Ding Ji rubber (IIR) is the world´s fourth largest synthetic rubber (SR) adhesive, is a product of cationic polymerization of isobutylene and isoprene in the presence of Friedel-Craft catalyst, the appearance is white or light yellow crystal, odorless, glass transition temperature is very low, not soluble in ethanol and acetone. The structural formula the viscosity average molecular weight of M= (35~45) * 104 (relative density of 17 DEG /4 DEG (0.92), 27 /4 OC 0.91), refractive index (n25D) of 1.5078~1.5081, the glass transition temperature -69, heat capacity 1.94Kj/ (kg K MJ/m3), cohesive energy density, thermal conductivity of 0.091W (M - K). 1016. Cm. The volume resistivity, dielectric constant (50Hz) 2.2~2.3. accounted for only 0.6%~3.0% backbone chain of isoprene, therefore the molecular Ding Ji rubber chain saturation is very high. Ding Ji rubber low permeability, good air tightness, heat aging resistance, vulcanized rubber Ding Ji using temperature can reach 150~200 degrees. With the absorption of vibration and impact energy Excellent electrical insulation properties, good resistance to ozone and weather resistance. The disadvantage of butyl rubber is low strength, low elasticity and poor adhesion.
One, performance
Butyl rubber product for gray white like rubber like solids, density 0.92g / cm3, tasteless, does not dissolve in water, can soluble in hexane, chloroform; products with low permeability, good air tightness, good ozone resistance, chemical corrosion resistance, electrical insulation, flexing resistance, also has the heat aging resistance and energy absorption characteristics.
Two, use
Butyl rubber is mainly applicable to the tire inner liner and inner tube, sulfurized capsules, medical bottle stopper, electrical insulation materials, sealing materials, cable head film industries. The iir1751 grades of butyl rubber is manufacturing radial tire inner tube and tubeless tyres and irreplaceable material.
Ding Ji rubber sealing tape
Ding Ji rubber sealing tape
Three, packaging
Butyl rubber products are bulk rubber, rubber block with high-pressure polyethylene film heat sealing into wooden boxes for storage and transport. Rubber block net weight for (25 + 0.2) kg. The net weight of each plastic box for 1050kg.
Four, storage
Ding Ji rubber should be kept in a well ventilated, clean, dry warehouse and is prohibited from open-air piling up and direct sunlight exposure.
Five, transport
Transportation in the sun, moisture, fire.
An overview of the production methods of butyl rubber in this section
At present, butyl rubber (IIR) with slurry method and solution method of two main production methods.
A slurry process.
The slurry method is based on the methyl chloride as diluent, with H20-A1C13 as initiator, at low temperature (-100 DEG C) to isobutene and small amounts of isoprene by cationic copolymerization of.IIR slurry production process mainly includes the preparation, polymerization, and recovery of rubber monomer and diluent postprocessing procedure in order to adapt. Process characteristics of slurry polymerization, polymerization reactor for tubular reactor. Around the center pipe lined with smaller diameter catheter, with axial flow agitator in the center of the bottom of the tube, the mixing material in high speed cycle, to enhance the mixing effect and to heat. Polymerizer material is 3.5% nickel or 9% stainless steel. With the production of different grades, monomer concentration and ratio of feed is different, although the feed monomer concentration of 30% (mass fraction, the same below), but because the circulation ratio, feeding near the mouth of the polymerizer In fact, the monomer concentration is about 5%-7%. of the production technology by Exxon company and Bayer company (now LANXESS) monopoly.
Two, solution method
The solution process is with alkyl aluminum chloride and water complex as the initiator in hydrocarbon solvents (such as isopentane) from -90 to -70 DEG C, and a small amount of isobutylene isoprene copolymer formed. The continuous running cycle of polymerization reactor for 10 days, the kettle glue in the dry rubber content below 12%. The advantages of the solution method can be used directly polymer glue halide IIR, avoid the dissolution process of slurry preparation of halogenated IIR required for solvent switching or sizing material. But the solution method of butyl rubber molecular weight distribution is wide, there are phenomena of branched molecular chains, and the performance of slurry products there is a certain gap. The technical cooperation with Italy by the Russian Synthetic Rubber Co toliatti Pressindustra company development, at present, the production of butyl rubber in the world only a Russian factory by solution method.
To edit the advantages and disadvantages of the performance of the butyl rubber
Butyl rubber, butyl rubber
Ding Ji rubber has excellent air tightness, tightness for all rubber head. At room temperature, the permeability coefficient of Ding Ji rubber for natural rubber, butadiene rubber 1/20, 1/45 1/8, styrene butadiene rubber, ethylene propylene rubber 1/13, nitrile rubber 1/2., in addition, the rubber has excellent heat resistance, weather resistance, ozone aging and resistance to chemicals corrosion properties. Through the formula design of special rubber, Ding Ji can be used at 150~170 deg.c for long time, heat resistance limit up to 200 DEG C; the rubber products of long-term exposure to sunlight and air, the performance change is very small, especially the anti ozone aging performance is better than rubber 10~20 times of natural rubber on Ding Ji; in addition to strong oxidation strong acid, alkali and redox resistance, has excellent solution in alcohol, ketones and esters in polar solvent, the swelling is very small.
Due to butyl rubber typical non polarity and water absorption of small (at room temperature, water absorption rate, other rubber 1/10-1/ 15) characteristics of, the electrical insulation and resistance to corona than the general synthetic rubber good, dielectric constant of only 2.1, and the resistivity is as high as above 1016 ohm x m, than the general high rubber 10-100 times.
Ding Ji is due to rubber molecular chain structure and cycle is long, so the low temperature is not easy to crystallization, so it has excellent cold resistance. The glass temperature of the rubber only higher than natural rubber, isoprene rubber, polybutadiene rubber and EPDM rubber, at -50 degrees Celsius temperature still has flexibility in its molecular chain there. With greater resistance, so under alternating stress, the amplitude attenuation, the absorption properties of shock or vibration, vibration and maintain good energy in the range -30~150 DEG C. Because Ding Ji rubber has crystallized under tension, so the rubber has higher tensile strength and elongation at break this. This means that people have not with black rubber high strength reinforcement, so it can be used for the manufacture of products of light color.
Two, the shortcomings of butyl rubber
Curing speed slow (need to ultra accelerator and by high temperature and long time for curing), poor processing (especially self-adhesive and mutual viscosity range, often need to with in adhesive or middle layer in order to ensure bonded to each other, and glue synergy is not high), room temperature elasticity is low, permanent deformation, hysteresis loss, dynamic heat build up higher and oil resistance is poor. In addition to EPDM rubber, butyl rubber and other rubber poor compatibility and difficulties.
Butyl rubber because of its prominent air tightness and heat resistance, so its largest application is manufacturing a pneumatic tire inner tubes and inner tube of tyre airtight layer (consumption accounted for the rubber consumption of 70% ". In addition, butyl rubber can also used to manufacture tires, wind tires, tape, rubber tube, wire and cable, coating adhesive, chemical container liner, heat, water seals, vibration isolation, anti vibration buffer and used in construction of the waterproof sheet etc..