JPS636598B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a protective lubricating composition for wire ropes, and its purpose is to provide a composition that has excellent lubricity, as well as a high degree of protection and chemical stability for wire ropes. Wire ropes are used in a wide variety of industrial fields, including cable railways, cableways, mines, cargo handling equipment, construction machinery, bridges, forestry, fishing, and ships. Therefore, various ropes are used depending on the purpose, and the diameter of the rope is up to 120 mm.
Usually, they are relatively large diameter ropes of 10 mm or more, but recently there are also ropes that have a simple structure with a rope diameter of about 4 mm or less. For example, inner wires of so-called conduits such as brake cables and control cables for automobiles, aircraft ropes with a rope diameter of about 0.8 to 10 mm, operating ropes with a diameter of about 0.6 to 6 mm, and aircraft target training ropes. Relatively small diameter ropes such as towing cables are widely used in industries such as automobiles, motorcycles, aircraft, and defense equipment. Unlike other large-diameter general ropes, these wire ropes can withstand movements such as friction, abrasion, and impact in a short period of time, such as repeated bending around sheaves, reciprocating motion in cable conduits, and twisting motion. It is susceptible to "intensive and continuous" damage, significantly endangering the life of the rope and leading to premature breakage. Therefore, the current situation is that wire ropes are required to have significantly higher lubricity to reduce friction, wear, etc. than other large-diameter general ropes. For wire ropes that are exposed to such harsh conditions, conventional soft solid rope greases made mainly of petrolatum and microswaths are not satisfactory in terms of lubricity, and other industrial lubricants and greases are recommended. However, I was unable to meet that demand. Especially for aircraft ropes, MIL-W-1511 and
The MIL-W-83420 standard requires a rope to have a certain residual strength after repeatedly bending the rope around a sheave at -50°C a certain number of times, and also Currently, it is required to move back and forth within the conduit hundreds of thousands of times, and to constantly increase the level of resistance in the direction of lower resistance. In addition, systems that handle these ropes often encounter corrosive factors such as contamination with rainwater, contact with wind, snow, and sand, and contamination with antifreeze agents sprinkled on the road, so protection is required. In addition to lubricity, protective properties and chemical stability are also required, such as properties that are chemically resistant to polymers because they are sometimes coated with polyethylene or other synthetic resins. As a result of extensive research into lubricating compositions that have excellent lubricity for use in these specific wire ropes and meet the above requirements, the present inventors have found that the lubricating compositions have a branched carbon number of 12 or more, and preferably have a viscosity of @ A higher alcohol of 15 centistokes or more at 40°C is used as a base oil, and a polymethacrylate polymer (preferably a molecular weight of 50,000 to 150,000) and an alkylaryl sulfonic acid metal salt are added as auxiliaries of 5 to 15 wt% each.
After confirming the fact that a liquid oil or semi-grease-like oil by adding it has excellent lubricity and a high level of protection for the special wire ropes and cables mentioned above, we have developed this book. The invention has been achieved. The branched higher alcohol used as the main base oil in the present invention is obtained by a synthetic method, and in contrast to natural alcohols produced from fats or waxes as raw materials, olefin hydrocarbons are obtained by the Ziegler method, Oxo method, It is produced by a synthetic reaction such as the Guerbet method. The oxo method is a method in which olefins are hydroformated with carbon monoxide and hydrogen, and various products with a linear to branched ratio of 90:10 to 50:50 are obtained, and in this case, relatively less branched The higher the ratio and the higher the ratio to the straight chain, the higher the viscosity tends to be. On the other hand, there is the Guerbet process, which is another method for directly producing highly branched higher alcohols, which can be produced by dimerizing straight chain alcohols. In any case, when used in the present invention, it has been confirmed that the higher the viscosity at room temperature, the more effective it is in terms of lubricity, and that it has a good mutual effect with additives as auxiliaries, and these points should be taken into consideration. if,
ISO viscosity grade @ 15 centistokes or higher at 40°C is preferred. For example, Oxocol 180 (manufactured by Nissan Chemical Co., Ltd., C number 18, OH value 200, viscosity 114 centistokes @ 40°C), NJ Coal 200A (C number 20,
OH number 184, viscosity 32 centistokes @ 40℃, manufactured by Shin Nippon Rika Co., Ltd.), Diadol 135 (C number 13-15,
OH value 260, viscosity 15 centistokes @ 40℃, manufactured by Mitsubishi Chemical Corporation), etc. Most of them have pour points of -10°C or lower, and some of them have a minimum of -50°C or lower, making them suitable for use in wire ropes at extremely low temperatures. In either case, most of the above-mentioned branched higher alcohols are liquid at room temperature, so that when applying oil to a wire, it can be easily dripped or flowed down at room temperature. Some alcohols with carbon (C) numbers exceeding 30 become solid; for example, branched alcohols in the range of 32 to 36 are wax-like with a melting point of 40°C, so conversely, this should be combined with the above liquid alcohol. Therefore, if it is made into a semi-grease-like material, it can be used for wire ropes in hot atmospheres. In addition, these higher alcohols have better stability to polymers than mineral oils; for example, when polyethylene is immersed at 70°C for 70 hours, the weight change rate shows that compared to 7 to 10 wt% of mineral oil of the same viscosity,
Higher alcohol shows a value reduced by about half to 3 to 5%, and brings advantageous results when coated with polyethylene or the like. Next, in order to improve the lubricity of the alcohols, it is more effective to increase their viscosity, and as a result of various mixing tests, polymethacrylate, polyisobutylene,
Among various polymer additives for improving the viscosity index, such as ethylene/propylene copolymers, polymethacrylate, which is a polymer with an ester structure, is the best in terms of solubility, effectiveness, and stability. Admitted. Polymethacrylate has a wide range of molecular weights, ranging from 20,000 to 1,500,000, but those with molecular weights from 50,000 to 150,000 are most compatible with base oils. The amount added is preferably in the range of 5 to 15%; if it is less than this, there will be no effect, and if it is too much, problems will arise in terms of solubility. These polymers not only improve the viscosity of the base oil, but also exist between each wire and tenaciously adsorb to the metal surface, seeping into the complex frictional interface between the wires and easily being washed away. It has the effect of holding and forming an oil film surface. Furthermore, as a result of conducting experiments to select various rust preventive agents to improve the protective properties of mixed oils of both base oil and polymer, it was found that metal salts of alkylaryl sulfonic acids are preferable. Alkylaryl sulfonate metal salts can be roughly divided into natural petroleum sulfonate metal salts, synthetic alkylbenzenesulfonate metal salts, and alkylnaphthalene sulfonate metal salts.
Synthetic ones are more consistent in quality and have better solubility in base oils. Metal salts of alkylnaphthalene sulfonic acids are particularly good, with barium and calcium salts being preferred. In terms of amount, it may be 5 to 15% based on the base oil, and if it is less than this amount, the effect will be weak, and if it is more than this, the protective property will not be particularly improved. As mentioned above, the polymer and rust preventive agent as the two auxiliary agents are well adsorbed and bonded between the wires physically and chemically, and promote the ductility of the oil film by the sliding action of the wire, thereby improving the oil film. It suppresses breakage and has a synergistic effect with the base oil, resulting in increased lubricity.
It also has anti-rust properties. In addition, commercially available antioxidants and the like may be added as long as they do not deteriorate the properties of the mixed oil. Below, typical examples (Table 1), reference examples, comparative examples (Table 2), and test results (Table 3) are shown to clarify the aspects and effects of the present invention. The test methods in the table are as follows. Viscosity: Expressed in centistokes (cst) of JIS K2283 @ 40℃. Fluidity: JIS K2269 Protection: JIS K2246 wet test (Class A: No rust,
E class: 51-100% rust) Lubricity: Use a Bekaert type fatigue tester. That is, three sheaves are fixed in advance to a holding plate, and a wire rope is hung around them in a U-shape, one end of the rope is fixed, and a load is applied to the other end to apply tension. Next, when the holding plate is reciprocated from side to side by pneumatic or hydraulic pressure, the three sheaves are forcibly moved while the wire rope is fixed, and the wire rope can be subjected to repeated bending fatigue. The measurement value is the number of times the fatigue rope breaks. Wire rope used: Aviation rope JISG3535, No. A3,
7×19, mesh/normal twist, diameter 4.76 m/m Sheave used: Diameter 76.2 m/m Load: Approximately 1/10 of wire rope breaking strength ≒ 190 kg Under these conditions, a rope without oil will break in 3269 times, so this The numerical value is 100, and it is expressed as the number of breaks in an oiled rope ÷ 3269 x 100 = lubricity.
The higher the value, the longer the life of the rope.However, this value must be 450 or higher to pass the MIL standard for aviation cable lubricity and to satisfy the lubricity for inner wires in motor vehicle cable conduits. It is necessary.

【table】

【table】

【table】

[Table] As is clear from the table above, each of the Examples using the branched higher alcohol of the present invention as the base oil is the same as Reference Example 3 using the base oil as the base oil of a straight-chain higher alcohol with no branches. Its lubricity is much higher than that of
The lubricity of each oil, such as ordinary rope grease (Comparative Example 1) and industrial lubricating oil (Comparative Examples 2 and 3), is 210 to 280.
The lubricity of each example is significantly improved from 450 to 900. Reference Examples 1 and 2, which had no protective properties with just branched alcohol, were improved to the extent that they would not rust at all by the formulations of Examples 1, 2, and 4, etc.
By applying the product of the present invention to actual aviation cables and control cables, severe requirements can be satisfied. Since the base oil of the product of the present invention is a higher alcohol with branches, infrared spectroscopy shows that the OH stretching vibration of the alcohol structure is strongly absorbed around 3600 cm ^-1 and the CO stretching vibration is strongly absorbed around 1050 cm ^-1 . It appears as a band, and if there are many branches, the absorption band around 710 cm ^-1 decreases, which makes it easy to check the quality of this oil and is useful for quality control.

Claims (1)

[Claims] 1. A protective lubricating composition for wire rope, characterized in that a branched higher alcohol having 12 or more carbon atoms is used as a base oil, and 5 to 15% by weight of each of a polymethacrylate polymer and a metal alkylallylsulfonic acid salt is added thereto. thing.