JPS6211670B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminated reinforcing material that contributes to weight reduction as reinforcement for plate materials.

Conventionally, in automobiles, various types of reinforcement have been applied to car body steel plates. For example, in the case of roofs, fenders, hoods, trunks, quarter panels, doors, which have relatively wide and flat shapes but are thin, they need to have appropriate structural rigidity against external forces. A method is used in which an inner plate made of a metal reinforcing member is attached to an outer plate by spot welding or adhesive. However, this method has drawbacks such as the heavy weight of the metal reinforcing members, which goes against the trend of thinning the outer skin, which was designed to reduce the weight of car bodies, increases weight and costs, and complicates the installation process. It had

In addition, for the purpose of damping and reinforcing the outer skin of the vehicle, polymeric materials such as asphalt rubber, epoxy resin, acrylic resin, phenolic resin, and unsaturated polyester resin are applied to the back side of the outer skin in a considerable thickness and over a considerable area. Coating or pasting methods are also known.
In this method, the rigidity is said to be proportional to the cube of the thickness, so increasing the thickness can increase the rigidity, but the increased amount of resin increases weight and costs. It has the same drawbacks as the metal reinforcing member.

The present invention was made in view of the conventional situation, and aims to provide a reinforcing material that is lightweight and inexpensive and can significantly improve the rigidity of the object to be attached. A first thermosetting resin layer in the form of a sheet having adhesive properties, and a second fiber base material laminated on this layer and shaped into a shape such that a hollow space is created between the layers. The first and second thermosetting resin layers are both in an uncured or semi-cured state as a laminated reinforcing material.

The present invention will be explained below based on the drawings.

FIG. 1 shows an example of the laminated reinforcing material of the present invention, in which 1 is a sheet-like first thermosetting resin layer having adhesive properties, and 2 is a layer laminated on the above-mentioned layer 1. A second thermosetting resin layer having a fiber base material 4 shaped into a substantially wave-shaped cross section such that two hollow parts 3, 3 are formed between the first and second thermosetting resin layers. Both of the curable resin layers 1 and 2 are in an uncured or semi-cured state.

2 and 3 show an example in which the laminated reinforcing material having the above structure is applied to a plate material such as an automobile body steel plate. In FIG. 2, when the steel plate 4 is a flat plate,
The figure shows a case where the steel plate 4 has a curved surface. As shown in the figures, the reinforcing material is temporarily attached to the steel plate 4 so that the first thermosetting resin layer 1 side becomes the adhesive surface of the steel plate 4, and then heated in a hot air circulation type heating furnace or infrared rays. This is carried out by a method in which both the first and second thermosetting resin layers 1 and 2 are melted and hardened by heating with an appropriate means such as a heating furnace or a high-frequency induction heating furnace. Note that the heating described above can also be carried out simultaneously with baking in the car body paint baking process on the automobile manufacturing line.

As a feature of the present invention, first, since the first thermosetting resin layer 1 has adhesiveness, temporary attachment to the steel plate 4 can be performed smoothly by utilizing the adhesiveness. In addition, the first and second thermosetting resin layers 1 and 2
Both layers are in an unhardened or semi-hardened state, and by selecting the fiber base material, the overall flexibility can be maintained as a whole, and when both layers are heated and hardened, they melt once and blend well with the steel plate surface. Since distortion is less likely to remain, the adhesion of the reinforcing material to the steel plate surface becomes better, and even when the steel plate has a curved surface as shown in Fig. 3, as well as the flat plate shown in Fig. No gaps are created.

Regarding this point, it should be noted that, for example, when the second thermosetting resin layer among the constituent elements of the reinforcing material is completely hardened in advance after shaping, the flexibility of the reinforcing material itself Moreover, since the melting effect by heating cannot be obtained, it is difficult to adhere well even to a flat plate, and it is almost impossible to apply it to a plate having a curved surface as shown in FIG.

Furthermore, a major feature of the present invention is that the shape of the second thermosetting resin layer 2 before heat curing hardly changes during heat curing, forming a hardened reinforcing layer in which the hollow parts 3 are maintained as they are. It is possible. That is, although the second layer melts once during heat curing as described above, the fiber base material 4 contained in this layer suppresses the change in shape due to melting.
It is cured with the hollow parts 3, 3 remaining.

The reinforcing material cured in this way has a fiber base material contained in the second thermosetting resin layer and a rib structure formed by the hollow parts 3, 3. In other words, it is lightweight and inexpensive, and exhibits an extremely large reinforcing effect by using a smaller amount of resin than the conventional single-layer structure.

In addition, in the laminated reinforcing material shown in FIG. 1, the second thermosetting resin layer 2 has two hollow parts 3,
Although the waveform shape is such that 3 is formed, it may be shaped such that there is only one hollow portion, or conversely, there are many hollow portions of 3 or more, and furthermore, the cross-sectional shape is also limited. figure,
It can take various shapes such as square.

Next, each component of the laminated reinforcing material of the present invention and its formation method will be explained in detail.

The first thermosetting resin layer is made of a thermosetting resin composition having adhesive properties, which is made by blending a thermosetting resin with a heat-activated curing agent and adding various additives as necessary. It is formed into a sheet in an uncured or semi-cured state by the method described above, and the above-mentioned tackiness can be easily imparted by selecting the properties of the thermosetting resin or by blending additives.

The second thermosetting resin layer is formed by forming a sheet of the same composition as the first layer on a fiber base material in an uncured or semi-cured state, and then applying a mold to this molded product. The material is shaped into the shape described above by performing shaping processing in an uncured or semi-cured state in the same manner as described above. This layer does not have to be particularly tacky, but may be if desired.

The shaped second thermosetting resin layer formed by the above method has appropriate flexibility, but also has appropriate rigidity by selecting a stiff fiber base material. This rigidity allows the shape of each shape to be maintained. Further, this second thermosetting resin layer is laminated on the first thermosetting resin layer while maintaining the above-mentioned shape to form a laminated reinforcing material of the present invention. The curable resin layer exhibits a shape-retaining function that prevents deformation of the second thermosetting resin layer, thereby further improving shape-retaining properties.

The thermosetting resin used for forming the first and second thermosetting resin layers includes glycidyl ether type, glycidyl ester type, glycidyl amine type, linear aliphatic epoxide type, alicyclic epoxide type, etc. Various epoxy resins are preferable in terms of adhesion to metal plates. However, other thermosetting resins such as melamine, polyester, phenol, urea, etc. can also be used.

The heat-activated curing agent to be added to this thermosetting resin may be any ordinary curing agent that exhibits curing action when heated, and generally it is sufficient if it is active in the temperature range of 80 to 200°C, for example, for curing epoxy resins. Examples of the agent include dicyandiamide, 4,4'-diaminodiphenylsulfone, imidazole derivatives such as 2-n-heptadecyl imidazole, isophthalic acid dihydrazide, N·N-dialkyl urea derivatives, N·N-dialkylthiourea derivatives, etc. is used. The amount used may be generally 1 to 15 parts by weight per 100 parts by weight of the epoxy resin.

In addition to the above components, the thermosetting resin composition also contains
Various additives are added as necessary to give the composition enough cohesive strength to form a sheet, and to prevent sagging or to reduce melt viscosity and improve wettability. .

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

Furthermore, in order to lower the melt viscosity and improve 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 used. Acid plasticizers etc. can be added. The amount of these components is preferably about 5 to 30 parts by weight based on 100 parts by weight of the thermosetting resin.

Further, fillers such as calcium carbonate, talc, asbestos powder, silicic acids, carbon black, and colloidal silica can be used to prevent the composition from sagging. At this time, when the laminated reinforcing material of the present invention is made using a thermosetting resin composition containing this filler and is used for reinforcing a door outer panel, etc., the amount of filler added is as follows after heat curing. Care should be taken to use it to the extent that it does not impair its adhesive strength with boards, etc. Among the fillers mentioned above, asbestos powder is preferably used for the purpose of preventing sagging, and the amount used is preferably determined by adjusting the amount of asbestos powder used in the polymer component (i.e., thermosetting resin and optionally used thermoplastic resin, rubber component) in the composition. 2 to 20 parts by weight per 100 parts by weight.

Next, the fiber base materials used for forming the second thermosetting resin layer include inorganic fiber cloth such as glass fiber and asbestos fiber, organic fiber cloth such as hemp, cotton, nylon, polyester, and polypropylene, and polyester fiber. , sheet-like fiber base materials such as nonwoven fabrics made of polypropylene fibers, etc. Among these, particularly preferred are inorganic fiber cloths, a typical example of which is glass fiber cloth. In addition, in this invention, the above-mentioned fiber base material may also be included in the first thermosetting resin layer as necessary.

The thickness of the above first and second thermosetting resin layers is usually 0.05 to 20 mm, preferably
It is best to set it to 0.1 to 15 mm. Furthermore, the first and second layers may have the same or different resin composition types and compositions, but it is desirable that their curing speeds be approximately similar.

In this invention, the means for laminating the second thermosetting resin layer on the first thermosetting resin layer is not particularly limited, but generally it can be done by utilizing the adhesiveness of the first layer, Alternatively, a method such as heating to an appropriate temperature to thermally fuse the material may be used.

The laminated reinforcing material of this invention is not limited to steel plates such as the outer panels of automobile doors as described above,
It can be widely applied to sheet materials such as metal sheets, which are generally thin sheets, such as cases for various vehicles, electric refrigerators, washing machines, and other home appliances.

As detailed above, the laminated reinforcing material of the present invention has a hollow structure formed by two thermosetting resin layers having a specific shape or properties that are in an uncured or semi-cured state. For example, it can be freely applied to plate materials with curved surfaces, and can be lightweight and inexpensive while providing a high degree of reinforcing effect.

EXAMPLES Below, examples of the present invention will be described in more detail. In addition, in the following, parts shall mean parts by weight.

Examples 70 parts of Epicote #828 (bisphenol A type liquid epoxy resin manufactured by Yuka Shell Co., Ltd.), 10 parts of Epicote #1001 (bisphenol A type solid epoxy resin manufactured by Yuka Shell Co., Ltd.), Byron #500 (Toyobo Co., Ltd.) polyester resin) 20 parts, phenolic resin
MP-120HH (curing agent manufactured by Gunei Chemical Co., Ltd.) 8 parts, 2
−Undecyl imidazole (manufactured by Shikoku Kasei Co., Ltd.) 0.5
An epoxy resin composition consisting of 0.5 parts of talc, 0.5 parts of asbestos powder, and 1 part of asbestos powder was kneaded using a normal mixing roll, formed into a sheet with a thickness of 0.3 mm using a direct pressure press, and then a glass nonwoven fabric (manufactured by Nippon Vilene Co., Ltd.). A first thermosetting resin sheet in an uncured state, which is sticky at room temperature, was obtained by laminating KYUMURAS EP-6025).

Separately, 40 parts of Epicote #828 (mentioned above), Epicote #1002 (Bisphenol A manufactured by Yuka Ciel Co., Ltd.)
Mold solid epoxy resin) 40 parts, Platamide H103P
(Copolymerized nylon resin manufactured by Nippon Rilsan Co., Ltd.) 20
part, 5 parts of dicyandiamide (epoxy resin curing agent manufactured by Nippon Carbide Co., Ltd.), Kyuazol 2MZ-
An epoxy resin composition consisting of 1 part of AZINE (an epoxy resin curing accelerator manufactured by Shikoku Kasei Co., Ltd.), 50 parts of talc, and 2 parts of asbestos powder is kneaded using a normal mixing roll, and the resulting resin mass is mixed using a direct pressure method. The sheet was formed into a sheet with a thickness of 0.4 mm using a press, and a glass fiber cloth (WK3030A manufactured by Nittobo Co., Ltd.) was further laminated to obtain a second thermosetting resin sheet in a semi-cured state.

After shaping the second thermosetting resin sheet using a mold with a corrugated cross section, this and the thermosetting resin sheet are fused or adhered to each other, and the first thermosetting resin sheet is shaped.
A laminated reinforcing material of the present invention having a hollow structure as shown in the figure was prepared.

This laminated reinforcing material was bonded to a 0.7 mm thick steel plate in the manner shown in Figure 2, and then heated and hardened in an atmosphere of 150°C for 60 minutes. Through this heat curing, the reinforcing material is firmly bonded to the steel plate, and a reinforcing layer consisting of a fiber-reinforced resin layer having the same hollow portion as before heat curing can be formed without causing any change in the shape of the second resin sheet. Ta. When the strength test described below was conducted using the steel plate reinforced in this way as a test piece, the maximum bending stress was 68Kg/50mm width at 20℃, which was the maximum bending stress of the steel plate alone without any reinforcement measures. Whereas it was 8Kg/50mm width,
It was found that a very good reinforcing effect was obtained.

The laminated reinforcing material described above was laminated onto a curved steel plate having a thickness of 0.7 mm as shown in FIG. 3, and then heated and cured in an atmosphere of 150° C. for 60 minutes. In this case as well, it was possible to form a reinforcing layer made of a fiber-reinforced resin layer that was tightly adhered to the steel plate surface without leaving any voids and had the same hollow portion as before heat curing, as described above. When the same strength test as above was conducted, the maximum bending stress was 70 kg/50 mm width at 20°C, and a good reinforcing effect was obtained.

<Strength test method> 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 10 mm between the tips, and a width of 50 mm. The test piece was supported horizontally, and a vertical flat plate (width
Maximum bending stress (Kg/
50mm width) was measured.

Reference Example The second thermosetting resin sheet obtained in the example was shaped in the same manner as in the example, and then heated to completely cure it. This was laminated with the first thermosetting resin sheet obtained in the example to obtain a laminated reinforcing material having a shape similar to that shown in FIG. Using this laminated reinforcement material,
When it was bonded to a 0.7mm thick steel plate from the first thermosetting resin layer side and heated and cured, some parts were raised, resulting in poor adhesion, and the maximum bending stress was 25Kg/50mm width in the strength test. Therefore, a sufficient reinforcing effect could not be obtained. Furthermore, when we tried to apply it to a curved steel plate surface with a thickness of 0.7 mm, there were many floating parts and the reinforcing material fell off during heat curing, making it difficult to apply.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of the laminated reinforcing material of the present invention, and FIGS. 2 and 3 are both cross-sectional views showing examples in which the laminated reinforcing material described above is applied to a plate material. DESCRIPTION OF SYMBOLS 1...First thermosetting resin layer, 2...Second thermosetting resin layer, 3...Hollow part, 4...Fibre base material.

Claims (1)

[Claims] 1 A first thermosetting resin layer in the form of a sheet with adhesive properties; a thermosetting resin layer, wherein the first and second thermosetting resin layers are both in an uncured or semi-cured state.