WO1998036915A1

WO1998036915A1 - Plastics film, its use in processes for producing packaging containers, the packaging containers thus produced, and the use of coatings for application over printing ink

Info

Publication number: WO1998036915A1
Application number: PCT/EP1998/000976
Authority: WO
Inventors: Harald Borgholte; Ursula Heimeier; Jürgen Kaczun; Peter Eric Van Rijn
Original assignee: PPG Industries Ohio Inc; PPG Industries Inc
Current assignee: PPG Industries Ohio Inc; PPG Industries Inc
Priority date: 1997-02-22
Filing date: 1998-02-20
Publication date: 1998-08-27
Anticipated expiration: 1999-08-22
Also published as: AU6722698A; DE19707185A1

Abstract

The present invention relates to a plastics film for producing packaging containers, one side of the film being coated with a sealable coating and the opposite side of the film being coated with an acrylate-based aqueous coating composition, wherein the coating composition applied to the side opposite to the sealable coating layer comprises, as binder, an aqueous solution or aqueous dispersion of an acrylate copolymer, the solution or dispersion being obtainable by a two-step emulsion polymerization of: a) from 1 to 15 % by weight of one or more α,β-ethylenically unsaturated carboxylic acids; b) from 30 to 60 % by weight of one or more alkyl acrylates having from 1 to 12 carbon atoms in the alkyl radical; c) from 20 to 50 % by weight of one or more alkyl methacrylates having from 1 to 12 carbon atoms in the alkyl radical and/or of vinyl aromatic hydrocarbons; d) from 5 to 35 % by weight of one or more fluorine-containing, ethylenically unsaturated monomers copolymerizable with the other monomers and e) up to 25 % by weight of further monomers, if desired, whereby all percentages are based on the total weight of a), b), c), d) and e).

Description

PLASTICS FILM, ITS USE IN PROCESSES FOR PRODUCING PACKAGING CONTAINERS, THE PACKAGING CONTAINERS THUS PRODUCED, AND THE USE OF COATINGS FOR

APPLICATION OVER PRINTING INK

The present invention relates to a plastics film for producing packaging containers, one side of the film being coated with a sealable coating and the opposite side of the film being coated with an aqueous acrylate- based coating composition.

The present invention moreover relates to a process for producing packaging containers using these plastics films, to the packaging containers thus produced, and also to a process for producing a multilayer coating, in which an aqueous acrylate-based coating composition is applied to a printing ink.

Plastics films which are intended to be used, for example, for packaging foods, e.g. chocolate, ice cream, nuts, potato chips and the like, are provided with adhesive coatings in order to allow an effective seal.

In addition, plastics films of the type mentioned at the outset are also applied to packaging containers made from glass and/or plastic, for example drinks bottles, in order to mark these and/or to provide them with a decorative surface. In this case too, the plastics films are provided with adhesive coatings.

The adhesive coatings in particul ar cases are either hot -seal able coatings , which can be sealed at el evated temperatures , or col d-seal able coatings , which are sealed at temperatures of from about 0 to about 80°C .

Col d-seal able coatings and thei r properties are described, for example, in L. Pl aczek in Coating, 18 (4) , pages 94 - 95 , 1985. Col d-seal able coatings are preferably applied from an aqueous phase. Pressure- sensitive adhesives, which are used in the cold-sealing process, are. predominantly used in the packaging of foods, e.g. for packaging of chocolates and ice cream.

Sealable coating agents for the sealing of plastics films, such as polypropylene films, are known, for example, from US-A-4,898,787, US-A- 4,888,395 and US-A-5,070, 164. The cold-sealable coatings are usually based on emulsion polymers, which have an average molecular weight of from about 20,000 to 150,000 and a glass transition temperature of from about -15 to about +15°C.

However, cold-sealable coatings have the disadvantage of poor antiblocking properties, i.e. when stored, plastics films coated with cold-sealable coatings, if stored over a prolonged period under normal storage conditions in the form of rolls, show a tendency to stick to the mutually superposed layer of film. In the case of printed plastics films, an undesirable transfer of printing inks from the outer side to the opposite inner side coated with the sealable coating is also found.

Cold-sealable coatings therefore require the application of a protective layer on the other side of the film. For this purpose, coatings may be applied directly to the appropriately pretreated plastics film. The coatings used for this must be printable and are usually called outside coatings. In the case of the printed films, printing inks are then applied to these outside coatings, either directly by the film manufacturer or else by the film user. A protective coating must once again be applied to the printing inks as well (see above), and this is usually called a release coat. In the case of unprinted films, e.g. those used for various industrial applications, these release coats may be applied directly to the generally appropriately pretreated plastics film, without prior application of printing inks, but the outer side opposite to the sealable coating may also remain uncoated.

The coating compositions for the printable outside coatings usually used either contain solvent or are aqueous and based on acrylate copolymers. The antiblocking properties are usually obtained by adding from 1 to 10* by weight, based on the solids content of wax and of acrylate copolymer, of a wax (added generally in the form of wax dispersion), as described, for example, in DE-A-2440112.

The release coats described above usually contain polyamide resins, often in combination with cellulose nitrate and with waxes, with fatty amides or with silicone oils. If low-molecular-weight silicone oils or waxes are used in the release coats, however, there is the danger of migration of these constituents into the sealable layer, resulting in an undesirable reduction in seal strength.

In other sectors moreover, for example the coating of wood, there is a need to provide a protective layer for substrates coated with printing inks.

The journal Polymers Paint Color Journal, April 1996 issue, pages 27 - 28, discloses the use of silicones in release coats. However, this article does not contain further details on the composition of the release coats.

The object on which the present invention is based is therefore to provide suitable plastics films for producing packaging containers, the films having good resistance to blocking. The plastics films should moreover fulfill the requirements usually placed upon plastics films which are used for producing packaging containers. The plastics films should therefore, for example, be sealable under the conditions usually used and have a good seal strength. In addition, the films obtained should have very good optical properties. They should, furthermore, preferably be odorless, so that they are also suitable for producing food packaging containers. Finally, the plastics films should also show no transfer of printing inks during storage of the printed films in the form of rolls.

Surprisingly, this object is achieved by means of the plastics films of the type described at the outset, wherein the coating composition applied to the side opposite to the sealable coating comprises an aqueous solution or aqueous dispersion of an acrylate copolymer which is obtainable by a two-step emulsion polymerization of

a) from 1 to 15* by weight, preferably from 2 to 8* by weight, of one or more α.β-ethylenically unsaturated carboxylic acids,

b) from 30 to 60* by weight, preferably from 35 to 50* by weight, of one or more alkyl acrylates having from 1 to 12 carbon atoms in the alkyl radical ,

c) from 20 to 50* by weight, preferably from 25 to 45* be weight, of one or more alkyl methacrylates having from 1 to 12 carbon atoms in the alkyl radical and/or of vinyl aromatic hydrocarbons,

d) from 5 to 35* by weight, preferably from 10 to 25* by weight, of one or more fluorine-containing, ethylenically unsaturated monomers copolymerizable with the other monomers and

e) up to 25* by weight, preferably up to 10* by weight, of further monomers, if desired, whereby all percentages are based on the total weight of a), b) , c), d) and e) .

The novel plastics films can be used for producing packaging containers, in particular for foods, and are distinguished by very good resistance to blocking. The coating applied to the side opposite to the sealable coating layer moreover does not reduce the seal strength unacceptably.

The present invention therefore also provides a process for producing packaging containers using these plastics films, and the packaging containers thus produced.

Finally, coating compositions which comprise, as binders, the fluorine- modified acrylate copolymers referred to are also suitable for producing a protective layer over printing inks applied to other substrates, such as wood. The present invention therefore also provides a process for producing a multilayer coating, in which process a coating composition based on these fluorine-modified acrylate copolymers is applied to a printing ink.

The fluorine-modified acrylate copolymers used according to the invention as binders in release coats will now be described in more detail below.

The composition for the release coat (i.e. the outside coating arranged over the printing ink, or the outside coating in the case of unprinted plastics films) used according to the invention for producing the plastics films is based on an aqueous acrylic copolymer dispersion or aqueous acrylic copolymer solution, which is prepared by a two-step emulsion polymerization of a) from 1 to 15* by weight, preferably from 2 to 8* by weight, of one or more α,β-ethylenically unsaturated carboxylic acids,

c) from 20 to 50* by weight, preferably from 25 to 45* by weight, of one or more alkyl methacrylates having from 1 to 12 carbon atoms in the alkyl radical and/or of vinyl aromatic hydrocarbons,

e) up to 25* by weight, preferably up to 10* by weight, of further monomers, if desired,

whereby all percentages are based on the total weight of a), b) , c), d) and e).

Examples of α,β-ethylenically unsaturated carboxylic acids are acrylic acid, methacryl ic acid, maleic acid, crotonic acid, and also mixtures of these. Preference is given to α.β-monoethylenically unsaturated monocarboxylic acids. Use of methacryl ic acid and acrylic acid is particularly preferred.

Examples of suitable alkyl acrylates having from 1 to 12 carbon atoms in the alkyl radical (component b) are methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, isopentyl acrylate, hexyl acrylate, n-octyl acrylate, 2-ethyl hexyl acrylate and decyl acrylate. The use of methyl acrylate is preferred.

Examples of suitable alkyl methacryl ates (component c) are methyl methacrylate, ethyl methacryl ate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacryl ate, tert-butyl methacrylate, n-pentyl methacryl ate, isopentyl methacryl ate, hexyl methacryl ate, n-octyl methacrylate, 2-ethyl hexyl methacryl ate, decyl methacrylate and dodecyl methacrylate. Preference is given to the use of methyl methacrylate.

Examples of suitable vinyl aromatics are styrene, α-alkylstyrene and vinyl toluene, in particular styrene.

The monomers d) preferably used are fluorine-containing acrylate and/or methacrylate monomers, particularly preferably tetrafluoropropyl methacrylate.

Examples of suitable monomers e) are acrylonitrile and methacrylonitrile, and also monomers containing amide groups. The monomers e) are preferably used in an amount of up to 25* by weight, preferably up to 10* by weight, based on the total weight of the monomer mixture.

The emulsion polymerization for preparing the aqueous acrylate copolymer dispersion or aqueous acrylate copolymer solution is carried out in aqueous medium in known apparatus, for example in a mixing vessel with heating and cooling equipment.

The procedure for adding the monomers may be such that a solution made from all of the water, the eulsifier and the initiator or some of the initiator is initially charged and, if some of the initiator is added during the polymerization, then separately therefrom but in parallel therewith the remainder of the initiator is slowly added at the polymerization temperature. It is moreover also possible initially to charge the water and to heat this to the desired temperature, and then to add the emulsifier and some of the initiator and to homogenize the mixture. It is also possible to charge initially some of the water and of the emulsifier, and to prepare, from the remainder of the water and of the emulsifier, and from the monomer mixture, a pre-emulsion which is slowly added at the polymerization temperature, the initiator again being initially charged separately, or some thereof being added separately. It is also possible to add the monomer mixture in the form of a pre-emulsion in the first step, and in the second step to add the monomer mixture in bulk, i.e. without water and emulsifier, and to add the initiator separately, but in parallel therewith. Preference is given to charging initially a solution made from water, the initiator and some of the emulsifier, and slowly adding the first part of the monomer mixture (including regulator if desired) at the polymerization temperature. After renewed addition of emulsifier, the remainder of the monomer mixture is then metered into the reactor in the second polymerization step.

The polymerization temperature is usually in the range from 70 to 90°C.

The ratio of amounts of monomers and water is advantageously selected in such a way that the resultant acrylate copolymer dispersion has a solids content in the range from 10 to 60* by weight, preferably from 10 to 30* by weight.

The emulsifiers used may be anionic and/or non-ionic emulsifiers. Examples of anionic emulsifiers are alkali metal salts or ammonium salts of sulfuric onoesters of alkyl phenols or of alcohols, and also the sulfuric monoesters of oxyethylated alkyl phenols or of oxyethylated alcohols, and also phosphoric esters of oxyalkylated alkylphenols. Use is made, for example, of alkali metal salts or of sulfuric monoesters of nonylphenol reacted with 23 mol of ethylene oxide per mole, alkyl- or arylsulfonate, sodium lauryl sulfate, sodium lauryl ethoxylate sulfate, and also the alkali metal salt of diesters of sulfosuccinic acid with alcohols having from 6 to 20 carbon atoms. The nonionic emulsifiers whose use is preferred are ethers of nonylphenols reacted with from 5 to 23 mol of ethylene oxide.

Preference is given to the use of phosphoric esters of oxyalkylated alkylphenols, in particular phosphoric esters of the reaction product of one mol of nonylphenol with 5 mol of ethylene oxide with an acid number of 125.

Suitable initiators for the emulsion polymerization are the usual inorganic peroxodisulfates, preferably potassium peroxodisulfate and ammonium peroxodisul fate, and also ammonium or alkali metal peroxydiphosphates. It is also possible to use redox initiators, for example hydrogen peroxide, benzoyl peroxide, organic peresters, such as perisopivalate, in combination with water-soluble reducing agents, such as ascorbic acid, sulfur compounds, triethylamine, sodium disulfite, hydrazine, hydroxylamine, glycolic acid or tartaric acid.

Examples of suitable chain-transfer agents are mercaptans or polyhalo compounds or branched aromatic hydrocarbons, such as trimethylbenzene. The chain transfer agents are preferably used in all of the steps of the emulsion polymerization.

In the first step of the emulsion polymerization, from 5 to 20* by weight of the monomer mixture of a), b) , c) , d) and, if desired e) is polymerized at a temperature of generally from 70 to 90°C. Preferably after renewed addition of emulsifier, in the second step of the polymerization, the remaining 80 to 95* by weight of the monomer mixture is polymerized at a temperature of generally from 70 to 90°C, in the presence of the polymer obtained in the first step of the emulsion polymerization.

The aqueous acrylate copolymer dispersion is particularly preferably prepared by emulsion polymerization of methacryl ic acid, methyl acrylate, methyl methacryl ate and tetrafluoropropyl methacryl ate.

The resultant acrylate copolymer is neutralized at least to some extent by adding bases, and, if desired, usual auxiliaries and additives are added for producing the aqueous release coat. The base used is ammonia and/or amines, advantageously in the form of an aqueous solution of the neutralizing agent. Ammonia is used in particular.

The coating compositions for the release coats according to the invention usually comprise from 80 to 100* by weight of the acrylate copolymer solution or acrylate copolymer dispersion described above, based on the total weight of the coating composition. These coating compositions for the release coats may moreover usually also contain from 0 to 20* by weight, based on the total weight of the coating composition, of usual auxiliaries and additives.

Examples of suitable auxiliaries and additives are flow control agents, stabilizers, thickeners, defoamers, pigments, fillers and the like. The coatings may, for example, contain insoluble, finely dispersed inorganic materials, such as talc and silica, e.g. the commercial product Syloid 63 FP from Grace.

According to the invention, the aqueous coatings composition are used in particular for coating plastics films. Possible plastics films are preferably polyolefin films, for example polyethylene and polypropylene films. These are particularly preferably of polypropylene, in particular oriented polypropylene.

In the plastics films referred to, one outer side of the plastics film is coated with a sealable coating, and the opposite outer side of the plastics film is coated with the coating described above.

The coating composition described above and used according to the invention (release coat) here is usually applied over a printing ink layer. The release coat used according to the invention prevents the mutually superposed film layers from adhering to one another during use and when the plastics films are stored in the form of rolls for a relatively long period under normal storage conditions. It also serves to prevent migration of the printing ink.

In this context, the plastics films under consideration may either be provided with a printing ink directly at the film manufacturer, or else (as is more common) only the application of the sealable coating takes place at the film manufacturer, and the printing ink (and therefore also the release coat) is applied only later by the user of the plastics film. In this second case, the film manufacturer initially provides the plastics film with a sealable coating and with an outside coating prepared from an aqueous coating composition which, like the coating described above and used according to the invention (release coat), serves to prevent adjacent film layers from sticking to one another during the storage and transport of the films on rolls. To this outside coating, the user of the film then applies firstly the printing ink and then the release coat. Wherever the coating of the plastics films with the printing ink takes place, the printed plastics films are provided, after application of the printing ink, with the release coat described above and based on the aqueous dispersion or solution of the fluorine- modified acrylate. The aqueous coating compositions referred to are moreover suitable for outside coating of unprinted plastics films, as used, for example, in industry. In this case, the coating is applied directly, with neither prior nor subsequent application of a printing ink, to the plastics film which may have been appropriately pretreated if desired.

To produce the novel plastics films, the surface of the films is generally pretreated before the coating composition for the sealable coating or the aqueous outside coating composition or the printing ink is applied to the plastics films, in order to ensure that the coating is firmly bonded to the film. This is to prevent the coating from becoming peeled off or pulled off from the film.

This treatment is carried out by known methods, e.g. by chlorination of the plastics film, treatment with oxidants, such as chromic acid or hot air, or by steam treatment or flame treatment. A particularly preferred pretreatment used is high-voltage corona discharge.

The plastics films are generally precoated after the pretreatment, in order to secure adhesion of the coating to the substrate film. Suitable precoating agents or primers are known from the literature and encompass, for example, alkyl titanates, and also primers based on epoxides, on me amine- formaldehyde resins and on polyethyleneimines. The latter are particularly suitable for precoating plastics films. These polyethyleneimines may be applied to the, if desired pretreated, plastics films either from organic or else from aqueous solution. The concentration of the polyethyleneimine in the aqueous or in the organic solution here is, for example, 0.5* by weight. Suitable polyethyleneimine primers are described, for example, in DE-A-2440 112 and US-A-3,753,769. The uncoated plastics films generally have a thickness of from 0.015 to 0.060 mm. The coating composition for the sealable coating, the aqueous coating composition , the printing ink if used and the coating composition for the release coat are applied to the plastics film in a usual manner, for example by gravure coating, roller coating, dipping, spraying, or with the aid of gravure or flexo printing or reverse-roll coating. The excess of coating composition may be removed in each case by squeegee rollers or doctors.

The coating compositions of the sealable coatings are usually applied in an amount which, on drying, gives a smooth, uniformly distributed layer with a weight of from 0.5 to 5 g/m², preferably with a weight of from 0.6 to 1.6 g/m². The aqueous outside coating compositions are usually applied in an amount which, on drying, gives a smooth, uniformly distributed layer with a weight of from 0.5 to 5 g/m², preferably with a weight of from 1 to 2 g/m². The printing inks are usually applied in an amount which, on drying, gives a smooth, uniformly distributed layer with a weight of from 0.5 to 5 g/m², preferably with a weight of from 1 to 2 g/m². The coating compositions for the release coats according to the invention are usually applied in an amount which, on drying, gives a smooth, uniformly distributed layer with a weight of from 1 to 5 g/m², preferably with a weight of from 2 to 3 g/m².

The coating formed by the release coat on the plastics film, like the sealable coating layer and the outside coating layer, if present, is dried separately or together with the sealable coating layer with hot air, radiant heat, or by any other usual means.

The sealable coatings used for producing the plastics films are known and are described, for example, in DE-A-4341815. Use is made, in particular of aqueous coating compositions for sealable coats based on an acrylate dispersion. The sealable coatings are preferably sealed at a temperature of from 0 to 80°C, particularly preferably at least 30°C and very particularly preferably from 40 to 70°C.

Known aqueous outside coating compositions, for example those described in DE-A-2440 112 and DE-A-4341815, may be used to coat the plastics films.

The printing inks used subsequently to print the plastics films are likewise known.

The coating compositions described above and based on the fluorine- modified acrylate copolymer may, however, also be applied over a printing ink for other applications. For example, they may also be applied over a printing ink layer which has been applied to other substrates, e.g. wood.

The invention is described in more detail below using working examples. All data on parts and percentages being by weight unless expressly otherwise stated.

Preparation of acr late copolymers 1 to 3

The amount given in Table 1 of water is weighed out in a polymerization vessel made from stainless steel, with sti rrer, reflux condenser, a monomer feed and an initiator feed, and heated to the temperature given in Table 1. The amounts given in Table 1 of monomers and regulator are then weighed out into the monomer tank and homogenized for 20 min. After the initial charge has reached the polymerization temperature, the amount given in Table 1 of e ulsifier/initiator mixture 1 is added to the reactor and stirring is carried out for 10 min. After this, 10* of the monomer mixture is metered into the reactor at a uniform rate over a period of 45 min, and then the temperature of the reaction mixture is maintained for 10 min. After this, the second amount of the emulsifier (emulsifier/water mixture 2) is added, and the remainder of the monomer mixture is then metered into the reactor at a uniform rate over a period of 4 h. During this second addition of monomer, the a ine mixture 2 given in Table 1 is weighed out and heated to a temperature of from 60 to 70°C. After addition of the second monomer mixture, the amine mixture 1 given in Table 1 is added, and homogenization is carried out for 15 min. The amine mixture 2 is then added uniformly within a period of from 30 to 45 min. The temperature is then held at from 70 to 75°C for one further hour, followed by cooling, and the reaction mixture is discharged through a screen. The resultant dispersion of the acrylate copolymer has the content of non-volatile fractions (1 h/130°C) , the pH value, the coagulated fraction content and the acid number which are given in each case.

Table 1: Composition and parameters of acrylate dispersions 1 to 3

Key to Table 1 :

Initi al charge: amount of water added as initial charge and heated to the reaction temperature. Emul . /Init . 1 : emulsifier/initiator mixture 1 added as initial charge and consisting of the phosphoric ester of the reaction product of 1 mol of nonylphenol with 5 mol of ethylene oxide with an acid number of 125 (HCA

0201) and ammonium peroxodisul fate (APS) MA: methyl acrylate

MMA: methyl methacryl ate

IOTG: isooctyl thioglycolate

MAA: methacryl ic acid

TFPMA: tetraf1 uoropropyl methacryl ate Emul. /Water 2: emulsifier/water mixture 2 added to the reaction mixture and consisting of the phosphoric ester of the reaction product of 1 mol or nonylphenol with 5 mol of ethylene oxide with an acid number of 125 (HCA

0201) and water Amine 1: amine mixture 1 added to the reaction mixture and consisting of ammonia (technical grade, 25* strength), water and a commercially available polysiloxane-based defoamer (Antifoam DC 1510)

Amine 2: amine mixture 2 added to the reaction mixture and consisting of ammonia (technical grade, 25* strength) and water

Water: amount of water added to dilute the reaction mixture Solids (*): solids content of the dispersion, measured after 1 h at 130°C Coagul ated fraction: coagulated fraction in *, by drying and weighing against the non- olatile fraction 2. Production of coating compostions 1 to 3 for the release coats

Coating compositions 1 to 3 for the release coats are produced using the acrylate copolymer dispersions 1 to 3, by adjusting the solids content of the dispersions to 20*.

3. Application of coating compositions 1 to 3 and test results from the resultant coatings

A commercially available flexo-printing ink (commercial product

Helioplastol HG A-2 from BASF Drucksysteme GmbH) is firstly applied with a wire-wound draw bar at a wet- film coating thickness of 12 μm to an oriented polypropylene 33MW247 commercially available from Mobil Plastics, Belgium which has been coated with an outside coating composition, and the ink is dried for 30 s at room temperature and then for 30 s at an air temperature of 60°C in a Helios laboratory heating cabinet.

To the resultant printing ink layer, each of the coating compositions 1 to 3 described above is applied with a wi e-wound draw bar at a wet film thickness of 12 μm, and dried for 30 s at room temperature and then for 30 s at an air temperature of 60°C in a Helios laboratory heating cabinet.

The resistance to blocking of these coated films 1 to 3 with respect to the packaging film coated with a cold-sealable coating is determined by pressing together, for a period of 2 h at 3.5 bar and 50°C, the film coated with the respective release coats 1 to 3 and OPP film made from oriented polypropylene 33MW247 from Mobil Plastics, Belgium, which has been coated with a cold-sealable coating according to DE-A-4341815. Test strips of width 25 mm are then cut from the test surface, and resistance to blocking is then determined by peeling with the aid of an apparatus for measuring tension/elongation. In all three cases, the film has the required resistance to blocking. The effect on seal strength is moreover studied for all of the films coated with the respective release coats 1 to 3, and the seal strength conforms to requirements.

Claims

1. A process for producing a multilayer coating on a substrate, in which firstly a printing ink is applied and an acrylate-based aqueous coating composition is applied to the printing ink, characterized in that the coating composition applied to the printing ink contains, as binder, an aqueous solution or dispersion of an acrylate copolymer, the solution or dispersion being obtainable by a two- step emulsion polymerization of

a) from 1 to 15* by weight of one or more α.β-ethylenically unsaturated carboxylic acids,

b) from 30 to 60* by weight of one or more alkyl acrylates having from 1 to 12 carbon atoms in the alkyl radical,

c) from 20 to 50* by weight of one or more alkyl methacryl ates having from 1 to 12 carbon atoms in the alkyl radical and/or of vinyl aromatic hydrocarbons,

d) from 5 to 35* by weight of one or more fluorine-containing, ethylenically unsaturated monomers copolymerizable with the other monomers and

e) up to 25* by weight of further monomers, if desired,

whereby all percentages are based on the total weight of a), b) c) , d) and e) .

2. The process according to claim 1, characterized in that the substrate is a plastics film, the side of the film opposite to the side with the printing ink being coated with a sealable coating.

3. The process according to claim 2, characterized in that an outside coating is applied on the side of the plastics film opposite to the sealable coating before the printing ink is applied.

4. A plastics film for producing packaging containers, one side of the film being coated with a sealable coating and the opposite side of the film being coated with an acrylate-based aqueous coating composition, wherein the coating composition applied to the side opposite to the sealable coating layer comprises, as binder, an aqueous solution or aqueous dispersion of an acrylate copolymer, the solution or dispersion being obtainable by a two- step emulsion polymerization of

a) from 1 to 15* by weight of one or more α,β-ethylenically unsaturated carboxylic acids,

c) from 20 to 50* by weight of one or more al yl methacryl ates having from 1 to 12 carbon atoms in the alkyl radical and/or of vinyl aromatic hydrocarbons, d) from 5 to 35* by weight of one or more fluorine-containing, ethylenically unsaturated monomers copolymerizable with the other monomers and

e) up to 25* by weight of further monomers, if desired,

5. A plastics film for producing packaging containers, one side of the film being coated with a sealable coating and the opposite side of the film being coated with a multilayer coating obtainable by the process according to claims 2 or 3.

6. The plastics film according to claims 4 or 5, characterized in that it is obtainable by using component (a) in an amount of from 2 to 8* by weight, component (b) in an amount of from 35 to 50* by weight, component (c) in an amount of from 25 to 45* by weight, component (d) in an amount of from 10 to 25* by weight and component (e) in an amount of up to 10* by weight.

7. The plastics film according to any of claims 4 to 6, characterized in that it is obtainable by using, as component (d), fluorine-containing acrylate monomers and/or fluorine-containing methacrylate monomers, preferably tetrafluoropropyl methacryl ate.

8. The plastics film according to any of claims 4 to 7, characterized in that the sealable coating is prepared from an aqueous coating composition based on an acrylate dispersion.

9. A process for producing packaging containers from plastics film, characterized by using the plastics film according to any of claims 4 to 8.

10. The process according to claim 9 characterized in that the sealable coatings are sealed at a temperature of from 0 to 80°C, preferably at least 30°C and particularly preferably from 40 to 70°C.

11. A packaging container obtainable by the process according to claims 9 or 10.