KR19990028207A - Amorphous transparent uv stabilization plate made of crystallizable thermoplastic - Google Patents

Abstract

In the present invention, a transparent amorphous plate having a thickness of 1 to 2 mm containing a crystallizable thermoplastic material as a main component is characterized by containing at least one UV stabilizer as a photoprotective agent. The invention also relates to a process for its preparation and its use.

Description

Amorphous transparent uv stabilization plate made of crystallizable thermoplastic

The present invention relates to an amorphous transparent UV stabilized plate of crystallizable thermoplastic having a thickness of 1 to 20 mm. The plate is characterized by containing at least one UV light stabilizer and having very good optical and mechanical properties. The invention also relates to a method for producing and the use of this plate.

Amorphous transparent plates with a thickness of 1 to 20 mm are well known. These two-dimensional structures include amorphous plastics that cannot be crystallized. Typical examples of such thermoplastics that can be converted into plates are polyvinyl chloride (PVC), polycarbonate (PC) and polymethyl methacrylic acid (PMMA). These semifinished products are produced on so-called extrusion lines (Polymer Werkstoffe, Volume II, Techonlogie 1, p. 136, Georg Thieme Verlag, Stuttgart, 1984). The raw material in powder or granular form is melted in an extruder. After extrusion, the amorphous thermoplastics are molded with an abrasive stack or other molding tool, using the property that the viscosity increases as the temperature decreases. After molding, the amorphous thermoplastics have a suitable stability, ie high viscosity, so that they can be self-supporting on a calibration die. However, it is still too fluid to be molded by a die. Since the melt viscosity and inherent stiffness of amorphous thermoplastics in the calibration die are high, the semifinished product in the calibration die does not collapse before cooling. Substances that are susceptible to decomposition, such as PVC, require special auxiliary treatments during extrusion, such as stabilizers against degradation and lubricant treatment for uncontrollable heating due to excessive internal friction. Lubrication should be applied externally to prevent sticking to walls and rolls.

Expensive additives are sometimes required to produce transparent plates from amorphous thermoplastics, which can migrate and cause problems due to the evaporation of semi-finished products and the formation of surface coatings. PVC plates can be difficult to recycle using special neutralization or electrolysis processes. PC and PMMA boards are equally difficult to reproduce but result in loss of mechanical properties or degradation.

In addition to these disadvantages, PMMA plates have a very low impact strength and are easily broken by cracks or mechanical loads. Moreover, PMMA boards are easy to burn and cannot be used for interior materials or display materials.

In addition, at low temperatures, the PMMA plate ruptures to form dangerous debris, and the PC plate cannot be molded because of its thin cracks and stress whitening.

DE-A-3 531 878 describes a plastic film made of thermoplastic polyester, containing a UV stabilizer and having a thickness of 0.5 to 0.03 mm.

This plastic film is partially crystalline because it can be obtained by extrusion blow molding. Thus, the amorphous film having a thickness of 1 mm or more can be obtained by the method described in this specification.

JP-A-5 320 528 describes thermoplastic resin compositions containing epoxidized polyesters. According to a preferred embodiment, the composition contains PVC as the main component. The plate obtained by blending the composition is transparent and has a thickness of 1 mm.

EP-A-0 471 528 describes a method of forming a product from a polyethylene terephthalate (PET) plate. Both sides of the PET plate are heat-treated in the hot film mold at a temperature between the glass transition temperature and the melting point. When the crystallinity of the molded PET plate is in the range of 25 to 50%, the molded PET plate is taken out of the mold. The PET plate described in EP-A-0 471 528 has a thickness of 1 to 10 mm. Since the thermoformed article made of PET is partially crystalline, it is not transparent and the surface properties of the molded article are determined by the thermoforming method, the thermoforming temperature and the mold. What is light transmissive? In general, the optical properties of PET plates are poor and need to be optimized.

In addition, the PET plate does not contain a UV stabilizer, so the plate or molded article produced therefrom is not suitable as a packaging material. When used as an exterior material, these plates or shaped articles exhibit yellowing and deterioration of mechanical properties as a result of photocatalytic decomposition by sunlight in a short time.

US-A-3,496,143 describes vacuum thermoforming of PET plates having a crystallinity of 5 to 25% and a thickness of 3 mm. However, the crystallinity of the thermoformed article is 25% or more. In addition, these PET plates also have no requirement regarding optical properties. The plate is turbid and opaque since the crystallinity of the plate used is already 5-25%. In addition, these plates do not contain a light stabilizer, which is not suitable as an exterior material.

In the method known in this document, an amorphous plate having a thickness of 1 mm or more and containing a crystallizable thermoplastic as a main component cannot be produced.

It is an object of the present invention to provide an amorphous transparent plate having a thickness of 1 to 20 mm, which is excellent in mechanical and optical properties and particularly has high UV stability.

High UV stability means that the plate is hardly damaged or damaged by sunlight or other UV radiation, making it suitable for external use and / or critical interior use. In particular, even after several years of use for exteriors, the plates do not show yellowing, cracking or cracking of the surface or deterioration of mechanical properties.

Good optical properties refer to, for example, high light transmittance and surface glossiness, very low haze and high clearness.

Excellent mechanical properties refer to particularly high impact strength and high burst strength.

In addition, the new plates can be regenerated without loss of mechanical properties in particular and have low combustibility and can be used for interior and display purposes.

The object of the present invention is achieved by an amorphous transparent plate having a thickness of 1 to 20 mm which contains, as a main component, a crystallizable thermoplastic and at least one UV stabilizer.

The transparent amorphous plate of this invention contains the crystallizable thermoplastic as a main component. Suitable examples of crystallizable or partially crystalline thermoplastics are polyethylene terephthalate, polybutylene terephthalate, cycloolefin polymers and cycloolefin copolymers, with polyethylene terephthalate being preferred.

In order to achieve the object of the present invention, a crystallizable thermoplastic means:

Crystallizable homopolymers,

Crystallizable copolymers,

Crystallizable compounds,

-Crystallized recyclables and

Other modifications of the crystallizable thermoplastics.

For the purposes of the present invention, an amorphous plate means a plate which is amorphous, although the crystallinity of the thermoplastics used is preferably 5 to 65%, particularly preferably 25 to 65%. Amorphous or amorphous means that the crystallinity is usually less than 5%, preferably less than 2%, particularly preferably less than 0%. New amorphous plates are not necessarily drawn.

The transparent amorphous plate also contains at least one UV stabilizer, preferably from 0.01 to 5% by weight, based on the weight of the crystallizable thermoplastic.

Light, especially the ultraviolet portion of 280-400 nm wavelength in sunlight, decomposes thermoplastics, not only showing the appearance change due to discoloration or yellowing, but also adversely affecting the mechanical-optical properties.

Suppression of these photocatalytic decomposition processes is of great importance both industrially and economically because they limit the use of many thermoplastics.

Polyethylene terephthalates begin to absorb UV light even below 360 nm and their absorption increases significantly below 320 nm and is very pronounced below 300 nm. Maximum absorption is between 280 and 300 nm.

The presence of oxygen mainly leads to chain splitting and no crosslinking is observed. Carbon monoxide, carbon dioxide and carboxylic acid represent the photoacidification main products in amounts. In addition to the direct photolysis of ester groups, attention should be paid to the oxidation reactions that form carbon dioxide by free radical peroxide.

The photooxidation reaction of polyethylene terephthalate produces hydrogen peroxide, its degradation products and associated chain fissions by removing the α-position hydrogen of the ester group (see H. Day, DMWiles: J. Appl. Polym. Sci 16, 1972). , p203).

UV stabilizers and UV absorbers as light stabilizers are chemicals that participate in the physical and chemical processes of photoinduced decomposition. Carbon black and other pigments also partially block light. However, these materials are not suitable for the transparent plate because they cause discoloration or discoloration. For transparent amorphous plates, organic or organometallic compounds which are very light or discolored or do not exhibit any color to the thermoplastic to be stabilized are suitable.

Suitable UV stabilizers include 2-hydroxy-benzophenone, 2-hydroxybenzotriazole, organic nickel compounds, salicylic acid esters, cinnamic acid ester derivatives, resorcinol monobenzoate, oxanilides, hydroxybenzoic acid esters, steric Amines and triazines impeded by, 2-hydroxybenzotriazole and triazine are preferred.

In a particularly preferred embodiment, the novel transparent amorphous plate comprises polyethylene terephthalate which can be crystallized as a main component and 0.01 to 5.0% by weight of 2- (4,6-diphenyl-1,3,5-triazin-2-yl)- 5- (hexyl) oxyphenol (structure of FIG. 1A) or 0.01-5.0% by weight of 2,2'-methylene-bis (6- (2H-benzotriazol-2-yl) -4- (1,1, 3,3-tetramethylbutyl) phenol (structure of Fig. 1B) In a preferred embodiment, a mixture of these two UV stabilizers or a mixture of one or more of the two UV stabilizers with another UV stabilizer is capable of crystallization. Based on the weight of the polyethylene terephthalate, the concentration of the light stabilizer may be preferably used to be 0.01 to 5.0% by weight.

The surface glossiness measured according to DIN 67530 (measuring angle 20 °) is at least 120, preferably at least 140, the light transmittance measured according to ASTM D 1003 is at least 84%, preferably at least 86%, ASTM D The turbidity measured according to 1003 is less than 15%, preferably less than 11%.

The transparency of the plate measured according to ASTM D 1003 at an angle of less than 2.5 ° is at least 96%, preferably at least 97%.

In the case of polyethylene terephthalate, no cracking occurs in the measurement of the Charpy impact strength (a _n ) according to ISO 179 / 1D. In addition, the Izod notch impact strength a _k of the plate measured according to ISO 180 / 1A is 2.0 to 8.0 kJ / m 2, preferably 3.0 to 8.0 kJ / m 2, particularly preferably 4.0 to 6.0 kJ / m 2.

The crystal melting point (T _m ) measured by DSC (differential scanning calorimetry) at a heating rate of 10 ° C./min is 220 to 280 ° C., preferably 250 to 270 ° C., and the crystallization temperature (T _C ) is 75 to 280 ° C. , Preferably 75 to 260 ° C., glass transition temperature (T _g ) is 65 to 90 ° C., density measured according to DIN 53479 is 1.30 to 1.45 g / cm 3, crystallinity is 5 to 65%, preferably Polyethylene terephthalate polymers of 25 to 65% are preferred polymers as starting materials for producing novel plates.

The standard viscosity (SV) (DSC) of polyethylene terephthalate measured in dichloroacetic acid according to DIN 53728 is 800 to 1800, preferably 950 to 1250, particularly preferably 1000 to 1200.

Intrinsic viscosity (IV) (DCA) is calculated from standard viscosity (SV) (DCA) as follows:

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

The bulk density measured according to DIN 53466 is preferably 0.75 to 1.0 kg / dm 3, particularly preferably 0.80 to 0.90 kg / dm 3.

The polydispersity (M _w / M _n ) of polyethylene terephthalate as determined by gel permeation chromatography is preferably 1.5 to 6.0, particularly preferably 2.0 to 3.5.

Weather resistance tests have shown that even after 5-7 years of outdoor use, the new UV stabilized plates show no yellowing, cracking, loss of surface gloss, surface cracking, or deterioration of mechanical properties.

In addition to good UV stability, it exhibited excellent low temperature formability without rupture, microcracks and / or stress whitening, which means that the new plate can be molded or bent without thermal action.

In addition, the novel PET plate has low combustibility and flammability, which is suitable for interior materials and display materials.

In addition, the new plates can be easily recycled without causing environmental pollution or loss of mechanical properties, indicating that they can be used as short-term billboards or other advertisements.

The novel transparent amorphous UV stabilized plate is produced by extrusion in an extrusion line.

An extrusion line of this type is shown in FIG. 2. The extrusion line consists essentially of:

An extruder (1), which is a plasticizer,

A plate die (2), a forming tool,

Calibration die-in polishing stack / calender (3),

Cooling bed 4 and / or roller conveyor 5 for post-cooling,

-Discharge roll (6),

Cutting saw (7),

Corner closures (9) and, in some cases,

-Loading device (8).

The novel plate production process uses polyethylene terephthalate as the thermoplastic and is described in detail below.

The process of the present invention optionally involves drying a crystallizable thermoplastic (e.g. polyethylene terephthalate) and then melting the dry polymer, preferably with a UV stabilizer in an extruder, extruding the melt through a die and polishing stack After calibrating, smoothing and cooling the plate at a predetermined size.

In the process of the invention the temperature of the first roll of the polishing stack should be between 50 and 80 ° C. Otherwise, an amorphous transparent plate having a thickness of 1 mm or more containing crystallizable thermoplastics cannot be obtained.

According to the invention, the light stabilizer can be added in advance by the manufacturer of the thermoplastic material or constantly added into the extruder at the time of manufacture of the plate.

It is particularly preferred that the light stabilizer is added via a masterbatch technique so as to be completely dispersed in the solid carrier material. Suitable carriers are the particular resin, the thermoplastic itself, such as polyethylene terephthalate, or any other polymer compatible with the thermoplastic.

It is important that the particle size and bulk density of the masterbatch be similar to the particle size and bulk density of the thermoplastics so that they are uniformly dispersed to induce uniform UV stabilization.

The polyethylene terephthalate is preferably dried for 4-6 hours at 160-180 ° C. before being extruded.

The polyethylene terephthalate is then melted in the extruder. The temperature of the PET melt is preferably 250 to 320 ° C., and the temperature of the melt is appropriately controlled through the extruder temperature and the residence time of the melt in the extruder.

The melt is then discharged out of the extruder through a die. The die is preferably a plate die.

The PET plate melted by the extruder and molded by the plate die is calibrated, i.e., cooled by extreme cooling and then smoothed by smoothing with a calender roll. The calendar rolls can be arranged in I, F, L or S shapes (see Figure 3).

The PET material is then cooled on a roller conveyor, cut to width, cut to the appropriate length and finally loaded.

The thickness of the PET plate is essentially determined by the discharge device arranged at the end of the cooling zone, the low temperature (smoothing) roll mating with the discharge device at speed, and the conveying speed of the extruder on one side and the separation between the rolls on the other side. .

The extruder used is a single screw or twin screw extruder.

The plate die consists of a prefabricated die body and jersey rods for lip and width control of flow. For this purpose, the resistant rod is bent by tension and pressure screws. The thickness can be set by adjusting the lip. It is important that the temperature of the PET granules is constant because the PET melt flows through different flow channels to different thicknesses.

A calibration tool, ie a smoothing calendar, determines the shape and volume of the PET melt. This is done by freezing the melt below the glass transition temperature by cooling and smoothing. The molding process should not be carried out at this time, otherwise surface defects will occur in this cooling state. Therefore, the calender rolls should preferably be driven in tandem with each other. In order to prevent the PET melt from sticking, the temperature of the calender roll should be below the crystal melting point. PET melt is discharged from the plate die at a temperature of 240 to 300 ° C. The temperature of the first smoothing / cold roll will be between 50 and 80 ° C. depending on the discharge rate and plate thickness. The cooler second roll cools the second or other surface.

The post-cooling device lowers the temperature of the PET plate to room temperature while the calibration device freezes the PET surface as flat as possible and cools the profile until the shape is fixed. After cooling takes place on the roller board. To avoid defects and changes in thickness, the discharge rate must match the speed of the calender roll exactly.

As an additional device, the extrusion line for producing the PET plate further includes a cutting saw, a side finisher, a loading device and an inspection table for cutting the plate to a certain length. It is preferable to use the side or edge finisher because the thickness of the edge portion may not be uniform. Measure the plate thickness and optical properties on the inspection table.

The novel transparent amorphous plates of the present invention, due to a number of excellent properties, are suitable for lighting panels and storefronts and shelf structures, as well as in interior panels, display materials and displays such as displays, signs, machines and vehicles, in protective glass screens, advertisements, menu boards and baseballs. It can be used as a back plate, an indoor divider, an aquarium, an information board, pamphlets, and a newsstand.

Because of the good UV stability, the new transparent amorphous plates are suitable for exterior materials such as greenhouses, roofs, glass curtains, safety glass, cladding, coverings, building materials, lighting advertisements, balcony exteriors, roof exits and caravan windows.

The present invention is described in more detail below without being limited thereto with reference to the examples.

Each characteristic is measured according to the following criteria or the following method.

How to measure

Surface glossiness:

Surface glossiness is measured at a measuring angle of 20 ° according to DIN 67530.

Light transmittance:

The light transmittance is obtained by averaging the ratio of the total amount of transmitted light and the amount of incident light.

Light transmittance is measured using a "Hazegard plus" instrument according to ASTM D 1003.

Turbidity and Transparency:

Turbidity is the percentage of transmitted light that is deflected by an average of 2.5 ° or more from incident light. Transparency is measured at an angle of less than 2.5 °.

Turbidity and transparency are measured using a "HazeGuard Plus" instrument according to ASTM D 1003.

Surface defects:

Surface defects are determined visually.

Charpy Impact Strength (a _n ):

This parameter is measured according to ISO 179 / 1D.

Izod notch impact strength (a _k ):

Izod notch impact strength (a _k ) is measured according to ISO 180 / 1A.

density:

Density is measured according to DIN 53479.

SV (DCA) and IV (DCA):

Standard viscosity (SV) (DCA) is determined according to DIN 53726 in dichloroacetic acid.

Intrinsic viscosity (IV) (DCA) is calculated from standard viscosity (SV) (DCA) as follows:

IV (DCA) = 6.67 × 10 ^-4 SV (DCA) + 0.118

Thermal properties:

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

Molecular Weight and Polydispersity:

Molecular weight (M _w and M _n ) and polydispersity (M _w / M _n ) are determined by gel permeation chromatography (GPC).

Weather resistance (both sides), UV stability:

UV stability is checked below according to ISO 4892 test specification:

Test instrument: Atlas Ci 65 weatherability tester

(Weather-O-meter)

Test conditions: ISO 4892 ie artificial outdoor exposure

Exposure time: 1000 hours (per side)

Exposure: 0.5 W / ㎡, 340 nm

Temperature: 63 ℃

Relative atmospheric humidity: 50%

Xenon lamp: Internal and external filters made of boron silicate

Exposure cycle: After 102 minutes of ultraviolet irradiation, 18 minutes of ultraviolet irradiation, 102 minutes of further ultraviolet irradiation together with water spray of the sample.

discoloration:

After artificial outdoor exposure, the discoloration of the sample is measured by spectrometer in accordance with DIN 5033.

Use the following symbol:

ΔL: difference in brightness

+ ΔL: The sample is brighter than the reference.

-ΔL: The sample is darker than the reference.

ΔA: red-green zone difference

+ ΔA: The sample is more red than the reference.

-ΔA: The sample is greener than the reference.

ΔB: blue-yellow area difference

+ ΔB: The sample is more yellow than the reference.

-ΔB: The sample is bluer than the reference.

ΔE: total discoloration

ΔE =

The larger the deviation of the measurement from the reference, the larger the color difference.

If the value is 0.3 or less, it can be ignored and shows little color change.

Yellow value:

The yellowing value (G) indicates the degree of discoloration to "yellow" and is measured according to DIN 6167. It is not noticeable that the yellowing value is 5 or less.

The examples and comparative examples below relate to single layer transparent plates of various thicknesses each produced from an extrusion line.

All plates are weather tested on both sides using an Atlas Ci 65 weather tester for 1000 hours per side in accordance with ISO 4892 to check mechanical properties, discoloration, surface defects, turbidity and gloss.

Example 1

Polyethylene terephthalate and UV stabilizer 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) -oxyphenol ( ^R Tinuvin 1577 manufactured by Ciba-Geigy as a main component) ) A transparent amorphous plate 3 mm thick containing 1.0 wt% is prepared.

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

To achieve a uniform distribution, the raw material producer directly adds 1.0% by weight of UV stabilizer to polyethylene terephthalate. The polyethylene terephthalate from which the transparent plate is made has a standard viscosity (SV) (DCA) 1010 corresponding to 0.79 dl / g inherent viscosity (IV) (DCA). The moisture content is less than 0.2% and the density (DIN 53479) is 1.41 g / cm 3. The crystallinity is 59% and the crystal melting point is 258 ° C by DSC measurement. The crystallization temperature range (T _c ) is 83 ° C. to 258 ° C. and the post crystallization temperature (also referred to as “low temperature-crystallization temperature”) (T _CN ) is 144 ° C. The polydispersity (M _w / M _n ) of polyethylene terephthalate is 2.14 and the glass transition temperature is 83 ° C.

Prior to extrusion, polyethylene terephthalate having a crystallinity of 59% was dried in a dryer for 5 hours at 170 ° C. and extruded and smoothed in a single screw extruder at an extrusion temperature of 286 ° C. through a plate die on a smoothing calender with rolls arranged in an S-shape. A plate having a thickness of 3 mm is obtained. The temperature of the first calender roll is 73 ° C and the temperature of the next roll is 67 ° C. Discharge rate and calender roll speed is 6.5 m / min.

After the post-cooling, the edges of the transparent PET plate having a thickness of 3 mm were trimmed using a cutting saw, cut into a predetermined length, and loaded.

The prepared transparent amorphous PET plate has the following characteristics:

Thickness: 3mm

Surface glossiness, first side: 198

(Measurement angle 20 °) 2nd side: 196

-Light transmittance: 91%

Transparency: 100%

Turbidity: 1.5%

-Surface defects per square meter (fish eye, orange peel, bubble, etc.): none

-Charpy impact strength (a _n ): no burst

-Izod notch impact strength (a _k ): 4.2kJ / ㎡

-Low temperature moldability: Good, no defect

Crystallinity: 0%

Density: 1.33 g / cm 3

After weathering tests for 1000 hours on each side using the Atlas Ci 65 weathering tester, the PET plates exhibit the following characteristics:

Thickness: 3mm

Surface glossiness, first side: 196

(Measurement angle 20 °) 2nd side: 195

-Light transmittance: 91.1%

Transparency: 100%

Turbidity: 1.6%

Total Discoloration ΔE: 0.22

-Darkness Discoloration ΔL: -0.18

Red-green discoloration ΔA: -0.08

-Cyan discoloration ΔB: 0.10

-Surface Defects (Crack, Crack): None

Yellow value (G): 4

-Charpy impact strength (a _n ): no burst

-Izod notch impact strength (a _k ): 4.1kJ / ㎡

-Low temperature moldability: Good

Example 2

Transparent amorphous plate weighed in the form of a masterbatch with UV stabilizer 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) -oxyphenol ( ^R Tinuvin 1577) To prepare in the same manner as in Example 1. The masterbatch consists of 5% by weight of ^R Tinuvin 1577 as active ingredient and 95% by weight of polyetherelin terephthalate of Example 1.

Before extrusion, 80% by weight of polyethylene terephthalate of Example 1 was dried at 170 ° C. for 5 hours with 20% by weight of masterbatch. The extrusion process and the manufacture of the plate were the same as in Example 1.

The resulting amorphous transparent PET plate has the following characteristics:

Thickness: 3mm

Surface glossiness, first side: 194

(Measurement angle 20 °) 2nd side: 193

-Light transmittance: 91.3%

Transparency: 100%

Turbidity: 1.4%

-Surface defects per square meter (fish eye, orange peel, bubble, etc.): none

-Charpy impact strength (a _n ): no burst

-Izod notch impact strength (a _k ): 4.0kJ / ㎡

-Low temperature moldability: Good

Crystallinity: 0%

Density: 1.33 g / cm 3

After weathering tests for 1000 hours on each side using the Atlas Ci 65 weathering tester, the PET plates exhibit the following characteristics:

Thickness: 3mm

Surface glossiness, first side: 192

(Measurement angle 20 °) Second Surface: 190

-Light transmittance: 91.1%

Transparency: 100%

Turbidity: 1.5%

Total Discoloration ΔE: 0.24

-Darkness Discoloration ΔL: -0.19

Red-green discoloration ΔA: -0.08

-Cyan discoloration ΔB: 0.12

-Surface Defects (Crack, Crack): None

Yellow value (G): 5

-Charpy impact strength (a _n ): no burst

-Izod notch impact strength (a _k ): 4.0kJ / ㎡

-Low temperature moldability: Good

Example 3

A transparent amorphous plate was prepared in the same manner as in Example 1 using polyethylene terephthalate having the following characteristics:

SV (DCA): 1100

IV (DCA): 0.85 dl / g

Density: 1.38 g / cm 3

Crystallinity: 44%

Crystal melting point (T _m ): 245 ° C

-Crystallization temperature range (T _c ): 82-245 ° C.

Post or low temperature crystallization temperature (T _CN ): 152 ℃

-Polydispersity (M _w / M _n ): 2.02

Glass transition temperature: 82 ℃

UV stabilizer 2,2'-methylene-bis- (6- (2H-benzotriazol-2-yl) -4- (1,1,3, based on the weight of the polymer and the polyethylene terephthalate described as the main component A transparent amorphous plate 6 mm thick containing 0.6 wt% of 3-tetramethylbutyl) phenol ( ^R Tinuvin 360 manufactured by Ciba-Geigy) was prepared.

Tinuvin 360 has a melting point of 195 ° C and is thermally stable up to about 250 ° C.

As in Example 1, the raw material producer incorporates 0.6% by weight of UV stabilizer directly into the polyethylene terephthalate.

Extrusion temperature is 286 degreeC. The temperature of the first calender roll is 66 ° C and the temperature of the next roll is 60 ° C. Discharge rate and calender roll speed is 2.9 m / min.

The transparent amorphous PET plate thus produced has the following characteristics:

Thickness: 6mm

Surface glossiness, first side: 175

(Measurement angle 20 °) 2nd side: 173

-Light transmittance: 88.6%

Transparency: 99.6%

Turbidity: 2.5%

-Surface defects per square meter (fish eye, orange peel, bubble, etc.): none

-Charpy impact strength (a _n ): no burst

-Izod notch impact strength (a _k ): 4.8kJ / ㎡

-Low temperature moldability: Good, no defect

Crystallinity: 0%

Density: 1.33 g / cm 3

After weathering tests for 1000 hours on each side using the Atlas Ci 65 weathering tester, the PET plates exhibit the following characteristics:

Thickness: 6mm

Surface glossiness, first side: 171

(Measurement angle 20 °) 2nd side: 169

-Light transmittance: 88.3%

Transparency: 99.5%

Turbidity: 2.7%

Total Discoloration ΔE: 0.56

-Darkness Discoloration ΔL: -0.21

Red-green discoloration ΔA: -0.11

-Cyan discoloration ΔB: +0.51

-Surface Defects (Crack, Crack): None

Yellow value (G): 6

-Charpy impact strength (a _n ): no burst

-Izod notch impact strength (a _k ): 4.6kJ / ㎡

-Low temperature moldability: Good, no defect

Example 4

In the same manner as in Example 3, an amorphous transparent plate was prepared. Extrusion temperature is 275 degreeC. The temperature of the first calender roll is 57 ° C and the temperature of the next roll is 50 ° C. Discharge rate and calender roll speed is 1.7m / min. As described in Example 3, the plate was light stabilized.

The PET plate thus produced has the following characteristics:

Thickness: 10㎜

Surface glossiness, first side: 163

(Measurement angle 20 °) Second Surface: 161

-Light transmittance: 86.5%

Transparency: 99.2%

Turbidity: 4.95%

-Surface defects per square meter (fish eye, orange peel, bubble, etc.): none

-Charpy impact strength (a _n ): no burst

-Izod notch impact strength (a _k ): 5.1kJ / ㎡

-Low temperature moldability: Good, no defect

Crystallinity: 0.1%

Density: 1.33 g / cm 3

After weathering tests for 1000 hours on each side using the Atlas Ci 65 weathering tester, the PET plates exhibit the following characteristics:

Thickness: 10㎜

Surface glossiness, first side: 160

(Measurement angle 20 °) 2nd side: 159

-Light transmittance: 86.2%

Transparency: 99.1%

Turbidity: 5.0%

Total Discoloration ΔE: 0.47

-Darkness Discoloration ΔL: -0.18

Red-green discoloration ΔA: -0.09

-Cyan discoloration ΔB: +0.42

-Surface Defects (Crack, Crack): None

Yellow value (G): 5

-Charpy impact strength (a _n ): no burst

-Izod notch impact strength (a _k ): 4.5kJ / ㎡

-Low temperature moldability: Good, no defect

Comparative Example 1

In the same manner as in Example 1, an amorphous transparent plate was prepared. However, unlike Example 1, the plate does not contain UV stabilizers. The polyethylene terephthalate, extrusion parameters, process parameters and temperature used are selected as in Example 1.

The transparent PET plate made in this way has the following characteristics:

Thickness: 3mm

Surface glossiness, first side: 200

(Measurement angle 20 °) 2nd side: 198

-Light transmittance: 91.4%

Transparency: 100%

Turbidity: 1.3%

-Surface defects per square meter (fish eye, orange peel, bubble, etc.): none

-Charpy impact strength (a _n ): no burst

-Izod notch impact strength (a _k ): 4.3kJ / ㎡

-Low temperature moldability: Good, no defect

Crystallinity: 0%

Density: 1.33 g / cm 3

After weathering tests for 1000 hours on each side using the Atlas Ci 65 weathering tester, the PET plates exhibit the following characteristics:

Thickness: 3mm

Surface glossiness, first side: 98

(Measurement angle 20 °) 2nd side: 95

-Light transmittance: 79.5%

Transparency: 81.2%

Turbidity: 7.8%

Total Discoloration ΔE: 3.41

-Darkness Discoloration ΔL: -0.29

Red-green discoloration ΔA: -0.87

-Cyan discoloration ΔB: +3.29

Surface defects (crack, crack): Crack

Yellow value (G): 17

-Charpy impact strength (a _n ): complete rupture at 34.8kJ / ㎡

-Izod notch impact strength (a _k ): 1.3kJ / ㎡

-Low temperature formability: crack

With the naked eye, the "yellowing" of the plates can be clearly observed. The surface is matte and cracks.

Comparative Example 2

In the same manner as in Example 3, a transparent amorphous plate was prepared. However, unlike Example 3, the amorphous plate does not contain UV stabilizers. The polyethylene terephthalate, extrusion parameters, process parameters and temperature used are selected as in Example 1.

The transparent PET plate made in this way has the following characteristics:

Thickness: 6mm

-Surface glossiness, first side: 180

(Measurement angle 20 °) Second Surface: 178

-Light transmittance: 88.9%

Transparency: 99.6%

Turbidity: 2.3%

-Surface defects per square meter (fish eye, orange peel, bubble, etc.): none

-Charpy impact strength (a _n ): no burst

-Izod notch impact strength (a _k ): 4.8kJ / ㎡

-Low temperature moldability: Good, no defect

Crystallinity: 0%

Density: 1.33 g / cm 3

After weathering tests for 1000 hours on each side using the Atlas Ci 65 weathering tester, the PET plates exhibit the following characteristics:

Thickness: 6mm

Surface glossiness, first side: 91

(Measurement angle 20 °) 2nd side: 87

-Light transmittance: 72.5%

Transparency: 78.3%

Turbidity: 12.9%

Total Discoloration ΔE: 3.61

-Darkness Discoloration ΔL: -0.26

Red-green discoloration ΔA: -0.91

-Cyan discoloration ΔB: +3.48

-Surface Defects (Cracks, Cracks): Cracks, Cracks

Yellow value (G): 18

-Charpy impact strength (a _n ): complete rupture at 46.2kJ / ㎡

-Izod notch impact strength (a _k ): 1.6kJ / ㎡

-Low temperature formability: crack

With the naked eye, the "yellowing" of the plates can be clearly observed. The surface is strongly shocked, loses luster, breaks and shows cracks.

Comparative Example 3

A UV stabilized transparent translucent plate was prepared using the polyethylene terephthalate, UV stabilizer and masterbatch of Example 3 in the same manner as in Example 3. The temperature of the 1st calender roll is 83 degreeC, and the temperature of the next roll is 77 degreeC, respectively.

The plates made in this way are very muddy and opaque to the naked eye. Light transmittance, transparency and glossiness are inferior. Defects appear on the surface and structure. Optical properties are also unacceptable for transparent materials.

The resulting transparent PET plate has the following characteristics:

Thickness: 6mm

Surface glossiness, first side: 86

(Measurement angle 20 °) 2nd side: 88

-Light transmittance: 8%

Transparency: Not measurable

Turbidity: Not measurable

-Surface defects per square meter (fish eye, orange peel, bubble, etc.)

: Bubble, orange peeling

-Charpy impact strength (a _n ): no burst

-Izod notch impact strength (a _k ): 5.0kJ / ㎡

-Low temperature moldability: Good

Crystallinity: about 8%

Density: 1.34 g / cm 3

Since the optical properties deviate from the acceptable level, the weathering test was not carried out for 6 mm thick plates.

Claims (24)

A transparent amorphous plate having a thickness of 1 to 20 mm, containing a crystallizable thermoplastic and at least one UV stabilizer as a main component. The plate according to claim 1, wherein the concentration of the UV stabilizer is from 0.01 to 5% by weight, based on the weight of the crystallizable thermoplastic. The plate of claim 1 or 2, wherein the UV stabilizer is selected from 2-hydroxybenzotriazole and triazine. The method according to claim 3, wherein the UV stabilizers used are 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) oxyphenol and 2,2'-methylene- And at least one compound selected from bis (6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol. The plate according to any one of claims 1 to 4, wherein the surface glossiness measured in accordance with DIN 67530 (measuring angle 20 °) is 120 or more. The plate according to any one of claims 1 to 5, wherein the light transmittance measured in accordance with ASTM D 1003 is 84% or more. The plate according to claim 1, wherein the turbidity measured according to ASTM D 1003 is less than 15%. The plate according to any one of claims 1 to 7, wherein the crystallinity of the crystallizable thermoplastic is 5 to 65%. The plate according to claim 1, wherein the crystallizable thermoplastic used is selected from polyethylene terephthalate, polybutylene terephthalate, cycloolefin polymer and cycloolefin copolymer. 10. The plate of claim 9 wherein the crystallizable thermoplastic used is polyethylene terephthalate. The plate of claim 10, wherein the polyethylene terephthalate used contains recycled polyethylene terephthalate. The plate according to claim 10 or 11, wherein no crack is involved in the measurement of the Charpy impact strength a _n measured according to ISO 179 / 1D. The plate according to any one of claims 10 to 12, wherein the Izod notch impact strength a _k measured according to ISO 180 / 1A is 2.0 to 8.0 kJ / m 2. The plate according to claim 10, wherein the plate has a transparency of at least 96% measured according to ASTM D 1003 at an angle of less than 2.5 °. The plate according to any one of claims 10 to 14, wherein the crystal melting point of polyethylene terephthalate measured by DSC at a heating rate of 10 ° C / min is 220 to 280 ° C. The plate according to any one of claims 10 to 15, wherein the crystallization temperature of polyethylene terephthalate measured by DSC at a heating rate of 10 ° C / min is 75 to 280 ° C. The plate according to claim 10, wherein the standard viscosity (SV) (DCA) of the polyethylene terephthalate used, measured in dichloroacetic acid according to DIN 53728, is from 800 to 1800. The crystallizable thermoplastic is melted in an extruder with a UV stabilizer, the melt is extruded through a die, and in a polishing stack having two or more rolls, where the temperature of the first roll of the polishing stack is between 50 and 80 ° C. 18. A method of making a transparent amorphous plate according to any one of claims 1 to 17, which comprises calibrating, smoothing and cooling the extrudate and cutting the plate to a certain size. 19. The method of claim 18, wherein the crystallizable thermoplastic is dried before melting in the extruder. 20. The method of claim 18 or 19, wherein the crystallizable thermoplastic is polyethylene terephthalate. The method of claim 20, wherein the polyethylene terephthalate is dried for 4-6 hours at 160-180 ° C. before being extruded. 22. The method of claim 20 or 21, wherein the temperature of the PET melt is 250 to 320 ° C. The method according to any one of claims 20 to 22, wherein the UV stabilizer is added by master batch method. Use of a transparent amorphous plate according to any one of claims 1 to 17 for use as an exterior material.