CZ103198A3 - Process for producing amorphous shaped bodies, shaped bodies produced in such a manner and their use - Google Patents

Abstract

The present invention relates to an amorphous, thermoformed moulding, with a thickness in the range of from 1 to 20 mm, which as the main component contains a crystallisable polyethylene terephthalate and is characterised by good mechanical and good optical properties. The moulding can optionally be transparent, dyed to be translucent or dyed to be opaque. In a preferred embodiment, it is also UV-stabilised. The invention also relates to a method for the production of said moulding, and use thereof.

Description

A process for the production of amorphous moldings molds produced in this way by CC pCU / Z-1H

Technical field

The invention relates to a process for the production of amorphous moldings from an amorphous polyethylene terephthalate sheet as well as to the amorphous moldings themselves. The shaped bodies may be transparent, transparent colored or opaque colored as desired. In addition to very good optical properties, shaped bodies are characterized by good mechanical properties.

BACKGROUND OF THE INVENTION

Amorphous, transparent sheets between 1 and 20 mm thick are well known. These sheets consist of amorphous, non-crystallizable thermoplastics. Typical examples of such thermoplastics that are processed into sheets are, for example, polyvinyl chloride (PVC), polycarbonate (PC) and polymethyl methacrylate (PMMA). These blanks are processed on so-called extrusion lines (see Polymer Verkstoffe, Band II, Technology 1, page 136, Georg Thieme Verlag, Stuttgart, 1984). Melting of the raw material in the form of powder or granules is carried out in an extruder. After extrusion, amorphous thermoplastics are easily molded through a smoothing mill or other molding tools due to the increasing viscosity as the temperature drops. The amorphous thermoplastics then have sufficient stability, i.e. high viscosity, to be self-supporting in the calibration tool. However, they are soft enough to be shaped by the tool.

• · · · · · 0 0 0 0 0 0 000 000 0 0 0000 0 * 00 * 0 * 0 0 0 0000 0 0 * 0 * 0 00 * 0 * 0 * * 0 * * 0 0 * 0 * 0 0 * 00

The melt viscosity and intrinsic stiffness of the amorphous thermoplastics in the calibration tool are so high that the preform does not collapse in the calibration tool before cooling. For easily degradable materials, such as PVC, special processing aids such as process stabilizers are required during extrusion, to prevent decomposition and glidants against high internal friction and thus uncontrolled temperature rise. External sliding means are necessary to prevent sticking to walls and cylinders.

In the PMMA treatment, a degassing extruder is used, for example, to remove moisture.

In the manufacture of transparent sheets from amorphous thermoplastics, expensive additives are in part necessary which migrate and can lead to manufacturing problems due to evaporation and to coatings on the surface of the blank. PVC plates are difficult to recycle or only with the help of special neutralization or electrolysis processes. PC and PMMA boards are also poorly recyclable and only for loss or extreme deterioration of mechanical properties.

In addition to these disadvantages, PMMA sheets also have extremely poor impact strength and break up under fracture or mechanical stress. In addition, PMMA boards are readily flammable so that they cannot be used, for example, indoors and in exhibitions.

In addition, PMMA and PC boards are not cold deformable. In cold forming, PMMA boards break into dangerous debris. When cold forming PC-boards, hairline cracks and whitish fracture arise.

4 4 4 5 6 7 8 9 10 11 12 13 14 15 16 17

PMMA boards and PC boards absorb moisture. The moisture content increases during production, during transport and during storage. Although the performance of the extruded sheets is not affected, the deformation (hot forming and vacuum forming) m results in the formation of bubbles and other surface defects due to the increased moisture, as well as the loss of properties. Prior to mechanical shaping, these sheets must be dried in a hot air circulating oven at a temperature above 120 ° C depending on the sheet thickness within 1 to 48 hours (see Technisches Handbuch GE Plastics Structured Products,

Massive Lexan-Platten), which is energy and time consuming.

German Patent Application 195 22 118.4 discloses an amorphous transparent plate having a thickness of 1 to 20 mm comprising as a main component a crystallizable thermoplastic and characterized in that it comprises at least one UV-stabilizer as a light protection agent. In addition to its high UV stability, the board is characterized by both good optical properties, such as high light transmission, high surface gloss, low haze and high image sharpness, as well as good mechanical properties, such as high impact strength and high breaking strength.

German Patent Application 195 22 120.6 describes an amorphous, transparent colored, UV-stabilized sheet of crystallizable thermoplastic having a thickness ranging from 1 to 20 mm. The plate comprises at least one UV-stabilizer as a light protection agent and at least one polymer-soluble dye. In addition to the high UV stability, the board has good optical as well as good mechanical properties.

0 0 0 ·

0 0 0 0

0 0

0 «0

German Patent Application 195 22 120.6 discloses an amorphous, colored, UV-stabilized sheet of crystallizable thermoplastic having a thickness ranging from 1 to 20 mm. The plate comprises at least one UV stabilizer as a light protection agent and at least one organic and / or inorganic pigment as a dye. In addition to the high UV stability, the board has homogeneous optical as well as good mechanical properties.

EP-A 0 471 528 describes a method for forming an article of polyethylene terephthalate (PET) sheet. The polyethylene terephthalate sheet is heat treated on both sides in a deep-drawing form between a glass transition temperature and a melting point. The molded polyethylene terephthalate sheet is removed from the mold when the crystallization rate of the molded PET sheet reaches a range of 25 to 50%. The polyethylene terephthalate sheets disclosed in EP-A 0 471 528 have a thickness of 1 to 10 mm. Since deep-drawn moldings made of this polyethylene terephthalate sheet have high crystallization, it is not possible to obtain transparent articles. Molded bodies are always transparent to light. In addition, deep-drawn molded bodies have poor mechanical properties, in particular poor impact strength, due to crystallization.

US-A 3,496,143 discloses deep drawing under vacuum of a 3 mm thick polyethylene terephthalate sheet, the crystallization rate of which is to be in the range of 5 to 25%. However, the crystallization rate of deep-drawn bodies is greater than 25%. Since the described plate and the deep-drawn moldings are partially crystalline, there is also no possibility of obtaining transparent objects or transparent plates. In addition, they have both boards and harvesting plates. 4 4 4 4 4 4 4 4 4

4 4 4 4 · Deeply drawn moldings due to crystallization Poor mechanical properties, especially low impact strength.

Processes for the production of transparent or clearly transparent moldings from amorphous or partially crystalline PET sheets with a thickness of up to 6 mm by deep drawing under vacuum are further described in Austrian Patent Nos. 304 086 and 285 160.

However, the PET used in AT-PS 304 086 is a so-called glycol-modified PET (PET-G), i.e. a copolymer of ether and ester units. PET-G is naturally amorphous and only hardly crystallizable. For this purpose, the PET used here has a crystallization temperature corresponding to the temperature after (cold) crystallization Tqj of at least 160 ° C.

According to AT-PS 285 160, a 3 mm thick PET plate having a degree of crystallization of 21% is used. The shaped bodies obtained therefrom are consequently partially crystalline and therefore not transparent.

SUMMARY OF THE INVENTION It is an object of the present invention to provide deep-drawn, i.e. thermoformed, shaped bodies which, if desired, are transparent, transparent or opaque, having a thickness of 1 to 20 mm, having both mechanical and optical properties, which would substantially correspond to the properties of the amorphous polyethylene terephthalate sheet.

Good optical properties in a transparent or transparent colored form include, for example, high light transmission and homogeneous optics.

· «1 2 3 4

4 · · 4444

4,444 * 4 4 4

4,444 444444 4444 4

4444 44 4,444

4 44 4 4 44 44

Good mechanical properties include particularly high impact strength and high strength.

Furthermore, the moldings of the present invention should be recyclable, economically processable and poorly flammable so that they can be used, for example, indoors.

In a particular embodiment, the shaped bodies should also be UV-resistant so that they are also suitable for outdoor use.

SUMMARY OF THE INVENTION

This object is solved by providing a process for the production of an amorphous molding, which comprises heating, thermoforming an amorphous sheet having a thickness of 1 to 20 mm, preferably 1 to 10 mm, containing as a major component crystallizable polyethylene terephthalate. , cooled and then removed from the mold.

Amorphous plates having a thickness in the range of 1 to 20 mm containing as a main component crystallizable polyethylene terephthalate suitable as a starting material for the process of the present invention and their production are described, for example, in German patent applications

195 19 Dec 579.5, 195 19 Dec 578.7, 195 19 Dec 577.9, 195 22nd 118.4, 195 22nd 120.6, 195 22nd 119.2, 195 28 336.8, 195 28 334.1 a 195 28 333.3.

According to the present invention is meant crystallizable polyethylene terephthalate

- crystallizable polyethylene terephthalate homo polymers,

- crystallizable polyethylene terephthalate copolymers,

- crystallizable polyethylene terephthalate compositions,

crystallizable polyethylene terephthalate recyclate, and

other variations of crystallizable polyethylene terephthalate.

Preferred starting materials for the production of amorphous plates are polyethylene terephthalate polymers having a crystallization temperature after cooling in the range of 120 ° C to 158 ° C, especially 130 ° C to 158 ° C.

For the purposes of the present invention, amorphous plates are those plates which, although the crystallizable thermoplastic used has a crystallization rate of between 25 and 65%, are not crystalline. That they are not crystalline, that is, they are substantially amorphous, with a degree of crystallization generally less than 5%, preferably less than 2% and particularly preferably 0%.

Unlike prior art sheets, such as polymethyl methacrylate (PMMA) and polycarbonate (PC), sheets that contain crystallizable polyethylene terephthalate as a major component do not need to be dried before deep drawing, i.e. before thermoforming, but can be processed directly without the usual preprocessing steps.

The heating or heating of the plate can be carried out by means of all deep drawing devices known to those skilled in the art. Preferably a hot air oven is used to heat the plate.

• or infrared heaters.

In order to achieve as uniform a heating of the board as possible, it is preferably heated on both sides, i.e. by top and bottom heating.

The board is preferably heated until the board temperature is in the range of 120 ° C to 160 ° C, preferably in the range of 130 ° C to 145 ° C.

If large-area panels are used, the panels may sag during heating. In this case, the plates are preferably supported by compressed air during heating.

Typically, the heating times of transparent sheets which contain polyethylene terephthalate as the main component are preferably about 1/3 of the time required for PMMA and PC boards.

Deviations can occur depending on the type and efficiency of the heating present. Colored plates may additionally have heating time variations due to other thermal behavior.

Upon heating, a deformation, also called thermoforming or deep drawing, occurs. The heated plates used can be thermoformed like other materials by standard methods.

In order to ensure a uniform thickness distribution over the entire material during the thermoforming process, conventional measures, such as variation of the plate temperature profile, targeted vacuum adjustment or blowing of the dome as a precursor to molding, may be used.

444444 · · 4 · 4 · 4 4 · 4 4 · 4 · 4 · 4 · 4 ·

4444 4444 4,444 4 4

4444 ·· 4,444

44 44 44 44

In addition, for the production of the amorphous molding, it is advantageous to keep the tool temperature below 80 ° C, preferably below 60 ° C.

Furthermore, the time between the end of the warm-up period and the end of the forming process should be kept short. Therefore, it is preferable to design a tool with a maximum number of boreholes and a maximum diameter (for example 1 mm).

Upon completion of the molding process, the molding should be rapidly cooled with air or a mixture of air and spray water.

The subsequent removal from the mold is preferably carried out only when the molding has a temperature below 60 ° C.

Due to the low and uniform shrinkage, which is preferably less than 1.0%, the molded part can be easily removed from the tool. Subsequent shrinkage of the molded part does not occur with time. The molded part remains dimensionally stable.

The present invention further provides amorphous, thermoformed moldings having a thickness in the range of 1 to 20 mm, comprising as a main component crystallizable polyethylene terephthalate and characterized in that their surface gloss, measured according to DIN 67530 (measuring angle 20 ^θ ), is greater than 90, preferably greater than 100.

For the purposes of the present invention, amorphous moldings are understood to be moldings whose crystallinity is generally less than 5%, preferably less than 2% and particularly preferably 0%.

·· ·· 4 4 4 4 5 6

4 ·

44

The shaped bodies of the present invention preferably exhibit no fracture when measuring Charpy impact resistance (measured according to ISO 179 / 1D).

In addition, the Izod notch toughness (measured according to ISO 180 / 1A) of the shaped bodies is preferably in the range of 2.0 to 8.0 kJ / m, particularly preferably in the range of 4.0 to 6.0 kJ / m 2.

The amorphous, thermoformed shaped bodies may be transparent, transparent colored or colored as desired.

In a transparent embodiment, the deep-drawn moldings according to the present invention have a light transmission, measured according to ASTM D 1003, of more than 80%, preferably more than 84%.

The haze of the moldings, measured according to ASTM D 1003, is less than 15%, preferably less than 11%, and the image sharpness of the moldings, also called clarity, and angled less than 2.5 ° (ASTM D 1003) is preferably higher more than 94% and particularly preferably greater than 96%.

In a transparent colored embodiment wherein the moldings comprise at least one polyethylene terephthalate soluble dye, preferably at a concentration of 0.01 to 20% by weight, based on the weight of the crystallizable polyethylene terephthalate, the deep-drawn moldings of the present invention have a light transmittance measured according to ASTM D 1003, in the range of 5 to 80%, preferably in the range of 10 to 84%.

flfl · flfl flfl fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll fll

The haze of the moldings, measured according to ASTM D 1003, is in the range of 2 to 40%, preferably in the range of 3 to 35%, and the sharpness of the image of the moldings, also called clarity and detected at less than 2.5 °. it is preferably greater than 90% and particularly preferably greater than 92%.

In a colored embodiment, wherein the moldings comprise at least one organic and / or inorganic pigment as a dye and optionally a sufficiently soluble dye, wherein the pigment concentration is 0.5 to 30% by weight based on the weight of the crystallizable polyethylene terephthalate, have deep-drawn moldings according to of the present invention, the light transmission, measured according to ASTM D 1003, is less than 5%.

Suitable soluble dyes are disclosed, for example, in German patent application P 195 19 578.7, and suitable organic and / or inorganic pigments are mentioned, for example, in German patent application P 195 19 577.9.

In a preferred embodiment, the amorphous, thermoformed moldings comprise at least one UV stabilizer as a light protection agent, wherein the UV stabilizer concentration is preferably in the range of 0.01 to 5% by weight, based on the weight of the crystallizable polyethylene terephthalate.

Suitable UV stabilizers as light stabilizers are disclosed, for example, in German patent applications P 195 22 118.4, 195 22 120.6 and 195 22 119.2.

It further showed that the moldings according to the invention

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000 0 0

0 0

00 ····

· 0 0

0 0 0

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0 0

They are poorly flammable and badly flammable, so they are suitable for indoor and exhibition use, for example.

Furthermore, the moldings according to the invention are recyclable without problems, without burdening the environment and without losing mechanical properties, so that they are suitable, for example, for use as temporary advertising signs or other promotional goods.

Due to the surprising number of outstanding properties, the amorphous moldings according to the invention are excellent for a wide variety of applications, for example for interior tiling, for exhibitions and display objects, for displays, for protective glazing of machines and vehicles, luminaires, shop building and construction shelves, as promotional items, as menu holders, for basketball baskets, as partition walls for rooms, for aquariums, as information boards and as racks for brochures and magazines.

In the UV-stabilized embodiment, the amorphous moldings according to the invention are also suitable for outdoor use, for example for greenhouses, roofing, glazing, safety glass, exterior tiles, blankets, for the building sector, illuminated signs, balcony tiles, roof superstructures and caravan windows .

In addition, it has surprisingly been found that the amorphous, deep-drawn moldings of the present invention have good mechanical properties even at low temperatures up to -40 ° C without loss of optical properties. Good mechanical properties include, among other things, high breaking strength, high notch toughness, and excellent · · né · · · · · · · · né né né né né né né né né né • Tensile and bending properties • • • • • • • • • • • • • • •.

The moldings of the present invention can therefore also be advantageously used in cooling systems. As examples of refrigeration systems or refrigeration equipment, electric refrigeration cabinets, household and industrial freezers, compressor refrigerators, milk refrigerators, refrigerated showcases, canned refrigerators, corpses refrigerators, medical refrigerators and laboratory refrigeration units.

The invention is illustrated by the following non-limiting examples.

DETAILED DESCRIPTION OF THE INVENTION

Measurement of individual properties is performed according to the following standards or procedures.

Measuring methods

Surface gloss:

The surface gloss is measured according to DIN 67530. The reflection value is measured as the optical quantity for the plate surface. Following the ASTM-D 523-78 and ISO 2813 standards, the irradiation angle was set to 20 °. The light beam is radiated to the plane of the test surface at the set irradiation angle and is reflected or scattered from it. The light beam incident on the photoelectric receiver is shown as a proportional quantity. The measured value is dimensionless and must be reported together with the irradiation angle.

• · ···· · · · ·

· 4

4 44

4 4 4 4

4 4

44

Light transmission:

Light transmittance is the ratio of all transmitted light to the incident amount of light.

The light transmittance is measured with a Hazegard plus meter according to ASTM D 1003.

Haze and clarity:

Haze is the percentage of transmitted light that deviates by more than 2.5 ° from the illuminating beam at the center. The image sharpness is measured at an angle of less than 2.5 °.

Haze and clarity are measured with a Hazegard plus meter according to ASTM D 1003.

Degree of whiteness:

The determination of the degree of whiteness is carried out using an ELREPHO electric remotion photometer from Zeiss, Oberkochem (DE), standard light type C, normal observer 2 °. The degree of whiteness is defined as:

VG = RY + 3RZ - 3RX, where VG = degree of whiteness, RY, RZ, RX = corresponding reflection factors when using color measuring filters Y,

Z and X. The barium sulphate compact (DIN 5033, part 9) is used as the whiteness standard.

• 0 00 0 · ·· 00 • · 0

0 0

0 0 0 0

0 0

00

Surface defects :

Surface defects are determined visually.

Charpy impact resistance a _n :

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

Notch toughness a ^ by Izod:

Notch impact strength and / or Izod impact strength are measured according to ISO 180 / 1A.

Density:

The density is determined according to DIN 53479.

SV (DCE), IV (DCE)

The standard viscosity SV (DCE) is measured according to DIN 53726 in dichloroacetic acid.

The intrinsic viscosity IV is calculated according to the following formula from the standard viscosity SV (DCE):

IV (DCE) = 6.67. 10 ⁴ MASS (DCE) + 0.118

Thermal properties:

The thermal properties, such as crystallite melting point T _m, crystallization temperature range Τθ, crystallization temperature upon cooling T (- <n ^and Tg are measured by differential scanning calorimetry (DSC) at a rate at • · φφφφ φ φφφφ φφ φ φφφ φφφφ φφ φ · · φ φ φ φ φ φ · · · φ φ φ φ φ φ φ φ φ φ φ φ φ φ φ h ří ří ří ří vání ří ří vání h ří h h h vání ří ří ří ří vání ří ří

Molecular weight, polydispersity:

Molecular weights M _w and M _n and the resulting polydispersity

M _w / M _n is measured by gel permeation chromatography (GPC).

Weather effects (bilateral), UV-stability:

UV stability is tested according to ISO 4892 Test Specification under the following conditions:

Tester: Atlas Ci 65 Veather Ometer

Test conditions: ISO 4892, ie simulated weather influence

Irradiation time: Irradiation: Temperature: Relative humidity Xenon lamp: Irradiation cycles:

1000 hours (each side)

0.5 V / m 2, 340 nm 63 ’C air; 50% inner and outer borosilicate filter 102 minutes UV-light, then 18 minutes UV-light with water spraying of samples, then 102 minutes UV-light and so on.

In the examples and comparative examples given below, these are in each case monolayer sheets which have been produced on the extrusion line described in the above-mentioned German patent applications.

Example 1

An amorphous, transparent polyethylene terephthalate plate, the manufacture of which is described in German patent application 195 ·· <0 * 0 0 ·· 00 0 «0 000 * 00 * 0 * * · * 0 * * 00 *

0 0 0 0 * 0 * 00 * 04 * 0 0

0 * 00 0 * 0 * 0 * * 0 00 * 0 0 00 00

180.0, with the following properties

Thickness : 4 mm Surface gloss 1st page: 178 (measuring angle 20 ”) 2nd page: 172 Light transmission: 89.4% Clarity: 99.7% Turbidity: 2.1% Surface defects per m: V Z J z zadně Crystallization rate: 0% Density: 1.33 g / cm 2 Impact toughness a _n according to Charpy at 23 ° C: there is no quarry Notch toughness and Izod at 23 ° C: 4.7 kJ / m ² ,

is subjected to deep drawing on an Illig / Heilbronn vacuum thermoforming machine, type UA 100 g with the following parameters

Plate size:

Thickness of the board :

Shaped surface:

Deep drawing height:

Pre-drying:

Molding tool temperature: Top heater power: Bottom heater power: Top and bottom heater / deep drawing

Vacuum:

Plate temperature:

Spray water cooling:

1000mm x 700mm 4mm

960 mm x 660 mm 200 mm min (not required) 50 ° C 65%%

with yes 140 ° C 40 s * 14 • 4 ··· 44 44 ♦ 4 · 4 · 4 · 4 · 4

4 • 4

4 • 4

4 · 4 • 4 4

4 · 44

Molded object temperature at tool removal: 50 ° C

In this way, the entire deep drawing cycle lasts only 78 seconds.

The manufactured article has the following characteristics:

Color:

Light transmission:

Turbidity:

Surface gloss 1st page:

(measuring angle 20 °) 2nd page: Shrinkage:

Density:

Crystallization rate:

Charpy impact strength a _n at 23 ° C:

Notch toughness α ^ Izod at 23 ° C:

Charpy impact resistance a _n at -40 ° C:

Notch toughness α ^ Izod at 23 ° C:

transparent 87,8%

3.4%

150,162 0.5%

1.33 g / cm ² 0% no fracture

4.7 kJ / m ² 78 kJ / m ²

2.4 kJ / m ²

Example 2

Analogously to Example 1, an amorphous, transparent plate of crystallizable polyethylene terephthalate containing 0.6% by weight UV stabilizer 2,2'-methylene-bis-6- (2H-benzotriazol-2-yl) - is produced by deep-drawing. 4- (1,1,3,3-tetramethyl-butyl) -phenol ( ^R Tinuvin 360 from Ciba-Geigy) based on polymer weight.

• ·

The UV-stabilized board has the following properties

Thickness : 4 mm Surface gloss 1st page: 176 (measuring angle 20 °) 2, page: 174 Light transmission: 89.1% Clarity: 99.5% Turbidity: 2.3% O Surface defects per m: none Crystallization rate: 0% Density: 1.33 g / cm ³ Impact toughness a _n according to Charpy at 23 ° C: there is no quarry Notch toughness and Izod at 23 ° C: 4.6 kJ / m @ 2.

The deep-drawing parameters and the deep-drawing time are selected analogously to Example 1.

The manufactured, UV-stabilized article has the following properties;

Color:

Light transmission:

Turbidity:

Surface gloss 1st page:

(measuring angle 20 °) 2nd page: Shrinkage:

Density:

Crystallization rate:

Charpy impact strength a _n at 23 ° C:

Notch toughness a. according to Izoda transparent 86.9%

3.6%

148 159 0.5%

1.33 g / cm ³ 0% no fracture 4 · 4 · 4 · 41 · at 23 ° C: 4.5 kJ / m ²

Charpy impact resistance a _n at -40 ° C: 79 kJ / m ²

Notched Izod toughness at 23 ° C: 2.2 kJ / m ²

Example 3

Analogously to Example 1, an amorphous, red transparent colored plate of crystallizable polyethylene terephthalate containing 2% by weight of the soluble dye solventrot 138, anthraquinone derivative from BASF (Thermoplast G from BASF), is produced by deep-drawing.

The red transparent plate has the following properties

Thickness : 2 mm Surface gloss 1st page: 130 (measuring angle 20 °) 2nd page: 127 Light transmission: 35.8% Clarity: 99.1% Turbidity: 3.5% O Surface defects per m: none Crystallization rate: 0% Density: 1.33 g / cm ³ Impact toughness a _n according to Charpy at 23 ° C: there is no quarry Notch toughness and Izod at 23 ° C: 4.1 kJ / m ² .

Deep drawing parameters and deep drawing time flflfl flflflfl flflflfl flflflfl flflfl flflfl flfl fl flflflfl are selected analogously to example 1. Due to the low plate thickness, the cycle time is only 37 s, requiring 20 s for bottom and top heating as well as for the deep drawing process and for spray water cooling.

The article produced has the following characteristics;

Color:

Light transmission:

Turbidity:

Surface gloss 1st page:

(measuring angle 20 °) 2nd page: Shrinkage:

Density:

Crystallization rate:

Charpy impact strength a _n at 23 ° C:

Izod notch toughness at 23 ° C:

Charpy impact resistance a _n at -40 ° C:

Notch toughness α ^ Izod at 23 ° C:

red-transparent 34,9%

3.8%

118 126 0.4%

1.33 g / cm ^%

there is no quarry

4.0 kJ / m ² kJ / m ² 2.0 kJ / m ²

Example 4

Analogously to Example 1, an amorphous, white-colored plate of crystallizable polyethylene terephthalate containing 6% by weight of titanium dioxide based on the weight of the polymer is produced by deep-drawing.

Titanium dioxide is of the rutile type with an inorganic overlay of aluminum oxide and an organic overlay of polydimethoxysilane 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 The titanium dioxide has a mean particle diameter of 0.2 µm.

The white plate has the following characteristics

Thickness : 5 mm Coloring: white Surface gloss 1st st: wound: 119 (measuring angle 20 °) 2. page: 117 Light transmission: 0% Degree of whiteness: 120 Surface defects per m none Crystallization rate: 0% Impact toughness i and _n according to Charpy at 23 ° C: there is no quarry Notch toughness and ^ by Izod at 23 ° C: 4.9 kJ / m ² .

The deep drawing parameters and the deep drawing temperature are selected analogously to Example 1. Due to the large plate thickness, the deep drawing cycle time is 95 seconds, requiring 90 seconds for the bottom and top heating as well as for the deep drawing process and 45 seconds for the spray water cooling.

The manufactured article has the following characteristics:

White color

Light transmission: 0%

Surface gloss 1st side: 108 (measuring angle 20 “) 2nd side: 113

Degree of whiteness: 118

- 23 Shrinkage:

Crystallization rate:

Charpy impact strength a _n at 23 ° C:

Notch toughness α ^ Izod at 23 ° C:

Charpy impact resistance a _n at -40 ° C:

Notch toughness α ^ Izod at 23 ° C:

Example 1 (comparative)

An amorphous PMMA plate (GS) is prepared analogously to the drawing process.

······ 4 4 4 4 4 ·· • · 4 4 ·· 4 * 44

4 4444 4444

4,444 444444 4444 4

4444 44 4,444

44 44 44 44

0.6%%

there is no quarry

4.8 kJ / m ² kJ / m ²

2.4 kJ / m ^{2 of} Example 1 with deep

TJ by Rohm (Plexiglas

This PMMA board has the following characteristics

Thickness : 4 mm Surface gloss 1st page: 138 (measuring angle 20 °) 2nd page: 136 Light transmission: 93.8% Clarity: 99.8% Turbidity: 0.5% O Surface defects per m none Density: 1.19 g / cm ³ Charpy impact strength a _n at 23 ° C: 16 kJ / m ² Notch toughness α ^ Izod at 23 ° C: 1.5 kJ / m ² .

Using deep drawing parameters, drawing temperature • 4

0 4 0

0

0 0 0 0 · 0 0 0 0 0 0 0 0 0 0

0 000 40000

0 0 0 0 0 0 0 0 0 0 0 4 0 and deep drawing times analogous to Example 1 cannot be made.

The PMMA board can only be thermoformed under the following considerably less economic conditions.

Plate size:

Thickness of the board :

Shaped surface:

Deep drawing height:

Pre-drying:

Molding tool temperature: Top heater power: Bottom heater power: Top and bottom heater / deep drawing

Vacuum:

Plate temperature:

Spray Water Cooling: Mold temperature when tool is removed:

1000mm x 700mm 4mm

960 mm x 660 mm 200 mm h at 125 ° C 50 ° C 75%%

with yes

180 ° C p

Noc: 2 ° C

The deep-drawing cycle is considerably longer for shaping an article having 159 s, which greatly reduces productivity compared to amorphous PET-sheet molding in the currently conventional, continuously operating thermoforming machines. In addition, the plate must have a considerably higher temperature during deep drawing, so that energy costs are higher compared to amorphous shaped bodies. In particular, the plates need to be dried for several hours at temperatures above 100 ° C in a special oven before the deep drawing process to remove the absorbed water. The total amount of air in the furnace must be replaced about six times per hour in order to remove water vapor. Without pre-drying, the shaped bodies exhibit unacceptable surface defects due to the water present.

Molded bodies made from a pre-dried PMMA plate with a substantially longer deep drawing cycle have the following characteristics:

Color:

Light transmission:

Turbidity:

Surface gloss 1st page:

(measuring angle 20 °) 2nd page: Shrinkage:

Density:

Crystallization rate:

Charpy impact strength a _n at 23 ° C:

Notch toughness α ^ Izod at 23 ° C:

Charpy impact resistance a _n at -40 ° C:

Notch toughness α ^ Izod at 23 ° C:

transparent

90.1%

2.3%

112

120%

1.19 g / cm ³ %

kJ / m ²

1.4 kJ / m ² no reproducible values are measurable (strong dispersion)

The moldings produced exhibit significantly higher shrinkage compared to amorphous PERT moldings and, even at room temperature, considerably worse impact and notch toughness. In addition, dangerous fragments with sharp edges are produced in the case of a slightly broken quarry.

Example 2 (comparative)

Analogous to that described in Example 1, deep

4 · 4 4 4 4 4 4 4 4 444444 4444 4

4444 44 4,444 to produce an amorphous polycarbonate sheet from GE Plastice (^ Lexan 121).

This PC board has the following features

Thickness : 4 mm Surface gloss 1st page: 176 (measuring angle 20 °) 2nd page: 174 Light transmission: 89% Clarity: 99.1% Turbidity: 0.5% O Surface defects per m: none Density: 1.20 g / cm 2 Impact toughness a _n according to Charpy at 23 ° C: there is no quarry Notch toughness and Izod at 23 ° C: 10 kJ / m ² .

Using the parameters of deep drawing, low drawing temperature, short deep drawing time and without pre-drying, analogously to Example 1, the shaped body cannot be produced.

A 4 mm thick PC board can only be thermoformed under the following considerably less economic conditions.

Plate size: 1000 mm x 700 mm

Plate thickness: 4 mm

Molded area: 960 mm x 660 mm

Deep drawing height: 200 mm

Pre-drying: 11 h at 126 ° C

Molding tool temperature: 70 ° C

Top heater power: 80% · 4444 4444 4444 4444 4444

4444 44 4,444

44 44 44 44

Bottom heater output: 80%

Preheating by top and bottom heating / deep drawing 85 s

Vacuum: yes

Plate temperature: 190 ° C

Spray water cooling: 70 s

Molded object temperature at tool removal: 70 ° C

The deep-drawing cycle is considerably longer for shaping a PC-board object compared to the exemplary embodiments, which, in the currently conventional, continuously operating thermoforming machines, greatly reduces productivity compared to amorphous PET-board moldings. In addition, the plate must have a considerably higher temperature during deep drawing, so that energy costs are higher compared to amorphous PET-shaped bodies. In particular, both PMMA and PC boards need to be dried for several hours at 125 ± 3 ° C in a hot-air circulation oven before the deep drawing process to remove the absorbed water. The total amount of air in the furnace must be replaced about six times per hour in order to remove water vapor. Without pre-drying, PC-shaped molded bodies exhibit unacceptable optics due to the water present.

when they have a transparent 87.2%

3.1%

148

159

Molded bodies made from a pre-dried PC board of the most disadvantageous deep drawing conditions have the following characteristics:

Color:

Light transmission:

Turbidity:

Surface gloss 1st side: (measuring angle 20 °) 2nd side about 5%

1.20 g / cm ^%

00 00

0 0 0 • 0 · · · 0000 · 0 · ··· • 0000 000 000 000 "0 0 0 0 0 0 0 000 00 * 0 00 0 00 00 no fracture kJ / m ² no break kJ / m ²

Shrinkage:

Density:

Crystallization rate:

Charpy impact strength a _n at 23 ° C:

Notch toughness a. according to Izod at 23 ° C:

Charpy impact resistance a _n at -40 ° C:

Notch toughness α ^ Izod at 23 ° C:

The moldings produced exhibit a significantly higher shrinkage compared to the amorphous PET moldings.

Example 3 (comparative)

A molding having a crystallization rate of about 35% is produced analogously to Example 1 of EP-A-0 471 528. As described herein, deep drawing cycle times are also considerably longer than amorphous PET-shaped bodies. In addition, the molding tool must have a temperature of about 160 ° C for crystallization to take place. Such high tool temperatures are not achievable by conventional water heating. There is a need for an oil or electrically heated tool which, due to high temperatures, must not be made of epoxy resin or wood, but must be made of aluminum.

PET-shaped body with crystallization of 35% has the following properties:

Color:

white due ·· · ·· ··

9

9

9,999 9,999 9

9 9 9 9 9

99 99 99 99

Light transmission:

Turbidity:

Clarity:

Surface gloss 1st page:

(measuring angle 20 °) 2nd page: Shrinkage:

Density:

Crystallization rate:

Charpy impact strength a _n at 23 ° C:

Notch toughness α ^ Izod at 23 ° C:

crystallization%

not measurable due to self crystallization of about 6%

1.37 g / cm ³ about 35% kJ / m ²

2.3 kJ / m ²

The moldings produced with a crystallization rate of about 35% are still light-transmissive due to crystallization. As a result, transparent or transparent colored products cannot be produced. In addition, these shaped bodies also exhibit high shrinkage and significantly lower impact and notch toughness even at room temperature.

Claims (18)

PATENT CLAIMS A process for the production of amorphous moldings, characterized in that an amorphous sheet having a thickness in the range of 1 to 20 mm, comprising as a main component crystallizable polyethylene terephthalate, is heated to a temperature in the range of 120 ° C to 160 ° C, thermoformed, cooled and then removed from the mold. Method according to claim 1, characterized in that the amorphous plate has a thickness in the range of 1 to 10 mm. Method according to claim 1 or 2, characterized in that the plate is heated by means of a hot air oven or infrared heating elements. Method according to claims 1 to 3, characterized in that the plate is heated until its temperature is in the range of 130 ° C to 145 ° C. Method according to one of Claims 1 to 4, characterized in that: The method of claim 1, wherein the temperature of the molding tool is kept below 80 ° C during thermoforming. Method according to claim 5, characterized in that the temperature of the molding tool is kept below 60 ° C during thermoforming. 7. Method according to any one of claims 1 to 6, 44 444 · 4 4 · 4 · 4 · 4 44 ·· <<4 4 4 · 4 4 4 4 4 4444 44 * 4 4 4 4 4 4 44 4,444 4 4 4 4 44 44 characterized in that the shaped bodies are cooled by air or a mixture of air and spray water. Method according to one of Claims 1 to 7, characterized in that the tare body is removed from the mold when its temperature is below 80 ° C. Method according to claim 8, characterized in that the tare body is removed from the mold when its temperature is below 60 ° C. The process according to claim 1, wherein the polyethylene terephthalate used has a crystallization temperature after cooling in the range of 120 ° C to 158 ° C. 11. An amorphous, thermoformed molding having a thickness in the range of 1 to 20 mm, comprising as the main component a crystallizable polyethylene terephthalate, characterized in that the surface gloss, measured according to DIN 67530, at a measuring angle of 20 DEG is greater than 90. Molding according to claim 11, characterized in that the Charpy impact resistance a _n , measured according to ISO 179 / ID, does not cause fracture. Molding according to claims 11 or 12, characterized in that the impact resistance and the like are as follows. according to Izod, measured according to ISO 180 / 1A, is in the range of 3.0 to 8.0 kJ / m 2. ······························· Molding according to one of Claims 11 to 13, characterized in that it is transparent, transparently colored or colored. Molding according to one of Claims 11 to 14, characterized in that it comprises at least one UV-stabilizer as a light protection agent. Molding according to claim 15, characterized in that the concentration of the UV stabilizer is in the range of 0.01 to 5% by weight, based on the weight of the crystallizable polyethylene terephthalate. Molding according to claim 11, characterized in that the polyethylene terephthalate used has a crystallization temperature after cooling in the range of 120 ° C to 158 ° C. Use of amorphous, thermoformed moldings according to any one of claims 11 to 17 in the indoor and outdoor areas and in cooling systems.