JPS61252292A - Lweis acid-resistant lubricating oil - Google Patents

Abstract

PURPOSE:To prevent decomposition, denaturation, occurrence of toxic substance, etc., accompanying contact with a Lewis acid, by using a specific fluoroalkoxy cyclic phosphonitrile ester lubricating oil as a lubricating oil used for apparatus which are brought into contact with a Lewis acid. CONSTITUTION:Aapparatus such as a dry etching apparatus which are brought into contact with a Lewis acid can be stably operated for a long period of time by using a specific fluoroalkoxy cyclic phosphonitrile ester lubricating oil of the formula (wherein 1.3<=m<=2.8, 2n-1>=l>=0, 3<=n<=4.3) as a lubricating oil. The compd. of the formula can be prepared by reacting an oligomer of a phosphonitrile halide (e.g.: trimer of phosphonitrile chloride) with a fluoro alcohol (e.g.: 1,1,5-trihydroperfluoropentanol), and the specific examples include hexakis(1,1,5-trihydroperfluoropentyloxy) cyclic triphosphonitrile ester.

Description

[Detailed description of the invention] Star! The top five! The present invention relates to a lubricating oil that has excellent stability against Lewis acids, and more particularly to a lubricating oil suitable for driving and sliding parts of equipment that come into contact with Lewis acids or where Lewis acids may be generated. Regarding.

In the rapidly developing modern society, remarkable technological innovation is progressing, and with this technological innovation, various substances are being manufactured, and the manufacturing equipment is also required to have advanced performance under harsher conditions. It is becoming more and more common. 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 drive and l3 moving parts, come into contact with Lewis acids such as aluminum chloride. Oils are also required to have high performance, particularly excellent Lewis acid resistance and lubricity.

At present, semiconductor manufacturing equipment such as dry etching equipment, ion implantation equipment, plasma CVD equipment, etc., and halogen lamp manufacturing equipment are known as equipment that comes into contact with Lewis acid. When a normal lubricating oil used in moving parts comes into contact with a Lewis acid, the lubricating oil undergoes deterioration and decomposition due to a reaction with the Lewis acid or a reaction in which the Lewis acid acts as a catalyst, resulting in an increase in viscosity, This causes gelation, a decrease in the degree of vacuum, and the formation of sludge, leading to equipment trouble, maintenance, and increased inspection time, resulting in a decrease in operating efficiency and 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 It produces highly toxic low molecular weight substances such as , chlorofluorocarbonyl, fluorocarbonyl, etc. Therefore, in equipment using perfluoropolyether oil as a lubricant,
The degree of vacuum decreases after a short period of operation, and therefore, it is necessary to change the oil frequently to maintain the specified degree of vacuum.
For this reason, the time when the apparatus is stopped becomes very large, and the operating rate inevitably decreases significantly. 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.

The present invention solves the above-mentioned problems and provides a lubricating oil composition that can fully demonstrate the performance of the above-mentioned manufacturing 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 (CF2CF2), nC mouth O] 2□-l [CF3C
F2ClI20], PiN7(1) [however, in the formula, (C
The segment indicated by F2 CF2 >m is (CF2
CF2 indicates a single segment that is an integral multiple of the unit, or a mixture of segments with different chain lengths that are an integral multiple, and in the case of a single segment, m = 2, and a mixture of segments with chain lengths. In the case of The value of 9 is within the range of 2n-1≧Q≧O, and n indicates the number of repeats of the PN unit in the phosphonitrile ring skeleton, and in the case of a mixture of rings with different repeat numbers, the average It indicates the number of repetitions 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.

Here, the oligomer of phosphonitrile halide is
Examples include trimers of phosphonitrile chloride, tetramers of phosphonitrile chloride, and mixtures thereof. In addition, examples of fluoroalcohol include 1,
1.3-trihydroperfluoropropanol, 1,1
．． 1.1 such as 5-trihydroperfluoropentanol
．． ω-trihydroperfluoroalcohol etc. and this and 2
．． Examples include mixtures with 2.3.3.3-pentafluoropropanol. Further, the fluoroalkoxy cyclic phosphonitrile ester of the above general formula (1) is the above-mentioned 1,
1. It can also be produced by reacting two or more types of ω-trihydroperfluoroalcohols in advance to form an alcoholade, and then reacting this alcoholade with an oligomer of phosphonitrile halide.

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, preferred ones include, for example, n in the above general formula (1).
Hexakis (1,1
, 5-trihydroperfluoropentyloxy) cyclic triphosphonitrile ester, n is 4, m is 2, and Q
Examples include mixtures of fluoroalkoxy cyclic tetraphosphonitrile esters, each of which is an integer of 1 to 7. These compounds have contradictory properties in terms of solubility in Lewis acids such as aluminum chloride; the former dissolves Lewis acids, while the latter hardly dissolves Lewis acids; therefore, their intended use is There is an advantage that both can be used properly depending on the situation, and the solubility of the Lewis acid can be controlled by appropriately selecting the mixing ratio of the two. For example, the former can be effectively used as a lubricant for opening parts where it is difficult to prevent the formation of Lewis acid and must be removed, and the latter can be effectively used as a lubricant for seals, bearings, etc. that need to be blocked from Lewis acid. .

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. It is. Therefore, the composition of the present invention can be used to drive semiconductor manufacturing equipment, typified by dry etching equipment, ion implantation equipment, plasma CVD equipment, etc., halogen lamp manufacturing equipment, etc. It is extremely suitable as a lubricating oil for use in moving parts.

On the other hand, reference examples, examples, and comparative examples are listed below to further clarify the present invention.

Reference Example 1 479 g (2,06 mol) of 1.1.5-trihydroperfluoropentanol and iooma of toluene were placed in a four-way flask equipped with a condenser, a stirrer, and a thermometer, and while cooling, 45.9 g of Na pieces cut into small pieces were added. 3g (1,
97 mol) was added, and the reaction was carried out at 40° C. for 4 hours until the sodium was completely dissolved. Add 5 toluene to this reaction solution.
A solution of 89 g (0,256 mol) of phosphonitrile chloride trimer dissolved in 0.00ml 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, 330q of an oily crude product was obtained. This was distilled under reduced pressure and 203-21
280 g of a fraction of 0° C. 10.03 to 0.08 mm HO was collected.

As a result of analysis, this colorless and transparent oily substance was found to be hexakis (1,
It was confirmed that 1,5-trihydroperfluoropentyloxy) cyclic triphosphonitrile ester was the main component, and the JR, NMR, and MS spectra also showed the structure. The specific gravity of this substance is 1.791 (15/4℃
), the kinematic viscosity was 89.52 cst (40°C), the viscosity index was 88, and the pour point was -45°C. This substance is referred to as F
It is called "Compound A."

Reference example 2 1.1.3-trihydroperfluoropropanol and 1
．． Alcoholade was synthesized in the same manner as in Reference Example 1 using an equimolar mixture of 1,5-trihydroperfluoropentanol. This alcoholade and phosphonitrile chloride trimer were reacted and treated in the same manner as in Reference Example 1 described in ①.
A fraction of 10.04 to 0.08 mm HCl at 4 to 178° C. was collected.

Based on the M/e value of each product determined by GC and GC-MS, m = 1 is 0.9% in the compound of the above general formula (1) where n is 3 and Q is O. , m=1
．． 17 is 5.8%, m-1,33 is 15.1%, m=1
．． 5 is 25.8%, m=1.67 is 27.2%, m=1
．． It was confirmed that there was a mixture of glJ with 15.2% of 83 and 9.9% of m=2, and it was clear that the mixture as a whole corresponded to a value of m of 1.595. Ta. The specific gravity of this substance is 1.736 and the viscosity is 184 cps
(40°C), and the vapor pressure was 1 mmHg/198°C.

This substance is hereinafter referred to as "compound B."

Reference Example 3 155 g (1,03 mol) of 2,2,3,3,3-pentafluoropropanol, 1.5-trihydroperfluoropentanol 24 , OC] (1.03 mol) and toluene 10001+112, and while cooling, 45.3 g (1.97 mol) of Na pieces cut into small pieces were added, and the mixture was allowed to react at 40°C for 4 hours until the sodium was completely dissolved. Ta. To this reaction solution, 89 g of bosphonitrile chloride tetramer (0,1
A solution of 92 mol) was added dropwise at about 50°C, and the reaction was carried out under reflux for 4 hours. To remove the generated sodium chloride,
After washing with water, dehydration, and concentration, an oily crude product 310C18 was obtained. This was distilled under reduced pressure to 160-193℃10.03mm
A 260 g fraction of HQ was collected. As a result of GC and GC-MS analysis, this colorless and transparent oil was found to be a compound of the above general formula (1) where n is 4 and m is 2, with 2=1 being 1.6% and Q=2 being 1.6%. 8.6%, Q=3 is 22.9%, Q
=4 is 32.7%, Q=5 is 23.3%, 9=6 is 8.
5% and 9=7h; It was confirmed that it was a mixture of seven components at a ratio of 1.5%. The specific gravity of this substance is 1.746
(20'C), viscosity is 204CI)S (40°C),
Vapor pressure is lmmHg/188℃1, pour point is -37.5
It was ℃. This substance is hereinafter referred to as "Compound C."

Example 1 Compound A was injected into a chemical-type oil rotary vacuum pump that had been thoroughly cleaned with a solvent, and the pump was connected to a test plasma etching device set for aluminum etching.
Operation was performed for 14 days using carbon tetrachloride gas. Exhaust gas was collected by connecting an air-cooled trap, dry ice trap, and liquid nitrogen trap in series. No abnormalities were observed in the device during 14 days of operation. When the oil was lost and examined, 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.

It was also found that the dark brown coloration was due to dissolution of aluminum chloride and the like. 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. J.I.
The amount of phosgene collected, measured based on S KOO90, was 0.0038 g, which was an amount that would pose no problem in terms of the working environment.

Comparative Example 1 The test apparatus was operated in the same manner as in Example 1 using commercially available perfluoropolyether oil. A few days after the start of operation, the degree of depressurization decreased and the amount of oil decreased, making it necessary to change the oil. In addition, a large amount of decomposition products were collected in the trap.

Example 2 Compound A5.0OCI was charged into a 25 ml four-bottle flask equipped with a nitrogen inlet tube, a thermometer, and an anhydrous aluminum chloride charging flask, and connected to the exhaust flow path with two stages of dry ice and liquid nitrogen, and dried. Bubble with nitrogen,
Aluminum chloride 5 pre-purified by sublimation at 00°C with stirring
．． OOQ was added for 15 minutes, and continued for 5 hours.
Heating and stirring were performed at 00°C.

After the test, the trapped material was suspended as phosgene in accordance with JIS K0090, and the residue in the Yotsuro flask was added to ice water, extracted with Freon 113, and recovered. As a result, the amount of phosgene generated was 5. ．． 55x10-'g
The recovery rate was 97%.

Comparative Example 2 The same procedure as in Example 2 was carried out except that a commercially available perfluoropolyether oil was used instead of Compound A. The amount of phosgene generated was 1.090, and the recovery rate was 69%.

Example 3 Using the compound caoo-, 14 was prepared in the same manner as in Example 1.
The equipment was operated for several days. There were no abnormalities in the equipment during operation, and a clear inspection revealed only a small amount of yellowish brown sludge at the bottom of the yellowish green oil. After Slutzin door-to-door, Freon 113
The sample extracted and recovered had no difference in viscosity, JR spectrum, etc. from the new song, and the recovery rate was 98%. In addition, the sludge collected from each house was mainly composed of aluminum chloride. Further, the amount of phosgene collected in the trap was 0.00.27 g, which was smaller than when Compound A was used.

Example 4 An oil rotary vacuum pump lubricated with compound B was subjected to reduced pressure CV for testing.
It was connected to the latter stage of the exhaust side trap of apparatus D, and an alumina coating test on cemented carbide for cutting was conducted for 20 days.

No maintenance was required other than trap replacement during the test period. After the test, the oil was blackish brown, but the oil extracted and recovered using Freon 113 had no difference in viscosity, IR spectrum, etc. from the new oil, and the recovery rate was 96%.

Example 5 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 at the bottom of the oil and on the inner wall. After separating the sludge from two homes, the oil extracted and recovered using Freon 113 had no difference in viscosity, IR spectrum, etc. from new songs, and the recovery rate was 98%. Also,? After washing the sludge with Freon 113, it was analyzed and found to be mainly composed of aluminum chloride and TMA. Further, the amount of phosgene collected in the trap was 0.0019 CI, which was an amount that caused no problems in terms of the working environment.

Claims (1)

[Scope of 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_2CF_2)_mCH_2O]_2_n_
-_l[CF_3CF_2CH_2CH_2O]_lP
_nN_n(1) (However, in the formula, (CF_2CF_2)
The segment indicated by _m indicates a single segment that is an integral multiple of the unit (CF_2CF_2) or a mixture of segments of different chain lengths that are integral multiples, and in the case of a single segment, m = 2. , and when segments of chain length are mixed, m means the average number of repetitions of (CF_2CF_2) units representing the average chain length, and the value of m is 1.3≦m≦2. .8, the value of l is in the range 2n-1≧l≧0, and n indicates the number of repeats of the PN unit in the phosphonitrile ring skeleton, and the mixture of rings with different numbers of repeats If so, it indicates the average number of repetitions and takes a real value within the range of 3≦n≦4.3. [2] Hexakis (1,1,5-
Claim 1 whose main component is trihydroperfluoropentyloxy) cyclic triphosphonitrile ester
Lubricating oils listed in Section. [3] A patent claim consisting mainly of a mixed fluoroalkoxy cyclic tetraphosphonitrile ester in which m is a single chain length segment with a value of 2, l is 1≦l≦7, and n is 4. A lubricating oil according to scope 1. [4] The lubricating oil according to claims 1 to 3, wherein the Lewis acid is a halide of B, Al, Fe, or Zn. [5] The lubricating oil according to claims 1 to 3, wherein the Lewis acid is aluminum chloride. [6] The lubricating oil according to any one of claims 1 to 5, wherein the lubricating oil is rotary pump oil.