Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
  • C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
  • C08G65/32—Polymers modified by chemical after-treatment
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
  • C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
  • C08G65/32—Polymers modified by chemical after-treatment
  • C08G65/321—Polymers modified by chemical after-treatment with inorganic compounds
  • C08G65/322—Polymers modified by chemical after-treatment with inorganic compounds containing hydrogen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
  • C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
  • C08G65/04—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers only
  • C08G65/06—Cyclic ethers having no atoms other than carbon and hydrogen outside the ring
  • C08G65/16—Cyclic ethers having four or more ring atoms
  • C08G65/20—Tetrahydrofuran

Definitions

• the present invention relates to a process for the preparation of polytetrahydrofuran, tetrahydrofuran copolymers, diesters or monoesters of these polymers with a low color number by hydrogenation of the polymers obtained by cationic polymerization of tetrahydrofuran in the presence of a macroporous heterogeneous catalyst.
• PTHF Polytetrahydrofuran
• polyoxybutylene glycol is a versatile intermediate in the plastic and synthetic fiber industry and is used, among other things, for the production of polyurethane, polyester and polyamide elastomers.
• PTHF polytetrahydrofuran
• it is a valuable auxiliary in many applications, for example as a dispersing agent or when decolorizing ("deinking") waste paper.
• PTHF is technically advantageously produced by polymerizing tetrahydrofuran (THF) on suitable catalysts in the presence of reagents, the addition of which enables the chain length of the polymer chains to be controlled and the average molecular weight to be adjusted to the desired value (chain termination reagents or “telogens”) ).
• the control is done by selecting the type and amount of the telogen.
• telogens chain termination reagents
• additional functional groups can be introduced at one end or both ends of the polymer chain.
• the mono- or diesters of PTHF can be produced by using carboxylic acids or carboxylic anhydrides as telogens.
• telogens not only act as chain termination reagents, but are also incorporated into the growing polymer chain of the PTHF, i.e. they not only function as a telogen, but also as a comonomer and can therefore be called telogen or comonomer with equal justification.
• comonomers are telogens with two hydroxyl groups, such as the dialcohols.
• dialcohols are ethylene glycol, propylene glycol, butylene glycol, 1,4-butanediol, 2-butyn-1, 4-diol, 1, 6-hexanediol or low molecular weight PTHF.
• comonomers are 1,2-alkylene oxides, such as, for example, ethylene oxide or propylene oxide, 2-methyltetrahydrofuran or 3-methyltetrahydrofuran.
• 1,2-alkylene oxides such as, for example, ethylene oxide or propylene oxide, 2-methyltetrahydrofuran or 3-methyltetrahydrofuran.
• the use of such comonomers leads to the production of tetrahydrofuran copolymers.
• the PTHF can be chemically modified.
• acidic catalysts are suitable for the polymerization of THF on an industrial, economic scale, but they have the disadvantageous effect that polymers with yellow to brownish discolorations are obtained. The discoloration increases with the temperature during the polymerization.
• the purity of the PTHF also depends on the quality of the THF used. Numerous processes for the pretreatment of technical THF for the purpose of quality improvement have therefore been proposed. For example, DE-A-2 801 792 describes a process in which THF is treated with bleaching earth before the polymerization. Although polymers with an improved color number are obtained, this treatment method cannot always be applied reproducibly to every available technical quality of the THF.
• polytetramethylene ether glycol or glycol diester with a low color number is prepared by subjecting the polymers obtained by cationic polymerization of THF to a treatment with hydrogen in the presence of a hydrogenation catalyst. If you use a THF quality for the polymerization that is available on the market, you are forced to use hydrogenating decolorization at very high hydrogen pressures of e.g. 50 to 300 bar.
• PCT / WO 94/05719 discloses a process for the production of polytetrahydrofuran diesters, in which the polymerization of the THF on acid-activated kaolin, zeolites or amorphous aluminum silicates is carried out in the presence of 1 to 10% by weight of a hydrogenation catalyst and hydrogen.
• a process has now been found for the preparation of polytetrahydrofuran, tetrahydrofuran copolymers, diesters or monoesters of these polymers with a low color number, which is characterized in that the polymers obtained by cationic polymerization of tetrahydrofuran in the presence of a macroporous, supported heterogeneous catalyst which is known as Active metal at least one metal from VII.
• Active metal at least one metal from VII.
• X Subgroup of the Periodic Table of the Elements, are hydrogenated.
• the new process enables high-purity polytetrahydrofuran, high-purity tetrahydrofuran copolymers and high-purity diesters or monoesters of these polymers with a low color number to be produced reliably and reproducibly. Because of the high activity and service life of the macroporous catalysts used, the hydrogenation can be carried out with short residence times and under gentle conditions.
• the process according to the invention can be applied to all polymers which are obtained by cationic polymerization of tetrahydrofuran.
• Polytetrahydrofuran, tetrahydrofuran copolymers, diesters or monoesters of these polymers can be obtained by processes known per se, as described, for example, in DE 44 33 606 and DE 19649803.
• polymerization discharges of the cationic polymerization of tetrahydrofuran can be used directly for the process according to the invention, which contain, among other things, unreacted tetrahydrofuran, telogen and / or comonomer.
• prepurified polymers i.e. polymers from which, for example, unreacted tetrahydrofuran or low molecular weight polymerization products have been separated off by distillation or other suitable processes.
• the polymers are hydrogenated in the presence of a macroporous heterogeneous catalyst which contains at least one metal from subgroup VII to X of the periodic table of the elements, applied to a support, as the active metal.
• a macroporous heterogeneous catalyst which contains at least one metal from subgroup VII to X of the periodic table of the elements, applied to a support, as the active metal.
• the pri- The yellowish brown color of the polymers disappears and colorless products are formed.
• the macroporous heterogeneous catalyst can in principle contain all metals from subgroups VII to X of the periodic table of the elements as active metal. Palladium, ruthenium, rhenium, nickel, iron and cobalt or a mixture of two or more active metals are preferably used as active metals,
• macroporous is used in the context of the present invention as used in Pure Appl. Chem., 46., S 79 (1976), namely as pores whose diameter is above
• the content of macropores of the heterogeneous catalyst used according to the invention with a pore diameter of more than 100 nm, based on the total pores, ie the macroporosity of the heterogeneous catalyst is more than 10% by volume, preferably more than 20% by volume, particularly preferably 25 to 90
• the content of the active metal is generally 0.01 to 10% by weight, preferably 0.05 to 5% by weight and in particular 0.1 to 3% by weight, based on the total weight of the catalyst.
• the total surface area of the metal on the macropous supported catalyst used according to the invention is preferably 0.01 to 10 m 2 / g, more preferably approximately 0.05 to 5 m 2 / g, in particular approximately 0.05 to 3 m 2 / g of the catalyst ,
• the macroporous heterogeneous catalysts used according to the invention can be produced industrially by various processes known per se, for example by applying at least one metal from sub-groups VII to X. Subgroup of the Periodic Table of the Elements on a suitable macroporous support.
• the application can be carried out by impregnating the carrier with aqueous metal salt solutions, such as. aqueous palladium salt solutions, by spraying on corresponding metal salt solutions the carrier or by other suitable methods.
• aqueous metal salt solutions such as. aqueous palladium salt solutions
• Subgroups of the Periodic Table of the Elements are nitrates, nitrosyl nitrates, halides, carbonates, carboxylates, acetylacetonates, chloro complexes, nitro complexes or amine complexes of the corresponding metals, nitrates and nitrosyl nitrates being preferred.
• the metal salts or their solutions can be applied simultaneously or in succession.
• the supports coated or impregnated with metal salt solutions are then dried, preferably at temperatures between 100 ° C. and 150 ° C., and optionally calcined at temperatures between 200 ° C. and 600 ° C., preferably 350 ° C. to 450 ° C.
• the catalyst is dried after each impregnation step and optionally calcined, as described above. The order in which the active components are soaked is freely selectable.
• the coated and dried and optionally calcined supports are then activated by treatment in a gas stream which contains free hydrogen at temperatures from 30 ° C. to 600 ° C., preferably between 150 ° C. and 450 ° C.
• the gas stream preferably consists of 50 to 100% by volume of H 2 and 0 to 50% by volume of N 2 .
• the support materials which can be used to prepare the catalysts used according to the invention are those which are macroporous and have an average pore diameter of at least 50 nm, preferably at least 100 nm, in particular 500 nm, and whose surface area according to BET is at most approximately 300 m 2 / g, preferably about 15 m 2 / g, more preferably about 10 m 2 / g, in particular about 5 m 2 / g and more preferably at most 3 m 2 / g.
• the surface of the support is determined by the BET method by N 2 adsorption, in particular in accordance with DIN 66131.
• the pore diameter and pore distribution are determined by mercury porosimetry, in particular in accordance with DIN 66133.
• activated carbon silicon carbide, silicon oxide, mullite, cordierite, aluminum oxide, titanium oxide, zirconium oxide, magnesium oxide, zinc oxide or de- mixtures, more preferably aluminum oxide and zirconium dioxide and mullite, are used, particularly preferably aluminum oxide.
• the macroporous heterogeneous catalysts used according to the invention can be produced industrially by the process known from EP-A-653 243, in which active metal and macropores are introduced in one step.
• the macroporous heterogeneous catalysts used according to the invention are obtained by dissolving a water-soluble salt of a metal from VII. To X. Subgroup of the Periodic Table of the Elements in an organic solvent, adding the solution thus obtained with an organic polymer , which is able to bind at least ten times its own weight in water, then mixing the polymer with a catalyst support material and molding the resulting mass, drying and calcining.
• Suitable water-soluble salts of a metal from VII. To X. Subgroup of the Periodic Table of the Elements are preferably nitrates, nitosyl nitrates, halides, carbonates, carboxylates, acetyl acetonates, chloro complexes, nitro complexes or amine complexes of the corresponding metals, nitrates and nitrosyl nitrates being particularly preferred are.
• Preferred solvents are water-miscible solvents such as alcohols, ethers and amines.
• Alcohols in particular include Cl-C4 alcohols such as methanol, ethanol, isopropanol and n-butanol; tetrahydrofuran can be used as an ether.
• Suitable amines are, for example, ammonia, monoamines such as diethylamine, methylamine, triethylamine, ethylamine, propylamine and butylamine.
• Crosslinked polymers of acrylic acid, acrylic acid and acrylamide and of acrylamide are preferably used as the organic polymer, partially neutralized sodium polyacrylates which are weakly crosslinked being particularly preferred.
• Suitable chemical crosslinking agents are, for example, diols such as ethylene glycol, polyethylene glycol and polyols, diamines, dienes in amounts of 0.1 to 5% by weight, based on the polymer.
• Preferred carrier materials are activated carbon, silicon carbide, aluminum oxide, titanium oxide, mullite, cordierite, zirconium oxide, magnesium oxide, zinc oxide or mixtures thereof, more preferably aluminum oxide and zirconium dioxide and mullite, particularly preferably aluminum oxide.
• the macroporous catalysts used according to the invention can be produced industrially using pore formers by the process known from EP-A 842 699.
• All water-miscible polymers can be used as pore formers, provided that they have a molar mass of more than approximately 6,000 to 500,000 g / mol.
• Their molecular weight is preferably from about 10,000 to about 200,000 g / mol, more preferably from about 13,000 to about 150,000 g / mol, and in particular from about 13,000 to about 50,000 g / mol.
• useful polymers include polyvinyl chloride, copolymers of an olefin with polar comonomers, e.g.
• Meth (methyl) acrylate copolymers such as e.g. Methacrylonitrile-styrene copolymers, polyalkyl (meth) acrylates, cellulose acetate, cellulose aceate butyrate, polycarbonates, polysulfones, polyphenyl oxide, polyesters, such as e.g. Butylene terephthalate and polyvinyl alcohol, with polyvinyl alcohol being particularly preferred.
• X. Subgroup of the Periodic Table of the Elements is first produced in a known manner according to the method known from DE 2 159 736.
• a kneading compound is then produced from this alloy, a shaping agent, water and the pore former, this kneading compound is deformed into shaped bodies, the shaped body is calcined, and finally the calcined shaped body is treated with a alkali metal hydroxide.
• the macroporous catalysts used according to the invention are preferably produced by impregnating at least one metal from sub-groups VII to X. Subgroup of the Periodic Table of the Elements on a suitable macroporous support.
• the macroporous catalysts used according to the invention can additionally be doped with bases in order to avoid cleavage of the polymer during the hydrogenation, especially at high hydrogenation temperatures.
• bases are, for example, basic oxides such as alkali or alkaline earth metal oxides such as sodium oxides, potassium oxides, calcium oxides, barium oxides. Sodium oxides are particularly preferred.
• These oxides, or their precursors such as the respective hydroxides, carbonates or hydroxide carbonates, can be concentrated, for example, by impregnation in the supernatant solution, spray impregnation or during the build-up agglomeration of the carrier in concentrations of 0.05-5%, based on the weight of the Catalyst to which catalyst is applied. If appropriate, this is followed by tempering for the thermal decomposition of the precursors.
• the macroporous catalysts used according to the invention can be pre-reduced with hydrogen before they are used in the hydrogenation.
• the macroporous catalysts which can be used according to the invention can be in the form of powder, for example when carrying out the process in suspension mode, or expediently as shaped articles, e.g. in the form of strands, cylinders, balls, rings or grit, in particular in the case of a fixed bed arrangement of the catalyst, can be used in the process according to the invention.
• the hydrogenation according to the invention can be carried out batchwise or continuously, the continuous mode of operation being generally preferred for economic reasons.
• the hydrogenation can be carried out in conventional reactors or reactor arrangements suitable for continuous processes in suspension or fixed bed procedures, for example in loop reactors or stirred reactors in the suspension mode or in the fixed bed mode in tubular reactors or fixed bed reactors, the fixed bed mode being preferred.
• the hydrogenation according to the invention will move at hydrogen from 1 to 200 bar of hydrogen, preferably at 1 to 50 bar, particularly preferably at 5 to 25 bar, and temperatures from 20 to 200 ° C., preferably at 50 to 150 ° C., particularly preferably 70 up to 140 ° C.
• the residence time depends on the desired color number result and is usually a maximum of approximately 20 h, preferably 15 h, particularly preferably a maximum of approximately 10 h.
• the catalyst loading is usually 0.05 to 2.0 kg of polymer / (1 catalyst * h), preferably 0.1 to 1.0 kg of polymer / (1 catalyst * h), particularly preferably 0.1 to 0 , 5 kg polymer / (1 catalyst * h).
• the hydrogenation according to the invention can be carried out in the presence and absence of a solvent or diluent.
• a solvent or diluent can be used as the solvent or diluent, which forms a homogeneous solution with the polymer to be hydrogenated and is largely inert under the reaction conditions, for example ethers such as tetrahydrofuran, dioxane or aliphatic alcohols, in which the alkyl radical preferably has a length of 1 to 10 carbon atoms, such as Methanol, ethanol and propanol. Tetrahydrofuran and / or methanol is preferably used.
• the amount of solvent or diluent used is not particularly limited and can be freely selected as required, but preference is given to amounts which are 10 to 90% by weight, preferably 20 to 50% by weight. lead solution of the polymer intended for hydrogenation.
• Catalyst B contained 0.22% by weight of palladium and a macropore content of approximately 36%.
• aqueous palladium nitrate solution (11% by weight palladium) were diluted with 420 ml of water and onto 730 g of a macroporous aluminum carrier in spherical form (2-4 mm spheres, gamma Al 0, BET surface area 230 m 2 / g) sprayed on.
• the drying and tempering was carried out as described for catalyst A.
• Catalyst C contained 0.21% by weight of palladium and a macropore content of approximately 32%.
• aqueous palladium nitrate solution (11% by weight palladium) were diluted with 1000 ml of water and on 1042 g of a macroporous aluminum support in the form of a strand (1.5 mm strands, gamma / theta-Al0 3 , BET surface area 85 m 2 / g) sprayed on.
• the drying and tempering was carried out as described for catalyst A.
• the catalyst D contained 0.22% by weight of palladium and a macropore fraction of approximately 33%.
• 59.3 g of an aqueous palladium nitrate solution (12.6% by weight palladium) were diluted with 940 ml of water and on 2993 g of a macroporous aluminum support in the form of a strand (4 mm strands, alpha-Al 0 3 , BET surface area 6, 4 m 2 / g) sprayed on.
• the drying and tempering was carried out as described for catalyst A.
• Catalyst E contained 0.24% by weight of palladium and a macropore content of approximately 70%.
• 59.3 g of an aqueous palladium nitrate solution (12.6% by weight of palladium) were diluted with 1020 ml of water and onto 2993 g of a macroporous aluminum support in the form of a strand (4 mm strands, alpha- A1 2 0 3 , BET surface 8 , 9 m 2 / g) sprayed on. Drying was carried out as described for Catalyst A. Then 2 h annealed at 650 ° c. Catalyst F contained 0.24% by weight of palladium and a macropore fraction of approximately 49%.
• Silicon dioxide in strand form (4 mm, BET surface area 140 m 2 / g) was mixed with a supernatant solution of nickel, copper and manganese nitrate and phosphoric acid (9.2% by weight Ni, 3.2% by weight Cu, 0 , 8% by weight of Mn and 0.65% by weight of phosphoric acid) soaked twice for 15 minutes. After each impregnation, the strands were dried at 120 ° C and annealed at 630 ° C.
• the catalyst H contained 21% by weight of NiO, 7.3% by weight of CuO, 2% by weight of Mn 3 0 4 and 1.2% by weight of H 3 P0 4 and a macropore fraction of less than 10%.

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• 2000
  • 2000-08-16 DE DE10040091A patent/DE10040091A1/de not_active Withdrawn
• 2001
  • 2001-07-24 CN CN01814129A patent/CN1446241A/zh active Pending
  • 2001-07-24 US US10/343,982 patent/US6852869B2/en not_active Expired - Fee Related
  • 2001-07-24 EP EP01960543A patent/EP1311583A1/de not_active Withdrawn
  • 2001-07-24 KR KR10-2003-7002245A patent/KR20030031155A/ko not_active Application Discontinuation
  • 2001-07-24 JP JP2002519539A patent/JP2004506763A/ja not_active Withdrawn
  • 2001-07-24 WO PCT/EP2001/008525 patent/WO2002014405A1/de not_active Application Discontinuation
  • 2001-07-24 AU AU2001282013A patent/AU2001282013A1/en not_active Abandoned
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