JPS6383185A - Reinforcing adhesive sheet - Google Patents

Abstract

PURPOSE:To obtain the title sheet which is light-weight and inexpensive, and gives a product with excellent stiffness, by sticking a bead-forming material provided with a specified partition layer to one side of a thermosetting resin sheet containing a reinforcing material. CONSTITUTION:100pts.wt. thermosetting resin preferably comprising an epoxy resin is mixed with 1-15pts.wt. heat-sensitive curing agent and 5-30pts.wt. additives such as a filler and a plasticizer. This mixture is molded to give a thermosetting resin sheet. A bead-forming material 5 comprising a flattened restorable foam, provided on one side or on both sides thereof with a partition layer 6 (e.g., a nonwoven polyester fabric) wider than the bead-forming material 5 and narrower than sheets 3 and 4, is inserted between the first thermosetting resin sheet 3 of a thickness of 0.2-20mm, made by coating or impregnating a reinforcing material 2 (e.g, a glass cloth) with the aforementioned resin mixture and the second thermosetting resin sheet 4 of a thickness of 0.1-30mm, molded as aforementioned, preferably having tackiness, thus giving the title sheet. This sheet is contact bonded to an adherend 7 comprising a metal sheet such as a car body steel panel, which is subjected to heat treatment.

Description

[Detailed description of the invention] (a) Industrial application fields The present invention relates to a reinforcing adhesive sheet.

(b) Prior Art Conventionally, various reinforcing measures have been applied to the steel plates of automobile bodies.

For example, for exterior panels that have a relatively wide and flat shape but are thin, such as roofs, fenders, trunks, quarter panels, and doors, appropriate structural rigidity is required to withstand external forces. Because of the need for common equipment, a method is used in which an inner plate made of a metal reinforcing member is attached by spot welding or adhesive to #.

■In addition, asphalt rubber, epoxy resin, acrylic resin, phenolic resin,
A method is also known in which a polymeric material such as unsaturated polyester 141111 is coated or pasted on the back side of the outer panel to a considerable thickness and over a considerable area.

(e) Problems to be Solved by the Invention However, in the method (2) above, the metal reinforcing members are heavy and are attached contrary to the thinning of the outer panel designed in line with the lightweighting of the car body, which increases weight and costs. Furthermore, the installation process is complicated.

In addition, in the method (2) above, it is said that the rigidity strength is proportional to the cube of the thickness, and therefore the effect of increasing the rigidity strength can be obtained by increasing the thickness, but the weight increase due to the increase in the tree mIL However, it has the same drawbacks as the metal reinforcing member described above, such as increased cost.

In view of the conventional situation, the present inventors have already proposed a reinforcing adhesive sheet that is lightweight, inexpensive, and can significantly improve the rigidity of an object to be attached.

That is, on one surface of an uncured or semi-cured thermosetting resin sheet containing a reinforcing base material, a bead is formed in a narrow upward direction and forms a bead-like bulge before the sheet is cured. A forming material is attached to the sheet, and the hem portion of the sheet extending from the bead forming material forms a mounting surface for an object to be mounted.

Examples of the bead-forming material include foamable resin sheets, which have the property of foaming when heated above the decomposition temperature of the foaming agent contained therein, and materials that are formed from a tubular body and then shaped into a tube by heating. A flattened product that can be restored and deformed, and a flattened product that is molded from a non-tubular body such as a rod or film, and that can be deformed into an elongated shape at least in the vertical direction by heating and can be restored to the non-tubular body. Heat recoverable materials are used.

Furthermore, as an improvement of this bead forming material, the above-mentioned bead forming material is a flattened material in which an elastic foam containing a bonding agent in the void is flattened and this flattened state is maintained by the above-mentioned bonding agent. It is made of a flattened foam that can be restored to its foamed state by heating.

When a reinforcing adhesive sheet using a bead-forming material made of flattened resilient foam is heated, the adhesive softens or melts and the adhesive force that maintains the flattened state is removed, so the flattened foam returns to its original state. It develops an elastic recovery force that attempts to restore the foam shape.

This elastic recovery force is larger than the recovery force of the flattened product formed from the above-mentioned tubular or non-tubular body, and due to this elastic recovery force, the softened thermosetting resin sheet is The thermosetting resin sheet is pushed up until it recovers to the foam shape, and in this state, it is further heated to harden the thermosetting resin sheet and form a bead-like bulge.

The bead-shaped bulge formed in this way has a shape that corresponds to the original foam shape of the flattened product, so the shape of the bead-shaped bulge can be easily set arbitrarily, and this shape may also be Since it can be stably restored, the reinforcing effect does not vary, and the rigidity of the adherend can always be significantly improved.

In addition, by appropriately selecting the fixing agent in the flattened foam, the temperature at which the flattened foam starts to recover can be set as desired, and the recovery speed is fast. types will be expanded.

However, when this type of reinforcing adhesive sheet is used in an actual production line, for example, an automobile production line, the following problems arise.

That is, the conventional reinforcing adhesive sheet (1') shown in FIG.
) is cured by heating, it usually forms a bead-shaped bulge as shown in FIG. ') is installed before the steel plate pre-treatment process from the viewpoint of workability. In this case, the reinforcement 11 pieces (1') are:
In an uncured or semi-cured state, it is immersed in an electrodeposition coating solution in a pretreatment process, but in such cases, it often hardens with the formation of a bead-shaped bulge as shown in FIG.

By the way, when a bead-like bulge as shown in Fig. 6 is formed and cured, that is, when a bead-like bulge is formed and cured as shown in Fig. 5, it becomes sharp as shown in Fig. 5. Since the reinforcing effect is significantly lower than that of a bulged one, it was necessary to improve this.

Table 1 The inventors presumed that this was caused by the large effect of moisture in each treatment solution, especially the moisture in the treatment solution, and that the bead-shaped bulges were changed due to the influence of this moisture. .

That is, if moisture is absorbed while uncured, the thixotropic properties of the epoxy resin will decrease, and as a result, the thermosetting resin sheet will normally shift in the χ direction and form a bead, as shown in Figure 5. While a bulge is formed, when moisture is absorbed, the thermosetting resin sheet F moves in the y direction, and as a result, it forms a bead-shaped bulge as shown in Figure 6 and hardens. considered to be a thing.

(d) Means for Solving the Problems Therefore, the inventors of the present invention conducted a thorough study again, and found that a first thermosetting resin sheet containing a reinforcing base material in an uncured or semi-cured state, and an uncured The amount of bead forming material laminated on the other side of the second thermosetting resin sheet in a semi-cured or semi-cured state (or with a barrier layer on one side) makes it possible to form stable beads without being affected by various processing solutions. It was discovered that the resin cured by forming a shaped bulge, and the present invention was completed.

That is, the present invention provides a thermosetting resin sheet of tJSl in an uncured or semi-cured state containing a reinforcing base material, a second thermosetting resin sheet in an uncured or semi-cured state, and a thermosetting resin sheet of tJS1 containing a reinforcing base material. The bead forming material is narrower than the resin sheet and forms a bead-shaped bulge before the thermosetting resin sheet is cured.
A reinforcing adhesive sheet laminated between thermosetting resin sheets, comprising a partition wall layer on one or both sides of the bead forming material, which is wider than the bead forming material and narrower than the above-mentioned self-curing resin sheet. Hereinafter, the present invention will be described in detail.

The ml thermosetting resin sheet and the second thermosetting resin sheet used in the present invention are made of a thermosetting material with a particularly strong adhesion to a metal plate. The tensile modulus and glass transition temperature of the composition after curing are mainly due to the four-fat composition. , it varies greatly depending on the type and amount of the curing agent and other ingredients.

The inventors initially developed a resin compound composition in which the above-mentioned tensile modulus was necessary and sufficient to improve the rigidity of a metal plate such as an outer panel of a car body, and the above-mentioned resin had a high lath transition temperature. When we prepared a thermosetting resin composition and used it to reinforce a metal plate, 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 occurred. could not escape the problem.

On the other hand, a thermosetting 8I resin composition was prepared in which the resin composition was such that the tensile modulus was insufficient to improve the rigidity of the metal plate and the glass transition temperature was low. When reinforcing the metal plate in this case, it was found that the metal plate suffered almost no distortion due to curing shrinkage, but the l! It has been found that depending on the thickness of the IM, the intended purpose of reinforcement may not be achieved.

However, the contradictory problems mentioned above can also be solved by using a first thermosetting resin sheet in which a reinforcing base material is embedded, a high tensile modulus after heat curing, and a high glass transition temperature after heat curing, and a fa
This problem can be easily solved by combining a layered thermosetting resin sheet with a m2 size that has a small tensile modulus after heating and a low glass transition temperature after heating.

That is, the reinforcing adhesive sheet of a preferred embodiment of the present invention is
The first thermosetting resin sheet in which the reinforcing base material is embedded has a high tensile modulus after heat curing and a high glass transition temperature, so that the rigidity of the metal plate can be improved, and the tensile modulus after heat curing is high. The second thermosetting resin sheet, which has a small elastic modulus and a low glass transition temperature, can suppress the occurrence of distortion in the metal plate.

In a preferred embodiment of the adhesive sheet for 11IIIiIII according to the present invention, in the first thermosetting resin sheet,
The tensile modulus after heat curing is necessary and sufficient to improve the rigidity of the metal plate, and the glass transition temperature after heat curing is raised, but this tensile modulus is generally 50 ~500g/-2, or a lath transition temperature of 80°C or higher.

If this tensile modulus becomes too thick (too much) 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 sheet. There is a possibility that it will not be possible to prevent the occurrence.

In addition, in this specification, the tensile modulus is I S
OR Recommendation R-5271 This means the value measured using a Type 1 test piece and 5 peed B according to the specified method.

On the other hand, the second thermosetting U (oil sheet) has a tensile modulus after heat curing that is insufficient to improve the rigidity of the metal plate, and has a low glass transition temperature. The tensile modulus is generally about 0.1 to 30 kg/am'', and the glass transition temperature is 80°C or less.

If this tensile modulus becomes too small or the lath transition temperature becomes too low, the reinforcing effect will be poor depending on the type, thickness, and shape of the metal plate.

For the above-mentioned first thermosetting resin sheet and second thermosetting resin sheet, epoxy resin is most preferably used as the thermosetting resin, and a heat-activated curing agent is added thereto, and then this is processed in a conventional manner. Similarly, it can be formed into a sheet by sheet-molding it in an uncured or semi-cured state.

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 tensile modulus and positive transition temperature of the first thermosetting resin sheet and the second thermosetting resin sheet after heat curing are adjusted as described above.

The epoxy resins most preferably used to form each sheet include various types of epoxy resins such as the usual glycytyl ether type, glycidyl ester type, glycidyl amine type, linear aliphatic epoxide type, and alicyclic epoxide type. Depending on the physical properties of the sheet, one type of IPl can be used alone or two or more types can be used in combination.

Further, as the heat-activated curing agent, any ordinary curing agent that exhibits curing action by heating may be used, and it is generally sufficient if it is active in the temperature range of 80 to 200°C. , 4,4'-diami/diphenylsulfone, imiguzole derivatives such as 2-n-heptadecyl imiguzole, isophthalic acid nohydracide, N-
N-noalkyl urea derivatives, N-N-turkylthiourea derivatives, etc. are used.

The amount of this curing agent used may be generally 1 to 15 parts by weight per 100 parts by weight of the epoxy resin.

In addition to the above-mentioned thermosetting resin and curing agent, the composition may be used for purposes such as giving the composition enough agglomeration force to be able to be formed into a sheet, preventing sagging, or improving wettability by lowering melt viscosity. Various additives may be used as desired.

For example, for the purpose of improving sheet forming ability, thermoplastic resins such as polyvinyl butyral, polyamide, polyamide derivatives, polyester, polysulfone, polyketone, epoxy resin of polymer 1 derived from bisphenol A and epichlorohydrin, and butanoene-7 Acrylonitrile copolymers or derivatives thereof can be blended.

The amount of these used is preferably about 5 to 100 parts by weight per 100 parts by weight of the thermosetting resin.

If the amount used is too small (less than the sin part), the effect will be poor, while if it exceeds 100 parts by weight, the desired strength may not be obtained, which is not preferable.

Further, for the purpose of preventing the composition from sagging, fillers such as calcium carbonate, talc, asbestos, clay, silicone PIlm, carbon black, and coloiglusilica are used.

Furthermore, for the purpose of lowering the melt viscosity and improving wettability, reactive diluents such as butyl glycicle ether and monoglycyl ether of long chain alcohols, heptatalic acid plasticizers such as nooctyl heptalate, and triclenc phosphate are added. A phosphoric acid plasticizer such as 7-ate can also be blended.

The blending amount of these additives is thermosetting 1111
w100! It is best to use a weight of about 5 to 30 weights.

Among the first thermosetting resin sheet and the second thermosetting resin sheet formed in this way, PIS2
It is desirable that the thermosetting reinforced tree sheet has tackiness under normal conditions.

This is because temporary adhesion before heat curing becomes easier when applied to a metal plate. Of course, the first thermosetting resin sheet may also have adhesive properties.

Furthermore, a reinforcing base material is embedded in the first thermosetting resin sheet in order to enhance the reinforcing effect of the metal plate.

When the first thermosetting resin sheet has a two-layer structure, an inner layer and an outer layer, a reinforcing base material is generally embedded in the outer layer.

This reinforcing base material is made of glass fiber, asbestos fiber, etc. Mass cloth made of quality fiber cloth, hemp, cotton, nylon, polyester, polypropylene, etc.
〆Plastic films such as polyester film and nylon film, paper such as kraft paper, polyester &
Examples include nonwoven fabrics made of polypropylene fibers and polypropylene fibers, and metal foils made of aluminum, iron, copper, zinc, and the like.

In order to embed the reinforcing base material, when molding the first thermosetting resin sheet, one or both surfaces of the reinforcing base material may be coated with or impregnated with a thermosetting resin composition.

In the above-mentioned M-strong base material, an inorganic fiber cloth that can obtain a sufficiently large reinforcing effect even by impregnation on one side is suitable, and Y-7/A41 cloth is particularly preferably used.

In addition, the thickness of the first thermosetting resin sheet and the second thermosetting resin sheet described above varies depending on the type of metal plate and the degree of reinforcement, but generally the thickness is 10th thermosetting resin sheet.
M! 0.2 to 201. Preferably 0.3-10m
m″C, and the second thermosetting resin sheet generally has a thickness of 0.1 to 30 mm, preferably 0.2 to 10 11 −.

A feature of the present invention is that a bead forming material is laminated between the thermosetting resin sheet of tj & 1 and the second thermosetting resin sheet, and beads are formed on one or both sides of the bead forming material. It has a partition wall layer that is wider than the material and m width than the thermosetting resin sheet.

By providing this partition layer, the reinforcing layer part and the laminated part are separated through the partition layer, so that the bead forming material can be easily foamed during heat curing, especially in the early stage of foaming, with low foaming pressure. Bead formation can now begin, and the first
Since the adhesion area between the thermosetting resin sheet (reinforcing layer) and the second thermosetting resin sheet (contact layer) is smaller than that of conventional products, the first When moving the thermosetting resin sheet, the movement (shift) in the χ direction becomes easier. This results in the formation of an ideal bead-shaped bulge with high reinforcing properties.

As a result, even if the thixotropic properties of the resin deteriorate as a result of passing through various treatment solutions in the pre-treatment process on the automobile line, the bead-shaped bulge remains stable and exhibits a sharp chevron shape, resulting in a highly reinforcing effect. It shows.

In the present invention, the partition layer refers to the first thermosetting resin sheet (reinforcing layer) and the PA2 thermosetting resin sheet (contact f).
fi/il) are laminated with the bead forming material inserted, any type of material may be used as long as the thermosetting resin sheets do not adhere to each other due to the partition layer, but this partition 5! It is preferable that the flexibility of the reinforcing adhesive sheet is not impaired by the addition of layers, because if the flexibility decreases, the workability of pasting will decrease in the case of an adherend having a curved surface. Specifically, various films and fiber base materials are suitable, but nonwoven fabrics made of polyester, acrylic, glass, etc. are particularly desirable.

The above-mentioned beads and forming material are obtained by impregnating the voids of an elastic foam with a fixing agent, softening or melting the elastic foam, flattening the elastic foam, and then using the above-mentioned fixing agent in this flattened state. A flattened resilient foam obtained by solidifying is used.

The above-mentioned elastic foam means that when the foam itself is compressed and deformed by an external force, it returns to its original state when the external force is removed, regardless of whether or not the polymer material itself that forms the foam has elasticity. It is acceptable as long as it can be recovered.

The foaming state of the elastic foam is preferably an open-cell type, which allows the adhesion agent to be contained in the voids and is easy to flatten, but the adhesion agent should be included to the extent that the flattened state can be maintained. If possible, closed cells may be mixed in -i.

The apparent density of this foam is usually in the range of 0.5 or less, the lower limit of which is approximately o, oos, and the more preferable range is 0.015 to 0.5. If this apparent density is too high, the volume will only decrease slightly even if the foam is flattened, and since there are few voids, it will not be possible to contain enough adhesive to maintain the flattened state, which is not preferable. On the other hand, if it is too low, it is not preferable because the restoring power of the flattened product will decrease.Also, the thickness of the elastic foam is usually about 2 to 50 mm, preferably 4 to 20+sta. .

The above elastic foam can be manufactured using various polymers and various known methods.

The polymer that can be used is not particularly limited as long as it can form an elastic foam having the above-mentioned functions.
Examples include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyurethane, and rubber.

Examples of the above-mentioned fixing agent include resins that soften or melt when heated and can solidify when cooled. This solid 5a
As for cutting, it is necessary that its melting point or softening point is lower than the melting point or softening point of the above-mentioned foam. If the melting point or softening point of this fixing agent is higher than the melting point or softening point of the above-mentioned foam, when the foam is flattened and fixed with the fixing agent to maintain this flattened state, and the fixed flattened material This is because when the foam is heated to remove the sticking force of the sticking agent, the cells in the foam collapse, and even if the sticking force is removed, the foam does not return to its original foamed state.

Further, the melting point* or softening point of the above-mentioned fixing agent is generally 10°C or more higher than room temperature, and more preferably melting point * or softening point is 40 to 140°C. If this melting point or softening point is too low, the foam flattened product will foam during storage and return to its original state, which is undesirable.On the other hand, if it is too high, high temperatures will be required to form the flattened product. However, this is not preferable because it generally causes thermal deterioration of the elastic foam and makes it difficult to restore the foam to its original shape.

As this adhesive, a variety of glues can be used as long as they have a melting point or softening point as described above, but among these, resins with a narrow melting point or softening point range and low molecular weight are more likely to be used because they are less likely to be rapidly heated when heated. This is preferable because the viscosity is reduced and the flattened product is quickly restored.

Examples of resins that can be used as the adhesive include epoxy resins, thermosetting resins such as polyester resins, and thermoplastic resins such as polyethylene, polypropylene, polyamide, and polybutyral. Various additives such as plasticizers and fillers may be added to these resins to reduce the viscosity *q of the solvent and cost.

Alternatively, a thermosetting resin with a curing agent added may be used as the adhesive, and the adhesive may be cured after the flattened foam is restored to its foamed state by heating.
This method is preferable because the hardness and strength of the restored foam can be improved and an excellent layer reinforcing effect can be obtained. It goes without saying that a resin should be used that can cure the resin at a temperature that does not proceed with curing and does not affect the shape of the restored foam.

In order to incorporate this adhesive into the voids of the elastic foam, there are two methods: dissolve the adhesive in a solvent, impregnate the foam with this solution, and then remove the solvent; There are methods such as rubbing the foam into the adhesive or vibrating the foam to soak it in, or immersing the foam in a molten adhesive.

The amount of adhesive to be included in the voids of the elastic foam is usually 25% of the total amount of the elastic foam and adhesive.
The weight is preferably about 90% by weight, and is determined as appropriate from the relationship between the elastic recovery force of the foam and the fixing force of the adhesive so that the flattened state of the foam can be maintained by the adhesive force. For example, in the case of polyurethane foam with an apparent +tr degree of 0.02 and a thickness of 10+am, it usually weighs 70~1*500g.
/m”.

A flattened resilient foam product is obtained by flattening an elastic foam containing a fixing agent in the voids as described above and maintaining this flattened state with the above-mentioned fixing agent.

To perform the above flattening, the foam containing the adhesive is heated to a temperature that softens or melts the adhesive to the extent that it can be fused, and then the adhesive is applied while maintaining this flattened state. Assimilate. The above-mentioned temperature does not necessarily need to be higher than the melting point of the fixing agent as long as it can be fixed, but it needs to be a temperature at which the foam does not soften or melt. A specific method for this flattening is, for example, a method of flattening with a hot press at a temperature near the melting point or softening point of the adhesive and then cooling in this flattened state (in this case, depending on the temperature of the hot press, the cooling step may be necessary). (In some cases, it is not necessary to just take it out of the press.) There are also methods in which the material is heated and then immediately flattened using a cooling roll.

The reinforcing adhesive sheet of the present invention is provided by attaching the bead forming material to one side of the first thermosetting resin sheet by molding it into a ram@ from the pi1 thermosetting resin sheet, and A partition layer wider than the bead forming material and narrower than the first thermosetting resin sheet is provided on one or both sides of the forming material, and the second thermosetting resin sheet is further provided on the exposed surface side of the partitioning layer. Obtained by laminating and integrating resin sheets.

A preferable property of the reinforcing adhesive sheet of the present invention thus obtained is that the first thermosetting resin sheet (the fat sheet or the second thermosetting resin sheet does not substantially flow at room temperature). Although it has self-retention properties, it is in a highly viscous state as a whole.This product has visibility and flexibility, and the sheet does not show any damage even when bent at 250 to 300 degrees and can be restored to its original state. Therefore, according to this preferred embodiment, since the reinforcing material (adherend such as a metal plate) has shape conformability, the material to be reinforced (adhered body such as a metal plate) can be shaped into a wave shape, a mountain shape, a square shape, a curved shape, etc. Even if it is, it can be stuck and can be more effectively applied as a reinforcing adhesive sheet.

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 reinforcing adhesive sheet to the back side of the metal plate as described above, such as a car body copper plate, on the back side of the w4@, and then use a normal heating method such as a hot air circulation heating furnace, infrared rays, etc. This can be achieved by heat treatment using a heating furnace, high-frequency induction heating furnace, or the like.

In addition, when the above-mentioned reinforcing adhesive sheet is applied to the auto body steel plate of *I11, the above heat treatment can be performed simultaneously in the paint baking process of the auto body steel plate in the automobile manufacturing line.

(e) Effect The present invention has the above configuration, and a partition layer is provided on one or both sides of the bead forming material, the partition layer being wider than the bead forming material and narrower than the thermosetting resin sheet. Possibly the first thermosetting 1111? Sheet (reinforced/11 parts)
and the second thermosetting FJ sheet (laminated part) are separated via the partition layer, which facilitates foaming of the bead forming material during heat curing, especially in the early stage of foaming, resulting in low foaming pressure. Bead formation can be started from the start, and the contact area between the first thermosetting resin sheet (IIll?lIi layer) and the second thermosetting resin sheet (main part of lamination) is smaller than that of conventional products. Therefore, in the movement of the first thermosetting resin sheet for the reinforcing layer at the time of bead formation, movement in the χ direction (7: shi) is facilitated.

This makes it possible to form an ideal bead-shaped bulge with high reinforcing properties, which makes it possible to form 3. l! Even if the thixotropic properties of the resin are reduced by passing through step a, the bead shape exhibits a stable and sharp chevron shape and exhibits a high reinforcing effect.

(f) Examples Hereinafter, the present invention will be explained in detail based on Examples, but the present invention is not limited thereto.

■Figure 1 of the sheet shows the structure of the present invention? lI! A sectional view of the reinforcing adhesive sheet (1) is shown, and the reinforcing adhesive sheet (1) is constructed as follows.

That is, the reinforcing adhesive sheet (1) of the present invention comprises a first thermosetting resin sheet (3) in an uncured or semi-cured state containing a reinforcing base material (2), and a first thermosetting resin sheet (3) in an uncured or semi-cured state. second thermosetting resin sheet (4), and this side thermosetting resin sheet 8!
The thermosetting resin sheet (3), (4) is laminated between the thermosetting resin sheets (3), (4), and is narrower than the thermosetting resin sheets (3), (4), and is laminated between the thermosetting resin sheets (3), (4). ) has a basic Vt structure made of a bead-forming material (5) which forms a bead-like bulge before curing.

(6) is a partition layer, and the partition wall/I (6) is provided on one or both sides of the bead forming material (5), in this case, on one side of the bead forming material (5), and Material (
5) Wider and above-mentioned thermosetting resin sheet) (3)
, (4) is formed narrower.

In this case, the bead forming material (5) is a flattened material in which an elastic foam containing a bonding agent in the void is flattened and this flattened state is maintained by the bonding agent, and is foamed by heating. It is made of flattened resilient foam that can be restored to its original state.

Further, the first thermosetting resin sheet (3) is the second thermosetting resin sheet (3).
The second thermosetting four-phase sheet (4) has a higher tensile modulus after heat curing and a higher glass transition temperature after heat curing than the second thermosetting resin sheet (4). 4) is formed to be sticky at room temperature.

In this configuration, the reinforcing adhesive sheet (1) is
As shown in Figure 2, the second thermosetting resin sheet (4)
This reinforcing adhesive sheet (1) is attached by pasting it on the back side of an adherend (7) such as an outer panel of an automobile door, and then, as shown in FIG. 3, by heating after attachment, this reinforcing adhesive sheet (1) becomes - While the viscosity decreases over time and the attachment surface adheres more closely to the adherend (7), the bead forming material (5) restores its original foam shape and becomes larger in cross section. The u4 resin sheet (3) is attached to the second thermosetting resin sheet (4
), and before it is pushed up from its adhesive surface and hardened, a bead-shaped bulge (8) is formed, and as the heating progresses over time, the first thermosetting resin sheet (3) and the second thermosetting resin sheet (3) are formed. (The sheet (4) will further harden.

Example Epicote $828 (bisphenol A type liquid epoxy resin manufactured by Yuka Shell Co., Ltd.) 50 weight 1 part, Ebitsu) #10
04 (bisphenol A type solid epoxy resin manufactured by Yuka Shell Co., Ltd.) 35 parts by weight, Byron #500 (manufactured by Toyobo Co., Ltd.) 15 parts by weight, Chiea Sol C, Z (manufactured by Shikoku Kasei Co., Ltd.)
0.5 parts by weight, dicyandiamide 5 parts by weight, Tal 210
An epoxy resin composition consisting of 0 parts by weight and 5 parts by weight of asbestos powder was kneaded using a normal mixing roll, and the resulting resin mass was formed into a sheet with a thickness of 0.5 ma+ using a direct pressure press, and further reinforced. A glass cloth (WE-22D-104 manufactured by Nittobo Co., Ltd.) serving as the base material (2) was laminated to obtain an uncured first thermosetting resin sheet (3).

Next, 2 pico) #871 (dimer acid-modified epoxy resin manufactured by Yuka Shell Co., Ltd.) 80 parts ffi, Epicoat #
1002 (Tosu 72 manufactured by Yuka Shell Co., Ltd.) - Type A solid epoxy resin) 5 parts by weight, Ebiko) # 828 (mentioned above) S mf 1 part Oyotliz squid - CTBN 13
10 parts by weight of 00X8 (reactive butadiene rubber manufactured by BF Gutdrich) were melt-mixed in a mixing pot, and to 1 part by weight of the resulting composition, 1 part by weight of Chieasol C+ + Z (mentioned above) and dicyanamide were added. (mentioned above) 5 parts by weight, 50 parts by weight of talc, and 5 parts by weight of asbestos powder were mixed together using a normal mixing roll, and then formed into a sheet using a direct pressure press to a thickness of 0. A second thermosetting resin sheet (4) of .8 am in an uncured state was obtained.

Note that this first thermosetting resin sheet (3) and the second
The tensile modulus of the first thermosetting resin sheet (3) after heat curing of the thermosetting resin sheet (4) is 95 kg/
l”, 3.0 kg with the second thermosetting resin sheet (4)
/-12.

In addition, the lath transition temperature after heat curing is 110°C for the first thermosetting resin sheet (3) and 50°C for the second thermosetting resin sheet (4). However, the heat curing conditions are as follows. is 30 minutes at a temperature of 150°C.

On the other hand, a urethane foam with a thickness of 8 cm (apparent density 0,
02[+/(4113)] was impregnated with a 7% methyl ethyl ketone solution of Epicoat #1001 (bisphenol A type epoxy resin manufactured by Yuka Shell Co., Ltd., melting point 64-74°C) as a fixing agent, and then the methyl ethyl ketone was removed. This resulted in the foam being impregnated with 150 g/m'' of epoxy resin.

Next, this foam was flattened using a hot press at a temperature of 70° C. to obtain a flattened resilient foam having a thickness of lll11. When this flattened material is placed in an open air at a temperature of 90°C, it becomes 1 to 2
This is a bead forming material (5) that restores the original shape of the urethane foam in minutes.

The above-mentioned first thermosetting resin sheet (3) and second thermosetting resin sheet (4) are cut into a width of 70 m, and this @1 and second thermosetting resin sheet (3) are cut. , (4), insert the bead forming material (5) cut to a width of 101 (the above flattened material), and then insert the bead forming material (5) and Pt52
Between the thermosetting resin sheets (4), a partition layer (6
) is provided and integrated to form the reinforcing adhesive sheet (1) of the present invention.
) was obtained.

Comparative Example A reinforcing adhesive sheet without a partition layer was obtained using the same manufacturing method as in the Example.

After attaching the characteristic test example products and comparative examples to a test steel plate, they were allowed to absorb water or moisture in an uncured state to form a test sample, and after heating and curing the test sample, the influence of water absorption or moisture absorption on reinforcement hardening was evaluated. evaluated.

Test sample size: width 70 x length 150 Test steel plate size: thickness 0.8 + mm
Immersed in warm water at ℃ ■Moisture absorption conditions Temperature 40℃ and relative humidity 90-95%.
The strength test shown below was conducted to evaluate the reinforcing effect.

Strength test Two vertical flat plates (2 vertical flat plates) whose tips exhibit an inverted U-shaped cross section with a radius of curvature of 5 mm, arranged in parallel with a distance of 1001 mm between the tips.
A test specimen formed to have a width of 70 mm is supported horizontally on a support stand having a width of 70 mm, and a vertical flat plate (width of 70 mm
) maximum bending stress (kg/70
am width) was measured.

The maximum bending stress after the water absorption test is shown in Table 2, and the maximum bending stress after the moisture absorption test is shown in Table Pt43.

(Margin below) As shown in Table 2 f53 Table 2 and @Table 3, the reinforcing adhesive sheet according to the present invention exhibits stable sharp bead-like swelling even when heated or cured in a water-absorbed state. Since a protruding part is formed and hardened, high reinforcing properties can be stably obtained, whereas in the comparative example, the bead-like protruding part changes due to water absorption or moisture absorption and shifts to the shape shown in Fig. 6. . As a result, reinforcing properties are reduced, which poses a problem in terms of reliability.

By the way, when the foam was cured and evaluated on an actual automobile production line, the results were as follows: Table 2 and Table 32! The maximum bending stress was 56 k[r/701 width in the example, whereas it was 41 kg/70-1 width in the comparative example.

Furthermore, when the reinforcing adhesive sheet was left for 3 days after pasting and then foamed and cured on the actual line, the maximum bending stress decreased from 59 kg/770 ml/width for the example to 32 kg/70 m-width for the comparative example. Was.

Note that the maximum bending stress of only the steel plate to which no reinforcing adhesive sheet was attached was 18 kg/70 mm width.

Further, when the steel plate was visually observed for distortion due to the reinforcing adhesive sheet, no distortion was observed and the appearance was good.

(g) Effects of the Invention The present invention has the above-mentioned configuration, and a partition layer is provided between the first thermosetting resin sheet and the second thermosetting resin sheet, and the partition layer allows heat to be removed from these sheets. Even if the thixotropic properties of the resin forming the curable resin sheet are reduced, sharp bead-like bulges can be obtained, so a stable and excellent reinforcing effect can always be obtained.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an embodiment of the present invention, Fig. 2 is a cross-sectional view showing the state in which it is adhered to an adherend, and Fig. 3 is a state in which it is heated to form a bead-shaped bulge. 4 is a sectional view showing a state in which a conventional reinforcing adhesive sheet is adhered to an adherend, and FIG. 5 is a sectional view showing the action when a bead-shaped bulge is formed. , and FIG. 6 is a sectional view showing a state in which a conventional reinforcing adhesive sheet is heated after absorbing water or moisture to form a bead-like bulge. (1)... Adhesive sheet for reinforcement, (2)... Reinforcement base material, (3)... First thermosetting resin sheet, (4)...
... second thermosetting resin sheet, (5) ... bead forming material, (6) ... partition layer, (7) ... adherend, (8
)...Bead-shaped bulge. ]・000 year old 1F1 Hoshoshu・F main seat 8・-・k
Figure 1 Figure 4 Figure 5

Claims (4)

[Claims] (1) A first thermosetting resin sheet in an uncured or semi-cured state containing a reinforcing base material, a second thermosetting resin sheet in an uncured or semi-cured state, and these thermosetting resin sheets A bead forming material having a narrower width and forming a bead-like bulge before the thermosetting resin sheet is cured is provided between the first thermosetting resin sheet and the second thermosetting resin sheet. A reinforcing adhesive sheet formed by lamination, characterized in that a partition layer is provided on one or both sides of the bead forming material, the width being wider than the bead forming material and the width being narrower than both of the thermosetting resin sheets. Adhesive sheet for use. (2) The bead forming material is a flattened material in which an elastic foam containing a fixing agent in the void is flattened and this flattened state is maintained by the above-mentioned fixing agent, and can be restored to the foamed state by heating. The reinforcing adhesive sheet according to claim 1, which is made of a flattened resilient foam. (3) The first thermosetting resin sheet has a higher tensile modulus after heat curing than the second thermosetting resin sheet,
The reinforcing adhesive sheet according to claim 1 or 2, wherein the reinforcing adhesive sheet has a high glass transition temperature after heat curing. (4) The reinforcing adhesive sheet according to any one of claims 1 to 3, wherein at least the second thermosetting resin sheet of both thermosetting resin sheets is adhesive at room temperature.