JP2005059391A - Magnetic metal thin sheet laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal thin sheet base material having excellent dimensional stability not causing expansion, interfacial peeling or the like even if subjected to a periodic cycle of high temperature and low temperature, a laminate thereof and a manufacturing method of them. <P>SOLUTION: This metal thin sheet laminate is a laminate comprising a metal thin sheet and a polymer compound and characterized in that the resin layer applied to the surface of the metal thin sheet has a void volume of 0-5%. It is preferable to use a heater for producing radiant heat due to electromagnetic waves having a wavelength easy to absorb the heat of the metal thin sheet, a coating resin or an organic solvent and the resin layer extremely reduced in void is formed without forming a resin film on a coating surface of resin varnish. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a laminate of a metal and a polymer compound and a method for producing the same.

  Conventionally, a plurality of thin magnetic metal material plates have been used. For example, when an amorphous metal ribbon is used as the magnetic metal material, the thickness is about 10 to 50 μm, so a specific adhesive is uniformly applied to the surface of the amorphous metal ribbon. Laminating this is often performed.

  JP-A-58-175654 (Patent Document 1) uniformly applies an adhesive mainly composed of a high heat-resistant polymer compound, evaporates the solvent, and then stacks amorphous metal ribbons to reduce the pressure. It describes a method for producing a laminate, characterized by being pressure-bonded with a roll and heat-bonded.

However, in the prior art, for example, in Patent Document 1, when a polyesterimide resin is applied, the solvent is volatilized in a drying furnace at 300 ° C. for 1 minute, or 50% phenoxy resin and 50% polyesterimide resin. "The solvent was removed by heating at 200 ° C for 1 minute", etc., but when the laminate produced by these methods was processed into a shape and heated in a reflow furnace, the laminate would swell. There has been a problem that peeling occurs at the interface between the metal thin plate and the resin layer.
JP 58-175654 A

 In the present invention, a metal thin plate base material having excellent dimensional stability that does not swell or peel off when exposed to a cyclic cycle of high and low temperatures (hereinafter sometimes referred to as “heat cycle”), A laminate and a method for producing the same are provided.

 The present inventors have found that by setting the bubble ratio in the resin layer to be in the range of 0% to 5%, it is possible to avoid swelling and delamination between layers even under a heat cycle.

  The present invention is a laminate of a metal thin plate and a polymer compound, wherein the bubble ratio in the resin layer applied to the surface of the metal thin plate is 0% to 5% by volume ratio. A laminate is provided.

 By the method of applying a resin layer with few bubbles to the metal thin plate of the present invention, it has become possible to realize a substrate and a laminate having excellent dimensional stability without swelling or peeling even under a heat cycle.

(Metal magnetic material)
The metal magnetic material used in the present invention can be any known metal magnetic material. Specific examples include 3% silicon steel plate, 6.5% silicon steel plate, permalloy, nanocrystalline metal magnetic material, and amorphous metal magnetic material. Furthermore, in the present invention, these materials are usually used as thin plates of several mm or less. In particular, a material that has a low heat generation and is a low-loss material is preferable, and a nanocrystalline metal magnetic material or an amorphous metal material is preferably used.
(Polymer compound)
As the polymer compound used in the present invention, a known so-called resin is used. In particular, when heat treatment at 200 ° C. or higher is required to improve the magnetic properties of the metal magnetic material, it is effective to exhibit excellent performance by combining a heat resistant resin having low thermoplasticity and elastic modulus.

  The heat-resistant resin used in the present invention may be heat-treated at an optimum heat treatment temperature that improves the magnetic properties of the amorphous metal ribbon or the nanocrystalline metal magnetic ribbon, so that the material is less thermally decomposed at the heat treatment temperature. Must be selected. For example, the heat treatment temperature of the amorphous metal ribbon varies depending on the composition of the amorphous metal ribbon and the intended magnetic properties, but the temperature for improving the good magnetic properties is generally in the range of 200 to 700 ° C. More preferably, it is the range of 300 degreeC-600 degreeC.

  Examples of the heat resistant resin used in the present invention include thermoplastic, non-thermoplastic, and thermosetting resins. Among these, it is preferable to use a thermoplastic resin. Further, the glass transition temperature Tg of the resin is preferably 420 ° C. or lower, more preferably, the glass transition temperature Tg is 50 ° C. or higher and 420 ° C. or lower, and more preferably the glass transition temperature Tg is 60 ° C. or higher and 350 ° C. The following are good. More preferably, the glass transition temperature Tg is 100 ° C. or higher and 300 ° C. or lower.

  As the heat resistant resin used in the present invention, as a pretreatment, drying is performed at 120 ° C. for 4 hours, and then the weight loss when kept at 300 ° C. for 2 hours in a nitrogen atmosphere is measured using DTA-TG. Usually, 1% or less, preferably 0.3% or less is used. Specific resins include polyimide resins, silicon-containing resins, ketone resins, polyamide resins, liquid crystal polymers, nitrile resins, thioether resins, polyester resins, arylate resins, sulfone resins, Examples thereof include imide resins and amide imide resins. Of these, it is preferable to use polyimide resins, sulfone resins, and amideimide resins.

  Further, in the present invention, when heat resistance of 200 ° C. or higher is not required, the present invention is not limited to this, but specific examples of the thermoplastic resin used in the present invention include polyethersulfone, polyetherimide, polyether There are ketone, polyethylene terephthalate, nylon, polybutylene terephthalate, polycarbonate, polyphenylene ether, polyphenylene sulfide, polysulfone, polyamide, polyamideimide, polylactic acid, polyethylene, polypropylene, etc. Among them, polyethersulfone, polyetherimide are desirable. Polyetherketone polyethylene, polypropylene, epoxy resin, silicone resin, rubber-based resin (chloroprene rubber, silicone rubber) and the like can be used.

The thickness of the resin layer of the present invention is preferably in the range of 0.1 μm to 1 mm, more preferably 1 μm to 10 μm, and even more preferably 2 μm to 6 μm.
(Production method of resin-coated magnetic metal sheet)
In the case of producing a laminate comprising the magnetic metal thin plate of the present invention, there are a method of laminating and bonding a resin layer to the magnetic metal thin plate, a method of impregnating the magnetic metal thin plate with a resin, and the like.

When applying a resin layer to a magnetic metal thin plate, first a coating device such as a roll coater is used to form a coating film on the thin plate with a varnish in which a resin is dissolved in an organic solvent, and then dried. It can be produced by a method of applying a heat resistant resin to an amorphous metal ribbon. Moreover, although the varnish coating film thickness to coat is preferable about 0.1 micrometer to 1 mm, it is not limited to this.
(Bubble rate)
The bubble rate is expressed by the following equation.
Bubble ratio (%) = (1− (mass of resin layer in which bubbles are mixed) / mass of resin layer in which bubbles are not mixed)) × 100
At this time, the thickness of the resin layer is constant.

  As a method of actually measuring only the mass of the resin, it can be measured by etching and removing the magnetic metal thin plate provided with the resin with an acidic liquid or an alkaline liquid and taking out only the resin layer.

  In the present invention, the bubble ratio is 0% to 5%, more preferably 0% to 0.5%, and even more preferably 0% to 0.1%, so that there is no swelling or peeling in a high temperature environment. It became clear that it was important in obtaining a good laminate. As a method of actually eliminating the bubbles, it can be obtained by appropriately adjusting the viscosity of the resin, selection of the organic solvent, drying speed of the organic solvent, set temperature of the heating device, arrangement, and the like.

  In the present invention, it has been found that the drying method is particularly important. That is, normally, when the solvent is evaporated from the coated resin varnish, if the hot air is blown and dried, the coated resin varnish may be dried from the surface and a resin film may be formed. (The resin varnish here refers to both a mixture of a resin and an organic solvent and a mixture of a precursor of the resin and an organic solvent.) When heated further after the resin film is formed, the solvent turned into a gas is contained inside by the resin film. It is trapped and bubbles remain in the resin layer, which becomes bubbles. Therefore, the present invention has found that the following method is effective as a method for drying a solvent without forming a resin film.

  That is, it is preferable to use a heater that emits radiant heat due to electromagnetic waves with a wavelength that easily absorbs heat, such as a thin metal plate, coating resin, organic solvent, etc. It has been found that a layer can be formed. Although the center wavelength of such a heater varies depending on the absorption wavelength band of the organic solvent to be evaporated, it is preferable to use a heater that emits electromagnetic waves in the infrared wavelength region. In particular, heating with infrared rays having a maximum energy wavelength of about 2 to 4 μm is effective, but not limited thereto. Further, the heater preferably has a planar shape, and can uniformly heat the coating surface, and it is difficult to form a local high temperature portion, so that bubbles due to bumping of the solvent are less likely to occur. It is also preferable to use a mixture of a hot air heater and an infrared heater.

In particular, when a relatively thick coating film having a coating thickness of 40 μm or more and 1 mm or less is dried, such heating and drying of the coating film by electromagnetic waves in the infrared region is preferable because the bubble ratio can be remarkably lowered.
(Coating substrate lamination)
When a magnetic base material having a multilayer structure in which a heat-resistant resin is applied to an amorphous metal ribbon, it can be laminated and integrated by, for example, hot pressing or hot roll. The temperature at the time of pressurization varies depending on the type of heat-resistant resin, but it is generally preferable to laminate and bond in the vicinity of the temperature at which it softens or melts above the glass transition temperature of the cured heat-resistant resin.
(Laminate manufacturing method)
The polymer compound is coated on a metal thin plate, dried, and then laminated with a plurality of metal thin plates to create a state in which a resin exists between the metal thin plates.

  The laminate of the present invention can be obtained by holding and integrating the thin metal plates under pressure while the resin flows. If it is a thermoplastic resin, a pressurized state is preferable while maintaining a fluid state even in the cooling process after heating. When using a thermosetting resin, a pressurized state is preferred until the desired thermal effect is completed. Moreover, when a solvent is contained in a varnish, it is preferable to make it a pressurized state at least while a solvent is removed and the high molecular compound is flowing between metal thin plates.

  Simultaneously with the heating, heat treatment for improving magnetic properties may be performed.

(Example 1)
3,3′-Diaminodiphenyl ether and 3,3,4,4′-biphenyltetracarboxylic dianhydride were subjected to polycondensation at a ratio of 1: 0.98 in a dimethylacetamide solvent at room temperature to obtain a polyamic acid varnish ( Polyamic acid 20%, viscosity 0.3 MPa at 25 ° C.) was obtained. An amorphous metal thin body (Co ₆₆ Fe ₄ Ni ₁ (BSi) ₂₉ (atomic%)) having a width of about 50 mm and a thickness of about 15 μm, this polyamic acid was manufactured by Honeywell, Metglas: 2714A (trade name) with a roll coater, After coating uniformly on one side of an amorphous metal thin body, it is dried and cured at 300 ° C. for 1 minute with a far infrared heater to obtain a laminate of a magnetic thin plate and a heat-resistant resin (polyimide resin) of about 6 microns. As a result of manufacturing under these conditions, the bubble ratio was 0%.

Next, 40 sheets of this base material were stacked, and a laminate having a thickness of 1.0 mm was produced by hot pressing in the atmosphere at 260 ° C. for 30 minutes and 5 MPa. In order to develop the magnetic properties, it was pressurized and heated in a nitrogen atmosphere at 400 ° C. for 1 hr. Furthermore, after heating from room temperature to 400 ° C. in a reflow furnace and returning to room temperature, the laminated body was observed for the presence or absence of swelling, peeling, etc. with an optical microscope.
(Comparative Example 1)

  The drying method is different from Example 1. The resin was hot-air dried at 300 ° C. for 1 minute with a hot air heater, and then the same operation was performed except that it was hot-air dried for 300 ° C. to obtain a laminate of the amorphous metal thin body and the resin. The cell rate of the coated resin layer was 8%.

  Furthermore, after heating from room temperature to 400 ° C. in a reflow furnace and returning to normal temperature, the presence or absence of swelling and peeling of the laminate was observed with an optical microscope.

  Inductance, choke coil, high frequency transformer, low frequency transformer, reactor, pulse transformer, step-up transformer, noise filter, transformer for transformer, magneto-impedance element, magnetostrictive vibrator, magnetic sensor, magnetic head, electromagnetic shield, shield connector, shield package, Materials that support the functions of various electronic devices and electronic components such as radio wave absorbers, motors, generator cores, antenna cores, magnetic disks, magnetic application transport systems, magnets, electromagnetic solenoids, actuator cores, and printed circuit boards. Used as

Claims (1)

A metal thin plate laminate comprising a metal thin plate and a polymer compound, wherein a bubble ratio in a resin layer applied to the surface of the metal thin plate is 0% to 5% by volume.