JPH0586835B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to lubricating oils having excellent stability against Lewis acids, and more particularly to lubricating oils that come into contact with Lewis acids or where Lewis acids may be formed. It relates to lubricating oil suitable for driving and sliding parts of devices.

Conventional technology In today's rapidly developing society, remarkable technological innovations are progressing, and with this technological innovation, various substances are manufactured, and the manufacturing equipment is also required to have advanced performance under harsher conditions. It is becoming. Particularly in recent years, with the expansion of the use of thin film manufacturing technology, there has been a rapid increase in the number of cases in which manufacturing equipment, especially driving and sliding parts, come into contact with Lewis acids such as aluminum chloride, and the lubricants used in such equipment Oils are also required to have high performance, particularly excellent Lewis acid resistance and lubricity.

Currently, devices that come into contact with Lewis acids include semiconductor manufacturing equipment, such as dry etching equipment, ion implantation equipment, and plasma CVD equipment;
Halogen lamp manufacturing equipment is known, but when the normal lubricating oil used in the driving or sliding parts of these equipment comes into contact with a Lewis acid, it may react with the Lewis acid or a reaction where the Lewis acid acts as a catalyst. This causes deterioration and decomposition of the lubricating oil, which in turn causes increased viscosity, gelation, reduced vacuum, and sludge formation, which reduces operational efficiency due to equipment trouble and increased maintenance and inspection time. This causes a decline in product quality.

Even with commercially available perfluoropolyether oil, which is generally considered to have excellent chemical resistance, when it is used as a lubricating oil for the above equipment, the lubricating oil is decomposed by Lewis acids, especially aluminum chloride, and phosgene , chlorofluorocarbonyl,
Generates highly toxic low molecular weight substances such as fluorocarbonyls. Therefore, in equipment using perfluoropolyether oil as a lubricant,
The degree of vacuum decreases after a short period of operation, and therefore frequent oil changes are required to maintain the desired degree of vacuum, which results in a significant amount of down time for the equipment and reduces the operating rate. A significant decline is inevitable. In addition, during this oil change, highly toxic substances such as the above-mentioned phosgene are dispersed into the atmosphere, which poses health and safety issues for workers.Furthermore, various fluorine-based decomposition products must be treated during waste oil treatment. However, there are also problems in terms of pollution prevention and industrial waste disposal.

Furthermore, JP-A No. 164698/1983 states, ``General formula {[H(CF ₂ CF ₂ ) _n CH ₂ O] ₂ PN} _o () [However, in formula (), (CF ₂ CF ₂ )m The segments shown represent a single segment that is an integral multiple of the unit (CF ₂ CF ₂ ) or a mixture of segments of different chain lengths that are integral multiples, and in the case of a single segment, m = 2. m if there are mixed chain length segments.
means the average number of repetitions of (CF ₂ CF ₂ ) units representing the average chain length, and the value of m is 1.3≦m≦2.8
and n represents the number of repeats of the PN unit in the phosphonitrile ring skeleton of the compound of formula (),
In the case of a mixture of rings with different numbers of repeats, it indicates the average number of repeats, and takes a real value in the range of 3≦n≦4. A perfluoroalkoxy cyclic phosphonitrile ester rotary pump oil containing a compound represented by the following as a main component is disclosed. However, the compound represented by the general formula () has the property of dissolving Lewis acids well, so if the compound is in contact with Lewis acids for a long time, the compounds may dissolve a large amount of Lewis acids. The drawback is that the viscosity inevitably increases, and as a result, the compound becomes waxy, making it difficult to function as a lubricating oil.

Means for Solving the Problems The present invention solves the above problems and provides a lubricating oil composition that can fully demonstrate the performance of the above production equipment.

That is, the present invention relates to a fluoroalkoxy cyclic phosphonitrile ester lubricating oil represented by the following formula (1) for use in devices that come into contact with Lewis acids.

[H(CF ₂ CF ₂ ) _n CH ₂ O] _2o-l [CF ₃ CF ₂ CH ₂ CH ₂ O] _l P _o N _o (1) [However, in the formula, (CF ₂ CF ₂ ) _n is The segment shown in the figure represents a single segment that is an integral multiple of the unit (CF ₂ CF ₂ ) or a mixture of segments of different chain lengths that are an integral multiple of the unit, and in the case of a single segment, m = 2. , and when segments of chain length are mixed, m means the average number of repeats of the (CF ₂ CF ₂ ) unit representing the average chain length,
The value of m is in the range 1.3≦m≦2.8, and the value of l is
2n-1≧l≧1, and n indicates the number of repeats of the PN unit of the phosphonitrile ring skeleton,
In the case of a mixture of rings with different numbers of repeats, it indicates the average number of repeats, and shall take a real value within the range of 3≦n≦4.3. ] In the present invention, the fluoroalkoxy cyclic phosphonitrile ester of the above general formula (1) used as an active ingredient is a substance produced from a phosphonitrile halide oligomer and a fluoroalcohol, as shown in the reference examples below. It is. Here, the oligomer of phosphonitrile halide includes, for example, a trimer of phosphonitrile chloride,
Examples include tetramers of phosphonitrile chloride and mixtures thereof. Examples of fluoroalcohols include 1,1,ω-trihydroperfluoroalcohols such as 1,1,3-trihydroperfluoropropanol and 1,1,5-trihydroperfluoropentanol;
An example is a mixture with 2,3,3,3-pentafluoropropanol. Further, the fluoroalkoxy cyclic phosphonitrile ester of the above general formula (1) can be prepared by reacting two or more of the above 1,1,ω-trihydroperfluoroalcohols in advance to form an alcoholate, and then converting this alcoholate into a phosphonitrile halide. It is also produced by reacting with oligomers.

In the present invention, the fluoroalkoxy cyclic phosphonitrile esters represented by the above general formula (1) may be used alone or in combination of two or more.

Among the fluoroalkoxy cyclic phosphonitrile esters represented by the above general formula (1) or mixtures thereof, preferable ones include those represented by the above general formula
Examples of (1) include mixtures of fluoroalkoxy cyclic tetraphosphonitrile esters in which n is 4, m is 2, and l is an integer of 1 to 7, respectively. These compounds have the excellent property of hardly dissolving Lewis acids, and can be effectively used, for example, as lubricating oils for seals, bearings, etc. where it is desired to block Lewis acids.

Effects of the Invention The composition of the present invention is an extremely safe lubricating oil composition that does not easily decompose even when it comes into contact with a Lewis acid, and does not substantially generate harmful and highly toxic substances such as phosgene and fluorocarbonyl. . Therefore, the composition of the present invention is extremely suitable as a lubricating oil for use in driving or sliding parts of semiconductor manufacturing equipment, typified by dry etching equipment, ion implantation equipment, plasma CVD equipment, etc., halogen lamp manufacturing equipment, etc. It is something.

Examples Reference examples, examples, and comparative examples are given below to further clarify the present invention.

Reference Example 1 4799 g (2.06 mol) of 1,1,5-trihydroperfluoropentanol and toluene were placed in a four-necked flask equipped with a condenser, stirrer, and thermometer.
Prepare 1000ml of Na pieces and cut into small pieces while cooling.
45.3 g (1.97 mol) was added and reacted at 40° C. for 4 hours until sodium was completely dissolved. A solution of 89 g (0.256 mol) of phosphonitrile chloride trimer dissolved in 500 ml of toluene was added dropwise to this reaction solution at about 50° C., and the reaction was carried out under reflux for 4 hours. After washing with water, dehydration, and concentration to remove generated sodium chloride, 330 g of an oily crude product was obtained.
This is distilled under reduced pressure to 203~210℃/0.03~
280 g of a 0.08 mmHg fraction was collected.

Analysis of this colorless and transparent oil confirmed that the main component was hexakis (1,1,5-trihydroperfluoropentyloxy) cyclic triphosphonitrile ester, and the IR, NMR, and MS spectra also showed that It showed the structure. The specific gravity of this material is 1.791 (15/4℃) and the kinematic viscosity is 89.52 cst (40
), the viscosity index was 88, and the pour point was -45°C.
This substance is hereinafter referred to as "compound A."

Reference Example 2 2,2,3,3,3-pentafluoropropanol 155g (1.03 mol), 1,1,5
-Trihydroperfluoropentanol 240g
(1.03 mol) and 1000 ml of toluene were charged, and while cooling, 45.3 g (1.97 mol) of Na pieces cut into small pieces were added, and the mixture was reacted at 40°C for 4 hours until the sodium was completely dissolved. To this reaction solution, add 89 g of phosphonitrile chloride tetramer dissolved in 500 ml of toluene.
(0.192 mol) was added dropwise at about 50°C, and the reaction was carried out under reflux for 4 hours. After washing with water, dehydration, and concentration to remove generated sodium chloride, 310 g of an oily crude product was obtained. This is distilled under reduced pressure to give 160 to 193
A fraction of 260 g was collected at a temperature of 0.03 mmHg. As a result of GC and GC-MS analysis, this colorless and transparent oily substance
In the compound of the above general formula (1) where n is 4 and m is 2, l = 1 is 1.6%, l = 2 is 8.6%, l
=3 is 22.9%, l=4 is 32.7%, l=5 is 23.3%,
It was confirmed that it was a mixture of seven components, with l=6 being 8.5% and l=7 being 1.5%. This material had a specific gravity of 1.746 (20°C), a viscosity of 204 cps (40°C), a vapor pressure of 1 mmHg/188°C, and a pour point of -37.5°C. This substance is hereinafter referred to as "Compound C."

Comparative Example 1 A chemical-type oil rotary vacuum pump that had been thoroughly cleaned with solvent was filled with 800 ml of Compound A, connected to a test plasma etching device set for aluminum etching, and operated for 14 days using carbon tetrachloride gas. . Exhaust gas was collected using an air-cooled trap, dry ice trap, and liquid nitrogen trap connected in series. No abnormalities were observed in the equipment during 14 days of operation. As a result of removing the oil and examining it, the oil was colored dark brown, but the oil extracted and recovered with Freon 113 had no difference in viscosity, IR spectrum, etc. from new oil, and the recovery rate was 98%. Ta. Also,
The dark brown coloration was found to be due to dissolution of aluminum chloride, etc. Note that carbon tetrachloride was collected in the air-cooled trap, trace amounts of phosgene, etc. were collected in the dry ice trap, and small amounts of chlorine, etc. were collected in the liquid nitrogen trap. The amount of phosgene collected was 0.0038 g, which was measured based on JIS K0090, which was an amount that would not pose any problem in terms of the working environment.

However, if the above operation was continued for 30 days, the viscosity of the oil would increase, causing overload of the motor, increase in temperature, and decrease in the degree of vacuum, necessitating maintenance.

Example 1 The apparatus was operated for 14 days in the same manner as in Example 1 using 800 ml of Compound C. There were no abnormalities in the equipment during operation, and only a small amount of yellow-brown sludge was observed at the bottom of the dark yellow-green oil during inspection. After separating the sludge, the oil extracted and recovered with Freon 113 had no difference in viscosity, IR spectrum, etc. from new oil, and the recovery rate was 98%. In addition, the separate sludge was mainly composed of aluminum chloride.
In addition, the amount of phosgene collected in the trap was
The amount was 0.0027 g, which was less than when Compound A was used. Furthermore, although the above operation was continued for more than 60 days, no increase in oil viscosity occurred, and no maintenance was required.

Example 2 Using Compound C, alumina was etched with boron trichloride for 10 days in the same manner as in Example 1. During operation, no abnormality was observed in the equipment, and upon inspection of the pump, the oil was colored grayish white, and yellowish brown sludge was observed on the bottom of the oil and on the inner wall. After separating the sludge, the oil extracted and recovered using Freon 113 was evaluated for viscosity and IR.
There is no difference in spectrum etc. from new oil, and the recovery rate is 98
It was %. In addition, the separate sludge is freon
After 113 washing, analysis revealed that the main components were aluminum chloride and boric acid. Further, the amount of phosgene collected in the trap was 0.0019 g, which was an amount that did not cause any problems in terms of the working environment. Furthermore, although the above operation was continued for more than 60 days, no increase in oil viscosity occurred, and no maintenance was required.

Claims (1)

[Claims] 1. A fluoroalkoxy cyclic phosphonitrile ester lubricating oil represented by the following formula (1) for use in devices that come into contact with Lewis acids. [H(CF ₂ CF ₂ ) _n CH ₂ O] _2o-1 [CF ₃ CF ₂ CH ₂ CH ₂ O] _l P _o N _o (1) [However, in the formula, (CF ₂ CF ₂ ) m is The segment shown in the figure represents a single segment that is an integral multiple of the unit (CF ₂ CF ₂ ) or a mixture of segments of different chain lengths that are an integral multiple of the unit, and in the case of a single segment, m = 2. , and when segments of chain length are mixed, m means the average number of repeats of the (CF ₂ CF ₂ ) unit representing the average chain length,
The value of m is in the range 1.3≦m≦2.8, and the value of l is
2n-1≧l≧1, and n indicates the number of repeats of the PN unit of the phosphonitrile ring skeleton,
In the case of a mixture of rings with different numbers of repeats, it indicates the average number of repeats, and shall take a real value within the range of 3≦n≦4.3. ] 2 is a single chain length segment with a value of m of 2,
The lubricating oil according to claim 1, which contains a mixed fluoroalkoxy cyclic tetraphosphonitrile ester in which l is 1≦l≦7 and n is 4 as a main component. 3. The lubricating oil according to claim 1 or 2, wherein the Lewis acid is a halide of B, Al, Fe, or Zn. 4. The lubricating oil according to claim 1 or 2, wherein the Lewis acid is aluminum chloride. 5. The lubricating oil according to any one of claims 1 to 4, wherein the lubricating oil is rotary pump oil.