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
  • C08F10/04—Monomers containing three or four carbon atoms
  • C08F10/08—Butenes
• • 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
  • C08F110/00—Homopolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
  • C08F110/04—Monomers containing three or four carbon atoms
  • C08F110/08—Butenes
  • C08F110/10—Isobutene

Definitions

• the present invention relates to a method for producing polybutene and, more particularly, to a method for producing high reactive polybutene (HRPB) in which carbon-carbon double bond is generally positioned at the end of the polybutene.
• HRPB high reactive polybutene
• Polybutene is generally produced by polymerizing C4 olefin including isobutene using Friedel-Craft type catalyst and has about 300 ⁇ 5000 of number average molecular weight Mn. Remains after extracting 1,3-butadiene from C4 olefin is C4 raffinate-1, and the C4 raffinate-1 comprises paraffin such as iso-butane and normal-butane and olefin such as 1-butene, 2-butene, and isobutene.
• the isobutene content is generally about 30 ⁇ 50 weight %.
• the C4 raffinate-1 is generally used for producing methyl-t-butylether (MTBE) which is used as an octane number improver, or polybutene.
• MTBE methyl-t-butylether
• polybutene is mainly composed of isobutene units since the isobutene has the highest reactivity among olefins in the C4 raffinate-1.
• Polybutene may also be produced from butane-butene oil (B-B oil) which is a C4 mixture derived from crude oil refining process, or can be produced from high purity isobutene.
• polybutene increases as its molecular weight increases and the viscosity is about 4 ⁇ 40000 cSt(centi-stocks) at 100° C.
• polybutene is pyrolyzed at a temperature of more than 275° C. without leaving residue, and has high solubility in lubricant or fuel because of its branched alkyl structure.
• polybutene is used as an anti-scuff agent or a viscosity index improver in engine oil, or used as detergent by being mixed with fuel of internal-combustion engine such as a vehicle.
• polyisobutenyl succinic anhydride manufactured by reacting polybutene with maleic anhydride.
• PIBSA polyisobutenyl succinic anhydride
• Most of lubricant additive or fuel detergent is manufactured with PIBSA as intermediate.
• high yield of PIBSA is obtained, however, when the double bond is positioned further towards the interior of the polybutene and the number of alkyl group substituted to the double bond increases, reactivity of polybutene is lowered, which decreases the PIBSA yield.
• European Patent No. 400,905 A1 there is disclosed that when boron trifluoride which forms complex with ethanol is used, the contact time can be extended to more than 1 minutes, possibly 8 ⁇ 70 minutes, and more preferably 12 ⁇ 20 minutes almost without isomerization of double bond in a product, and therefore, reaction variables can effectively controlled.
• the invention of this patent is regarded as an advanced one because the product can maintain the content of vinylidene of more than 70% while maintaining the contact time of more than 8 minutes.
• the most desirable result is obtained when ether having both the secondary alkyl and the tertiary alkyl (for example, isopropyl t-butylether) is used.
• ether having both the secondary alkyl and the tertiary alkyl for example, isopropyl t-butylether
• the above-mentioned ether compound is a material not commercialized, so, to use the material as co-catalyst (initiator), an additional equipment to produce the compound is required. For this reason, the above-mentioned method is supposed not to be commercially generalized.
• the present invention provides a method of producing polybutene having 300 ⁇ 5000 of number average molecular weight (Mn) from (a) isobutene, (b) C4 hydrocarbon compounds derived from cracking of naphtha, and containing more than 10 weight % of isobutene, or (c) C4 hydrocarbon compounds derived from a refining process of crude oil or from catalytic cracking of heavy gas oil, and containing more than 10 weight % of isobutene, with using catalyst comprising secondary alkylether, tertiary alcohol, and boron trifluoride.
• Mn number average molecular weight
• the amount of boron trifluoride catalyst is 0.05 ⁇ 1.0 weight part per 100 weight part of isobutene in hydrocarbon compounds
• the mole ratio of co-catalyst formed of secondary alkylether and tertiary alcohol:boron trifluoride is 1.0 ⁇ 2.0:1 and more preferably, the mole ratio of secondary alkylether:tertiary alcohol is 0.5 ⁇ 1.2:1.
• the present invention is characterized in that catalyst formed of secondary alkylether, tertiary alcohol, and boron trifluoride is used to produce polybutene in which the content of terminal double bond to entire double bond is more than 80%.
• tertiary alcohol is not used as co-catalyst. That is because the content of vinylidene is lowered when tertiary alcohol is used compared with cases when secondary or primary alcohol is used.
• the inventors of the present invention discovered a fact that when tertiary alcohol is used with secondary alkylether, the content of terminal double bond of polybutene increases and is not influenced much by the contact time.
• Secondary alkylether used for the present invention is symmetrical or asymmetrical secondary alkyl ether having alkyl group of carbon number of 3 ⁇ 20, preferably, selected from the group consisting of diisopropylether, di(sec-butyl)ether, di(sec-hexyl)ether, di(sec-octyl)ether and mixtures thereof, and more preferably diisopropylether.
• polybutene which has high content of vinylidene and is not influenced much by contact time in polymerization reaction can be produced by using catalyst obtained as follows: boron trifluoride is added to diisopropylether to form solid complex and then, tertiary alcohol, such as t-butylalcohol (TBA), is added to the solid complex to form liquid catalyst.
• boron trifluoride is added to diisopropylether to form solid complex and then, tertiary alcohol, such as t-butylalcohol (TBA), is added to the solid complex to form liquid catalyst.
• TSA t-butylalcohol
• Tertiary alcohol used for the present invention is tertiary alcohol having carbon number of 4 ⁇ 20, preferably, selected from the group consisting of t-butylalcohol, diacetonalcohol (4-hydroxy-4-methyl-2-pentanone), 2-methyl-2-butanol and mixtures thereof, and more preferably, t-butylalcohol or 2-methyl-2-butanol.
• Diisopropylether as secondary alkylether and t-butylalcohol as tertiary alcohol is easy to purchase, therefore additional equipment for producing diisopropylether or t-butylalcohol is not required.
• tertiary alcohol for example, t-butylalcohol is added to dissolve the solid material, so that the dissolved material is used as catalyst.
• boron trifluoride it is preferable to add boron trifluoride to mixture of secondary alkylether and tertiary alcohol. It is experimentally verified that the properties of catalyst are not influenced in this case.
• the reaction for forming complex of boron trifluoride and co-catalyst is exothermic reaction, it is preferable to remove heat of reaction for preventing the decomposition of catalyst and run-away reaction. Accordingly, it is preferable that the catalyst manufacturing reaction is performed at a temperature of lower than 40° C., preferably lower than 20° C., and more preferably ⁇ 4° C. ⁇ 0° C. at which the stability of catalyst can maintain because the heat of reaction is satisfactorily removed.
• the amount of catalyst component, BF 3 is preferably 0.05 ⁇ 1.0 weight part per 100 weight part of isobutene in raw material (hydrocarbon compounds), and polybutene produced according to the present invention generally has 300 ⁇ 5000 of number average molecular weight (Mn).
• Mn number average molecular weight
• the mole ratio of secondary alkylether/tertiary alcohol used for the present invention is 0.5 ⁇ 1.2. It is more preferable that the amount of tertiary alcohol does not exceed the amount of secondary alkylether, that is, the more preferable mole ratio of secondary alkylether/tertiary alcohol is 1.0 ⁇ 1.2. If the amount of tertiary alcohol increases, the amount of boron trifluoride should increase to maintain activity of catalyst. In this case, there is possibility that catalyst is degraded.
• the mole ratio of co-catalyst formed of secondary alkylether and tertiary alcohol to boron trifluoride is preferably 1.0 ⁇ 2.0:1, and more preferably 1.2 ⁇ 1.8:1 in an aspect of catalyst activity.
• the mole ratio of co-catalyst/boron trifluoride is over 2.0, the activity of catalyst is lowered to remarkably reduce the yield of polybutene, and when the mole ratio thereof is less than 1.0, the content of vinylidene is considerably lowered.
• polar solvent may additionally be used to disperse the catalyst in the raw material.
• polar solvent more than one compound selected from the group consisting of chloromethane, dichloromethane, and chloroform can be used, and it is preferable to use more than 50 weight part of the polar solvent per 100 weight part of the catalyst and co-catalyst.
• the catalyst can be added to the polymerization reaction in various ways.
• the catalyst of the present invention can be separately formed, and then the obtained liquid catalyst can be added into a polymerization reactor.
• the raw material (hydrocarbon) of polybutene, co-catalyst, and catalyst can be put into the reactor at the same time through separately formed supply lines.
• the co-catalyst and the raw material of polybutene are mixed, and the mixed material is put into the reactor, and then gaseous boron trifluoride catalyst is supplied into the reactor through another supply line.
• the amount of catalyst, the mole ratio of catalyst and co-catalyst and the mole ratio of co-catalysts should be maintained as described above.
• Examples of raw material for producing polybutene of the present invention includes (a) isobutene, (b) C4 hydrocarbon compounds (for example C4 raffinate) derived from cracking of naphtha, and containing more than 10 weight % of isobutene, and (c) C4 hydrocarbon compounds (for example, B—B oil) derived from a refining process of crude oil or from catalytic cracking of heavy gas oil, and containing more than 10 weight % of isobutene.
• C4 hydrocarbon compounds for example C4 raffinate
• C4 hydrocarbon compounds for example, B—B oil
• B—B oil or C4 raffinate comprises normal butene such as 1-butene and 2-butene as well as isobutene and is outstandingly low in price in comparison with that of pure isobutene, the same is generally used as raw material for producing polybutene.
• This normal butene has low reactivity in comparison with that of isobutene, but has ordinary reactivity, so a part thereof is converted into resin.
• the reaction temperature increases, the more normal butene participates in the polymerization reaction. Then the viscosity of polybutene becomes high, and thermal stability thereof is lowered in comparison with that of polybutene not including normal butene.
• the preferable temperature is ⁇ 50° C. ⁇ 20° C., more preferably ⁇ 40° C. ⁇ 10° C., and most preferably, ⁇ 30° C. ⁇ 0° C.
• the reaction temperature is more than 20° C.
• the participation ratio of normal butene increases though the conversion ratio is maintained low.
• the reaction temperature is less than ⁇ 50° C., the reactivity is excessively lowered, which results in lower productivity and the excessively high molecular weight. In this case, it is difficult to use polybutene as fuel detergent or lubricant additive.
• the reaction pressure should be set for the raw material to be maintained in a liquid state at the reaction temperature, and the preferable reaction pressure is more than 3 kg/cm 2 .
• the contact time meaning the time for which the raw material is in the polymerization condition in a continuous polymerization reaction, is closely related with the conversion ratio.
• the contact time should be set in consideration of an aspect of economical use of raw material and the participation ratio of normal butene.
• the preferable conversion ratio of isobutene is more than 50%, more preferably 70 ⁇ 99%, and most preferably 80 ⁇ 95%.
• the contact time required to obtain such a conversion ratio is approximately 5 ⁇ 180 minutes though the contact time can be varied according to the reaction temperature and the amount of catalyst.
• the reaction temperature is lowered, the reaction speed is slow; accordingly, it is required to extend the contact time to obtain the desired conversion ratio.
• Catalyst which was produced in example 2, and in which free BF 3 was removed, was used, and the raw material including 65weight % of isobutene and 35 weight % of isobutane was used.
• the polymerization was performed at ⁇ 12° C. of reaction temperature and for 45 minutes of contact time. After-treatment was performed in the same way as described in example 1, and properties of resin was analyzed. As a result, the molecular weight (Mn) was 1850, the polydispersity(Pd) was 1.85, the content of vinylidene was 93%, and the conversion ratio of isobutene was 82%.
• Catalyst was produced according to the method in example 1 except that 20 g of dichloromethane and 1.1 g (15 mmol) of t-butylalcohol were used instead of 5.4 g of t-butylalcohol. Polymerization was performed in the same way as that of example 1 with using the above-mentioned catalyst. As a result, the conversion ratio of isobutene was 99%, the molecular weight (Mn) was 1040, the polydispersity(Pd) was 1.50, and the content of vinylidene was 84%.
• Catalyst was produced according to the method in example 1 except that 20 g of dichloromethane was used instead of 5.4 g of t-butylalcohol. Polymerization was performed in the same way as that of example 1 with using the above-mentioned catalyst. As a result, the conversion ratio of isobutene was 99%, the molecular weight (Mn) was 1050, the polydispersity(Pd) was 1.55, and the content of vinylidene was 81%.
• Catalyst was produced by adding 16.0 g (236 mmol) of boron trifluoride to 22.32 g (370 mmol) of isopropylalcohol (IPA) at ⁇ 5° C., and then nitrogen was passed through the catalyst for 5 minutes.
• the raw material of table 1 was used, and the continuous polymerization was performed with using 0.1 weight % of catalyst at ⁇ 8° C. for 15 minutes of contact time to obtain polybutene.
• the conversion ratio of isobutene was 86%
• the molecular weight (Mn) of the obtained resin was 1450
• the distribution degree was 1.75
• the content of vinylidene was 81%.
• Catalyst was obtained by cooling 17.82 g (202 mmol) of methyl-t-butylether, adding 9.79 g (144 mmol) of boron trifluoride at ⁇ 5° C., and passing nitrogen through the catalyst for 5 minutes.
• the continuous polymerization was performed in condition of ⁇ 8° C. of reaction temperature, 15 minutes of contact time, and 0.2 weight % of catalyst to obtain polybutene.
• the conversion ratio of isobutene was 84%
• the molecular weight (Mn) of the obtained resin was 1300
• the polydispersity was 1.82
• the content of vinylidene was 83%.
• Polybutene was produced in the same way as that of comparative example 3 except not performing the step of passing nitrogen to remove free BF 3 after producing catalyst.
• the conversion ratio of isobutene was 86%
• the molecular weight (Mn) of the obtained resin was 1250
• the polydispersity was 1.92
• the content of vinylidene was 77%.
• Catalyst used in the present invention has advantages in that the catalyst is easy to commercially obtain, and the after-treatment process is not required.
• the catalyst according to the present invention makes it possible to produce polybutene having at least same or considerably high content of vinylidene in comparison with that of the conventional catalyst.
• polybutene having high content of vinylidene can be produced by using catalyst formed of secondary alkylether, tertiary alcohol, and boron trifluoride. Further, the catalyst of the present invention is not influenced much by the contact time, and easy to commercially obtain. In addition, the properties of the produced polybutene do not change much even though free BF 3 is not removed from the catalyst.

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• 2000
  • 2000-11-13 KR KR10-2000-0067057A patent/KR100486044B1/ko active IP Right Grant
• 2001
  • 2001-11-09 AU AU2002224154A patent/AU2002224154A1/en not_active Abandoned
  • 2001-11-09 WO PCT/KR2001/001901 patent/WO2002038630A1/en not_active Application Discontinuation
  • 2001-11-09 US US10/169,547 patent/US20030088135A1/en not_active Abandoned
  • 2001-11-09 CN CNB018036015A patent/CN1157420C/zh not_active Expired - Lifetime
• 2006
  • 2006-03-28 US US11/390,880 patent/US7411104B2/en not_active Expired - Lifetime

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