DE19519578A1 - Transparent coloured amorphous sheet with good optical properties etc. - Google Patents

Abstract

Transparent coloured amorphous sheet (I) with a thickness of 1-20 mm, contg. a crystallisable thermoplastic (II) as the main component, together with dye(s) (III) which is/are soluble in (II). Also claimed is a process for the prodn. of (I), by (a) melting (II) with (III) in an extruder, (b) extruding the melt through a die, (c) calibrating, smoothing and cooling on a glazing mill with at least two rollers, the first of which is at a temp. of 50-80 deg C, and (d) cutting to size.

Description

The invention relates to an amorphous, transparent colored plate from one crystallizable thermoplastic, the thickness of which is in the range from 1 to 20 mm. The plate contains at least one polymer-soluble dye and is characterized by very good optical and mechanical properties. The The invention further relates to a method for producing this plate and its Use.

Amorphous, transparent colored plates with a thickness between 1 and 20 mm are well known. These flat structures consist of amorphous, non-crystallizable thermoplastics. Typical examples of such thermoplastics, which are processed into sheets, are, for. B. Polyvinyl chloride (PVC), polycarbonate (PC) and polymethyl methacrylate (PMMA). These semi-finished products are manufactured on so-called extrusion lines (cf. Polymer Materials, Volume II, Technology 1, Georg Thieme Verlag, Stuttgart 1984). The powdered or granular raw material is melted in an extruder. The amorphous thermoplastics are the result of extrusion the steadily increasing viscosity of the amorphous with decreasing temperature Thermoplastics easily over smoothing units or other shaping tools to reshape. Amorphous thermoplastics then have one after molding sufficient stability, d. H. a high viscosity in order to "in the calibration tool to stand ". But they are still soft enough to get away from the tool to be shaped. The melt viscosity and inherent stiffness of amorphous Thermoplastic is so high in the calibration tool that the semi-finished product is not in front cooling coincides in the calibration tool. With easily decomposable Materials such as B. PVC are special processing aids in extrusion,  such as B. processing stabilizers against decomposition and lubricants against high internal friction and therefore uncontrollable heating necessary. Outer Lubricants are required to keep walls and rollers from getting stuck prevent.

When processing PMMA z. B. for the purpose of dehumidification Degassing extruder used.

In the production of transparently colored sheets made of amorphous Thermoplastics are e.g. T. costly additives required, some of them migrate and to production problems due to evaporation and to Can lead surface coverings on the semi-finished product. PVC sheets are heavy or can only be recycled using special neutralization or electrolysis processes. PC and PMMA disks are also bad and only at loss or extreme deterioration of the mechanical properties recyclable.

In addition to these disadvantages, PMMA sheets also have an extremely poor one Impact resistance and fragmentation in the event of breakage or mechanical stress. In addition, PMMA boards are combustible like wood, so that they can be used for Indoor applications and in exhibition stand construction may not be used.

PMMA and PC sheets are also not cold-formable. Cold forming break PMMA sheets into dangerous fragments. When cold forming PC Panels appear hairline cracks and whitening.

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.

In US-A-3,496,143 the vacuum deep drawing of a 3 mm thick PET Plate 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.

The object of the present invention is to make an amorphous, transparent provide colored plate with a thickness of 1 to 20 mm, which both has good mechanical and optical properties.

Good optical properties include, for example, high ones Light transmission, high surface gloss, extremely low haze as well as high clarity.

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.

The task is solved with an amorphous, transparently colored plate  a thickness in the range of 1 to 20 mm, which is characterized in that they as a main component a crystallizable thermoplastic and one contains soluble dye. The concentration of the soluble dye is preferably in the range from 0.001 to 20% by weight, based on the weight of the crystallizable thermoplastic.

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

The color change as a result of the coloring of the amorphous plate is due on the wavelength-dependent absorption and / or scattering of light. Dyes can only absorb light, not scatter it, because the physical A certain minimum particle size is required for scattering.

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

Of the different classes of soluble dyes, especially those fat and aromatic soluble dyes preferred. It is about for example azo and anthraquinone dyes. They are suitable especially for coloring PET, because of the high Glass transition temperature of PET, the migration of the dye is restricted is.

(Literature J. Koerner: Soluble dyes in the plastics industry in VDI-Gesellschaft Kunststofftechnik: Coloring plastics, VDI-Verlag, Düsseldorf 1975).

Suitable soluble dyes are, for example: Solvent yellow 93 a Pyrazolone derivative, solvent yellow 16 a fat-soluble azo dye, fluorol green gold a fluorescent polycyclic dye, solvent red 1 an azo dye,  Azo dyes such as Thermoplastrot BS, Sudanrot BB, Solventrot 138 Anthraquinone derivative, fluorescent benzopyran dyes such as fluorol red GK and fluorine orange GK, solvent blue 35 an anthraquinone dye, solvent blue a phthalocyanine dye and many others.

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

According to the invention, the soluble dye can be used in the desired concentration already metered in at the raw material manufacturer or during plate production be metered into the extruder.

However, the addition of the color additive via the Master batch technology. The soluble dye is in a solid Carrier material fully dispersed and / or dissolved. Come as a backing certain resins, the polyethylene terephthalate polymer itself or others Polymers sufficient with the polyethylene terephthalate polymer are tolerated, in question.

It is important that the grain size and the bulk weight of the masterbatch similar to the grain size and bulk density of the crystallizable Thermoplastics are, so that a homogeneous distribution and thus a homogeneous, transparent coloring can take place.

The surface gloss of the plate according to the invention, measured in accordance with DIN 67530 (Measuring angle 20 °) is greater than 100, preferably greater than 110, the Light transmission, measured according to ASTM D 1003, is in the range from 5 to 80%, preferably in the range from 10 to 70% and the cloudiness of the plate, measured according to ASTM D 1003, is in the range from 2 to 40, preferably in Range from 3 to 35%.

The main component of the amorphous, transparent colored plate is one crystallizable thermoplastics. Suitable crystallizable or partially crystalline  Thermoplastics are, for example, polyethylene terephthalate, Polybutylene terephthalate, cycloolefin and cycloolefin copolymers, wherein Polyethylene terephthalate is preferred.

In a particularly preferred embodiment, the inventive transparent amorphous plate as the main component crystallizable Polyethylene terephthalate.

In the case of polyethylene terephthalate in the measurement of impact strength a _n occurs Charpy (measured according to ISO 179 / 1D) on the board preferably no fracture. 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 3.0 to 8.0 kJ / m², particularly preferably in the range from 4.0 to 6.0 kJ / m².

The sharpness of the plate, also called Clarity, and under one Angle less than 2.5 is determined, (ASTM D 1003) is preferably above 93% and particularly preferably over 94%.

Polyethylene terephthalate polymers with a crystallite melting point T _m , measured with DSC (differential scanning calorimetry) with a heating rate of 10 ° C / min, from 240 ° C to 280 ° C, preferably from 250 ° C to 270 ° C, with a crystallization temperature range T _c between 75 ° C and 280 ° C, a glass transition temperature T _g between 65 ° C and 90 ° C and with a density, measured according to DIN 53479, of 1.30 to 1.45 g / cm³ and a crystallinity between 25% and 65% are preferred polymers as starting materials for the production of the plate.

The standard viscosity of the polyethylene terephthalate SV (DCE), measured in Dichloroacetic acid according to DIN 53728, is between 800 and 1400, preferably between 950 and 1250, especially between 1000 and 1200.  

The intrinsic viscosity IV (DCE) is calculated as follows from the Standard viscosity:

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

The bulk density, measured according to DIN 53466, 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 polyethylene terephthalate M _w / M _n measured by GPC is preferably between 1.5 and 4.0 and particularly preferably between 2.0 and 3.5.

According to the invention, crystallizable polyethylene terephthalate is understood

• crystallizable polyethylene terephthalate homopolymers,
• crystallizable polyethylene terephthalate copolymers,
• crystallizable polyethylene terephthalate compounds,
• - Crystallizable recycled polyethylene terephthalate and
• - other variations of crystallizable polyethylene terephthalate.

For the purposes of the present invention, amorphous plates are such Sheets understood that, although the crystallizable thermoplastic is a Has crystallinity between 25% and 65%, are not crystalline. Not crystalline, d. H. essentially amorphous means that the degree of crystallinity in generally less than 5%, preferably less than 2% and particularly preferred Is 0%.

In addition, good cold-formability without breaking became unexpected Hairline cracks and / or found without whitening, so that the invention Plate can be deformed and bent without the influence of temperature.

In addition, measurements showed that the PET plate according to the invention flame retardant and flame retardant, so that the  plate according to the invention is suitable for indoor use and in exhibition stand construction.

Furthermore, the plate according to the invention is without environmental pollution and without Loss of mechanical properties easily recyclable, which makes them are particularly suitable for use as short-lived advertising signs or others Promotional items are suitable. Since the dye is soluble in the polymer, Reuse of the recyclate no agglomerates on the optical Would negatively affect properties.

The production of the transparently colored, translucent, amorphous plates can be extruded in one Extrusion line take place.

Such an extrusion line is shown schematically in FIG. 1. It essentially comprises

• an extruder as a plasticizing system,
• - a slot die as a tool for shaping,
• - a calender / calender as a calibration tool,
• - a cooling bed and / or a roller conveyor for after-cooling,
• - a roller take-off,
• - a saw,
• - A side cutter, and if necessary
• - a stacking device.

The process for producing the plate of the invention is as follows described in detail for polyethylene terephthalate.

The process is characterized in that the polyethylene terephthalate if necessary dries, then melts in the extruder, the melt through a Molds the nozzle and then calibrates, smoothes and cools in the calender before the plate is made to measure.  

The polyethylene terephthalate is dried before extrusion preferably for 4 to 6 hours at 160 to 180 ° C.

The polyethylene terephthalate is melted in the extruder. Preferably the temperature of the PET melt is in the range from 250 to 320 ° C, whereby the temperature of the melt essentially by both the temperature of the Extruder, as well as the residence time of the melt in the extruder can.

The melt then leaves the extruder through a nozzle. This nozzle is preferably a slot die.

The PET melted by the extruder and shaped by a slot die is calibrated by smoothing calender rolls, ie intensively cooled and smoothed. The calender rolls can, for example, be arranged in an I, F, L or S shape (see FIG. 2).

The PET material can then be cooled on a roller conveyor, cut to the side, cut to length and finally stacked.

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

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

The slot die preferably consists of the separable tool body, the lips and the dust bar for flow regulation across the width. This can the control bar can be bent by tension and pressure screws. The The thickness is adjusted by adjusting the lips. It is important on one  ensure that the temperature of the PET and the lip is even, otherwise the PET Melt flows out through the different flow paths to different thicknesses.

The calibration tool, d. H. the smoothing calender gives shape to the PET melt and the dimensions. This is done by freezing below the Glass transition temperature by cooling and smoothing. Be deformed should no longer be in this state, otherwise in this cooled state Surface defects would arise. For this reason, the Calender rolls preferably driven together. The temperature of the Calender rolls must be used to avoid sticking of the PET melt be less than the crystallite melting temperature. The PET melt leaves with the slot die at a temperature of 240 to 300 ° C. The first smooth cooling Depending on the output and plate thickness, the roller has a temperature between 50 ° C and 80 ° C. The second, somewhat cooler roller cools the second or the other Surface.

While the calibration device smoothes the PET surfaces as smoothly as possible Freezing brings and cools the profile so far that it is dimensionally stable, lowers the After-cooling device the temperature of the PET plate to almost room temperature from. 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 for the production of PET plates a cutting saw as a cutting device, the side trimming, the Stacking facility and a control point. The side or Edge trimming is advantageous because the thickness in the edge area may be can be uneven. At the control point, the thickness and appearance of the Plate measured.  

Due to the surprising number of excellent properties, the outstandingly transparent, colored, amorphous PET plate according to the invention for a variety of different uses, for example for Interior cladding, for stand construction and articles, as displays, for Signs, for protective glazing of machines and vehicles, in Lighting sector, in shop and shelf construction, as promotional items, as Menu card stand and as basketball goal boards.

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 Norms and methods:

Surface gloss

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

Light transmission

Under the light transmission is the ratio of the total let through To understand light to the incident amount of light.

The light transmission is carried out with the "Hazegard plus" measuring device according to ASTM 1003 measured.

Turbidity and Clarity

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

The haze and clarity are measured using the "Hazegard plus" measuring device ASTM 1003 measured.  

Surface defects

The surface defects are determined visually.

Charpy impact strength a _n

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

Notched 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 53479.

SV (DCE), IV (DCE)

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

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

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

Thermal properties

The thermal properties such as crystallite 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 / Mn are measured by means of gel permeation chromatography.

The following are examples and comparative examples in each case around single-layer panels of different thickness, which on the extrusion line described are produced.

Example 1

A 2 mm thick, transparently colored, amorphous plate is produced, the main ingredient is polyethylene terephthalate and 2% by weight of the soluble Dye Solventrot 138, an anthraquinone derivative from BASF (®Thermoplast G) contains.

The polyethylene terephthalate from which the transparent colored, amorphous plate is 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 _CN at 144 ° C. The polydispersity M _w / M _{n of} the polyethylene terephthalate polymer is 2.14.
The glass transition temperature is 83 ° C.

The soluble dye Solventrot 138 is in the form of a masterbatch admitted. The masterbatch consists of 20% by weight of the dye Solventrot 138 as active ingredient and 80 wt .-% of the above described polyethylene terephthalate polymers together as a carrier material.

Before the extrusion 90% by weight of the polyethylene terephthalate polymer and 10% by weight of the masterbatch in a dryer at 170 ° C. for 5 hours dried and then in a single screw extruder at a Extrusion temperature of 286 ° C through a slot die on one Smoothing calender, the rollers of which are arranged in an S-shape, extruded and into one 2 mm thick plate smoothed. The first calender roll has a temperature of  73 ° C and the following rollers each have a temperature of 67 ° C. The speed of the take-off and the calender rolls is included 6.5 m / min.

After cooling, the transparent colored 2 mm thick PET board lined with cutting saws on the edges, cut to length and stacked.

The red-transparent colored PET sheet produced has the following Property profile:

• - Thickness: 2 mm
• - Surface gloss 1st side: 130
• - (measuring angle 20 °) 2nd side: 127
• - Light transmission: 35.8%
• - Clarity: 99.1%
• - turbidity: 3.5%
• - Surface defects per m² (Specks, orange peel, blisters, etc.): none
• - impact strength a _n Charpy no break
• - Notched impact strength a _k acc. To Izod: 4.2 kJ / m²
• - Cold formability: good, no defects
• - Crystallinity: 0%
• - Density: 1.33 g / cm³

Example 2

Analogously to Example 1, a transparent colored plate is produced, with a Polyethylene terephthalate is used, which has the following properties:

SV (DCE): 1100
IV (DCE): 0.85 dl / g
Density: 1.38 g / cm³
Crystallinity: 44%
Crystallite melting point T _m : 245 ° C
Crystallization temperature range T _c : 82 ° C to 245 ° C
Post (cold) crystallization temperature T _CN : 152 ° C
Polydispersity M _w / M _n : 2.02
Glass transition temperature: 82 ° C

The masterbatch consists of 20% by weight of the dye Solventrot 138 and 80% by weight of the polyethylene terephthalate polymer of this example (SV 1100) together.

The extrusion temperature is 280 ° C. The first calender roll has one Temperature of 66 ° C and the subsequent rollers have a temperature of 60 ° C. The speed of the take-off and the calender roll is included 2.9 m / min.

The red-transparent colored PET sheet produced has the following Property profile:

• - Thickness: 6 mm
• - Surface gloss 1st page: 122
• - (measuring angle 20 °) 2nd side: 120
• - Light transmission: 28.1%
• - Clarity: 98.9%
• - turbidity: 9.6%
• - Surface defects per m² (Specks, orange peel, blisters, etc.): none
• - impact strength a _n Charpy no break
• - Notched impact strength a _k acc. To Izod: 4.8 kJ / m²
• - Cold formability: good, no defects
• - Crystallinity: 0%
• - Density: 1.33 g / cm³

Example 3

Analogously to Example 1, a transparent, translucent plate is colored manufactured. The 2 mm thick, transparent colored plate contains 4% by weight of the soluble dye solvent blue 35, a fat-soluble anthraquinone dye from BASF (®Sudan Blue 2).

The 4% by weight of the dye solvent blue 35 are also in the form of a Masterbatches added, the masterbatch from 20 wt .-% of Dye solvent blue 35 and 80% of the polyethylene terephthalate polymer composed of Example 1. 80% by weight of the polyethylene terephthalate Polymers from Example 1 are used with 20% by weight of the masterbatch.

The blue-transparent colored plate produced has the following
Property profile:

• - Thickness: 2 mm
• - Surface gloss 1st page: 128
• - (measuring angle 20 °) 2nd side: 126
• - Light transmission: 30.6%
• - Clarity: 99.0%
• - turbidity: 5.7%
• - Surface defects per m² (Specks, orange peel, blisters, etc.): none
• - impact strength a _n Charpy no break
• - Notched impact strength a _k according to Izod: 4.3 kJ / m²
• - Cold formability: good, no defects
• - Crystallinity: 0%
• - Density: 1.33 g / cm³

Example 4

Analogously to Example 2, a transparent colored plate is produced. The 6 mm thick, transparent colored plate contains, as in Example 3, 4% by weight of the soluble dye solvent blue 35 (®Sudan blue 2 from BASF). As in  Example 3 shows the 4% by weight of the dye solvent blue 35 in the form of a Masterbatches added, the masterbatch from 20 wt .-% of Dye solvent blue 35 and 80% of the polyethylene terephthalate from Example 2 composed.

The blue-transparent colored plate produced has the following Property profile:

• - Thickness: 6 mm
• - Surface gloss 1st page: 124
• - (measuring angle 20 °) 2nd side: 123
• - Light transmission: 20.2%
• - Clarity: 98.4%
• - turbidity: 13.8%
• - Surface defects per m² (Specks, orange peel, blisters, etc.): none
• - impact strength a _n Charpy no break
• - Notched impact strength a _k acc. To Izod: 5.0 kJ / m²
• - Cold formability: good, no defects
• - Crystallinity: 0%
• - Density: 1.33 g / cm³

Example 5

Analogously to Example 2, a transparent colored plate is produced. The Extrusion temperature is 275 ° C. The first calender roll has one Temperature of 57 ° C and the subsequent rollers have a temperature of 50 ° C. The speed of the take-off and the calender roll is included 1.7 m / min.  

The PET sheet produced has the following property profile:

• - Thickness: 10 mm
• - Surface gloss 1st side: 120
• - (measuring angle 20 °) 2nd side: 118
• - Light transmission: 21.5%
• - Clarity: 98.4%
• - turbidity: 12.2%
• - Surface defects per m² (Specks, orange peel, blisters, etc.): none
• - impact strength a _n Charpy no break
• - Notched impact strength a _k according to Izod: 5.3 kJ / m²
• - Cold formability: good, no defects
• - Crystallinity: 0.1%
• - Density: 1.33 g / cm³

Example 6

Analogously to Example 5, a transparent colored plate is produced, with a Polyethylene terephthalate is used, which has the following properties:

SV (DCE): 1200
IV (DCE): 0.91 dl / g
Density: 1.37 g / cm³
Crystallinity: 36%
Crystallite melting point T _m : 242 ° C
Crystallization temperature range T _c : 82 ° C to 242 ° C
Post (cold) crystallization temperature T _CN : 157 ° C
Polydispersity M _w / M _n : 2.2
Glass transition temperature: 82 ° C

The extrusion temperature is 274 ° C. The first calender roll has one Temperature of 50 ° C and the subsequent rollers have a temperature  of 45 ° C. The speed of the take-off and the calender rolls is included 1.2 m / min.

The transparent colored PET sheet produced has the following Property profile:

• - Thickness: 15 mm
• - Surface gloss 1st page: 114
• - (measuring angle 20 °) 2nd side: 112
• - Light transmission: 18.8%
• - Clarity: 95.4%
• - Turbidity: 21.8%
• - Surface defects per m² (Specks, orange peel, blisters, etc.): none
• - impact strength a _n Charpy no break
• - Notched impact strength a _k acc. To Izod: 5.9 kJ / m²
• - Cold formability: good, no defects
• - Crystallinity: 0.5%
• - Density: 1.33 g / cm³

Example 7

Analogously to Example 2, a transparent colored plate is produced. 60% Polyethylene terephthalate from Example 2 with 30% recyclate from this Polyethylene terephthalate and 10% of the masterbatch mixed.

The transparent colored panel produced has the following property profile:

• - Thickness: 6 mm
• - Surface gloss 1st page: 118
• - (measuring angle 20 °) 2nd side: 117
• - Light transmission: 28.2%
• - Clarity: 98.9%  
• - Turbidity: 9.9%
• - Surface defects per m² (Specks, orange peel, blisters, etc.): none
• - impact strength a _n Charpy no break
• - Notched impact strength a _k according to Izod: 4.9 kJ / m²
• - Cold formability: good, no defects
• - Crystallinity: 0%
• - Density: 1.33 g / cm³

Comparative Example 1

Analogously to example 1, a transparent colored plate is produced. The Polyethylene terephthalate used has a standard viscosity SV (DCE) of 760, which corresponds to an intrinsic viscosity IV (DCE) of 0.62 dl / g. The other properties are within the measurement accuracy with the Properties of the polyethylene terephthalate from Example 1 identical. The The masterbatch used is identical to the masterbatch from example 1. The Process parameters and the temperature were chosen as in Example 1. Due to the low viscosity, plate production is not possible. The Melting stability is insufficient, so that the melt is on before cooling the calender rolls coincides.

Comparative Example 2

Analogously to example 2, a transparent, translucent plate is colored prepared, including polyethylene terephthalate and masterbatch from Example 2 be used. The first calender roll has a temperature of 83 ° C and the following rollers each have a temperature of 77 ° C.

The plate produced is extremely cloudy and almost opaque. The Light transmission, clarity and gloss are significantly reduced. The plate shows surface defects and structures. The optics are for a transparent colored application unacceptable.  

The plate produced has the following property profile:

• - Thickness: 6 mm
• - Surface gloss 1st page: 86
• - (measuring angle 20 °) 2nd side: 88
• - Light transmission: 8%
• - Clarity: not measurable
• - Turbidity: not measurable
• - Surface defects per m² (Specks, orange peel, blisters, etc.): blisters, orange peel
• - impact strength a _n Charpy no break
• - Notched impact strength a _k acc. To Izod: 5.0 kJ / m²
• - Cold formability: good
• - Crystallinity: approx. 8%
• - Density: 1.34 g / cm³

Claims (23)

1. Transparent colored, amorphous plate, with a thickness in the range of 1 to 20 mm, characterized in that it contains a crystallizable thermoplastic and at least one dye that is soluble in the thermoplastic as the main component. 2. Plate according to claim 1, characterized in that the concentration of the soluble dye in the range of 0.001 to 20 wt .-%, based on the weight of the crystallizable thermoplastic. 3. Plate according to claim 1 or 2, characterized in that the soluble dye a fat and aromatic soluble azo and Anthraquinone dye is. 4. Plate according to at least one of the preceding claims, characterized characterized in that the surface gloss, measured according to DIN 67530 (Measuring angle 20 °) is greater than 100. 5. Plate according to at least one of the preceding claims, characterized characterized in that the light transmission, measured according to ASTM D 1003, is in the range of 5 to 80%. 6. Plate according to at least one of the preceding claims, characterized characterized in that the turbidity, measured according to ASTM D 1003, in Range is from 2 to 40%. 7. Plate according to at least one of the preceding claims, characterized characterized in that as a crystallizable thermoplastic Polyethylene terephthalate, polybutylene terephthalate, a cycloolefin and / or a cycloolefin copolymer is used.   8. Plate according to claim 7, characterized in that as Crystallizable thermoplastic polyethylene terephthalate is used. 9. Plate according to claim 8, characterized in that the Contains polyethylene terephthalate, polyethylene terephthalate recyclate. 10. Plate claim 8 or 9, characterized in that in the measurement of impact strength a _n Charpy, measured according to ISO 179 / 1D, no breakage occurs in accordance with. 11. Plate according to at least one of claims 8 to 10, characterized in that the notched impact strength a _k according to Izod, measured according to ISO 180 / 1A, is in the range from 3.0 to 8.0 kJ / m². 12. Plate according to at least one of claims 8 to 11, characterized characterized in that the image sharpness, measured according to ASTM D 1003 under an angle less than 2.5 °, is over 93%. 13. Plate according to at least one of claims 8 to 12, characterized characterized in that the polyethylene terephthalate is preferably a Crystallite melting point, measured by DSC with a Heating rate of 10 ° C / min., In the range of 240 to 280 ° C. 14. Plate according to at least one of claims 8 to 13, characterized characterized in that the polyethylene terephthalate is preferably a Crystallization temperature, measured by DSC with a Heating rate of 10 ° C / min., In the range of 75 to 280 ° C having.   15. Plate according to at least one of claims 8 to 14, characterized characterized in that the polyethylene terephthalate used a Has crystallinity that is in the range of 25 to 65%. 16. Plate according to at least one of claims 8 to 15, characterized characterized in that the polyethylene terephthalate used a Standard viscosity SV (DCE), measured in dichloroacetic acid according to DIN 53728, which ranges from 800 to 1400. 17. Process for the production of a transparently colored, translucent, amorphous plate according to at least one of claims 1 to 16, characterized in that the crystallizable thermoplastic if necessary dries, then melts in the extruder, the melt formed by a nozzle and then in the smoothing unit with at least Two rollers calibrated, smoothed and cooled before taking the plate to size brings. 18. The method according to claim 17, characterized in that the Crystallizable thermoplastic is polyethylene terephthalate. 19. The method according to claim 18, characterized in that one Polyethylene terephthalate before extrusion for 4 to 6 hours at 160 to Dries 180 ° C. 20. The method according to claim 18 or 19, characterized in that the The temperature of the PET melt is in the range from 250 to 320 ° C. 21. The method according to at least one of claims 18 to 20, characterized characterized in that the addition of the dye over the Masterbatch technology is carried out.   22. The method according to at least one of claims 18 to 21, characterized characterized in that the first roller of the calender has a temperature has, which is in the range of 50 to 80 ° C. 23. Use of a transparent colored amorphous plate according to at least one of claims 1 to 16 for indoor applications and Exhibition stand construction.