JPS6121141B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a 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, for roofs, fenders, hoods, trunks, quarter panels, and doors that have relatively wide and flat shapes but are thin, it is necessary to provide appropriate structural rigidity against external forces. Since then, a method has been adopted 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 thinner outer panels designed to reduce the weight of car bodies, increases weight and costs, and complicates the installation process. It had

In addition, as shown in Japanese Utility Model Application Publication No. 55-101659, for example, for the purpose of vibration isolation and reinforcement of the outer panel of the vehicle body,
A method is also known in which a polymeric material such as asphalt rubber, epoxy resin, acrylic resin, phenolic resin, or unsaturated polyester resin is coated or pasted on the back side of the outer panel to a considerable thickness and over a considerable area. 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.

This invention was made in view of the conventional situation, and aims to provide a reinforcing material that is lightweight, inexpensive, and significantly improves the rigidity of an object to be attached. An uncured or semi-cured thermosetting reinforced resin sheet (hereinafter referred to as "non-sagging property imparting substance") containing a substance for imparting a melt viscosity that can prevent drooping during heating and melting (hereinafter referred to as "non-sagging property imparting material"). A bead-forming material that is made narrower than this sheet and forms a bead-shaped bulge on the sheet before the sheet is cured is attached to one side of the reinforced resin sheet (simply referred to as a reinforced resin sheet), and The reinforcing material is constructed such that the wide hem portion of the sheet on the side of the bead forming material forms a mounting surface for the object to be mounted.

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

FIG. 1 and FIG. 2 show an embodiment of the reinforcing material according to the present invention, in which the reinforcing material 1 is a fiber base material 2.
A reinforcing resin sheet 3 of thermosetting resin, such as an epoxy resin, prepared in an uncured or semi-cured and flexible prepreg state and containing a non-sagging property imparting substance; It consists of a bead forming material 4 made of a foamed resin sheet attached to one side, and this bead forming material 4 is formed narrower than the reinforcing resin sheet 3. The hem portions 3a, 3a of the reinforcing resin sheet on the side of the bead forming material 4, which protrude beyond the width of the bead forming material 4, constitute a mounting surface to be attached to an object to be mounted, such as a back surface 5a of a door outer panel 5 of an automobile.

The reinforcing material 1 is attached to the mounting surface 3 as shown in FIG.
a, 3a are attached to the back surface 5a of the door outer panel 5, and by heating after attachment, the viscosity of the reinforcing resin sheet 3 temporarily decreases, and the reinforcing resin sheet 3 is attached to the attached surface 3 on the door outer panel 5.
While a and 3a are brought into closer contact with each other, the bead forming material 4 is foamed and its cross section becomes larger, and the reinforcing resin sheet 3 is pushed up from the roots 3c and 3c of the mounting surface 3a, and the bead-shaped swollen portion 3b is formed before it hardens. As the reinforcing resin sheet 3 is formed and further heated over time, it hardens and becomes the state shown in FIG. 3.

In the present invention, the fiber base material in the reinforced resin sheet can be positioned, for example, outside the intermediate portion of the layers of the sheet. FIG. 2 shows this example, in which the fiber base material is unevenly distributed on the outside (that is, the bead forming material is attached to the non-uniformly distributed side of the fiber base material).

Next, the fiber base material 2, reinforcing resin sheet 3, and bead forming material 4 in the reinforcing material 1 will be explained in more detail. First, the reinforcing resin sheet 3 is a thermosetting resin made by blending a thermosetting resin with a heat-activated curing agent and a non-sagging property imparting substance that becomes non-sagging property when the resin is molten. It can be produced by molding the composition into a sheet in an uncured or semi-cured state according to a conventional method, and then fusion-bonding it to a fiber base material at the same time as this sheet molding or each time the sheet is molded.

A typical non-sagging material that is an important component in the above-mentioned thermosetting resin composition is asbestos powder. The proportion is preferably 2 to 20 parts by weight, particularly preferably 4 to 15 parts by weight, based on 100 parts by weight of the total amount of the curable resin and the thermoplastic resin and rubber component used in combination. Another typical example is a mixed system of finely powdered silica and glycerin, in which the ratio of finely powdered silica used is 4 to 10 parts by weight per 100 parts by weight of the polymer component in the thermosetting resin composition. Parts by weight, particularly preferably from 2 to 7 parts by weight, and for glycerin from 0.5 to 3 parts by weight, particularly preferably from 0.7 to 2.5 parts by weight.

If an excessive amount of these non-sagging imparting substances is used, the initial adhesion to the door outer panel 5 or the like becomes insufficient, and temporary adhesion to the door outer panel 5 or the like becomes difficult, which tends to impair workability. Furthermore, the adhesion force to the door outer panel 5 and the like after heating and curing decreases, and there is a risk that the fiber-reinforced resin layer may peel off from the door outer panel surface during handling such as bending. In addition, these anti-sagging property imparting substances are effective in imparting non-sagging properties to thermosetting resins, and also provide good results in terms of the strength of the fiber-reinforced resin layer. It is the chosen one.

The thermosetting resin in which such a non-sagging property imparting substance is to be blended has fixed shape at room temperature, and as long as this condition is met, it may be a mixture of a solid resin and a liquid resin at room temperature. , or may be semi-hardened. Specific examples of such thermosetting resins include glycidyl ether type,
Various epoxy resins such as glycidyl ester type, glycidyl amine type, linear aliphatic epoxide type, and alicyclic epoxide type are preferable from the viewpoint 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 blended as necessary for the purpose of imparting cohesive force to the composition to the extent that it can be formed into a sheet, and improving wettability to a metal plate.

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 epichlordrine, and rubbers such as butadiene-acrylonitrile copolymers or derivatives thereof. You can mix ingredients etc. 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 improving the wettability of door outer panels, etc., reactive diluents such as butyl glycidyl ether and monoglycidyl ether of long-chain alcohols, phthalic acid plasticizers such as dioctyl phthalate, and triclean diphosphate are used. Phosphoric acid plasticizers and the like can be added. The amount of these components is preferably about 5 to 30 parts by weight per 100 parts by weight of the thermosetting resin. Other general fillers, such as calcium carbonate, silicic acids, carbon black, etc., which have some function of imparting anti-sagging properties, may be blended within a range that does not impair adhesive strength or other properties.

Furthermore, as the fiber base material in the reinforced resin sheet, sheets such as inorganic fiber cloth such as glass fiber or asbestos fiber, organic fiber cloth such as linen, cotton, nylon, polyester, or polypropylene, or nonwoven fabric made of polyester fiber, polypropylene fiber, etc. There are fiber base materials. Among these, particularly preferred are inorganic fiber cloths, a typical example of which is glass fiber cloth.

When a woven fabric is used as the fiber base material in the present invention, its porosity is preferably 70% or less. The porosity means a value expressed by a-b/a×100 (%), where a is the planar area of the woven fabric and b is the planar area of the fibers occupying this planar area.

The thickness of the reinforced resin sheet of this invention varies depending on the reinforced location and purpose of reinforcement, but is generally 0.1
~40mm, preferably 0.3~20mm. Further, it is desirable that this reinforcing resin sheet has adhesiveness at room temperature for temporary adhesion to the door outer panel 5 and the like.

Next, the foamable resin sheet as the bead forming material 4 has the property of foaming when heated above the decomposition temperature of the foaming agent contained therein, and the above-mentioned reinforcing resin provided on this sheet so that the sheet 3 can be in close contact with the door outer panel 5 on at least both sides in the width direction of the bead forming material 4;
It is formed into a narrower width than the reinforced resin sheet 3 described above.

Such foamable resin sheets are made by, for example, adding various thermosetting or thermoplastic polymers to a blowing agent and, if necessary, a foaming auxiliary agent, a curing agent, a curing accelerator, a crosslinking agent, a crosslinking auxiliary agent, a filler, and a coloring agent. After mixing the foaming agent, stabilizer, etc. with a mixing roll, etc., the foaming agent is mixed under temperature conditions that do not decompose (slight decomposition is fine).
It can be made by sheet molding according to conventional methods.

Thermosetting or thermoplastic polymers used above include thermosetting resins such as epoxy resins, phenolic resins, and polyester resins, polyethylene, ethylene-vinyl acetate copolymers, adhesive polyolefins, etc. The agent may be any agent that foams when the reinforcing resin sheet is heated and cured 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 during heating is practically 2 to 30 times.

Next, to explain the curing process of the reinforcing material 1 in more detail, the reinforcing material 1 is brought into close contact with the door outer panel 5 as shown in FIG. The elastic resin sheet is foamed, and the curing of the sheet 3 is completed each time the foaming is completed. As a result, as shown in FIG. 3, a fiber-reinforced resin layer having bead-shaped bulges 3b is formed by the expansion force caused by foaming. At this time, it is preferable to take care that the gelation time of the reinforcing resin sheet at a certain temperature is about 1 to 20 minutes longer than the foaming completion time of the foamable resin sheet at the same temperature.

As the heating means, a conventional heating method such as a hot air circulation heating furnace, an infrared heating furnace, a high frequency induction heating furnace, etc. can be adopted. It is also possible to heat the paint at the same time as the paint baking process for car bodies in the car manufacturing line.

By the way, in such heating and foaming curing, if the reinforcing resin sheet 3 causes a rapid viscosity drop when melted, the resin component that softened and flowed at the initial stage of heating may become hardened by the fiber base material 2. There is a risk that the resin will drip down, especially the resin near the base 3c of the bulging portion 3b.

However, the above-mentioned reinforced resin sheet 3 of the present invention
Since the composition contains a non-sagging additive substance and is given the property that it does not easily sag in a molten and fluid state, the above-mentioned sagging phenomenon hardly occurs. However, before it begins to sag, it begins to gel, its viscosity rapidly increases, and it hardens.

Therefore, the fiber-reinforced resin layer that is finally hardened and formed exhibits its original strength without thinning or resin loss at the bases 3c and 3c, and also suppresses overall thinning or resin loss. Due to the functions of the fiber reinforced resin layer, the foam layer and the bulging portion 3b, the effect of reinforcing the door outer panel 5, etc. is increased, and further improved strength or rigidity can be obtained.

As detailed above, according to the method of the present invention, when constructing a reinforcing material using a reinforcing resin sheet and a bead forming material, the reinforcing resin sheet blended with a non-sagging property imparting substance is used as the reinforcing resin sheet. Therefore, it is possible to provide a highly reliable reinforcing material that can better exhibit its original reinforcing effect when reinforcing this reinforcing material by closely adhering it to a door outer panel or the like and heat-curing it.

The reinforcing material of the present invention is not limited to steel plates such as the outer panels of automobiles mentioned above, but can be applied to a wide variety of thin metal plates, such as cases of various vehicles and home appliances such as electric refrigerators and washing machines. Can be applied.

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

Example 1 55 parts of Epicote #828 (bisphenol A type liquid epoxy resin manufactured by Yuka Shell Co., Ltd.), 15 parts of Epicote #1004 (bisphenol A type solid epoxy resin manufactured by Yuka Shell Co., Ltd.), Vylon #500 (30 parts of polyester resin manufactured by Toyobo Co., Ltd.), 3 parts of Kyuazol 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.),
An epoxy resin composition consisting of 30 parts of talc and 7 parts of asbestos powder was kneaded using an ordinary mixing roll, and then formed into a sheet with a predetermined thickness using a hot press. Next, a glass fiber cloth (3020A manufactured by Nitto Boseki Co., Ltd.) was fused and integrated on one side of this sheet by heat pressing to obtain a reinforced epoxy resin sheet with a thickness of 1.2 mm.

Separately, ethylene-vinyl acetate copolymer (Evaflex P-2807 manufactured by Mitsui Polychemical Co., Ltd.) 100
1 part, 6 parts of a blowing agent (FE-9 manufactured by Eiwa Kasei Co., Ltd.),
After uniformly kneading with a mixing roll and pelletizing with a pelletizer, a foamable resin sheet (bead forming material) with a thickness of 1 mm was obtained using an extrusion molding machine at an extrusion temperature of 120°C.

Next, add the reinforced epoxy resin sheet to 5 cm.
It was cut into widths, and the foamed resin sheet cut into 1 cm width was pasted on the opposite side from the base material to serve as a reinforcing material. This reinforcing material was pasted on a 0.7mm thick steel plate with the foamed resin sheet on the inside and heated to 150°C.
It was heated in an atmosphere for 60 minutes to strongly adhere to the steel plate surface.

During this heating, the resin component of the reinforced epoxy resin sheet does not separate from the base material and sag, and the foam layer has a predetermined expansion ratio and a bead-shaped bulge is formed by this foam layer. A reinforcing layer consisting of a good fiber-reinforced resin layer was obtained. This reinforcing layer also had a good appearance.

The following strength tests were conducted using the thus reinforced steel plates as test pieces.

<Strength test> A test with a width of 50 mm on a support stand having two vertical flat plates (width 50 mm) whose tips exhibit 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. The piece is supported horizontally, and a vertical flat plate (width
Maximum bending stress (Kg/
50mm width).

The above test results showed that the steel plate was 45Kg/50mm width, and the maximum bending stress of the steel plate alone without any reinforcement measures was 8Kg/50mm width, but an extremely excellent reinforcing effect was obtained. I found out.

Comparative Example A reinforcing material was obtained in the same manner as in Example 1, except that asbestos powder was not blended into the epoxy resin composition. An attempt was made to reinforce a steel plate using this reinforcing material in the same manner as in Example 1, but during heating, the resin content of the reinforcing epoxy resin sheet dripped, resulting in a poor appearance and making it impossible to obtain the desired reinforcing effect. I couldn't do it.

Example 2 Epicor #828 (above) 10 copies, Epicor #1004 (above) 55 copies, Hiker CTBN1300 x 8
An epoxy resin composition consisting of 35 parts of carboxyl group-containing liquid nitrile rubber (manufactured by BF Gutudoritsu), 4 parts of DP hardener (hardening agent manufactured by Maruwa Biochemical Co., Ltd.), 5 parts of dicyandiamide, 30 parts of talc, and 10 parts of asbestos powder. After kneading with a normal mixing roll, the mixture was formed into a sheet with a predetermined thickness using a hot press. Next, glass fiber cloth (WE21D104 manufactured by Nitto Boseki Co., Ltd.) was fused and integrated on one side of this sheet by heat pressing to obtain a reinforced epoxy resin sheet with a thickness of 1.0 mm.

Next, the above-mentioned sheet was cut into a 5 cm width, and the foamed resin sheet obtained in Example 1 cut into a 1 cm width was attached to the surface opposite to the base material to serve as a reinforcing material.
This reinforcing material is pasted on the underside of a 0.7mm thick steel plate placed parallel to the ground, with the foamed resin sheet on the inside, and then heated in an atmosphere of 150℃ for 60 minutes to strengthen the steel plate surface. It was fixed to.

During the above heating, there was no phenomenon in which the resin component of the reinforced epoxy resin sheet dripped from the base material, and a bead-shaped bulge was formed by the foam layer with a predetermined expansion ratio and this foam layer. A reinforcing layer consisting of a fiber-reinforced resin layer with good strength was obtained. This reinforcing layer also had a good appearance. The maximum bending stress of the steel plate reinforced in this way was 42 kg/50 mm width.

Example 3 A reinforcing material was obtained in the same manner as in Example 1, except that 6 parts of finely powdered silica and 1 part of glycerin were used instead of 7 parts of asbestos powder in the epoxy resin composition. When a steel plate was reinforced using this reinforcing material in the same manner as in Example 1, a reinforcing layer similar to that in Example 1 could be formed without dripping of the resin during heating. The maximum bending stress of the steel plate reinforced in this way was 43 kg/50 mm width.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the reinforcing material of the present invention, FIG. 2 is a sectional view showing the reinforcing material in a state in which it is installed before heating, and FIG. 3 is a sectional view showing the state after heating. DESCRIPTION OF SYMBOLS 1... Reinforcement material, 2... Fibrous base material, 3... Reinforced resin sheet, 3a... Mounting surface, 3b... Bead-shaped swelling part, 4... Bead forming material.

Claims (1)

[Scope of Claims] 1. An uncured or semi-cured thermosetting reinforced resin sheet containing a fiber base material and containing a substance to impart a melt viscosity that can prevent drooping during heating and melting. A bead forming material having a width narrower than that of the sheet and forming a bead-shaped bulge on the sheet before the sheet is cured is attached to one side, and a bead of the sheet protrudes wider than the width of the bead forming material. A reinforcing material characterized in that a hem on the side of the forming material forms a mounting surface. 2. The substance for imparting a melt viscosity that can prevent drooping during heating and melting is composed of asbestos powder, and this asbestos powder is added in an amount of 2 to 20 parts by weight per 100 parts by weight of the polymer component in the thermosetting resin composition. The reinforcing material according to claim 1, in which the reinforcing material is blended in parts by weight. 3 The substance for imparting a melt viscosity that can prevent drooping during heating and melting is a mixture of finely powdered silica and glycerin, which is added to 100 parts by weight of the polymer component in the thermosetting resin composition. 4 to 10 parts by weight of finely powdered silica and 0.5 to 3 parts by weight of glycerin
The reinforcing material according to claim 1, in which the reinforcing material is blended in parts by weight. 4. The reinforcing material according to any one of claims 1 to 3, wherein the fiber base material is a glass fiber cloth.