JPH11128899A - Method of recovering copper resources from mold parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that in order to reuse windings as copper metal of high grade, electrolytic refining is required because mold parts have been subjected to earth filling treatment when discarded and valuable metals therein have not much been recovered and insulation coating films of the windings cannot be removed by crushing treatment only. SOLUTION: After mold parts containing winding parts and part or all thereof are covered with mold material are crushed, winding parts are moved from the crushed article and immersed in alkaline water solution, and warmed and pressurized to 150 deg.C or more and 2 atm or more to remove insulation films and recover metal copper of high grade needing no electrolytic refining. By this method, the metal copper can be recovered from the mold parts easily and with high recovery rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the treatment of solid waste, and more particularly to a method for recovering copper resources in a molded part.

[0002]

2. Description of the Related Art Conventionally, a molded part molded with a resin or the like is generally buried directly in the soil at the time of disposal. Therefore, the metal valuables included in the molded part are hardly collected. These metal valuables mainly include iron and copper, and iron is used as an iron core.
Copper is often used as a winding.

[0003] In addition, as a method for treating a molded part, there is a method in which after crushing treatment, specific gravity separation, magnetic separation, etc. are performed to separate valuable components into valuable components. As it is, it cannot be completely recovered as metal, resulting in low-grade copper wire scrap.

[0004]

As described above, molded parts are often landfilled as they are,
Recovery of valuable materials such as metals inside the parts is hardly performed. However, in recent years, from the viewpoint of global environmental problems, promotion of recycling has been required for effective use of resources.

[0005] As a process for recycling molded parts, there is a crushing process as described above. However, in many cases, the winding material collected and separated has a molding material attached thereto. However, an insulating coating is applied, and a step of removing them is necessary in order to reuse the copper metal. In order to reduce the amount of mold material adhering to the windings, it is advantageous to crush as finely as possible in the crushing process.However, for this purpose, there are many types of crushing machines and crushing is performed many times. Time and processing costs,
Processing energy consumption increases. In addition, when finely crushed, separation from a mold material or the like becomes difficult, and the recovery rate of the winding decreases.

Conventionally, the crushed maker hardly removes the insulating coating. The metal maker or the like picks up copper wire scraps, and after being subjected to dry refining, is cast on an anode for electrolysis, and is subjected to a process by electrolytic refining. It is common practice to apply it to a form that can be reused as high-grade copper metal. Therefore, large-scale equipment such as a melting furnace that can be heated to a high temperature is required, and economical advantages cannot be obtained unless the treatment is performed in large quantities. Also, melting the copper wire with the insulation coating attached will generate slag containing a lot of impurities, greatly reducing the recovery rate of high-grade metallic copper, and depending on the dissolution conditions, harmful substances such as harmful substances in the exhaust gas May occur, which may have an adverse effect on the environment.

[0007] In order to regenerate electrolytic copper only by dry refining without the need for electrolytic refining, copper scrap having a purity of 99% or more or copper wire scrap having the same melting grade as copper scrap is treated. It is necessary to do. In view of the above-mentioned drawbacks of the conventional method, an object of the present invention is to provide a method for recovering copper resources in a molded component that can easily recover high-purity copper metal from the molded component after disposal.

[0008]

SUMMARY OF THE INVENTION The present invention comprises a step of crushing a molded part including a winding part and partially or entirely covered with a molding material, and separating the winding part from the crushed product. A method of recovering copper resources in a mold part, comprising a step of immersing the separated winding part in an alkaline aqueous solution and heating and pressing the same at 150 ° C. or more and 2 atm or more. It is a solution to the above problem.

The resin in the molding material is an unsaturated polyester resin, and is thermoset using a monomer containing at least one of 2, hydroxyethyl methacrylic acid and 2, hydroxyethyl acrylic acid as an addition polymerizable monomer. This is preferable because the mold material attached to the winding can be easily removed. Further, it is preferable that the insulating coating applied to the winding surface is a polyester-based or polyurethane-based resin because the temperature and pressure of the immersion treatment in an alkaline aqueous solution can be minimized and the treatment time can be shortened.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A molded part to be used in the present invention may be any part obtained by resin-molding a part containing copper metal as a winding, such as a molded motor or a molded transformer. However, it is needless to say that a component containing copper metal other than the form of the winding may be used.

The crushing process used in the present invention includes, for example, a commonly used coarse crusher such as a shredder, a jaw crusher, a cone crusher, a hammer crusher, a roll crusher, a stamp mill, a cutter mill, and a finer pulverizer. A fine pulverizer such as a rod mill, a high-speed rotary pulverizer, a stirring mill, and a ball mill may be used.

However, it is advantageous not to crush the particles too finely in terms of processing cost, energy, and recovery rate of copper.
In particular, when the unsaturated polyester resin of the second invention of the present invention is used as the resin for the molding material, a slight amount of the molding material may be adhered to the winding, so that the degree of coarse pulverization is sufficient. is there. In the step of separating the winding portion from the crushed material after the crushing treatment, for example, a magnetic separator, a specific gravity separator, a sieve separator, or the like is used.

The resin contained in the molding material used in the present invention is generally a thermosetting resin such as an unsaturated polyester resin, an epoxy resin, or a phenol resin. Examples of the resin include polyethylene terephthalate and polybutylene terephthalate. Any resin can be applied, regardless of the thermoplastic resin. Among them, a resin which is easily susceptible to alkali is preferable because the necessity of separating the copper wire portion and the molding material lump by the crushing treatment and the separation treatment is reduced. Particularly, the unsaturated polyester resin can improve the permeability of the alkaline aqueous solution to the resin by using a monomer containing at least one kind of 2, hydroxyethyl methacrylic acid or 2, hydroxyethyl acrylic acid as a crosslinkable monomer,
This is more preferable because it promotes the decomposability of the resin, causes a softening phenomenon of the molding material, and enables the molding material attached to the winding to be easily removed.

As the unsaturated polyester used in the present invention, any unsaturated polyester composed of an unsaturated polybasic acid, a saturated polybasic acid, and glycols can be used as a main raw material. As the unsaturated polybasic acid, for example, maleic anhydride, fumaric acid, itaconic acid and the like are used.

The saturated polybasic acids include, for example, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, tetrabromophthalic anhydride, adipic acid, sebacic acid And the like. Examples of the glycols include propylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, dibromoneopentyl glycol, 1,3 butanediol, 1,4 butanediol, hydrogenated bisphenol A, and the like.

The addition-polymerizable monomer serving as a crosslinking agent used in the present invention is a commonly used monomer such as styrene, methyl methacrylate, vinyl acetate, vinyltoluene, α-methylstyrene, methyl acrylate and the like. However, by using a monomer containing at least one kind of 2, hydroxyethyl methacrylic acid or 2, hydroxyethyl acrylic acid, it is possible to improve the permeability of the alkaline aqueous solution to the resin, promote the decomposability of the resin, and mold This causes a softening phenomenon of the material, and makes it possible to easily remove the mold material attached to the winding.

It is preferable that the monomer is added in a molar ratio of 1.3 or more with respect to the unsaturated polybasic acid. If the molar ratio is 1.3 or less, the amount of the unreacted unsaturated polybasic acid increases, and the strength and the like of the resin and the molding material using the resin as a binder may decrease. The molding material provided in the present invention may be composed of only a resin, but is generally, for example, a reinforcing material such as glass fiber, carbon fiber, and organic fiber, calcium carbonate, kaolin, and aluminum hydroxide. , Talc, mica and the like, a curing agent, a coloring agent, a thickener, a release agent, and the like.

As the filler, for example, calcium carbonate, calcium silicate, magnesium carbonate, barium sulfate, calcium sulfate, kaolin, aluminum hydroxide,
Examples include talc, mica, diatomaceous earth, and glass balls. As the reinforcing material, glass fiber is mainly used,
In addition, organic fibers such as polyacrylonitrile-based, rayon-based or pitch-based carbon fibers, vinylon, polypropylene, polyester, and aramid fibers can also be used.

As the curing agent, for example, t-butyl peroxyate, benzoyl peroxide, t-butyl perbenzoate, 2,2, bis (t-butylperoxy) butane, 3,3,5, trimethyl (t -Butylperoxy) cyclohexane and the like. As the colorant, general dyes and pigments can be used, for example, iron oxide, titanium oxide, cadmium yellow, cadmium red, chromium yellow, chrome vermilion, inorganic pigments such as ultramarine blue, azo compounds, cyanine blue, Organic pigments such as chlorinated cyanine blue and cyanine green; dyes such as indigo red and oil red; and carbon black.

Examples of the thickener include magnesium oxide, magnesium hydroxide, calcium hydroxide, polyvalent isocyanate compounds and the like. Examples of the release agent include a fluorine-based surfactant and zinc stearate. The alkaline aqueous solution used in the present invention is an aqueous solution containing an alkaline alkali metal compound or an alkaline alkaline earth metal compound. Examples of the alkaline alkali metal compound or alkaline earth metal compound include sodium hydroxide, potassium hydroxide, barium hydroxide, sodium ethoxide, potassium butoxide and the like. The higher the concentration of the solution of the alkaline alkali metal compound or alkaline alkaline earth metal compound, the greater the number of hydroxyl ions, the greater the attack on ester bonds, urethane bonds, etc., to promote hydrolysis. However, depending on the processing time, if the concentration is too high, the copper surface may be oxidized, and the like. In addition, when a large amount of molding material adheres to the winding, it is necessary to decompose the binder resin in the molding material to such an extent that the molding material can be removed, and for this purpose, an alkaline aqueous solution permeates into the molding material. However, as the alkali concentration increases, the amount of sodium ions and potassium ions increases, so that the viscosity of the solution also increases, and the permeability of the solution into the molding material decreases. Therefore, it is preferable that the concentration be such that a sufficient hydrolysis reaction or the like occurs, the permeability of the solution does not decrease, and the influence on copper is small. Therefore, the solution concentration of the alkaline alkali metal compound or the alkaline alkaline earth metal compound is preferably 5 N or less, more preferably 0.1 to 3 N.

The alkaline alkali metal compound or alkaline earth metal compound may be contained not only in a single component but also in a plurality. Also,
In order to improve the permeability of the solution into the mold material, for example, alcohols such as methyl alcohol and ethyl alcohol, acetone, tetrahydrofuran, ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol, diethylene glycol Diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dimethylformamide, dimethylamine and the like may be added.

When the treatment temperature with the alkaline aqueous solution is lower than 150 ° C., the insulating film and the resin of the molding material have low decomposability and the treatment requires a long time.
Preferably, the treatment is performed at a temperature of 150 ° C. or higher. The insulating coating applied to the winding is preferably a polyester-based or polyurethane-based coating having an ester bond or a urethane bond susceptible to hydrolysis by alkali. Of course, these coatings are made of nylon with a thickness of several μm to improve the processing resistance.
It may be overcoated with a thickness of. Polyamide and polyimide wires are not hydrolysable,
Although it is difficult to recover copper by the method of the present invention, any of such films having a hydrolyzable bond in a part of the coating can be applied to the present invention. Further, by increasing the treatment temperature, there is a high possibility that a film having no hydrolyzable bond can be treated.

According to the recovery method of the present invention, it is possible to easily recover the windings as copper metal from molded parts that have become waste after use or defective products during manufacture.

[0024]

The present invention will be described in more detail with reference to specific examples. (Embodiment 1) In this embodiment, a molded motor whose schematic longitudinal sectional view is shown in FIG. 1 is used as a molded part. The shaft 4 of the rotor 3 is mounted on the bearing 2 provided on the bracket 1.
Are rotatably supported. A stator winding 6 made of an enamel-coated copper wire is wound around a silicon steel plate of a stator iron core 5 arranged so as to surround the rotor 3 at a distance. The stator core 5, the stator windings 6, and the bracket 1 are molded with a molding material 7 in contact with the bracket 1. 8 is a mounting hole. The thickness of the mold was about 4 mm at the thin part and about 10 mm at the thick part.

The molding material used here was prepared by the following method. First, an unsaturated alkyd composed of phthalic anhydride, fumaric anhydride and propylene glycol, styrene as a crosslinkable monomer, and polycaprolactone as a low-shrinkage agent were mixed so as to be 100 parts by weight in total, and a polymerization initiator t- 1 part by weight of butyl peroxybenzoate was added and mixed by stirring to obtain a resin liquid composition.

The proportion of polycaprolactone in the resin composition was adjusted to 6.5 wt%, and the molar ratio of unsaturated alkyd / crosslinkable monomer was adjusted to 2.8. Next, 68.3 parts by weight of calcium carbonate as a filler, 0.7 parts by weight of vinylon chopped strand, 0.9 parts by weight of zinc stearate as a release agent, 0.3 parts by weight of carbon powder as a coloring agent, 1.8 parts by weight of polyethylene powder, which is a surface gloss material, was transferred to a kneader and dry-mixed. About 5
After 2 minutes, 21.2 parts by weight of the previously mixed resin liquid composition was gradually added to the uniformly mixed dry mixture, followed by kneading to obtain a uniform paste-like mixture.

Further, 6.8 was added to this paste-like mixture.
While the glass fibers in parts by weight were uniformly dispersed, they were added as quickly as possible, and when the glass fibers were wet and uniformly dispersed, kneading was completed to obtain a molding material. Using this molding material, a molding motor as shown in FIG. 1 was prepared by an injection molding machine at 150 ° C. for 5 minutes under curing and molding conditions.

The enamel-coated copper wire is a polyester wire 1-SMPEWN overcoated with nylon.
(Daiichi Denko Co., Ltd.) was used. This mold motor is crushed by a single-shaft rotary shear crusher (Horai Co., Ltd.)
What passed through the 20 mm screen was collected. Then, it is separated into a ferrous component and a non-ferrous component by a magnetic separator. When separated by a mesh sieve of No. 9,
Most of the transmitted light was the copper wire portion. The mold material hardly adhered to the copper wire collected here,
The enamel coating remained almost completely. Therefore, in order to reuse this recovered copper wire as copper metal,
Generally, it was necessary to perform electrolytic refining after dry refining.

The recovered copper wire was subjected to an alkali immersion treatment under the following conditions. Using sodium hydroxide as an alkali species, its aqueous solution concentration is 0.1, 0.5, 1.0N
Were used. 100 g of the aqueous solution and 20 g of the recovered copper wire were placed in a pressure-resistant container, immersed at 180 ° C. for 3 hours, then the copper wire was taken out, washed with water, and air blow dried. The weight loss rate and wire diameter after the treatment (Table 1)
Shown in

The diameter of the copper wire without the enamel coating is 520 μm. In addition, NaOH concentration 0.1N
In the case of (1), when the copper wire was taken out from the alkaline aqueous solution, many enamel coatings remained adhered, but could be removed visually by washing with water or air blow drying.
In the case of NaOH concentrations of 0.5 and 1.0 N, the adhesion of the enamel coating could not be confirmed visually when the copper wire was taken out from the alkaline aqueous solution.

[0031]

[Table 1]

The copper wire after drying had a beautiful glossy copper color at NaOH concentrations of 0.1 and 0.5 N, but turned red-black at 1.0 N. From the above results, when the NaOH concentration is 0.1 and 0.5N, the enamel coating of the copper wire can be removed cleanly, and the copper surface is not attacked. It is considered to be oxidized and partially eluted.

Therefore, when treating at 180 ° C. for 3 hours, it is desirable to use an aqueous solution having a NaOH concentration of 0.1 to 0.5N. When a copper wire treated with an aqueous solution having a NaOH concentration of 0.1 N was melted by a high-frequency vacuum melting apparatus, a copper lump having a purity of 99.95% was obtained at a recovery rate of 99%, and no electricity was required for electrolytic refining. The purity was sufficient to be reused as copper. This indicates that high-grade copper metal can be recovered by immersion treatment in an alkaline aqueous solution, and treatment such as electrolytic refining becomes unnecessary.

When the same immersion treatment was performed at 180 ° C. for 5 hours using tap water to which no alkali was added, the weight loss rate was 0.6 wt%, and the copper wire surface became reddish brown. It was discolored. From this fact, if the temperature is increased only with water, the enamel coating is slightly attacked, but the treatment requires a long time, so that the treatment can be performed more efficiently by using an alkaline aqueous solution.

(Embodiment 2) In this embodiment, the same molding motor as in Embodiment 1 was crushed, and the separated and collected copper wires were treated under the following conditions. As an alkaline aqueous solution, 0.1.
Using an aqueous 1N sodium hydroxide solution, the aqueous solution 1
Put 100g and 20g of recovered copper wire in a pressure vessel,
The immersion treatment was performed for three hours under each of five temperature conditions of 50, 160, 170, and 180 ° C. Thereafter, the copper wire was taken out, washed with water, and then subjected to air blow drying. The weight loss after the treatment is shown in (Table 2).

The gauge pressure at each temperature is also shown.

[0037]

[Table 2]

In the case of a temperature lower than 180 ° C., none of the treatments for 3 hours completely removed the enamel coating, but the higher the temperature, the larger the weight loss rate and the higher the coating removal rate. I understand. In particular, it tends to be rapidly removed from 150 ° C. or higher. In addition, the enamel-coated copper wire was replaced with 1-SMPEWN, and a polyurethane-based wire 1-UEWE (Daiichi Denko) overcoated with nylon.
(Table 3) shows the weight reduction rate of the copper wire when the same material was used and the same treatment was performed using the same materials as in Example 1.

However, the recovered copper wire was treated at an alkali immersion treatment temperature of 150, 160, 170 and 180 ° C.

[0040]

[Table 3]

Also in this case, as in 1-SMPEWN, 1
At 80 ° C., the film could be completely removed, and at less than 180 ° C., complete removal was not possible. However, the higher the temperature, the greater the weight loss rate, and the tendency of the film removal was 1-SM.
Almost the same as PEWN. The heat-resistant temperatures of 1-SMPEWN and 1-UEWE are 155 ° C. and 130 ° C., respectively. However, since the coating tends to be rapidly removed from a processing temperature of 150 ° C. or more, polyester-based or polyurethane-based enamels are used. It can be seen that in order to recover copper resources from a molded component using a copper wire having a coating as a winding, it is important to perform immersion treatment using an alkaline aqueous solution at 150 ° C. or higher.

(Embodiment 3) In this embodiment, a molded motor having the same configuration as that of the embodiment 1 was used as a molded part. However, the molding material was changed to a molding material created by the following method. First, phthalic anhydride, fumaric anhydride, and 65 parts by weight of an unsaturated alkyd composed of propylene glycol were mixed with 35 parts by weight of styrene, and 0.01 part by weight of a polymerization inhibitor methoxyhydroquinone was added. Then, the mixture was stirred and dissolved at room temperature to obtain an unsaturated polyester resin.

Also, 36 parts by weight of polydipropylene adipate was stirred and dissolved at room temperature in 64 parts by weight of 2, hydroxyethyl methacrylic acid to obtain a low-shrinking agent. Based on 74 parts by weight of the unsaturated polyester resin, 26 parts by weight of a low-shrinking agent and 1,1- (t-butylperoxy) polymerization initiator
One part by weight of 3,3,5-trimethylcyclohexane was added and mixed by stirring to obtain a resin liquid composition.

Next, calcium carbonate as a filler 17.
8 parts by weight, 48.5 parts by weight of aluminum hydroxide, 1.5 parts by weight of zinc stearate as a release agent, and 0.4 parts by weight of carbon powder as a colorant were transferred to a kneader, and dry-mixed. After about 5 minutes, 22 parts by weight of the previously mixed resin liquid composition was gradually added to the uniformly mixed dry mixture,
The mixture was kneaded to obtain a uniform paste-like mixture.

Further, 9.8 was added to this paste-like mixture.
While the glass fibers in parts by weight were uniformly dispersed, they were added in as short a time as possible, and when the glass fibers were wet and uniformly dispersed, kneading was completed to produce a molding material. Using this molding material, a molding motor was prepared in the same manner as in Example 1. The enamel-coated copper wire is 1-SMPEWN
Was used.

This mold motor was crushed by a single-shaft rotary shearing crusher (Horai Co., Ltd.), and the one that passed through a Φ40 mm screen was recovered. Then, it is separated into a ferrous component and a non-ferrous component by a magnetic separator. 5 mesh sieve. What was transmitted was most of the copper wire portion and the molding material powder. Many of the copper wires collected here have considerable mold material attached,
In many cases, several copper wires were solidified and partially embedded in the mass of the mold material. In addition, the enamel coating remained almost completely on the copper wire.

In this state, in many cases, the winding cannot be removed even if the winding is pulled from the molding material block. An alkali immersion treatment was performed under the following conditions using the copper wire portion of the mold material adhered and recovered. Using an aqueous 0.1 N sodium hydroxide solution as an alkaline aqueous solution, 100 g of this aqueous solution and 20 g of the recovered copper wire portion were placed in a pressure-resistant container, and subjected to immersion treatment at 180 ° C. for 3, 5, 10, and 15 hours. Thereafter, the copper wire portion was taken out, and the removable mold material was removed by washing with water or rubbing with a brush, and then air blow drying was performed.

Table 4 shows the results of visual observations on the removability of the enamel film and the molding material of the winding portion. Since the enamel coating on the portion where the molding material was not adhered was completely removed, the removability of the enamel coating on the portion where the adhering molding material could be removed is shown.

[0049]

[Table 4]

In about 15 hours, the copper wire from which the adhering mold material was able to be removed and the enamel coating was also able to be recovered was obtained. When this copper wire was dissolved to form a copper lump, metallic copper having a purity of 99.92% and being recyclable as electrolytic copper was obtained. When the mold motor using the molding material of Example 1 was crushed, separated and subjected to alkali immersion in the same manner as in this example, only a small molding material lump could be removed even after treatment for 15 hours. In order to completely remove the adhered mold material, it is necessary to soak for a longer time, to increase the processing temperature, and to increase the concentration of the alkaline aqueous solution.

As described above, when the resin in the molding material is an unsaturated polyester resin and the molding material is heat-cured by using a monomer containing 2, hydroxyethyl methacrylic acid as an addition-polymerizable monomer, Since it is softened by immersion and can be easily peeled and removed with a brush etc., there is no need to completely separate the copper wire part and the mold material lump when crushing the mold parts. Can be smaller.

Further, when 2, hydroxyethylacrylic acid was used in place of 2, hydroxyethylmethacrylic acid, almost the same results as in Example 3 were obtained. In addition,
As the ratio of 2, hydroxyethyl methacrylic acid or 2, hydroxyethyl acrylic acid in the monomer increases, decomposition by immersion in an alkaline aqueous solution,
Softening is also increased, and removal becomes easier, so that the crushing step can be further simplified. However, since the characteristics such as the water resistance of the molding material are deteriorated, it is necessary to set the ratio within an allowable range of the characteristic deterioration.

In the above embodiments, the unsaturated polyester resin is used as the resin of the molding material. However, the present invention is not limited to this resin, and any resin as described above can be applied. In particular, it is more effective to use a resin which is easily attacked by an alkaline aqueous solution. Further, in the above embodiment, sodium hydroxide was used as the alkali, but other alkalis may be used.

Further, in the above embodiments, a molded motor is used as a molded component, but a component using a large number of windings, such as a molded transformer, may be used.

[0055]

As described above, according to the present invention, after crushing a molded part including a winding, the separated part is immersed in an alkaline aqueous solution of 2 atm or more at 150 ° C. to separate the collected winding part. A method that can be recovered as high-quality copper metal can be provided. If the resin in the molding material is an unsaturated polyester resin and is thermoset using a monomer containing 2, hydroxyethylmethacrylic acid or 2, hydroxyethylacrylic acid as an addition-polymerizable monomer, the molding material may be alkaline. Since the mold material is softened by immersion in an aqueous solution and can be easily peeled and removed with a brush etc., there is no need to completely separate the copper wire part and the mold material mass when the mold parts are crushed. Therefore, efficient processing can be performed in a shorter time.

In addition, this recovery method does not require high temperatures such as thermal decomposition and melting, and can reduce the size of the processing apparatus.
Easy installation and industrialization.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a molded motor according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bracket 2 Bearing 3 Rotor 4 Rotor shaft 5 Stator iron core 6 Stator winding 7 Molding material 8 Mounting hole

Claims (3)

[Claims] 1. A step of crushing a molded part including a winding part and partially or entirely covered with a molding material; a step of separating the winding part from a crushed product; Immerse the wire in an alkaline aqueous solution
A step of heating and pressurizing to 50 ° C. or more and 2 atm or more. 2. The resin in the molding material is an unsaturated polyester resin, and thermally cured by using a monomer containing at least one of 2, hydroxyethyl methacrylic acid and 2, hydroxyethyl acrylic acid as an addition polymerizable monomer. 2. The method for recovering copper resources in a molded part according to claim 1, wherein: 3. The method for recovering copper resources in a molded part according to claim 1, wherein the insulating coating applied to the surface of the winding is a polyester-based or polyurethane-based resin.