JP2003309009A - Magnetic core and adhesive resin composition for magnetic core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic core whose shape is maintained after an annealing heat treatment without handling a fragile thin band, having good core loss characteristics and to provide an adhesive resin composition for a magnetic core, which is useful for efficiently manufacturing such a magnetic core without using organic solvent and is stable thermally and temporally. <P>SOLUTION: A laminated edge face of a thin band is coated and adhered with a composition containing a resin with specific characteristics, and the rate of a thin band surface part coated with the composition is made not more than a fixed value. Thereby, a magnetic core can be obtained, whose shape is maintained after an annealing heat treatment without handling the fragile thin band, having good core loss characteristics. The adhesive resin composition containing particles of resin with specific characteristics is a useful composition for manufacturing such a fine magnetic core efficiently without using organic solvent, and furthermore, it is stable thermally and temporally. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic core made of an amorphous alloy ribbon and an adhesive resin composition for the magnetic core. More specifically, the laminated end face is coated and adhered with a resin-containing composition. And a magnetic core and an adhesive resin composition for the magnetic core.

2. Description of the Related Art Amorphous alloys are amorphous solids produced by rapidly cooling from a molten state using iron, boron, silicon, etc. as raw materials, and usually have a thickness of about 0.01-
It can be obtained as a ribbon of about 0.1 mm. Amorphous alloy has a random structure with no regular arrangement of atoms, and has excellent characteristics as a soft magnetic material, such as high magnetic permeability, small coercive force, and a wide frequency range corresponding to a wide range of frequencies. is doing. Also, energy loss (hysteresis loss) when the magnetic flux passes.
Since the thickness of the ribbon is smaller than that of the silicon steel strip, the core loss (sum of hysteresis loss and eddy current loss) can be reduced. For this reason, magnetic cores manufactured by laminating amorphous alloy ribbons are used in many electric and electronic devices as transformers, etc. by utilizing their excellent characteristics. It also contributes greatly to weight reduction. Further, from the viewpoint of energy saving, a transformer using an amorphous iron core, which is one of the magnetic cores, has been attracting much attention in recent years. A magnetic core using an amorphous alloy is generally manufactured as follows. First, a precursor of a magnetic core having a predetermined shape is prepared by a method of winding or superposing an amorphous alloy ribbon. Next, a predetermined annealing heat treatment is performed to develop a specific magnetic property. The conditions of the annealing heat treatment vary depending on the magnetic properties to be expressed, but in an inert atmosphere, the temperature is about 330 to 440 ° C., the time is 0.1 to
It is common to carry out at a high temperature for a long time of 100 hours. By the way, since the amorphous alloy ribbon becomes an extremely fragile ribbon by the annealing heat treatment, it is an important subject in the manufacturing process to maintain the shape of the magnetic core subjected to the annealing heat treatment and prevent the damage. If the amorphous alloy ribbon forming the magnetic core is subjected to excessive stress when the shape of the magnetic core that has been subjected to the annealing heat treatment is maintained, hysteresis loss, which is one of the core losses, increases and affects the performance of the magnetic core. However, it is known that the influence may become large especially in a low frequency region.
Therefore, in maintaining the shape of the magnetic core, it is necessary to fully consider this. As a method of fixing a thin strip weakened by annealing heat treatment without applying excessive stress, a thermosetting resin such as epoxy resin is coated and impregnated on the laminated end surface of the magnetic core subjected to annealing heat treatment, and the temperature is kept at about 150 ° C. A method of re-heat-treating for time and heat-curing is generally known. By this method, the fragile ribbon can be integrated, and the shape retention as a magnetic core can be provided. However, since the curable resin is used at the time of cooling after the annealing heat treatment, there is a problem that the mechanical loss is applied to the magnetic core due to the shrinkage of the resin accompanying the curing, and the core loss increases. In addition, since the ribbon after annealing heat treatment is extremely fragile, it is very careful to handle it such as taking it out from the annealing furnace, coating and impregnating the thermosetting resin such as epoxy resin, and transferring it to the heating curing furnace. Careful operation is essential,
In some cases, specific equipment may be required. In particular, a large magnetic core having a relatively large weight, such as an amorphous iron core used in a transformer, generally has a heavy weight of about 100 kilograms, which makes it difficult to handle as a heavy object. There is always the risk of partial damage due to its own weight. Furthermore, in order to heat-harden the thermosetting resin that has been applied and impregnated, it is necessary to perform annealing heat treatment and then heat treatment again. This operation not only complicates the manufacturing process, but also requires the installation of a dedicated furnace. Further, since it is difficult to increase the viscosity of the resin, it is impossible to apply the resin with the application surface vertical, for example, and the working method is limited. On the other hand, there has been disclosed a method of simultaneously curing a resin and annealing heat treatment using a varnish containing an organic substance as a main component which is resistant to an annealing temperature such as a polyimide resin (Japanese Patent Laid-Open No. 62-126615). According to this method, since the shape of the magnetic core is retained by the resin after annealing, it is possible to solve operational problems such as handling a brittle amorphous alloy ribbon after annealing. Further, the varnish can be hardened simultaneously with the annealing, and the mechanical strain applied to the magnetic core when the varnish hardens is relatively small. Therefore, the increase in core loss can be suppressed to a low level as compared with the case where the thermosetting resin having a large shrinkage property such as the above-mentioned epoxy resin is annealed and then cooled and bonded. However, since a liquid varnish in which a heat-resistant resin is dissolved is used as an adhesive, the amorphous alloy ribbon is impregnated with unnecessary stress due to the strain caused by the contraction during curing, which penetrates the layers of the amorphous alloy ribbon, and the core loss characteristics are Still not enough. Regarding this problem,
It was recognized even when this method was disclosed, and as a countermeasure against this, a method of tightening with an iron plate etc. is also disclosed, but it not only requires extra equipment and work, but its effect is not sufficient and core loss Has not been reduced to a practical level. On the other hand, a method of reducing stress load by using a varnish of siloxane-modified polyimide resin having a small elastic modulus has been disclosed (JP-A-2-251439). However, although the core loss is improved by reducing the elastic modulus, it is still insufficient, and the heat resistance of the siloxane-modified polyimide is low, so that the annealing temperature of the magnetic core is set to 330 to 4
After a long time at a high temperature of about 40 ° C. for 0.1 to 100 hours, a part of it decomposes, and there is a problem in maintaining the shape of a large magnetic core such as an amorphous iron core. In addition, in the method using these polyimide resin varnishes, organic solvents such as N, N-dimethylacetamide, N-methylpyrrolidone, dimethylimidazolidinone, and dimethylsulfoxide are generally used as a solvent for the varnish. While these have excellent solubility, they are also compounds that are feared to adversely affect the human body. Therefore, when manufacturing a magnetic core using varnish,
It is necessary to give sufficient consideration to handling and diffusion into the atmosphere and capital investment. Furthermore, the properties of varnish are prone to deterioration over time and require storage and equipment such as refrigeration and freezing. Further, since the viscosity of the varnish decreases remarkably as the temperature rises, when applied to a vertical surface, for example, there is a problem that the varnish sags before curing. It is required for the efficiency of the operation that the state of the coated surface does not matter. Although there is a method of gradually raising the temperature to prevent sagging, there is a problem that the heat treatment time is increased and the production efficiency is reduced. As described above, the magnetic core manufactured by the method of simultaneously performing the annealing and the curing of the resin using the heat-resistant resin that withstands the annealing conditions, because the shape of the magnetic core is retained by the resin after the annealing in the manufacturing,
There is no operational problem such as handling a fragile amorphous alloy ribbon after annealing, and it is possible to make a magnetic core with low core loss because it can be bonded with resin at the same time as annealing. . However, only a varnish in which a resin is dissolved in an organic solvent has been disclosed as a form of an adhesive for achieving this. When a varnish is used, unnecessary stress is applied because the resin permeates between the laminations of the amorphous alloy ribbons, and not only is the core loss characteristic practically inadequate, but also due to the work associated with the use of an organic solvent. There are many problems such as environmental problems, thermal and temporal stability problems of the varnish itself, and work problems such as sagging.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, an object of the present invention is to maintain the shape after annealing heat treatment without handling a brittle ribbon and to provide an excellent core. To provide a magnetic core having loss characteristics, and further useful for efficiently producing such a magnetic core without using an organic solvent, which itself is thermally and temporally stable. An object is to provide an adhesive resin composition for a magnetic core.

As a result of intensive studies to solve the above problems, the present inventors have found that a magnetic core produced by laminating amorphous alloy ribbons has a resin having specific characteristics. The laminated end face of the ribbon is coated and adhered by the composition containing, and the ratio of the ribbon surface portion covered by the composition is set to a certain value or less,
It was found that after annealing heat treatment without handling a fragile ribbon, the magnetic core has a shape-retaining state and has excellent core loss characteristics, and further contains resin particles having specific characteristics. It has been found that the adhesive resin composition is a composition useful for efficiently producing such an excellent magnetic core without using an organic solvent and is thermally and temporally stable. The present invention has been completed. That is, the present invention provides the following [1] to [11].
It is specified by the items described in. [1] In a magnetic core manufactured by laminating amorphous alloy ribbons, a part or all of the laminated end faces of the amorphous alloy ribbons are coated and adhered with a composition containing a resin, and the resin is under a nitrogen atmosphere 365. The tensile strength at 30 ° C. after passing through the heat history at 2 ° C. for 2 hours is 30 MPa or more, and the weight loss rate due to the thermal decomposition after passing through the heat history at 365 ° C. for 2 hours in a nitrogen atmosphere is 2% by weight or less. A magnetic core, which is a resin having certain characteristics, wherein the ratio of the area covered by the composition on the surface of the amorphous alloy ribbon is 10% or less. [2] The resin is one or more thermoplastic resins selected from a polyimide resin, a polyetherimide resin, a polyamideimide resin, a polyamide resin, a polysulfone resin, and a polyetherketone resin [ 1] The magnetic core as described above. [3] The magnetic core according to [1], wherein the resin is one or more thermoplastic resins selected from resins having the repeating units represented by the chemical formulas (1) to (10) in the main chain skeleton.

[Chemical 3] (However, in the chemical formula (1), a and b are a + b =
1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, and X and Y are bonding groups selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond, It may be the same or different. Further, in the chemical formula (2), Z is a bonding group selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond. Further, in the chemical formula (6), c and d are c + d
= 1 and 0 ≦ c ≦ 1 and 0 ≦ d ≦ 1. ). [4] An adhesive resin composition for a magnetic core, which contains resin particles, and the resin has the following two characteristics. 3 after a thermal history of 2 hours at 365 ° C under a nitrogen atmosphere
The tensile strength at 0 ° C. is 30 MPa or more, and the weight loss rate due to thermal decomposition is 2% by weight or less when subjected to thermal history at 365 ° C. for 2 hours in a nitrogen atmosphere. It is a thermoplastic resin and has a melt viscosity of 2 at 365 ° C.
It is 0 to 50,000 Pa · sec. [5] The adhesive resin composition for a magnetic core according to [4], which contains a liquid that does not dissolve the resin. [6] The adhesive resin composition for a magnetic core according to [5], wherein the liquid is one kind or two or more kinds selected from water, methanol and ethanol. [7] The resin is one or more thermoplastic resins selected from a polyimide resin, a polyetherimide resin, a polyamideimide resin, a polyamide resin, a polysulfone resin, and a polyetherketone resin. An adhesive resin composition for a magnetic core according to items [4] to [6]. [8] The resin is one or more thermoplastic resins selected from resins having a repeating unit represented by the chemical formulas (1) to (10) in the main chain skeleton.
[6] Adhesive resin composition for magnetic core according to

[Chemical 4] (However, in the chemical formula (1), a and b are a + b =
1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, and X and Y are bonding groups selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond, It may be the same or different. Further, in the chemical formula (2), Z is a bonding group selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond. Further, in the chemical formula (6), c and d are c + d
= 1 and 0 ≦ c ≦ 1 and 0 ≦ d ≦ 1. ). [9] A magnetic core manufactured using the adhesive resin composition according to [4] to [8]. [10] The magnetic core according to [1] to [3], which is manufactured using the adhesive resin composition according to [4] to [8]. [11] The adhesive resin composition according to any one of claims [4] to [8] is applied to the magnetic core before the annealing heat treatment, and then the predetermined annealing heat treatment is performed to develop specific magnetic properties. A method for producing a magnetic core, wherein the coating adhesion by the adhesive resin composition and the annealing heat treatment are performed in the same step.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises an invention relating to a magnetic core and an invention relating to an adhesive resin composition for a magnetic core. As a method for producing the magnetic core of the former invention, the adhesiveness for the magnetic core of the latter invention is used. A method using a resin composition can be applied. The magnetic core of the present invention is a magnetic core manufactured by laminating amorphous alloy ribbons, and part or all of the laminated end faces of the amorphous alloy ribbons are coated and adhered with a composition containing a resin having specific properties. The resin has a tensile strength of 30 MPa or more at 30 ° C. after being subjected to a thermal history of 365 ° C. for 2 hours in a nitrogen atmosphere, and due to thermal decomposition when subjected to a thermal history of 365 ° C. for 2 hours in a nitrogen atmosphere. A magnetic core which is a resin having a characteristic that a weight reduction rate is 2% by weight or less, and an area ratio of a portion of a surface of an amorphous alloy ribbon coated with a composition containing the resin is 10% or less. Is.
As the amorphous alloy ribbon used in the magnetic core of the present invention, a soft magnetic material is targeted. For example, Fe-based or Co-based amorphous metal materials, Fe-based or Co-based nanocrystalline metal materials, and the like can be mentioned. Specifically, for example, Fe-Si-B is used as the Fe-based amorphous metal material.
System, Fe-B system, Fe-PC system, and other Fe-metalloid amorphous metal materials, Fe-Zr system, Fe-Hf system, Fe
Fe-transition metal-based amorphous metal materials such as —Ti system can be cited, and Co-based amorphous metal materials include Co—Si—B system and Co—B system amorphous metals. Materials can be mentioned. Further, in a nanocrystalline metal material obtained by crystallizing an amorphous metal material into a nanosize by heat treatment, Fe-Si-B-Cu-Nb system, Fe-B
-Cu-Nb system, Fe-Zr-B- (Cu) system, Fe-
Zr-Nb-B- (Cu) system, Fe-Zr-P- (C
u) system, Fe-Zr-Nb-P- (Cu) system, Fe-T
a-C type, Fe-Al-Si-Nb-B type, Fe-Al
-Si-Ni-Nb-B system, Fe-Al-Nb-B system,
A Co-Ta-C type | system | group etc. can be mentioned. All of these are annealed and heat-treated under predetermined conditions before being usually used in order to develop specific magnetic properties. The conditions of the annealing heat treatment differ depending on the type of material used and the magnetic characteristics to be exhibited, but the temperature range is generally 300 to 500 ° C. for the amorphous metal material and 400 to 700 ° C. for the nanocrystalline metal material. Is common. The thickness of the amorphous alloy ribbon used in the magnetic core of the present invention is preferably 10 to 100 μm,
More preferably, it is 10-40 microns. The method for laminating the amorphous alloy ribbons is not limited in the present invention, and a method suitable for the shape of the magnetic core to be produced can be used, and any known method can be applied. Generally, a method of winding tape-shaped amorphous alloy ribbons, a method of stacking amorphous alloy ribbons processed into a predetermined size, and the like are used. In the magnetic core of the present invention, a part or all of the laminated end faces of the amorphous alloy ribbon are coated and adhered with a composition containing a resin having specific properties. The laminated end surface of the amorphous alloy ribbon in the present invention is a surface formed by laminating the thickness surfaces of the amorphous alloy ribbon, and is, for example, the surface shown in FIG. The coating adhesion is performed on a part or all of the laminated end faces, but the ratio is not limited as long as the effect of the present invention of the shape retention of the magnetic core can be exhibited. In general, an amorphous iron core or the like having a large size and a large weight of the magnetic core itself tends to preferably have a high proportion of a portion to be adhered by coating from the viewpoint of shape retention. Further, in consideration of avoiding damage to the amorphous alloy ribbon due to impact from the outside, it is preferable that the entire laminated end face is covered and adhered. Further, in the present invention, the outer surface other than the laminated end surface may be coated and adhered. However, since coating adhesion may cause unnecessary stress to the amorphous alloy ribbon at the same time and lead to reduction of core loss characteristics, coating adhesion is excessively performed on either the laminated end face or the other outer surface. It is not desirable to be there. If the coating and adhesion are more than necessary, the effect of the present invention may not be obtained. The magnetic core of the present invention is coated and adhered with a composition containing a resin having specific properties. In the composition, a resin having specific properties plays an important role in achieving the effect of the present invention, but as long as the effect of the present invention is not impaired, it is contained in a composition other than the resin. The component is not particularly limited, and may include, for example, an inorganic filler or another resin. Further, it may be composed only of the resin relating to the present invention. The proportion of the resin in the composition is not particularly limited, but is preferably 20% by weight or more, more preferably 50% by weight or more. The resin used in the magnetic core of the present invention has a tensile strength of 30 MPa or more at 30 ° C. after undergoing a thermal history of 365 ° C. for 2 hours in a nitrogen atmosphere, and a thermal history of 365 ° C. for 2 hours in a nitrogen atmosphere. It is a resin having a characteristic that the weight reduction rate due to thermal decomposition is 2% by weight or less. If the tensile strength at 30 ° C. after applying a heat history at 365 ° C. for 2 hours in a nitrogen atmosphere is less than 30 MPa, not only the shape retention becomes insufficient, but also the stress increases and the core loss may increase. There is. Further, when the weight reduction rate when kept at 365 ° C. for 2 hours in a nitrogen atmosphere exceeds 2% by weight, not only the shape retention property is reduced, but also volatile components and carbonaceous substances generated by decomposition are annealed. Problems can occur that contaminate the furnace in which the heat treatment is performed. It should be noted that 2 at 365 ℃ under nitrogen atmosphere
The upper limit of the tensile strength at 30 ° C. after the heat history of time is not particularly limited, but if the tensile strength is too high, the load on the magnetic core increases and the effect of the present invention is sufficiently obtained. There is a possibility that it will disappear, so 300
The pressure is preferably MPa or less, more preferably 250 MPa or less. In the present invention, the tensile strength at 30 ° C. after passing through a thermal history of 365 ° C. for 2 hours under a nitrogen atmosphere in the present invention is measured according to Japanese Industrial Standard JIS-K7127.
According to. First, a film having a predetermined thickness is prepared by using a usual method such as hot pressing or casting. Specifically, when a film is formed by hot pressing, resin particles or pellets are preliminarily heated to 100 to 200 ° C.
Dry in an inert gas stream such as nitrogen for about 10 hours,
After that, the glass transition temperature of the resin is 10 to 150 ° C.,
It is preferably prepared by hot pressing at a temperature as high as about 30 to 100 ° C. In addition, it is necessary to select the temperature and time for performing the hot pressing under the condition that the heat does not substantially affect the resin characteristics. When the film is formed by the casting method, the resin is dissolved in an organic solvent in which the resin is uniformly dissolved at a concentration of 1 to 50% by weight, preferably 5 to 30% by weight, and a bar coater or a spin coater is used. The solution is cast to a thickness of about 10 to 2000 microns on a flat glass substrate or the like. The thickness varies depending on the thickness of the film to be formed, the type of resin, the type of solvent, the amount of resin in the solution, etc., and is also affected by the boiling point of the solvent, etc., so that a film of uniform and desired thickness can be produced. It is necessary to select the size. The cast film is dried together with the substrate in a drying oven under conditions where the organic solvent can be sufficiently removed. In addition, in order to prevent foaming, it is preferable that the boiling point of the organic solvent is about 1 to 30 ° C./min, and that the organic solvent is kept at a temperature near the boiling point for several hours, and then dried under the condition that the organic solvent can be sufficiently removed. In addition, it is necessary to select the drying temperature and time such that the heat does not substantially affect the resin characteristics. Films produced by any of the usual methods do not affect the measurement in the present invention, but the hot pressing method is preferably used in the present invention. If the organic solvent remains in the film to be used for measurement, it may affect the measurement results. Therefore, the organic solvent does not substantially remain, that is, the residual amount is 0.01% by weight with respect to the resin. It is preferably less than. The tensile strength in the present invention is measured according to Japanese Industrial Standard JIS-K7.
Although it conforms to 127, the film thickness is not specified in this standard, and the target is 1 mm or less. In the present invention, the thickness of the film to be measured is 10
It is preferably in the range of 0 to 300 microns, but is not limited to this range. The film thus prepared is previously subjected to heat history at 365 ° C. for 2 hours in a nitrogen atmosphere. Up to 365 ° C., the temperature is raised from room temperature at a rate of 10 ° C./min. After subjecting it to a heat history, it is processed into a test piece shape that conforms to the standards by punching, etc. and used for measurement. A No. 3 type test piece is adopted in the measurement of the present invention. In the present invention, the measurement of the weight reduction rate due to thermal decomposition when subjected to a thermal history of 365 ° C. for 2 hours under a nitrogen atmosphere is carried out by a usual thermogravimetric method (TG method). The resin sample is dried in a nitrogen stream at 200 ° C. for 2 hours before measurement. After setting the resin sample in the thermogravimetry device, the temperature was raised at a rate of 10 ° C / min in a nitrogen atmosphere, and when the temperature reached 365 ° C, the temperature was raised to 2
Keep on time. The rate of weight loss due to thermal decomposition is the ratio of the weight reduced during the period of 2 hours at 365 ° C. to the weight of the sample when it reached 365 ° C. As the resin used in the magnetic core of the present invention, a polyimide resin, a polyetherimide resin, a polyamideimide resin, a polyamide resin, a polysulfone resin, or a polyetherketone resin can be preferably used. One kind selected from these may be used, or two or more kinds may be used in combination. More specifically, as the resin used in the magnetic core of the present invention, a thermoplastic resin having a repeating unit represented by the chemical formulas (1) to (10) in the main chain skeleton can be preferably used. One kind selected from these may be used, or two or more kinds may be used in combination. However, in the chemical formula (1), a and b are a + b = 1, 0 ≦ a ≦
1, a number satisfying 0 ≦ b ≦ 1, and X and Y are bonding groups selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond, which may be the same or different. good. Further, in the chemical formula (2), Z is a bonding group selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond. Further, in the chemical formula (6), c and d are c + d = 1, 0 ≦ c
It is a number that satisfies ≦ 1 and 0 ≦ d ≦ 1.

[Chemical 5] The method for producing the resin used in the magnetic core of the present invention is not particularly limited, and any known method can be used. The type and amount of impurities contained in the resin are not particularly limited, but the impurities may impair the effects of the present invention depending on the application. Therefore, the total amount of impurities is 1% by weight or less, especially sodium or It is desirable that the ionic impurities such as chlorine be 0.5% by weight or less. For example, a polyimide resin having a repeating unit represented by the chemical formulas (1) and (2) in the main chain skeleton is pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 1 selected from bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, etc.
Or two or more aromatic tetracarboxylic dianhydrides, 4,4'-bis (3-aminophenoxy) biphenyl, bis (4- (3-aminophenoxy) phenyl) sulfide, bis (4- (3 -Aminophenoxy) phenyl) sulfone, bis (4- (3-aminophenoxy) phenyl) ether, 1,3-bis (3-aminophenyl) benzene, 1,4-bis (3-aminophenyl) benzene, 1, It can be produced using one or two or more aromatic diamines selected from 3-bis (4-aminophenyl) benzene and the like, by using a commonly known method. Further, a polyetherimide resin having a repeating unit represented by the chemical formula (3) in the main chain skeleton, a chemical formula (4),
A polyimide resin having the repeating unit represented by (5) in the main chain skeleton, a polyamideimide resin having the repeating unit represented by the chemical formula (6) in the main chain skeleton, and chemical formulas (7) to
Both the polysulfone-based resin having the repeating unit represented by (9) in the main chain skeleton and the polyetherketone-based resin having the repeating unit represented by the chemical formula (10) in the main-chain skeleton are prepared by known methods. It is possible to manufacture.
These are resins that are industrially manufactured, for example,
A polyetherimide resin having a repeating unit represented by the chemical formula (3) in the main chain skeleton is Ultem (trade name ULTE
Polyimide resins having repeating units represented by the chemical formulas (4) and (5) in the main chain skeleton, such as M, Japan GE Plastics Co., Ltd., are represented by the chemical formula (6), such as UPILEX (trade name, Ube Industries). Polyamideimide resin having a repeating unit in the main chain skeleton is represented by chemical formula (7) to Torlon (trade name TORLON, Teijin Amoco) and the like.
The polysulfone-based resin having a repeating unit represented by (9) in the main chain skeleton is a repeating unit represented by the chemical formula (10) such as Udel (trade name UDEL, Teijin Amoco), Radel (trade name RADEL, Teijin Amoco), etc. Polyether ether ketone-based resin having a main chain skeleton can be obtained as Victrex (trade name, Victrex EMC), etc., by appropriately selecting brands and the like that match the scope of the present invention. is there.
In addition, as an example of a specific method for producing a resin having the repeating units represented by the chemical formulas (1) to (10) in the main chain skeleton, Kyoritsu Shuppan Co., Ltd., New Polymer Experiments 3 Polymer Synthesis / Reaction ( 2) Synthesis of Condensed Polymers Described in The Society of Polymer Science, Japan. The molecular weight and the molecular weight distribution of the resin used in the magnetic core of the present invention are not particularly limited. However, when the molecular weight is extremely small or extremely large, the strength of the coating may be affected. The value of the logarithmic viscosity measured at 35 ° C. after dissolution in a solvent capable of dissolving at a concentration of 0.5 g / 100 ml is 0.
It is preferably 2 deciliter / g or more and 2.0 deciliter / g or less, and 0.3 deciliter / g or more.
It is more preferably 5 deciliter / g or less. The resin used in the magnetic core of the present invention is not particularly limited in the repeating of the structural unit, and may have any of an alternating structure, a random structure, a block structure and the like. The molecular shape that is usually used is linear, but a branched shape may be used. Further, it may be in a graft form. In the magnetic core of the present invention, the area ratio of the amorphous alloy ribbon surface portion covered with the composition is 10% or less.
If it exceeds 10%, unnecessary stress is applied to the amorphous alloy ribbon, and core loss characteristics may be deteriorated. The area ratio of the amorphous alloy ribbon surface portion coated with the composition is more preferably 8% or less, and 6
% Or less is more preferable. Since the magnetic core of the present invention has a small area ratio of the surface area of the amorphous alloy ribbon coated with the composition, the magnetic core has excellent core loss characteristics as compared with the magnetic core manufactured using the varnish of the related art. ing. When using a conventional varnish,
It is unavoidable that the varnish soaks between the layers of the amorphous alloy ribbon, and the area ratio of the covered amorphous alloy ribbon surface portion cannot be 10% or less. bad. The area ratio of the amorphous alloy ribbon surface portion coated with the composition of the present invention is such that the laminated ribbons constituting the magnetic core are peeled off one by one to form a ribbon shape, and the amorphous alloy ribbon surface portion is It is determined by calculating the area of the coated portion of the composition caused by penetration and the like. The coated portion can usually be easily identified by visual observation. If necessary, a method of combining mapping of a carbon element or the like by surface element analysis such as wavelength dispersive XRF and structural analysis such as NMR or IR can be used. The analysis target is preferably all of the amorphous alloy ribbons constituting the magnetic core, but when a part reflects the whole, that part may be the analysis target, and specifically, the entire range of 0. 1
About 10% can be the analysis target. The magnetic core adhesive resin composition of the present invention contains resin particles,
An adhesive resin composition for a magnetic core, wherein the resin has the following two characteristics. 3 after a thermal history of 2 hours at 365 ° C under a nitrogen atmosphere
The tensile strength at 0 ° C. is 30 MPa or more, and the weight loss rate due to thermal decomposition is 2% by weight or less when subjected to thermal history at 365 ° C. for 2 hours in a nitrogen atmosphere. It is a thermoplastic resin and has a melt viscosity of 2 at 365 ° C.
It is 0 to 50,000 Pa · sec. The resin used in the adhesive resin composition for a magnetic core of the present invention has a tensile strength of 30 MPa or more at 30 ° C. after undergoing a heat history of 2 hours at 365 ° C. in a nitrogen atmosphere, and at 350 ° C. in a nitrogen atmosphere, 2 It is a resin having a characteristic that the weight reduction rate due to thermal decomposition after passing through a thermal history of time is 2% by weight or less. The tensile strength at 30 ° C. after applying a heat history at 365 ° C. for 2 hours in a nitrogen atmosphere was 30.
If it is less than MPa, not only the shape retention property becomes insufficient, but also the stress increases and the core loss may increase. Further, when the weight reduction rate when kept at 365 ° C. for 2 hours in a nitrogen atmosphere exceeds 2% by weight, not only the shape retention property is reduced, but also volatile components and carbonaceous substances generated by decomposition are annealed. Problems can occur that contaminate the furnace in which the heat treatment is performed. The upper limit of the tensile strength at 30 ° C after the heat history of 2 hours at 365 ° C under a nitrogen atmosphere is not particularly limited, but if the tensile strength is too high, the load on the magnetic core increases and Since there is a possibility that the effects of the invention may not be sufficiently obtained, 300 MPa
It is preferably not more than 250 MPa, more preferably not more than 250 MPa. The tensile strength and the weight loss rate are measured by the same method as that described above. The resin used in the adhesive resin composition for a magnetic core of the present invention is a thermoplastic resin and has a melt viscosity at 365 ° C. of 20 to 50000 Pa · sec. If the melt viscosity at 365 ° C. is less than 20 Pa · sec, the resin may soak into the layers of the amorphous alloy ribbon and apply unnecessary stress to the magnetic core, which may reduce core loss characteristics and also cause the resin to drip or form. The resulting coating becomes non-uniform and the shape retention of the magnetic core may be reduced. Further, when the melt viscosity at 365 ° C. exceeds 50,000 Pa · sec, the resin is not sufficiently adhered to the laminated end surface of the amorphous alloy ribbon during the annealing heat treatment, and the resin does not fit well, resulting in a decrease in adhesiveness and a deterioration in shape retention. There is a fear. The melt viscosity in the present invention is measured by using a general extrusion type capillary rheometer. For example, a Koka type flow tester is preferably used, and an orifice having a diameter of 0.1 cm and a length of 1 cm is used, the temperature is kept at 365 ° C. for 5 minutes, and then the pressure is extruded at a pressure of 100,000 hectopascals for measurement. As the resin used in the adhesive resin composition for a magnetic core of the present invention, a polyimide resin, a polyetherimide resin, a polyamideimide resin, a polyamide resin, a polysulfone resin, or a polyetherketone resin is preferably used. You can One kind selected from these may be used, or two or more kinds may be used in combination. As the resin used in the adhesive resin composition for a magnetic core of the present invention, more specifically, a thermoplastic resin having repeating units represented by the chemical formulas (1) to (10) in the main chain skeleton is preferably used. be able to. One kind selected from these may be used, or two or more kinds may be used in combination. However, in the chemical formula (1), a and b are a + b = 1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1.
X and Y are bonding groups selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond,
It may be the same or different. Further, in the chemical formula (2), Z is a bonding group selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond. Further, in the chemical formula (6), c and d are c + d = 1, 0 ≦ c ≦ 1, 0 ≦ d ≦
It is a number that satisfies 1.

[Chemical 6] The method for producing the resin used in the adhesive resin composition for a magnetic core of the present invention is not particularly limited, and any known method can be used. The type and amount of impurities contained in the resin are not particularly limited, but the impurities may impair the effects of the present invention depending on the application. Therefore, the total amount of impurities is 1% by weight or less, especially sodium or 0.5% by weight of ionic impurities such as chlorine
The following is desirable. For example, a polyimide resin having a repeating unit represented by the chemical formulas (1) and (2) in the main chain skeleton is pyromellitic dianhydride, 3,3 ′,
4,4′-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride,
One or more aromatic tetracarboxylic acid dianhydrides selected from bis (3,4-dicarboxyphenyl) sulfone dianhydride and 4,4′-bis (3-aminophenoxy) biphenyl, bis (4- (3-aminophenoxy) phenyl) sulfide, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (3-aminophenoxy) phenyl) ether, 1,3-bis (3
-Aminophenyl) benzene, 1,4-bis (3-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene or the like is used, and one or more aromatic diamines are used. It can be manufactured using a known method. Further, a polyetherimide resin having a repeating unit represented by the chemical formula (3) in the main chain skeleton, a polyimide resin having a repeating unit represented by the chemical formulas (4) and (5) in the main chain skeleton, a chemical formula (6) Polyamideimide resin having a repeating unit represented by the main chain skeleton, polysulfone resin having a repeating unit represented by the chemical formulas (7) to (9) in the main chain skeleton, repeating unit represented by the chemical formula (10) It is possible to manufacture any of the polyetherketone-based resins having a main chain skeleton by a known method, but these are industrially manufactured resins, for example, in the chemical formula (3): The polyether imide resin having the repeating unit represented in the main chain skeleton is Ultem (trade name ULTEM, Japan GE Plastics Co., Ltd.)
A polyimide resin having a repeating unit represented by the chemical formulas (4) and (5) in the main chain skeleton has a repeating unit represented by the chemical formula (6) in the main chain skeleton such as UPILEX (trade name, Ube Industries, Ltd.). Polyamide-imide resins include Torlon (trade name TORLON, Teijin Amoco) and the like, and polysulfone-based resins having repeating units represented by chemical formulas (7) to (9) in the main chain skeleton are Udel (trade name UDE).
L, Teijin Amoco), Radel (trade name RADEL,
Polyetheretherketone-based resins having a repeating unit represented by the chemical formula (10) in the main chain skeleton, such as Teijin Amoco, are available from Victrex (trade name).
It is also possible to obtain each by appropriately selecting a brand or the like that conforms to the scope of the present invention. An example of a specific method for producing a resin having the repeating units represented by the chemical formulas (1) to (10) in the main chain skeleton is Kyoritsu Shuppan Co., Ltd.
Polymer Synthesis / Reaction (2) Condensation Polymer Synthesis Described in The Society of Polymer Science, Japan. The molecular weight and the molecular weight distribution of the resin used in the adhesive resin composition for a magnetic core of the present invention are not particularly limited, but the molecular weight and the molecular weight distribution are sufficient so that the melt viscosity at 365 ° C. satisfies 20 to 50,000 Pa · sec. It is necessary to have. If the molecular weight is extremely small, the strength of the resin coating may be affected.
The value of logarithmic viscosity measured at 35 ° C. after dissolving in a solvent capable of dissolving at a concentration of 00 ml is preferably 0.2 deciliter / g or more, and more preferably 0.3 deciliter / g or more. preferable. Further, when the molecular weight is extremely large, the fluidity of the resin during annealing heat treatment may be reduced and an appropriate resin film may not be formed. Therefore, use a solvent that can dissolve the resin at a concentration of 0.5 g / 100 ml. The value of logarithmic viscosity measured at 35 ° C. after dissolution is preferably 2.0 deciliter / g or less, and more preferably 1.5 deciliter / g or less. The amount of the organic solvent remaining in the resin used in the magnetic core adhesive resin composition of the present invention is not particularly limited, but is preferably 1% by weight or less. When the amount of the organic solvent remaining in the resin exceeds 1% by weight, bubbles are generated in the resin due to the vaporization of the organic solvent during the temperature rise and the annealing heat treatment, which exerts an unnecessary stress on the magnetic core, resulting in a core loss characteristic. There is a risk of reduction. The amount of the organic solvent remaining in the resin can be measured by, for example, FID gas chromatography. The resin sample is heated to 400 by the heater built into the gas chromatography.
The organic solvent is separated by heating at ℃, and quantified using calibration curves of various organic solvents prepared in advance. The resin used in the adhesive resin composition for a magnetic core of the present invention is not particularly limited in the repeating of structural units, and may have any of an alternating structure, a random structure, a block structure and the like. The molecular shape that is usually used is linear, but a branched shape may be used. Further, it may be in a graft form. The adhesive resin composition for a magnetic core of the present invention is in a suitable state depending on its use and workability, but when the powder electrostatic coating method is applied, for example, a powder containing resin particles is used. The composition of the form is preferred. A liquid or paste composition containing resin particles and a liquid that does not dissolve the resin can be preferably used when a spray method, a brush coating method, or the like is applied. Incidentally, as long as the effect of the present invention is not impaired, the magnetic core adhesive resin composition of the present invention may contain a component other than a liquid that does not dissolve the resin particles and the resin, and the component is It is not particularly specified, for example, an inorganic filler or other resin,
It may contain a liquid or the like. Alternatively, the magnetic core adhesive resin composition of the present invention may be composed only of resin particles and a liquid that does not dissolve the resin. The particles of the resin used in the adhesive resin composition for a magnetic core of the present invention have optimum conditions for properties such as size depending on the state of the adhesive resin composition for a magnetic core of the present invention according to the use and workability. However, it is preferable to use a different one according to each situation. For example, when the powder electrostatic coating method is applied, the volume-based average particle diameter is 5 to 200 microns, and the surface area per unit weight is 0.02 to 1 m.
It is preferably 2 / g for uniformly coating the adhesive resin composition for a magnetic core of the present invention. Further, for example, when a spray method or a brush coating method is applied as a liquid or paste containing resin particles and a liquid that does not dissolve the resin, the volume-based average particle diameter is 0.5.
It is preferable that the surface area per unit weight is from 0.04 to 10 m2 / g, the volume-based average particle size is from 2 to 50 microns, and the surface area per unit weight is from 0.05 to 4 m2 / g. More preferably, it is g. Within this range, the viscosity of the adhesive resin composition for a magnetic core of the present invention, which affects workability and the like, can be suitably adjusted. However, these are merely examples of suitable conditions, and the suitable conditions may vary depending on other components and constituent ratios contained in the adhesive resin composition for a magnetic core of the present invention. It is not limited. In the adhesive resin composition for a magnetic core of the present invention, the proportion of resin particles contained is not particularly limited, but is preferably 1% by weight or more, and more preferably 20% by weight. As a method of applying the adhesive resin composition for a magnetic core of the present invention, a method of powder electrostatic coating using a powder form, a brush containing a liquid that does not dissolve the resin or a paste form is used. A method of applying with a trowel or the like and a spray method can be suitably applied. The spraying method can be more suitably applied from the viewpoint that a special device is not required and uniform and rapid application is possible. When carrying out by the spraying method, it is preferable to adjust properties such as viscosity to conditions suitable for the spraying method. For example, it can be adjusted by the particle size and content of the resin powder. The atomizing method can be performed using a commercially available spray gun and a compressed gas such as air. Furthermore, by adjusting the viscosity of the resin composition to be sprayed, it is possible to apply without dripping on the application surface,
The applied thickness may be arbitrary. Although a spray method or the like has been specifically exemplified as a suitable method for coating,
The present invention is not limited to these. In the magnetic core adhesive composition of the present invention, when the resin particles and a liquid that does not dissolve the resin are contained, it is preferable to use water, methanol, or ethanol as the liquid that does not dissolve the resin. Is more preferably used. The type and amount of impurities contained in the water to be used are not particularly limited, but there is a risk that impurities may increase core loss depending on the application, so the total amount of impurities is 1% by weight or less, especially Ionic impurities such as sodium and chlorine are preferably 0.5% by weight or less. The method for producing the adhesive resin composition for a magnetic core of the present invention is not particularly limited,
A known method can be applied. Resin particles include, for example, a method in which resin pellets are freeze-pulverized by an impact pulverizer, a method in which a resin insoluble solution is added little by little to a solvent in which the resin is insoluble, and the resin is deposited in a particulate form. Can be mentioned. Further, when the resin particles and a liquid that does not dissolve the particles are contained, for example, the resin may be formed into desired particles and then mixed with the liquid, or after mixing the resin and the liquid, a suitable pulverizing method. The resin may be used as desired particles. As the latter method, specifically, for example, a method of mixing resin powder roughly pulverized to about several hundreds of microns and water and finely pulverizing it using a wet jet mill (eg, Ultimaizer system manufactured by Sugino Machine Ltd.). Can be mentioned. The mixing method is not particularly limited, but it is preferable to use a method capable of uniformly mixing the resin powder and the liquid. The magnetic core adhesive resin composition of the present invention is a magnetic core adhesive resin composition containing resin particles having specific properties, and also resin particles having specific properties and the resin thereof. An adhesive resin composition for a magnetic core containing a liquid which does not dissolve, preferably water. Unlike the case of using an organic solvent which is concerned about safety and workability such that a resin can be dissolved, it is not necessary to take special measures for handling at the time of work and release into the atmosphere. In addition, no special consideration is required at the time of raising the temperature in the annealing heat treatment, and foaming which may occur when a varnish is used does not occur. Moreover, since the contained component is a chemically stable resin particle or a resin particle and a liquid that does not dissolve it, it is chemically extremely stable at around room temperature and does not deteriorate with time like a varnish and is stored during storage. There is no need to take special measures such as refrigeration and freezing. Moreover,
When the adhesive resin composition for a magnetic core of the present invention is applied to the laminated end surface of the amorphous alloy ribbon of the magnetic core, particles of the resin do not penetrate between the laminated layers, and the resin has a specific melt fluidity during annealing heat treatment. As a result, the resin does not substantially permeate between the laminated amorphous alloy ribbons during the annealing heat treatment. Therefore, the magnetic core manufactured using the adhesive resin composition for a magnetic core of the present invention retains its shape without applying unnecessary stress, and has better core loss characteristics than the case of using a varnish. This phenomenon is a characteristic that is significantly different from a varnish in which a resin component is dissolved in an organic solvent at a molecular level and the resin substantially permeates between the layers of the amorphous alloy ribbons. It is a technology that can only be achieved by using a composition. Thus, by using the adhesive resin composition for a magnetic core of the present invention, it is possible to solve the problems that could not be solved when using the varnish of the prior art, a magnetic core having excellent core loss characteristics Further, it can be efficiently produced without using an organic solvent, and the adhesive resin composition for a magnetic core of the present invention itself is thermally and temporally stable. As a method for producing a magnetic core using the adhesive resin composition for a magnetic core of the present invention, the adhesive resin composition for a magnetic core of the present invention is applied to a magnetic core before annealing heat treatment, and then a specific magnetic It is possible to suitably apply a method in which a predetermined annealing heat treatment is carried out to express the characteristics, and the coating adhesion by the magnetic core adhesive resin composition of the present invention and the annealing heat treatment are performed in the same step. Since shape retention by film formation and annealing heat treatment can be performed at the same time, no additional process or equipment is required, and complicated operations such as handling fragile amorphous alloy ribbon after heat treatment annealing are not required. . The location to which the adhesive resin composition for a magnetic core of the present invention is applied is not particularly limited as long as the effects of the present invention can be obtained, but it is both laminated end faces of the amorphous alloy ribbons constituting the magnetic core. It is preferable. By coating the laminated end face and annealing heat treatment, a coating film is formed on the laminated end face, and the laminated end face is bonded and fixed to maintain the shape. Even if the adhesive resin composition of the present invention is applied to other portions to form a resin coating, not only the effect on shape retention is small, but also unnecessary stress is applied to the magnetic core to reduce core loss characteristics. There is a fear. The thickness of the coating formed on the laminated end face of the amorphous ribbon by the adhesive resin composition for a magnetic core of the present invention depends on the required shape retention, the type of resin used, the magnetic performance of the magnetic core to be expressed, etc. Although the optimum value is different, it is usually preferably in the range of 5 to 2 millimeters, more preferably in the range of 10 to 300 microns. Since the thickness of the coating may affect the core loss characteristics, it is preferable to reduce the thickness as long as the effects of the present invention such as shape retention are not impaired. The thickness of the coating can be controlled by adjusting the coating thickness when the adhesive resin composition for a magnetic core of the present invention is applied. The magnetic core of the present invention is a magnetic core that retains its shape after annealing heat treatment without handling a brittle ribbon and has excellent core loss characteristics. It was something that could not be achieved. Further, the adhesive resin composition for a magnetic core of the present invention is a composition useful for efficiently producing such an excellent magnetic core without using an organic solvent, and further, in terms of heat and time. It is stable.

EXAMPLES The present invention will be described in detail below with reference to examples. In addition, the measurement of various physical properties in Examples and the like was performed by the following methods. Logarithmic viscosity η: In the case of a resin, the resin was dissolved in a soluble solvent (for example, chloroform, 1-methyl-2-pyrrolidone, dimethylformamide, ortho-dichlorobenzene, cresol, etc.) at a concentration of 0.5 g / 100 ml. After that, the measurement was performed at 35 ° C. For varnish,
Resin component is 0.5g / 1 in the same solvent as varnish
After diluting to a concentration of 00 ml, 35 ℃
Was measured at. Glass transition temperature Tg: Measured by the DSC method (Shimadzu DSC-60) under a temperature rising rate condition of 10 ° C./min. 3 after a thermal history of 2 hours at 365 ° C under a nitrogen atmosphere
Tensile strength at 0 ° C: Japanese Industrial Standard JIS-K7
It measured according to 127. A film with a thickness of about 100 to 300 μm is prepared by hot pressing or casting, and this is preheated in a nitrogen atmosphere from room temperature to 365 ° C.
After heating at 0 ° C./min, heat history was applied at 365 ° C. for 2 hours, punching was performed to form a No. 3 test piece, and the test piece was subjected to measurement. Weight reduction rate due to thermal decomposition when subjected to a thermal history of 365 ° C. for 2 hours in a nitrogen atmosphere: a sample was dried in a nitrogen stream at 200 ° C. for 2 hours before measurement, and a thermogravimetric measuring device (Shimadzu TG
A-50) After setting the sample in a nitrogen atmosphere,
The temperature was raised at a rate of 0 ° C./minute, and when the temperature reached 365 ° C., the temperature was maintained for 2 hours. Weight loss due to thermal decomposition is 3
365 ° C relative to the sample weight when it reaches 65 ° C
The ratio of the weight decreased in the period of 2 hours was used. Melt viscosity at 365 ° C .: diameter 0.1 cm, length 1 cm using a Koka type flow tester (Shimadzu CFT-500)
The melt viscosity was measured using the orifice of. After maintaining at a predetermined temperature for 5 minutes, it was extruded at a pressure of 100,000 hectopascals. Volume-based average particle diameter: Measured with a particle diameter measuring device (Microtrack 9320-X100 manufactured by Nikkiso Co., Ltd.). Percentage of the area of the amorphous alloy ribbon surface covered with the composition: The laminated ribbons constituting the magnetic core are peeled off one by one to form ribbons, and the amorphous alloy ribbon surface portion is impregnated. It was calculated by discriminating the coated portion of the composition caused by the above by visual observation.
The object of analysis was 1% by weight of the total weight of the magnetic core from the outer peripheral portion, the inner peripheral portion, and the intermediate peripheral portion therebetween, and the average value was calculated. Core loss: BH analyzer (IWATSU SY) under the conditions of frequency 60 Hz and maximum magnetic flux density 1.3 Tesla
-8216). The core loss of the magnetic core that was subjected to the same heat treatment and the like except that the composition or the like was not applied was taken as a blank, and the ratio of the core loss increased to the blank was taken as the core loss increase rate.

[Synthesis Example] As shown in Table 1, chemical formulas (11) to
A resin having a repeating unit represented by (21) and a main chain skeleton and a logarithmic viscosity is prepared by synthesis or the like, and the resin number is P
1 to P13 were given. Each characteristic of these resins (glass transition temperature, 365 ° C. under nitrogen atmosphere, tensile strength at 30 ° C. after 2 hours heat history, under nitrogen atmosphere 36
The weight loss rate due to thermal decomposition at the temperature of 5 ° C. for 2 hours was measured, and the melt viscosity at 365 ° C.) was measured.
Described in.

[Table 1] As shown in Table 2, a composition was prepared using the resins P1 to P13, and C1 to C15 were given as the composition numbers. A freeze pulverization method using an impact pulverizer and / or a wet jet mill (Sugino Machine Ultimate System) was used for the resin granulation. Table 2 also shows the volume-based average particle diameter of the resin particles, the composition ratio of the resin particles and water in the composition, and the properties of the composition. C12 is C1 stored at 30 ° C. for 6 months.

[Table 2] As shown in Table 3, pyromellitic dianhydride, 3,
Chemical formula (22) was prepared by dissolving 3 ', 4,4'-biphenyltetracarboxylic dianhydride and 4,4'-bis (3-aminophenoxy) biphenyl in N, N'-dimethylacetamide at room temperature. Polyamic acid varnish having the repeating unit represented in the main chain skeleton, U manufactured by Ube Industries, Ltd.
-Varnish, a siloxane-modified polyimide resin varnish synthesized according to the example of JP-A-02-251439 was prepared, and V1 to V3 were given as varnish numbers. Further, varnish V1 stored at 30 ° C. for 6 months was designated as V4.

[Table 3]

[Chemical 7]

Example 1 Atomic ratio of Fe: Si: B = 78: 9: 13
A plurality of amorphous alloy ribbons (width: 142 mm, thickness: 25 μm) having the composition of (1) were laminated and a magnetic core of 55 kg was prepared by a usual method. The shape and size of the magnetic core are shown in FIG. A metal fitting as a spacer is used at the center of the iron core and a metal fitting is also used at the outer peripheral portion to fix the amorphous alloy ribbon so that it cannot be unraveled.
The resin composition C1 shown in Table 2 was applied to the entire laminated end surface of the magnetic core by a spraying method using a spray gun (SC-110 manufactured by Olympus Corporation) and compressed air. The outline of the work is shown in FIG. No dripping of the composition was observed during the coating operation,
It could be applied uniformly and quickly. Application time is about 3
The coating thickness was about 120 microns. The magnetic core coated with the composition is placed under a nitrogen atmosphere for 3 hours.
The temperature is raised from 0 ° C to 365 ° C over 1 hour at a constant rate,
After holding at 365 ° C. for 2 hours to perform annealing heat treatment, it was allowed to cool. When the spacers for fixing were removed after cooling, the shape retention of the magnetic core was good, and even if a load of 10 kg was applied to the upper part with the magnetic core standing in the same way as during work, the shape retention was completely unaffected. Did not affect. The ratio of the laminated end surface of the magnetic core coated and adhered with the resin was the entire surface, the coating was uniform, and the coating thickness was 102 microns. Peeling the laminated ribbons constituting the magnetic core one by one to form a ribbon shape, and visually observing the resin coating portion caused by the infiltration in the amorphous alloy ribbon surface portion, the outer peripheral portion of the magnetic core, The proportion was almost the same at any of the inner peripheral portion and the intermediate peripheral portion therebetween, and the average was 2.5%. When the core loss was measured, it was 0.290 W / kg, which was higher than the blank core loss of 0.250 W / kg when the annealing heat treatment was performed in exactly the same manner except that the resin composition was not applied. Was 16%. The results are summarized in Table 4.

[Table 4]

Example 2 Examination was conducted in the same manner as in Example 1 except that the laminated end face of the magnetic core was masked in a mesh shape to reduce the area of the applied portion to 50%. The results are summarized in Table 4. The coating workability and the shape retention of the magnetic core after the annealing heat treatment were good, and the core loss increase rate was 16%, which was an excellent low level.

Example 3 Examination was conducted in the same manner as in Example 1 except that the coating method was changed to a method using a trowel. The results are summarized in Table 4. The coating workability and the shape retention of the magnetic core after the annealing heat treatment are good except that the coating work required 10 minutes.
Moreover, the core loss increase rate was 16%, which was an excellent low level.

Example 4 Examination was conducted in the same manner as in Example 1 except that a powdery composition was used and coating was carried out by a usual powder electrostatic coating method. The results are summarized in Table 4. The coating workability and the shape retention of the magnetic core after the annealing heat treatment were good, and the core loss increase rate was 16%, which was an excellent low level.

[Examples 5 to 14] The resin composition used was C3 described in Table 2.
Examination was conducted in the same manner as in Example 1 except that C12 was replaced with C12. The results are summarized in Table 4. In all cases, the coating workability, the shape retention of the magnetic core after the annealing heat treatment, etc. were good, and the core loss increase rate was 16-28%, which was an excellent low level.

Comparative Example 1 An examination was conducted in the same manner as in Example 1 except that the resin composition used was changed to C13 shown in Table 2. The results are summarized in Table 5. The coating workability is C as a resin composition.
1 was the same as the example used, but when the fixing spacer and the like were removed after the annealing heat treatment, the magnetic core was distorted, and a load of 10 kg was applied to the upper part in the state where the magnetic core was stood, Part of the resin film was peeled off and further distorted. Further, the coating film after the annealing heat treatment had some cracks and peeling. The core loss increase rate was 75%, and the core loss characteristics were poor.

Comparative Example 2 The same examination as in Example 1 was conducted except that the resin composition used was changed to C14 shown in Table 2. The results are summarized in Table 5. The coating workability is C as a resin composition.
It was as good as the example used as No. 1 and No. 1. Also, the shape retention of the magnetic core is good even when the fixing spacers are removed after the annealing heat treatment, and the shape retention is good even when a load of 10 kg is applied to the top of the magnetic core in the same state as when working. Had no effect on. However, the resin coating after the annealing heat treatment had traces of sagging during heating, and a part of the resin was solidified at the lower part of the application site. On the surface of the amorphous alloy ribbon, a large amount of resin coating, which was considered to be caused by penetration, was observed. When the portion was visually observed, the ratio was as high as 12%. Moreover, the core loss increase rate was 51%, and the core loss characteristics were poor.

Comparative Example 3 The same examination as in Example 1 was conducted except that the resin composition used was changed to C15 shown in Table 2. The results are summarized in Table 5. The coating workability is C as a resin composition.
1 was the same as that of the example used, but when the fixing spacer and the like were removed after the annealing heat treatment, the magnetic core was slightly distorted, and the magnetic core stood up to 10 kg in the standing state.
When a load of 1 was applied, a gap was partially formed between the magnetic core and the resin coating. In addition, the resin coating after the annealing heat treatment had some unevenness. The core loss increase rate is 53%,
The core loss characteristics were poor.

Comparative Examples 4 to 5 Examination was conducted in the same manner as in Example 1 except that the resin composition C1 used was replaced with the varnishes V1 and V2 shown in Table 3 and the coating method was changed from the spraying method to the brush coating method. The results are summarized in Table 5. During the varnish coating operation, since the coating surface is vertical, a part of the varnish sags, and it was difficult to obtain an arbitrary thickness. Further, a part of the applied varnish seemed to penetrate between the layers of the amorphous alloy ribbon. The working time required about 10 minutes. It was difficult to apply thickly, and the unevenness of the laminated end surface of the magnetic core was exposed after application. The shape retention of the magnetic core after the annealing heat treatment was good, but the resin coating was extremely thin, less than 10 microns, and the unevenness of the laminated end surface of the magnetic core was exposed as in the coating. On the surface of the amorphous alloy ribbon, a large amount of resin coating, which is considered to be caused by penetration, was observed. When the portion was visually observed, the ratio was as high as 21 to 25%. The core loss increase rate is 8
It was 8 to 98%, and the core loss characteristic was poor.

Comparative Example 6 An examination was conducted in the same manner as in Example 1 except that the resin composition C1 used was changed to the varnish V3 shown in Table 3 and the coating method was changed from the spraying method to the brush coating method. The results are summarized in Table 5. During the varnish coating operation, since the coating surface is vertical, a part of the varnish sags, and it was difficult to obtain an arbitrary thickness. Further, a part of the applied varnish seemed to penetrate between the layers of the amorphous alloy ribbon. The working time required about 10 minutes. It was difficult to apply thickly, and the unevenness of the laminated end surface of the magnetic core was exposed after application. When the spacers for fixing were removed after annealing heat treatment, no distortion was found in the magnetic core, but when a load of 10 kg was applied to the upper part with the magnetic core standing, part of the magnetic core was easily deformed. did. The resin film was extremely thin and was less than 10 microns, and the unevenness of the laminated end surface of the magnetic core was exposed as in the coating. On the surface of the amorphous alloy ribbon, a large amount of resin coating, which was thought to be caused by penetration, was observed. When the portion was visually observed, the ratio was as high as 26%. Moreover, the core loss increase rate was 81%, and the core loss characteristics were poor.

Comparative Example 7 An examination was conducted in the same manner as in Example 1 except that the resin composition C1 used was changed to the varnish V4 shown in Table 3 and the coating method was changed from the spraying method to the brush coating method. The results are summarized in Table 5. The varnish was partly gel-like and some cloudy parts were also seen. During the varnish coating operation, since the coating surface is vertical, a part of the varnish sags, and it was difficult to obtain an arbitrary thickness. Further, a part of the applied varnish seemed to penetrate between the layers of the amorphous alloy ribbon. The working time required about 10 minutes. It was difficult to apply thickly, and the unevenness of the laminated end surface of the magnetic core was exposed after application. When the spacers for fixing were removed after annealing heat treatment, no distortion was found in the magnetic core, but when a load of 10 kg was applied to the upper part with the magnetic core standing, part of the magnetic core was easily deformed. did. The resin film was extremely thin and was less than 10 microns, and the unevenness of the laminated end surface of the magnetic core was exposed as in the coating. On the surface of the amorphous alloy ribbon, a large amount of resin coating, which is considered to be caused by penetration, was observed. When the portion was visually observed, the ratio was as high as 24%. Moreover, the core loss increase rate was 84%, and the core loss characteristics were poor.

[Table 5]

The magnetic core of the present invention is a magnetic core which is in a state of maintaining its shape after annealing heat treatment without handling a brittle ribbon and has excellent core loss characteristics.
This cannot be achieved by the method using the varnish of the prior art. Further, the adhesive resin composition for a magnetic core of the present invention has a problem that this composition cannot be solved by the varnish of the prior art, that is, the core loss property is not practically sufficient, and the organic solvent It is possible to solve working and environmental problems associated with use, thermal and temporal stability problems of the varnish itself, working problems such as sagging, and the like, and the adhesive resin composition for a magnetic core of the present invention can be solved. To efficiently produce a magnetic core that retains its shape after annealing heat treatment without handling a fragile ribbon and has excellent core loss characteristics without using an organic solvent. You can

[Brief description of drawings]

FIG. 1 is a diagram showing a stacking end face of an amorphous alloy ribbon according to the present invention.

FIG. 2 is a diagram showing the shape and size of a magnetic core according to the present invention.

FIG. 3 is a diagram showing an operation of applying the laminated end surface by spraying in the present invention.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09J 181/06 C09J 181/06 H01F 27/24 H01F 41/02 C 41/02 27/24 C F term ( Reference) 4J040 EE061 EG001 EH031 EJ031 MA02 NA19 5E062 AA02 AC01 AC06

Claims (11)

[Claims] 1. In a magnetic core produced by laminating amorphous alloy ribbons, a part or all of the laminated end faces of the amorphous alloy ribbons are coated and adhered with a composition containing a resin, and the resin is in a nitrogen atmosphere. Tensile strength of 30 MPa at 30 ° C. after undergoing thermal history at 365 ° C. for 2 hours
The above is a resin having a characteristic that the weight loss rate due to thermal decomposition is 2% by weight or less when subjected to thermal history at 365 ° C. for 2 hours in a nitrogen atmosphere, and the composition on the surface of the amorphous alloy ribbon. A magnetic core, characterized in that the ratio of the area covered by the object is 10% or less. 2. The resin is one or more thermoplastic resins selected from a polyimide resin, a polyetherimide resin, a polyamideimide resin, a polyamide resin, a polysulfone resin, and a polyetherketone resin. The magnetic core according to claim 1. 3. The magnetic material according to claim 1, wherein the resin is one or more thermoplastic resins selected from resins having the repeating units represented by the chemical formulas (1) to (10) in the main chain skeleton. Core [Chemical 1] (However, in the chemical formula (1), a and b are a + b =
1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, and X and Y are bonding groups selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond, It may be the same or different. Further, in the chemical formula (2), Z is a bonding group selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond. Further, in the chemical formula (6), c and d are c + d
= 1 and 0 ≦ c ≦ 1 and 0 ≦ d ≦ 1. ). 4. A resin containing particles of the resin, the resin comprising
An adhesive resin composition for a magnetic core, which has two characteristics. 3 after a thermal history of 2 hours at 365 ° C under a nitrogen atmosphere
The tensile strength at 0 ° C. is 30 MPa or more, and the weight loss rate due to thermal decomposition is 2% by weight or less when subjected to thermal history at 365 ° C. for 2 hours in a nitrogen atmosphere. It is a thermoplastic resin and has a melt viscosity of 2 at 365 ° C.
It is 0 to 50,000 Pa · sec. 5. The adhesive resin composition for a magnetic core according to claim 4, which contains a liquid that does not dissolve the resin. 6. The adhesive resin composition for a magnetic core according to claim 5, wherein the liquid is one or more selected from water, methanol and ethanol. 7. The resin is one or more thermoplastic resins selected from a polyimide resin, a polyetherimide resin, a polyamideimide resin, a polyamide resin, a polysulfone resin, and a polyetherketone resin. The adhesive resin composition for a magnetic core according to any one of claims 4 to 6. 8. The resin is one or more thermoplastic resins selected from resins having a repeating unit represented by the chemical formulas (1) to (10) in the main chain skeleton.
Adhesive resin composition for magnetic core described in (However, in the chemical formula (1), a and b are a + b =
1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, and X and Y are bonding groups selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond, It may be the same or different. Further, in the chemical formula (2), Z is a bonding group selected from a direct bond, an ether bond, an isopropylidene bond, a sulfide bond, a sulfone bond, and a carbonyl bond. Further, in the chemical formula (6), c and d are c + d
= 1 and 0 ≦ c ≦ 1 and 0 ≦ d ≦ 1. ). 9. A magnetic core manufactured using the adhesive resin composition according to claim 4. 10. The magnetic core according to claim 1, which is manufactured by using the adhesive resin composition according to any one of claims 4 to 8. 11. An adhesive resin composition according to any one of claims 4 to 8 is applied to a magnetic core before being subjected to annealing heat treatment, and then a predetermined annealing heat treatment is carried out for exhibiting specific magnetic properties, A method for producing a magnetic core, characterized in that coating adhesion with an adhesive resin composition and the annealing heat treatment are performed in the same step.