DE10110432A1 - Amorphous, covered colored sheet of a bibenzo-modified thermoplastic, process for its preparation and its use - Google Patents

Abstract

The invention relates to a single or multiple-layered, subduedly colored amorphous film, containing as main ingredients a crystallizable, bibenzol-modified thermoplastic material, preferably having an enhanced diethylene glycol and/or polyethylene glycol content, preferably a bibenzol-modified polyester such as bibenzol-modified polyethylene terephthalate, bibenzol-modified polybutylene terephthalate or bibenzol-modified polyethylene naphthalate, the bibenzolic acid content thereof preferably lying between 1 and 50 percent by weight, and an inorganic white pigment, such as TiO2, BaSO4, and/or an inorganic or organic colored pigment, such as carbon black, iron oxides, azopigments. Said films are inherently UV stable and have a surface luster higher than 5 and a light transmission of less than 85 %. Multi-layered embodiments of said films can be produced by extrusion or coextrusion, wherein the polymers used for the base and cover layers preferably have similar standard viscosities, they can be functionally coated on one or both sides and are suitable for a plurality of internal and external applications.

Description

The invention relates to an amorphous, covered colored film of a crystallizable, bibenzo-modified thermoplastics, a process for the preparation this film and its use.

Covered colored films of crystallizable thermoplastics are known.

These foils are not inherently UV stable, so neither the foils nor the foils made of articles for outdoor use. For outdoor applications show these films after a short time yellowing and deterioration the mechanical properties due to a photo-oxidative degradation by Sunlight.

In EP-A-0 620 245 biaxially oriented crystalline films are of polyethylene terephthalate, which are improved in terms of their thermal stability. These films contain antioxidants which are suitable formed in the film Catch radicals and break down formed peroxide. A proposal how the UV Stability of such films should be improved, this document is not apparent.

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

The object of the present invention was to produce a covered, amorphous film to provide a thickness of preferably 30 to 1000 microns, in addition to a economic thermoformability and good optical properties especially one has high inherent UV stability.

A high inherent UV stability means that the films are protected by sunlight or other UV radiation is not or only extremely little damaged, so that the Films are suitable for outdoor and / or critical indoor applications. In particular, the films should not yellow during outdoor use for many years, show no embrittlement or cracking on the surface and none Have deterioration of mechanical properties. High UV stability means, therefore, that the film absorbs the UV light and light only in the visible Lets through the area.

Among the good optical properties are preferably a low Light transmission (<85%), a high surface gloss (<15) and a high Turbidity (<20%).

Economical thermoformability means that the film is based on commercial Thermoforming machines without unprofitable predrying to complex and deep-drawing or thermoforming large-area moldings.

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

This problem is solved by a covered colored, amorphous film with a Thickness in the range of preferably 30 to 1000 .mu.m, the main component of a  crystallizable, bibenzo-modified thermoplastics and at least one pigment contains. Such a film is inherently UV stable.

The film according to the invention contains as its main constituent a crystallizable, bibenzol modified thermoplastics. Suitable crystallizable or semi-crystalline For example, bibenzol modified thermoplastics are polyesters such as bibenzo-modified polyethylene terephthalate (PETBB), bibenzo-modified Polybutylene terephthalate (PBTBB), bibenzo-modified polyethylene naphthalate (PENBB), with bibenzo-modified polyethylene terephthalate (PETBB) being preferred.

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

• Crystallizable bibenzo-modified copolymers,
• Crystallizable bibenzo-modified compounds,
• Crystallizable bibenzol modified recycle and
• Other variations of crystallizable bibenzo-modified thermoplastics,

wherein crystallizable bibenzo-modified copolymers are preferred.

For the preparation of the preferred copolymers polyalkylene terephthalate or Polyalkylene naphthalate can in addition to the main monomers such. B. Dimethyl terephthalate (DMT), ethylene glycol (EG), propylene glycol (PG), 1,4-butanediol, Terephthalic acid (TA), bisbenzoic acid (BB), 2,6-naphthalenedicarboxylate (NDC) and / or 2,6-naphthalene dicarboxylic acid (NDA), also isophthalic acid (IPA), trans and / or cis-1,4- Cyclohexanedimethanol (c-CHDM, t-CHDM or c / t-CHDM) can be used.

Main ingredient is that the amount of bibenzo-modified thermoplastic, based on the weight of the layers equipped therewith, preferably between 50 and 99% by weight, more preferably between 75 and 95% by weight. The rest of Quantity to 100%, in addition to the pigment more common for film production Additives.  

Bibenzolmodifizierte polyethylene terephthalate polymers having a crystallite melting point T _m , measured by DSC (Differential Scanning Calorimetry) at a Aufheizge speed of 20 ° C / min. in the range of 180 ° C to over 365 ° C, preferably from 180 ° C to 310 ° C, depending on the Bibenzöläuregehalt, with a crystallization temperature range T _c between 75 ° C and 280 ° C, a glass transition temperature T _g between 65 ° C. and 130 ° C and having a density, measured according to DIN 53479, of 1.15 to 1.40 g / cm ³ and a crystallinity between 10% and 65%, preferably between 20% and 65%, are preferred starting materials for the preparation of inventive film.

Bibenzolmodifizierte polyethylene naphthalate polymers having a crystallite melting point T _m , measured by DSC (Differential Scanning Calorimetry) at a Aufheizge speed of 10 ° C / min. in the range from 120 ° C to 310 ° C, preferably from 140 ° C to 280 ° C, depending on the Bibenzöläuregehalt, 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 between 10% and 65%, preferably between 20% and 65%, are also preferred starting materials for the preparation of inventive film.

It is preferred that the crystallisable thermoplastic has a diethylene glycol content (DEG) of <1.0 wt .-%, preferably <1.2 wt .-%, in particular <1.3 wt .-% 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 having.

Preferably, the bibenzolic acid content of the thermoplastics of the invention 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 both single-layered and multilayered. The  Film can also be coated with various copolyesters or adhesion promoters.

Under amorphous film in the context of the present invention, such films Although, the crystallizable thermoplastic has a crystallinity of 10% 65%, preferably from 20% to 65%, are themselves not crystalline. Not crystalline, d. H. amorphous or substantially amorphous, means that the Crystallinity level of the film is generally less than 3%, preferably less than 1%. Such a film is substantially in the unoriented state. The The degree of crystallinity is determined by the density determination according to ASTM D 1505-68, method C, determined at a temperature of 23 ° C. There is one between density and crystallinity linear relationship. The higher the density, the higher the crystallinity.

Light, in particular the ultraviolet portion of solar radiation, d. H. the waves length range of 280 to 400 nm, initiates degradation processes in thermoplastics, as The result is not only the visual appearance due to color change or Yellowing changes, but also negatively affects the mechanical-physical properties to be influenced.

The inhibition of these photooxidative degradation processes is of considerable technical and economic importance, otherwise the possible applications of numerous thermoplastics are drastically limited.

For example, unmodified polyethylene terephthalates begin below below Absorb 360 nm UV light, its absorption decreases 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, thermoplastics are mainly chains splits, but no crosslinks observed. Carbon monoxide, carbon dioxide and Carboxylic acids represent the quantitatively predominant photo-oxidation products. In addition to the direct photolysis of the ester groups still have oxidation reactions in  Whereas the use of peroxide radicals also inhibits the formation of Carbon dioxide result.

The photooxidation of z. B. Polyethylene terephthalates can also be hydrogen cleavage in the a-position of the ester groups to hydroperoxides and their decomposition products as well as associated chain cleavages (H. Day, D. M. Wiles: J. Appl. Polym. Sci 16, 1972, 203).

UV stability can basically 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 Intervene degradation. Soot and other pigments can partially Cause light protection. However, these substances are for covered colored films unsuitable because they lead to discoloration or color change. For covered colored Foils are suitable only organic and organometallic compounds that the stabilizing thermoplastics no or only an extremely small color or Give color change.

UV stabilizers are very expensive, partially evaporate during film production or migrate over time, leaving the film an undesirable after 1 to 2 years Pavement shows. As a result, the gloss of the film is adversely affected.

In light of the fact that UV stabilizers can provide protection, the skilled person would have used commercially available UV stabilizers. He would have found that

• - The UV stabilizer has a lack of thermal stability and at Temperatures between 200 ° C and 240 ° C decomposes or outgassing
• - Large amounts (about 10 to 15 wt .-%) UV stabilizer are 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  Time. Furthermore, the mechanical properties of such a film are negative affected. In the film production problems occur such. B.

• - nozzle deposits, which leads to profile fluctuations
• - Roller deposits from the UV stabilizer, resulting in the impairment of optical properties (adhesive defects, inhomogeneous surface) leads
• - deposits during 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 level of inherent UV protection

• The color of the film compared to a standard PET homopolymer film does not change as part of the measurement accuracy;
• - No outgassing, no nozzle deposits set, causing the film has an excellent appearance and an excellent profile and a has excellent flatness;
• - The inherently UV-stabilized film by an excellent process capability characterized, so that they are produced process-safe and production-safe can be. Thus, the film of the invention is also economically viable.

It should also be mentioned that also cutting material used in film production accumulates during operation, can be used again as a regenerate in the film production, without to negatively influence the color of the film produced therewith.

The film of the invention contains at least in the base layer and / or the Cover layers an inorganic white pigment and / or an inorganic or organic colored and / or black pigment. The concentration of the pigments is preferably between 0.2 and 40% by weight, preferably between 0.3 and 25% by weight, based on the weight of the layers equipped therewith. It can too Pigment mixtures are used.  

The pigment is preferably metered in via masterbatch technology, but it can also be added be incorporated directly at the raw material manufacturer.

Suitable white pigments are preferably titanium dioxide, barium sulfate, calcium carbonate, kaolin, silica, with titanium dioxide (anatase and / or rutile) and Barium sulfate are preferred.

The optionally used titanium dioxide particles may have a coating of inorganic oxides commonly used as a coating for TiO ₂ white pigment in papers or paints to improve light fastness. (cf., for example, Gächter / Müller, Kunststoff-Additive, Carl Hanser Verlag, Munich).

TiO ₂ is photoactive. When exposed to UV rays, free radicals form on the surface of the particles. These free radicals can migrate to the film-forming polymers, which can lead to degradation reactions and yellowing. To avoid this, the TiO ₂ particles can be oxidized. Particularly suitable oxides include the oxides of aluminum, silicon, zinc or magnesium or mixtures of two or more of these compounds. TiO ₂ particles with a coating of several of these compounds are z. In EP-A-0 044 515 and EP-A-0 078 633. Furthermore, the coating may contain organic compounds with polar and non-polar groups. The organic compounds must be sufficiently thermostable for the production of the film by extrusion of the polymer melt. Polar groups are, for example, -OH; -OR; --COOX; (X = R, H or Na, R = alkyl with 1-34 C atoms). Preferred organic compounds are alkanols and fatty acids having 8-30 carbon atoms in the alkyl group, especially fatty acids and primary n-alkanols having 12-24 carbon atoms, and polydiorganosiloxanes and / or polyorganohydrogensiloxanes such. As polydimethylsiloxane and polymethyl hydrogensiloxane.

The coating for the titanium dioxide particles usually consists of 1 to 12, in particular  2 to 6 g of inorganic oxides and / or 0.5 to 3, in particular 0.7 to 1.5 g organic compounds based on 100 g of titanium dioxide particles. The coating will open the particles are applied in aqueous suspension. The inorganic oxides become from water-soluble compounds, e.g. B. alkali, especially sodium nitrate, Sodium silicate (water glass) or silica precipitated in the aqueous suspension.

Under inorganic oxides such as Al ₂ O ₃ or SiO ₂ are also the hydroxides or their various dewatering stages such. As oxide hydrate to understand without their exact composition and structure recognizes. On the TiO ₂ pigment, after the annealing and milling in aqueous suspension, the oxide hydrates z. As the aluminum and / or silicon, the pigments are then washed and dried. This precipitation can thus be done directly in a suspension, as obtained in the manufacturing process after the annealing and the subsequent wet grinding. The precipitation of the oxides and / or oxide hydrates of the respective metals is carried out from the water-soluble metal salts in the known pH range, for aluminum, for example, aluminum sulfate in aqueous solution (pH less than 4) is used and by addition of aqueous ammonia solution or sodium hydroxide in the pH range between 5 and 9, preferably between 7 and 8.5, the oxide hydrate like. Assuming a water glass or alkali aluminate solution, the pH of the TiO ₂ suspension should be in the strongly alkaline range (pH greater than 8). The precipitation is then carried out by addition of mineral acid such as sulfuric acid in the pH range 5 to 8. After the precipitation of the metal oxides, the suspension is stirred for another 15 minutes to about 2 hours, whereby the precipitated layers undergo aging. The coated product is separated from the aqueous dispersion and after washing at elevated temperature, in particular at 70 to 100 ° C, dried.

In another embodiment, barium sulfate is preferred as the pigment. Preferably, the barium sulfate is also converted via the so-called masterbatch Technology dosed directly during film production.

In the case of pigmentation with barium sulfate, the film preferably additionally contains  at least one optical brightener, wherein the optical brightener in amounts of 10 ppm to 50,000 ppm, in particular from 20 ppm to 30,000 ppm, particularly preferred from 50 ppm to 25,000 ppm, based on the weight of the so-equipped Layers, is used. Preferably, the optical brightener on the so-called masterbatch technology dosed directly during film production. Also When using other pigments, it may be appropriate to optical brightener use.

The optical brighteners of the invention are capable of absorbing UV rays in the range from 360 to 380 nm and as a longer-wavelength, visible blue-violet To turn off the light.

Suitable optical brighteners are bis-benzoxazoles, phenylcoumarins and bis- sterylbiphenyls, especially phenylcoumarins, particularly preferred are triazine phenylcoumarin (Tinopal®, Ciba-Geigy, Basel, Switzerland), Hostalux® KS (Clariant, Germany) as well as Eastobrite® OB-1 (Eastman).

If appropriate, in addition to the optical brightener also in the be added to bibenzolmodifizierten thermoplastics soluble blue dyes. When suitable blue dyes are cobalt blue, ultramarine blue and Anthraquinone dyes, in particular Sudanblau® 2 (BASF, Ludwigshafen, Federal Republic of Germany).

The blue dyes are used in amounts of 10 ppm to 10,000 ppm, in particular 20 ppm to 5,000 ppm, more preferably 50 ppm to 1,000 ppm, based on the Weight of the layers equipped with it.

In a preferred embodiment, precipitated barium sulfate types are used. Precipitated barium sulphate is obtained from barium salts and sulphates or sulfuric acid as a finely divided colorless powder whose particle size by the precipitation conditions to control is. Precipitated barium sulfates can be prepared by the usual methods, the z. In  Plastics Journal, Nos. 10, 30-36 and No. 11, 26-31 (1974) become.

The amount of barium sulfate is suitably 0.2 to 40 wt .-%, preferably 0.3 to 25 wt .-%, particularly preferably 1 to 25 wt .-% based on the weight of the layers equipped with it.

The average particle size of these barium sulfate types is relatively small and is preferably in the range of 0.1 to 5 .mu.m, particularly preferably in the range of 0.2 to 3 .mu.m, measured by the Sedigraph method. The density of the barium sulfate used is preferably between 4 and 5 g / cm ³ .

In a particularly preferred embodiment, the film according to the invention contains the main component is a crystallizable bibenzo-modified polyethylene terephthalate and 1 wt .-% to 25 wt .-% precipitated barium sulfate, preferably with a Particle diameter from 0.4 to 1 μm, with Blanc fixe® XR-HX or Blanc fixe® HXH is particularly preferred by the company Sachtleben Chemie.

Furthermore, this film preferably contains 10 to 50,000 ppm of an optical one Brightener.

In a further particular embodiment, the film according to the invention can also colored be colored. The film of this embodiment may also be used in the base and / or the outer layers inorganic color pigments, inorganic black pigments and inorganic or organic colored pigments. The pigment is preferably added via masterbatch technology, but can also be added directly to the Raw material manufacturers are incorporated.

Typical inorganic black pigments are carbon black modifications, which are also coated carbon pigments, which differs from the carbon black pigments by a differ in higher ash content, and black oxide pigments such as black iron oxide  and copper, chromium, iron oxide mixtures (mixed phase pigments).

Suitable inorganic colored pigments are oxidic colored pigments, hydroxyl-containing Pigments, sulfidic pigments and chromates.

Examples of oxidic colored pigments are iron oxide red, titanium oxide-nickel oxide Mixed antimony oxide pigments, titanium dioxide-chromium oxide, antimony oxide Mixed phase pigments, mixtures of the oxides of iron, zinc and titanium, chromium oxide Iron oxide brown, spinels of the system cobalt-aluminum-titanium-nickel-zinc oxide and Mixed phase pigments based on other metal oxides.

Typical hydroxyl-containing pigments are, for example, oxide hydroxides of trivalent iron, such as FeOOH.

Examples of sulfidic pigments are cadmium sulfide selenides, cadmium Zinc sulfides, sodium aluminum silicate with polysulfide-bonded sulfur in the Grid.

Examples of chromates are bleaching chromates which are monoclinic in the crystal forms, rhombic and tetragonal.

All colored pigments can be ungecoated as well as the white and black pigments also inorganic and / or organic coated.

The organic colored pigments are usually divided into azo pigments and so-called Non-azo pigments on.

Characteristic of the azo pigments is the azo (-N = N -) group. Azo pigments can Monoazo pigments, diazo pigments, diazo condensation pigments, salts of Azofarbsäuren and mixtures of the azo pigments.  

The pigments to be used according to the invention are known to the person skilled in the art and are commercially available.

The thermoforming process, which is also applicable to the film according to the invention, usually includes the steps of predrying, heating, molding, cooling, Demolding, tempering. The thermoforming process found that the films According to the invention deep-draw surprisingly without prior predrying to let. This advantage compared to z. B. thermoformable polycarbonate or Polymethyl methacrylate films in which, depending on the thickness, predrying times of 10 15 hours, at temperatures ranging from 100 ° C to 120 ° C are required, drastically reduces the cost of the forming process. Besides, it was surprising that the detail reproduction of molded articles produced therefrom is excellent. The foil can also be supplied to the thermoforming process, for example, as a roll product.

For the thermoforming of the film according to the invention, the following process parameters have generally proved suitable:

step Film according to the invention Pre-drying not mandatory Temperature of the mold 100 to 140 ° C Heating time per 10 μm film thickness <5 sec per 10 μm film thickness Film temperature during deformation 100 to 160 ° C Possible draw factor 1.5 to 4.0 Detail reproduction outstanding Shrinkage (shrinkage) <1.5%

According to the invention, the film may 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, ie during the Folienher stellprozesses. Particularly preferred is the application by means of the so-called "reverse gravure-roll coating" process, in which the coatings can be applied very homogeneously in the layer thicknesses mentioned. The coatings are preferably applied as solutions, suspensions or dispersions, more preferably as an aqueous solution, suspension or dispersion. The coatings mentioned give the film surface an additional function z. B. is the film thereby sealable, printable, metallizable, sterilizable, antistatic or they improve z. The aroma barrier or allow adhesion to materials that would otherwise not adhere to the film surface (e.g., photographic emulsions). Examples of substances / compositions which confer additional functionality are:
Acrylates, such as For example, WO 94/13476 describes ethylvinyl 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 No. 144,878, US Pat. No. 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 confer the additional functionality may contain further conventional additives, such as antiblocking agents, pH stabilizers in amounts of preferably 0.05% by weight. to 5% by weight, preferably 0.1% to 3% by weight, in each case based on the weight of the coating agent (eg solution, emulsion, dispersion).

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

The film may also be corona treated at least on one side and / or at least On one side with a scratch-resistant coating, with a copolyester or with a  Adhesive coated and / or with ethylene-vinyl alcohol copolymer, ethyl Be coated vinyl alcohol, polyvinyl alcohol or polyvinylidene dichloride.

Furthermore, the films may 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 in particular their gas barrier properties.

Furthermore, the film is suitable for the production of composite films, wherein the Composite z. Example of the film according to the invention, optionally with an ethylene Vinyl alcohol copolymer, ethyl vinyl alcohol, polyvinyl alcohol or polyvinylidene Dichloride coating is provided, and a second film. This second slide can z. B. also a bibenzolmodifizierte thermoplastic film, a standard thermo plastic film, z. A polyethylene terephthalate film, or a polyolefin film, e.g. Legs Polyethylene or polypropylene film, be.

The second film may be single-layered or multi-layered and may be like the first film amorphous, d. H. be unoriented, and may, for. B. have a sealing layer. The second Film can be bonded with or without adhesive to the first, inventive film his.

The thickness of this second film is preferably in the range of 30 to 500 microns.

The composite film is generally obtained by lamination or Laminating the two films, with or without intermediate adhesive layer, by passing the films between tempered at 30 ° C to 90 ° C rollers.

The two films can, for example, with or without adhesive layer by a Laminating be joined together. It is, for example, too possible, the second layer on the first, coated layer by in-line Apply coating (melt extrusion to an existing layer).  

When using adhesives, these are applied to a film surface by known methods, in particular by application of 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.

Particularly useful adhesives have proven that of thermoplastic Resins, such as cellulose esters and ethers, alkyl and acrylic esters, polyamides, Polyurethanes or polyesters, or thermosetting resins such as epoxy resins, Urea / formaldehyde, phenyl / formaldehyde or melamine / formaldehyde resins, or consist of synthetic rubbers.

As a solvent for the adhesive itself z. For example, 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 according to DIN 67530 (Measuring angle 20 °), is preferably greater than 15, preferably greater than 20, the Light transmission L *, measured according to ASTM D 1003, is preferably less than 85 %, preferably less than 80%, and the haze of the film as measured by ASTM D 1003, is preferably more than 20%, preferably more than 25%.

The standard viscosity SV (DCE) of the preferably to be used bibenzolmodifi grained 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 more preferably between 0.80 kg / dm ³ and 0.90 kg / dm ³ .

The polydispersity of the likewise preferred, bibenzo-modified polyalkylene naphthalate or bibenzo-modified polyalkylene terephthalate Mw / Mn  by GPC is preferably between 1.5 and 4.0, and particularly preferred between 2.0 and 3.5.

The film according to the invention can be both single-layered and multilayered.

In the multilayer embodiment, the film is at least one core layer and at least one cover layer, wherein in particular a three-layered A-B-A or A-B-C structure is preferred, wherein the outer layers A and C are the same or can be different. There may also be additional intermediate layers be present, so that z. B. a total of 5 layers.

For this embodiment it is advantageous if the bibenzol modified thermoplastic the core layer has a similar standard viscosity as the bibenzol modified Thermoplastic coating layers adjacent to the core layer.

In a further particular embodiment, the cover layers can also be made an unmodified polyalkylene terephthalate homopolymer, from a bibenzol modified and / or unmodified polyalkylene naphthalate polymers or from a bibenzol modified and / or unmodified polyalkylene terephthalate Polyalkylene naphthalate copolymers or compound exist. Even in these cases PET and PEN are preferred polymers to use.

In this embodiment, the thermoplastics of the outer layers are preferred also similar standard viscosities such. B. the bibenzol modified Polyalkylene terephthalate of the core layer.

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

In the production of the film, it was found that the film according to the invention can be produced very economically. Furthermore, no outgassing in Production process found, which is very beneficial.

In addition, measurements of cold resistance (DIN 53372) showed that the film up to -200 ° C meets the requirements of the standard, d. H. not embrittled.

Furthermore, the film according to the invention is free from environmental pollution and loss the mechanical properties are easily recyclable, making them themselves for example, for use as short-lived billboards or others Promotional and / or thermoformed items is suitable.

The preparation of the film according to the invention can, for example, according to a known extrusion process in an extrusion line.

The films can be prepared by a known method from a bibenzolmodifiziert Thermoplastics and optionally other raw materials, the pigments of the invention and / or other conventional additives in the usual amount of about 0.1 to a maximum of 10 wt .-% both as monofilms and as multilayer, possibly coextruded films be made with the same or differently shaped surfaces, wherein For example, one surface is pigmented and the other surface is not a pigment contains. Likewise, one or both surfaces of the film according to known Procedures are provided with a conventional functional coating. The said further raw materials / additives are preferably by means of the so-called Dosed masterbatch technology; But you can also directly with the raw material be incorporated.

The polymers or raw material mixtures are an extruder or in multilayer Sheets fed to multiple extruders. About existing foreign body or Impurities can be filtered out of the polymer melt prior to extrusion. The melt (s) are then in a Monodüse or in a multilayer case in a  Multilayer nozzle formed into flat melt films and in the multilayer case layered on top of each other. Subsequently, the monofilm or the multilayer film quenched with the aid of a chill roll and as amorphous or largely amorphous, d. H. solidified unoriented film. Subsequently, the cooled, amorphous film lined and wound up.

Due to the surprising combination of excellent properties is the Inventive film excellent for a variety of applications, For example, for interior trim, for trade fair construction and trade show products, as Displays, for signs, for protective glazing of machines and vehicles, in Lighting sector, in shop and shelf construction, as promotional items, as laminating medium, as packaging film, as a composite film, as a furniture film and in particular for Application in the thermoforming sector, d. H. for producing a variety of moldings.

Due to the good UV stability and low temperature resistance, the inventive is Film also for outdoor applications, such. For greenhouses, roofs, Exterior cladding, covers, applications in the construction sector, applications in the Refrigeration and freezing areas and for illuminated advertising profiles, in credit cards, telephone cards or other card sector.

The invention will be explained in more detail below with reference to exemplary embodiments.

The measurement of the individual properties is carried out according to the following standards or procedure.

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 / IPA 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

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

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

cloudiness

Turbidity is the percentage of transmitted light from the on radiated light bundles deviates on average by more than 2.5 °. The sharpness is under an angle smaller than 2.5 °.

The haze is measured with the "Hazegard plus" measuring instrument according to ASTM D 1003.

yellowness

The yellow value YID is the deviation from the colorlessness in the direction "yellow" and becomes measured according to DIN 6167.

surface defects

The surface defects are determined visually.

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)

(DCE) = 6.67.10 ^-4. SV (DCE) + .118 IV

Weathering (two-sided), UV stability

The UV stability is tested according to the test specification ISO 4892 as follows
Test equipment: Atlas Ci 65 Weather Ometer (Atlas, England)
Test conditions: ISO 4892, ie artificial weathering
Irradiation time: 1000 hours (per page)
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 UV light, then 18 minutes UV light with water spray on the samples, then again 102 minutes UV light, etc.

cold resistance

The cold resistance is determined according to DIN 53372.

In the following examples and comparative examples are each Covered colored amorphous films of different thickness, which are on a Extrusion line are produced.

All films were tested according to the test specification ISO 4892 on both sides per 1000 hours per Page with the Atlas Ci 65 Weather Ometer of the company Atlas weathered and then concerning the thermoformability, the discoloration, the surface defects, the Gloss and cold resistance tested.

Examples example 1

It was a 150 micron thick, covered colored, single-layer, amorphous film containing as main constituent PETBB and 7% by weight of titanium dioxide (anatase type, Particle diameter 0.2 μm).

The titanium dioxide used (Sachtleben, Germany) was in the form of a Masterbatches added, in addition to PETBB 50 wt .-% titanium dioxide.

The PETBB from which the covered colored film was made had one Standard viscosity SV (DCE) of 1010, which corresponds to an intrinsic viscosity IV (DCE) of Corresponds to 0.792 dl / g. The bisbenzene acid content was 15% by weight, the glass over transition temperature was 86 ° C. The DEG content was 2.1% by weight.

Example 2

Analogously to Example 1, a covered dyed, 150 micron thick monofilm was prepared. In contrast to Example 1, 25 wt .-% self-regenerant were used.

The film was coated on both sides by means of "reverse gravure-roll coating" process with an aqueous dispersion. The dispersion contained, in addition to water, 3% by weight of hydrophilic polyester (5-Na-sulfoisophthalic acid-containing PET / IPA polyester, SP41®, Ticona, USA), 0.1% by weight of colloidal silica (Nalco 1060®, Deutsche Nalco Chemie, Germany) as antiblocking agent and 0.1% by weight of ammonium carbonate (from Merck, Germany) as pH buffer. The wet application weight is 1.5 g / m ² per coated side. After drying, the calculated thickness of the coating is 50 nm.

Example 3

Analogously to Example 1, a covered colored film 150 μm thick monofilm manufactured. In contrast to Example 1, the film contains 18 wt .-% barium sulfate (Blanc fixe XR-HX, Sachtleben chemistry) instead of titanium dioxide as a pigment and 200 ppm optical brightener (Tinopal®, Ciba-Geigy, Basel).  

The additives barium sulfate and optical brightener are added as a masterbatch. The bibenzo-modified polyethylene terephthalate used to prepare the masterbatches has a standard viscosity SV (DCE) in the range of 900 to 1100. The masterbatch is made from clear raw material (PETBB), 50% by weight barium sulfate and 600 ppm optical brightener together.

Example 4

After coextrusion technology becomes a 150 μm thick multilayer PETBB film with the layer sequence A-B-A, where B is the core layer and A is the Cover layers represent. The core layer B is 146 μm thick and the two Cover layers covering the core layer are each 2 μm thick.

The composition of the core layer B is identical to the composition of Monofilm from Example 1.

The outer layers A contain, in addition to PETBB, 0.1% by weight of Sylobloc®. The Sylobloc® used (SiO ₂ , from Grace, Germany) is added in the form of a masterbatch which contains 10,000 ppm Sylobloc in addition to PETBB.

Comparative Example (VB 1)

Analogously to Example 1, a 150 μm thick monofilm of unmodified PET Homopolymer prepared, which is pigmented with 7 wt .-% titanium dioxide. Here too lies the SV value of the PET homopolymer at 1010. The DEG content is 0.6 wt%.

The film is not coated in-line.

The following table summarizes the most important properties of the products produced in this way Slides together.  

Table 1

Property profile of the produced films

After each 1000 hours of weathering per side show with Atlas Ci 65 Weather Ometer the bibenzol modified PET films from Examples 1 to 4 barely changed Properties.

After 1000 hours of weathering per side with Atlas CI 65 Weather Ometer, the Film of Comparative Example VB 1 on the surface cracks and embrittlement Scheer on. A precise property profile - especially with regard to the mechani properties - can therefore no longer be measured. In addition, this shows Foil a visibly visible yellowing.

Claims (29)

1. Amorphous, single or multilayer film, characterized in that it contains as a main constituent a crystallizable, bibenzolmodifizierten thermoplastic and at least one pigment. 2. A film according to claim 1, characterized in that the degree of crystallinity of Film is less than 3%, preferably less than 1%. 3. A film according to claim 1 or 2, characterized in that the amount of the bibenzol modified thermoplastics, based on the weight of it equipped layers, 50 to 99 wt .-%, preferably 75 to 95 wt .-%, is. 4. A film according to one or more of claims 1 to 3, characterized marked that it consists of a base layer B and two cover layers A and C with the layer sequence A-B-C is constructed, wherein the cover layers are the same or can be different. 5. A film according to one or more of the claims. 1 to 4, characterized records that used as a thermoplastic a bibenzolmodifizierter polyester becomes. 6. A film according to one or more of claims 1 to 5, characterized marked characterized as bibenzol modified polyester bibenzolmodifiziertes Polyethylene terephthalate, bibenzo-modified polybutylene terephthalate or bibenzo-modified polyethylene naphthalate is used. 7. A film according to one or more of claims 1 to 6, characterized marked records that as a bibenzol modified thermoplastic bibenzolmodifiziertes  Polyethylene terephthalate is used. 8. A film according to one or more of claims 1 to 7, characterized marked indicates 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 1.3 wt .-%, and / or a polyethylene glycol content of greater than 1.0 wt .-%, preferably greater than 1.2 wt .-%, in particular greater than 1.3 wt .-%, and / or has an isophthalic acid content of 3 to 10 wt .-%. 9. A film according to one or more of claims 1 to 6, characterized gekenn that the standard viscosity SV (DCE) of the bibenzol modified Polyethylene terephthalate between 600 and 1300, preferably between 700 and 1200, lies. 10. A film according to one or more of claims 1 to 9, characterized records that the bibenzolic acid content, based on the weight of bibenzol modified thermoplastics, 1 to 50 wt .-%, preferably 5 to 45 wt .-%, especially 10 to 40 wt .-%, is. 11. A film according to one or more of claims 1 to 10, characterized marked characterized in that the cover layers comprise a bibenzylene-modified thermoplastic, preferably that of the base layer. 12. A film according to one or more of claims 1 to 11, characterized marked characterized in that the cover layers comprise unmodified polyalkylene terephthalate, bibenzo-modified and / or unmodified polyalkylene naphthalate or bibenzo-modified and / or unmodified polyalkylene terephthalate-poly alkylenenaphthalate copolymer. 13. A film according to one or more of claims 1 to 12, characterized records that the polymers of the base and top coats are similar  Have standard viscosities. 14. A film according to one or more of claims 1 to 13, characterized gekenn characterized in that the film is an inorganic white or black pigment or a contains inorganic or organic colored pigment or pigment mixtures. 15. A film according to one or more of claims 1 to 14, characterized marked records that as inorganic white pigment titanium dioxide or barium sulfate is used. 16. A film according to one or more of claims 1 to 15, characterized marked indicates that the titanium dioxide used as a white pigment forms a coating inorganic oxides or hydroxides, preferably of aluminum or Silicon oxides or hydroxides. 17. A film according to one or more of claims 1 to 16, characterized gekenn records that, as pigments, soot modifications, copper, chromium or Iron oxides, spinels containing cobalt, aluminum, titanium or nickel oxides or azo pigments which are coated or uncoated can. 18. A film according to one or more of claims 1 to 17, characterized gekenn records that the concentration of the pigment, based on the weight of the layers equipped therewith, 0.2 to 40 wt.%, preferably 0.3 to 25 wt. %, is. 19. A film according to one or more of claims 1 to 18, characterized marked draws that it contains an optical brightener. 20. A film according to one or more of claims 1 to 19, characterized marked records that the film is functional on one or both surfaces  is coated. 21. A film according to one or more of claims 1 to 20, characterized gekenn records that it has a surface gloss of greater than 15, preferably larger than 20. 22. A film according to one or more of claims 1 to 21, characterized gekenn records that it prefers a light transmission of less than 85% less than 80%. 23. A film according to one or more of claims 1 to 22, characterized marked that it has a haze of greater than 20%, preferably greater than 25%, having. 24. A film according to one or more of claims 1 to 23, characterized records that the film conventional additives such as antiblocking agents, stabilizers or Contains lubricant. 25. Inherently UV-stabilized film, characterized in that it is a film according to one or more of claims 1 to 24 corresponds. 26. A process for producing a film according to one or more of the claims 1 to 25, characterized in that the one for the production of the film required starting materials extruded through a monodüse or at multilayer structure coextruded through a multi-layer die, the obtained Foil quenched and solidified and optionally one or both sides coated. 27. Use of a film according to one or more of claims 1 to 25 for Production of composite films.   28. Use of a film according to one or more of claims 1 to 25 for Production of moldings. 29. Moldings produced using a film according to one or more of claims 1 to 25.