JP2017096898A - Crack detection multilayer sheet, crack detection multilayer sheet roll, method for manufacturing crack detection multilayer sheet, wall surface processing method, and concrete structure with processed wall surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crack detection multilayer sheet that can easily process a wall surface of a concrete structure, as well as can detect cracks generated in the wall surface.SOLUTION: The crack detection multilayer sheet includes: a base material film; an adhesive layer on one surface of the film; a first removable releasing sheet on one surface of the adhesive layer; and a second removable releasing sheet on the other surface of the adhesive layer, the base material film having a first layer and a second layer on the other surface of the first layer, the first layer containing a light emission agent emitting light by an excitation light and/or a luminous agent, the second layer containing a shieling agent shielding the excitation light and/or the light emitted from the first layer. The first layer has a breaking elongation percentage of 50% to 300%, both inclusive, and the second layer has a breaking elongation percentage of 10% or less. The base material film desirably has the other surface with a 60° glossiness of 30 or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a crack detection multilayer sheet, a crack detection multilayer sheet roll, a crack detection multilayer sheet manufacturing method, a wall surface processing method, and a wall surface processed concrete structure.

  Concrete structures are widely used for walls such as buildings and tunnels, and bridges. The concrete structure is used, for example, on the wall surface of a building, so that the durability of the building is kept high, and the earth and sand are prevented from collapsing into the tunnel by being used on the wall surface of the tunnel.

  However, such a concrete structure has high rigidity, but may crack due to internal stress or the like. Further, when such a crack occurs in a concrete structure, the original strength may not be maintained. Therefore, when a crack occurs in a concrete structure, it is important to detect and repair the crack at an early stage.

  In view of such circumstances, today, a first layer containing a fluorescent whitening agent and having a certain stretchability is formed by coating on the surface of a base made of a concrete structure, and further contains an ultraviolet absorber. And the wall surface processing method of the concrete structure which forms the 2nd layer whose elasticity is lower than the 1st layer on the surface of the 1st layer by coating is proposed (refer JP, 2013-88405, A).

  Since the first layer of the concrete structure formed by the method of processing a wall surface of the concrete structure has a relatively high stretchability, even if a crack occurs in the base, it is difficult to break due to the extension of the portion overlapping the crack. On the other hand, since the second layer of the concrete structure is less stretchable than the first layer, when a crack occurs in the base, the portion corresponding to the crack is easily broken or thinned. Further, in this concrete structure, since the first layer contains a fluorescent whitening agent and the second layer contains an ultraviolet absorber, the first layer is exposed when irradiated with ultraviolet rays from the second layer side. While the portion emits light by the fluorescent whitening agent, the portion where the second layer covers the first layer is difficult to emit light. For this reason, in this concrete structure, the first layer emits light at the portion overlapping with the crack and does not emit light at other portions, so the presence or absence of the crack can be detected relatively easily by confirming the presence or absence of light emission from the first layer. It is said that.

  However, this concrete structure is formed by forming the first layer on the surface of the base by coating, and further forming the second layer on the surface of the first layer by coating. That is, when performing the wall surface processing of the concrete structure, it takes about 5 to 10 days for the step of forming the first layer by coating and the step of forming the second layer by coating.

  In addition, when processing the wall surface of the concrete structure, it is necessary to control the temperature, humidity, and the like during the formation of the first layer and the second layer to an appropriate range. Furthermore, for example, when the first layer and the second layer are sequentially formed on the wall surface of an existing tunnel, the tunnel cannot be used during the formation period of the first layer and the second layer.

  Thus, this concrete structure has the inconvenience that the construction period becomes longer, the construction conditions such as temperature and humidity need to be adjusted, and it is difficult to apply to existing structures.

JP 2013-88405 A

  The present invention has been made in view of such circumstances, and is capable of detecting a crack generated on a wall surface of a concrete structure and is capable of detecting a crack on the wall surface of the concrete structure, and for detecting a crack. An object of the present invention is to provide a multilayer sheet roll and a method for producing the multilayer sheet for crack detection. Another object of the present invention is to provide a wall surface processing method and a wall surface processed concrete structure capable of easily and reliably detecting a crack generated on the wall surface of the concrete structure.

  The multilayer sheet for crack detection according to the present invention made to solve the above problems is a base film, an adhesive layer laminated on one surface side of the base film, and one surface of the adhesive layer. A first release sheet laminated in a peelable manner and a second release sheet laminated in a peelable manner on the other surface side of the base film, and the base film emits light by excitation light. A first layer containing an agent and / or a phosphorescent agent, and a second layer containing a shielding agent that is laminated on the other surface side of the first layer and shields the excitation light and / or light emitted from the first layer. The breaking elongation of the first layer is 50% or more and 300% or less, and the breaking elongation of the second layer is 10% or less.

  For example, after the first release sheet is peeled off, the crack detecting multilayer sheet is bonded to the wall surface of the concrete structure via the adhesive layer, and further peeled off from the second release sheet. Wall surface processing of the structure can be easily performed. The multilayer sheet for crack detection is a second layer in which the base film is laminated on the first layer and the other surface side of the first layer (opposite side of the concrete structure in a state of being stuck to the concrete structure). The breaking elongation rate of the first layer is 50% or more and 300% or less, and the breaking elongation rate of the second layer is 10% or less. Therefore, even when the second layer breaks, the first layer extends. . For this reason, when a crack occurs in the wall surface of the concrete structure, the second layer breaks, but the first layer extends according to the crack (that is, the first layer does not break). In the crack detecting multilayer sheet, the first layer contains a light-emitting agent and / or a phosphorescent agent that emits light by excitation light, and the second layer contains a shielding agent. When the excitation light is applied to the portion where the light is exposed, the exposed portion emits light, while the second layer does not emit light (or emits light slightly) even when the second layer is irradiated with the excitation light. Therefore, the multilayer sheet for crack detection can easily detect the presence or absence of cracks in the wall surface of the concrete structure by irradiating excitation light and confirming whether or not the first layer emits light.

  The 60 ° glossiness of the other surface of the base film is preferably 30 or less. Thus, when the 60 ° glossiness of the other surface of the base film is not more than the above upper limit, reflection of light when the other surface of the base film is irradiated with light can be suppressed, Thereby, it is easy to detect a crack generated in the concrete structure.

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is preferably an acrylic pressure-sensitive adhesive, the amount of the pressure-sensitive adhesive layer laminated is preferably 20 g / m ² or more and 100 g / m ² or less, and the pressure-sensitive adhesive force is 30 N / 25 mm or more and 60 N / 25 mm or less is preferable. As described above, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive, and the amount of lamination of the pressure-sensitive adhesive layer and the pressure-sensitive adhesive force are within the above range. Can be securely fixed. In addition, when the amount of the adhesive layer is within the above range, even if a fine dent or the like is present on the wall surface of the concrete structure, the adhesive layer is embedded in the dent, and the concrete structure of the multilayer sheet for crack detection Adhesion to objects can be increased.

  Moreover, the multilayer sheet roll for crack detection according to the present invention made to solve the above problems is configured by winding the multilayer sheet for crack detection into a roll.

  In the crack detecting multilayer sheet, since the second release sheet is laminated on the other surface side of the second layer, even if the elongation at break of the second layer is as small as the above upper limit or less, the second release sheet By supporting the other surface side of the second layer, the second layer can be wound into a roll while preventing the second layer from cracking. Thus, the crack detection multilayer sheet roll obtained by winding the crack detection multilayer sheet into a roll can reduce storage space and is excellent in handleability.

  Moreover, the manufacturing method of the multilayer sheet for crack detection based on this invention made | formed in order to solve the said subject coats the base film formation composition on the one side surface which is a mold release surface of a 2nd mold release sheet. And a step of obtaining a multilayer sheet body in which a pressure-sensitive adhesive layer and a first release sheet that can be peeled on one surface of the pressure-sensitive adhesive layer are laminated on one side surface of the base material film, A first layer containing a fluorescent agent and / or a phosphorescent agent that emits light by excitation light, and a shielding agent that is laminated on the other surface side of the first layer and shields the excitation light and / or light emitted from the first layer. And the second layer has a breaking elongation of 50% or more and 300% or less, and the second layer has a breaking elongation of 10% or less.

  The manufacturing method of the crack detecting multilayer sheet includes a base film, an adhesive layer laminated on one surface side of the base film, and a first release layer that is peelably laminated on one surface of the adhesive layer. A mold sheet and a second release sheet that is releasably laminated on the other surface side of the base film, and can detect cracks in the concrete structure and facilitate wall processing of the concrete structure. The above-mentioned crack detecting multilayer sheet can be easily and reliably produced.

  Further, a wall surface processing method according to the present invention made to solve the above-mentioned problems is a wall surface processing method for facilitating detection of cracks generated on the wall surface of a concrete structure, wherein the crack detection multilayer sheet A step of peeling the first release sheet, a step of sticking the base film to the wall surface of the concrete structure through the adhesive layer exposed by peeling the first release sheet, and the base material And a step of peeling the second release sheet from the film.

  According to the wall surface processing method, the first layer is laminated on the surface side of the concrete structure, and further, the second layer is laminated on the surface side of the first layer. By confirming the presence or absence of light emission in one layer, it is possible to easily detect the presence or absence of cracks in the wall surface of the concrete structure. According to the wall surface processing method, the first release sheet of the crack detecting multilayer sheet is peeled off, the base film is adhered to the wall surface of the concrete structure via the adhesive layer, and the second release sheet is further removed. By peeling off, the wall surface processing of the concrete structure can be performed easily and reliably. Since the wall surface processing method does not sequentially form the first layer and the second layer by coating unlike the conventional wall surface processing method, for example, even a wall surface of a concrete structure such as an existing tunnel has a short work period. Can be easily processed.

  Moreover, the wall surface processed concrete structure based on this invention made in order to solve the said subject has a concrete structure, a base film, and an adhesion layer, and it is on the wall surface of a concrete structure through this adhesion layer. A first layer containing a light-emitting agent and / or a phosphorescent agent that emits light by excitation light, and the excitation layer laminated on the surface side of the first layer. A second layer containing a shielding agent that shields light and / or light emitted from the first layer, and the elongation at break of the first layer is 50% or more and 300% or less, The elongation at break is 10% or less.

  For example, the wall-processed concrete structure is peeled off from the first release sheet of the crack detecting multilayer sheet, and the base film is adhered to the wall surface of the concrete structure via the adhesive layer. It is obtained by peeling the mold sheet. The wall surface processed concrete structure has a first layer laminated on the surface side of the concrete structure, and further a second layer laminated on the surface side of the first layer, so that the excitation light is irradiated as described above. And the presence or absence of the crack of a concrete structure is easily detectable by confirming the presence or absence of light emission of a 1st layer.

  In the present invention, the “elongation at break” refers to the elongation at break at 23 ° C. and 50 RH. “Glossiness” refers to a value based on JIS-Z8741: 1997. “Adhesive strength” refers to a value based on JIS-Z0237: 2009.

  As described above, the multilayer sheet for crack detection and the multilayer sheet roll for crack detection of the present invention can detect cracks generated on the wall surface of the concrete structure and can easily process the wall surface of the concrete structure. Moreover, the method for manufacturing a crack detecting multilayer sheet of the present invention can easily and reliably manufacture the crack detecting multilayer sheet of the present invention. Furthermore, the wall surface processing method and the wall surface processed concrete structure of the present invention can detect cracks generated in the concrete structure easily and reliably.

It is a typical sectional view showing the multilayer sheet for crack detection concerning one embodiment of the present invention. It is typical sectional drawing which shows the 1st coating process in the manufacturing method of the multilayer sheet for crack detection of FIG. It is typical sectional drawing which shows the 2nd coating process in the manufacturing method of the multilayer sheet for crack detection of FIG. It is typical sectional drawing which shows the adhesion layer lamination process in the manufacturing method of the multilayer sheet for crack detection of FIG. It is typical sectional drawing which shows the 1st release sheet lamination process in the manufacturing method of the crack detection multilayer sheet of FIG. It is a typical perspective view which shows the multilayer sheet roll for crack detection which wound the multilayer sheet for crack detection of FIG. It is typical sectional drawing which shows the 1st release sheet peeling process in the wall surface processing method using the multilayer sheet for crack detection of FIG. It is typical sectional drawing which shows the sticking process in the wall surface processing method using the multilayer sheet for crack detection of FIG. It is typical sectional drawing which shows the 2nd release sheet peeling process in the wall surface processing method using the multilayer sheet for crack detection of FIG. It is a typical end view for demonstrating the crack detection method by the wall surface processed concrete structure which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[First Embodiment]
<Multilayer sheet for crack detection>
The crack detecting multilayer sheet 1 shown in FIG. 1 is used to detect a crack generated in a wall surface of a concrete structure such as a tunnel. The crack detecting multilayer sheet 1 includes a base film 2, an adhesive layer 3 laminated on one surface side of the base film 2, and a first release laminated on one surface of the adhesive layer 3 in a peelable manner. A mold sheet 4 and a second release sheet 5 that is detachably laminated on the other surface side of the base film 2 are provided. The base film 2 has flexibility. The base film 2 includes a first layer 6 and a second layer 7 laminated on the other surface side of the first layer 6. The crack detecting multilayer sheet 1 has flexibility as a whole. The multilayer sheet 1 for crack detection, for example, peels the first release sheet 4, sticks the base film 2 to the wall surface of the concrete structure via the adhesive layer 3, and further peels the second release sheet 5. By doing so, the wall surface processing of the concrete structure can be easily performed.

  In the multilayer sheet for crack detection 1, the adhesive layer 3 is directly laminated on one surface of the base film 2, and the first release sheet 4 is directly laminated on one surface of the adhesive layer 3. The first release sheet 4 is directly laminated on the other surface. The base film 2 is configured as a two-layer structure in which the second layer 7 is directly laminated on the other surface of the first layer 6. That is, in the multilayer sheet for crack detection 1, the first release sheet 4, the adhesive layer 3, the first layer 6, the second layer 7, and the second release sheet 5 are directly laminated in this order from one side to the other side. It consists of a structured. Further, in the crack detection multilayer sheet 1, the adhesive layer 3, the first layer 6 and the second layer 7 are laminated in this order from the concrete structure side in a state where the multilayer sheet 1 is adhered to the wall surface of the concrete structure. It is configured as a three-layer structure in which the two layers 7 are disposed on the outermost surface side (hereinafter, the structure in the attached state is also referred to as “crack detection film 1a”).

(First layer)
The first layer 6 has a relatively high stretchability. When the first layer 6 is cracked on the wall surface of the concrete structure in a state where the multilayer sheet 1 for crack detection is adhered to the wall surface of the concrete structure, a portion corresponding to the crack corresponds to the crack. Elongate. The first layer 6 contains a light emitting agent and / or a phosphorescent agent that emits light by excitation light. Specifically, the first layer 6 includes a light emitting agent and / or a phosphorescent agent dispersedly contained in a resin matrix. The “main component” refers to a component having the highest content, for example, a component having a content of 50% by mass or more.

  As a minimum of average thickness of the 1st layer 6, 30 micrometers is preferred, 40 micrometers is more preferred, and 50 micrometers is still more preferred. On the other hand, the upper limit of the average thickness of the first layer 6 is preferably 200 μm, more preferably 150 μm, and even more preferably 120 μm. If the average thickness of the first layer 6 is less than the above lower limit, this crack is detected when a crack occurs on the wall surface of the concrete structure with the crack detecting multilayer sheet 1 adhered to the wall surface of the concrete structure. There is a possibility that the thickness of the corresponding part becomes too thin or breaks. Conversely, if the average thickness of the first layer 6 exceeds the above upper limit, the flexibility may be reduced, making it difficult for the first layer 6 to follow the curved surface or the like of the concrete structure.

  The lower limit of the elongation at break of the first layer 6 is 50%, preferably 100%, and more preferably 150%. On the other hand, the upper limit of the elongation at break of the first layer 6 is 300%, more preferably 270%, and further preferably 250%. If the elongation at break of the first layer 6 is less than the lower limit, a crack occurs on the wall surface of the concrete structure when the crack detecting multilayer sheet 1 is adhered to the wall surface of the concrete structure. There is a possibility that the one layer 6 becomes difficult to extend according to the crack. On the contrary, when the elongation at break of the first layer 6 exceeds the above upper limit, the hardness is lowered and the durability may be insufficient. On the other hand, if the breaking elongation rate of the first layer 6 is within the above range, for example, even if a crack of about 2 to 3 mm occurs on the wall surface of the concrete structure, the first layer 6 is stretched according to the crack. be able to. The elongation at break of the first layer 6 can be adjusted by the molecular structure of the main component of the resin matrix.

  The other surface of the first layer 6 is preferably flat. The upper limit of the arithmetic average roughness Ra of the other surface of the first layer 6 is preferably 0.7 μm, more preferably 0.5 μm, and further preferably 0.3 μm. When the arithmetic average roughness Ra of the other surface of the first layer 6 exceeds the above upper limit, when a crack occurs on the wall surface of the concrete structure to which the multilayer sheet for crack detection 1 is adhered, When the excitation light is irradiated, the light emitted from the first layer 6 may be diffused, refracted, or the like, making it difficult to view. The lower limit of the arithmetic average roughness Ra of the other surface of the first layer 6 is not particularly limited, but can be set to 0.01 μm, for example, from the viewpoint of moldability. The “arithmetic average roughness Ra” refers to a value with a cutoff λc of 2.5 mm and an evaluation length of 12.5 mm in accordance with JIS-B0601: 2001.

  Since the resin matrix needs to transmit excitation light, it is transparent, particularly colorless and transparent. The resin matrix has a synthetic resin as a main component. An example of the synthetic resin is a thermosetting resin. In addition, since the 1st layer 6 contains the luminescent agent and / or luminous agent which light-emits by excitation light as mentioned above, when the 1st layer 6 is irradiated with an ultraviolet-ray, it will be absorbed by the luminescent agent and / or luminous agent. There is a case. Therefore, when the light-emitting agent and / or the phosphorescent agent absorb ultraviolet rays, the main component of the first layer 6 is not preferably an ultraviolet curable resin that is cured by ultraviolet irradiation.

  Examples of the thermosetting resin include epoxy resin, silicone resin, phenol resin, urea resin, unsaturated polyester resin, melamine resin, alkyd resin, polyimide resin, acrylic resin, amide functional copolymer, urethane resin, and acrylic urethane. Examples thereof include resins. Especially, as said thermosetting resin, the acrylic urethane resin which is easy to adjust the breaking elongation rate of the 1st layer 6 to the above-mentioned range is preferable.

  As a minimum of the content rate of the urethane part in the above-mentioned acrylic urethane resin, 50 mass% is preferred, 55 mass% is more preferred, and 60 mass% is still more preferred. On the other hand, as an upper limit of the content rate of the urethane part in the said acrylic urethane resin, 95 mass% is preferable, 85 mass% is more preferable, 75 mass% is further more preferable. If the content ratio of the urethane part in the acrylic urethane resin is less than the lower limit, the breaking elongation of the first layer 6 may not be sufficiently high. On the other hand, when the content ratio of the urethane portion in the acrylic urethane resin exceeds the upper limit, the hardness of the first layer 6 may be lowered and the durability may be insufficient.

  The resin matrix can also contain an additive in addition to the synthetic resin. Examples of the additive include a silicone-based additive, a fluorine-based additive, and an antistatic agent. Moreover, as content of the said additive of solid content conversion with respect to 100 mass parts of said synthetic resin components of the said resin matrix, it can be 0.05 mass part or more and 5 mass parts or less, for example.

  As the luminescent agent, for example, a material that emits visible light when excited by invisible light such as ultraviolet rays or infrared rays is used. Examples of the luminescent agent include benzothiazole, benzimidazole, benzoxazole, stilbene, distilbene, pyrazoline, oxazole, coumarin, aminocoumarin, imidazole, styryl-oxazole, and pyrene-oxazole. , Distyryl-biphenyl, thiazole, triazole, oxadiazole, thiadiazole, naphthalimide, acenaphthene, diaminostilbene, brighteners, metal chelated oxonium compounds, styrylbenzene compounds, aromatic Group dimethylidin compounds and the like.

As the luminous agent, for example, an agent that emits visible light when excited by ultraviolet rays or visible light is used. Examples of the phosphorescent agent include ZnO (activator: Zn, emission color: white green), SrAl ₂ O ₄ (emission color: green), Sr ₄ Al ₁₄ O ₂₅ (emission color: blue), CaWO ₄ (emission color). : Blue-green), MgWO ₄ (light emission color: blue), ZnSiO ₄ (activator: Mn, light emission color: green) and the like.

  Especially, it is preferable that the 1st layer 6 contains a luminescent agent, and it is especially preferable to contain a fluorescent whitening agent among this luminescent agent. When the first layer 6 contains a fluorescent whitening agent, the crack detecting multilayer sheet 1 can use invisible light (ultraviolet rays) as excitation light, and the fluorescent whitening agent is relatively dark and easily visible. Since blue-violet light is emitted, it is easy to detect the presence or absence of cracks in a concrete structure such as a tunnel.

  The lower limit of the total content of the light-emitting agent and / or phosphorescent agent with respect to 100 parts by mass of the synthetic resin component of the resin matrix is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, and further 1 part by mass preferable. On the other hand, the upper limit of the total content of the light-emitting agent and / or phosphorescent agent with respect to 100 parts by mass of the synthetic resin component of the resin matrix is preferably 5 parts by mass, more preferably 4.8 parts by mass, and 4.5 parts by mass Is more preferable. If the total content of the light-emitting agent and / or the phosphorescent agent is less than the lower limit, the content of the light-emitting agent and / or the phosphorescent agent in the resin matrix becomes insufficient, and cracks generated on the wall surface of the concrete structure There is a possibility that the detection accuracy is lowered. Conversely, when the total content of the light-emitting agent and / or the phosphorescent agent exceeds the upper limit, the dispersibility of the light-emitting agent and / or the phosphorescent agent may be reduced.

(Second layer)
The second layer 7 has low stretchability. In the second layer 7, when a crack occurs on the wall surface of the concrete structure with the crack detecting multilayer sheet 1 adhered to the wall surface of the concrete structure, a portion corresponding to the crack is broken. The second layer 7 contains a shielding agent that shields excitation light and / or light emitted from the first layer 6. Specifically, the second layer 7 contains a light absorber dispersed in a resin matrix.

  The lower limit of the average thickness of the second layer 7 is preferably 30 μm, more preferably 40 μm, and even more preferably 50 μm. On the other hand, the upper limit of the average thickness of the second layer 7 is preferably 200 μm, more preferably 150 μm, and still more preferably 120 μm. The 2nd layer 7 is located in the outermost surface side in the state which stuck the said multilayer sheet 1 for a crack detection to the wall surface of the concrete structure. Therefore, if the average thickness of the second layer 7 is less than the above lower limit, the second layer 7 is damaged when a force is applied from the surface side, and the first layer is formed in a portion other than the crack portion of the wall surface of the concrete structure. Layer 6 may be exposed. Conversely, if the average thickness of the second layer 7 exceeds the above upper limit, the flexibility may be reduced, making it difficult for the first layer 6 to follow the curved surface or the like of the concrete structure.

  The lower limit of the elongation at break of the second layer 7 is preferably 1% and more preferably 2%. On the other hand, the upper limit of the elongation at break of the second layer 7 is 10%, more preferably 8%, and even more preferably 6%. If the elongation at break of the second layer 7 is less than the lower limit, the flexibility of the second layer 7 becomes insufficient, and the crack detecting multilayer sheet 1 may not be wound in a roll shape. On the other hand, when the elongation at break of the second layer 7 exceeds the above upper limit, when the crack is generated in the concrete structure in a state where the crack detecting multilayer sheet 1 is adhered to the wall surface of the concrete structure, There is a possibility that the second layer 7 is difficult to break at the portion corresponding to the crack.

  The second layer 7 is disposed on the outermost surface side of the other surface side of the base film 2, and the other surface of the second layer 7 constitutes the other surface of the base film 2. The upper limit of the 60 ° glossiness of the other surface of the second layer 7 constituting the other surface of the base film 2 is preferably 30, more preferably 28, and even more preferably 25. When the 60 ° glossiness of the other surface of the second layer 7 is equal to or lower than the above upper limit, reflection of light incident on the other surface of the second layer 7 is suppressed and cracks generated on the wall surface of the concrete structure are prevented. It can be easily detected.

  The other surface of the second layer 7 is preferably a mat surface on which a plurality of fine irregularities are formed. The lower limit of the arithmetic mean roughness Ra of the other surface of the second layer 7 when formed as such a mat surface is preferably 0.8 μm, more preferably 0.9 μm, and even more preferably 1 μm. If the arithmetic average roughness Ra of the other surface of the second layer 7 is less than the lower limit, it is difficult to detect cracks generated on the wall surface of the concrete structure due to reflection of light incident on the other surface of the second layer 7. There is a risk. On the other hand, when the arithmetic mean roughness Ra of the other surface of the second layer 7 is equal to or higher than the lower limit, it is easy to detect a fine crack generated on the wall surface of the concrete structure. In addition, as an upper limit of arithmetic mean roughness Ra of the other surface of the 2nd layer 7, it can be set as 1.5 micrometers, for example. When the arithmetic mean roughness Ra of the other surface of the second layer 7 exceeds the above upper limit, the other surface of the second layer 7 has irregularities more than necessary, and a concrete structure in which the multilayer sheet 1 for crack detection is adhered. There is a risk that the appearance of things will deteriorate.

  The resin matrix of the second layer 7 is mainly composed of a synthetic resin. As said synthetic resin, the thermosetting resin similar to the main component of the resin matrix of the 1st layer 6 is mentioned, for example, Acrylic urethane resin is especially preferable.

  As a minimum of the content rate of the urethane part in acrylic urethane resin contained as a main ingredient of the 2nd layer 7, 3 mass% is preferred, 5 mass% is more preferred, and 10 mass% is still more preferred. On the other hand, the upper limit of the content ratio of the urethane portion in the acrylic urethane resin contained as the main component of the second layer 7 is preferably 45% by mass, more preferably 35% by mass, and even more preferably 25% by mass. If the content ratio of the urethane portion in the acrylic urethane resin is less than the lower limit, the flexibility of the second layer 7 becomes insufficient, and the crack detecting multilayer sheet 1 may not be wound in a roll shape. On the contrary, when the content rate of the urethane part in the said acrylic urethane resin exceeds the said upper limit, there exists a possibility that the fracture | rupture elongation rate of the 2nd layer 7 may not become low enough.

  The molecular weight of the acrylic urethane resin contained as the main component of the second layer 7 is preferably larger than the molecular weight of the acrylic urethane resin contained as the main component of the first layer 6. Thus, when the molecular weight of the acrylic urethane resin contained as the main component of the second layer 7 is larger than the molecular weight of the acrylic urethane resin contained as the main component of the first layer 6, the first layer 6 and the second layer 7. It is easy to increase the difference in elongation at break.

  The resin matrix of the second layer 7 can also contain an additive in addition to the synthetic resin. Examples of the additive include a silicone-based additive, a fluorine-based additive, and an antistatic agent. Moreover, as content of the said additive of solid content conversion with respect to 100 mass parts of synthetic resin components of the said resin matrix, it is 0.05 mass part or more and 5 mass parts or less, for example.

  The light absorber is not particularly limited as long as excitation light and / or light emitted from the first layer 6 can be shielded, and examples thereof include an ultraviolet absorber, a visible light absorber, and an infrared absorber. Can be mentioned. Among these, as the light absorber, those that absorb excitation light are preferable. The crack detecting multilayer sheet 1 prevents the excitation light from passing through the second layer 7 by the light absorber absorbing the excitation light, and the second layer 7 covers the first layer 6. It is possible to prevent light emission at the portion where the crack is present, and it is easy to improve the crack detection accuracy of the wall surface of the concrete structure. In particular, in the crack detecting multilayer sheet 1, it is preferable that the first layer 6 contains a fluorescent whitening agent as a luminescent agent and the second layer 7 contains an ultraviolet absorber as a light absorbing agent. According to such a configuration, the crack detecting multilayer sheet 1 is visible only in a portion corresponding to a crack in the wall surface of the concrete structure portion in a state where the crack detecting multilayer sheet 1 is adhered to the wall surface of the concrete structure. Since light is emitted, the presence or absence of cracks in the wall surface of the concrete structure can be detected with high accuracy.

  Examples of the UV absorber include salicylic acid UV absorbers, benzophenone UV absorbers, benzotriazole UV absorbers, cyanoacrylate UV absorbers, triazine UV absorbers, and benzoxazinone UV absorbers. 1 type, or 2 or more types of these can be used. Among these, a benzotriazole-based ultraviolet absorber that is soluble in a solvent is preferable. As the ultraviolet absorber, a polymer having an ultraviolet absorbing group in the molecular chain is also preferably used. By using a polymer having an ultraviolet absorbing group in such a molecular chain, it is possible to prevent deterioration of the ultraviolet absorbing function due to bleeding out of the ultraviolet absorbent. Examples of the ultraviolet absorbing group include a benzotriazole group, a benzophenone group, a cyanoacrylate group, a triazine group, a salicylate group, and a benzylidene malonate group. Among these, a benzotriazole group is particularly preferable.

  As a minimum of content of the above-mentioned light absorber to 100 mass parts of synthetic resin ingredients of the above-mentioned resin matrix, 0.1 mass part is preferred, 0.5 mass part is more preferred, and 1 mass part is still more preferred. On the other hand, the upper limit of the content of the light absorber relative to 100 parts by mass of the synthetic resin component of the resin matrix is preferably 5 parts by mass, more preferably 4.8 parts by mass, and even more preferably 4.5 parts by mass. If the content of the light absorber is less than the lower limit, the content of the light absorber in the resin matrix becomes insufficient, and the detection accuracy of cracks generated on the wall surface of the concrete structure may be reduced. On the contrary, when the content of the light absorber exceeds the upper limit, the dispersibility of the light absorber may be lowered.

(Adhesive layer)
The adhesive layer 3 is mainly composed of an adhesive and has tackiness. The pressure-sensitive adhesive layer 3 is composed of a pressure-sensitive adhesive having a pressure-sensitive adhesive property at room temperature.

  As an adhesive which comprises the adhesion layer 3, an acrylic adhesive, a urethane adhesive, a silicone adhesive, a styrene adhesive, a polyester adhesive, a polyether adhesive, an epoxy adhesive, etc. are mentioned. . Among them, an acrylic pressure-sensitive adhesive that is excellent in adhesion to a concrete structure and easily stretches in response to a crack in the wall surface of the concrete structure is preferable as the pressure-sensitive adhesive. In the multilayer sheet for crack detection 1, as described above, the first layer 6 contains a luminescent agent and / or a phosphorescent agent that emits light with excitation light, and the second layer 7 has excitation light and / or the first layer 6. In other words, when the first layer 6 and the second layer 7 are irradiated with ultraviolet rays, the ultraviolet rays may be absorbed. Therefore, when the 1st layer 6 and the 2nd layer 7 absorb an ultraviolet-ray, it is preferable not to use an ultraviolet curing adhesive as an adhesive which comprises the adhesion layer 3. FIG.

  The adhesive layer 3 may contain a light-emitting agent and / or a phosphorescent agent that emits light by excitation light. Moreover, it is preferable that this luminescent agent and / or luminous agent are the same as the luminescent agent and / or luminous agent which the 1st layer 6 contains. In this way, the crack detecting multilayer sheet 1 further easily detects the presence or absence of cracks in the wall surface of the concrete structure by including the light emitting agent and / or the phosphorescent agent in addition to the first layer 6 in the adhesive layer 3. can do. Moreover, according to this structure, even if the 1st layer 6 fractures | ruptures due to the crack of the wall surface of a concrete structure, this crack can be detected when the adhesion layer 3 is not fractured.

  In addition to the above components, the adhesive layer 3 may contain various additives such as an antioxidant, an antioxidant, a hygroscopic agent, an ultraviolet absorber, an antistatic agent, and a silane coupling agent as appropriate.

As a minimum of the amount of lamination of adhesion layer 3, 20 g / m ² is preferred, 25 g / m ² is more preferred, and 30 g / m ² is still more preferred. If the amount of the adhesive layer 3 is less than the lower limit, when the first release sheet 4 is peeled off and the adhesive layer 3 is adhered to the wall surface of the concrete structure, sufficient adhesion with the concrete structure is obtained. There is a risk of not being able to. On the other hand, if the amount of the adhesive layer 3 laminated is equal to or more than the above lower limit, the crack detecting multilayer sheet 1 can be obtained by embedding the adhesive layer in the recess even when a fine recess or the like is present on the wall surface of the concrete structure. Can be firmly fixed to the concrete structure. In addition, as an upper limit of the lamination amount of the adhesion layer 3, it can be 100 g / m < ² > from points, such as productivity and handleability.

  The lower limit of the adhesive strength of the adhesive layer 3 is preferably 30 N / 25 mm, more preferably 35 N / 25 mm, and even more preferably 40 N / 25 mm. If the adhesive strength of the adhesive layer 3 is less than the above lower limit, the first release sheet 4 is peeled off and the adhesive layer 3 is adhered to the wall surface of the concrete structure. There is a risk of not being able to. In addition, as an upper limit of the adhesive force of the adhesion layer 3, it can be set to 60 N / 25mm, for example so that the adhesion layer 3 can be peeled from a concrete structure as needed. The “adhesive strength” refers to the adhesive strength at the time when the adhesive layer is stuck to a concrete structure.

  In the crack detecting multilayer sheet 1, it is particularly preferable that the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 3 is an acrylic pressure-sensitive adhesive, and that the lamination amount and the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer 3 are both within the above ranges. According to such a configuration, the crack detecting multilayer sheet 1 can be reliably fixed to the wall surface of the concrete structure.

(First release sheet)
The first release sheet 4 has flexibility and covers the entire one surface of the adhesive layer 3. The first release sheet 4 has a base material layer. This base material layer is formed of various materials having heat resistance, mechanical strength that can withstand manufacturing, solvent resistance, and the like. Examples of the main component contained in the base material layer include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polyethylene, polypropylene and polymethylpentene, polyamides such as nylon 6, vinyl resins such as polyvinyl chloride, and polymethyl. Examples thereof include acrylic resins such as methacrylate, cellulose resins such as cellulose acetate, and synthetic resins such as polycarbonate. The base material layer may be formed using paper as a main component. Furthermore, the base material layer may be a laminate of two or more layers.

  When the base material layer is mainly composed of a synthetic resin, the base material layer may be either a stretched film or an unstretched film, but is stretched uniaxially or biaxially from the viewpoint of improving strength. Is preferred. Note that additives such as a filler, a plasticizer, a colorant, and an antistatic agent may be added to the base material layer as necessary.

  Moreover, as for the 1st release sheet 4, the release layer may be laminated | stacked on the lamination surface side of the adhesion layer 3 of the said base material layer. The release layer is provided in order to improve the peelability between the first release sheet 4 and the pressure-sensitive adhesive layer 3, and when the peelability between the first release sheet 4 and the pressure-sensitive adhesive layer 3 is adjusted. Is not necessary. Examples of the main component of the release layer include silicone resin, melamine resin, and fluorinated polymer. The release layer is formed by applying a coating solution containing a release layer forming material and an organic solvent on a base material layer by a known method such as a gravure coating method, a roll coating method, a comma coating method, a lip coating method, and the like. And it can form by the coating method to harden. In forming the release layer, the laminated surface may be subjected to corona treatment or easy adhesion treatment.

Among them, as the first release sheet 4, a film (polyethylene film) containing polyethylene as a main component is laminated on the laminated surface side of the paper single layer or the adhesive layer 3 of the paper as the base material layer 2. A multilayer body using a layer body and using a silicone resin as a main component of the release layer is preferable. The 1st release sheet 4 which has this structure has waist and is excellent in the peelability with respect to the adhesion layer 3. FIG. Further, the basis weight of the paper is preferably 50 g / m ² or more and 100 g / m ² or less so that the waist of the first release sheet 4 can be sufficiently increased, and the average thickness of the polyethylene film is 15 μm or more. 30 μm or less is preferable.

  The release layer may contain a crosslinking agent. Examples of the crosslinking agent contained in the release layer include epoxy crosslinking agents, isocyanate crosslinking agents, methylol crosslinking agents, chelating crosslinking agents, aziridine crosslinking agents, melamine crosslinking agents, and polyvalent metal chelating crosslinking agents. Agents and the like.

  As a minimum of content of the above-mentioned crosslinking agent to 100 mass parts of the main ingredients of the above-mentioned mold release layer, 0.5 mass parts is preferred and 2 mass parts is more preferred. On the other hand, the upper limit of the content of the crosslinking agent relative to 100 parts by mass of the main component of the release layer is preferably 20 parts by mass, and more preferably 10 parts by mass. When the content of the crosslinking agent is within the above range, a stable high molecular weight product can be obtained.

  Examples of the organic solvent include aliphatic hydrocarbons such as hexane, heptane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, propanol and butanol; methyl ethyl ketone, 2-pentanone and isophorone. Examples include ketones; esters such as ethyl acetate, butyl acetate and methoxypropyl acetate; cellosolv solvents such as ethyl cellosolve; glycol solvents such as methoxypropanol, ethoxypropanol and methoxybutanol. These organic solvents can be used alone or in combination.

  Moreover, a filler, a softening agent, an antioxidant, an ultraviolet absorber, a tackifier, an antistatic agent, and the like can be added to the release layer as necessary.

(Second release sheet)
The second release sheet 5 has flexibility and covers the entire other surface of the second layer 7. The second release sheet 5 has a base material layer. The component, average thickness and the like of the base layer of the second release sheet 5 can be the same as those of the base layer of the first release sheet 4 described above. The second release sheet 5 may have a release layer laminated on the lamination surface side of the base film 2. The component, average thickness, and the like of the release layer can be the same as those of the release layer of the first release sheet 4 described above.

  The second release sheet 5 is preferably matted on one surface (the surface on which the base film 2 is laminated). The lower limit of the arithmetic average roughness Ra of one surface of the second release sheet 5 when the mat processing is performed is preferably 0.8 μm, more preferably 0.9 μm, and further preferably 1 μm. On the other hand, the upper limit of the arithmetic average roughness Ra of one surface of the second release sheet 5 is preferably 1.5 μm. When the arithmetic average roughness Ra of one surface of the second release sheet 5 is within the above range, the other of the second layer 7 is the first coating step in the method for manufacturing the crack detecting multilayer sheet described later. Fine irregularities can be easily and reliably formed on the surface.

  Moreover, it is preferable that the adhesive strength between the second release sheet 5 and the base film 2 is greater than the adhesive strength between the first release sheet 4 and the pressure-sensitive adhesive layer 3. It is preferable that the crack detecting multilayer sheet 1 peels the first release sheet 4 and sticks the adhesive layer 3 to the wall surface of the concrete structure, and then peels the second release sheet 5. Therefore, by making the adhesive strength between the second release sheet 5 and the base film 2 larger than the adhesive strength between the first release sheet 4 and the adhesive layer 3, the concrete structure using the multilayer sheet 1 for crack detection. It is possible to facilitate the wall surface processing. “Adhesive strength” refers to the relative value of stress required to peel off an object.

  The lower limit of the bending strength of the crack detecting multilayer sheet 1 is preferably 20 MPa, more preferably 25 MPa, and even more preferably 30 MPa. If the bending strength is less than the lower limit, the crack detection multilayer sheet 1 may be broken when rolled into a roll. In addition, although it does not specifically limit as an upper limit of the bending strength of the said multilayer sheet 1 for a crack detection, For example, it can be 100 Mpa. “Bending strength” refers to the width of the test piece of 15 mm, the length of 40 mm, the distance between the fulcrums of 15 mm, the radius of curvature of the fulcrum and the indenter of 3 mm, and the load speed in accordance with JIS-K6911: 2006. The value measured as 2 mm / min.

<Manufacturing method of multilayer sheet for crack detection>
Next, with reference to FIGS. 2-5, the manufacturing method of the said multilayer sheet 1 for a crack detection is demonstrated. The method for producing the multilayer sheet for crack detection includes a step of coating the base film-forming composition on one side which is the release surface of the second release sheet 5 (coating step), and the above coating step. The process of obtaining the multilayer sheet body which laminated | stacked the adhesive layer 3 and the 1st release sheet 4 which can be peeled on one side of this adhesion layer 3 on the one side of the formed base film 2 (multilayer sheet body formation process) With.

(Coating process)
The coating process includes a first coating process for coating the second layer-forming composition on one surface of the second release sheet 5 and a second layer 7 formed in the first coating process. A second coating step of coating the first layer-forming composition on one surface.

(First coating process)
In the first coating step, as shown in FIG. 2, the second layer forming coating solution containing the above-described synthetic resin, the above-described shielding agent and the organic solvent constituting the resin matrix of the second layer 7 is secondly added. The second layer 7 is formed on one surface of the second release sheet 5 by applying to one surface of the release sheet 5 and drying and curing. The second layer 7 formed by the first coating step contains a shielding material that blocks excitation light and / or light emitted from the first layer 6 formed by the second coating step described later, and The elongation at break is 10% or less.

  The organic solvent is not particularly limited, and examples thereof include aliphatic hydrocarbons such as hexane and octane; aromatic hydrocarbons such as toluene and xylene; alcohols such as ethanol, 1-propanol, isopropanol, and 1-butanol. Ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate, butyl acetate and isobutyl acetate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether Glycol ethers such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, etc. Such as over ethers, and the like. The said organic solvent may be used independently and may mix and use 2 or more types as needed.

  Examples of the coating method for the second layer forming coating liquid include known methods such as a gravure coating method, a bar coating method, a knife coating method, a roll coating method, a blade coating method, and a die coating method.

  In addition, although one surface of the 2nd release sheet 5 used at the said 1st coating process may be a flat surface, it is preferable that it is the mat surface to which the above-mentioned mat process was given. Thus, when the one surface of the second release sheet 5 used in the first coating step is a mat surface, the above-described fine irregularities are easily and reliably formed on the other surface of the second layer 7. It is possible to facilitate the detection of cracks generated on the wall surface of the concrete structure by the crack detection multilayer sheet 1 obtained by the crack detection multilayer sheet manufacturing method.

(Second coating process)
In the said 2nd coating process, as shown in FIG. 3, for the 1st layer formation containing the above-mentioned synthetic resin which comprises the resin matrix of the 1st layer 6, the above-mentioned fluorescent agent and / or luminous agent, and an organic solvent The first layer 6 is laminated on one surface of the second layer by applying the coating liquid to one surface of the second layer 7 formed in the first coating step, followed by drying and curing. The first layer 6 formed by the second coating step contains a fluorescent agent and / or a phosphorescent agent that emits light by excitation light, and has an elongation at break of 50% or more and 300% or less. The organic solvent used in the second coating step can be the same as the organic solvent used in the first coating step. Moreover, as a coating method of the 1st layer formation coating liquid in the said 2nd coating process, the method similar to the said 1st coating process is mentioned.

(Multilayer sheet forming process)
The multilayer sheet body forming step includes a pressure-sensitive adhesive layer laminating step for laminating the pressure-sensitive adhesive layer 3 on one surface of the first layer 6, and a first separation on one surface of the pressure-sensitive adhesive layer 3 laminated in the pressure-sensitive adhesive layer laminating step. A first release sheet laminating step for laminating the mold sheet 4.

(Adhesive layer lamination process)
In the said adhesion layer lamination process, as shown in FIG. 4, the adhesion layer 3 is laminated | stacked on one surface of the 1st layer 6 by apply | coating an adhesive solution to one surface of the 1st layer 6, and making it dry. . In addition, as the adhesive layer lamination step, it is also possible to adopt a method in which the adhesive solution is previously applied to one side of the release sheet and dried and then bonded to one surface of the first layer 6. is there.

(First release sheet lamination step)
In the first release sheet laminating step, as shown in FIG. 5, the release surface of the first release sheet 4 is laminated on one surface of the adhesive layer 3 laminated in the adhesive layer laminating step. Thereby, the said crack detection multilayer sheet 1 of FIG. 1 is obtained. In addition, the manufacturing method of the said multilayer sheet | seat for crack detection uses the said 1st release sheet 4 as a release sheet used at the said adhesion layer lamination process, The said adhesion layer lamination process and a 1st release sheet lamination process are carried out. It is also possible to do it simultaneously.

<Advantages>
In the crack detecting multilayer sheet 1, the base film 2 is laminated on the first layer 6 and the other surface side of the first layer 6 (opposite side of the concrete structure in a state of being stuck to the concrete structure). The second layer 7 has a breaking elongation of 50% to 300%, and the second layer 7 has a breaking elongation of 10% or less. Even in this case, the first layer 6 extends. For this reason, when a crack occurs in the wall surface of the concrete structure, the second layer 7 breaks, but the first layer 6 expands according to the crack (that is, the first layer 6 does not break). In the crack detecting multilayer sheet 1, the first layer 6 contains a light emitting agent and / or a phosphorescent agent that emits light by excitation light, and the second layer 7 contains a shielding agent, so that the second layer 7 is broken. When the excitation light is applied to the portion where the first layer 6 is exposed, the exposed portion emits light, whereas when the excitation light is applied to the portion where the second layer 7 covers the first layer 6, no light is emitted (or slightly Only emit light). Therefore, the multilayer sheet for crack detection 1 can easily detect the presence or absence of cracks in the wall surface of the concrete structure by irradiating excitation light and confirming whether or not the first layer 6 emits light.

  The method for producing the crack detecting multilayer sheet includes a base film 2, an adhesive layer 3 laminated on one surface side of the base film 2, and a peelable laminate on one surface of the adhesive layer 3. A first release sheet 4 and a second release sheet 5 that is releasably laminated on the other surface side of the base film 2, and can detect cracks generated on the wall surface of the concrete structure, The crack detecting multilayer sheet 1 in which the wall surface processing of the concrete structure is easy can be easily and reliably manufactured.

[Second Embodiment]
<Multilayer sheet roll for crack detection>
The crack detecting multilayer sheet roll 11 of FIG. 6 is configured by winding the crack detecting multilayer sheet 1 of FIG. 1 in a roll shape. The crack detecting multilayer sheet roll 11 is formed, for example, by winding the crack detecting multilayer sheet 1 around a core X.

<Advantages>
As described above, in the multilayer sheet for crack detection 1, since the second release sheet 5 is laminated on the other surface side of the second layer 7, the elongation at break of the second layer 7 is as small as the above upper limit. However, by supporting the other surface side of the second layer 7 with the second release sheet 5, the second layer 7 can be wound in a roll shape while preventing the second layer 7 from cracking. Thus, the crack detection multilayer sheet roll 11 obtained by winding the crack detection multilayer sheet 1 in a roll shape can reduce the storage space and is excellent in handleability.

[Third Embodiment]
<Wall processing method>
Next, a wall surface processing method for facilitating detection of cracks generated on the wall surface of a concrete structure using the crack detection multilayer sheet 1 will be described. The wall surface processing method is expressed by a process of peeling the first release sheet 4 of the crack detecting multilayer sheet 1 (first release sheet peeling process) and the first release sheet 4 being peeled. A step of attaching the base film 2 to the wall surface of the concrete structure via the adhesive layer 3 (sticking step), and a step of peeling the second release sheet 5 from the base film 2 (second release sheet peeling) Step).

(First release sheet peeling step)
In the said 1st release sheet peeling process, as shown in FIG. 7, the 1st release sheet 4 laminated | stacked on one surface of the adhesion layer 3 is peeled. At this time, as described above, the adhesive strength between the second release sheet 5 and the base film 2 of the crack detection multilayer sheet 1 is made larger than the adhesive strength between the first release sheet 4 and the adhesive layer 3. When it exists, it is easy to peel the 1st release sheet 4, without peeling the 2nd release sheet 5. FIG.

(Attaching process)
In the sticking step, as shown in FIG. 8, the pressure-sensitive adhesive layer 3 exposed by peeling the first release sheet 4 in the first release sheet peeling step is stuck to the wall surface of the concrete structure 22. . In the said sticking process, when the lamination amount of the adhesion layer 3 of the said multilayer sheet 1 for crack detection is adjusted in the range mentioned above, even when a fine dent etc. exist in the wall surface of a concrete structure, it is in this dent. By embedding the adhesive layer, the adhesion of the crack detecting multilayer sheet 1 to the concrete structure 22 can be enhanced.

(Second release sheet peeling step)
In the second release sheet peeling step, as shown in FIG. 9, the second release sheet is laminated on the other surface of the second layer 7 disposed on the outermost surface side (the side opposite to the concrete structure 22) of the base film 2. The second release sheet 5 is peeled off. Thereby, it has the concrete structure 22, the said film 1a for crack detection stuck to the wall surface of the concrete structure 22 through this adhesion layer 3 while having the base film 2 and the adhesion layer 3, and a base material The film 2 is laminated on the surface side of the first layer 6 containing a luminescent agent and / or a luminous agent that emits light by excitation light, and the excitation light and / or light that is emitted from the first layer 6. The second layer 7 containing a shielding agent that shields the first layer 6, the breaking elongation of the first layer 6 is 50% or more and 300% or less, and the breaking elongation of the second layer 7 is 10% or less. A wall-processed concrete structure 21 is obtained.

  In addition, in the said wall surface processing method, it is also possible to perform the said 2nd release sheet peeling process before the said sticking process. However, if the second release sheet peeling step is performed before the sticking step, the base film 2 is likely to be damaged during the wall surface processing, so the second release sheet peeling step is stuck. It is preferable to carry out after the process.

<Advantages>
According to the wall surface processing method, the first layer 6 is laminated on the surface side of the concrete structure 22, and the second layer 7 is laminated on the surface side of the first layer 6. By irradiating and confirming the presence or absence of light emission of the first layer 6, the presence or absence of cracks in the wall surface of the concrete structure can be easily detected. Further, according to the wall surface processing method, the first release sheet of the crack detecting multilayer sheet 1 is peeled 4 and the base film 2 is adhered to the wall surface of the concrete structure 22 via the adhesive layer 3. By peeling off the second release sheet 5, the wall surface processing of the concrete structure 22 can be performed easily and reliably. Since the wall surface processing method does not form the first layer and the second layer by sequential coating as in the conventional wall surface processing step, for example, even a wall surface of a concrete structure such as an existing tunnel has a short work period. Can be easily processed.

[Fourth Embodiment]
<Concrete structure with wall processing>
The wall surface processed concrete structure 21 is obtained by the wall surface processing method described above. The wall structure processed concrete structure 21 has a breaking elongation of the first layer 6 of 50% or more and 300% or less. Therefore, as shown in FIG. 10, when a crack Y occurs on the wall surface of the concrete structure 22, The first layer 6 extends according to the crack Y. On the other hand, the wall structure processed concrete structure 21 has a breaking elongation rate of the second layer 7 of 10% or less. Therefore, when a crack Y occurs on the wall surface of the concrete structure 22, a portion corresponding to the crack Y breaks. To do. In the concrete structure 21 subjected to the wall processing, the first layer 6 contains a light-emitting agent and / or a phosphorescent agent that emits light by excitation light, and the second layer 7 contains a shielding agent. When the excitation light is applied to the portion where the first layer 6 is exposed by breaking, the exposed portion emits light, while the second layer 7 does not emit light even when the excitation light is applied to the portion covering the first layer 6 ( Or it emits light only a little).

<Advantages>
The wall-processed concrete structure 21 has the first layer 6 laminated on the surface side of the concrete structure 22 and the second layer 7 laminated on the surface side of the first layer 6. By irradiating the surface of 7 with excitation light and confirming whether or not the first layer 6 emits light, the presence or absence of cracks in the wall surface of the concrete structure 22 can be easily detected.

[Other Embodiments]
In addition, the multilayer sheet for crack detection according to the present invention, the multilayer sheet roll for crack detection, the manufacturing method of the multilayer sheet for crack detection, the wall surface processing method and the wall surface processed concrete structure, in addition to the above-described aspects, various modifications, It can be implemented in an improved manner. For example, in the crack detecting multilayer sheet, the base film may have a layer other than the first layer and the second layer. Such other layers may be laminated on one surface side of the first layer, may be laminated on the first layer and the second layer, or laminated on the other surface side of the second layer. It may be. Moreover, as such another layer, specifically, a hard coat layer or the like laminated on the other surface side of the second layer is exemplified. In the crack detecting multilayer sheet, other layers may be laminated between the base film and the adhesive layer, but when a crack occurs on the wall surface of the concrete structure, the first layer is formed according to the crack. It is preferable that the base film and the adhesive layer are directly laminated so as to extend and the second layer is more reliably broken.

  The crack detecting multilayer sheet is not necessarily required to cover the entire surface of one side of the adhesive layer with one first release sheet. That is, in the crack detecting multilayer sheet, one surface of the adhesive layer may be covered with a plurality of first release sheets. In the crack detecting multilayer sheet, the other surface side of the base film may be covered with a plurality of second release sheets.

  The manufacturing method of the crack detecting multilayer sheet does not necessarily have the above-described first coating step and second coating step. In the manufacturing method of the crack detecting multilayer sheet, the first layer and the second layer may be formed by an extrusion process instead of the first coating process and the second coating process. Moreover, when forming a 1st layer and a 2nd layer by an extrusion molding process, it is preferable to use a coextrusion molding method. Furthermore, when the first layer and the second layer are formed by the extrusion molding process, a thermoplastic resin can be used as the main component of the resin matrix of the first layer and the second layer. In addition, the manufacturing method of the said multilayer sheet | seat for a crack detection manufactures a 1st layer and a 2nd layer separately by extrusion molding etc., for example, these are adhere | attached with an adhesive agent etc., and a 1st layer is laminated | stacked on a 2nd layer May be.

  As described above, the crack detecting multilayer sheet of the present invention can detect cracks generated on the wall surface of the concrete structure and can easily process the wall surface of the concrete structure, and is suitable for, for example, the wall surface processing of a tunnel.

DESCRIPTION OF SYMBOLS 1 Multi-layer sheet for crack detection 1a Film for crack detection 2 Base film 3 Adhesive layer 4 1st release sheet 5 2nd release sheet 6 1st layer 7 2nd layer 11 Multi-layer sheet roll 21 for crack detection Concrete structure 22 Concrete structure X Winding core Y Crack

Claims (7)

A base film, an adhesive layer laminated on one side of the base film, a first release sheet laminated on one side of the adhesive layer in a peelable manner, and the other of the base film A second release sheet laminated in a peelable manner on the surface side,
The base film is
A first layer containing a luminescent agent and / or a phosphorescent agent that emits light by excitation light;
A second layer containing a shielding agent that is laminated on the other surface side of the first layer and shields the excitation light and / or light emitted from the first layer, and
A multilayer sheet for crack detection, wherein the breaking elongation of the first layer is 50% or more and 300% or less, and the breaking elongation of the second layer is 10% or less.   The multilayer sheet for crack detection according to claim 1, wherein the 60 ° glossiness of the other surface of the base film is 30 or less. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive,
The crack detection multilayer sheet according to claim 1 or 2, wherein the pressure-sensitive adhesive layer has a lamination amount of 20 g / m ² or more and 100 g / m ² or less and an adhesive strength of 30 N / 25 mm or more and 60 N / 25 mm or less.   The multilayer sheet roll for crack detection by which the multilayer sheet for crack detection of Claim 1, Claim 2 or Claim 3 was wound by roll shape. A step of coating the base film-forming composition on one side surface which is the release surface of the second release sheet;
And a step of obtaining a multilayer sheet body in which an adhesive layer and a first release sheet that can be peeled on one surface of the adhesive layer are laminated on one side surface of the base film,
The base film is
A first layer containing a fluorescent agent and / or a phosphorescent agent that emits light by excitation light;
A second layer containing a shielding agent that is laminated on the other surface side of the first layer and shields the excitation light and / or light emitted from the first layer;
A method for producing a crack-detecting multilayer sheet, wherein the first layer has a breaking elongation of 50% to 300% and the second layer has a breaking elongation of 10% or less. A wall surface processing method for facilitating detection of a crack generated on a wall surface of a concrete structure,
Peeling the first release sheet of the multilayer sheet for crack detection according to claim 1, claim 2 or claim 3,
A step of adhering the base film to the wall surface of the concrete structure through the adhesive layer exposed by peeling the first release sheet;
And a step of peeling the second release sheet from the base film. It has a concrete structure, a crack detection film having a base film and an adhesive layer and attached to the wall surface of the concrete structure through the adhesive layer,
The base film is
A first layer containing a luminescent agent and / or a phosphorescent agent that emits light by excitation light;
A second layer containing a shielding agent that is laminated on the surface side of the first layer and shields the excitation light and / or light emitted from the first layer, and
A wall-processed concrete structure in which the breaking elongation of the first layer is 50% or more and 300% or less, and the breaking elongation of the second layer is 10% or less.

Images