Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F10/00—Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond

Definitions

• Supported catalysts obtainable in this way are known to be used in the context of processes for producing homopolymers of ethylene or copolymers of Ethylene with up to 15 mol.% Based on the ethylene C 3 - to C 8 - ⁇ -monoplefins by polymerizing the monomer (s) at temperatures of 100 to 200 ° C in a saturated hydrocarbon liquid under the process conditions in both the monomer or monomers and the polymer formed dissolve.
• a certain intermediate catalyst product serves as the starting material for use in the new process.
• This preliminary product has no special features; it can be one which is customary in the polymerization of olefins by means of supported chromium oxide catalysts.
• the preliminary product is based on a carrier which has a particle size of 0.02 to 3, in particular 0.04 to 1.5 mm.
• the carrier consists of silicon dioxide or is a silicon dioxide which is chemically or physically connected to a component made from the elements aluminum, titanium, zirconium, molybdenum, vanadium or thor, which component is an oxide of the element concerned or a composition of the element concerned which changes into an oxide under the conditions of stage (1).
• this (calculated as oxide) can make up up to 20, in particular up to 15 percent by weight, based on the total weight of the carrier.
• Silicon dioxide / aluminum oxide mixed oxides which contain 0.1 to 15 percent by weight, based on the total weight of the carrier, of aluminum oxide are particularly suitable as a carrier.
• the catalyst precursor ie that with a chromium compound, which chromium trioxide or a chromium compound which changes into chromium trioxide under the conditions of step (1) is, - in a manner known per se - loaded carrier, is treated in a first stage (1) in a certain manner defined above with oxygen. It is of particular importance that the solid is left in the form of a fluidized bed; - Where you can use such devices and procedures, as are common in fluidized bed processes. As has been shown, air is the preferred carrier gas. As has also been shown, the period of whirling - apart from the minimum period of 30 minutes - is not critical, but should generally be 2 to 15 hours for reasons of convenience.
• the oxygen treatment in stage (1) is combined with a treatment by a promoter.
• the promoters can be the relevant customary ones, such as, in particular, ammonium silicofluoride (NH 4 ) 2 SiF 6 , and can be added to the catalyst precursor before or during the vortexing.
• stage (2) the product obtained from stage (1), which is preferably flushed free of oxygen, is treated with carbon monoxide in a certain manner defined above and is thus converted into the actual supported chromium oxide catalyst. It is also special here It is important that the solid be left in the form of a fluidized bed and that the carrier gas is anhydrous and oxygen-free.
• Polymers of ethylene are produced using the new catalysts by means of the so-called “solution polymerization process”, cyclohexane in particular being considered as a solvent.
• solution polymerization process cyclohexane in particular being considered as a solvent.
• the polymerization process as such has no special features and can be carried out in the relevant conventional technological configurations.
• a catalyst precursor consists of a homogeneously loaded silicon dioxide / aluminum oxide mixed oxide containing chromium trioxide in a weight ratio of carrier: chromium trioxide of 100: 4.4, which contains 0.4% by weight, based on the total weight of the mixed oxide, of aluminum oxide and one Has particle size of 0.04 to 1.5 mm.
• This preliminary product is mixed with a promoter (ammonium silicofluoride) in the weight ratio catalytic sator precursor: 100: 2.5 promoter.
• a promoter ammonium silicofluoride
• the chromium oxide supported catalyst thus obtained is used for the polymerization as described below.
• a stirred autoclave is charged with 1000 parts by weight of cyclohexane, followed by flushing with nitrogen and adding 0.1 part by weight of catalyst.
• a thermostatically controlled temperature of 150 ° C. pure ethylene is pressed up to a pressure of 35 bar, the process is continued until the pressure has dropped to 25 bar due to the formation of polyethylene, and then ethylene is pressed again up to a pressure of 35 bar and so on for 90 minutes.
• the polymerization is then terminated by cooling to room temperature and relaxing.
• a catalyst precursor consists of a silica / alumina mixed oxide loaded homogeneously with chromium trioxide in a weight ratio of carrier: chromium trioxide of 100: 2.0, which contains 0.1 weight percent - based on the total weight of the misohoxide - and one Has particle size of 0.04 to 1.5 mm.
• This precursor is mixed with a promoter (ammonium silicofluoride) in a weight ratio of catalyst precursor: promoter of 100: 1.5.
• promoter ammonium silicofluoride
• Example 3 The procedure is as in Example 3, with the exception that the first stage 1 is carried out at a temperature of 570 ° C. (instead of 680 ° C.).
• Example 2 The procedure is as in Example 1, with the exceptions that a temperature of 146 ° C. (instead of 150 ° C.) is used and that instead of ethylene, a mixture of 98.5 parts by weight of ethylene and 1.5 parts by weight of butene-1 is polymerized .

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
• Catalysts (AREA)
• Polymerization Catalysts (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 1977
  • 1977-08-03 DE DE19772734928 patent/DE2734928A1/de active Pending
• 1978
  • 1978-07-21 IT IT7825981A patent/IT7825981A0/it unknown
  • 1978-07-28 EP EP78100537A patent/EP0000751A1/fr not_active Withdrawn
  • 1978-07-31 FI FI782361A patent/FI782361A/fi not_active Application Discontinuation
  • 1978-07-31 US US05/929,702 patent/US4180481A/en not_active Expired - Lifetime
  • 1978-08-02 JP JP9371078A patent/JPS5426985A/ja active Pending
  • 1978-08-02 NO NO782638A patent/NO782638L/no unknown
  • 1978-08-02 AT AT559478A patent/ATA559478A/de not_active Application Discontinuation
  • 1978-08-02 DK DK342178A patent/DK342178A/da unknown
  • 1978-08-03 ES ES472324A patent/ES472324A1/es not_active Expired

Patent Citations (5)

Non-Patent Citations (1)

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