KR0154891B1 - Fire resistant water-glycol hydraulic oil composition - Google Patents

Abstract

Among the hydraulic oils, the water glycol system has excellent flame retardancy, but there is a problem that the raw material is expensive. The present invention uses PAG (polyalkylene glycol) in which ethylene glycol and propylene oxide are randomly polymerized using ethylene glycol as a starting material, thereby significantly lowering raw material prices and improving hydraulic oil properties, and other lubricants, rust inhibitors, In combination with the solvent to provide a working oil with excellent flame retardant rust resistance.

Description

Flame retardant water-glycol hydraulic fluid composition

The present invention relates to a lubricating oil composition, and more particularly to a flame retardant water-glycol hydraulic fluid.

Hydraulic hydraulic oil is a medium for power transmission, which plays a role of lubrication, rust prevention, sealing, cooling, etc. of each hydraulic device, and is classified into three types of petroleum, hydrous, and synthetic systems depending on the composition. The functional system is again classified into emulsion type and solution type. Since emulsion type contains mineral oil, there is a risk of separation and corruption. Japanese Patent Application Laid-Open No. 5-263094 discloses an ether compound of the general formula R ₁ -OR ₂ -OH (wherein R ₁ is a saturated or unsaturated hydrocarbon group having ₁ to 8 carbon atoms and R ₂ is a hydrocarbon group having ₂ to 8 carbon atoms). It contained ~ 0.3% by weight to extend lubricity and lifespan. However, this ether compound was expensive and had very low economic feasibility.

The present invention is a solution type containing water, glycol, and water-soluble medium as the main ingredient, and other additives are blended, and there is no concern about the above. Also, since the flame retardancy is excellent in high temperature safety, there is a risk of fire such as high temperature metal, electric spark, heating furnace, etc. The present invention aims at providing a new hydraulic fluid composition which can be used even in the presence of the present invention and has excellent characteristics such as wear resistance, corrosion resistance, cooling property, and rust resistance.

Moreover, the water-glycol hydraulic fluid has excellent lubricity compared to the petroleum hydraulic fluid, and has excellent wear resistance and oxidation stability as well as a price advantage compared to the synthetic hydraulic oil. Due to the limitation of lubricity, it has been used until recently to be limited to low to medium pressure hydraulics.

The present invention improves the lubricating performance of the working oil by adding an appropriate amount of abrasion resistance and lubricity improving additives and at the same time contains other special additives, and has a high viscosity index (220 or more) product having excellent shear stability. ^It maintains stable viscosity even in the harsh working conditions and continuous operation of ² ), and maximizes the volumetric efficiency of the pump and the hydraulic transmission efficiency. In addition, the hydraulic oil has excellent resistance to most non-ferrous metals and ferrous metals except for Cd and Zn in corrosion resistance, and has excellent compatibility with synthetic rubber for packing and sealing, as well as excellent oxidation, heat and low temperature stability. It is a hydraulic oil for four seasons that can be started even at low temperature due to low pour point (-45 ℃) and can be used for a long time even in the temperature change. In addition, it is not toxic and can be easily identified with other oils by adding red pigment, and it is easy to find the oil leakage part of hydraulic system, and it has the advantage of identifying the degree of contamination by the color and transparency of the emulsion. .

The composition of the present invention is a water and glycol-based solvent and other special additives are formulated as a main component as a main component, the mixing ratio and the main functions of each component are as follows.

The composition of the present invention is composed of 35 to 50 parts by weight of water, 25 to 50 parts by weight of solvent, 10 to 20 parts by weight of medium agent, 1 to 5 parts by weight of lubricant, 1 to 3 parts by weight of rust preventive agent, and residual amount of antifoaming agent. Water in the composition is indispensable for cooling the working oil and maintaining flame retardancy, and uses 35 to 50 parts by weight of ion-exchanged sulfur water or distilled water, which prevents combustion by cooling the water by evaporation of water and diluting the oxygen concentration in the air. It works by complexing it will be digested.

As a solvent, it is preferable to use about 25 to 50 parts by weight of glycol which is well dissolved in water. If the weight of glycol is 50 or more, the fire resistance of the working oil is lowered and the viscosity is too low. Examples of glycols that can be used include ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol. In the embodiment, ethylene glycol was used, which facilitates dissolution of various additives along with a drop in the pour point of the working oil. It serves to increase.

Polyalkylene glycol (PAG; Poly Alkylene Glycol) used as a mid-weight agent is classified into block type and random type according to addition polymerization method. PAG used in the present invention belongs to random type among them. The nonionic surfactant having an average molecular weight of 15,000 to 20,000 by random addition polymerization of ethylene oxide (E0) and propylene oxide (P0) can be represented as follows.

In the above formula (1), a and c represent the number of moles of E0, b represents the number of moles of P0, and the molar ratio of E0: P0 in the present copolymer is 10: 1 to 1:10. PAG is suitable for maintaining the proper viscosity of the hydraulic oil to obtain a suitable hydraulic oil for various ISO Viscosity Grades by adjusting the addition amount of the central agent, the preferred weight of the PAG is 10-20, if the weight is 20 or more, the suppression effect is reduced. Less than 10 makes it difficult to obtain a proper viscosity. PAG used in the present invention is a substitute for expensive imported PAG, which has been widely used in the past, and is not toxic, and is very stable against acids, alkalis, peroxides, metal ions, etc., and has a low pour point, excellent lubricity and shear stability, It has a high viscosity index. Examples of fatty acids used as lubricants for water-glycol hydraulic fluids are saturated fatty acids, unsaturated fatty acids, straight fatty acids, and branched fatty acids, the general formula of which can be represented as follows.

N represents an integer and the total carbon number is preferably 10-22. Generally, if the carbon number is less than 10, the oil film formation is insufficient and the lubricity is poor, and if the carbon number is 22 or more, the use stability is inferior. The mixing ratio of fatty acids is preferably 1-5 parts by weight of hydraulic oil, and if the weight part is less than 1, the wear resistance is inferior.

As a rust preventive additive, two kinds of liquid rust preventive agent and gas phase rust preventive agent were used in total 1-3 parts by weight.The liquid rust preventive agent was dimethylamino-2-propanol, and the vapor rust preventive agent isopropyl diethanolamine and diethylethanolamine. This was used. The above-mentioned gaseous rust inhibitors also serve as pH adjusters, and the importance of gaseous rust preventers is more important when considering that most water-glycol hydraulic fluids are alkaline by stabilizing wear resistant lubricant additives. do. In general, when the pH is less than 10, the solubility of the sludge is reduced, and if it is more than 12, the wear resistance is reduced.

Antifoaming agent used a small amount of silicone antifoaming agent.In general, when the antifoaming property is bad, the compressibility of the hydraulic fluid is increased, which causes malfunction of the hydraulic system, and the noise is generated due to the space formation of the pump. Since it can be promoted, the selection of a suitable antifoaming agent is very significant. In addition, a small amount of tolutriazole is added to the working oil as a red pigment and a corrosion inhibitor, and in a water-glycol hydraulic fluid, a triazole type corrosion inhibitor provides sufficient corrosion resistance to iron and nonferrous metals. do.

Examples of the hydraulic fluid (manufacturing example) are shown in Table 1 below, and the results of the analysis of the main properties are shown in Table 2 below.

Claims (2)

35-50 parts by weight of water; 25-50 weight part of solvents which consist of ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol; 10 to 20 parts by weight of the middle agent of the following formula (I) in which ethylene glycol is a starting material and randomized polymerization of ethylene oxide and propylene oxide; 1 to 5 parts by weight of a lubricant comprising a straight saturated saturated fatty acid of formula (I); Flame-retardant water glycol type hydraulic operating composition composed of liquid anticorrosive agent of diethylamino-2-propanol and vapor phase preservative such as isopropyl diethanolamine and diethylethanolamine (Wherein a and C are moles of E0, b is moles of P0 and E0: P0 = 10: 12 1:10 and n is 10-22). The flame-retardant water glycol-based hydraulic oil composition according to claim 1, wherein the midpoint agent is a nonionic surfactant having an average molecular weight of 15,000 to 20,000, and the pH of the rust preventive agent is less than 10.