EP1395618A1 - Procede pour la production d'homopolymeres et de copolymeres d'ethylene par polymerisation radicalaire a haute pression - Google Patents

Procede pour la production d'homopolymeres et de copolymeres d'ethylene par polymerisation radicalaire a haute pression

Info

Publication number
EP1395618A1
EP1395618A1 EP02743142A EP02743142A EP1395618A1 EP 1395618 A1 EP1395618 A1 EP 1395618A1 EP 02743142 A EP02743142 A EP 02743142A EP 02743142 A EP02743142 A EP 02743142A EP 1395618 A1 EP1395618 A1 EP 1395618A1
Authority
EP
European Patent Office
Prior art keywords
zone
reactor
mfr
tubular reactor
ethylene
Prior art date
Legal status (The legal status 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 status listed.)
Withdrawn
Application number
EP02743142A
Other languages
German (de)
English (en)
Inventor
Wilhelm Zoller
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Basell Polyolefine GmbH
Original Assignee
Basell Polyolefine GmbH
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
Application filed by Basell Polyolefine GmbH filed Critical Basell Polyolefine GmbH
Publication of EP1395618A1 publication Critical patent/EP1395618A1/fr
Withdrawn legal-status Critical Current

Links

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
    • C08F10/02—Ethene
    • 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
    • C08F110/02—Ethene

Definitions

  • Polyethylene is produced by polymerizing ethylene using two fundamentally different methods, the high-pressure and the low-pressure / medium-pressure process.
  • the low pressure / medium pressure process can be carried out as solution polymerization, as suspension / emulsion polymerization or as gas phase polymerization.
  • the high pressure process is carried out at pressures higher than 1500 bar (corresponding to 150 to 400 MPa) and takes place according to a radical mechanism.
  • the low-pressure / medium-pressure process is carried out at pressures below 100 bar and as a rule catalyzed.
  • products from the high-pressure process which have a high branching, a lower crystallinity and a low density
  • products from the low-pressure / medium-pressure process are mostly of a linear, little branched structure, and have a high crystallinity (mostly 60 - 90%), a high melting range (typically 120 - 35 ° C) and a high density (usually 0.93 - 0.97 g / cm 3 ).
  • a high density of polyethylene is usually combined with a high glass transition temperature, high hardness, a high melting range, high brittleness and low stickiness. The above properties generally characterize low-pressure / medium-pressure polyethylene.
  • the low-density polyethylene (LDPE) which is produced by the high-pressure process in tubular reactors, is still a standard plastic, for which the highest demand is still registered worldwide because of the material is less brittle and is simply easier to process for numerous applications.
  • the high-pressure polymerization process is still a proven process for the production of low-density polyethylene (LDPE), which is carried out on a large scale in numerous plants worldwide with great success.
  • the start of the polymerization is usually effected by atmospheric oxygen or by peroxides or by other free radical formers or by mixtures of these.
  • the radical chain initiators used to start the polymerization have to be added to the reaction medium in a suitable manner.
  • the high-pressure polymerization of ethylene is therefore to be considered below, in which comonomers such as vinyl acetate, vinyl esters, olefinically unsaturated carboxylic acids or alpha-olefins are also used. It is a copolymerization in which the crystallinity of the product obtained can be controlled in a targeted manner by varying the amount of comonomer in the monomer mixture.
  • the reaction gas is first heated to a temperature in the range from 90 to 200 ° C. in order to start the strongly exothermic polymerization reaction.
  • the heat of reaction released is removed by water cooling, with up to 40% of the monomers used being converted to polymer in one pass through the continuously operated reactor.
  • the resulting polymer is separated in a two-stage process comprising high-pressure and low-pressure separation.
  • the polymer arriving in the low-pressure separation is then freed from the remaining part of the unreacted reaction gases by further depressurization to 1 to 5 bar.
  • the gases are returned while the polymer obtained is fed to a melt extruder, homogenized and then granulated.
  • the polymer so produced tends to speckle to a certain extent.
  • the object of the present invention was therefore to carry out the high-pressure polymerization of ethylene and other comonomers in such a way that a higher throughput is achieved by optimizing the reactor cooling mode, the reaction temperature and the cooling water distribution while maintaining the quality of the polymer produced in this way.
  • This object is achieved by a process for high-pressure polymerization of ethylene in a tubular reactor which is designed as a double-tube heat exchanger, in which fresh ethylene is first subjected to low-pressure compression and then brought to reaction pressure together with recyclate, initiators, moderators and comonomer in a high-pressure compressor,
  • the characteristics of which can be seen in the fact that the polymer is carried out at a pressure in the range from 2000 to 3500 bar and that the reaction mixture runs through a temperature profile in the range from 100 to 350 ° C within the tubular reactor.
  • the reaction mixture of inert gas, molecular weight regulator, ethylene and comonomer is preferably first compressed to a pressure of 2800 bar and then heated to a temperature of 120 ° C.
  • the hot reaction mixture is then fed into the tubular reactor, where the high pressure piston pumps are used at the very beginning Peroxide initiator in an amount of 10 to 400 ppm, based on the weight of the reaction mixture, is added.
  • the immediately occurring exothermic polymerization reaction releases heat of reaction, which must be dissipated quickly by water cooling, because otherwise the reaction mixture would overheat and there would be a risk of uncontrolled decomposition of the ethylene.
  • the cooling is carried out according to the invention in such a way that the entire reactor is divided lengthwise into two zones.
  • the first zone comprises the two front thirds of the total length of the tubular reactor
  • the second zone comprises the rear third of the total length of the tubular reactor.
  • Both zones of the reactor are cooled separately with water of different temperatures, the preferred water temperature for the production of ethylene homopolymer in the two zones being calculated using the following formula:
  • MFR represents the melt index of the product obtained at the end of the reactor in [dg / min], measured according to ASTM D-1238, Condition (E), i.e. at a temperature of 190 ° C and a weight of 2.16 kg.
  • the water temperature preferred according to the invention for the production of ethylene copolymer with vinyl acetate in the two zones is calculated using the following formula:
  • MFR also represents the melt index of the product obtained at the end of the reactor in [dg / min], measured in accordance with ASTM D-1238, Condition (E), ie at a temperature of 190 ° C. and a coating weight of 2.16 kg.
  • E ASTM D-1238, Condition
  • the reaction mixture is cooled and, by reducing the pressure to a value in the range between 10 to 70 MPa, essentially freed of volatile constituents.
  • the polymer melt is freed of the residual adhering reaction gases by further depressurization to 1 to 5 bar, as described above, homogenized in the extruder, granulated and filled.
  • molecular weight regulators Conventional polar or non-polar organic compounds such as ketones, aldehydes, alkanes or alkenes having 3 to 20 carbon atoms can be used as molecular weight regulators.
  • Preferred molecular weight regulators are acetone,
  • peroxides such as aliphatic diacyl (C 3 to C 2 ) peroxides, tertiary-butylperoxypivalate (TBPP), tertiary-butylperoxy-3,5,5-trimethylhexanoate (TBPIN), di-tertiary-butyl peroxide (DTBP), tertiary- Butyl perisononate or mixtures or solutions of these can be used in suitable solvents.
  • the radical chain initiators are fed in amounts in the range from 10 to 1000 g / t of PE produced, preferably from 100 to 600 g / t of PE produced.
  • the flowing flow medium to which the above-mentioned radical chain initiators are fed according to the invention can, in addition to ethylene as a comonomer, additionally 1-olefins having 3 to 20 C atoms, preferably having 3 to 10 C atoms, in an amount in the range from 0 to 10% by weight .-%, Based on the amount of ethylene monomer, preferably in an amount in the range of 1 to 5 wt .-%.
  • the flowing fluid medium according to the invention Contain polyethylene in an amount in the range of 0 to 40 wt .-%, based on the total weight of the monomers, preferably from 1 to 30 wt .-%.
  • the radical chain starters are supplied in a region of the tubular reactor in which the diameter of the tubular reactor is reduced to a value of approximately 0.6 to 0.9 times the diameter D of the reactor in the feed zone, the flow rate of the flowing fluid medium is 1.2 to 2.8 times, preferably 1.8 to 2.5 times, the flow rate within the feed zone of the tubular reactor is increased.
  • Flow velocity of the flowing flow medium in the supply area of the radical chain starters according to the invention in the range from 10 to 40 m / s, preferably from 15 to 30 m / s, particularly preferably from 20 to 25 m / s.
  • the process according to the invention has the advantage that stable reactor operation can be maintained at unusually high maximum temperatures of up to 350 ° C. without a tendency to decompose.
  • Another advantage of the process according to the invention is that the start of the polymerization starts at lower temperatures and that the temperature rise of the reaction mixture then takes place in a controlled manner.
  • the service life of the radical chain starters which usually have only a relatively short half-life, is better utilized for the polymerization and thus for the production of LDPE.
  • the process according to the invention improves sales and above all product properties such as density and MFR.
  • the amount of radical chain starter to be used could be reduced by approximately 15% and the operating constancy of the tubular reactor was increased.
  • the polyethylene worked up at the end of the reactor in a known manner had a density of 0.924 g / cm 3 and an MFR of 0.65 dg / min.

Landscapes

  • 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 pour la production d'homopolymères et de copolymères d'éthylène dans un réacteur tubulaire par polymérisation radicalaire, à des pressions supérieures à 1000 bars et à des températures comprises entre 120 et 400 DEG C. Selon le procédé de l'invention, de faibles quantités d'initiateur de chaîne radicalaire sont d'abord amenées à un milieu liquide s'écoulant, qui contient de l'éthylène, des régulateurs de masse molaire et, éventuellement, du polyéthylène. Puis, la polymérisation a lieu. Selon l'invention, la polymérisation s'effectue à une pression comprise entre 2000 et 3500 bars et le mélange réactionnel à l'intérieur du réacteur tubulaire parcourt un profil de températures allant de 100 à 350 DEG C.
EP02743142A 2001-06-11 2002-06-04 Procede pour la production d'homopolymeres et de copolymeres d'ethylene par polymerisation radicalaire a haute pression Withdrawn EP1395618A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10128221A DE10128221A1 (de) 2001-06-11 2001-06-11 Verfahren zur Herstellung von Ethylenhomo-und -copolymeren durch radikalische Hochdruckpolymerisation
DE10128221 2001-06-11
PCT/EP2002/006074 WO2002100907A1 (fr) 2001-06-11 2002-06-04 Procede pour la production d'homopolymeres et de copolymeres d'ethylene par polymerisation radicalaire a haute pression

Publications (1)

Publication Number Publication Date
EP1395618A1 true EP1395618A1 (fr) 2004-03-10

Family

ID=7687872

Family Applications (1)

Application Number Title Priority Date Filing Date
EP02743142A Withdrawn EP1395618A1 (fr) 2001-06-11 2002-06-04 Procede pour la production d'homopolymeres et de copolymeres d'ethylene par polymerisation radicalaire a haute pression

Country Status (6)

Country Link
US (1) US6894126B2 (fr)
EP (1) EP1395618A1 (fr)
JP (1) JP4150335B2 (fr)
CN (1) CN1233670C (fr)
DE (1) DE10128221A1 (fr)
WO (1) WO2002100907A1 (fr)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100210800A1 (en) 2004-03-24 2010-08-19 Ciba Corporation Method of preparing ethylene polymers by controlled high pressure polymerization
JP5138363B2 (ja) * 2004-03-24 2013-02-06 チバ ホールディング インコーポレーテッド 制御された高圧重合によるエチレンポリマーの調製方法
RU2007120631A (ru) * 2004-11-02 2008-12-10 Дау Глобал Текнолоджиз Инк. (Us) Способ получения композиций полиэтилена низкой плотности и полимеры, получаемые этим способом
FR2971510B1 (fr) * 2011-02-10 2013-03-22 Arkema France Polymerisation radicalaire de l'ethylene amorcee par des peroxydes organiques a haute productivite
EP2681250B2 (fr) * 2011-03-03 2018-11-14 Basell Polyolefine GmbH Procédé pour la préparation d'homopolymères ou de copolymères d'éthylène dans un réacteur tubulaire doté d'au moins deux zones de réaction présentant des concentrations différentes en agent de transfert de chaîne
CN107880193A (zh) * 2016-09-29 2018-04-06 中国石油化工股份有限公司 一种热熔胶用高熔指 ldpe 专用料的制备方法
US11879691B2 (en) * 2017-06-12 2024-01-23 General Electric Company Counter-flow heat exchanger
CN108264592A (zh) * 2018-01-25 2018-07-10 国家能源投资集团有限责任公司 生产聚乙烯的方法
WO2024002393A1 (fr) * 2022-07-01 2024-01-04 中国石油化工股份有限公司 Procédé de polymérisation radicalaire oléfinique et appareil de polymérisation radicalaire oléfinique
CN116120493A (zh) * 2023-01-05 2023-05-16 万华化学（宁波）有限公司 一种低密度聚乙烯的制备方法、聚烯烃组合物的制备方法和其应用

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE325130B (fr) 1963-11-05 1970-06-22 Monsanto Co
GB1191168A (en) * 1966-10-06 1970-05-06 Halcon International Inc Production of Polyethylene
DE1795365A1 (de) * 1968-09-20 1972-01-05 Basf Ag Verfahren zum kontinuierlichen Herstellen von AEthylenhomopolymerisaten
DE2151649A1 (de) * 1970-05-15 1972-04-20 Exxon Research Engineering Co Verfahren und Vorrichtung zur Polymerisation von AEthylen
DE2034534B2 (de) * 1970-07-11 1978-08-03 Basf Ag, 6700 Ludwigshafen Verfahren zum Herstellen niedermolekularer, wachsartiger Polyäthylene
US3806499A (en) * 1970-12-23 1974-04-23 It Resine Spa Soc Process for polymerizing ethylene
US4175169A (en) * 1971-03-19 1979-11-20 Exxon Research & Engineering Co. Production of polyethylene
DD108546A1 (fr) * 1973-02-05 1974-09-20
DE2524204C2 (de) * 1975-05-31 1986-07-17 Basf Ag, 6700 Ludwigshafen Verfahren zur Herstellung von Hochdruckpolyäthylen
DD151070A1 (de) 1977-08-01 1981-09-30 Leuna Werke Veb Verfahren zur polymerisation von aethylen
DD137591A1 (de) * 1978-07-12 1979-09-12 Manfred Raetzsch Verfahren zur herstellung von aethylenhomo-und-kopolymerisaten
DD151069A1 (de) 1979-04-03 1981-09-30 Leuna Werke Veb Herstellung von homo-bzw.copolymerisaten des aethylens
DD146298A1 (de) 1979-09-27 1981-02-04 Wolfgang Haeussler Verfahren zur herstellung von hochdruckpolyaethylen mit verbesserten eigenschaften
DE3141507A1 (de) * 1981-10-20 1983-04-28 Basf Ag, 6700 Ludwigshafen Verfahren zur herstellung von ethylenpolymerisaten in einem zweizonen-rohrreaktor bei druecken oberhalb 500 bar
DE3227746A1 (de) 1982-07-24 1984-01-26 Basf Ag, 6700 Ludwigshafen Verfahren zur herstellung von polymerisaten des ethylens
DE4102808A1 (de) * 1991-01-31 1992-08-06 Leuna Werke Ag Verfahren zur herstellung von ethylenhomo- und ethylencopolymerisaten in mehrzonenrohrreaktoren
DE4132012A1 (de) 1991-09-26 1993-04-01 Basf Ag Ethylenhomopolymerisate und -copolymerisate sowie ein verfahren zu ihrer herstellung
DE19829399A1 (de) 1998-07-01 2000-02-03 Buna Sow Leuna Olefinverb Gmbh Verfahren zur Herstellung von Ethylenhomo- und Ethylencopolymerisaten niederer Dichte
DE10021886A1 (de) 2000-05-05 2001-11-15 Basell Polyolefine Gmbh Verfahren zum Herstellen von Phillips-Katalysatoren für die Polymerisation von Olefinen mit verbesserten Produktivitäten im Paricle-Form-Verfahren
DE10064752A1 (de) 2000-12-22 2002-07-04 Basell Polyolefine Gmbh Geruchlose Polyethylenhomo- und copolymere mit guten mechanischen Eigenschaften

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO02100907A1 *

Also Published As

Publication number Publication date
US20040220358A1 (en) 2004-11-04
CN1527850A (zh) 2004-09-08
DE10128221A1 (de) 2002-12-19
WO2002100907A1 (fr) 2002-12-19
JP4150335B2 (ja) 2008-09-17
CN1233670C (zh) 2005-12-28
JP2004529253A (ja) 2004-09-24
US6894126B2 (en) 2005-05-17

Similar Documents

Publication Publication Date Title
KR101971308B1 (ko) 저 밀도 에틸렌계 중합체의 제조를 위한 프레쉬 에틸렌 분포를 사용한 중합 방법
US4135044A (en) Process for achieving high conversions in the production of polyethylene
EP1263812B1 (fr) Procede de production de polyethylene
WO2000001740A2 (fr) Procede de production d'homopolymerisats et de copolymerisats d'ethylene de faible masse volumique
KR20170125804A (ko) 고압 자유 라디칼 중합에 의해 형성된 에틸렌계 중합체의 생산량과 품질을 제어하는 방법
DE3615562A1 (de) Verfahren zur herstellung von copolymerisaten des ethylens mit acrylsaeureestern in einem roehrenreaktor bei druecken oberhalb 500 bar
EP1395618A1 (fr) Procede pour la production d'homopolymeres et de copolymeres d'ethylene par polymerisation radicalaire a haute pression
US6300430B1 (en) Method for copolymerizing ethylene with vinyl carboxylates
DE3141507C2 (fr)
DE60106302T2 (de) Verfahren zur radikalisch kontrollierten Polymerisation oder Co-Polymerisation von Ethylene unter hohem Druck in Gegenwart von Radikalinitiatoren und Indoline Nitroxydradikalen
DE4219129A1 (de) Verfahren zur Herstellung von Copolymerisaten des Ethylens mit Acrylsäureestern
JP2004083919A (ja) １，１−ジフルオロエチレンの高圧重合方法
CN110770259B (zh) 用于生产基于乙烯的聚合物的高压自由基聚合
DE3308804A1 (de) Verfahren zur herstellung von ethylenpolymerisaten bei druecken oberhalb von 500 bar in einem zweizonen-rohrreaktor
DE2439103A1 (de) Verbessertes verfahren zur aethylenpolymerisation
DE2748263C2 (fr)
EP1287045B2 (fr) Procede de polymerisation a haute pression d'ethylene en presence d'eau surcritique
DE3225171A1 (de) Verfahren zur herstellung von ethylen-acrylsaeureester-copolymerisaten in einem zweizonen-reaktor bei druecken oberhalb 500 bar
DE2558266A1 (de) Verfahren zur herstellung von aethylenpolymeren
EP0475124A2 (fr) Copolymères de l'éthylène et de l'acétate de vinyle à point de solidification élevé
JP6785685B2 (ja) エチレン−アクリル酸エチル共重合体の製造方法
DE2044655C3 (de) Verfahren zur Herstellung von Copolymerisaten des Äthylens
WO2018167610A1 (fr) Procédé de commande de l'élasticité de fusion dans un ldpe
DE19818216A1 (de) Verfahren zur Polymerisation und Copolymerisation von Ethylen
DD300294A7 (de) Verfahren zur herstellung von ethylenhomo- und ethylencopolymerer mit verbesserter reinheit

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20031108

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: BASELL POLYOLEFINE GMBH

17Q First examination report despatched

Effective date: 20070810

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20131123