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Compared to other synthetic rubbers, fluoro rubber has outstanding heat resistance, oil resistance, and chemical resistance.
This is due to the extremely strong C-F bond (fluorine bond) in the copolymerization composition.
The C-H bonds found in many other synthetic rubbers are inferior in bonding strength and cannot achieve this performance.
This C-F bond is what gives fluoroelastomers their outstanding heat resistance, oil resistance, and chemical resistance.
In 1914, World War I broke out, which made it difficult to obtain natural rubber.
As a result, the development and industrialization of synthetic rubber began.
This wave led to the development and industrial commercialization of synthetic rubber one after another from the 1930s to the 1950s, and the development of the fluorine rubber brand Viton began.
The fluoro-rubber brand "Viton" was developed.
The world's first trademark was "Viton," and FKM imported to Japan became popular under the name of "Viton.
The name "Viton" became widely used.
This may be the reason why some people still recognize all FKMs as "Viton.
Is this the same phenomenon as calling portable music players "Walkmans"?
The boots worn by the astronauts aboard Apollo 11, launched in 1969, were famously made of 3M fluorocarbon rubber.
This may be where the image of rubber used in the harshest environment on earth began.
F" stands for "Fluoro. It means fluorinated.
K" stands for Kautschuk. It means Rubber in German.
M is M Group. It means rubber with a saturated main chain of polymethylene type.
Here we introduce the composition structure, characteristics and properties of each type.
Binary type fluoroelastomer VDF - HFP copolymer
(VDF: Vinylidene fluoride, HFP: Propylene hexafluoride)
Ternary fluoroelastomer VDF - HFP - TFE copolymer
(VDF: Vinylidene fluoride, HFP: Propylene 6-fluoride, TFE: Tetrafluoroethylene)
Low temperature type fluoroelastomer VDF - PMVE - TFE copolymer
(VDF: Vinylidene fluoride, PMVE: Perfluoromethyl vinyl ether, TFE: Tetrafluoroethylene)
Binary system: (Typical example) VDF - HFP system
Standard type with excellent heat resistance and oil resistance.
It also offers good cost performance with a good balance of low-temperature resistance and chemical resistance.
This type of FKM accounts for nearly 80% of the market and is the mainstay product of each polymer manufacturer.
In addition, VDF-CTFE type with excellent acid resistance is also available.
Ternary system: (Typical example) VDF - HFP - TFE
TTFE is increased by reducing the amount of VDF.
It is positioned as upwardly compatible with VDF-HFP and has excellent mechanical and chemical properties.
It also has excellent chemical resistance due to its high fluorine content. However, it has inferior low-temperature properties.
There are alternatives to the VDF-PMVE-TFE series, which have superior low-temperature properties that eliminate this drawback.
Fluorine content in general FKM grades is set at around 65-71%.
The performance differences resulting from this difference in content are as follows.
Typical monomers that compose fluoroelastomers are VDF/HEP/TFE, but
Each of these monomers has its own characteristics.
Low temperature characteristics↑
Oil and base resistant properties↓
HFP 76 126Heat and oil resistant properties↑
Low-temperature characteristics↓
TFE 76 165Heat and oil resistant properties↑
Low-temperature characteristics↓
By changing the combination ratio of these monomers in detail, grades with different characteristics are produced.
In addition, there are also types with a reduced fluorine content and a third component.
This type sacrifices some of the characteristics of fluoroelastomers, such as heat resistance, oil resistance, and chemical resistance.
This type sacrifices some of the characteristics of fluoroelastomers, such as heat resistance, oil resistance, and chemical resistance, but has other unique properties.
There are three major types of vulcanization systems for fluoroelastomers.
This was the first vulcanization system developed and has excellent strength, elongation characteristics, and metal bonding properties.
However, due to its high reactivity, it is prone to scorch due to the effects of gradual vulcanization even in storage conditions.
Compression set is also poor.
It also has the disadvantage of a short shelf life, and its use has been decreasing in recent years.
The vulcanizing agent uses diamine as a catalyst to form a double bond containing a diamine compound through a defluoridation reaction.
A catcher agent (acid-receptive agent) must be added to neutralize the hydrofluoric acid generated by this reaction.
This vulcanization system is synonymous with fluoroelastomers and is characterized by its good overall balance.
It has good scorch and compression set properties and low mold contamination, which are drawbacks of polyamine vulcanization.
Polyol vulcanization can be strictly classified into two types due to the difference in vulcanization accelerators.
One type uses quaternary phosphonium salts (BTPPC), which provide good scorch stability and sealing properties.
This type has high cross-linking efficiency and most of the cross-linking can be completed with only primary vulcanization.
This type is superior in production efficiency and processability such as burr treatment after molding.
The other type uses quaternary ammonium salt (DBU-B), which is superior to the BTPPC type in terms of vulcanization stability and adhesiveness.
Also known as organic peroxide vulcanization, this vulcanization system is used not only for fluoroelastomers but also for other general-purpose rubbers.
Unlike polyamine vulcanization and polyol vulcanization, which form double bonds from the defluoridation reaction, peroxide vulcanization
radicals generated from a radical-reactive cure-site monomer (CSM) or polyfunctional unsaturated compound and an organic peroxide.
The cross-linking bonds are formed by the reaction of radicals generated by organic peroxides with radical-reactive cure-site monomers (CSMs) and polyfunctional unsaturated compounds.
Organic peroxides alone do not have enough cross-linking capacity for the molecular weight of fluoroelastomer.
This is compensated for with cure-site monomers and polyfunctional unsaturated compounds, which is the difference from other general-purpose rubbers.
Bromine was initially used as the cure-site monomer, but due to reactivity problems, iodine is now used.
Iodine is now used due to reactivity issues. The vulcanization system is characterized by excellent strength, elongation, chemical resistance, and steam resistance.
It compensates for the disadvantages of the dehydrofluoric acid reaction (reduced water resistance and acid resistance).
Pre-compound refers to the state in which the various compounding materials are kneaded together.
The finished state in which all other compounding agents are added is called "full compound".
As a supplement, the compound to which no compounding agents have been added is called "raw rubber" or "raw polymer.
Hoses connecting fuel tanks to gasoline tanks have a low-permeation structure to accommodate the evaporative properties of gasoline.
Fluoroelastomers have extremely low gas permeability and are indispensable for fuel hoses.
This hose is used for turbochargers.
Turbocharger hoses are used in turbochargers because of the heat generated by the intake compression of the turbocharger (adiabatic compression) and the vibration caused by the passage of high-temperature air.
Turbocharger hoses must have heat resistance, pressure resistance, and elasticity to withstand vibration.
Oil seals are indispensable sealing materials for machinery. Oil seals come in a variety of shapes depending on the part to be sealed and the structure, and the base material varies depending on the environmental conditions in which they are used.
It is said that as many as 40 to 50 oil seals are used in automobiles.
This is also a type of sealing material, but it is a sealing material for fixed parts that do not slide.
Conversely, O-rings and gaskets are used to seal sliding and rotating parts.
Diaphragms are elastic thin films that expand and contract in response to pressure, and are made by coating both sides of a base fabric with oil- and heat-resistant rubber to maintain airtightness and oil-tightness while requiring flexibility.
The part of the engine cylinder that converts the explosion into rotational motion is called the crankshaft, and the part that serves as the shaft is called the crankshaft.
The crankshaft is the shaft of the crankshaft.
The crankshaft seal seals the oil in this part and is required to have sliding performance with the shaft.
The O2 sensor is a component that measures the amount of oxygen in the exhaust gas of a car.
It is an important product that adjusts and controls the fuel injection amount by measuring the amount of oxygen in the exhaust gas and determining whether there is too much or too little oxygen relative to the amount of fuel injected.
There are various parts and devices in semiconductor manufacturing equipment such as vacuum pumps and wet process equipment. Vacuum pumps require low outgassing and
Wet process and dry process equipment require resistance to various chemicals. Fluoroelastomers are used as the most suitable material for such needs.
In addition to the above applications, fluororubber sponges are often used in semiconductor equipment for gasket packing of equipment parts.
Click here for more information on fluororubber sponge.
In these days of ecology, fluorine rubber sponge is used as a sealing material for eco-cute systems, automobile fuel cells, and hydrogen tanks.
These devices are often used to seal hot water and chlorine water. These devices use hot or chlorinated water, so they need to be resistant to such water.
Used as sealing material for various chemical components.
However, there are some solvents that are not compatible with these materials, so care must be taken.
Deep-sea and underground operations require strict specifications in terms of pressure and heat resistance.
Fluoroelastomers are also used as sealing materials in this field.
Fluoroelastomers with low outgassing properties are used in hard disk drives, etc., in consideration of the risk of internal contamination.
Fluoroelastomers are the best solution for the use of highly corrosive fuels.
Fluoroelastomers are used for oil-resistant seals and gaskets required for various machine parts and equipment, large and small.
Disinfection and sterilization are important management items for many parts and devices that come into contact with the human body.
Generally, dia (sodium hypochlorite) is widely used.
Fluoroelastomers have excellent resistance to dia and steam.
Fluoroelastomers are used as sealing materials for toilets, drainpipes, and other water-related areas.
The same properties are required for disinfection and sterilization as in the food and medical industries.
Fluoroelastomers are gradually being used in fields where they have not been widely used in the past.
Fluoroelastomer's unique sense of weight and mass, as well as its moist and fine surface texture, give it a luxurious feel.
Combined with its high resistance to fragrance, fluorine rubber has been used in recent years for high-end wristwatch belts.
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