JPH02281939A - Titanium laminated steel sheet superior in processability and corrosion resistance - Google Patents

Abstract

PURPOSE:To improve the processability and corrosion resistance, by a method wherein a joining resin layer is constituted of an epoxy resin primer layer and a polyamide resin adhesive agent layer which are provided in order from a titanium sheet side. CONSTITUTION:A joining resin layer 3 is constituted of an epoxy resin primer layer 4 and a polyamide resin adhesive agent layer 5 which are provided in order from a titanium sheet 2 side and are 0.2-20mum and 2-200mum thick respectively. The primer layer 4 can be formed by applying a solvent primer onto a metallic sheet with an ordinary method such as roll coating or curtain coating or immersing method or press coating. The adhesive agent layer 5 is formed by applying polyamide resin adhesive agent resin in a form of a powdery state, or a waxlike state containing a solvent or a liquidlike state to either one side or both sides of adhesive surface of the titanium sheet 2 to which a primer is applied or a steel sheet 1 with a dipping method or a bar coating method or an electrostatic coating method. With this construction, processability and corrosion resistance can be improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to steel plates used in large quantities for various building materials, electrical equipment, automobiles, furniture, containers, etc., and more specifically relates to steel plates or stainless steel plates on one side or This invention relates to a titanium laminated steel plate formed by laminating titanium plates on both sides with resin layers interposed therebetween.

[Conventional technology]

Although titanium has extremely excellent corrosion resistance and is coveted as a building material, it is still not widely used due to its high cost. Therefore, various studies have been made on laminating or composite materials with steel plates or stainless steel plates.

Explosion bonding, pressure bonding, fusion bonding, and adhesive methods are known as methods for laminating metal plates, but these methods have advantages and disadvantages in terms of productivity, bonding strength, surface appearance, etc. was there.

For example, the adhesive method has the advantage of being easy to mass produce, has a good product appearance, and has excellent sound insulation and vibration damping properties, but has the major drawback of poor bonding strength.

In particular, titanium has poor wettability and an extremely inert surface, making it significantly inferior in adhesive properties compared to other metal plates.
It is difficult to secure the adhesive strength necessary for applications such as building panels, and there are various problems in putting it into practical use, such as peeling easily at the adhesive interface during press processing or due to deterioration over time. Further, the aging deterioration is also promoted by the material properties specific to titanium. In other words, titanium has almost the same material strength as steel plate, but its elastic modulus is about 2 that of steel plate.
Therefore, when the two are bonded together and press work is performed such as bending so that the titanium side becomes a convex surface, a large springback force remains in the titanium plate. This residual springback force acts as a peeling force at the adhesive interface, promotes peeling over time, and shortens the adhesive life of the laminate.

As described above, the practical application of titanium laminated steel sheets has many unique problems compared to laminated steel sheets made of other metals, and at present, it is still at the stage where it is necessary to satisfy consumer demands in terms of usage performance such as adhesive strength and durability. has not yet been reached.

[Problem to be solved by the invention]

In order to solve the problems of the prior art of titanium laminated steel sheets described above, the present inventors have developed a method of reciprocal combination of surface activation treatment of titanium by etching etc., chemical conversion treatment by chromic acid treatment etc., primer treatment etc. and adhesive. We have conducted various studies on the effect of improving adhesive strength, discovered an adhesive method suitable for titanium, and have come to form the present invention.

[Means to solve the problem]

That is, according to the present invention, in a titanium laminated N steel plate in which a titanium plate is bonded to one or both sides of a steel plate or a stainless steel plate via a bonding resin layer, the thickness of the bonding resin layer is set sequentially from the titanium plate side. A titanium laminated N steel plate with excellent workability and corrosion resistance is provided, which is composed of an epoxy resin primer layer with a thickness of 0.2 to 20 μm and a polyamide resin adhesive layer with a thickness of 2 to 200 μm, and furthermore, a steel plate or a stainless steel plate. A titanium laminated steel plate is provided in which an epoxy resin primer layer having a thickness of 0.2 to 20 μm is also provided between the polyamide adhesive layer and the polyamide adhesive layer.

The present invention will be explained in detail below.

Figures 1 and 2 are cross-sectional views for explaining embodiments of the present invention, in which Figure 1 shows a laminated steel plate in which a titanium plate is bonded to only one side of the steel plate, and Figure 2 shows both sides of the steel plate. This is an example of laminated steel plates laminated together.

In these figures, ■ is a steel base made of a steel plate or stainless steel plate, 2 is a titanium plate, 3 is a bonding resin layer, and 4 is a steel base made of a steel plate or a stainless steel plate.
5 is an epoxy resin primer layer, and 5 is a polyamide adhesive layer.

The titanium plate 2 used in the present invention may be an annealed plate or a cold rolled plate of pure titanium or alloy titanium.

The thicknesses of the steel substrate 1 and the titanium plate 2 are not particularly restricted and may be selected appropriately depending on the application, but from the purpose of the present invention to provide an inexpensive multi-N steel plate with excellent corrosion resistance, titanium It is desirable that the thickness of the plate be at least η or less than that of the steel base.

Note that selecting a steel substrate 1 having a small difference in coefficient of thermal expansion from titanium will help prevent warpage after bonding. preferred above.

Further, it is not preferable to make the titanium plate too thick because it tends to cause peeling force due to springback force after press working such as bending work.

Prior to lamination, the surface of these metal plates is usually cleaned with an organic solvent or alkaline solution, and then a bonding resin layer is formed on the surface. The surface may be previously subjected to chrome plating, nickel plating, various alloy plating, chemical conversion treatment, or surface roughening processing.

Note that when the steel substrate 1 is subjected to such pretreatment, it is not necessarily necessary to provide the epoxy resin primer layer 4 on the steel substrate 1 side.

In the present invention, the thickness of the epoxy resin primer layer 4 formed on the surface of the titanium plate 2 or, if necessary, the steel substrate 1 is generally 0.2 to 20 μm. If the thickness of the epoxy resin primer layer 4 is less than 0.2 μm, the surface convex portions of the steel substrate 1 or the titanium plate 2 will be insufficiently covered, and the desired adhesion improvement effect cannot be achieved.
If it exceeds uN, the effect of improving adhesion will be saturated, and it will also be disadvantageous in terms of cost.

The epoxy resin-based primer layer used in the present invention is formed of a primer made of an epoxy resin and its curing agent, and a solution type primer in which the above components are dissolved in an organic solvent is preferably used as the primer.

The epoxy resin in this primer has a molecular weight of 300 to 600, has excellent adhesion to both titanium plates and polyamide adhesives, and has appropriate cohesion.
0 bisphenol type epoxy resin or novolac type epoxy resin is preferable, and these can be used alone or in combination of two or more types.

As the curing agent, organic amine curing agents commonly used for epoxy resins can be used. General amines, secondary amines, or tertiary amines that are liquid at room temperature are preferred because they can be cured at low temperatures and in a short time. More preferably, diethylenetriamine, tetraethylenepentamine, diethylamine propylamine, N-aminoethylpiperazine, isophorodiamine, menthenediamine, metaxylylenediamine, diaminodiethyldiphenylmethane, benzyldimethylamine, 2, 4.6- Tris(dimethylaminomethyl)phenol, piperidine and N,N-
Examples include dimethylpiperazine.

Furthermore, in order to improve the storage stability of the solution type primer, it is preferable to use an adduct of the amine to the epoxy resin as a curing agent, and such an adduct is heated in an organic solvent at a temperature of 40 to 100" It is obtained by reacting the epoxy resin and the amine for about 3 to 6 hours under reflux.

The preferred mixing ratio of epoxy resin and curing agent in the primer is epoxy resin: curing agent (weight ratio): 95:5
~70:30.

The organic solvent for dissolving the primer is preferably one with a low boiling point that evaporates easily, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, or a mixed solvent thereof. The preferred solid content concentration in the solution type primer is 1 to 50% by weight, more preferably 5 to 50% by weight.
It is 30% by weight.

When the solid content concentration exceeds 50% by weight, the storage stability tends to be poor, and the paintability on metal plates tends to be poor. -・If it is less than 1%, the required film thickness,
In other words, it becomes difficult to form a primer layer of 0.2 to 20μ, ff.

The primer layer can be formed by applying a solution-based primer onto the metal plate by conventional methods such as roll coating, curtain coating, dipping, and spray coating.

In addition, an anticorrosive agent, a penetrant, etc. can be added to the primer solution as necessary.

After applying and drying the primer, a polyamide adhesive layer 5 is formed.

The polyamide adhesive layer used in the present invention can be formed from various polyamides, such as ε-caprolactam, ω-aminoundecanoic acid, or ω-aminoundecanoic acid.
- Polyamides generally called nylon 6, nylon 11 or nylon 12 obtained by condensation polymerization of lauryl lactam etc.; polycondensation of dicarboxylic acid such as adipic acid, sebacic acid or dodecadiic acid with hexamethylene diamine Nylon 6-6, nylon 6-10 obtained by
Alternatively, polyamide called nylon 6-12 may be copolyamide obtained by copolymerizing the above-mentioned lactam, dicarboxylic acid, diamine, etc., such as 6/6-6/10 copolyamide. Furthermore, mixtures of two or more polyamides can also be used, and preferred polyamides are copolyamides having a temperature in the range of 100 to 220''C from the viewpoint of adhesion and workability.

In the present invention, it is preferable to use a polyamide adhesive containing a crosslinkable substance shown below as the polyamide. These adhesives are thermosetting types in which the polyamide crosslinks during heat bonding, so when these adhesives are used, the resulting adhesive layer has good creep strength, heat resistance,
Excellent in water resistance and durability.

Examples of the above-mentioned crosslinkable substances include polyvinylated phenol resins, phenol-formaldehyde prepolymers, organosilicon compounds having hydrolyzable groups such as alkoxy groups, and epoxy resins. It is preferable to use the organosilicon compound or to use the organosilicon compound in combination with other crosslinkable substances.

As the organosilicon compound, tetramethoxysilane,
Tetraethoxysilane, phenyltormexysilane, diphenyldimethoxysilane, dimethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-
Examples include (β-methylglycidoxy)propyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, T-ruaminopropyltriethoxysilane, and T-mercaptopropyltrimethoxysilane.

In the present invention, the thickness of the polyamide adhesive layer 5 is
It is set to 200 μm. If the thickness of the adhesive layer 5 is less than 2 μm, the surface protrusions of the metal plate will be insufficiently covered, and a satisfactory adhesive strength will not be obtained, and the lid vibration damping properties will be poor.
If it exceeds m, the adhesive effect will be saturated and the workability in the manufacturing process will deteriorate, which is not preferable.

The adhesive layer 5 is made by applying the polyamide adhesive resin in the form of powder, wax containing a solvent, liquid, etc. to either or both of the adhesion surfaces of the titanium plate 2 or the steel substrate l coated with a primer. , by coating by a known dipping method, bar code method, electrostatic coating method, or the like. After coating, the titanium plate 2 and the steel substrate 1 are stacked with their adhesive surfaces facing each other after being fused or dried. Heating temperature: approx. 150-280°C; heating time: approx. 0.2-30 minutes; adhesive pressure: approx. 0.1-10k
Perform crimping process using gf/c. When bonding titanium plates 2 to both sides of a steel substrate 1 as exemplified in FIG. 2, the steel substrate 1 and two titanium plates treated by the same method and procedure as described above are stacked with their adhesive surfaces facing each other. It is sufficient to perform a crimping process.

The steel substrate 1 and the titanium plate 2 used in the titanium laminated steel plate according to the present invention can be produced by changing the surface properties, that is, the surface roughness, the pitch of the unevenness, etc., to give a metallic luster or a dull silvery white color, or by anodizing or other methods. It can be adjusted to various appearances, such as various colors.

In addition, since titanium and titanium alloys are harder than aluminum etc., they are less susceptible to scratches during processing and use, and even if they are slightly scratched, the underlying organic resin layer maintains good corrosion resistance. , vibration damping properties, etc. can also be imparted.

Furthermore, since this laminated IW4 board has excellent workability, it can be used not only for processing such as bending and light drawing, which are commonly used for building materials, various equipment, and panel members of vehicles, etc.
It can also be subjected to severe processing such as deep drawing and ironing, which are used for containers and the like.

In addition, titanium plates need only be installed on surfaces that require good corrosion resistance and good appearance, for example, when used as building material panels for coastal resorts, it is only necessary to install titanium plates on the outer surface. Which one to bond to may be appropriately selected depending on the use and purpose of use.

Furthermore, it goes without saying that the type of titanium plate to be used should be selected according to the intended use, such as using cold-rolled reinforced material if wear resistance is required due to dust etc. .

[Examples] Examples of the present invention will be described in detail below, but the scope of the present invention is not limited to the following examples.

An external wall panel made of titanium laminated steel sheets manufactured by the method shown in Table 1 and made into a square shape with a side of 80 cm and a drawing depth of 2 cm by shallow drawing, as a building material for buildings such as those for coastal resorts. was made with the titanium plate facing the outside, and after conducting a 35-day accelerated deterioration test under the conditions shown below, the appearance, such as peeling at the adhesive interface at the drawn end, was observed and evaluated on a 5-point scale. (5 is good, 1 is bad). The accelerated deterioration test consisted of 24 hours per cycle, 6 hours of salt spray (NaCl aqueous solution at 35°C), 4 hours of drying (70°C), 4 hours of wetness (49°C, 95% relative humidity), and then cooling. The treatment was carried out for 4 hours (-20°C), and the transition time was 1 hour before and after salt water spraying, and 2 hours for the other times. In addition, for reference, we separately prepared a T-shaped peel test piece with a width of 25 strips, and measured the T-shaped peel strength before and after the aforementioned accelerated test using the JIS standard.
Measured in accordance with K6854.

The results of these observations and measurements are shown in Table 2.

From these results, it is clear that the titanium laminated steel sheet according to the present invention has no peeling of the adhesive interface at the drawing edge, has excellent corrosion resistance and durability, and has extremely minimal deterioration in appearance over time. It is.

〔Effect of the invention〕

The laminated steel sheet of the present invention has excellent corrosion resistance and workability, has a good appearance, and can be easily mass-produced, so it can be used for a variety of purposes, mainly as building panels, and is of great benefit to related industrial fields.

Remaining days below

[Brief explanation of drawings]

FIG. 1 is a sectional view of a plate illustrating a single-sided titanium laminated steel plate, which is an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a plate illustrating a double-sided titanium laminated N steel plate, which is another embodiment B of the present invention. FIG. ■... Steel base, 2... Titanium plate, 3... Bonding resin layer, 4... Epoxy resin primer layer, 5...
Polyamide adhesive layer. Patent distributor Nippon Steel Corporation Toagosei Chemical Industry Co., Ltd. Patent application agent

Claims (1)

[Claims] 1. In a titanium laminated steel plate in which a titanium plate is bonded to one or both sides of a steel plate or a stainless steel plate via a bonding resin layer, the thickness of the bonding resin layer provided sequentially from the titanium plate side. A titanium laminated steel sheet with excellent workability and corrosion resistance, characterized by comprising an epoxy resin primer layer with a thickness of 0.2 to 20 μm and a polyamide resin adhesive layer with a thickness of 2 to 200 μm. 2. The titanium laminated steel sheet according to claim 1, further comprising an epoxy resin primer layer having a thickness of 0.2 to 20 μm between the steel sheet or stainless steel sheet and the polyamide adhesive layer.