JP3318279B2 - Lubricating oil for copper pipe processing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil for processing copper pipes which is suitable for drawing and rolling of long annealed coil copper pipes used for heat exchangers of refrigeration systems such as air conditioners and refrigerators. In particular, for copper pipe machining, the residue after coiled annealing (oil residue and other carbides in the pipe) is small, and the lubricity of the pipe inner surface and the anti-seizure property of the processing tool can be improved. Lubricating oil. In addition,
When referred to as a copper tube in the present specification, in addition to a pure copper tube,
It also includes copper alloy tubes.

[0002]

2. Description of the Related Art Conventionally, room air conditioners, package air conditioners, automotive air conditioners, refrigerators, dehumidifiers, freezers, freezer cold storage warehouses, vending machines, heat exchangers for refrigeration systems such as showcases and chemical plants, etc. Heat transfer tubes are used. As a heat transfer tube, after processing the copper tube in consideration of workability, heat transferability, workability and corrosion resistance,
A long coiled copper tube or the like softened by annealing is used. In the process of manufacturing such a long annealed coil copper tube, the raw tube is processed into a copper tube by a drawing process using lubricating oil on the inner surface and the outer surface, and after being wound into a coil shape, reduced. Heat annealing is performed at a temperature of 500 ° C. or more in an atmosphere or an inert atmosphere. As the annealing conditions, after heating at a temperature of about 500 ° C. for several tens of minutes, cooling is performed to obtain a predetermined refining.

[0003] When a copper pipe is subjected to drawing processing, a lubricating oil whose kinematic viscosity has been adjusted by adding a fatty acid ester or isoparaffin to a high-viscosity synthetic hydrocarbon such as polybutene has been conventionally used. Is used on the inner and outer surfaces of the pipe. When a heat treatment is performed on the copper tube at about 500 ° C., which is an annealing cycle of the long coil copper tube, for several tens of minutes, these lubricating oils conventionally used evaporate or become one. The part is reduced in molecular weight and evaporates.

However, in this annealing cycle, the molecular weight of the lubricating oil may not be sufficiently reduced, and as a result, components that do not vaporize at room temperature may be generated. Therefore, when the coil length is long or in the case of a copper pipe having a small pipe diameter, the inner surface lubricating oil used for the copper pipe processing is not completely discharged outside the pipe only by volume expansion of the gasified lubricating oil component. Sometimes. As a result, some of the gas components are condensed in the cooling process, and residual oil and residues are generated in the tubes.

[0005] In recent years, chlorofluorocarbons (HCF) have been used as refrigerants for refrigeration and air-conditioning systems.
Instead of C-type) and chlorofluorocarbon-type (CFC-type) refrigerants, hydrofluorocarbon-type (HFC-type) refrigerants containing no chlorine have been used.

However, the HFC-based refrigerant is not compatible with the hydrocarbon-based oil, and when oil remains in the copper pipe, the residual oil in the pipe may hinder the operation of the refrigeration system in the refrigeration system. It may cause problems such as capillaries of capillaries due to contamination or contamination.

[0007] Furthermore, residual oil in the long coiled copper tube may cause gas or generate carbides during brazing operation during assembling operation of the heat exchanger of the refrigeration system, causing brazing failure. ing. In order to solve these various drawbacks, there is a strong demand for reducing the residual oil in the long coil copper pipe and reducing the influence of the residue after annealing on the refrigeration system.

As a conventional method of reducing residual oil in such a long coil copper tube, there is a method of using an exhaust pump at the time of heat annealing or a method of sucking and removing gas in the tube in a vacuum chamber. Further, a method has been proposed in which the gas in the pipe is purged with nitrogen or an inert gas during heat annealing (Japanese Patent Application Laid-Open No. Hei 6 (1994) -6380).
-279860, JP-A-7-197283). It is also known that the combination of the two can reduce the residual lubricating oil on the inner surface of the pipe (Japanese Patent Application Laid-Open No. 6-228649).

[0009]

However, a method of sucking and removing gas remaining in the copper tube by an exhaust pump during heat annealing of the copper tube, a method of sucking and removing gas in the tube in a vacuum chamber,
Or when using the method of purging the gas in the pipe with an inert gas etc., it is necessary to modify the equipment for that,
There is a problem that productivity decreases and manufacturing cost increases. Further, if the kinematic viscosity of the lubricating oil is not adjusted, or if a solvent and an oil agent for adjusting the kinematic viscosity are not properly selected, the lubricity may be reduced during drawing of the copper tube. This causes seizure of the plug.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made at low cost without performing a special residual oil removing treatment such as purging on the inner surface of a long coil copper tube in an annealing furnace. Oil can be reduced, thereby improving the brazing property of the copper tube, increasing the lubricity at the time of drawing or rolling and preventing seizure, and further reducing the residue after annealing. It is an object of the present invention to provide a lubricating oil for processing copper pipes, which can prevent adverse effects on a refrigeration system.

[0011]

Copper pipe processing lubricating oil of the present invention SUMMARY OF THE INVENTION The lubricating oil total mass, polybutene: 60 to 99.5 wt% and a trivalent or higher polyhydric alcohol partial ether compound: 0 0.5 to 40% by mass, and the polybutene has an infrared absorbance I per reflection at 1230 cm ^-1 of 0.025 or more when the infrared absorbance I is measured by an infrared total reflection absorption method. It is characterized by.

[0012] The copper tube processing lubricant is preferably a kinematic viscosity at 40 ° C. of 50 to 5000 mm ² / s, the lubricating oil total mass, polyhydric alcohol content and the trihydric or higher of the polybutene Is preferably 90% by mass or more in total.

Further, the lubricating oil for processing copper pipes according to the present invention comprises:
It can be used as an internal lubricating oil for heat treatment of copper or copper alloy tubes. Furthermore, the lubricating oil for copper pipe processing according to the present invention may be supplied to the inner surface of the copper or copper alloy pipe when processing the copper or copper alloy pipe wound into a coil.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present application have conducted various studies to reduce residual oil in long coiled copper tubes and to develop lubricating oils for copper tube processing having excellent lubricity during drawing and rolling. Was done. As a result, when infrared absorbance I was measured by the infrared total reflection absorption method, polybutene having an infrared absorbance I of 0.025 or more per reflection at 1230 cm ^-1 and a predetermined amount of polyhydric alcohol were used. By using the lubricating oil containing a partially etherified compound,
It is possible to obtain a long-coil copper pipe in which lubricity at the time of drawing or rolling is enhanced, residual oil in the pipe after annealing is significantly reduced, and adverse effects of the residue after annealing on a refrigeration system are significantly reduced. Was found.

Hereinafter, the lubricating oil for copper pipe processing according to the present invention will be described in detail.

(1) Measured by infrared total reflection absorption method
Infrared absorbance I per reflection at 1230 cm ^-1
Is 0.025 or more: 60 to 99.5
In the present invention, the thermal decomposition of polybutene is improved by increasing the isobutene ratio in the molecular structure of polybutene used as a raw material for lubricating oil. The isobutene ratio in the molecular structure of polybutene can be determined by measuring the infrared absorbance I of polybutene using an infrared total reflection absorption method. When the infrared absorbance I of polybutene is measured by the infrared total reflection absorption method, a peak appears at a position of 1230 cm ^-1 derived from the skeletal vibration of quaternary carbon contained in the molecular structure of polybutene. That is, since polybutene using isobutene as a raw material has quaternary carbon in its molecular structure, the larger the infrared absorbance I of polybutene at 1230 cm ^-1 is, the higher the isobutene ratio in the molecular structure of polybutene is. Is shown.

If the infrared absorbance I of polybutene at 1230 cm ^-1 is less than 0.025, the ratio of isobutene contained in the polybutene molecule is small, so that the thermal decomposability of polybutene is reduced and the residual oil in the tube is reduced. Can not do. Therefore, in the present invention, the infrared absorbance I of polybutene at 1230 cm ^-1 is 0.025 or more.

The infrared absorbance I defined in the present invention is:
ZnSe with a crystal length of 70 mm and a crystal thickness of 3 mm
Horizontal total reflection absorption measurement device (MCT detector (Mercury Cadmium Telluride:
It can be measured using a JEOL FT-IR having a mercury cadmium telluride compound semiconductor detector). The measurement is performed under the condition that the incident angle is 60 °, the resolution is 4 cm ⁻¹ , and the number of integration is 1,000. However, under these conditions, an infrared absorption spectrum corresponding to the number of reflections of 6.7 is obtained, so that the infrared absorption I of polybutene at 1230 cm ^-1 is obtained.
As the absolute value of the absorption intensity per reflection. According to the above measurement conditions, the absorption peak of infrared absorbance I derived from quaternary carbon is generally 1230 cm ^-1.
, But the position where this peak appears is 1220 to 1
There may be a slight shift between 240 cm ^-1 . Therefore, in the present invention, 1170 to 1190c are set so that the height of the peak appearing at 1230 cm ^-1 is the highest.
m- ¹ and the valleys of the spectrum appearing at 1250-1
A base line is drawn between the base between 270 cm ^-1 and the valley of the spectrum appearing between them, and the absorption intensity is determined.

If the content of polybutene whose isobutene ratio in the molecular structure is regulated as described above is less than 60% by mass based on the total mass of the lubricating oil, the effect of using this polybutene cannot be sufficiently obtained. Residual oil content may increase. On the other hand, when the content of polybutene exceeds 99.5% by mass, the effect of the partially etherified polyhydric alcohol having 2 or more alcohols contained in the lubricating oil cannot be obtained. Therefore, in the present invention, the content of polybutene relative to the total mass of the lubricating oil is set to 60 to 99.5% by mass.

(2) Partial d of trihydric or higher polyhydric alcohol
-Terride: 0.5 to 40% by mass The processing rate per elongation (drawing reduction rate) in the drawing process even when only polybutene in which the isobutene ratio in the molecular structure is specified by the infrared absorbance I is used as a lubricating oil. For example 2
When a drawing process is performed on a copper tube using a bull block, a die and a floating plug as a tool at a drawing speed of 0% or more, for example, at a drawing speed of 10 m / sec or more, the lubrication boundary portion is generated due to heat generated during the processing. Becomes high temperature, the lubricating property decreases, seizure occurs in the floating plug, and the production yield may decrease due to drawing fracture. In particular, when a long copper tube is used, the temperature of the tube increases due to the drawing process, and the lubricity is significantly reduced.

In addition, when polybutene having a defined isobutene ratio in the molecular structure is used as a base oil, lubricating properties are insufficient by some drawing methods to improve high-temperature lubricating properties only by adding an alcohol. Can not. Furthermore,
If the chain length is increased by increasing the carbon number of the alcohol in order to improve lubricity, the amount of residual oil after annealing increases, and the adverse effects of the residue after annealing on the refrigeration system increase.

[0022] Therefore, in the present invention, a lubricating oil containing the partially etherified products of polyhydric alcohols of the polybutene and trivalent or more. If the content of the partially etherified polyhydric alcohol is less than 0.5% by mass based on the total mass of the lubricating oil, good lubricity cannot be maintained. On the other hand, when the content of the partially etherified polyhydric alcohol is 40
Even if the amount exceeds mass%, the effect of improving lubricity is saturated,
The effect associated with the added amount cannot be obtained. Also,
This partially etherified polyhydric alcohol is liable to be decomposed or vaporized by heat during annealing. However, if the content of the partially etherified polyhydric alcohol in the lubricating oil exceeds 40% by mass, it remains after the annealing. The probability of remaining as an oil component increases. Accordingly, in the present invention, the content of tri- or higher polyhydric alcohols partially etherified product of lubricating oil and 0.5 to 40 wt%.

[0023]

Specific examples of the trihydric or higher polyhydric alcohol include
Include , for example, trimethylolethane, trimethylolpropane, trimethylolbutane, di- (trimethylolpropane), tri- (trimethylolpropane), pentaerythritol, di- (pentaerythritol), tri- (pentaerythritol), glycerin , Polyglycerin (glycerin dimer to octamer), 1,3,5-pentanetriol, sorbitol, sorbitan, sorbitol glycerin condensate, polyhydric alcohols such as adonitol, arabitol, xylitol and mannitol
There is.

Further, xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose,
There are sugars such as raffinose, gentianose, and melezitose, and their partially etherified products and methylglucoside (glycoside). These can be used alone or as a mixture and added to polybutene as a base oil to form a lubricant. .

[0026] Among these polyhydric alcohols, especially, grayed <br/> glycerin, diglycerol, triglycerol, trimethylolethane, lubricating oil in part etherified trimethylol propane and trimethylol butane and mixtures thereof In addition, excellent workability can be obtained and the amount of residual oil in the pipe after annealing can be reduced. Among these, ethylene glycol and polyethylene glycol (2 to 8 of ethylene glycol)
More preferably, lubricating oil contains propylene glycol, polypropylene glycol (2 to octamer of propylene glycol), glycerin and diglycerin, and partially etherified products of these mixtures. Most preferably, the lubricating oil contains ethylene glycol, polyethylene glycol (ethylene glycol dimer to hexamer), propylene glycol and glycerin, and partially etherified products of these mixtures.

In the above-mentioned polyhydric alcohols, if all the hydroxyl groups are etherified, the lubricity is undesirably reduced. Therefore, in the present invention, it is preferable that at least one of the hydroxyl groups of the polyhydric alcohol remains without being etherified. Particularly, a monoetherified product in which one of the hydroxyl groups of the polyhydric alcohol is etherified is more preferable.

As the etherification, any of alkyl etherification, alkenyl etherification, cycloalkyl etherification, alkylcycloalkyl etherification, aryl etherification, alkylaryl etherification and arylalkyl etherification may be used. In particular, when the above-mentioned polyhydric alcohol is alkyl etherified, a lubricating oil capable of further reducing the amount of residual oil in the pipe after annealing can be obtained.

The number of carbon atoms in the alkyl group to be ether-bonded is not particularly limited. For example, an etherified product of an alkyl group having 1 to 18 carbon atoms and a polyhydric alcohol is used as the lubricating oil component. Can be. As the alkyl group having 1 to 18 carbon atoms, specifically, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, scc-butyl group, tert-butyl group, Straight or branched pentyl group, straight or branched hexyl group, straight or branched heptyl group, straight or branched octyl group, straight or branched nonyl group , Straight or branched decyl group, straight or branched undecyl group, straight or branched dodecyl group, straight or branched tridecyl group, straight or branched tetradecyl group A linear or branched pentadecyl group, a linear or branched hexadecyl group, a linear or branched heptadecyl group, and a linear or branched octadecyl group.

Among these alkyl groups, alkyl groups having 3 or more carbon atoms are preferred from the viewpoint of odor, more preferably 5 or more carbon atoms, and most preferably 7 or more carbon atoms. When the carbon number is 16 or less,
The amount of residual oil in the pipe after annealing can be further reduced, and the adverse effect of the residue after annealing on the refrigeration system can be further reduced. Furthermore, when the carbon number is 1
The number is preferably 4 or less, and more preferably 12 or less.

(3) Part of polybutene and polyhydric alcohol
In the present invention, a total amount of etherified compounds: 90% by mass or more In the drawing step in which drawing property is required, a known lubricating oil additive, for example, for the purpose of enhancing the performance as a drawing lubricating oil, for example, , An oily agent or the like may be contained in the lubricating oil alone or in combination. As the oily agent, fatty acids, fatty acid esters, fatty acid metal salts, aliphatic alcohols, and the like can be used. However, when the content of the additional component such as the oily agent increases, the residual oil in the pipe after annealing the coil and other oils Residue such as carbide may increase, or the residue after annealing may adversely affect the refrigeration system. Therefore, the content of the additional component such as an oil agent is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 2.5% by mass or less based on the total mass of the lubricating oil.

That is, the total amount of polybutene and partially etherified polyhydric alcohol is 90% by mass based on the total mass of the lubricating oil.
It is preferably at least 95 mass%, more preferably at least 95 mass%, even more preferably at least 97.5 mass%. Also, when using a lubricating oil that does not contain additional components and consists only of a partially etherified product of polybutene and a polyhydric alcohol, and the remainder is inevitable impurities,
Even more preferred. When a lubricating oil containing an additional component such as an oil agent is used as a lubricating oil for drawing processing, the lubricating oil containing no additional component is used for finishing and the attached lubricating oil in the pipe is added to the additional component. It is preferable to perform annealing after replacing with lubricating oil containing no.

(4) Kinematic viscosity of lubricating oil at 40 ° C .: 5
When the kinematic viscosity of 0 to 5000 mm ² / sec Lubricating oil is less than 50 mm ² / s, sometimes oil amount remaining in the tube after the annealing increases. Also,
If the kinematic viscosity of the lubricating oil is less than 50 mm ² / sec, the lubricity may decrease. On the other hand, the kinematic viscosity of the lubricating oil is 500
If the viscosity is as high as more than 0 mm ² / sec, the amount of residual oil in the tube after annealing may increase. Therefore, in the present invention, the kinematic viscosity of the lubricating oil at 40 ° C. is preferably set to 50 to 5000 mm ² / sec.

In the present invention, as the refrigerant used for the heat exchanger or the like of the refrigeration system, an HFC-based refrigerant and a mixed refrigerant of the HFC-based refrigerant and a hydrocarbon (HC refrigerant) can be used.

The HFC-based refrigerant has 1 to 3 carbon atoms.
Are known. Specifically, difluoromethane (HFC-32), trifluoromethane (HFC-23), pentafluoroethane (HFC)
FC-125), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1-trifluoroethane (HFC -143a) and hydrofluorocarbons (HFCs) such as 1,1-difluoroethane (HFC-152a), and mixtures of two or more thereof.

As the mixed refrigerant of the HFC-based refrigerant, for example, a mixed refrigerant of 60 to 80% by mass of HFC-134a and 20 to 40% by mass of HFC-32, 40 to 70% by mass
Mass% HFC-32 and 30 to 60 mass% HFC-
HFC-1 containing 40 to 60% by mass of a mixed refrigerant with 125
A mixed refrigerant of 25 and 40 to 60% by mass of HFC-143a, 60% by mass of HFC-134a and 30% by mass of H
A refrigerant mixture of FC-32 and 10% by mass of HFC-125, 40 to 70% by mass of HFC-134a, 15 to 35% by mass of HFC-32 and 5 to 40% by mass of HFC
-125 and HF of 35 to 55% by mass
C-125 and 1 to 15% by mass of HFC-134a and 4
A refrigerant mixture with 0 to 60% by mass of HFC-143 can be used.

More specifically, as a mixed refrigerant of the HFC-based refrigerant, a mixed refrigerant of 70% by mass of HFC-134a and 30% by mass of HFC-32, 60% by mass of HFC-32
Mixed refrigerant with HFC-125 of 50% by mass and HFC-32 of 50% by mass and HFC-125 of 50% by mass (R410A; manufactured by Allied Signal Inc., Gentron
AZ-20), 45% by weight of HFC-32 and 55% by weight of H
Refrigerant mixed with FC-125 (R410B; manufactured by DuPont, SUVA AC9100), 50% by mass of HFC-125 and 5
0% by mass of a mixed refrigerant with HFC-134a (R507
C; Gentron AZ-50, manufactured by Allied Signal Inc.), 30% by mass of HFC-32 and 10% by mass of HFC-125 and 6
0 mass% mixed refrigerant with HFC-134a, 23 mass%
Refrigerant (R407C; manufactured by DuPont, SUVA AC9000) containing HFC-32, 25% by mass of HFC-125 and 52% by mass of HFC-134a, and 44% by mass of HFC
-125 and 4% by mass of HFC-134a and 52% by mass of HFC-143a (R404A; manufactured by DuPont; SUVA HP-62).

As the hydrocarbon-based refrigerant, alkanes, cycloalkanes and alkenes having 1 to 6 carbon atoms, and refrigerant mixtures thereof can be used. Specifically, for example, methane, ethylene, ethane, propylene, propane, cyclopropane, butane, isobutane,
Cyclobutane and methylcyclopropane, and mixtures of two or more thereof, can be used.

Further, in the present invention, the refrigerating machine oil used in the refrigerating system, that is, the compressor oil in the refrigerating system, may be any one of at least one selected from the group consisting of mineral oil and synthetic oil, if necessary. Can be used.

The mineral oil used as the refrigerating machine oil includes:
Specifically, for example, the lubricating oil fraction obtained by atmospheric distillation and vacuum distillation of crude oil, solvent dewaxing, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, Among the sulfuric acid washing and the clay treatment, a paraffinic or naphthenic mineral oil obtained by combining one or more refining means can be used.

Specific examples of the synthetic oil used as the refrigerator oil include synthetic oxygenated oils such as polyolefins, alkylbenzenes, esters, ethers, silicates and polysiloxanes.
In particular, it is preferable to use polyolefin, alkylbenzene, ester, ether and the like.

Of the synthetic oils used as refrigerating machine oils,
The polyolefin refers to homopolymers and copolymers of olefins having 2 to 16 carbon atoms, preferably 2 to 12 carbon atoms, and hydrides thereof. When the polyolefin is a copolymer of olefins having different structures, there is no particular limitation on the monomer ratio and monomer arrangement in the copolymer, and any of a random copolymer and an alternating copolymer may be used. Is also good.

The olefin monomer forming the polyolefin may be an α-olefin or an internal olefin, and may be a linear olefin or a branched olefin.

Examples of the olefin that can be used in producing the polyolefin include, for example, ethylene, propylene, 1-butene, 2-butene, isobutene, linear or branched pentene (α- Olefins and internal olefins, linear or branched hexene (including α-olefins and internal olefins), linear or branched heptene (including α-olefins and internal olefins), linear Octene (including α-olefin and internal olefin), linear or branched nonene (including α-olefin and internal olefin), linear or branched decene (α-olefin) Olefin and internal olefin), linear or branched undecene (including α-olefin and internal olefin), linear or branched dodecene alpha-olefin and an internal olefin), linear or branched tridecene (alpha-
Olefins and internal olefins), linear or branched tetradecenes (including α-olefins and internal olefins), linear or branched pentadecenes (including α-olefins and internal olefins), and Examples include linear or branched hexadecenes (including α-olefins and internal olefins), and mixtures thereof.

In particular, it is preferable to use ethylene, propylene, 1-butene, 2-butene, isobutene, an α-olefin having 5 to 12 carbon atoms, and a mixture thereof, and having 5 to 12 carbon atoms. It is even more preferred to use 1-octene, 1-decene and 1-dodecene and mixtures thereof among the α-olefins.

The above-mentioned polyolefin can be produced by any method. For example, in addition to being able to be produced by a thermal reaction without a catalyst, it is possible to produce a polyolefin by homopolymerizing or copolymerizing an olefin using a known organic peroxide catalyst such as benzoyl peroxide. it can. Examples of the organic peroxide catalyst include Friedel-Crafts catalysts such as aluminum chloride, aluminum chloride-polyhydric alcohol, aluminum chloride-titanium tetrachloride, aluminum chloride-alkyltin halide, and boron fluoride. . Organic aluminum chloride-titanium tetrachloride and organic aluminum-
Ziegler-type catalysts such as titanium tetrachloride can also be used. Further, using known catalyst systems such as aluminoxane-zirconocene-based, ionic compound-zirconocene-based metallocene-type catalysts, and aluminum chloride-base-based and boron fluoride-base-based Lewis acid complex-based catalysts such as, for example, The olefin can be homopolymerized or copolymerized.

In the present invention, the above-mentioned polyolefin can be used as a component of the refrigerating machine oil. However, since this polyolefin usually has a double bond, heat stability and oxidation stability are taken into consideration. Then, a hydride of a polyolefin obtained by hydrogenating a double bond in a polymer may be used. As a method for obtaining a polyolefin hydride, an appropriate method can be used.For example, a polyolefin is hydrogenated with hydrogen in the presence of a known hydrogenation catalyst to saturate a double bond present in the polyolefin. A method can be used. Also, by selecting the catalyst to be used, after polymerizing the olefin,
The two steps of the polymerization step of the olefin and the hydrogenation step of the double bond present in the polymer can be simultaneously performed without sequentially performing the two steps of hydrogenation.

Among the polyolefins that can be used as components of the refrigerating machine oil, ethylene-propylene copolymer and polybutene (butane-butene (a mixture of 1-butene, 2-butene and isobutene) by-produced during naphtha pyrolysis) fraction , 1-octene oligomer, 1-decene oligomer and 1-dodecene oligomer, and their hydrides and mixtures thereof have thermal stability, oxidation stability, viscosity-temperature. It can be used because of its excellent properties and low temperature fluidity. In particular, it is preferable to use ethylene-propylene copolymer hydride, polybutene hydride, 1-octene oligomer hydride, 1-decene oligomer hydride, 1-dodecene oligomer hydride, and a mixture thereof.

Incidentally, synthetic oils such as ethylene-propylene copolymer, polybutene and poly-α-olefin which are commercially available as base oils for lubricating oils are usually those whose double bonds have already been hydrogenated. These commercial products can also be used as components of refrigerating machine oil.

Of the synthetic oils used as refrigerator oil, any alkyl benzene can be used. For example, an alkyl benzene having 1 to 4 alkyl groups having 1 to 40 carbon atoms can be used. Can be used. As the alkyl group having 1 to 40 carbon atoms, specifically, for example, a methyl group, an ethyl group,
Propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl Group, icosyl group, henycosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, nonacosyl group, triacontyl group, hentriacontyl group, dotriacontyl group, tritriacontyl group, tetratria There are contyl group, pentatriacontyl group, hexatriacontyl group, heptatriacontyl group, octatriacontyl group, nonatriacontyl group, and tetracontyl group. body Alkylbenzene containing can be used as synthetic oils.

As the alkyl group of the alkylbenzene,
Although it may be linear or branched, it is preferable to use an alkylbenzene having a branched alkyl group as a synthetic oil from the viewpoint of stability and viscosity characteristics. Among them, alkylbenzene having a branched alkyl group derived from an oligomer of olefin such as propylene, butene and isobutylene is particularly preferably used as a refrigerating machine oil because it is easily available.

The number of alkyl groups in the alkylbenzene is preferably 1 to 4, but from the viewpoint of stability and availability, a monoalkylbenzene having one alkyl group and two alkyl groups are preferred. The dialkylbenzenes having these and mixtures thereof can be used as refrigerating machine oil. In addition, as alkylbenzene,
Not only alkylbenzene having a single structure but also a mixture of alkylbenzenes having different structures may be used.

The method for producing alkylbenzene is not limited, but can be generally synthesized by the following synthesis method. As the aromatic compound serving as a raw material, specifically, for example, benzene, toluene, xylene, ethylbenzene, methylethylbenzene, diethylbenzene, a mixture thereof and the like can be used. Also, as the alkylating agent,
For example, among lower monoolefins such as ethylene, propylene, butene, and isobutylene, a linear or branched olefin having preferably 6 to 40 carbon atoms obtained by polymerization of propylene can be used. In addition, n- to C-6 to C40 linear or branched olefins obtained by pyrolysis of wax, heavy oil, petroleum fraction, polyethylene and polypropylene, and petroleum fractions such as kerosene and gas oil. It is also possible to use a linear olefin having 9 to 40 carbon atoms obtained by separating paraffin and subjecting it to olefination with a catalyst, or a mixture of these olefins.

Further, as the alkylation catalyst for the alkylation, a Friedel-Crafts type catalyst such as aluminum chloride and zinc chloride, and an acid catalyst such as sulfuric acid, phosphoric acid, silicotungstic acid, hydrofluoric acid and activated clay are used. Catalysts, etc.
Known alkylation catalysts can be used.

Among the synthetic oils used as refrigerating machine oils,
Esters include dibasic acid esters, polyol esters, complex esters and carbonate esters. Esters that can be used as a component of refrigerating machine oil are substantially all esters when polybasic acids such as dibasic acids and polyhydric alcohols are used as the acids and alcohols constituting the ester. Only partial esters are shown, and do not include partial esters in which carboxyl groups, hydroxyl groups, etc. remain without being esterified.

As the dibasic acid ester, glutaric acid,
Dibasic acids having 5 to 10 carbon atoms, such as adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid, and methanol, ethanol, linear or branched propanol, linear or branched Butanol, linear or branched pentanol, linear or branched hexanol, linear or branched heptanol, linear or branched octanol, linear or branched Branched nonanol, straight or branched decanol, straight or branched undecanol, straight or branched dodecanol, straight or branched tridecanol, straight or branched Branched tetradecanol, linear or branched pentadecanol,
Linear or branched hexadecanol, linear or branched heptadecanol, linear or branched octadecanol, linear or branched nonadecanol, linear or Straight-chained eicosanols, straight-chain or branched henicosanols, straight-chain or branched docosanols, straight-chain or branched tricosanols and straight-chain or branched tetracosanols An ester with a monohydric alcohol having 1 to 24 carbon atoms having a chain or branched alkyl group,
And mixtures thereof, and specifically, use of ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate and di 2-ethylhexyl sebagate, and mixtures thereof, and the like. Can be.

Among the esters used as refrigerator oil, polyol esters include diols or polyols having 3 to 20 hydroxyl groups, and polyols having 6 to 2 carbon atoms.
Preference is given to using esters with fatty acids which are 0. As the diol, specifically, for example, ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5 −
Pentanediol, neopentyl glycol, 1,6-
Hexanediol, 2-ethyl-2-methyl-1,3-
Propanediol, 1,7-heptanediol, 2-methyl-2-propyl-1,3-propanediol, 2,
2-diethyl-1,3-propanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-
There are decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

Examples of the polyol having 3 to 20 hydroxyl groups include, for example, trimethylolethane, trimethylolpropane, trimethylolbutane and di-methylolbutane.
(Trimethylolpropane), tri- (trimethylolpropane), pentaerythritol, di- (pentaerythritol), tri- (pentaerythritol), glycerin, polyglycerin (glycerin dimer to 20mer), 1,3,5 -Pentanetriol, sorbitol, sorbitan, sorbitol glycerin condensate, polyhydric alcohols such as adonitol, arabitol, xylitol and mannitol, and xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isobutyrate Saccharides such as maltose, trehalose, sucrose, raffinose, gentianose and melezitose, and partially etherified products thereof, and methyl glucoside ( Totai), and the like.

As a fatty acid having 6 to 20 carbon atoms,
Specifically, for example, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid,
Linear or branched ones such as dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, icosanoic acid and oleic acid, and α-carbon atoms are quaternary Neo acids and the like.

More specifically, valeric acid, isopentanoic acid, capric acid, pelargonic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, caprylic acid, 2-ethylhexanoic acid, normal nonanoic acid, 3,5,5 5-trimethylhexanoic acid and the like. Some polyol esters have a free hydroxyl group. Incidentally, particularly preferably,
Neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di- (trimethylolpropane), tri- (trimethylolpropane), pentaerythritol, di- (pentaerythritol), tri- (pentaerythritol), etc. Is an ester of hindered alcohol. Specifically, neopentyl glycol-2-ethylhexanoate, trimethylolpropane caprylate, trimethylolpropaneperargonate, pentaerythritol-2-ethylhexanoate, and pentaerythritol pelargonate, and mixtures thereof, etc. is there.

Of the esters used as refrigerator oil, complex esters are esters of fatty acids and dibasic acids with monohydric alcohols and polyols, and include esters of fatty acids, dibasic acids, monohydric alcohols and polyols. Can be the same as those exemplified for the dibasic acid ester and the polyol ester.

The carbonic acid ester is an ester of carbonic acid with a monohydric alcohol and a polyol. The monohydric alcohol and the polyol may be the same as those described above, or may be homopolymerized or copolymerized with an alkylene oxide. Polyglycols obtained by adding polyglycol to the above-mentioned polyols and the above-mentioned polyols can be used.

The ethers usable as the refrigerating machine oil include polyglycols, polyvinyl ethers,
There are polyphenyl ether, cyclic ether, perfluoroether and the like, and among these ethers, it is preferable to use polyglycol and polyvinyl ether.

As the polyglycol, it is preferable to use polyalkylene glycol and its etherified product, and modified compounds thereof. As the polyalkylene glycol, those obtained by homopolymerizing or copolymerizing alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide can be used. In the polyalkylene glycol, when alkylene oxides having different structures are copolymerized, the polymerization form of the oxyalkylene group is not particularly limited, and may be random copolymerized or block copolymerized. .

The etherified polyalkylene glycol is obtained by etherifying the hydroxyl group of the above-mentioned polyalkylene glycol. As the etherified product of the polyalkylene glycol, specifically, monomethyl ether,
Monoethyl ether, monopropyl ether, monobutyl ether, monopentyl ether, monohexyl ether, monoheptyl ether, monooctyl ether,
Examples include monononyl ether, monodecyl ether, dimethyl ether, diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether, and didecyl ether.

The modified compounds of polyglycol include alkylene oxide adducts of polyols and etherified products thereof. As this polyol, the same polyols as those exemplified for the polyol ester can be used.

Further, as the polyvinyl ether, those having a structural unit represented by the following general formula (1) can be used.

[0068]

Embedded image Here, R ₁ , R ₂ and R ₃ each represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, which may be the same or different. R ₄ has 2 carbon atoms
A divalent hydrocarbon group having 1 to 10 carbon atoms; and R ₅ is a hydrocarbon group having 1 to 10 carbon atoms. Further, m is an integer having an average value of 0 to 10, and R _{1 to} R ₅ may be the same or different for each structural unit. Furthermore,
If R ₄ -O there are a plurality, that is, when m is 2 or more, plural R ₄ -O may be those being the same or different.

When oxygen-containing synthetic oil is used among these refrigerating machine oils, the residue in the copper pipe after annealing has a large effect on the refrigerating system. When used, a remarkable effect can be obtained.

[0070]

EXAMPLES Hereinafter, examples of the lubricating oil for copper pipe processing according to the present invention will be specifically described in comparison with comparative examples.

First, the ingot of phosphorous deoxidized copper is subjected to hot extrusion and cold rolling, and then a bull block is used to obtain a copper pipe lubricating oil having various characteristics. 5
A copper tube having a thickness of 2 mm and a wall thickness of 0.41 mm was drawn, and the presence or absence of seizure of the tool (plug) was evaluated. Regarding the seizure of the tool, when a predetermined number of drawing processes are performed on a small-diameter product from a large-diameter raw tube using a plug, seizure does not occur on the plug even if the total drawing length of the copper tube is 3 km. Were evaluated as ○, and those in which image sticking occurred by drawing less than 3 km were evaluated as ×.

Next, a long copper tube having a length of 2 km after drawing was wound in a coil shape, and the obtained long coil copper tube was annealed in a bright annealing furnace. Before annealing, a reducing gas (DX gas) containing nitrogen gas as a main component and containing CO gas, CO ₂ gas, and H ₂ gas is flowed into the tube at a flow rate of 20 liter / min for 30 minutes. Replaced with DX gas. In the bright annealing furnace, the lowest temperature part is at least 450 ° C
The temperature of the atmosphere gas was set to 600 ° C. so that the temperature was maintained for 10 minutes as described above, and after heating and annealing for about 25 minutes, it was cooled.

Next, after replacing the residual gas in the cooled long annealed coil copper tube with dry air, the copper tube was disassembled, and the residual oil mass at various portions in the tube was measured by the following method. First, from a coiled copper tube, 15
After taking a point sample and cutting it to a length of 10m,
Hydrochlorofluorocarbon (HCFC-141
The inner surface of the tube was washed according to b), and residual oil adhering to the inner surface was extracted. Next, after heating the residual oil to evaporate the solvent, the residual amount is measured, converted into the amount of residual oil per 1 m long copper tube, the maximum residual oil mass and the average residual oil. The mass was calculated.

Further, two test tubes were cut from the manufactured long annealed coil copper tube, and one end of the test tube was expanded, and then the other test tube was inserted. Then, using a phosphor copper brazing wire (BCuP-2) having a wire diameter of 1.6 mm, both were brazed by heating with propane combustion gas for 6 seconds. And 30kg / c in the pipe
When the Freon gas was charged at a pressure of m ^2, no gas leakage occurred, and a symbol was given when the gas was not filled with the brazing material.

Further, 60 g of the lubricating oils of Examples and Comparative Examples were injected into a copper tube, the ends of both tubes were crushed and annealed under the same annealing conditions as described above. In addition, both ends of the copper tube were crushed so that the inside of the tube was not completely sealed and gas inside hardly leaked to the outside. After the end of the tube was cut open after annealing, the residual oil in the tube was extracted with an ultrasonic cleaner using a 1: 1 mixed solvent of acetone and n-hexane. Then, 10 mm at a temperature of 40 ° C.
Vacuum distillation was performed at a pressure of Hg to remove the solvent and low-boiling components, thereby producing an annealing residue.

Thereafter, in order to investigate the effect of the obtained residual oil on the refrigeration system, JIS K2211 was used.
A shield tube test was conducted in accordance with Annex 2 “Chemical stability test method with refrigerant (shield tube test)” of “Refrigeration oil”. The detailed test conditions are shown below. First, 1 ml of refrigerant, 1 ml of sample oil, and a catalyst made of a metal wire having a thickness of 1.6 mm and a length of 50 mm were put into a glass tube having an inner diameter of 10 mm. The top was melted and sealed. Next, after maintaining the glass tube at a temperature of 175 ° C. for 14 days, a change in the state of the liquid layer was observed. Then, as a result of the observation, a case where there was no change was evaluated as 、, and a case where deterioration of the catalyst, discoloration of the sample oil or cloudiness or a precipitate was present was evaluated as ×.

In this example, a mixture of 0.3 mg of annealing residual oil and 1.0 g of refrigerating machine oil was used as a sample oil, and a metal wire made of iron, copper, aluminum or the like was used as a catalyst. It was used. In addition, as a refrigerant,
R410A and R407C were used, and as a refrigerating machine oil, a tetraester of ester oil (pentaerythritol and a mixed fatty acid of 2-ethylhexanoic acid and 3,5,5-trimethylhexanoic acid (molar ratio 50:50) (at 40 ° C.) Kinematic viscosity: 68 mm ² / sec)) was used.

The types and properties of the base oils used as components of the lubricating oil are shown in Table 1 below, and the types of partially etherified polyhydric alcohols used as the components of the lubricating oil are shown in Table 2 below. Table 3 below shows the types of components added to the lubricating oil. Further, the composition and kinematic viscosity of the lubricating oil are shown in Table 4 below, and the evaluation results of various tests are shown in Table 5 below.

[0079]

[Table 1]

[0080]

[Table 2]

[0081]

[Table 3]

[0082]

[Table 4]

[0083]

[Table 5]

As shown in Tables 1 to 5 above, Example N
o. 1 to 12 use a polybutene and a partially etherified polyhydric alcohol whose infrared absorbance I at 1230 cm ^-1 is defined as a lubricating oil, and the content of each component is appropriately defined. The residual oil content of the coiled copper tube after annealing was 0.50 mg / m or less at the maximum, and no poor brazing and no seizure of the tool (plug) occurred. Further, in the shield tube test, no cloudiness and no precipitates were observed.

On the other hand, in Comparative Example No. No. 13 uses polybutene as a base oil.
Since the infrared absorbance I at m ^-1 was less than the lower limit of the range of the present invention, the amount of residual oil in the tube increased, and a leak occurred after brazing. Comparative Example No. 14 while the polybutene content as a base oil exceeds the upper limit of the scope of the present invention,
Since the content of the partially etherified polyhydric alcohol is less than the lower limit of the present invention, seizure occurred in the plug. Comparative Example No. In Nos. 15 and 16, refined mineral oil was used as the base oil, and polybutene was not used. Therefore, the amount of residual oil in the pipe increased, and a leak occurred after brazing. In the shield tube test, cloudiness or a precipitate was observed.

[0086]

As described in detail above, according to the present invention,
1230cm of polybutene used as base oil for lubricating oil
Together defining infrared absorbance I at ^-1, since the content of the lubricating oil of the polybutene and the trivalent or higher polyhydric alcohol partial ether compound are appropriately regulated, after the introduction or processing of large-scale facilities It is possible to reduce the residual oil in the tube at low cost without performing a special residual oil removal treatment or the like for the long coil copper tube, thereby improving the brazing property of the copper tube, Further, it is possible to reduce the adverse effect of the residue after annealing on the refrigeration system.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C10N 20:02 C10N 20:02 30:06 30:06 30:08 30:08 40:24 40:24 Z (72) Inventor Kozo Saeki 1-5-5 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture Kobe Steel, Ltd.Kobe Research Institute (72) Inventor Takeki Otsuka 1-5-5 Takatsudai, Nishi-ku, Kobe City, Hyogo Prefecture Kobe Co., Ltd. Steel Works Kobe Research Institute (72) Inventor Hideo Yokota 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Japan Japan Petroleum Co., Ltd. (72) Inventor Kazuhiko Endo 8 Chidori-cho, Naka-ku, Yokohama, Kanagawa Japan Petroleum Corporation Central Technology Research Institute (72) Inventor Kazuka Dai 8 Chidoricho, Naka-ku, Yokohama-shi, Kanagawa Japan Japan Petroleum Corporation Central Technology Research Institute (72) Inventor Noboru Ishida Yokohama, Kanagawa Prefecture 8, Chidori-cho, Naka-ku, Japan The Central Research Laboratory of Petroleum Co., Ltd. (56) References JP-A-10-130679 (JP, A) JP-A-9-272889 (JP, A) JP-A-10-298583 (JP, A A) JP-A-11-209781 (JP, A) JP-A-9-176738 (JP, A) JP-A-10-130675 (JP, A) JP-A-2000-96073 (JP, A) JP-A-2000-169874 (JP, A) JP-A-5-331484 (JP, A) Petroleum and Petrochemical, May 1, 1971, Vol. 15, No. 6, pp. 69-74 (58) Fields investigated (Int. Cl. ⁷ , DB name) C10M 169/04 C10M 105/18 C10M 107/08 C10M 129/16 C10N 20:00-20:02 C10N 30:06-30:08 C10N 40:24

Claims (5)

(57) [Claims] 1. Polybutene: 60 per total mass of lubricating oil
To 99.5% by mass and a partially etherified product of a polyhydric alcohol having 3 or more valences: 0.5 to 40% by mass, and the polybutene is 1230 cm when the infrared absorbance I is measured by an infrared total reflection absorption method. ^1. A lubricating oil for copper pipe processing, wherein the infrared absorption I per reflection at ^-1 is 0.025 or more. 2. A kinematic viscosity at 40 ° C. of 50 to 500.
Copper pipe processing lubricating oil according to claim 1, characterized in that the 0 mm ² / sec. 3. A copper tube according to claim 1 or 2, wherein the content and the content of the trihydric or higher polyhydric alcohols partially etherified product of the polybutene is 90 mass% or more in total Lubricating oil for processing. 4. The lubricating oil for processing copper pipes according to claim 1, wherein the lubricating oil is used as an internal lubricating oil for heat treatment of copper or copper alloy pipes. 5. The method according to claim 1, wherein when the copper or copper alloy tube wound in a coil shape is processed, the copper or copper alloy tube is supplied to an inner surface of the copper or copper alloy tube. The lubricating oil for copper pipe processing as described.