WO1995024445A2 - Flame-retardant recycled polyester compositions - Google Patents
Flame-retardant recycled polyester compositions Download PDFInfo
- Publication number
- WO1995024445A2 WO1995024445A2 PCT/US1995/002651 US9502651W WO9524445A2 WO 1995024445 A2 WO1995024445 A2 WO 1995024445A2 US 9502651 W US9502651 W US 9502651W WO 9524445 A2 WO9524445 A2 WO 9524445A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- phosphinic acid
- polyester
- carboxyethyl
- carboxy
- recycled
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/68—Polyesters containing atoms other than carbon, hydrogen and oxygen
- C08G63/692—Polyesters containing atoms other than carbon, hydrogen and oxygen containing phosphorus
- C08G63/6924—Polyesters containing atoms other than carbon, hydrogen and oxygen containing phosphorus derived from polycarboxylic acids and polyhydroxy compounds
- C08G63/6926—Dicarboxylic acids and dihydroxy compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/49—Phosphorus-containing compounds
- C08K5/51—Phosphorus bound to oxygen
- C08K5/53—Phosphorus bound to oxygen bound to oxygen and to carbon only
- C08K5/5313—Phosphinic compounds, e.g. R2=P(:O)OR'
-
- 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
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/68—Polyesters containing atoms other than carbon, hydrogen and oxygen
- C08G63/692—Polyesters containing atoms other than carbon, hydrogen and oxygen containing phosphorus
-
- 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
- C08J11/00—Recovery or working-up of waste materials
- C08J11/04—Recovery or working-up of waste materials of polymers
Definitions
- This invention relates to new flame retardant polyester compositions and a method for producing the polyester compositions. More particularly, this invention relates to new flame retardant copolyesters produced from recycled polyesters and to a method for producing the polyester compositions. More particularly this invention relates to new flame retardant copolyesters produced from recycled polyethylene terephthalate and carboxy- phosphinic acids, a process for producing the copolyesters and shaped articles produced from the copolyesters. DESCRIPTION OF THE PRIOR ART
- polyesters One of the major uses of polyesters is the production of shaped polyester articles and of woven and non-woven textiles such as fabrics, filaments, staples or yarn and of sheets. In recent years efforts to make textiles less flammable, to improve the safety characteristics of products such as apparel, bedding, home furnishings, aircraft and automobile interior fabrics and industrial fabrics, have increased. It is also recognized that the textiles may be blends, particularly blends of natural fibers, such as cotton, and synthetic fibers, such as polyesters.
- U.S. Patent 4,034,141 teaches the use of brominated phosphoramidates to treat combustible materials to impart fire retardant properties.
- the combustible materials are fabrics such as cotton, rayon and paper and synthetic fibers such as polyesters.
- the fire retardant composition is applied by treating the fabric with a solution of the composition, drying the fabric and curing the composition.
- U.S. Patent 3,969,437 teaches the use of a specific class of cyclic phosphorus esters to prepare a durable, flame retardant textile finish for cotton- polyester blends.
- the phosphorus ester used must contain at least one carbon-bonded primary alcohol group, and preferably two or more, plus a pentavalent phosphorus ester group.
- U.S. Patent 3,922,323 teaches a process for improving the flame resistance of polyesters, especially unsaturated polyesters, by chemically binding and/or admixing organic phosphorus compounds and, if desired, halogen compounds into the polyesters. Halogen containing, at least bicyclic phosphonic esters which are free from hydroxy and carboxylic groups are used.
- U.S. Patent 3,941,752 teaches a flame retarded, synthetic linear polyester modified with carboxy-phosphinic acids. The linear polyester is the polycondensation product of a dicarboxlyic acid, a diol and a flame-retarding carboxy-phosphinic acid monomer which may contain hetero atoms.
- a need remains for flame retardant recycled polyethylene terephthalate materials, with properties equal to, or better than, the properties of virgin polyethylene terephthalate, which will maintain their flame retardant properties throughout their useful life and for a process to produce such a polyester.
- copolyesters of recycled polyethylene terephthalate and a carboxy- phosphinic acid monomer which have flame retardant properties are directed to copolyesters of recycled polyethylene terephthalate and a carboxy- phosphinic acid monomer which have flame retardant properties.
- the copolyester is preferably a polyethylene dicarboxylate copolyester having from about 99.9% to about 90% by weight of recycled polyethylene terephthalate and from about 0.1% to about 10% by weight of the carboxy-phosphinic acid monomer.
- the copolyester is produced by placing the desired amounts of recycled polyethylene terephthalate and carboxy-phosphinic acid in a nitrogen filled reactor in the presence of ethylene glycol and a catalyst which is preferably based upon antimony such as, for example, antimony oxide.
- the reactor is heated to a temperature within the range of from about 263°C. to about 293°C. for a period of from about 1 hour to about 3 hours.
- a vacuum is applied slowly to reduce the pressure to a pressure within the range of from about 0.5 to about 1.0 mm of mercury.
- the invention also includes copolyesters of other polyalkylene dicarboxylates such as polybutylene terephthalate and polyethylene naphthanate. DESCRIPTION OF THE PREFERRED EMBODIMENTS
- the present invention relates to copolyesters of recycled polyesters having flame retardant properties.
- the copolyesters of this invention have an intrinsic viscosity greater than about 0.7, and preferably within the range of from about 0.7 to about 1.2 and a glass transition temperature greater than about 65°C.
- copolyesters of the preferred recycled polyethylene terephthalate are preferably a polyethylene dicarboxylate copolyester having from about 99.9% to about 90% by weight recycled polyethylene terephthalate and from about 0.1% to about 10% by weight of a flame retarding carboxy-phosphinic acid monomer having the general formula:
- R is a saturated open-chain or cyclic alkylene radical having from one to about 15 carbon atoms, preferably from 2 to about 10 carbon atoms, or an arylene or aralkylene radical such as, for example, methyl, ethyl, propyl, isopropyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, 2-ethylhexyl, iso-octyl, decyl, isodecyl, dodecyl, tetradecyl, -C 6 H 4 -, -C 6 H 4 -CH 2 - , and -C 6 H 4 -CH 2 -CH 2 -, and R 1 is an alkyl radical having up to about 6 carbon atoms, an aryl radical or an alkaryl radical wherein the alkyl substituent has from 1 to about 6 carbon atoms such as, for example,methyl, methyl
- the carboxy-phosphinic acid is preferably 2-carboxyethyl (phenyl)phosphinic acid, 2-carboxyethyl (methyl) phosphinic acid, the cyclic anhydride of 2-carboxyethyl (phenyl)phosphinic acid or the cyclic anhydride of 2-carboxyethyl (methyl)phosphinic acid.
- Polymerization of 90% by weight recycled polyethylene terephthalate and 10% by weight 2- carboxyethyl (phenyl)phosphinic acid produced a flame retardant polyester having an intrinsic viscosity of about 0.70.
- the polyester however, had a slight drop in the glass transition temperature, the melting point and the crystallinity when compared to virgin polyethylene terephthalate, but the color of the polyester was improved. Recycling polyethylene terephthalate produces a polyester which has a lower molecular weight than virgin polyethylene terephthalate.
- the inclusion of the phosphinic acid moiety in the process of this invention promotes chain bonding to produce longer carbon chains and, thus, higher molecular weights.
- the inclusion of the phosphinic acid moiety is a complex process in which the intrinsic viscosity of the process fluid drops originally from the viscosity of the polyethylene terephthalate to as low as about 0.25 before it begins to rise and the intrinsic viscosity of the copolyester may reach as high as about 1.2 if the process is allowed to go to completion.
- the preferred acid, 2-carboxyethyl (phenyl) phosphinic acid may be prepared in accordance with the teaching in U.S. Patent 4,081,463.
- the 2-carboxyethyl (phenyl)phosphinic acid is prepared in two stages by first reacting dichloro(phenyl)phosphine with acrylic acid employed at a molar excess of 25% to 45% to form a mixture of three intermediates, 3- (chlorophenylphosphinyl) propionyl chloride, the cyclic anhydride of 2-carboxyethyl (phenyl)phosphinic acid and the mixed anhydride of acrylic acid with 3- chlorocarbonylethyl (phenyl)phosphinic acid.
- the second stage of the process is the hydrolysis of the of the mixture of the three intermediates to obtain the desired product, 2-carboxyethyl (phenyl)phosphinic acid.
- the flame retardant copolyesters of recycled polyethylene terephthalate are preferably polyethylene dicarboxylate copolyesters having from about 99.9% to 90% by weight recycled polyethylene terephthalate and from about 0.1% to about 10% of the flame retarding 2- carboxyethyl (phenyl)phosphinic acid, or the cyclic anhydride thereof.
- the desired polyester of this invention may be produced by the polymerization of from about 99.9% to about 90% by weight recycled polyethylene terephthalate and from about 0.1% to about 10% by weight of 2-carboxyethyl (phenyl)phosphinic acid.
- the high molecular weight of the product polyester indicated that the phosphinic acid group was highly reactive and the end- group analysis did not show terminal phosphinic acid groups in a high proportion. Further, the addition of phosphorus compounds usually creates additional observable color in the product.
- the addition of the carboxy-phosphinic acid in this invention allowed the use of higher amounts of catalyst and still had less color in the product than polyesters produced without the included acid.
- the copolyesters were produced by placing the desired amounts of recycled polyethylene terephthalate and 2-carboxyethyl (phenyl)phosphinic acid in a nitrogen filled reactor in the presence of ethylene glycol and a catalyst which is preferably antimony oxide.
- the reactor was heated to a temperature within a range of from about 250°C. to about 293°C, preferably within a range of from about 263°C. to about 293°C. , for a period of from about 1 hour to about 3 hours.
- a vacuum was applied slowly to reduce the pressure to a pressure of from about 0.5 to about 1.0 mm of mercury. The reaction continued at those conditions for an additional 45 minutes before the heat and vacuum were removed.
- Ethylene glycol was used in the description of the process and it is the preferred diol. However, other aliphatic diols such as, for example, aliphatic diols having from 3 to about 7 carbon atoms, may also be used.
- the carboxy-phosphinic acid and its cyclic anhydride are not volatile under the process conditions for production of the polyesters so they can be incorporated in the polyester by inclusion in the condensation reaction. When incorporated into the molecule during the condensation reaction the phosphorus containing structural unit is randomly distributed in the linear polyester product.
- the polyesters of this invention may be made into shaped articles. They may be spun into filaments and fibers using well known processes and the standard additional treatments. The polyesters may also be extruded into sheets or formed into shaped articles which may be solid or hollow by press molding, injection molding and extrusion. All of these shaped articles (fibers, sheets and other shapes) are also an object of this invention.
- the fibers and filaments have very good and permanent flame retardant and self-extinguishing properties. Since they have a good degree of whiteness, they have very good dyeing properties for disperse dyestuffs and their receptivity includes acid dyestuffs in color shades of average to deep intensity.
- the tensile strength of the filaments and fibers, second order transition temperature and melting point approximately correspond to the values for polyesters which do not contain the flame retardant carboxy-phosphinic acid.
- the fibers and filaments are generally useful for applications where readily ignitable textiles cannot be tolerated and it is possible to use these fibers in combination with natural fibers, such as cotton, and other synthetic fibers.
- Sheets and shaped articles produced from the flame retardant polyester are generally used in locations where it is desired to reduce the possible serious risks if ignition and a fire occur. If the transparency of the shaped articles is not of concern, their solidity and flame retarding properties can be enhanced by the inclusion of inorganic fiber materials such as, for example, glass and quartz fibers and carbon in the usual quantities, in the polyester before molding.
- EXAMPLE 1 After the label was removed, a polyethylene terephthalate bottle, such as those which contain soft drinks, was washed with detergent and water, cut into pieces and dried at a temperature of about 60°C. for 7 hours in a vacuum oven. A mixture of 18 grams of recycled bottle polyethylene terephthalate, 2 grams of 2-carboxyethyl (phenyl)phosphinic acid, 3.2 grams of ethylene glycol and 0.02 grams of antimony oxide was placed within a 50 milliliter flask with a stainless steel stirrer. The flask had a nitrogen inlet and outlet and a provision for pulling a vacuum.
- a polyethylene terephthalate bottle such as those which contain soft drinks
- the flask was evacuated and filled with nitrogen 3 times at room temperature and then a continuous, slow flow of nitrogen was maintained through the flask.
- the flask was placed in a salt bath which had been preheated to about 250°C.
- the temperature of the salt bath was raised from 250°C. to about 285°C. over a period of about 1.5 hours and ethylene glycol was distilled off.
- the pressure was then reduced to 150 millitorr over a period of about 1 hour.
- the pressure in the flask was further reduced to about 50 millitorr over a period of about 30 minutes and the reaction was continued at these conditions for an additional 45 minutes at which time the heat and vacuum were removed.
- the resulting copolymer had an intrinsic viscosity of 0.85 at a concentration of 0.5 grams/deciliter in a solution of 60% phenol/40% tetrachloroethane at 25°C.
- the glass transition temperature was determined to be 69°C. by differential scanning calorimeter.
- Example 1 The reaction of Example 1 was modified. In this reaction, 19 grams of recycled bottle polyethylene terephthalate, 1 gram of 2- carboxyethyl (phenyl)phosphinic acid and 1.6 grams of ethylene glycol were reacted in the presence of 0.004 grams of antimony oxide. The conditions of the reaction were as set forth in Example 1 above. The resulting copolymer had an intrinsic viscosity of 0.83 at a concentration of 0.5 grams/deciliter in a solution of 60% phenol/40% tetrachloroethane at 25°C. The glass transition temperature was determined to be 69.8°C. by differential scanning calorimeter.
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Polyesters Or Polycarbonates (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
MX9604038A MX9604038A (en) | 1994-03-11 | 1995-03-03 | Flame-retardant recycled polyester compositions. |
KR1019960705013A KR970701757A (en) | 1994-03-11 | 1995-03-03 | Flame-retardant Regenerated Polyester Composition (FLAME-RETARDANT RECYCLED POLYESTER COMPOSITIONS) |
JP7523534A JPH09510245A (en) | 1994-03-11 | 1995-03-03 | Flame-retardant recycled polyester composition |
EP95912042A EP0754202A1 (en) | 1994-03-11 | 1995-03-03 | Flame-retardant recycled polyester compositions |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US20993194A | 1994-03-11 | 1994-03-11 | |
US209,931 | 1994-03-11 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO1995024445A2 true WO1995024445A2 (en) | 1995-09-14 |
WO1995024445A3 WO1995024445A3 (en) | 1995-11-16 |
Family
ID=22780922
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1995/002651 WO1995024445A2 (en) | 1994-03-11 | 1995-03-03 | Flame-retardant recycled polyester compositions |
Country Status (7)
Country | Link |
---|---|
EP (1) | EP0754202A1 (en) |
JP (1) | JPH09510245A (en) |
KR (1) | KR970701757A (en) |
CA (1) | CA2183662A1 (en) |
MX (1) | MX9604038A (en) |
TW (1) | TW333542B (en) |
WO (1) | WO1995024445A2 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997035903A1 (en) * | 1996-03-26 | 1997-10-02 | Ems-Inventa Ag | Process for direct chemical modification of (co)polyesters |
EP1837339A1 (en) * | 2006-03-21 | 2007-09-26 | Clariant International Ltd. | Phosphorous compound containing mixtures, a method of their preparation, and their use |
EP1837338A1 (en) * | 2006-03-21 | 2007-09-26 | Clariant International Ltd. | Phosphorous compound containing mixtures, a method of their preparation, and their use |
EP1837340A1 (en) * | 2006-03-21 | 2007-09-26 | Clariant International Ltd. | Phosphorous compound containing mixtures, a method of their preparation, and their use |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2291230A2 (en) * | 1974-11-15 | 1976-06-11 | Hoechst Ag | PROCESS FOR PREPARING FLAME-RESISTANT LINEAR POLYESTERS |
EP0174062A2 (en) * | 1984-05-25 | 1986-03-12 | Toray Industries, Inc. | Process for the depolymerization of polyester scrap |
EP0547701A2 (en) * | 1991-12-18 | 1993-06-23 | GREAT LAKES CHEMICAL ITALIA S.r.l. | Linear copolyester containing phosphorous, procedure for its preparation and its use as a flame-retardant additive |
-
1995
- 1995-03-03 WO PCT/US1995/002651 patent/WO1995024445A2/en not_active Application Discontinuation
- 1995-03-03 JP JP7523534A patent/JPH09510245A/en active Pending
- 1995-03-03 MX MX9604038A patent/MX9604038A/en unknown
- 1995-03-03 CA CA002183662A patent/CA2183662A1/en not_active Abandoned
- 1995-03-03 EP EP95912042A patent/EP0754202A1/en not_active Withdrawn
- 1995-03-03 KR KR1019960705013A patent/KR970701757A/en not_active Application Discontinuation
- 1995-03-07 TW TW084102145A patent/TW333542B/en active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2291230A2 (en) * | 1974-11-15 | 1976-06-11 | Hoechst Ag | PROCESS FOR PREPARING FLAME-RESISTANT LINEAR POLYESTERS |
EP0174062A2 (en) * | 1984-05-25 | 1986-03-12 | Toray Industries, Inc. | Process for the depolymerization of polyester scrap |
EP0547701A2 (en) * | 1991-12-18 | 1993-06-23 | GREAT LAKES CHEMICAL ITALIA S.r.l. | Linear copolyester containing phosphorous, procedure for its preparation and its use as a flame-retardant additive |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997035903A1 (en) * | 1996-03-26 | 1997-10-02 | Ems-Inventa Ag | Process for direct chemical modification of (co)polyesters |
EP1837339A1 (en) * | 2006-03-21 | 2007-09-26 | Clariant International Ltd. | Phosphorous compound containing mixtures, a method of their preparation, and their use |
EP1837338A1 (en) * | 2006-03-21 | 2007-09-26 | Clariant International Ltd. | Phosphorous compound containing mixtures, a method of their preparation, and their use |
EP1837340A1 (en) * | 2006-03-21 | 2007-09-26 | Clariant International Ltd. | Phosphorous compound containing mixtures, a method of their preparation, and their use |
US7655715B2 (en) | 2006-03-21 | 2010-02-02 | Clariant Finance (Bvi) Limited | Phosphorus-containing mixtures, a process for their preparation and their use |
US7820850B2 (en) | 2006-03-21 | 2010-10-26 | Clariant Finance (Bvi) Limited | Phosphorus-containing mixtures, a process for their preparation and their use |
US8063123B2 (en) | 2006-03-21 | 2011-11-22 | Clariant Finance (Bvi) Limited | Phosphorus-containing mixtures, a process for their preparation and their use |
Also Published As
Publication number | Publication date |
---|---|
WO1995024445A3 (en) | 1995-11-16 |
JPH09510245A (en) | 1997-10-14 |
TW333542B (en) | 1998-06-11 |
KR970701757A (en) | 1997-04-12 |
EP0754202A1 (en) | 1997-01-22 |
CA2183662A1 (en) | 1995-09-14 |
MX9604038A (en) | 1997-09-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR100404666B1 (en) | Flame Retardant Polyester Copolymer | |
SU850010A3 (en) | Method of preparing linear polyesters | |
US5151494A (en) | Flame resistant, low pilling polyester fiber | |
US5180793A (en) | Flame resistant, low pilling polyester fiber | |
US5399429A (en) | Flame retardant recycled polyester copolymers | |
US5145941A (en) | Flame resistant, low pilling polyester fiber | |
US4214069A (en) | Flame-resistant copolyesters containing phosphonic groups | |
WO1995024445A2 (en) | Flame-retardant recycled polyester compositions | |
US4940772A (en) | Process for producing flame resistant polyester | |
KR100449383B1 (en) | Manufacturing method of fire retardant polyester fiber having excellent mechanical properties | |
US5494993A (en) | Low-pill, low-flammability polyesters, production thereof and structures formed therefrom | |
MXPA96004038A (en) | Recirculated polyester compositions retarders of ll | |
US4210740A (en) | Copolyesters prepared from phosphorus compounds which can be shaped and which have reduced flammability | |
JP2865910B2 (en) | Flame retardant polyester copolymer | |
MXPA96004005A (en) | Copolymers of polyester pirorretardan | |
KR20000020667A (en) | Method for producing polyester conjugated fiber of high fire retardancy | |
KR0170068B1 (en) | Preparation process of fire-retardant polyester | |
KR930005143B1 (en) | Process for the preparation of polyester | |
WO1994019388A1 (en) | Flame retardant polyester | |
KR980009312A (en) | Manufacturing method of flame retardant polyester | |
JPH05140283A (en) | Flame-retardant copolyester | |
JPH0551441A (en) | Flame retardant copolyester |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A2 Designated state(s): CA JP KR MX |
|
AL | Designated countries for regional patents |
Kind code of ref document: A2 Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE |
|
AK | Designated states |
Kind code of ref document: A3 Designated state(s): CA JP KR MX |
|
AL | Designated countries for regional patents |
Kind code of ref document: A3 Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2183662 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1995912042 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1995912042 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1995912042 Country of ref document: EP |