JPH0212268B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a composite consisting of a metal and a polyamide resin. Polyamide resins such as 6-nylon, 6,6-nylon, and 1,2-nylon are excellent in strength, elastic modulus, and abrasion resistance, and more recently, there are also those reinforced with glass fiber or carbon fiber.
Its strength has improved dramatically and has reached the level of strength of some metals such as aluminum. For this reason, some metal composite products that use aluminum as a part of their components can be replaced with polyamide resin, which is lighter and cheaper than aluminum, and it is currently possible to replace the aluminum part with polyamide resin, which is lighter and cheaper than aluminum. Composite products comprising resin have also been proposed. However, currently known composite products of this type are manufactured by bonding already formed metal parts and resin parts using an epoxy adhesive, and therefore it is difficult to form both the metal and resin parts. It requires a total of three steps: a step of applying adhesive, and a step of joining both parts, and it is difficult to achieve high adhesion dimensional accuracy in the joining process, and furthermore, it is difficult to join the molded parts together. However, there was a major restriction in that both the metal and resin molded bodies had to have a shape that allowed them to be joined. It is obvious that if this geometrical constraint could be overcome, the possibilities of use of this type of composite would be significantly expanded. In order to remove this restriction, it is conceivable to bring a resin in a hot molten state into contact with the surface of the metal molded body coated with an adhesive, and then to cool and solidify the resin in a desired shape. Specifically, this is the application of injection molding and extrusion molding methods, and is intended to reduce the number of steps and improve bonding dimensional accuracy. However, when using conventional epoxy adhesives as adhesives, In practice, this application would not be possible unless new adhesives were developed, since strong adhesion between metal and resin does not occur. The purpose of the present invention is to provide a method for manufacturing a composite consisting of a metal and a polyamide resin, and basically, if possible, this type of composite can be manufactured using an injection molding method or an extrusion molding method. The goal is to develop adhesives that will tighten. This type of adhesive is required to have the following functions. 1. It has strong bonding ability with both metal and polyamide, 2. The adhesive itself has extremely high final strength,
and 3. Since polyamide resin shrinks during its cooling and solidification process, it must be able to cope with this resin shrinkage. As a result of intensive research to develop an adhesive that satisfies these conditions, it has been found that an adhesive containing the following two components as main components is suitable. (A)A-1 A compound having two or more NCO groups in one molecule, A-2 A compound with the formula in the molecule (In the formula, n means an integer of 1 to 3) A-3 A compound having a methylolated phenol in the molecule (In the formula, m means an integer of about 10) Compound (B) An acrylonitrile butadiene copolymer having an α,β-unsaturated carboxylate group in the molecule. Among the A components, typical A-1 components include triene diisocyanate, diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, triphenylmethane diisocyanate, trimethylolpropane-tris(3-isocyanate tolyl carbamate) ), etc. Typical examples of component A-2 include resol type phenol resins and compounds containing phenol resins as part of their molecular chains. Representative examples of component A-3 include novolak type phenolic resins and compounds containing them as part of the molecular chain. α, β- contained in the copolymer that is component B
The unsaturated carboxylate group is a group represented by the following general formula. (In the formula, X represents a halogen atom selected from chlorine, bromine and iodine, R ₁ , R ₂ and R ₃ represent a hydrogen atom or a hydrocarbon residue having 1 to 10 carbon atoms, and n represents 2 to
5, m represents an integer of 1 to 4, l represents an integer of 1 to 30). Of the above components A and B, component A forms a strong bond with both metal and polyamide and contributes to increasing the final strength of the adhesive itself, while component B is a rubber component that follows the shrinkage of the resin. In addition to fulfilling its role, the presence of carboxylate groups improves adhesion to metals, and anaerobic polymerization occurs during the curing process, so it is administered to help strengthen the adhesive layer. Incidentally, since both metal and polyamide have high surface energy, the acrylonitrile butadiene copolymer used as component B preferably has a high polarity, and it is advantageous to use one having a nitrile content of 35 to 50%. The α,β-unsaturated carboxylate group can be introduced into the acrylonitrile butadiene copolymer by the method described in Japanese Patent Publication No. 53-6198. The adhesive used in the method of the present invention is the above A and B.
A curing accelerator for the other A component of both components and/or
It may contain polyhydric alcohols and polyamines that can react with component A. Typical examples of curing accelerators include heavy metal ions, naphthenic acid salts, tin compounds, and the like. The polyhydric alcohol is N,N-(2-hydroxypropyl)-
Examples of polyamines include diols such as aniline, various glycols, triols such as glycerin and trimethylolpropane, and aliphatic polyamines such as diethylenetriamine and triethylenetetramine.
Examples include aromatic polyamines such as 3'-dichloro-4,4'-diamino-diphenylmethane and methylene dianiline. Next, a filler, a curing agent, etc. can be added to the A-2 component. Examples of fillers include wood flour, pulp, cotton waste, mica, and the like. Examples of the curing accelerator include organic acids such as para-toluenesulfonic acid and benzoic acid, lime, and magnesium oxide. Further, the same filler as in the case of the B-2 component can be added to the A-3 component. Furthermore, A-
Since the three components do not cause crosslinking independently, a curing agent is required. The curing agent is usually hexamethylenetetramine in an amount of about 10% by weight of component A-3. The composition ratio of component A and component B is A in terms of solid content weight ratio.
The amount of component B may be in the range of 1 to 500 parts per 100 parts of component, but if component B is less than 5 parts, the shrinkage suppressing effect will be low.
If it exceeds 100 parts, the strength of the adhesive layer may be insufficient, so it is preferable to use 5 to 100 parts of component B. The adhesive is used in the form of a solution in which both components A and B, as well as additional components such as a curing accelerator added as necessary, are dissolved in an appropriate solvent. As a solvent, aliphatic solvents such as pentane and hexane,
Alicyclic solvents such as cyclohexane, aromatic solvents such as toluene and xylene, ether solvents such as dioxane and tetrahydrofuran, ethyl acetate,
Among ester solvents such as methyl acetate, ketone solvents such as acetone and methyl ethyl ketone, and halogen solvents such as methylene chloride and chloroform,
A single solvent or a mixed solvent can be appropriately selected depending on the types of components A and B used. In carrying out the method of the present invention, the bonding surface of the metal member is previously polished, degreased, and dried. Polishing can be performed using sandpaper, a grinder, etc., and degreasing can be performed using the above-mentioned organic solvent. Typical examples of materials constituting the metal member include iron, aluminum, and copper. Methods for applying the adhesive to metal members include dipping, brushing, and spraying, and the adhesive is dried after forming a uniform coating. As component A, A-2, A-
3, further baking is performed after drying. Bake in a heating device such as an oven at 150°C.
Do this for about 30 minutes at a temperature around ℃. Polyamide resins include 6-nylon, 6,6-nylon, 1,
Examples include 2-nylon, 1,1-nylon, and copolymerized nylon, and these resins may contain reinforcing materials such as glass fibers and carbon fibers, and fillers such as calcium carbonate. There are injection molding methods and extrusion molding methods for bringing hot-melt polyamide resin into contact with a metal member coated with an adhesive, and when using the injection molding method, the metal member treated with an adhesive is fixed in a mold, Hot melt resin is injected, and during the subsequent cooling process, molding of the resin part and adhesion of the resin part to the metal member are performed at the same time.
When extrusion molding is used, the extruded resin is brought into contact with the metal member and simultaneously cooled under pressure using a roll or the like to bond the two together. In the blow molding method, a hot melt resin film is expanded under pressure in a mold, brought into contact with a metal member fixed thereto, and bonded together during the subsequent cooling process. The description will now be made in conjunction with the accompanying drawings. FIG. 1 is a schematic cross-sectional view showing part of an apparatus for carrying out the method of the invention. 10 is a mold of an injection molding machine, 12 is an upper mold thereof, 14 is a lower mold thereof, and 121 is a passage formed in the upper mold 12 for injection of hot melt polyamide resin. 16 is a metal molded body fixed in the mold 10, and 18 is a passage 1
This is a polyamide resin injected into the mold 10 through the tube 21. The shape of the composite body manufactured by the molding machine shown in Figure 1 is as shown in Figures 2a and 2b, and the dimensions of each part of the samples manufactured in the manufacturing examples and comparative examples described below are as follows. It was hot on the street. Metal part Resin part is a cylindrical body with a diameter of 25.4 mm and a length of 40 mm.The large diameter part has a diameter of 25.4 mm and a length of 10 mm, and the small diameter part has a diameter of 12 mm and a length of 15 mm. Each end face in the length direction is molded and bonded. Next, the present invention will be explained in more detail with reference to examples and comparative examples in which molding machines and molded samples were manufactured as shown in the accompanying drawings. Examples 1 to 2 and Comparative Examples 1 to 4 (Composites made of steel and 6-nylon) (a) Preparation of steel molded bodies The test molded bodies were made of SS41 and buffed with #100 sandpaper. The poppies were washed with acetone and air-dried. (b) Preparation of adhesive (i) Component A As component A-1, Coronate (trade mark), a polyisocyanate adhesive (Example 1)
and Desmodyur (trademark) (Example 2) are used as the A-2 component, Sumilite Resin (trademark) PR11078, which is a resol type phenolic resin.
(Example 3) and Sumilite Resin (trademark) PR7031A (Example 4), which is a novolac type phenolic resin, were used as the A-3 component. (ii) Component B acrylonitrile butadiene copolymer 50g
After masticating with a roll at a temperature of 50℃, it was dissolved in 450g of methyl ethyl ketone in a separable flask, and 4.3% of methacrylic acid was added while stirring.
(1 mole of methacrylic acid per 1000 g of copolymer) was added dropwise, and further 5.4 g of t-butylhypochloride (equal mole to methacrylic acid) was added and mixed, and stirring was continued for about 1 day. The reaction mixture was added to about 1500 g of methanol to precipitate the reaction product, collected by filtration, the solvent was removed, and this was dissolved again in about 450 g of methyl ethyl ketone to give about
Make a 10% solution and use this as component B. (iii) Mixing of component A and component B The stock solution of component A and the solution of component B are mixed at the composition ratio (solid weight ratio) shown in the table to form an adhesive. (c) Application of adhesive to steel molding A uniform thin film of the above adhesive is formed on the surface of the degreased steel molding by brush coating, and then dried. In some cases, baking was performed at 150°C for 30 minutes while the film was open. (d) Molding of composite The adhesive-treated steel molded body was fixed in a mold in the manner shown in Figure 1, and hot-melted 6-nylon (containing 30% glass fiber) at 240°C was placed in the mold. A composite body having the shape shown in FIGS. 2a and 2b was prepared. (e) Tensile test The obtained composite was set in a tensile testing machine and tested at a tensile speed of 0.5 mm/min in the direction shown by the arrow in Figure 2a. This result shows that commercially available epoxy adhesive (Epoxy Araldite), chlorinated rubber adhesive (Chemrock)
mark), polyurethane adhesive (Coronate-
Tests on composite samples (Comparative Examples 1 to 4) produced in the same manner as in the embodiment described in the previous section, using a polyfunctional polyisocyanate adhesive (Desmodyur Mark) and a polyfunctional polyisocyanate adhesive (Desmodyur Mark), respectively. The results are shown in Table 1 below.

[Table] Examples 3 to 4 and Comparative Examples 5 to 8 Composite samples were produced in the same manner as in Examples 1 and 2 and Comparative Examples 1 to 4 except that 6,6-nylon was used as the polyamide resin, The results of an adhesion test conducted under similar conditions are shown in Table 2 below.

[Table] Examples 5 to 6 and Comparative Examples 9 to 12 Composite samples were produced in the same manner as in Examples 1 and 2 and Comparative Examples 1 to 4, except that 1,2-nylon was used as the polyamide resin, The results of an adhesion test conducted under similar conditions are shown in Table 3 below.

[Table] Examples 7 to 8 and Comparative Examples 13 to 16 Composite samples were produced in the same manner as Examples 1 and 2 and Comparative Examples 1 to 4, except that an aluminum solid cylinder was used as the metal molded body. However, the results of an adhesion test under similar conditions are shown in Table 4 below.
It was as shown.

[Table] Examples 9 to 10 and Comparative Examples 17 to 20 An aluminum solid cylinder was used as a metal molded body,
In addition, composite samples were prepared in the same manner as in Examples 1 and 2 and Comparative Examples 1 to 4, except that 6,6-nylon was used as the polyamide resin, and adhesive strength tests were conducted under the same conditions. The results were as shown in Table 5 below.

[Table] Examples 11-12 and Comparative Examples 21-24 An aluminum solid cylindrical body was used as a metal molded body,
In addition, composite samples were prepared in the same manner as in Examples 1 and 2 and Comparative Examples 1 to 4, except that 1,2-nylon was used as the polyamide resin, and adhesive strength tests were conducted under the same conditions. The results were as shown in Table 6 below.

[Table] Example 13 In order to investigate the effect of the composition ratio of component A and component B on adhesive strength, Coronate (trademark), a polyurethane adhesive, was used as component A, and the composition ratio was varied. Composite samples were prepared in the same manner as in Examples 1 and 2, and adhesive tests were conducted. The results were as shown in Table 7 below.

【table】

[Table] Example 14 The same procedure as in Examples 1 and 2 was carried out except that the α,β-unsaturated carboxylate group introduction treatment was not performed on the acrylonitrile butadiene copolymer, which was the raw material for preparing the adhesive B component. This B component and A
Composite samples were prepared with various composition ratios of the components (using Coronate - trademark) and an adhesion test was conducted. The results are shown in Table 8 below, and these are used as examples. Comparison with the results shown in Table 7 of No. 13 shows that the adhesive force is significantly reduced, that is, the presence of the α,β-unsaturated carboxylate group contributes to the improvement of the adhesive force.

【table】 [Brief explanation of drawings]

In the accompanying drawings, FIG. 1 shows metal-
FIG. 2 is a cross-sectional view illustrating a mold part of an apparatus for producing a polyamide resin composite, FIG. 2 is a side view illustrating an example of a metal-polyamide resin composite manufactured by the method of the present invention, and FIG. FIG. 3 is a front view of the complex shown. 10... Mold, 12... Upper mold, 121... Molten resin injection passage, 14... Lower mold, 16... Metal molded body, 18... Polyamide resin.

Claims (1)

[Claims] 1. A compound having two or more NCO groups in one molecule, or a compound having the formula (In the formula, n means an integer of 1 to 3) A compound having a methylolated phenol,
Or in the molecule (in the formula, m means an integer of about 10);
An adhesive whose main component is component B, which is an acrylonitrile butadiene copolymer having β-unsaturated carboxylate groups in the molecule, is applied to the surface of the metal molded object, and this is brought into contact with the polyamide resin in a hot melt state. , a method for producing a composite consisting of a metal and a polyamide resin, characterized in that the two are bonded together by subsequent cooling. 2 The α,β-unsaturated carboxylate group has the general formula (In the formula, X represents a halogen atom selected from chlorine, bromine and iodine, R ₁ , R ₂ and R ₃ represent a hydrogen atom or a hydrocarbon residue having 1 to 10 carbon atoms, and n represents 2 to
5, m is an integer of 1 to 4, and l is an integer of 1 to 30. manufacturing method. 3. Claim 1 or 2, characterized in that the composition ratio of component A and component B of the adhesive is 5 to 100 parts of component B to 100 parts of component A in terms of solid weight ratio. Preparation of the described complexes. 4. A method for producing a composite according to any one of claims 1 to 3, characterized in that the metal molded body and the hot-melt polyamide resin are brought into contact by injection molding or extrusion molding. .