SG43193A1 - Latent catalysts cure-inhibited epoxy resin compositions and laminates prepared therfrom - Google Patents

Latent catalysts cure-inhibited epoxy resin compositions and laminates prepared therfrom

Info

Publication number
SG43193A1
SG43193A1 SG1996005258A SG1996005258A SG43193A1 SG 43193 A1 SG43193 A1 SG 43193A1 SG 1996005258 A SG1996005258 A SG 1996005258A SG 1996005258 A SG1996005258 A SG 1996005258A SG 43193 A1 SG43193 A1 SG 43193A1
Authority
SG
Singapore
Prior art keywords
acid
polyepoxide
boric acid
mixture
catalyst
Prior art date
Application number
SG1996005258A
Other languages
English (en)
Inventor
James L Bertram
Charlie Z Hotz
Louis L Walker
Joseph Gan
Original Assignee
Dow Chemical Co
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 US07/526,488 external-priority patent/US5169473A/en
Application filed by Dow Chemical Co filed Critical Dow Chemical Co
Publication of SG43193A1 publication Critical patent/SG43193A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
    • C08G59/4007—Curing agents not provided for by the groups C08G59/42 - C08G59/66
    • C08G59/4014—Nitrogen containing compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
    • C08G59/50—Amines
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2363/00—Characterised by the use of epoxy resins; Derivatives of epoxy resins
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
    • H10W44/00—Electrical arrangements for controlling or matching impedance
    • H10W44/20—Electrical arrangements for controlling or matching impedance at high-frequency [HF] or radio frequency [RF]
    • H10W44/203—Electrical connections
    • H10W44/206—Wires

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Epoxy Resins (AREA)
  • Reinforced Plastic Materials (AREA)
  • Paints Or Removers (AREA)
  • Laminated Bodies (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Other Resins Obtained By Reactions Not Involving Carbon-To-Carbon Unsaturated Bonds (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Professional, Industrial, Or Sporting Protective Garments (AREA)
  • Wrappers (AREA)
  • Retarders (AREA)
SG1996005258A 1990-05-21 1991-05-13 Latent catalysts cure-inhibited epoxy resin compositions and laminates prepared therfrom SG43193A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US52648790A 1990-05-21 1990-05-21
US07/526,488 US5169473A (en) 1990-05-21 1990-05-21 Latent catalysts, epoxy compositions incorporating same, and coating, impregnating and bonding methods employing the compositions

Publications (1)

Publication Number Publication Date
SG43193A1 true SG43193A1 (en) 1997-10-17

Family

ID=27062123

Family Applications (1)

Application Number Title Priority Date Filing Date
SG1996005258A SG43193A1 (en) 1990-05-21 1991-05-13 Latent catalysts cure-inhibited epoxy resin compositions and laminates prepared therfrom

Country Status (15)

Country Link
EP (1) EP0458502B1 (ko)
JP (5) JP3080245B2 (ko)
KR (1) KR100229301B1 (ko)
CN (3) CN1035823C (ko)
AT (1) ATE243227T1 (ko)
AU (1) AU657264B2 (ko)
BR (1) BR9102108A (ko)
CA (1) CA2042858A1 (ko)
DE (1) DE69133280T2 (ko)
FI (1) FI912435A7 (ko)
IL (1) IL98185A (ko)
MY (1) MY141502A (ko)
NO (1) NO911933L (ko)
PT (1) PT97724A (ko)
SG (1) SG43193A1 (ko)

Families Citing this family (71)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4981926A (en) * 1990-02-06 1991-01-01 The Dow Chemical Company Composition of epoxy resin, amino group-containing phosphonium catalyst and curing agent
GB9103402D0 (en) * 1991-02-19 1991-04-03 Pilkington Plc Fire resistance
GB9208955D0 (en) * 1992-04-24 1992-06-10 Dow Europ Sa Dicyandiamide solution
US5407977A (en) * 1993-04-20 1995-04-18 The Dow Chemical Company Solvent system
US5464910A (en) * 1993-12-22 1995-11-07 Shikoku Chemicals Corporation Epoxy resin adduct combined with a borate ester and phenolic compound
GB9421407D0 (en) * 1994-10-21 1994-12-07 Dow Chemical Co Curable epoxy resin accelerated by boric acid and its analogs
GB9421405D0 (en) * 1994-10-21 1994-12-07 Dow Chemical Co Low voc laminating formulations
US5508328A (en) * 1994-11-17 1996-04-16 Alliedsignal Inc. Curing epoxy resins using dicy, imidazole and acid
US6613839B1 (en) 1997-01-21 2003-09-02 The Dow Chemical Company Polyepoxide, catalyst/cure inhibitor complex and anhydride
WO1998031750A1 (en) † 1997-01-21 1998-07-23 The Dow Chemical Company Latent catalysts for epoxy curing systems
US6353080B1 (en) 1997-06-26 2002-03-05 The Dow Chemical Company Flame retardant epoxy resin composition
GB9817799D0 (en) * 1998-08-14 1998-10-14 Dow Deutschland Inc Viscosity modifier for thermosetting resin compositioning
WO2001042253A2 (en) 1999-12-13 2001-06-14 The Dow Chemical Company Phosphorus element-containing crosslinking agents and flame retardant phosphorus element-containing epoxy resin compositions prepared therewith
CN1423678B (zh) 1999-12-13 2010-11-10 陶氏环球技术公司 含磷元素阻燃剂环氧树脂组合物
KR100419063B1 (ko) * 2000-06-10 2004-02-14 주식회사 엘지화학 에폭시 수지 조성물 및 이를 이용한 적층판
JP4534344B2 (ja) * 2000-11-27 2010-09-01 住友ベークライト株式会社 難燃性樹脂組成物、これを用いたプリプレグ及び積層板
KR100854544B1 (ko) * 2001-09-12 2008-08-26 다우 글로벌 테크놀로지스 인크. 에폭시-말단의 에스테르를 포함하는 망상구조 중합체
EP1391490A1 (en) * 2002-08-23 2004-02-25 Vantico Gmbh Modified epoxy resins for triboelectric coating processes
ATE346877T1 (de) * 2003-04-16 2006-12-15 Huntsman Adv Mat Switzerland Härtungsbeschleuniger für epoxyharzzusammensetzungen härtend bei niedriger temperatur
JP4895487B2 (ja) * 2003-08-05 2012-03-14 一般財団法人川村理化学研究所 熱硬化性樹脂組成物及びその製造方法、成型物の製造方法
US20060247334A1 (en) * 2003-08-05 2006-11-02 Akira Ohbayashi Epoxy resin composition and method for producing heat-resistant laminate sheet
JP4558359B2 (ja) * 2004-03-22 2010-10-06 財団法人川村理化学研究所 エポキシ樹脂組成物及びそれを用いた銅張積層板
EP1753772B1 (en) 2004-05-28 2016-12-28 Blue Cube IP LLC Phosphorus-containing compounds useful for making halogen-free, ignition-resistant polymers
WO2006109744A1 (ja) 2005-04-07 2006-10-19 Asahi Kasei Chemicals Corporation エポキシ樹脂組成物
DE102005029146A1 (de) * 2005-06-23 2006-12-28 Cognis Ip Management Gmbh Härter für Überzugmassen (IV)
EP1754733A1 (en) * 2005-07-26 2007-02-21 Huntsman Advanced Materials (Switzerland) GmbH Composition
US7998653B2 (en) 2005-09-15 2011-08-16 Ciba Corp. Coating compositions comprising a latent activator for marking substrates
WO2007037024A1 (ja) * 2005-09-27 2007-04-05 Sumitomo Bakelite Co., Ltd. 潜伏性触媒の製造方法及びエポキシ樹脂組成物
KR20080077639A (ko) * 2005-12-22 2008-08-25 다우 글로벌 테크놀로지스 인크. 경화성 에폭시 수지 조성물 및 이로부터 제조한 적층물
JP5114111B2 (ja) * 2006-09-07 2013-01-09 日東シンコー株式会社 樹脂組成物、熱伝導シート、金属箔付高熱伝導接着シート、ならびに、金属板付高熱伝導接着シート
JP5114112B2 (ja) * 2006-09-07 2013-01-09 日東シンコー株式会社 樹脂組成物、熱伝導シート、金属箔付高熱伝導接着シート、ならびに、金属板付高熱伝導接着シート
MY146613A (en) 2007-06-11 2012-09-14 Basf Se Catalyst for curing epoxides
CN101679607B (zh) 2007-06-12 2012-05-30 巴斯夫欧洲公司 用于固化环氧化物的催化剂
ES2354399T3 (es) 2007-06-13 2011-03-14 Basf Se Catalizador para el endurecimento de epóxidos.
CN101687977B (zh) * 2007-06-14 2012-08-15 巴斯夫欧洲公司 用于固化环氧化物的催化剂
JP5581208B2 (ja) 2007-07-18 2014-08-27 データレース リミテッド レーザー感受性被覆配合物
EP2174969A4 (en) * 2007-07-26 2012-07-25 Ajinomoto Kk RESIN COMPOSITION
US20110136993A1 (en) 2008-08-28 2011-06-09 Dow Global Technologies Llc Phosphorus-containing compounds and polymeric compositions comprising same
KR101782567B1 (ko) 2008-10-23 2017-09-27 데이터레이즈 리미티드 열 흡수 첨가제
US9267042B2 (en) 2008-10-27 2016-02-23 Datalase Ltd. Coating composition for marking substrates
KR20110139271A (ko) * 2009-03-17 2011-12-28 다우 글로벌 테크놀로지스 엘엘씨 사이클릭 디아민을 함유하는 경화성 조성물 및 이로부터의 경화물
DE102009027826A1 (de) 2009-04-29 2010-11-04 Evonik Degussa Gmbh Katalyse von Epoxidharzformulierungen
KR100925986B1 (ko) 2009-06-20 2009-11-10 정송옥 상·하수도 노후관 갱생용의 잠재성 중온 속경화형 에폭시 수지 조성물의 제조방법.
US8871892B2 (en) * 2009-11-12 2014-10-28 Dow Global Technologies Llc Polyoxazolidone resins
CN101728038A (zh) * 2009-12-04 2010-06-09 上海长园维安电子线路保护股份有限公司 热固性正温度系数热敏电阻器的制造方法及所用导电胶
EP2452978A1 (de) 2010-11-16 2012-05-16 Basf Se Verfahren zur Herstellung von mit Kohlenstoff-Füllstoffen gefüllten Epoxidharzformmassen
US9499653B2 (en) * 2011-02-23 2016-11-22 Alzchem Ag Curing agents for epoxy resins
WO2012136273A1 (de) 2011-04-08 2012-10-11 Basf Se Hyperverzweigte polymere zur modifikation der zähigkeit von anionisch gehärteten epoxidharz-systemen
CN102443168B (zh) * 2011-10-10 2016-03-09 苏州科技学院 一种多孔固体胺及其制备方法
WO2013188071A1 (en) * 2012-06-15 2013-12-19 Dow Global Technologies Llc Latent catalyst for curable compositions
DK2695903T3 (en) * 2012-08-08 2019-01-14 Siemens Ag Process for modifying the rate of temperature change of an epoxy resin composition in a resin container in a casting process
RU2015120176A (ru) * 2012-12-11 2017-01-19 Клариент Дайагностик Сервисез, Инк. Фотоактивированное химическое обесцвечивание красителей
JP5758463B2 (ja) * 2013-03-26 2015-08-05 太陽インキ製造株式会社 エポキシ樹脂組成物、穴埋め充填用組成物およびこれらを用いたプリント配線板
KR101885703B1 (ko) * 2013-05-14 2018-08-06 쓰리엠 이노베이티브 프로퍼티즈 컴파니 피라진-함유 화합물을 포함하는 에폭시 수지
DE102013008723A1 (de) 2013-05-23 2014-11-27 Deutsche Institute Für Textil- Und Faserforschung Denkendorf Polymerisierbare Reaktionsmischung zur Herstellung von Epoxidharzen und deren Verwendung
US10253136B2 (en) 2014-02-06 2019-04-09 Adeka Corporation Compound and epoxy resin composition containing same
JP6240940B2 (ja) * 2014-02-06 2017-12-06 株式会社Adeka エポキシ樹脂組成物
EP3137560B1 (en) * 2014-04-29 2020-06-03 Akzo Nobel Coatings International B.V. Coating method for surfaces in chemical installations
US10556985B2 (en) * 2015-11-17 2020-02-11 Evonik Operations Gmbh Nitrogen-containing heterocyclic epoxy curing agents, compositions and methods
US10465039B2 (en) 2015-11-17 2019-11-05 Evonik Degussa Gmbh Epoxy curing agents, compositions and uses thereof
CN107446535A (zh) * 2017-08-16 2017-12-08 浙江林境新材料科技有限公司 一种复合板
CN108565041B (zh) * 2018-04-20 2020-04-28 四川省银河化学股份有限公司 一种高电导耐焊接型低温银浆及其制备方法
EP3569629B1 (de) * 2018-05-17 2022-07-06 Evonik Operations GmbH Schnell härtende epoxysysteme
WO2020050200A1 (ja) 2018-09-05 2020-03-12 三菱ケミカル株式会社 シートモールディングコンパウンド、および繊維強化複合材料
JP7261563B2 (ja) * 2018-11-02 2023-04-20 谷川油化興業株式会社 熱交換媒体
KR102161362B1 (ko) * 2018-12-24 2020-10-05 주식회사 하이플럭스 내화 조성물
DE102019121195A1 (de) * 2019-08-06 2021-02-11 Alzchem Trostberg Gmbh Lagerstabile Epoxidharz-Zusammensetzung
CN111892695B (zh) * 2020-07-13 2022-12-30 四川省玻纤集团有限公司 耐γ辐照的改性树脂及其制备方法、层压板及其制备工艺与应用
KR102906330B1 (ko) * 2023-01-12 2025-12-30 도레이첨단소재 주식회사 인장신율이 향상된 에폭시 수지 조성물과 이로부터 제조되는 강화섬유 복합재료
CN117124521B (zh) * 2023-07-25 2026-02-03 中国工程物理研究院化工材料研究所 一种通过取向填料含量V字形调控热压成型环氧vitrimer复合材料动态性能的方法
CN118421192B (zh) * 2024-07-04 2024-08-30 湖南飘峰电气股份有限公司 防火耐高温聚酰亚胺电磁线及其制备方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4001156A (en) * 1972-08-03 1977-01-04 Ppg Industries, Inc. Method of producing epoxy group-containing, quaternary ammonium salt-containing resins
US4594291A (en) * 1984-07-17 1986-06-10 The Dow Chemical Company Curable, partially advanced epoxy resins
IL75806A (en) * 1984-07-17 1988-10-31 Dow Chemical Co Partially advanced epoxy resin compositions and products resulting from reacting and curing said compositions
US4668758A (en) * 1985-09-30 1987-05-26 Shell Oil Company Cure rate control in epoxy resin compositions

Also Published As

Publication number Publication date
JP2000309626A (ja) 2000-11-07
EP0458502A2 (en) 1991-11-27
CN1050617C (zh) 2000-03-22
KR100229301B1 (ko) 1999-11-01
AU657264B2 (en) 1995-03-09
CN1118794A (zh) 1996-03-20
IL98185A (en) 1994-06-24
JP2000136288A (ja) 2000-05-16
CN1050618C (zh) 2000-03-22
JP3269621B2 (ja) 2002-03-25
IL98185A0 (en) 1992-06-21
ATE243227T1 (de) 2003-07-15
JP3080245B2 (ja) 2000-08-21
EP0458502B1 (en) 2003-06-18
CN1118793A (zh) 1996-03-20
NO911933D0 (no) 1991-05-16
CN1035823C (zh) 1997-09-10
PT97724A (pt) 1992-03-31
DE69133280D1 (de) 2003-07-24
JP2002178342A (ja) 2002-06-26
BR9102108A (pt) 1991-12-24
DE69133280T2 (de) 2004-05-06
JPH11310627A (ja) 1999-11-09
AU7721191A (en) 1991-11-21
JP3321429B2 (ja) 2002-09-03
EP0458502A3 (en) 1992-12-02
CN1056699A (zh) 1991-12-04
FI912435A7 (fi) 1991-11-22
KR910020060A (ko) 1991-12-19
JP3383658B2 (ja) 2003-03-04
CA2042858A1 (en) 1991-11-22
JP3333762B2 (ja) 2002-10-15
NO911933L (no) 1991-11-22
JPH04227924A (ja) 1992-08-18
FI912435A0 (fi) 1991-05-20
MY141502A (en) 2010-05-14

Similar Documents

Publication Publication Date Title
SG43193A1 (en) Latent catalysts cure-inhibited epoxy resin compositions and laminates prepared therfrom
KR850003154A (ko) 화재보험, 팽창성 매스틱 조성물
MY114313A (en) Halogen-free flame-retardant epoxy resin composition as well as prepreg and laminate containing the same
ES2074991T3 (es) Composicion de resina para revestimiento.
TW364006B (en) Tackified substrates for resin transfer molding and methods to use thereof, tackifier formulations and matrix resin formulations
EP0075827A3 (en) Polyepoxide curing by polymercaptans plus catalytic co-curing agents
EP1162225A4 (en) CURING AGENT FOR EPOXY RESINS AND EPOXY RESIN COMPOSITION
ES8500295A1 (es) Procedimiento para la preparacion de resinas epoxidicas por el metodo de avance
MY129866A (en) Catalyst and epoxy resin composition containing the same.
AU682006B2 (en) Method and composition for using substituted melamines as novolak resin curing agents
DE59602725D1 (de) Epoxidharzformmassen mit halogenfreiem flammschutz
MY130069A (en) Precatalysed catalyst compositions, process for preparing epoxy resins, curable compositions,articles resulting from curing the resultant compositions
CA2101766A1 (en) Latent Acid Curable Compositions
DE3563749D1 (en) Heat-curable epoxy resin compositions
ES8301256A1 (es) "un procedimiento para preparar una composicion de revestimiento que tiene un mecanismo de curado doble".
ES8706734A1 (es) Un metodo para endurecer una pelicula de una composicion de recubrimiento a base de un compuesto polimercapto y un multi-isocianato.
EP0328411A3 (en) Composition for vibration damper, process for manufacture thereof, and vibration damper
BR9811165A (pt) Processos para a produção de compostos e de compostos epóxi, e, resina epóxi obtensìvel pelo mesmo
ES2118074T3 (es) Procedimiento catalitico para la preparacion de compuestos que contienen puentes de nitrogeno.
DE3381765D1 (de) Haertbare epoxyharzmischungen.
DE59813301D1 (de) Epoxidharzmischung, daraus hergestellte verbundwerkstoffe und deren verwendung
JPS54160496A (en) Curable composition
ATE149553T1 (de) Bindemittel für lagerfähige überzugsmassen
ES8302005A1 (es) Procedimiento para preparar compuestos cefalosporanicos