Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
  • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
  • B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
  • B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
  • B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
  • B29K2995/0037—Other properties
  • B29K2995/0059—Degradable
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B38/00—Ancillary operations in connection with laminating processes
  • B32B38/0012—Mechanical treatment, e.g. roughening, deforming, stretching
  • B32B2038/0028—Stretching, elongating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2367/00—Polyesters, e.g. PET, i.e. polyethylene terephthalate
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2519/00—Labels, badges
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
  • B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
  • B32B37/15—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer being manufactured and immediately laminated before reaching its stable state, e.g. in which a layer is extruded and laminated while in semi-molten state
  • B32B37/153—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer being manufactured and immediately laminated before reaching its stable state, e.g. in which a layer is extruded and laminated while in semi-molten state at least one layer is extruded and immediately laminated while in semi-molten state

Definitions

• the invention relates to biodegradable, in particular compostable, films which are produced by extrusion from the melt.
• the invention relates to low-curl, multilayer, at least two-layer films with an asymmetrical layer structure, which can be produced by coextrusion and are obtained directly as matt films without further treatment steps in the manufacturing process.
• the films consist of compostable polymers or copolymers and contain large amounts of mineral filler in one of the outer layers. Due to the unexpected similar volume contraction of the filled and unfilled layers of the at least two-layer film during the manufacturing process, the films according to the invention have an extremely low tendency to curl. They can also contain proportions of processing aids, color pigments and stabilizers. Due to their silky matt surface characteristics, these foils are suitable for low-gloss covering of surfaces. For example, they can be used as carrier films for wound plasters, adhesive plasters or plaster strips.
• the films according to the invention are suitable for a large number of applications, the main emphasis here being on the use as carrier films for wound plasters.
• Wound plasters generally consist of a carrier material coated with a pressure sensitive adhesive, a wound covering which is smaller in area than the carrier material and a release material which protects the pressure sensitive adhesive and wound covering during storage. Films for such applications have to meet a multitude of requirements, in addition to the technical and aesthetic requirements.
• Films for medical plasters must be dimensionally stable, can be chemically or physically pretreated in order to be printed and / or coated.
• the aesthetic requirements include primarily a silky matt
• Plaster cuts differ here from roller plasters, where higher peel forces can occur because there is no separating layer and the adhesive layer lies on the outside of the plaster.
• films for roller plasters are not very soft
• PVC polyvinyl chloride
• polymeric materials can undergo biodegradation.
• Mainly materials to be mentioned here are those that are obtained from naturally occurring polymers directly or after modification, for example polyhydroxyalkanoates such as polyhydroxybutyrate, plastic Celluloses, cellulose esters, plastic starches, chitosan and pullulan.
• polyhydroxyalkanoates such as polyhydroxybutyrate
• plastic Celluloses plastic Celluloses
• cellulose esters plastic starches
• chitosan and pullulan a targeted variation of the polymer composition or the structures, as is desirable on the part of the polymer application, is difficult and often only possible to a very limited extent due to the natural synthesis process.
• polyesters represent an important class within these materials. Synthetic raw materials which only contain aliphatic monomers have a relatively good biodegradability, but can only be used to a very limited extent on account of their material properties, cf. Witt et al. in Macrom Chem Phys, 195 (1994) S 793 - 802. Aromatic polyesters, on the other hand, show significantly deteriorated biodegradability with good material properties
• biodegradable polymers have been known recently (see DE 44 32 161). These have the property that they can be processed easily thermoplastically and, on the other hand, are biodegradable, ie their entire polymer chain is split by microorganisms (bacteria and fungi) via enzymes and completely degraded to carbon dioxide, water and biomass A corresponding test in a natural environment under the influence of microorganisms, as u. a. prevails in a compost, among other things. in the
• the object of the present invention is to provide thermoplastically processable and completely biodegradable plastic films with fillers in such a way that no synthetic materials remain in the compost and have a good mechanical profile of properties, in particular strength and impact resistance
• the film according to the invention should be free of halogen compounds and aromatic plasticizers with a comparatively low molecular weight. It should have at least one side with a good adhesion, so that it is self-adhesive can be easily coated with a pressure sensitive adhesive on common transfer laminating machines.
• the film should be adjustable so that it can adapt flexibly to skin movements in the wound area. Largely isotropic properties in the film level are advantageous for the universal use of the film.
• the object is achieved by incorporating mineral fillers into at least one layer of a multilayer film which can be produced from thermoplastic, biodegradable molding materials.
• the present invention thus relates to rigid, yet tough, biodegradable plastic films, characterized in that mineral
• biodegradable and compostable polymers or foils are understood in the sense of this invention to mean goods which are tested for biodegradability in accordance with the test according to DIN 54 900 from the 1996 draft
• the film according to the invention is preferably obtained by processing from the melt, the different layers showing only slight differences in their volume contraction when cooling, so that a low-curl structure is obtained.
• the film according to the invention can contain the additives customary in plastics processing.
• the invention also relates to a film which has a biaxial orientation and consists of one or more all biodegradable and compostable polymers and possibly contains additional additives to improve processability.
• the biaxial orientation takes place in the case of amorphous thermoplastics in temperature ranges above the glass transition temperature and in the case of partially crystalline thermoplastics below the crystallite melting temperature.
• the invention also relates to the use of the matted compostable films as a carrier web of adhesive tapes which are coated on one side with the pressure-sensitive adhesives known from the prior art. In particular, this relates to adhesive tapes that are processed into wound or active substance plasters.
• the layer structure according to the invention is made up of at least one layer (1) made of a compostable polymer and / or a compostable copolymer and / or mixtures thereof, optionally with the addition of suitable colors and stabilizing additives in effective amounts and at least one second matted layer (2) educated
• the layer (2) is characterized in that it is a matrix, i. h with a predominant proportion, has compostable polymers and receives the matting by adding a filler.
• the same polymer as layer (1) is preferably used as the matrix material for layer (2). Possibly. can be arranged between layers (1) and (2) further layers (3), which in turn are preferably formed from a compostable matrix resin
• Suitable polymers are:
• linear bifunctional alcohols for example ethylene glycol, hexanediol or preferably butanediol, and / or optionally cycloaliphatic bifunctional alcohols, for example cyclohexanedimethanol, and additionally, if appropriate, small amounts of higher-functionality alcohols, for example 1,2,3-propanetriol or neopentyl glycol, and also from linear bifunctionals Acids, for example succinic acid or adipic acid, and / or optionally cycloaliphatic bifunctional acids, for example cyclohexanedicarboxylic acid, and / or optionally aromatic bifunctional acids, for example terephthalic acid or isophthalic acid or naphthalenediarboxylic acid, and additionally optionally small amounts of higher-functionality acids, for example trimellitic acid, or B) from acid- and alcohol-functionalized building blocks, for example hydroxybutyric acid or hydroxyvaleric acid, or their derivatives, for example ⁇
• the acids can also be used in the form of derivatives, for example acid chlorides or esters
• Succinic acid or adipic acid and / or optionally cycloaliphatic and / or aromatic bifunctional acids, for example cyclohexanedicarboxylic acid and terephthalic acid, and additionally optionally small amounts of highly functional acids, for example trimellitic acid, or
• ester content C) and / or D) is at least 75% by weight based on the sum of C), D) and E).
• linear bifunctional alcohols for example ethylene glycol, butanediol, hexanediol, preferably butanediol, and / or cycloaliphatic bifunctional alcohols, for example cyclohexanedimethanol, and additionally, if appropriate, small amounts of higher-functional alcohols, for example 1,2,3-propan ⁇ ol or neopentyl glycol, as well as from linear bifunctional acids, for example succinic acid or adipic acid, and / or possibly cycloaliphatic bifunctional acids, for example cyclohexanedicarboxylic acid, and, if appropriate, small amounts of higher-functionality acids, for example trimellitic acid, or
• a carbonate component which is produced from aromatic bifunctional phenols, preferably bisphenol A and carbonate donors, for example phosgene,
• ester fraction F) and / or G) is at least 70% by weight based on the sum of F), G) and H).
• Alcohols for example ethylene glycol, hexanediol or butanediol, preferably butanediol or cyclohexanedimethanol, and additionally if necessary, small amounts of higher-functional alcohols, for example 1,2,3-propanetriol or neopentylgycol, and of linear and / or cycloaliphatic bifunctional acids, for example succinic acid, adipic acid, cyclohexanedicarboxylic acid, preferably adipic acid and additional, if appropriate, small amounts of higher-functional acids, for example trimellitic acid, or
• ester fraction I) and / or K) at least 30% by weight based on the
• biodegradable and compostable raw materials according to the invention can be equipped with processing aids and additives, such as, for example, nucleating agents (for example 1,5-naphthalene disodium sulfonate), stabilizers or lubricants.
• processing aids and additives such as, for example, nucleating agents (for example 1,5-naphthalene disodium sulfonate), stabilizers or lubricants.
• the biodegradable copolyesters, polyester urethanes, polyester carbonates and polyester amides have a molecular weight of at least 10,000 g / mol and have a statistical distribution of the starting materials (monomers) in the polymer.
• the biodegradable polymers mentioned are preferably polyester urethanes and polyester carbonates and particularly preferably polyester amides.
• the invention furthermore relates to the use of a certain class of materials of the biodegradable and compostable polymers for the production of the film, this class of material being polyester amide.
• the film according to the invention can be produced from a polyester amide or a mixture of different polyester amides.
• Suitable matting agents for layer (1) of the film according to the invention are minerals which are used in powder form, as is customary for incorporation into non-biodegradable thermoplastic materials.
• the mineral fillers include, for example and preferably, gypsum, wollastonite, and particularly preferably chalk and kaolin. Natural and synthetic silicas are also to be regarded as suitable. Layered silicates are particularly suitable.
• thermoplastic molding compositions for layer (1) contain 1% by weight to 80% by weight, preferably 10% by weight to 60% by weight, particularly preferably 20% by weight to 40% by weight of minerals, preferably of natural origin
• the layered silicate portion of the matted layer of the film according to the invention should advantageously be at least 10
• the invention also relates to a method for producing the reinforced thermoplastic molding compositions according to the invention, characterized in that the fillers z. B are intimately mixed with the biodegradable polymer in a kneader or preferably extruder.
• Layer has a small proportion of the total layer thickness of the one-sided matt film. Thickness combinations in are therefore of particular interest where the proportion of the layer matted with layered silicate is 15 - 40% of the total layer thickness.
• the matting layered silicate is preferably added in the form of an additive masterbatch, which in a particularly preferred embodiment has a proportion by weight of layered silicate between 30 and 80% by weight.
• a smaller proportion has economic disadvantages, while a higher proportion of layered silicate in the masterbatch has a poor distribution brings with it, which is shown, for example, in unwanted silicate agglomerates. This causes a more uneven roughness and thus a more unpleasant feel
• individual or all layers of the multilayer film according to the invention can be modified by further addition of processing aids, fillers, paints and stabilizers. Colors enable the production of plasters for special areas of application
• At least one of the layers of colored pigments contains a beige-colored film, which is popular when the wound and wound covering are not to be openly visible. Colorful colors and printing applications are often used in children's plasters. Other additives such as
• Silicates and waxes modify the application properties, in particular the sliding behavior.
• Stabilizers make it possible to preserve the films according to the invention over a longer period of time or to avoid damage during processing.
• the common additives for plastics are from Gachter and Muller in the handbook of plastic additives, Hanser Publishing company,
• the film can be wound up, but also further treatment by tempering and / or orientation and / or surface finishing on one or both sides
• the films according to the invention can be modified in their surface properties by means of a surface finishing process.
• Conventional corona, plasma or fluorine but also flame treatments are particularly suitable for this purpose.
• Such processes were described, for example, by Dorn and Wahono in Maschinen strig 96 (1990 ) 34-39 or Milker and Moller in Kunststoffe 82 (1992) 978-981 detailed.
• a preferred method is the corona treatment
• the corona treatment is expediently carried out in such a way that the film is passed between two conductor elements serving as electrodes, with such a high voltage between the electrodes - usually an alternating voltage of approximately 10 kV with a frequency? of 10 kHz - is present that spray or corona discharges can take place. These discharges ionize the air along the film surface, so that there are reactions on the film surface which are more polar compared to the polymer matrix
• the treatment intensities required for the pretreatment of the films according to the invention are in the usual range, action intensities are preferred which result in surface tensions of 38 to 50 mN / m
• the films according to the invention can be pretreated on one or both sides. Such treatments serve to improve the surfaces with regard to their adhesion properties to printing and / or coating materials.
• the usual printing applications are, for example, colorful animals or objects, which are preferably printed on the matt side of children's plasters with pressure sensitive adhesives is a common procedure for plasters; it is preferably carried out on the smoother side of the film
• Film may be surface-finished in m-line.
• the finishing can be carried out with a corona, a flame, a plasma or an oxidative substance or mixture of substances such that there is an increase in the surface tension on the film
• the invention also relates to a method for stretching the
• the biaxial stretching can be carried out in the simultaneous stretching process or in the two-stage sequential process, where both first longitudinal and then transverse stretching and first transverse and then slow stretching, or in the three-stage sequential process, both longitudinal, then transverse and finally slow stretching as well as first crosswise, then longitudinally and finally laterally stretching, or in the four-stage sequential process, where both first longitudinally, then laterally, then longitudinally and finally laterally stretched, and first laterally, then longitudinally, then laterally and finally can be stretched slowly
• the film may be attached to each individual stretching.
• the individual stretching in the longitudinal and transverse directions can be carried out in one or more stages
• the biaxial stretching is characterized in that it is a sequential process which begins with the elongation.
• the biaxial stretching is characterized in that the total stretching ratio in the longitudinal direction is 1 1, 5 to 1 * 10 and the total stretching ratio in the transverse direction is 1 2 to 1 20
• the biaxial stretching is characterized in that the total stretching ratio in the longitudinal direction is 1 2.8 to 1 8 and the total stretching ratio in the transverse direction is 1 3.8 to 1 15
• the film according to the invention has a thickness which is ⁇ 500 ⁇ m
• a special embodiment of the films according to the invention is characterized in that the film has a total thickness between at least 30 ⁇ m and at most 200 ⁇ m. Films with a thickness of at least 50 ⁇ m and at most 100 ⁇ m are particularly suitable
• the invention furthermore relates to the use of the film according to the invention.
• the use of this film as a solo film in pretreated or untreated as well as in printed or unprinted form is suitable for coating with PSAs.
• the film coated in this way is suitable, for example, as a label or adhesive strip.
• the finishing stage is the application of wound dressings or drug release functions that are common with plasters
• the film surface can be pretreated with a corona, a flame, a plasma or another oxidative substance or mixture of substances during production and / or subsequently during further processing, so that there is an increase in the surface tension
• a corona, a flame, a plasma or another oxidative substance or mixture of substances during production and / or subsequently during further processing, so that there is an increase in the surface tension
• only substances which are biodegradable and compostable are used to produce a plaster structure, so that the overall composite is also biodegradable and compostable.
• the invention furthermore relates to the use of the film according to the invention as a starting material for the production of an adhesive tape or plaster with very high water vapor permeability, by piercing this film with a cold or tempered needle roller.
• the purpose of this film is the wound covering and protective film in the hygiene area
• a two-layer film was produced by coextrusion on a blown film line.
• the extruders used for melting were operated with temperature programs of 130-145 ° C, the temperature of the blown film tool was 145 ° C
• the formed film had a layer thickness sequence of 20 ⁇ m, 60 ⁇ m. Due to the inaccuracy of a thickness determined by mechanical scanning, which is caused by the roughening effect of the addition of the layered silicate according to the invention, the indicated thicknesses are nominal layer thicknesses, which arithmetically assume a smooth surface of the real rough, matted On the basis of the densities of the raw materials or the averaged densities of the raw material mixtures, these nominal layer thicknesses or the total nominal layer thickness can be calculated by adding the values obtained for the respective layers
• the outer layer (1) of the tube bladder was made from a compostable polyester amide.
• the polyester amide used was built up from the building blocks butanediol, adipic acid and caprolactam. It had a melt viscosity of 250 Pas at 190 ° C (measured according to DIN 5481 1-B) and a melting point of 125 ° C measured according to ISO 146 / C2 The density of the
• Polyesteramids was 1.07 g / cm 3 , measured according to ISO 1 183
• the outer layer formed from the polyester amide resin with the addition of lubricants was subjected to a corona treatment after the film production and a surface tension of 35 mN / m was achieved
• the 20 ⁇ m thick inner layer (2) of the film was produced from a mixture consisting of 70% by weight of the polyester amide resin used for the 60 ⁇ m thick layer and 30% by weight of a layered silicate masterbatch.
• This masterbatch had a talcum content of 50% by weight
• the size of the talc particles was smaller than 22 ⁇ m.
• the melting temperature measured according to Dusenaust ⁇ tt was 152 ° C
• a two-layer film structure with a total thickness of 51 ⁇ m made of biodegradable polyester amide with a melt viscosity of 250 Pas at 190 ° C (measured according to DIN 54 811-B) and a melting point of 125 ° C measured according to ISO 3146 / C2 was measured under the following process parameters biaxially stretched
• the maximum extrusion temperature was 205 ° C
• the extruder temperature zones were heated to a maximum of 182 ° C and the mold to a maximum of 205 ° C.
• the melt was cooled as a two-layer flat film on a cooling roll mill at roll temperatures of 20 ° C. A solid thick film was formed, which in the next process step
• the smooth layer (1) consisted of polyester amide with the addition of lubricants. It had a thickness of 39 ⁇ m
• the matted layer (1) with a thickness of 12 ⁇ m was made from a mixture consisting of 80% by weight of that used for the 39 ⁇ m thick layer
• Polyester amide resin and 20% by weight of a silica masterbatch The masterbatch had a silica content of 40% by weight.
• the size of the silica particles was ⁇ 15 ⁇ m
• the actual stretching rollers were operated at a temperature of 70 ° C. First the flat film was twisted in two stages
• the post-heating rollers over which the film then ran had a temperature of 85 ° C.
• the preheating zones of the The transverse stretching oven was heated to 100 ° C.
• the temperature in the actual transverse stretching part was 95 ° C
• Ratio 1 5 stretched in the transverse direction This gave a calculated area stretch ratio of 1 18.75.
• the film was fixed at a temperature of 105 ° C.
• the production speed at the outlet of the transverse stretch was 32.0 m / min Comparative Example A
• Example 2 Using a blown film tool, a single-layer film with a thickness of 100 ⁇ m was formed analogously to Example 1.
• the polyester amide resin used was lubricated.
• Example 2 Analogously to Example 2, a single-layer flat film made of polyester amide was oriented.
• the polyester amide resin was equipped with lubricants.
• the film thickness was 46 ⁇ m
• the mechanical great tensile strength and elongation at break in both the longitudinal and transverse directions of the samples were determined in accordance with DIN 53 455.
• the modulus of elasticity in the longitudinal and transverse directions was determined in accordance with DIN 53 457.
• the thickness of the individual samples was determined in accordance with DIN 53 370
• the surface gloss was determined as optical properties on the films in accordance with DIN 67 530 at a test angle of 20 °. The gloss measurement was carried out separately on both sides of the film.
• the compostability was carried out in accordance with the test regulation of the DIN standard draft DIN 54 900 part 3 from 1996. Based on the test results, the film samples were classified into the appropriate class in accordance with the DIN recommendations

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Laminated Bodies (AREA)
• Biological Depolymerization Polymers (AREA)
• Manufacture Of Macromolecular Shaped Articles (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 1996
  • 1996-07-26 DE DE19630231A patent/DE19630231A1/de not_active Withdrawn
• 1997
  • 1997-07-14 CA CA002262000A patent/CA2262000A1/en not_active Abandoned
  • 1997-07-14 BR BR9710571A patent/BR9710571A/pt not_active Application Discontinuation
  • 1997-07-14 KR KR1019997000615A patent/KR20000029557A/ko not_active Application Discontinuation
  • 1997-07-14 CN CN97196781A patent/CN1226203A/zh active Pending
  • 1997-07-14 IL IL12807497A patent/IL128074A0/xx unknown
  • 1997-07-14 EP EP97933673A patent/EP0914250A1/de not_active Withdrawn
  • 1997-07-14 AU AU36947/97A patent/AU718448B2/en not_active Ceased
  • 1997-07-14 WO PCT/EP1997/003745 patent/WO1998004412A1/de not_active Application Discontinuation
  • 1997-07-14 JP JP10508432A patent/JP2000516545A/ja active Pending

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