OA10552A - Transparent amorphous plate stabilized against UV in a crystallizable thermoplastic - Google Patents

Abstract

A transparent, amorphous plate with a thickness in a range from 1 to 20 mm that contains as main component a thermoplastic material capable of crystallising is characterised in that it contains at least one UV stabiliser as light protective agent. Also disclosed is a process for producing the same and its use.

Description

i

The invention relates to an amorphous, transparent, UV-stabilized sheet of crystallizable thermoplastic, the thickness of which is in the range of 1 to 20 mm. The plate 5 contains at least one UV stabilizer as a photoprotective agent and is characterized by very good optical and mechanical characteristics. The invention furthermore relates to a process for preparing this plate and its use. Transparent, amorphous plates having a thickness of between 1 and 20 mm are well known. These two-dimensional products consist of amorphous, non-crystallizable thermoplastics. Typical examples of such thermoplastics that can be formed into plates are, for example, polyvinyl chloride (PVC), polycarbonate (PC) and poly (methyl methacrylate) (PMMA). These semi-finished products are prepared on so-called extrusion units (see Polymer Werkstoffe, Vol II, Technology 1, pg 136, Georg Thieme Verlag, Stuttgart, 1984). The melting of the pulverulent or granulated raw material is carried out in an extruder. Amorphous thermoplastics can be converted afterextrusion because of the continuously increasing viscosity as a function of temperature decrease, using calenders or other finishing tools. Amorphous thermoplastics then have a sufficient viscosity, ie, high viscosity, to "stand up alone" in the calibration tool. But they are flexible enough to be profiled by the tool. The melting viscosity and the inherent stiffness of the thermoplastic amorphos are so high in the sizing tool that the semi-finished product does not collapse in the calibration tool. In the case of easily decomposable materials, such as PVC, in the extrusion stage, special processing aids, such as, for example, anti-decomposition stabilizers and lubricants for internal friction are required. too strong and therefore against an uncontrollable heating. External lubricants are necessary to prevent clinging to walls and cylinders.

In the implementation of PMMA, for example, to eliminate moisture, a degassing extruder is used.

In the preparation of transparent, amorphous, transparent thermoplastic plates, there is a need for additives, some of which are expensive, which can migrate in part and cause production problems due to evaporation and superficial deposits on the semi-finished product. The PVC sheets can only be recycled with difficulty or only by means of special neutralization or electrolysis processes. Likewise, PC and PMMA plates can only be recycled with difficulty and only at the cost of extreme loss or degradation of the mechanical characteristics. In addition to these drawbacks, the PMMA plates also have an extreme low toughness, and they burst during the breaking or mechanical stressing. In addition, the PMMA plates are easily flammable, so that they can not be used for example for the coating of interior walls and in the construction of exposure halls.

In addition, it is not possible to cold profile PMMA and PC plates. In cold forming, PMMA plates break into dangerous chips. In cold profiling, filiform cracks and white fracture are formed in the PC slabs. 3 010552

DE-A-3,531,878 discloses synthetic thermoplastic polyester sheets which contain a UV stabilizer and have a thickness of from 0.5 to 0.03 mm.

These sheets are obtained by blown extrusion and are therefore partially crystalline. With the aid of the method described by this publication, therefore, amorphous sheets having a thickness of 1 mm or more can no longer be obtained.

JP-A-5 320 528 discloses a composition of thermoplastic resins which contains an epoxidized polyester. According to a preferred embodiment, this composition contains PVC as the main constituent. The plates obtained from it by mixing are transparent and have a thickness of 1 mm.

EP-A-0 471 528 discloses a method for profiling an object to obtain a poly (ethylene terephthalate) (PET) plate. Both sides of the PET plate are thermally treated in a tipping tool in a range of temperatures between the glass transition temperature and the melting temperature. The profiled PET plate is included in the shape when the degree of crystallization of the shaped PET plate is in a range of 25% to 50%. The PET plates disclosed by the patent specification EP-A-0 471 528 have a thickness of 1 to 10 mm. Since the stamped profile, prepared from this plate is partially crystalline, so it is no longer transparent and the surface characteristics of the profile are determined by the stamping process, the temperatures and shapes given in this process, the optical properties (for example brightness, lightness and light transmission) of the PET plates used are not essential. As a general rule of thumb, the optical properties of these plates are poor and require optimization.

In addition, these plates do not contain UV stabilizer as a photoprotective agent, so that neither the plates nor the profiles prepared therefrom are suitable for outdoor applications. In external applications, these plates, respectively the profiles show, already after a short time, a yellowing and a degradation of the mechanical characteristics following degradation by photooxidation induced by the light of the sun.

US-A-3,496,143 discloses deep-vacuum deep drawing of a 3 mm PET plate having a range of 5% to 25%. The crystallinity of the pressed profile is greater than 25%. These PET plates also do not fulfill any requirement regarding the optical properties. Since the crystallinity of the plates used is already between 5% and 25%, these plates are cloudy and opaque. These plates also do not contain a photoprotective agent and therefore are unsuitable for external applications. With the aid of the processes known to date, it has been possible to prepare amorphous plates containing a crystallizable thermoplastic as a main constituent having a thickness of 1 mm or more, the quality of which is not satisfactory.

The object of the present invention is to prepare a transparent amorphous plate, having a thickness of 1 to 20 mm, which has next to the good mechanical properties that optical, above all a high UV stability.

High UV stability means that the plates are not or only extremely slightly damaged by sunlight or other UV radiation, so that the plates are suitable for outdoor use and / or for critical interior use. In particular, the plates must not present a yellowing, a fragilization or a cracking of the surface, nor a degradation of the mechanical characteristics.

Good optical properties include, for example, high light transmission as well as high surface gloss, extremely low turbidity, and high image clarity.

Good mechanical properties include, among other things, high resilience and high resistance to fracture.

In addition, the plate according to the invention must be recyclable, more particularly without loss of mechanical characteristics, and hardly inflammable, so that it can be used for example for the coating of interior walls and in the construction of exhibition halls.

This problem is solved with the aid of a transparent glass plate having a thickness in the range of 1 to 20 mm, comprising a thermoplastic material as a main component, characterized in that the plate contains at least one UV stabilizer as a photoprotective agent.

The transparent, amorphous plate contains a crystallizable component as crystalline or partially crystalline thermoplastic, for example polyethylene terephthalate, polybutylene terephthalate, cycloolefin polymers and cycloolefin copolymers, preferably polyethylene terephthalate. ).

By crystallizable thermoplastic is meant in accordance with the invention crystallizable homopolymers, thermoplastic principal. Crystallizable copolymers, crystallizable compounds, crystallizable recyclables and other crystallizable thermoplastics.

For the purposes of the present invention, amorphous plate is understood to mean such plates which, although the crystallizable thermoplastic used has a crystallinity of between 5% and 65%, particularly preferably between 25% and 65%, are not crystalline. Non-crystalline, i.e., amorphous, means that the degree of crystallinity is generally less than 5%, preferably less than 2%, and more preferably 0%. The amorphous plate according to the invention is in a substantially unoriented state.

The amorphous, transparent plate additionally contains at least one UV stabilizer as a photoprotective agent, the concentration of UV stabilizer is preferably from 0.01% by weight to 5% by weight, based on the weight of the crystallizable thermoplastic.

The light, in particular the ultraviolet component of the sun rays, that is to say in the wavelength range of 280 to 400 nm, induces in the thermoplastics degradation processes, which only cause visual changes in appearance. changes in color, respectively after yellowing, but also influences negatively the physical and mechanical properties. Inhibition of these photochemical degradation processes is of considerable technical and economic importance, since otherwise the applicability of many thermoplastics will be extremely limited.

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

In the presence of oxygen, chain dissociations are mainly observed, but not de-crosslinking. Carbon monoxide, carbon dioxide and carboxylic acids represent photooxidation products whose quantity is preponderant. In addition to the direct photolysis of the ester groups, oxidation reactions which also cause the formation of carbon dioxide via the radical-peroxide have to be taken into account.

The photooxidation of the polyethylene terephthalates can lead to the hydroperoxides and their degradation products also by dissociation of the hydrogen at the ester group position, as well as the chain dissociations associated with this process (H. Day, DM Wiles: J. Appl., Polym., Sci., 16, 1972, page 203).

UV stabilizers, or UV absorbers as photoprotectants, are chemical compounds that can be involved in the physical and chemical processes of light-induced degradation. Carbon black and other pigments may partially act as photoprotective agents. However, these substances are not suitable for the plates, as they cause discoloration or change of color. For amorphous plates, transparencies are suitable only for organic and organometallic compounds which do not cause a change of color or only to an extremely low extent in lethermoplastic to stabilize.

UV stabilizers suitable as photoprotective agents are, for example, 2-hydroxybenzophenones, 2-hydrobenzotriazoles, organic nickel compounds, salicylic acid esters, cinnamate derivatives, monobenzoates of resorcinol, oxanilides, hydroxybenzoates, sterically hindered desamines and triazines, with 2-hydroxybenzotriazoles and triazines being preferred.

In a particularly preferred embodiment, the transparent amorphous plate according to the invention contains a crystallizable poly (ethylene terephthalate) as the main component and from 0.01% by weight to 5.0% by weight of 2- (4, 6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) oxyphenol (structure in Figure 1a) or 0.01% by weight to 5.0% by weight of 2,2 '- methylene-bis (6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol (structure in Figure 1b) In a preferred embodiment, it is also possible to using mixtures of these two UV stabilizers or mixtures of at least one of these two UV stabilizers with other UV stabilizers, the total concentration of photoprotective agent being preferably between 0.01% by weight and 5.0% by weight relative to crystalline poly (ethylene terephthalate) weight.

The surface gloss measured according to DIN67530 (angle of incidence 20 °) is greater than 120, preferably greater than 140, the light transmission, measured according to ASTM D 1003, is greater than 84%, preferably more than 86%, and the Plate turbidity, measured according to ASTM D 1003, is less than 15%, preferably less than 11%.

The image sharpness, also referred to as "Clarity" and which is determined at an angle less than 2.5 ° (ASTM D 1003), is preferably 96% and particularly preferred, greater than 97% .

In the case of poly (ethylene terephthalate), when measuring the Charpy resilience (measured according to DIN 179 / 1D), there is no breakage of the plate. On the other hand, the akIzod notch resilience (measured according to ISO 180 / IA) is preferably in the range 2.0 to 8.0 kJ / m 2, particularly preferably in the range of 4.0 to 6, 0 kJ / m2.

Poly (ethylene terephthalates) with a melting point of crystallites Tm, measured by DSC (Differential Scanning Calorimetry) with a heating rate of 10 ° C / min, from 220 ° C to 280 ° C, preferably 250 ° C C at 270 ° C., with a crystallization temperature range Tc of between 75 ° C. and 280 ° C., preferably between 75 ° C. and 260 ° C., a glass transition temperature Tg of 65 ° C. to 90 ° C. and a density Measured according to DIN 53479 form of 1.30 to 1.45 g / cm3 and a crystallinity of between 5% and 65%, preferably 25% to 65%, represent preferred polymers as starting materials for the preparation of the plate.

The standard VS (ADA) viscosity of poly (ethylene terephthalate), measured in acyclicacetic acid (ADA) according to DIN 53728, is between 800 and 1800, preferably between 950 and 1250, and particularly preferably between 1000 and 1200.

The intrinsic viscosity VI (ADA) is calculated from the standard viscosity as follows: VI (ADA) = 6.67 × 10 -4 VS (ADA) + 0.118

The bulk density, measured according to DIN53466, 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 Mw / Mn of poly (terephthalate ethylene) measured by gas chromatography is preferably between 1.5 and 6.0 and particularly preferably between 2.0 and 3.5.

Weathering tests have shown that after 5 to 7 years of outdoor use, the UV stabilized plates do not exhibit yellowing, embrittlement, loss of surface gloss, surface cracking and degradation of mechanical properties. .

In addition to the excellent UV stability, it has been found a good aptitude for cold profiling that is completely unexpected, without breaks, without filiform cracks and / or without white breakage, so that the plates according to the invention can be profiled and folded without any adverse effect. the heat.

In addition, the measurements have demonstrated that the PET plate according to the invention ignites only with difficulty and that it is not very combustible, so that it is suitable, for example, for interior wall coatings and in the construction of exposure halls.

In addition, one can recycle without problem the plate conforms to the invention without polluting the environment and without loss of mechanical properties, which makes itparticulièrementappropriate for the uses of courtedurée as billboards or other articles advertisitaires.

The amorphous, transparent, UV-stabilized plate according to the invention can be prepared, for example, by an extrusion process in an extrusion assembly.

Such an extrusion assembly is shown schematically in Figure 2. It essentially comprises a extruder (1) laminator, a flat die (2) as a profiling tool, a finisher / calender (3) as a calibration tool, a cooling bed (4). ) and / or roll conveyor (5) for cooling, a roll draft (6), a cut-off saw (7), a diagonal cutting device (9), and possibly a stacking device (8).

The method of preparing the plate according to the invention is described in detail on the example of poly (ethylene terephthalate) as thermoplastic.

The process is characterized in that the crystalline thermoplastic (eg, polyethylene terephthalate) is optionally dried, then it is melted in the extruder, preferably together with the UV stabilizer, the melt is profiled in a filter and then , it is calibrated in a calender-finisher, smoothed and cooled before sizing the plate.

It is essential for the process according to the invention that the first cylinder of the calender and finisher has a temperature in the range of 50 ° C to 80 ° C, otherwise it is difficult to obtain a transparent amorphous plate with a thickness of 1mm or more using a thermosetecrystallizable.

In accordance with the invention, the photoprotective agent can be dosed already in the producer of the thermoplastic raw materials or during the preparation of the plate in the extruder.

The addition of the photoprotective agent is particularly preferred by means of the masterbatch technology. The photoprotective agent is fully dispersed in a solid support material. Suitable carrier materials are certain resins, such as thermoplastics, for example poly (ethylene terephthalate) or other polymers which are sufficiently compatible with thermoplastics.

It is important that the particle size and bulk density of the solid pigment preparation or the masterbatch be similar to the particle size and bulk density of the thermoplastic, so that a uniform distribution can be obtained and hence a homogeneous stabilization against UV.

Drying of the poly (ethylene terephthalate) before extrusion is preferably carried out for 4 to 6 hours at a temperature of 160 to 180 ° C.

Then, the poly (ethylene terephthalate) is melted in the extruder. Preferably, the temperature of the melt PET is in the range of 250 to 320 ° C, the temperature of the melt being essentially established by both the temperature of the extruder and the residence time of the melt in the extruder.

The melt leaves the extruder through a line. This die is preferably a flat die.

The PET melted in the extruder and profiled in the flat thread is calibrated by the rollers of the finisher, i.e., intensely cooled and smoothed. The rolls of the calender can be arranged, for example, in the form of I, F, L or S (Fig. 3).

Then, the material, PET, can be cooled on a roller conveyor, cut on the sides to the dimensions, cut lengthwise and finally stacked. The thickness of the PET plate essentially depends on the drawing device installed at the end of the cooling zone, the cooler cylinders (straighteners) coupled to this device according to the speed and the speed of transport of the extruder both on the one hand and on the other. difference of cylinders on the other hand.

As an extruder, it is possible to use single-screw or twin-screw extruders.

The flat die preferably consists of the body of the decomposable tool, the lips and the device for regulating the flow over the width. To do this, the device for the regulation of the flow over the width can be warped by means of clamping screw and pressure. The adjustment of the thickness is done by adjusting the lips. It is important to ensure that the temperature of the PET and the lip is uniform, otherwise the PET melt flows outwardly with a different thickness through the different flow paths. The calibration tool, that is, the calender-finisher, gives shape and dimensions to PETfondu. This is done by freezing below the glass transition temperature by cooling and smoothing. We should no longer be profiled in this state because it would form superficial defects in this cooled state. For this reason, it is preferable to drive the cylinders of the calandria together. The temperature of the calender cylinders must be lower than the crystalline temperature in order to avoid the adhesion of the molten PET. The melted PET leaves the flat die with a temperature of 240 to 300 ° C. The temperature of the first cooling cylinder of the calender, in each case according to the production and the thickness of the plate, is between 50 and 80 ° C. The second cylinder, a little colder, cools the second or other surface.

While the calibration tool freezes the PET surfaces as directly as possible and cools the profile to such an extent that it becomes undeformable, the cooling system reduces the temperature of the PET plate to substantially room temperature. Cooling can be carried out on a roller conveyor. The speed must be adjusted exactly in relation to the speed of the calender rolls, in order to avoid defects and variations in thickness.

As auxiliary equipment, the extrusion assembly may comprise a cut-off saw to prepare the plates in lengthwise cut, the side cut, the stacking installation and a control station. The lateral cutting or edges is advantageous, since the thickness in the part of the edges may sometimes be irregular. The control station measures the thickness and optics of the plate.

Thanks to the surprisingly large number of excellent properties, the amorphous and transparent sheet, according to the invention, is perfectly suitable for a large number of different applications, for example for the coating of interior walls, in the construction of exhibition halls and for exhibition articles , for billboards, as screens, as screens for the protection of machines and vehicles, in the lighting sector, in the installation of magazines and shelves, as advertising articles, as debasket-ball baskets, as partitions, for aquariums, as billboards and as a medium for flyers and newspapers.

Thanks to the good stability against UV, the amorphous plate, transparent according to the invention, is also suitable for outdoor applications, such as, for example, greenhouses, roof covers, glazings, safety glasses, the outer cover, coatings, building applications, illuminated advertising profiles, balcony cladding, roof lifts and caravan windows. The invention is explained below with the help of exemplary embodiments without being limited to these examples.

The measurement of the different properties is carried out according to the following standards or methods. 010552 Measuring methods

brightness

The gloss of the surface is determined under an angle of incidence of 20 ° according to DIN 67530.

Transmission of light:

By transmission of light we must hear the contribution of all the light transmitted to the quantity of incident light.

The light transmission is measured with a measuring device "Hazegrad plus" according to ASTM 1003.

Turbidity and image sharpness

Turbidity is the percentage of light transmitted which deviates by more than 2.5 ° from the incident light beam. Image density is determined at an angle smaller than 2.5 °.

Turbidity and image sharpness are measured using the "Hazegard plus" hiding apparatus according to the ASTM 1003 form.

The surface defects are visually evaluated. Resilience an Charpy:

This quantity is determined according to ISO179 / 1D. Resilience ak Izod:

The notched resilience, Izod notch resistance according to ISO 180 / 1A, is measured.

Density:

The density is determined according to DIN 53479. 16 010552 VS (ADA), VI (ADA):

The standard viscosity SV (ADA) is measured on the basis of DIN 53728 in dichloroacetic acid (ADA).

The intrinsic viscosity is calculated from the standard viscosity as follows VI (ADA) = 6.67 × 10 -4VS (ADA) + 0.118

Thermal properties:

The thermal properties, such as the melting point of crystallites Tm, the temperature range of crystallization Tc, the settt-crystallization temperature (of cold crystallization) TCN and the glass transition temperature Tg, differential scanning calorimetry (DSC) are measured. ") with a heating rate of 10 ° C / min.

Molar mass, polydispersity:

The molar masses Mw and Mn and the resulting Mw / Mn polydispersivity are measured by gel permeation chromatography.

Exposure to weather (both sides), UV stability: UV stability is tested according to ISO 4892 test specification as follows: Test Apparatus: Atlas CiOmeter 65 Weather Test conditions: ISO 4892, weathering .a.d. artificial Irradiation time: 1000 hours (per side) Irradiation: 0.5 W / m2, 340 nm Temperature: 63 ° C 17 010552

Humidity of the airrelative: 50%

Xenon lamp

Irradiation cycles internal and external borosilicate filter: 102 minutes UV rays, then 18 minutes UV rays, samples in a water mist and then again for 10 minutes UV light, etc.

Color change :

The color change of the samples after exposure to artificial weather was measured by a spectrophotometer according to DIN 5033.

It applies: AL: Difference in brightness + Al: the sample is lighter than the standard -AL: the sample is darker than the standard ΔΑ: Difference in the field of red-green

Aa: the sample is redder than the standardAa: the sample is less red than the AB standard: Difference in the field of blue-yellow + ΔΒ: the sample is yellower than the standard-Ab: l sample is more blue than standard ΔΕ: Total color change: Δε = V Al2 + Aa2 + Ab2

The larger the standard deviation of the standard, the greater the difference in color.

The numerical values of <0.3 can be neglected because they do not represent significant color changes. 18 010552

Yellow index: The yellow index G is the difference from the absence of color towards the "yellow" and is measured according to DIN 6167. Values <5 of the yellow index G are not visible.

In the following examples and comparative examples, each of these is a monolayer plate, transparent, of a different thickness that is after the extrusion assembly described.

The weather conditions according to the ISO 4892 test specifications are exposed to both faces of all the sheets, which are tested against UV at each 1000 hours per side, in the Atlas Ci 65 Weather Ometer device of the Atlas company and then the mechanical properties, the discoloration, superficial defects, turbidity and gloss.

Example 1

A 3 mm thick transparent amorphous plate is prepared which contains, as the main component of polyethylene terephthalate and 1.0% by weight of the UV stabilizer, 2- (4,6-diphenyl-1,3,5 triazin-2-yl) -5- (hexyl) oxyphenol (®Tinuvin 1577 from Ciba-Geigy Company).

Tinuvin 1577 has a melting point of 149 ° C and is heat resistant up to about 330 ° C.

For a homogeneous distribution, 1.0% by weight of the UV stabilizer is incorporated into the poly (ethylene terephthalate) directly from the producer of the raw materials. The poly (ethylene terephthalate), from which the transparent plate is prepared, has a standard viscosity VS (ADA) of 1010, which corresponds to an intrinsic viscosity VI (ADA) 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 being 258 ° C. as measured by the DSC. The range of crystallization temperatures Tc 010552 is between 83 ° C and 258 ° C, the temperature deposition-crystallization (also temperature cold decristallization) TCN is 144 ° C. The Mw / Mn dispersivity of the poly (ethylene terephthalate) polymer is 2.14. The glass transition temperature is 83 ° C.

Before extrusion, the poly (ethylene terephthalate) having a crystallinity of 59% was dried for 5 hours at 170 ° C. in a drier and then extruded in a single screw extruder at a 286 ° C. extrusion temperature in a flat die. on a finisher, whose cylinders are arranged in S shape and smooth to obtain a plate with a thickness of 3 mm. The temperature of the first cylinder of the calender is 73 ° C and that of each of the other cylinders 67 ° C. The speed of pulling and descylinders of the calender is 6.5 m / min.

After cooling, the edges of the transparent PET plate 3 mm thick were sawed with the chainsaw, cut in length and stacked.

The amorphous, transparent, prepared PET plate has the following characteristic profile:

Thickness: 3 mm

Surface brightness, face 1: 198 (angle of incidence 20 °), face 2: 196

Light transmission: 91%

Image clarity: 100%

Turbidity: 1.5% Superficial defects per m2: none (speckles, orange peel, bubbles, etc.) Resilience an Charpy Resilience with notch akIzod no break 4.2 kJ / m2 20 010552 Cold deformability: good, not of defects

Crystallinity: 0%

Density: 1.33 g / cm3

After each 1000 hours of weather exposure per face in an Atlas Ci 65 Weather Ometer, the PET plate has the following characteristics:

Thickness: 3 mm Surface gloss, face 1: 196 (20 ° angle of incidence), face 2: 195 Light transmission: 91.1% Image clarity: 100% Turbidity: 1.6% Total color change ΔΕ: 0,22 Dark color change AL: -0,18 Color change red-: -0,08 green ΔΑ Color change blue-: 0,10 3 aune ΔΒ Superficial defects: none (cracks, weakening) Yellow index G: 4 Resilience yr Charpy: no rupture Resilience with notch ak: 4.1 kJ / m2 Izod Cold deformability: ^ good

Example 2

In a similar manner to Example 1, a transparent amorphous plate is prepared by adding UV stabilizer, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) - oxyphenol (®Tinuvin 1577) in the form of a masterbatch. The masterbatch is composed of 5% by weight of Tivinuv 1577 as the active component and 95% by weight using poly (ethylene terephthalate) of Example 1.

Before extrusion, 80% by weight of the poly (ethylene terephthalate) of Example 1 was dried with 20% by weight of the masterbatch for 5 hours at 170 ° C. Extrusion and preparation of plates are made analogously to Example 1.

The prepared transparent amorphous PET plate has the following characteristic profile:

Thickness

Surface gloss, face 1 (20 ° angle of incidence), face 2Transmission of light Image clarity Clarity Superficial defects per m2 (speckles, orange peel, bubbles, etc.) Resilience Charpy Resilience with notch akIzod Cold deformabilityCrystallinityMass volume 3 mm 194. 193 91.3% 100% 1.4% no breakthrough4.0 k J / m2 good0% 1.33 g / cm3

After each 1000 hours of weather exposure per face in an Atlas Ci 65 Weather Ometer, the PET plate has the following characteristics:

Thickness: 3 mm

Surface brightness, face 1: 192 (angle of incidence 20 °), face 2: 190

Transmission of light: 91.1%

Image clarity: 100%

Turbidity: 1.5% 22 010552

Total color change ΔΕ: 0.24 Dark color change AL: -0.19 Red-green color change Δα. : -0.08 Change of blue-yellow color ΔΒ: 0.12 Superficial defects (cracks, embrittlement): none Yellow index G: 5 Resilience an Charpy: no rupture Resilience with a notch Izod: 4.0 kJ Cold deformability: good Example 3: In a similar manner to Example 1, an amorphous plate is prepared, transparent, using a poly (ethylene terephthalate) with the following characteristics: which exhibits VS (ADA): 1100 VI (ADA): 0.85 dl / g Density: 1.38 g / cm3 Crystallinity: 44% Melting point: 245 ° C crystallites Tm Temperature range: 82 ° C to crystallization Tc 242 ° C post- :, 152 ° C crystallisation (cold crystallization) TCN Polydispersity Mw / Mn: 2.02 Transition temperature: 82 ° C glassy Tg An amorphous, transparent plate, 6 mm thick, containing as component the main polyethylene terephthalate described and 0.6% in weight of the stabilizer t UV, 2,2'-methylene-bis- (6-2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) -phenol (®Tinuvin 360 from Ciba-Geigy Company ), relative to the weight of the polymer.

As in Example 1, poly (ethylene terephthalate) stabilizer UV directly first materials. m / min. melting at 195 ° C and 250 ° C. it is incorporated at 0.6% by weight of: the producer is of 2 80 ° C. the calender is: 60 ° C. The calender speed is 2.9: 6 mm

Thickness

Surface gloss, face 1 (20 ° angle of incidence), face 2Transmission of light Image clarity Clarity Superficial defects per m2 (speckles, orange peel, bubbles, etc.) Resilience Charpy Resilience with notch akIzod Cold deformability

crystallinity

Density 175 173 88.6% 99.6% 2.5% no breakthrough rate4.8 kJ / m2 good, no defects 0% 1.33 g / cm3

After every 1000 hours of weathering per face in an Atlas Ci 65 Weather Ometer, the PET plate has the following characteristics: 24 010552 - Thickness: 6 mm - Surface gloss, face 1: 171 - (angle d incidence 20 °), side 2: 169 - Light transmission: 88.3% - Image clarity: 99.5% - Turbidity: 2.7 - Total color change ΔΕ: 0.56 - Dark color change AL: -0,21 Red-green color change ΔΑ: -0,11 - Blue-yellow color change ΔΒ: +0,51 - Superficial defects (cracks,: no embrittlement)

Yellow index G Resilience an Charpy Resilience with notch akIzod 6 no break4.6 kJ / m2 Cold deformability good, no defects

Example 4

In a similar manner to Example 3, an amorphous, transparent plate is prepared. The extrusion temperature is 27 ° C. The temperature of the first cylinder of the lake is 57 ° C and that of the other 50 C cylinders. The draft speed and that of the calender rolls is 1.7 m / min. The plate is stabilized as in Example 3. The prepared PET plate has the following characteristic profile: Thickness: 10 mm Surface gloss, Side 1: 163 (angle of incidence 20 °), Side 2 : 161 - Transmission of light: 86.5% - Image clarity: 99.2% 25 010552

Turbidity Superficial defects per m2 (speckles, orange peel, bubbles, etc.) Resilience an Charpy Resilience with notch akIzod Cold deformability

crystallinity

Density: 4.95%: none: no break: 5.1 kJ / m2: good, no defects: 0.1%: 1.33 g / cm3

After each 1000 hours of weather exposure per face in an Atlas Ci 65 Weather Ometer, the PET plate has the following characteristics:

Thickness

Surface gloss, face 1 (20 ° angle of incidence), face 2Transmission of light Image clarity (clarity) - Turbidity - Total color change ΔΕ - Dark color change AL - Change color red-green ΔΑ

Blue-yellow color change Δβ Superficial defects (cracks, embrittlement)

Yellow index G Resiliency an Charpy Resilience with notch akIzod Cold deformability 10 mm 160 159 86,2% 99,1% 5,00,47-0,18 -0,09 + 0,42 none 5 no break4,5 kJ / m2 good, no defects 26 010552

Comparative Example 1

In a similar manner to Example 1, an amorphous, transparent plate is prepared. Unlike Example 1, the plate does not contain UV stabilizer. The poly (ethylene terephthalate) used, the extrusion parameters, the process parameters and the temperatures are selected as in Example 1.

The prepared, transparent PET plate has the following feature profile:

Thickness

Surface brightness, face 1 (20 ° angle of incidence), face 2Transmission of light Image clarity

Turbidity Superficial defects per m2 (speckles, orange peel, bubbles, etc.) Resilience an Charpy Resilience with notch akIzod Cold deformability

CrystallinityMass volume: 3 mm: 200: 198: 91.4%: 100%: 1.3%: none: no break: 4.3 kJ / m2: good, no defects: 0% 1.33 g / cm3

After each 1000 hours of weather exposure per face in an Atlas Ci 65 Weather Ometer, the PET plate has the following characteristics:

Thickness

Surface gloss, face 1 (20 ° angle of incidence), face 2Transmission of light Image clarity 3 mm 98 95 79.5% 81.2% 27 010552

TurbidityChange Change Change Dies ΔΑ

Change of yellow ΔΒ Surface defects per m2 (cracks, embrittlement)

Yellow index G Resilience an Charpy Resilience with notch akIzod Cold deformability color color total color ΔΕfuncted ALrouge- blue color-: 7.8%: 3,41: -0,29: -0,87: +3,29: embrittlement : 17: complete rupture at 34.8 kJ / m2: 1.3 kJ / m2: cracking At visual observation, the plate shows a clearly visible "yellow" discoloration. Surfacess are blunted and weakened. 10

Comparative Example 2

In a similar manner to Example 3, an amorphous, transparent plate is prepared. In contrast to Example 3, the prepared plate does not contain UV stabilizer. The polyethylene terephthalate used, the extrusion parameters, the process parameters and the temperatures are selected as in Example 3.

The prepared PET plate, transparent, has the following profile of characteristics

Thickness: 6 mm

Surface brightness, face 1: 180 (angle of incidence 20 °), face 2: 187

Transmission of light: 88.9%

Image clarity: 99.6%

Turbidity: 2.3% 15 28 010552 Surface defects per m2 (speckles, orange peel, bubbles, etc.): none - Resilience an year Charpy: no breakage - Resilience with notch Izod: 4.8 kJ / m2 - Cold deformability: good, no defects - Crystallinity: 0% - Density: 1.33 g / cm3 After every 1000 hours of weathering per face in an Atlas Ci 65 Weather Ometer, the PET plate presents the following characteristics: - Thickness: 6 mm - Surface gloss, face 1: 91 - (angle of incidence 20 °), face 2: 87 - Light transmission: 72.5% - Image sharpness (clarity ): 78.3% - Turbidity: 12.9% - Total color change ΔΕ: 3.61 - Dark color change Al: -0.26 - Color change red-green Δα: -0.91 - Change of color blue-yellow color ΔΒ: +3,48 - Superficial defects (cracks, embrittlement): embrittlement, "cracks - Yellow index G: 18 - Resilience Charpy: complete rupture 46.2 kJ / m2 - Izod notch toughness: 1.6 kJ / m2 Cold deformability cracking 29 010552 At visual observation, the plate shows a clearly visible "yellow" discoloration. Surfacess are blunted and weakened. Comparative Example 3

In a similar manner to Example 3, a transparent, UV-stabilized, transparent, translucent plate is prepared using the poly (ethylene terephthalate), the UV stabilizer and the masterbatch of Example 3. The temperature of the first cylinder of lacalander is 83 ° C and those of each of the other cylinders 77 ° C.

The prepared plate has extreme turbidity and is practically opaque. Light transmission, image sharpness and brightness are reduced significantly. The plate has defects and superficial structures. Optics are unacceptable for transparent use.

The prepared plate has the following profile of 20 characteristics:

Thickness

Surface gloss, face 1 (20 ° angle of incidence), face 2Transmission of light Image clarity Clarity Superficial defects per m2 (speckles, orange peel, bubbles, etc.) Resilience Charpy Resilience with notch akIzod 6 mm86 888% not measurable not measurable bubbles, orange peel: no break: 5.0 k J / m2 Cold deformabilityCrystallinityMass volume good about 8% 1.34 g / cm3 30 010552 Because of optics unacceptable, the plate was not exposed to bad weather.

Claims (18)

010552 CLAIMS 1. Amorphous plate, transparent, having a thickness in the range of 1 to 20 mm, containing as a main component a crystallizable thermoplastic, characterized in that it contains at least one UV stabilizer as a photoprotective agent. 2. Plate according to claim 1, characterized in that the concentration of UV stabilizer is in the range of 0.01 to 5% by weight based on the weight of the crystallizable thermoplastic. 3. Plate according to claim 1 or 2, characterized in that the UV stabilizer is selected from 2-hydroxybenzotriazoles and triazines. 4. Plate according to claim 3, characterized in that at least one compound selected from 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -4- (1) is used as the UV stabilizer. 1,3,3-tetramethylbutyl) -phenol and 2,2'-methylene-bis (6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol. 5. Plate according to one of the preceding claims, characterized in that the gloss of the surface, measured according to DIN 67530 (angle of incidence 20 °) is greater than 120. * 6. Plate according to one of the preceding claims, characterized in that the transmission of the lumièrmesurée according to ASTM-D 1003 is greater than 84%. Plate according to at least one of the preceding claims, characterized in that the turbidity, measured according to ASTM D 1003, is less than 15%. 8. Plate-according to one of the preceding claims, characterized in that the crystallizable thermoplasticpresente a crystallinity in the range of 5 to 65%. 9. Plate according to one of the preceding claims, characterized in that the crystallizable thermoplastic is taken from poly (ethylene terephthalate) (PET), poly (butylene terephthalate) (PBT), a cyclo-olefinic polymer and a cycloolefin copolymer. Plate according to claim 9, characterized in that poly (ethylene terephthalate) is used as the crystallizable thermoplastic. 11. Plate according to claim 10, characterized in that the poly (ethylene terephthalate) contains recycled poly (ethylene terephthalate). 12. Plate according to claim 10 or 11, characterized in that in the measurements of the resilient Charpy, measured according to ISO 179 / 1D, there is no breakage. 13. Plate according to one of claims 10 to 12, characterized in that the impact resilience akIzod, measured according to ISO 180 / 1A, is in the range of 2.0 to 8.0 kJ / m2. 14. Plate according to one of claims 10 to 13, characterized in that the image sharpness, measured according to ASTM-D 1003 at an angle of less than 2.5 °, is greater than 96%. 34 010552 21. The method of claim 20, wherein the polyethylene terephthalate is dried prior to extrusion for 4 to 6 hours at a temperature of 160 to 180 ° C. 22. Process according to claim 20 or 21, characterized in that the temperature of the molten PET is in the range of 250 to 320 ° C. 23. Method according to one of claims 20 to 22, characterized in that the addition of the UV stabilizer is effected by masterbatch technology. 23. Use of the transparent amorphous plate according to at least one of claims 1 to 17 in outdoor applications.