JPH02258336A - Manufacture of composite steel plate - Google Patents

Abstract

PURPOSE:To control the generation of resin blister and obtain stabilized plate thickness by heating a resin layer with far infrared rays before placing the resin layer between two steel plates, heating and fixing by pressure. CONSTITUTION:In the manufacturing method of a composite steel plate including the process of clamping a resin layer between two steel plates, heating and fixing by pressure, the resin layer is heat dried preliminarily by means of far infrared rays before placing the resin layer between the steel plates. The water content in the resin is removed quickly with extremely good efficiency and blister is controlled irrespective of environmental temperature, humidity, kind of resin or the like by said process. The uneven distribution of plate thickness of a product, therefore, is prevented and a composite steel plate of stabilized product thickness can be manufactured.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for manufacturing a composite steel plate in which a resin layer is sandwiched and crimped between two steel plates, and in particular to a method for manufacturing a composite steel plate in which a resin layer is sandwiched between two steel plates. By suppressing this, the thickness of the product plate is stabilized.

[Conventional technology]

Composite steel plates, in which a resin layer is sandwiched between two steel plates, are beginning to be widely used as vibration-damping steel plates in automobile parts, civil engineering construction parts, electrical product parts, etc., and various proposals have been made regarding their manufacturing methods. .

For example, in Japanese Patent Application Laid-open No. 60-71250, a metal band is heated in advance with a heating roll to a temperature higher than the melting point of the resin film, and the resin film is sandwiched between the two heated metal bands, and the resin film is melted by passing it through a heated pressure bonding roll. A method of manufacturing a composite steel sheet has been proposed in which heating efficiency is improved and peel strength is improved by cooling with a cooling device after crimping.

[Problem to be solved by the invention]

However, in the conventional manufacturing method described above, although a stable adhesive strength of the composite steel plate can be obtained, there is a problem that the thickness of the product plate is not constant and becomes unstable. As a result of repeated research to find out the cause, the present inventors have found that the swelling of the resin due to the moisture in the resin has an adverse effect.

In other words, in the conventional method, the water originally contained in the resin film has no place to escape after the resin film is sandwiched between the metal bands, and most of it remains in the resin. When heated, it vaporizes and expands, causing the resin to swell. For example, a resin film having a thickness of 40 .mu.m may reach a thickness of 70 .mu.m, resulting in a problem that the thickness of the product plate varies.

On the other hand, in Japanese Patent Application Laid-open No. 63-93486, 1
When rolling and joining a set of rolled materials by gradually approaching them and entering between the rolling rolls, dry gas heated to a temperature of 100°C or more is blown onto the surfaces to be joined to remove dirt and moisture from the surfaces to be joined. A method for manufacturing a multilayer material has been proposed in which a set of rolled materials is joined together by removing the material, raising the temperature to a predetermined temperature, and applying rolling force.

When this method of preheating a rolled material using gas is applied to a composite steel plate in which a resin film is bonded between two steel plates, for example, the resin film before entering between the rolling rolls,
If a heating drying gas of 100° C. or more is sprayed, there is a risk that the resin film will soften and melt before entering the rolling roll.

Furthermore, the moisture content in the resin varies depending on the type of resin used in the composite steel sheet, the environmental humidity and temperature during resin coating, and so the temperature and spray amount of the drying gas must be adjusted each time. The work is complicated, the cost of drying equipment is expensive, and the drying efficiency is not sufficiently high.

The present invention has been made by focusing on these conventional problems, and by completely removing the moisture in the resin in advance using far infrared rays, which is the most efficient means of heating and drying the moisture in the resin, The purpose is to solve the unique problem of resin blistering in composite steel plates and to provide a method for manufacturing composite copper plates with a stable product thickness.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a method for manufacturing a composite steel plate that includes a step of sandwiching a resin layer between two steel plates and heat-pressing them, in which the resin layer is heated by far infrared rays before the heat-pressing step. Heat and dry using.

The present invention will be explained in detail below.

When a resin layer is sandwiched between two steel plates and heated above the melting and softening temperature of the resin and pressed together, the moisture in the resin is heated to a temperature above its boiling point. Blistering of the resin occurs due to the vaporization of this heated moisture. Therefore, in order to prevent this resin from blistering, it is necessary to remove moisture from the resin. However, it is very difficult to remove the moisture sealed in the resin sandwiched between the steel plates. Therefore, it is recommended to heat and remove the moisture in the resin before the resin is sandwiched between the steel plates. Effective.

As the resin preheating and drying means of the present invention, far infrared rays, which are the most efficient for moisture removal, are used to heat and dry the resin before sending it to the compression process.

The steel plate of the present invention includes a cold rolled steel plate, a chromate treated steel plate,
It may be a zinc-treated steel plate, a phosphate-treated steel plate, a stainless steel plate, etc., or it may be a coiled original plate or a cut piece.

The thickness of the plate is 0.2 to 1.2 in terms of formability.
s is preferred.

The synthetic resin (also simply referred to as resin) used in the present invention is a thermoplastic resin such as polyethylene, polypropylene, thermoplastic polyester, or polyvinyl chloride. Alternatively, it is a thermosetting resin such as epoxy, polyurethane, acrylic, or thermosetting polyester.

These resins can be used alone or by mixing a thermoplastic resin and a thermosetting resin to form a mixed resin that provides stable hardness over a wider temperature range than when using each resin alone. When using a mixed resin, use the above thermoplastic resin as a base and adjust the mixing ratio of the thermosetting resin to it to achieve the optimal vibration damping characteristics depending on the operating environment temperature, such as room temperature, medium temperature, or high temperature. It is also possible to give

These resins are used as they are or in a state dissolved in a solvent such as toluene, xylene, acetone, thinner, methylene chloride, or the like. Then, it is possible to form a resin layer by coating at least one of the opposing surfaces of two steel plates, or to form a resin film and supply it so as to be sandwiched between the two steel plates.

To form a resin layer of a predetermined thickness on the surface of a steel plate, for example, if the resin is mixed with a solvent, it is applied using a roll coater or by spraying.

To form a resin film, if the resin is solvent-based,
After coating a release sheet with a resin dissolved in a solvent, the solvent is blown off to form a film. If the resin is a non-solvent type, the resin is heated and melted and extruded using a T-die to form a film.

Heat the resin layer coated on one side of the steel plate by any of the above methods, the resin film placed on the steel plate, or a single resin film through a far-infrared oven to evaporate the moisture in the resin and dry it. .

The dry heating means of the present invention is limited to far infrared rays.

This is because water in the resin can be removed more efficiently and quickly than using hot air.

The dried resin layer is sandwiched between two steel plates and pressed together using a heated pressure roll, a hot press, or the like.

The compression temperature is usually 150 to 250, which is higher than the water vaporization temperature.
"C, but since the water in the resin has been removed,
No resin blisters occur. After heat and pressure bonding, natural cooling or forced cooling is performed.

Note that the resin of the present invention may contain metal filler. In other words, it may be a resin in which approximately spherical particles of a highly conductive metal such as iron, copper, nickel, stainless steel, zinc, or aluminum having a particle size of approximately 50 to 1100 mm are mixed, and such metal particles may be mixed into the resin layer. To do this, fisi particles are dispersed in a resin in advance (or they are later sprayed and adhered to a resin surface formed on a steel plate surface).

Composite steel sheets using resin containing metal fillers can be spot welded, and in that case, if the moisture in the resin is removed in advance using the manufacturing method of the present invention, the resin will not blister, which will improve the spot weldability of the product. It becomes extremely good.

[Effect]

When heat-pressing a steel plate with a resin layer in between, the moisture in the resin layer evaporates and expands, causing the resin to swell.

However, if the resin layer is heated and dried with far infrared rays before sandwiching it between steel plates, the moisture in the resin will be removed extremely efficiently and quickly regardless of the environmental temperature, humidity, type of resin, etc. The flow is suppressed.

In this way, variations in product sheet thickness due to resin blistering, which have been overlooked in the past, are eliminated, and a composite steel sheet with a stable product thickness can be manufactured.

〔Example〕

Examples of the present invention will be shown below, but the present invention is not limited thereto.

Examples 1 to 5 and Comparative Examples 1 to 4 Four kinds of synthetic resins were used: thermosetting polyester resin, polyethylene resin, polyvinyl chloride resin, and epoxy resin.

The steel plate used was a cold-rolled steel plate with a thickness of 0.45 mm.

As the heating furnace, a far-infrared furnace was used in the case of the example, and a hot air furnace was used in the case of the comparative example.

A resin was coated in advance on one side of one steel plate using a roll coater to a predetermined resin film thickness, and the plate was placed in a heating furnace, and the resin on the coated surface was heated and dried at a predetermined temperature for a predetermined period of time. Thereafter, the increase in the thickness of the resin film at 180°C (resin swelling amount) and the amount of residual moisture in the resin were measured and compared.

Thereafter, the other steel plate was laminated on the resin-coated surface of the above resin-coated steel plate and bonded using a hot press to form a composite steel plate, and the change in the product plate thickness was evaluated.

The results are shown in Table 1.

Table 1 In all of the above examples, residual moisture in the resin was extremely small, resin blistering was slight, and the thickness of the product plate after pressure bonding was stable.

On the other hand, in the case of Comparative Example 1, even though the heating temperature was the same as in Example 1 for 2 hours, residual moisture remained.

The resin bulge has become larger. Further, in Comparative Example 2, although the heating time was tripled, the residual moisture did not decrease, and the decrease in blistering was slight. Comparative Example 3 had residual moisture despite being heated at the same heating temperature as Example 2 for 1 hour.

There was a lot of resin blistering. A similar phenomenon was observed regardless of the type of resin.

In addition, although the above-mentioned example described the case where cut plates were cut, the present invention is not limited to this, and a coil-shaped steel plate is used, and a film-shaped resin is continuously applied between two strip-shaped steel plates. Alternatively, it can be applied to a continuous manufacturing line that manufactures composite steel sheets while sandwiching coated resin layers.

〔Effect of the invention〕

As explained above, according to the present invention, before the step of sandwiching the resin layer between two steel plates and heat-pressing the resin layer, the resin layer is heated using far infrared rays to efficiently and quickly dry the resin layer. .

As a result, the blistering of the resin, which was previously large, is suppressed and the temperature of the environment during manufacturing is reduced.

There is an effect that a composite steel plate having a stable plate thickness can be provided without being affected by humidity and the type of resin.

Claims (1)

[Claims] (1) In a method for manufacturing a composite steel plate that includes a step of sandwiching a resin layer between two steel plates and heat-pressing them, the resin layer may be heated and dried using far infrared rays before the heat-pressing step. Characteristic manufacturing method of composite steel plate.