JP6575886B1 - Adhesive sheet for detecting cracks in structures - Google Patents

Abstract

An adhesive sheet for detecting cracks in a structure, which can be easily and quickly formed on a substrate surface of the structure. An adhesive sheet for detecting cracks using a high extensibility lower layer 2 and a low extensibility upper layer 3, wherein the lower layer 2 is mixed with a fluorescent dye that emits light by excitation light. The adhesive layer 1 is formed on the lower surface of the resin sheet, and the upper layer 3 mixed with a light shielding material is formed on the lower layer 2 by applying a resin. . By preparing this adhesive sheet in advance, the work can be completed simply by sticking to the base 4 of the structure at the work site. When the crack 5 is generated in the substrate 4, the crack 5 is generated in the low extensibility upper layer 3, but no crack 5 is generated in the high extensibility lower layer 2. Since the light emitting portion 6 of the lower layer 2 that emits light by excitation light corresponds to the crack 5 of the base 4, the occurrence of the crack 5 can be easily detected. [Selection] Figure 4

Description

  The present invention relates to an adhesive sheet for detecting cracks in a structure for detecting cracks and loosening of screws that occur with time on the surface of a base body of a structure such as a tunnel, bridge, or building.

  In the patent document 1, the inventor forms, on a substrate constituting a structure such as a tunnel, a fluorescent pigment that emits light by excitation light and a highly extensible first coating layer (lower layer), A shielding material (that is, a light shielding material) that blocks transmission of excitation light is mixed on the first coating layer, and a second coating layer (upper layer) having low extensibility is formed. Then, the structure is excited. Disclosed is a method for detecting deterioration of a structure that detects cracks that have occurred in the structure over time by irradiation with light.

  In the present invention, when the structure deteriorates and a crack occurs in the substrate, the crack also occurs in the low-stretchability second coating layer, but the high-stretchability first coating layer follows the crack. It just stretches and does not crack. Therefore, when excitation light such as ultraviolet rays is irradiated upon inspection, the excitation light reaches the first coating layer through the crack in the second coating layer and can emit light in this portion, so that the structure is cracked. Can be detected.

  However, in order to form the first coating layer at a work site such as a tunnel, it is necessary to form the first coating layer by brushing or spraying, and it is necessary to perform troublesome work in high places and dark places. . Moreover, in order to form a 2nd application layer, it was necessary to dry the 1st application layer, and there existed a problem that this took time and effort.

JP 2013-83493 A

  SUMMARY OF THE INVENTION In view of the above-described problems of the prior art, an object of the present invention is to provide an adhesive sheet for detecting cracks in a structure that can be easily and quickly formed on the surface of a substrate of the structure.

An adhesive sheet for detecting cracks in a structure of the present invention, which has been made to achieve the above object, has a structure for detecting cracks in a structure using a high extensibility lower layer and a low extensibility upper layer. An adhesive sheet for detecting cracks in objects,
The lower layer is made of a highly extensible resin sheet mixed with a fluorescent dye that emits light when excited, and an adhesive layer is formed on the lower surface of the resin sheet.
The low extensibility upper layer mixed with a light shielding material is formed on the lower layer by applying a dual cure resin, and is cured after being attached to a structure .

The structure crack detection adhesive sheet of the present invention is a structure crack detection adhesive sheet for detecting a crack in a structure using a high extensibility lower layer and a low extensibility upper layer. There,
The lower layer has a two-layer structure composed of a lower highly extensible resin base sheet and an upper extensible resin coating layer mixed with the upper fluorescent dye, and the lower surface of the basic sheet. In addition to forming an adhesive layer on
The low-stretchable upper layer mixed with a light shielding material is formed on the coating layer by applying a dual cure resin, and is cured after being attached to a structure .

The structure crack detection adhesive sheet of the present invention is a structure crack detection adhesive sheet for detecting a crack in a structure using a high extensibility lower layer and a low extensibility upper layer. There,
The lower layer is made of a highly extensible and light-transmitting resin base sheet, and after forming an adhesive layer mixed with a fluorescent dye on the lower surface of the base sheet,
On the base sheet, the low extensibility upper layer mixed with a light shielding material is formed by application of a dual cure resin, and is cured after being attached to a structure .

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The structure crack detection adhesive sheet according to the present invention is a structure crack detection adhesive sheet that detects a crack in a structure using a high extensibility lower layer and a low extensibility upper layer. And
The lower layer is made of a highly extensible resin sheet mixed with a fluorescent dye that emits light when excited, and an adhesive layer is formed on the lower surface of the resin sheet.
On the lower layer, the low extensibility upper layer mixed with a light-shielding material is formed by application of a resin. By preparing this in advance, application and drying time at the work site can be reduced. The adhesive sheet for crack detection can be easily attached to the surface of the structure.

Also, the lower layer has a two-layer structure comprising the lower layer, a lower highly extensible resin base sheet and an upper coated layer of a highly extensible paint mixed with an upper fluorescent dye. After forming an adhesive layer on the bottom surface of the foundation sheet,
Since the upper layer of low extensibility mixed with a light-shielding material is formed on the coating layer by applying a resin, by preparing it in advance, the coating and drying time at the work site can be reduced. It is not necessary to attach the detection adhesive sheet to the surface of the structure easily, and the labor of the operation can be greatly simplified.

Further, the lower layer is made of a highly extensible and light-transmitting resin base sheet, and after forming an adhesive layer mixed with a fluorescent dye on the lower surface of the base sheet,
On the base sheet, the low extensibility upper layer mixed with light-shielding material is formed by applying resin, so it is possible to greatly simplify the work by preparing it in advance. can do.

The inventor odor mentioned above, when using a dual-cure type resin as a resin for forming the upper side layer, before pasting the structure previously formed the soft upper layer by reaction main agent and the curing agent. In this state, the upper layer can cope with a slight deformation and can be attached to an uneven structure. And affixing to a structure and making it harden | cure an ultraviolet-ray can detect a crack by making an upper layer a thing of low extensibility.

It is a sectional view of an adhesive sheet for crack detection in which the lower layer is made of a resin sheet mixed with a fluorescent dye that emits light by excitation light, and an adhesive layer is formed on the lower surface. The lower layer has a two-layer structure consisting of a lower resin base sheet and a coating layer mixed with the upper fluorescent dye, and an adhesive sheet for crack detection in which an adhesive layer is formed on the lower surface of the base sheet FIG. FIG. 3 is a cross-sectional view of an adhesive sheet for crack detection in which a lower layer is made of a highly extensible resin-made base sheet and an adhesive layer mixed with a fluorescent dye is formed on the lower surface. FIG. 2 is a cross-sectional view illustrating a crack detection state by sticking the crack detection adhesive sheet shown in FIG. 1 to a substrate. It is sectional drawing which shows the state affixed on the screw which fastened the adhesive sheet for crack detection shown in FIG. It is sectional drawing which shows the state which a crack generate | occur | produces in the adhesive sheet shown in FIG. 5, and detects the looseness of a screw.

The present invention will be described in detail based on an embodiment.
FIG. 1 is a cross-sectional view showing a first embodiment of the present invention, in which 1 is a sticking adhesive layer, 2 is a high extensibility mixed with a fluorescent dye, a high ductility lower layer, and 3 is a light shield. It is a low extensibility and low ductility upper layer mixed with a material.

  For the adhesive layer 1, natural rubber, synthetic rubber adhesive, acrylic adhesive, and silicone adhesive can be used as appropriate. A release paper is attached to the lower side of the adhesive layer 1 in order to prevent adhesion during conveyance. Further, when the upper layer 3 is made of a dual cure resin and applied in advance, a release paper is pasted to shield the ultraviolet rays in order to prevent curing during transportation.

  The lower layer 2 needs to have a high extensibility that can extend corresponding to the widening of the crack without breaking even when a crack occurs in the substrate of the structure. And in that, the fluorescent pigment | dye light-emitted by excitation light, such as an ultraviolet-ray, is mixed. The lower layer 2 is made of a resin sheet, and it is preferable to use polyolefin as the resin. This is because polyolefin is flexible and has weather resistance. Examples of the polyolefin include polyethylene and polypropylene. Further, as a method for producing the resin sheet, a known melt extrusion molding method, solution casting molding method, calendar molding method, or the like can be appropriately used.

  The fluorescent pigment is a general term for fluorescent pigments and fluorescent dyes. Examples of fluorescent pigments include phosphorescent materials and fluorescent materials, and examples of fluorescent dyes include fluorescent whitening materials. The phosphorescent material continues to emit light even after the excitation light such as ultraviolet rays and blue-based visible light disappears. As this phosphorescent material, an inorganic pigment of alumina oxide can be used, and various rare earth-based materials can be used. A phosphorescent material (strontium aluminate + europium, neodymium dope, calcium aluminate + europium, dysprosium dope, etc.) or zinc sulfide + copper dope can be used.

  In addition, the fluorescent material emits fluorescence when stimulated by excitation light, and the light emission stops when the stimulation is stopped. As this fluorescent material, fluorescein-based, stilbene-based, various rare earth fluorescent materials, barium, Examples include sulfides such as strontium and zinc.

  A fluorescent whitening material is a material that selectively absorbs ultraviolet rays in sunlight and converts it into visible purple to blue visible light, which is then emitted. For example, a general fluorescent whitening material such as a diaminostilbenzyl sulfonic acid derivative system, a bisstyryl biphenyl derivative system, a coumarin derivative system, a pyrazolone derivative system, a bisbenzoxazole derivative system, or a naphthalimide derivative system may be used. it can.

  In contrast to the flexible and highly ductile lower layer 2, the upper layer 3 has low extensibility and is hard and brittle, and when the base layer cracks due to deterioration, the upper layer 3 also cracks. It is necessary. As a material for forming such an upper layer 3, for example, a resin containing a carboxyl group, an epoxy group, a hydroxyl group, an alkoxysilyl group, or the like as a vehicle component, or a pigment containing concentration is increased, or the amount of crosslinkable functional groups is increased Thus, a material obtained by a technique such as increasing the number of cross-linking points can be used. Such an upper layer 3 can be formed on the lower layer 2 by application such as brush coating or spray coating. Further, as the resin for forming the upper layer 3, a reactive curable resin can be used. In the case of using a two-component reactive curable resin composed of a main agent and a curing agent, the upper layer 3 having low extensibility can be formed by quickly curing after application. Examples of the main component of the reaction curable resin include epoxy resins and polyurethane resins, examples of the curing agent include amines such as aliphatic amines and aromatic amines, and polyamide resins.

  The upper layer 3 needs to be mixed with a light shielding material that blocks transmission of excitation light. As the light shielding material, an ultraviolet absorber, an ultraviolet scattering agent, or the like can be used. Examples of the ultraviolet absorber include octyl methoxycinnamate, oxybenzene, and t-butylmethoxydibenzoylmethane. Examples of the ultraviolet scattering agent include titanium oxide and zinc oxide. These ultraviolet absorbers and ultraviolet scatterers may also have an effect of shielding blue visible light.

  In the normal state where cracks do not occur as shown in FIG. 1, even if this is stuck to the base of the structure, the excitation light is blocked by the light shielding material in the upper layer 3, so that it cannot reach the lower layer 2. Therefore, the lower layer 2 does not emit light.

  However, as shown in FIG. 4, when a crack 5 occurs in the substrate 4, no crack occurs in the high-extensible lower layer 2, but cracks 5 occur almost simultaneously in the low-extensible upper layer 3. . Since the excitation light passes through the crack 5 of the upper layer 3 and reaches the lower layer 3 due to the generation of the crack 5, the portion corresponding to the crack emits light by the fluorescent dye. Since the light emitting portion 6 is bluish white, an operator can easily find a crack even in a dark place.

  Examples of the substrate 1 include those that are relatively hard and brittle and easily cracked, such as resin mortar, cement mortar, slate plate, gypsum board, extruded plate, concrete, metal, glass, porcelain tile, plastic, and ceramics. It is done.

  Note that as the excitation light, ultraviolet light or blue visible light having a wavelength of 500 nm or less can be used. When the wavelength is longer than 500 nm, the fluorescent dye cannot emit light. An ultraviolet lamp, an ultraviolet LED, or the like can be used as the ultraviolet light source, and a blue LED light can be used as the blue visible light source.

  In the structure-detecting adhesive sheet for crack detection according to the present invention, as shown in FIG. 2, the lower layer 2 is made of a resin base sheet 21 and a resin coating layer 22 mixed with an upper fluorescent dye. A two-layer structure consisting of As the base sheet 21, the above-described polyolefin can be used. On this basic sheet 21, a coating layer 22 of a resin such as polyolefin mixed with a fluorescent dye is formed by coating such as brush coating or spray coating, and dried. By forming the lower layer 2 with the base sheet 21 and the coating layer 22, it is easier to form the lower layer 2 than when forming only the lower layer 2 containing the fluorescent dye shown in FIG. This is because the layer 2 can be formed and the cost can be reduced. On the lower layer 2 having the two-layer structure, that is, on the coating layer 22, a low extensibility upper layer 3 mixed with a light shielding material can be formed by application of a reactive curable resin. In this case, since the upper layer 3 may be cracked when the crack detection adhesive sheet is affixed to a large uneven surface, it is desirable that the crack detection adhesive sheet be affixed to the flat surface as much as possible. Such a low extensibility upper layer 3 can be formed also in the adhesive sheet of the form of FIG. 1 and the adhesive sheet of the form of FIG.

  Moreover, in the adhesive sheet for detecting cracks of a structure according to the present invention, as shown in FIG. 3, the lower layer 2 is made of a highly extensible and resin base sheet, and the bottom surface of the base sheet The purpose can also be achieved by forming the adhesive layer 1 in which the fluorescent dye is mixed. An upper layer 3 in which a light shielding material is mixed is formed on the base sheet by applying a resin. In this case, the resin base sheet is transparent or translucent, and the excitation light needs to be transmitted to the adhesive layer 1. Even if a crack occurs in the upper layer 3, no crack occurs in the adhesive layer 1, so that the adhesive layer 1 can emit light corresponding to the crack 5. In addition, when the adhesion layer 1, the lower layer 2, and the upper layer 3 are made transparent, it is possible to visually confirm the crack occurrence state of the pasted substrate 4.

  In the crack detection adhesive sheet of the form shown in FIGS. 1 to 3, the upper layer 3 can be formed by applying a dual cure resin. In the dual cure resin, for example, a polyol, an isocyanate as the curing agent, a monomer, an oligomer, and a photopolymerization initiator as the photocurable resin can be used as the main agent. Examples of the polyol include ethylene glycol, diethylene glycol, polyethylene glycol, glycerin, pentaerythritol, and trimethylolpropane. As isocyanate. Examples include methyl isocyanate, toluene diisocyanate, and hexamethylene diisocyanate. An acrylic resin, a urethane resin, a vinyl ester resin, or a polyester / alkyd resin can be used as a photo-curable resin by ultraviolet rays. Examples of the photopolymerization initiator include benzoin isopropyl ether, benzophene, chlorothioxanthone, and Michler's ketone.

  The reason for using the dual cure type resin is as follows. That is, the upper layer 3 needs to have low extensibility. However, when the high extensibility lower layer 2 and the low extensibility upper layer 3 are formed in advance, depending on the shape of the structure, the upper layer 3 may be attached. There is a risk of cracks 5 occurring. Therefore, when the upper layer 3 is formed by coating the lower layer 2, the soft upper layer 3 is formed by the reaction between the main agent and the curing agent. Then, the lower layer 2 and the upper layer 3 are attached to the base 4 of the structure using an adhesive sheet in a soft state. When ultraviolet light is applied after pasting, the photocurable resin is inspired by the photopolymerization initiator and causes a polymerization reaction to be cured and hardened to form the low extensibility upper layer 3.

  When the upper layer 3 is formed by coating using a mixture of four components, that is, polyol, isocyanate, photocurable resin, and photopolymerization initiator, the polyol and isocyanate easily react to form a gel-like soft layer. Is done. When the adhesive sheet in this state is applied to the substrate 4 and then irradiated with ultraviolet rays, the photocurable resin is inspired by the photopolymerization initiator to cause a polymerization reaction and is cured, and the low-extensible upper layer 3 is formed. Since the upper layer 3 is mixed with a light shielding material, excitation light is not transmitted in a normal state without cracks. However, when a crack occurs in the base 4 of the structure, a crack also occurs in the upper layer 3, so that a part of the lower layer 2 can emit light along the crack, and the crack is detected. Can do.

  The loosening of the screw can be detected using the crack detection adhesive sheet according to the present invention. That is, as shown in FIG. 5, the crack detection sheet is attached so as to cover the head of the screw after the fastening. In the figure, a fluorescent dye is contained in the high extensibility lower layer 2 and a light shielding material is contained in the low extensibility upper layer 3. When affixing a crack detection adhesive sheet to such an object with large undulations, the upper layer mixed with a light-shielding material is resin after affixing the crack detection adhesive sheet of only the highly extensible lower layer. The upper layer is previously formed by application of a dual cure resin and pasted in a soft state. And it is ultraviolet-cured by irradiating sunlight and artificial ultraviolet-ray after sticking.

  When loosening occurs in the screw after long-term use, a crack 5 is generated in the upper layer 3 that has been cured and has low extensibility. When an ultraviolet ray is irradiated in the inspection, the portion having the crack 5 emits light as shown in FIG. 6 and the light emitting portion 6 is formed, so that it is possible to detect that the screw is loosened. Therefore, the operator can take measures against occupational accidents by quickly retightening, and can ensure safety. Of course, it is possible to use the crack detection adhesive sheet according to FIGS.

  A large number of crack-detecting adhesive sheets including the adhesive layer 1, the lower layer 2, and the upper layer 3 as described above are prepared in advance so that they are adhered to the substrate 4 of the structure at the work site. Just complete the work. Therefore, the work can be greatly simplified and shortened as compared with the case where the first coating layer having high extensibility is formed and the second coating layer having low extensibility is formed thereon. it can. Therefore, the present invention is of great industrial value as an adhesive sheet for detecting cracks in structures.

DESCRIPTION OF SYMBOLS 1 Adhesive layer, 2 Lower layer, 3 Upper layer, 4 Structure base body 5 Crack, 6 Light emission part

Claims (3)

An adhesive sheet for detecting cracks in a structure that detects cracks in a structure using a high extensibility lower layer and a low extensibility upper layer,
The lower layer is made of a highly extensible resin sheet mixed with a fluorescent dye that emits light when excited, and an adhesive layer is formed on the lower surface of the resin sheet.
On the lower layer, a low extensibility upper layer mixed with a light-shielding material is formed by applying a dual-cure resin, and is applied to the structure and cured after being cracked. Adhesive sheet for detection. An adhesive sheet for detecting cracks in a structure that detects cracks in a structure using a high extensibility lower layer and a low extensibility upper layer,
The lower layer has a two-layer structure composed of a lower highly extensible resin base sheet and an upper extensible resin coating layer mixed with the upper fluorescent dye, and the lower surface of the basic sheet. In addition to forming an adhesive layer on
Detection of a crack in a structure characterized in that the low-stretchable upper layer mixed with a light shielding material is formed on the coating layer by applying a dual-cure resin, and is cured after being applied to the structure. Adhesive sheet. An adhesive sheet for detecting cracks in a structure that detects cracks in a structure using a high extensibility lower layer and a low extensibility upper layer,
The lower layer is made of a highly extensible and light-transmitting resin base sheet, and after forming an adhesive layer mixed with a fluorescent dye on the lower surface of the base sheet,
Detection of cracks in a structure , wherein the low-stretchable upper layer mixed with a light shielding material is formed on the base sheet by applying a dual-cure resin, and is cured after being applied to the structure. Adhesive sheet.

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