JP3592832B2 - Hydraulic hydraulic oil - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to hydraulic elevator hydraulic oil.
[0002]
[Prior art]
In general, hydraulic elevator hydraulic oils using mineral oil are manufactured from a base oil and additives added thereto. Mineral oil is processed by atmospheric distillation and vacuum distillation, which are lubricating oil refining means used in ordinary oil refinery industry, to obtain a distillate having an appropriate viscosity, and the distillate is extracted with furfural and hydrorefined. The desired degree of purification is obtained by known purification means such as dewaxing and, if necessary, white clay treatment. The base oil of a general hydraulic elevator hydraulic oil has a kinematic viscosity in the range of 20 to 100 cSt at an oil temperature of 40 ° C., about 65% by mass of paraffin, about 30% by mass of naphthene, and an aromatic component. Those containing about 5% by mass of aroma, about 0.1% by mass of sulfur and about 10 ppm of nitrogen are used.
[0003]
Since the base oil having such a composition contains aromatic components, such as aroma, sulfur, and nitrogen components, the odor is increased. Therefore, when used as hydraulic oil for hydraulic elevators, odors are trapped in the hoistway that constitutes the oil, and passengers who use the odors are uncomfortable. In order to solve this problem, the hydraulic elevator hydraulic oil described in JP-A-7-34078 has an aroma content of 1.5% by mass or less.
[0004]
[Problems to be solved by the invention]
However, even the above-mentioned conventional base oil is not enough to satisfy the low odor property as a hydraulic elevator hydraulic oil. That is, hydraulic oils are usually commercialized by adding additives to improve base oil performance such as antioxidant properties and rust prevention properties, but no consideration was given to the odor caused by the additives. . For example, phenol-based 2.6-ditert-butyl-4-methylphenol and amine-based pp'-dioctyldiphenylamine, which are added as antioxidants, are contained in a large amount. It turned out to be worse. Furthermore, it was found that the use of only these antioxidants could not suppress the generation of peroxide, which causes odor deterioration due to the deterioration of the hydraulic oil, and also deteriorated the odor in this respect. Was. Further, imide-based alkenyl succinimide added as a rust preventive also has a high odor, so that the odor is further deteriorated.
[0005]
An object of the present invention is to provide a hydraulic elevator hydraulic oil capable of suppressing odor even during long-term use without impairing good oxidation stability, which is the original performance of the hydraulic hydraulic oil. .
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a hydraulic elevator hydraulic oil using a mineral oil having an aroma content of 1.5% by mass or less as a base oil, wherein the additive is a secondary class having 3 to 6 carbon atoms. 0.03 to 0.08 wt% of dialkyl thio zinc phosphate with an alkyl group, 2.6 to ditertiary butyl-4-methylphenol 0.03 to 0.20 wt%, p-p'-dioctyl It is characterized by containing 0.01 to 0.05% by mass of diphenylamine.
[0007]
Hydraulic elevator hydraulic oil of the present invention, dialkyl thiophosphoric zinc having secondary alkyl groups having 3 to 6 carbon atoms of sulfur-based antioxidant (hereinafter referred to s econdly-C3 / 6- ZDTP) 0. As a result of conducting an odor sensory test and a gas chromatographic odor analysis test, the amount of addition was preferably 0.08% by mass or less in consideration of odor. As a result of the mass test and the accelerated aging test, in consideration of the suppression of peroxide generation and the prolongation of the antioxidant property, a determination was made based on the finding that the content is preferably 0.03% by mass or more. 2.6-Ditertiabutyl-4-metalphenol was added in an amount of 0.03 to 0.20% by mass, and the amount of addition was determined as the antioxidant property of secondly-C3 / 6-ZDTP, a sulfur-based antioxidant. As a result of the antioxidant residual amount test, it is preferable to add 0.03% by mass or more to maintain the antioxidant property. The result of the odor sensory test and gas chromatographic odor analysis test It was determined on the basis of the result of an investigation that the content is preferably set to 0.20% by mass or less in consideration of odor. Further, pp'-dioctyldiphenylamine was added in an amount of 0.01 to 0.05% by mass. It is preferably added in an amount of not less than 01% by mass. Based on the results of conducting an odor sensory test and a gas chromatographic odor analysis test, it was determined based on the finding that the amount was preferably 0.05% by mass or less in consideration of odor. In this way, it was possible to obtain a hydraulic elevator hydraulic oil capable of suppressing odor even after long-time use without deteriorating good oxidation stability, which is the original performance of the hydraulic hydraulic oil.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described.
[0009]
First, a base oil having an aroma content of 1.5% by mass or less, for which low odor was confirmed, was used. That is, those having a kinematic viscosity at 40 ° C. as shown in FIG. 3, an aromatic content of 0.72 mass%, a sulfide content of 0.01 mass%, and a nitrogen content not detected were used. .
[0010]
As the additives to be added to the base oil, an antioxidant, a rust inhibitor, and a metal deactivator were selected as follows. In other words, it is a sulfur-based antioxidant additive that has a high antioxidant ability as an antioxidant, has the ability to suppress the generation of peroxides generated due to the deterioration of hydraulic oil, and has relatively low odor characteristics. They were selected dialkyl thiophosphoric acid zinc (s econdly-C3 / 6- ZDTP ) having a certain secondary alkyl group having 3 to 6 carbon atoms. In addition, 2.6-ditert-butyl-4-methylphenol was selected as a phenolic additive having an auxiliary effect of the antioxidant ability of the sulfur-based antioxidant and low odor characteristics with respect to the sulfur-based one. . Furthermore, pp'-dioctyldiphenylamine was selected as an amine-based additive which produces a synergistic effect with a phenol-based additive and has an effect of obtaining a longer life of the ability to inhibit oxidation deterioration.
[0011]
As the rust preventive, an overbased Ca sulfonate with low odor is selected, and as a metal deactivator that suppresses the catalytic reaction between the hydraulic oil and the metal, it is possible to obtain a metal deactivation ability in a trace amount. As a result, a benzotriazole having low odor characteristics was selected.
[0012]
The physical properties of each hydraulic oil prepared by mixing the above-described base oil and additives were evaluated based on the following tests, and the evaluation results of the examples are shown in FIG. 1 and the evaluation results of the comparative examples are shown in FIG. ing.
[0013]
First, the odor sensory test will be described. In this evaluation test, the strength of the odor is evaluated by 12 examiners according to the 6-step odor intensity display method usually performed in the odor test, and the maximum and minimum of the 12 persons are evaluated. Those with the respective evaluation points deleted were used as evaluation targets. This evaluation score indicates that the lower the score, the higher the low odor characteristics. 0: odorless, 1: odor that can be detected at last, 2: weak odor that can be discerned, what odor, 3: odor that can be easily detected, 4: Evaluated as strong odor, 5: Intense odor.
[0014]
In this test method, 30 ml of the material was sealed in a screw-bore bottle having a diameter of 27 mm and a capacity of 50 ml and shaken vigorously. Thereafter, the bottle lid was opened, and the test tube was smelled. As shown in FIG. 2, the evaluation average points are rounded off, and a single point is marked with “以上” as good, and a point beyond that is marked with “x” as having odor.
[0015]
The gas chromatographic analysis test is an analysis test for measuring light components (total ions) which are odor components contained in hydraulic oil. As a test method, a sample of 5 ml is put into an impinger having a capacity of 30 ml, and the sample oil temperature is measured. While maintaining the temperature at 30 ° C. in an oil bath, He gas was introduced into the impinger at a flow rate of 30 to 100 ml / min, and light components were discharged from the impinger together with the inflowing gas. Was collected over. This collection tube was connected to a gas chromatography analyzer to measure light components. As a result of the measurement, a light oil having an area value of less than 1 million ion area value for a new oil and an accelerated deteriorated oil having an area value of less than 2 million ion area value for a later-described oil were evaluated as good, and were marked with a triangle.
[0016]
The RBOT deterioration test is a test for measuring the amount of the antioxidant remaining in the hydraulic oil to determine the continuity of the antioxidant ability, and was carried out in accordance with the rotating cylinder oxidation stability test method of JIS-K-2514. In this test, those satisfying the general performance are those for 150 min or more.
[0017]
The wet test is an evaluation test for evaluating rust prevention properties for suppressing the generation of rust due to moisture in the air, and was performed in accordance with the rust-preventive oil 5.34 wet test method specified in JIS-K-2246. In this evaluation, A, B, C, and D were assigned in the order of good evaluation. If the evaluation was better than D, it was determined that general performance was satisfied.
[0018]
The shell four-ball wear test is based on the ASTM-D-2783 shell four-ball wear test method. The test conditions are as follows: the vertical axis rotation speed is 1800 rpm, the load is 30 kgf, the test time is 30 minutes, and the test temperature is room temperature. The material was prepared using a 1/2 inch precision ball for AKS ball bearing steel ball. In this test result, if the wear scar diameter was 0.5 mm or less, it was determined that general performance was satisfied.
[0019]
Next, an accelerated deterioration test for obtaining accelerated deteriorated oil will be described.
[0020]
First, 50 g of a sample and a 3 m copper wire wound in a spiral shape with a new metal skin that has been polished in advance and whose polished skin is degreased with diethyl ether are placed in a glass bottle having an inner diameter of 50 mm and a capacity of 200 mm. This glass bottle is put in a copper container, oxygen at room temperature is sealed in the copper container at a pressure of 0.6 MPa, and the copper container is tilted by 30 ° in an oil bath using silicon oil at 150 ° C. Put in. In this state, the copper container is continuously rotated at 100 rpm for 1 hour, and the sample in the glass bottle is agitated and deteriorated by heating to obtain a deteriorated oil.
[0021]
Here, the deteriorated oil thus obtained was subjected to an infrared absorption test and the gas chromatography analysis test described above.
[0022]
This infrared absorption test is a test for measuring the rate of increase of organic degradation products in a sample as compared with fresh oil, and determining the antioxidant ability of the sample. As the testing method, performed by an infrared absorption wavelength 1790- ¹ cm (Kaiser) in thickness of 0.5 mm KRS-5 cell transmission method, in the drawing as an antioxidant ability good things increase rate is within 10% Was marked with a triangle. In the degraded oil, when the peroxide polymerized to form oxidative polymerization (sludge) which was deposited in the oil, the presence or absence of the generation was stored in the figure. Here, the sludge generated is determined to have low antioxidant ability.
[0023]
Next, various test deteriorations and their evaluations will be described with reference to FIGS.
[0024]
First, the odor characteristics are evaluated based on the test results of the odor sensory test and the gas chromatographic analysis test.
[0025]
The content of the antioxidant was 0.10% by mass of sulfur-based secondly-C3 / 6-ZDTP and phenol-based, as in Examples 1 to 14 and Comparative Examples 15 to 26 shown in FIGS. When 2.6-di-tert-butyl-4-metalphenol was 0.25% by mass and amine-based pp'-dioctyldiphenylamine was 0.07% by mass, each of them exhibited high odor. 0.08% by mass or less of secondly-C3 / 6-ZDTP, 0.20% by mass or less of phenol-based 2.6-ditert-butyl-4-methylphenol, and amine-based pp'-dioctyldiphenylamine Was set to 0.05% by mass or less.
[0026]
In addition, when the preservative Ca sulfonate was 0.10% by mass and 50 ppm, and when the addition amount of the metal deactivator benzotriazole was 0.10% by mass and 50 ppm, high odor was exhibited. The addition amounts of the preservative Ca sulfonate and the metal deactivator benzotriazole were 0.07% by mass or less and 30 ppm or less, respectively.
[0027]
By containing the additive in this manner, the hydraulic oil exhibits an initial odor of the new oil of 1 or less in the sensory test in the organoleptic test, and a light component which is an odor component in the gas chromatographic analysis test. Showed less than 1 million ions in the new oil and less than 2 million ions in the degraded oil, and could be an ultra-low odor hydraulic oil with suppressed odor.
[0028]
Next, the antioxidant ability of the antioxidant is evaluated based on the test results of the PBO test and the infrared absorbance test.
[0029]
Based on the test results, the content of the antioxidant was 0.01% by mass for sulfur-based secondly-C3 / 6-ZDTP and 0.01% by mass for phenol-based 2.6-ditert-butyl-4-methylphenol. When the content of the amine-based pp'-dioctyldiphenylamine was 0.005% by mass, the rate of increase in the absorbance exceeded the allowable range and exhibited poor oxidation stability. Therefore, the sulfur-based secondly-C3 / 0.06% by mass or more of 6-ZDTP, 0.03% by mass or more of phenol-based 2.6-ditert-butyl-4-methylphenol, and 0.03% by mass of an amine-based pp'-dioctyldiphenylamine. It was at least 01% by mass. As a result, it was possible to obtain a hydraulic oil having a high level of antioxidant ability, which showed 150 minutes or more in the RBOT test and 4% or less in the infrared absorbance test for the deteriorated oil. In addition, when the rustproofing ability is evaluated based on a wet test, a good rustproofing ability of C or more can be obtained when the content of Ca sulfonate is 0.01% by mass or more.
[0030]
In this way, 0.03 to 0.08% by mass of secondly-C3 / 6-ZDTP, which is an antioxidant, and 0.03 to 0.20% by mass of 2.6-ditert-butyl-4-methylphenol. It has been found that a hydraulic oil having ultra-low odor characteristics and good antioxidant ability can be obtained by adding 0.03 to 0.05% by mass of pp'-dioctyldiphenylamine. Further, by setting the content of Ca sulfonate, which is a rust preventive, to 0.01 to 0.07% by mass, it is possible to obtain a hydraulic oil having ultra-low odor characteristics and good rust preventive ability, and By containing benzotriazole as an activator in an amount of 30 ppm or less, a hydraulic oil having ultra-low odor characteristics can be obtained.
[0031]
【The invention's effect】
As described above, the hydraulic oil for hydraulic elevator according to the present invention comprises secondly-C3 / 6-ZDTP, which is an antioxidant, in an amount of 0.03 to 0.08% by mass and 2.6-ditert-butyl-4-methylphenol. 0.03 to 0.20% by mass, and pp'-dioctyldiphenylamine containing 0.03 to 0.05% by mass, without impairing the antioxidant ability which is the basic performance of hydraulic oil. It can also have ultra-low odor characteristics.
[Brief description of the drawings]
FIG. 1 is a diagram showing characteristics and evaluation results of a hydraulic elevator hydraulic oil according to an embodiment of the present invention.
FIG. 2 is a diagram showing characteristics and evaluation results of a hydraulic elevator hydraulic fluid as a comparative example.
FIG. 3 is a diagram showing the composition of a base oil used for hydraulic elevator hydraulic oil.

Claims (3)

In hydraulic elevators hydraulic oil with mineral oil aroma content was 1.5 mass% or less as a base oil, a dialkyl thiophosphoric zinc having secondary alkyl groups having 3 to 6 carbon atoms which is additive 0 0.03 to 0.08% by mass, 0.03 to 0.20% by mass of 2.6-ditert-butyl-4-methylphenol, and 0.01 to 0.05% by mass of pp'-dioctyldiphenylamine. % Hydraulic oil for hydraulic elevators. 2. A hydraulic elevator hydraulic oil according to claim 1, further comprising 0.01 to 0.07% by mass of Ca sulfonate as a rust preventive. 2. The hydraulic oil for a hydraulic elevator according to claim 1, further comprising 30 ppm or less of benzotriazole as a metal deactivator.

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