WO1996034765A1 - Impression par transfert thermique et a diffusion de colorant - Google Patents

Impression par transfert thermique et a diffusion de colorant Download PDF

Info

Publication number
WO1996034765A1
WO1996034765A1 PCT/GB1996/001022 GB9601022W WO9634765A1 WO 1996034765 A1 WO1996034765 A1 WO 1996034765A1 GB 9601022 W GB9601022 W GB 9601022W WO 9634765 A1 WO9634765 A1 WO 9634765A1
Authority
WO
WIPO (PCT)
Prior art keywords
dye
sheet
receiver
melting point
thermal transfer
Prior art date
Application number
PCT/GB1996/001022
Other languages
English (en)
Inventor
Andrew Slark
Alan Butters
Original Assignee
Imperial Chemical Industries Plc
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 Imperial Chemical Industries Plc filed Critical Imperial Chemical Industries Plc
Priority to JP8533106A priority Critical patent/JPH11504277A/ja
Priority to EP96912112A priority patent/EP0823879A1/fr
Publication of WO1996034765A1 publication Critical patent/WO1996034765A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
    • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
    • B41M5/382—Contact thermal transfer or sublimation processes
    • B41M5/385—Contact thermal transfer or sublimation processes characterised by the transferable dyes or pigments
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
    • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
    • B41M5/382—Contact thermal transfer or sublimation processes
    • B41M5/385—Contact thermal transfer or sublimation processes characterised by the transferable dyes or pigments
    • B41M5/388—Azo dyes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
    • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
    • B41M5/382—Contact thermal transfer or sublimation processes
    • B41M5/385—Contact thermal transfer or sublimation processes characterised by the transferable dyes or pigments
    • B41M5/39—Dyes containing one or more carbon-to-nitrogen double bonds, e.g. azomethine

Definitions

  • This invention relates to dye diffusion thermal transfer printing (DDTTP or D2T2 printing, D2T2 is a trade mark of Imperial Chemical Industries PLC), especially to a dye sheet carrying a dye or a dye mixture which has an improved print stability and to a transfer printing process in which the dye or the dye mixture is transferred from the transfer sheet to a receiver sheet by the application of heat.
  • DDTTP dye diffusion thermal transfer printing
  • D2T2 is a trade mark of Imperial Chemical Industries PLC
  • TTP thermal transfer printing
  • a sublimable dye is applied to a paper substrate (usually as an ink also containing a resinous or polymeric binder to bind the dye to the substrate until it is required for printing) in the form of a pattern, to produce a transfer sheet comprising a paper substrate printed with a pattern which it is desired to transfer to the textile.
  • the dye is then transferred from the transfer sheet to the textile material, to form an identical pattern on the textile material, by placing the patterned side of the transfer sheet in contact with the textile material and heating the sandwich, under light pressure from a heated plate, to a temperature from 180-220°C for a period of 30-120 seconds.
  • the dye As the surface of the textile substrate is fibrous and uneven it will not be in contact with the printed pattern on the transfer sheet over the whole of the pattern area. It is therefore necessary for the dye to be sublimable and vaporise during passage from the transfer sheet to the textile substrate in order for dye to be transferred from the transfer sheet to the textile substrate over the whole of the pattern area.
  • a dye sheet is formed by applying a heat- transferable dye (usually in the form of a solution or dispersion in a liquid also containing a polymeric or resinous binder to bind the dye to the substrate) to a thin (usually ⁇ 20 micron) substrate having a smooth plain surface in the form of a continuous even film over the entire printing area of the dye sheet.
  • a heat- transferable dye usually in the form of a solution or dispersion in a liquid also containing a polymeric or resinous binder to bind the dye to the substrate
  • Dye is then selectively transferred from the transfer sheet by placing it in contact with a material having a smooth surface with an affinity for the dye, hereinafter called the receiver sheet, and selectively heating discrete areas of the reverse side of the dye sheet for periods from about 1 to 20 milliseconds (msec) and temperatures up to 300°C, in accordance with a pattern information signal, whereby dye from the selectively heated regions of the dye sheet diffuses from the dye sheet to the receiver sheet and forms a pattern thereon in accordance with the pattern in which heat is applied to the dye sheet.
  • the shape of the pattern is determined by the number and location of the discrete areas which are subjected to heating and the depth of shade in any discrete area is determined by the period of time for which it is heated and the temperature reached.
  • Heating is generally, though not necessarily, effected by a line of heating elements, over which the receiver and transfer sheets are passed together.
  • Each element is approximately square in overall shape, although the element may optionally be split down the centre, and may be resistively heated by an electrical current passed through it from adjacent circuitry.
  • Each element normally corresponds to an element of image information and can be separately heated to 300°C to 400°C, in less than 20 msec and preferably less than 10 msec, usually by an electric pulse in response to a pattern information signal. During the heating period the temperature of an element will rise to about 300-400°C over about 5-8 msec.
  • any discrete area on the receiver sheet will depend on the period for which an element is heated while it is in contact with the reverse side of the dye sheet.
  • the process is selective in terms of location and quantity of dye transferred and the transferred dye remains close to the surface of the receiver sheet.
  • heating may be effected using a light source in a light-induced thermal transfer (LITT or L2T2 printing, L2T2 is a trade mark of imperial Chemical Industries PLC) printer where the light source can be focused, in response to an electronic pattern information signal, on each area of the dye sheet to be heated.
  • the heat for effecting transfer of the dye from the dye sheet is generated in the dye sheet which has an absorber for the inducing light.
  • the absorber is selected according to the light source used and converts the light to thermal energy, at a point at which the light is incident, sufficient to transfer the dye at that point to the corresponding position on the receiver sheet.
  • the inducing fight usually has a narrow waveband and may be in the visible, infra-red or ultra violet regions although infra- red emitting lasers are particularly suitable.
  • the surfaces of the dye sheet and receiver sheet are even so that good contact can be achieved between the printed surface of the dye sheet and the receiving surface of the receiver sheet over the entire printing area because it is believed that the dye is transferred substantially by diffusion in the molten state in condensed phases.
  • any defect or speck of dust which prevents good contact over any part of the printing area will inhibit transfer and lead to an unprinted portion on the receiver sheet on the area where good contact is prevented, which can be considerably larger than the area of the speck or defect.
  • the surfaces of the substrate of the dye and receiver sheets are usually a smooth polymeric film, especially of a polyester, which has some affinity for the dye.
  • a dye for DDTTP is its thermal properties, fastness properties, such as light fastness, and facility for transfer by diffusion into the substrate in the DDTTP process.
  • the dye or dye mixture should transfer evenly and rapidly, in proportion to the heat applied to the dye sheet so that the amount transferred to the receiver sheet is proportional to the heat applied.
  • the dye should preferably not migrate or crystallise and should have excellent fastness to light, heat, rubbing, especially rubbing with a oily or greasy object, e.g. a human finger, such as would be encountered in normal handling of the printed receiver sheet , and when in contact with plastics materials containing plasticisers, particularly poly(vinyi chloride) e.g. by being placed in a wallet of such material.
  • the dye should be sufficiently mobile to migrate from the transfer sheet to the receiver sheet at the temperatures employed, 100-400°C, in the short time-scale, generally ⁇ 20 msec.
  • Many potentially suitable dyes are also not readily soluble in the solvents which are commonly used in, and thus acceptable to, the printing industry; for example, alcohols such as i-propanol, ketones such as methyl ethyl ketone (MEK), methyl i-butyi ketone (MIBK) and cyclohexanone, ethers such as tetrahydrofuran and aromatic hydrocarbons such as toluene.
  • the dye can be applied as a dispersion in a suitable medium or as a solution in a suitable solvent to the substrate from a solution.
  • the dye In order to achieve the potential for a high optical density (OD) on the receiver sheet it is desirable that the dye should be readily soluble or readily dispersible in the ink medium. It is also important that a dye which has been applied to a dye sheet from a solution should be resistant to crystallisation so that it remains as an amorphous layer on the dye sheet for a considerable time. Crystallisation not only produces defects which prevent good contact between the dye receiver sheet but gives rise to uneven prints.
  • One way in which improved stability can be achieved is to use dyes with enhanced thermal properties, more particularly dyes with higher melting points..
  • an increase in melting point can be accompanied by an increase in the molecular weight, and an increase in the size of the molecule. Whilst an increase in molecular size means that the dye is less likely to migrate and/or crystallise after transfer to the receiver coat, it also means that there are problems in the actual transfer. Therefore it is desirable that the molecular weight of the dye is not too high.
  • a dye sheet comprising a substrate having thereon a dye coat comprising a dye or mixture of dyes having a melting point greater than 150 °C and a molecular weight of less than 440.
  • the dye has a melting point greater than 190 °C, more preferably greater than 210 °C.
  • the dye has a solubility in tetrahydrofuran of greater than 1% to allow the dye coat to be easily applied to the substrate.
  • the dye is a propyl analogue of azopyridone having a melting point of 288 °C, a molecular weight of 340 and a solubility in THF of 5.5%
  • the dye has the Formula ( R a Yachi > ,
  • Ch is a chromogen
  • Ra and Rb each independently is a spacer group Y is an interactive functional group w and x each independently is 0 or an integer equal to or greater than 1 , and m and n each independently is an integer equal to or greater than 1 , provided that w and x are not both equal to 0 and when one of w or x is 0 at least one of m and n is equal to or greater than 2.
  • chromogen is defined as meaning the arrangement of atoms which substantially governs the absorbance of electromagnetic radiation by the dye molecule and, particularly in the case of visible radiation, the arrangement of atoms which causes the dye molecule to be coloured.
  • the spacer groups represented by R" and R" may be any groups capable of carrying one or more interactive functional groups (Y) and minimising steric and electronic effects of the Y group and thereby minimising any changes in the absorption characteristics of the chromogen group Ch and thus shade which the Y group would otherwise cause.
  • Y interactive functional groups
  • the spacer groups each comprise an atom or group of atoms connected to the chromogen by at least one sigma bond and to the interactive group by at least one sigma bond.
  • the spacer groups may contain at least one of a carbon, silicon or sulphur atom, preferably two carbon atoms and more preferably from three to ten carbon atoms.
  • the interactive functional group represented by Y are such that the Y groups on different dye molecules may be interact with each other to form dye complexes of larger size and thus of lower mobility and/or the Y groups may interact with a dye receptive polymer on the receiver sheet.
  • the Y groups may be the same or different and the R" and R" may carry one more Y groups. The interactions between different Y groups or between the Y groups and the dye receptive polymer produces an image on the receiver sheet which is resistant to crystallisation and migration of the dyes is minimised.
  • a release layer comprising a styrene /butadiene copolymer is provided on the surface of the dye coat.
  • the coating suitably comprises a binder together with a dye or mixture of dyes of Formula (1).
  • the ratio of dye to binder is preferably 1 :2 to 4:1 in order to provide good adhesion between the dye and the substrate and inhibit migration of the dye during storage.
  • the coating may also contain other additives, such as curing agents, preservatives, etc., these and other ingredients being described more fully in EP 133011 A, EP 133012A and EP 111004A.
  • the Binder may also contain other additives, such as curing agents, preservatives, etc., these and other ingredients being described more fully in EP 133011 A, EP 133012A and EP 111004A.
  • the binder may be any resinous or polymeric material suitable for binding the dye to the substrate which has acceptable solubility in the ink medium, i.e. the medium in which the dye and binder are applied to the transfer sheet. It is preferred however, that the dye is soluble in the binder so that it can exist as a solid solution in the binder on the transfer sheet. In this form it is generally more resistant to migration and crystallisation during storage.
  • binders include cellulose derivatives, such as ethylhydroxyethylcellulose (EHEC), hydroxypropylcellulose (HPC), ethyicellulose, methylcellulose, cellulose acetate and cellulose acetate butyrate; carbohydrate derivatives, such as starch; alginic acid derivatives; alkyd resins; vinyl resins and derivatives, such as polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetoacetal and polyvinyl pyrrolidone; polycarbonates such as AL-71 from Mitsubishi Gas Chemicals and MAKROLON 2040 from Bayer (MAKROLON is a trade mark); polymers and co-polymers derived from acrylates and acrylate derivatives, such as polyacrylic acid, polymethyi methacrylate and styrene-acrylate copolymers, styrene derivatives such as polystyrene, polyester resins, polyamide resins
  • mixtures preferably comprise a vinyl resin or derivative and a cellulose derivative, more preferably the mixture comprises polyvinyl butyral and ethyicellulose. It is also preferred to use a binder or mixture of binders which is soluble in one of the above-mentioned commercially acceptable organic solvents.
  • the dye or mixture of dyes has good thermal properties giving rise to even prints on the receiver sheet, whose depth of shade is accurately proportional to the quantity of applied heat so that a true grey scale of coloration can be attained.
  • the dye or mixture of dyes also has strong absorbance properties and is soluble in a wide range of solvents, especially those solvents which are widely used and accepted in the printing industry, for example, alkanols, such as i-propanol and butanol; aromatic hydrocarbons, such as toluene, ethers, such as tetrahydrofuran and ketones such as MEK, MIBK and cyclohexanone.
  • the mixture of dyes may be dispersed by high shear mixing in suitable media such as water, in the presence of dispersing agents. This produces inks (solvent plus mixture of dyes and binder) which are stable and allow production of solution or dispersion coated dyesheets. The latter are stable, being resistant to dye crystallisation or migration during prolonged storage.
  • the combination of strong absorbance properties and good solubility in the preferred solvents allows the achievement of good OD of the dye or mixture of dyes on the receiver sheet.
  • the transfer sheets of the present invention have good stability and produce receiver sheets with good OD and which are fast to both light and heat.
  • the substrate may be any sheet material preferably having at least one smooth even surface and capable of withstanding the temperatures involved in DDTTP, i.e. up to 400C for periods up to 20 msec, yet thin enough to transmit heat applied on one side through to the dyes on the other side to effect transfer of the dye onto a receiver sheet within such short periods.
  • suitable materials are polymers, especially polyester, polyacrylate, polyamide, cellulosic and polyalkyiene films, metallised forms thereof, including co-polymer and laminated films, especially laminates incorporating a smooth even polyester receptor layer on which the dye is deposited.
  • a laminated substrate preferably comprises a backcoat, on the opposite side of the laminate from the receptor layer, which, in the printing process, holds the molten mass together, such as a thermosetting resin, e.g a silicone, acrylate or polyurethane resin, to separate the heat source from the polyester and prevent melting of the latter during the DDTTP operation.
  • a thermosetting resin e.g a silicone, acrylate or polyurethane resin
  • the thickness of the substrate depends to some extent upon its thermal conductivity but it is preferably less than 20 ⁇ m and more preferably less than 10 ⁇ m.
  • a dye diffusion thermal transfer printing process which comprises contacting a dye sheet comprising a coating comprising a dye or mixture of dyes having a melting point greater than 150°C and a molecular weight less than 440 with a receiver sheet, so that the coating is in contact with the receiver sheet and selectively applying heat to discrete areas on the reverse side of the dye sheet whereby the dye on the opposite side of the sheet to the heated areas is transferred to the receiver sheet.
  • Heating in the selected areas may be effected by contact with heating elements, which can be heated to 200-450C, preferably 200-400°C, over periods of 2 to 10 msec, whereby the dye mixture may be heated to 150-300°C, depending on the time of exposure, and thereby caused to transfer, substantially by diffusion, from the transfer to the receiver sheet.
  • Heating elements which can be heated to 200-450C, preferably 200-400°C, over periods of 2 to 10 msec, whereby the dye mixture may be heated to 150-300°C, depending on the time of exposure, and thereby caused to transfer, substantially by diffusion, from the transfer to the receiver sheet.
  • Good contact between coating and receiver sheet at the point of application is essential to effect transfer.
  • the density of the printed image is related to the time period for which the transfer sheet is heated.
  • the heat may be generated by means of a laser, in which case the dye coat also contains an absorber material for absorbing and converting the laser light to heat.
  • the receiver sheet conveniently comprises a polymeric sheet material substrate, preferably a white polymeric film.
  • the design of receiver and transfer sheets is discussed further in EP 133,011 and EP 133012.
  • thermo transfer dye sheet/receiver sheet combination in which the dye sheet comprises a dye having a melting point greater than 150 °C and a molecular weight of less than 440 and in which the receiver sheet comprises a substrate having thereon a receiver coat consisting of a polymer more hydrophilic than polyester.
  • the receiver coat preferably contains at least one polymer capable of interacting with Y.
  • the receiver coat polymer is poly (vinyl pyridene), poly (vinyl pyrrolidone) or a vinyl pyrrolidone. vinyl acetate copolymer.
  • a dye sheet was produced by coating a 6 micron thick substrate supplied by Diafoil with a solution containing 1.4% w/w dye and 2.8%w/w poly (vinyl butyral) in tetrahydrofuran using a K3 wire bar and drying the coating at 110 ° C for 20 seconds to 1.0 ⁇ m thickness and then applying a 1.2% w/w solution in hexane of a copolymer containing equal amounts of styrene and butadiene (Europrene ® Sol S141 from Enichem) with a K2 wire bar to produce a release layer 0.15 ⁇ m in thickness.
  • a receiver sheet was prepared by coating a Melinex 990 ® substrate with a solution containing 11.1 %w/w of an amorphous polyester ( Vylon 103 ®) using a K4 wire bar and dried at 140 °C for 3 minutes to give a final coat of 4 ⁇ m.
  • Printing was carried out at different print times using a laboratory thermal printer having a head voltage of 12 v. After measuring the optical density using a Macbeth densitomiter , the receiver sheets were placed in wallets of PVC containing dioctyl phthalate as plasticiser and maintained under pressure in an oven at 45°C/85% RH for 16 hours. The sheets were removed from the wallets and the OD of the dye which had transferred to the PVC sheet was measured. The ratio of transfer OD/original OD gives a measure of the stability of the image.
  • Example 1 was repeated except that the polyester binder was replaced with a vinyl pyrrolidone/ vinyl acetate resin. The results are shown in Table 2.
  • Example 1 was repeated except that isothiazole dyes were used at a print time of
  • Examples 1 to 3 were repeated at print times of 8.4 and 14.8 ms using dye sheets containing 2.1%w/w of dye Y2 and 2.1%w/w poly vinyl butyral. The results are shown in Table 5.

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Thermal Transfer Or Thermal Recording In General (AREA)

Abstract

Cette invention concerne une feuille de colorant à transfert thermique permettant d'obtenir des images d'une meilleure stabilité lors de l'impression, laquelle feuille comprend un substrat sur lequel se trouve un revêtement de colorant. Ce revêtement se compose d'un colorant ou d'un mélange de colorants dont la température de fusion est supérieure à 150° C et d'un poids moléculaire inférieur à 440.
PCT/GB1996/001022 1995-05-02 1996-04-30 Impression par transfert thermique et a diffusion de colorant WO1996034765A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP8533106A JPH11504277A (ja) 1995-05-02 1996-04-30 染料拡散熱転写捺染
EP96912112A EP0823879A1 (fr) 1995-05-02 1996-04-30 Impression par transfert thermique et a diffusion de colorant

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9508877.9 1995-05-02
GBGB9508877.9A GB9508877D0 (en) 1995-05-02 1995-05-02 Dye diffusion thermal transfer printing

Publications (1)

Publication Number Publication Date
WO1996034765A1 true WO1996034765A1 (fr) 1996-11-07

Family

ID=10773833

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1996/001022 WO1996034765A1 (fr) 1995-05-02 1996-04-30 Impression par transfert thermique et a diffusion de colorant

Country Status (4)

Country Link
EP (1) EP0823879A1 (fr)
JP (1) JPH11504277A (fr)
GB (1) GB9508877D0 (fr)
WO (1) WO1996034765A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6612176B2 (en) * 2000-12-28 2003-09-02 Mks Instruments, Inc. Pressure transducer assembly with thermal shield

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0389101A1 (fr) * 1989-03-23 1990-09-26 Zeneca Limited Impression par transfert thermique
EP0413229A1 (fr) * 1989-08-16 1991-02-20 BASF Aktiengesellschaft Colorants phénonazoiques et procédé de leur transfert thermique
EP0442466A1 (fr) * 1990-02-14 1991-08-21 Mitsubishi Chemical Corporation Feuille d'enregistrement pour le transfert thermique et composition d'encre pour la produire

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0389101A1 (fr) * 1989-03-23 1990-09-26 Zeneca Limited Impression par transfert thermique
EP0413229A1 (fr) * 1989-08-16 1991-02-20 BASF Aktiengesellschaft Colorants phénonazoiques et procédé de leur transfert thermique
EP0442466A1 (fr) * 1990-02-14 1991-08-21 Mitsubishi Chemical Corporation Feuille d'enregistrement pour le transfert thermique et composition d'encre pour la produire

Also Published As

Publication number Publication date
GB9508877D0 (en) 1995-06-21
JPH11504277A (ja) 1999-04-20
EP0823879A1 (fr) 1998-02-18

Similar Documents

Publication Publication Date Title
CA1316039C (fr) Feuille d'impression par transfert a chaud
JP2004122756A (ja) 保護層熱転写シートおよびマット調印画物
EP0673320B1 (fr) Impression par transfert thermique et par diffusion de colorant
EP0823881B1 (fr) Impression par transfert thermique et a diffusion de teinture
EP0492911B1 (fr) Impression par transfert thermique
US5693766A (en) Dye diffusion thermal transfer printing
EP0823879A1 (fr) Impression par transfert thermique et a diffusion de colorant
JPH02581A (ja) マゼンタ色系感熱転写シート
EP0389101B1 (fr) Impression par transfert thermique
EP0756546B1 (fr) Impression par transfert thermique a diffusion de colorants
EP0546700B1 (fr) Impression par transfert thermique
EP0302628B1 (fr) Impression par transfert thermique
EP0708710B1 (fr) Impression par transfert thermique a diffusion de colorants
EP0469723A1 (fr) Impression par tranfert thermique
EP0823880B1 (fr) Impression par transfert thermique a diffusion de colorant
WO1994004370A1 (fr) Impression par transfert thermique
US4892859A (en) Thermal transfer printing
JPH02139291A (ja) 黄色系感熱転写シート
JPH02188296A (ja) 感熱転写記録用転写シート
JP2552487B2 (ja) 熱転写記録媒体
JPS6360797A (ja) 熱転写記録方法

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP US

AL Designated countries for regional patents

Kind code of ref document: A1

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

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 1996912112

Country of ref document: EP

ENP Entry into the national phase

Ref country code: US

Ref document number: 1997 952563

Date of ref document: 19971030

Kind code of ref document: A

Format of ref document f/p: F

ENP Entry into the national phase

Ref country code: JP

Ref document number: 1996 533106

Kind code of ref document: A

Format of ref document f/p: F

WWP Wipo information: published in national office

Ref document number: 1996912112

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1996912112

Country of ref document: EP