Structural adhesive application thickness adjustment method, application thickness adjustment joint member, and application thickness adjustment structure

Abstract

[Problem] To easily adjust the application thickness of a structural adhesive. [Solution] Provided is a thickness adjustment method characterized by using a magnet as a spacer when adherends (A), at least one of which has the property of being attracted to the magnet, are bonded together using a structural adhesive.

Description

Method for adjusting the thickness of structural adhesive coating, bonding member with adjustable coating thickness, and coating thickness adjustable structure

[0001] The present invention relates to a method for adjusting the thickness of a structural adhesive coating, and more particularly to a field application method that is excellent in thickness adjustment when applying a thick film.

[0002] Structural adhesives are defined in JIS K 6800, Adhesives and Bonding Terminology, as "reliable adhesives that can withstand heavy loads for long periods of time," and commonly used adhesives include epoxy-based adhesives, acrylic-based adhesives, and urethane-based adhesives. Such structural adhesives have been used in a variety of fields in recent years, and as their application fields expand, even higher performance is required. When an adhesive is applied to an adherend, the performance of the joint can be improved by appropriately determining the adhesive application thickness and application area. For example, Patent Document 1 describes that when forming a column-beam steel frame joint structure using an adhesive, the adhesive application thickness is most likely to vary depending on the on-site construction, and controlling this thickness determines the feasibility of the joint.

[0003] Various methods for properly controlling the thickness of adhesive coating have been proposed. Patent Document 2 proposes a method using steel plates as spacers, but this method requires welding to secure the spacers, posing problems in terms of workability and construction. Patent Document 3 also proposes a method of introducing a coating device to control the coating thickness during in-factory construction, but this requires large-scale equipment, making it difficult to apply to construction sites or existing structures. Patent Documents 4 and 5 propose a method in which glass beads or resin beads are mixed into the adhesive in advance, but these methods make it impossible to adjust the thickness on-site other than by the bead diameter, and they cannot be applied to thick films.

[0004] On the other hand, Patent Document 6 proposes a method of installing solar cell panels in which magnets are previously attached to the panel with double-sided tape and an adhesive is used in combination, but this method requires a step of fixing the magnets using double-sided tape in advance, which is not only time-consuming but also has the disadvantage of generating waste release paper for the double-sided tape.Patent Document 7 proposes a construction method in which an adhesive and a magnet are used in combination when attaching an adherend to a base surface, making it easy to correct the position of the adherend until the adhesive hardens, but only gives examples of adhesives such as modified silicone resin adhesives and construction caulking materials, and makes no mention of structural adhesives.

[0005] JP 2016-216951 A JP 2015-124554 A JP 7-892 A WO2019 / 230881 A JP 2019-194322 A JP 6-85303 A JP 2015-174982 A

[0006] There is a need for a simple and inexpensive method for adjusting the thickness of a structural adhesive coating, particularly when applying the adhesive to a construction site or an existing structure, especially when applying a thick film.

[0007] An object of the present invention is to provide a method for adjusting the coating thickness of a structural adhesive simply and inexpensively.

[0008] As a result of extensive research to solve the above problems, the inventors discovered that when using a structural adhesive to bond adherends (A), at least one of which has the property of being attracted to a magnet, the application thickness of the structural adhesive can be adjusted easily and inexpensively by using a magnet as a spacer, and have thus completed the present invention.

[0009] [Item 1] A method for adjusting the coating thickness of a structural adhesive, characterized in that when two adherends (A), at least one of which has the property of being attracted to a magnet, are bonded together with a structural adhesive, a magnet is used as a spacer.

[0010] [Item 2] The method for adjusting the coating thickness of a structural adhesive according to Item 1, wherein the magnet is a neodymium magnet.

[0011] [Item 3] The method for adjusting the coating thickness of a structural adhesive according to Item 1 or 2, wherein the adherend (A) having the property of being attracted to a magnet is a steel material.

[0012] [Item 4] The method for adjusting the coating thickness of a structural adhesive according to item 1 or 2, wherein the adherends are steel materials.

[0013] [Item 5] A coating thickness-adjustable joining member in which one adherend (A) and another adherend are joined using the method for adjusting the coating thickness of a structural adhesive according to claim 1 or 2.

[0014] [Item 6] A coating thickness adjustable structure constructed using a coating thickness adjustable joining member (a member in which one adherend (A) and another adherend are joined using the coating thickness adjustment method of the structural adhesive described in claim 1 or 2).

[0015] The present invention allows for easy and inexpensive adjustment of the thickness of adhesive when applying it, particularly when applying it to a construction site or an existing structure, without the need for special equipment or tools. This method also makes it possible to easily install spacers on slopes, vertical surfaces, ceilings, and other surfaces in addition to horizontal surfaces.

[0016] (a) and (b) are figures for explaining Example 1; (b) are figures for explaining Example 2; (c) are figures for explaining Example 4; (a) and (b) are figures for explaining Example 6; (a) and (b) are figures for explaining Example 7; (c) are figures for explaining Example 9; and (d) are figures for explaining Example 12.

[0017] The present invention is a method for adjusting the coating thickness of a structural adhesive, characterized in that when adherends (A), at least one of which has the property of being attracted to a magnet, are bonded together with a structural adhesive, a magnet is used as a spacer.

[0018] <Adherend> The adherend (A) having the property of being attracted to a magnet is not particularly limited as long as it can attract the magnet used as a spacer, but examples thereof include iron, cobalt, nickel, and alloys containing these metals. Composites, laminates, and mixtures using these as one of the raw materials can also be used as adherends. Examples of iron include carbon steel and alloy steel, in addition to pure iron. These adherends may be painted or plated as long as they are still magnetic.

[0019] The shape of the adherend can be plate, pipe, rod, or any other material with a variety of cross-sectional shapes, such as H-shaped, I-shaped, mountain-shaped, or groove-shaped. The other adherend (B) to be bonded with the adhesive is not particularly limited as long as it can be bonded with an adhesive. Examples of suitable adherends include metals such as iron, aluminum, and stainless steel; resins; glass; concrete; mortar; ceramics; paper; cloth; fiber; and wood; as well as composites, laminates, and mixtures that use these materials as one of their raw materials. Among resins, composite plastics such as CFRP, GFRP, and FRP are preferred. Preferred combinations of adherends include joining steel to steel, steel to concrete, steel to wood, and steel to composite plastics, with joining steel to steel being even more preferred.

[0020] <Magnet Used as Spacer> The magnet used as a spacer is not particularly limited as long as it can be attached to at least one of the substrates without the use of other tools or parts, and various types can be used. Examples of types of magnets include ferrite magnets, neodymium magnets, samarium-cobalt magnets, alnico magnets, iron-chromium-cobalt magnets, and resin-bonded magnets made by solidifying and molding these magnet powders with a binder. Among these, ferrite magnets, neodymium magnets, and resin-bonded magnets are preferred because they are inexpensive and easily available, and neodymium magnets or resin-bonded magnets that use neodymium magnet powder as one of their raw materials are more preferred because of their strong magnetic force. Various neodymium magnets, such as N35, N35H, N35SH, N40, N45, N48, N50, and N52, are used.

[0021] The shape of the magnet is not particularly limited as long as it can be used as a spacer. For example, it may be a hexahedron such as a cube, rectangular parallelepiped, or flat plate, or a circular shape such as a disk, cylinder, or donut shape. It may also be a cylinder, rectangular tube, sphere, or pyramid such as a triangular or square pyramid. It may also be a segmented type with a curved fan-shaped cross section. It may also be a flat plate or disk with a screw hole or countersunk screw hole formed in the center. The screw hole or countersunk screw hole may have multiple holes. These may also be used with protrusions. If the binder of the bonded magnet is flexible, it can be in the form of a sheet, string, or rod, and can be cut into any shape, size, or length for use.

[0022] The thickness of the spacer may be determined according to the desired thickness, but is preferably 0.1 mm to 50 mm, more preferably 0.2 mm to 20 mm, and even more preferably 0.3 mm to 5 mm. If it is thinner than 0.1 mm, the spacer becomes difficult to handle and the coating thickness cannot be adequately adjusted. Furthermore, if it is thicker than 50 mm, a large amount of adhesive is required, which is economically disadvantageous. The coating thickness adjustment method of the present invention is more effective when the adhesive is applied to a thicker thickness.

[0023] The size of the spacer may be determined according to the size and shape of the members to be bonded, but is preferably 0.01 mm to 1,000,000 mm, and more preferably 1 mm to 10,000 mm. If it is smaller than 0.01 mm, it will be too small and difficult to handle, and if it is larger than 1,000,000 mm, it will be too heavy and difficult to handle, and it will also be economically disadvantageous.

[0024] The magnetization direction of the magnet used as a spacer can be any direction, such as vertical, horizontal, or two-pole on one side, but it is preferable to use one that is manufactured to be economical. The magnet used as a spacer may be a combination of a magnet and a resin material or a metal material. Disk-shaped magnets covered with plastic products, leaving only the magnetic surface on the bottom, are widely used as household magnets, and such magnets can also be used as spacers. A magnet with a similar shape covered with iron material is preferable because it strengthens the magnetic force. It is also possible to form convex portions on the resin material or metal material to be combined and use it as a spacer and anti-slip device when installing a sheet-shaped adhesive on a vertical surface.

[0025] It is also possible to combine components other than magnets with flat plates or disks with holes, screw holes, or countersunk screw holes in the center. For example, by combining a screw with a screw hole, a convex portion can be formed on the spacer, allowing it to be used as both a spacer and a non-slip surface when installing a sheet adhesive on a vertical surface. The surface of the magnet used as a spacer may be surface treated to the extent that its function as a spacer is not impaired. For example, because magnets are relatively weak against impact and prone to cracking, they can be coated or plated with resin or metal to provide a protective layer. These surface treatments can also provide rust prevention to the magnet. A pressure-sensitive adhesive layer may be formed on one or both sides of the surface of the magnet used as a spacer that comes into contact with the substrate to provide a temporary adhesive function. The provision of a pressure-sensitive adhesive layer allows the spacer to be attached to substrates that do not have magnetic properties.

[0026] <Structural Adhesive> The structural adhesive used in the present invention is not particularly limited, and a general structural adhesive can be used, for example, epoxy adhesives, urethane adhesives, acrylic adhesives, etc. These structural adhesives have high adhesive strength and are suitable for joining steel materials together, but among these, adhesives that have the ability to enable the adhesive joint to follow large displacements, i.e., so-called toughness, are preferred.

[0027] As a structural adhesive, it is necessary for it to be "an adhesive that can withstand large loads for a long period of time," and therefore the tensile shear bond strength must be 5 N / mm2 or more, preferably 10 N / mm2 or more, more preferably 15 N / mm2 or more, and even more preferably 20 N / mm2 or more. Furthermore, in the fields of construction and civil engineering, where heating on-site is difficult, adhesives that cure quickly at room temperature (25°C ± 5°C) are preferred. More preferably, adhesives that develop an adhesive strength of 80% or more of their final strength within 24 hours at room temperature (25°C ± 5°C) are preferred.

[0028] <Thickness Adjustment Method> The method for adjusting the coating thickness of the structural adhesive of the present invention may be any method that ensures the desired adhesive thickness. For example, a magnet serving as a spacer may be attached to an adherend (A) that has the property of being attracted to a magnet, and then an adhesive may be applied to the adherend (A), and then the other adherend (B) may be attached to the adherend. Alternatively, the adhesive may be applied to the adherend (B), which is then attached to the adherend (A) to which the magnet serving as a spacer has been attached. Depending on the type and usage of the adhesive, the adhesive may be applied to both the adherends (A) and (B). An adhesive may be applied to one surface of the magnet serving as a spacer, or adhesive tape may be attached to fix the magnet to the adherend (B).

[0029] After lamination, until the adhesive hardens and develops sufficient strength, a heavy object may be placed on the surface, or the surfaces may be temporarily fixed using various methods such as clips, adhesive tape, a vice, bolts, welding, etc. The magnet serving as a spacer is used to adjust the thickness of the adhesive applied, but if the adherend (B) has the property of being attracted to a magnet, the joint will not come off even without temporary fixing by other means, and sufficient adhesive strength is obtained after the adhesive hardens, temporary fixing is not necessary.

[0030] The arrangement of the magnets serving as spacers is not limited in number or location, as long as the adhesive layer is applied uniformly to the thickness specified by the spacers, and is determined appropriately depending on the size, shape, and magnetic force of the magnets and the size, shape, and rigidity of the adherend. However, it is preferable that they have the same height if they are on the same plane. Since the goal is to apply the adhesive uniformly to a constant thickness within the adhesive surface, if only one magnet is installed, it is preferable to install it in the center of the adhesive surface, and it is preferable that the magnet have as large an area as possible. It is preferable to install multiple magnets, and in that case, they are preferably installed at the edge of the area where the adhesive is applied. However, if the rigidity of the adherend is low and the areas without magnets bend, preventing the required coating thickness from being maintained, spacers are also required in the bent areas.

[0031] <Applications> The coating thickness adjustment method of the present invention allows for simple and inexpensive thickness adjustment and can therefore be used in a variety of fields, including various electrical and electronic applications, automobiles, airplanes, ships, motorcycles, trains, machinery, buildings, civil engineering, office supplies, and household goods. It is particularly suitable for application to construction sites and existing structures, where the coating thickness can often be adjusted inexpensively and easily during on-site work. The method can be applied to various adherends, such as bonding between steel materials, steel and aluminum or stainless steel, steel and CFRP, steel and concrete, steel and wood, laminated materials, and laminated boards. Examples of applications include, but are not limited to, attaching a reinforcing member to steel to improve its rigidity or strength, joining a steel reinforcing plate to concrete or wood, installing earthquake-resistant braces on pillars or beams, and attaching repair plates to steel or concrete bridges and other structures.

[0032] [Components] A variety of components can be provided as components joined using the method of adjusting the adhesive coating thickness of the present invention, and structures using such components can also be provided.

[0033] The present invention will be described in more detail below with reference to the accompanying drawings and examples. It should be noted that these examples are merely illustrative and should not be construed as limiting.

[0034] [Structural adhesives used in the examples] Adhesive A: Metallock Y612 BLACK (manufactured by Cemedine, a two-component structural acrylic adhesive) Adhesive B: Scotch Weld Metal Grip (manufactured by 3M Japan, a two-component structural acrylic adhesive) Adhesive C: Bolt Lock 1 (manufactured by Denka, a two-component acrylic adhesive for steel plates) Adhesive D: Scotch Weld DP460 (manufactured by 3M Japan, a two-component structural epoxy adhesive) Adhesive E: Scotch Weld DP6330NS (manufactured by 3M Japan, a two-component structural urethane adhesive)

[0035] [Adherends used in the examples] (Adherends (A) having the property of being attracted to a magnet) Adherend a: SPCC (common steel, cold-rolled steel plate) 1.6 mmt x 25 mm x 100 mm Adherend b: SS400 (carbon steel, general structural rolled steel) 3.2 mmt x 25 mm x 100 mm Adherend c: SS400 4.5 mmt x 25 mm x 100 mm Adherend d: SS400 4.5 mmt x 40 mm x 150 mm Adherend e: SS400 12.0 mmt x 25 mm x 100 mm Adherend i: hot-dip galvanized steel plate (SGHC F12) 1.6 mmt x 25 mm x 100 mm Adherend j: melamine-coated steel plate 1.6 mmt x 25 mm x 100 mm (Substrates that do not stick to magnets) Substrate f: SUS304 1.5mmt x 25mm x 100mm Substrate g: CFRP (matrix: epoxy resin) 3.0mmt x 25mm x 100mm Substrate h: Aluminum (A1100P) 2mmt x 25mm x 100mm

[0036] [Magnets used in the examples] Magnet 1: Adhesive magnet sheet 0.8mmt x 10mm x 20mm Magnet 2: Magnet sheet 0.6mmt x 15mm x 60mm Magnet 3: Cylindrical neodymium magnet 1mmt x 2mmφ Magnet 4: Cubical neodymium magnet 3mmt x 6mm x 12mm Magnet 5: Disc-shaped neodymium magnet 0.3mmt x 10mmφ Magnet 6: Disc-shaped neodymium magnet 0.5mmt x 4mmφ Magnet 7: Cubical neodymium magnet 3mmt x 3mm x 18mm Magnet 8: Cubical neodymium magnet 1mmt x 5mm x 20mm Magnet 9: Cubical neodymium magnet 2mmt x 5mm x 25mm Magnet 10: Cubical neodymium magnet 3mmt x 5mm x 25mm

[0037] Example 1 will be described with reference to FIGS. 1(a) and 1(b). Adherend a was used as the adherend (A), and the area S1 (25 mm x 12.5 mm) where the adhesive was to be applied was sandblasted and then washed with a solvent to form the adherend surface. Two magnets 1 were placed as spacers on the adherend surface, sandwiching the area S1 where the adhesive was to be applied (see FIG. 1(a)). The release paper attached to the magnets 1 was not removed, and the magnet surfaces were placed facing the adherend. The spacers attached to the adherend a were attached by magnetic force, making them easy to install and not easily peeled off. The adherend surface was placed on a desk, and adhesive A was mixed and applied to the application area S1. Then, adherend a was attached to the other adherend (B), to produce a bonded assembly. When the thickness of the hardened adhesive was measured after two days, it was 1.0 mm, which was equivalent to the thickness of the magnet + release paper (1.0 mm), and the thickness of the adhesive was controlled (see Figure 1(b)).

[0038] Example 2 Example 2 will be described with reference to Figure 2. A bonded structure was prepared in the same manner as in Example 1, except that adherend f was used as the other adherend (B) to be bonded with the adhesive, and adhesive B was used as the adhesive. The spacer was easily installed and did not peel off easily. After bonding the adherend (B), it was temporarily fixed using two eye clips. After one day, the eye clips were removed, and the applied thickness of the cured adhesive was measured. It was 1.0 mm, which is equivalent to the thickness of the magnet + release paper (1.0 mm), and the applied thickness was controlled.

[0039] Example 3 A bonded structure was prepared in the same manner as in Example 2, except that adherend g was used as the other adherend (B) to be bonded with the adhesive. The spacer was easily installed and did not peel off easily. After one day, the eye clip was removed and the thickness of the cured adhesive coating was measured. It was 0.9 mm, which is approximately the same as the thickness of the magnet + release paper (1.0 mm), indicating that the coating thickness was well controlled.

[0040] Example 4 Example 4 will be described with reference to Figure 3. A bonded structure was prepared in the same manner as in Example 2, except that adherend h was used as the other adherend (B) to be bonded with the adhesive, and the adherend was installed vertically. The spacer was easily installed even on vertical surfaces and did not slip off or peel off. After one day, the eye clip was removed, and the applied thickness of the cured adhesive was measured. It was 0.9 mm, which is approximately the same as the thickness of the magnet + release paper (1.0 mm), indicating that the applied thickness was controlled.

[0041] [Example 5] A bonded structure was prepared in the same manner as in Example 1, except that adherend d was used as adherends (A) and (B), the bonding area (40 mm x 50 mm) was left as the bonding surface without sandblasting, two magnets 2 were used as spacers, and adhesive B was used as the adhesive. The spacers were easily installed and did not peel off easily. After bonding adherend (B), the bonded structure was temporarily fixed using a vice. After one day, the vice was removed and the thickness of the cured adhesive was measured. It was 0.5 mm, which was approximately the same as the thickness of the magnet, 0.6 mm, and the coating thickness was controlled.

[0042] Example 6 Example 6 will be described with reference to Figures 4(a) and 4(b). A bonded structure was fabricated in the same manner as in Example 1, except that four magnets 3 were placed as spacers at the four corners of the bonding area S6 (see Figure 4(a)), and adhesive C was used as the adhesive. The spacers were easily placed and did not easily peel off. The thickness of the applied adhesive that had hardened after one day was measured and found to be 0.9 mm (see Figure 4(b)), which is approximately equivalent to the magnet thickness of 1.0 mm, demonstrating that the applied thickness was well controlled.

[0043] Example 7 will be described with reference to Figures 5(a) and 5(b). A bonded structure was prepared in the same manner as in Example 6, except that adherend d was used as adherends (A) and (B), the bonding area was 40 mm x 70 mm, and the adherends were installed vertically. The spacer was easily installed even on vertical surfaces and did not slip off or peel off. After one day, the eye clips were removed and the thickness of the cured adhesive coating was measured. It was 0.9 mm, which is approximately equivalent to the magnet thickness of 1.0 mm, indicating that the coating thickness was controlled.

[0044] Example 8 A bonded structure was produced in the same manner as in Example 1, except that adherend d was used as adherends (A) and (B), the bonding area was 40 mm x 60 mm, two magnets 4 were used as spacers, and adhesive C was used as the adhesive. The spacers were easily installed and did not peel off easily. When the thickness of the applied adhesive that had hardened after two days was measured, it was 3.0 mm, which was equivalent to the thickness of the magnets, 3.0 mm, and the applied thickness was controlled.

[0045] Example 9 Example 9 will be described with reference to Figure 6. A bonded assembly was produced in the same manner as in Example 8, except that when applying the adhesive, a support H (10 mmt x 35 mm x 50 mm) having a three-dimensional knitted structure was placed in the bonding area and the adhesive was injected and impregnated into the support H. The spacer was easily installed and did not easily peel off. When the thickness of the applied adhesive after two days was measured, it was 3.1 mm, which was approximately the same as the thickness of the magnet, 3.0 mm, and the applied thickness was controlled.

[0046] Example 10 A bonded structure was produced in the same manner as in Example 1, except that surface-polished adherend e was used as adherends (A) and (B), two magnets 4 were used as spacers, and adhesive D was used as the adhesive. The spacers were easily installed and did not peel off easily. When the thickness of the applied adhesive that had hardened after two days was measured, it was 3.1 mm, which was approximately the same as the thickness of the magnets, 3.0 mm, and the applied thickness was controlled.

[0047] Example 11 A bonded structure was prepared in the same manner as in Example 10, except that the adherends were installed vertically. The spacer was easily installed even on vertical surfaces and did not slip off or peel off. After two days, the thickness of the cured adhesive was measured and found to be 3.1 mm, which was approximately the same as the thickness of the magnet (3.0 mm), demonstrating that the coating thickness was well controlled.

[0048] Example 12 will be described with reference to Figure 7. A bonded structure was produced in the same manner as in Example 10, except that adhesive E was used as the adhesive, the adherend (A) was fixed in the air with a clamp, and the adhesive was applied to the lower surface L12 (assuming the ceiling surface). The spacer was fixed to the lower surface L12 and did not fall off or peel off. When the thickness of the applied adhesive after two days was measured, it was 3.1 mm, which was approximately the same as the thickness of the magnet, 3.0 mm, and the applied thickness was controlled.

[0049] Example 13 A bonded structure was produced in the same manner as in Example 1, except that adherend b was used as adherends (A) and (B), two magnets 6 were used as spacers, and adhesive E was used as the adhesive. The spacers were easily installed and did not peel off easily. When the thickness of the cured adhesive was measured after one day, it was 0.5 mm, which was equivalent to the thickness of the magnets (0.5 mm), and the coating thickness was controlled.

[0050] Example 14 A bonded structure was prepared in the same manner as in Example 1, except that adherend b was used as adherends (A) and (B), two magnets 7 were used as spacers, adhesive E was used as the adhesive, and the adherends were installed vertically. The spacers were easily installed even on vertical surfaces and did not slip off or peel off. The thickness of the applied adhesive after curing was measured one day later and was 3.1 mm, which was approximately the same as the thickness of the magnets (3.0 mm), indicating that the applied thickness was controlled.

[0051] Example 15 A bonded structure was produced in the same manner as in Example 1, except that adherend b was used as adherend (A), adherend i was used as the other adherend (B), two magnets 8 were used as spacers, and adhesive E was used as the adhesive. The spacers were easily installed and did not peel off easily. When the thickness of the applied adhesive after one day was measured, it was 1.0 mm, which was equivalent to the thickness of the magnet, 1.0 mm, and the applied thickness was controlled.

[0052] Example 16 A bonded structure was prepared in the same manner as in Example 15, except that adherend j was used as the other adherend (B) and two magnets 9 were used as spacers. The spacers were easily installed and did not easily peel off. After one day, the thickness of the cured adhesive was measured and found to be 2.0 mm, which was equivalent to the thickness of the magnets (2.0 mm), demonstrating that the coating thickness was well controlled.

[0053] Example 17: Adherend b was used as adherends (A) and (B), the bonding area (25 mm x 25 mm) was left as the adherend surface without sandblasting, and magnets 9 and 10 were stacked as spacers to adjust the coating thickness to 5 mm. The spacers were easily installed even on vertical surfaces and did not slip off or peel off. The coating thickness of the cured adhesive was measured after one day and was found to be 5.0 mm, which was equivalent to the 5.0 mm thickness of the magnet, demonstrating that the coating thickness was controlled.

[0054] Example 18 A bonded structure was prepared in the same manner as in Example 17, except that the adherend (A) was fixed in the air with a clamp and the adhesive was applied to the underside (presumably the ceiling surface). The spacer and adherend were fixed by magnetic force and did not fall or peel off. After one day, the thickness of the cured adhesive coating was measured and found to be 5.0 mm, which was equivalent to the thickness of the magnet (5.0 mm), demonstrating that the coating thickness was controlled.

[0055] [Example 19] A bonded structure was produced in the same manner as in Example 17, except that adhesive A was used as the adhesive, two magnets 8 were stacked as spacers to adjust the coating thickness to 2 mm, and the bonded surface was placed on a desk with the surface to be bonded facing up. The spacers were easily installed and did not easily peel off. When the coating thickness of the cured adhesive was measured after one day, it was 2.0 mm, which was equivalent to the thickness of the magnet, 2.0 mm, and the coating thickness was controlled.

[0056] From the above examples, it can be seen that when using a structural adhesive to bond adherends (A), at least one of which has the property of being attracted to a magnet, the use of a magnet as a spacer makes it possible to easily install the spacer without the need for temporary fixation, and the thickness of the adhesive coating can be accurately controlled by the spacer. Spacers can be easily installed not only on horizontal surfaces, but also on vertical surfaces, ceilings, etc., without the need for temporary fixation. Furthermore, because the effort required to overlap and fix the spacers is simple, unevenness on site can be easily addressed.

Claims

1. A method for adjusting the coating thickness of a structural adhesive, characterized in that when bonding a adherend (A) having the property of adhering to a magnet with a structural adhesive, a magnet is used as a spacer.

2. The method for adjusting the coating thickness of a structural adhesive according to claim 1, wherein the magnet is a neodymium magnet.

3. The method for adjusting the coating thickness of a structural adhesive according to claim 1 or 2, wherein the adherend (A) having the property of adhering to a magnet is a steel material.

4. The method for adjusting the coating thickness of a structural adhesive according to claim 1 or 2, wherein the adherends are steel materials.

5. A coating thickness-adjusted joint member in which one of the adherends (A) and the other adherend are joined using the method for adjusting the coating thickness of the structural adhesive according to claim 1 or 2.

6. A structure constructed using the coating thickness-adjusted joint member, wherein the coating thickness-adjusted joint member is a coating thickness-adjusted structure in which one of the adherends (A) and the other adherend are joined using the method for adjusting the coating thickness of the structural adhesive according to claim 1 or 2.

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