A SILICONE GREASE COMPOSITION
The present invention relates to a silicone grease composition or, more particularly, to a fire-resistant and self-extinguishable silicone grease composition imparted with decreased inflammability and useful as a filling material for electric cables including those for connection of electric instruments, underground communication cables, loose-type optical fibers and the like.
Needless to say, various kinds of grease compositions are widely used in household electric appliances, communication cables and the like including mineral oil-based greases, synthetic oil-based greases, silicone-based greases and others. While fire resistance or flame retardancy is very essential in greases used in such applications, most of the mineral oil-based greases are inflammable and silicone-based greases prepared from a silicone fluid of low viscosity, e.g., 30 centistokes or below, as the base oil are also inflammable. Silicone greases prepared from a silicone fluid of medium or high viscosity as the base oil are flame retardant but still not self-extinguishable.
A proposal has been made in Japanese Patent Kokai 57-28157 for a self-extinguishable silicone grease prepared by admixing a flame retardant agent and a silicone fluid as the base oil, the flame retardant agent being miscible with the base oil. This silicone grease is also not quite satisfactory because the silicone fluid as the base oil is not self-extinguishable. Accordingly, it is eagerly desired to develop a self-extinguishable silicone grease which can be used as a reliable filling material of communication cables in view of the chaotic troubles in the telephone system which resulted from a fire in the underground communication cables in 1984 in Tokyo.
The silicone grease composition of the present invention comprises, in admixture: (a) 100 parts by weight of an organopolysiloxane having a viscosity in the range from 10 to 1,000,000 centistokes at 25 DEG C represented by the average unit formula RaSiO(4-a)/2, ..... (I) in which R is a monovalent hydrocarbon group or a halogen-substituted monovalent hydrocarbon group and the subscript a is a positive number in the range from 2 to 3, from 0.1 to 30% by moles of the groups denoted by R being vinyl groups; (b) from 0.001 to, preferably, 0.1 part by weight of platinum or a platinum compound; and (c) from 5 to 50 parts by weight of a thickening agent.
The silicone grease of the present invention, of which the essential ingredients are the components (a), (b) and (c) given above, contains the unique combination of the very specific organopolysiloxane fluid having vinyl groups as the component (a) and platinum or a platinum compound as the component (b). This combination imparts the silicone grease composition with self-extinguishability without significantly affecting the properties inherent in silicone grease compositions such as heat and cold resistance, electric properties, water repellency, sealability and the like and further decreases the volume of toxic gases produced when the grease is set on fire.
The component (a) is an organopolysiloxane represented by the average unit formula RaSiO(4-a)/2, in which R is a monovalent hydrocarbon group or a halogen-substituted monovalent hydrocarbon group. The monovalent hydrocarbon group is exemplified by alkyl groups, e.g., methyl, ethyl, propyl and butyl groups, cycloalkyl groups, e.g., cyclohexyl group, alkenyl groups, e.g., vinyl and allyl groups, and aryl groups, e.g., phenyl and tolyl groups. The halogen (e.g. chlorine or fluorine)-substituted monovalent hydrocarbon group, which is obtained by replacing a part or all of the hydrogen atoms in the above named hydrocarbon groups with halogen atoms, is exemplified by chloromethyl and 3,3,3-trifluoropropyl groups.
It is essential that from 0.1 to 30% by moles of the groups denoted by R in a molecule are vinyl groups. When the molar content of vinyl groups is too small, insufficient self-extinguishability is imparted to the grease composition. When the molar content of vinyl groups is too large, on the other hand, the grease composition may be somewhat poor in the heat resistance. The subscript a in the above given average unit formula is a positive number in the range from 2 to 3. The organopolysiloxane fluid as the component (a) in the inventive silicone grease composition should have a viscosity in the range from 10 to 1,000,000 centistokes or, preferably, from 50 to 500,000 centistokes at 25 DEG C. When the viscosity of the organopolysiloxane fluid is too low, the grease composition prepared therefrom has poor stability as a grease with eventual separation of the base oil.
When the viscosity of the organopolysiloxane fluid is too high, on the other hand, the grease prepared therefrom is poorly workable due to the excessively stiff consistency thereof.
The component (b) in the inventive silicone grease composition is platinum or a platinum compound which serves to impart self-extinguishability to the grease composition. Elementary platinum such as platinum black or a platinum compound such as chloroplatinic acid are suitable for the purpose. It is preferable to use a platinum compound, especially one soluble in or compatible with the organopolysiloxane, for example those used in organosilicone chemistry for catalytically promoting the addition reaction between a vinyl-containing organopolysiloxane and an organohydrogenpolysiloxane.
The amount of platinum or a platinum compound as the component (b) in the inventive silicone grease composition is in the range from 0.001 to, preferably, 0.1 part by weight or, preferably, from 0.002 to 0.02 part by weight calculated as platinum per 100 parts by weight of the organopolysiloxane fluid as the component (a). When the amount thereof is too small, insufficient self-extinguishability is imparted to the silicone grease composition. On the other hand, no further additional improvement can be obtained in the self-extinguishability of the grease composition by increasing the amount of the component (b) over the above mentioned upper limit.
The component (c) in the inventive grease composition is a thickening agent which may, for example, be any known one conventionally used in various grease compositions. In particular, the thickening agent as the component (c) may be selected from inorganic ones, for example silica, alumina, iron oxide, zinc oxide or carbon, optionally, surface-treated with an organosilane compound, e.g., an alkoxy silane compound, low-molecular organopolysiloxane terminated at the molecular chain ends with silanolic hydroxy groups, or an organic amine or organoboron compound and the like.
The silicone grease composition of the present invention can be prepared by uniformly mixing together the above described components (a), (b) and (c) each in a calculated and weighed amount. It is of course optional that the composition is further admixed with various kinds of additives, e.g., antioxidants conventionally used in grease compositions. These ingredients are mixed and thoroughly kneaded together by using a three-roller mill or colloid mill, for example, with heating or under reduced pressure according to need until the composition has a grease-like consistency.
Being prepared from an organopolysiloxane as the base oil, the silicone grease composition of the invention has the properties inherent in silicone fluids such as heat and cold resistance, electric properties, water repellency and sealability, for example. In addition, the grease composition is imparted with high self-extinguishability by the addition of platinum or a platinum compound. Accordingly, the silicone grease composition of the invention is particularly useful as a filling material of communication cables including optical fibers.
In the following, the silicone grease composition of the invention is described in more detail by way of examples, in which the term of "parts" always refers to "parts by weight" and the values of viscosity are obtained by the measurement at 25 DEG C.
The inflammability of the silicone grease compositions prepared in the following examples was evaluated by a burning test carried out in the following manner. A glass fiber sleeve of 2 mm diameter and 50 mm length filled with the grease composition was vertically hung and the lower end thereof was put into the flame of an alcohol lamp for 15 seconds to start burning of the sleeve. Thereafter, the alcohol lamp was removed away and records were made of the length of time from that moment until the flame went out when burning of the sleeve did not continue. Examples 1 to 7 and Comparative Examples 1 to 5.
In each of these Examples and Comparative Examples, 100 parts of an organopolysiloxane fluid were mixed together with an octyl alcohol solution of chloroplatinic acid in a concentration of 2% by weight as platinum in an amount indicated in the table below and fine silica filler of the kind shown below in an amount indicated in the table,and the mixture was kneaded on a three-roller mill to give a silicone grease composition.
The organopolysiloxane fluids used in these experiments were characterized as follows. Example 1: dimethylpolysiloxane fluid having a viscosity of 50 centistokes, of which the content of vinyl groups was 5.0% by moles of the overall organic groups Example 2: dimethylpolysiloxane fluid having a viscosity of 60 centistokes, of which the content of vinyl groups was 3.0% by moles of the overall organic groups Example 3: dimethylpolysiloxane fluid having a viscosity of 500 centistokes, of which the content of vinyl groups was 10.0% by moles of the overall organic groups Example 4: methyl phenyl polysiloxane fluid having a viscosity of 700 centistokes, of which the contents of phenyl groups and vinyl groups were each 5.0% by moles of the overall organic groups Example 5:
methyl phenyl polysiloxane fluid having a viscosity of 1000 centistokes, of which the contents of phenyl groups and vinyl groups were 5.0% by moles and 0.1% by moles, respectively, of the overall organic groups Example 6: dimethylpolysiloxane fluid having a viscosity of 100,000 centistokes, of which the content of vinyl groups was 20.0% by moles of the overall organic groups Example 7: dimethylpolysiloxane fluid having a viscosity of 500,000 centistokes, of which the content of vinyl groups was 30.0% by moles of the overall organic groups Comparative Example 1: dimethylpolysiloxane fluid having a viscosity of 50 centistokes, of which the content of vinyl groups was 0.05% by moles of the overall organic groups Comparative Example 2:
dimethylpolysiloxane fluid having a viscosity of 500 centistokes, of which the content of vinyl groups was 5.0% by moles of the overall organic groups Comparative Example 3: methyl phenyl polysiloxane fluid having a viscosity of 1000 centistokes, of which the contents of phenyl groups and vinyl groups were 5.0% by moles and 25.0% by moles, respectively, of the overall organic groups Comparative Example 4: dimethylpolysiloxane fluid having a viscosity of 500 centistokes and containing no vinyl groups Comparative Example 5: dimethylpolysiloxane fluid having a viscosity of 700 centistokes, of which the content of vinyl groups was 10.0% by moles of the overall organic groups
The following four finely divided silica fillers were used in the formulations. I: a fumed silica filler, Aerosil 200, manufactured by DEGUSSA Co., West Germany II: a fumed silica filler surface-treated with hexamethyl disilazane and admixed with 0.5 % by weight of an antioxidant (Ionox 220, manufactured by Shell Petroleum Co.) III: a fumed silica filler surface-treated with diphenyl silane diol IV: finely divided silica filler, R-972, manufactured by DEGUSSA Co., West Germany
The table given below summarizes the amount of the platinum compound in the form of a solution, kind and amount of the silica filler as the thickening agent, consistency of the grease compositions as worked and time for self-extinguishment in the inflammability test. EMI9.1
FAQs
Does silicone grease contain petroleum? ›
Silicone greases also offer water-washout resistance, support reliable electrical connections, and contain no harmful or flammable petrochemicals.
What is silicone based grease? ›Silicone grease is a type of viscous lubricant that is made with a combination of silicone oil and an inert filler, such as silica powder and thickeners such as lithium soap. The grease is generally a thick, white paste.
Is silicone grease non petroleum based? ›Non-petroleum oils include synthetic oils, such as silicone fluids, tung oils, and wood-derivative oils such as resin/rosin oils.
Is Lithium Grease a silicone grease? ›Though both are used for lubrication, lithium greases and silicone lubricants have different specialties and use. It is so important to know these differences in order to pick the correct product for the job you need to be done to protect and maximise the productivity of your equipment.
What should you not use silicone grease on? ›Silicone oils are dielectric and so is silicone grease, silicone is generally low cost and widely available. However we do not recommend using any silicone based lubricant for use on electrical connectors or contacts.
Is WD 40 silicone or petroleum based? ›A: WD-40 is a petroleum based product which means it will degrade plastic or rubber over time… Silicone will not.
What is an example of a silicone based lubricant? ›An example of quality silicone lubricant is WD-40 High Performance Silicone spray. WD-40 provides a versatile solution to the type of problems automotive professionals encounter every day. WD-40 effectively lubricates and waterproofs.
What type of lubricant is silicone? ›Silicone fluids, or oils as they are sometimes known, have been used for many decades as excellent lubricants for polymers and rubbers because, by nature, they have very low coefficients of friction. The viscosity of silicones is much less dependent on temperature compared to petroleum oils.
What is the difference between silicone grease and synthetic grease? ›Learn about this topic in these articles:
Synthetic grease may consist of synthetic oils containing standard soaps or may be a mixture of synthetic thickeners, or bases, in petroleum oils. Silicones are greases in which both the base and the oil are synthetic.
The one time you should never use silicone lube is when you're using silicone sex toys. “Like damages like,” Dr. Rowen says. “Silicone lubes will break down sex toys." Instead, opt for a water-based with a silicone sex toy or oil-based if you don't need to use any latex barrier on the toy.
Is Vaseline a silicone based lubricant? ›
Vaseline, or petroleum jelly, is an oil-based ointment.
Is silicone grease PTFE? ›Silicone or PTFE products are suitable for plastic-to-plastic lubrication, but the silicone will form a thicker, wetter layer that may collect dust and dirt. PTFE will have a thinner, yet harder layer that will not attract dust or absorb grime.
Is dielectric grease just silicone grease? ›Silicone grease, sometimes called dielectric grease, is a waterproof grease made by combining a silicone oil with a thickener.
What is the slipperiest lubricant? ›HI-T-LUBE is recognized as the world's “slipperiest” solid by The Guinness Book Of World Records.
Is Ceramic Grease the same as silicone grease? ›Ceramic Grease is free of silicones and metal, as a result of which the product meets the environmental regulations on the use of heavy metals. Thanks to its ceramic particles the product has a superior pressure and temperature resistance range.
Does silicone grease get hard? ›Plastic & Rubber Lubricant
It is resistant to oil, water and chemicals and with a temperature range of -40°C to +200°C it will not harden, freeze, dry or melt.
Silicone and PFPE are generally safe with all plastics. Synthetic hydrocarbons and mineral oils are usually compatible with most plastics, though high and low operating temperatures may rule out mineral oils.
Does silicone grease degrade plastic? ›They are used in many everyday items, from cooking utensils to cosmetics. In lubricants, a silicone base oil is commonly used in greases for plastic gears, control cables, and seals because they are inert, compatible with most plastics and elastomers, and remain stable over a wide temperature range.
Is motor oil silicone based? ›Silicon is used in many oil types as an antifoaming additive. As an additive, silicon is used in engine, gear, circulating and other types of oils. The consistent variable in the use of silicon is the amount in the new oil. Oil manufacturers will use amounts of silicon based on different types of oil (Figure 1).
Can I use silicone spray instead of grease? ›Silicone spray is a highly effective lubricant for a wide array of vehicle and household applications. It's ideal for lubricating surfaces that may be damaged by conventional lubricants such as grease or oil, and it also helps prevent the cracking and drying of rubber and locks out moisture.
Is synthetic grease silicone based? ›
Conventional greases employ a petroleum-based product, such as mineral oil. Synthetic greases use a synthetic lubricant, such as silicone. Consequently, they can withstand temperature extremes and maintain lubricating effectiveness better than conventional greases.
Is KY jelly a silicone lubricant? ›K-Y True Feel is a premium intimate lubricant that helps you feel close and natural to your partner. This long-lasting silicone formula provides a naturally smooth experience so you can focus on your sensual connection to each other. K-Y True Feel also protects against discomfort during intimacy and is non-irritating.
Is WD-40 considered a silicone lubricant? ›Yes, WD-40 Specialist Silicone lubricates, resists water and protects metal and non-metal surfaces with a clear, non-staining formula that doesn't make a mess.
Is KY jelly safe for silicone? ›KY Jelly is safe to use with latex and polyisoprene condoms, diaphragms and silicone sex toys.
What is the formula of silicone? ›The general formula of silicone is (R2SiO)x, where R belongs to any one of the organic groups. Poly-dimethylsiloxane is the most silicone compound can which illustrates the primary characteristics of the organic class. The first substance is metallic silicon, obtained from silica sand.
What are the four types of grease? ›- Calcium-Based Grease.
- Lithium-Based Grease.
- Bentone-Based Grease.
- Barium Complex Grease.
White lithium grease demonstrates excellent adhesion to metal and is perfect for lubricating metal on metal surfaces.
How long does silicone grease last? ›Last but not least, its excellent shelf life allows it to retain its reliable functional properties for up to 12 months before application and maintain its protective properties for several years, once installed.
What lube do gynecologists use? ›Surgilube® Sterile Surgical Lubricant is a water-based, carbomer-free lubricant that has been trusted by medical practitioners around the world since 1932. Surgilube® adheres to instruments well and is available in a range of sizes including single-use packets and multi-use tubes.
Why is silicone lube the best? ›Silicone lube is the longest lasting of all sexual lubricants. It won't evaporate, so it retains its glide-ability over a longer period of time. This means that you can use less product and have longer sex without interruptions. Like water-based, silicone lube is also condom safe.
Is KY jelly water or silicone based? ›
Added lubrication for increased intimate comfort. K-Y Jelly Personal Lubricant has a water-based, fragrance-free, non-greasy formula that quickly prepares you for sexual intimacy and eases the discomfort of personal dryness for women during sex.
What is plumbers grease made of? ›A: This plumber's grease is waterproof and is comprised of silicone oil (polydimethylsiloxane) in combination with silicone grease. It's a dielectric grease in nature, but is relatively thicker than regular grease. ... It's commonly used by plumbers when installing O-rings and faucets. Helpful?
Is silicone a Teflon? ›Silicone wire is similar to Teflon in the context of temperature and voltage ratings, but is unique in plenty of other ways. Silicone is one of the most flexible cables that can perform within harsh high-temperature applications.
Is silicone a petroleum byproduct? ›How Silicone is Made. Unlike most plastics, which are most often made through the synthetic processing of fossil fuels, silicone is made with the raw material silica.
Does grease contain petroleum? ›Greases of mineral or synthetic origin consist of a thickening agent dispersed in a liquid lubricant such as petroleum oil or a synthetic fluid. The thickening agent may be soap, an inorganic gel, or an organic substance.
What is petroleum based grease? ›Petroleum-derived lubricating oil is a mixture produced by atmospheric and vacuum distillation of selected paraffinic and naphthenic crude oils, after which chemical changes may be required to produce the desired properties of the refined product.
What is the chemical composition of silicone? ›Chemical Structure of silicone
The basic structure of silicone is made up of polyorganosiloxanes, where silicon atoms are linked to oxygen to create the «siloxane» bond. The remaining valences of silicon are linked to organic groups, mainly methyl groups (CH3): Phenyl, vinyl or hydrogen.
Silicone rubber (SIR) is an elastomer composed of silicone containing silicon, carbon, hydrogen, and oxygen, in the form of a polymer. Untreated silicone in gel or liquid form will convert to solid after curing. The curing method can be either vulcanized or catalyzed.
Is silicone a carcinogen? ›Silicone for Storage & Cooking
Studies have shown siloxanes leaching from silicone nipples in baby bottles and bakeware, and that siloxanes can impair fertility, and are potentially carcinogenic and endocrine disruptors.
Grease generally consists of a soap emulsified with mineral or vegetable oil.
What chemicals are in grease? ›
“Grease” is basically oil that contains a thickening agent to increase its viscosity. The thickening agent may be a soap or it can be a solid with a high surface area. Fatty-acid soaps of lithium, calcium, sodium, aluminum, and barium are commonly used in concentrations of 8%–25%.
Is Vaseline a petroleum grease? ›Vaseline has been used for more than 140 years as a healing balm and ointment for wounds, burns, and chafed skin. Petroleum is the main ingredient of Vaseline. You may be more familiar with other petroleum byproducts, such as kerosene and gasoline.
What are the three types of lubricating greases? ›There are mainly three different types of lubrication commonly available in the market: boundary, mixed and full film. Each type has a different application and they rely on a secondary lubricant or in some cases the additives within the oils to protect against wear and tear.
What grease does the military use? ›What gun grease does the military use? MIL-COMM TW25B® Extreme Performance Gun Grease for all firearms (pistols, rifles, AR's, shotguns and heavy weaponry) All branches of the U.S. military – including U.S. Special Forces – use MIL-COMM TW25B® synthetic grease, along with major armaments manufacturers.