Anti-spraying sheet, fiberglass sheet, set for forming anti-spraying sheet, and anti-spraying construction method

Abstract

To provide a peeling prevention sheet with excellent peeling prevention properties and base visibility.SOLUTION: An peeling prevention sheet of the present invention is a peeling prevention sheet that can be fixed onto a surface of a structure, and comprises a fiberglass sheet and a fiber adhesive impregnated into the fiberglass sheet. The fiberglass sheet includes one or more selected from a group consisting of a triaxial fabric, a four-axis fabric, and a five-axis fabric.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a peeling prevention sheet, a glass fiber sheet, a set for forming a peeling prevention sheet, and a peeling prevention construction method. [Background technology]

[0002] Various technologies have been developed to prevent spalling. One such technology is the one described in Patent Document 1. Patent Document 1 describes a technology for fixing a concrete spalling prevention material to a concrete surface, which is made of FRP grid reinforcement formed by laminating multiple vertical and horizontal reinforcing bars impregnated with vinyl ester resin onto a glass fiber net with a square mesh and then hardening it (Claim 1, paragraph 0073, Figure 1, etc., of Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-038661 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, as a result of the inventors' investigations, it was found that there is room for improvement in terms of spalling prevention performance and substrate visibility in concrete spalling prevention materials comprising a glass fiber net and resin, as described in Patent Document 1 above. [Means for solving the problem]

[0005] Further investigation by the inventors revealed that impregnating a fiber adhesive into a glass fiber sheet containing a triaxial or more woven fabric can improve the peel-resistant properties of the cured peel-resistant sheet, as evaluated by a punch test, and also improve the visibility of the substrate, thus completing the present invention.

[0006] According to the present invention, A peeling prevention sheet that can be fixed on the surface of a structure, a glass fiber sheet, and a fiber adhesive impregnated in the glass fiber sheet, comprising: the glass fiber sheet includes one or more selected from the group consisting of a 3-axis fabric, a 4-axis fabric, and a 5-axis fabric, a peeling prevention sheet is provided.

[0007] Also according to the present invention, a glass fiber sheet used for forming a peeling prevention sheet disposed on the surface of a structure, a glass fiber sheet including one or more selected from the group consisting of a 3-axis fabric, a 4-axis fabric, and a 5-axis fabric is provided.

[0008] Also according to the present invention, a peeling prevention sheet forming set used for forming a peeling prevention sheet disposed on the surface of a structure, a glass fiber sheet including one or more selected from the group consisting of a 3-axis fabric, a 4-axis fabric, and a 5-axis fabric, and a fiber adhesive impregnated in the glass fiber sheet, comprising: a peeling prevention sheet forming set is provided.

[0009] Also according to the present invention, placing the above peeling prevention sheet on the surface of the structure, placing the peeling prevention sheet obtained by impregnating the above glass fiber sheet with a fiber adhesive on the surface of the structure, or using the above peeling prevention sheet forming set to impregnate the glass fiber sheet with a fiber adhesive and placing the obtained peeling prevention sheet on the surface of the structure, a placing step; a fixing step of fixing a cured body of the peeling prevention sheet on the surface of the structure by curing the fiber adhesive in the peeling prevention sheet; A peeling prevention construction method including is provided.

Advantages of the Invention

[0011] [Figure 1] This is a schematic cross-sectional view showing the peeling prevention sheet of this embodiment placed on the surface of a structure. [Figure 2] This diagram schematically shows the configuration of the testing apparatus used for the punch-out test. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted as appropriate. Also, the drawings are schematic diagrams and do not correspond to the actual dimensional ratios.

[0013] The outline of the peeling prevention sheet of this embodiment will be described.

[0014] The peeling prevention sheet of this embodiment can be fixed onto the surface of a structure and comprises a glass fiber sheet and a fiber adhesive impregnated in the glass fiber sheet, wherein the glass fiber sheet includes one or more selected from the group consisting of triaxial fabric, quaternary fabric, and pentaxial fabric.

[0015] By placing and fixing the peeling prevention sheet of this embodiment onto the surface of a structure, it is possible to suppress the peeling of a part of the structure from its surface.

[0016] Examples of structures include mortar structures and concrete structures, but are not particularly limited to any structure that is susceptible to spalling due to deterioration over time. Examples of concrete structures include roads; tunnels; bridges such as bridge girders, piers, abutments, and deck slabs; and structural elements such as walls and ceilings in buildings and facilities.

[0017] When concrete structures deteriorate due to various factors, concrete fragments can peel off and fall from the surface due to changes in surface condition, cracks, etc. A spalling prevention sheet fixed to the surface of the concrete structure can hold the peeled-off concrete fragments, thereby suppressing the falling of these fragments.

[0018] According to the inventors' findings, it has been found that by using a peel-preventing sheet in which a fiber adhesive is impregnated into a glass fiber sheet containing a triaxial or more woven fabric, the peel-preventing properties evaluated by a punch test can be improved in the cured product, as well as the visibility of the substrate can be improved.

[0019] When comparing known biaxial woven glass fiber sheets under standardized basis weight conditions, it was found that the maximum displacement and / or maximum load during the punch-out test were sometimes insufficient. On the other hand, when using braided fabric (registered trademark), a known type of glass fiber, instead of woven fabric, comparisons were made under the same conditions of basis weight and number of axes, and it was found that sufficient transparency in visible light could not be obtained. Here, braided fabric (registered trademark) refers to a continuous yarn nonwoven fabric in the form of a cloth, made by braiding threads in the warp, weft, or diagonal directions and fixing them with adhesive, without using a loom. Although the detailed mechanism is not clear, it is presumed that the adhesive constituting the braided fabric (registered trademark) hinders the impregnation of the fiber adhesive, thus preventing sufficient transparency from being obtained. In addition, braided fabric (registered trademark) is prone to twisting and movement of threads during installation, which may result in insufficient workability.

[0020] In contrast, the peeling prevention sheet of this embodiment appropriately selects the number of axes and weaving method of the glass fiber sheet, and among them, uses a glass fiber sheet that includes a weave with three or more axes. This improves the maximum displacement and / or maximum load during the puncture test, and because the impregnation of the fiber adhesive into the weave with three or more axes is relatively good, transparency in visible light can be improved. Therefore, when the peeling prevention sheet is applied (placed and fixed) on the surface of a structure, both peeling prevention and substrate visibility can be improved. In addition, thread twisting is suppressed, so workability can be improved.

[0021] The following describes in detail the components of the peeling prevention sheet of this embodiment.

[0022] The peeling prevention sheet comprises a glass fiber sheet and a fiber adhesive.

[0023] The glass fiber sheet in the peel-preventing sheet may be configured such that part or all of it is contained within a layer made of fiber adhesive. In other words, the peel-preventing sheet may comprise an impregnated portion of the fiber adhesive that is impregnated into the glass fiber sheet, and an exposed layer of fiber adhesive formed on at least one or both of the front and back surfaces of the glass fiber sheet.

[0024] An example of the state in which the peeling prevention sheet 100 of this embodiment is placed on the surface of the structure 50 will be explained using Figure 1. Figure 1(a) shows the state in which the spalling prevention sheet 100 is directly placed on the surface of the structure 50, Figure 1(b) shows the state in which the spalling prevention sheet 100 is placed on the surface of the structure 50 with a primer layer 130, and Figure 1(c) shows the structure in which a protective layer 150 is further formed on the surface of the spalling prevention sheet 100 in Figure 1(b). The fiber adhesive 120 shown in Figures 1(a) to 1(c) has an impregnated portion in the glass fiber sheet 110, as well as exposed layers 120A and 120B that are exposed from at least one side of the front and back surfaces of the glass fiber sheet 110. These exposed layers 120A and 120B harden and exhibit adhesion to the interface of the substrate layer or other layers. The primer layer 130 and protective layer 150 will be explained later.

[0025] The glass fiber sheet includes one or more selected from the group consisting of triaxial, quaternary, and pentaxial fabrics. From the viewpoint of impregnation of the fiber adhesive, triaxial or quaternary fabrics are preferred.

[0026] A triaxial or quadriaxial fabric refers to a fabric in which threads in three or four axes, such as warp threads, weft threads, and diagonal threads on one or both sides, are interwoven three-dimensionally according to a specific method.

[0027] The glass filaments constituting the glass fiber sheet may be, for example, E glass, AR glass, S glass, C glass, D glass, ECR glass, or the like. Among these, from the viewpoints of strength, durability, and the balance between these and cost, it is preferable that the glass fiber sheet contains one or more selected from the group consisting of E glass, AR glass, and ECR glass.

[0028] The lower limit of the air permeability of the glass fiber sheet is, for example, 30 cm 2 ,

[0030] , / (cm 2 ·s) or more, preferably 50 cm 3 / (cm 2 ·s) or more, more preferably 60 cm 3 / (cm 2 ·s) or more. Thereby, the impregnation property of the fiber adhesive can be improved. Further, when the glass fiber sheet is attached and impregnated with a roller after applying the fiber adhesive, air bubbles can easily escape, improving the visibility of the base and preventing the glass fiber sheet from floating. The upper limit of the air permeability of the glass fiber sheet is, for example, 800 cm 3 / (cm 2 ·s) or less, preferably 600 cm 3 / (cm 2 ·s) or less, more preferably 500 cm 3 / (cm 2 ·s) or less. Thereby, the yarn can be prevented from sagging, improving the workability.

[0029] The lower limit of the basis weight of the glass fiber sheet is, for example, 120 g / m 2 or more, preferably 140 g / m 2 or more, more preferably 160 g / m 2 or more. Thereby, the peeling prevention property can be further improved. The upper limit of the basis weight of the glass fiber sheet is, for example, 350 g / m 2 or less, preferably 300 g / m 2 or less, more preferably 260 g / m 2 or less. Thereby, the transparency can be improved.

[0030] The lower limit of the fineness of the fiber bundles constituting the glass fiber sheet is, for example, 50 tex or more, preferably 60 tex or more, and more preferably 70 tex or more. This allows for the creation of appropriately sized openings in the fiber sheet, and when the fiber adhesive is applied, the glass fiber sheet is attached, and impregnated with a roller, air bubbles are more easily released, improving the visibility of the substrate and preventing the fiber sheet from lifting. The upper limit of the fineness of the fiber bundle described above is, for example, 1500 tex or less, preferably 1000 tex or less, and more preferably 400 tex or less. This allows the density of the glass fiber sheet to be set above a certain level, improving the resistance to yarn twisting.

[0031] The upper limit of the ignition loss of the fiber bundles constituting the glass fiber sheet is, for example, 1% or less, preferably 0.8% or less, and more preferably 0.5% or less. This improves the impregnation of the fiber adhesive. The lower limit of the ignition loss for the above fiber bundle is not particularly limited, but may be 0.01% or more.

[0032] The lower limit for the amount of fiber adhesive to be applied is, for example, 200 g / m². 2 Preferably 300 g / m² 2 Above, a comfortable 400g / m 2 That concludes the explanation. This improves the impregnation properties of the glass fiber sheet. The upper limit for the amount of fiber adhesive to be applied is, for example, 2000 g / m². 2 Preferably 1500 g / m² 2 Below, more comfortably 1000g / m 2 The following benefits can be achieved. This improves transparency and reduces the harmfulness of gases produced during a fire.

[0033] Fiber adhesives include curing adhesives such as epoxy adhesives, urethane adhesives, silicone adhesives, and (meth)acrylic adhesives. Fiber adhesives with a transparent cured body are preferred, and fiber adhesives with a small difference between the refractive index of the glass fiber sheet and the refractive index of the cured body are more preferred. Among these, epoxy adhesives are preferred from the viewpoint of superior adhesion to concrete surfaces and glass fiber sheets.

[0034] The fiber adhesive is not particularly limited in form, but may be a one-component adhesive or a two-component adhesive. A two-component adhesive is preferred from the viewpoint of stability during storage.

[0035] An example of a two-component fiber adhesive may include a main component and a hardening agent. In the case of a two-part fiber adhesive that is an epoxy adhesive, the main component (first component) contains an epoxy compound, and the hardener (second component) is not limited as long as it contains a component that hardens the epoxy compound, but one example is an amine compound.

[0036] As the epoxy compound, epoxy compounds having one or more epoxy groups or glycidyl groups in the molecule are used. Specific examples of epoxy compounds include, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol A bis(polypropylene glycol glycidyl ether) ether, bisphenol A bis(polyethylene glycol glycidyl ether) ether, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, biphenyl type epoxy resin, urethane-modified epoxy resin, rubber-modified epoxy resin, alkyl glycidyl ether, cresyl glycidyl ether, phenyl glycidyl ether, alkyl diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, and the like. These may be used individually or in combination of two or more.

[0037] As the amine compound, an amine compound having a primary amine group and / or a secondary amine group is used. Specific examples of amine compounds include, for example, aliphatic amines, alicyclic amines, modified aliphatic polyamines, modified alicyclic amines, and polyamidoamines. These may be used individually or in combination of two or more.

[0038] In a two-component fiber adhesive, the main component and the curing agent may be mixed such that the ratio of the active hydrogen equivalent of the amine compound (the component that cures the epoxy compound) to the epoxy equivalent of the epoxy compound is, for example, 0.5 to 1.5, preferably 0.8 to 1.2. The active hydrogen equivalent of an amine compound is expressed as the mass (g) of the amine compound per mole of active hydrogen. When two or more amine compounds are used in combination, the active hydrogen equivalent of the amine compound is calculated from the total mass of the amine compounds and the total amount of active hydrogen.

[0039] Fiber adhesives may contain additives commonly used in adhesives, if necessary. In the case of two-part adhesives, at least one of the main component and the hardener may contain additives.

[0040] Examples of additives include fillers, curing accelerators, light stabilizers, light absorbers, antioxidants, degradation inhibitors, pigments, dyes, silane coupling agents, defoamers, leveling agents, dispersants, rheology control agents, waxes, solvents, and water. These may be used individually or in combination of two or more. Among these, fillers and rheology control agents may also be used.

[0041] Fillers include organic fillers and inorganic fillers. Examples of organic fillers include resin particles such as (meth)acrylic acid ester particles and polystyrene particles. Examples of inorganic fillers include fumed silica, calcium carbonate, talc, clay, metal oxides, metal hydroxides, and silica. Among these, from the viewpoint of transparency, one or more of the group consisting of silica and fumed silica are preferred, and hydrophilic fumed silica is more preferred.

[0042] The BET specific surface area of ​​an inorganic filler is, for example, 80 g / m². 2 More than 400g / m 2 More preferably 100g / m 2 More than 300g / m 2 The following applies. By keeping the values ​​within this range, the viscosity can be adjusted to an appropriate range while maintaining the transparency of the fiber adhesive, and dripping of the fiber adhesive can be suppressed.

[0043] The lower limit of the inorganic filler content is, for example, 0.1% by mass or more, preferably 0.5% by mass or more, and more preferably 1.0% by mass or more, based on 100% by mass of the solid content of the fiber adhesive. This improves the suppression of dripping due to increased viscosity. The upper limit of the inorganic filler content is, for example, 10.0% by mass or less, preferably 7.0% by mass or less, and more preferably 4.0% by mass or less, based on 100% by mass of the solid content of the fiber adhesive. This improves the transparency of the fiber adhesive. The solid content of a fiber adhesive refers to the non-volatile components, which are the remainder after removing volatile components such as water and solvents.

[0044] Rheology control agents can suppress dripping and improve the workability of adhesives. As a rheology control agent, amides are preferred, for example. Examples of amides include higher fatty acid amides, polyamides, and amide oligomers.

[0045] The lower limit of the rheology control agent content is, for example, 0.1% by mass or more, preferably 0.2% by mass or more, and more preferably 0.3% by mass or more, based on 100% by mass of the solid content of the fiber adhesive. This improves the suppression of dripping due to thickening. The upper limit of the rheology control agent is, for example, preferably 10.0% by mass or less, more preferably 7.0% by mass or less, and more preferably 4.0% by mass or less, based on 100% by mass of the solid content of the fiber adhesive. This improves the tensile properties of the fiber adhesive. The lower limit of the rheology control agent is, for example, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, based on 100% by mass of the solid content of the fiber adhesive.

[0046] The lower limit of the pot life for fiber adhesives is, for example, preferably 10 minutes or more, more preferably 20 minutes or more, and more preferably 30 minutes or more. This improves workability and impregnation into glass fiber sheets. The upper limit of the pot life for fiber adhesives is, for example, preferably 300 minutes or less. The upper limit of the pot life for fiber adhesives is not particularly limited, as long as it is within a range that is practically usable. The pot life of fiber adhesives can be measured according to the exothermic method specified in JIS K 6870. If the fiber adhesive is a two-part adhesive, the mixture should be measured within 5 minutes of mixing the main component and the hardener.

[0047] Using a cone-plate type rotary viscometer, the viscosity (mPa·s) of the fiber adhesive measured at 23°C and 2 rpm is defined as V2, and the viscosity (mPa·s) of the fiber adhesive measured at 20 rpm is defined as V20. If the fiber adhesive is a two-part adhesive, the mixture measured is the mixture immediately after mixing the main component and the hardener, and within 10 minutes of mixing. The lower limit of V2 is, for example, 2,000 mPa·s or more, preferably 5,000 mPa·s or more, and more preferably 10,000 mPa·s or more. This improves the ability to prevent liquid dripping. The upper limit of V2 is, for example, 100,000 mPa·s or less, preferably 90,000 mPa·s or less, and more preferably 80,000 mPa·s or less. This improves the impregnation of the fiber adhesive into the glass fiber sheet.

[0048] Furthermore, the thixotropic index of the fiber adhesive will be set to V2 / V20. The lower limit of V2 / V20 is, for example, 2.0 or higher, preferably 2.5 or higher, and more preferably 3.0 or higher. This allows for a balance between preventing liquid dripping and impregnation into the glass fiber sheet. The upper limit of V2 / V20 is, for example, 8.0 or less, preferably 7.5 or less, and more preferably 7.0 or less. This improves the leveling properties of the coating surface.

[0049] The visible light transmittance of the fiber adhesive at wavelengths of 380 to 780 nm is, for example, 30% or more, preferably 40% or more, and more preferably 50% or more. This improves the transparency of the cured product of the peeling prevention sheet. The method for measuring visible light transmittance is as follows: First, the fiber adhesive is applied to a PET sheet to a cured state thickness of approximately 1 mm. It is then cured at 23°C and 50% relative humidity for 7 days to produce a 1 mm thick cured state. The PET sheet is then peeled off this cured state to obtain a measurement sample. Using a spectrophotometer, the spectral transmittance of the obtained measurement sample is measured in the normal (90°) direction in the wavelength range of 380 to 780 nm, in accordance with the visible light transmittance test of JIS A 5759. The visible light transmittance (%) is calculated by multiplying the weighting coefficient for each wavelength by the "weighting coefficient for calculating visible light transmittance" specified in JIS A 5759 and taking a weighted average. In the case of a two-component adhesive, the mixture of the main agent and the hardener is used as the fiber adhesive described above. The visible light transmittance measurement method may also be applied to the cured state of the peel-prevention sheet.

[0050] Next, the method for preventing peeling according to this embodiment will be described.

[0051] An example of a spalling prevention construction method according to this embodiment includes a placement step of placing the spalling prevention sheet on the surface of a structure such as a concrete structure, and a fixing step of fixing the hardened spalling prevention sheet to the surface of the structure by curing the fibrous adhesive in the spalling prevention sheet.

[0052] The placement process includes (i) a method of placing the above-mentioned peeling prevention sheet on the surface of a structure, (ii) a method of placing a peeling prevention sheet, which is made by impregnating a glass fiber sheet for forming the peeling prevention sheet described below with a fiber adhesive, on the surface of a structure, and (iii) a method of placing a peeling prevention sheet, which is made by impregnating a glass fiber sheet with a fiber adhesive using the peeling prevention sheet forming set described below, on the surface of a structure.

[0053] Here, in each of the methods described in 1(i) to (iii) above, the order and method of impregnating the fiber adhesive into the glass fiber sheet are arbitrary. In other words, the fiber adhesive may be applied to the surface of the structure and the glass fiber sheet may be impregnated into this coating, or the fiber adhesive may be applied to a glass fiber sheet placed on the surface of the structure and then impregnated, or a peeling prevention sheet may be prepared in advance by impregnating the glass fiber sheet in fiber adhesive and placing this peeling prevention sheet on the surface of the structure.

[0054] The anti-peeling sheet used in method (i) above can be the same as the one described above.

[0055] The glass fiber sheet used for forming the peeling prevention sheet in the method described in (ii) above is a glass fiber sheet used to form a peeling prevention sheet to be placed on the surface of a structure, and includes one or more selected from the group consisting of triaxial fabrics, quaternary fabrics, and pentaxial fabrics. The same type of fiberglass sheet used for this peeling prevention sheet can be the same as the one described above.

[0056] The peeling prevention sheet forming set used in the method described in (iii) above is a peeling prevention sheet forming set used for forming a peeling prevention sheet to be placed on the surface of a structure, and includes a glass fiber sheet containing one or more selected from the group consisting of triaxial fabrics, quaternary fabrics, and pentaxial fabrics, and a fiber adhesive impregnated into the glass fiber sheet. The glass fiber sheet and fiber adhesive can be the same as those described above. In the set for forming the peel-resistant sheet, the glass fiber sheet and the fiber adhesive may be packaged separately. Furthermore, the set for forming the peeling prevention sheet may include one or more selected from the group consisting of the primer described later, the modifier described later, and the topcoat paint described later.

[0057] The fixing process involves curing the fiber adhesive using an appropriate method according to its curing mechanism. Examples of curing treatments include curing agent mixing, heat curing, solvent evaporation, moisture curing, anaerobic curing, or ultraviolet curing. These may be used individually or in combination of two or more. As a specific example, in the case of a two-part epoxy adhesive for fiber, the curing process can be performed by mixing the main component and the hardener and curing it for a predetermined period of time under predetermined temperature and humidity conditions.

[0058] The minimum thickness of the cured body of the peeling prevention sheet may be, for example, 0.10 mm or more, preferably 0.2 mm or more, and more preferably 0.3 mm or more. This further improves the peeling prevention performance. The upper limit of the thickness of the cured body of the peeling prevention sheet may be, for example, 2.0 mm or less, preferably 1.5 mm or less, and more preferably 1.0 mm or less. This further improves the visibility of the substrate.

[0059] Furthermore, in any of the above steps (i) to (iii) of the placement process, a peeling prevention sheet, a glass fiber sheet, or a coating of fiber adhesive may be placed on the surface of the primer-treated structure. In other words, the spalling prevention construction method may include an undercoating step that forms a primer layer on the surface of the structure before the placement step. This improves the adhesion between the spalling prevention sheet and the surface of the structure.

[0060] Primer treatment refers to the process of applying a primer, commonly used in surface treatment, to the surface of a structure to form a primer layer. Examples of primers include epoxy primers, urethane primers, and acrylic primers. These may be used individually or in combination of two or more. Among these, epoxy primers are preferred from the viewpoint of excellent adhesion to the surface of structures.

[0061] The primer is not particularly limited in form, but may be a single-component primer or a two-component primer. From the viewpoint of handling, a two-component primer is preferred. An example of a two-component primer may include a main component and a curing agent. If the two-component primer is an epoxy-based primer, the primer main component contains an epoxy compound. If the two-component primer is an epoxy-based primer, the primer curing agent is not limited as long as it contains a component that cures the epoxy compound, but one example is an amine compound.

[0062] The lower limit of the primer application amount is, for example, 50 g / m². 2 Preferably 80 g / m² 2 Above, comfortably 120g / m 2 That concludes the explanation. This improves the adhesion of the sheet to the structure. The upper limit for the amount of primer to be applied is, for example, 600 g / m². 2 Preferably 400 g / m² 2 More preferably 300g / m² 2 The following is the result. This improves the suppression of harmful gas generation during fires.

[0063] The priming process may include a modification treatment to alter the surface of the structure. As an example of the modification treatment, it is preferable to form one or more layers of a modifying agent on the surface of the structure, each layer containing one modifying agent selected from the group consisting of impregnation reinforcing agents, cross-sectional repair agents, and unevenness adjusters. The modifying agent layer may be formed, for example, between the primer layer and the spalling prevention sheet, or between the structure and the primer layer.

[0064] In the method for preventing peeling, a topcoat step may be performed after the fixing step to form a protective layer on the surface of the hardened peeling prevention sheet. For forming a protective layer, general protective coatings and topcoat coatings are used. Examples of topcoat coatings include fluorine-based coatings.

[0065] Although embodiments of the present invention have been described above, these are merely examples, and various other configurations can be adopted. Furthermore, the present invention is not limited to the embodiments described above, and modifications, improvements, etc., within the scope that can achieve the objectives of the present invention are included in the present invention. Examples of reference formats are provided below. 1. A peeling prevention sheet that can be fixed onto the surface of a structure, Glass fiber sheet and The glass fiber sheet comprises a fiber adhesive impregnated within it, The glass fiber sheet includes one or more selected from the group consisting of triaxial fabrics, quadraxial fabrics, and pentaxial fabrics. Peeling prevention sheet. 2. The peeling prevention sheet described in 1. The air permeability of the aforementioned glass fiber sheet is 30 cm 3 / (cm 2 ·s) over 800cm 3 / (cm 2 • The following are peeling prevention sheets. 3. A peeling prevention sheet as described in 1. or 2., The basis weight of the aforementioned glass fiber sheet is 120 g / m². 2 More than 350g / m 2 The following is a peeling prevention sheet. 4. A peeling prevention sheet as described in any one of items 1 to 3. A peel-preventing sheet in which the fineness of the fiber bundles constituting the glass fiber sheet is 50 tex or more and 1500 tex or less. 5. A peeling prevention sheet as described in any one of items 1 to 4. A peel-resistant sheet in which the ignition loss of the fiber bundles constituting the glass fiber sheet is 1% or less. 6. A peeling prevention sheet described in any one of items 1 to 5, The amount of the fiber adhesive applied is 200 g / m². 2 More than 2000g / m 2 The following is a peeling prevention sheet. 7. A peeling prevention sheet described in any one of items 1 to 6, The glass fiber sheet is a peel-preventing sheet comprising one or more glass fibers selected from the group consisting of E-glass, AR-glass, and ECR-glass. 8. A peeling prevention sheet described in any one of items 1 to 7, A peel-resistant sheet having a pot life of 10 minutes or more and 300 minutes or less for the fiber adhesive, as measured in accordance with the exothermic method of JIS K 6870. 9. A peeling prevention sheet described in any one of items 1 to 8, When the viscosity of the fiber adhesive measured at 23°C and 2 rpm is V2, and the viscosity of the fiber adhesive measured at 20 rpm is V20, A peeling prevention sheet in which V2 / V20 is between 2.0 and 8.0, and V2 is between 2,000 mPa·s and 100,000 mPa·s. 10. A glass fiber sheet used to form a spalling prevention sheet to be placed on the surface of a structure, A fiberglass sheet comprising one or more selected from the group consisting of triaxial, quadriaxial, and quinaxial fabrics. 11. A set for forming a spalling prevention sheet, used for forming a spalling prevention sheet to be placed on the surface of a structure, A glass fiber sheet comprising one or more selected from the group consisting of triaxial, quaternary, and quinaxial fabrics, The glass fiber sheet contains a fiber adhesive, Set for forming peeling prevention sheets. 12. Placing a delamination prevention sheet described in any one of 1. to 9. on the surface of the structure; placing a delamination prevention sheet made by impregnating a glass fiber sheet with fiber adhesive as described in 10. on the surface of the structure; or placing a delamination prevention sheet made by impregnating a glass fiber sheet with fiber adhesive using the delamination prevention sheet forming set described in 11. on the surface of the structure; A fixing step involves curing the fiber adhesive in the peeling prevention sheet to fix the cured body of the peeling prevention sheet onto the surface of the structure, A method for preventing peeling, including a construction method for preventing peeling. 13. The method for preventing peeling described in 12. A method for preventing spalling, wherein the surface of the structure is treated with a primer during the placement process. 14. A method for preventing peeling as described in 12. or 13. A method for preventing spalling, wherein the aforementioned structure is a concrete structure. [Examples]

[0066] The present invention will be described in detail below with reference to examples, but the present invention is not limited in any way to the descriptions of these examples.

[0067] The raw materials shown in Table 1 are as follows: <Glass fiber sheet> • Glass fiber sheets G1-G7: Sheets with the characteristics shown in Table 1 were used. In Table 1, "laminated" refers to woven fabric (registered trademark). Air permeability was measured in accordance with JIS L 1096 Method A (Fragile method). The ignition loss was measured as follows: First, approximately 10 mg was sampled from a fiber bundle of glass fiber sheets, after removing any synthetic fiber stitching threads or heat-sealing threads used for sealing. The sample was then heated from 25 to 500°C at a rate of 10°C / min in an air atmosphere using a high-sensitivity differential thermal balance STA 2500 Regulus (manufactured by Netch Japan Co., Ltd.), and the mass loss (%) was measured. The mass loss obtained in this way was defined as the ignition loss. <Fiber adhesive> • Main ingredient (first ingredient) E1: Bisphenol A type epoxy resin (ADEKA Resin EP4100, manufactured by ADEKA, epoxy equivalent: 190 g / ep, viscosity at 25°C: 13,000 mPa·s) E2: Bisphenol A type epoxy resin (ADEKA Resin EP4000, manufactured by ADEKA, epoxy equivalent: 320 g / ep, viscosity at 25°C: 4,500 mPa·s) E3: Bisphenol A type epoxy resin (ADEKA Resin EP4005, manufactured by ADEKA, epoxy equivalent: 510 g / ep, viscosity at 25°C: 800 mPa·s) E4: Orthocresyl glycidyl ether (SY-OCG, manufactured by Sakamoto Pharmaceutical Co., Ltd., epoxy equivalent: 180 g / ep, viscosity at 25°C: 8 mPa·s) Filler: Hydrophilic fumed silica (AEROSIL 200, manufactured by Evonik, primary particle size: 12 nm, BET specific surface area: 200 g / m²) 2 , degree of hydrophobicity 0%) • Hardening agent (second component) N1: Polyamidoamine (Tomide 245S, manufactured by T&K TOKA, active hydrogen equivalent: 80g / ep) N2: Polyamidoamine (Tomide 235A, manufactured by T&K TOKA, active hydrogen equivalent: 95g / ep) N3: Modified alicyclic polyamine (Fujicure 8116, manufactured by T&K TOKA, active hydrogen equivalent: 72g / ep) Additive: Rheology control agent (BYK R607, manufactured by BYK Chemie, polyaminoamide)

[0068] A fiber adhesive was obtained by mixing the main component and the hardener in the proportions shown in Table 1. For fiber adhesives obtained within 5 minutes, the pot life (min) was determined according to Method 5 of JIS K 6870, which specifies the method of determining the exothermic reaction temperature. Each component of the fiber adhesive was kept at 23±1℃, weighed out in the specified mixing ratio, the start of the test was recorded, and after mixing for 60±2 seconds, 100g was weighed into a 200mL disposable cup. A thermocouple was immersed in the center of the batch, and the temperature was measured. Half the elapsed time when the highest temperature was reached was defined as the pot life (min). A cone-plate type rotational viscometer (TPE-100 model, manufactured by Toki Sangyo Co., Ltd.) was used to measure the viscosity V2 (mPa·s) at 23°C and 2 rpm, and the viscosity V20 (mPa·s) at 23°C and 20 rpm.

[0069] <Primer> • PE1: Bisphenol A type epoxy resin (ADEKA Resin EP4100, manufactured by ADEKA, epoxy equivalent: 190 g / ep, viscosity at 25°C: 13,000 mPa·s) • PE2: Orthocresyl glycidyl ether (SY-OCG, manufactured by Sakamoto Pharmaceutical Co., Ltd., epoxy equivalent: 180 g / ep, viscosity at 25°C: 8 mPa·s) • PN1: Modified alicyclic polyamine (Fujicure 8116, manufactured by T&K TOKA, active hydrogen equivalent: 72g / ep)

[0070] [Table 1] A dash (-) in the table indicates that the measurement was not taken.

[0071] <Penetration Test> In accordance with JSCE K 533, a punch test was performed using the test apparatus shown in Figure 2, and the displacement (mm) and load (kN) of the sample 20 formed on the surface of the test substrate 10 were measured. Figure 2(a) shows a cross-sectional view of the test apparatus, and Figure 2(b) shows a perspective view of the test apparatus.

[0072] The specific procedure for the punch-out test was as follows: In accordance with the preparation of test specimens in JSCE K 533, concrete with a water / cement ratio of 44% and a sand / cement ratio of 2.7 was placed in a metal formwork with internal dimensions of 400mm (length) x 600mm (width) x 60mm (thickness), cured for 24 hours at a temperature of 20±2℃ and a relative humidity of 80% or higher, then demolded, and subsequently cured in water at a temperature of 20±2℃ for 6 days. After the water curing period, it was cured for 7 days or more at a temperature of 23±2℃ and a relative humidity of 50±5%, and a concrete slab (porous material) was used to produce a top cover for a U-shaped side ditch (not shown) with a top cover, as specified in JIS A 5372 Annex E (Type 1, 300). Next, the obtained concrete slab was ground from the back side until it reached a position 5 mm from the surface, forming a cylindrical indenter 30 with a diameter of 100 mmφ and a thickness of 55 mm ± 3 mm on the test substrate 10. Next, the main component and hardener were mixed according to the proportions shown in Table 1 to prepare the primer and fiber adhesive, respectively. Next, the surface (working surface) of the test substrate 10 was scraped using a disc sander, and then degreased. Next, the primer obtained above was applied to the surface of the test substrate 10 using a roller at a coating rate of 0.15 kg / m². 2 The primer layer was applied using [a specific method] and cured for one day at 23±2℃ and 50±20% relative humidity to form a dry primer layer. Apply the fiber adhesive obtained above onto the primer layer using a rubber spatula at a rate of 0.6 kg / m². 2 The coating was applied, and a fiberglass sheet was immediately attached to this coating. After attachment, the fiberglass sheet was pressed into the coating using a roller so that the fiber adhesive would permeate the fiberglass sheet. Then, the surface of the coating with the fiber adhesive that was present on the surface of the fiberglass sheet was smoothed with a rubber spatula to form a peel-resistant sheet. This peeling prevention sheet was cured (left standing) for 7 days at 23±2℃ and 50±20% relative humidity to obtain sample 20 in which a hardened peeling prevention sheet was formed on the primer layer. Next, at room temperature of 23°C, a load of 1 mm / min was applied to the joint between the test substrate 10 and the indenter 30 until it broke. After that, the indenter 30 was loaded toward the sample 20 at a rate of 5 mm / min. Loading was stopped when the sample 20 fractured. The maximum load until fracture was defined as the maximum load (kN), and the displacement at fracture was defined as the maximum displacement (mm). The load and displacement were recorded every 0.05 kN. Loading was temporarily suspended every 10 mm of displacement, the peeling area was marked on sample 20, and the load was recorded.

[0073] <Visibility of the base surface> Mortar specimens measuring 70 mm (length) x 150 mm (width) x 10 mm (thickness) were prepared in accordance with JIS R 5201. Crack scales simulating cracks with widths of 0.2 mm and 0.5 mm were attached to the surface of the obtained mortar specimens. On the surface of the mortar specimen, the primer obtained in the above <push-out test> was applied using a roller at a rate of 0.15 kg / m². 2 The primer layer was applied using [a specific method] and cured for one day at 23±2℃ and 50±20% relative humidity to form a dry primer layer. On top of the primer layer, apply the fiber adhesive obtained in the above <punching test> using a rubber spatula at a rate of 0.6 kg / m². 2 The coating was applied, and a fiberglass sheet was immediately attached to this coating. After attachment, the fiberglass sheet was pressed into the coating using a roller so that the fiber adhesive would permeate the fiberglass sheet. Then, the surface of the coating with the fiber adhesive that was present on the surface of the fiberglass sheet was smoothed with a rubber spatula to form a peel-resistant sheet. This peeling prevention sheet was cured (left standing) for 7 days at 23±2℃ and 50±20% relative humidity to obtain an evaluation sample in which a hardened body of the peeling prevention sheet had formed on the primer layer. The obtained evaluation samples were assessed to determine whether cracks in the crack scale (0.2 mm, 0.5 mm) were visible. A circle (○) indicates that it was visible, and a cross (×) indicates that it was not visible.

[0074] <Visible light transmittance> On the PET sheet, the fiber adhesive obtained in the above <punching test> was applied using a rubber spatula at a rate of 0.6 kg / m². 2 The coating was applied, and a fiberglass sheet was immediately attached to this coating. After attachment, the fiberglass sheet was pressed into the coating using a roller so that the fiber adhesive would permeate the fiberglass sheet. Then, the surface of the coating with the fiber adhesive that was present on the surface of the fiberglass sheet was smoothed with a rubber spatula to form a peel-resistant sheet. This peeling prevention sheet was cured (left undisturbed) for 7 days at 23±2℃ and 50±20% relative humidity to form a hardened peeling prevention sheet. Subsequently, the PET sheet was peeled off to obtain a hardened peel-resistant sheet with a thickness of 0.6 mm. For the cured sheets of the obtained anti-peeling sheets, the spectral transmittance in the wavelength range of 380 to 780 nm was measured from the direction normal (90°) to the surface of the cured sheet, in accordance with the visible light transmittance test of JIS A 5759, using a Shimadzu Corporation UV-VIS-NIR spectrophotometer SolidSpec-3700i. The visible light transmittance (%) was calculated by multiplying the weighting coefficient for each wavelength by the "weighting coefficient for calculating visible light transmittance" specified in JIS A 5759 and taking a weighted average. The calculated visible light transmittances are shown in Table 1.

[0075] <Workability> In the above <punch test>, the workability when fiber adhesive was impregnated into the fiberglass sheet was evaluated. A ○ was given if no fraying, twisting, or thread loss occurred in the fiberglass sheet, and a × was given if fraying occurred.

[0076] The peeling prevention sheets containing glass fiber sheets in each of Examples 1 to 5 showed superior peeling prevention and substrate visibility compared to Comparative Example 1, with a larger maximum displacement during the puncture test (larger than the NECXO structural standard of 10 mm maximum displacement and 1.5 kN maximum load), and better visibility of cracks in the substrate compared to Comparative Example 2. Furthermore, the peeling prevention sheets in each example also showed excellent workability. By implementing a spalling prevention construction method using a spalling prevention sheet as described in this embodiment, the generation of spalling fragments in structures (especially concrete structures) can be suppressed, and periodic visual observation and inspection of the surface condition of the structure after construction becomes easier. [Explanation of Symbols]

[0077] 10 Test boards 20 samples 30. Pressing and pulling indenter 50 Structures 100 Anti-peeling sheets 110 Fiberglass Sheet 120 Fiber Adhesive 120A, 120B exposed layer 130 Primer layer 150 protective layer

Claims

1. A peeling prevention sheet that can be fixed onto the surface of a structure, Glass fiber sheet and The glass fiber sheet comprises a fiber adhesive impregnated within it, When the mass loss (%) when the temperature is raised from 25 to 500°C in an air atmosphere at a heating rate of 10°C / min is defined as the ignition loss, the ignition loss of the fiber bundle constituting the glass fiber sheet is 1% or less. The glass fiber sheet includes one or more selected from the group consisting of triaxial fabrics, quadraxial fabrics, and pentaxial fabrics. Peeling prevention sheet.

2. A peeling prevention sheet according to claim 1, The air permeability of the aforementioned glass fiber sheet is 30 cm ３ / (cm ２ ・s) or more 800cm ３ / (cm ２ - s) A peeling prevention sheet that is below the specified size.

3. A peeling prevention sheet according to claim 1 or 2, The basis weight of the aforementioned glass fiber sheet is 120 g / m². ２ 350g / m or more ２ The following is a peeling prevention sheet.

4. A peeling prevention sheet according to any one of claims 1 to 3, A peeling prevention sheet in which the fineness of the fiber bundles constituting the glass fiber sheet is 50 tex or more and 1500 tex or less.

5. A peeling prevention sheet according to any one of claims 1 to 4, The amount of the fiber adhesive applied is 200 g / m ２ More than 2000g / m ２ The following is a peeling prevention sheet.

6. A peeling prevention sheet according to any one of claims 1 to 5, The glass fiber sheet is a peel-prevention sheet that includes one or more selected from the group consisting of E-glass, AR-glass, and ECR-glass.

7. A peeling prevention sheet according to any one of claims 1 to 6, A peel-preventing sheet having a pot life of 10 minutes or more and 300 minutes or less in the fiber adhesive, as measured in accordance with the exothermic method of JIS K 6870.

8. A peeling prevention sheet according to any one of claims 1 to 7, When the viscosity of the fiber adhesive measured at 23°C and 2 rpm is V2, and the viscosity of the fiber adhesive measured at 20 rpm is V20, A peeling prevention sheet in which V2 / V20 is between 2.0 and 8.0, and V2 is between 2,000 mPa·s and 100,000 mPa·s.

9. A glass fiber sheet used to form a spalling prevention sheet placed on the surface of a structure, It includes one or more selected from the group consisting of triaxial fabrics, tetraaxial fabrics, and pentaxial fabrics, When the mass loss (%) when the temperature is increased from 25 to 500°C in an air atmosphere at a heating rate of 10°C / min is defined as the ignition loss, the ignition loss of the fiber bundle constituting the glass fiber sheet is 1% or less. Glass fiber sheet.

10. A set for forming a spalling prevention sheet, used for forming a spalling prevention sheet to be placed on the surface of a structure, A glass fiber sheet comprising one or more selected from the group consisting of triaxial, quaternary, and pentaxial fabrics, The glass fiber sheet contains a fiber adhesive, When the mass loss (%) when the temperature is increased from 25 to 500°C in an air atmosphere at a heating rate of 10°C / min is defined as the ignition loss, the ignition loss of the fiber bundle constituting the glass fiber sheet is 1% or less. Set for forming peeling prevention sheets.

11. A placement step of placing a peeling prevention sheet according to any one of claims 1 to 8 on the surface of a structure, placing a peeling prevention sheet made by impregnating a glass fiber sheet with fiber adhesive according to claim 9 on the surface of a structure, or placing a peeling prevention sheet made by impregnating a glass fiber sheet with fiber adhesive using a peeling prevention sheet forming set according to claim 10 on the surface of a structure, A fixing step involves curing the fiber adhesive in the peeling prevention sheet to fix the cured body of the peeling prevention sheet onto the surface of the structure, A method for preventing peeling, including a construction method for preventing peeling.

12. A method for preventing peeling according to claim 11, A method for preventing spalling, wherein the surface of the structure is treated with a primer during the placement process.

13. A method for preventing peeling according to claim 11 or 12, A method for preventing spalling, wherein the aforementioned structure is a concrete structure.

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