DE19630817A1 - Multilayer, colored sheet made of a crystallizable thermoplastic, process for its production and use - Google Patents

Abstract

An amorphous, coloured, multilayered plate with 1 to 20 mm thickness contains a crystallising thermoplastic material as its main component and at least one inorganic and/or organic pigment as dye in at least one of the layers. Other additives, such as UV stabilisers, antioxidants and soluble dyes may also be contained therein.

Description

The invention relates to an amorphous, colored, multi-layer plate a crystallizable thermoplastic, whose thickness ranges from 1 to 20 mm lies. The colored plate is characterized in that it is made of at least one core layer and at least one cover layer put together. The plate also contains at least one organic and / or inorganic pigment as colorant in at least one of the core and / or Cover layers and optionally other additives such as UV stabilizers and Antioxidants. The plate is characterized by good mechanical Characterized by homogeneous optical properties. The invention also relates to a method for producing this plate and its use.

Multi-layer plates made of plastic materials are known per se.

Such plates made of branched polycarbonates are in EP-A-0 247 480, EP-A-320 632 and U.S. Patent 5,108,835.

DE-A-34 14 116 and US-PS 4,600,632 are UV-stabilized Shaped polycarbonate body known from polydiorganosiloxane-polycarbonate block copolymers are built up.

From US-PS 5,137,949 multilayer plastic sheets are known with Layers of polydiorganosiloxane-polycarbonate block copolymers, the UV absorber contain. EP-A-0 416 404 discloses UV-stabilized, branched Polycarbonates known from special diphenols. It is mentioned that such  Polycarbonates for the production of sheets or multi-wall sheets can be used.

All of these sheets are made of polycarbonate, an amorphous thermoplastic, which is not crystallizable. Polycarbonate sheets have the disadvantage that they often efflorescence in the form of white spots and surface deposits, show in particular in the UV-stabilized embodiment (cf. EP-A-0 649 724). According to EP-A-0 649 724, for example, UV absorber evaporation is strongly linked to the average molecular weight.

Furthermore, these PC boards are easily flammable and therefore require the Addition of flame retardants in order for certain purposes like for Indoor applications. When processing these plates to form parts are lengthy pre-drying times and relatively long Processing times at high temperatures required. Furthermore must Degassing extruder in the manufacture of plates for the purpose of dehumidification are used, which also means the additives added to the raw material can also be removed, especially if low molecular weight, volatile additives are used.

The applicant has already used single-layer, colored, amorphous plates with a thickness in the range of 1 to 20 mm described as Main component of a crystallizable thermoplastic such. B. Polyethylene terephthalate and an organic and / or inorganic pigment included as colorant (German patent application no. 195 19 577.9, 195 22 116.2, 195 28 333.3). These plates can be one Standard viscosity of 800-6000 and a UV stabilizer contain.

EP-A-0 471 528 describes a method for molding an article a polyethylene terephthalate (PET) plate. The PET plate is in  a deep-drawing mold on both sides in a temperature range between Glass transition temperature and the melting temperature heat treated. The molded PET sheet is removed from the mold when the size the crystallization of the molded PET sheet is in the range of 25 to 50%. The PET sheets disclosed in EP-A-0 471 528 have a thickness of 1 to 10 mm. Because the thermoformed molded article made from this PET sheet is partially crystalline and therefore no longer transparent and the Surface properties of the molded body by the deep-drawing process, the given temperatures and shapes, it is irrelevant which optical properties (e.g. gloss, cloudiness and Light transmission) have the PET plates used. As a rule, they are optical properties of these plates poor and in need of optimization. These polyethylene terephthalate plates also have a single-layer structure on and are not colored.

In US-A-3 496 143 the vacuum deep drawing of a 3 mm thick PET sheet, whose crystallization should be in the range of 5 to 25%. The crystallinity of the deep-drawn molded body is greater than 25%. Also on these PET sheets have no optical requirements Properties provided. Because the crystallinity of the plates already used is between 5 and 25%, these plates are cloudy and opaque. These semi-crystalline PET sheets are also single-layer.

In Austrian Patent No. 304 086 a method for Manufacture of transparent moldings using the deep-drawing process described, with a PET plate or film with a Degree of crystallinity below 5% is used.

The plate or film used as the starting material is single-layer and made of a PET with a crystallization temperature of at least 160 ° C been made. From this relatively high crystallization temperature it follows that this is not a PET homopolymer, but rather  Glycol-modified PET, or PET-G for short, which is a PET copolymer. In contrast to pure PET, PET-G shows due to the additional built-in Glycol units has an extremely low tendency to crystallize and lies usually in the amorphous state The object of the present invention is to provide a multilayer, amorphous, to provide colored plate with a thickness of 1 mm to 20 mm characterized by good mechanical and homogeneous optical properties.

Homogeneous optical properties include, for example homogeneous light transmission with a high surface gloss.

The good mechanical properties include a high one Impact strength and high breaking strength.

In addition, the plate according to the invention should be recyclable especially without loss of mechanical properties, as well as heavy flammable, so that they can also be used for indoor applications and Exhibition stand construction can be used.

This task is solved by a multi-layer, colored, amorphous Plate with a thickness of 1 to 20 mm, which is the main component at least contains a crystallizable thermoplastic, which is characterized in that that the plate has at least one core layer and at least one top layer has, wherein the standard viscosity of the crystallizable thermoplastic Core layer is higher than the standard viscosity of the crystallizable Thermoplastic of the top layer and that at least one layer at least contains an organic and / or inorganic pigment as a colorant.

For the purposes of the present invention, amorphous plates are such Sheets understood that, although the crystallizable thermoplastic used  preferably has a crystallinity between 5 and 65%, not crystalline are. Not crystalline, i.e. H. essentially amorphous means that the Degree of crystallinity is generally below 5%, preferably below 2% and is particularly preferably 0% and that the plate is essentially none Orientation.

According to the invention, crystallizable thermoplastic is understood

• crystallizable homopolymers,
• - crystallizable copolymers,
• - crystallizable compounds,
• - Crystallizable recyclate and
• - other variations of crystallizable thermoplastics.

Examples of suitable thermoplastics are polyalkylene terephthalates with C1 to C12 alkylene radical, such as polyethylene terephthalate and polybutylene terephthalate, Polyalkylene naphthalates with C1 to C12 alkylene radical, such as polyethylene naphthalate and polybutylene naphthalate, crystallizable cycloolefin polymers and Cycloolefin copolymers, the thermoplastic or the thermoplastics for the Core layer (s) (also called base layer) and the thermoplastic or the thermoplastics for the cover layer (s) can be the same or different.

Polyolefins have also proven suitable for the top layer.

Thermoplastics with a crystallite melting point T _m , measured with DSC (differential scanning calorimetry) with a heating rate of 10 ° C / min, from 220 ° C to 260 ° C, preferably from 230 ° C to 250 ° C, with a crystallization temperature range T _c between 75 ° C and 260 ° C, a glass transition temperature T _g between 65 ° C and 90 ° C and with a density, measured according to DIN 53 479, of 1.30 to 1.45 g / cm³ and a crystallinity between 5% and 65 % represent preferred polymers for the core layer and the top layer as starting materials for the production of the plate.

A thermoplastic with a cold (post) crystallization temperature T _CN of 120 to 158 ° C., in particular 130 to 158 ° C., is particularly preferred for the purposes of the invention.

The bulk density, measured according to DIN 53 466, is preferably between 0.75 kg / dm³ and 1.0 kg / dm³, and particularly preferably between 0.80 kg / dm³ and 0.90 kg / dm³.

The polydispersity of the thermoplastic M _w / M _n , measured by means of GPC, is preferably between 1.5 and 6.0 and particularly preferably between 2.0 and 5.0.

A particularly preferred crystallizable thermoplastic for the core layer (s) or the cover layer (s) is polyethylene terephthalate. The invention preferred polyethylene terephthalate consists essentially of Monomer units of the following formula

It is essential to the invention that the thermoplastic or the thermoplastics Core layer (s) has a higher standard viscosity than the thermoplastic or the thermoplastics of the cover layer (s). The standard viscosities of the Thermoplastics of different core and / or outer layers one multilayer board can be different.

The standard viscosity SV (DCE) of the crystallizable thermoplastic Core layer or base layer, measured in dichloroacetic acid according to DIN 53 728, is preferably between 800 and 5000 and particularly preferably between 1000 and 4500.  

The standard viscosity SV (DCE) of the crystallizable thermoplastic Cover layer, measured in dichloroacetic acid according to DIN 53 728 preferably between 500 and 4500 and particularly preferably between 700 and 4000.

The intrinsic viscosity IV (DCE) can be determined from the standard viscosity SV (DCE) can be calculated as follows:

IV (DCE) = 6.67 x 10 ^-4 SV (DCE) + 0.118.

In the amorphous, multilayer plate according to the invention is also contain at least one organic and / or inorganic pigment. The Pigment or a mixture of pigments can be one or more of the Layers can be added. The concentration of the colorant is preferably in the range of 0.1 to 30 wt .-%, based on the weight of the Thermoplastics in the layer equipped with pigment.

Suitable organic and inorganic pigments for the invention are in the the aforementioned German patent applications No. 195 19 577.9, 195 22 119.2 and 195 283 33.3. These registrations are valid through Quote as belonging to the disclosure of the present application.

In terms of colorants, a distinction is made between dyes according to DIN 55 944 and pigments. Pigments are under the respective processing conditions almost insoluble in the polymer, while dyes are soluble (DIN 55 949). The coloring effect of the pigments is caused by the particles themselves. The term pigment generally refers to a particle size of 0.01 to 1.0 µm bound. According to DIN 53 206, a distinction is made in the definition of Pigment particles between primary particles, aggregates and agglomerates.

Have primary particles, as they usually occur during production  a pronounced due to their extremely small particle size Tendency to gather together. This creates the primary particles by aggregating the units, which is why they are smaller Have surfaces as the sum of the surface area of their primary particles corresponds. By stacking primary particles and / or aggregates Agglomerates form over corners and edges, the total surfaces of which deviates only slightly from the sum of the individual areas. If you - without further details Information - speaks of pigment particle size, refers to the Aggregates as they are essentially after coloring.

In powdered pigments, the aggregates are always agglomerates stored together, which split up during the coloring, wetted by the plastic and must be distributed homogeneously. These simultaneous processes are called dispersion. When coloring with dyes it is a solution process, as a result of which Dye is molecularly dissolved.

In contrast to the inorganic pigments, individual organic Pigments are not completely insoluble, especially not simple pigments with low molecular weights.

Dyes are adequately described by their chemical structure. However, pigments of the same chemical composition can in each case various crystal modifications are produced and available. A A typical example of this is the white pigment titanium dioxide, which is in the rutile form and may be in the anatase form.

In the case of pigments, coating, i.e. H. by post-treatment of the Pigment particle surface, with organic or inorganic agents Improvement in performance characteristics can be achieved. This improvement lies particularly in facilitating dispersion and raising  light, weather and chemical resistance. Typical coating agents for Pigments are, for example, fatty acids, fatty acid amides, siloxanes and Aluminum oxides.

Suitable inorganic pigments are, for example, the white pigments Titanium dioxide, zinc sulfide and tin sulfide, which are organic and / or inorganic can be coated.

The titanium dioxide particles can consist of anatase or rutile, preferably predominantly made of rutile, which has a higher opacity compared to anatase shows. In a preferred embodiment, the titanium dioxide particles exist at least 95% by weight of rutile. You can use a standard procedure e.g. B. after the chloride or sulfate process. The middle Particle size is relatively small and is preferably in the range of 0.10 to 0.30 µm.

Titanium dioxide of the type described produces within the polymer matrix no vacuoles during plate production.

The titanium dioxide particles can be coated with inorganic oxides have, as usually as a coating for TiO₂ white pigment in papers or paints are used to improve lightfastness. TiO₂ is known to be photoactive. When exposed to UV rays, free ones are formed Radicals on the surface of the particles. These free radicals can lead to the film-forming constituents of the paint migrate to what Degradation reactions and yellowing. To the particularly suitable oxides include the oxides of aluminum, silicon, zinc or magnesium or Mixtures of two or more of these compounds. TiO₂ particles with a coating of several of these compounds, for. B. in the EP-A-0 044 515 and EP-A-0 078 633. Furthermore, the Coating organic compounds with polar and non-polar groups  contain. The organic compounds must be used in the manufacture of the plate be sufficiently thermostable by extrusion of the polymer melt. Polar Groups are for example -OH, -OR, -COOX, (X = R, H or Na, R = alkyl with 1 to 34 C atoms). Preferred organic compounds are alkanols and fatty acids with 8 to 30 carbon atoms in the alkyl group, in particular Fatty acids and primary n-alkanols with 12 to 24 carbon atoms, as well Polydiorganosiloxanes and / or polyorganohydrogensiloxanes such as. B. Polydimethylsiloxane and polymethylhydrogensiloxane.

The coating on the titanium dioxide particles usually consists of 1 to 12, in particular 2 to 6 g of inorganic oxides and 0.5 to 3, in particular 0.7 to 1.5 g of organic compound, based on 100 g of titanium dioxide particles. Of the Coating is applied to the particles in aqueous suspension. The inorganic oxides are made from water-soluble compounds, e.g. B. alkali, especially sodium aluminate, aluminum hydroxide, aluminum sulfate, Aluminum nitrate, sodium silicate (water glass) or silica in the aqueous Suspension failed.

Among inorganic oxides such as Al₂O₃ and SiO₂ are the hydroxides or whose different drainage levels such. B. to understand oxide hydrates, without knowing their exact composition and structure. On the TiO₂ pigment are the after annealing and grinding in aqueous suspension Oxide hydrates e.g. B. of aluminum and / or silicon, then the pigments washed and dried. This precipitation can thus take place directly in a Suspension happen as in the manufacturing process after annealing and the subsequent wet grinding occurs. The precipitation of the oxides and / or Oxide hydrates of the respective metals are made from the water-soluble metal salts in the known pH range, for the aluminum, for example Aluminum sulfate in aqueous solution (pH less than 4) and added of aqueous ammonia solution or sodium hydroxide solution in the pH range between 5 and 9, preferably between 7 and 8.5, the oxide hydrate precipitates. If you assume  a water glass or alkali aluminate solution, the pH of the submitted TiO₂ suspension in the strongly alkaline range (pH greater than 8). The precipitation is then carried out by adding mineral acid such as sulfuric acid in the pH range from 5 to 8. After the precipitation of the metal oxides, the Suspension stirred for another 15 minutes to about 2 hours, the precipitated layers undergo aging. The coated product will separated from the aqueous dispersion and after washing at elevated Temperature, especially at 70 to 110 ° C, dried.

Typical inorganic black pigments are soot modifications, which are also can be coated, carbon pigments that differ from the carbon black pigments differ by a higher ash content and oxidic Black pigments such as iron oxide black 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 colored oxide pigments are iron oxide red, titanium dioxide-nickel oxide-antimony oxide mixed-phase 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 cobalt-aluminum-titanium-nickel-zinc oxide system and mixed phase pigments based on other metal oxides.

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

Examples of sulfidic pigments are cadmium sulfide selenides, cadmium zinc sulfides, Sodium aluminum silicate with sulfur bound like polysulfide in the grid.  

Examples of chromates are the lead chromates that exist in the crystal forms can be monoclinic, rhombic and tetragonal.

Like the white and black pigments, all colored pigments can uncoated as well as inorganic and / or organically coated.

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

The azo (-N = N -) group is characteristic of the azo pigments. Azo pigments can monoazo pigments, diazo pigments, diazo condensation pigments, salts of azo coloring acids and mixtures of the azo pigments.

In special embodiments, the amorphous, multilayer plate can also Mixtures of inorganic and / or organic pigments as well additionally soluble dyes in the core layer and / or top layer contain.

The concentration of the soluble dye is preferably in the range from 0.01 to 20% by weight, particularly preferably in the range from 0.5 to 10 wt .-%, based on the weight of the crystallizable thermoplastic.

Of the soluble dyes, the fat and aromatic-soluble dyes preferred. These are azo and Anthraquinone dyes.

Soluble dyes suitable for the present invention are described in US Pat German patent applications No. 195 19 578.7, 195 22 120.6 and 195 28 334.1 called. These applications belong to the disclosure content by quotation of the present application.

The crystallizable thermoplastics used in accordance with the invention can be after  usual methods known to those skilled in the art can be obtained. In general, thermoplastics as used in the invention be, by polycondensation in the melt or by a two-stage Polycondensation can be obtained. The first step is up to one average molecular weight - corresponding to an average intrinsic Viscosity IV from about 0.5 to 0.7 - in the melt and the Further condensation carried out by means of solid condensation. The polycondensation is usually carried out in the presence of known Polycondensation catalysts or catalyst systems carried out. At the solid condensation are chips from the thermoplastic under reduced pressure or under protective gas at temperatures in the range heated from 180 to 320 ° C until the desired molecular weight is reached.

For example, the production of polyethylene terephthalate that is particularly preferred according to the invention, in a variety of Patent applications described in detail, as in JP-A-60-139 717, DE-C-24 29 087, DE-A-27 07 491, DE-A-23 19 089, DE-A-16 94 461, JP- 63-41 528, JP-62-39 621, DE-A-41 17 825, DE-A-42 26 737, JP-60-141 715, DE-A-27 21 501 and US-A-S 296 586.

Polyethylene terephthalates with particularly high molecular weights can be e.g. B. by polycondensation of dicarboxylic acid diol precondensates (Oligomers) at elevated temperature in a liquid heat transfer medium Presence of conventional polycondensation catalysts and, if necessary, co-condensable ones Manufacture modifiers if the liquid heat transfer medium is inert and free of aromatic assemblies and a boiling point in the range of 200 to 320 ° C, the weight ratio of dicarboxylic acid diol precondensate used (Oligomers) to liquid heat transfer medium in the range from 20:80 to 80:20, and the polycondensation in the boiling reaction mixture in Is carried out in the presence of a dispersion stabilizer.  

The multi-layer, colored, amorphous plate according to the invention can in addition, if desired, be equipped with suitable additives. This Depending on requirements, additives can be used individually or as a mixture of one or more Layers of the plate are added, which are also layers with Colorants can act.

Examples of suitable additives are UV stabilizers and antioxidants such as they in German Patent Application No. 195 22 119.2 and the same time pending application by the same applicant entitled "Polyethylene Terephthalate Plate with improved hydrolysis stability ". These applications are considered part of the disclosure content of the present by quotation Registration.

As stated above, the multi-layer, colored, amorphous In addition, at least one UV stabilizer as a light stabilizer in the plate (s) cover layer (s) and / or the core layer (s) contain.

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

The inhibition of these photooxidative degradation processes is significant technical and economic importance, otherwise the Applications of numerous thermoplastics drastically is restricted.

High UV stability means that the plate is exposed to sunlight or others UV radiation is not or only extremely little damaged, so that the Plate suitable for outdoor applications and / or critical indoor applications and even after several years of outdoor use, no or only minor ones  Yellowing shows.

For example, polyethylene terephthalates start below 360 nm To absorb UV light, its absorption decreases below 320 nm considerably and is very pronounced below 300 nm. The maximal Absorption is between 280 and 300 nm.

In the presence of oxygen, chain cleavages, however, no networking was observed. Carbon monoxide, carbon dioxide and Carboxylic acid is the predominant quantity of photooxidation products In addition to the direct photolysis of the ester groups Oxidation reactions are considered that involve peroxide radicals also result in the formation of carbon dioxide.

The photooxidation of polyethylene terephthalates can also take place Hydrogen splitting in the α-position of the ester groups to form hydroperoxides and their decomposition products as well as related chain cleavages (H. Day, D. M. Wiles: J. Appl. Polym. Sci 16, 1972, page 203).

UV stabilizers, also called light stabilizers or UV absorbers, are chemical compounds involved in the physical and chemical processes of light-induced degradation can intervene.

Certain pigments such as e.g. B. Soot can partially protect the sun cause. However, these substances are for the inventive Colored plates are unsuitable because they are used for discoloration or color change to lead. Expedient for the amorphous according to the invention Plates only such UV stabilizers, e.g. B. from the class of organic and organometallic compounds used in the stabilized Thermoplastics no or only an extremely slight color or color change cause.

Examples of UV stabilizers suitable for the present invention are 2-hydroxybenzophenones,  2-hydroxybenzotriazoles, nickel organic Compounds, salicylic acid esters, cinnamic acid ester derivatives, Resorcinol monobenzoates, oxalic acid anilides, hydroxybenzoic acid esters, steric hindered amines and triazines, with 2-hydroxybenzotriazoles and triazines are preferred.

Mixtures of several UV stabilizers can also be used.

The UV stabilizer is expediently in one layer in one Concentration from 0.01 wt .-% to 8 wt .-%, preferably from 0.01 to 5 wt .-%, based on the weight of the thermoplastic in the with Stabilizer-equipped layer, before.

However, if the UV stabilizer is added to a core layer in general a concentration of 0.01% by weight to 1% by weight based on the weight the thermoplastic in the core layer equipped with the stabilizer, sufficient.

According to the invention, several layers can be treated simultaneously with a UV stabilizer be equipped. In general, however, it is sufficient if the layer, on which the UV radiation occurs.

The core layer (s) can be finished to prevent possible damage to the top layer of UV radiation underlying core layer impaired.

In a particularly preferred embodiment, the inventive colored, amorphous plate as the main component a crystallizable Polyethylene terephthalate for core layer and top layer and 0.01 wt .-% to 8.0% by weight of 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) oxyphenol or 0.01 % By weight to 8.0% by weight of 2,2'-methylene-bis (6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbut-yl) phenol in the top layer.

Of course, a mixture of these compounds and a Mixture of at least one of these compounds with at least one  other UV stabilizer can be used.

The plate according to the invention can also contain at least one antioxidant be equipped.

Antioxidants are chemical compounds that are the oxidizing and Signs of hydrolysis and the resulting aging are delayed can.

Antioxidants suitable for the plate according to the invention can be as follows split:

Furthermore, mixtures of primary and secondary antioxidants and / or mixtures of secondary and / or primary antioxidants with UV stabilizers be used. Surprisingly, it was found that such mixtures show a synergistic effect.

In a preferred embodiment, the amorphous contains Plate as a phosphite and / or a phosphonite and / or a carbodiimide Hydrolysis and oxidation stabilizer.

Examples of antioxidants used according to the invention are 2 - [(2,4,8,10- Tetrakis (1,1-dimethylethyl) dibenzo [d, f] [1,3,2] dioxaphosphepin-6-yl] o-xy) ethyl] ethanamine and tris (2,4-di-tert-butylphenyl) phosphite.  

The antioxidant is usually in a concentration of 0.01 to 6 % By weight, based on the weight of the thermoplastic of the so equipped Layer, before.

The thickness of the multilayer board according to the invention varies between 1 mm and 20 mm, the thickness of the top layer (s) depending on the panel thickness can be between 10 µm and 1 mm. The cover layers preferably have each have a thickness between 400 and 500 µm.

As already stated, the plate according to the invention can have several core and Have cover layers that are sandwiched one above the other. However the plate can also consist of only one cover layer and one core layer.

A structure with two cover layers is particularly preferred according to the invention and a core layer lying between the cover layers.

The individual cover and core layers can be different or the same contain crystallizable thermoplastics as main components, as long as the Thermoplastic of a core layer has a higher standard viscosity than that Thermoplastics of the outer layers directly adjacent to this core layer. A layer can also consist of a mixture of crystallizable thermoplastics consist.

If desired, the colored, amorphous, multilayer board, which optionally contains one or more additives, be equipped on one or more sides with a scratch-resistant surface.

As coating systems and materials for the scratch-resistant surface (Coating) come all systems and materials known to the person skilled in the art in question.

Suitable coating systems and materials are particularly in the  German Patent Application No. 196 25 534.1 described by the applicant which is used in its entirety for the present invention.

From the multitude of possible coating systems and materials some are mentioned below as examples.

• (1) In US-A-4822828 are aqueous radiation-curable Coating compositions disclosed, each based on the Weight of the dispersion, (A) from 50 to 85% of a silane with vinyl groups, (B) from 15 to 50% of a multifunctional acrylate and optionally (C) 1 have up to 3% of a photoinitiator.
• (2) Inorganic / organic polymers known as ormocers are also known (Organically Modified Ceramics) the properties of ceramic materials and combine polymers. Ormocere are particularly hard and / or scratch-resistant coatings on polymethyl methacrylate (PMMA) and Polycarbonate (PC) used. The hard coatings are based on Al₂O₃, ZrO₂, TiO₂ or SiO₂ as network formers and epoxy or Methacrylate groups with Si bound by ≡Si-C≡ compounds.
• (3) Coating agent for acrylic resin plastics and polycarbonate Silicone resin base in aqueous organic solution, which is a particularly high Have storage stability, z. B. in EP-A-0 073 362 and EP-A-0 073 911. This technique uses the Condensation products of partially hydrolyzed organosilicon Compounds as coating agents, especially for glass and in particular for Acrylic resin plastics and PC.
• (4) Also known are acrylic coatings such. B. the uvecryl Products from UCB Chemicals. An example is the Uvecryl 29203, which is cured with UV light. This material consists of a mixture of  Urethane acrylate oligomers with monomers and additives. Components are about 81% acrylate oligomers and 19% hexanediol diacrylate. These coatings are also described for PC and PMMA.
• (5) Further in the literature are CVD or PVD coating technologies with the help of a polymerizing plasma as well as diamond-like Coatings described (thin-film technology, published by Dr. Hartmut Frey and Dr. Gerhard Kienel, VDI Verlag, Düsseldorf, 1987). This Technologies are used here especially for metals, PC and PMMA.

Other commercially available coatings are e.g. B. Peeraguard from Peerless, Clearlite and Filtalite from Charvo, coating types such as B. the UVHC series from GE Silicones, Vuegard like the 900 series from TEC Electrical Components, from the Societ´ Francaise Hoechst Highlink OG series, PPZ® products sold by Siber Hegner (manufactured by Idemitsu) and coating materials from Vianova Resins, Toagoshi, Toshiba or Mitsubishi. These coatings are also described for PC and PMMA.

Coating methods known from the literature are e.g. B. offset printing, Pouring, immersion, flooding, spraying or spraying, Squeegees or rollers.

Coatings applied by the described methods then for example by means of UV radiation and / or thermally hardened. In the coating process, it can be advantageous to coating surface before applying the coating with a Primers, e.g. B. to treat acrylic or acrylic latex.

Other known methods are e.g. B .:
CVD process or vacuum plasma process, such as. B. vacuum plasma polymerization, PVD processes such as coating with electron beam evaporation, resistance-heated evaporator sources or coating by conventional methods in a high vacuum, such as in a conventional metallization.

Literature on CVD and PVD is e.g. E.g .: modern coating processes by H.-D. Steffens and W. Brandl. DGM Information Society Verlag Oberursel. Other literature on coatings: Thin Film Technology by L. Maissel, R. Glang, McGraw-Hill, New York (1983).

Particularly suitable for the purposes of the present invention Coating systems are systems (1), (2), (4) and (5), whereby in particular the coating system (4) is preferred.

As a coating method such. B. also the casting, the spraying, the Spraying, immersion and offset processes, whereby for the Coating system (4) the spray method is preferred.

When coating the amorphous plates, curing can take place with UV radiation and / or at temperatures which are preferably not 80 ° C exceed, take place, UV curing being preferred.

The coating according to system (4) has the advantage that there is no crystallization occurs that could cause turbidity. Furthermore shows the Coating excellent adhesion, excellent optical Properties, a very good chemical resistance and does not cause any Impairment of the intrinsic color.

The thickness of the scratch-resistant coating is generally between 1 to 50 µm.  

The amorphous plate according to the invention, the main component of a crystallizable thermoplastic such. B. contains PET, has excellent mechanical and optical properties. For example, when measuring the impact strength a _n according to Charpy (measured according to ISO 179 / 1D), there is preferably no fracture on the plate. In addition, the notched impact strength a _k according to Izod (measured according to ISO 180 / 1A) of the plate is preferably in the range from 2.0 to 8.0 kJ / m², particularly preferably in the range from 4.0 to 6.0 kJ / m².

The surface gloss, measured according to DIN 67530 (measuring angle 20 °), is preferably greater than 100 and the light transmission, measured according to ASTM D 1003, is preferably less than 60%.

Weathering tests have shown that the UV-stabilized according to the invention Plate shows no visible yellowing even after 5 to 7 years of outdoor use and no visible loss of gloss and no visible surface defects having.

In addition, the plate according to the invention is flame retardant and drips at very low smoke development does not burn off, so that it too especially suitable for indoor applications and trade fair construction.

Furthermore, the plate according to the invention is without environmental pollution and Loss of mechanical properties easily recyclable, which is why for example for the production of short-lived advertising signs or other promotional items.

In addition, it was completely unexpectedly an excellent and economical one Thermoforming behavior (thermoforming and vacuum forming behavior) determined. Surprisingly, unlike polycarbonate sheets, it is not  required, the plate according to the invention before thermoforming pre-dry. For example, polycarbonate sheets must be placed in front of the Thermoforming depending on the plate thickness 3 to 50 hours at approx. 125 ° C be pre-dried.

In addition, the plate according to the invention can be used with very little Thermoforming cycle times and at low temperatures during thermoforming receive. On the basis of these properties, Plate on conventional thermoforming machines economically and with high Produce molded articles.

The production of the multilayer, colored, amorphous, optionally equipped with one or more additives Plate can, for example, according to the coextrusion process known per se in an extrusion line.

Coextrusion as such is known from the literature (see, for example, EP-110 221 and EP-110 238, to which express reference is made here).

There are extruders for plasticization on each coextruder adapter and production of the core layer and a further extruder per cover layer connected. The adapter is designed so that the cover layers forming melts as thin layers adhering to the melt of the Core layer are applied. The multilayer created in this way The melt strand is then in the connected nozzle molded and calibrated in the calender, smoothed and cooled before the plate is cut to length.

The following is the process for producing the plates according to the invention generally explained.  

If necessary, the thermoplastic polymer can be coextruded be dried.

The drying can expediently take place at temperatures in the range of 110 up to 190 ° C over a period of 1 to 7 hours. Of the Main dryer is with the main extruder and there is one dryer per top layer connected to a coextruder.

Then the thermoplastic for the core layer (s) and the Cover layer (s) melted in the main extruder and in the coextruders. The temperature of the melt is preferably in the range from 230 to 330 ° C. the temperature of the melt is essentially determined by both Temperature of the extruder, as well as the residence time of the melt in the extruder can be adjusted.

Is the preferred according to the invention as a thermoplastic polyethylene terephthalate used, is usually dried at 160 to 180 ° C for 4 to 6 hours and the temperature of the melt is in the range of 250 to 320 ° C set.

The colorant and optionally the additive such as a UV stabilizer and / or an antioxidant can be the thermoplastic of the corresponding Layer can already be metered in at the raw material manufacturer or at the Plate production can be metered into the extruder.

The addition of the colorant and the additives via the Masterbatch technology or via the solid pigment preparation. In doing so the colorant and possibly the additives in a solid carrier material dispersed. Certain resins, the thermoplastic, come as carrier materials itself or other polymers that are sufficient with the thermoplastic are tolerated, in question.

It is important that the grain size and the bulk weight of the masterbatch  are similar to the grain size and bulk density of the thermoplastic, so that a homogeneous distribution and thus a homogeneous effect of the colorant and the additives, such as. B. homogeneous coloring and UV and hydrolysis stabilization, can take place.

As already stated above, the main extruder for producing the Core layer and the co-extruder or so on a co-extruder adapter connected that the melts forming the cover layers as thin Layers are adhered to the melt of the core layer. Of the Multilayer melt strand thus produced is in a connected nozzle molded. This nozzle is preferably a slot die.

The multilayer melt strand formed by a slot die is then calibrated by smooth calender rolls, d. H. intensely chilled and smoothed. The calender rolls used can, for example, in an I-, F, L or S shape can be arranged.

The material can then be cooled on a roller conveyor, laterally to measure cut, cut to length and stacked.

The thickness of the plate obtained is essentially the deduction that is made at the end the cooling zone is arranged, the speed coupled with it Cooling (smoothing) rolls and the conveying speed of the extruder on the one hand and the distance of the rollers on the other hand.

Both single-screw and twin-screw extruders can be used as extruders be used.

The slot die preferably consists of the dismountable Tool body, the lips and the control bar for flow regulation above the width. To do this, the control bar can be tightened using tension and compression screws  be bent. The thickness is adjusted by adjusting the lips. It is important that the temperature of the multilayer is even Melt strand and the lip is respected, otherwise the melt strand flows out to different thicknesses through the different flow paths.

The calibration tool, d. H. the smoothing calender gives the melt strand the Shape and dimensions. This is done by freezing below the Glass transition temperature by cooling and smoothing. In this condition should not be deformed anymore, otherwise due to the cooling Surface defects would arise. For this reason, the Calender rolls preferably driven together. The temperature of the Calender rolls must be used to prevent the melt strand from sticking be less than the crystallite melting temperature. The melt strand leaves the Wide slot nozzle preferably with a temperature of 240 to 300 ° C. The The first smoothing-cooling roller has a temperature depending on the output and plate thickness between 50 ° C and 80 ° C. The second, somewhat cooler roller cools the second or other surface.

To a uniform thickness in the range of 1 to 20 mm with good optical To get properties, it is essential that the temperature of the first Smoothing roller is at 50 to 80 ° C.

While the calibration device the surfaces of the plate as smooth as possible Freezing brings and cools the profile so far that it is dimensionally stable, lowers the After-cooling device the temperature of the plate from almost room temperature. After-cooling can be done on a roller board.

The speed of the trigger should match the speed of the Calender rolls are precisely matched to defects and thickness fluctuations to avoid.  

Additional equipment can be used in the extrusion line to manufacture the plates according to the invention a cutting saw as a cutting device that Side trimming, the stacking system and a control point are located. The Side or edge trimming is advantageous because the thickness in the edge area may be uneven under certain circumstances. At the checkpoint there will be thickness and optics of the plate measured.

Due to the surprising number of excellent properties, the Colored, amorphous plate according to the invention excellent for a variety different applications, for example for interior cladding, for Exhibition stand construction and exhibition articles, as displays, for signs, in the lighting sector, in shop and shelf construction, as promotional items, as menu card stands, as Basketball goal boards, as room dividers, as aquariums, as information boards, as brochures and Newspaper stands and also for outdoor applications, such as. B. Greenhouses, canopies, exterior claddings, covers, for Applications in the construction sector, illuminated advertising profiles, balcony cladding and Roof hatches.

The invention is explained in more detail below on the basis of exemplary embodiments explained without being restricted thereby.

The individual properties are measured in accordance with the following Standards or procedures.

Measurement methods Surface gloss

The surface gloss is determined in accordance with DIN 67 530. The is measured Reflector value as an optical parameter for the surface of a plate. Based on to the standards ASTM-D 523-78 and ISO 2813, the angle of incidence was included  20 ° set. A light beam strikes at the set angle of incidence the level test surface and is reflected or scattered by it. The light rays striking the photoelectronic receiver become displayed as a proportional electrical quantity. The measured value is dimensionless and must be specified together with the angle of incidence.

Whiteness

The degree of whiteness is determined using the electrical "ELREPHO" remission photometer from Zeiss, Oberkochem (DE), Standard illuminant C, 20 normal observers. The whiteness is defined as

WG = RY + 3RZ - 3RX.

WG = whiteness, RY, RZ, RX = corresponding reflection factors when used of the Y, Z and X color measurement filter. A compact is made as the white standard Barium sulfate (DIN 5033, part 9) used.

Surface defects

The surface defects are determined visually.

Charpy impact strength a _n

This size is determined according to ISO 179/1 D.

Impact strength a _k according to Izod

The notched impact strength or strength a _k according to Izod is measured according to ISO 180 / 1A.

density

The density is determined according to DIN 53 479.  

SV (DCE), IV (DCE)

The standard viscosity SV (DCE) is based on DIN 53 728 in Dichloroacetic acid measured.

The intrinsic viscosity is calculated from the standard viscosity as follows

IV (DCE) = 6.67 x 10 ^-4 SV (DCE) + 0.118

Thermal properties

The thermal properties such as crystal melting point T _m , crystallization temperature range T _c , post- (cold) crystallization temperature T _CN and glass transition temperature T _g are measured by differential scanning calorimetry (DSC) at a heating rate of 10 ° C / min.

Molecular weight, polydispersity

The molecular weights M _w and M _n and the resulting polydispersity M _w / M _n are measured by means of gel permeation chromatography.

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 / m², 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.

The following are examples and comparative examples each around colored plates of different thickness, which on the extrusion line described are produced.

example 1

According to the coextrusion process described, a 4 mm thick multilayer, colored, amorphous polyethylene terephthalate plate with the Layer order A-B-A, where B is the base layer and A the Represent top layer. The base layer B is 3.5 mm thick and the two Cover layers that cover the base layer are each 250 mm thick.

The polyethylene terephthalate used for the base layer B has the following properties:
SV (DCE): 1100
IV (DCE): 0.85 dl / g
Density: 1.38 g / cm³
Crystallinity: 44%
Crystalline melting point Trn: 245 ° C
Crystallization temperature range T _c : 82 to 245 ° C
Post (cold) crystallization temperature range T _c : 152 ° C
Polydispersity M _w / M _n : 2.02
Glass transition temperature: 82 ° C
The main component of the base layer is the polyethylene terephthalate described and 8% by weight of titanium dioxide.

The titanium dioxide is of the rutile type and has an inorganic coating made of Al₂O₃ and with an organic coating of polydimethylsilane  coated. The titanium oxide has an average particle diameter of 0.2 µm.

The titanium dioxide is added in the form of a master batch. The master batch consists of 40 wt .-% of the titanium dioxide described as Active ingredient component and 60 wt .-% of that described Polyethylene terephthalate together as a carrier material.

The polyethylene terephthalate from which the outer layers are made has a standard viscosity SV (DCE) of 1010, which corresponds to an intrinsic viscosity IV (DCE) of 0.79 dl / g. The moisture content is <0.2% and the density (DIN 53479) is 1.41 g / cm³. The crystallinity is 59%, the crystallite melting point according to DSC measurements being 258 ° C. The crystallization temperature range T _c is between 83 ° C and 258 ° C, the post-crystallization temperature (also cold crystallization temperature) T _c N being 144 ° C. The polydispersity M _w / M _{n of} the polyethylene terephthalate polymer is 2.14.
The glass transition temperature is 83 ° C.

Before the coextrusion, 80% by weight of the polyethylene terephthalate is used for the Base layer and 20 wt .-% of the masterbatch mixed and 5 hours at 170 ° C in the main dryer, which is connected to the main extruder, dried.

The polyethylene terephthalate for the base or core layer and that Masterbatch are in the main extruder and the polyethylene terephthalate for the Cover layers are melted in the coextruders. The Extrusion temperature of the main extruder for the core layer is 281 ° C.

The extrusion temperatures of the two coextruders for the outer layers are at 294 ° C. The main extruder and the two coextruders are in one Coextruder adapter connected, which is designed so that the Melt-forming top layers as thin layers adhering to the  Melt the core layer are applied. The multilayer created in this way Melt strand is formed in the connected slot die and on a smoothing calender, the rolls are arranged in an S-shape three-layer, 4 mm thick plate smoothed.

The first calender roll has a temperature of 65 ° C and the following ones Rollers each have a temperature of 58 ° C. The speed of the Deduction is 4.2 m / min.

Following the after-cooling, the three-layer colored plate is also used Separating sagas hemmed, cut to length and stacked at the edges.

The white colored, amorphous, three-layer PET sheet has following property profile:

• - Layer structure: A-B-A
• - Overall thickness: 4 mm
• - Base layer thickness: 3.5 mm
• - Thickness of the cover layers: 0.25 mm each
• - Surface gloss 1st page: 152
• (Measuring angle 20 °) 2nd side: 148
• - light transmission: 0%
• - Whiteness: 118
• - Coloring: white, homogeneous
• - Surface defects: none
• (Specks, blisters, orange peel, etc.)
• - impact strength a _n Charpy no break
• - Notched impact strength a _k acc. To Izod: 5.1 kJ / m²
• - Crystallinity: 0%
• Roller coverings after 2 hours of production: none

Example 2

A three-layer colored plate is produced analogously to Example 1, a polyethylene terephthalate having the following properties being used for the core layer:
SV (DCE): 2717
IV (DCE): 1.9 dl / g
Density: 1.38 g / cm³
Crystallinity: 44%
Crystalline melting point Trn: 245 ° C
Crystallization temperature range T _c : 82 to 245 ° C
Cold crystallization temperature T _CN : 154 ° C
M _w : 175,640 g / mol
M _n : 49,580 g / mol
Polydispersity M _w / M _n : 2.02
Glass transition temperature: 82 ° C
The titanium dioxide masterbatch is composed of 40% by weight of the titanium dioxide described in Example 1 and 60% by weight of the polyethylene terephthalate of this example.

The extrusion temperature is 280 ° C. The first calender roll has one Temperature of 56 ° C and the subsequent rollers have a temperature of 50 ° C. The speed of the take-off and the calender rolls is included 2.9 m / min.

The three-layer PET sheet produced has the following properties:

• - Layer structure: A-B-A
• - Overall thickness: 6 mm
• - Thickness of the base layer: 5.5 mm  
• - Thickness of the cover layers: 0.25 mm each
• - Surface gloss 1st page: 149
• (Measuring angle 20 °) 2nd side: 143
• - light transmission: 0%
• - Whiteness: 125
• - Coloring: white, homogeneous
• - Surface defects: none
• (Specks, blisters, orange peel, etc.)
• - impact strength a _n Charpy no break
• - Notched impact strength a _k acc. To Izod: 5.2 kJ / m²
• - Crystallinity: 0%
• - Roller coverings after 2 hours of production: none

Example 3

Analogously to Example 1, a three-layer, white-colored PET sheet is used produced. 50% by weight of the polyethylene terephthalate from Example 1 are added 30% by weight of recyclate from the plates of Example 1 and 20% by weight of the Titanium dioxide masterbatches mixed and dried analogously to Example 1 and coextruded.

The three-layer, colored PET sheet produced has the following Characteristics:

• - Layer structure: A-B-A
• - Overall thickness: 4 mm
• - Base layer thickness: 3.5 mm
• - Thickness of the cover layers: 0.25 mm each
• - Surface gloss 1st side: 150
• (Measuring angle 20 °) 2nd side: 144
• - light transmission: 0%
• Whiteness: 127  
• - Coloring: white, homogeneous
• - Surface defects: none
• (Specks, blisters, orange peel, etc.)
• - impact strength a _n Charpy no break
• - Notched impact strength a _k acc. To Izod: 4.9 kJ / m²
• - Crystallinity: 0%
• - Roller coverings after 2 hours of production: none

Example 4

A three-layer PET panel is produced analogously to Example 1. The The base layer contains the main component as described in Example 1 Polyethylene terephthalate and 1.0% by weight of the titanium dioxide from Example 1. The titanium oxide is directly into the polyethylene terephthalate at the raw material manufacturer incorporated for the base layer.

The two top layers contain this as the main component Polyethylene terephthalate of the cover layers from Example 1 and 0.5 wt .-% of Titanium dioxide for the base layer. The titanium oxide is directly at the Raw material manufacturers metered. Drying, coextrusion and plate making takes place analogously to example 1.

The three-layer PET sheet produced has the following properties:

• - Layer structure: A-B-A
• - Overall thickness: 4 mm
• - Base layer thickness: 3.5 mm
• - TiO₂ content in the base layer: 1.0% by weight
• - Thickness of the cover layers: 0.25 mm each
• - TiO₂ content in the outer layers: 0.5% by weight
• - Surface gloss 1st page: 121
• (Measuring angle 20 °) 2nd side: 118  
• - Light transmission: 36%
• - Color: opal, white
• - Surface defects: none
• (Specks, blisters, orange peel, etc.)
• - impact strength a _n Charpy no break
• - Notched impact strength a _k acc. To Izod: 4.8 kJ / m²
• - Crystallinity: 0%

Example 5

A three-layer plate is produced analogously to Example 2. The plate is not colored white but green. The base layer contains this as the main component Polyethylene terephthalate from Example 2 and 9% by weight pigment green 17. Pigment green 17 is a chromium oxide (Cr₂O₃) from BASF (C-Sicopal green 9996).

The chromium oxide is added in the form of a master batch. The master batch is composed of 45 wt .-% chromium oxide and 55 wt .-% of Polyethylene terephthalate from Example 2 together.

The two top layers contain this as the main component Polyethylene terephthalate from Example 2 and 2 wt .-% chromium oxide, the Chromium oxide is metered in directly from the raw material manufacturer.

Drying, coextrusion and plate production are carried out analogously to Example 2.

The three-layer PET sheet produced has the following properties:

• - Layer structure: A-B-A
• - Overall thickness: 6 mm
• - Thickness of the base layer: 5.5 mm
• - Cr₂O₃ content in the base layer: 9% by weight
• - Thickness of the cover layers: 0.25 mm each
• - Cr₂O₃ content in the outer layers: 2% by weight
• - Surface gloss 1st page: 116
• (Measuring angle 20 °) 2nd side: 114
• - light transmission: 0%
• - Color: muted green, homogeneous
• - Surface defects: none
• (Specks, blisters, orange peel, etc.)
• Impact strength a _n Charpy no break
• - Notched impact strength a _k according to Izod: 5.3 kJ / m²
• - Crystallinity: 0%
• - Roller coverings after 2 hours of production: none

Example 6

Analogously to example 2, a three-layer, white-colored, amorphous PET sheet is used produced.

The two top layers contain this as the main component Polyethylene terephthalate from Example 2 and 2.5% by weight of the UV stabilizer 2- (4,6-Diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) oxyphenol (®Tinuvin 1577 from the company Ciba Geigy) contains. Tinuvin 1577 has a melting point of 149 ° C and is thermally stable up to approx. 330 ° C.

2.5% by weight of the UV stabilizer is added directly to the raw material manufacturer Polyethylene terephthalate incorporated.

The drying, coextrusion and process parameters are as in Example 2 chosen.

The three-layer PET sheet produced has the following properties:

• - Layer structure: A-B-A
• - Overall thickness: 6 mm
• - Thickness of the base layer: 5.5 mm
• - Thickness of the cover layers: 0.25 mm each
• - Surface gloss 1st page: 138
• (Measuring angle 20 °) 2nd side: 134
• - light transmission: 0%
• - Whiteness: white, homogeneous
• - Surface defects: none
• (Specks, blisters, orange peel, etc.)  
• - impact strength a _n Charpy no break
• - notch impact strength a _n Izod: 5.1 kJ / m²
• - Crystallinity: 0%
• - Roller coverings after 2 hours of production: none

After 1000 hours of weathering per side with the Atlas Ci 65 Weather Ometer shows the PET sheet the following properties:

• - Surface gloss 1st page: 126
• (Measuring angle 20 °) 2nd side: 125
• - light transmission: 0%
• - Whiteness: 120
• - Coloring: white, homogeneous
• - Surface defects: none
• (Specks, blisters, orange peel, etc.)
• - impact strength a _n Charpy no break
• - Notched impact strength a _k according to Izod: 4.6 kJ / m²
• - Crystallinity: 0%

Example 7

A three-layer plate is produced analogously to Example 1.

The cover layers contain 3.5% by weight of the UV stabilizer 2,2'-methylene bis (6- (2H-benzotrialzol-2-yl) 4- (1,1,3,3-tetramethylbutyl) phenyl (®Tinuvin 360 from Ciba Geigy), based on the weight of the top layer. Tinuvin 360 has a melting point of 195 ° C and is up to approx. 250 ° C thermally stable.

As in Example 6, 3.5% by weight of the UV stabilizer is added directly to the Raw material manufacturers incorporated into the polyethylene terephthalate.  

The three-layer PET sheet produced has the following properties:

• - Layer structure: A-B-A
• - Overall thickness: 4 mm
• - Base layer thickness: 3.5 mm
• - Thickness of the cover layers: 0.25 mm each
• - Surface gloss 1st page: 146
• (Measuring angle 20 °) 2nd side: 142
• - light transmission: 0%
• - Whiteness: 116
• - Coloring: white, homogeneous
• - Surface defects: none
• (Specks, blisters, orange peel, etc.)
• - impact strength a _n Charpy no break
• - Notched impact strength a _n according to Izod: 4.9 kJ / m²
• - Crystallinity: 0%

After 1000 hours of weathering per side with the Atlas Ci 65 Weather Ometer shows the PET sheet the following properties:

• - Surface gloss 1st page: 138
• (Measuring angle 20 °) 2nd side: 134
• - light transmission: 0%
• - Whiteness: 113
• - Coloring: white, homogeneous
• - Surface defects: none
• (Specks, blisters, orange peel, etc.)
• - impact strength a _n Charpy no break
• - Notched impact strength a _k according to Izod: 4.6 kJ / m²
• - Crystallinity: 0%

Comparative example

A colored plate is produced as in Example 1. The used Polyethylene terephthalate for the core layer has a standard viscosity SV (DCE) of 760, indicating an intrinsic viscosity IV (DCE) of 0.62 dl / g corresponds. The other properties are within the measurement accuracy the properties of the polyethylene terephthalate from Example 1 are identical. The Titanium oxide masterbatch, the cover layers, the process parameters and the Temperatures are chosen as in Example 1. Due to the low viscosity plate production is not possible. The melt stability is insufficient. Of the emerging melt strand shows a variety of flow and flows Inhomogeneities.

Claims (37)

1. Multilayer, colored, amorphous plate with a thickness in the range from 1 to 20 mm, which contains a crystallizable thermoplastic as the main component, characterized in that it has a multilayer structure comprising at least one core layer and at least one top layer, the standard viscosity of the in the thermoplastic containing the core layer is greater than the standard viscosity of the thermoplastic contained in the cover layer and wherein at least one layer of the plate contains at least one colorant selected from organic and inorganic pigments. 2. The plate of claim 1, wherein the standard viscosity of the thermoplastic the at least one core layer in the range from 800 to 5000 and that of the Thermoplastics of the at least one cover layer in the range from 500 to 4500 lies. 3. Plate according to claim 1 or 2, wherein the plate two cover layers and has a core layer lying between the cover layers. 4. Plate according to one of the preceding claims, wherein the Concentration of the pigment in the range from 0.5 to 30% by weight, based on the weight of the crystallizable thermoplastic of the so equipped Layer. 5. Plate according to one of the preceding claims, wherein the plate additionally contains a soluble dye. 6. Plate according to one of the preceding claims, wherein at least one of the core and / or top layer (s) with at least one UV stabilizer is equipped.   7. The plate of claim 6, wherein the concentration of the UV stabilizer in the at least one layer is 0.01 to 8 wt .-%, based on the Weight of the thermoplastic of the layer containing the UV stabilizer. 8. The plate of claim 6 or 7, wherein the concentration of the UV stabilizer in which at least one core layer is 0.01 to 1% by weight, based on the weight of the thermoplastic of the UV stabilizer containing core layer. 9. Plate according to one of claims 6 to 8, wherein the UV stabilizer is selected from 2-hydroxybenzotriazoles, triazines and their Mixtures. 10. Plate according to claim 9, wherein the UV stabilizer is selected from 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) oxyphenol and 2,2'-methylene-bis (6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbut-yl) phenol. 11. Plate according to one of the preceding claims, wherein at least one of the core and / or outer layers with at least one antioxidant is equipped. 12. The plate of claim 11, wherein the antioxidant is at a concentration from 0.1 to 6% by weight, based on the weight of the thermoplastic equipped layer. 13. The plate of claim 11 or 12, wherein the at least one Antioxidant is selected from sterically hindered phenols, secondary, aromatic amines, phosphites, phosphonites, thioethers, carbondiimides and zinc dibutyldithiocarbamate.   14. The plate of claim 13, wherein the antioxidant 2- [2,4,8,10- Tetrakis (1,1-dimethylethyl) dibenzo [d, f] [1,3,2idioxaphosphepin-6-yl] o-xy) ethyl] ethanamine and / or tris (2,4-di-tert-butylphenyl) phosphite. 15. Plate according to one of the preceding claims, wherein the crystallizable thermoplastic for the core layer is selected among Polyalkylene terephthalate with C1 to C12 alkylene radical, polyalkylene naphthalate with C1 to C12 alkylene radical, a cycloolefin polymer and a Cycloolefin copolymer. 16. Plate according to one of the preceding claims, wherein the Crystallizable thermoplastic for the top layer is selected among Polyalkylene terephthalate with C1 to C12 alkylene radical, polyalkylene naphthalate with C1 to C12 alkylene, a polyolefin, a cycloolefin polymer and one Cycloolefin copolymer. 17. Plate according to claim 15 or 16, wherein the alkylene radical is ethylene or Is butylene. 18. Plate according to one of the preceding claims, wherein the Thermoplastic for the core and top layer is the same. 19. Plate according to one of claims 15 to 18, wherein the thermoplastic Is polyethylene terephthalate. 20. Plate according to one of claims 15 to 19, wherein the thermoplastic Contains recyclate of the thermoplastic. 21. Plate according to one of the preceding claims, wherein the Thermoplastic a crystallite melting point, measured with a DSC Heating rate of 10 ° C / min., In the range of 220 to 280 ° C.   22. Plate according to one of the preceding claims, wherein the Thermoplastic a crystallization temperature, measured with a DSC Heating rate of 10 ° C / min., In the range of 75 to 280 ° C. 23. Plate according to one of the preceding claims, wherein the inserted Thermoplastic has a crystallinity that is in the range of 5 to 65. 24. Plate according to one of the preceding claims, wherein the thermoplastic used has a cold (post) crystallization temperature T _CN in a range from 120 to 158 ° C. 25. Plate according to one of the preceding claims, wherein the plate Surface gloss, measured according to DIN 67530 (measuring angle 20 °), of larger 110 has. 26. Plate according to one of the preceding claims, wherein the plate Light transmission, measured according to ASTM D 1003, has less than 60%. 27. Plate according to one of the preceding claims, wherein no fracture occurs when measuring the impact strength according to Charpy a _n , measured according to ISO 179 / 1D. 28. Plate according to one of the preceding claims, wherein the plate has a notched impact strength a _n according to Izod, measured according to ISO 180/1 A, in the range from 2.0 to 8.0 kJ / m². 29. Plate according to one of the preceding claims, wherein the plate has a scratch-resistant coating on at least one side. 30. The plate of claim 29, wherein the scratch-resistant coating silicon and / or is acrylic.   31. A process for producing a multi-layer, colored, amorphous Plate according to one of the preceding claims, wherein the thermoplastic for the at least one core layer and the thermoplastic for the at least one The top layer is melted in a coextruder, which melts stacked on top of each other and the merged layers by a Molded nozzle and then in the smoothing unit with at least two rollers calibrated, smoothed and cooled, the temperature of the first roller of the smoothing unit is in a range of 50-80 ° C and the colorant together with the thermoplastic of the layer (s) containing the colorant, is melted. 32. The method of claim 31, wherein at least one additive together melted with the thermoplastic of the layer to be treated with additive becomes. 33. The method of claim 31 or 32, wherein the thermoplastic Is polyalkylene terephthalate or polyalkylene naphthalate. 34. The method of claim 33, wherein the polyalkylene terephthalate or Polyalkylene naphthalate at 160 to 180 ° C for 4 to 6 hours before extrusion is dried. 35. The method according to any one of claims 33 or 34, wherein the temperature the polyalkylene terephthalate or polyalkylene naphthalate melt in the range of 250 to 320 ° C is. 36. The method according to any one of claims 31 to 35, wherein the at least a colorant and optionally the at least one additive via the Masterbatch technology is added.   37. Use of a multi-layer, colored, amorphous plate after one of the preceding claims for outdoor and indoor use.