JPS621666B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reinforcing adhesive sheet.

Conventionally, various reinforcing measures have been applied to car body steel plates in automobiles and the like. For example, roof,
For outer panels that are relatively wide and flat but thin, such as fenders, hoods, trunks, quarter panels, and doors, it is necessary to provide appropriate structural rigidity against external forces, so metal is used. A method of attaching an inner plate made of a reinforcing member using spot welding or adhesive is used. However, this method has drawbacks such as the heavy weight of the metal reinforcing members, which goes against the trend of thinner outer panels designed to reduce the weight of car bodies, increases weight and costs, and complicates the installation process. It had

In addition, to dampen and reinforce the outer skin of the vehicle, polymeric materials such as asphalt rubber, epoxy resin, acrylic resin, and phenolic unsaturated polyester resin are applied to the back side of the outer skin to a considerable thickness and over a considerable area. A method of pasting is also known. In this method, the rigidity is said to be proportional to the cube of the thickness, so by increasing the thickness, it is possible to increase the rigidity, but the increase in weight and cost due to the increase in the amount of resin increases. It has the same drawbacks as the metal reinforcing member.

In view of such conventional circumstances, the inventors
Previously, we proposed a reinforcing adhesive sheet that is lightweight, inexpensive, and can significantly improve the rigidity of the material to be attached.
56-36575). That is, it is a bead that is formed on one surface of an uncured or semi-cured thermosetting reinforcing resin sheet containing a reinforcing material and that is narrower than the sheet and forms a bead-like bulge before the sheet is cured. A forming material is attached to the sheet, and a hem portion of the sheet protruding from the bead forming material forms a mounting surface for an object to be mounted.

By the way, when the object to be reinforced is an automobile body, in consideration of workability, a reinforcing adhesive sheet is pasted before the baking process of the top coat, especially before the electrodeposition coating, and then heated and cured in a paint baking oven after the electrodeposition coating. It is preferable to let However, unlike after electrodeposition painting, there may be a small amount of lubricant attached to the car body before electrodeposition painting, and the adhesion of the reinforcing adhesive sheet to the car body is poor, resulting in the above configuration. In the case of the reinforcing adhesive sheet, the bead forming material hardens while pushing up the thermosetting reinforcing resin sheet, and voids tend to be formed around the bead-shaped bulges. Therefore, the portion of the vehicle body corresponding to the gap around the bead-shaped bulge is exposed. In other words, no electrodeposition paint was applied to this part. Therefore, if it is subsequently left in a humid atmosphere, rust will develop in the bare, unpainted portion, which may cause a serious defect if the object to be reinforced is an automobile exterior panel.

This invention was made to eliminate the above-mentioned drawbacks, and provides a reinforcing adhesive sheet that is lightweight, inexpensive, and can significantly improve the rigidity of the object to be attached, as well as improve rust prevention. The purpose is to provide the following.

That is, the present invention provides a bead-shaped bulge that is made narrower than this sheet and is formed on one surface of a first uncured or semi-cured thermosetting reinforcing resin sheet containing a reinforcing material and before the sheet is cured. Reinforcement by laminating a second thermosetting reinforcing resin sheet in an uncured or semi-cured state covering the bead forming material on the first thermosetting reinforcing resin sheet. This relates to an adhesive sheet for use.

By using the reinforcing adhesive sheet having the above structure, the object to be reinforced can be effectively bonded to the entire surface of the second thermosetting reinforcing resin sheet, and the bead forming material can be bonded to the object to be reinforced using the first thermosetting resin sheet. Even if a gap is created in that area by pushing up the reinforcing resin sheet, the second
Since the thermosetting reinforcing resin sheet is in close contact with the surface of the object to be reinforced, the surface of the object will not be exposed, thereby making it possible to prevent the occurrence of rust as much as possible.

In the reinforcing adhesive sheet according to the present invention, the first and second sheets are composed of a thermosetting resin composition. However, they differ largely depending on the resin composition, that is, the types and amounts of the resin, curing agent, and other ingredients.

The inventors initially developed a resin composition that would have a tensile modulus as large as necessary and sufficient to improve the rigidity of a metal plate such as an outer panel of a car body, and would raise the glass transition temperature as described above. When we prepared a thermosetting resin composition and tried reinforcing a metal plate with it, the reinforcing effect was satisfactory, but depending on the type and thickness of the metal plate, distortion of the metal plate due to curing shrinkage may occur. There was no escaping the problem. Conversely, a thermosetting resin composition is prepared in which the tensile modulus is insufficient to improve the rigidity of the metal plate and the glass transition temperature is low. When we reinforced the plate, we found that the distortion of the metal plate due to curing shrinkage hardly appeared in this case.
It was found that the intended purpose of reinforcement could not be achieved depending on the type and thickness of the metal plate.

However, the above-mentioned contradictory problems can also be solved by using a first thermosetting reinforcing resin sheet in which a reinforcing material is embedded, a high tensile modulus after heat curing, and a high glass transition temperature after heat curing, and a first thermosetting reinforcing resin sheet laminated thereon. The second material has a low tensile modulus after heating and a low glass transition temperature after heating.
This can be easily solved by combining it with a thermosetting reinforced resin sheet. That is, in the adhesive sheet of a preferred embodiment of the present invention, the first thermosetting reinforcing resin sheet in which the reinforcing material is embedded has a high tensile modulus after heat curing and a high glass transition temperature, so that it can be bonded to a metal plate. In addition, the second thermosetting reinforcing resin sheet, which has a small tensile modulus after heat curing and a low glass transition temperature, can suppress the occurrence of distortion in the metal plate. .

In a preferred embodiment of the reinforcing adhesive sheet according to the present invention, the first thermosetting reinforcing resin sheet has a tensile modulus after heat curing that is necessary and sufficient to improve the rigidity of the metal plate, In addition, the glass transition temperature after heat curing is raised, and the tensile modulus is generally about 30 to 500 Kg/mm ² and the glass transition temperature is 80°C or higher. If this elastic modulus becomes too large or the glass transition temperature becomes too high, distortion may occur depending on the type, thickness, and shape of the metal plate, despite the presence of the second thermosetting resin composition layer. There is a possibility that it will not be possible to prevent the occurrence.

In addition, in this specification, tensile modulus is
Speed B using a Type 1 test piece according to the method specified in ISO Recommendation R-527.
It means the value measured by

On the other hand, the second thermosetting reinforced resin sheet has a tensile modulus after heat curing that is insufficient to improve the rigidity of the metal plate and a glass transition temperature that is low. What is elastic modulus in general?
Approximately 0.1 to 22Kg/ ^mm2 , and glass transition temperature is 70℃
These are as follows. If this elastic modulus becomes too small or the glass transition temperature becomes too low, the reinforcing effect may be poor depending on the type, thickness, and shape of the metal plate.

A further preferred embodiment of the reinforcing adhesive sheet of the present invention is that the first thermosetting reinforcing resin sheet has a two-layer structure. In other words, the first
The thermosetting reinforcing resin sheet has a two-layer structure consisting of an inner layer on the bead forming material side and an outer layer on the exposed surface side, and the outer layer has a higher tensile strength after heat curing than the inner layer and the second thermosetting reinforcing resin sheet. It is characterized by having a high elastic modulus and a high glass transition temperature after heat curing.

Also in this case, similarly to the above embodiment, the outer layer can increase the rigidity of the metal plate, and the inner layer and the second thermosetting reinforcing resin sheet can suppress the occurrence of distortion in the metal plate. Furthermore, by using the second thermosetting reinforcing resin sheet that is entirely adhered to the metal plate to be reinforced, it is possible to prevent the occurrence of rust, and the adhesion area is increased, resulting in better adhesion.

In this case, the tensile modulus after heat curing is 30 to 500 Kg/mm ² in the outer layer of the first thermosetting reinforced resin sheet,
0.1 for inner layer and second thermosetting reinforced resin sheet
~22Kg/ ^mm2 , and the glass transition temperature after heat curing is 80Kg/mm2 in the outer layer of the first thermosetting reinforced resin sheet.
℃ or higher, and 70℃ or lower for the inner layer and the second thermosetting reinforcing resin sheet.

In addition, if electrodeposition painting is performed after pasting the reinforcing adhesive sheet on a metal plate, the paint will not adhere to the interface of the metal plate at the peripheral edge of the adhesive sheet.
This part may also be the cause of rust. Therefore, by making the second thermosetting reinforcing resin sheet or the inner layer of the first thermosetting reinforcing resin sheet electrically conductive, the occurrence of rust can be suppressed, and this invention is effective in preventing rust. More effective for the main purpose.

The above-mentioned first and second thermosetting reinforcing resin sheets each preferably contain an epoxy resin as the thermosetting resin, and a heat-activated curing agent is blended therein, and various additives are added as necessary. It can be formed by adding and forming a sheet in an uncured or semi-cured state according to a conventional method.
Of course, thermosetting resins other than epoxy resins can also be used.

When forming this sheet, by appropriately setting the type of epoxy resin, curing agent, and other additives, or by setting the blending amount of each component, the first and second thermosetting reinforcements are The tensile modulus and glass transition temperature of the resin sheet after heat curing are adjusted as described above.

Epoxy resins that are preferably used to form both sheets include various epoxy resins such as ordinary glycidyl ether type, glycidyl ester type, glycidyl amine type, flocculent aliphatic epoxide type, and alicyclic epoxide type. Depending on the physical properties, one type can be used alone or two or more types can be used in combination.

In addition, the heat-activated curing agent may be a normal curing agent that exhibits a curing effect when heated, and is generally 80% curing agent.
It is sufficient if it is active in the temperature range of ~200°C, for example, dicyandiamide, 4,4'-diaminodiphenylsulfone, imidazole derivatives such as 2-n-heptadecyl imidazole, isophthalic acid dihydrazide, N-N-dialkyl urea derivatives,
N.N-dialkylthiourea derivatives and the like are used. The amount used may be generally 1 to 15 parts by weight per 100 parts by weight of the thermosetting resin.

In addition to the above-mentioned thermosetting resin and curing agent, the composition may have cohesive strength to the extent that it can be formed into a sheet, and may also be used to prevent sagging or to improve wettability by lowering melt viscosity. Various additives are used as necessary.

For example, in order to improve sheet forming ability,
Thermoplastic resins such as polyvinyl butyral, polyamide, polyamide derivatives, polyesters, polysulfones, polyketones, high molecular weight epoxy resins derived from bisphenol A and epichlorohydrin, butadiene-acrylonitrile copolymers or derivatives thereof can be blended. . The amount used is preferably about 5 to 100 parts by weight per 100 parts by weight of the thermosetting resin.

In addition, for the purpose of preventing the composition of each sheet from sagging,
Fillers such as calcium carbonate, talc, asbestos, silicic acids, carbon black, and colloidal silica are used. Further, for the purpose of imparting conductivity to the second sheet or the inner layer of the second sheet and the first sheet, metal powder such as iron powder or aluminum powder, graphite powder, etc. are used in forming these sheets. These compounding amounts are based on thermosetting resin
Usually, the amount may be about 10 to 300 parts by weight per 100 parts by weight.

Furthermore, for the purpose of lowering the melt viscosity and improving wettability, reactive diluents such as butyl glycidyl ether and monoglycidyl ether of long-chain alcohols, phthalic acid plasticizers such as dioctyl phthalate, and phosphorus such as triclean diphosphate are added. Acid plasticizers etc. can be added. The amount of these components is preferably about 5 to 30 parts by weight per 100 parts by weight of the epoxy resin.

Among the first and second thermosetting reinforcing resin sheets formed in this way, it is particularly desirable that the second thermosetting reinforcing resin sheet has tackiness in its normal state. This is because temporary adhesion before heat curing becomes easier when applied to a metal plate. Of course, the first thermosetting reinforced resin sheet may have adhesiveness as well. In particular, when the second thermosetting reinforcing resin sheet is made narrower than the first thermosetting reinforcing resin sheet, it is preferable that the first sheet has adhesive properties. In this case, when a two-layer structure is used, inside and outside, it is sufficient that only the inner layer has adhesiveness.

Furthermore, a reinforcing material is embedded in the first thermosetting reinforcing resin sheet in order to enhance the reinforcing effect of the metal plate. When the first sheet has a two-layer structure, an inner and outer layer, a reinforcing material is generally embedded in the outer layer. This reinforcing material can be inorganic fiber cloth made of glass fiber or asbestos fiber, linen, etc.
Organic fiber cloth made of cotton, nylon, polyester, polypropylene, etc.; plastic film such as polyester film and nylon film; paper such as kraft paper; nonwoven fabric made of polyester fiber, polypropylene fiber, etc.; made of aluminum, iron, copper, zinc, etc. There are metal foils, etc.

In order to embed the reinforcing material, when molding the first thermosetting reinforcing resin sheet, one or both surfaces of the reinforcing material may be coated with or impregnated with a thermosetting composition. Among the above-mentioned reinforcing materials, inorganic fiber cloth is preferred since it can be impregnated on one side and a sufficiently large reinforcing effect can be obtained, and glass fiber cloth is particularly preferably used.

The thickness of the first and second thermosetting reinforcing resin sheets described above varies depending on the type of metal plate, the degree of reinforcement, etc., but generally the thickness of the first thermosetting reinforcing resin sheet is 0.2~ 40mm, preferably 0.5~
20 mm, and when this sheet has a two-layer structure, the outer layer has a thickness of about 0.01 to 10 mm, preferably 0.1 to 5 mm.
mm, the inner layer is about 0.1 to 30 mm, preferably 0.5 to 10 mm, and the total thickness is usually about 0.2 to 40 mm, preferably 0.5 to 20 mm. In addition, the second thermosetting reinforced resin sheet is generally 0.1 to 30 mm, preferably 0.5 to 30 mm.
It is 10mm.

Next, the bead forming material, which is another important component of the reinforcing adhesive sheet of the present invention, is a foamable resin sheet, which has the property of foaming when heated above the decomposition temperature of the foaming agent contained therein. Examples include those having the following. In addition, there are flattened products that are formed from a tube-like body and can be deformed almost back to the tube-like shape by heating, and flattened products that are formed from a non-tube-like body such as a rod or film and are deformed into an elongated shape at least in the vertical direction by heating. A heat-recoverable material such as a flattened material that can be substantially restored to the above-mentioned non-tubular body can also be used. Among these, particularly preferred are foamable resin sheets.

Such a foamable resin sheet is made by adding, for example, various thermosetting or thermoplastic polymers to a foaming agent and, if necessary, a foaming aid, a curing agent, a curing accelerator,
After blending the crosslinking agent, crosslinking aid, filler, coloring agent, stabilizer, etc., and kneading this mixture using a mixing roll, etc., the temperature conditions are such that the blowing agent does not decompose (slight decomposition is fine). It can be made by sheet molding according to the conventional method.

Examples of the thermosetting or thermoplastic polymer used above include thermosetting resins such as epoxy resins, phenolic resins, and polyester resins, polyethylene, ethylene-vinyl acetate copolymers, and adhesive polyolefins. The foaming agent may be any foaming agent that foams during heat curing of the reinforced resin sheet and does not foam during sheet molding, such as azo compounds, nitroso compounds, hydrazide compounds, and the like.

The thickness of the above foamable resin sheet is usually 0.2~
5 mm, preferably about 0.5 to 2 mm,
Further, it is desirable that the foaming ratio after heating is practically 2 to 30 times.

In the reinforcing adhesive sheet of the present invention, the bead forming material is formed on one surface of the first thermosetting reinforcing resin sheet (on the inner layer side in the case of a two-layer structure), to be narrower than the sheet. Further, the second thermosetting reinforcing resin sheet is laminated and integrated with the sheet so as to cover the bead forming material. This lamination and integration may be carried out by utilizing their adhesive properties, or may be fused by heating to an extent that the curing does not proceed completely.

Preferred properties of the adhesive sheet of the present invention obtained in this way include the first and second properties.
Although the thermosetting reinforced resin sheet does not substantially flow at room temperature and has self-retention properties, it is in a highly viscous state as a whole. This sheet has flexibility and pliability, and even when bent 250 to 300 degrees, the sheet does not show any damage and can be restored to its original state. Therefore, according to this preferred embodiment,
Since it has shape adaptability, it can be attached even if the material to be reinforced (metal plate) is wavy, mountain-shaped, square, curved, etc., and can be applied more effectively as a reinforcing sheet.

FIGS. 1 and 2 show an example of the reinforcing adhesive sheet of the present invention, and 1 is a reinforcing material 5.
2 is a bead forming material attached to the sheet 1 and made narrower than the sheet 1;
3 is the first layer so as to cover the bead forming material 2;
This sheet 3 is a second thermosetting reinforcing resin sheet laminated on the sheet 1 , and this sheet 3 constitutes a mounting surface 4 to the object to be reinforced.

The reinforcing adhesive sheet is attached to the second layer as shown in Figure 3.
The thermosetting reinforcing resin sheet 3 is used as an automobile door outer panel 6.
The reinforcing adhesive sheet is attached to the back surface 6a of the door, and when heated after attachment, the viscosity of the reinforcing adhesive sheet temporarily decreases and the attachment surface further adheres to the door outer panel 6, while the bead forming material 2 is foamed or shaped. is restored and the cross section becomes larger, and the first thermosetting reinforced resin sheet 1
is the second thermosetting resin sheet 3 and its adhesive surface 1
A bead-shaped bulging portion 1b is formed before being pushed up from a, 1a and hardened, and as heating progresses over time, the first and second thermosetting reinforcing resin sheets 1, 3 harden, and the third The state shown in the figure will be reached.

FIG. 4 shows another example of the reinforcing adhesive sheet of the present invention, in which an uncured or semi-cured thermosetting reinforcing resin sheet containing a reinforcing material 1
However, when the reinforcing material 5 is embedded and provided on a metal plate as an object to be reinforced and heated and hardened, the tensile elastic modulus becomes necessary and sufficient to improve the rigidity of the metal plate, and when the reinforcing material 5 is heated and hardened. The first thermosetting resin composition layer 1c has a resin composition that increases the glass transition temperature of The structure is the same as that shown in FIG. 1, except that it is composed of a second thermosetting resin composition layer 1d having a resin composition that lowers the glass transition temperature after heat curing. ing.

In addition, in FIGS. 2 and 4, the second thermosetting reinforcing resin sheet 3 preferably has a lower tensile strength after heat curing than the first thermosetting reinforcing resin sheet 1 in FIG. The elastic modulus is small and the glass transition temperature is low, and in FIG. 4, the structure has a small tensile elastic modulus and a low glass transition temperature similar to the inner layer 1d of the first thermosetting reinforced resin sheet 1. It is.

Typical objects to be reinforced using the reinforcing adhesive sheet of the present invention are metal plates, especially car body steel plates such as the outer panels of automobiles, but also various other vehicles, washing machines, home appliances such as televisions, etc. It can be widely applied to metal plates that are generally considered to be thin plates, such as metal plates.

The reinforcing method of the present invention is to press the adhesive sheet to the back side of the metal plate as described above, for example, a car body steel plate, and then use a conventional heating method such as a hot air circulation heating furnace, an infrared heating furnace, This can be achieved by heating and curing using a high frequency induction heating furnace or the like. Note that the above-mentioned heat curing can be performed at the same time as the paint baking process for car body steel plates in an automobile manufacturing line.

As described in detail above, the present invention provides a bead that is made narrower than the sheet and forms a bead-like bulge on one side of a thermosetting reinforcing resin sheet in which a reinforcing material is embedded before the sheet is cured. A reinforcing adhesive obtained by attaching a forming material and laminating a second thermosetting reinforcing resin sheet in an uncured or semi-cured state covering the bead forming material onto the first thermosetting reinforcing resin sheet. This sheet is essentially a sheet, and by simply pressing this sheet onto the object to be reinforced in a specific state and heating and curing it, a great reinforcing effect can be obtained, and the construction is extremely simple, and it is especially effective for improving rust prevention. This will bring about effects such as being able to achieve better results.

Next, examples of this invention will be described. In the following, parts shall mean parts by weight.

Examples 50 parts of Epicote #828 (bisphenol A type liquid epoxy resin manufactured by Yuka Shell Co., Ltd.), 35 parts of Epicote #1002 (bisphenol A type solid epoxy resin manufactured by Yuka Shell Co., Ltd.), Byron #500 (Toyobo Co., Ltd.) polyester resin) 15 parts, Kyuazol
Epoxy resin composition consisting of 1 part of 2MZ-AZINE (latent curing agent for epoxy resin manufactured by Shikoku Kasei Co., Ltd.), 5 parts of dicyandiamide (latent curing agent for epoxy resin manufactured by Nippon Carbide Co., Ltd.), 50 parts of talc, and 2 parts of asbestos powder. The resulting resin mass was kneaded using a regular mixing roll, and the resulting resin mass was pressed to a thickness of 0.5 using a direct pressure press.
mm, and further laminated with glass cloth (WE-22D-104 manufactured by Nittobo Co., Ltd.) to form the outer layer of the first thermosetting reinforcing resin sheet in an uncured state.

Next, 80 parts of Epikot #871 (dimer acid-modified epoxy resin manufactured by Yuka Ciel Co., Ltd.), 5 parts of Epicoat #1002 (mentioned above), and Epicoat #828 (mentioned above)
5 parts and 10 parts of Hiker CTBN 1300×8 (nitrile rubber manufactured by BF. Gutdrich) were melt-mixed in a mixing pot, and 100 parts of the resulting composition was added with 1 part of Kyuazol 2MZ-AZINE (mentioned above) and dicyandiamide. 5 parts of graphite (scale graphite CPB-3 manufactured by Chuetsu Graphite Manufacturing Co., Ltd.), 75 parts of asbestos powder, and 3 parts of asbestos powder were mixed together using a regular mixing roll, and then formed into a sheet using a direct pressure press. Thus, an inner layer of the first thermosetting reinforced resin sheet in an uncured state having a thickness of 0.4 mm was obtained. This was bonded to the outer layer of the first thermosetting reinforcing resin sheet to obtain a first thermosetting reinforcing resin sheet. The tensile modulus of the outer layer and inner layer of this thermosetting reinforced resin sheet after heat curing is 95 for the outer layer.
Kg/mm ² , and 4.0 Kg/mm ² in the inner layer. Further, the glass transition temperature was 110°C in the outer layer and 50°C in the inner layer. However, the heat curing conditions are 150°C for 60 minutes.

Separately, 100 parts of polyethylene (manufactured by Sumitomo Chemical Co., Ltd., Sumikasen G801), a blowing agent (manufactured by Eiwa Kasei Co., Ltd., FE-
9) 8 parts were uniformly kneaded using a mixing roll, pelletized using a pelletizer, and then formed into a sheet using an extrusion molding machine to obtain a foamable sheet with a thickness of 1 mm.

Next, the first thermosetting reinforcing resin sheet having a two-layer structure is cut into a 5 cm width, and the foam sheet cut into a 1 cm width is pasted on the inner layer side of the first sheet. The exact same resin composition used for this inner layer was pressed to a thickness of 0.4 mm using a direct pressure press.
A second thermosetting reinforcing resin sheet is formed by sheet-forming, and this is used as a first sheet to which the foamable sheet is attached.
It was attached to the inner layer side of a thermosetting reinforcing resin sheet to obtain a reinforcing adhesive sheet.

This reinforcing adhesive sheet was pressure-bonded to a 0.8 mm thick steel plate so that the second thermosetting reinforcing resin sheet was on the steel plate side. After this pressure bonding, electrodeposition coating was performed and heated in an atmosphere of 180° C. for 30 minutes. When a strength test was conducted using the steel plate reinforced in this way as a test piece by the method described below, the maximum bending stress was 46Kg/50mm width, and the maximum bending stress of the steel plate alone was 9Kg/50mm width. However, it was found that a very good reinforcing effect was obtained.

Next, a rust test was conducted on the cured sample using a salt spray tester (Model ST-JR manufactured by Toyo Rika Kogyo Co., Ltd.), and it was found that the electrodeposition coating properties at the interface between the steel plate and the reinforcing adhesive sheet were good. Due to the provision of the second thermosetting reinforced resin sheet, no rust occurred after 500 hours of salt water spraying.

<Strength test> A support stand with two vertical flat plates (width 50 mm) whose tips have an inverted U-shaped cross section with a radius of curvature of 5 mm, arranged in parallel with a distance of 100 mm between the tips, and a width of 50 mm. The test piece was supported horizontally, and the maximum bending stress (Kg/50 mm width) was measured when a load was applied from the top to the center of the test piece using a vertical flat plate (width 50 mm) exhibiting a U-shaped cross section with a radius of curvature of 10 mm.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of the reinforcing adhesive sheet of the present invention, Fig. 2 is a sectional view showing the reinforcing adhesive sheet in a state where it is installed before heating, and Fig. 3 is a sectional view showing the state after heating. , FIG. 4 is a sectional view showing another example of the reinforcing adhesive sheet of the present invention in an installed state. 1...First thermosetting reinforcing resin sheet, 1c...
...Outer layer, 1d...Inner layer, 2...Bead forming material, 3
...Second thermosetting reinforced resin sheet.

Claims (1)

[Scope of Claims] 1. On one side of the first thermosetting reinforcing resin sheet in an uncured or semi-cured state containing a reinforcing material, a bead-shaped expanded layer is formed which is made narrower than this sheet and before the sheet is cured. A bead forming material forming the protrusion was attached, and a second thermosetting reinforcing resin sheet in an uncured or semi-cured state covering the bead forming material was laminated on the first thermosetting reinforcing resin sheet. A reinforcing adhesive sheet characterized by: 2. The first thermosetting reinforcing resin sheet has a higher tensile modulus after heat curing and a higher glass transition temperature after heat curing than the second thermosetting reinforcing resin sheet. The reinforcing adhesive sheet according to item 1. 3 The tensile modulus after heat curing is 30 to 500 Kg/mm ² for the first thermosetting reinforcing resin sheet, and 0.1 to 15 Kg/mm ² for the second thermosetting reinforcing resin sheet, and The reinforcing adhesive sheet according to claim 2, wherein the first thermosetting reinforcing resin sheet has a glass transition temperature of 70°C or higher and the second thermosetting reinforcing resin sheet has a glass transition temperature of 60°C or lower. 4 The first thermosetting reinforcing resin sheet has a two-layer structure including an inner layer on the bead forming material side and an outer layer on the exposed surface side, and the outer layer is heated more than the inner layer and the second thermosetting reinforcing resin sheet. The reinforcing adhesive sheet according to claim 1, which has a large tensile modulus after curing and a high glass transition temperature after heat curing. 5 The tensile modulus after heat curing is 30 to 500 Kg/mm ² for the outer layer of the first thermosetting reinforcing resin sheet, and the tensile modulus for the inner layer of the first thermosetting reinforcing resin sheet and the second thermosetting reinforcing resin sheet. 0.1 to 22 Kg/ ^mm2 , and the glass transition temperature after heat curing is 80°C or higher in the outer layer of the first thermosetting reinforcing resin sheet, and the inner layer of the first thermosetting reinforcing resin sheet and the second heat Claim 4, which is a curable reinforced resin sheet and has a temperature of 70°C or less
Adhesive sheet for reinforcing as described in section. 6 Claims 1 to 5, wherein the second thermosetting reinforcing resin sheet or the inner layer of this and the first thermosetting reinforcing resin sheet are electrically conductive.
The reinforcing adhesive sheet according to any of the above.