JPH10266963A - Component for freezing compressor, and freezing compressor using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability, by performing treatment for preventing degradation of refrigerator oil to at least refrigerator oil contacting part of a freezing compressor, which uses hydrofluorocarbon groups as refrigerant and composition made of compound which has at least one ester group as refrigerator oil. SOLUTION: Hydrofluorocarbon group or hydrochlorofluorocarbon group is used as refrigerant and composition made of compound which has at least one ester group is used as refrigerator oil. Components which contacts with refrigerator oil of components of a freezing compressor are a casing 1, a stator 2, a rotor 3, a motor coil 4, a binding thread 5, and a compressing element 6, at least a part contacting with refrigerator oil of these components is formed with compound which has at least one carbodiimide group and can become membranous. Alternatively, by coating the component with compound which has at least one carbodiimide group and can become membranous, degradation of refrigerator oil is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component for a refrigerating compressor having a function of preventing deterioration of refrigerating machine oil and a refrigerating compressor using the component, and more particularly, to a component of a refrigerating compressor. In contrast, the present invention relates to a component for a refrigerating compressor provided with a function of preventing deterioration of refrigerating machine oil without impairing the functions required of the component and a refrigerating compressor using the component.

[0002]

2. Description of the Related Art Conventionally, non-polar dichlorodifluoromethane (CF ₂ Cl ₂ ) has been mainly used as a refrigerant in refrigeration cycles of refrigerators, refrigerators, air conditioners and the like. Mineral oil and the like were used. However, due to the recent problem of depletion of the ozone layer, the above-mentioned dichlorodifluoromethane containing a chlorine atom cannot be used, and instead, hydrofluorocarbons (hereinafter abbreviated as HFC) and hydrochlorofluorocarbons (hereinafter HCFC) are used. Abbreviated) is being used.

However, HFCs represented by HFC-134a have poor compatibility with conventionally used mineral oil-based refrigerating machine oils, and the mineral oil-based refrigerating machine oils precipitate at a low temperature portion in a refrigeration cycle. However, there is a problem that the mineral oil-based refrigerating machine oil does not efficiently circulate in the refrigerating cycle, and the lubricating property is reduced, and the wear of the compressor is increased. It is presumed that it does not endure.

For this reason, use of a composition comprising a compound having at least one ester group has been proposed as a refrigerating machine oil instead of a mineral oil based refrigerating machine oil.

However, the use of a refrigerating machine oil comprising a compound having one or more ester groups has the following problems. 1) Since the refrigerating machine oil is hydrophilic and contains moisture therein, depending on the operating conditions of the refrigerating compressor, the refrigerating machine oil is hydrolyzed depending on the operating conditions of the refrigerating compressor, which not only deteriorates the lubricating performance but also seizes the inside of the refrigerating compressor. May be broken.

2) Low molecular weight substances in organic materials used for insulating films, coil enameled wires, gaskets, etc., which are components of refrigeration compressors, have higher solubility of organic substances than mineral oil refrigeration oils. The organic material itself is extracted by the refrigerating machine oil or degraded by the refrigerating machine oil or refrigerant,
Decomposition products are generated, and these extractables and decomposition products themselves deteriorate the refrigerating machine oil, and further cause secondary reactions to degrade the refrigerating machine oil, or precipitate as precipitates and form capillaries in the refrigerating cycle. Not only may it clog or cause seizure of the refrigerating compressor, but also the deterioration of the organic material itself may impair the insulation of the components.

In order to solve the above problems, the following proposals have been made and various studies have been made. 1) Increase the hydrolysis resistance of refrigerator oil. 2) Develop materials with low molecular weight (extractable) as organic materials for use in insulating films, coil enamel wires, gaskets, etc., which are components of refrigeration compressors. 3) Improving the decomposition resistance of the organic material itself to the refrigerant and oil properties of a refrigerator.

[0008] Specifically, with respect to the above proposal 1),
For example, JP-A-6-287586 and JP-A-6-33
No. 6,594, JP-A-7-11278, JP-A-7-26279, etc., in order to increase the hydrolysis resistance of refrigerator oil, additives are added to the refrigerator oil or the structure of the refrigerator oil itself is modified. It has been suggested to do so.

Regarding the proposals 2) and 3),
For example, Japanese Patent Application Laid-Open Nos.
No. 78, JP-A-4-174909, JP-A-5
JP-A-15098, JP-A-6-345915, JP-A-7-336921, etc., have conventionally been used to improve the hydrolysis resistance of an insulating film which is a component of a refrigerating compressor. Use high molecular weight polyester film with reduced low molecular weight polyester film, or even stop using polyester film, polyphenylene sulfide with high hydrolysis resistance,
While it has been proposed to use polysulfone, polyimide, and polyethersulfone films, and to combine these highly hydrolyzable films with polyester films, it has been proposed to devise a cross-linking agent to be used as a coating material for motor coils. By modifying the coating material itself, the H
Attempts have been made to improve the resistance to HFC represented by FC-134a.

[0010]

However, the proposals made in the above-mentioned various prior arts involve improving the material in question or using an alternative material. Therefore, it is never a matter of improving those materials or developing a balanced material for the components of the refrigeration compressor while maintaining the performance conventionally required for the components of the refrigeration compressor. It's not easy.

For example, when an additive is added or the structure of the refrigerating machine oil itself is modified in order to increase the hydrolysis resistance of the refrigerating machine oil, physical properties such as viscosity, lubrication performance, and compatibility with the refrigerant of the refrigerating machine oil are reduced. Unlike the physical properties before addition or modification, hydrolysis resistance is good, but other properties may be insufficient.

[0012] For example, the replacement or compounding of a material in an insulating film complicates the processing step, increases the cost of the raw material itself, or has inferior properties such as workability in terms of physical properties. It is hard to say that it can withstand use.

The present invention solves the above-mentioned disadvantages of the prior art, and provides a refrigeration compressor provided with a function of preventing deterioration of refrigeration oil for components of the refrigeration compressor without impairing the functions required for them. It has been made to provide a component for a machine and a refrigeration compressor using such a component.

[0014]

Means for Solving the Problems In order to achieve the above object, the construction of the components for a refrigerating compressor adopted by the present invention is as follows.
In a refrigerating compressor using a composition comprising a compound having at least one ester group as a refrigerating machine oil, a component used in a portion in contact with the refrigerating machine oil (e.g., a hydrofluorocarbon or a hydrochlorofluorocarbon as a refrigerant) Motor excluding an enameled wire and an insulating film), wherein at least a portion of the refrigerating machine oil which is in contact with the refrigerating machine oil has a function of preventing the refrigerating machine oil from deteriorating. Is made using this component.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The refrigerating compressor referred to in the present invention means a composition comprising a hydrofluorocarbon or hydrochlorofluorocarbon as a refrigerant and a compound having at least one ester group as a refrigerating machine oil, for example, a polyoxyalkylene glycol-based, ester-modified One or more compounds selected from synthetic lubricating oils based on compounds having one or more ester groups in the molecule, such as ether-based or ester-based, are specifically used for refrigerators, room air conditioners, and district heating and cooling systems. Reciprocating compressor used for vending machines,
A rotary compressor, a scroll compressor and the like can be mentioned. A typical refrigerating compressor is shown in FIG. 1 (cross-sectional view) and FIG. 2 (cross-sectional view of a winding portion).

The components of the refrigerating compressor according to the present invention are used in the above-mentioned refrigerating compressor in a portion in contact with the refrigerating machine oil, and include a casing 1 as shown in FIG. The stator 2, the rotor 3, the motor coil 4, the binding yarn 5, and the compression element 6 can be exemplified.
Incidentally, the components of the refrigerating compressor according to the present invention do not include the enameled wire of the motor and the insulating film.

According to the present invention, at least a portion of the component of the refrigerating compressor described above, which is in contact with the refrigerating machine oil,
For example, by being formed of a compound having one or more carbodiimide groups and capable of forming a film, the compound has an effect of preventing deterioration of refrigerating machine oil.

The compound having at least one carbodiimide group and capable of forming a film as used in the present invention includes:
For example, the expression

Embedded image (Wherein, R ₁ is an isocyanate residue, n ₁ is 10 or more and 1
Group (I) represented by the following formula:

Embedded image (Wherein, R ₂ represents an isocyanate residue, R ₃ and R ₄ represent a terminal group, and n ₂ represents an integer of 10 or more and 100 or less) or a group (II) represented by the following formula:

Embedded image (Wherein, Y is a residue of a compound having a functional group reactive with isocyanate, R ₅ and R ₆ are isocyanate residues,
n ₃ and m are 100 ≧ n ₃ ≧ 10, 10 ≧ m ≧ 1 or 10
≧ n ₃ ≧ 1, 100 ≧ m ≧ 10 or 100 ≧ n ₃ ≧ 10,
And 100 to m, each representing an integer of m ≧ 10).

R ₁ in the above formula (I) is
The following groups can be exemplified.

Embedded image

The formula of the above group (I) is based on the infrared absorption (I
R) Those in which no isocyanate group is detected in the spectrum are represented by

Embedded image (R ₁ in the formula may not be the same). The same applies to the formula of the above group (III).

R ₃ and R ₄ in the above formula (II) include, for example,

Embedded image Or a residue of a monoisocyanate such as —NH ₂ , —N
HX (X represents an alkyl group), -COOH, -S
Functional groups such as H and -OH,

Embedded image And the like, and a terminal group of a compound having one functional group reactive with an isocyanate group due to a residue reacted with the isocyanate group.

As R ₂ in the formula of the above group (II), the same groups as R ₁ in the formula of the above group (I) can be exemplified.

On the other hand, as the Y in the formula of the above group (III), the following structures can be exemplified.

Embedded image (In the formula, Z is an alkylene group, a divalent cycloalkyl group,
A divalent cycloalkyl group having a substituent, a divalent aryl group or a divalent aryl group having a substituent, or

Embedded image And a group having a substituent such as a lower alkyl group or a lower alkoxy group on these skeletons. )

Examples of R ₅ and R ₆ in the formula of group (III) include the same groups as R ₁ in the formula of group (I).

That is, the compound represented by the formula of the above-mentioned group (III) is a copolymer of a compound obtained by reacting the compound giving the residue Y with an isocyanate group and a compound having at least one carbodiimide group. It represents. Note that n ₃ and m in the formula of the above group (III) are
100 ≧ n ₃ ≧ 10, 10 ≧ m ≧ 1 or 10 ≧ n ₃ ≧ 1,
100 ≧ m ≧ 10, or 100 ≧ n ₃ ≧ 10, 100 ≧
represents an integer of m ≧ 10.

The component of the present invention is, for example, a compound having one or more carbodiimide groups as described above and capable of forming a film, at least a portion of which is in contact with the refrigerating machine oil, and has a function of preventing the refrigerating machine oil from deteriorating. As an embodiment of the method, a method of coating a surface of a component for a refrigerating compressor (for example, a back surface of a casing or the like) with the above-mentioned compound or incorporating a member made of the above-mentioned compound is exemplified. can do.

In the component of the present invention, at least the portion in contact with the refrigerating machine oil only needs to have the action of preventing the refrigerating machine oil from deteriorating. Or another member different from the component may be incorporated.

As a method for coating the surface of a component for a refrigerating compressor with the above compound, the component is immersed in a solution of the above compound, and then dried to form a coating film or the inside of a casing. For example, a method of spray-coating or brush-coating a solution of the above compound can be exemplified.

The thickness of the compound having at least one carbodiimide group and capable of forming a film for exhibiting the effect of preventing deterioration of the refrigerating machine oil is preferably about 5 μm to 50 μm, and is preferably too thin at 5 μm or less. Therefore, the function of preventing deterioration cannot be exhibited, and the function is saturated when the thickness is 50 μm or more, and it is not necessary to further increase the thickness unless otherwise required.

On the other hand, in order to incorporate a member made of the above-mentioned compound into a component, it is necessary to first manufacture the member. It may be coated.

Examples of the member formed from the above compound itself include a film of the above compound. For example, the member may be produced from a solution of the above compound by a casting method or a compression molding method. The thickness is preferably 5 μm to 50 μm, and more preferably 25 μm to 50 μm, which is easy to handle.

Examples of the member obtained by coating the above-mentioned compound on an appropriate substrate include those obtained by applying a solution of the above-mentioned compound to a polyester film (substrate) or the like.
In this case, the thickness of the compound is preferably about 5 μm to 50 μm for the same reason as described above.

Furthermore, a member in which a thread-like or string-like base material is coated with the above compound may be obtained by immersing a conventionally used binding yarn in a solution of the above compound and then removing the solvent.

If the member manufactured as described above is used as, for example, a casing, a stator or a rotor, sandwiched between coils, or knitted into a binding yarn, the components can be prevented from deteriorating the refrigerating machine oil. An effect can be imparted.

[0036]

As described above, the present invention does not impair or hinder the function of the components of the refrigerating compressor.
Components for refrigeration compressors with a function to prevent deterioration of refrigeration oil without changing the components currently used,
Further, the present invention provides a refrigeration compressor using such components.

When a compound having at least one carbodiimide group and capable of forming a film is used, acidic components such as carboxylic acid, hydrogen halide, and phosphoric acid generated by decomposition of a refrigerating machine oil, a refrigerant and additives are used. In addition, the carbodiimide group of this compound captures water existing in the system before the ester bond is hydrolyzed, and prevents the oxidation value in the system from increasing, thereby preventing deterioration of the refrigerating machine oil. .

[0038]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

In the examples, the following compounds having a carbodiimide group were used. Compound 1

Embedded image Compound 2

Embedded image Compound 3

Embedded image Compound 4

Embedded image Compound 5

Embedded image Compound 6

Embedded image Compound 7

Embedded image Compound 8

Embedded image Compound 9

Embedded image Compound 10

Embedded image

Example 1 A 6% by weight solution of the above compound 1 in tetrachloroethylene was
After spraying the inside of the casing 1 shown in FIG. 1, the solvent is removed, and a baking treatment is further performed at 200 ° C. for 3 minutes.
A 10 μm thick coating of Compound 1 was applied. A refrigeration compressor was prepared using this casing, and a refrigerant and refrigeration oil were injected and operated for three months. Thereafter, the refrigerating compressor was disassembled, and the appearance of the coating film and the total oxidation value of the refrigerating machine oil were measured.
Table 1 shows the results.

Example 2 A 6% by weight solution of the above compound 2 in tetrachloroethylene was
After immersing the rotor 4 shown in FIG.
A baking treatment was performed at 20 ° C. for 5 minutes. This rotor was immersed again in the above solution, and after removing the solvent,
For 5 minutes to prepare a rotor with a coating film having a thickness of 15 μm. A refrigeration compressor was prepared using this rotor, and a refrigerant and refrigerating machine oil were injected and operated for three months. Thereafter, the refrigerating compressor was disassembled, and the appearance of the coating film and the total oxidation value of the refrigerating machine oil were measured. Table 1 shows the results.

Example 3 An 8% by weight solution of a 3: 1 (weight ratio) mixture of the above-mentioned compound 2 and compound 3 was applied several times to the coil 7 shown in FIG. 1 with a brush, and the solvent was removed. A baking treatment was performed at 170 ° C. for 5 minutes to form a coil having a coating film having a thickness of 7 μm. A refrigerating compressor was prepared using this coil, and a refrigerant and refrigerating machine oil were injected and operated for three months. Thereafter, the refrigerating compressor was disassembled, and the appearance of the coating film and the total oxidation value of the refrigerating machine oil were measured. Table 1 shows the results.

Example 4 A 30 μm thick film was prepared from a 10% by weight solution of the above compound 4 in tetrachloroethylene by a casting method. This film was sandwiched between the coil and the wedge-shaped insulating film 7 shown in FIG. A refrigerating compressor was prepared using this coil, and a refrigerant and refrigerating machine oil were injected and operated for three months. Thereafter, the refrigerating compressor was disassembled, and the appearance of the compound 4 film and the total oxidation value of the refrigerating machine oil were measured. Table 1 shows the results.

Example 5 A slot insulating film 8 shown in FIG. 2 was immersed twice in a 7% by weight solution of a mixture of the above compound 5 and compound 2 in a 1: 5 (weight ratio) tetrahydrofuran to remove the solvent. ,
A baking treatment was performed at 200 ° C. for 8 minutes, and a 10 μm coating film was applied to both sides of the slot insulating film. A refrigerating compressor was prepared using the slot insulating film, and a refrigerant and a refrigerating machine oil were injected and operated for three months. Thereafter, the refrigerating compressor was disassembled, and the appearance of the slot insulating film and the total oxidation value of the refrigerating machine oil were measured. Table 1 shows the results.

Example 6 A powder of the above compound 6 was applied at 200 ° C. for 3 minutes under a surface pressure of 50 k.
The film was compression molded at a pressure of g / cm ² to obtain a film having a thickness of 20 μm. This film was sandwiched between coils as a pair with the interlayer insulating film 9 shown in FIG. A refrigerating compressor was prepared using this coil, and a refrigerant and refrigerating machine oil were injected and operated for three months. After that, dismantle the refrigeration compressor,
The appearance of the film and the total oxidation value of the refrigerator oil were measured. Table 1 shows the results.

Example 7 The binding yarn 5 shown in FIG. 1 was immersed in a 6% by weight solution of the above compound 7 in tetrahydrofuran / N-meterpyrrolidone = 50: 50, the solvent was removed, and the mixture was baked at 150 ° C. for 10 minutes. After the treatment, a binding yarn having a coating film of compound 7 having a thickness of 8 μm was prepared, and a coil was prepared using the binding yarn. A refrigerating compressor was prepared using this coil, and a refrigerant and refrigerating machine oil were injected and operated for three months. Thereafter, the refrigerating compressor was disassembled, and the appearance of the binding yarn and the total oxidation value of the refrigerating machine oil were measured. Table 1 shows the results.

Example 8 A film having a thickness of 20 μm was prepared from an 8 wt% solution of a mixture of the above-mentioned compound 8 and compound 4 in a 1:10 (weight ratio) tetrahydrofuran by a casting method. This film was sliced into a string with a width of 0.5 mm. Knitting this string-like film as a core material into the binding yarn 5 shown in FIG.
Using this, a coil was created. A refrigerating compressor was prepared using this coil, and a refrigerant and refrigerating machine oil were injected and operated for three months. Thereafter, the refrigerating compressor was disassembled, and the appearance of the binding yarn and the total oxidation value of the refrigerating machine oil were measured. Table 1 shows the results.

Example 9 A 6% by weight solution of the above compound 9 in tetrahydrofuran / N-methylpyrrolidone = 50: 50 was sprayed on the stator 2 shown in FIG. 1 to remove the solvent. Then 180
A baking treatment was performed at 5 ° C. for 5 minutes to prepare a stator having a 10 μm coating film of Compound 9. A refrigeration compressor was prepared using this stator, and a refrigerant and refrigerating machine oil were injected and operated for three months. Thereafter, the refrigerating compressor was disassembled, and the appearance of the coating film and the total oxidation value of the refrigerating machine oil were measured. Table 1 shows the results.

Example 10 A 6% by weight solution of the above-mentioned compound 10 in tetrahydrofuran was applied by brush to portions of the compression element 6 shown in FIG. 1 which did not impair the original function and which were in contact with the refrigerating machine oil. After the removal, baking treatment was performed at 200 ° C. for 10 minutes. A refrigerating compressor was prepared using the compression element, the coil prepared in Example 4, and the binding yarn prepared in Example 7, and a refrigerant and a refrigerating machine oil were injected and operated for three months. Thereafter, the refrigerating compressor was disassembled, and the appearance of each of the coating film and the binding yarn and the total oxidation value of the refrigerating machine oil were measured. Table 1 shows the results.

Comparative Example 1 A refrigeration compressor was prepared using exactly the same components except that a compound having at least one carbodiimide group was not used, and a refrigerant and a refrigerating machine oil were injected and operated for 3 months. Was. Thereafter, the refrigerating compressor was disassembled, and the appearance of each component and the total oxidation value of the refrigerating machine oil were measured. Table 1 shows the results.

[0051]

[Table 1]

The refrigerant and refrigerating machine oil used in the examples and comparative examples are as follows. Refrigerant: R407C (R32 / R134a, R125-3)
R410A (Two mixed refrigerants of R32 / R125) R404A (Third mixed refrigerant of R125 / R143a / R134a) Refrigeration oil: Ester oil (water content 500 ppm)

[0053]

As is apparent from the above Examples and Comparative Examples, the components for a refrigerating compressor of the present invention have an excellent effect of sufficiently suppressing the increase in the total oxidation value and having the effect of preventing the refrigerating machine oil from deteriorating. It is a thing.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a refrigerating compressor.

FIG. 2 is a sectional view of a winding portion in the refrigeration compressor of FIG.

[Explanation of symbols]

 Reference Signs List 1 casing 2 stator 3 rotor 4 motor coil 5 binding thread 5 6 compression element 7 wedge-shaped insulating film 8 slot insulating film 9 interlayer insulating film

Claims (10)

[Claims] 1. A part in contact with a refrigerating machine oil in a refrigerating compressor using a composition comprising a compound having at least one ester group as a refrigerating machine oil, using a hydrofluorocarbon or a hydrochlorofluorocarbon as a refrigerant. A component for a refrigerating compressor, which is a component (except for an enameled wire of a motor and an insulating film), wherein at least a portion in contact with the refrigerating machine oil has a function of preventing the refrigerating machine oil from deteriorating. 2. The component for a refrigerating compressor according to claim 1, wherein the component is a casing, a stator, a rotor, a coil, a binding thread, or a compression element. 3. The method according to claim 1, wherein at least a portion in contact with the refrigerating machine oil is formed of a compound having at least one carbodiimide group and capable of forming a film, thereby having an effect of preventing the refrigerating machine oil from deteriorating. Component for a refrigeration compressor as described. 4. A film having at least one carbodiimide group and coated with a compound capable of forming a film.
A component for a refrigeration compressor according to claim 1. 5. A function of preventing deterioration of the refrigerating machine oil by incorporating a member made of a compound having at least one carbodiimide group and capable of forming a film at least in a portion in contact with the refrigerating machine oil. A component for a refrigeration compressor according to claim 1. 6. The component for a refrigerating compressor according to claim 5, wherein the member made of a compound having at least one carbodiimide group and capable of forming a film is formed of the compound. 7. The component for a refrigerating compressor according to claim 5, wherein the member made of a compound having at least one carbodiimide group and capable of forming a film is obtained by coating a base material with the compound. 8. The component for a refrigerating compressor according to claim 6, wherein the member made of a compound having at least one carbodiimide group and capable of forming a film is in the form of a film. 9. The component for a refrigerating compressor according to claim 6, wherein the member made of a compound having at least one carbodiimide group and capable of forming a film is in the form of a thread or a string. 10. A refrigeration compressor using the components according to claim 1.