MXPA97009366A - Lamina amorfa transparent made of thermoplastic materials cristalizab - Google Patents

Abstract

The present invention relates to an amorphous transparent sheet with a thickness in the scale of 1 to 20 mm, containing crystallizable thermoplastic materials as its main component, its luster, measured in accordance with DIN 67530 (measurement angle of 20§), is greater than 130, its transparency to light, measured in accordance with ASTM D 1003, is greater than 84%, and its opacity, measured according to ASTM D 1003, is less than 15%, a process for manufacturing this blade and its us

Description

LAMINA AMORFA TRANSPARENT MADE OF CRYSTALLIZABLE THERMOPLASTIC MATERIALS FIELD OF THE INVENTION The invention relates to a transparent amorphous sheet of a transparent silver wool, whose thickness is in the range of 1 to 20 nm. The sheet is distinguished by its very good optical and mechanical properties. The invention also relates to a process for the production of this sheet and to the sheet.

BACKGROUND OF THE INVENTION Transparent amorphous sheets having a thickness of between 1 and 20 inrn are well known. These two-dimensional structures are comprised of amorphous terrnoplasts that do not cpstalize them. Typical examples of these thermoplastics which are converted to sheets are, for example, polyvinyl chloride (PV), polycarbonate (P) and polymethyl methacrylate (PMMA). These sernitted products are produced in the so-called extrusion lines (see Polyrner Uerkstoffe [Polirnepic Materials], Volume II, Technology 1, Georg Thierne Verlag, Stuttgart, 1984). The powdered or granular starting material is melted in an extruder. After the extrusion, the amorphous thermoplastic can be reshaped by polishing piles or other forming dies due to its viscosity which increases (always with the decrease in temperature). After its shaping, the amorphous epnoplatforms have a For example, they are still soft enough to be shaped, for example, a viscosity to sustain themselves on the calibration die, but they are still soft enough to be shaped by the given melt viscosity and the inherent rigidity of the The amorphous compounds are so high in the calibration die that the finished product is not crushed before it is cooled in the calibration die, in the case of easily decomposable materials, such as PVC, auxiliaries are needed. of particular treatment such as, for example, anti-decomposition treatment stabilizers and lubricants with excessive internal friction and thus heating Uncontrollable during extrusion. External lubricants are necessary to prevent the material from adhering to the s and rollers. The treatment of PMhfl is carried out using, for example, a ventilated extruder to allow the removal of moisture. The production of transparent sheets from amorphous terrnoplastics sometimes requires expensive additives, which in some cases migrate and can cause production problems due to evaporations and surface coatings on the semi-finished product. PVC sheets can be recirculated only with difficulty or using special neutralization or elec- trolar processes. Thus, PC and PMMR sheets can only be recirculated with difficulty and only with loss or extreme deterioration of their mechanical properties. In addition to these disadvantages, the PMMA sheets also have extremely low impact strengths and are splintered by mechanical fracture or load. In addition, the PMMA sheets are easily combustible, which means that they can not be used, for example, for interior applications and in exhibitions. The sheets of PMMA and PC, in addition, can not be formed when they are cold; PMMA sheets are disintegrated to form dangerous splinters, while PVC sheets suffer capillary cracking and stress whitening. EP-A-0 471 528 discloses a process for forming an article from a sheet of polyfill tere phthalate (PET). The PET sheet is heat treated on both sides in the thermal film forming mold on a temperature scale between the glass transition temperature and the melting temperature. The shaped PET sheet is removed from the mold when the degree of crystallization of the shaped PET sheet is in the region of 25 to 50%. The PET sheets described in EP-A-0 471 528 have a thickness of 1 to 10 m. Since the thermoformed molding produced at the bottom of the PET film is partially crystalline and thus no longer necessary, the surface properties of the modeling are determined by the forming process and the mold., it is not important that you use optics (for example, Luster, opacity and light transmission) have the PET sheets used. In general, the optimal properties of these sheets are deficient and require optimization. US-A-3, 496, 143 describes the vacuum thermoforming of a PET sheet of 3 nm thickness whose degree of crystallization is said to be in the range of 5 to 25%. However, the cp talinity of the thermoformed molding is greater than 25%. Again, no requirements are made regarding the optical properties of these PET sheets. Since the size of the sheets used is between 5 and 25%, these sheets are opaque and non-transparent. The object of the present invention is to provide a transparent amorphous sheet having a thickness of 1 to 20 nm which has both good mechanical properties and good optical properties. Good optical properties include, for example, high light transmission, high surface gloss, extremely low opacity and high clarity. Good mechanical properties include, among other things, high impact strength and high break strength. In addition, the novel sheet must be recirculated, in particular without loss of mechanical properties, and have a high level of combustion that can be used, for example, for interior applications and exhibitions. This object is achieved by a transpar- ent amorphous sheet having a thickness on the scale of 1 to 20 nm, which contains, as the main constituent, a thermoplastic foam, where the surface luster, measured in accordance with DTN. b753D (measurement angle 20 °), is greater than 130, preferably greater than 140, and the light transmission, measured in accordance with ASTM D 10 (13, is greater than 86%, and the opacity of the sheet, as measured by According to ASTM D 1003, it is less than 15%, preferably less than 11% The transparent amorphous lamella contains, as a main constituent, a crystalline tepnoplastic.The suitable crystallizable or partially crystalline thermoreplates are, for example, example, polyethylene terephthalate, polybutylene terephthalate, cycloolefin polymers and cycloolefin copolymers, with letlleno polymer terephthalate being particularly preferred For the purposes of the invention, the following crystallizable thermoplastic term is used. Nifica: - Crystallisable furnace polymers - Copol irneros cp stal izizables - Compound compounds - Recyclable crystalline material, and - Other variations of crystallizable plastics.

For the purposes of the present invention, the term "amorphous sheet" means those sheets that are non-crystalline, although the cpstaplatable epnoplastically employed preferably has a crystallinity of 25% to 65%. Non-crystal, that is to say, essentially amorphous, means that the degree of stability in general is less than 5%, preferably less than 2%, and particularly 0% is preferred. In the case of polyalkylene terephthalate, preferably fracture does not occur in the measurement of Charpy impact resistance, an (measured in accordance with 150 179 / 1D) of the sheet. In addition, the Izod impact strength, ak (measured according to ISO 180 / iA) of the sheet is preferably in the range of 2.0 to 8.0 kJ / rn2, particularly in the range of 4.0 to 6.0 l / rn2"The clarity of the sheet measured at an angle of less than 2.5 ° (ASTM I) 1003) is preferably greater than 96%, particularly preferably more than 97%. The polyethylene terephthalate polymers having a melting point of Tf crystal, measured by DSC (differential scanning calorimetry) with a heating rate of up to 10 ° C / nm, from 220 ° C to 2 ° C, preferably from 250 ° C to 270 ° C, a crystallization temperature scale Tc between 75 ° C and 280 ° C, a glass transition temperature Tv between 65 ° C and 90 ° C, and a density, measured according to with DIN 53479, from 1.30 to 1.45 and a cr ist between 5% and 65%, preferably 25 to 65%, are the preferred polymers as starting materials for the production of Lu sheet. The normal viscosity VN of the thermoplastic according to the invention (DCA), measured in di chloroacetic acid according to DIN 53728, is from T00 to less than 1,800, in particular from 800 to 1,400, preferably from 950 to 1250, and is preferred particularly from 1,000 to 1,200. The intrinsic viscosity VI (DCA) is calculated as or follows from the normal viscosity: VI (DCA) ** 6.67 X 10- * VN (DCA) + 0.118 The overall density, measured in accordance with DIN 53466, is preferably between 0.75 g / drn3 and 1.0 |. g / dm3, and particularly preferably from 0.80 Lg / drn3 to f) .9Q kg / drn3. The polystyrene content M / Mn of the polyethylene terephthalate measured by means of GPC is preferably 1.5 and 6.0, and is particularly preferred between 2.0 and 3.5. Furthermore, a good cold forging without fracture, micro-puffs and / or tension bleaching was observed in a completely unexpected way, so that the novel sheet can be shaped and bent without the action of heat. In addition, the measurements showed that the novel sheet has low combustibility and low fillability, so that it is suitable, for example, for interior and display applications.

The novel larnina, moreover, can easily be recycled without contamination of the environment and without loss in mechanical properties, which means that it is suitable for use as a bulletin board of short duration or other public items. The novel transparent amorphous sheet can be produced, for example, by extrusion in an extrusion Line. An extrusion line of this type is shown in the form of a diagram in Figure L. It essentially comprises: an extruder as a plasticizing unit, a sheet die as a forming tool - a calender / polishing stack as a calibration die, - a cooling bed and / or a roller conveyor for subsequent cooling, - a separation roller, - a separation saw, - an edge trimming device and, if it is appropriate, - a stacking unit. The process for the production of the novel sheet is described in detail below using the example of polyethylene terephthalate. The process comprises drying the polyetheylene terephthalate, if appropriate, then melting the dry polymer in the oxtrusor, extruding the molten material through a die, calibrating, smoothing and cooling to the polishing roller sheet., and then cut the sheet to its size. The ethylene terephthalate? preferably dried before s? Extrusion at 160-180 ° C for 4 to 6 hours. The polyethylene terephthalate is then melted in the extruder. The melting temperature of PET is preferably in the range of 250 to 320 ° C, it being then possible to adjust the melting temperature essentially both by the temperature of the extruder and by the residence time of the molten material in the extruder. Then, the molten material leaves the extruder through a die. This die is preferably a roll die. The PET melted by the extruder and formed by means of a die of sheet is calibrated, that is, it is cooled and polished intensively by means of calender rollers. The calender rolls can be arranged, for example, in a form I-, F-, L ~ or S- (see Figure 2). The PET material can then be cooled on a roll conveyor, cut to size in width, cut to the appropriate lengths and finally stacked. The thickness of the PET film is determined essentially by the separation unit, arranged at the end of the cooling zone, the LO rolls. cooling (smoothing) coupled to the separation unit, with respect to the speed, and the speed of transportation of the extruder by a pair and the separation between the rollers on the other hand. The extruders used can be either single-helix extruders or double-helix extruders. The sheet die preferably comprises a collapsible die body, the edges and the rest bar for flow regulation by its width. For this, the restrictor bar can be doubled by tension and pressure screws. The thickness is fixed by adjusting the edges. It is important to ensure that the PET and the edge have a uniform temperature, since otherwise the molten PET flows out through different flow channels in different thicknesses. The calibration tool, that is, the smoothing calender, gives the molten PET mixture the shape and dimensions. This is achieved by freezing below the glass transition temperature by cooling and smoothing. In this state no shaping should be performed, since otherwise surface defects could be formed in this cooled state. For this reason, the calender rolls are preferably driven together. The temperature of the calender rolls should be less than the glass melting temperature to avoid adhesion of the melted PET. The molten PET leaves the slot die at a temperature of 240 to 300 ° C. The first smoothing / rolling roller is at an temperature between 50 ° C and HU ° C, depending on the exit velocity and thicknesses of the sheet. The second roller, a cooler pore, cools the second surface or another. To obtain an amorphous sheet with a thickness of 1 to 20 in., It is essential that the temperature of the first plating / cooling roll is 50 ° C to 80 ° C. Although the calibration unit freezes the PET surfaces as evenly as possible, and cools the profile to the degree that it is rigid, the back-flow device decreases the temperature of the PET sheet vertically until the room temperature. It may have-place subsequent cooling on a roller board. The speed of the separation must coincide precisely with the speed of the calender roller to avoid defects and variations in thickness. As additional equipment, the extrusion line for the production of sheets can also include a separating saw for cutting in length, a side trimmer, a stacking unit and a rolling station. The edge or side trimmer is advantageous, since under certain circumstances the thickness in the region of the margin may not be uniform. The thicknesses and the optical properties of the sheet are measured in the monitoring station. The surprising multiplicity of excellent properties makes the novel transparent amorphous sheet highly suitable for a multitude of different uses, by L2 example for interior room panels, for exhibitions and display items, such as displays, for signs, par-a < istalepa protective of machines and vehicles, in the field of lighting, in shop accessories and construction of shelves, as advertising items, as stand-sets of menus and co or basket to a basketball. The invention will now be described in more detail with reference to working examples without this being a limitation. The individual properties were measured in accordance with the following patterns or by the following procedures. Measurement methods Surface luster: Surface luster was determined in accordance with DIN 67530 at an angle of measurement of 20 °. Light Transmission: The transmission of light is understood as the relation between the total amount of light transmitted and the amount of light involved. Light transmission was determined using a "Hazegard plus" instrument in accordance with ASTM 1003. Opacity and Clarity: Opacity is the percentage of transmitted light that deviates from the incident light beam by an average greater than 2.5 °. The clarity was determined at an angle of less than 2.5 °.

I. Opacity and clarity were measured using an "Hazegard plus" facility in accordance with ASTM 1003. Superficial defects: Surface defects were determined visually. Impact resistance Charpy, an: This parameter was determined in accordance with ISO 179/1 D. Izod impact strength Izod, a? < : Izod notched impact strength was determined in accordance with ISO 180 / 1A. Density: The density was determined in accordance with DIN 53479. VN (DCA) and VI (OCA): The normal viscosity VN (DCA) was measured in d-chloroacetic acid according to DEN 53728. The intrinsic viscosity (VI) was calculated as if from normal viscosity (VN). VI (DCA) = 6.67 X 10-4 VN (DCA) + 0.118 Thermal properties: Thermal properties were measured, such as melting point of Tf crystal, crystallization temperature scale Tc, temperature of subsequent or cold crystallization, TCN and glass transition temperature T, by means of differential scanning calorimetry (DSC) at a heating rate of 10 ° C per minute.

Molecular weight- and polydispersity: Molecular weights Mw and Mn and the resulting polydispersivity Mw / M were measured by means of gel permeation chromatography (GPC). The following examples and examples are each referring to transparent single-layer sheets of different thicknesses produced in the extrusion line described.

EXAMPLE 1 The polyethylene terephthalate from which the transparent sheet was produced had a normal viscosity VN (DCA) of 1010, which corresponds to an intrinsic viscosity VI (DCA) of 0.79 dl / g. The moisture content is < 0.2% and the density (DIN 53479) is 1.41 g / crn3- The crystallinity ee of 59%, and the crystal melting point, according to the DSC measurements, is 258 ° C. The crystallization temperature scale T < "is between 83 ° C and 258 ° C, the subsequent crystallization temperature (also known as cold crystallization temperature) Te" is 144 ° C. The poly-dispersion Mw / Mn polymers of polyethylene terephthalate polymer is 2.14. The glass transition temperature is 03 ° C. Prior to extrusion, the polyethylene terephthalate was crystallized with a crystallinity of 59% in a dryer at 170 ° C for 5 hours, and then extruded in a single-screw extruder at an extrusion temperature of 206 ° C. through a roll die on a smoothing calender whose rollers were arranged in an S-shape, and polished to form a 2-millimeter thick sheet. The first calender roll had a temperature of 73 ° C and the subsequent rolls each have a temperature of 67 ° C. The speed of the separation and of the calender rollers is 6.5 in / rninuto. After the subsequent cooling, the transparent PET sheet of 2 m thickness was cut at the edges using separating saws, cut to length and stacked. The transparent PET sheet produced had the following properties profile: - Thickness: 2 rnrn - Surface luster 1Q side: 200 (measurement angle of 20 °) 22 side: 198 - Light transmission: 91% - Clarity: 100% - Opacity: 1.5% - Surface defects by rn2: none (eyes of fish, appearance of orange peel, bubbles, etc) - Impact resistance Charpy, an: no fracture - Impact resistance with Izod notch, a? < : 4 . 2 kJD / rn2 - Cold workability: good, no defects - Crystallinity: 0% - Density: 1. 33 g / crn3 EXAMPLE 2 A ranspar-like form was produced analogous to Example 1 using a poly thienyl terephthalate having the following properties: VN (DCA): 1100 VI (DCA): 0.05 dl / g Density ^ * 1.38 g / cm3 Crystallinity: 44% Melting point of glass Tf: 245 ° C Crystallization temperature scale Tc: 820C to 245 ° C posterior crystallization- or cold TCN: 152 ° C Polydispersity Mw / M ": 2.02 Glass transition temperature: 82 ° C The extrusion temperature is 280 ° C. The first calender roll had a temperature of 66 ° C and the subsequent rolls had a temperature of 60 ° C. The speed of separation and the speed of the calender rollers is 2.9 rn / minute. The transparent PET film produced had the following properties profile: - Thickness: 6 rnrn Surface luster 1Q side: 172 (measurement angle of 20")? Side: lr-0 - Light transmission * 88.1% - Company dad: 99.6% - Opacity: 2.6% - Surface defects by rn2: none (fish eyes, appearance of orange peel, bubbles, etc) - Charpy impact resistance, an: no fracture - Impact resistance with Izod notch , ak "4.0 l'JJJi / rn2 - Cold workability: good, no defects - Cr-i stalinity: 0% - Density; 1.33 g / crn3 EXAMPLE 3 A transparent sheet was produced analogously to Example 2. The extrusion temperature is 275 ° C. The first calender roll had a temperature of 57 ° C and the subsequent rolls had a temperature of 50 ° C. The speed of separation and the speed of the calender roller are 1.7 / rnin. The transparent PET sheet produced had the following properties profile: - Thickness: 10 rnm - Surface luster 1Q side: 163 (measurement angle of 20 °) 2Q side: 161 IB - Transmission of light: 06.5% - Clarity :: 99.2% - Opacity: 4.95% Surface defects by rn2: none (fish eyes, appearance of orange peel, bubbles, etc) - Impact resistance Charpy, an : no h and fracture - Impact resistance with notch Izod,: 5, .1 1-3 / rn2 - Cold fornability: good, no defects - Cpstaiir dad: 0.1% - Density: 1.33 g / cm3 EXAMPLE 4 A transparent sheet was produced in a manner analogous to Example 3 using a polyethylene ter phthalate with the following properties: VN (DCA): 1200 VI (DCA): 0.91 dl / g Density: 1.37 g / cm3 Cpstatinity: 36% Dot glass melting temperature Tf: 242 ° C Crystallization temperature scale Tc: 82 ° C to 242 ° C Post-coolant temperature (cold) TCN: 157 ° C Polydispersity Mw / Mn: 2.2 breakthrough t ransition of glass B2 ° C The extrusion temperature is 274 ° C. The first calender roll has a temperature of 50 ° C and the subsequent rollers give you a temperature of 45 ° C. The speed of the separation and the speed of the calender roll is 1.2 rn / rninuto. Transparent PET film produced theme the following properties profile: - Thickness: 15 mm - Surface luster 1Q side: 144 (measurement angle of 20 °) 2Q side: 138 - Light transmission: 86.4% - Clarity: 97.4% - Opacity: 10.5% - Surface defects [tor? N2: none (fish eyes, appearance of orange peel, bubbles, etc) - Impact resistance Charpy, an: no fracture - Impact resistance with notch Uzod, ak r 5. 1 k J / rn2 - Cold fornability: good, no defects - Cstability: 0.1% - Density: 1.33 g / crn3 EXAMPLE 5 A film was produced in an analogous manner to Example 2. 70% of fereft alato de pol let was mixed. i Log of example 2 with 30% recycleable made from this polyether terettalate. The transparent PET sheet produced had the following properties profile: - Thickness: 6 mrn - Surface luster 19 side: 168 (measurement angle of 20 °) 2Q side: 166 - Light transmission: 88.0% - Clarity: 99. ?% - Opacity: 3.2% - Surface defects by rn2: none (fish eyes, appearance of orange peel, bubbles, etc) - Impact resistance Charpy, an: no fracture - Impact resistance with Izod, k : 4.7 kJ / rn2 - Fopnatul idad in cold: good, without defects - Cristalmidad: 0% - Density: 1.33 g / crn3 COMPARATIVE EXAMPLE 1 A transparent sheet was produced analogously to Example 1. The polyethylene terephthalate used te at a normal viscosity VN (DCA) of dO, which corresponds to an intrinsic viscosity Vi (DCA) of 0.62 dl / g. The other properties are identical to the polyethylene terephthalate coatings of Example 1 within the limits of measurement accuracy. The parameters of the process and the temperature were chosen as in example 1. As a consequence of the low viscosity, the production of sheets was not possible. The stability of the molten material is inadequate, so that the molten material is crushed before cooling on the rollers of the calender.

COMPARATIVE EXAMPLE 2 A clear sheet was produced analogously to Example 2, the polyethylene terephthalate of Example 2 being also used. The first roll of the calender had a temperature of 83 ° C, and the subsequent rolls each had a temperature of 77 ° C. The laminate produced is extremely opaque. The transmission of light, clarity and luster were significantly reduced. The sheet shows defects and surface structures. The optical properties are unacceptable for a transparent application. The laminate produced has the following properties profile: - Thickness: 6 inrn - Surface luster 1 Q side: 95 (measurement angle of 20 °) 2Q side:; 93 - Light transmission: 74% - Clarity: 90% - Opacity: 52% - Surface defects by rn2: bubbles, appearance of (fish eyes, appearance of orange peel, orange peel, bubbles, etc) - Resistance to Charpy impact, an: no fracture - Impact resistance with notch Izod, ak: 5.0 kJ /? N2 - Cold workability: good - Cnstability: approx. 8% - Density: i.34 g / crn3

Claims (19)

NOVELTY OF THE INVENTION CLAIMS

1. - A transparent amorphous sheet that has a thickness in the scale of 20 nm that contains, as its main constituent, a crystal-stable thermoplastic, where the surface luster, measured in accordance with DIN 67530 (measurement angle 20 °) ), is greater than 130, the light transmission, measured in accordance with ASTM D 1003, is higher than 84%, and the opacity of the sheet, measured in accordance with ASTM D 1003, is less than 5%.

2.- A sheet in accordance with the claim 1, characterized in that the used thermosetting coplastic is selected from polyethylene terephthalate, polybutylene terephthalate, a cycloolefin polymer and a cycloolefin copolymer.

3.- A sheet in accordance with the reivi nication 2, characterized in that the cpstalizable thermoplastic used is polyethylene terephthalate.

4.- A sheet in accordance with the claim 3, characterized in that the polyethylene terephthalate contains recirculated polyether terephthalate.

5. A sheet according to claim 3 or 4, characterized in that the measurement of the impact resistance Charpy, an, measured in accordance with ISO 179 / 1D, is not accompanied by fractions.

6.- An ina in accordance with any of claims 3 to 5, characterized in that the resistance to the Izod k-bolt gap, measured in accordance with ISO 180 / lA, is on the scale from 2.0 to 8.30. kD / in2.

7. A sheet according to any of claims 3 to 6, characterized in that the clarity, measured according to ASTM D 1003, at an angle of less than 2.5 °, is greater than 96%.

8. A sheet according to any of claims 3 to 7, characterized in that the polyethylene terephthalate has a glass melting point, measured by DSC at a heating rate of 10o / rn? N, in the scale of 220 ° at 280 ° C.

9. A sheet according to any of claims 3 to 8, characterized in that the polyethylene terephthalate has a crystallization temperature, measured by DSC at a heating rate of 10 ° C / minute, in the scale of 75. ° at 280 ° C.

10. A sheet according to any of claims 3 to 9, characterized in that the cooled polyethylene terephthalate has a crispness in the range of 5 to 65%.

11. A sheet according to any of claims 3 to 10, characterized in that the polyethylene terephthalate used has a normal viscosity VN (DCA) J > 5 measured in dichloroacetic acid of contopnity with DTN 53728, in the scale from 800 to 1800.

12.- A sheet in accordance with the rei iication 11, characterized in that the polyethylene terephthalate used has a normal viscosity VN (DCA), measured in dichloroacetic acid according to DIN 53720, in the scale of 800 to

1400.

13. A sheet according to any of claims 1 to 12, characterized in that the sheet has a degree of cpst at the value of less than 5%.

14.- A procedure par-a The production of a transparent amorphous larnina according to any of the claims 13 comprising the following steps: melt the cpsfalble terinoplastico in the extruder, the extrusion of the molten material through a die, calibration, smoothing and cooling of the extruded product with at least two rollers in a polishing stack, and trimming the sheet to size, wherein the first roll of the polishing stack has a temperature in the range of 50 to 80 ° C.

15. The process according to claim 14, characterized in that the crystallizable terrnoplastic is dried before melting.

16. The process according to claim 14 or 15, characterized in that the crystallizable terrnoplastic is polyethylene terephthalate.

17. The process according to claim 16, characterized in that the ethylene terephthalate is dried at 160 to 180 ° C for 4 to 6 hours before s? extrusion.

18. The process according to claim 16 or 17, characterized in that the temperature of the melted PET product is in the range of 250 to 320 ° C.

19. The use of a transpar- ent amorphous sheet according to any of claims 1 to 13, for internal applications and in exhibitions.