JPS61252284A - Reinforcing material made of resin - Google Patents

Abstract

PURPOSE:To provide a reinforcing material capable of not only exhibiting both reinforcing and vibration damping effects when used as a reinforcing material for a sheet metal member such as a steel plate, e.g., an outside plate of a door for automobiles but also having an improved storage stability and a workability for mounting, by preparing a laminated sheet using two thermoset ting resin layers which are different in curing rate from each other. CONSTITUTION:A laminated sheet is prepared from a first thermosetting resin layer and a second thermosetting resin layer in which the curing rate of the first thermosetting resin layer is later than that of the second thermosetting resin layer. It is preferred that the second thermosetting resin layer be provided with a fiber base (preferably a glass fiber fabric). The difference in curing rate at the time of heat curing between the first thermosetting resin and the second thermosetting resin can simply be provided, e.g., in such a manner that the same kind of a main curing agent is added to the first and second thermosetting resin layers while the kind or amount of a curing agent and/or a curing accelerator for adjusting the curing rate or degree of cure are appropriately adjusted.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention provides resin reinforcement for sheet metal members such as steel plates, which has excellent reinforcing effects and distribution effects, and has excellent storage stability and installation workability. Regarding materials.

(b) Prior Art Conventionally, various reinforcing measures have been applied to the steel plates of automobile bodies. For example, Roof, 7J, Ngu, 7
- For relatively wide and flat but thin outer panels such as cars, trunks, quarter panels, doors, etc., metal reinforcing members are used to provide appropriate structural rigidity against external forces. A method of attaching it to the inside of the outer panel using spot welding or adhesive is used. However, this method has disadvantages such as the weight of the metal reinforcing material is heavy, which goes against the trend of thinning the outer skin, which was designed to reduce the weight of the car body, and increases weight and cost.Furthermore, the installation process becomes complicated. It had In addition, in the case of metal reinforcing members, rust is likely to occur at spots and the like, and reinforcement with metal reinforcing members does not provide a vibration damping effect, so a reinforcing method using resin is adopted.

Conventionally, the following methods have been proposed as reinforcing methods using resin.

The first method involves coating or pasting a polymer material such as asphalt rubber, butyl rubber, epoxy resin, phenol resin, acrylic resin, or unsaturated polyester resin on the back side of the outer panel.

The second method is to reinforce the outer panel of the vehicle body with a laminate of two resin layers. That is, it is a resin reinforcing material made of a laminate of a first resin layer for enhancing reinforcing properties and a second resin layer having low rigidity for preventing the occurrence of distortion in the steel plate.

(c) Problems to be Solved by the Invention In the first method described above, a material with a high tensile modulus and strong adhesive force is selected as the polymer material, and if this is applied thickly, a considerable reinforcing effect can be obtained. It also has the advantage of being lighter and simpler to construct than methods using metal reinforcing members.

However, on the other hand, most polymeric materials with high tensile modulus or adhesive strength use thermosetting resins, and with these resin materials, residual stress after curing caused by curing shrinkage causes the outer panel to deteriorate. This has the fatal problem of causing distortion (dents) in the car body and impairing the flushness of the car body, which seriously impairs the product value.As a result, only resins with low elastic modulus can be used, so The situation was such that it could not exhibit reinforcing properties.

Although the second method can satisfy the contradictory properties of reinforcing the steel plate and preventing distortion to some extent, it has the following drawbacks.

That is, the resin layer of tlIJ1 needs to have adhesiveness at room temperature from the viewpoint of workability in pasting it onto a steel plate, but in this case, when the first resin layer and the second resin layer are heated, Although resins with the same or almost the same curing speed are used, the low viscosity resin, that is, the first resin layer, has high reactivity, so the reaction progresses even further during storage even at low temperatures around room temperature. Adhesive strength rapidly decreases, and as a result, accidents occur in which the resin reinforcing material cannot be sufficiently adhered to an adherend (such as a steel plate), making it unusable.

This accident is particularly likely to occur in an atmosphere where the temperature is 30° C. or higher, for example in the summer, and there has been a strong demand for improvement.

(d) Means for Solving the Problems In view of the conventional situation, the present inventors have made extensive studies and found that when the second thermosetting resin layer, which has rigidity after heating and hardening, is heated and hardened, If the degree of curing of the first thermosetting resin layer having adhesiveness is 25% or more, the adhesive strength is sufficient for the layer of the first layer to transfer the rigidity of the second layer to the adherend (sheet metal member). As a result, we have completed a resin reinforcing material that is lightweight, inexpensive, and improves the rigidity of sheet metal members such as steel plates, and also has significantly improved storage stability and can be stored without being stored at low temperatures. .

That is, the present invention provides a laminated sheet consisting of a first thermosetting resin layer that is sticky at room temperature and a second thermosetting resin layer, wherein the first thermosetting resin layer is adhesive to the second thermosetting resin layer. 6 The thermosetting resin used in the first and first and second thermosetting resin layers includes glycidyl ether type, glycidyl ether type, glycidyl ether type, glycidyl ether type, Various epoxy resins such as tullester type, glycinolamine 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. resins can also be used.

The heat-activated curing agent to be added to this thermosetting resin may be a normal curing agent that exhibits curing action when heated.
Generally, it is sufficient that it is active in the temperature range of 80 to 200°C. For example, as the main curing agent for epoxy resin, dicyanamide, 4,4'-diaminodiphenylsulfone, phenol, various acids or acid anhydrides, polyamide amines, etc. There are 2-
imiguzole derivatives such as n-hebutadecylimigzole, isophthalic acid nohydrazide, guanizone group, N-
N-dialkyl urea derivatives, N., N-dialkylthiourea derivatives, etc. are used. The amount of each main curing agent used is usually 3 parts by weight per 100 parts by weight of the epoxy resin.
The ratio may be up to 30 parts by weight and 11 parts by weight, and the curing accelerator may be 10 parts by weight or less.

In addition to the above-mentioned components, the thermosetting resin composition obtained in this manner has a cohesive force that can be formed into a sheet, and also has wettability by preventing sagging or lowering the melt viscosity. Various additives may be added as desired to improve the properties.

For example, for the purpose of improving sheet forming ability, thermoplastic resins such as polyvinyl butyral, polyamide, polyamide derivatives, polyester, polysulfone, polyketone, high molecular weight epoxy resins derived from bisphenol A and epichlorohydrin, and butanoene-ac+7
A rubber component such as a zero nitrile copolymer or a derivative thereof can be blended. The amount of these used is 10% of the thermosetting resin.
It is best to use about 5 to 100 parts by weight to 0 parts by weight.
/m.

Furthermore, for the purpose of lowering the dissolution viscosity and improving wettability, reactive diluents such as butyl glycidyl ether and long-chain alcohol monoglycidyl ether, phosphoric acid plasticizers such as dioctyl heptatalate, etc. can be blended. The amount of these components is preferably about 3 to 30 parts by weight based on 100 parts by weight of the thermosetting resin.

In addition, for the purpose of preventing the above composition from sagging, calcium carbonate, talc, bentonite clay, asbestos powder,
Fillers such as various short fibers such as vinylon, silicic acids, carbon black, and colloid resin can be used. At this time, when the resin 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 determined after heating and curing. Care is taken to use it to the extent that the adhesion to the above-mentioned outer panels etc. is not impaired. Among the above-mentioned fillers, various short fibers such as asbestos short fibers are preferably used for the purpose of preventing sagging, and the amount used is preferably determined by the amount of the polymer component (
That is, it is preferably 2 to 30 parts by weight based on 100 parts by weight of the thermosetting resin, optionally used thermoplastic resin, and rubber components.

In particular, it is preferable to provide the second thermosetting resin layer with a fiber base material in order to further improve the rigidity of the resin reinforcing material when it is cured.

Specific examples of this fiber base material include inorganic fiber cloth such as lath fiber and asbestos fiber, hemp, cotton, nylon,
Examples include sheet-like fiber base materials such as organic fiber cloths such as polyester and polypropylene, and nonwoven fabrics made of polyester fibers and polypropylene fibers. Among these, particularly preferred are inorganic fiber cloths, a typical example of which is glass fiber cloth.

In addition, in the present invention, the above-mentioned fiber base material may also be included in the first thermosetting resin layer as necessary.

Next, the method for forming eJ1 and the second thermosetting If M N will be briefly described in detail.

The first thermosetting resin layer is prepared by preparing a thermosetting resin composition having adhesive properties by blending a thermosetting resin with a heat-activated curing agent and adding various additives as desired.
For example, it is formed by forming a sheet in an uncured or semi-cured state using a direct pressure press, etc., and the above-mentioned tackiness can be easily imparted by selecting the properties of the thermosetting resin or adding additives. I can do it.

The second thermosetting U4 resin layer is made of a composition similar to or different from that of the first layer in an uncured or semi-cured state, and is formed into a sheet shape in the same way as the first thermosetting resin layer. be done.

In this case, if the composition is formed into a sheet on the M&fiber base material in an uncured or semi-cured state, a second thermosetting resin layer with further improved rigidity can be obtained. That is, by providing a fiber base material on the outer surface or inside of the m2 layer, the rigidity of the second layer can be further improved.

Also, this second layer does not have to be particularly tacky, but may be tacky if desired.

The thickness of the first and second thermosetting resin IIWN is usually 0.05 to 15 mm, preferably 0.1 to 15 mm.
It is preferable to set it to 10 mm.

In the present 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 and thermally fusing it may be used.

The most significant feature of the resin reinforcing material of the present invention is that the first thermosetting resin layer has a slower curing speed than the second thermosetting resin layer, in other words, the resin reinforcing material is hardened. In this case, the degree of curing of the first thermosetting resin is made smaller than the degree of curing of the second thermosetting resin.

A simple and simple method for creating a difference in the curing speed during heat curing in the first and second thermosetting resin layers is to add a main curing agent to each of the above-mentioned natural curable resin layers. Use the same type of material, and check the curing speed or degree of curing! It may be convenient to adjust the type or amount of the curing agent and/or curing accelerator. For example, the curing speed can be easily adjusted by reducing the amount of curing accelerator added to the PIIJl thermosetting resin layer to half or less than the amount added to the second thermosetting resin layer. can. Also, instead of using the same type of curing agent or curing accelerator, curing agents or curing accelerators with different reaction rates are used to increase the curing speed of layers 1 and 2 above. You may adjust it.

According to the research results of the present inventors, in order to set the above-mentioned curing speed to 11g, the preferable range is that when the above-mentioned resin reinforcement material is cured, the degree of curing of the first thermosetting resin layer is equal to that of the second thermosetting resin layer. It is desirable to adjust the degree of curing to 25 to 90% of the degree of curing of the curable resin layer. When the degree of hardening is less than 25%, the degree of hardening is insufficient to maintain the rigidity of the resin reinforcing material in relation to the second thermosetting resin layer, and a sufficient reinforcing effect cannot be achieved. On the other hand, if the degree of hardening is 90% or more, the reinforcing effect will be sufficient, but the workability and storage stability of attaching it to sheet metal members such as steel plates are seriously poor, and the resin reinforcing material cannot be attached to the sheet metal members. This is because conventional problems such as the occurrence of distortion in the sheet metal member when it is hardened cannot be solved.

The second thermosetting resin layer in the resin reinforcing material has a tensile modulus of elasticity after heat curing that is necessary and sufficient to improve the rigidity of the sheet metal member.
The tensile modulus is generally preferably about 30 to 500 kg/m2.

Note that here, the tensile modulus is ISOReco
T by the method specified in wmendation R527.
It means the value measured at 5 peedB using a ype 1 test piece.

The first thermosetting resin layer in the resin reinforcing material is used to prevent distortion of the sheet metal member during heat curing, and the tensile modulus is generally 0.1 to 1.
It is about 5 kg/mm2. If this modulus of elasticity becomes too small, the reinforcing effect of the sheet metal member will be poor.

The resin reinforcing material of the present invention can be used not only for sheet metal members such as steel plates such as the outer panels of automobile doors as described above, but also for thin metal plates such as the cases of various vehicles, home appliances such as electric refrigerators, and washing machines. It can be widely applied to sheet metal members such as.

(e) Function The resin reinforcing material of the present invention has a first
Since it is composed of a sheet-like laminate consisting of a thermosetting resin layer and a second thermosetting resin layer that has relatively high rigidity after curing, the resin reinforcing material is attached to a sheet metal member and cured. This significantly improves the reinforcing properties of the sheet metal member, and since the first thermosetting resin layer has pressure-sensitive adhesive properties, it can be easily attached to the sheet metal member.

In particular, in the resin reinforcing material of the present invention, the first
Since the thermosetting resin layer is set to have a slower curing speed than the second thermosetting resin layer, the reaction (gelation) progresses slowly during storage, and as a result, the adhesive strength does not decrease during storage. Therefore, it has excellent storage stability.

(r) Examples Hereinafter, structural examples and examples of the present invention will be shown, but the present invention is not limited thereto.

(a) Hereinafter, structural examples of the resin reinforcing material of the present invention will be explained with reference to the drawings.

FIG. 1 shows an example of the resin reinforcing material (1) of the present invention,
The resin reinforcing material (1) consists of a sheet-like first thermosetting resin 1 (2) having adhesive properties and a sheet-like second thermosetting resin layer (3). The second thermosetting resin layers (2) and (3) are laminated to form a sheet, and both are in an uncured or semi-cured state.

In this case, the second thermosetting resin layer (3) includes a second
As shown in the figure, it is preferable to stretch the fiber base material (4) on the surface thereof, thereby further improving the strength of the resin reinforcing material (1) after curing. It is desirable to use plus fiber cloth as it shows excellent strength. In the above example, the fiber base material was coated with the second thermosetting q(
Although the case where the fiber base material is formed on the surface of the fat layer has been described, the present invention is not limited thereto (it goes without saying that the fiber base material may be provided inside the layers a & 2 above).

The first thermosetting resin layer (2) in the resin reinforcing material (1) is set to have a slower curing speed than the second thermosetting resin layer (3). Reinforcement material (
When 1) is heated and cured, the degree of curing of the second layer (3) is approximately 100%, while the degree of curing of the first layer (3) is approximately 100%.
2) is formed by adjusting the degree of hardening to be in the range of 25 to 90%.

That is, the layer of tJ&2 in the resin reinforcing material (1) (
As a result of almost 100% curing of 3), the resin reinforcing material (1) exhibits high rigidity, but in relation to N(3) of @2 above, it has poor reinforcing properties for sheet metal members (not shown). In addition, the above U (the fat reinforcing material (1) does not fall off from the sheet metal member,
Moreover, the #C adhesion strength that does not impair the rigidity (reinforcing properties) of the second layer in the resin reinforcing material (1) is the first N (
It is sufficient if the degree of curing of 2) is 25% or more.

In addition, in the resin reinforcing material (1), a narrow foam sheet (5) is interposed between the first thermosetting resin/1 (2) and the second thermosetting resin layer (3). When the narrow foamable sheet (5) is heated and cured, the sheet-shaped resin reinforcing material is heated and melted to form the first and second thermosetting resins N (2), ( 3) foams several times as much as it softens, and due to this foaming force, the sheet-like second layer (3)
bulges outward to form a rib, and then, in this state, the above-mentioned PtIJl and the second Jtl (2), (3) are hardened. As a result, due to the effect of this rib shape, the reinforcing property is higher than that of a simple sheet-like material.

Note that (6) is a release film that protects the first layer.

(b) Next, an example of manufacturing the resin reinforcing material of the present invention will be described. In addition, in the following, parts mean parts by weight.

Example 1 ■ Creation of the first thermosetting resin layer An epoxy resin composition having the composition shown in Example 1 in Table 1 was heated at a temperature of 120°C in a mixing pot with an internal volume of 51 mm and equipped with a stirrer.
The mixture was kneaded for 2 hours in a mixing pot, and then the curing agent (dicyandiamide) and curing accelerator (2-undecyl imiguzole) in the numbers shown in Table 1 were added, and the mixture was kneaded at 100°C for 10 hours.
A first thermosetting resin composition was obtained by mixing for minutes. After that, using a direct pressure press, the thickness is 0 by a known method.
．． A 6 mm sheet was molded to obtain a $1 thermosetting resin layer in an uncured state that had tackiness at room temperature.

(2) Preparation of second thermosetting resin layer A second thermosetting resin composition having the composition shown in Example 1 in Table 1 was obtained in the same manner as in (2) above.

The obtained resin composition was formed into a sheet with a thickness of 0.91 mm using a direct pressure press in the same manner as described in ① above, and further laminated with glass fiber cloth to form a semi-cured @2 thermosetting resin composition. A resin layer was obtained.

■ Creation of resin reinforcing material Next, the first thermosetting resin layer and the second thermosetting resin layer were laminated to create the reinforcing material (δ(III!f!) of the present invention. .

The characteristic evaluation is shown in Table 2.

Example 2 First and second thermosetting resin compositions having the compositions shown in Example 2 in Table 1 were obtained in the same manner as in Example 1 (1) and (2).

Example 1 The first thermosetting resin composition was formed into a layer with a thickness of 0.13 mm in the same manner as in Example 1, while the second thermosetting resin composition was made to contain plus cloth. Each layer was formed into a layer with a thickness of 0.6+ am using the same method as in 1, and a narrow (width 10 mm) foaming sheet was interposed between the center of the first and second thermosetting 0 (fat layers). A bulging type resin reinforcing material was obtained.The evaluation of its characteristics is shown in Table 2.

Examples 3 to 5 Examples 3 to 5 in Table 1 were prepared in the same manner as in Example 1.
A sheet-shaped resin reinforcing material having the composition shown below was created.

The thickness of the resin reinforcing material in Examples 3 to 5 is 1
, 5 Arguments were made.

Comparative Example 1 A sheet-shaped resin reinforcing material having the composition shown in Comparative Example 1 in Table 1 was prepared in the same manner as in Example 1.

The thickness of this resin reinforcing material is 1.5++++++.

The characteristic evaluation is shown in Table 2.

Comparative Example 2 A bulging resin reinforcing material having the composition shown in Comparative Example 2 in Table 1' was prepared in the same manner as in Example 2.

The thickness of this resin reinforcing material is 1.5 mm.

The characteristic evaluation is shown in Table 2.

<Steel plate strain test method> The resin reinforcing materials of each of the above examples and comparative examples were tested to a thickness of 0.
．． 3 in an atmosphere of 160℃ after pasting on a steel plate surface of 8+am.
It was cured by heating for 0 minutes. It was visually observed whether or not distortion occurred in the steel plate during this heat hardening.

The strength test described below was conducted using the thus obtained laminate of the resin reinforcing material and the steel plate as a test piece.

Strength test method〉 A supporting stand with two vertical flat plates (width 501) 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 m5+ between the tips, and a width of 70 mm. The test piece is supported horizontally, and a radius of curvature of 1
A vertical flat plate with a U-shaped cross section of 0LIIIl (width 50m)
Maximum bending stress (1 (6/7 m) when a load is applied
0 m+s width) was measured.

Initial adhesion> Resin reinforcing material (width 2
5 mm) was attached, and the 90 degree peeling force was measured according to JIS ZO237 to evaluate the initial adhesion of each resin reinforcing material.

Degree of hardening> Adherent 1B11. IIW# [To L, JISK6850
The tensile shear adhesive strength of the first thermosetting I (fat layer) is measured according to Using the adhesion strength when the second thermosetting resin layer is completely cured as a reference (100), compare it with the adhesion strength when cured under predetermined curing conditions. The degree of curing of the curable resin layer was measured.

(g) Effects of the Invention The resin reinforcing material of the present invention consists of a first thermosetting resin layer that is adhesive at room temperature and a second thermosetting resin layer, and the first layer It has excellent workability because it can be attached extremely easily, and when the second layer is heated and hardened, the rigidity of the second layer is significantly high, which significantly improves the reinforcing effect of the sheet metal member. .

In particular, in the resin reinforcing member of the present invention, since the first thermosetting resin layer is set to have a slower curing speed than the second thermosetting resin layer, the reaction of the resin reinforcing member during storage (Delling) progresses slowly, and as a result, it is possible to suppress a decrease in adhesive strength during storage, resulting in outstanding storage stability.

[Brief explanation of the drawing]

tIS1, FIG. 2, and FIG. 3 are cross sections of essential parts showing other embodiments of the present invention, and #S4 is an explanatory diagram showing the relationship between the degree of curing and the curing time. 1...Resin reinforcing material 2...First thermosetting resin layer 3...Second thermosetting resin layer Fig. 1 Fig. 2 Fig. 2 1... Tree tag Crab Shizurujin No. 3 Figure 4 Kikagin Fl'l (Time) Procedure 7 fJjE Concave: (Spontaneous) July 18, 1985 Commissioner of the Patent Office Manabu Shiga Tonoga 1, Indication of Case Patent Application No. 1988-94210 2, Invention Name of Resin Reinforcing Material 3, Relationship with the Case of the Person Who Proceeds the Procedures Patent Applicant 1t Location (Residence) 1-1-2 Shimohozumi, Ibaraki City, Osaka Name (Name) (396) Nitto Electric Industry Co., Ltd. 6 , Details of the amendment (2) "Table 1" on page 20 of the specification fjrJ will be corrected as shown in the attached sheet.

Claims (3)

[Claims] (1) a first thermosetting resin layer that is sticky at room temperature;
In a laminated sheet consisting of a second thermosetting resin layer,
A reinforcing material made of resin, characterized in that the first thermosetting resin layer is set to have a slower curing speed than the second thermosetting resin layer. (2) The resin reinforcing material according to claim 1, wherein the second thermosetting resin layer is provided with a fiber base material. (3) The resin reinforcing material according to claim 2, wherein the fiber base material is a glass fiber cloth.