Manufacturing method for laminates of soft magnetic alloy strips

Abstract

To provide a method for manufacturing a laminate of a soft magnetic alloy material using a thermosetting resin, which can suppress bubble traces remaining on an adhesive surface.SOLUTION: A method for manufacturing a laminate of a soft magnetic alloy ribbon according to the present invention includes a first step of applying a thermosetting resin adhesive to a first soft magnetic alloy ribbon, a second step of heating the first soft magnetic alloy ribbon that has undergone the first step, a third step of obtaining a laminate by bonding the second soft magnetic alloy ribbon and the first soft magnetic alloy ribbon that has undergone the second step together in a heated state via the thermosetting resin adhesive, and a fourth step of curing the thermosetting resin adhesive.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for producing a laminate of soft magnetic alloy ribbons. [Background Art]

[0002] Among soft magnetic alloy materials, amorphous alloys are known to exhibit superior properties such as mechanical properties, magnetic properties, and corrosion resistance compared to ordinary crystalline alloys. In particular, Fe-based and Co-based amorphous alloys are known to be capable of forming soft magnetic materials with low coercive force because no grain boundaries are formed therein. Due to the production process, amorphous alloys are manufactured as extremely thin ribbons, and therefore, in the production of products using amorphous alloy ribbons, development of technologies for improving processability and handling properties by laminating amorphous alloy ribbons to form a laminate is progressing.

[0003] Patent Document 1 discloses, as a technology for laminating amorphous alloy ribbons and / or nanocrystalline magnetic alloy ribbons and fixing the interlayer of the laminate, a technology of applying and laminating an epoxy resin and curing the same at 150°C for 1 hour. Further, Patent Document 2 discloses a technology for a laminate obtained by thermocompression bonding of amorphous metal ribbons to each other via a polyamide-imide resin, wherein the thermocompression bonding temperature is 30°C or more and 90°C or less (specifically 300 to 360°C) of the glass transition point of the polyamide-imide resin. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. Hei 7-278763 [Patent Document 2] Japanese Unexamined Patent Publication No. 2009-194724 [Disclosure of the Invention] [Problems to be Solved by the Invention]

[0005] However, in the technologies disclosed in Patent Documents 1 and 2, when manufacturing a laminate of soft magnetic alloy material in which the interlayers of the laminate are fixed using a thermosetting adhesive (hereinafter also referred to as a thermosetting resin), air bubble marks remain on the adhesive surface, resulting in problems such as a decrease in adhesive strength and variations in the thickness of the laminate, which can lead to a decline in quality.

[0006] Therefore, the present invention aims to provide a method for manufacturing a laminate of soft magnetic alloy material using a thermosetting resin that can suppress air bubble marks remaining on the adhesive surface. [Means for solving the problem]

[0007] The present invention comprises a first step of applying a thermosetting resin adhesive to a first soft magnetic alloy thin strip, In order to volatilize the gaseous components contained in the thermosetting resin adhesive applied to the first soft magnetic alloy thin strip without curing the thermosetting resin adhesive, A second step of heating the first soft magnetic alloy thin strip that has undergone the first step, before The first soft magnetic alloy thin strip after undergoing the second step. of Heating state Maintain in, The first soft magnetic alloy thin strip and the second soft magnetic alloy thin strip are, A third step of obtaining a laminate by bonding the materials together via the thermosetting resin adhesive, and a fourth step of curing the thermosetting resin adhesive. 、 to have The second and third steps are carried out in the same heating furnace. This is a method for manufacturing a laminate of soft magnetic alloy strips.

[0008] Furthermore, the present invention includes a first step of applying a thermosetting resin adhesive to a first soft magnetic alloy thin strip, In order to volatilize the gaseous components contained in the thermosetting resin adhesive applied to the first soft magnetic alloy thin strip without curing the thermosetting resin adhesive, A second step of heating the first soft magnetic alloy thin strip that has undergone the first step, before The first soft magnetic alloy thin strip after undergoing the second step. of Heating state Maintain in, Without lowering the temperature , The first soft magnetic alloy thin strip and the second soft magnetic alloy thin strip are, A third step of obtaining a laminate by bonding the materials together via the thermosetting resin adhesive, and a fourth step of curing the thermosetting resin adhesive. 、 This is a method for manufacturing a laminate of soft magnetic alloy thin strips having [a specific characteristic].

[0009] Furthermore, in the third step of the present invention, when the first soft magnetic alloy ribbon and the second soft magnetic alloy ribbon are bonded together ,before it is preferable to apply a pressing force from the bonding direction of the first soft magnetic alloy ribbon and the second soft magnetic alloy ribbon.

[0010] Furthermore, in the second step of the present invention, when the glass transition temperature of the thermosetting resin adhesive is defined as Tg (°C), it is preferable to hold the first soft magnetic alloy ribbon and the second soft magnetic alloy ribbon in a temperature range of not lower than Tg-150 (°C) and lower than Tg+20 (°C) for 1 second or more and 15 seconds or less.

[0011] Furthermore, in the fourth step of the present invention, when the glass transition temperature of the thermosetting resin adhesive is defined as Tg (°C), it is preferable to hold the laminate obtained in the third step in a temperature range of not lower than Tg-10 (°C) and lower than Tg+20 (°C) for 25 seconds or more and 180 seconds or less.

[0012] Furthermore, in the present invention of the soft magnetic alloy ribbon is an amorphous alloy ribbon or a nanocrystalline alloy ribbon It is preferable that it consists only of this. Furthermore, the present invention the thermosetting resin adhesive is No organic solvents are used. preferably an epoxy resin.

Effects of the Invention

[0013] According to the present invention, there can be provided a method for producing a laminate of a soft magnetic alloy material using a thermosetting resin, which is capable of suppressing bubble marks remaining on the adhesive surface.

Brief Description of Drawings

[0014] [Figure 1] It is a schematic diagram of a laminate of soft magnetic alloy ribbons in one embodiment of the present invention. [Figure 2] It is a schematic diagram of the step of bonding (joining) a laminate of soft magnetic alloy ribbons in one embodiment of the present invention. [Figure 3]It is a schematic diagram of a flexographic printing apparatus according to an embodiment of the present invention. [Figure 4] It is a schematic diagram of a laminate manufacturing process when using Roll to Roll according to an embodiment of the present invention. [Figure 5] It is a schematic diagram of a laminate (test piece) of soft magnetic alloy ribbons used in an example according to the present invention. [Figure 6] It is a schematic diagram of a peel strength test jig used in an example according to the present invention. [Figure 7] It is a conceptual diagram of an apparatus for performing the second to fourth steps in a drying furnace with constant temperature control according to an embodiment of the present invention. [Figure 8] It is a graph showing the temperature change of a soft magnetic alloy ribbon in the drying furnace of an apparatus for performing the second to fourth steps in a drying furnace with constant temperature control according to an embodiment of the present invention. [Figure 9] It is a schematic diagram showing the configuration of the temperature sensor 15. Description of Embodiments

[0015] Hereinafter, embodiments of a method for producing a laminate according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. In addition, for clarity of explanation, the following description and drawings are simplified as appropriate.

[0016] An embodiment of the present invention is The present invention relates to a method for manufacturing a laminate of soft magnetic alloy strips, comprising: a first step of applying a thermosetting resin adhesive to a first soft magnetic alloy strip; a second step of heating the first soft magnetic alloy strip after the first step; a third step of bonding a second soft magnetic alloy strip and the first soft magnetic alloy strip after the second step together via the thermosetting resin adhesive while heated to obtain a laminate; and a fourth step of curing the thermosetting resin adhesive. In this embodiment, after applying a thermosetting resin adhesive to a plurality of soft magnetic alloy strips, heating the thermosetting resin adhesive without curing it before bonding the strips together makes it possible to suppress air bubble marks remaining on the bonded surface after bonding.

[0017] (First embodiment) A first embodiment of the method for manufacturing a laminate 11 of soft magnetic alloy strips will be described in detail using Figures 1 to 3. Figure 1 is a schematic cross-sectional view of the laminate 11 of soft magnetic alloy strips, and Figure 2 is a diagram showing the process of bonding (joining) the soft magnetic alloy strips together. This embodiment is a method for manufacturing a laminate of soft magnetic alloy strips, comprising: a first step of applying a thermosetting resin adhesive (hereinafter referred to as thermosetting resin 2) to a first soft magnetic alloy strip 1a; a second step of heating the first soft magnetic alloy strip that has gone through the first step without curing the thermosetting resin adhesive; a third step of bonding the first soft magnetic alloy strip 1a and the second soft magnetic alloy strip 1b that have gone through the second step together via the thermosetting resin 2 while heating them to obtain a laminate; and a fourth step of heat-treating the bonded first and second soft magnetic alloy strips 1a and 1b to cure the thermosetting resin adhesive.

[0018] <First step> First, a thermosetting resin 2 is applied to the first soft magnetic alloy thin strip 1a. [Soft magnetic alloy ribbon] In this embodiment, an amorphous alloy thin strip can be used as the soft magnetic alloy thin strip, such as an Fe-based amorphous alloy thin strip like Metglas' 2605HB1M material. "2605HB1M" is a registered trademark of Hitachi Metals, Ltd. Furthermore, as the soft magnetic alloy strip, a nanocrystalline alloy strip in which nanocrystals have crystallized by heat treatment of an amorphous alloy strip can also be used. For example, it is preferable to use a nanocrystalline alloy strip with a saturation magnetic flux density of 1.6T or higher. The thickness of these soft magnetic alloy strips 1a is not particularly limited, but for example, it is good to have a thickness of 10 to 100 μm, preferably 10 to 30 μm.

[0019] [Thermosetting resin] Thermosetting resins 2 used for bonding (joining) purposes include epoxy resins, polyimide resins, and polyimidoamide resins. Each can be selected according to the environment to which the laminate 11 is exposed and the intended use. Epoxy resins are particularly preferred from the viewpoint of high heat resistance and a relatively high glass transition temperature (Tg). There are also one-component types that use water added to the solvent, and two-component types that require mixing and stirring the liquid agent and hardener in a predetermined ratio before use. For example, one-component epoxy resins are relatively inexpensive and do not use solvents such as organic solvents, making it easier to manage the work environment and safety, and reducing manufacturing costs.

[0020] The viscosity of the thermosetting resin 2 is not particularly limited, but for example, selecting an epoxy resin with a high heat resistance temperature tends to result in a higher viscosity.

[0021] [Method of applying adhesive] Methods for applying a thermosetting resin to the surface of a soft magnetic alloy thin strip 1a include flexographic printing and coater methods. With flexographic printing, it is possible to control the coating film thickness. In this embodiment, the term "high viscosity range" specifically refers to a viscosity of 2.0 Pa·s or higher. Here, if the viscosity of the thermosetting resin 2 is high, for example, it can be applied to the surface of a soft magnetic alloy strip 1a during transport, making it difficult to wet and spread, which is effective when manufacturing laminates of soft magnetic alloy strips using a continuous production method such as a roll-to-roll system.

[0022] Using Figure 3, we will explain coating by flexographic printing using a flexographic printing apparatus. Flexographic printing involves accumulating the liquid agent 3b to be applied to the substrate 3a in the recesses of an anilox roll 3c, which has a textured surface. The liquid agent 3b accumulated in the recesses is then transferred to a transfer roll 3d (rotating in the direction of the arrow in Figure 3), and the liquid agent 3b transferred to the transfer roll 3d is then transferred to the substrate 3a. Furthermore, a jig called a doctor blade 3e is used to scrape off the liquid agent 3b accumulated in the recesses on the outer surface of the anilox roll 3c so that the amount of liquid agent 3b remains constant, thus ensuring a consistent coating thickness.

[0023] In this embodiment, the substrate 3a can be a soft magnetic alloy strip 1a or a soft magnetic alloy strip 1b, and the liquid agent 3b can be a thermosetting resin 2. Furthermore, the anilox roll 3c and the transfer roll 3d may be made of resin, metal, or ceramic.

[0024] The coating thickness when applied to the surface of soft magnetic alloy strips 1a and 1b should be approximately 2 to 10 μm. If the height in the stacking direction is limited, a thinner coating thickness is preferable in order to stack more soft magnetic alloy strips 1a and 1b. For example, 2 to 8 μm is more preferable.

[0025] [Glass transition temperature] The glass transition temperature (Tg) is the temperature at which a glass transition occurs in an amorphous solid. That is, above the glass transition temperature, the material becomes rubbery, and below the glass transition temperature, it becomes glassy. Generally, the glass transition temperature (Tg) varies depending on the type of resin, but for epoxy resins, it is around 150°C to 180°C.

[0026] <Second step> After the first step, the first soft magnetic alloy thin strip 1a is heated. By heating the first soft magnetic alloy thin strip 1a before overlapping it in the third step, it is possible to prevent gases that volatilized when heating the thermosetting resin from remaining in the bonding surface, thus preventing air bubble marks from remaining on the bonding surface. As for the heating conditions, for example, it is desirable to hold the temperature in the range of Tg -150 (°C) or higher and Tg +20 (°C) or lower for 1 second to 15 seconds. Furthermore, it is preferable to heat both the first soft magnetic alloy thin strip 1a and the second soft magnetic alloy thin strip 2a. By heating both the first soft magnetic alloy thin strip 1a and the second soft magnetic alloy thin strip 2a, when bonding the first soft magnetic alloy thin strip 1a and the second soft magnetic alloy thin strip 2a in the third step, bonding can be achieved without the influence of a temperature gradient on the bonding surface.

[0027] [Heating method] Methods for heating the soft magnetic alloy strips 1a and 1b include using induction heating to raise the temperature of the strips themselves, using a gas heater or electric heater to raise the temperature of the atmosphere and then heating the strips in that atmosphere, or placing them on a hot plate for heating.

[0028] <Third step> After the second step, one side of the first soft magnetic alloy strip 1a and one side of the second soft magnetic alloy strip 1b are bonded together. At this point, heating may be applied when bonding one side of the first soft magnetic alloy strip 1a and one side of the second soft magnetic alloy strip 1b, or the heated state from the heating in the second step may be maintained without actively heating. Furthermore, when bonding the soft magnetic alloy strip 1a and the soft magnetic alloy strip 1b, it is preferable to apply pressure to the soft magnetic alloy strip 1a and the soft magnetic alloy strip 1b from a direction perpendicular to the main surface of the strip using a pressure device. The pressure device may be, for example, a roller, which can be applied from an up-and-down direction perpendicular to the plane of the laminate 10 (a direction perpendicular to the main surface of the soft magnetic alloy strip, the bonding direction). The pressing force can be, for example, 1 MPa to 100 MPa, or even 1 MPa to 50 MPa. In this case, when bonding one side of the first soft magnetic alloy thin strip 1a and one side of the second soft magnetic alloy thin strip 1b while heating them, a heated pressurizing device, such as a heated roller, may be used. Furthermore, if the temperatures of the first soft magnetic alloy thin strip 1a and the second soft magnetic alloy thin strip 1b, which were heated in the second step, decrease before they are bonded together in the third step, air bubble marks may remain on the bonding surface. For this reason, it is desirable to prevent temperature drops by performing the second and third steps in the same heating furnace, as shown in Figure 4, for example.

[0029] [Heating method] As a method for heating one side of the soft magnetic alloy strips 1a and 1b, or for example, the rollers of a pressurizing device, induction heating can be used to raise the temperature of the soft magnetic alloy strips or the rollers themselves. Alternatively, a gas heater or electric heater can be used to raise the temperature of the atmosphere, and the soft magnetic alloy strips or rollers can be heated in that atmosphere.

[0030] <Fourth step> After the second step, the first and second soft magnetic alloy strips are subjected to a heat treatment in which they are held at a temperature not exceeding 10°C below the glass transition temperature of the thermosetting resin (Tg -10°C or higher) for 180 seconds or less. [Heating and holding conditions (heat treatment conditions)] The bonded first and second soft magnetic alloy strips are further heated and held to cure the thermosetting resin, thereby bonding them together. The laminate 10, formed by bonding the soft magnetic alloy strips 1a and 1b, is heated within a temperature range suitable for the glass transition temperature (Tg) of the thermosetting resin 2 used as the adhesive (bonding agent), and held for a very short time. As for specific heating temperatures and holding times, (a) when the glass transition temperature is Tg, the temperature range can be 60 seconds to 180 seconds above Tg-10 (°C) and Tg+5 (°C) or below, (b) when the glass transition temperature is Tg, the temperature range can be 40 seconds to 180 seconds above Tg+5 (°C) and Tg+20 (°C) or below, (c) when the glass transition temperature is Tg, (d) When the glass transition temperature is Tg, the time can be 25 seconds or more and 180 seconds or less. (e) When the temperature is 40°C (Tg+40°C) or more higher than the glass transition temperature (Tg), the time can be 15 seconds or more and 180 seconds or less. When the glass transition temperature is Tg, the time can be 15 seconds or more and 180 seconds or less when the temperature is Tg+40°C or higher. As the heating temperature increases, extremely short control times become necessary, and time control becomes complicated. Therefore, it is preferable that the glass transition temperature (Tg) does not exceed 60°C (Tg+60°C), and more preferably 50°C (Tg+50°C) or lower. Furthermore, the term "maintaining" as used here includes not only cases where a constant heating temperature is maintained, but also cases where the temperature changes continuously or stepwise within the target temperature range. By heating and holding the laminate 10 of soft magnetic alloy strips under these heating and holding conditions, a laminate 11 of soft magnetic alloy strips with reduced air bubble marks on the adhesive surface can be manufactured. This is because, when heating and holding is performed under the above conditions, excess gas generated when heating the thermosetting resin volatilizes beforehand.

[0031] [Heating method] As for methods of heating the laminate 10, in addition to using induction heating to raise the temperature of the laminate 10 itself, it is also possible to use a gas heater or electric heater to raise the temperature of the atmosphere and then heat the laminate 10 in that atmosphere, or to place it on a hot plate and heat it.

[0032] In this embodiment of the present invention, the number of soft magnetic alloy strips to be laminated is not limited to two. For example, if a new soft magnetic alloy strip 1c is prepared and the soft magnetic alloy strips 1a, 1b, and 1c are laminated in that order, the thermosetting resin 2 can be applied to one surface of the soft magnetic alloy strip 1a and one surface of the soft magnetic alloy strip 1c, or to one surface of the soft magnetic alloy strip 1a and one surface of the soft magnetic alloy strip 1b, or to both surfaces of the soft magnetic alloy strip 1b. In other words, the soft magnetic alloy strips can be laminated with the thermosetting resin present between each strip. In this case, the soft magnetic alloy strip coated with the thermosetting resin is the first soft magnetic alloy strip, and the soft magnetic alloy strip without the thermosetting resin is the second soft magnetic alloy strip.

[0033] (Second Embodiment) <Manufacturing method for laminates using a continuous production system> A second embodiment of the method for manufacturing a laminate 11 of soft magnetic alloy strips will be described in detail with reference to Figure 4. This embodiment corresponds to the case where a continuous production method such as roll-to-roll is applied. Figure 4 shows the manufacturing process of a laminate 11 when a continuous production method such as roll-to-roll is applied to the lamination of three soft magnetic alloy strips 1a, 1b, and 1c. The arrows in Figure 4 indicate the rotation direction of the coil body and the rotation direction when winding it into a coil.

[0034] As shown in Figure 4, for example, the soft magnetic alloy strips 1a, 1b, and 1c, which are wound around a coil, are unwound (unwounding process in Figure 4), and the thermosetting resin 2 is applied to one side of the soft magnetic alloy strip 1a and one side of the soft magnetic alloy strip 1b using a flexographic printing apparatus 3 (first process; coating process in Figure 4). At this point, the soft magnetic alloy strips 1a and 1b, to which the thermosetting resin 2 has been applied, become the first soft magnetic alloy strip, and the soft magnetic alloy strip 1c becomes the second soft magnetic alloy strip. Next, the soft magnetic alloy strips 1a, 1b, and 1c are bonded together while being heated in a heating device 5a (second step; preheating step in Figure 4). Then, a pressurizing device 4a (for example, a roller heated to a predetermined temperature by the heating device 5b) is pressed against the strips from an up-and-down direction perpendicular to the direction of advancement (a direction perpendicular to the main surface of the soft magnetic alloy strip, the bonding direction), that is, from an up-and-down direction perpendicular to the winding direction, to obtain a laminate 10 (third step; bonding step in Figure 4). The laminate 10 is then heat-treated in a heating device 5c having a region heated to a predetermined temperature (fourth step; heating and holding (heat treatment) step in Figure 4), and the laminate 11 obtained after heat treatment is wound into a coil (winding step in Figure 4), thereby enabling production.

[0035] Here, the laminate of soft magnetic alloy strips obtained by the process of winding it into a coil using a roll-to-roll (winding process in Figure 4) has a certain peel strength or holding force. Furthermore, by performing additional heating in a constant temperature bath or the like after winding (additional heating process after winding of the laminate), the hardening of the adhesive is accelerated, and it is expected that the effect of supplementing insufficient heating and strengthening the adhesive strength can be increased. In addition, by shortening the heating process of the roll-to-roll and allowing complete hardening over time with additional heating after winding, it is possible to simplify the heating equipment, reduce costs, and speed up the process. The heating conditions are preferably 40°C to 130°C for 1 hour or more.

[0036] Furthermore, in this embodiment, it is preferable to carry out the second to fourth steps in a drying oven with controlled temperature. By carrying out multiple steps in a drying oven with controlled temperature, the soft magnetic alloy strip can be processed without being exposed to the outside air, and the process can be carried out without the adhesive being affected by the outside temperature. Here, the drying oven is not limited to one; multiple drying ovens can be connected in a series as long as controlled temperature can be maintained.

[0037] Figure 7 shows a conceptual diagram of an apparatus in which the second to fourth steps are carried out in a drying oven with constant temperature control. This apparatus, for example, consists of four drying ovens 9a, 9b, 9c, and 9d arranged in a row, and is used to bond three soft magnetic alloy strips 1a, 1b, and 1c together. The arrows in Figure 7 indicate the rotation direction of the coil body and the rotation direction when winding it into a coil.

[0038] Similar to Figure 4, for example, the soft magnetic alloy strips 1a, 1b, and 1c, which are wound on a coil, are unwound (unwounding process in Figure 4), and the thermosetting resin 2 is applied to one side of the soft magnetic alloy strip 1a and one side of the soft magnetic alloy strip 1b using a flexographic printing apparatus 3 (first process; coating process in Figure 4). At this point, the soft magnetic alloy strips 1a and 1b, to which the thermosetting resin 2 has been applied, become the first soft magnetic alloy strip, and the soft magnetic alloy strip 1c becomes the second soft magnetic alloy strip. Next, the soft magnetic alloy strips 1a, 1b, and 1c are heated as they advance into the drying oven 9a (second step; preheating step in Figure 4). A laminate 11 is obtained by pressing the roller 4b, heated in the drying oven 9a, against the strips from the vertical direction perpendicular to the direction of advancement (the direction perpendicular to the main surface of the soft magnetic alloy strip, the bonding direction), that is, from the vertical direction perpendicular to the unwinding and winding direction (third step; bonding step in Figure 4). After that, the laminate 11 is heat-treated in the drying ovens 9a, 9b, 9c, and 9d, which have regions heated to a predetermined temperature (fourth step; heating and holding (heat treatment) step in Figure 4). The laminate 11 obtained after heat treatment is then wound into a coil (winding step in Figure 4).

[0039] (Laminate for evaluating peel strength) Figure 5 shows a schematic diagram of the laminate 12 (laminated material for evaluating peel strength) used in the peel strength test. As shown in Figure 5, the laminate 12 is a laminate formed by bonding a portion of one side of the soft magnetic alloy strip 1a to a portion of one side of the soft magnetic alloy strip 1b. In other words, one end of the laminate in the longitudinal direction is not bonded (not adhered).

[0040] (Method for measuring peel strength) The peel strength of the laminate 12 is the force required to separate the laminated soft magnetic alloy strips 1a and 1b, i.e., the peel strength or holding force. One method for measuring peel strength is the 90° or 180° peel test (JIS Z 023:2009). As a specific example of the 180° peel test method, the peel strength can be measured using a peel strength measuring device 6 as shown in Figure 6. First, the other side of the soft magnetic alloy strip constituting the laminate 12 (the side not coated with thermosetting resin), for example, the other side of the soft magnetic alloy strip 1a, is fixed to the metal base 6d with double-sided tape 6e. Next, the unbonded end of the laminate 12 is grasped with a clip 6a, and the grip 4a is pulled with a force gauge 6b fixed via a linear guide 6c. By measuring the load at that time, the peel strength of the laminate 12 can be measured.

[0041] As described above, the manufacturing method for laminated soft magnetic alloy strips according to this embodiment makes it possible to remove air bubbles that form on the adhesive surface due to gases volatilized from the thermosetting resin used as an adhesive during heat curing, resulting in a manufacturing method that is excellent in processability and handling, and highly productive. In particular, by using a continuous production method such as roll-to-roll, laminated soft magnetic alloy strips can be manufactured with even higher productivity. Furthermore, since the heat treatment time of the laminate 10 can be shortened, it becomes possible to manufacture with energy savings, and a reduction in the heating zone (furnace length) can also be expected. [Examples]

[0042] The following describes in detail an example based on the second embodiment. First, a long laminate was fabricated using a roll-to-roll apparatus based on the manufacturing method of the second embodiment. Then, it was cut into 150 mm lengths to produce an evaluation laminate, which was designated as Example 1. For the soft magnetic alloy strip, we used Metglas' Fe-based amorphous alloy strip HB1M, with an average thickness of 25 μm and a width of 30 mm. For the adhesive, we used Somar's E-530, a one-component epoxy resin (viscosity 2.26 Pa·s / 25℃, glass transition temperature (Tg): 180℃). For the flexographic printing system, we used the Esiproof from RK PrintCoat Instruments.

[0043] First, a coating roll from a flexographic printing device, incorporated into a roll-to-roll machine, was pressed vertically against the unwound amorphous alloy strip, transferring epoxy resin onto one flat surface of the amorphous alloy strip in a width of 30 mm (first step). Next, an amorphous alloy strip coated with epoxy resin is passed over a metal plate heated to 170°C, which is incorporated into a roll-to-roll device, and heated for approximately 1 second (second step). After this, another amorphous alloy strip is placed on top. At this time, the side of the amorphous alloy strip (the side opposite to the side coated with thermosetting resin) is pressed from above and below by a pressurizing device 4a (metal roller) incorporated into the roll-to-roll device to bond them together (third step). The laminate obtained by bonding was heated and held in a drying oven at 180°C for 60 seconds (fourth step) and then wound up. A length of 150 mm was cut from the wound-up long laminate, and then one of the bonded amorphous alloy strips was peeled off approximately 30 mm in the longitudinal direction from the end of the laminate to produce a laminate (Example 1). Furthermore, a laminate prepared without heating before bonding and under the same conditions as Example 1 was used as a comparative example. To evaluate the peel strength of the laminate, the peel strength measuring device shown in Figure 5 was used to peel off one of the thin strips of the laminate, and the maximum load was evaluated as the peel strength (gf / mm).

[0044] (Experimental results) Ten sets each of Example 1 and the Comparative Example were prepared, and their peel strength was measured. The average peel strength when no heating was performed before bonding was 5.6 gf / mm, while the average peel strength when heating was performed before bonding was 7.0 gf / mm, confirming an increase of approximately 20% in peel strength.

[0045] Table 1 shows the thickness measurement results for the evaluation laminate (Example 1). For comparison, the thickness measurement results for a comparative example prepared without heating before bonding are also shown. Nine sets of laminates for peel strength evaluation were prepared under each condition, and their thicknesses were measured. As shown in Table 1, the thickness variation 3σ was 62.2 mm when no heating was performed before bonding, while the thickness variation 3σ was 5.5 mm when heating was performed before bonding, confirming a dramatic improvement in the thickness of the evaluation laminate.

[0046] The factors contributing to these experimental results regarding peel strength and thickness are thought to be that heating before bonding caused gases generated from the epoxy resin to volatilize, reducing the amount of air bubbles remaining on the bonding surface, increasing the bonding area, and improving the bonding strength, as well as suppressing variations in the thickness of the adhesive within the bonding surface.

[0047] [Table 1]

[0048] Next, a long laminate was fabricated using the manufacturing method described in the second embodiment, in which the second to fourth steps are carried out in a drying oven with constant temperature control. An evaluation laminate was then cut from the fabricated long laminate to form Example 2.

[0049] First, we will describe the apparatus used in the fabrication of Example 2, which carried out the second to fourth steps in a drying oven with constant temperature control. Here, as a drying oven with constant temperature control, we prepared a drying oven consisting of four drying ovens (hereinafter referred to as units), arranged in a continuous line from Unit 1 to Unit 4. The units used were drying ovens of model K248M930 manufactured by Himeji Rika Co., Ltd., and each unit measured approximately 1250 mm in length, 600 mm in height, and 1000 mm in width. The heating method of the units was a hot air drying method using heaters and blowers, and the hot air circulated within the oven, allowing the oven temperature (furnace temperature) to be controlled up to a maximum of 280°C. Furthermore, Unit 1 was equipped with rollers 4 that pressed and bonded the soft magnetic alloy thin strips that were transported into the drying oven from above and below. The roller 4b used in this device was a rubber roller made of a cylindrical SUS304 seamless tube with a diameter of 76.3 mm, a length of 300 mm, and a thickness of 7.0 mm, lined with silicone rubber.

[0050] Figure 8 shows the temperature change of a soft magnetic alloy strip when it is transported at a speed of 3 m / min using this device. This data was obtained by transporting a soft magnetic alloy strip with a thermocouple 7 attached as a temperature sensor 15 inside the device.

[0051] The configuration of the temperature sensor 15 will be explained using Figure 9. A 70 mm wide Metglas Fe-based amorphous alloy thin strip HB1M was prepared as the soft magnetic alloy thin strip. As shown in Figure 9, a thermocouple 7 was sandwiched between two 100 mm long amorphous alloy thin strips 16a and 16b, and the amorphous alloy thin strips 16a and 16d were fixed with Kapton tape 8. Here, the thermocouple used was model TH-8162-20 manufactured by Three High Co., Ltd.

[0052] Looking at the temperature changes in Figure 8, we can see that the temperature starts to rise from about 30°C at the furnace inlet, then rises to about 130°C and up to a maximum of 183°C after passing the area where the rollers are installed, and then drops back down to 130°C before being discharged from the furnace outlet.

[0053] Using this apparatus, two soft magnetic alloy strips were laminated and bonded together to produce an evaluation laminate. A 70mm wide Fe-based amorphous alloy strip (HB1M material) manufactured by Metglas was used as the soft magnetic alloy strip, and epoxy resin (Somar E-530) was prepared as the thermosetting resin adhesive. Before the amorphous alloy strip was transported into the apparatus, the coating roll of a flexographic printing device was pressed perpendicularly against the unwound amorphous alloy strip to transfer and coat the epoxy resin onto one surface of the amorphous alloy strip in a width of 30mm (first step).

[0054] Subsequently, the amorphous alloy strip coated with epoxy resin and another amorphous alloy strip that had been unwound were transported together into the apparatus. As shown in the temperature change in Figure 7, they were heat-treated from 30°C to 130°C for 15 seconds (second step), and then the two amorphous alloy strips were bonded together by pressing them from above and below with rubber rollers (third step). The bonded amorphous alloy strips were then heat-treated from 130°C to a maximum of 183°C for 80 seconds as shown in Figure 7 (fourth step), and were transported out of the furnace as a long laminate and wound up. A length of 150 mm was cut from the wound long laminate, and then one of the bonded amorphous alloy strips was peeled off about 30 mm in the longitudinal direction from the end of the laminate to obtain Example 2.

[0055] In Example 2, the peel strength (gf / mm) was measured using the peel strength measuring device shown in Figure 5, just as in Example 1. The peel strength was 7.1 gf / mm, which was a result similar to that of Example 1. [Explanation of symbols]

[0056] 1a: Soft magnetic alloy ribbon 1b: Soft magnetic alloy ribbon 1c: Soft magnetic alloy ribbon 2:Thermosetting resin 3: Flexographic printing machine 3a: Printing material 3b: Liquid (thermosetting resin) 3c: Anilox Roll 3D: Transfer Roll 3e: Doctor Blade 4a: Pressurizing device 4b: Roller 5a, 5b, 5c: heating device 6: Peel strength measuring device 6a: Clip 6b: Force Gauge 6c: Linear guide 6d: Metal base 6e: Double-sided tape 7: Thermocouple 8: Kapton tape 9a: Drying oven (Unit 1) 9b: Drying oven (Unit 2) 9c: Drying oven (Unit 3) 9d: Drying oven (Unit 4) 10: Laminate 11: Laminate 12: Laminate 13: Feed roller 14: Guide roller 15: Temperature sensor 16a: Amorphous alloy thin strip 16b: Amorphous alloy thin strip

Claims

1. A first step involves applying a thermosetting resin adhesive to a first soft magnetic alloy thin strip, A second step involves heating the first soft magnetic alloy thin strip after the first step in order to volatilize the gaseous components contained in the thermosetting resin adhesive applied to the first soft magnetic alloy thin strip without curing the thermosetting resin adhesive, A third step is to maintain the heated state of the first soft magnetic alloy strip that has undergone the second step, and to bond the first soft magnetic alloy strip and the second soft magnetic alloy strip together via the thermosetting resin adhesive to obtain a laminate, A fourth step of curing the thermosetting resin adhesive, It has, The second to the third steps are carried out in the same heating furnace. A method for manufacturing a laminate of soft magnetic alloy strips.

2. A first step involves applying a thermosetting resin adhesive to a first soft magnetic alloy thin strip, A second step involves heating the first soft magnetic alloy thin strip after the first step in order to volatilize the gaseous components contained in the thermosetting resin adhesive applied to the first soft magnetic alloy thin strip without curing the thermosetting resin adhesive, A third step is to maintain the heated state of the first soft magnetic alloy thin strip that has undergone the second step, without lowering the temperature, and to bond the first soft magnetic alloy thin strip and the second soft magnetic alloy thin strip together via the thermosetting resin adhesive to obtain a laminate, A fourth step of curing the thermosetting resin adhesive, A method for manufacturing a laminate of soft magnetic alloy strips having the properties of a soft magnetic alloy.

3. In the third step described above, When bonding the first soft magnetic alloy thin strip and the second soft magnetic alloy thin strip, a pressing force is applied from the direction in which the first soft magnetic alloy thin strip and the second soft magnetic alloy thin strip are bonded together. A method for manufacturing a laminate of soft magnetic alloy strips according to claim 1 or claim 2, characterized by the above.

4. In the second step described above, When the glass transition temperature of the thermosetting resin adhesive is Tg (°C), the first soft magnetic alloy thin strip and the second soft magnetic alloy thin strip are held in a temperature range of Tg - 150 (°C) or higher and Tg + 20 (°C) or lower for 1 second or more and 15 seconds or less. A method for manufacturing a laminate of soft magnetic alloy strips according to claim 1 or claim 2, characterized by the above.

5. In the fourth step described above, When the glass transition temperature of the thermosetting resin adhesive is Tg (°C), the laminate obtained in the third step is held in a temperature range of Tg - 50 (°C) or higher and Tg + 20 (°C) or lower for 25 seconds or more and 180 seconds or less. A method for manufacturing a laminate of soft magnetic alloy strips according to claim 1 or claim 2, characterized by the above.

6. The soft magnetic alloy thin strip consists solely of amorphous alloy thin strips or nanocrystalline alloy thin strips. A method for manufacturing a laminate of soft magnetic alloy strips according to claim 1 or claim 2, characterized by the above.

7. The aforementioned thermosetting resin adhesive is an epoxy resin that does not use organic solvents. A method for manufacturing a laminate of soft magnetic alloy strips according to claim 1 or claim 2, characterized by the above.

Images