JPH1077493A - Oil composition for reciprocating compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil compsn. for a reciprocating compressor which is excellent in the effect of preventing the formation of carbon and the deposition of carbon. SOLUTION: A mineral oil, wherein the difference between 95vol% recovered temp. (in terms of atmospheric pressure: T95 ) and 2 vol % recovered temp. (in terms of atmospheric pressure: T2 ), ΔT (T95 -T2 ), in distillation is 145 deg.C or below and the kinematic viscosity at 40 deg.C is 10 to 200mm<2> /sec, is used as a base oil. An amine antioxidant is incorporated, in an amt. of 0.01 to 5wt.% based on the total amt. of the compsn., into the base oil. Alternatively, an amine antioxidant in an amt. of 0.01 to 5wt.% based on the total amt. of the compsn. and a sulfur-contg. antioxidant in an amt. of 0.01 to 5wt.% based on the total amt. of the compsn. may be incorporated into the base oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reciprocating compressor oil composition, and more particularly to a reciprocating compressor oil composition particularly suitable for a reciprocating air compressor.

[0002]

2. Description of the Related Art A compressor is a machine for compressing a gas and increasing its pressure. As the gas to be compressed, air, carbon dioxide, nitrogen, hydrogen, various hydrocarbon gases and the like are used. . Compressors are classified into positive displacement type and turbo type according to the operation principle of increasing gas pressure, and positive displacement type compressors are further classified into reciprocating compressors and rotary compressors.
In this reciprocating compressor, the lubricating oil mixed into the compressed gas due to the reciprocating motion of the piston becomes carbon due to the heat generated when the gas is compressed, and adheres to the periphery of the valve, causing malfunction of the valve or causing adhesion. Ignition due to carbon heat storage often occurs. Therefore, the most important performance of a reciprocating compressor oil is to produce no carbon. However, the reciprocating compressor oil currently on the market, although the carbon adhesion and generation are suppressed, its performance is still inadequate. The deposited carbon must be opened in some continuous operation to remove the deposited carbon. Extending the open period of this device not only reduces the maintenance cost of the device, but also has significant advantages such as preventing ignition due to the heat storage phenomenon of the deposited carbon. Therefore, carbon is generated and deposited as reciprocating compressor oil. The development of something that does not work is desired.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object of the present invention is to provide a reciprocating compressor oil composition having excellent carbon generation and adhesion suppressing effects.

[0004]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, by using a mineral oil having a specific boiling point range as a base oil, and using the base oil as a base oil. It has been found that a reciprocating compressor oil composition having excellent carbon generation and suppression effects can be obtained by blending a specific oxidation stabilizer.

That is, the gist of the present invention is as follows. (1) Distillation temperature of 95% by volume in distillation (normal pressure conversion value:
T ₉₅ ) and 2% by volume distillation temperature (normal pressure converted value: T ₂ ) difference Δ
T (T ₉₅ -T ₂₎ or less is 145 ° C., and reciprocating compressor oil composition kinematic viscosity characterized by the use of mineral oil is 10 to 200 mm ² / s as a base oil at 40 ° C.. (2) 0.0% based on the total amount of the composition in the base oil described in (1).
The reciprocating compressor oil composition according to (1), further comprising 1 to 5% by weight of an amine antioxidant. (3) 0.0% based on the total amount of the composition in the base oil described in (1).
The reciprocating compressor oil composition according to (1), further comprising 1 to 5% by weight of an amine antioxidant and 0.01 to 5% by weight of a sulfur-containing antioxidant.

[0006]

Embodiments of the present invention will be described below. The base oil according to the first aspect of the present invention is a mineral oil in which the difference between the 95% by volume distillation temperature and the 2% by volume distillation temperature in distillation is 145 ° C. or less. Lubricating oil fractions are generally JIS-K
It is obtained by performing normal pressure distillation or reduced pressure distillation operation according to −2254.
Both vol% distillation temperature, in the case of vacuum distillation is a normal pressure converted value, respectively expressed in T _95, T _2, and represents the difference in [Delta] T. If ΔT exceeds 145 ° C., the amount of adhered carbon is undesirably large. ΔT is preferably 130 ° C. or less, more preferably 115 ° C. or less. As the type of mineral oil, for example, a paraffin-based crude oil, an intermediate-based crude oil, a lubricating oil fraction obtained by distillation under normal pressure or reduced pressure of a naphthenic-based crude oil, solvent removal, solvent extraction, hydrocracking, Refined oils purified according to conventional methods such as solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment can be used, and they may be used alone or in combination of two or more. The kinematic viscosity at 40 ° C. is 10 to 200 m.
m ² / s, preferably 40 to 120 mm ² / s. If the kinematic viscosity is less than 10 mm ² / s, the oil film on the sliding portion of the piston or piston ring becomes too thin, resulting in abnormal wear and seizure. If it exceeds 200 mm ² / s, the viscous resistance at a low temperature becomes large, and starting cannot be performed due to an increase in torque, which is not preferable.

[0007] A second aspect of the present invention is a reciprocating compressor oil composition obtained by blending an amine antioxidant with the base oil according to the first aspect. Examples of the amine-based antioxidant include monooctyldiphenylamine; monoalkyldiphenylamines such as monononyldiphenylamine;
4,4'-dibutyldiphenylamine;4,4'-dipentyldiphenylamine;4,4'-dihexyldiphenylamine;4,4'-diheptyldiphenylamine;
4,4'-dioctyldiphenylamine; dialkyldiphenylamines such as 4,4'-dinonyldiphenylamine;tetrabutyldiphenylamine;tetrahexyldiphenylamine;tetraoctyldiphenylamine; polyalkyldiphenylamines such as tetranonyldiphenylamine; and naphthylamine-based ones. Specifically, α-naphthylamine; phenyl-α-naphthylamine; further butylphenyl-α-naphthylamine; pentylphenyl-α-naphthylamine; hexylphenyl-α-naphthylamine; heptylphenyl-α
-Naphthylamine; octylphenyl-α-naphthylamine; alkyl-substituted phenyl-α-naphthylamine such as nonylphenyl-α-naphthylamine. The amine-based antioxidants may be used alone or in combination of two or more. The compounding amount is in the range of 0.01 to 5% by weight, preferably 0.1 to 1% by weight based on the total amount of the composition. 0.01% by weight
If the amount is less than 5%, the amount of attached carbon is large, and even if it exceeds 5% by weight, the effect corresponding to the blending amount is not improved.

A third aspect of the present invention is a reciprocating compressor oil composition obtained by blending an amine antioxidant and a sulfur-containing antioxidant with the base oil according to the first aspect. The kind and amount of the amine-based antioxidant are the same as those described in the second aspect. As the sulfur-containing antioxidant, any antioxidant containing sulfur and having peroxide decomposability may be used. For example, dialkylthiodipropionates such as dilaurylthiodipropionate and distearylthiodipropionate may be used. , Zinc dialkyldithiocarbamate (Zn-DTC), zinc dialkyldithiophosphate (Zn
-DTP), alkyltriesters of dithiophosphoric acid, bis (3,5-di-t-butyl-4-hydroxybenzyl) sulfide, mercaptobenzothiazole, reaction products of phosphorus pentasulfide and olefins, dicetyl sulfide, etc. And Zn-DTP, Zn-D
TC is preferred.

The above sulfur-containing antioxidants may be used singly or in combination of two or more. The compounding amount is in the range of 0.01 to 5% by weight, preferably 0.1 to 1.5% by weight based on the total amount of the composition. If it is less than 0.01% by weight, the amount of attached carbon is large, and if it exceeds 5% by weight, the effect corresponding to the blending amount is not improved. In the reciprocating compressor oil composition of the inventions of claims 1 to 3, known additives can be further used, if necessary. Examples of the additives include metal deactivators such as benzotriazole and thiadiazole, rust inhibitors such as petroleum sulfonate and dinonylnaphthalene sulfonate, defoamers such as silicone oil, pour points such as polymethacrylate and polyisobutylene. Depressants, demulsifiers such as polyoxyethylene polyoxypropylene copolymers, metal detergents such as metal phenates and metal salicylates, succinimides,
Examples thereof include ashless dispersants such as succinates, and these can be used alone or in combination of two or more.

[0010]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the invention thereto. Examples 1 to 5 and Comparative Examples 1 and 2 Paraffin mineral oil and naphthenic mineral oil were mixed in 6 to 7: 4 to 3
(Weight ratio) and distilled under reduced pressure to prepare a predetermined base oil. The physical properties are shown in Table 1. Next, a predetermined additive was blended at a predetermined ratio to prepare a lubricating oil composition. Next, carbon production and adhesion tests were performed on these lubricating oil compositions as described below. The results are shown in Table 2. [Carbon generation and adhesion test] After measuring the weight of a new piston, piston ring and valve plate into a commercially available reciprocating air compressor (single-stage V-type two-cylinder, output: 3.7 kW), install the lubricating oil. After filling the composition, the discharge pressure was adjusted to 0.98 MPa, and continuous operation was started. On the way, the amount of lubricating oil that had been consumed after 500 and 1000 hours had elapsed was replenished. After 2,000 hours of operation, the valve plate was removed from each cylinder and the weight was measured.

[0011]

[Table 1]

[0012]

[Table 2]

[0013]

[Table 3]

(Note) * 1: Monooctyldiphenylamine * 2: Zn-DTP * 3: Ba sulfonate * 4: Silicone oil

[0015]

[Table 4]

(Note) * 1 to 4 are the same as in Table 2 As is apparent from Table 2, it is understood that ΔT is 145 ° C. or less in the examples and the amount of carbon attached to the discharge valve is small.

[0017]

Industrial Applicability The reciprocating compressor oil composition of the present invention has excellent carbon generation and adhesion suppressing effects, and is particularly suitably used for reciprocating air compressors.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C10N 20:00 20:02 40:30

Claims (3)

[Claims] 1. Distillation temperature of 95% by volume (normal pressure converted value: T ₉₅ ) in distillation and 2% by volume distillation temperature (converted value of normal pressure: T ₉₅ )
T ₂ ) difference ΔT (T ₉₅ −T ₂ ) is 145 ° C. or less;
A reciprocating compressor oil composition comprising a mineral oil having a kinematic viscosity at 40 ° C of 10 to 200 mm ² / s as a base oil. 2. The reciprocating compressor oil composition according to claim 1, wherein the base oil according to claim 1 is blended with 0.01 to 5% by weight of an amine antioxidant based on the total amount of the composition. 3. The base oil according to claim 1, comprising 0.01 to 5% by weight, based on the total amount of the composition, of an amine-based antioxidant and 0.1% by weight of the amine-based antioxidant.
2. The reciprocating compressor oil composition according to claim 1, wherein the composition contains from 0.01 to 5% by weight of a sulfur-containing antioxidant.