IL140139A0 - Microgels and process for their preparation - Google Patents

Microgels and process for their preparation

Info

Publication number
IL140139A0
IL140139A0 IL14013999A IL14013999A IL140139A0 IL 140139 A0 IL140139 A0 IL 140139A0 IL 14013999 A IL14013999 A IL 14013999A IL 14013999 A IL14013999 A IL 14013999A IL 140139 A0 IL140139 A0 IL 140139A0
Authority
IL
Israel
Prior art keywords
initiator
ratio
olefinic monomer
olefinic
mono
Prior art date
Application number
IL14013999A
Other languages
English (en)
Original Assignee
Du Pont
Commw Scient Ind Res Org
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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=22232549&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=IL140139(A0) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Du Pont, Commw Scient Ind Res Org filed Critical Du Pont
Publication of IL140139A0 publication Critical patent/IL140139A0/xx

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
    • C08F265/00—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00
    • C08F265/04—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00 on to polymers of esters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
    • B01J13/02—Making microcapsules or microballoons
    • B01J13/06—Making microcapsules or microballoons by phase separation
    • B01J13/14—Polymerisation; cross-linking
    • 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
    • C08F2/00—Processes of polymerisation
    • C08F2/38—Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation
    • 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
    • C08F287/00—Macromolecular compounds obtained by polymerising monomers on to block polymers
    • 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
    • C08F290/00—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups
    • C08F290/02—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups on to polymers modified by introduction of unsaturated end groups
    • C08F290/04—Polymers provided for in subclasses C08C or C08F
    • 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
    • C08F290/00—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups
    • C08F290/02—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups on to polymers modified by introduction of unsaturated end groups
    • C08F290/06—Polymers provided for in subclass C08G
    • C08F290/061—Polyesters; Polycarbonates
    • 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
    • C08F293/00—Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule
    • 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
    • C08F293/00—Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule
    • C08F293/005—Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L53/00—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
    • 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
    • C08F2438/00—Living radical polymerisation
    • C08F2438/03—Use of a di- or tri-thiocarbonylthio compound, e.g. di- or tri-thioester, di- or tri-thiocarbamate, or a xanthate as chain transfer agent, e.g . Reversible Addition Fragmentation chain Transfer [RAFT] or Macromolecular Design via Interchange of Xanthates [MADIX]

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Health & Medical Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
  • Polymerisation Methods In General (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
  • Immobilizing And Processing Of Enzymes And Microorganisms (AREA)
  • Steroid Compounds (AREA)
  • Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)
  • Medicinal Preparation (AREA)
  • Macromonomer-Based Addition Polymer (AREA)
  • Graft Or Block Polymers (AREA)
IL14013999A 1998-07-10 1999-07-09 Microgels and process for their preparation IL140139A0 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US9229398P 1998-07-10 1998-07-10
PCT/US1999/015538 WO2000002939A1 (en) 1998-07-10 1999-07-09 Microgels and process for their preparation

Publications (1)

Publication Number Publication Date
IL140139A0 true IL140139A0 (en) 2002-02-10

Family

ID=22232549

Family Applications (1)

Application Number Title Priority Date Filing Date
IL14013999A IL140139A0 (en) 1998-07-10 1999-07-09 Microgels and process for their preparation

Country Status (16)

Country Link
US (5) US6355718B1 (de)
EP (1) EP1123332B1 (de)
JP (1) JP2002520432A (de)
KR (1) KR100570245B1 (de)
AT (1) ATE266687T1 (de)
AU (1) AU746495B2 (de)
BR (1) BR9912258A (de)
CA (1) CA2336960A1 (de)
DE (1) DE69917311T2 (de)
DK (1) DK1123332T3 (de)
ES (1) ES2221401T3 (de)
IL (1) IL140139A0 (de)
MX (1) MXPA01000263A (de)
NZ (1) NZ509746A (de)
PT (1) PT1123332E (de)
WO (1) WO2000002939A1 (de)

Families Citing this family (36)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AUPP337298A0 (en) * 1998-05-07 1998-05-28 University Of Melbourne, The Process for microgel preparation
FR2802209B1 (fr) * 1999-12-10 2002-03-01 Rhodia Chimie Sa Latex a chimie de surface modifiee et poudres redispersables , leur obtention et leurs utilisations
AU5143901A (en) * 2000-04-07 2001-10-23 Du Pont Process of microgel synthesis and products produced therefrom
AUPQ679400A0 (en) * 2000-04-07 2000-05-11 Commonwealth Scientific And Industrial Research Organisation Microgel synthesis
US7064151B1 (en) 2000-04-07 2006-06-20 E. I. Du Pont De Nemours And Company Process of microgel synthesis and products produced therefrom
FR2814170B1 (fr) * 2000-09-18 2005-05-27 Rhodia Chimie Sa Nouveau latex a proprietes de surface modifiees par l' ajout d'un copolymere hydrosoluble a caractere amphiphile
JP4889867B2 (ja) * 2001-03-13 2012-03-07 株式会社カネカ 末端にアルケニル基を有するビニル系重合体の製造方法、ビニル系重合体および硬化性組成物
EP1411070A4 (de) * 2001-07-16 2005-06-29 Kaneka Corp Blockcopolymer
JP4199666B2 (ja) * 2001-10-29 2008-12-17 株式会社カネカ アクリロニトリル含有ブロック共重合体及び熱可塑性樹脂組成物
CA2470522C (en) * 2001-12-21 2012-05-01 University Of Sydney Aqueous dispersions of polymer particles
US7585924B2 (en) * 2002-07-11 2009-09-08 E. I. Du Pont De Nemours And Company Pressurized high temperature polymerization process and polymerization system used therein
FR2843314B1 (fr) 2002-08-06 2004-09-24 Rhodia Chimie Sa Synthese de microgels statistiques par polymerisation radicalaire controlee
FR2846973B1 (fr) 2002-11-07 2004-12-17 Rhodia Chimie Sa Composition d'antifroissage comprenant un copolymere a architecture controlee, pour articles en fibres textiles
AU2002953369A0 (en) * 2002-11-27 2003-01-09 The University Of Melbourne Free radical polymerisation process for microgel preparation
AU2002953359A0 (en) * 2002-11-27 2003-01-09 The University Of Melbourne Microgel composition
US7959906B2 (en) * 2002-12-13 2011-06-14 L'oreal S.A. Hair-cosmetic composition comprising at least one film-forming gradient copolymer, aerosol composition comprising the cosmetic composition and method for treating hair using the composition
FR2848417B1 (fr) * 2002-12-13 2006-06-16 Oreal Composition cosmetique ou dermatologique comprenant un copolymere a gradient et procede cosmetique de maquillage ou de soin employant ledit copolymere
FR2848430B1 (fr) * 2002-12-13 2006-06-23 Composition capillaire comprenant un copolymere filmogene a gradient, composition aerosol la comprenant et procedes de traitement
FR2848429B1 (fr) * 2002-12-13 2006-06-16 Oreal Composition capillaire comprenant un copolymere filmogene a gradient, composition aerosol la comprenant et procedes de traitement
FR2870245B1 (fr) * 2004-05-14 2008-08-22 Rhodia Chimie Sa Synthese de copolymeres en forme d'etoile mikto par polymerisation radicalaire controlee
US8085875B2 (en) 2004-07-16 2011-12-27 Qualcomm Incorporated Incremental pilot insertion for channnel and interference estimation
EP3575332A1 (de) 2004-10-25 2019-12-04 The Lubrizol Corporation Verfahren zur herstellung von polymeren und zusammensetzungen daraus
AU2005299676B2 (en) 2004-10-25 2011-02-10 The Lubrizol Corporation Star polymers and compositions thereof
US7279446B2 (en) 2004-11-15 2007-10-09 Rhodia Inc. Viscoelastic surfactant fluids having enhanced shear recovery, rheology and stability performance
DE102004062551A1 (de) * 2004-12-24 2006-07-06 Rhein Chemie Rheinau Gmbh Mikrogel-enthaltende duroplastische Zusammensetzung
US7344752B2 (en) * 2004-12-27 2008-03-18 The Goodyear Tire & Rubber Company Core-shell particles synthesized through controlled free radical polymerization
FR2894971B1 (fr) * 2005-12-20 2008-05-16 Rhodia Recherches & Tech Composition pour le traitement et/ou la modification de surfaces dures, comprenant un polymere synthetique
FR2903109B1 (fr) * 2006-06-30 2012-08-03 Rhodia Recherches & Tech Polymerisation a partir d'une amine di-allylique et compose comprenant une chaine macromoleculaire comprenant des unites derivant de cette amine
JP2009215374A (ja) * 2008-03-07 2009-09-24 Sumitomo Chemical Co Ltd オレフィン−極性モノマーランダム共重合体、およびその製造方法
JP2009215373A (ja) * 2008-03-07 2009-09-24 Sumitomo Chemical Co Ltd ブロック共重合体、およびその製造方法
FR2965564B1 (fr) * 2010-09-30 2012-10-26 Rhodia Operations Preparation de polymeres hydrophiles de haute masse par polymerisation radicalaire controlee
EP2965742B1 (de) * 2011-02-15 2020-09-09 3M Innovative Properties Company Dentale zusammensetzungen mit ethylenisch ungesättigtem additions-fragmentierungsmittel
FR3034421B1 (fr) * 2015-03-30 2017-04-28 Total Marketing Services Copolymere etoile et son utilisation comme ameliorant de viscosite
US10808065B2 (en) * 2016-05-02 2020-10-20 Kyoto University Method for producing multibranched polymer and multibranched polymer
JP2019099728A (ja) * 2017-12-06 2019-06-24 三菱ケミカル株式会社 共重合体、レベリング剤、塗料組成物及び塗装物品
FR3088067B1 (fr) * 2018-11-06 2020-11-06 S N F Sa Procede de synthese de polymeres par polymerisation radicalaire controlee en emulsion inverse

Family Cites Families (37)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4085168A (en) 1971-02-22 1978-04-18 Cpc International Inc. Chemically joined, phase separated self-cured hydrophilic thermoplastic graft copolymers and their preparation
US3928255A (en) 1971-02-22 1975-12-23 Cpc International Inc Chemically joined, phase separated self-cured hydrophilic thermoplastic graft copolymers and their preparation
DE2427957A1 (de) 1974-06-10 1976-01-08 Basf Ag Verfahren zur herstellung von netzfoermig aufgebauten polymerisaten
US4235982A (en) * 1977-06-03 1980-11-25 Hercules, Incorporated Organic pigments
US4196253A (en) * 1977-09-22 1980-04-01 Hercules Incorporated Paper coated with binder and organic pigment particles
DE3486145T2 (de) 1983-07-11 1993-09-23 Commw Scient Ind Res Org Verfahren zur polymerisation und nach diesem verfahren hergestellte polymere.
KR910002473B1 (ko) 1984-07-05 1991-04-23 이 아이 듀우판 디 네모아 앤드 캄파니 아크릴 별모양 중합체
DE3574260D1 (en) * 1984-07-05 1989-12-21 Du Pont Acrylic star polymers
DE3608556A1 (de) 1986-03-14 1987-10-01 Akzo Gmbh Telechele polymere
EP0293871B1 (de) * 1987-06-04 1993-03-17 Ciba-Geigy Ag Lichtstabilisierte, sternförmig polymerisierte Mikropartikel
US4845156A (en) * 1987-12-21 1989-07-04 E. I. Du Pont De Nemours And Company Preparation of macromonomers
US5169914A (en) 1988-05-03 1992-12-08 Edison Polymer Innovation Corporation Uniform molecular weight polymers
DE69231754T2 (de) * 1991-08-19 2001-11-15 Mississippi Polymer Technologies, Inc. Macromonomere mit reaktiven endgruppen
US5502114A (en) 1992-02-10 1996-03-26 Tonen Corporation Terminal-modified polyolefins
US5322912A (en) 1992-11-16 1994-06-21 Xerox Corporation Polymerization processes and toner compositions therefrom
JPH06157618A (ja) 1992-11-27 1994-06-07 Fuji Photo Film Co Ltd 非水系樹脂分散物の製造方法及び静電写真用液体現像剤
US5444135A (en) 1992-12-17 1995-08-22 Exxon Chemical Patents Inc. Direct synthesis by living cationic polymerization of nitrogen-containing polymers
US5310807A (en) * 1992-12-30 1994-05-10 E. I. Du Pont De Nemours And Company Star polymers made from macromonomers made by cobalt chain transfer process
US5344737A (en) 1993-02-25 1994-09-06 Xerox Corporation Polywax toner compositions and processes
US5312871A (en) 1993-07-27 1994-05-17 Carnegie Mellon University Free radical polymerization process
US5395885A (en) 1993-12-17 1995-03-07 The University Of Akron Multi-arm cationic star-polymers
US5458796A (en) * 1994-03-31 1995-10-17 Shell Oil Company Synthesis of polyisobutylene star-branched polymers via living carbocationic polymerization
US5412047A (en) 1994-05-13 1995-05-02 Xerox Corporation Homoacrylate polymerization processes with oxonitroxides
US5530079A (en) 1995-01-03 1996-06-25 Xerox Corporation Polymerization processes
US5608023A (en) 1995-03-30 1997-03-04 Xerox Corporation Rate enhanced polymerization processes
JPH08269107A (ja) 1995-03-30 1996-10-15 Xerox Corp フリーラジカル重合方法
US5498679A (en) 1995-03-30 1996-03-12 Xerox Corporation Process for producing telechelic, branched and star thermoplastic resin polymers
US5773510A (en) 1995-03-30 1998-06-30 Xerox Corporation Processes for the preparation of branched polymers
US5627248A (en) 1995-09-26 1997-05-06 The Dow Chemical Company Difunctional living free radical polymerization initiators
US5723511A (en) 1996-06-17 1998-03-03 Xerox Corporation Processes for preparing telechelic, branched and star thermoplastic resin polymers
US5789487A (en) * 1996-07-10 1998-08-04 Carnegie-Mellon University Preparation of novel homo- and copolymers using atom transfer radical polymerization
US5728747A (en) 1996-08-08 1998-03-17 Xerox Corporation Stable free radical polymerization processes and compositions thereof
US6075105A (en) 1996-08-26 2000-06-13 Xerox Corporation Polymerization processes and resin particles formed thereby
AUPO460797A0 (en) * 1997-01-15 1997-02-06 University Of Melbourne, The Polymerisation process
AU727232B2 (en) * 1997-01-15 2000-12-07 University Of Melbourne, The A process for preparing polymeric microgels
US6143848A (en) * 1997-10-23 2000-11-07 The B.F.Goodrich Company End-functionalized polymers by controlled free-radical polymerization process and polymers made therefrom
AUPP337298A0 (en) * 1998-05-07 1998-05-28 University Of Melbourne, The Process for microgel preparation

Also Published As

Publication number Publication date
ES2221401T3 (es) 2004-12-16
US20020022684A1 (en) 2002-02-21
US20020019475A1 (en) 2002-02-14
US20020019476A1 (en) 2002-02-14
US20020022683A1 (en) 2002-02-21
EP1123332A1 (de) 2001-08-16
MXPA01000263A (es) 2002-04-24
JP2002520432A (ja) 2002-07-09
PT1123332E (pt) 2004-08-31
KR100570245B1 (ko) 2006-04-12
DK1123332T3 (da) 2004-06-07
US6646055B2 (en) 2003-11-11
CA2336960A1 (en) 2000-01-20
US6653407B2 (en) 2003-11-25
US6355718B1 (en) 2002-03-12
US6462114B2 (en) 2002-10-08
BR9912258A (pt) 2001-04-17
AU4868699A (en) 2000-02-01
WO2000002939A1 (en) 2000-01-20
KR20010053462A (ko) 2001-06-25
NZ509746A (en) 2003-09-26
DE69917311T2 (de) 2004-12-09
US6822056B2 (en) 2004-11-23
EP1123332B1 (de) 2004-05-12
DE69917311D1 (de) 2004-06-17
AU746495B2 (en) 2002-05-02
ATE266687T1 (de) 2004-05-15

Similar Documents

Publication Publication Date Title
DK1123332T3 (da) Mikrogeler og fremgangsmåde til deres fremstilling
PL340695A1 (en) Method of obtaining synthetic polymers of very low content of residual monomers, products obtained thereby and their application
AU2002227427A1 (en) Olefin polymerization process to produce branched polymer compositions
EP1178059A3 (de) Wasserabsorbierendes Harz, Hydropolymer, Verfahren zu seiner Herstellung und seiner Verwendung
ES441031A1 (es) Procedimiento para preparar una mezcla copolimerica en blo- que de un dieno conjugado y un hidrocarburo vinilaromatico.
AU6079700A (en) Process for preparing comb-branched polymers
ES8401993A1 (es) Procedimiento para la preparacion de una dispersion de polimero.
EP0814095A3 (de) Verfahren zur Herstellung eines Formkörpers
AU1754399A (en) Method for producing water-soluble or water-swellable polymerizates with a very low residual monomer content, products produced according to this method and the use thereof
Shah et al. Polymer-drug conjugates: manipulating drug delivery kinetics using model LCST systems
ZA989859B (en) A process for the production of cationic polyelectrolytes.
AU4126089A (en) Process for producing styrene-based polymers
WO2003033546A1 (en) Process for producing vinyl polymer
EP0230138A3 (de) Verfahren zur Herstellung von Latexpolymeren aus gasförmigen Monomeren
EP0606492A4 (de) Verfahren zur herstellung eines tetrafluorethylen/hexafluorpropen copolymers.
EP0303057A3 (de) Kontinuierliches Verfahren und System für die Herstellung von Polymeren von Maleinsäureanhydrid und bestimmten Alpha-Olefinen
ES8702448A1 (es) Un procedimiento para preparar un polimero vinilico no gelificado.
MX232718B (de)
JPS5618611A (en) Production of diallyldialkylammonium chloride
MX9706282A (es) Método para preparar composiciones de pol.meros que contienen funcionalidad tanto de ??cido como de amina.
Galina et al. Cyclization in chain-crosslinking copolymerization
MXPA02000469A (es) Proceso para la produccion continua de polimeros epoxi-(met) acrilico-estireno y su uso en revestimiento.
JPS6485398A (en) Production of paper
JPS53118489A (en) Production of vinyl ester polymer
JPS52103487A (en) Improved process for preparing acrylonitrile polymer melts