AU670096B2

AU670096B2 - Process for producing a metal-plastic film composite material, metal-plastic film composite material produced according to said process and its use for producing packaging containers

Info

Publication number: AU670096B2
Application number: AU43207/93A
Authority: AU
Inventors: Leonidas Kiriazis
Original assignee: BASF Lacke und Farben AG
Current assignee: BASF Farben und Fasern AG
Priority date: 1992-06-04
Filing date: 1993-06-01
Publication date: 1996-07-04
Anticipated expiration: 2013-06-01
Also published as: CA2136746A1; DK0689505T3; EP0689505B1; AU4320793A; ES2111749T3; WO1993024324A1; ATE158985T1; ZA933713B; DE4218369A1; DE59307521D1; EP0689505A1

Abstract

A process is disclosed for producing a metal-plastic film composite material by sheet die extrusion of a statistical polypropylene copolymer into a plastic film. After leaving the sheet die, the polypropylene is cooled by means of cooling cylinders and the plastic film thus obtained is laminated onto at least one of the main surfaces of a metal sheet. The process is characterized in that the polypropylene copolymer is directly cooled after leaving the sheet die of the extruder down to temperatures between 0 C and 15 C. Once the plastic film has been laminated onto the metal sheet by means of a solvent-containing or aqueous adhesive, the metal-plastic film composite material thus obtained is cooled down to temperatures from 0 C to 25 C, when the film is laminated onto the metal sheet at temperatures above the melting point of the polypropylene copolymer, or when the plastic film is laminated onto the metal sheet by means of a coextruded bonding agent the metal-plastic film composite material thus obtained is cooled down to temperatures from 0 C to 25 C. Also disclosed is a metal-plastic film composite material produced according to this process and its use for producing packaging containers.

Description

t lip- 'i OPI DATE 30/12/93 APPLN. ID 43207/93 AOJP DATE 10/03/94 PCT NUMBER PCT/EP93/01371 1IIIIII I AU934311111211111110111111111 0 lll AU9343207 (51) Internationale Patentklassifikation 5 (11) Internationale Veroffentlichungsnummer: WO 93/24324 B32B 31/00, 31/30, 15/08 Al (43) Internationales Verdffentlichungsdatum: 9. Dezember 1993 (09.12.93) (21) Internationales Aktenzeichen: PCT/EP93/01371 (81) Bestimmungsstaaten: AU, CA, NO, US, europfisches Patent (AT, BE, CH, DE, DK, ES, FR, GB, GR, IE, IT, (22) Internationales Anmeldedatum: 1. Juni 1993 (01.06.93) LU, MC, NL, PT, SE).

Priorititsdaten: Veroffentlicht P 42 18 369.3 4. Juni 1992 (04.06.92) DE Mit internationalem Recherchenbericht.

(71)Anmelder (fiir alle Bestimmungssaaten ausser US): BASF LACKE FARBEN AKTIENGESELLSCHAFT[DE/ DE]; Glasuritstrage 1, D-4400 Minster (DE).

(72) Erfinder; und (nur futr US) KIRIAZIS, Leonidas [DE/DE]; ScharnhorststraBe 49 A, D-4400 Miinster

(DE).

(54) Title: PROCESS FOR PRODUCING A METAL-PLASTIC FILM COMPOSITE MATERIAL, METAL-PLASTIC FILM COMPOSITE MATERIAL PRODUCED ACCORDING TO SAID PROCESS AND ITS USE FOR PRO- DUCING PACKAGING CONTAINERS (54) Bezeichnung: VERFAHREN ZUR HERSTELLUNG EINES METALL-KUNSTSTOFFOLIE-VERBUNDES, NACH DIESEM VERFAHREN HERGESTELLTER METALLKUNSTSTOFFOLIE-VERBUND SOWIE DES- SEN VERWENDUNG ZUR HERSTELLUNG VON VERPACKUNGSBEHALTERN (57) Abstract A process is disclosed for producing a metal-plastic film composite material by sheet die extrusion of a statistical polypropylene copolymer into a plastic film. After leaving the sheet die, the polypropylene is cooled by means of cooling cylinders and the plastic film thus obtained is laminated onto at least one of the main surfaces of a metal sheet. The process is characterized in that the polypropylene copolymer is directly cooled after leaving the sheet die of the extruder down to temperatures between 0 °C and 15 OC. Once the plastic film has been laminated onto the metal sheet by means of a solvent-containing or aqueous adhesive, the metal-plastic film composite material thus obtained is cooled down to temperatures from 0 'C to 25 when the film is laminated onto the metal sheet at temperatures above the melting point of the polypropylene copolymer, or when the plastic film is lamrinated onto the metal sheet by means of a coextruded bonding ageat the metal-plastic film composite material thus obtained is cooled down to temperatures from 0 °C to 25 Also disclosed is a metal-plastic film composite material produced accurding to this process and its use for producing packaging containers.

ILL LL i 1 May 27, 1992/fe PAT 92 333 FEC890 BASF Lacke Farben Aktiengesellschaft, Munster Production of a metal-plastic film laminate, the metalplastic film laminate, and use thereof for manufacturing packaging containers The present invention relates to a process for producing a metal-plastic film laminate by slot die extrusion of random polypropylene copolymer as a film which, on emerging from the slot die, is cooled by means of chill rolls and laminated onto at least one of the main surfaces of a metal sheet. The invention futher relates to metal-plastic film laminates proaiQed by the process of the invention and to the use of these laminates for manufacturing packaging containers.

II

A can or closure for use as a packaging material, in particular for foods, is manufactured from tinplate, chromated steel such as ECCS (electroliytic [sic] chromium-coated steel) and aluminum sheet after coating in panel or coil form. The coating acts as a protective layer, first protecting the metal from attack by the contents and the resulting corrosion and secondly preventing corrosion products of the metal affecting the contents. Of course, the contents must not be affected or impaired by the coating either, for example by constituents dissolved out of it, either in TOte eae omtlpasi imlmntspo

LI

2 -I -2the course of the sterilization of the contents carried out after filling or in the course of the subsequent storage of the packed goods, in particular foods.

Furthermore, the coatings must be such that, in the course of the further processing forming, stamping, fringing, crimping and the like of the coated sheets into cans or closures, they withstand the mechanical stresses which arise.

Moreover, high solvent emissions of the drying coating make it necessary to take precautions to minimize these emissions and the associated pollution.

An advantageous method for coating metal sheets which are to be used in particular for manufacturing food packages is film coating. For instance, DE-A-3 128 641 describes a process for producing laminates for fiod packages by heating the metal sheet and a thermoplastic resin film together with a carboxylcontaining polyolefin adhesive in between these layers to temperatures above the melting point of the adhesive and then cooling everything down together under pressure, thereby producing the metal-plastic laminate.

Furthermore, DE-A-2 912 023, GB-A-2 027 391 and EP-B-31 701 disclose laminates and food packaging containers, in particular bags, manufactured from these laminates.

Metal-plastic laminates are also used for example for stamping into valve plate carriers for aerosol cans.

i 4 1 -3- The films for metal-plastic film laminates are customarily produced in an extrusion process in which the extruder is charged with thermoplastics in the form of powders or granules and the material is homogenized, plasticated, screw transported and forced through a shaping die in the extrusion head. A suitable way of producing polypropylene film is in particular the slot die extrusion process where the melt emerges hot from a wide slot in the die and then runs continuously directly over one or more chill rolls for cooling. The cooled film is edge trimmed, then usually coronapretreated and subsequently wound up.

It is known that the chill roll temperature has an effect on the crystallinity and hence the optical and mechanical properties of the film in that low chill roll temperatures lead to films of relatively high j transparency and toughness but of relatively lower i stiffness and higher tendency to block. However, it is also known that the quenching of film can lead to stresses. Customary coolant feed temperatures are between 15°C and Conventional chill roll ranges produce polypropylene mono and coex films by cooling the chill rolls to temperatures above 20CC. With metal-laminated films produced in this way there is the problem that, after stamping, the laminates exhibit appreciable crazing. The crazing' of metal-film laminates produced in this way is particularly pronounced in the case of 1 plastic films based on random polypropylene copolyme:s.

7 4 Finally, EP-B-312 309 discloses a process for producing metal-polypropylene laminates in which a polypropylene film is laminated to a metal sheet and heated to a temperature above the melting point of polypropylene and the laminate is then cooled down to room temperature by flooding with a cold liquid. The advantages of the known process are that unevenness in the coating is suppressed. However, there is a problem with the process known from EP-B-312 309 in that the laminates produced by it are not completely free of crazing.

It is an object of the present invention to develop a process for producing metal-plastic laminates based on polypropylene random copolymers which are free of crazing and suitable for manufacturing packaging containers, in particular for the food sector. The metal-plastic laminates shall have excellent barrier properties low optical transmissivity, low water vapor permeability and generally low gas permeability.

The laminates shall be suitable in particular for packaging foods and snacks.

This object is surprisingly achieved by a process for producing a metal-plastic film laminate by slot die extrusion of random polypropylene copolymer as a film which, on emerging from the slot die, is cooled by means of chill rolls and laminated onto a metal sheet, which comprises quenching the polypropylene copolymer to temperatures between 0°C and 15 C directly on emerging from the slot die of the extruder and, 5 after the plastic film has been laminated to the metal sheet by means of a solvent-containing or aqueous adhesive, cooling the resulting metal-plastic film laminate to temperatures of O0C to 25 0 C when the laminating of the film onto the metal sheet has taken place at temperatures above the melting point of the polypropylene copolymer of the plastic film, or, after the plastic film has been laminated onto the metal sheet by means of a coextruded adhesion promoter, cooling the resulting metal-plastic film laminate to temperatures of O°C to Preferably the extruded polypropylene copolymer is quenched to temperatures within the range from to 10°C directly after emerging from the slot die of the extruder.

It is suiprising and was unforeseeable that, in the process of the invention, no stresses arise in the films and the films or metal-plastic film laminates are free of crazing after stamping.

The present process utilizes for example the following coolants for cooling the roll downstream of the slot die extruder: water, water-cattle salt mixtures, coolants based for example on ethylene glycol, for example the commercially available coolant Glysantins (BASF AG).

The coolant feed temperatures are within the range from 0OC to 15°C. Owing to the thickness of the extruded films, usually within the range from 10 to 250 pm, and the customary high production speeds, the 6 polypropylene random copolymer films emerging from the slot die are therefore brought immediately to temperatures between 0°C and 15 0

C.

The random polypropylene copolymers used in the process of the invention are random copolymers comprising 92 to 99% by weight of propylene and 1 to 8% by weight of comonomers, each percentage being based on the total weight of the monomer composition. Suitable comonomers are C 2

-C

12 preferably C 2 -C6-a-mornoolefins, for example ethene, 1-butene, 4-methyl-l-pentene, 1-hexene, n-1-octene, n-1-decene and n-1-dodecene.

Polypropylene copolymers of this type are well known and commercially available in a multiplicity of grades, for example under the namen Novolen (BASF AG). The random copolymers are preparable for example in the process described in DE-A-3 730 022. They have a melt ii flow index MFI 230°C/2.16 kp within the range from 4 to 12 g/10 min (measured in accordance with DIN 53 735).

The films obtainable from the polypropylene random copolymers are used as the thermoplastic top layer of the metal-plastic film laminate. Of course, laminate films obtained by coextruding of at least two different resins can also be used as the top layer of the laminate. For instance, the random polypropylene copolymers can be for example mixed and coextruded with other random copolymers or with polypropylene homopolymers or else with further polyolefins, polyamides, polyesters, polyvinyl chloride, polyvinylidene R chloride and polycarbonates. The preferred 7 thermoplastic film, which constitutes the innermost layer the layer in contact with the contents) of the metal-plastic film laminate, however, comprises polypropylene random copolymers only.

The particularly preferred plastic film base material for the process of the invention comprises random polypropylene copolymers obtained by random copolymerization of 1 to 4% by weight of ethylene and 99 to 96% by weight of propylene, each percentage being based on the total weight of the monomer composition.

The metal-plastic film laminates produced by the process of the invention using these copolymers are completely free of any tinplate [sic] after stamping.

The thermoplastic polypropylene copolymer films usually additionally comprise additives, for example internal and external lubricants, antiblocking agents, stabilizers, antioxidants, pigments, crystallization 'iids and the like. These additives are used in the amounts necessary for synthesis, processing, fabrication and application, in the form of coarse powders, fine powders, granules or a concentrate incorporated directly in the polymer. Details of the amounts customarily used and examples of suitable additives may be found for example in Gachter-MUller, Kunststoffadditive, Carl-Hanser Verlag.

The process of the invention can utilize mono or multi-layar films which are laminated onto the metal Ssheet by means of a solvent-containing or aqueous syq adhesive. In addition, however, it is also possible to I l i 8 coextrude the polypropylene plastic together with an adhesion promoter and to laminate the resulting coexfilm onto the metal sheet.

The polymers used in the process of the invention as adhesive or as adhesion promoter layer can be both copolymers, terpolymers, graft copolymers and ionomers, provided they contain carboxyl or anhydride groups or groups which are hydrolyzable to carboxyl groups and that the melt flow index of the polymer, measured at 190°C under a load of 2.16 kg, is between 0.1 and 30 g/10 min, preferably between 0.2 aid g/min and particularly preferably between 0.5 and g/10 min.

Suitable co- and terpolymers are preparable by copolymerization of ethyleno with ap-unsaturated carboxylic acids such as, for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid and fumaric acid, the corresponding anhydrides or the corresponding esters or monoesters having from 1 to 8 carbon atoms in the alcohol moiety, such as, for example, the methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl and 2-ethylhexyl esters of the acids mentioned. It is also possible to use the corresponding salts of the carboxylic acids mentioned, for example the sodium, potassium, lithium, magnesium, calcium, zinc and ammonium salts. Preference is given to using the carboxylic acids and their anhydrides.

7;Ai -9- Further monomers that are copolymerizable with ethylene and the unsaturated carbonyl compounds can be used in the copolymerization. Examples are alpha olefins having 3 to 10 carbon atoms, vinyl acetate and vinyl propionate.

The amounts of the monomers used are chosen in such a way that the resulting polymer has a carboxyl group content of 0.1 to 30% by weight, preferably 2 to by weight.

Suitable graft copolymers are preparable by grafting at least one polymer of the group of the polyolefins with up to 10% by weight, preferably up to by weight, based on the total weight of the monomers, of at least one monomer from the group of the ua,-unsaturated carboxylic acids, their anhydrides, their esters o r salts in the presence or absence of peroxides. DE-A-3 800 307 and DE-A-3 639 564 describe suitable adhesion promoters based on graft copolymers and methods for preparing them, The ionomers used as adhesion promoter layer are preparable by the above-described copolymerization of ethylene ad optionally further monomers with salts of a,p-unsaturated carboxylic acids or by partial neutralization of the above-described carboxylcontaining co-, ter- and graft polymers with salts, oxides and hydroxides of sodium, potassium, lithium, magnesium, calcium, zinc and ammonium. The neutralization can be carried out in the melt or in solution.

S The amount of basic compound is chosen in such a way i n i of the above-dcrib croy |i L 25 cotiin o, ter an rf oyer ihsls 10 that the degree of neutralization of the polymer is between 0.1 and 99%, preferably between 0.1 and and very particularly preferably between 0.1 and The adhesion promoter which is coextruded with the polypropylene random copolymer is particularly preferably a polypropylene which has been polar modified, preferably grafted with maleic anhydride.

The contemplated adhesives are applied from solutions or dispersions in water or organic solvents.

The solutions or dispersions generally have an adhesive content of 5 to 60% by weight. Particularly suitable adhesives comprise thermoplastic resins, such as cellulose esters, cellulose ethers, acrylic esters, polyamides, polyurethanes and polyesters, thermosetting resins, such as epoxy resins, urea-formaldehyde resins, phenol-formaldehyde resins and melamine-formaldehyde resins. The preferred adhesive is a solvent-containing two-component polyurethane adhesive.

Suitable metal sheets are sheets from 0.04 to 1 mm in thickness made of blackplate, tinplate, aluminum and various iron alloys which may have been optionally provided with a passivating layer based on A nickel, chromium and zinc compounds.

In the process of the invention, the polypropylene film is laminated onto the metal sheet, the film being adhered to the metal using either a solventcontaining or aqueous adhesive or a coextruded adhesion promoter. The production of metal-plastic film i_ -d 1ii I -r I 11 laminates by means of adhesion promoters is a generally known process.

It comprises first coextruding the thermoplastic polymer and the adhesion promoter. The metal sheet is then covered with the coextruded film in such a way that the adhesion promoter layer of the coexfilm touches the metal surface. The polypropylene top layeradhesion promoter-metal laminate is produced either by means of a temperature controllable press or in the nip of a pair of squeeze rolls or of a calender by means of temperature controllable rolls by application of pressure and heat. The pressure and temperature have to be chosen in such a way that the adhesion promoter enters a firm and stable bond with the metal foil or sheet and that, on the other hand, the thermoplastic top layer should ideally not melt. Afterwards the laminate is cooled down to temperatures of 0°C to This is preferably done by passing the laminate through

I;

a cooling bath. However, it is also possible to cool down the laminates by means of an air blower.

If a solvent-containing or aqueous adhesive is used, the metal-plastic film laminate is produced by 4$ applying the adhesive to a metal sheet, heating, and laminating the plastic film onto the metal sheet by application of pressure and heat.

Bonding propylene film to metal by means of an aqueous or solvent-containing adhesive can be carried out on slow-running machines, i.e. at laminating speeds TR of 5 to 60 m/min, at temperatures below 130°C. If the I m i 4,I i ~L 12 laminating of the plastic film to the metal sheet is carried out at temperatures below 130 0 C, it is in general not necessary to cool the metal-plastic film laminate obtained, since no melting of the polypropylene plastic film takes place. According to the invention, however, if the film has been laminated to the metal sheet at temperatures above the melting point of the polypropylene plastic film, i.e. in general above 130 0 C, the resulting metal-plastic film laminate is cooled down to temperatures of 0°C to 25°C. High speed machinery is run at bonding or laminating speeds between 60 and 150 m/min, so that elevated temperatures of about 180°C to 220°C are necessary for producing the metal-plastic film laminates. In this case the invention provides that, after the film has been laminated to the metal sheet and the laminate heated, it be quenched to temperatures of 0OC to 25°C. The laminate is quenched for example by passing it through a cooling bath.

If the film has been laminated to the metal sheet at temperatures above the melting point of the polypropylene of the plastic film, the laminate is A, cooled down to temperatures of 0°C to The quenching of the laminates can take place for example in a water or ice-water bath through which the laminates pass. It is also possible, as mentioned earlier, to cool down the metal-plastic laminates by means of an air blower.

j 2 11"rT J, r, 13 The coating of the metal sheet, i.e. the thermoplastic lamination film, generally has a total dry film thickness of less than 500 pm, preferably to 200 Am. In this the thickness of the adhesion promoter layer or of the adhesive layer accounts for between 0.5 and 100 Am. The top layer accordingly has a thickness of between 10 and 499.5 Am.

For the purposes of the present invention metal-plastic film laminates also include laminates in which the metal sheet has been coated with a polypropylene film on both sides.

The invention likewise concerns the metalplastic film laminates produced by the process of the invention. These laminates are stamped for example to form cans, jar closures, crown cork or valve plate carriers for aerosol cans. The laminates are notable in particular for their absence of crazing. If, for comparison, the polypropylene copolymers emerging from the slot die of the extruder are not cooled down to temperatures of 0°C to 15*C and if, after the films have been laminated to the metal sheet at temperaturns of above 130C, there is no cooling down to temperatures of from 5°C to 25°C, films of the metal-plastic laminates show distinct crazing.

The metal-plastic film laminates of the invention are used for manufacturing packaging containers, in particular for manufacturing bottoms and lids of cans, valve plates of aerosol cans, and closures. The moo manufactdring methods employed are conventional (cf.

0L -14for example VR-INTERPACK 1969, pages 600-606: W. Panknin, A. Breuer, M. Sodeik, "Abstreckziehen als Verfahren zum Herstellen von Dosen aus WeiBblech"; SHEET METAL INDUSTRIES, August 1976: W. Panknin, CH. Schneider, M. Sodeik, "Plastic Deformation of Tinplate in Can Manufacturing"; Verpackungs-Rundschau, No. 4/1971, pages 450-458: M. Sodeik, I. Siewert, "Die nahtlose Dose aus WeiBblech"; Verpackungs-Rundschau, No. 11/1975, pages 1402 to 1407: M. Sodeik, K. HaaS, I. Siewert, "Herstellen von Dosen aus WeiBblech durch Tiefziehen"; Arbeitsmappe fUr den Verpackungspraktiker, Metalle, Teil II, Gruppe 2, WeiBblech, Lfd.-No. 220.042 to 220.048 in neue Verpackung 12/87, page B 244 to B 246 and neue Verpackung 1/88, pages B 247 to B 250).

For further details reference is therefore made to the literature.

The invention will now be illustrated by examples: Example 1: A commercially available polypropylene copolymer (trade name Novoleno 3225 MCX from BASF AG) is coextruded with a commercially available adhesion promoter based on maleic anhydride-grafted polypropylene (trade name Modic P 301 from Mitsubishi Chemical Ind.) on a slot die extrusion range.

Both the materials are used in granule form. The main extruder is a 90 mm 0 25 D extruder from Barmag, and the coextruder is a 45 mm 0 25 D extruder from S Schwabethan. The bushing of the ain extruder is ,V O 15 smooth, while that of the coextruder has grooves. The melt of the polypropylene Novolen 3225 MCX is at 260*C, while that of the adhesion promoter is at 232°C. The melt pressure of the Novolen is 60 bar and that of the adhesion promoter 35 bar. The zone temperatures of the main extruder are between 2100C and 235°C and those of the coextruder between 180°C and 210°C. The watercooled chill roll is at 10°C. The thickness of the polypropylene base film is 40 Am and that of the adhesion promoter film 10 um. An air knife is run at mbar.

Using temperature controllable rolls at 30 C, the coextruded film is laminated onto a hot metal sheet at 1700C. The laminate obtained is then passed through a water bath at 16°C.

The metal-plastic film laminate is stamped. It IJ is free of crazing.

Example 2: Example 1 is repeated with the difference that, in the slot die extrusion, the coextruded film emerging from the slot die is cooled down to 20°C. The metalplastic laminate obtained exhibits crazing on stamping.

Example 3: The polypropylene copolymer obtainable under the trade name Novolens 3225 MCX (BASF AG) is extruded on a slot die extrusion range from Barmag mm 0 25 The polypropylene is used in granule form. The bushing of the extruder is smooth. The melt of the polypropylene plastic is at 260°C and its V 1 16 16 pressure is 60 bar. The zone temperatures of the extruder are between 210°C and 235°C. On emerging from the slot die the film is cooled down to 8°C with the aid of a water-cooled chill roll. The thickness of the polypropylene film is 80 um. An air knife is operated at 60 mbar.

A commercial solvent-containing two-component polyurethane adhesive is applied to a metal sheet by roller coating in a wet film thickness of 6 to 8 Am and passed through an oven at about 180°C. The metal foil to which the adhesive has been applied is laminated with the polypropylene film at a temperature of 110°C.

The metal-plastic film laminate obtained is stamped. It is completely free of crazing.

Example 4: Example 3 is repeated with the difference that f the laminating of the polypropylene film onto the metal sheet is carried out at a temperature of 180°C. The resulting laminate shows crazing on stamping.

Example 5: Example 3 is repeated with the difference that the laminating of the polypropylene film onto the metal sheet is carried out at a temperature of 180°C. The resulting metal-plastic laminate is afterwards passed I through a water bath at a temperature of 10°C. The laminate obtained is free of crazing on stamping.

Claims

1. A process for producing a metal-plastic film laminate comprising producing a film of random polypropylene copolymer by slot die extrusion wherein on emerging from the slot die the film is cooled by means of chill rolls and laminated onto at least one surface of a metal sheet, comprising the steps of quenching the polypropylene copolymer to a temperature between 0 0 C and 0 C immediately after the polypropylene copolymer emerges from the slot die of the extruder, laminating the plastic film to the metal sheet by means of a solvent-containing or aqueous adhesive and cooling the resulting metal-plastic film laminate to a temperature of between 0 0 C to 25 0 C.

2. A process for producing a metal-plastic film 15 laminate as claimed in claim 1 wherein the film is laminated on to the metal sheet at a temperature above the melting point of the polypropylene copolymer of the plastic film. 9t,3. A process for producing a metal-plastic film laminate as claimed in claim 1 wherein the plastic film is t I tlaminated onto the metal sheet by means of a coextruded adhesion promoter.

4. A process as claimed in any one of the preceding claims wherein the polypropylene copolymer is quenched to a temperature between 5 0 C and 10 0 C immediately after emerging I~(4 from the slot die of the extruder. C5. A process as claimed in any one of the preceding claims wherein the polypropylene plastic film is a mono film which is laminated onto the metal sheet by means of a ii 2 ~30 solvent containing poly-urathane adhesive.

6. A process Ls claimed in any one of claims 1, 3 or 4 wherein the polypropylene plastic is coextruded together with an adhesion promoter comprising polar modified polypropylene and the coextruded film is then laminated onto the metal sheet.

7. A process as claimed in any one of the preceding staffaeAkeap/spocV432O? 24.4,96 -18- claims wherein the random polypropylene copolymer is obtainable from 1 to 4% by weight of ethylene and 99 to 96% by weight of propylene, based on the total weight of the monomer composition.

8. A metal-plastic film laminate produced by the process as claimed in any one of claims 1 to 7.

9. The use of a metal-plastic film laminate of claim 8 for manufacturing packaging containers. A process for producing a metal-plastic film laminate as hereinbefore described with reference to any one of examples 1, 3 or

11. A netal-plastic film laminate as hereinbefore described with reference to any one of examples 1, 3 or

12. The use of a metal-plastic film laminate as 15 hereinbefore described with reference to any one of examples 1, 3 or DATED THIS 24th DAY OF APRIL 1996. BASF LACKE FARBEN AG By its Patent Attorneys: GRIFFITH HACK CO Fellows Institute of Patent Attorneys of Australia Sstaff p/spe 4320 24.4.9 ystala/e/kep/spocv43207 24.4.96 r~~n17~' Abstract Production of a metal-plastic film laminate, the metal- plastic film laminate, and use thereof for manufacturing packaging containers The present invention relates to a process for producing a metal-plastic film laminate by slot die extrusion of random polypropylene copolymer as a film which, on emerging from the slot die, is cooled by means of chill rolls and laminated onto at least one of the main surfaces of a metal sheet, which comprises quenching the polypropylene copolymer to temperatures between 0°C and 15°C directly on emerging from the slot die of the extruder and, after the plastic film has been laminated to the metal sheet by means of a solvent-containing or aqueous adhesive, cooling the resulting metal-plastic film laminate to temperatures of 0C to 25*C when the laminating of the film of the metal sheet has taken place at temperatures above the melting point of the polypropylene copolymer of the plastic film, or, after the plastic film has been laminated onto the metal sheet by means of a coextruded adhesion promoter, cooling the resulting metal-plastic film laminate to temperatures of 0*C to The present invention further relates to the metal-film laminate produced by the process of the invention and to its use for manufacturing packaging containers. T RA i, i I A-' INTERNATIONAL SEARCH REPORT international application No. PCT/EP 93/01371 A. CLASSIFICATION OF SUBJECT MATTER Int.Cl. B32B 31/00; B32B 31/30; B32B 15/08 According to International Patent Classification (IPC) or to both national classification and IPC B. FIELDS SEARCHED Minimum documentation searched (classification system followed by classification symbols) 5 Int.Cl. B32B B29C Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched Electronic data base consulted during the international search Iname of data base and. where practicable. search terms used) C. DOCUMENTS CONSIDERED TO BE RELEVANT Category* Citation of document, with indication, where appropriate, of the relevant passages Relevant to claim No. X EP, A, 0 312 309 (MB GROUP PLC) 19 April 1989 1-7 cited in the application see page 2,line 35 line 37 see page 4,line 30 line 31 see page 5,1ine 39 line 44 see abstract A US, A, 3 361 728 (COEN ET AL.) 2 January 1968 1,2 see column l,line 66 line 72 A EP, A, 0 135 628 (IDEMITSU PETROCHEMICAL) 3 April 1985 1,2 see page 3,line 13 page 4,line 3 see page 9,line 10 line 22 A US, T, 104 502 (LIU) 7 August 1984 1-7 A DATABASE WPI week 9018, Derwent Publications Ltd., 1-7 London GB; AN 90-137000 JP, A, 2 086 433 (SUMITOMO LIGHT META.) 27 March 1990 see abstract D Further documents are listed in the continuation of Box C. See patent family annex. Special categories of cited documents: laterdocument published after the international filinz dae or noril A date and not in conlitt wiih the application but cid to unoerstand document defining the general state of the an which is not considered the principle or o uderly e th invention to be of particular relevance the principle or eory underlyng the invention earlier document but published on or after the international filing date document o particular relevance; the claimed invention cannot be considered novel or cannot be considered to involve an invennve document which may throw doubts on priority claim(s) or which is sep e the or cannt is ken alondered to invove an nven cited to establish the publication date of another citation or other special reason (as specified) document of particular relevance: the claimed inveition can-- be document referring to an oral disclosure, use, exhibition or other considered to involve an inventive step when the docurr; is means combined with oneor more ohersuch documents. such combinalton en being obvious to a person skilled in the art document published prior to the international filing date but later than the prionty date claimed document member of the same patent family Date of the actual completion of the international search Date of mailing of the international search report 7 September 1993 (07.09.93) 17 September 1993 (17.09.93) Name and mailing address of the ISA' Authorized officer EUROPEAN PATENT OFFICE Facjimile No. Telephone No. Forrm PCT/ISA/210 isecond sheet) (July 1992) b -1 r i -)~li-LL ~JU-L~IL 1 F- INTERNATIONAL SEARCH REPORT International application No. PCT/EP 93/01371 C (Continuation). DOCUMENTS CONSIDERED TO BRPRELEVANT Category* Citation of document, with indication, where appropriate, of the relevant passages Relevant to claim No. EP, A, 0 312 307 (MB GROUP PLC) 19 April 1989 see page 2,line 50 line 51;claim 24 DATABASE WPI week 8832, Derwent Publications Ltd., London, GB; AN 88-225020 JP, A, 63 160 835 (MITSUBISHI PETROCHEM.) 4 July 1988 see abstract L Ferm PCT/ISA/210 (continuation of second sheet) (July 1992) r >1 I C ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INIERNATIONAL PA"ANT APPLICATION NO. EP 9301371 SA 74838 This annex fists the potent fomdly members relating to the patent documents cited in the above-mentioned international search repoet. The members are as contained in the European Patent Office EDP file on The European Patent Office is in no way liable for theme particulars which arm merely given for Vqe purpose of information. 07/09/93 Patent doessnet Pulcton Patent family Pblication cited in search report daI member(s) dat I EP-A-0312309 19-04-89 AU-A- DE-A- WO-A- GB-A, B JP-T- US-A- 606479 2565888 3867415 8903301 2211140 2501642 5238517 07-02-91 02-05-89

13-02-92

20-04-89

28-06-89 07-06-90 24-08- l. US-A-3361728 NL-A- 293193 EP-A-0135628 03-04-85 None US-T- 104502 Nohe EP- 12307 19-04-89 AU-B- AU-A- CA-A- DE-A- WO-A- GB-A, B JP-T- US-A- 602267 2555688 1299478 3867414 8903307 2211138 2501643 4945008 04-10-90 02-05-89 28-04-92 13-02-92 20-04-89 28-06-889 07-06-90

31-07-90 6' 'W For more detaif sbout this mmux see Official Journal of the European Patent Office, No. 12132 4, INTERNATIONALER RECHERCHENBERICHT Intervaiolmm Aktoozaikes PCT/EP 93/01371 I. KASIIKATION DES ANNEWLUNGSGEGE'4STANDS (bal moerowen KWaufitrAnmibcon ad all$ azugbm)6 Nwac der mivoaali Patseaaiflation (IMC oder nach der m Irnis. Klasafikaio mad der WC Int.Kl. 5 B32831/00; B32B31/30; B32815/08 U. UXR aMMRDETE SACHGEOWET RaCheChister MlndutplhStoff 7 Racharclt. michi um lmdestprifftff glhkade Verbiffstlichungso, sowuit dine anter did rodchele Sachgls fail=s Ml. EINSCHLAGIGE VEROFFENTIJCHUNGEN 9 Tls1 a.AnpuhNU I Art. K-anaclnung der Veaffentlldaung 1,sowait efordersli states' Angabs der' manloabichanTelaBtz niuhN X EP,A,0 312 309 (MB GROUP PLC) 1-7 19. April 1989 in der Anmeldung erwihnt siehe Seite 2, Zeile 35 Zeile 37 siehe Seite 4, Zeile 30 Zeile 31 siehe Seite 5, Zeile 39 Zeile 44 siehe Zusammenfa ssung A US,A,3 361 728 (COEN ET AL.) 1,2 2. Januar 1968 siehe Spalte 1, Zeile 66 eile 72 A EP,A,0 135 628 (IDEMIYSU PETROCHEMICAL) 1,2 3. April 1985 siehe Seite 3, Zeile 13 Seite 4, Zeile 3 siehe Selte 9, Zeile 10 Zelle 22 luodere KAtmprso Von angelh~s Varw fmmchungm1 0 VarwfamtIclsu ,dl do! alleia.i Stn atTdml" Spite. Vartffatjcbu, die much damt intenmatiomals An- daflhat abmlcb al be de utadsam avausebso, iat cmlaatmoer dazlorltiatum veffantilcht wards. 11teme Dok~ufmn, des Iadocha am= ode macb dams intedus. ist Und saft der Ane'adung mici: hallidlut, tne u a tionals. Anaddatum vaiffesticit wods s Vestinadmis desder EAfiung zguadalilagmds. Pimulp L Veiffslhuga Il a~ lit r a i Ptio ditdas ."ir Verfenlldauag You husondweeUdatungi die haasach- zwafchaf a slow =nln. ode duthd.dsvff feetlchunadt.amads in Radaedamharct W to Etfiadusg an aickt mis at o v aid efndercher Tiltir manaten =afffnlcaung belat word" nil Oode us asam hail berubbed btaa wres andes. besondemn Giud eagegaban iat (wie asgaulit) T M Y VwWffutl0bug von haoadwere dauug die hanch- O0' Veabftilcung, die ich ant #duea mundlidas Otfamiarstag. to Erfte-.rig kano midtt ala aud wfim~dics Tlitlgk t bo. adma 111ctm~ala ntiug ne tbsd hstnacktsl werdsm, die VerOffndldsung milt ,zaisAusellg s advehtum am oder Eows andaes Vefiffticm a dimer Kats- bodet ws I Veriadua g iskacit wird ad dimss Vig,imug flit wP Vuntfstilchung. die vor dei lateoemlm Anadda. =is Fecm aah.iugd lIt Wro. a~e such does boassoodts Priuitlesdtuss vef1m- 0&1 Veasfsmilciuni, dle &Ztgilad dosibm Paesdtafillir lidat qffrd. iat Datom da Abacilus der lmteradwtions acerhe Ahasadatum dm intanmatla Ra~sv'hmbchW 07.SEPTEMBER 1993 17. 09-93 Intermzdoesle Raecbbblde Ulethaift des Wv'Onlatits. Uadismatst" EUROPMSCHES PATENTAMT ATTALLA G. 1 1 Fait IPCTr/IAAIO lIM 3) (J i 1US? I PCT/EP 93/01371 InteaiwoAaj Aktumzdcbm E~u. LnCILAbGIGVEKO 4)'TLJCHi14GEN l~UU U UFraamIUU Art 4 iKaichu der VoWflftIung. sowrt afrdwficb matw Aliuw dir uaflichm TdI. J_3.Anwh! US,T, 104 502 (LIU) 7. August 1984 DATABASE WPI Week 9018, Derwent PubHIi.ations Ltd., London, GB; AN 90-137000 JP,A,2 086 433 (SUMITOMO LIGHT META.) 27. Mirz 1910 siehe Zusanirenfassung EP,A,0 312 307 (MB GROUP PLC) 19. April1 1989 siehe Seite 2, Zeile 50 Zeile 51; Anspruch 24 DATABASE WPI Week 8832, Derant Publications Ltd., London, GB; ANI 88-225020 JIP,A,63 160 835 (MITSUBISHI PETROCHEM.) Jul i 1988 siehe Zusanimenfassung 1-7 1-7 3 Fuat PCI=A/10 IZ-*q. Jin£US p 'I, ANHAq ZUM !NTERNATIONALEN RECHERCHENBERICHT OBER DIE INTERNATIONALE PATENTANMELDUNG NIL EP 9301371 SA 74838 In im Anhong sand die Mfitfieder dir Pabterdmiien dir im sbaageumtea iternationaalm Redmvrbbdsaabt aotd~wte. Patudokumente angeg k. Die Anginbe fiber die Familamutoleder entsprecene dem Stand dir Datui des Europiicben PabtwUinut an Diem Angsben dienen nar mar Unterricitung sand erfol gin ohme Gewihr. 07/09/93 Ian Roeedmabiricht ndihesPat=Wtoksamit Datuns der veafenwechang Mtglicd(er) dir pateafamilie DWa=a de Veuiffmawlidung EP-A-0312309 19-04-89 AU-B- AU-A- DE-A- WO-A- GB-A,B8 JP-T- US-A- 606479 Z555888 3867415 8903301 2211140 2501642 5238517 07-02-91- 02-05-89 13-02-92 20-04-89 28-06-89 07-06-90 24-08-93 US-A-3361728 NL-A- 293193 EP-A-0135US 03-04-85 Keine US-1-104502 Keine EP-A-03 12307 19-04-89 AU-B- AU-A- CA-A- DE-A- WO-A- GB-A, B JP-T- US-A- 602267 2555688 1299478 3867414 8903307 2211138 2501643 4945008 04-10-90 02-05-89 28-04-92 13-02-92 20-04-89 28-06--89 07-06-90 31-07-90 Ffr afte re lam a diminm Abg ujuim Aafbimt ds Eaarpiesm NPmt=04 Nr.1ZIIR