JP2011220190A - Electric compressor, permanent magnet for the same, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet that can exhibit superior corrosion resistance, even if an acid is generated in a cooling medium circulation passage of an air conditioner, along with a method of manufacturing the same and an electric compressor with the permanent magnet.SOLUTION: The electric compressor includes: a housing 10 having an inhalation port 11 and a discharging port 12; a compression unit 15 which is arranged in the housing 10, compresses the cooling medium inhaled from the inhalation port 11, and discharges it from the discharging port 12; and an electric motor 2 which is arranged in the housing 10, and rotates a rotating shaft 21 for driving the compression unit 15. The electric motor 2 includes a rotor 22 fixed around the rotating shaft 21, a stator 23 supported to the housing 10, and a plurality of the permanent magnets 3 embedded in the rotor 22. The permanent magnet 3 has, on its surface, a chemical adsorption film having at least one of a hydroxy group and an amino group.

Description

  The present invention relates to an electric compressor used in a refrigeration cycle.

In refrigeration cycles such as in-vehicle air conditioners, refrigerants that have less influence on ozone layer destruction than conventional refrigerants have been used as part of measures to prevent global warming. As such a new type of refrigerant, for example, a molecular formula represented by CF ₃ —CF═CH ₂ (2,3,3,3-tetrafluoro-1-propene) described in Patent Document 1: C ₃ H _m F _n (where m is an integer of 1 to 5, n is an integer of 1 to 5, and m + n = 6), and a refrigerant having one double bond in the molecular structure has attracted attention. (Hereinafter referred to as “HFO1234yf type refrigerant” as appropriate).

JP 2009-225636 A

  Since the HFO1234yf type refrigerant includes a double bond as described above, it has a characteristic that it is relatively easily decomposed by the influence of air, water, acid, heat, and the like. Therefore, when air, water, or an acid is mixed in the refrigerant circulation path, the refrigerant is decomposed, and hydrofluoric acid (HF) is generated from F constituting the refrigerant. So-called “acids” such as hydrofluoric acid cause corrosion of metal members having low corrosion resistance relatively early.

  Among the components constituting the electric compressor used in the refrigeration cycle, the one having the lowest corrosion resistance is a permanent magnet built in the electric motor. As the permanent magnet, a ferrite magnet or a rare earth magnet is mainly used, and these are easily corroded in the presence of an acid. In particular, rare earth magnets tend to corrode more easily than ferrite magnets. If the permanent magnets of the electric motor are corroded, the performance is lowered, and as a result, the performance of the entire electric compressor may be lowered.

  Such problems are not limited to HFO1234yf type refrigerants, and new types of refrigerants to be developed in the future, or lubricating oils arranged in the electric compressor together with the refrigerants, can be decomposed for some reason to generate acid. If this is the case, similar problems may arise.

The present invention has been made in view of such problems, and includes a permanent magnet that can exhibit excellent corrosion resistance even if acid is generated in the refrigerant circulation path of the refrigeration cycle, a method for manufacturing the permanent magnet, and the permanent magnet. An electric compressor is to be provided.
The permanent magnet built in the electric motor can be usually provided with a desired magnetic property by forming it into a desired shape and then applying a magnetizing step. Regardless of before and after the process, a magnet body that is finally formed into a desired shape to be incorporated in an electric motor is expressed as a permanent magnet.

According to a first aspect of the present invention, there is provided a housing provided with a suction port and a discharge port, a compression portion that is disposed in the housing and that compresses refrigerant sucked from the suction port and discharges the refrigerant from the discharge port, and is disposed in the housing And an electric compressor having an electric motor that rotates a rotating shaft that drives the compression unit,
The electric motor has a rotor fixed around the rotating shaft and a stator supported by the housing, and a plurality of permanent magnets built in the rotor,
The permanent magnet is in an electric compressor characterized in that a chemical adsorption film having at least one of a hydroxy group and an amino group is formed on the surface of the permanent magnet.

  A second invention is a permanent magnet used in the electric compressor of the first invention, wherein a chemical adsorption film having at least one of a hydroxy group and an amino group is formed on the surface of the permanent magnet. It exists in the permanent magnet for compressors (Claim 7).

A third invention is a method of manufacturing a permanent magnet used in the electric compressor of the first invention,
A film-forming aqueous solution comprising an alkaline aqueous solution containing at least one of amines and hydroxys and having a pH adjusted to 8 to 10 is prepared. After the permanent magnet is brought into contact with the film-forming aqueous solution, the permanent An electric compressor comprising a film forming step of forming a chemically adsorbing film having at least one of a hydroxy group and an amino group on the surface of the permanent magnet by drying the film forming aqueous solution on the magnet surface. A method for manufacturing a permanent magnet for use (claim 9).

  As described above, the electric compressor of the present invention (first invention) is a permanent magnet (second magnet) formed by positively forming a chemical adsorption film having at least one of a hydroxy group and an amino group, which are alkali groups, on the surface. This is incorporated and incorporated. Therefore, even if the circulating refrigerant or lubricating oil changes in quality and acid is generated, it is possible to suppress the permanent magnet from being corroded by the acid, thereby suppressing the performance degradation of the permanent magnet, and hence the performance degradation of the entire electric compressor. Can be achieved.

  That is, by forming the chemical adsorption film on the permanent magnet, it is possible to block the active sites that are the starting points of corrosion on the surface of the permanent magnet and suppress the occurrence of corrosion. A functional group having an alkalinity, such as a hydroxy group or an amino group, reacts with an acid to neutralize the acid. In other words, the chemical adsorption film exhibits an anticorrosion / neutralization effect. Thereby, the permanent magnet provided with the said chemical adsorption film becomes difficult to corrode also in presence of an acid, and becomes the thing excellent in durability.

  Further, the permanent magnet having excellent corrosion resistance is obtained by bringing a permanent magnet formed into a desired shape into contact with an alkaline aqueous solution having a pH of 8 to 10 containing at least one of amines and hydroxys, and then on the permanent magnet. It can be easily prepared by drying the aqueous solution for film formation (third invention). That is, the acid corrosion resistance of the permanent magnet can be improved by simply bringing the permanent magnet into contact with the aqueous solution for film formation and then drying. Therefore, a permanent magnet suitable for an electric compressor can be easily manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram illustrating a configuration of an electric compressor according to a first embodiment. FIG. 3 is an explanatory diagram illustrating a configuration of an electric motor in the first embodiment. FIG. 3 is an explanatory diagram when the rotor is viewed from the axial direction in the first embodiment. FIG. 3 is a perspective view of a permanent magnet in the first embodiment. Explanatory drawing which shows the structure of the vehicle-mounted air conditioner in Example 1. FIG. Explanatory drawing which shows the reaction process in Example 1 which a refrigerant | coolant decomposes | disassembles and becomes hydrofluoric acid.

The chemical adsorption film provided on the permanent magnet of the electric compressor of the present invention is formed by chemically adsorbing an amino group, a hydroxy group, or a compound having these on the surface of the permanent magnet. Here, the amino group is defined as a monovalent functional group (—NH ₂ , —NHR, —NRR ′) obtained by removing hydrogen from ammonia, a primary or secondary amine. Note that this definition is not intended to limit the raw material of the amino group, but merely defines the structure, and those having the above structure from a tertiary amine are naturally included in the amino group.

  Further, the components of the chemical adsorption film depend on the amines and hydroxys contained in the film-forming aqueous solution used in the film-forming step, and depend on the structure containing only the hydroxy group, the structure containing only the amino group, and the hydroxy group and amino group. Either of the configurations including both groups can be taken.

The chemisorbed film is a very thin film formed by chemically adsorbing each of the so-called functional groups or a compound having the functional group at the molecular level.
The presence or absence of the chemical adsorption film can be confirmed by confirming the presence of an amino group or a hydroxy group by a method such as Raman spectroscopy, infrared spectroscopy, or SIMS analysis.

  The permanent magnet may be a rare earth magnet. As a permanent magnet for an electric compressor, a ferrite magnet or the like can be applied, but a rare earth magnet is more suitable from the viewpoint of magnetic characteristics. On the other hand, rare earth magnets tend to corrode more easily than ferrite magnets. Therefore, it is particularly effective to adopt a configuration in which the chemical adsorption film is formed on the surface of the permanent magnet.

  In addition, the permanent magnet may have a structure in which a film made of a nonmagnetic metal is formed on the surface thereof, and the chemical adsorption film is formed on the surface of the film (claims 2 and 8). Examples of the coating made of the nonmagnetic metal include a coating of a metal such as aluminum, nickel, and copper. As a film forming method, various known film forming methods such as a plating method, a sputtering method, and a vapor deposition method can be employed. Then, as in this case, a film made of a nonmagnetic metal is provided on the surface of the permanent magnet, and the chemical adsorption film having at least one of a hydroxy group and an amino group is formed on the surface, thereby forming the film. The anticorrosion effect and the anticorrosion / neutralization effect by the chemical adsorption film can be combined to further enhance the corrosion resistance of the permanent magnet.

  Moreover, it is preferable that the said electric compressor is for vehicle-mounted air conditioners provided with nonmetallic piping in the circulation path (Claim 4). The on-vehicle air conditioner includes a condenser, an expansion valve, an evaporator, and the like in addition to the compressor, and has a configuration in which refrigerant and lubricating oil are enclosed in a circulation path that connects these. In order to give flexibility to a part of the pipes constituting the circulation path, rubber pipes as non-metallic pipes are often adopted. Non-metallic pipes such as rubber pipes have a characteristic of allowing moisture to permeate even though very little. Therefore, for example, if it is used for many years in a hot and humid environment, there is a risk that moisture may enter the circulation path from the air through rubber piping or the like. Therefore, in-vehicle air conditioners equipped with rubber piping etc. in the circulation path generate acid due to decomposition of the refrigerant as described above, compared to other refrigeration cycles that do not use non-metallic piping such as rubber piping. It can be said that is likely to occur. Therefore, the configuration in which the chemical adsorption film is provided on the surface of the permanent magnet is a very effective configuration for improving the durability of the electric compressor employed in the on-vehicle air conditioner having a non-metallic pipe in the circulation path.

The electric compressor has a molecular formula: C ₃ H _m F _n (where m is an integer of 1 to 5, n is an integer of 1 to 5, and m + n = 6). It is preferably used in a refrigeration cycle in which a refrigerant having one bond or a mixed refrigerant containing the refrigerant is circulated. This HFO1234yf type refrigerant may decompose in the presence of moisture to generate hydrofluoric acid as described above. Therefore, a configuration in which the chemical adsorption film capable of exhibiting the anticorrosion / neutralization effect is provided on the surface of the permanent magnet is very effective.

  The electric compressor is also effective when a lubricating oil containing at least one of polyol ester (POE), polyvinyl ether (PVE), and polyalkylene glycol (PAG) is contained in the housing. 6). Even when these lubricating oils are included, it is not preferable that water, acid, or the like enter the refrigerant circulation path. For example, a polyol ester is hydrolyzed in the presence of moisture to generate an organic carboxylic acid. The organic carboxylic acid can cause the permanent magnet to corrode similarly to the hydrofluoric acid described above. Therefore, also in this case, it is very effective to provide the above-mentioned chemical adsorption film on the surface of the permanent magnet that can exhibit the anticorrosion and neutralization effect.

  Next, as described above, the method for producing the permanent magnet prepares a film-forming aqueous solution comprising an alkaline aqueous solution containing at least one of amines and hydroxys and having a pH adjusted to 8 to 10, and A chemical adsorption film having at least one of a hydroxy group and an amino group on the surface of the permanent magnet by contacting the permanent magnet with the aqueous solution for film formation and then drying the aqueous solution for film formation on the surface of the permanent magnet. A film forming step for forming the film.

  By making the film-forming aqueous solution weakly alkaline with a pH of 8 to 10, it is possible to create an environment in which amino groups or hydroxy groups derived from amines or hydroxys are easily chemically adsorbed to the metal constituting the permanent magnet. The pH may be adjusted by simply mixing amines or hydroxys with water, and may be adjusted by adding sodium carbonate or other alkali as necessary.

  The amines preferably comprise at least one of triethanolamine, methylamine, etheramine, ethylamine, trimethylamine, triethylamine, and benzotriazole (claim 10). By using the weak alkaline aqueous solution for film formation containing these amines, amino groups generated from the respective amines can be easily chemically adsorbed on the surface of the permanent magnet. .

  The hydroxys are propane-1,2-diol, 2,6-dimethylphenol, 2- (hydroxymethyl) phenol, 1- (3-hydroxyphenyl) -2 (methylamino) ethane-1-ol. Of these, it is preferable to comprise at least one kind. By using the weak alkaline film-forming aqueous solution containing these hydroxys, compounds containing hydroxy groups generated from the hydroxys can be easily chemically adsorbed on the surface of the permanent magnet.

  The film-forming aqueous solution preferably contains a surfactant (claim 12). In this case, the effect of washing the surface of the permanent magnet with the surfactant can be obtained, and the adsorption effect can be enhanced to increase the production reaction rate of the chemical adsorption film. Examples of the surfactant include a nonionic surfactant alkyl ether type.

  The contact between the permanent magnet and the aqueous solution for film formation in the film formation step is preferably performed by immersing the permanent magnet in the aqueous solution for film formation and holding for 1 to 60 minutes. ). That is, as a method for bringing the permanent magnet into contact with the film-forming aqueous solution, the dipping method (dipping) as described above is adopted, and the method for holding the time is relatively easy and preferable. The holding time can be selected within the above time although the optimum time varies depending on the properties and temperature of the aqueous solution for film formation. The optimum time for mass production can be easily confirmed without requiring excessive trial and error by conducting a plurality of preliminary experiments in which the composition of the aqueous solution for film formation and the immersion time are changed.

  The film-forming aqueous solution in which the permanent magnet is immersed is preferably heated to a temperature of 60 to 90 ° C. Thereby, the adsorption reaction rate of the chemical adsorption film on the surface of the permanent magnet can be increased. As described above, the optimum temperature and immersion time can be easily confirmed by performing a plurality of preliminary experiments without particularly requiring excessive trial and error. When the film-forming aqueous solution is less than 60 ° C., the reaction rate improving effect is small, and when it exceeds 90 ° C., the concentration of the film-forming aqueous solution may not be stable.

  Moreover, it is preferable to dry the aqueous solution for film formation by holding the permanent magnet in an atmosphere of 100 to 150 ° C. Thereby, the water | moisture content of the aqueous solution for film formation which exists on a permanent magnet can be removed at an early stage. When the atmospheric temperature is less than 100 ° C, the effect of early moisture removal is small, and when it exceeds 150 ° C, the magnet may be deteriorated.

  In addition, as the film forming step, for example, after the permanent magnet is molded, when the cleaning liquid for cleaning the surface is sprayed, the film forming aqueous solution is mixed in the cleaning liquid. Can be substituted.

Example 1
An electric compressor and a permanent magnet used therefor according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the electric compressor 1 of this example includes a housing 10 provided with a suction port 11 and a discharge port 12, and compresses refrigerant that is disposed in the housing 10 and sucks from the suction port 11 to discharge the port 12. And the electric motor 2 that rotates the rotating shaft 21 that is disposed in the housing 10 and drives the compression unit 15.

  The compression unit 15 includes a fixed scroll 13 fixed in the housing 10 and a movable scroll 14 disposed to face the fixed scroll 13. A variable volume compression chamber 150 for compressing the refrigerant is formed between the fixed scroll 13 and the movable scroll 14. The movable scroll 14 is connected to the eccentric pin 210 of the rotary shaft 21 via the bearing 216 and the eccentric bush 215, and swings in accordance with the rotation of the rotary shaft 21 to change the volume of the compression chamber 150. Has been.

The rotating shaft 21 is fixed to the center hole 221 of the rotor 22 constituting the electric motor 2, and both ends protruding from the center hole 221 to both sides are fixed to the housing 10 via bearing portions 41 and 42 so as to be rotatable. .
As shown in FIGS. 1 and 2, the electric motor 2 includes a rotor 22 fixed around the rotating shaft 21 and a stator 23 supported by the housing 10 on the outer peripheral side of the rotor 22. The stator 23 is provided with a coil 235, and the rotor 22 having the permanent magnet 3 built therein is rotated by energizing the coil 235.

  As shown in FIGS. 1 to 3, the rotor 22 is formed in a cylindrical shape by laminating a plurality of electromagnetic steel plates, and has six magnet arrangement holes 222 penetrating in the axial direction. . These magnet arrangement holes 222 are each provided in a shape corresponding to the plate-like permanent magnet 3 (FIG. 4), and are arranged so as to exhibit a hexagonal shape as a whole when viewed from the axial direction.

  As the permanent magnet 3 inserted and arranged in each magnet arrangement hole 222, a known neodymium magnet (rare earth magnet) mainly composed of neodymium (Nd), iron (Fe), and boron (B) was employed. The permanent magnet 3 of this example is formed by forming a chemical adsorption film having at least an amino group on the surface thereof.

Here, a method for manufacturing the permanent magnet 3 will be described.
In producing the permanent magnet 3 of this example, first, a sintered magnet body is cut and polished using a powder prepared as a desired component of a neodymium magnet, and a plate-like magnet body (permanent magnet 3) having a desired shape is obtained. Is made.
Next, after cleaning the surface of the permanent magnet 3 to remove foreign matters, a film forming process for forming a chemical adsorption film is performed.

The film forming step is performed by bringing the permanent magnet 3 into contact with an aqueous solution for film formation that is an alkaline aqueous solution having a pH of 8 to 10, and then drying.
Specifically, first, as an aqueous solution for film formation, an aqueous solution in which 3 wt% of triethanolamine and 1 wt% of polyoxyalkylene alkyl ether as a surfactant are added to 1 liter of water to adjust the pH to 8. Prepare.

  Next, the film-forming aqueous solution is heated to 60 ° C., and the permanent magnet 3 is immersed in this for 3 minutes. Thereafter, the permanent magnet 3 is pulled up from the alkaline aqueous solution, put into an oven having an air atmosphere of 100 ° C., and held for 60 minutes. The permanent magnet 3 taken out from the oven is left until it reaches room temperature. Thereby, the film forming step is completed, and a chemically adsorbed film containing an amino group is formed on the surface of the permanent magnet 3. The obtained chemisorbed film is a thin film at the molecular level and is not shown.

  The permanent magnet 3 having the chemical adsorption film on its surface is inserted into the magnet arrangement hole 222 of the rotor 22. Thereafter, the permanent magnet 3 incorporated in the rotor 22 is subjected to a magnetizing step so that the permanent magnet 3 has desired magnetic characteristics. Thereafter, the state in which the permanent magnet 3 itself is attracted to the rotor 22 is maintained by the magnetic attractive force of the permanent magnet 3. The arrangement state of the electric motor 2 including the rotor 22 in the electric compressor 1 is as described above.

In this example, as shown in FIG. 5, the electric compressor 1 having the above configuration is used as a compressor of the in-vehicle air conditioner 5.
As shown in the figure, the in-vehicle air conditioner 5 includes a condenser 51, a receiver 52, an expansion valve 53, and an evaporator 54 that are sequentially communicated by a circulation path 55 from the discharge port 12 side of the electric compressor 1. . The expansion valve 53 is configured such that the valve opening degree of the expansion valve 53 is adjusted by the control unit 57 in accordance with the temperature of the refrigerant measured by the temperature sensor 56 disposed on the downstream side of the evaporator 54. In addition, CF ₃ —CF═CH ₂ (2,3,3,3-tetrafluoro-1-propene) is sealed as a refrigerant in the circulation path 55, that is, the electric compressor 1, and the lubricating oil As a result, a polyol ester is encapsulated. And as for some piping which comprises the circulation path 55, the rubber piping which is nonmetallic piping is employ | adopted.

  When the vehicle-mounted air conditioner 5 having such a configuration is operated for a long period of time, moisture penetrates into the circulation path 55 through the rubber piping constituting the circulation path 55. Due to the moisture, the refrigerant may be decomposed to generate hydrofluoric acid. As shown in FIG. 6, the refrigerant decomposition reaction can be described as follows.

First, as a first step (Step I), a phenomenon occurs in which the OH group of water (H ₂ O) that has entered the refrigerant attacks the double bond portion in CF ₃ —CF═CH ₂ . Then, the process proceeds from the first step (Step I) to the second step (Step II), the double bond portion is broken and the OH group is bonded, and further proceeds to the third step (Step III). As a result, it is pulled back and O and C are double-bonded and F is released as in the fourth step (Step IV). Thereby, F and H are combined to generate hydrofluoric acid (HF).

  In this example, polyol ether is used as the lubricating oil. This may be hydrolyzed in the presence of water to produce a carboxylic acid (not shown).

  When hydrofluoric acid or carboxylic acid is generated in the refrigerant in this way, the permanent magnet 3 containing Fe and Nd is placed in an environment where it is easily corroded. The ease of corrosion can generally be evaluated by the standard electrode potential in the molten salt, and it can be said that Fe has a low standard electrode potential, but Nd is much lower than Fe and is a very base metal. It is. For this reason, when the permanent magnet is a neodymium magnet, the Nd-rich grain boundary portion in the metal structure tends to be an active point that becomes the base point of corrosion.

  Here, as described above, the permanent magnet 3 employed in this example has a chemical adsorption film having an amino group on its surface. The chemically adsorbed film plays a role of blocking the active sites that are the starting points of corrosion of the surface of the permanent magnet 3. Furthermore, an alkaline functional group called an amino group reacts with an acid and functions to neutralize the acid. That is, in the permanent magnet 3 of the present example, the chemically adsorbed film present on the surface exhibits an anticorrosion / neutralization effect. Thereby, compared with the case where the permanent magnet 3 is not provided with the said chemical adsorption film, corrosion resistance improves remarkably and it becomes the thing excellent in durability. As a result, the performance degradation of the permanent magnet 3 can be suppressed, and consequently the performance degradation of the entire electric compressor 1 can be suppressed.

  The moisture that has entered the inside from the rubber pipe can be removed by the desiccant disposed in the receiver 52 for a considerable period, and there is almost no adverse effect due to the moisture during the period when the desiccant is functioning. Needless to say.

DESCRIPTION OF SYMBOLS 1 Electric compressor 10 Housing 11 Suction port 12 Discharge port 15 Compression part 2 Electric motor 21 Rotating shaft 22 Rotor 23 Stator 3 Permanent magnet 5 In-vehicle air conditioner

Claims (15)

A housing provided with a suction port and a discharge port; a compression unit disposed in the housing for compressing a refrigerant sucked from the suction port and discharging the refrigerant from the discharge port; and a drive unit disposed in the housing for driving the compression unit In an electric compressor having an electric motor for rotating a rotating shaft
The electric motor has a rotor fixed around the rotating shaft and a stator supported by the housing, and a plurality of permanent magnets built in the rotor,
The permanent magnet is obtained by forming a chemically adsorbing film having at least one of a hydroxy group and an amino group on the surface of the permanent magnet.   2. The electric compressor according to claim 1, wherein the permanent magnet is a rare earth magnet.   3. The electric compression according to claim 1, wherein the permanent magnet has a film made of a non-magnetic metal formed on a surface thereof, and the chemical adsorption film is formed on the surface of the film. Machine.   The electric compressor according to any one of claims 1 to 3, wherein the electric compressor is for an in-vehicle air conditioner having a non-metallic pipe in a circulation path. 5. The electric compressor according to claim 1, wherein the electric compressor has a molecular formula: C ₃ H _m F _n (where m is an integer of 1 to 5, n is an integer of 1 to 5, and m + n = 6) An electric compressor characterized by being used in a refrigeration cycle in which a refrigerant having one double bond in a molecular structure or a mixed refrigerant containing the refrigerant is circulated.   The electric compressor according to any one of claims 1 to 5, wherein the electric compressor includes a lubricating oil containing at least one of a polyol ester (POE), a polyvinyl ether (PVE), and a polyalkylene glycol (PAG) in the housing. The electric compressor characterized by including in.   It is a permanent magnet used for the electric compressor of any one of Claims 1-6, Comprising: The chemical adsorption film which has at least one of a hydroxyl group and an amino group is formed in the surface of this permanent magnet The permanent magnet for electric compressors characterized by the above-mentioned.   8. The electric compressor according to claim 7, wherein a film made of a nonmagnetic metal is formed on the surface of the permanent magnet, and the chemical adsorption film is formed on the surface of the film. permanent magnet. A method for producing a permanent magnet for use in the electric compressor according to any one of claims 1 to 6,
A film-forming aqueous solution comprising an alkaline aqueous solution containing at least one of amines and hydroxys and having a pH adjusted to 8 to 10 is prepared. After the permanent magnet is brought into contact with the film-forming aqueous solution, the permanent An electric compressor comprising a film forming step of forming a chemically adsorbing film having at least one of a hydroxy group and an amino group on the surface of the permanent magnet by drying the film forming aqueous solution on the magnet surface. Of manufacturing permanent magnets for use.   10. The permanent magnet for an electric compressor according to claim 9, wherein the amine comprises at least one of triethanolamine, methylamine, etheramine, ethylamine, trimethylamine, triethylamine, and benzotriazole. Production method.   11. The hydroxy compound according to claim 9, wherein the hydroxy group includes propane-1,2-diol, 2,6-dimethylphenol, 2- (hydroxymethyl) phenol, 1- (3-hydroxyphenyl) -2 (methylamino). ) A method for producing a permanent magnet for an electric compressor, comprising at least one of ethane-1-ol.   The method for producing a permanent magnet for an electric compressor according to any one of claims 9 to 11, wherein the film-forming aqueous solution contains a surfactant.   The contact between the permanent magnet and the film-forming aqueous solution in the film forming step according to any one of claims 9 to 12, wherein the permanent magnet is immersed in the film-forming aqueous solution for 1 to 60 minutes. The manufacturing method of the permanent magnet for electric compressors characterized by performing by hold | maintaining.   The method for producing a permanent magnet for an electric compressor according to claim 13, wherein the film-forming aqueous solution in which the permanent magnet is immersed is heated to a temperature of 60 to 90 ° C.   15. The permanent compressor for an electric compressor according to claim 9, wherein the film-forming aqueous solution is dried by holding the permanent magnet in an atmosphere of 100 to 150 ° C. 15. Magnet manufacturing method.

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