. When this uncured body is allowed to harden through known processes such as being left for a long period of time, it becomes a hardened body. In this specification, "embedded" means that the fibrous structure is surrounded by the hydraulic composition. Therefore, all embedded fibrous structures to which the composition is attached exist within the uncured material and are not exposed from the uncured material.

[0074] In one preferred embodiment of the uncured material, the total amount of silane compounds and polyvinyl alcohol compounds per 100 g of cement within a range of 10 mm from the fibrous structure is greater than the total amount of silane compounds and polyvinyl alcohol compounds per 100 g of cement in the entire uncured material. Here, the "range within 10 mm from the fibrous structure" as described herein does not include the fibrous structure, or anything fixed or set to the surface of the fibrous structure or fibers. That is, the range within 10 mm from the fibrous structure means the range from more than 0 mm to within 10 mm from the fibrous structure. Also, in this case, the volume of the uncured material within a range of 10 mm from the fibrous structure is smaller than the total volume of the uncured material.

[0075] One preferred embodiment of the uncured material described above shows that a localized high concentration of silane compounds released from the fibrous structure is present in the hydraulic composition near the fibrous structure in the uncured material (specifically, the hydraulic composition within 10 mm of the fibrous structure). Therefore, if the amount of silane compounds within 10 mm of the fibrous structure is greater than the amount of silane compounds per 100 g of cement in the entire uncured material, the desired uneven distribution of silane compounds in the uncured material can be achieved. Due to this uneven distribution, sufficient water-repellent, hydrophobic, and / or rust-preventive effects can be achieved in the cured material even with a significantly lower amount of silane compounds compared to when a silane compound-containing composition, or cut fibers mixed with or coated with a silane compound-containing composition, are incorporated into the entire cured material. Such uneven distribution of silane compounds can be achieved by producing an uncured product using a fibrous structure to which the composition of the present invention is attached, and in particular by producing an uncured product using a fibrous structure to which the composition of the present invention is attached, as described in the preferred embodiment.

[0076] The total amount of silane compounds and polyvinyl alcohol-based compounds per 100g of cement in a specific region of the unhardened material or in the entire unhardened material can be measured, for example, using pyrolysis gas chromatography. Here, the amount of silane compound or, if the silane compound has an alkyl group, the amount of such alkyl group (hereinafter sometimes referred to as "silane compound-derived alkyl group") and the amount of polyvinyl alcohol compound or, if the polyvinyl alcohol compound has an alkyl group, the amount of such alkyl group (hereinafter sometimes referred to as "polyvinyl alcohol compound-derived alkyl group") remain substantially unchanged due to the curing of the hydraulic composition. Therefore, the amount of silane compound or silane compound-derived alkyl group and polyvinyl alcohol compound or polyvinyl alcohol compound-derived alkyl group in the entire uncured body can be considered equivalent to the amount of silane compound or silane compound-derived alkyl group and polyvinyl alcohol compound or polyvinyl alcohol compound-derived alkyl group in the entire cured body obtained by curing the uncured body. Furthermore, the amount of silane compound or silane compound-derived alkyl group and polyvinyl alcohol compound or polyvinyl alcohol compound-derived alkyl group in a specific region of the uncured body can be considered equivalent to the amount of silane compound or silane compound-derived alkyl group and polyvinyl alcohol compound or polyvinyl alcohol compound-derived alkyl group in the cured body obtained by cutting out and curing the uncured body in that specific region. Furthermore, the amount of silane compounds or alkyl groups derived from silane compounds and polyvinyl alcohol compounds or alkyl groups derived from polyvinyl alcohol compounds in a specific region of an uncured body that has undergone some degree of curing can be considered equivalent to the amount of silane compounds or alkyl groups derived from silane compounds and polyvinyl alcohol compounds or alkyl groups derived from polyvinyl alcohol compounds in the same specific region of a cured body obtained by curing the uncured body.

[0077] An example of a specific measurement method using pyrolysis gas chromatography is shown below. Hydraulic compositions are prepared by adding different amounts of silane compounds and polyvinyl alcohol compounds to each of several mortars with a W / C ratio of 50% by mass and a cement-to-fine aggregate mass ratio of 1:3, and mixing until homogeneous. Each hydraulic composition is poured into a wooden formwork, the poured surface of the wooden formwork is wrapped and sealed, and after 28 days the seal is removed and the formwork is demolded. A hardened body is obtained by leaving it in an environment of 20°C and 60% RH for 30 days or more. Samples are cut out from each hardened body, and the amount of hydrocarbons derived from alkyl groups detached from the silane compound and / or polyvinyl alcohol compound in the sample is measured by pyrolysis gas chromatography to create a calibration curve. Specifically, the cut-out sample is pulverized to a maximum size of 250 μm or less, 10 mg of it is placed on the sample stage, and the chamber is replaced with nitrogen gas. Next, the temperature is increased from 60°C to the set temperature of 260°C at a rate of 10°C / min, held at 260°C for 8 minutes, and then cooled to 60°C. A mass spectrum is obtained for the hydrocarbon gas generated from the sample, and a calibration curve is prepared for the mass (g) of hydrocarbons derived from alkyl groups detached from silane compounds and / or polyvinyl alcohol-based compounds contained in the sample, per 100g of cement contained in the sample. Next, for the hardened body to be measured, a mass spectrum is obtained using pyrolysis gas chromatography, following the same procedure as above, except that the entire hardened body is ground instead of grinding a sample cut from it. Furthermore, for another hardened body to be measured, a mass spectrum is obtained using pyrolysis gas chromatography, following the same procedure as above, except that a sample from within 10 mm of the fibrous structure is cut and ground. Using the obtained mass spectrum and the prepared calibration curve, the mass (g) of hydrocarbons derived from alkyl groups detached from silane compounds and / or polyvinyl alcohol compounds contained in the hardened body per 100g of cement, and the mass (g) of hydrocarbons derived from alkyl groups detached from silane compounds and / or polyvinyl alcohol compounds contained in a hardened body excision piece within 10mm of the fibrous structure excised from the hardened body per 100g of cement are determined. The alkyl groups mentioned above are alkyl groups possessed by silane compounds and / or polyvinyl alcohol-based compounds, i.e., alkyl groups derived from silane compounds and / or polyvinyl alcohol-based compounds. A high amount of alkyl group-derived hydrocarbons per 100g of cement detected by pyrolysis gas chromatography-mass spectrometry of the sample indicates a high amount of silane compounds and / or polyvinyl alcohol-based compounds in the sample.

[0078] When examining the amount of silane compounds or alkyl groups derived from silane compounds and polyvinyl alcohol compounds or alkyl groups derived from polyvinyl alcohol compounds within a 10 mm range from the fiber structure in an uncured material, for example, if the fiber structure to which the composition is attached is a fabric or the like which is positioned horizontally to the bottom surface of the uncured material, the amount of silane compounds or alkyl groups derived from silane compounds and polyvinyl alcohol compounds or alkyl groups derived from polyvinyl alcohol compounds will be examined within a 10 mm range below and 10 mm above the fabric or the like. However, in an uncured material, silane compounds released from the fiber structure can usually be released in any direction, not just a specific direction. In that case, the amount of silane compounds or alkyl groups derived from silane compounds and polyvinyl alcohol compounds or alkyl groups derived from polyvinyl alcohol compounds within a 10 mm range below the fabric or the amount of silane compounds or alkyl groups derived from silane compounds and polyvinyl alcohol compounds or alkyl groups derived from polyvinyl alcohol compounds within a 10 mm range above the fabric or the like may be substantially the same. In such cases, the amount of silane compounds or alkyl groups derived from silane compounds and polyvinyl alcohol compounds or alkyl groups derived from polyvinyl alcohol compounds in the lower 10 mm range of the fabric, or the amount of silane compounds or alkyl groups derived from silane compounds and polyvinyl alcohol compounds or alkyl groups derived from polyvinyl alcohol compounds in the upper 10 mm range of the fabric, can be examined, and this amount can be simply considered as the amount of silane compounds or alkyl groups derived from silane compounds and polyvinyl alcohol compounds or alkyl groups derived from polyvinyl alcohol compounds within 10 mm of the fiber structure.

[0079] In one embodiment of the present invention, the uncured body further contains reinforcing bars, and the fibrous structure to which the composition is attached and the reinforcing bars are embedded in the hydraulic composition in the order of fibrous structure to which the composition is attached and reinforcing bars, starting from the surface of the uncured body and moving inward. Here, "surface of the uncured body" means the interface between the uncured body and another phase (typically the formwork containing the uncured body, or the atmosphere). "Interior" of the uncured body means the area inside the surface of the uncured body, i.e., the side opposite to the other phase, and "exterior" of the uncured body means the area outside the surface of the uncured body, i.e., the side with the other phase. The same applies to the surface, interior, and exterior of the cured body.

[0080] In the uncured material, silane compounds released from the fibrous structure to which the composition is attached diffuse into the hydraulic composition, undergo hydrolysis and polymerization near the fibrous structure, and the polymerized silane compounds can preferably exist as a film. Because the fibrous structure and reinforcing bars are arranged in the order of fibrous structure and reinforcing bars from the surface to the interior of the uncured material, in the cured material of the uncured material, moisture from the outside of the cured material reaches the film-like substance before the reinforcing bars and can be blocked by the film-like substance. This prevents moisture from reaching the reinforcing bars located inside the film-like substance, and thus rust prevention of the reinforcing bars can be achieved.

[0081] Figure 1 shows a schematic cross-sectional view of an uncured body (1) in one embodiment. As shown in this schematic cross-sectional view, multiple reinforcing bars (4) are located inside the fibrous structure (3) to which the composition is attached, and the fibrous structure (3) and reinforcing bars (4) are surrounded by the hydraulic composition (2). The silane compound polymer produced by the diffusion of the silane compound released from the fibrous structure into the hydraulic composition and subsequent hydrolysis and polymerization near the fibrous structure can preferably exist as a film-like substance, but this is not shown in Figure 1. Note that in Figure 1, the dimensions and proportions of each component have been appropriately varied to improve the clarity of the drawing.

[0082] In one embodiment in which the unhardened body further includes reinforcing bars, the distance between the reinforcing bar and the fibrous structure to which the composition is attached is preferably 10 mm or less, more preferably 5 mm or less, even more preferably 1 mm or less, and may be 0 mm. This distance is the distance between the reinforcing bar and the fibrous structure to which the composition is attached that is closest to the reinforcing bar. When the distance between the reinforcing bar and the fibrous structure to which the composition is attached is less than or equal to the above upper limit, a film-like polymerized silane compound can exist near the reinforcing bar, thereby achieving good rust prevention of the reinforcing bar. The above distance can be measured by cutting the unhardened body after it has hardened to the extent that its shape is maintained even when cut, measuring the distance between the reinforcing bar and the fibrous structure to which the composition is attached at one or more points (preferably three or more points) at any 20 cm intervals, and calculating the average value. Alternatively, since the distance between the fibrous structure to which the composition is attached and the reinforcing steel does not substantially change due to the hardening of the hydraulic composition, a piece of mortar near the reinforcing steel in the hardened body can be split, and the distance between the reinforcing steel and the fibrous structure to which the composition is attached can be measured at one or more points (preferably three or more points) at any 20 cm intervals. The average value of these measurements can then be calculated and used as the distance between the fibrous structure to which the composition is attached and the reinforcing steel in the unhardened body. Alternatively, the unhardened body in which the fibrous structure to which the composition is attached and the reinforcing bars are embedded is usually manufactured by fixing the fibrous structure to which the composition is attached and the reinforcing bars to a formwork, and then pouring the hydraulic composition into the formwork. Since the positions of the fibrous structure to which the composition is attached and the reinforcing bars do not substantially change due to this pouring, the distance between the fixed fibrous structure to which the composition is attached and the reinforcing bars can be measured at one or more points (preferably three or more points) at arbitrary 20 cm intervals before pouring the hydraulic composition, and the average value can be calculated and used as the distance between the fibrous structure to which the composition is attached and the reinforcing bars in the unhardened body.

[0083] <Hydraulic composition> The hydraulic composition contains cement. The cement is not particularly limited, and any cement specified in JIS R 5210:2019 to JIS R 5214:2019 can be used. Examples include Portland cement such as ordinary Portland cement, rapid-hardening Portland cement, ultra-rapid-hardening Portland cement and moderate-heat Portland cement; alumina cement; blast furnace cement; silica cement; and fly ash cement; and white Portland cement. These cements may be used individually or in combination of two or more types.

[0084] The cements described above are commercially available from companies such as Taiheiyo Cement Corporation, Sumitomo Osaka Cement Co., Ltd., and UBE Mitsubishi Cement Corporation, and such commercially available products can be used in the present invention.

[0085] Hydraulic compositions typically further contain water. The amount of water in a hydraulic composition can be adjusted as appropriate according to known proportions, depending on the desired hardened product. The water-cement ratio (W / C), where W is the mass of water and C is the mass of cement, is preferably 25-65% by mass, more preferably 35-60% by mass, and even more preferably 40-55% by mass.

[0086] The hydraulic composition may also further contain aggregates well known in the art. Examples of such aggregates include lightweight concrete aggregate as specified in JIS A5002:2003, crushed stone and crushed sand as specified in JIS A 5005:2020, slag aggregate as specified in JIS A 5011-1:2018 to JIS A 5011-4:2018, and recycled aggregate H as specified in JIS A 5021:2018. These aggregates may be used individually or in combination of two or more types.

[0087] Furthermore, the hydraulic composition may further contain admixtures and / or admixtures. Examples of admixtures include fly ash as specified in JIS A 6201:2015, expansive materials as specified in JIS A 6202:2017, blast furnace slag powder as specified in JIS A 6206:2013, silica fume as specified in JIS A 6207:2016, and synthetic short fibers as specified in JIS A 6208:2018. Examples of admixtures include chemical admixtures as specified in JIS A 6204:2011. These admixtures or admixtures may be used individually or in combination of two or more types.

[0088] If the hydraulic composition contains aggregates, admixtures, and / or admixtures, these may be included in a range commonly used.

[0089] <Method for preparing a hydraulic composition> The method for preparing the hydraulic composition is not particularly limited. It is sufficient that cement, water, and optionally the well-known aggregates, admixtures, and / or admixtures described above are uniformly stirred and mixed. All materials may be stirred and mixed simultaneously, or some materials may be stirred and mixed first, and then the remaining materials may be added and further stirred and mixed.

[0090] Any known stirring device can be used, and the stirring conditions can be set as appropriate. Examples of stirring devices include dissolvers, screw-line mixers, ultrasonic homogenizers, colloid mills, planetary mixers, static mixers, Nauter mixers, ribbon blenders, tumble mixers, and paddle mixers.

[0091] [Method for manufacturing uncured material] An uncured body can typically be manufactured by a method that includes fixing a fibrous structure to which the composition, etc., is attached, and reinforcing bars, if included, within a formwork, and then pouring the hydraulic composition into the formwork. The method for fixing the fibrous structure to which the composition, etc., is attached is not particularly limited, as long as the fibrous structure to which the composition, etc., is attached is fixed to the formwork and / or reinforcing bars, if included, to the extent that it does not move when the hydraulic composition is poured in. For example, as illustrated in Figure 1, when embedding multiple reinforcing bars in a hydraulic composition, the multiple reinforcing bars (4) can be fixed to the formwork by a conventionally known method, a fibrous structure to which the composition, etc., is attached, for example, in a mesh-like form, can be wrapped around them, and the ends of the fibrous structure can be joined together with a binding wire or other joining member to fix the fibrous structure.

[0092] [Cured body and method for manufacturing the same] A cured product is obtained by curing the uncured product. The present invention also covers such cured products of uncured products.

[0093] In the uncured state, silane compounds released from the fibrous structure to which the composition is attached diffuse into the hydraulic composition and undergo hydrolysis and polymerization near the fibrous structure. Therefore, the cured body contains polymer silane compounds. The inclusion of polymer silane compounds produced by the hydrolysis and polymerization in the cured body allows the cured body to have sufficient water repellency, hydrophobicity, and / or corrosion resistance against external moisture. The cured product may, in some cases, contain unreacted monomer silane compounds. It may also contain unreacted oligomeric silane compounds and / or oligomeric silane compounds produced by hydrolysis and polymerization of monomer silane compounds.

[0094] The curing of the uncured material can be carried out using general methods, depending on the intended use of the cured material. [Examples]

[0095] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by such examples. The physical properties in the examples and comparative examples were measured or evaluated according to the following procedure.

[0096] <Water solubility of additives> 0.02 g of the additive was added to 100 g of water, stirred at 95°C for 1 hour, filtered through a filter (pore size: 40 μm), and the components that did not pass through the filter were recovered. The solid content was measured after drying at 105°C until a constant mass was reached. Solubility was calculated using the following formula. If the maximum size of the additive was 2 mm or more, it was cut to less than 2 mm using scissors or a pulverizer before being used for the test. Solubility (mass%) =[1-{Amount of solids that did not pass through the filter (g)} / {Amount of additive used (g)}]×100 If the solubility was 90% by mass or higher, the additive was determined to be water-soluble.

[0097] <Viscosity-average degree of polymerization and degree of saponification of polyvinyl alcohol-based compounds> The degree of viscosity polymerization and saponification of polyvinyl alcohol-based compounds were measured in accordance with JIS K6726:1994.

[0098] <Analysis of structural units of polyvinyl alcohol-based compounds and calculation of modification levels> Using the LAMBDA 500 nuclear magnetic resonance spectrometer manufactured by JEOL Ltd., the polyvinyl alcohol-based compounds used in the examples or comparative examples were analyzed. 1 1H-NMR was measured in deuterated dimethyl sulfoxide at room temperature, and the presence of each structural unit was confirmed by the characteristic peaks of each structural unit (for example, the peak derived from methine, the vinyl alcohol unit, was 3.2-4.0 ppm). If the polyvinyl alcohol compound was a modified polyvinyl alcohol, the amount of modification was calculated from the integral value of the peak derived from the modified monomer.

[0099] <Amount of silane compound-containing composition and amount of additive attached to 100 parts by mass of a fiber structure without silane compound-containing composition and additives attached> The silane compound-containing composition and the fibrous structure without any additives were dried at 80°C until a constant weight was reached, and their mass (W0) was measured. The mass (W1) of the fibrous structure with the silane compound-containing composition and the additives attached, prepared in the examples or comparative examples, was measured. The total amount of silane compound-containing composition and additives attached to the fibrous structure was calculated relative to 100 parts by mass of the fibrous structure without the silane compound-containing composition and additives attached, using the following formula (1). (Total amount of adhesion) [mass portion] = {(W1-W0) / W0} × 100 (1) When manufacturing a fiber structure to which a silane compound-containing composition and an additive are attached, the amount of silane compound-containing composition and the amount of additive attached per 100 parts by mass of a fiber structure to which the silane compound-containing composition and the additive are attached was determined by multiplying the ratio of the silane compound-containing composition and the additive in the aqueous solution containing the silane compound-containing composition and the additive, respectively, by the total amount of attachment. Specifically, when the ratio of the silane compound-containing composition to the total amount of attachment of the silane compound-containing composition and the additive in the aqueous solution is R1 (mass%), and the ratio of the additive to the total amount of attachment of the silane compound-containing composition and the additive in the aqueous solution is R2 (mass%), the amount of silane compound-containing composition and the amount of additive attached per 100 parts by mass of a fiber structure to which the silane compound-containing composition and the additive are attached was determined according to the following formulas (2) and (3). (Amount of the silane compound-containing composition attached) [parts by mass] = (Total amount of adhesion) × R1 / 100 (2) (Amount of the aforementioned additive attached) [parts by mass] = (Total amount of adhesion) × R2 / 100 (3)

[0100] <Ratio of the amount of additive attached to the total amount of silane compound-containing composition and additive attached> Using the total amount of silane compound-containing composition (parts by mass) and additive (parts by mass) per 100 parts by mass of fiber structure without silane compound-containing composition and additives, and the amount of additive (parts by mass) per 100 parts by mass of fiber structure without silane compound-containing composition and additives, obtained by the method described above, the ratio (mass%) of the amount of additive (parts by mass) per 100 parts by mass of fiber structure without silane compound-containing composition and additives to the total amount of silane compound-containing composition and additive (parts by mass) per 100 parts by mass of fiber structure without silane compound-containing composition and additives was calculated using the following formula (4). (The above ratio) = {(Amount of the above additive attached) / (The above total amount attached)} × 100 (4)

[0101] <Total release rate of silane compound-containing compositions and additives from fibrous structures to which compositions are attached> Using the same procedure as described above, the total amount (parts by mass) of the silane compound-containing composition and additives attached to 100 parts by mass of the fibrous structure without any attached silane compound-containing composition or additives was determined. This amount is referred to as the "initial total amount attached [parts by mass]". Next, the mass (W2) (g) of the fiber structure to which the silane compound-containing composition and additives were attached was measured. Subsequently, the fiber structure to which the silane compound-containing composition and additives were attached was immersed in water adjusted to 20-25°C for a predetermined time (5 minutes or 240 minutes), then removed from the water, dried at 90°C for 30 minutes, and its mass (W3) (g) was measured. The total amount of silane compound-containing composition and additives released into the water was determined by dividing W3 by W2. Using the calculated total amount released and the previously measured mass (W4) (g) of the fiber structure without the silane compound-containing composition and additives attached, the total amount of silane compound-containing composition and additives released per 100 parts by mass of the fiber structure without them attached was calculated using the following formula (5). This total amount released is referred to as "total release amount [parts by mass]". (Total release amount [parts by mass])={(W2-W3) / W4}×100 (5) Using the initial total amount attached [parts by mass] and the total amount released [parts by mass], the total release rate (by mass) of the silane compound-containing composition and additives from the fibrous structure to which the silane compound-containing composition and additives were attached was determined using the following formula (6). (Total release rate mentioned above) = (Total discharge amount [parts by mass] / Initial total adhesion amount [parts by mass]) × 100 (6) For the fiber structure of Comparative Example 1, the release rate of the silane compound-containing composition was determined using the same procedure as described above, instead of the total release rate of the silane compound-containing composition and the additive.

[0102] <Water-repellent or hydrophobic properties of the hardened body> The water-repellent or hydrophobic properties of the cured bodies produced in the examples and comparative examples were evaluated using the following procedure. One side of the outer surface of the hardened body, where the composition or a fibrous structure to which the composition is attached is embedded (the surface that was in contact with the inner surface of one side of the formwork, as described later, the water-repellent or hydrophobic evaluation surface), was exposed to tap water for 10 to 30 seconds. Areas where water repellency or hydrophobicity was sufficiently exhibited remained white or light gray, while areas where water repellency or hydrophobicity was not sufficiently exhibited changed to dark gray due to wetting. Photographs of the water-repellent or hydrophobic evaluation surface were taken, and the photographs were subjected to black and white binarization with a threshold of 150, and the area displayed in white was calculated. Photoshop was used for image analysis. The former area (m²) 2 The area of ​​the water-repellent or hydrophobic evaluation surface (m²) of the (referred to as "water-repellent area") 2 The percentage (%) of ) was calculated using the following formula (7). The water repellency or hydrophobicity of the cured material was evaluated according to the following criteria. Ratio of water-repellent area = (Water-repellent area / Area of ​​water-repellent or hydrophobic surface) × 100 (7) A: Water-repellent surface area is 80% or more B: Water-repellent area is 60% or more but less than 80% C: Water-repellent area is 50% or more but less than 60% D: Water-repellent area is 40% or more but less than 50% E: Water-repellent area is 20% or more but less than 40%

[0103] [Example 1] <Manufacturing of fibrous structures to which compositions, etc., are attached> A mixture was prepared by mixing Protectosil® WA CIT (manufactured by Evonik Industries, silane compound concentration 50% by mass, containing alkylsilane monomers, and an emulsion of alkylsilane oligomers having propoxy or propyl groups) as a silane compound-containing composition with a 14% by mass aqueous solution of water-soluble, unmodified polyvinyl alcohol as a polyvinyl alcohol-based compound-containing additive. A Raschel net [mesh opening 30 mm, net thread thickness 4 mm in diameter (30,000 dtex), net thread viscosity average degree of polymerization 1750, degree of saponification 99.9%, single thread average fiber diameter 13 μm (fineness 2 dtex), composed of bundled non-water-soluble polyvinyl alcohol fibers] in this mixture for 5 minutes. Then, the Raschel net was removed from the mixture and subjected to centrifugal dehydration at 300 rpm for 60 seconds, followed by drying at 90°C for 30 minutes to obtain a fibrous structure to which the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive were attached. <Manufacturing of uncured and cured materials> Wire mesh and a fibrous structure manufactured by the above method were embedded in mortar with a W / C ratio of 50% by mass and a cement-to-fine aggregate mass ratio of 1:3. Specifically, a wooden formwork with inner dimensions of 100mm x 300mm x 300mm was prepared. Wire mesh (250mm x 250mm, wire thickness 3mm, mesh opening 50mm) was fixed to the wooden formwork at a position 10mm inward from the inner surface of one side of the 300mm x 300mm side. The fibrous structure, cut to 250mm x 250mm, was inserted between the wire mesh and the aforementioned side, and secured with cable ties so that the fibrous structure overlapped and was in contact with the wire mesh. Next, mixed mortar was poured into this wooden formwork to produce an unhardened body in which the fiber structure and wire mesh were embedded in the hydraulic composition in the order of fiber structure and wire mesh, starting from the surface of the unhardened body (the surface of the unhardened body in contact with the inner surface of one side of the wooden formwork) and moving inward. In the produced unhardened body, the amount of silane compound per 100g of cement within 10mm of the fiber structure was greater than the amount of silane compound per 100g of cement in the entire unhardened body. Next, the wooden formwork was wrapped and sealed, and after 7 days, the seal was removed and the formwork was demolded. The hardened body was then produced by leaving it in an environment of 20°C and 60%RH for more than 28 days. The type of fiber, the composition of the mixed solution, and the measurement or evaluation results of the fiber structure and cured body to which the composition is attached are summarized in Table 1 below.

[0104] [Examples 2-4] Except for changing one or more elements selected from the group consisting of the amount of silane compound-containing composition, the type of additive, and the amount of the additive, as shown in Table 1, fiber structures, uncured materials, and cured materials to which the silane compound-containing composition and polyvinyl alcohol-based compound-containing additive were attached were manufactured in the same manner as in Example 1, and they were measured or evaluated.

[0105] [Examples 5-7] Except for using a water-soluble modified polyvinyl alcohol with a viscosity-average degree of polymerization of 1400, a degree of saponification of 99.9 mol%, and a methyl acrylate modification amount of 5.2 mol% as an additive, and changing one or more elements selected from the group consisting of the amount of the silane compound-containing composition and the amount of the additive as shown in Table 1, fiber structures, uncured materials, and cured materials to which the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive were attached were manufactured in the same manner as in Example 1, and they were measured or evaluated.

[0106] [Example 8] Except for changing the type of fiber structure as shown in Table 1, fiber structures, uncured materials, and cured materials to which the silane compound-containing composition and the polyvinyl alcohol-based compound-containing additive were attached were prepared in the same manner as in Example 6, and they were measured or evaluated. As the fiber structure, a Raschel net was used (mesh opening of 30 mm, net yarn thickness of 2 mm in diameter, net yarn consisting of bundled non-water-soluble polyester fibers with an average single-fiber diameter of 34 μm).

[0107] [Comparative Example 1] Except for not using any additives, a fibrous structure, an uncured material, and a cured material to which a silane compound-containing composition was attached were prepared in the same manner as in Example 1, and these were measured or evaluated.

[0108] [Comparative Example 2] Except for using PEG-600 (water-soluble polyethylene glycol with an average molecular weight of 560-640 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)) instead of polyvinyl alcohol, and changing the concentration of the silane compound-containing composition as shown in Table 1, fiber structures to which the silane compound-containing composition and additives were attached, uncured products, and cured products were manufactured in the same manner as in Example 2, and then measured or evaluated.

[0109] [Table 1] [Explanation of Symbols]

[0110] 1 Uncured body 2 Hydraulic composition 3. Fiber structures to which silane compound-containing compositions and polyvinyl alcohol-based compound-containing additives are attached. 4 Reinforcement bars

Claims

1. A fibrous structure to which a composition containing a silane compound and an additive are attached, The aforementioned additive includes a polyvinyl alcohol-based compound. The amount of the composition to be attached is 10 to 300 parts by mass per 100 parts by mass of the fiber structure to which the composition and the additive are not attached. The amount of the additive attached is 0.05 to 35 parts by mass per 100 parts by mass of the fiber structure that does not have the composition and the additive attached, in a fiber structure.

2. The fiber structure according to claim 1, wherein when the fiber structure is immersed in water at 20 to 25°C for 240 minutes, the total release rate of the composition and the additive into the water is 68% by mass or more.

3. The fiber structure according to claim 1, wherein when the fiber structure is immersed in water at 20 to 25°C for 5 minutes, the total release rate of the composition and the additive into the water is 50% by mass or less.

4. The fiber structure according to claim 1, wherein the fibers constituting the fiber structure are polyvinyl alcohol fibers.

5. The fibrous structure according to claim 1, wherein the additive is water-soluble.

6. The fiber structure according to claim 1, wherein the polyvinyl alcohol compound is one or more selected from the group consisting of modified polyvinyl alcohol and unmodified polyvinyl alcohol.

7. The fiber structure according to claim 1, wherein the viscosity-average degree of polymerization of the polyvinyl alcohol-based compound is 100 to 2,400.

8. The fiber structure according to claim 1, wherein the degree of saponification of the polyvinyl alcohol-based compound is 75 to 100 mol%.

9. The fiber structure according to claim 1, wherein the ratio of the amount of the additive to the total amount of the composition and the additive is 0.1 to 15% by mass.

10. The fiber structure according to claim 6, wherein the modified polyvinyl alcohol has structural units derived from an unsaturated carboxylic acid or a derivative thereof.

11. The fiber structure according to claim 10, wherein the unsaturated carboxylic acid or its derivative is at least one selected from the group consisting of (meth)acrylic acid, alkyl (meth)acrylic acid esters, and metal salts of (meth)acrylic acid.

12. The fiber structure according to claim 6, wherein the degree of saponification of the modified polyvinyl alcohol is 88 mol% or more.

13. The fiber structure according to claim 6, wherein the amount of modification of the modified polyvinyl alcohol is 0.1 to 10 mol%.

14. An unhardened body comprising a fibrous structure according to any one of claims 1 to 13 and a hydraulic composition containing cement, wherein the fibrous structure is embedded in the hydraulic composition.

15. A cured body of an uncured body according to claim 14.

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