DE10043784A1 - New mono- or multilayer film useful for making shaped products e.g. wall coverings, displays, signs, roofing, comprises a crystallizable bibenzoate-modified thermoplastic polymer and at least one additional functionality - Google Patents

Abstract

New mono- or multilayer film comprises a crystallizable bibenzoate-modified thermoplastic polymer and at least one additional functionality. An Independent claim is also included for a process for producing the film, and comprises: (1) coextruding the corresponding starting materials through a slit die; (2) biaxially stretching and thermofixing the resulting film; and (3) optionally coating the film on one or both sides.

Description

The invention relates to a transparent, biaxially oriented, partially crystalline film made of one Bibenzol-modified thermoplastics with additional functionality. The invention also relates to a method for producing this film and its use.

Transparent films made of crystallizable thermoplastics are known.

These films are not inherently UV stable, so that neither the films nor the articles made therefrom are suitable for outdoor use. For outdoor applications these films show yellowing and deterioration after a short time the mechanical properties due to photooxidative degradation Sunlight. These films are also not flame retardant, which makes them are not suitable for areas where high flame protection is required. The slides continue to be insufficiently sealable.

EP-A-0 620 245 describes films made of polyethylene terephthalate, which are improved in terms of their thermal stability. These slides included Antioxidants which are suitable for trapping radicals formed in the film and break down formed peroxide. A proposal on how the UV stability of such films there is no need to improve this document.

DE 198 23 991 describes amorphous plates which contain a bibenzene-modified polyalkylene terephthalate and / or a bibenzene-modified polyalkylene naphthalate as the main constituent. These plates are 0.1 to 20 mm thick, amorphous, ie not crystalline, undrawn and unoriented. The plates are particularly characterized by good mechanical properties in a wide temperature range. Under good mechanical properties is understood to mean that in the measurement of impact strength a (D 179/1 ISO) _n Charpy no breakage occurs and that the Izod impact strength according to IS0 180 at -40 ° C preferably in the range from 10 to 140 kJ / m ² lies. The amorphous plates described are produced using smoothing calender technology and by freezing below the glass transition temperature by means of cooling and smoothing.

DE AS 23 46 787 describes a flame-retardant raw material. Next to the It is also used as a raw material for the production of foils and fibers claimed.

The following deficits emerge when producing a film from this phospholane-modified raw material:

• - The raw material is very sensitive to hydrolysis and must be pre-dried very well become. When drying the raw material with dryers that are state of the art Technique correspond, the raw material glues, so that only under the most difficult Conditions a film can be produced.
• - The films produced in this way become brittle when exposed to temperature, i.e. H. the mechanical properties deteriorate due to embrittlement, so that the film becomes unusable. Already occurs after 48 h of thermal stress this embrittlement.

GB-A 1 465 973 describes a coextruded, two-layer polyester film described, the one layer of isophthalic and copolyesters containing terephthalic acid and their other layer There is polyethylene terephthalate. About the sealing behavior of the film can be found in the Font no usable information. Due to the lack of pigmentation, the film is not Can be produced reliably (film cannot be wound) and only with restrictions further processed.

EP 0 035 835 describes a coextruded, sealable polyester film which to improve the winding and processing behavior in the sealing layer  Particles are added whose average particle size is the layer thickness of the Sealing layer exceeds. Due to the particulate additives Surface protrusions formed that prevent unwanted blocking and sticking to rollers or prevent tours. Over the other, non-sealable layer of the film, no further details are given on the incorporation of antiblocking agents. It It remains open whether this layer contains antiblocking agents. By choosing particles with larger diameter than the thickness of the sealing layer and in the in the examples specified concentrations, the sealing behavior of the film deteriorates. The script does not give any information on the sealing temperature range of the film. The seal seam strength is measured at 140 ° C and is in a range of 63 up to 120 N / m (0.97 N / 15 mm to 1.8 N / 15 mm film width).

EP 0 432 886 describes a coextruded multilayer polyester film which has a first surface on which a sealable layer is arranged and which has a second surface on which an acrylate layer is arranged. The sealable top layer can also be made of isophthalic acid and copolyesters containing terephthalic acid. Thanks to the coating on the back the film gets an improved processing behavior. Sealing area information the film is not made in the script. The seal seam strength is at 140 ° C measured. For an 11 µm thick sealing layer, a sealing seam strength of 761.5 N / m (11.4 N / 15 mm). A disadvantage of the acrylic coating on the back is that this side no longer seals against the sealable top layer. The foil can only be used to a limited extent.

EP 0 515 096 describes a coextruded, multilayer, sealable polyester film described, which contains an additional additive in the sealable layer. The Additive can e.g. B. contain inorganic particles and is preferably in a aqueous layer applied to the film during its manufacture. This is supposed to Foil maintain the good sealing properties and be easy to process. The Back contains very few particles that are mainly in the regranulate get this layer. Information on the sealing temperature range of the film is also given  not made in this writing. The seal seam strength is measured at 140 ° C and is more than 200 N / m (3 N / 15 mm). For a 3 µm thick sealing layer one Seal seam strength of 275 N / m (4.125 N / 15 mm) specified.

WO 98/06575 describes a coextruded multilayer polyester film which has a sealable top layer and a non-sealable base layer. The The base layer can be constructed from one or more layers, the interior of the layers is in contact with the sealable layer. The other (outer) Layer then forms the second non-sealable top layer. The sealable The top layer can also consist of isophthalic acid and terephthalic acid There are copolyesters that do not contain antiblocking particles. The slide contains also at least one UV absorber, which is the base layer in one Weight ratio of 0.1 to 10% is added. As a UV absorber preferably triazines, e.g. B. Tinuvin® 1577 from Ciba. The base layer is equipped with common antiblocking agents. The film is characterized by a good one Sealability, but does not have the desired processing behavior and exhibits also deficits in the optical properties (gloss and cloudiness).

The object of the present invention was to provide a transparent, biaxially oriented, To provide semi-crystalline film with a thickness of preferably 1 to 500 microns, the in addition to good stretchability in the longitudinal and transverse directions, good mechanical as well as optical properties especially a high inherent UV stability in Combination with at least one additional functionality and the above is also economically producible.

Additional functionality means that the film according to the invention is flame-retardant and / or is equipped with additional UV stabilizers and / or is sealable and / or is coated on one or both surfaces and / or on one or is corona treated on both sides.  

A high inherent UV stability means that the films are exposed to sunlight or other UV radiation are not or only extremely little damaged, so that the Films are suitable for outdoor applications and / or critical indoor applications. In particular, the films should not yellow when used outdoors for several years, show no embrittlement or cracking on the surface and also none Have deterioration in mechanical properties. High UV stability means that the film absorbs UV light and light only in the visible Area lets through.

The good optical properties preferably include high light transmission (<65%), a high surface gloss (<100), a low haze (<30%) as well a low yellow number (YID <20).

The good mechanical properties preferably include a high modulus of elasticity (EMD <3800 N / mm ² ; ETD <4500 N / mm ² ) and good tensile strength values (in MD <100 N / mm ² , in TD <180 N / mm ² ) and good elongation at break values in the longitudinal and transverse directions (in MD <90%; in TD <70%).

Good stretchability includes e.g. B. that the film in its manufacture Orient well both lengthways and crossways and without breaks leaves.

In addition, the film according to the invention should be recyclable, in particular without significant deterioration in the optical and mechanical properties.

This task is solved by a transparent, biaxially oriented, partially crystalline Film with a thickness in the range of preferably 1 to 500 microns, which is the main component contains a crystallizable, bibenzene-modified thermoplastic. This slide is inherently UV stable and can be flame retardant and / or with additional UV Stabilizers must be equipped and / or is sealable and / or is on one or  both surfaces coated and / or is on one or both sides corona treated.

The main component of the film according to the invention is a crystallizable, Bibenzol-modified thermoplastics. Suitable crystallizable or partially crystalline Bibenzol-modified thermoplastics are, for example, polyesters such as Bibenzol-modified polyethylene terephthalate (PETBB), bibenzol-modified Polybutylene terephthalate (PBTBB), bibenzene-modified polyethylene naphthalate (PENBB), with bibenzene-modified polyethylene terephthalate (PETBB) being preferred.

According to the invention, bibenzene-modified crystallizable thermoplastics are understood

• Crystallizable bibenzene-modified copolymers,
• - crystallizable bibenzol-modified compounds,
• - Crystallizable bibenzene-modified recyclate and
• - other variations of crystallizable bibenzol-modified thermoplastics.

For the production of the copolymers polyalkylene terephthalate or polyalkylene naphthalate can in addition to the main monomers such. B. dimethyl therephthalate (DMT), Bisbenzenic acid (BB), ethylene glycol (EG), propylene glycol (PG), 1,4-butanediol, Terephthalic acid (TA), and / or 2,6-naphthalene dicarboxylic acid (NDA), too Isophthalic acid (IPA), trans and / or cis-1,4-cyclohexanedimethanol (c-CHDM, t-CHDM or c / t-CHDM) can be used.

The main ingredient is that the amount of bibenzene-modified thermoplastic preferably between 50 and 99.9% by weight, particularly preferably between 75 and 99 % By weight is based on the weight of the layers equipped therewith. The the remaining amount of 100% can be conventional additives for biaxially oriented films.

Bibenzene-modified polyethylene terephthalate polymers with a crystallite melting point Tm, measured with DSC (differential scanning calorimetry) at a heating rate of 20 ° C./min. from 180 ° C to over 365 ° C, preferably from 180 ° C to 310 ° C, depending on the bibenzenic acid content, with a crystallization temperature range Tc between 75 ° C and 280 ° C, a glass transition temperature Tg between 65 ° C and 130 ° C and With a density, measured according to DIN 53479, of 1.15 g / cm ³ to 1.40 g / cm ³ and a crystallinity between 5% and 65%, preferably 20% and 65%, are preferred starting materials for the production of the film according to the invention represents.

Bibenzene-modified polyethylene naphthalate polymers with a crystallite melting point Tm, measured with DSC (Differential Scanning Calorimetry) at a heating rate of 10 ° C / min. from 120 ° C to 310 ° C, preferably from 140 ° C to 280 ° C, depending on the bibenzenic acid content, with a crystallization temperature range Tc between 75 ° C and 280 ° C, a glass transition temperature Tg between 65 ° C and 120 ° C and with a density, measured according to DIN 53479, of 1.20 g / cm ³ to 1.45 g / cm ³ and a crystallinity between 5% and 65%, preferably 20% and 65%, are preferred starting materials for the production of the film according to the invention ,

It is essential to the invention that the bibenzol-modified thermoplastic used is crystallizable. According to the invention, the bibenzenic acid content is preferably between 1 and 50 wt .-%, preferably between 5 and 45 wt .-%, in particular between 10 and 40 wt .-%, based on the weight of the bibenzol-modified thermoplastic. If the bibenzenic acid content is <50% by weight, the film according to the invention is u. U. insufficiently crystallizable after orientation. In this case, the mechanical properties deteriorate significantly.

The film according to the invention can have one or more layers. multilayer Embodiments are at least two layers and comprise a base layer a bibenzol-modified thermoplastic, preferably PETBB, and at least one further top layer.  

In a preferred embodiment, the PETBB-containing layer forms the Base layer of the film with at least one, preferably with both sides Cover layers, with one or both sides of intermediate layers if necessary can be present.

The cover layers and / or intermediate layers can be the same or different. A preferred embodiment is a film with the layer sequence A-B-C, wherein B are the base layer and A and C are top layers.

In a particularly preferred embodiment, the cover and possibly also the intermediate layers containing PETBB.

In a further preferred embodiment, the cover layers and / or the intermediate layers also from an unmodified polyalkylene terephthalate - Homopolymers, from a bibenzol-modified and / or unmodified Polyalkylene naphthalate polymers or from a bibenzene-modified and / or unmodified polyalkylene terephthalate-polyalkylene naphthalate copolymers or Compound exist. In these cases too, PET and PEN are preferred using polymers.

Further embodiments with intermediate layers preferably containing PETBB are five-layer structure and have a PETBB-containing base layer on both sides Intermediate layers containing PETBB. In a further embodiment, the PETBB-containing layer in addition to the base layer, a cover layer on the one side Form base or intermediate layer. The base layer is in the sense of the present Invention that layer which more than 50% to 99.5%, preferably 60 to 95%,  of the total film thickness. The cover layers are the layers that the form outer layers of the film. The thickness of the overall film is between 1 and 500 µm,  especially between 10 and 500 µm. The layer thicknesses of the cover layers are 0.5 to 2.5 µm. The layer thicknesses of the intermediate layers are preferred 1 µm to 10 µm.  

Light, especially the ultraviolet portion of solar radiation, i.e. H. the Wavelength range from 280 to 400 nm, initiates degradation processes with thermoplastics, as a result not only the visual appearance due to color change or yellowing changes, but also the mechanical-physical properties be adversely affected.

The inhibition of these photooxidative degradation processes is of considerable technical and economic importance, since otherwise the application possibilities of numerous thermoplastics are drastically restricted.

Unmodified polyethylene terephthalates, for example, only start below Absorb 360 nm UV light, their absorption takes below 320 nm considerably and is very pronounced below 300 nm. The maximum absorption is between 280 and 300 nm.

In the presence of oxygen there are mainly chain cleavages, but none Networking observed. Carbon monoxide, carbon dioxide and carboxylic acids are the quantitatively predominant photo-oxidation products. In addition to the direct Photolysis of the ester groups still need to consider oxidation reactions that also lead to the formation of carbon dioxide via peroxide radicals to have.

The photooxidation of e.g. B. polyethylene terephthalates can also over Hydrogen elimination in the α-position of the ester groups to form hydroperoxides and their Decomposition products and the associated chain cleavages (H. Day, D. M. Wiles: J. Appl. Polym. Sci 16, 1972, page 203).

UV stability can in principle be achieved by adding UV stabilizers become. UV stabilizers, d. H. UV absorbers as light stabilizers are chemical Compounds involved in the physical and chemical processes of light-induced Degradation can intervene. Soot and other pigments can partially  Effect sun protection. However, these substances are for transparent films unsuitable as they lead to discoloration or color change. For transparent films only organic and organometallic compounds that are suitable for this stabilizing thermoplastics no or only an extremely low color or Give color change.

UV stabilizers are very expensive, some of them evaporate during film production or migrate over time, so the film e.g. B. after 1 to 2 years unwanted coating shows. This increases the gloss and transparency of the film adversely affected.

In view of the fact that UV stabilizers can offer protection, the person skilled in the art would have used commercially available UV stabilizers. He would have noticed that

• - The UV stabilizer has a lack of thermal stability and at Temperatures between 200 ° C and 240 ° C decomposed or outgassed
• - Large amounts (approx. 10 to 15% by weight) of UV stabilizer are incorporated so that the UV light is absorbed and the film is not damaged.

At these high concentrations, the film is already yellow after production Yellowness index differences (YID) of approx. 25. Furthermore, the mechanical Properties of such a film adversely affected. Kick when stretching Problems on such. B.

• - Demolition due to lack of strength, d. H. Modulus
• - Nozzle deposits, which leads to profile fluctuations
• - Roller deposits from the UV stabilizer, which affects the optical properties (cloudiness, adhesive defect, inhomogeneous surface)
• - Deposits in stretching and fixing frames that drip onto the film.

It was therefore surprising that excellent UV protection could already be achieved by using the bibenzene-modified thermoplastics according to the invention without the addition of UV stabilizers. It was also surprising that this high UV protection

• - The yellowness index of the film compared to a non-stabilized film in the frame the measuring accuracy does not change;
• - no outgassing, no nozzle deposits, no frame evaporation set, which gives the film an excellent appearance and a has an excellent profile and flatness;
• - The inherently UV-stabilized film due to its excellent stretchability in Longitudinal and transverse direction, so that they are reliable and stable on so-called high speed film lines with speeds of 420 m / min can be produced reliably. This is the invention Film also economically profitable.

It should also be mentioned that the regenerated material is again used in the production of the film can be used without negatively affecting the yellowness index of the film.

In a preferred embodiment, the film according to the invention can still contain additional UV stabilizers.

UV stabilizers suitable as light stabilizers for the purposes of the present invention are UV stabilizers that are soluble in Bibenzol-modified thermoplastics preferably at least 70%, preferably 80%, particularly preferably 90%, of the UV Light in the wavelength range from 180 nm to 380 nm, preferably 280 to 350 nm absorb. These are particularly suitable if they are in the temperature range are thermally stable from 260 to 300 ° C, d. H. do not decompose and not to Outgassing. Suitable UV stabilizers are, for example, 2- Hydroxybenzophenones, 2-hydroxybenzotriazoles, nickel-organic compounds, Salicylic acid esters, cinnamic acid ester derivatives, resorcinol monobenzoates, oxalic acid anilides, Hydroxybenzoic acid esters, sterically hindered amines, benzoxazinones and triazines, the 2-hydroxybenzotriazoles and the triazines being preferred. It can too Mixtures of UV stabilizers are used.  

The UV stabilizer or stabilizers are preferably contained in the cover layers. at The base layer and any existing intermediate layers can also be used if required UV stabilizer.

It was surprising that the use of the above UV stabilizers in Combination with the inherently UV-stable thermoplastic in films into one more led to better UV protection.

In a very particularly preferred embodiment, the film according to the invention contains 0.01% by weight to 5.0% by weight of 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- ( hexyl) oxy phenol of the formula

or 0.01% to 5.0% by weight of 2,2-methylene-bis (6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) - phenol of the formula

or 0.01% to 5.0% by weight of 2,2 '- (1,4-phenylene) to [4H-3,1-benzoxazin-4-one]

In a preferred embodiment, mixtures of these UV Stabilizers or mixtures of at least one of these UV stabilizers with other UV stabilizers can be used. The total concentration Light stabilizers preferably between 0.01% and 5.0% by weight, based on the weight of the layers equipped with it.

The films according to the invention can additionally be flame-retardant, d. H. they then contain at least one flame retardant or mixtures various flame retardants. The flame retardant is preferred in the Base layer included, but can also in all or only in individual film layers (e.g. in the cover and / or intermediate layers).

A flame retardant effect means that the film according to the invention in one so called fire protection test the requirements according to DIN 4102 part 2 and especially meets the requirements of DIN 4102 Part 1 and in the building material class B2 and in particular B1 of the flame retardant substances can be classified.

Furthermore, the flame-retardant film should meet UL test 94 "horizontal Burning Test for Flammability of Plastic Material "so that it can pass into the class 94 VTM-0 can be classified.

The film according to this embodiment of the invention contains at least one Flame retardant, which is preferred directly via the so-called masterbatch technology is metered in during film production. The concentration of the flame retardant is preferably in the range from 0.5 to 30.0% by weight, preferably from 1.0 to 20.0% by weight,  based on the weight of the layers equipped with it. In the Production of the master batch is generally a ratio of Flame retardants for thermoplastic in the range from 60 to 40% by weight to 10 to 90% by weight % complied with.

Typical flame retardants include bromine compounds, chlorinated paraffins and other chlorine compounds, antimony trioxide, aluminum trihydrates, the Halogen compounds due to u. The resulting halogen-containing by-products can be disadvantageous. Furthermore, the low light resistance is one of them equipped film in addition to the development of hydrogen halide in the event of a fire disadvantageous.

Suitable flame retardants, which are preferably used according to the invention, are, for example, organic phosphorus compounds such as carboxyphosphinic acids, their anhydrides and dimethyl methylphosphonate. It is advantageous if the organic Phosphorus compound is soluble in the thermoplastic, since otherwise the required optical properties u. May not be met.

Since the flame retardants generally have a certain sensitivity to hydrolysis have, the additional use of a hydrolysis stabilizer may be useful.

As hydrolysis stabilizers, phenolic stabilizers, alkali / Alkaline earth stearates and / or alkali / alkaline earth carbonates in amounts of preferably 0.01 up to 1.0 wt .-%, based on the weight of the so equipped Layers. Phenolic stabilizers are used in an amount of 0.05 to 0.6% by weight, in particular 0.15 to 0.3 wt .-% and with a molecular weight of more than 500 g / mol prefers. Pentaerythrityl tetrakis-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate or 1,3,5-trimethyl-2,4,6-tris (3,5-di-tertiary-butyl-4-hydroxybenzyl) benzene particularly advantageous. Mixtures of different types can also be used Hydrolysis stabilizers are used.  

In a preferred embodiment, the invention contains heavy flammable film is a crystallizable, bibenzene-modified polyethylene terephthalate, 1% by weight to 20% by weight of an organic phosphorus compound soluble in PETBB as a flame retardant and 0.1% to 1.0% by weight of a hydrolysis stabilizer. Dimethyl methylphosphonate is preferred as the flame retardant.

This information regarding flame retardants and hydrolysis stabilizers also applies with regard to other thermoplastics to be used according to the invention.

Fire protection tests according to DIN 4102 and the UL test are very surprising shown that in the case of a three-layer film it is quite sufficient that preferably 0.5 to 2 mm thick top layers with flame retardant to to achieve improved flame retardancy. If necessary and at high Fire protection requirements can also include the base layer with flame retardant be equipped, d. H. include so-called basic equipment.

In addition, measurements showed that the film of the invention Temperature loads of 100 ° C do not become brittle over a longer period of time.

No embrittlement after temperature exposure means that the film after 100 Hours of annealing at 100 ° C in a forced air oven, no embrittlement and none has adverse mechanical properties.

An economical production includes. B. that the raw materials or Raw material components that are used to manufacture the possibly flame-retardant film are required with commercially available industrial dryers, such as vacuum dryers, Fluidized bed dryer, fluid bed dryer or fixed bed dryer (shaft dryer), can be dried. It is essential that the raw materials do not stick together be thermally degraded. The dryers mentioned work at temperatures between about 100 and 170 ° C, at which those mentioned in the prior art  glue the flame-retardant raw materials and the dryers or extruders can clog that no film production is possible.

The raw material goes through one in the most gently drying vacuum dryer Temperature range from approx. 30 ° C to 130 ° C at a vacuum of 50 mbar. After that is a so-called drying in a hopper at temperatures from 100 to 130 ° C and a residence time of approx. 3 to 6 hours is required. Even here it sticks in the stand raw materials described in technology.

During the production of the film according to the invention, it was also found that preferably using masterbatch technology, a suitable predrying or Precrystallization of the masterbatch and, if necessary, by using small Concentrations of hydrolysis stabilizer without the flame retardant film Can be glued in the dryer. Furthermore, no outgassing and Deposits found in the production process.

Surprisingly, films according to the invention in the thickness range 10-350 μm the requirements of building material classes B2 and B1 according to DIN 4102 and UL test 94.

Furthermore, the film according to the invention can be sealable. Where a very good one Sealability is required and where this property is not available online Coating can be achieved, at least the film according to the invention three layers and then includes as layers the base layer B, the sealable cover layer A and cover layer C, which are sealable or not sealable can be. In the embodiment in which the cover layer C is sealable, these are Cover layers A and C are preferably identical.

The sealable cover layer applied to base layer B by coextrusion A is preferably based on polyester copolymers and then consists of essentially from copolyesters, predominantly from isophthalic acid, Bibenzolcarboxylic acid and terephthalic acid units and from ethylene glycol units  are composed. The remaining monomer units come from others aliphatic, cycloaliphatic or aromatic diols or dicarboxylic acids, such as they can also occur in the base layer. The preferred copolyesters that Provide desired sealing properties are those that come from Ethylene terephthalate and ethylene isophthalate units are constructed. The share of Ethylene terephthalate is preferably 40 to 95 mol% and the corresponding proportion of ethylene isophthalate 60 to 5 mol%. Copolyesters in which the proportion is preferred of ethylene terephthalate 50 to 90 mol% and the corresponding proportion Ethylene isophthalate is 50 to 10 mol% and copolyesters are very preferred which the proportion of ethylene terephthalate 60 to 85 mol% and the corresponding proportion of ethylene isophthalate is 40 to 15 mol%.

For the other, non-sealable top layer C or for any existing one Intermediate layers can in principle be the same polymers as they are used were previously described for the base layer.

The desired sealing and processing properties of the inventive film are from the combination of the properties of the for sealable top layer used copolyesters and the topographies of sealable cover layer A and the sealable or non-sealable cover layer C received.

A seal starting temperature of preferably less than 110 ° C and one Seal seam strength of at least 1.3 N / 15 mm can be achieved if for the sealable top layer A uses the copolymers described in more detail above become. The best sealing properties of the film are obtained when the copolymer no other additives, especially no inorganic or organic fillers be added. In this case, you get the given copolyester lowest sealing starting temperature and highest sealing seam strengths. In this case, however, the handling of the film deteriorates because of the surface the sealable cover layer A tends to block. The film can be bad  wrap and is for further processing on high-speed Packaging machines not suitable. To improve the handling of the film and Processability, it is necessary to modify the sealable cover layer A. This is best done with the help of suitable antiblocking agents from a selected one Size that are added to the sealing layer in a certain concentration and in such a way that on the one hand the blocking is minimized and on the other hand the Sealing properties are only slightly deteriorated.

In another embodiment, the film can also be colored transparently. For this purpose, the film according to the invention can be a dye that is soluble in thermoplastics contain, the concentration of the soluble dye preferably in the range from 0.01% by weight to 20.0% by weight, in particular in the range from 0.05 to 10.0% by weight, based on the weight of the layers equipped with it.

Soluble dyes are substances that are molecular in the polymer are solved (DIN 55949).

The color change of the film is based on the wavelength-dependent absorption and / or scattering of light. Dyes can only absorb light, but not scatter, because a certain particle size is the physical requirement for a Scattering is.

Coloring with dye is a solution process. As The result of this solution process is the dye, for example in the Crystallizable thermoplastics solved. Such coloring is considered transparent, translucent, translucent or opal.

Of the various classes of soluble dyes, the fat and aromatic-soluble dyes are preferred. These are, for example Azo and anthraquinone dyes. They are particularly suitable for. B. for coloring PET or PETBB, because of the high glass transition temperatures of PET  Migration of the dye is restricted. (Literature J. Koerner: Soluble dyes in the plastics industry in "VDI-Gesellschaft Kunststofftechnik:" coloring of Plastics, VDI-Verlag, Düsseldorf 1975).

Suitable soluble dyes are, for example: C.I. Solvent Yellow 93 (a Pyrazolone derivative), C.I. solvent yellow 16 (a fat-soluble azo dye), fluorolegreen gold (a fluorescent polycyclic dye), C.I. Solvent Red 1 (an azo dye), Azo dyes such as Thermoplastic Red BS, Sudan Red BB, C.I. Solvent Red 138 (a Anthraquinone derivative), fluorescent benzopyran dyes such as fluorol red GK and Fluorolange GK, C.I. solvent blue 35 (an anthraquinone dye), C.I. solvent blue 15: 1 (a phthalocyanine dye) and many others.

Mixtures of two or more of these soluble dyes are also suitable.

The soluble dye is preferably metered in using masterbatch technology but can also be incorporated directly at the raw material manufacturer. The concentration of Color additives in the masterbatches are between 0.01% and 40% by weight, preferably between 0.05% and 25% by weight, based on the weight of the crystallizable thermoplastics.

According to the invention, the film can be coated on at least one of its surfaces be so that the coating on the finished film has a thickness of preferably 5 to 100 nm, preferably 20 to 700 nm, in particular 30 to 50 nm. The Coating is preferably applied in-line, i. H. during the Foil manufacturing process, expediently before transverse stretching. Especially application by means of the so-called "reverse gravure-roll coating" is preferred. Process in which the coatings are extremely homogeneous in the mentioned Have layer thicknesses applied. The coatings are preferred as solutions Suspensions or dispersions applied, particularly preferably as aqueous Solution, suspension or dispersion. The coatings mentioned give the Foil surface an additional function, e.g. B. the film becomes sealable,  printable, metallizable, sterilizable, antistatic, or they improve z. B. the Aroma barrier or allow liability for materials that are otherwise not on the Film surface would adhere (e.g. photographic emulsions). examples for Substances / compositions that provide additional functionality:

Acrylates such as z. B. are described in WO 94/13476, ethyl vinyl alcohols, PVDC, water glass (Na ₂ SiO ₄ ), hydrophilic polyesters (5-Na-sulfoisophthalic acid-containing PET / IPA polyesters as described, for example, in EP-A-0 144 878, US-A-4,252,885 or EP-A-0 296 620, vinyl acetates as described, for example, in WO 94/13481, polyvinyl acetates, polyurethanes, alkali metal or alkaline earth metal salts of C ₁₀ -C ₁₈ fatty acids, Butadiene copolymers with acrylonitrile or methyl methacrylate, methacrylic acid, acrylic acid or their esters The substances / compositions which impart the additional functionality can contain the usual additives, such as antiblocking agents, pH stabilizers in amounts of preferably 0.05% by weight Up to 5 wt .-%, preferably 0.1 wt .-% to 3 wt .-%. wt .-% are each based on the weight of the coating agent (z. B. solution, emulsion, dispersion).

The substances / compositions mentioned are a dilute solution, emulsion or dispersion preferably as an aqueous solution, emulsion or dispersion on a or both film surfaces are applied, and then the solvent volatilized. If the coatings are applied in-line before transverse stretching, Usually the thermal treatment in the transverse stretching and subsequent is sufficient Heat fixation to volatilize the solvent and the coating too dry. The dried coatings then have preferred layer thicknesses 5 to 100 nm, preferably 20 to 70 nm, in particular 30 to 50 nm.

The film can also be corona or be flame treated. The treatment intensity is chosen so that the Surface tension of the film is generally over 45 mN / m.

The surface gloss of the films according to the invention, measured in accordance with DIN 67530 (Measuring angle 20 °), is preferably greater than 100, preferably greater than 110  Light transmission L *, measured according to ASTM D 1003, is preferably more than 65%, preferably more than 70% and the haze of the film, measured in accordance with ASTM D 1003, is preferably less than 30%, preferably less than 25%, which for the achieved UV stability in combination with one or more functionalities such as B. Flame retardant, coating, corona treatment, sealing and / or more transparent Coloring is surprisingly good.

The standard viscosity SV (DCE) of the bibenzene-modified polyethylene terephthalate, measured in dichloroacetic acid according to DIN 53728, lies between 600 and 1000, preferably between 700 and 900.

The bulk density, measured according to DIN 53466, is preferably between 0.70 kg / dm ³ and 1.0 kg / dm ³ , and particularly preferably between 0.75 kg / dm ³ and 0.90 kg / dm ³ .

The polydispersity of the bibenzene-modified polyalkylene naphthalate or bibenzene-modified polyalkylene terephthalate Mw / Mn measured by GPC preferably between 1.5 and 4.0 and particularly preferably between 2.0 and 3.5.

The film according to the invention can be produced, for example, according to a known extrusion or coextrusion processes take place in an extrusion line.

The flame retardant is preferably added via masterbatch technology. The flame retardant is dispersed in a carrier material. As a carrier material come the bibenzol-modified thermoplastic or other polymers that come with the Thermoplastics are acceptable.

The advantage of masterbatch technology is if the grain size and that Bulk weight of the masterbatch similar to the grain size and bulk density of the Thermoplastics are, so that a homogeneous distribution and thus z. B. a homogeneous Flame resistance is guaranteed.  

It is also advantageous if the masterbatch containing the flame retardant and optionally contains the hydrolysis stabilizer, pre-crystallized or pre-dried becomes. This predrying involves gradual heating of the masterbatch reduced pressure (20 to 80 mbar, preferably 30 to 60 mbar, in particular 40 to 50 mbar) and with stirring and, if necessary, drying at constant, elevated temperature also under reduced pressure. The masterbatch will preferably at room temperature from a dosing container in the desired one Mixing together with the polymers of the base and / or cover layers and / or intermediate layers and possibly further raw material components in batches a vacuum dryer that turns on during the drying or dwell time Temperature range from approx. 10 ° C to 160 ° C, preferably 20 ° C to 150 ° C, passes through in particular 30 ° C to 130 ° C, filled. During the approximately 6-hour the residence time is preferably 5 hours, in particular 4 hours Raw material mixture with 10 to 70 rpm, preferably 15 to 65 rpm, in particular 20 stirred up to 60 rpm. The raw material mixture thus pre-crystallized or pre-dried in a downstream likewise evacuated container at 90 ° to 180 ° C, preferably 100 ° C to 170 ° C, in particular 110 ° C to 160 ° C for 2 to 8 hours, preferably post-dried for 3 to 7 hours, in particular 4 to 6 hours.

The film according to the invention has one or more layers. In the multilayer The embodiment is made of at least one base layer B and at least one a top layer, in particular a three-layer A-B-A or A-B-C Structure is preferred. The cover layers A and C can be the same or different.

For this embodiment, it is advantageous if the bibenzol-modified thermoplastic the base layer has a similar standard viscosity as the thermoplastic Cover layers that adjoin the base layer.

In a particular embodiment, a cover layer or the Top layers also made of an unmodified polyalkylene terephthalate - Homopolymers, from an isophthalic acid-modified polyalkylene terephthalate  a bibenzene-modified and / or unmodified polyalkylene naphthalate Polymers or from a bibenzol-modified and / or unmodified Polyalkylene terephthalate-polyalkylene naphthalate copolymers or compound exist. In this case too, PET and PEN are preferred polymers to use.

In this embodiment, the thermoplastics of the cover layers have preferred standard viscosities similar to the bibenzol-modified thermoplastic of the Base layer.

The films according to the invention can be produced from a Bibenzol-modified thermoplastics with possibly further masterbatches and / or Raw materials / polymers and / or other conventional additives in the usual amount of approx. 0.1 to a maximum of 10% by weight are produced as single or multilayer films, the multilayer, coextruded films having the same or different trained surfaces can be made, one surface for example, is pigmented and the other surface contains no pigment. As well can one or both surfaces of the film by known methods with the described functional coatings can be provided.

In the preferred extrusion or coextrusion process for the production of the film according to the invention, the procedure is such that the melts corresponding to the individual layers of the film are extruded or coextruded through a slot die and the largely amorphous pre-film thus obtained is quenched on a cooling roll. This film is then heated again and stretched in the longitudinal and transverse directions or in the transverse and in the longitudinal direction or in the longitudinal, in the transverse and again in the longitudinal direction and / or transverse direction. The stretching temperatures are generally T _g + 10 ° C to T _g + 60 ° C (T _g = glass temperature), the stretching ratio of the longitudinal stretching is usually 2 to 6, in particular 3 to 4.5, that of the transverse stretching is approx 2 to 5, in particular in the case of 3 to 4.5, and that of the second longitudinal stretching which may be carried out at 1.1 to 3. The first longitudinal stretching can optionally be carried out simultaneously with the transverse stretching (simultaneous stretching).

The film is then heat-set at oven temperatures of approx. 200 to 280 ° C, especially at 220 to 270 ° C. The film is then cooled and wound.

During the production of the film, it was found that the film of the invention excellent orientation in the longitudinal and transverse directions without tears. Of Furthermore, no outgassing was found in the production process, which is very is advantageous.

In addition, measurements of cold resistance (DIN 53372) showed that the film according to the invention down to -200 ° C meets the requirements of the standard, d. H. Not brittle.

Weathering tests have shown that the films according to the invention themselves Weathering tests with a projected 5 to 7 years of outdoor use in general no yellowing, no embrittlement, no loss of gloss on the surface, none Cracking on the surface and no deterioration of the mechanical Have properties.

Furthermore, the film according to the invention is without environmental pollution and without significant deterioration of the mechanical properties can be easily recycled, which makes them suitable for use as short-lived advertising signs or other promotional items.

Due to the surprising combination of excellent properties, the film according to the invention excellent for a large number of different applications, for example for interior cladding, for exhibition stand construction and exhibition items, as Displays, for signs, for protective glazing of machines and vehicles, in Lighting sector, in shop and shelf construction, for promotional items, as a lamination medium, in the packaging and automotive sectors and for a large number of others Moldings.  

Due to its good UV stability, flame stability and low temperature resistance, it is suitable inventive film also for outdoor applications such. B. for Greenhouses, canopies, exterior cladding, covers, applications in the construction sector and in the electrical industry, for applications in cooling and Freezer area and for illuminated advertising profiles.

The invention is explained in more detail below on the basis of exemplary embodiments.

The individual properties were measured in accordance with the following standards or procedure.

measurement methods

DIN = German Institute for Standardization
ISO = International Organization for Standardization
ASTM = American Society for Testing and Materials

surface gloss

The surface gloss is measured at a measuring angle of 20 ° according to DIN 67530.

light transmission

Below the light transmission is the ratio of the total transmitted light to understand the amount of incident light.

The light transmission is carried out with the "Hazegard plus" measuring device in accordance with ASTM D 1003 measured.

cloudiness

Haze is the percentage of light that passes through the radiated light beam deviates by more than 2.5 ° on average. The sharpness will determined at an angle less than 2.5 °.  

The haze is measured using the "Hazegard plus" measuring device in accordance with ASTM D 1003.

surface defects

The surface defects are determined visually.

Mechanical properties

The modulus of elasticity, the tensile strength and the elongation at break are in longitudinal and Transverse direction measured according to ISO 527-1-2.

SV (DCE), IV (DCE)

The standard viscosity SV (DCE) is based on DIN 53726 in dichloroacetic acid measured.

The intrinsic viscosity (IV) is calculated as follows from the standard viscosity (SV) IV (DCE) = 6.67. 10 ^-4 . SV (DCE) + 0.118

Weathering (both sides), UV stability

The UV stability is tested according to the test specification ISO 4892 as follows

Test device: Atlas Ci 65 Weather Ometer
Test conditions: ISO 4892, ie artificial weathering
Irradiation time: 1000 hours (per side)
Irradiation. 0.5 W / m ² , 340 nm
Temperature 63 ° C
Relative humidity: 50%
Xenon lamp: inner and outer filter made of borosilicate
Irradiation cycles: 102 minutes of UV light, then 18 minutes of UV light with water spraying the samples, then again 102 minutes of UV light, etc.

Yellowness Index (YID)

The yellowness index YID is the deviation from the colorlessness in the direction of "yellow" and will measured according to DIN 6167.

cold resistance

The cold resistance is determined according to DIN 53372.

fire behavior

The fire behavior is according to DIN 4102 part 2, building material class B2 and DIN 4102 Part 1, building material class B1 and determined according to UL test 94.

Determination of the sealing start temperature (minimum sealing temperature)

The sealing device HSG / ET from Brugger (Germany) is used to heat seal Samples (sealing seam 20 mm × 100 mm) were made, the film at different Temperatures with the help of two heated sealing jaws at a sealing pressure of 2 bar and a sealing time of 0.5 s is sealed. From the sealed samples were Cut test strips 15 mm wide. The T-seal strength was the same as for the Determination of the seal seam strength measured. The seal starting temperature is that Temperature at which a seal seam strength of at least 0.5 N / 15 mm is reached becomes.

Seal strength

Two 15 mm wide film strips were used to determine the seal seam strength one on top of the other and at 130 ° C, a sealing time of 0.5 s and a sealing pressure of 2 bar (device: Brugger type NDS, one-sided heated sealing jaw) sealed. The Seal seam strength was determined by the T-Peel method.

All foils were processed on both sides per 1000 hours per the test specification ISO 4892 Weathered side with the Atlas Ci 65 Weather Ometer from Atlas and then in terms of mechanical properties, discoloration, surface defects, of turbidity and gloss checked.  

Examples example 1

A 50 µm thick, transparent monofilm is produced, which is the main component Contains PETBB and 0.1% by weight Sylobloc®. The film also contains 30 wt .-% of inherent in the film production of self-regeneration.

The Sylobloc® used (SiO ₂ , Grace, Germany) is added in the form of a masterbatch which, in addition to PETBB, contains 10,000 ppm Sylobloc.

The PETBB from which the transparent film is made has one Standard viscosity SV (DCE) of 810, indicating an intrinsic viscosity IV (DCE) of Corresponds to 0.658 dl / g. The bisbenzene acid content is 15% by weight Glass transition temperature is 86 ° C.

After the longitudinal stretching, the film is coated on both sides with an aqueous dispersion by means of the “reverse gravure-roll coating” method. In addition to water, the dispersion contains 4.2% by weight of hydrophilic polyester (5-Na-sulfoisophthalic acid-containing PET / IPA polyester, SP41®, from Ticona, USA), 0.15% by weight of colloidal silicon dioxide (Nalco 1060®, Deutsche Nalco Chemie, Germany) as an antiblocking agent and 0.15% by weight ammonium carbonate (Merck, Germany) as a pH buffer. The wet application weight is 2 g / m ² per coated side. After the transverse stretching, the calculated thickness of the coating is 40 nm.

Example 2

A 50 μm thick monofilm is produced analogously to Example 1. In contrast to Example 1 contains an additional 0.6 to improve the UV stability % By weight of the UV stabilizer 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) oxyphenol (®Tinuvin 1577 from Ciba-Geigy). The UV stabilizer is in the form of a 20 wt. % masterbatches added.  

Tinuvin 1577 has a melting point of 149 ° C and is thermal up to approx. 330 ° C stable.

Example 3

A 19 µm thick, transparent, co-extruded A-B-A film is produced.

The main component of the 16 μm thick base layer B is PETBB, 0.2% by weight Hydrolysis stabilizer and 4% by weight flame retardant. The layer still contains 30% by weight of the self-generated regenerative material inherent in film production.

In addition to PETBB, the two 1.5 µm thick outer layers contain 0.1% by weight Sylobloc® as an antiblocking agent.

For the purpose of homogeneous distribution, the Sylobloc, which is not soluble in PET, is used in the Raw material manufacturers incorporated into the PETBB.

The PETBB from which the transparent film is made has one Standard viscosity SV (DCE) of 810, indicating an intrinsic viscosity IV (DCE) of 0.658 dl / g.

The hydrolysis stabilizer and the flame retardant are in the form of a Masterbatches added. The masterbatch consists of 20% by weight Flame retardant, 1 wt .-% hydrolysis stabilizer and 79 wt .-% PETBB together.

The hydrolysis stabilizer is pentaerythrityl tetrakis-3- (3,5-di- Tertiarybutyl-4-hydroxyphenyl) propionate. The flame retardant is the organic phosphorus compound dimethyl methylphosphonate.

Example 4

Analogously to example 3, a 19 μm thick transparent ABA film is produced. In contrast to Example 3, the film is coated on one side with an aqueous dispersion after the longitudinal stretching by means of a "reverse gravure-roll coating" process. In addition to water, the dispersion contains 4.2% by weight of hydrophilic polyester (5-Na-sulfoisophthalic acid-containing PET / IPA polyester, SP41®, Ticona, USA), 0.15% by weight of colloidal silicon dioxide (Nalco 1060®, Deutsche Nalco Chemie, Germany) as an antiblocking agent and 0.15% by weight ammonium carbonate (Merck, Germany) as a pH buffer. The wet application weight is 2 g / m ² per coated side. After the transverse stretching, the calculated thickness of the coating is 40 nm.

Example 5

It becomes a 12 µm thick, transparent, co-extruded, sealable A-B-C film manufactured.

The 10 μm thick base layer B contains PETBB as the main component and 30% by weight. of the inherent regenerate that is inherent in film production.

A copolyester is used as the thermoplastic for the 1 µm thick sealable cover layer A. from 78 mol% ethylene terephthalate and 22 mol% ethylene isophthalate (produced via the transesterification process with Mn as transesterification catalyst, Mn- Concentration: 100 ppm).

It also contains 3.0% by weight of a masterbatch composed of 97.75% by weight of copolyester and 1.0% by weight of cSylobloc 44 H (synthetic SiO ₂ from Grace) and 1.25% by weight of ® Aerosil TT 600 (pyrogenic SiO ₂ from Degussa)

In addition to PETBB, the 1 μm thick top layer C contains 3.0% by weight of a masterbatch from 97.75% by weight PETBB, 1.0% by weight ®Sylobloc 44 H and 1.25% by weight ®Aerosil TT 600 as an anti-blocking agent.

For the purpose of homogeneous distribution, the Sylobloc and the Aerosil, which are not in PET are soluble, incorporated into the PETBB at the raw material manufacturer.  

The PETBB from which the transparent film is made has one Standard viscosity SV (DCE) of 810, indicating an intrinsic viscosity IV (DCE) of 0.658 dl / g.

Example 6

Analogously to example 5, a 12 μm thick, transparent, coextruded, sealable ABC film is produced. In contrast to Example 5, the non-sealable top layer C is coated on one side with an aqueous dispersion after the longitudinal stretching by means of the “reverse gravure-roll coating” method. In addition to water, the dispersion contains 4.2% by weight of hydrophilic polyester (5-Na-sulfoisophthalic acid-containing PET / IPA polyester, SP41®, Ticona, USA), 0.15% by weight of colloidal silicon dioxide (Nalco 1060®, German Nalco Chemie, Germany) as an antiblocking agent and 0.15% by weight ammonium carbonate (Merck, Germany) as a pH buffer. The wet application weight is 2 g / m ² per coated side. After the transverse stretching, the calculated thickness of the coating is 40 nm.

Example 7

Analogously to Example 6, a 12 µm thick, transparent, coextruded, sealable A-B C-film produced, which is also on the top layer C with the SP41® bonding agent is coated.

In contrast to the film from Example 6, the base layer B contains 1.5% by weight Solvent Blue 35 (fat-soluble anthraquinone dye, ®Sudan Blue 2, BASF, Germany). The colorant is added in the form of a masterbatch, which is next to PETBB contains 20 wt .-% blue colorant.

Example 8

Analogously to Example 7, a 12 µm thick, transparent, coextruded, colored, sealable A-B-C film produced. In contrast to example 7, the film is uncoated.  

The film is corona-treated on the top layer C. The intensity is chosen so that the surface tension is <45 mN / m.

Example 9

Analogously to Example 2, a 50 μm thick monofilm is produced.

Analogously to Example 2, the film contains to improve the already inherent one UV stability additionally 0.6% by weight of the UV stabilizer 2- (4,6-diphenyl-1,3,5-triazine-2- yl) -5- (hexyl) oxyphenol (®Tinuvin 1577 from Ciba-Geigy). The UV stabilizer will added in the form of a 20 wt .-% masterbatch.

The film also contains 0.2% by weight of hydrolysis stabilizer and 4% by weight. Flame retardants. The hydrolysis stabilizer and the flame retardant are in Formed into a master batch. The masterbatch consists of 20% by weight Flame retardant, 1 wt .-% hydrolysis stabilizer and 79 wt .-% PETBB together. The hydrolysis stabilizer is pentaerythrityl tetrakis-3- (3,5-di- Tertiarybutyl-4-hydroxyphenyl) propionate. The flame retardant is the organic phosphorus compound dimethyl methylphosphonate.

The film also contains 1.5% by weight of solvent blue 35 (fat-soluble anthraquinone Dye, ®Sudan Blue 2, BASF, Germany). The colorant is in the form of a Masterbatches metered in, which contains 20% by weight of blue colorant in addition to PETBB.

After the longitudinal stretching, the film is coated on both sides with an aqueous dispersion using the “reverse gravure-roll coating” method. In addition to water, the dispersion contains 4.2% by weight of hydrophilic polyester (5-Na-sulfoisophthalic acid-containing PET / IPA polyester, SP41®, Ticona, USA), 0.15% by weight of colloidal silicon dioxide (Nalco 1060®, Deutsche Nalco Chemistry, Germany) as an antiblocking agent and 0.15% by weight ammonium carbonate (Merck, Germany) as a pH buffer. The wet application weight is 2 g / m ² per coated side. After the transverse stretching, the calculated thickness of the coating is 40 nm.

Example 10

A 50 µm thick, coextruded film is produced.

The composition of the 47 μm thick base layer B corresponds to that Composition of the monofilm from Example 9, so it contains one in addition to PETBB additional UV stabilizer, a flame retardant and a soluble dye.

The composition of the 1.5 µm thick cover layers A and C corresponds to that from example 5.

Analogously to Example 9, the top layer C is coated with the SP41® adhesion promoter.

Comparative Example 1 (VB)

Analogously to Example 1, a 50 µm thick transparent monofilm is produced. Instead of PETBB's thermoplastic is an unmodified PET homopolymer with the same Viscosity used. The film is coated on both sides analogously to Example 1.

The properties of the films produced can be found in the table below.

Show after every 1000 hours of weathering per page with Atlas Ci 65 Weather Ometer hardly changed the bibenzol-modified PET films from Examples 1 to 10 Characteristics.

After 1000 hours of weathering per side with Atlas Cl 65 Weather Ometer, the Film from comparative example 1 on the surfaces of cracks and Signs of embrittlement. A precise property profile - especially regarding the mechanical properties - can therefore no longer be measured. This film also shows a visually visible yellow color.

Claims (28)

1. Single or multilayer film, characterized in that it contains a crystallizable, bibenzol-modified thermoplastic as the main component and has at least one additional functionality. 2. Film according to claim 1, characterized in that the amount of Bibenzol-modified thermoplastics, based on the weight of the finished layers, 50 to 99.9% by weight, preferably 75 to 99% by weight, is. 3. Film according to claim 1 or 2, characterized in that it consists of a Base layer B and two cover layers A and C with the layer sequence A-B-C is constructed, the cover layers can be the same or different. 4. Film according to one or more of claims 1 to 3, characterized characterized that as a thermoplastic a bibenzol-modified polyester is used. 5. Film according to one or more of claims 1 to 4, characterized characterized as bibenzol-modified polyester Polyethylene terephthalate, bibenzene-modified polybutylene terephthalate or Bibenzol-modified polyethylene naphthalate is used. 6. Film according to one or more of claims 1 to 5, characterized characterized that as a bibenzol-modified thermoplastic Bibenzol-modified polyethylene terephthalate is used. 7. Film according to one or more of claims 1 to 6, characterized characterized that the standard viscosity SV (DCE) of the  bibenzene-modified polyethylene terephthalate between 600 and 1000, preferably between 700 and 900. 8. Film according to one or more of claims 1 to 7, characterized characterized in that the bibenzenic acid content, based on the weight of the bibenzene-modified thermoplastics, 1 to 50% by weight, preferably 5 to 45 % By weight, in particular 10 to 40% by weight. 9. Film according to one or more of claims 1 to 8, characterized characterized that the top layers have a bibenzol-modified Thermoplastics, preferably those of the base layer, contain. 10. Film according to one or more of claims 1 to 9, characterized characterized that the top layers are unmodified Polyalkylene terephthalate, bibenzene-modified and / or unmodified Polyalkylene naphthalate or bibenzene-modified and / or unmodified Polyalkylene terephthalate - Polyalkylene naphthalate copolymer included. 11. Film according to one or more of claims 1 to 10, characterized characterized in that the polymers of the base and cover layers are similar Have standard viscosities. 12. Film according to one or more of claims 1 to 11, characterized characterized in that the film has at least one flame retardant and / or contains at least one UV stabilizer and / or is sealable and / or on one or both surfaces is coated and / or corona treated. 13. Film according to one or more of claims 1 to 12, characterized characterized in that the film as a UV stabilizer or 2-hydroxybenzotriazoles Contains triazines or mixtures of various UV stabilizers.   14. Film according to one or more of claims 1 to 13, characterized characterized in that the film contains the UV stabilizer in a concentration of 0.01 to 5 wt .-%, based on the weight of the so equipped Layers. 15. Film according to one or more of claims 1 to 14, characterized characterized that the film as a flame retardant organic Phosphorus compounds, preferably carboxyphosphinic acids or their Anhydrides, especially dimethyl methylphosphonate, or mixtures contains various flame retardants. 16. Film according to one or more of claims 1 to 15, characterized characterized in that the film contains the flame retardant in a concentration from 0.5 to 30% by weight, preferably from 1 to 20% by weight, based on the Weight of the layers equipped with it. 17. Film according to one or more of claims 1 to 16, characterized characterized in that the film is a hydrolysis stabilizer, preferably in a Concentration of 0.01 to 1 wt .-%, based on the weight of it equipped layers. 18. Film according to one or more of claims 1 to 17, characterized characterized in that the sealable film has a seal starting temperature of less than 110 ° C and a seal seam strength of at least 1.3 N / 15 mm having. 19. Film according to one or more of claims 1 to 18, characterized characterized that the film is colored transparent.   20. Film according to one or more of claims 1 to 19, characterized characterized in that the film is functional on one or both surfaces is coated. 21. Film according to one or more of claims 1 to 20, characterized characterized that they have a surface gloss greater than 100, preferably greater than 110. 22. Film according to one or more of claims 1 to 21, characterized characterized that it has a light transmission of greater than 65%. 23. Film according to one or more of claims 1 to 22, characterized characterized in that it has a haze of less than 30%, preferably less than 25%. 24. Film according to one or more of claims 1 to 23, characterized characterized in that the film usual additives such as antiblocking agents, Contains stabilizers or lubricants. 25. Inherently UV-stabilized film, characterized in that it is a film according to one or more of claims 1 to 24. 26. A method for producing a film according to one or more of the claims 1 to 25, characterized in that one for the production of the film required raw materials extruded through a slot die or at multilayer structure coextruded, the film obtained biaxially stretched and heat-set and optionally coated on one or both sides. 27. Use of a film according to one or more of claims 1 to 25 for Manufacture of moldings. 28. Shaped body produced using a film according to one or more of claims 1 to 25.