What are the hydraulic oil additives?

Oiliness agent
Oil agent is a strong polarity of the substance, at low temperature and pressure, and the metal surface adsorption, the formation of a solid adsorption film, prevent metal and metal direct contact, improve the strength of the oil film, reduce the friction and wear of metal.
In hydraulic oil, commonly used oil agents are: oleic acid, vulcanized whale oil (T401), vulcanized cottonseed oil (T404), vulcanized olefin cottonseed oil (T405), dimeric acid (T402), etc.

Antiwear agent
At high friction temperature, the decomposition products of antiwear agent react with the metal surface to produce compound film with low shear stress and low melting point to prevent the occluding or welding of the contact surface, resulting in plastic deformation, filling the uneven part between the friction surface, so that the contact surface increases, the pressure decreases and the wear decreases.
In the antiwear agent, usually contain sulfur, phosphorus and chlorine, their compounds have their own characteristics. The antiwear agent containing sulfur, under the condition of high temperature friction, sulfide reacts with iron to form iron sulfide film, plays an antiwear role; The anti-wear agent containing phosphorus, at not too high temperature and moderate friction conditions, by the product of thermal decomposition of phosphate ester and steel interaction, the formation of low melting point, high plasticity of phosphate mixture, so as to play the anti-wear effect; The antiwear agent containing chlorine, under extreme pressure conditions, produces ferric chloride film, the film is lamellar structure, the friction coefficient is small, easy to shear, good lubrication.
In hydraulic oil, the commonly used antiwear agents are: dialkylzinc dithiophosphate (T203), trimethylphenyl phosphate (T306), thiophosphate (T303), sulfide olefin (T321), chlorinated paraffin (T301), etc.

viscosifier
Viscosifier is a kind of additive to improve the viscosity and temperature of hydraulic oil and increase the viscosity index. This is a kind of high polymer, at low temperature, in the oil contraction and curling into a tight ball, low temperature viscosity has little influence, high temperature, swelling and stretching in the oil, increase viscosity, can improve viscose-temperature characteristics.
In hydraulic oil, commonly used viscosifier are: polyn-butyl vinyl ether (T601), polyisobutene (T603), ethyl-propylene copolymer (T611), polymethacrylate (KT8602) and so on.

Antifoaming agent
Anti-foaming agent is a kind of substance that can reduce the stability of foam adsorption film and shorten the existence time of foam. Adding anti-foaming additives in hydraulic oil can reduce the surface tension, so that bubbles can quickly overflow the oil surface, so as to eliminate bubbles.
In hydraulic oil, commonly used anti-foam agents are: dimethyl silicone oil (T901), polyester non-silicon anti-foam agent (T911), metal soap, fatty acid and so on.

coagulant
Coagulant is a kind of additive that can inhibit the formation of network crystallization of paraffin wax in oil, reduce the freezing point and maintain the fluidity of oil. By means of adsorption or eutectic formation on the surface of paraffin crystal, the agent changes the shape and size of the paraffin crystal to reduce the condensation point of the oil.
In hydraulic oil, commonly used point reducing agents are: alkyl naphthalene (T801), polymethacrylate (T602B),α olefin copolymer (M), vinyl vinyl acetate poly (T804) and so on.

antioxidant
Antioxidant is a kind of additives that are easy to be oxidized and can generate compound films on the surface of metals to isolate contact with oxygen and other corrosive substances and prevent the catalytic oxidation of metals on oil and oil on metal corrosion.
Generally several antioxidant additives compound use, antioxidant effect is better, such as sulfide and aromatic hydrocarbon compound, will produce synergistic effect; The compound of free radical terminator and peroxide decomposing agent also has obvious synergistic effect.
In hydraulic oil, commonly used antioxidants are :2, 6-di-tert-butylp-cresol (T501), n-phenyl-alphanaphthylamine (T531), isobutylene sulfide (T321), dialkyldithiocarbamate, aromatic hydrocarbons, bisphenol, etc.

Rust inhibitor
Rust inhibitor is a kind of polar compound, which can form a strong hydrophobic adsorption film on the metal surface to prevent metal rust.
In hydraulic oil, the commonly used rust prevention agents are: dodecene succinic acid (T746), barium dinonyl naphthalene sulfonate (T705), heptadenyl imidazoline dodecene succinic acid (T703), etc.

Antifungal agent
Mildew repellent can prevent and inhibit mildew in emulsified oil.
In hydraulic oil, commonly used anti-mold agents are: phenolic compounds, formaldehyde compounds.

deemulsifier
Demulsifier is a kind of substance that can make water and oil separate well or settle out.
In hydraulic oil, commonly used demulsifier are: polyether polymer compounds and a variety of ethylene oxide, propylene oxide polymer.

Metal passivating agent
Metal passivating agent is a kind of additives that can protect non-ferrous metals, especially copper surface corrosion. The agent can also increase the oxidation resistance of oil products and inhibit and passivate the corrosion of acid substances to copper.
There are two types of metal passivating agents used in hydraulic oil: one is film forming passivating agents, which can form a coating with the surface of copper to prevent the erosion of acids, active sulfides and corrosive extreme pressure agents. Commonly used are benzotriazole (T706) and active sulfur scavenger, which reacts with active sulfur compounds to produce low or non-corrosive polysulfide compounds.