KR0169565B1 - Polyol ester based hydraulic oil composition by high-temperature non-catalytic reduction - Google Patents

Abstract

Synthetic lubricating oil was developed to improve the properties of petroleum-based lubricants, but a catalyst was used to obtain a polyol ester in which the existing synthetic lubricating oil was used as the gas, and problems such as reverse reaction and discoloration due to residual catalyst were raised. . The present invention is based on a partial polymerization of a polyol compound and a higher fatty acid obtained under a high-temperature, non-catalytic atmosphere, and a new synthetic lubricating oil comprising a phenylnaphthylamine antioxidant, an aryl phosphate antiwear additive, a thickener, a corrosion inhibitor, and an antifoaming agent. As a result, there was no problem such as reverse reaction and discoloration due to residual catalyst, and it was confirmed experimentally that flash point, pour point, viscosity index, oxidation stability, abrasion resistance, and load resistance are better than petroleum lubricant.

Description

[Name of invention]

Polyol Ester Hydraulic Fluid Composition by Hot-Catalyst Reaction

Detailed description of the invention

[Purpose of invention]

[Technical field to which the invention belongs and the prior art in that field]

The present invention relates to a lubricating oil composition, and more particularly to a synthesis of a polyol ester-based hydraulic oil base by a hot-catalyst reaction and a hydraulic oil using the same.

Various hydraulic hydraulic oils have been developed and used to date, and it is well known that the petroleum system based on mineral oil occupies most of them. However, this petroleum hydraulic fluid is not suitable for high speed and high pressure equipment due to lack of lubricity, and the high risk of fire due to the nature of mineral oil is not preferable.

In addition, the petroleum hydraulic fluid has a low viscosity index, so the viscosity change is severe and it is very difficult to maintain the proper viscosity. To reinforce this, various polymers are used as viscosity index improvers. As a result of the breakdown, a sudden viscosity and viscosity index drop occur.

The present inventors have developed a polyol ester hydraulic fluid, which is a hydraulic fluid of the type that solves the drawbacks of the conventional hydraulic fluid. (Korean Patent No. 88842) However, the conventional polyol ester hydraulic fluid is synthesized using a catalyst at low temperature. As a result, catalyst remains in the base oil, which causes problems such as reverse reaction, discoloration and oxidation of the base oil.

[Technical problem to be achieved]

The present invention relates to a new type of hydraulic fluid that solves the above-mentioned defects of the polyol ester-based hydraulic fluid due to the petroleum-based and low-temperature catalyst reaction. The present invention relates to a polyol obtained by synthesizing monobasic higher fatty acids and polyols in a high-temperature non-catalyst atmosphere. Used as ester base. The viscosity index of this polyol ester system itself is very high, and the flash point is not restricted by the use place due to petroleum hydraulic fluid, and also there is no residue of catalyst material in the paper, thus providing hydraulic oil which is not affected by reverse reaction or discoloration. It is about.

[Configuration and Function of Invention]

The polyol ester system used in the present invention is synthesized using a C6-20 saturated or unsaturated fatty acid and a polyhydric alcohol of the following formula (I). Here, the alkyl group of the fatty acid is applicable to both linear and branched forms, and the selection should consider the lubricity of the composition or other physical properties.

R ₁ and R ₂ are the same or different alkyl groups having 1 to 4 carbon atoms or (CH ₂ ) nOH, n is an integer of 1 to 2;

This invention is obtained by mix | blending an appropriate amount of antioxidant, antiwear additive, a thickener, etc. with the polyol ester synthesize | combined by high temperature-catalyst. Specifically, the antioxidant has the best effect of the phenylnaphthylamine system of the following formula (II), and the amount is 0.1 to 7.0 parts by weight, preferably 1.0 to 3.0 parts by weight. In general, less than 0.5 parts by weight of the effect is small and more than 7.0 parts by weight of the anti-oxidation effect can be expected, but problems such as discoloration of the emulsion and degradation of the flame retardant effect may be raised.

Wherein R ₃ is hydrogen or an alkyl group having 1 to 10 carbon atoms

As an anti-wear additive, when the effect of the aryl phosphate system of following formula (III) is the most favorable, the addition amount is 0.1-6.0 weight part, Preferably it is 0.3-2.0 weight part.

R ₄ may be the same or different from each other as hydrogen or an alkyl group having 1 to 4 carbon atoms.

As the thickener, an olefin copolymer, polymethacrylate, or the like may be used, and a polymethacrylate of 100,000 or less, preferably 50,000 or less, is preferred, having excellent shear stability and low viscosity change. The low molecular weight and high molecular weight thickener combinations can complement both low temperature fluidity and viscosity index.

The amount of addition depends on the target viscosity of the lubricating oil composition, but 0.5 to 5.0 parts by weight is appropriate, preferably 0.5 to 3.0 parts by weight.

In the present invention, if necessary, 0.02 to 0.10 parts by weight of a corrosion inhibitor, an antifoaming agent, or the like may be added.

The above-mentioned additives are very necessary in the lubricating oil composition, but when the excess amount is used, it may cause the reduction of the flame retardant effect, the viscosity drop due to shearing, the generation of the tailings and the discoloration of the emulsion. It must be considered.

In selecting the reaction temperature for obtaining the polyol ester base used in the present invention, the experiment was performed by changing the temperature range from 120 ° C to 260 ° C. At this time, when the synthesis temperature is less than 180 ℃ reaction rate is very slow and a large amount of the carrier gas (Carrier gas) is injected while the acid value is difficult to reach the desired target value. In addition, the reaction rate is faster than 240 ℃, it was confirmed that serious effects on the ester base by thermal oxidation and evaporation of polyol and low molecular weight fatty acids. The results are shown in Table 1.

Example 1 Preparation of Base

1) A mixture of 645.6 g of oleine and 127.6 g of trimethylolpropane is reacted under a nitrogen atmosphere (500 cc per minute) at 180 ° C. 240 ° C. for 10 to 15 hours. When the acid value was 2.5 or less, the reaction was terminated to obtain 736.4 g of an oleic acid ester of trimethylolpropane (hereinafter referred to as base 1). (Yield: 95%) The properties of the ester are as follows.

2) A mixture of 677.8 g of isostearic acid and 127.6 g of trimethylolpropane are reacted under a nitrogen atmosphere (500 cc per minute) at 180 to 240 ° C. for 10 to 15 hours. When the acid value was 2.5 or less, the reaction was terminated to obtain 767.0 g of isostearic acid ester of trimethylolpropane (hereinafter referred to as base 2). (Yield: 95%) The properties of the ester are as follows.

3) A mixture of 302.2 g of caprylic acid and 127.6 g of trimethylolpropane is reacted under a nitrogen atmosphere (500 cc per minute) at 180 to 240 ° C. for 10 to 15 hours. When the acid value was 2.5 or less, the reaction was terminated to obtain 410.2 g of a caprylic acid ester of trimethylolpropane (hereinafter referred to as "base 3"). (Shoo: 95%) The properties of this ester are as follows.

4) A mixture of 645.6 g of oleic acid and 129.5 g of pentaerythritol is reacted under a nitrogen atmosphere (500 cc per minute) at 180 to 240 ° C. for 10 to 15 hours. When the acid value was 2.5 or less, the reaction was terminated to obtain 738.2 g of an oleic acid ester of pentaerythritol (hereinafter referred to as Base 4). (Yield: 95%) The properties of the ester were as follows.

5) A mixture of 677.8 g of isostearic acid and 129.5 g of pentaerythritol is reacted under a nitrogen atmosphere (500 cc per minute) at 180 to 240 ° C. for 10 to 15 hours. When the acid value was 2.5 or less, the reaction was terminated to obtain 768.8 g of isostearic acid ester of pentalerythritol (hereinafter referred to as "base 5") (yield: 95%). The properties of this ester were as follows.

6) A mixture of 645.6 g of oleic acid and 99.0 g of neopentyl glycol is reacted under a nitrogen atmosphere (500 cc per minute) at 180 to 240 ° C. for 10 to 15 hours. When the acid value was 2.5 or less, the reaction was terminated to obtain 709.3 g of oleic acid ester of neopentyl glycol (hereinafter referred to as base 6). (Yield: 95%) The properties of the ester are as follows.

7) A mixture of 677.8 g of isostearic acid and 99.0 g of neopentyl glycol is reacted under a nitrogen atmosphere (500 cc per minute) at 180 to 240 ° C. for 10 to 15 hours. When the acid value was 2.5 or less, the reaction was terminated to obtain 739.7 g of isostearic acid ester of neopentyl glycol (hereinafter referred to as base 7). (Yield: 95%) The properties of the ester are as follows.

8) A mixture of 302.2 g of caprylic acid and 99.0 g of neopentyl glycol is reacted under a nitrogen atmosphere (500 cc per minute) at 180 to 240 ° C. for 10 to 15 hours. When the acid value was 2.5 or less, the reaction was terminated to obtain 383.0 g of a caprylic acid ester of neopentyl glycol (hereinafter referred to as "8"). (Yield: 95%) The properties of this ester were as follows.

Example 2 Preparation of Hydraulic Hydraulic Oil

About the base compound obtained in Example 1, it mix | blended as Table-2 and measured the property. The results are shown in Table 3.

Claims (2)

80.0 to 99.0 partially synthesized polyol ester by reacting a saturated or unsaturated fatty acid having 6 to 20 carbon atoms with a polyhydric alcohol of the following formula (I) at a temperature of 120 to 260 ° C. for 5 to 40 hours under a nitrogen atmosphere. A polyol ester hydraulic hydraulic oil composition by a high temperature non-catalytic reaction prepared by mixing 0.1 to 7.0 parts by weight of a phenylnaphthylamine-based antioxidant of the formula (II) and a residual amount of modifier with parts by weight. According to claim 1, wherein the modifier is 0.5 to 5.0 parts by weight of a thickener having a molecular weight of less than 100,000 selected from 0.1 to 6.0 parts by weight of aryl phosphate-based formula (III), olefin copolymer, polymethacrylate, etc., 0.02 to 0.1 weight of corrosion inhibitor Part, a polyol ester hydraulic hydraulic oil composition by a high temperature non-catalytic reaction, characterized in that consisting of a small amount of antifoaming agent.