WO2002081208A1

WO2002081208A1 - Amorphous film consisting of a bibenzol-modified thermoplastic, method for the production thereof and use of the same

Info

Publication number: WO2002081208A1
Application number: PCT/EP2002/001471
Authority: WO
Inventors: Ursula Murschall; Ulrich Kern; Günther Crass
Original assignee: Mitsubishi Polyester Film Gmbh
Priority date: 2001-02-23
Filing date: 2002-02-13
Publication date: 2002-10-17
Also published as: DE10108759A1

Abstract

The invention relates to single or multi-layer transparent amorphous films, containing as the main constituent a crystallisable bibenzol-modified thermoplastic with preferably an increased diethylene glycol and/or polyethylene glycol content, preferably a bibenzol-modified polyester, such as for example a bibenzol-modified polyethylene terephthalate, bibenzol-modified polybutylene terephthalate or bibenzol-modified polyethylene naphthalate, whose bibenzolic acid content is preferably between 1 and 50 wt. %. Said films are inherently UV stable and have a surface lustre of greater than 100, a light transmission greater than 64 % and an opacity of less than 30 %. Multi-layered embodiments of said films can be produced by extrusion or coextrusion, whereby the polymers used for the base and top layers preferably have similar standard viscosities. They can be functionally coated on one or both sides and are suitable for a plurality of interior and exterior applications.

Description

Amorphous film made from a bibenzene-modified thermoplastic, process for its production and its use

The invention relates to an amorphous, transparent film made of a crystallizable, bibenzol-modified thermoplastic, a process for the production of 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 from them are suitable for outdoor use. In outdoor applications, these films show yellowing and deterioration of the mechanical properties after a short time due to photooxidative degradation by sunlight.

EP-A-0 620 245 describes biaxially oriented, crystalline polyester films which are improved in terms of their thermal stability. These films contain antioxidants which are suitable for trapping radicals formed in the film and for degrading the peroxide formed. However, this document does not provide any suggestion of how the UV stability of such films should be improved.

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. 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 ISO 180 at -40 ° C preferably in the range from 10 to 140 kJ / m ² lies. The amorphous plates described are made using smooth calender technology and through Freezing below the glass transition temperature is made by cooling and smoothing.

The object of the present invention was to provide a transparent, amorphous film with a thickness of preferably 30 to 1000 μm, which, in addition to economical thermoformability and good optical properties, above all has high inherent UV stability.

A high inherent UV stability means that the films are not or only slightly damaged by sunlight or other UV radiation, so that the films are suitable for outdoor applications and / or critical indoor applications. In particular, the films should not yellow over several years of outdoor use, should not show any embrittlement or cracking on the surface, and should not show any deterioration in the mechanical properties. High UV stability means that the film absorbs the UV light and only lets light through in the visible range.

The good optical properties preferably include high light transmission (> 64%), high surface gloss (> 100), low haze (<30%) and a low yellowness index (YID <10).

Economical thermoformability means that the film can be thermoformed or thermoformed into commercially available thermoforming machines without inefficient pre-drying to form complex and large-area shaped bodies.

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

This object is achieved by a transparent, amorphous film with a thickness in the range of preferably 30 to 1000 μm, which contains a crystallizable, bibenzene-modified thermoplastic as the main component. Such a film is inherently UV stable. The main component of the film according to the invention is a crystallizable, bibenzol-modified thermoplastic. Suitable crystallizable or partially crystalline bibenzene-modified thermoplastics are, for example, polyesters such as bibenzene-modified polyethylene terephthalate (PETBB), bibenzene-modified polybutylene terephthalate (PBTBB), bibenzene-modified polyethylene naphthalate (PENBB), bibenzene-modified polyethylene terephthalate being preferred (PETBB).

According to the invention, bibenzene-modified crystallizable thermoplastics are understood to be crystallizable bibenzol-modified copolymers, crystallizable bibenzol-modified compounds, crystallizable bibenzol-modified recyclate and other variations of crystallizable bibenzene-modified thermoplastics, with crystallizable bibenzene-modified copolymers being preferred.

To produce the preferred copolymers, polyalkylene terephthalate or polyalkylene naphthalate, in addition to the main monomers such as e.g. Dimethyl terephthalate (DMT), ethylene glycol (EG), propylene glycol (PG), 1,4-butanediol, terephthalic acid (TA), bisbenzenic acid (BB), 2,6-naphthalene dicarboxylate (NDC) and / or 2,6-naphthalene dicarboxylic acid (NDA) , Isophthalic acid (IPA), trans and / or cis-1, 4-cyclohexanedimethanol (c-CHDM, t-CHDM or c / t-CHDM) can be used.

The main constituent means that the amount of bibenzol-modified thermoplastic, based on the weight of the layers provided with it, is preferably between 50 and 99.9% by weight, particularly preferably between 75 and 99% by weight. The remaining amount of 100% can be other additives customary for film production.

Bibenzene-modified polyethylene terephthalate polymers with a crystallite melting point

T _m , measured with DSC (differential scanning calorimetry) with a heating rate of 20 ° C / min, from 180 ° C to over 365 ° C, preferably from 180 ° C to

310 ° C, depending on the Bibenzolsaurehalt, with a crystallization temperature range T ₀ between 75 ° C and 280 ° C, a glass transition temperature T _g between 65 ° C and 130 ° C and with a density, measured according to DIN 53479, of 1.15 to 1.40 g / cm ³ and a crystallinity in A range between 10% and 65%, preferably between 20% and 65%, are preferred starting materials for the production of the film according to the invention.

Bibenzene-modified polyethylene naphthalate polymers with a crystallite melting point T _m , measured with DSC (differential scanning calorimetry) with 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 T _c between 75 ° C and 280 ° C, a glass transition temperature T _g between 65 ° C and 120 ° C and with a density, measured according to DIN 53479, of 1, 20 to 1, 45 g / cm ³ and a crystallinity in the range between 10% and 65%, preferably between 20% and 65%, are further preferred starting materials for the production of the film according to the invention.

It is preferred that the crystallizable thermoplastic has a diethylene glycol content (DEG) of> 1.0% by weight, preferably> 1.2% by weight, in particular> 1.3% by weight and / or a polyethylene glycol content (PEG) of > 1.0% by weight, preferably> 1.2% by weight, in particular> 1.3% by weight and / or an isophthalic acid content of 3% by weight to 10% by weight.

The bibenzenic acid content of the thermoplastics for the film according to the invention is preferably in the range between 1 and 50% by weight, preferably between 5 and 45% by weight, in particular between 10 and 40% by weight.

The film according to the invention can be either single-layer or multi-layer. The film can also be coated with various copolyesters or adhesion promoters.

For the purposes of the present invention, amorphous film is understood to mean films which, although the crystallizable thermoplastic has a crystallinity of 10% to 65%, preferably from 20% to 65%, are themselves not crystalline. Non-crystalline, ie amorphous or essentially amorphous, means that the degree of crystallinity of the film is generally below 3%, preferably below 1%. Such a film is essentially in the unoriented state. The degree of crystallinity is determined by density determination according to ASTM D 1505-68, Method C, at a temperature of 23 ° C. There is a linear relationship between density and crystallinity. The higher the density, the higher the crystallinity.

Light, especially the ultraviolet portion of solar radiation, i.e. H. the wavelength range from 280 to 400 nm initiates degradation processes in thermoplastics, as a result of which not only the visual appearance changes as a result of color change or yellowing, but also the mechanical-physical properties are negatively influenced.

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 begin to absorb UV light below 360 nm, their absorption increases considerably below 320 nm and is very pronounced below 300 nm. The maximum absorption is between 280 and 300 nm.

In the presence of oxygen, chain splits are mainly observed in thermoplastics, but no cross-links. Carbon monoxide, carbon dioxide and carboxylic acids are the predominant quantities of photooxidation products. In addition to the direct photolysis of the ester groups, oxidation reactions must also be considered, which also result in the formation of carbon dioxide via peroxide radicals. The photooxidation of e.g. B. Polyethylene terephthalates can also lead to hydroperoxides and their decomposition products and the associated chain cleavages via elimination of hydrogen in the α-position of the ester groups (H. Day, DM Wiles: J. Appl. Polym. Sei 16, 1972, page 203).

UV stability can in principle be achieved by adding UV stabilizers. UV stabilizers, i.e. UV absorbers as light stabilizers are chemical compounds that can intervene in the physical and chemical processes of light-induced degradation. Soot and other pigments can partially protect against light. However, these substances are unsuitable for transparent films because they lead to discoloration or color change. Only organic and organometallic compounds are suitable for transparent foils, which give the thermoplastic to be stabilized no or only an extremely small color or color change.

UV stabilizers are very expensive, partially evaporate during film production or migrate over time, so that the film shows an undesirable coating after 1 to 2 years. This adversely affects the gloss and transparency of the film. .

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 poor thermal stability and decomposes at temperatures between 200 ° C and 240 ° C or that large amounts (approx. 10 to 15% by weight) of UV stabilizer have to be incorporated, so that the UV light is absorbed and the film is not damaged.

At these high concentrations, the color of the film changes after a short time. Furthermore, the mechanical properties of such a film are adversely affected. Problems arise in film production such as Nozzle deposits, which leads to profile fluctuations

Roller deposits from the UV stabilizer, which leads to impairment of the optical properties (cloudiness, adhesive defect, inhomogeneous surface)

Deposits in the manufacturing process. •

It was therefore surprising that an excellent UV protection could already be achieved by using a bibenzol-modified thermoplastic without the addition of UV stabilizers. It was also surprising that this high inherent UV protection - the yellowness index of the film compared to a standard film made of PET -

Homopolymer does not change within the measurement accuracy; no outgassing, no nozzle deposits, which means that the film has an excellent appearance and an excellent profile and flatness; - The inherently UV-stabilized film is characterized by an excellent process capability, so that it can be produced reliably and reliably. The film according to the invention is therefore also economically viable.

It should also be stated that the waste material that is produced during the production of the film can be reused as regrind for the film production without negatively influencing the yellowness index of the film produced in this way.

The thermoforming process usually comprises the steps of predrying, heating, molding, cooling, demolding, tempering. During the thermoforming process, it was found that the films according to the invention can surprisingly be thermoformed without prior predrying. This advantage compared to e.g. B. thermoformable polycarbonate or polymethyl methacrylate films, in which depending on the thickness predrying times of 10 - 15 hours, at temperatures of 100 ° C to 120 ° C are required, drastically reduces the costs of the forming process. It was also surprising that the detailed reproduction of molded articles made from it is outstanding. The film can also be fed to the thermoforming process, for example as a roll.

The following process parameters have generally proven to be suitable for thermoforming the film according to the invention:

Process step film according to the invention

Predrying is not necessary

Mold temperature 100 to 140 ° C Heating time per 10 μm film thickness <5 sec per 10 μm film thickness

Foil temperature during forming 100 to 160 ° C

Possible stretch factor 1, 5 to 4.0

Excellent detail reproduction

Shrinkage (shrinkage) <1.5%

Furthermore, the film is suitable for the production of composite films. B. from the film according to the invention, which is optionally provided with an ethylene-vinyl alcohol copolymer, ethyl vinyl alcohol, polyvinyl alcohol or polyvinylidene dichloride coating, and a second film. This second film can e.g. B. also a bibenzol-modified thermoplastic film, a standard thermoplastic film such. B. a polyethylene terephthalate film or a polyolefin film, such as. B. a polyethylene or polypropylene film.

The second film can be single-layer or multi-layer and, like the first film, can be amorphous, i. H. be disoriented, and can e.g. B. have a sealing layer. The second film can be connected to the first film according to the invention with or without adhesive.

The thickness of this second film is preferably in the range from 30 to 500 μm. The composite film is generally obtained by laminating or laminating the two films to one another, with or without an intermediate adhesive layer, by passing the films between rollers heated to 30 ° C. to 90 ° C.

The two films can be connected to one another, for example, with or without an adhesive layer, by a lamination process. But it is also possible, for example, the second z. B. transparently colored, layer on the first, coated layer by in-line coating (melt extrusion onto an existing layer).

If adhesives are used, they are applied to a film surface by known methods, in particular by application from solutions or dispersions in water or organic solvents. The solutions usually have an adhesive concentration of 5 to 40% by weight in order to give an amount of adhesive of preferably 1 to 10 g / m ² on the film.

Adhesives made from thermoplastic resins, such as cellulose esters and ethers, alkyl and acrylic esters, polyamides, polyurethanes or polyesters, or from thermosetting resins, such as epoxy resins, urea / formaldehyde, phenyl / formaldehyde or melamine / - Formaldehyde resins, or consist of synthetic rubbers.

Suitable solvents for the adhesive are e.g. Hydrocarbons such as ligroin and toluene, esters such as ethyl acetate, or ketones such as acetone and methyl ethyl ketone.

The surface gloss of the film according to the invention, measured in accordance with DIN 67530

(Measuring angle 20 °), is preferably greater than 100, preferably greater than 1 0

Light transmission L ^* , measured according to ASTM D 1003, is preferably more than 64%, preferably more than 66%, and the haze of the film, measured according to ASTM D 1003, is preferably less than 30%, preferably less than 25%, which is surprisingly good for the UV stability achieved.

The standard viscosity SV (DCE) of the preferred bibenzene-modified polyethylene terephthalate, measured in dichloroacetic acid according to DIN 53728, is between 600 and 1300, preferably between 700 and 1200.

The bulk density, measured according to DIN 53466, is preferably between 0.75 kg / dm ³ and 1.0 kg / dm ³ , and particularly preferably between 0.80 kg / dm ³ and 0.90 kg / dm ³ .

The polydispersity of the likewise preferred bibenzene-modified polyalkylene naphthalate or bibenzene-modified polyalkylene terephthalate MJM _n measured by GPC is preferably between 1.5 and 4.0 and particularly preferably between 2.0 and 3.5.

The film according to the invention can be either single-layer or multi-layer.

In the multilayered embodiment, the film is composed of at least one core layer and at least one cover layer, a three-layer A-B-A or A-B-C structure being preferred, wherein the cover layers A and C can be the same or different. Additional intermediate layers can also be present, so that e.g. there are a total of 5 layers.

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

In a further particular embodiment, the outer layers can also be made from an unmodified polyalkylene terephthalate homopolymer, from a bibenzene-modified and / or unmodified polyalkylene naphthalate polymer or consist of a bibenzene-modified and / or unmodified polyalkylene terephthalate-polyalkylene naphthalate copolymer or compound. In these cases too, PET and PEN are preferred polymers.

In this embodiment, the thermoplastics of the cover layers preferably also have similar standard viscosities such as e.g. the bibenzene-modified polyalkylene terephthalate of the core layer.

The film can also be corona-treated on at least one side and / or coated on at least one side with a scratch-resistant coating, with a copolyester or with an adhesion promoter and / or vapor-coated with ethylene-vinyl alcohol copolymer, ethyl-vinyl alcohol, polyvinyl alcohol or polyvinylidene dichloride.

According to the invention, the film can be coated on at least one of its surfaces, so that the coating on the finished film has a thickness of preferably 5 to 100 nm, preferably 20 to 70 nm, in particular 30 to 50 nm. The coating is preferably applied in-line, i.e. during the film manufacturing process. Application by means of the so-called "reverse gravure roll coating" method is particularly preferred, in which the coatings can be applied extremely homogeneously in the layer thicknesses mentioned. The coatings are preferably applied as solutions, suspensions or dispersions, particularly preferably as an aqueous solution, suspension or dispersion. The coatings mentioned give the film surface an additional function such. B. the film is sealable, printable, metallizable, sterilizable, antistatic or they improve z. B, the aroma barrier or enable adhesion to materials that would otherwise not adhere to the film surface (e.g. photographic emulsions). Examples of substances / compositions that add additional functionality are:

Acrylates as described, for example, in WO 94/13476, ethyl vinyl alcohols, PVDC, water glass (Na ₂ Si0 ₄ ), hydrophilic polyesters (containing 5-Na-sulfoisophthalic acid)

PET / IPA polyester such as B. are described in EP-A-0 144 878, US-A- 4,252,885 or EP-A-0296620, vinyl acetates as e.g. B. are described in WO 94/13481, polyvinyl acetates, polyurethanes, alkali metal or alkaline earth metal salts of C10-C18 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 customary additives, such as, for example, antiblocking agents, pH stabilizers, in amounts of preferably 0.05% by weight to 5% by weight, preferably 0.1% by weight to 3 wt .-% included. % By weight are in each case based on the weight of the coating composition (for example solution, emulsion, dispersion).

The substances / compositions mentioned are applied as a dilute solution, emulsion or dispersion, preferably as an aqueous solution, emulsion or dispersion, to one or both film surfaces, and the solvent is then volatilized by means of temperature treatment. The dried coatings then have layer thicknesses of preferably 5 to 100 nm, preferably 20 to 70 nm, in particular 30 to 50 nm.

Furthermore, the films can be coated with metals such as aluminum or with ceramic materials such as SiO _x or Al _x O _y , preferably in an off-line process. This improves their gas barrier properties in particular.

Weathering tests have shown that even in weathering tests with an extrapolated 5 to 7 years of outdoor use, the films according to the invention generally have no yellowing, no embrittlement, no loss of gloss on the surface, no cracking on the surface and no deterioration in the mechanical properties.

During the production of the film, it was found that the film according to the invention can be produced very economically. Furthermore, no outgassing was found in the production process, which is very advantageous. In addition, measurements of cold resistance (DIN 53372) showed that the film meets the requirements of the standard down to a temperature of -200 ° C, ie it does not become brittle.

Furthermore, the film according to the invention can be easily recycled without environmental pollution and without loss of mechanical properties, which makes it suitable, for example, for use as short-lived advertising signs or other promotional items and / or thermoforming articles.

The film according to the invention can be produced, for example, by a known extrusion process in an extrusion line.

The films can be made according to known processes from a bibenzol-modified thermoplastic and possibly further raw materials and / or further conventional additives in the usual amount of approx. 0.1 to a maximum of 10% by weight both as monofilms and as multilayer, optionally coextruded films are produced with the same or different surfaces, one surface being pigmented, for example, and the other surface containing no pigment. Likewise, one or both surfaces of the film can be provided with a conventional functional coating by known methods. The other raw materials / additives mentioned are preferably metered in using so-called masterbatch technology, but they can also be incorporated directly at the raw material manufacturer.

The polymers or raw material mixtures are fed to an extruder or, in the case of multilayer films, to a plurality of extruders. Any foreign bodies or impurities that may be present can be filtered off from the polymer melt before extrusion. The melt (s) are then formed into flat melt films in a mono nozzle or, in the multilayer case, in a multilayer nozzle, and in the multilayer case are layered one on top of the other. Subsequently, the monofilm or the multilayer film is quenched with the aid of a cooling roll and as an amorphous or largely amorphous, ie unoriented film solidified. The cooled, amorphous film is then hemmed and wound up.

Due to the surprising combination of excellent properties, the film according to the invention is outstandingly suitable for a large number of different applications, for example for interior cladding, for trade fair construction and trade fair articles, as displays, for signs, for protective glazing of machines and vehicles, in the lighting sector, in shop and shelf construction, as Promotional items, as laminating medium, as packaging film, as composite film, as furniture film and in particular for use in the thermoforming sector, ie for the production of a large number of moldings.

Due to the good UV stability and low-temperature resistance, the film according to the invention is also suitable for outdoor applications, such as for greenhouses, canopies, outer cladding, covers, applications in the construction sector, applications in the cooling and freezer sector and for illuminated advertising profiles, in the credit card, telephone card or other card sector.

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

The individual properties are measured according to the following standards and procedures.

measurement methods

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

DEG content PEG content / IPA content

The DEG / PEG / I PA content is determined by gas chromatography after saponification in methanolic KOH and neutralization with aqueous HCl. Surface gloss:

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

Light transmission: The light transmission is the ratio of the total transmitted light to the amount of incident light.

The light transmission is measured using the "Hazegard plus" measuring device (Byk Gardener, Germany) in accordance with ASTM D 1003.

cloudiness

Haze is the percentage of the transmitted light that deviates by more than 2.5 ° on average from the incident light beam. The image sharpness is determined at an angle of 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.

SV (DCE), IV (DCE):

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

The intrinsic viscosity (IV) is calculated as follows from the standard viscosity (SV)

IV (DCE) = 6.67-10 ^{"4 ■} SV (DCE) + 0.118

Embossing (both sides), UV stability:

The UV stability is tested according to the test specification ISO 4892 as follows Atlas Ci 65 Weather Ometer (Atlas, England)

Test conditions ISO 4892, i.e. H. 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

Water spraying the samples, then 102 again

Minutes of UV light etc.

Yellow value:

The yellowness index YID is the deviation from the colorlessness in the "yellow" direction and is measured in accordance with DIN 6167.

Cold resistance:

The cold resistance is determined according to DIN53372.

The following examples and comparative examples are each transparent films of different thicknesses which are produced on an extrusion line.

All foils were weathered on both sides with the Atlas Ci 65 Weather Ometer from Atlas according to the test specification ISO 4892 on both sides and then tested for thermoformability, discoloration, surface defects, haze, gloss and cold resistance. Examples:

Example 1 :

There was a 150 micron thick transparent, single-layer, produced amorphous film containing as a main component PETBB and 0.1 wt .-% Sylobloc ^®.

The Sylobloc used (Si0 ₂ , Grace, Germany) was added in the form of a masterbatch which, in addition to PETBB, contained 10,000 ppm of Sylobloc.

The PETBB from which the transparent film was produced had a standard viscosity SV (DCE) of 1010, which corresponds to an intrinsic viscosity IV (DCE) of 0.792 dl / g. The bisbenzene acid content was 15% by weight and the glass transition temperature was 86 ° C. The DEG content was 2.1% by weight.

Example 2:

Analogous to Example 1, a transparent film 150 μm thick monofilm was produced. In contrast to Example 1, 25% by weight of self-regenerated material was used.

The film was coated on both sides with an aqueous dispersion by means of the "reverse gravure-roll coating" method. The dispersion comprised water and 3 wt .-% hydrophilic polyester (5-Na-sulfoisophthalsäurehaltiges PET / I PA polyester, SP41 ^®, Fa.Ticona, USA), 0.1 wt .-% colloidal silica (Nalco 1060 ^®, German Nalco Chemie, Germany) as an antiblocking agent and 0.1% by weight ammonium carbonate (Merck, Germany) as a pH buffer. The wet application weight was 1.5 g / m ² per coated side. After drying, the calculated thickness of the coating was 50 nm.

Example 3:

According to the coextrusion technology, a 150 mm thick multilayer PETBB film with the layer sequence ABA was produced, with B the core layer and A the Represented cover layers. The core layer B was 146 mm thick and the two outer layers covering the core layer were each 2 mm thick.

The PETBB used for the core layer B was identical to that from Example 1, but the core layer did not contain any Sylobloc.

The composition of the outer layers A was identical to the composition of the monofilm from Example 1, i.e. H. the top layer raw material was equipped with 0.1% by weight of Sylobloc.

Comparative Example 1 (VB1)

A 150 μm thick monofilm made from PET homopolymer was produced analogously to Example 1. Here, too, the SV value of the unmodified PET homopolymer used was 1010. The DEG content was 0.6% by weight.

The film was not coated in-line.

The properties of the films produced in this way are shown in Table 1 below.

Table 1: Property profile of the films produced:

After each 1000 hours of weathering per side with Atlas Ci 65 Weather Ometer, the bibenzol-modified PET films from Examples B1 to B3 show hardly any changed properties.

After 1000 hours of weathering per side with Atlas Ci 65 Weather Ometer, the film from comparative example VB1 shows cracks and embrittlement on the surfaces. A precise property profile - particularly with regard to the mechanical properties - can therefore no longer be measured. This film also shows a visually visible yellow color.

Claims

claims

1. Amorphous, single or multilayer film, characterized in that it contains a crystallizable, bibenzol-modified thermoplastic as the main component.

2. Film according to claim 1, characterized in that the degree of crystallinity of the film is less than 3%, preferably less than 1%.

3. Film according to claim 1 or 2, characterized in that the amount of the bibenzol-modified thermoplastic, based on the weight of the layers equipped therewith, is 50 to 99.9% by weight, preferably 75 to 99% by weight.

4. Film according to one or more of claims 1 to 3, characterized in that it is composed of a base layer B and two cover layers A and C with the layer sequence A-B-C, wherein the cover layers can be the same or different.

5. Film according to one or more of claims 1 to 4, characterized in that a bibenzol-modified polyester is used as the thermoplastic.

6. Film according to one or more of claims 1 to 5, characterized in that bibenzol-modified polyester, bibenzol-modified polyethylene terephthalate, bibenzol-modified polybutylene terephthalate or bibenzol-modified polyethylene naphthalate is used.

7. Film according to one or more of claims 1 to 6, characterized in that bibenzol-modified polyethylene terephthalate is used as the bibenzol-modified thermoplastic.

8. Film according to one or more of claims 1 to 7, characterized in that the bibenzol-modified thermoplastic has a diethylene glycol content of greater than 1.0% by weight, preferably greater than 1.2% by weight, in particular greater than 1.3% by weight. %, and / or a polyethylene glycol content of greater than 1.0% by weight, preferably greater than 1.2% by weight, in particular greater than 1.3% by weight, and / or an isophthalic acid content of 3 to 10% by weight having.

9. Film according to one or more of claims 1 to 8, characterized in that the standard viscosity SV (DCE) of the bibenzol-modified polyethylene terephthalate is between 600 and 1300, preferably between 700 and 1200.

10. Film according to one or more of claims 1 to 9, characterized in that the bibenzene acid content, based on the weight of the bibenzol-modified thermoplastic, 1 to 50 wt .-%, preferably 5 to 45 wt .-%, in particular 10 to 40 wt .-%.

11. Film according to one or more of claims 1 to 10, characterized in that the cover layers contain a bibenzol-modified thermoplastic, preferably that of the base layer.

12. Film according to one or more of claims 1 to 11, characterized in that the cover layers contain unmodified polyalkylene terephthalate, bibenzene-modified and / or unmodified polyalkylene naphthalate or bibenzene-modified and / or unmodified polyalkylene terephthalate-polyalkylene naphthalate copolymer.

13. Film according to one or more of claims 1 to 12, characterized in that the polymers of the base and the cover layers have similar standard viscosities.

14. Film according to one or more of claims 1 to 13, characterized in that the film is functionally coated on one or both surfaces.

15. Film according to one or more of claims 1 to 14, characterized in that it has a surface gloss of greater than 100, preferably greater than 110.

16. Film according to one or more of claims 1 to 15, characterized in that it has a light transmission of greater than 64%, preferably greater than 66%.

17. Film according to one or more of claims 1 to 16, characterized in that it has a haze of less than 30%, preferably less than 25%.

18. Film according to one or more of claims 1 to 17, characterized in that the film contains conventional additives such as antiblocking agents, stabilizers or lubricants.

19. Inherently UV-stabilized film, characterized in that it corresponds to a film according to one or more of claims 1 to 18.

20, method for producing a film according to one or more of the claims

1 to 19, characterized in that the starting materials required for the production of the film are extruded through a mono-die or, in the case of a multi-layer structure, co-extruded through a multi-layer die, the resultant Foil quenched and solidified and optionally coated on one or both sides.

21. Use of a film according to one or more of claims 1 to 19 for the production of composite films.

22. Use of a film according to one or more of claims 1 to 19 for the production of moldings.

23. Shaped body produced using a film according to one or more of claims 1 to 19.