JP2017031978A - Refrigerant compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed refrigerant compressor including a member (internal member) using nitrile rubber not including phthalic acid ester, capable of suppressing degradation of quality of the member and realizing high reliability.SOLUTION: A refrigerant compressor is disposed in a sealed container 10 accommodating a refrigerant or a lubricant in which the refrigerant is dissolved, and at least one internal member configuring an electric element 20 and a compression element 30, is composed of a rubber material. The rubber material has a condition 1 that a content of bound acrylonitrile is within a range of 35-51 wt.%, a condition 2 that an organic compound forming double bond with sulfur atom, nitrogen atom or carbon atom, and including carbon atom forming single bond with sulfur atom or nitrogen atom, is not included as vulcanization accelerator, a condition 3 that phthalic acid ester is not included, and an additional condition that nitrile rubber having hardness within a range of 55°-80° is used.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a refrigerant compressor used for a refrigerator, an air conditioner and the like.

  In recent years, high efficiency of hermetic refrigerant compressors has been promoted. This is mainly to reduce the use of fossil fuels from the viewpoint of protecting the global environment. As one of high efficiency techniques, a technique for improving the refrigerating capacity by reducing the temperature of the refrigerant at the time of suction is known. In this technique, generally, a member made of an elastomer is used as a member (referred to as an “internal member” for convenience of explanation) provided in the refrigerant compressor.

  For example, Patent Document 1 or Patent Document 2 discloses a technique in which a rubber guide is provided between a suction pipe for introducing a refrigerant into a sealed container and a suction muffler (or a silencer) provided in the sealed container. It is disclosed. This rubber guide corresponds to the internal member described above, and nitrile rubber is preferably used as disclosed in Patent Document 1, for example.

  Here, the internal member made of nitrile rubber usually contains a phthalate ester as a plasticizer for nitrile rubber. In recent years, it has been pointed out that phthalic acid esters may affect the human body and the natural environment.

JP 2008-223605 A JP 2008-215194 A

  Therefore, if an internal member using nitrile rubber containing no phthalate ester is manufactured, the quality of the internal member may be deteriorated.

  For example, the refrigerant used in the refrigerant compressor includes hydrocarbon refrigerants such as R600a or so-called alternative CFCs such as hydrofluorocarbon (HFC). Further, oil-based materials such as lubricating oil are also used in the sealed container. When these refrigerants, oil-based materials, or mixtures thereof come into contact with nitrile rubber that does not contain phthalate, deposits or blisters may be formed on the surface of the nitrile rubber. These surface abnormalities cause deterioration of the quality of the internal member.

  The present invention has been made in order to solve the above-described problems, and is a hermetic refrigerant compressor including a member (inner member) using nitrile rubber not containing a phthalate ester therein. The purpose is to suppress the deterioration of quality and to realize good reliability.

  The refrigerant compressor according to the present invention stores lubricating oil having a viscosity of VG3 to VG22 in an airtight container, and houses an electric element and a compression element that is driven by the electric element and compresses the refrigerant. At least one member of a member constituting the electric element and a member (inner member) constituting the compression element is made of a rubber material, and the rubber material has a bound acrylonitrile content within a range of 35 to 51% by weight. Yes, at the time of crosslinking, use an organic compound containing a carbon atom that forms a double bond with a sulfur atom, nitrogen atom, or carbon atom and that forms a single bond with a sulfur atom or nitrogen atom as a vulcanization accelerator. And a nitrile rubber containing no phthalate ester.

  According to the above configuration, the nitrile rubber does not use the vulcanization accelerator (Condition 1), does not contain a phthalate ester (Condition 2), and the bound acrylonitrile content is within the above range (Condition 3). Therefore, even if the internal member comes into contact with, for example, an HFC refrigerant, deterioration in quality is suppressed. As a result, the reliability of the hermetic refrigerant compressor can be further improved.

  In the refrigerant compressor, the nitrile rubber may be vulcanized by peroxide vulcanization.

  According to the above configuration, since the nitrile rubber further satisfies the condition of peroxide vulcanization (condition 4), deterioration in quality is suppressed even when the internal member comes into contact with, for example, a hydrocarbon-based refrigerant. As a result, the reliability of the hermetic refrigerant compressor can be further improved.

  In the present invention, with the above configuration, in a hermetic refrigerant compressor including a member (inner member) using nitrile rubber that does not contain a phthalate ester inside, the deterioration of the quality of the member is suppressed and good There is an effect that reliability can be realized.

It is a cross-sectional view showing a typical example of the configuration of the refrigerant compressor according to the present invention. FIG. 2 is a longitudinal sectional view showing a cross section of the refrigerant compressor shown in FIG. 1 as viewed from the axial direction of the suction pipe. It is a graph which shows the relationship between the joint acrylonitrile content of a nitrile rubber, and a glass transition temperature. It is a result of the comparative example 1 of this invention, Comprising: In the sample of the internal member using the nitrile rubber which does not contain a phthalate ester, the deposit | attachment produced on the surface was measured with the Fourier transform infrared spectrophotometer (FT-IR). It is IR spectrum which shows the result of analysis. It is an IR spectrum which shows the result of the comparative example 2 of this invention, Comprising: In the sample of the internal member using the nitrile rubber which does not contain a phthalate ester, the result of having analyzed the deposit | attachment produced on the surface by FT-IR .

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and redundant description thereof is omitted.

  The refrigerant compressor according to the present invention stores lubricating oil having a viscosity of VG3 to VG22 in an airtight container, and houses an electric element and a compression element that is driven by the electric element and compresses the refrigerant. Of the members constituting the electric element and the members constituting the compression element, at least one member (inner member) is made of a rubber material, and the rubber material has a bound acrylonitrile content in the range of 35 to 51% by weight. At the time of crosslinking, an organic compound containing a carbon atom that forms a double bond with a sulfur atom, nitrogen atom, or carbon atom and that forms a single bond with a sulfur atom or nitrogen atom is used as a vulcanization accelerator. And a nitrile rubber that does not contain a phthalate ester.

  According to the above configuration, the nitrile rubber has a condition 1: the vulcanization accelerator is not used, a condition 2: a phthalate ester is not included, and a condition 3: the bound acrylonitrile content is within the above range. Even if the internal member comes into contact with, for example, an HFC-based refrigerant, deterioration in quality is suppressed. As a result, the reliability of the hermetic refrigerant compressor can be further improved.

In the refrigerant compressor configured as described above, the nitrile rubber may have a Mooney viscosity ML _{1 + 4 at} 100 ° C. in the range of 50 to 150 and a hardness in the range of 55 ° to 80 °.

  According to the above configuration, since the nitrile rubber satisfies the additional condition of the Mooney viscosity range and the hardness range, manufacture and mounting are facilitated depending on the type of the internal member. Therefore, the reliability of the refrigerant compressor can be further improved.

  In the refrigerant compressor configured as described above, the nitrile rubber may have a bound acrylonitrile content of 40 to 51% by weight.

  According to the said structure, if a bound acrylonitrile content is in the said range, the physical property of a nitrile rubber can be made more favorable. Therefore, the reliability of the refrigerant compressor can be further improved.

  Further, in the refrigerant compressor having the above configuration, the refrigerant is a hydrofluorocarbon (HFC) refrigerant or a mixed refrigerant containing the HFC refrigerant, and the lubricating oil includes ester oil, alkylbenzene oil, polyvinyl It may be at least one selected from the group consisting of ether and polyalkylene glycol.

  According to the said structure, when the nitrile rubber is satisfy | filling the said conditions 1-3, especially the reliability of a refrigerant | coolant compressor can be made still more favorable.

  In the refrigerant compressor configured as described above, the nitrile rubber may be vulcanized by peroxide vulcanization.

  According to the above configuration, since the nitrile rubber satisfies the condition 4: peroxide vulcanization in addition to the above conditions 1 to 3, even if the internal member comes into contact with, for example, a hydrocarbon-based refrigerant, the quality is improved. Reduction is suppressed. As a result, the reliability of the hermetic refrigerant compressor can be further improved.

  Further, in the refrigerant compressor having the above configuration, the refrigerant is at least one of R600a and R290, or a mixed refrigerant containing the hydrocarbon refrigerant, and the lubricating oil is mineral oil, It may be at least one selected from the group consisting of ester oil, alkylbenzene oil, polyvinyl ether, and polyalkylene glycol.

  According to the said structure, when the nitrile rubber is satisfy | filling the conditions of said 1-4, especially the reliability of a refrigerant compressor can be made still better.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and redundant description thereof is omitted.

(Embodiment 1)
[Configuration example of refrigerant compressor]
As shown in the transverse sectional view of FIG. 1 and the longitudinal sectional view of FIG. 2, the refrigerant compressor 100 according to the present embodiment includes a sealed container 10, an electric element 20, and a compression element 30.

  The sealed container 10 is a casing that is sealed in a state in which the electric element 20 and the compression element 30 are accommodated therein, and the lubricating oil 11 can be stored at the bottom thereof. In the present embodiment, the lubricating oil 11 has a viscosity within the range of VG3 to VG22, preferably within the range of VG5 to VG22, according to the ISO viscosity classification. Further, the inside and outside of the sealed container 10 are communicated by a suction pipe 40.

  Although the specific kind of the lubricating oil 11 is not particularly limited, in the present invention, at least one oil material selected from the group consisting of ester oil, alkylbenzene oil, polyvinyl ether, and polyalkylene glycol is preferably used. These oil materials may be used alone as the lubricating oil 11, or a mixture of two or more types appropriately combined may be used as the lubricating oil 11.

  Generally, the lubricating oil 11 used in the refrigerant compressor 100 adjusts the viscosity by blending oil materials having different viscosities. Therefore, also in this invention, what is necessary is just to adjust the lubricating oil 11 so that it may enter into the range of VG3-VG22 by blending 2 or more types of the said oil material. Also, only one type of oil material whose viscosity falls within the range of VG3 to VG22 can be used as the lubricating oil 11.

  The electric element 20 includes at least a stator 21 and a rotor 22, and drives the compression element 30 to rotate. The compression element 30 is integrally assembled with the electric element 20, and includes a cylinder block 31, a piston 32, and a suction muffler 33. The cylinder block 31 is provided so as to form a cylindrical compression chamber 311. The piston 32 is provided so as to reciprocate in the internal space of the cylinder block 31. The suction muffler 33 has a sound deadening space 331 that communicates with the compression chamber 311.

  The suction muffler 33 further has a suction port 332 through which the refrigerant from the suction pipe 40 can be introduced. The suction port 332 is provided at a position that does not overlap the suction pipe 40 (a position that deviates from the projection position of the suction pipe 40) in the projection view seen from the axial direction of the suction pipe 40. The suction port 332 is provided with a guide 333 made of nitrile rubber.

  The guide 333 is fixed to the suction muffler 33 so as to extend from the suction port 332. Further, the connection portion between the suction pipe 40 and the sealed container 10 is an opening that communicates the inside of the suction pipe 40 and the sealed container 10, but the guide 333 is disposed at a position facing the opening of the suction pipe 40. Has been.

  Therefore, the refrigerant sucked from the suction pipe 40 can be introduced into the suction port 332 through the guide 333. Since the suction port 332 is an “introduction opening” of the refrigerant in the suction muffler 33, the refrigerant introduced into the suction muffler 33 is further introduced into the compression chamber 311 from the sound deadening space 331 of the suction muffler 33.

  The refrigerant compressor 100 shown in FIG. 1 and FIG. 2 has a general configuration, and in addition to the above-described sealed container 10, electric element 20, compression element 30, and suction pipe 40, various known mechanisms or members are used. I have. Moreover, the specific structure of the airtight container 10, the electric element 20, the compression element 30, and the suction pipe 40 is not specifically limited, A well-known thing is used suitably.

  The refrigerant that can be used in the present invention is not particularly limited, and examples thereof include hydrocarbon refrigerants such as R600a and R290; HFC refrigerants such as R134a; other known refrigerants that can be mixed with these refrigerants; . Only one kind of these refrigerants may be used, or a mixture of a plurality of kinds appropriately combined may be used. Note that R600a, R290, R134a, etc. are all refrigerant numbers defined by ISO817.

  An example of the operation of the hermetic refrigerant compressor 100 having the above configuration will be specifically described.

  First, when electric power is supplied to the electric element 20 by connecting an external power source (not shown in FIG. 1 and FIG. 2) to the electric element 20, the rotor 22 of the electric element 20 rotates. As the rotor 22 rotates, the piston 32 of the compression element 30 reciprocates for compression in the internal space of the cylinder block 31.

  In the step of sucking the refrigerant, the pressure in the compression chamber 311 is lowered by the operation of the compression element 30 as described above. Thereby, the internal pressure of the airtight container 10 also falls. Although not shown in FIGS. 1 and 2, since an external refrigeration system is connected to the suction pipe 40, the refrigerant from the external refrigeration system passes through the suction pipe 40, and temporarily enters the sealed container 10. And is opened to the front of the guide 333.

  The lubricating oil 11 is scattered in the sealed container 10. Therefore, many refrigerants collide with the guide 333 facing the suction pipe 40 together with the scattered lubricating oil 11. Alternatively, the liquid refrigerant directly collides with the guide 333. Here, since the guide 333 is connected to the suction port 332 of the suction muffler 33, the refrigerant (and the lubricating oil 11) colliding with the guide 333 is guided to the suction port 332 having a low pressure and sucked into the suction muffler 33. Is done.

  The refrigerant sucked into the suction muffler 33 passes through the silencing space 331 of the suction muffler 33 and is sucked into the compression chamber 311 of the compression element 30. The refrigerant (and lubricating oil 11) sucked into the compression chamber 311 is compressed in the compression chamber 311 by the reciprocating motion of the piston 32. The compressed refrigerant is discharged again to the external refrigeration system.

  In the above configuration, the guide 333 and the suction pipe 40 face each other in a close proximity. Therefore, the refrigerant introduced from the external refrigeration system is sucked into the suction muffler 33 at a relatively low temperature and compressed in the compression chamber 311. Thereby, the suction | inhalation mass (refrigerant circulation amount) in the unit time of a refrigerant | coolant becomes large. As a result, the refrigerant compressor 100 can achieve good efficiency, and can improve the refrigeration capacity of the external refrigeration system.

[Inner member made of nitrile rubber]
In the present embodiment, the above-described guide 333 corresponds to an internal member made of nitrile rubber provided inside the refrigerant compressor 100.

  The rubber material used for the guide 333 may be a known nitrile rubber, that is, a nitrile butadiene rubber (a copolymer of NBR, acrylonitrile and 1,3-butadiene). In the present invention, the unsaturated bond is hydrogenated. Hydrogenated nitrile rubber; modified nitrile rubber such as carboxyl group-modified nitrile rubber, silicone-modified nitrile rubber, maleic acid-modified nitrile rubber, hydroxyl group-modified nitrile rubber, or hydrogenated acrylonitrile in which part of butadiene is replaced by isoprene -Butadiene-isoprene copolymer; etc. are also included in "nitrile rubber".

  In the present invention, the rubber material used as an internal member such as the guide 333 may be any material that uses nitrile rubber, and therefore may contain a rubber material other than the nitrile rubber described above. Various additives may be included except for the acid ester. Therefore, the rubber material used for the internal member may be a nitrile rubber composition containing nitrile rubber as a main component. Therefore, in the present specification, “inner member made of nitrile rubber” or “guide 333 made of nitrile rubber” refers to “an inner member or guide 333 manufactured using a nitrile rubber composition”. To do.

  Examples of rubber materials other than nitrile rubber include natural rubber, ethylene propylene rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, butyl rubber, and acrylic rubber, but are not particularly limited.

  Additives include inorganic fillers such as carbon, talc, clay and graphite; processing aids such as palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, paraffin wax: zinc oxide, magnesium oxide, hydro Acid acceptors such as talcite; anti-aging agents such as quinoline-based, amine-based, and phenol-based; plasticizers other than phthalate esters;

  Furthermore, a vulcanizing agent is used for producing the nitrile rubber, and any known vulcanizing agent can be used. For example, sulfur vulcanization using sulfur or a sulfur-based compound as a vulcanizing agent, peroxide vulcanization using an organic peroxide or the like as a vulcanizing agent, or sulfur vulcanization and peroxide vulcanization. A combination can be mentioned.

  The specific type of organic oxide used for peroxide vulcanization is not particularly limited. For example, alkyl peroxide, acyl peroxide, ketone peroxide peroxide, diacyl peroxide peroxide. Examples thereof include oxides, hydroperoxide peroxides, dialkyl peroxide peroxides, peroxyketal peroxides, alkyl perester peroxides, and carbonate peroxides. These peroxides may be used alone or in appropriate combination of two or more.

  In the production of nitrile rubber, a vulcanization accelerator may be used in combination with the vulcanizing agent. As this vulcanization accelerator, known ones can be preferably used. However, in the present invention, organic compounds such as thiuram are not used as vulcanization accelerators. This point will be described later.

  In addition, some of the additives described above exhibit a vulcanization promoting action (that is, components that can also be used as a vulcanization accelerator) (for example, an acid acceptor such as zinc oxide, stearic acid, olein). Fatty acids such as acids (processing aids)). Therefore, when these additives also function as a vulcanization accelerator, it is not necessary to add a vulcanization accelerator separately.

  In addition, zinc oxide used as an acid acceptor for nitrile rubber can be used as an inorganic compound vulcanizing agent. In the present invention, the vulcanizing agent is the sulfur vulcanization or peroxide described above. It is limited to vulcanization and vulcanization using other vulcanizing agents is not performed.

  Moreover, in this Embodiment, although the guide 333 is illustrated as an internal member made from a nitrile rubber, this invention is not limited to this. The internal member in the present invention is a member that constitutes the electric element 20 and a member that constitutes the compression element 30, and is (i) located in the sealed container 10 of the refrigerant compressor 100, (ii) a refrigerant, or Any member may be used as long as the lubricating oil 11 in which the refrigerant is melted is easily contacted (iii) a member made of rubber or a member that can be manufactured using a rubber material. As an internal member other than the guide 333, for example, the suction port 332 of the suction muffler 33 can be cited. That is, if the suction port 332 is an opening member made of nitrile rubber, it corresponds to the internal member in the present invention.

[Conditions for filling nitrile rubber]
Here, the nitrile rubber used for the internal member (guide 333) in the present invention has a condition 1: as a vulcanization accelerator, forms a double bond with a sulfur atom, a nitrogen atom, or a carbon atom, and a sulfur atom or It is manufactured without using an organic compound containing a carbon atom that forms a single bond with a nitrogen atom and without containing a phthalate ester. Furthermore, in the present invention, Condition 3: The content of bound acrylonitrile in the nitrile rubber is in the range of 35 to 51% by weight.

  Here, “the organic compound containing a carbon atom that forms a double bond with a sulfur atom, a nitrogen atom, or a carbon atom and that forms a single bond with a sulfur atom or a nitrogen atom” in the present invention means a molecule. In the structure, -C (= S) -N, -C (= N) -N, -C (= C) -N, -C (= N) -S, -C (= S) -S, etc. Refers to a compound containing a structure. Specifically, for example, thiuram (including -C (= S) -N structure and -C (= S) -S structure), thiazole (-C (= C) -N structure and -C (= N) -S structure included), thiourea (including -C (= S) -N structure), dithiocarbamic acid (including -C (= S) -N structure and -C (= S) -S structure), and guanidine (Including a —C (═N) —N structure).

  The “dithiocarbamic acid” in the present invention includes a compound having the basic structure of dithiocarbamic acid (N—C (═S) —S). Specifically, various dithiocarbamates are included in “dithiocarbamic acid” in the present invention. The “dithiocarbamic acid” in the present invention is not limited to “narrowly defined dithiocarbamic acid (salt)” in which two hydrogen atoms are bonded to the nitrogen atom (N) of the basic structure, and an organic group such as an alkyl group is present on the nitrogen atom. Including those that are combined.

  According to the study by the present inventors, by using a nitrile rubber satisfying the above conditions 1 to 3, the oil resistance and chemical resistance of the nitrile rubber are good even without including a phthalate ester. Therefore, even if the refrigerant contacts the internal member made of nitrile rubber, it is possible to effectively avoid the quality deterioration. Therefore, high efficiency can be achieved while maintaining the reliability of the refrigerant compressor 100.

  Consider each condition. First, regarding the condition 1, when the vulcanization accelerator is used, as shown in the examples described later, generation of deposits is recognized on the surface of the inner member made of nitrile rubber. This deposit is judged to be a part of the vulcanization accelerator that bleeds out to the surface. Therefore, if the condition 1 is not satisfied, bleedout of the vulcanization accelerator occurs in the internal member made of nitrile rubber, and the quality of the internal member is deteriorated.

  Moreover, about the condition 2, various concerns derived from a phthalate ester can be avoided by not including a phthalate ester. In the present invention, the phthalic acid ester not contained in the nitrile rubber refers to an ester of ortho-phthalic acid and alcohol, and is not limited to a specific compound but is defined as a comprehensive one. Typical phthalate esters include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, di-normal octyl phthalate, diisononyl phthalate, dinonyl phthalate, diisodecyl phthalate, butyl benzyl phthalate, etc. However, it is not limited to these.

  As for condition 3, if the bound acrylonitrile content of the nitrile rubber is within the range of 35 to 51% by weight, good physical properties as rubber can be exhibited, and nitrile groups derived from acrylonitrile ( -CN) increases. As a result, the polarity of the nitrile rubber itself is increased, so that the affinity for the low-polarity refrigerant (or the lubricating oil 11 in which the refrigerant is mixed) is reduced. As a result, it is possible to suppress excessive penetration of the refrigerant and the like into the nitrile rubber internal member.

  On the other hand, if the acrylonitrile content of the nitrile rubber is less than 35% by weight, the refrigerant or the like tends to excessively penetrate into the internal member, and the occurrence of surface abnormality may not be effectively suppressed. On the other hand, when the content of bound acrylonitrile exceeds 51% by weight, the glass transition temperature of the nitrile rubber becomes −10 ° C. or more as shown in FIG. These characteristics cannot be maintained. Therefore, the content of bound acrylonitrile may be in the range of 35 to 51% by weight, and preferably in the range of 40 to 51% by weight as shown in the examples.

  Next, taking the environment of the guide 333 in the sealed container 10 as an example, the suppression of the deterioration of the quality of the internal member by the nitrile rubber satisfying the above conditions 1 to 3 will be specifically described.

  As described above, phthalate is used as a plasticizer for nitrile rubber, but its use is limited in recent years. Here, the phthalic acid ester added to the nitrile rubber not only functions as a plasticizer but also has a function of preventing the penetration of the refrigerant. That is, when the phthalic acid ester is added to the nitrile rubber, it is held in a state where it enters the gap between the rubber molecules of the nitrile rubber which is a chain polymer. Therefore, even if the internal member comes into contact with the refrigerant or the lubricating oil 11 in which the refrigerant is dissolved, the phthalate ester between the rubber molecules inhibits the penetration of the refrigerant.

  On the other hand, when no phthalate is added to the nitrile rubber, the existence of filling the gap between the rubber molecules is eliminated. Therefore, when the internal member comes into contact with the refrigerant or the lubricating oil 11 (including the refrigerant), the refrigerant easily penetrates between the rubber molecules. As a result, there is a possibility that deposits may be generated on the surface of the internal member made of nitrile rubber or material defects such as blisters may occur. These surface abnormalities reduce the quality of the internal members.

  In particular, the guide 333 is provided in a position facing the suction pipe 40 in the vicinity of the suction pipe 40. Therefore, when a refrigerant is introduced from the suction pipe 40, the refrigerant directly collides. Therefore, the guide 333 is frequently exposed to a high concentration refrigerant. Further, if the refrigerant collides with the guide 333 while in a liquid state, the refrigerant evaporates due to the collision. Therefore, the temperature of the guide 333 may decrease due to evaporation of the refrigerant.

  On the other hand, in this invention, an internal member (for example, guide 333) is manufactured using the nitrile rubber which satisfy | fills the conditions 1-3 mentioned above. Therefore, as shown in the examples described later, even if the refrigerant contacts the internal member, it is possible to avoid the possibility that surface abnormality will occur in the internal member. Even if it is lowered, sufficient physical properties as a rubber material can be exhibited. As a result, the reliability of the refrigerant compressor can be improved. In particular, in the present embodiment, as shown in the examples described later, when the refrigerant is an HFC refrigerant such as R134a, the occurrence of surface abnormality can be more effectively suppressed.

Furthermore, in the present invention, the nitrile rubber has an additional condition 1: Mooney viscosity ML _{1 + 4 at} 100 ° C. in the range of 50 to 150 in addition to the above conditions 1 to 3, and an additional condition 2: hardness. Is preferably in the range of 55 ° to 80 °. The Mooney viscosity of the nitrile rubber is measured based on JISK6300-1, and the hardness of the nitrile rubber is measured based on JISK6253-3.

  If the nitrile rubber satisfies the additional conditions 1 and 2, mechanical properties such as tensile strength of the nitrile rubber are improved. Therefore, if the inner member is the guide 333, its manufacture and mounting are facilitated. Therefore, if the nitrile rubber satisfies the conditions 1 to 3 and the additional conditions 1 and 2, the occurrence of surface abnormality can be suppressed, and the quality of the internal member can be improved. As a result, the reliability of the refrigerant compressor 100 can be further improved.

(Embodiment 2)
In the first embodiment, the nitrile rubber used for the internal member of the refrigerant compressor 100 satisfies at least the above conditions 1 to 3, but in this second embodiment, the nitrile rubber satisfies the conditions 1 to 1. In addition to 3, the condition 4 is satisfied.

  The refrigerant compressor 100 used in the present embodiment is the same as that described in the first embodiment (see FIGS. 1 and 2). The configuration of the nitrile rubber used for the internal member is also the same as that described in the first embodiment.

  In the present embodiment, when the refrigerant is R600a and / or R290 or includes these, condition 4: In addition to conditions 1-3, condition 4: nitrile rubber vulcanized by peroxide vulcanization If so, it is possible to favorably suppress the penetration of the refrigerant.

  In the first embodiment, the vulcanization of the nitrile rubber may be sulfur vulcanization or peroxide vulcanization. In contrast, in the present embodiment, vulcanization is specified as peroxide vulcanization according to condition 4. Thereby, as shown in the Example mentioned later, even if a hydrocarbon type refrigerant | coolant osmose | permeates nitrile rubber, generation | occurrence | production of surface abnormality can be suppressed favorably.

  Specifically, when a nitrile rubber satisfying the conditions 1 to 3 is brought into contact with a hydrocarbon solvent such as R600a or R290, as shown in the examples described later, the generation of deposits and blisters can be suppressed, but the surface roughness is reduced. May occur. In the present embodiment, since the nitrile rubber satisfies the condition 4 peroxide vulcanization, it is possible to substantially prevent the occurrence of surface abnormality such as surface roughness. For this reason, it is possible to effectively avoid the deterioration of the quality of the nitrile rubber internal member (such as the guide 333), and thus it is possible to provide the refrigerant compressor 100 with high reliability.

Also in the present embodiment, in addition to the above conditions 1 to 4, the nitrile rubber has the additional condition 1: the Mooney viscosity ML _{1 + 4 at} 100 ° C. is in the range of 50 to 150, and the above Additional condition 2: It is preferable to satisfy that the hardness is in the range of 55 ° to 80 °. If the nitrile rubber satisfies all of the conditions 1 to 4 and the additional conditions 1 and 2, the penetration of the refrigerant can be more effectively suppressed, and the quality of the internal member can be improved. The reliability of the machine 100 can be further improved.

  In the above embodiment, ester oil, alkylbenzene oil, polyvinyl ether, and polyalkylene glycol are exemplified as the oil material that can be suitably used as the lubricating oil 11. In this embodiment, in addition to these oil materials, Mineral oil can also be suitably used.

  The refrigerant compressor 100 illustrated in the first embodiment and the second embodiment is a reciprocating type as shown in FIGS. 1 and 2, but the present invention is not limited to this. Needless to say, the refrigerant compressor 100 usable in the present invention has a sliding portion, a discharge valve, and the like, and may be, for example, a rotary type, a scroll type, or a vibration type.

  The present invention will be described more specifically based on examples, comparative examples, and conventional examples, but the present invention is not limited to these. Those skilled in the art can make various changes, modifications, and alterations without departing from the scope of the present invention.

(Conventional example 1)
Samples were prepared using a conventional nitrile rubber containing a phthalate ester, vulcanized by sulfur vulcanization, and using thiuram as a vulcanization accelerator. The bound acrylonitrile content of this nitrile rubber was 32% by weight. This sample was sealed in a sealed container together with R134a and polyol ester, and subjected to aging treatment at 125 ° C. for 2 hours. Thereafter, the surface of the sample was observed visually. The results are shown in Table 1.

(Comparative Example 1)
A sample similar to Conventional Example 1 using a comparative nitrile rubber (containing 32% by weight of bound acrylonitrile) that does not contain a phthalate ester, is vulcanized by sulfur vulcanization, and uses thiuram as a vulcanization accelerator. Was made. This sample was aged under the same conditions as in Conventional Example 1. Thereafter, the surface of the sample was observed visually. The results are shown in Table 1.

Example 1
The nitrile rubber was vulcanized by sulfur vulcanization, did not contain a phthalate ester (Condition 2), did not contain thiuram as a vulcanization accelerator (Condition 1), and the bound acrylonitrile content was 40% by weight ( A sample similar to that in Conventional Example 1 was prepared using the condition 3). This sample was aged under the same conditions as in Conventional Example 1. Thereafter, the surface of the sample was observed visually. The results are shown in Table 1.

(Example 2)
A sample similar to Conventional Example 1 is prepared using the same nitrile rubber as in Example 1 except that the vulcanization is not a sulfur vulcanization but a peroxide vulcanization, and aging is performed under the same conditions as in Conventional Example 1. Processed. Thereafter, the surface of the sample was observed visually. The results are shown in Table 1.

  According to the results of Comparative Example 1, even when a nitrile rubber not containing phthalate was used, deposits were observed on the surface of the sample. When this deposit was analyzed by a Fourier transform infrared spectrophotometer (FT-IR), as shown in the IR spectrum of FIG. 4, a sulfur-carbon double bond (C = S) characteristic of a vulcanization accelerator was obtained. ) Was observed. Therefore, if only the phthalate ester is not contained (condition 2 only), there arises a problem that a part of the vulcanization accelerator (thiuram) bleeds out to the surface.

  On the other hand, according to the results of Examples 1 and 2, the phthalate is not contained (condition 2), the vulcanization accelerator (thiuram) is not used (condition 1), and the bound acrylonitrile content is 35. When nitrile rubber is used in a range of ˜51% by weight (Condition 3), no deposits were observed on the sample regardless of whether the vulcanization was sulfur vulcanization or peroxide vulcanization. .

  Therefore, based on the results of Conventional Example 1, Comparative Example 1, and Examples 1 and 2, when a nitrile rubber satisfying the conditions 1 to 3 is brought into contact with the HFC refrigerant (R134a), it is considered as follows.

  In the sample using nitrile rubber containing no phthalate ester (Comparative Example 1), there is no material that inhibits the penetration of the refrigerant in the gap between the rubber molecules. In particular, the polyol ester in which R134a is dissolved is reduced in viscosity due to the dissolution of R134a and easily enters the gap between the rubber molecules. Therefore, R134a or the polyol ester that has entered the gap between the rubber molecules pushes a part of the vulcanization accelerator previously present in the gap between the rubber molecules to the surface. As a result, it is considered that deposits were generated on the surface of the nitrile rubber sample.

  On the other hand, in the samples using nitrile rubber that does not use a vulcanization accelerator (Examples 1 and 2), the vulcanization accelerator is not pushed out onto the surface of the nitrile rubber, and the deposits bleed out. No longer.

  Moreover, no bleed-out of deposits was observed in either (Example 1) or (Example 2) regardless of whether the nitrile rubber was sulfur vulcanized (Example 1) or peroxide vulcanized. In the case of sulfur vulcanization, cross-linking occurs between rubber molecules due to the bond between sulfur (-SS-). On the other hand, in the case of peroxide vulcanization, the rubber molecules are crosslinked between the rubber molecules by carbon-carbon bonds (—C—C—). Of these two types of bridges, the —C—C— bond has a higher binding energy than the —S—S— bond. Therefore, in the nitrile rubber of Example 2 having —S—S— bond crosslinks, naturally, in the nitrile rubber of Example 2 having —C—C— bond crosslinks, if the occurrence of deposits on the surface can be prevented. Is also effective.

(Conventional example 2)
Samples were prepared using a conventional nitrile rubber containing a phthalate ester, vulcanized by sulfur vulcanization, and using thiuram as a vulcanization accelerator. The bound acrylonitrile content of this nitrile rubber was 32% by weight. This sample was sealed in an airtight container together with R600a and subjected to aging treatment at 125 ° C. for 2 hours. Thereafter, the surface of the sample was observed visually. The results are shown in Table 2.

(Comparative Example 2)
A sample similar to Conventional Example 1 using a comparative nitrile rubber (containing 32% by weight of bound acrylonitrile) that does not contain a phthalate ester, is vulcanized by sulfur vulcanization, and uses thiuram as a vulcanization accelerator. Was made. This sample was aged under the same conditions as in Conventional Example 2. Thereafter, the surface of the sample was observed visually. The results are shown in Table 2.

(Comparative Example 3)
A sample was prepared in the same manner as in Comparative Example 2 except that the bound acrylonitrile content of the nitrile rubber was 40% by weight. This sample was aged under the same conditions as in Conventional Example 2. Thereafter, the surface of the sample was observed visually. The results are shown in Table 2.

(Comparative Example 4)
A sample was prepared in the same manner as in Comparative Example 3 except that no vulcanization accelerator was used during nitrile rubber vulcanization. This sample was aged under the same conditions as in Conventional Example 2. Thereafter, the surface of the sample was observed visually. The results are shown in Table 2.

(Example 3)
Nitrile rubber does not contain phthalate (condition 2), thiuram does not contain vulcanization accelerator (condition 1), bound acrylonitrile content is 40% by weight (condition 3), peroxide vulcanization A sample similar to Conventional Example 2 was produced using the vulcanized product (condition 4). This sample was aged under the same conditions as in Conventional Example 2. Thereafter, the surface of the sample was observed visually. The results are shown in Table 2.

Example 4
A sample was prepared in the same manner as in Example 2 except that the bound acrylonitrile content of the nitrile rubber was 51% by weight. This sample was aged under the same conditions as in Conventional Example 2. Thereafter, the surface of the sample was observed visually. The results are shown in Table 2.

  As is clear from the results of Conventional Example 2 and Comparative Example 2, even if the medium exposed to the nitrile rubber sample is changed from R134a and polyol ester to R600a, nitrile rubber that does not contain phthalate ester is used. Deposits were observed on the surface of the sample, and blistering was also observed.

  When the deposit on the sample was analyzed by FT-IR, a peak of a sulfur-carbon double bond (C = S) characteristic of the vulcanization accelerator was observed as shown in the IR spectrum of FIG. Therefore, if only the phthalate ester is not contained (only condition 2), a problem that a part of the vulcanization accelerator (thiuram) bleeds out to the surface as in the result of Comparative Example 1 occurs.

  Next, from the results of Comparative Example 3, although no blisters were observed on the surface of the sample, deposits were observed. Therefore, only by increasing the bound acrylonitrile content of the nitrile rubber from 32% by weight to 40% by weight (conditions 2 and 3), the generation of deposits cannot be effectively avoided. Next, looking at the results of Comparative Example 4, although no vulcanization accelerator (thiuram) is used (Conditions 1 to 3), the generation of deposits can be avoided, but surface roughness is recognized as a new surface abnormality. It was.

  Here, if the results of Comparative Examples 2 to 4 are compared, the bleedout of the deposits can be avoided by not including the phthalate ester (Condition 2) and not using the vulcanization accelerator (Condition 1). It has been found that blistering can be prevented by increasing the bound acrylonitrile content of the nitrile rubber.

  Increasing the bound acrylonitrile content increases the number of nitrile groups (—CN) derived from acrylonitrile in the rubber molecules of the nitrile rubber. Since the nitrile group has polarity, the polarity becomes strong even when viewed as a whole nitrile rubber. Here, since R600a is a hydrocarbon refrigerant, its polarity is low. Therefore, if the polarity of the nitrile rubber is relatively high, the penetration of R600a into the nitrile rubber material is effectively suppressed. Thereby, generation | occurrence | production of a blister can be substantially prevented.

  On the other hand, from the results of Examples 3 and 4, when the vulcanization of nitrile rubber is peroxide vulcanization instead of sulfur vulcanization (conditions 1 to 4), blisters, deposits, and surface roughness Neither was recognized.

  When the vulcanization of the nitrile rubber is sulfur vulcanization, the oil resistance of the nitrile rubber is lowered unless a vulcanization accelerator such as thiuram is used. When oil resistance falls, it will become easy to produce surface roughness by contacting hydrocarbon refrigerants, such as R600a. On the other hand, in Examples 3 and 4, the vulcanization of the nitrile rubber is a peroxide vulcanization. As described above, in sulfur vulcanization, crosslinking is a sulfur-to-sulfur bond (-S-S-), but in peroxide vulcanization, crosslinking is a carbon-to-carbon bond (-C-C-). . Of these two types of bridges, the —C—C— bond has a higher binding energy than the —S—S— bond. Therefore, in Examples 3 and 4, surface roughness of the nitrile rubber can be substantially prevented.

  It should be noted that the present invention is not limited to the description of the above-described embodiment, and various modifications are possible within the scope shown in the scope of the claims, and are disclosed in different embodiments and a plurality of modifications. Embodiments obtained by appropriately combining the technical means are also included in the technical scope of the present invention.

  As described above, according to the present invention, it is possible to provide a highly reliable refrigerant compressor, and thus it can be widely applied to devices using a refrigeration cycle.

DESCRIPTION OF SYMBOLS 10 Airtight container 11 Lubricating oil 20 Electric element 21 Stator 22 Rotor 30 Compression element 31 Cylinder block 32 Piston 33 Suction muffler 40 Suction pipe 100 Refrigerant compressor 311 Compression chamber 331 Silent space 332 Suction port 333 Guide

Claims (6)

In the sealed container, the lubricating oil having a viscosity of VG3 to VG22 is stored, and an electric element and a compression element that is driven by the electric element and compresses the refrigerant are accommodated.
Of the internal member constituting the electric element and the internal member constituting the electric element, provided in the sealed container where the refrigerant or lubricating oil in which the refrigerant is dissolved is present, at least one internal member is made of a rubber material. Configured,
As the rubber material,
The bound acrylonitrile content is in the range of 35-51% by weight;
As a vulcanization accelerator, it does not contain organic compounds containing carbon atoms that form a double bond with a sulfur atom, nitrogen atom, or carbon atom, and that form a single bond with a sulfur atom or nitrogen atom, and phthalic acid Using a nitrile rubber that does not contain an ester and has a hardness in the range of 55 ° to 80 °,
Refrigerant compressor. The nitrile rubber is
Mooney viscosity ML _{1 + 4 at} 100 ° C. is in the range of 50-150,
The refrigerant compressor according to claim 1. The nitrile rubber has the bound acrylonitrile content in the range of 40 to 51% by weight,
The refrigerant compressor according to claim 2. The refrigerant is a hydrofluorocarbon (HFC) refrigerant or a mixed refrigerant containing the HFC refrigerant;
The lubricating oil is at least one selected from the group consisting of ester oil, alkylbenzene oil, polyvinyl ether, and polyalkylene glycol.
The refrigerant compressor of any one of Claims 1-3. The nitrile rubber is vulcanized by peroxide vulcanization.
The refrigerant compressor according to claim 1 or 2. The refrigerant is at least one hydrocarbon refrigerant of R600a and R290 or a mixed refrigerant containing the hydrocarbon refrigerant;
The lubricating oil is at least one selected from the group consisting of mineral oil, ester oil, alkylbenzene oil, polyvinyl ether, polyalkylene glycol,
The refrigerant compressor according to claim 5.

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