WO2014106067A1 - Procédé pour améliorer l'alimentation par un comonomère d'acide carboxylique d'un réacteur à haute pression - Google Patents

Procédé pour améliorer l'alimentation par un comonomère d'acide carboxylique d'un réacteur à haute pression Download PDF

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Publication number
WO2014106067A1
WO2014106067A1 PCT/US2013/078020 US2013078020W WO2014106067A1 WO 2014106067 A1 WO2014106067 A1 WO 2014106067A1 US 2013078020 W US2013078020 W US 2013078020W WO 2014106067 A1 WO2014106067 A1 WO 2014106067A1
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WIPO (PCT)
Prior art keywords
compound
comonomer
pressure
mixture
ethylene
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PCT/US2013/078020
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English (en)
Inventor
Otto J. Berbee
Jeffery S. Bradley
Stefan Hinrichs
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Dow Global Technologies Llc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from PCT/US2013/032501 external-priority patent/WO2014105110A2/fr
Application filed by Dow Global Technologies Llc filed Critical Dow Global Technologies Llc
Priority to CN201380068054.5A priority Critical patent/CN104870481B/zh
Priority to KR1020157016827A priority patent/KR102182955B1/ko
Priority to EP13827061.6A priority patent/EP2938640B1/fr
Priority to US14/438,930 priority patent/US9416209B2/en
Priority to JP2015550805A priority patent/JP6563340B2/ja
Priority to EP18170183.0A priority patent/EP3372619B1/fr
Priority to ES13827061.6T priority patent/ES2674082T3/es
Priority to BR112015010925-0A priority patent/BR112015010925B1/pt
Publication of WO2014106067A1 publication Critical patent/WO2014106067A1/fr

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    • 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
    • C08F210/00—Copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
    • C08F210/02—Ethene

Definitions

  • This invention relates to a feeding mode of carboxylic comonomer using new
  • polymerization processes to make ethylene-based interpolymers, and to such interpolymers.
  • the polymerization process involves one or more compounds, such as polar chain transfer agents and/or secondary polar comonomers.
  • carboxylic acid comonomers There are several inherent problems associated to the use of carboxylic acid comonomers including the following: a) the acidity of the acid comonomer can cause corrosion problems, b) the high reactivity and self-polymerizability of the acid comonomers require them to be stored at low temperature conditions and preferably in the liquid state, c) carboxylic acids require stabilization with either nitroxyl containing inhibitors, like phenolthiazine, or mono-methyl-ether of hydroquinone (MEHQ) activated with oxygen, and the nitroxyl containing inhibitors can inhibit or retard polymerization, while the oxygen present in the MEHQ can act as an initiator when applied at elevated temperatures.
  • nitroxyl containing inhibitors like phenolthiazine, or mono-methyl-ether of hydroquinone (MEHQ) activated with oxygen
  • MEHQ mono-methyl-ether of hydroquinone
  • carboxylic acid monomers in pressure free radical polymerization, which is carried at pressures preferably above 1000 bar, more preferably above 1500 bar and most preferably above 2000 bar. At these elevated pressures, the melting point of carboxylic acid monomer is significantly increased.
  • the carboxylic acid has to be fed to the process in the liquid state, and is moved through the compression, the polymerization, and the separation sections, preferably in the gaseous phase (dissolved and diluted in gaseous or super critical ethylene), in order to avoid self polymerization of liquid or solid carboxylic acid monomer to carboxylic acid homopolymer.
  • the high pressure polymerization process makes use of reciprocating plunger compressors to pressurize the ethylene/carboxylic acid monomer feed and recycle streams. It is known that application of carboxylic acid monomer negatively affects the reliability of rotating and reciprocating equipment, due to its corrosion and self polymerization potential. The formation of carboxylic acid homopolymer in the sealing ring or bearing areas of the rotating and moving equipment items in compressors, plunger pumps, agitators etc, could hinder, or stop, lubrication, and could cause friction and extra heat formation, which could lead to equipment failure. Compressor reliability could be improved by decreasing the carboxylic acid monomer level in the ethylene stream(s) to be compressed through feeding all, or a part of, the make-up carboxylic acid monomer directly at high pressure to the reactor.
  • Feeding carboxylic acid monomer to a high pressure reactor requires a high pressure diaphragm or reciprocating plunger pump. These pumps have to be operated at higher temperatures in order to avoid solidification of the carboxylic acid monomer. High pressure pump operation with carboxylic acid monomer is challenging, unreliable, if not impossible, by the higher temperature operation required to avoid solidification of the carboxylic acid monomer, the compression energy (further heat up) and the self-polymerization potential. Thus there remains a need to pump carboxylic acid monomer reliably at lower temperatures to pressures above 1000 bar.
  • the invention provides for the improved feeding of carboxylic acid monomer with the help of a polar compound, which reduces significantly the melting point of carboxylic acid mixtures, thus allowing direct feeding of the carboxylic acid monomer to the reactor and improving secondary compressor reliability. Furthermore the invention allows wide melt index control capability, while the reactor and compressor phase equilibria can be positively influenced for a wide range (MI and carboxylic acid monomer level) of ethylene-carboxylic acid copolymers.
  • the invention provides a method of injecting a compressed "comonomer/compound mixture,” comprising a “comonomer comprising a carboxylic acid,” and at least one compound, into at least one reactor;
  • said method comprising, adding the at least one compound to the comonomer to form the
  • crystallization temperature, at pressure P, of the "comonomer/compound mixture” is at least 5°C lower than the crystallization temperature, at pressure P, of the comonomer, without the presence of the at least one compound;
  • the molar ratio of the at least one compound to the comonomer in the mixture is from 1/10 to 1/1;
  • the comonomer/compound mixture comprises greater than, or equal to, 30 weight percent of the comonomer, based on the weight of the comonomer/compound mixture;
  • the melting temperature, at atmospheric pressure, of the at least one compound is less than the melting temperature, at atmospheric pressure, of the comonomer.
  • the invention also provides a method of forming an ethylene-based polymer, said method comprising polymerizing a comonomer, comprising a carboxylic acid, in the presence of ethylene and at least one free radical initiator; and
  • crystallization temperature, at pressure P, of the "comonomer/compound mixture” is at least 5°C lower than the crystallization temperature, at pressure P, of the comonomer, without the presence of the at least one compound;
  • the molar ratio of the at least one compound to the comonomer in the mixture is from 1/10 to 1/1;
  • the comonomer/compound mixture comprises greater than, or equal to, 30 weight percent of the comonomer, based on the weight of the comonomer/compound mixture;
  • the melting temperature, at atmospheric pressure, of the at least one compound is less than the melting temperature, at atmospheric pressure, of the comonomer.
  • Figure 1 is a schematic of a high -pressure cell used in the present invention.
  • Figure 2 depicts two melting temperature profiles of acrylic acid, and of an acrylic acid/ MEK mixture, each as a function of pressure.
  • Figure 5 depicts the melting point of AA/Compound mixtures at the noted compositions, and 2500 bar.
  • Figure 6 is a schematic of a flow diagram for an interpolymer polymerization system comprising a two zone autoclave reactor.
  • the invention provides, in a first aspect, a method of injecting a compressed "comonomer/compound mixture,” comprising a “comonomer comprising a carboxylic acid,” and at least one compound, into at least one reactor;
  • said method comprising, adding the at least one compound to the comonomer to form the
  • crystallization temperature, at pressure P, of the "comonomer/compound mixture” is at least 5°C lower than the crystallization temperature, at pressure P, of the comonomer, without the presence of the at least one compound;
  • the molar ratio of the at least one compound to the comonomer in the mixture is from 1/10 to 1/1; and wherein the comonomer/compound mixture comprises greater than, or equal to, 30 weight percent of the comonomer, based on the weight of the comonomer/compound mixture;
  • the melting temperature, at atmospheric pressure, of the at least one compound is less than the melting temperature, at atmospheric pressure, of the comonomer.
  • the comonomer comprising a carboxylic acid
  • An inventive method may comprise a combination of two or more embodiments as described herein.
  • the invention also provides, in a second aspect, a method of forming an ethylene-based polymer, said method comprising polymerizing a comonomer, comprising a carboxylic acid, in the presence of ethylene and at least one free radical initiator; and
  • crystallization temperature, at pressure P, of the "comonomer/compound mixture” is at least 5°C lower than the crystallization temperature, at pressure P, of the comonomer, without the presence of the at least one compound;
  • the molar ratio of the at least one compound to the comonomer in the mixture is from 1/10 to 1/1;
  • the comonomer/compound mixture comprises greater than, or equal to, 30 weight percent of the comonomer, based on the weight of the comonomer/compound mixture;
  • the melting temperature, at atmospheric pressure, of the at least one compound is less than the melting temperature, at atmospheric pressure, of the comonomer.
  • An inventive method may comprise a combination of two or more embodiments as described herein.
  • the pressure P is greater than, 800 bar, further greater than 1000 bar. In one embodiment, the pressure P is greater than, or equal to, 1200 bar, further greater than, or equal to, 1500 bar, further greater than, or equal to, 1800 bar.
  • the pressure P is greater than, or equal to, 2000 bar, further greater than, or equal to, 2500 bar, further greater than, or equal to, 3000 bar, further greater than, or equal to, 3500 bar.
  • the pressure P is from “greater than 500 bar” to 5000 bar, further from “greater than 800 bar” to 4000 bar, further from greater than 1000 to 3500 bar.
  • the crystallization temperature of the comonomer/compound mixture is reduced by at least 10°C, further by at least 15°C, and further by at least 20°C, relative to the crystallization temperature of the comonomer, without the presence of the at least one compound, and at the same pressure.
  • the crystallization temperature of the comonomer is reduced by at least 10°C, further by at least 15°C, and further by at least 20°C, relative to the crystallization temperature of the comonomer, without the presence of the at least one compound, and at the same pressure.
  • the crystallization of the comonomer takes place at a pressure P greater than, or equal to, 1500 bar, further greater than, or equal to, 2500 bar, further greater than, or equal to, 3000 bar.
  • the molar ratio of the at least one compound to the comonomer is from 1/8 to 1/1, further from 1/6 to 1/1, and further from 1 ⁇ 4 to 1/1.
  • the mixture comprises greater than, or equal to, 40 weight percent, further greater than, or equal to, 50 weight percent, further greater than, or equal to, 60 weight percent, further greater than, or equal to, 70 weight percent, of the comonomer, based on the weight of the mixture.
  • the at least one compound has a boiling temperature, at atmospheric pressure, greater than, or equal to, 70°C.
  • the at least one compound has a boiling temperature, at atmospheric pressure, from 70°C to 160°C, further from 70°C to 140°C, further from 70C to 110°C.
  • the at least one compound has a boiling temperature, at atmospheric pressure, less than, or equal to, 160°C, further less than, or equal to, 140°C. In a further embodiment, the at least one compound is an alkylacrylate. In one embodiment, the at least one compound has a boiling temperature, at atmospheric pressure, greater than, or equal to, 125°C.
  • the at least one compound has a boiling temperature, at atmospheric pressure, less than, or equal to, 110°C, further less than, or equal to, 100°C, further less than, or equal to, 90°C.
  • the at least one compound is an alkylacrylate.
  • the at least one compound has a boiling temperature
  • atmospheric pressure from 70°C to 160°C.
  • the at least one compound has a boiling temperature
  • atmospheric pressure from 70°C to 110°C, further from 72°C to 100°C, further from 74°C to 90°C.
  • the at least one compound has a melting temperature, at atmospheric pressure, less than, or equal to, 10°C, further less than, or equal to, 0°C, further less than, or equal to, -10°C.
  • the mixture comprises less than 2 weight percent ethylene, further less 1 weight percent ethylene, and further less than 0.5 weight percent, ethylene, based on the weight of the mixture.
  • the at least one compound comprises at least one heteroatom (for example, O, N, P or S, and preferably O).
  • the at least one compound has a "dielectric constant" greater than 3.0 (see references 11 and 12 below).
  • the at least one reactor is present in a reactor configuration comprising at least one autoclave reactor.
  • the reactor configuration comprises at least one autoclave and at least one tubular reactor.
  • the pressure in the at least one reactor is greater than, or equal to, 1000 bar, further greater than, or equal to, 1200 bar, further greater than, or equal to, 1500 bar.
  • the method further comprises polymerizing the comonomer in the presence of ethylene and at least one free radical initiator, and further at a pressure greater than 1000 bar.
  • the polymerization takes places in a reactor configuration comprising at least one autoclave reactor.
  • the polymerization takes place in an autoclave-tube combination.
  • the at least one reactor is present in a reactor configuration, in which non converted ethylene is recycled back to a reactor.
  • the at least one reactor is present in a reactor configuration that comprises a split ethylene feed configuration, and further, a part of the ethylene is fed to the top zone of a reactor.
  • the ethylene fed to the top zone is used to cool an internal agitator motor. Further, this ethylene is acid monomer free or contains a low amount of commoner (acid comonomer).
  • the at least one reactor is present in a reactor configuration, in which the comonomer (for example, acrylic acid (AA)) is injected into an ethylene feed, which is fed directly or indirectly to the top zone of a reactor.
  • a CTA is fed primarily the top zone (for example, to narrow MWD of high acid products).
  • a polar cosolvent is used during the start up phase for direct comonomer injection.
  • the at least one reactor is present in a reactor configuration, in which at least some unreacted ethylene and/or some unreacted comonomer is/are recycled to a reactor inlet.
  • the pressure in the at least one reactor is greater than 1000 bar.
  • the at least one reactor is present in a reactor configuration, in which a majority of unreacted ethylene and/or a majority of unreacted comonomer is/are recycled to a reactor inlet.
  • the pressure in the at least one reactor is greater than 1000 bar.
  • the level of the at least one compound in a reactor feed is maintained from 1.0 to 10.0 molar percent, further from 1.5 to 8.0 molar percent, further from 2.0 to 6.0 molar percent, based on the total moles of components in the feed.
  • the at least one reactor is present in a reactor configuration, in which at least some of the at least one compound is condensed and recycled to one or more comonomer feed stream(s).
  • the level of the at least one compound is maintained in a reactor feed from 0.5 to 10.0 molar percent, further from 1.0 to 8.0 molar percent, further from 1.5 to 6.0 molar percent based on the total moles of components in the feed.
  • the comonomer contains from 3 to 8 carbon atoms, further from 3 to 6 carbon atoms, further from 3 to 4 carbon atoms.
  • the comonomer contains an internal carbon-carbon double bond
  • the at least one compound is a CTA (chain transfer agent). In a further embodiment, the at least one compound has a chain transfer activity coefficient (Cs at 130 °C and 1360 atm) from 0.0025 to 0.5.
  • the at least one compound comprises at least one heteroatom.
  • the level of the at least one compound in a reactor feed is maintained from 1 to 10 molar percent, based on the total moles of components in the feed.
  • the at least one compound has a chain transfer activity coefficient (Cs at 130°C and 1360 atm) from 0.0025 to 0.5.
  • the at least one compound is a second comonomer.
  • the at least one compound comprises an ester group.
  • the at least one compound is an alkyl acrylates, an alkylmethacrylates, or a vinyl acetate.
  • the at least one compound is an alkylacrylate.
  • Suitable acrylates include methyl, ethyl, propyl, butyl and higher acrylates.
  • the at least one compound is an alkylmethacrylate.
  • Suitable methacrylates include methyl, ethyl, propyl, butyl and higher methacrylates.
  • At least two compounds are added to the comonomer, and wherein one compound has a higher Cs value than the other compound.
  • the ratio of the "Cs value of the compound with the higher Cs value" to the "Cs value of the other compound" is greater than, or equal to, 2, further greater than, or equal to, 3, and further greater than, or equal to, 4.
  • the at least one compound contains at least one chemical group selected from the following: an alcohol, a ketone, an aldehyde, an ester, a carboxylic acid, vinyl group, or a combination thereof.
  • the at least one compound contains at least one chemical group selected from the following: a ketone, an ester, or a combination thereof. In a further embodiment, the at least one compound is an ester.
  • the pressure in the at least one reactor is greater than 500 bar, further greater than, or equal to, 1000 bar, further greater than, or equal to, 1500 bar, further greater than, or equal to, 1700 bar.
  • the temperature in the at least one reactor is greater than, or equal to, 170°C, further greater than, or equal to, 200°C, further greater than, or equal to, 220°C.
  • An inventive method may comprise a combination of two or more embodiments as described herein.
  • the invention also provides an ethylene-based polymer formed from an inventive method of one or more embodiments described herein.
  • the ethylene-based polymer comprises, in the polymerized form, from 1 to 30 weight percent comonomer, further from 3 to 28 weight percent comonomer, and further from 5 to 25 weight percent comonomer, based on the weight of the polymer.
  • the ethylene-based polymer has a melt index (12) from 0.2 to 5000 g/10 min, further from 0.5 to 4000 g/10 min, and further 1 to 3000 g/10 min.
  • the ethylene-based polymer may comprise a combination of two or more embodiments as described herein.
  • the invention also provides a composition comprising an ethylene-based polymer formed from an inventive method of one or more embodiments described herein.
  • the composition further comprises a second ethylene-based polymer.
  • the second ethylene-based polymer is selected from an
  • ethylene/alpha-olefin copolymer ethylene/alpha-olefin copolymer, a low density polyethylene (LDPE), a high density
  • HDPE polyethylene
  • the second ethylene-based polymer is a LDPE homopolymer.
  • the second ethylene-based polymer is a linear low density polyethylene (LLDPE).
  • Linear low density polyethylenes include copolymers of ethylene with one or more alpha-olefins, such as, but not limited to, propylene, butene-1, pentene- 1 , 4-methylpentene- 1 , pentene- 1 , hexene- 1 and octene- 1.
  • the composition has a melt index (12) from 0.2 to 5000 g/10 min, further from 0.5 to 4000 g/10 min, and further 1 to 3000 g/10 min.
  • composition may comprise a combination of two or more embodiments as described herein.
  • invention also provides an article comprising at least one component formed from an inventive composition.
  • the article is selected from a coating, a film, a foam, a laminate, a fiber, or a tape.
  • the article is an aqueous dispersion (for example, a dispersion coating for paper, (fertilizer) granules, etc.).
  • a aqueous dispersion for example, a dispersion coating for paper, (fertilizer) granules, etc.
  • the article is an extrusion coating. In another embodiment, the article is a film.
  • An inventive article may comprise a combination of two or more embodiments as described herein.
  • high pressure polymerization process refers to a free radical polymerization process in which homo- and or copolymerization is carried out at an elevated pressure typically of at least 1000 bar (for example, 1000 to 5000 bar) and elevated temperature (for example, 100 to 400°C) conditions.
  • elevated pressure typically of at least 1000 bar (for example, 1000 to 5000 bar) and elevated temperature (for example, 100 to 400°C) conditions.
  • High molecular weight, normally solid copolymers of ethylene and unsaturated carboxylic acids, such as acrylic acid and methacrylic acid are well known (see for example, U.S. Patent 3,132,120).
  • the level of total polar solvent in polymerization plant can be controlled, and set at a level that will significantly improve phase equilibrium conditions in the reactor, the compressor, and other sections.
  • the process of the present invention is a free radical polymerization process.
  • the type of free radical initiator to be used in the present process is not critical.
  • Free radical initiators that are generally used include organic peroxides, such as peresters, perketals, peroxy ketones, percarbonates and cyclic multifunctional peroxides. These organic peroxide initiators are used in conventional amounts, typically from 0.005 to 0.2 weight percent based on the weight of polymerizable monomers.
  • Other suitable initiators include azodicarboxylic esters,
  • azodicarboxylic dinitriles and 1,1,2,2-tetramethylethane derivatives and other components capable of forming free radicals in the desired operating temperature range.
  • Peroxides are typically injected as diluted solutions in a suitable solvent, for example, in a hydrocarbon solvent.
  • Chain transfer agents or telogens are used to control the melt index in a polymerization process. Chain transfer involves the termination of growing polymer chains, thus limiting the ultimate molecular weight of the polymer material. Chain transfer agents are typically hydrogen atom donors that will react with a growing polymer chain, and stop the polymerization reaction of the chain, and initiate the growth of a new polymer molecule. These agents can be of many different types, from saturated hydrocarbons, or unsaturated hydrocarbons, to aldehydes, ketones or alcohols. By controlling the concentration of the selected chain transfer agent, one can control the length of polymer chains, and, hence the molecular weight, for example, the number average molecular weight, Mn. The melt flow index (MFI or I 2 ) of a polymer, which is related to Mn, is controlled in the same way.
  • MFI melt flow index
  • Suitable chain transfer agents include, but are not limited to, aliphatic and olefinic hydrocarbons, such as pentane, hexane, cyclohexane, propene, pentene or hexane; ketones such as acetone, diethyl ketone, methyl ethyl ketone (MEK) or diamyl ketone ; aldehydes such as formaldehyde or acetaldehyde, propionaldehyde; and saturated aliphatic aldehyde alcohols such as methanol, ethanol, propanol or butanol.
  • the chain transfer agent may also be a monomeric chain transfer agent. For example, see WO 2012/057975, US 61/579067 and US 61/664956.
  • a further way to influence the melt-index includes the build up and control, in the ethylene recycle streams, of the compound. Furthermore the melt-index can be influenced by the build up and control of incoming ethylene impurities, like methane and ethane, peroxide dissociation products, like tert-butanol, acetone, etc., and or solvent components used to dilute the initiators. These ethylene impurities, peroxide dissociation products and/or dilution solvent components can act as chain transfer agents.
  • an ethylene-based polymer of this invention has a density from 0.910 to 0.950, more typically from 0.915 to 0.945, and even more typically from 0.920 to 0.940, grams per cubic centimeter (g/cc or g/cm ). In one embodiment, an ethylene-based polymer of the invention has a melt index (I 2 ) from 0.2 to 5000 grams per 10 minutes (g/10 min) at
  • the ethylene-based polymer is selected from ethylene acrylic acid (EAA), ethylene methacrylic acid (EMAA), vinyl acetate, ethyl acrylate, or butyl acrylate.
  • optional secondary comonomers include carbon monoxide, silane-containing comonomers, and others. Terpolymers, such as ethylene- AA-MAA terpolymers may also be formed.
  • Other suitable secondary or higher comonomers to be used in the ethylene polymers of the present invention include, but are not limited to, ethylenically unsaturated monomers and especially C3-20 alpha-olefins, carbon monoxide, vinyl acetate, and C 2 -6 alkyl acrylates.
  • One or more additives may be added to a composition comprising an inventive polymer.
  • Suitable additives include stabilizers; fillers, such as organic or inorganic particles, including clays, talc, titanium dioxide, zeolites, powdered metals, organic or inorganic fibers, including carbon fibers, silicon nitride fibers, steel wire or mesh, and nylon or polyester cording, nano- sized particles, clays, and so forth; tackifiers, oil extenders, including paraffinic or napthelenic oils.
  • fillers such as organic or inorganic particles, including clays, talc, titanium dioxide, zeolites, powdered metals, organic or inorganic fibers, including carbon fibers, silicon nitride fibers, steel wire or mesh, and nylon or polyester cording, nano- sized particles, clays, and so forth
  • tackifiers such as paraffinic or napthelenic oils.
  • An inventive composition may be employed in a variety of conventional thermoplastic fabrication processes to produce useful articles, including extrusion coatings; dispersion coating; films; and molded articles, such as blow molded, injection molded, or rotomolded articles;
  • foams ; wire and cable, fibers, and woven or non-woven fabrics.
  • carboxylic acid-containing comonomer or “comonomer comprising a carboxylic acid,” as used herein, refer to an unsaturated organic compound comprising at least one -COOH group.
  • acid comonomer refers to a carboxylic acid-containing comonomer.
  • Melting temperature, at pressure (P), of the carboxylic acid-containing comonomer, as used herein, is the temperature, at pressure (P), when the last crystal of the comonomer disappears upon depressurization.
  • the crystallization temperature at pressure (P), of the carboxylic acid-containing comonomer, as used herein, is equal to the melting temperature, at pressure (P), as discussed above.
  • the “melting temperature at atmospheric pressure” refers to the melting temperature at 1.0 atm pressure.
  • boiling temperature at atmospheric pressure refers to the boiling temperature at 1.0 atm pressure.
  • chain transfer coefficient refers to the ratio between the “rate of chain transfer” to the “rate of ethylene propagation.”
  • Cs at 130°C and 1360 atm refers to the chain transfer coefficient measured at a temperature of 130°C and at a pressure of 1360 atm. See references 1-6 below.
  • CTA activity is the product of the chain transfer coefficient (Cs value) with the molar concentration.
  • CTA system includes a single CTA or a mixture of CTAs added to the polymerization process, typically to control the melt index.
  • a CTA system or a CTA includes a component able to transfer a hydrogen atom to a growing polymer molecule containing a radical, by which the radical is formed on the CTA molecule, which can then initiate the start of a new polymer chain.
  • CTA is also known as telogen or telomer.
  • recycled ethylene refers to the ethylene-rich feed streams that are removed from the polymer, for example, in the high pressure and low pressure separators, and the recycled ethylene comprises ethylene, other components and reactants not converted in the reactor.
  • reaction zone refers to a reactor zone where polymerization reaction is initiated or reinitiated by, for example, addition of radicals or components which dissociate into radicals.
  • component activity refers to the reactivity ratios rl and r2, which discloses information of the reaction rate of the comonomer versus the "rate of ethylene propagation.” See Ehrlich/ Mortimer reference 1 for definitions and typical values for rl and r2.
  • solvent system refers to a compound or a mixture of compounds for diluting carboxylic acid.
  • Solvent or cosolvent system may be a vinyl containing monomer(s), maybe an organic peroxide diluent, or may be a chain transfer agent.
  • a compound refers to an organic molecule.
  • a compound may be a vinyl containing monomer, may be an organic peroxide diluent, and/or may be a chain transfer agent.
  • composition refers to a mixture of materials which comprises the composition, as well as reaction products and decomposition products formed from the materials of the composition.
  • polymer refers to a compound prepared by polymerizing monomers, whether of the same or a different type.
  • the generic term polymer thus embraces the term homopolymer (which refers to polymers prepared from only one type of monomer, with the understanding that trace amounts of impurities can be incorporated into the polymer structure), and the term
  • interpolymer as defined infra. Trace amounts of impurities may be incorporated into and/or within the polymer structure
  • interpolymer refers to polymers prepared by the polymerization of at least two different types of monomers.
  • the generic term interpolymer includes copolymers (which refers to polymers prepared from two different monomers), and polymers prepared from more than two different types of monomers.
  • ethylene-based polymer or "ethylene polymer” refers to a polymer that comprises a majority amount of polymerized ethylene based on the weight of the polymer, and, optionally, may comprise at least one comonomer.
  • ethylene-based interpolymer or "ethylene interpolymer” refers to an interpolymer that comprises a majority amount of polymerized ethylene, based on the weight of the interpolymer, and at least one comonomer.
  • ethylene-based copolymer or "ethylene copolymer” refers to an interpolymer that comprises a majority amount of polymerized ethylene, based on the weight of the copolymer, and only one comonomer (thus, only two monomer types).
  • ethylene-based terpolymer refers to an interpolymer that comprises a majority amount of polymerized ethylene, based on the weight of the copolymer, and only two comonomers (thus, only three monomer types).
  • autoclave-based products or “autoclaved-based polymers,” as used herein, refer to polymers prepared in a reactor system comprising at least one autoclave reactor.
  • high pressure, free-radical polymerization process refers to a free radical initiated polymerization carried out at an elevated pressure of at least 1000 bar (100 MPa).
  • compressed comonomer/compound mixture refers to a
  • comonomer/compound mixture at a pressure of greater than 500 bar, more preferably greater than, or equal to, 1000 bar, more preferably greater than, or equal to, 1500 bar.
  • compositions claimed through use of the term “comprising” may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless stated to the contrary.
  • Density Samples for density measurement are prepared according to ASTM D 1928. Polymer samples are pressed at 190°C and 30,000 psi (207 MPa) for three minutes, and then at 21°C and 207 MPa for one minute. Measurements are made within one hour of sample pressing using ASTM D792, Method B.
  • Melt Index Melt index, or I 2 , (grams/10 minutes or dg/min) is measured in accordance with ASTM D 1238, Condition 190°C/2.16 kg. I 10 is measured with ASTM D 1238, Condition 190°C/10 kg.
  • Table 1 lists the reagents used in the studies below, the supplier, and their purity of the tested carboxylic acids, cosolvents and secondary comonomers.
  • Figure 1 shows the following equipment parts: flange, moveable piston; cell body; steel cap; sheathed thermocouple; plug; bolt; sapphire window; cooling jacket; TEFLON O-ring; connecting plug to the pressurizing system;
  • pressurizing fluid (heptane); internal volume with stirrer bar.
  • Peroxide/solvent mixtures were contained in a high-pressure cell of Figure 1, with a variable internal volume.
  • the cylindrical cell body (170 mm length with inner and outer diameter of 22 and 80 mm, respectively) was sealed conically, with a steel plug on each side of the cylindrical cell body .
  • the plugs were pressed against the cell body with six bolts on each side of the cylindrical cell body.
  • Tightly fitted into the internal boring was a moveable piston sealed with a TEFLON O-ring, which separated the mixture under investigation from heptanes, which acted as the pressurizing fluid.
  • a sheathed thermocouple was introduced into the peroxide solution.
  • the flat surface of the moveable piston which faced the sapphire window (of 18 mm diameter and 10 mm thickness) was polished to facilitate observation of phase behavior, in particular of the appearance and disappearance of crystals.
  • the internal volume was monitored by an endoscope camera, and the pictures were permanently displayed on a screen.
  • the pictures also included the actual pressure and temperature readings, to enable a more detailed analysis of the phase behavior.
  • the pressure was recorded by a transducer (DMS 3 kbar, HBM-Messtechnik) in the ambient-temperature part of the heptane system.
  • a cryostat operated with methanol, was used for thermo starting the autoclave.
  • the cooling fluid was passed through a brass mantle, which was closely fitted to the outer wall of the high-pressure cell.
  • the temperature was measured within + 0.3°C, via the thermocouple sitting inside the mixture under investigation.
  • the liquid mixture was stirred by a TEFLON-coated magnet, driven through the non-magnetic wall of the stainless-steel cell body (RGT 601, German Werkstoff-No. 2.4969, Arbed Saarstahl) by a large rotating magnet positioned under the autoclave.
  • the experimental procedure was as follows.
  • the sapphire window was fixed on the right-hand side plug (see Figure 1) and this plug sealed against the cell body.
  • the peroxide solution was filled into the internal volume, followed by introducing the moveable piston into the cylindrical boring.
  • the second plug was sealed against the cell body, heptane was filled into the pressurizing unit, and a pressure of about 100 bar was applied.
  • the thermostating mantle was connected with the pre-cooled thermostat, and the autoclave brought to the lowest temperature selected for a particular experimental series. After reaching constant temperature, the pressure was raised, until solidification occurred.
  • the pressure associated with the solid/liquid equilibrium was determined at the point when the last crystal disappears upon depressurization (the pressure at this point was recorded as the pressure at the set melting temperature; or Tm at recorded pressure).
  • Tm the pressure at the set melting temperature
  • the pressure was lowered in steps of about 50 bar, each step being followed by temperature equilibration.
  • Melting temperature at pressure (P), as used herein, is the temperature at pressure (P) when the last crystal of the "carboxylic acid-containing comonomer" disappears upon depressurization.
  • the crystallization temperature at pressure (P), as used herein, is equal to the melting temperature at pressure (P), as discussed above. Homogeneous-phase behavior could be easily seen from the twofold penetration of the clear solution by the illuminating the light, which was reflected at the polished flat surface of the moveable piston. As a first indication of crystallization, the internal volume turned slightly dark. Subsequently, crystals could be seen, and finally, the rotation of the magnetic stir bar ceased. Crystallization was additionally indicated by a rise in temperature.
  • Table 2 shows the main physical and/or chemical properties of the tested carboxylic acids, cosolvents and secondary comonomer.
  • Figure 2 shows the experimental data, fitting melting temperature of AA and AA/compound mixtures as function of pressure.
  • Figure 2 shows the measured melting points of acrylic acid (AA) and AA:MEK system at molar ratio 2: 1.
  • the observed melting temperatures and pressure levels associated with the pure AA and the "AA:MEK system at molar ratio of 2: 1" are listed in Table 3.
  • the pressure examined in this "melting point reduction" study correlate with typically pressures used in an high pressure reactor, and the "Tm versus pressure" equations (for example, see Table 4) can be used to predict melting temperature reductions at pressures above 2500 bar.
  • Table 4 shows the equation factors derived, when applying a second order polynomial to the measured melting point (of mixture or of comonomer, as noted in Table 4), as function of pressure level.
  • a second order polynomial for each carboxylic acid/cosolvent mixture, and for each molar ratio, a separate equation was derived, as function of pressure.
  • a separate equation was also derived for each pure comonomer as a function of pressure.
  • the derived equation can be used to calculate the needed melting points.
  • the crystallization temperature at pressure (P) is equal to the melting temperature at pressure (P).
  • Tm (at the specified pressure) of the comonomer; or the Tm (at specified pressure) in the comonomer/compound mixture.
  • Table 5 lists the temperature and melting temperature reduction of "AA/compound” systems at varying pressures.
  • the data in Table 5 show that the largest melting reductions of AA (acrylic acid) are provided by acetates and ketonic solvents. The lowest melting reduction was measured for isododecane. Since isododecane is a non-polar solvent, it cannot interfere with hydrogen bonding, leading to anhydride formation between two carboxylic acid molecules (dimer formation, see reference 9 below). It was surprisingly discovered that alcohols reduced the melting temperature to a lower degree, compared to the acetates and ketonic solvents, although an alcohol potentially could interfere more effectively the hydrogen bonding between the carboxylic acid groups on two or more comonomer molecules.
  • A) Compound was a comonomer.
  • the solvent isododecane
  • ethylene glycol bifunctional alcohol
  • ethyl acetate with a dielectric constant 6, performed better than tert-butanol, with a dielectric constant of 10.9.
  • the AA/ethylene glycol system measured at 4:1 molar ratio, data has been added to this data set, since ethylene glycol is a bifunctional alcohol.
  • that there is no correlation between melting temperature reduction of acrylic acid and the dipole moment of the solvent, applied at a molar ratio of AA:solvent 2:1.
  • the additional data point of the AA/ethylene glycol system, measured at 4: 1 molar data, does not provide additional insight.
  • the tested acetates and ketones provide the largest reduction in melting temperature.
  • Figure 5 shows the melting point temperature of acrylic acid/compound mixtures, at the noted compositions, at 2500 bar.
  • Table 6 shows the cosolvent (compound) needed to maintain the molar ratio, AA: solvent, at 2:1, at varying AA levels.
  • the varying AA levels reflect the feed conditions for interpolymers made at varying acid levels.
  • polar cosolvents By applying two or more polar cosolvents with varying chain transfer activities, a significant level of polar cosolvent can be maintained, regardless of the level of acid monomer, or the melt index of the product to be produced.
  • the significant level of polar cosolvent will ensure a positive impact on the "AA/cosolvent" melting temperature, the reactor cloud point pressure, and the phase homogeneity in the high pressure compression systems.
  • Figure 6 depicts a flow diagram for a copolymer (ethylene-based polymer) polymerization containing a two zone autoclave reactor.
  • fresh ethylene is compressed together with the outlet of the booster compressor, by the primary compressor, to the suction pressure of the secondary compressor.
  • the feed of the secondary compressor consists of ethylene rich feed streams, coming from the high pressure recycle and the primary compressor outlet. Additional monomers, including carboxylic acid-containing monomer(s), can be fed at the inlet side of the secondary compressor, or further downstream of the secondary compressor.
  • the discharge stream of the secondary compressor is split into two feedstreams.
  • feedstreams pass coolers, and could receive, according to the present invention, a high pressure feed of carboxylic acid, mixed with a cosolvent and/or secondary comonomers (or compounds).
  • feed streams are fed to the autoclave top reactor zone and autoclave bottom reactor zone, respectively.
  • LDV Let Down Valve
  • the reactor outlet stream is received, and separated, in the high pressure separator (HPS).
  • HPS high pressure separator
  • the gaseous overhead is cooled, and cleaned from entrained polymer and/or dissolved waxes in the high pressure recycle.
  • the liquid bottom stream from the HPS is further depressurized in the low pressure separator (LPS).
  • the polymer, with residual monomers, CTA and/or solvents, is transferred to the product finishing section.
  • the gaseous overhead of the LPS is cooled in the LPR (Low Pressure Recycle), and compressed and cooled in the booster compressor.
  • LPR Low Pressure Recycle
  • various components like CTA(s), cosolvent(s), comonomer(s) and other compounds, may condense and separate, and be removed in the various compression and cooling stages.
  • the remaining gaseous flow from the booster compressor is fed to the primary compressor.
  • the polymerization flow diagram shown in Figure 6 can be used to polymerize ethylene with one or more carboxylic acid-containing comonomers, and optionally, other comonomers, without the undesirable crystallization of the carboxylic acid-containing comonomer(s) in the feeds, compression equipment and/or pump equipment contained in the polymerization process. Furthermore, this polymerization flow scheme allows for the condensation and reuse of cosolvents.
  • Ethylene/Poly(ethylene-co-acrylic acid) Effects of solvent, density, hydrogen bonding, and copolymer composition", Helvetica Chimica Acta; Vol. 85 (2002); pp 659-670.
  • the melting point data for the pure compounds are: AA (13 °C) and MAA (16 °C)

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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)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
  • Polymerisation Methods In General (AREA)

Abstract

L'invention concerne un procédé d'injection d'un "mélange comonomère/composé" comprimé comprenant un "comonomère comprenant un acide carboxylique" et au moins un composé, dans au moins un réacteur. Ledit procédé comprend l'addition du ou des composés au comonomère pour former le "mélange comonomère/composé", avant de comprimer et d'injecter le mélange dans le réacteur, dans lequel la température de cristallisation, à la pression P, du "mélange comonomère/composé" est inférieure d'au moins 5 °C à la température de cristallisation, à la pression P, du comonomère, en l'absence du ou des composés, et dans lequel la pression P est supérieure à 500 bars, et dans lequel le rapport molaire du ou des composés au comonomère dans le mélange est de 1/10 à 1/1, et dans lequel le mélange comonomère/composé comprend une proportion supérieure ou égale à 30 % du comonomère, par rapport au poids du mélange comonomère/composé, et dans lequel la température de fusion, à pression atmosphérique, du ou des composés est inférieure à la température de fusion, à pression atmosphérique, du comonomère. L'invention concerne également un procédé de formation d'un polymère à base d'éthylène, comme il est décrit ici.
PCT/US2013/078020 2012-12-28 2013-12-27 Procédé pour améliorer l'alimentation par un comonomère d'acide carboxylique d'un réacteur à haute pression WO2014106067A1 (fr)

Priority Applications (8)

Application Number Priority Date Filing Date Title
CN201380068054.5A CN104870481B (zh) 2012-12-28 2013-12-27 改良高压反应器中羧酸共聚单体的馈入的方法
KR1020157016827A KR102182955B1 (ko) 2012-12-28 2013-12-27 카르복실산 공단량체의 고압 반응기 내로의 공급을 개선하는 방법
EP13827061.6A EP2938640B1 (fr) 2012-12-28 2013-12-27 Procédé pour améliorer l'alimentation par un comonomère d'acide carboxylique d'un réacteur à haute pression
US14/438,930 US9416209B2 (en) 2012-12-28 2013-12-27 Method to improve the feeding of a carboxylic acid comonomer into a high pressure reactor
JP2015550805A JP6563340B2 (ja) 2012-12-28 2013-12-27 高圧反応器へのカルボン酸コモノマーの供給を改善する方法
EP18170183.0A EP3372619B1 (fr) 2012-12-28 2013-12-27 Procédé pour améliorer l'alimentation par un comonomère d'acide carboxylique d'un réacteur à haute pression
ES13827061.6T ES2674082T3 (es) 2012-12-28 2013-12-27 Método para mejorar la alimentación de un comonómero de ácido carboxílico a un reactor de alta presión
BR112015010925-0A BR112015010925B1 (pt) 2012-12-28 2013-12-27 Método para injetar uma mistura comprimida e método para formar um polímero baseado em etileno

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US201261747003P 2012-12-28 2012-12-28
US61/747,003 2012-12-28
USPCT/US2013/032501 2013-03-15
PCT/US2013/032501 WO2014105110A2 (fr) 2012-12-28 2013-03-15 Procédé pour réduire la température de cristallisation de comonomère d'acide carboxylique à des pressions élevées et pour améliorer sa copolymérisation

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WO2016077512A2 (fr) 2014-11-13 2016-05-19 Dow Global Technologies Llc Compositions de lubrifiant pour polymérisations radicalaires à haute pression perfectionnées
WO2017004320A1 (fr) * 2015-06-30 2017-01-05 Dow Global Technologies Llc Polymérisations radicalaires à haute pression
WO2017223467A1 (fr) * 2016-06-24 2017-12-28 Dow Global Technologies Llc Procédé de production de copolymères d'éthylène à radicaux libres haute pression
US9861862B1 (en) * 2015-06-08 2018-01-09 Callaway Golf Company Golf ball cover layer with improved rebound resilience

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US4252924A (en) * 1979-04-05 1981-02-24 E. I. Du Pont De Nemours And Company Continuous process for the preparation of nonrandom ethylene/acid copolymer
US5028674A (en) * 1990-06-06 1991-07-02 E. I. Du Pont De Nemours And Company Methanol copolymerization of ethylene
WO2012044503A1 (fr) * 2010-09-30 2012-04-05 Dow Global Technologies Llc Interpolymères à base d'éthylène et leurs procédés de fabrication

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Publication number Priority date Publication date Assignee Title
US4252924A (en) * 1979-04-05 1981-02-24 E. I. Du Pont De Nemours And Company Continuous process for the preparation of nonrandom ethylene/acid copolymer
US5028674A (en) * 1990-06-06 1991-07-02 E. I. Du Pont De Nemours And Company Methanol copolymerization of ethylene
WO2012044503A1 (fr) * 2010-09-30 2012-04-05 Dow Global Technologies Llc Interpolymères à base d'éthylène et leurs procédés de fabrication

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016077512A2 (fr) 2014-11-13 2016-05-19 Dow Global Technologies Llc Compositions de lubrifiant pour polymérisations radicalaires à haute pression perfectionnées
US10144898B2 (en) 2014-11-13 2018-12-04 Dow Global Technologies Llc Lubricant compositions for improved high pressure free-radical polymerizations
US9861862B1 (en) * 2015-06-08 2018-01-09 Callaway Golf Company Golf ball cover layer with improved rebound resilience
WO2017004320A1 (fr) * 2015-06-30 2017-01-05 Dow Global Technologies Llc Polymérisations radicalaires à haute pression
KR20180022822A (ko) * 2015-06-30 2018-03-06 다우 글로벌 테크놀로지스 엘엘씨 고압 자유 라디칼 중합
CN107873035A (zh) * 2015-06-30 2018-04-03 陶氏环球技术有限责任公司 高压自由基聚合
US10457757B2 (en) 2015-06-30 2019-10-29 Dow Global Technologies Llc High pressure free-radical polymerizations
CN107873035B (zh) * 2015-06-30 2021-04-09 陶氏环球技术有限责任公司 高压自由基聚合
KR102571535B1 (ko) * 2015-06-30 2023-08-29 다우 글로벌 테크놀로지스 엘엘씨 고압 자유 라디칼 중합
WO2017223467A1 (fr) * 2016-06-24 2017-12-28 Dow Global Technologies Llc Procédé de production de copolymères d'éthylène à radicaux libres haute pression
US10941220B2 (en) 2016-06-24 2021-03-09 Dow Global Technologies Llc Process for making high pressure free radical ethylene copolymers

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