CA2262543A1 - Multilayered crystallizable thermoplastic plate, process for its production and use thereof - Google Patents
Multilayered crystallizable thermoplastic plate, process for its production and use thereof Download PDFInfo
- Publication number
- CA2262543A1 CA2262543A1 CA002262543A CA2262543A CA2262543A1 CA 2262543 A1 CA2262543 A1 CA 2262543A1 CA 002262543 A CA002262543 A CA 002262543A CA 2262543 A CA2262543 A CA 2262543A CA 2262543 A1 CA2262543 A1 CA 2262543A1
- Authority
- CA
- Canada
- Prior art keywords
- sheet
- thermoplastic
- layer
- range
- measured
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/02—Physical, chemical or physicochemical properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
- E04C2/54—Slab-like translucent elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2305/00—Condition, form or state of the layers or laminate
- B32B2305/70—Scrap or recycled material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/40—Properties of the layers or laminate having particular optical properties
- B32B2307/412—Transparent
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/50—Properties of the layers or laminate having particular mechanical properties
- B32B2307/584—Scratch resistance
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/702—Amorphous
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2367/00—Polyesters, e.g. PET, i.e. polyethylene terephthalate
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2607/00—Walls, panels
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Laminated Bodies (AREA)
Abstract
A multilayered transparent amorphous thermoplastic plate with at least one central layer and at least one outer layer which are mainly composed of crystallizable thermoplastic. The thermoplastic of the central layer has a higher standard viscosity than the outer layer. The invention also relates to a method of manufacture for the above-mentioned plate as well as to its use.
According to the invention the plate can also contain at least one additive such as ultra violet stabilizers, antioxidant agents and/or one anti-scratch coating on at least one side.
According to the invention the plate can also contain at least one additive such as ultra violet stabilizers, antioxidant agents and/or one anti-scratch coating on at least one side.
Description
WO 98/05496 ~ ~ - PCT/EP97/03856 Multilayered sheet of a crystallizable thermoplastic, a process for itsproduction and its use The invention relates to an amorphous, transparent, multilayered sheet of a crystallizable thermoplastic, the thickness of which is in the range from 1 to 20 mm. The invention furthermore relates to a process for the production of this sheet and its use.
Multilayered sheets of plastics materials are known per se.
Such sheets of branched polycarbonates are described in EP-A-0 247 480, EP-A-320 632 and US-A 5,108,835.
UV-stabilized polycarbonate shaped articles which are built up from polydiorganosiloxane-polycarbonate block copolymers are known from DE-A-34 14 116 and US-A 4,600,632.
Multilayered sheets of plastic with layers of polydiorganosiloxane-polycarbonate block copolymers which comprise UV absorbers are known from US-A 5,137,949. UV-stabilized, branched polycarbonates from specific diphenols are known from EP-A-0 416 404. It is mentioned that such polycarbonates can be employed for the production of sheets or webbed multiple sheets.
All these sheets are made of polycarbonate, an amorphous thermoplastic which cannot be crystallized. Polycarbonate sheets have the disadvantage that they often lead to blooming in the form of white specks and surface deposits, especially in the UV-stabilized embodiment (cf. EP-A-0 649 724).
According to EP-A-0 649 724, for example, evaporating out of the UV
absorber is linked to a high degree to the average molecular weight.
These PC plates furthermore are readily flammable and therefore require the addition of flameproofing agents so that they can be employed for CA 02262~43 1999-01-29 . _ .
certain purposes, such as for interior applications. Tedious predrying times and relatively long processing times at high temperatures are necessary for further processing of these sheets to moldings. Devolatilizing extruders must furthermore be used during sheet production for the purpose of 5 withdrawing moisture, which means that the additives added to the raw material can also be removed at the same time, especially if low molecular weight, readily volatile additives are employed.
Single-layered, transparent amorphous sheets having a thickness in the 10 range from 1 to 20 mm which comprise, as the main constituent, a crystallizable thermoplastic, such as, for example, polyethylene terephthalate, have already been described by the Applicant (German Patent Applications Nos 19519579.5,19522118. 4 and 19528336.8).
These sheets can have a standard viscosity of 800-6000 and comprise a 15 UV stabilizer.
EP-A-0 471 528 describes a process for shaping an object from a polyethylene terephthalate (PET) sheet. The PET sheet is heat-treated on both sides in a thermoforming mold in a temperature range between the 20 glass transition temperature and the melting temperature. The shaped PET
sheet is removed from the mold when the extent of crystallization of the shaped PET sheet is in the range from 25 to 50%. The PET sheets disclosed in EP-A-0 471 528 have a thickness of 1 to 10 mm. Since the thermoformed shaped article produced from this PET sheet is partly 25 crystalline and therefore no longer transparent and the surface properties of the shaped article are determined by the thermoforming process and the temperatures and shapes given by this, the optical properties (for example gloss, clouding and light transmission) of the PET sheets employed are unimportant. As a rule, the optical properties of these sheets are poor and 30 in need of optimization. These polyethylene terephthalate sheets also have a single-layer construction.
US-A-3 496 143 describes vacuum thermoforming of a 3 mm thick PET
sheet, the crystallization of which should be in the range from 5 to 25%.
CA 02262~43 1999-01-29 The crystallinity of the themmoformed shaped article is greater than 25%.
On these PET sheets also, no requirements are imposed in respect of optical properties. Since the crystallinity of the sheets employed is already between 5% and 25%, these sheets are cloudy and nontransparent. These 5 partly crystalline PET sheets are also single-layered.
Austrian Patent Specification No. 304 086 describes a process for the production of transparent shaped articles by the thermoforming process, a PET sheet or film having a degree of crystallinity of less than 5% being 10 employed as the starting material.
The sheet or film used as the starting material has been produced from a PET having a crystallization temperature of at least 1 60~C. From this relatively high crystallization temperature it follows that the PET here is not a PET homopolymer but a glycol-modified PET, called PET-G for short, 15 which is a PET copolymer.
In contrast to pure PET, PET-G shows an extremely low tendency toward crystallization and is usually present in the amorphous state because of the glycol units additionally incorporated.
20 The object of the present invention is to provide a multilayered, amorphous, transparent sheet having a thickness of 1 mm to 20 mm which is distinguished by good mechanical and optical properties.
The good optical properties include, for example, a high light transmission, 25 a high surface gloss, an extremely low clouding and a high image sharpness (clarity).
The good mechanical properties include, inter alia, a high impact strength and a high fracture strength.
Furthermore, the sheet according to the invention should be recyclable, in particular without loss of the mechanical properties, and poorly combustible, so that, for example, it can also be used for interior applications and in exhibition construction.
CA 02262~43 1999-01-29 This object is achieved by a multilayered, transparent, amorphous sheet having a thickness of 1 to 20 mm which comprises a crystallizable thermoplastic as the main constituent, wherein the sheet has at least one core layer and at least one covering layer, and wherein the standard 5 viscosity of the crystallizable thermoplastic of the core layer is higher thanthe standard viscosity of the crystallizable thermoplastic of the covering layer.
Amorphous sheet in the context of the present invention is understood as 10 meaning those sheets which are noncrystalline, although the crystallizable thermoplastic employed preferably has a crystallinity of between 5 and 65%. Noncrystalline, i.e. essentially amorphous, means that the degree of crystallinity is in general below 5%, preferably below 2%, and particularly preferably is 0%, and that the sheet essentially shows no orientation.
~ According to the invention, crystallizable thermoplastic is understood as meaning - crystallizable homopolymers, - crystallizable copolymers, 20 - crystallizable compounds, - crystallizable recycled material and - other variations of crystallizable thermoplastics.
Examples of suitable thermoplastics are polyalkylene terephthalates with a 25 C1 to C12-alkylene radical, such as polyethylene terephthalate and polybutylene terephthalate, polyalkylene naphthalate with a C1 to C12-alkylene radical, such as polyethylene naphthalate and polybutylene naphthalate, and crystallizable cycloolefin polymers and cycloolefin copolymers, it being possible for the thermoplastic or thermoplastics for the 30 core layer(s) and the thermoplastic or thermoplastics for the covering layer(s) to be identical or different.
Polyolefins have also proved to be suitable for the covering layer.
Thermoplastics having a crystallite melting point Tm~ measured by DSC
CA 02262~43 1999-01-29 (differential scanning calorimetry) with a heating-up rate of 10~C/minute, of 220~C to 260~C, preferably 230~C to 250~C, a crystallization temperature range Tc ~f between 75~C and 260~C, a glass transition temperature Tg of between 65~C and 90~C and a density, measured in accordance with DIN
53479, of 1.30 to 1.45 g/cm3 and a crystallinity of between 5% and 65%
are preferred polymers for the core layer and the covering layer as starting materials for production of the sheet. A thermoplastic having a cold (after-)crystallization temperature TCC ~f 120 to 158~C, in particular 130 to 158~C, is particularly preferred for the purposes according to the invention.
The bulk density, measured in accordance with DIN 53466, is preferably between 0.75 kg/dm3 and 1.0 kg/dm3, and particularly preferably between 0.80 kg/dm3 and 0.90 kg/dm3.
The polydispersity M~,JMn of the thermoplastic, measured by means of GPC, is preferably between 1.5 and 6.0, and particularly preferably between 2.0 and 5Ø
A particularly preferred crystallizable thermoplastic for the core layer(s) and the covering layer(s) is polyethylene terephthalate. The polyethylene terephthalate preferably used according to the invention essentially comprises monomer units of the following formula O O
ECH2-CH2-O C~C O~
It is essential to the invention that the thermoplastic or thermoplastics of the core layer(s) has or have a higher standard viscosity than the thermoplastic or thermoplastics of the covering layer(s). The standard 30 viscosities of various core and/or covering layers of a multilayered sheet can differ.
The standard viscosity SV (DCA) of the crystallizable thermoplastic of the core layer, measured in dichloroacetic acid in accordance with DIN 53728, CA 02262~43 1999-01-29 is preferably between 800 and 5000, and particularly preferably between 1000 and 4500.
The standard viscosity SV (DCA) of the crystallizable thermoplastic of the covering layer, measured in dichloroacetic acid in accordance with DIN
53728,is preferably between 500 and 4500, and particularly preferably between 700 and 4000.
The intrinsic viscosity IV (DCA) can be calculated from the standard viscosity SV (DCA) as follows:
IV (DCA)= 6.67 x 10-4 SV(DCA)+ 0.118 The crystallizable thermoplastics used according to the invention can be obtained by customary processes known to the expert. In general, thermoplastics such as are used according to the invention can be oblained by polycondensation in the melt or by a two-stage polycondensation. The first step here is carried out up to a moderate molecular weight - corresponding to a moderate intrinsic viscosity IV of about 0.5 to 0.7- in the melt, and the further condensation is carried out by means of solid condensation. The polycondensation is usually carried out in the presence of known polycondensation catalysts or catalyst systems.
In the solid condensation, chips of the thermoplastic are heated at temperatures in the range from 180 to 320~C under reduced pressure or under an inert gas until the desired molecular weight is reached.
For example, the preparation of polyethylene terephthalate, which is particularly preferred according to the invention, is described in detail in a large number of patent applications, such as in JP-A-60-139 717,DE-C-2 429 087, DE-A-27 07 491,DE-A-23 19 089,DE-A-16 94 461,JP-63-41 528,JP-62-39 621,DE-A-41 17 825,DE-A-42 26 737,JP-60-141 715,DE-A-27 21 501 and US-A-5 296 586.
Polyethylene terephthalates having particularly high molecular weights can CA 02262~43 1999-01-29 be prepared, for example, by polycondensation of dicarboxylic acid-diol precondensates (oligomers) at elevated temperature in a liquid heat transfer medium in the presence of customary polycondensation catalysts and, if appropriate, cocondensable modifying agents, if the liquid heat 5 transfer medium is inert and free from aromatic structural groups and has a boiling point in the range from 200 to 320~C, the weight ratio of dicarboxylic acid-diol precondensate (oligomers) employed to liquid heat transfer medium is in the range from 20:80 to 80:20, and the polycondensation is carried out in a boiling reaction mixture in the presence of a dispersion 10 stabilizer.
The multilayered, transparent, amorphous sheet according to the invention can furthermore be treated with suitable additives, if desired. These additives can be added, as required, to one or more layers of the sheet 15 individually or as a mixture.
- Examples of suitable additives are UV stabilizers and antioxidants, such as are described in German Patent Application No. 195 221 18.4 and the application by the same Applicant, attached at the same time, entitled 'Polyethylene terephthalate sheet of improved stability to hydrolysis'. By 20 citation, these applications are valid as a constituent of the disclosure content of the present application.
As stated above, the multilayered, transparent, amorphous sheet can additionally comprise at least one UV stabilizer as a light stabilizer in the 25 covering layer(s) and/or the core layer(s).
Light, in particular the ultraviolet portion of solar radiation, i.e. the wavelength range from 280 to 400 nm, initiates degradation processes in thermoplastics, as a consequence of which not only does the visual 30 appearance change, owing to a change in color or yellowing, but also the mechanical-physical properties are adversely influenced.
Inhibition of these photooxidative degradation processes is of considerable industrial and economic importance, since otherwise the possible uses of CA 02262~43 1999-01-29 numerous thermoplastics are limited drastically.
A high UV stability means that the sheet is not damaged or is damaged only extremely little by sunlight or other UV radiation, so that the sheet is 5 suitable for exterior applications and/or critical interior applications, and shows no or only slight yellowing even after several years of external use.
Polyethylene terephthalates, for example, already start to absorb UV light below 360 nm, and their absorption increases considerably below 320 nm 10 and is very pronounced below 300 nm. The maximum absorption is between 280 and 300 nm.
In the presence of oxygen, chiefly chain splitting reactions but no crosslinking reactions are observed here. Carbon monoxide, carbon dioxide and carboxylic acids are the predominant photooxidation products 15 in terms of amount. In addition to direct photolysis of the ester groups, ~ oxidation reactions which likewise result in the formation of carbon dioxide via peroxide radicals must also be taken into consideration.
The photooxidation of polyethylene terephthalates can also lead, via splitting-off of hydrogen in the cx-position of the ester groups, to 20 hydroperoxides and decomposition products thereof and to associated chain splitting reactions (H. Day, D. M. Wiles: J. Appl. Polym. Sci 16,1972, page 203).
UV stabilizers, also called light stabilizers or UV absorbers, are chemical 25 compounds which can intervene in the physical and chemical processes of light-induced degradation.
Certain pigments, such as, for example, carbon black, can also partly have the effect of light stabilization. However, these substances are unsuitable 30 for the transparent sheets according to the invention, since they lead to discoloration or a change in color. Only those UV stabilizers, for example, from the class of organic and organometallic compounds which bring about very, very little or no color or change in color in the thermoplastic to be stabilized are expediently used for the amorphous sheets according to the CA 02262~43 1999-01-29 invention.
Examples of UV stabilizers which are suitable for the present invention are 2-hydroxybenzophenones, 2-hydroxybenzotriazoles, organonickel compounds, salicylic acid esters, cinnamic acid ester derivatives, resorcinol monobenzoate, oxalic acid anilides, hydroxybenzoic acid esters, sterically hindered amines and triazines, 2-hydroxybenzotriazoles and triazines being preferred.
Mixtures of several UV stabilizers can also be employed.
The UV stabilizer is expediently present in a covering layer in a concentration of 0.01% by weight to 8% by weight, based on the weight of the thermoplastic in the covering layer treated with the stabilizer. However, the UV stabilizer can also be added to a core layer. In this case, a concentration of 0.01% by weight to 1% by weight, based on the weight of ~ the thermoplastic in the core layer treated with the stabilizer, is sufficient.
According to the invention, several layers can be treated simultaneously with UV stabilizer. In general, however, it is sufficient for the layer on whichthe UV radiation impinges to be treated.
The core layer(s) can be treated in order to prevent UV radiation impairing the underlying core layer in the event of possible damage to the covering layer.
In a particularly preferred embodiment, the transparent, amorphous sheet according to the invention comprises, as the main constituent, a crystallizable polyethylene terephthalate for the core layer and covering layer and 0.01% by weight to 8.0% by weight of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyl)oxyphenol or 0.01% by weight to 8.0% by weight of 2,2'-methylenebis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetra-methylbutyl)phenol in the covering layer.
A mixture of these compounds and a mixture of at least one of these compounds with at least one other UV stabilizer can of course also be used.
CA 02262~43 1999-01-29 The sheet according to the invention can also be treated with at least one antioxidant.
Antioxidants are chemical compounds which can delay the oxidation and hydrolysis phenomena and the resulting aging.
Antioxidants which are suitable for the sheet according to the invention can be classified as follows:
Additive group Substance class Primary antioxidants Sterically hindered phenols and/or secondary aromatic amines Secondary antioxidants Phosphites and phosphonites, thioethers, carbodiimides, zinc dibutyldithio-carbamate Mixtures of primary and secondary antioxidants and/or mixtures of secondary and/or primary antioxidants with UV stabilizers can furthermore 15 be used. It has been found, surprisingly, that such mixtures show a synergistic effect.
In a preferred embodiment, the amorphous sheet according to the invention comprises a phosphite and/or a phosphonite and/or a 20 carbodiimide as a hydrolysis and oxidation stabilizer.
Examples of antioxidants used according to the invention are 2-[(2,4,8,10-tetrakis(1 ,1 -dimethylethyl)dibenzo[d,f][1 ,3,2]-dioxaphosphepin-6-yl]oxy)-ethyl]ethanamine and tris(2,4-di-tert-butylphenyl) phosphite.
The antioxidant is usually present in a concentration of 0.01 to 6% byweight, based on the weight of the thermoplastic of the layer treated with this.
30 The thickness of the multilayered sheet according to the invention varies between 1 mm and 20 mm, it being possible for the thickness of the CA 02262~43 1999-01-29 covering layer(s) to be between 10 ~m and 1 mm, depending on the sheet thickness. The covering layers preferably each have a thickness of between 400 and 5001~m.
As already stated, the sheet according to the invention can have several core and covering layers which are laid one on top of the other like a sandwich. However, the sheet can also consist of only one covering layer and one core layer.
A structure having two covering layers and a core layer Iying between the covering layers is particularly preferred according to the invention.
The individual covering and core layers can comprise different or identical crystallizable thermoplastics as the main constituents, as long as the thermoplastic of a core layer has a higher standard viscosity than the thermoplastic of the covering layers directly adjacent to this core layer.
If desired, the transparent, amorphous, multilayered sheet according to the invention, which optionally comprises one or more additives, can be provided with a scratch-resistant surface on one side or several sides.
Possible coating systems and materials for the scratch-resistant surface (coating) are all the systems and materials known to the expert.
Suitable coating systems and materials are described, in particular, in the applicant's German Patent Application No. 196 255 34.1, to the full contents of which reference is made for the present invention.
From the large number of possible coating systems and materials, some are mentioned as examples below.
(1) US-A-4822828 discloses aqueous, radiation-curable coating compositions which comprise, in each case based on the weight of the dispersion, (A) from 50 to 85% of a silane having vinyl groups, (B) from 15 to 50% of a multifunctional acrylate and, if appropriate, (C) 1 to 3% of a CA 02262~43 1999-01-29 photoinitiator.
(2) Inorganic/organic polymers, so-called ormocers (organically modified ceramics), which combine the properties of ceramic materials and 5 polymers, are also known. Ormocers are employed, in particular, as hard and/or scratch-resistant coatings on polymethyl methacrylate (PMMA) and polycarbonate (PC). The hard coatings are bonded on the basis of Al2O3, ZrO2, TiO2 or SiO2 as network formers and epoxide or methacrylate groups with Si by -Si-C- compounds.
Multilayered sheets of plastics materials are known per se.
Such sheets of branched polycarbonates are described in EP-A-0 247 480, EP-A-320 632 and US-A 5,108,835.
UV-stabilized polycarbonate shaped articles which are built up from polydiorganosiloxane-polycarbonate block copolymers are known from DE-A-34 14 116 and US-A 4,600,632.
Multilayered sheets of plastic with layers of polydiorganosiloxane-polycarbonate block copolymers which comprise UV absorbers are known from US-A 5,137,949. UV-stabilized, branched polycarbonates from specific diphenols are known from EP-A-0 416 404. It is mentioned that such polycarbonates can be employed for the production of sheets or webbed multiple sheets.
All these sheets are made of polycarbonate, an amorphous thermoplastic which cannot be crystallized. Polycarbonate sheets have the disadvantage that they often lead to blooming in the form of white specks and surface deposits, especially in the UV-stabilized embodiment (cf. EP-A-0 649 724).
According to EP-A-0 649 724, for example, evaporating out of the UV
absorber is linked to a high degree to the average molecular weight.
These PC plates furthermore are readily flammable and therefore require the addition of flameproofing agents so that they can be employed for CA 02262~43 1999-01-29 . _ .
certain purposes, such as for interior applications. Tedious predrying times and relatively long processing times at high temperatures are necessary for further processing of these sheets to moldings. Devolatilizing extruders must furthermore be used during sheet production for the purpose of 5 withdrawing moisture, which means that the additives added to the raw material can also be removed at the same time, especially if low molecular weight, readily volatile additives are employed.
Single-layered, transparent amorphous sheets having a thickness in the 10 range from 1 to 20 mm which comprise, as the main constituent, a crystallizable thermoplastic, such as, for example, polyethylene terephthalate, have already been described by the Applicant (German Patent Applications Nos 19519579.5,19522118. 4 and 19528336.8).
These sheets can have a standard viscosity of 800-6000 and comprise a 15 UV stabilizer.
EP-A-0 471 528 describes a process for shaping an object from a polyethylene terephthalate (PET) sheet. The PET sheet is heat-treated on both sides in a thermoforming mold in a temperature range between the 20 glass transition temperature and the melting temperature. The shaped PET
sheet is removed from the mold when the extent of crystallization of the shaped PET sheet is in the range from 25 to 50%. The PET sheets disclosed in EP-A-0 471 528 have a thickness of 1 to 10 mm. Since the thermoformed shaped article produced from this PET sheet is partly 25 crystalline and therefore no longer transparent and the surface properties of the shaped article are determined by the thermoforming process and the temperatures and shapes given by this, the optical properties (for example gloss, clouding and light transmission) of the PET sheets employed are unimportant. As a rule, the optical properties of these sheets are poor and 30 in need of optimization. These polyethylene terephthalate sheets also have a single-layer construction.
US-A-3 496 143 describes vacuum thermoforming of a 3 mm thick PET
sheet, the crystallization of which should be in the range from 5 to 25%.
CA 02262~43 1999-01-29 The crystallinity of the themmoformed shaped article is greater than 25%.
On these PET sheets also, no requirements are imposed in respect of optical properties. Since the crystallinity of the sheets employed is already between 5% and 25%, these sheets are cloudy and nontransparent. These 5 partly crystalline PET sheets are also single-layered.
Austrian Patent Specification No. 304 086 describes a process for the production of transparent shaped articles by the thermoforming process, a PET sheet or film having a degree of crystallinity of less than 5% being 10 employed as the starting material.
The sheet or film used as the starting material has been produced from a PET having a crystallization temperature of at least 1 60~C. From this relatively high crystallization temperature it follows that the PET here is not a PET homopolymer but a glycol-modified PET, called PET-G for short, 15 which is a PET copolymer.
In contrast to pure PET, PET-G shows an extremely low tendency toward crystallization and is usually present in the amorphous state because of the glycol units additionally incorporated.
20 The object of the present invention is to provide a multilayered, amorphous, transparent sheet having a thickness of 1 mm to 20 mm which is distinguished by good mechanical and optical properties.
The good optical properties include, for example, a high light transmission, 25 a high surface gloss, an extremely low clouding and a high image sharpness (clarity).
The good mechanical properties include, inter alia, a high impact strength and a high fracture strength.
Furthermore, the sheet according to the invention should be recyclable, in particular without loss of the mechanical properties, and poorly combustible, so that, for example, it can also be used for interior applications and in exhibition construction.
CA 02262~43 1999-01-29 This object is achieved by a multilayered, transparent, amorphous sheet having a thickness of 1 to 20 mm which comprises a crystallizable thermoplastic as the main constituent, wherein the sheet has at least one core layer and at least one covering layer, and wherein the standard 5 viscosity of the crystallizable thermoplastic of the core layer is higher thanthe standard viscosity of the crystallizable thermoplastic of the covering layer.
Amorphous sheet in the context of the present invention is understood as 10 meaning those sheets which are noncrystalline, although the crystallizable thermoplastic employed preferably has a crystallinity of between 5 and 65%. Noncrystalline, i.e. essentially amorphous, means that the degree of crystallinity is in general below 5%, preferably below 2%, and particularly preferably is 0%, and that the sheet essentially shows no orientation.
~ According to the invention, crystallizable thermoplastic is understood as meaning - crystallizable homopolymers, - crystallizable copolymers, 20 - crystallizable compounds, - crystallizable recycled material and - other variations of crystallizable thermoplastics.
Examples of suitable thermoplastics are polyalkylene terephthalates with a 25 C1 to C12-alkylene radical, such as polyethylene terephthalate and polybutylene terephthalate, polyalkylene naphthalate with a C1 to C12-alkylene radical, such as polyethylene naphthalate and polybutylene naphthalate, and crystallizable cycloolefin polymers and cycloolefin copolymers, it being possible for the thermoplastic or thermoplastics for the 30 core layer(s) and the thermoplastic or thermoplastics for the covering layer(s) to be identical or different.
Polyolefins have also proved to be suitable for the covering layer.
Thermoplastics having a crystallite melting point Tm~ measured by DSC
CA 02262~43 1999-01-29 (differential scanning calorimetry) with a heating-up rate of 10~C/minute, of 220~C to 260~C, preferably 230~C to 250~C, a crystallization temperature range Tc ~f between 75~C and 260~C, a glass transition temperature Tg of between 65~C and 90~C and a density, measured in accordance with DIN
53479, of 1.30 to 1.45 g/cm3 and a crystallinity of between 5% and 65%
are preferred polymers for the core layer and the covering layer as starting materials for production of the sheet. A thermoplastic having a cold (after-)crystallization temperature TCC ~f 120 to 158~C, in particular 130 to 158~C, is particularly preferred for the purposes according to the invention.
The bulk density, measured in accordance with DIN 53466, is preferably between 0.75 kg/dm3 and 1.0 kg/dm3, and particularly preferably between 0.80 kg/dm3 and 0.90 kg/dm3.
The polydispersity M~,JMn of the thermoplastic, measured by means of GPC, is preferably between 1.5 and 6.0, and particularly preferably between 2.0 and 5Ø
A particularly preferred crystallizable thermoplastic for the core layer(s) and the covering layer(s) is polyethylene terephthalate. The polyethylene terephthalate preferably used according to the invention essentially comprises monomer units of the following formula O O
ECH2-CH2-O C~C O~
It is essential to the invention that the thermoplastic or thermoplastics of the core layer(s) has or have a higher standard viscosity than the thermoplastic or thermoplastics of the covering layer(s). The standard 30 viscosities of various core and/or covering layers of a multilayered sheet can differ.
The standard viscosity SV (DCA) of the crystallizable thermoplastic of the core layer, measured in dichloroacetic acid in accordance with DIN 53728, CA 02262~43 1999-01-29 is preferably between 800 and 5000, and particularly preferably between 1000 and 4500.
The standard viscosity SV (DCA) of the crystallizable thermoplastic of the covering layer, measured in dichloroacetic acid in accordance with DIN
53728,is preferably between 500 and 4500, and particularly preferably between 700 and 4000.
The intrinsic viscosity IV (DCA) can be calculated from the standard viscosity SV (DCA) as follows:
IV (DCA)= 6.67 x 10-4 SV(DCA)+ 0.118 The crystallizable thermoplastics used according to the invention can be obtained by customary processes known to the expert. In general, thermoplastics such as are used according to the invention can be oblained by polycondensation in the melt or by a two-stage polycondensation. The first step here is carried out up to a moderate molecular weight - corresponding to a moderate intrinsic viscosity IV of about 0.5 to 0.7- in the melt, and the further condensation is carried out by means of solid condensation. The polycondensation is usually carried out in the presence of known polycondensation catalysts or catalyst systems.
In the solid condensation, chips of the thermoplastic are heated at temperatures in the range from 180 to 320~C under reduced pressure or under an inert gas until the desired molecular weight is reached.
For example, the preparation of polyethylene terephthalate, which is particularly preferred according to the invention, is described in detail in a large number of patent applications, such as in JP-A-60-139 717,DE-C-2 429 087, DE-A-27 07 491,DE-A-23 19 089,DE-A-16 94 461,JP-63-41 528,JP-62-39 621,DE-A-41 17 825,DE-A-42 26 737,JP-60-141 715,DE-A-27 21 501 and US-A-5 296 586.
Polyethylene terephthalates having particularly high molecular weights can CA 02262~43 1999-01-29 be prepared, for example, by polycondensation of dicarboxylic acid-diol precondensates (oligomers) at elevated temperature in a liquid heat transfer medium in the presence of customary polycondensation catalysts and, if appropriate, cocondensable modifying agents, if the liquid heat 5 transfer medium is inert and free from aromatic structural groups and has a boiling point in the range from 200 to 320~C, the weight ratio of dicarboxylic acid-diol precondensate (oligomers) employed to liquid heat transfer medium is in the range from 20:80 to 80:20, and the polycondensation is carried out in a boiling reaction mixture in the presence of a dispersion 10 stabilizer.
The multilayered, transparent, amorphous sheet according to the invention can furthermore be treated with suitable additives, if desired. These additives can be added, as required, to one or more layers of the sheet 15 individually or as a mixture.
- Examples of suitable additives are UV stabilizers and antioxidants, such as are described in German Patent Application No. 195 221 18.4 and the application by the same Applicant, attached at the same time, entitled 'Polyethylene terephthalate sheet of improved stability to hydrolysis'. By 20 citation, these applications are valid as a constituent of the disclosure content of the present application.
As stated above, the multilayered, transparent, amorphous sheet can additionally comprise at least one UV stabilizer as a light stabilizer in the 25 covering layer(s) and/or the core layer(s).
Light, in particular the ultraviolet portion of solar radiation, i.e. the wavelength range from 280 to 400 nm, initiates degradation processes in thermoplastics, as a consequence of which not only does the visual 30 appearance change, owing to a change in color or yellowing, but also the mechanical-physical properties are adversely influenced.
Inhibition of these photooxidative degradation processes is of considerable industrial and economic importance, since otherwise the possible uses of CA 02262~43 1999-01-29 numerous thermoplastics are limited drastically.
A high UV stability means that the sheet is not damaged or is damaged only extremely little by sunlight or other UV radiation, so that the sheet is 5 suitable for exterior applications and/or critical interior applications, and shows no or only slight yellowing even after several years of external use.
Polyethylene terephthalates, for example, already start to absorb UV light below 360 nm, and their absorption increases considerably below 320 nm 10 and is very pronounced below 300 nm. The maximum absorption is between 280 and 300 nm.
In the presence of oxygen, chiefly chain splitting reactions but no crosslinking reactions are observed here. Carbon monoxide, carbon dioxide and carboxylic acids are the predominant photooxidation products 15 in terms of amount. In addition to direct photolysis of the ester groups, ~ oxidation reactions which likewise result in the formation of carbon dioxide via peroxide radicals must also be taken into consideration.
The photooxidation of polyethylene terephthalates can also lead, via splitting-off of hydrogen in the cx-position of the ester groups, to 20 hydroperoxides and decomposition products thereof and to associated chain splitting reactions (H. Day, D. M. Wiles: J. Appl. Polym. Sci 16,1972, page 203).
UV stabilizers, also called light stabilizers or UV absorbers, are chemical 25 compounds which can intervene in the physical and chemical processes of light-induced degradation.
Certain pigments, such as, for example, carbon black, can also partly have the effect of light stabilization. However, these substances are unsuitable 30 for the transparent sheets according to the invention, since they lead to discoloration or a change in color. Only those UV stabilizers, for example, from the class of organic and organometallic compounds which bring about very, very little or no color or change in color in the thermoplastic to be stabilized are expediently used for the amorphous sheets according to the CA 02262~43 1999-01-29 invention.
Examples of UV stabilizers which are suitable for the present invention are 2-hydroxybenzophenones, 2-hydroxybenzotriazoles, organonickel compounds, salicylic acid esters, cinnamic acid ester derivatives, resorcinol monobenzoate, oxalic acid anilides, hydroxybenzoic acid esters, sterically hindered amines and triazines, 2-hydroxybenzotriazoles and triazines being preferred.
Mixtures of several UV stabilizers can also be employed.
The UV stabilizer is expediently present in a covering layer in a concentration of 0.01% by weight to 8% by weight, based on the weight of the thermoplastic in the covering layer treated with the stabilizer. However, the UV stabilizer can also be added to a core layer. In this case, a concentration of 0.01% by weight to 1% by weight, based on the weight of ~ the thermoplastic in the core layer treated with the stabilizer, is sufficient.
According to the invention, several layers can be treated simultaneously with UV stabilizer. In general, however, it is sufficient for the layer on whichthe UV radiation impinges to be treated.
The core layer(s) can be treated in order to prevent UV radiation impairing the underlying core layer in the event of possible damage to the covering layer.
In a particularly preferred embodiment, the transparent, amorphous sheet according to the invention comprises, as the main constituent, a crystallizable polyethylene terephthalate for the core layer and covering layer and 0.01% by weight to 8.0% by weight of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyl)oxyphenol or 0.01% by weight to 8.0% by weight of 2,2'-methylenebis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetra-methylbutyl)phenol in the covering layer.
A mixture of these compounds and a mixture of at least one of these compounds with at least one other UV stabilizer can of course also be used.
CA 02262~43 1999-01-29 The sheet according to the invention can also be treated with at least one antioxidant.
Antioxidants are chemical compounds which can delay the oxidation and hydrolysis phenomena and the resulting aging.
Antioxidants which are suitable for the sheet according to the invention can be classified as follows:
Additive group Substance class Primary antioxidants Sterically hindered phenols and/or secondary aromatic amines Secondary antioxidants Phosphites and phosphonites, thioethers, carbodiimides, zinc dibutyldithio-carbamate Mixtures of primary and secondary antioxidants and/or mixtures of secondary and/or primary antioxidants with UV stabilizers can furthermore 15 be used. It has been found, surprisingly, that such mixtures show a synergistic effect.
In a preferred embodiment, the amorphous sheet according to the invention comprises a phosphite and/or a phosphonite and/or a 20 carbodiimide as a hydrolysis and oxidation stabilizer.
Examples of antioxidants used according to the invention are 2-[(2,4,8,10-tetrakis(1 ,1 -dimethylethyl)dibenzo[d,f][1 ,3,2]-dioxaphosphepin-6-yl]oxy)-ethyl]ethanamine and tris(2,4-di-tert-butylphenyl) phosphite.
The antioxidant is usually present in a concentration of 0.01 to 6% byweight, based on the weight of the thermoplastic of the layer treated with this.
30 The thickness of the multilayered sheet according to the invention varies between 1 mm and 20 mm, it being possible for the thickness of the CA 02262~43 1999-01-29 covering layer(s) to be between 10 ~m and 1 mm, depending on the sheet thickness. The covering layers preferably each have a thickness of between 400 and 5001~m.
As already stated, the sheet according to the invention can have several core and covering layers which are laid one on top of the other like a sandwich. However, the sheet can also consist of only one covering layer and one core layer.
A structure having two covering layers and a core layer Iying between the covering layers is particularly preferred according to the invention.
The individual covering and core layers can comprise different or identical crystallizable thermoplastics as the main constituents, as long as the thermoplastic of a core layer has a higher standard viscosity than the thermoplastic of the covering layers directly adjacent to this core layer.
If desired, the transparent, amorphous, multilayered sheet according to the invention, which optionally comprises one or more additives, can be provided with a scratch-resistant surface on one side or several sides.
Possible coating systems and materials for the scratch-resistant surface (coating) are all the systems and materials known to the expert.
Suitable coating systems and materials are described, in particular, in the applicant's German Patent Application No. 196 255 34.1, to the full contents of which reference is made for the present invention.
From the large number of possible coating systems and materials, some are mentioned as examples below.
(1) US-A-4822828 discloses aqueous, radiation-curable coating compositions which comprise, in each case based on the weight of the dispersion, (A) from 50 to 85% of a silane having vinyl groups, (B) from 15 to 50% of a multifunctional acrylate and, if appropriate, (C) 1 to 3% of a CA 02262~43 1999-01-29 photoinitiator.
(2) Inorganic/organic polymers, so-called ormocers (organically modified ceramics), which combine the properties of ceramic materials and 5 polymers, are also known. Ormocers are employed, in particular, as hard and/or scratch-resistant coatings on polymethyl methacrylate (PMMA) and polycarbonate (PC). The hard coatings are bonded on the basis of Al2O3, ZrO2, TiO2 or SiO2 as network formers and epoxide or methacrylate groups with Si by -Si-C- compounds.
(3) Coating compositions for acrylic resin plastics and polycarbonate based on silicone resin in aqueous-organic solution which have a particularly high storage stability are described, for example, in EP-A-0 073 362 and EP-A-0 073 911. This technique uses the condensation products 15 of partly hydrolyzed organosilicon compounds as coating compositions, - above all for glass, and in particular for acrylic resin plastics and PC.
(4) Acrylic-containing coatings are also known, such as, for example, the Uvecryl coatings from UCB Chemicals. One example is Uvecryl 29203, 20 which is cured with UV light. This material comprises a mixture of urethane acrylate oligomers with monomers and additives. Constituents are about 81% of acrylate oligomers and 19% of hexanediol diacrylate. These coatings are likewise described for PC and PMMA.
25 (5) CVD or PVD coating technologies with the aid of a polymerizing plasma and diamond-like coatings are also described in the literature (Dunnschichttechnologie [thin-layer technology], edited by Dr. Hartmut Frey and Dr. Gerhard Kienel, VDI Verlag, Dusseldorf,1987). These technologies are used here in particular for metals, PC and PMMA.
Other commercially obtainable coatings are, for example, Peeraguard from Peerless, Clearlite and Filtalite from Charvo, coating types such as, for example, the UVHC series from GE Silicones, Vuegard such as the 900 series from TEC Electrical Components, Highlink OG series from Société
CA 02262~43 1999-01-29 Francaise Hoechst, PPZ(~ products marketed by Siber Hegner (produced by Idemitsu) and coating materials from Vianova Resins, Toagoshi, Toshiba or Mitsubishi. These coatings are also described for PC and PMMA.
Coating processes known from the literature are, for example, offset printing, pouring on, dipping processes, flooding processes, spray processes or atomizing processes, knife-coating or rolling.
10 Coatings applied by the processes described are then cured, for example by means of UV radiation and/or heat. For the coating processes, it may be advantageous to treat the surface to be coated with a primer, for example based on acrylate or an acrylic latex, before application of the coating.
15 Other known processes are, for example:
~ CVD processes and vacuum plasma processes, such as, for example, vacuum plasma polymerization, PVD processes, such as coating with electron beam vaporization, resistance-heated vaporizer sources or coating by conventional processes under a high vacuum, such as in the 20 case of a conventional metallization.
Literature on CVD and PVD is, for example: Moderne Beschichtungs-verfahren [Modern coating processes] by H.-D. Steffens and W. Brandl.
DGM Informationsgesellschaft Verlag Oberursel. Other literature on 25 coatings: Thin Film Technology by L. Maissel, R. Glang, McGraw-Hill, New York ( 1 983) .
Coating systems which are particularly suitable for the purposes of the present invention are systems (1), (2), (4) and (5), coating system (4) being 30 particularly preferred.
Suitable coating processes are, for example, also the pouring, the spraying, the atomizing, the dipping and the offset process, the atomizing process being preferred for the coating system (4).
CA 02262~43 1999-01-29 For coating the amorphous sheets, curing with UV radiation and/or at temperatures which preferably do not exceed 80~C can be carried out, UV
curing being preferred.
25 (5) CVD or PVD coating technologies with the aid of a polymerizing plasma and diamond-like coatings are also described in the literature (Dunnschichttechnologie [thin-layer technology], edited by Dr. Hartmut Frey and Dr. Gerhard Kienel, VDI Verlag, Dusseldorf,1987). These technologies are used here in particular for metals, PC and PMMA.
Other commercially obtainable coatings are, for example, Peeraguard from Peerless, Clearlite and Filtalite from Charvo, coating types such as, for example, the UVHC series from GE Silicones, Vuegard such as the 900 series from TEC Electrical Components, Highlink OG series from Société
CA 02262~43 1999-01-29 Francaise Hoechst, PPZ(~ products marketed by Siber Hegner (produced by Idemitsu) and coating materials from Vianova Resins, Toagoshi, Toshiba or Mitsubishi. These coatings are also described for PC and PMMA.
Coating processes known from the literature are, for example, offset printing, pouring on, dipping processes, flooding processes, spray processes or atomizing processes, knife-coating or rolling.
10 Coatings applied by the processes described are then cured, for example by means of UV radiation and/or heat. For the coating processes, it may be advantageous to treat the surface to be coated with a primer, for example based on acrylate or an acrylic latex, before application of the coating.
15 Other known processes are, for example:
~ CVD processes and vacuum plasma processes, such as, for example, vacuum plasma polymerization, PVD processes, such as coating with electron beam vaporization, resistance-heated vaporizer sources or coating by conventional processes under a high vacuum, such as in the 20 case of a conventional metallization.
Literature on CVD and PVD is, for example: Moderne Beschichtungs-verfahren [Modern coating processes] by H.-D. Steffens and W. Brandl.
DGM Informationsgesellschaft Verlag Oberursel. Other literature on 25 coatings: Thin Film Technology by L. Maissel, R. Glang, McGraw-Hill, New York ( 1 983) .
Coating systems which are particularly suitable for the purposes of the present invention are systems (1), (2), (4) and (5), coating system (4) being 30 particularly preferred.
Suitable coating processes are, for example, also the pouring, the spraying, the atomizing, the dipping and the offset process, the atomizing process being preferred for the coating system (4).
CA 02262~43 1999-01-29 For coating the amorphous sheets, curing with UV radiation and/or at temperatures which preferably do not exceed 80~C can be carried out, UV
curing being preferred.
5 The coating according to system (4) has the advantage that no crystallization which could cause clouding occurs. Furthermore, the coating shows an outstanding adhesion, outstanding optical properties and a very good resistance to chemicals and causes no impairment of the intrinsic color.
The thickness of the scratch-resistant coating is in general between 1 and 50 ~m.
The amorphous sheet according to the invention, which comprises a 15 crystallizable thermoplastic, such as, for example, PET, as the main - constituent, has outstanding mechanical and optical properties. Thus, when the impact strength an according to Charpy (measured in accordance with ISG 179/1 D) is measured on the sheet, preferably no fracture occurs.
Furthermore, the notched impact strength ak according to Izod (measured 20 in accordance with ISO 1 80/1A) of the plate is preferably in the range of 2.0 to 8.0 kJ/m2, particularly preferably in the range from 4.0 to 6.0 kJ/m2.
The distinctness of image of the sheet, which is also called clarity and is determined at an angle of less than 2.5~ (ASTM D 1003), is preferably 25 more than 95%, and particularly preferably more than 96%.
The surface gloss, measured in accordance with DIN 67530 (measurement angle 20~), is greater than 110, preferably greater than 120; the light transmission, measured in accordance with ASTM D 1003, is more than 30 80%, preferably more than 84%; and the clouding of the sheet, measured in accordance with ASTM D 1003 is less than 15%, preferably less than 1 1 %.
Weathering tests have shown that even after 5 to 7 years of exterior use, CA 02262~43 1999-01-29 the UV-stabilized sheet according to the invention shows no visible yellowing and no visible loss of gloss, as well as no visible surface defects.
Furthermore, the sheet according to the invention is poorly flammable and 5 produces non-burning drips with very little evolution of smoke, so that it is also particularly suitable for interior applications and in exhibition construction.
The sheet according to the invention furthermore can recycled without 10 problems, without pollution of the environment and without loss in the mechanical properties, which means that it is suitable, for example, for the production of short-lived advertising signs or other advertising articles.
Outstanding and economical thermoforming properties (heat forming and 15 vacuum forming properties) have in addition completely unexpectedly been ~ found. Surprisingly, in contrast to polycarbonate sheets, it is not necessary to predry the sheet according to the invention before thermoforming. For example, polycarbonate sheets must be predried at about 1 25~C for 3 to 50 hours before thermoforming, depending on the sheet thickness.
Furthermore, the sheet according to the invention can be obtained withvery low thermoforming cycle times and at low temperatures during the thermoforming. On the basis of these properties, shaped articles can be produced economically and with a high productivity from the sheet 25 according to the invention on customary thermoforming machines.
The production of the multilayered, transparent, amorphous sheet according to the invention, which has been treated with one or more additives if appropriate, can be carried out, for example, by the coextrusion 30 process known per se in an extrusion line.
In this case, an extruder for plasticizing and producing the core layer and a further extruder per covering layer are each connected to a coextruder adapter. The adapter is constructed such that the melts which form the CA 02262~43 1999-01-29 covering layers and, if appropriate, are UV-stabilized are applied as thin layers adhesively to the melt of the core layer. The multilayered melt strand thus produced is then shaped in the downstream die and sized, polished and cooled in the polishing stack, before the sheet is cut to size.
The process for the production of the sheets according to the invention is described generally below.
If necessary, the thermoplastic polymer can be dried before the 1 0 coextrusion.
Drying can expediently be carried out at temperatures in the range from 110 to 1 90~C over a period of 1 to 7 hours. The main drier is associated with the main extruder, and, per covering layer, one drier is associated with one coextruder.
- Thereafter, the thermoplastics for the core layer(s) and the top layer(s) are melted in the main extruder and in the coextruders. The temperature of the melt is preferably in the range from 230 to 330~C, it then being possible for the temperature of the melt to be established essentially both by the temperature of the extruder and by the residence time of the melt in the extruder.
If polyethylene terephthalate, which is preferred according to the invention as the thermoplastic, is used, drying is usually carried out at 160 to 1 80~C
for 4 to 6 hours and the temperature of the melt is established in the range from 250 to 320~C.
If an additive, such as a UV stabilizer and/or an antioxidant, is used, these can already be metered in by the manufacturer of the raw material or can be metered into the extruder during sheet production.
Addition of additives via masterbatch technology is particularly preferred. In this case, the additives are dispersed completely in a solid carrier material.
Possible carrier materials are certain resins, the thermoplastic itself or else other polymers which are sufficiently compatible with the thermoplastic.
CA 02262~43 1999-01-29 It is important that the particle size and bulk density of the masterbatch are similar to the particle size and bulk density of the thermoplastic, so that homogeneous distribution and thus a homogeneous effect of the additives, such as, for example, stabilization to UV and hydrolysis, can be achieved.
As already stated, the main extruder for production of the core layer and the coextruder or coextruders are connected to a coextruder adapter such that the melts forming the covering layers are applied as thin layers adhesively to the melt of the core layer. The multilayered melt strand thus 10 produced is shaped in a die connected to the line. This die is preferably a slot die.
The multilayered melt strand shaped by a slot die is then sized by polishing calender rolls, i.e. cooled intensively and polished. The calender rolls used 15 can be arranged, for example, in an 1-, F-, L- or S-shape.
The material can then be aftercooled on a roller conveyor, trimmed to size at the edges, cut to length and stacked.
20 The thickness of the resulting sheet is essentially determined by the take-off, which is positioned at the end of the cooling zone, by the cooling (polishing) rolls coupled to this in terms of speed, and by the conveying speed of the extruder on the one hand and the distance between the rolls on the other hand.
Both single-screw and twin-screw extruders can be employed as the extruder.
The slot die preferably comprises the dismountable die body, the lips and 30 the restrictor bar for flow regulation via the width. For this, the restrictor bar can be bent by tension and pressure screws. The thickness is set by adjusting the lips. It is important to ensure that the multilayered melt strand and the lip have a uniform temperature, since otherwise the melt strand flows out in different thicknesses via the different flow paths.
CA 02262~43 1999-01-29 The sizing die, i.e. the polishing calender, gives the melt strand the shape and the dimensions. This is effected by freezing to below the glass transition temperature by means of cooling and polishing. Shaping should no longer take place in this state, since otherwise surface defects would 5 form because of the cooling which has taken place. For this reason, the calender rolls are preferably driven jointly. The temperature of the calender rolls must be lower than the crystallite melting temperature in order to avoid sticking of the melt strand. The melt strand preferably leaves the slot die with a temperature of 240 to 300~C. The first polishing/cooling roll has a 10 temperature between 50~C and 80~C, depending on the output and sheet thickness. The second, somewhat cooler, roll cools the second or other surface.
To obtain a uniform thickness in the range from 1 to 20 mm, with good 15 optical properties, it is essential for the temperature of the first polishing roll ~ to be 50 to 80~C.
While the sizing device freezes the surfaces of the sheet as smoothly as possible and cools the profile to the extent that it is dimensionally stable, 20 the aftercooling device lowers the temperature of the sheet to virtually room temperature. Aftercooling can take place on a roller board.
The speed of the take-off should be coordinated precisely with the speed of the calender rolls in order to avoid defects and variations in thickness.
As additional devices, the extrusion line for production of the sheetsaccording to the invention can comprise a separating saw as a device for cutting to length, the edge trimmer, the stacking unit and a control station.
The edge or margin trimmer is advantageous, since under certain 30 circumstances the thickness in the margin region may be nonuniform. The thickness and visual properties of the sheet are measured at the control station.
As a result of the surprisingly large number of excellent properties, the CA 02262~43 1999-01-29 transparent, amorphous sheet according to the invention is outstandingly suitable for a large number of various uses, for example for interior paneling, for exhibition construction and exhibition articles, as displays, for signs, in the illumination sector, in shopfitting and shelf construction, as 5 advertising articles, as menu stands, as basketball backboards, as room dividers, as aquaria, as information boards, as brochure and newspaper stands, and also for extemal applications, such as, for example, greenhouses, roofing, exterior paneling, coverings, for applications in the building sector, illuminated advertising profiles, balcony paneling and 10 skylights.
The invention is illustrated in more detail in the following with the aid of embodiment examples, without being limited by these.
15 Measurement of the individual properties is carried out here in accordance ~ with the following standards or methods.
Measurement methods 20 Surface gloss:
The surface gloss is determined at a measurement angle of 20~ in accordance with DIN 67530. The reflector value is measured as the optical parameter for the surface of a sheet. In accordance with the standards ASTM-D 523-78 and ISO 2813 the angle of incidence was set at 20~.
25 Under the angle of incidence set, a ray of light strikes the flat test surface and is reflected or scattered by this. The rays of light incident on the photoelectronic receiver are indicated as a proportional electrical value.
The measurement value is dimensionless and must be stated together with the angle of incidence.
Light transmission:
Light transmission is to be understood as meaning the ratio of the total light allowed through to the amount of incident light.
CA 02262~43 1999-01-29 The light transmission is measured with a "Hazegard plus" measuring instrument in accordance with ASTM D 1003.
Clouding and clarity:
5 Clouding is the percentage content of light allowed through which deviates from the incident light bundle on average by more than 2.5~. The distinctness of image is determined at an angle of less than 2.5~.
The clouding and the clarity are measured with the "Hazegard plus"
10 measuring instrument in accordance with ASTM D 1003.
Surface defects:
The surface defects are determined visually.
15 Charpy impact strength an:
This value is determined in accordance with ISO 179/1 D.
Izod impact strength ak:
The Izod notched impact strength or resistance ak is measured in 20 accordance with ISO 180/1A.
Density:
The density is determined in accordance with DIN 53479.
25 SV (DCA), IV (DCA):
The standard viscosity SV (DCA) is measured in dichloroacetic acid in accordance with DIN 53728.
The intrinsic viscosity (IV) is calculated as follows from the standard 30 viscosity (SV) IV (DCA) = 6.67 x 10-4 SV (DCA) + 0.118 CA 02262~43 l999-0l-29 Thermal properties:
The thermal properties, such as crystallite melting point Tml crystallization temperature range Tc, after-(cold)crystallization temperature TCC and glass transition temperature Tg are measured by means of differential scanning 5 calorimetry (DSC) at a heating-up rate of 10~C/minute.
Molecular weight, polydispersity:
The molecular weights Mw and Mn and the resulting polydispersity MW/Mn are measured by means of gel pemmeation chromatography (GPC).
Weathering (both sides), UV stability:
The UV stability is tested as follows in accordance with test specification Test apparatus : Atlas Ci 65 Weather Ometer - Test conditions : ISO4892, i.e. simulated weathering Irradiation time : 1000 hours (per side) Irradiation : 0.5 W/m2, 340 nm Temperature : 63~C
20 Relative atmospheric humidity : 50 %
Xenon lamp : internal and external filter of borosilicate Irradiation cycles : 102 minutes UV light, then 18 minutes UV light with spraying of the specimens with water, then 102 minutes UV light again and so on.
Change in color:
The change in color of the specimens after simulated weathering is 30 measured with a spectrophotometer in accordance with DIN 5033.
The symbols have the following meanings:
~L: Difference in lightness +~L: The specimen is lighter than the standard CA 02262~43 1999-01-29 -~L: The specimen is darker than the standard ~A: Difference in the red-green range +~A: The specimen is redder than the standard -~A: The specimen is greener than the standard QB: Difference in the blue-yellow range +~B: The specimen is yellower than the standard -~B: The specimen is bluer than the standard ~E: Total change in color ~E = (~L2 + ~A2 + ~B2)1\2 The greater the numerical deviation from the standard, the greater the 15 difference in color.
~ Numerical values of < 0.3 are negligible and mean that no significant change in color exists.
Yellow value:
20 The yellow value Y is the deviation from colorlessness in the direction of yellow and is measured in accordance with DIN 6167. Yellow value Y
values of < 5 are not visually detectable.
In the following examples and comparison examples, the sheets are in 25 each case transparent sheets of different thickness produced on the extrusion line described.
Example 1:
A 4 mm thick, multilayered, transparent, amorphous polyethylene 30 terephthalate sheet having the layer sequence A-B-A is produced by the coextrusion process described, B representing the core layer and A the covering layer. The core layer B is 3.5 mm thick and the two covering layers, which coat the core layer, are each 250 ~Jm thick.
CA 02262~43 1999-01-29 The polyethylene terephthalate employed for the base layer B has the following properties:
SV (DCA) 1100 IV (DCA) : 0.85 dl/g Density : 1.38 g/cm3 Crystallinity : 44 %
Crystallite melting pointTm : 245~C
Crystallization temperature range Tc : 82~C to 245~C
After-(cold)crystallization temperature TCC : 152~C
Polydispersity MV~/Mn : 2.02 Glass transition temperature : 82~C
The covering layers A comprise polyethylene terephthalate, as the main - constituent, and 3.0% by weight of the UV stabilizer 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol (t~)Tinuvin 1577 from Ciba-Geigy) .
Tinuvin 1577 has a melting point of 140~C and is stable to heat up to about 330~C.
To ensure a homogeneous distribution, 3.0% by weight of the UV stabilizer is incorporated into the polyethylene terephthalate directly by the manufacturer of the raw material.
The polyethylene terephthalate from which the covering layers are produced has a standard viscosity SV (DCA) of 1010, which corresponds to an intrinsic viscosity IV (DCA) of 0.79 dl/g. The moisture content is < 0.2% and the density (DIN 53479) is 1.41 g/cm3. The crystallinity is 59%, the crystallite melting point, according to DSC measurements, being 259~C. The crystallization temperature range Tc is between 83~C and 258~C, the after-crystallization temperature (also the cold crystallization temperature) TCC being 144~C. The polydispersity MW/Mn of the polyethylene terephthalate is 2.14. The glass transition temperature is 83~C.
CA 02262~43 1999-01-29 Before the coextrusion, the polyethylene terephthalate for the core layer and the UV-stabilized polyethylene terephthalate for the covering layers are each dried in a dryer at 1 70~C for 5 hours and then coextruded through 5 a slot die onto a polishing calender, the rolls of which are arranged in a S-shape, and polished to form a three-layered sheet 4 mm thick.
The extrusion temperature of the main extruder for the core layer is 282~C.
The extrusion temperatures of the two coextruders for the covering layers are 294~C. The first calender roll has a temperature of 65~C and the subsequent rolls each have a temperature of 58~C. The speed of the take-off is 4.2 m/minute.
After the aftercooling, the three-layered transparent sheet is trimmed at the 15 edges with separating saws, cut to length and stacked.
The transparent, amorphous, three-layered PET sheet obtained has the following set of properties - Layer build-up : A-B-A
- Total thickness : 4 mm - Thickness of the core layer : 3.5 mm - Thickness of the covering layer : 0.25 mm each - Surface gloss 1 st side : 185 (measurement angle 20~) 2nd side : 183 - Light transmission : 93.6%
- Clarity : 100%
- Clouding : 0.7%
- Surface defects perm2 : none (specks, orange peel, bubbles and the like) - Charpy impact strength an : no fracture - Izod notched impact strength ak : good, no defects - Crystallinity : 0%
CA 02262~43 1999-01-29 - Density : 1.33 g/cm3 After weathering for 1000 hours per side with the Atlas Ci 65 Weather Ometer, the PET sheet has the following properties:
- Total thickness : 4 mm - Surface gloss 1 st side : 166 (measurement angle 20~) 2nd side : 164 - Light transmission : 91 .1 %
- Clarity : 100%
- Clouding : 1.2%
- Total discoloration ~E : 0.22 - Dark discoloration ~L : -0.18 - Red-green discoloration ~A : -0.08 - Blue-yellowdiscoloration ~B : 0.10 ~ - Surface defects : none (cracks, embrittlement) - Yellowvalue Y : 4 20 Example 2:
A transparent, three-layered PET sheet 4 mm thick is prepared analogously to Example 1.
The core layer B is composed of 50% of the polyethylene terephthalate from Example 1 and 50% of recycled sheet from Example 1.
The transparent PET sheet obtained has the following properties profile:
- Total thickness : 4 mm - Surface gloss 1 st side : 172 (measurement angle 20~) 2nd side : 170 - Light transmission : 92.1%
- Clarity : 99.8%
- Clouding : 2.0%
- Surface defects perm2 : none CA 02262~43 1999-01-29 (specks, orange peel, bubbles and the like) - Charpyimpact strength an : no fracture - Izod notched impact strength ak : 4.6 kJ/m2 - Cold forming properties : good, no defects - Crystallinity : 0%
- Density : 133 g/cm3 After weathering for 1000 hours with the Atlas Ci 65 Weather Ometer, the PET sheet has the following properties:
- Total thickness : 4 mm - Surface gloss 1st side : 158 (measurement angle 20~) 2nd side : 154 - Light transmission : 91.1%
- Clarity : 99.4%
~ - Clouding : 2.9%
- Total discoloration ~E : 0.24 - Dark discoloration ~L : -0.19 - Red-green discoloration~A : -0.08 - Blue-yellow discoloration ~B : 0.12 - Surface defects : none - Yellowvalue Y : 4 Example 3:
25 A three-layered, transparent, amorphous sheet 6 mm thick is produced analogously to Example 1.
The covering layers comprise 3.5% by weight of the UV stabilizer 2,2'-methylene-bis-(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethyl-30 butyl)phenol ((~)Tinuvin 360 from Ciba-Geigy), based on the weight of the thermoplastic of the covering layers.
Tinuvin 360 has a melting point of 195~C and is stable to heat up to about 250~C .
CA 02262~43 1999-01-29 As in Example 1, 3.5% by weight of the UV stabilizer is incorporated directly into the polyethylene terephthalate by the manufacturer of the raw material.
5 The first calender roll has a temperature of 59~C and the subsequent rolls have a temperature of 51 ~C. The speed of the take-off is 2.5 m/minute.
The transparent PET sheet obtained has the following properties profile:
- Layer build-up : A-B-A
- Thickness of the covering layers : 0.4 mm each - Thickness of the core layer : 5.2 mm - Total thickness : 6 mm - Surface gloss 1st side : 165 (measurement angle 20~) 2nd side : 163 ~ - Light transmission : 89.1%
- Clarity : 99.6%
- Clouding : 2.4%
- Surface defects per m2 : none (specks, orange peel, bubbles and the like) - Charpy impact strength an : no fracture - Izod notched impact strength ak : 4.9 kJ/m2 - Cold forming properties : good, no defects - Crystallinity : o%
- Density : 1.33 g/cm3 After weathering for 1000 hours per side with the Atlas Ci 65 Weather Ometer, the PET sheet has the following properties:
- Thickness : 6 mm - Surface gloss 1st side : 151 (measurement angle 20~) 2nd side : 150 - Light transmission : 88.3%
- Clarity 99 5%
CA 02262~43 1999-01-29 . _ .
- Clouding : 3.1 %
Total discoloration ,~E : 0.56 - Dark discoloration ~L : -0.21 - Red-green discoloration ~A : -0.11 - Blue-yellow discoloration ~B : +0.51 - Surface defects : none (cracks, embrittlement) - Yellowvalue Y : 5 10 Example 4:
A three-layered, transparent PET sheet is produced analogously to Example 1. As in Example 3, the covering layers comprise 3.5% by weight of Tinuvin 360 as a UV stabilizer, based on the weight of the thermoplastic of the covering layer, which has been incorporated directly by the 15 manufacturer of the raw material.
~ The polyethylene terephthalate employed for the core layer has the following properties:
- SV (DCA) : 3173 - IV (DCA) : 2.23 dl/g - Density : 1.34 g/cm3 - Crystallinity : 112%
- Crystallite melting pointTm : 240~C
- Crystallization temperature range Tc : 82~C to 240~C
- After-(cold)crystallization temperature TCC : 156~C
Polydispersity MW/Mn 3.66 - Glasstransition temperature : 82~C
Mw : 204 660 g/mol - Mn : 55 952 g/mol The polyethylene terephthalate for the covering layers is the same as in Example 1. The extrusion temperature is 274~C. The first calender roll has a temperature of 50~C and the subsequent rolls have a temperature of CA 02262~43 1999-01-29 45~C. The speed of the take-off and of the calender rolls is 2.4 m/minute.
The sheet produced has the following properties profile:
- Layer build-up : A-B-A
- Thickness of the covering layers : 0.4 mm each - Thickness of the core layer : 5.2 mm - Total thickness : 6 mm - Surface gloss 1st side : 162 (measurement angle 20~) 2nd side : 159 - Light transmission : 89.3%
- Clarity : 99.3%
- Clouding : 2.2%
- Surface defects perm2 : none (specks, orange peel, bubbles and the like) - Charpy impact strength an : no fracture ~ - Izod notched impact strength ak : 5.1 kJ/m2 - Cold forming properties : good, no defects - Crystallinity : o%
- Density : 1.33 g/cm3 After weathering for 1000 hours with the Atlas Ci 65 Weather Ometer, the PET sheet has the following properties:
- Thickness : 6 mm - Surface gloss 1st side : 150 (measurement angle 20~) 2nd side : 149 - Light transmission : 86.2%
- Clarity : 99.1 %
- Clouding : 3.2%
- Total discoloration ~E : 0.47 - Dark discoloration ~L : -0.18 - Red-green discoloration aA : -0.09 - Blue-yellowdiscoloration ~B : +0.42 - Surface defects : none CA 02262~43 1999-01-29 (cracks, embrittlement) - YellowvalueY : 5 Comparison example:
5 A transparent, amorphous sheet is produced analogously to Example 1. In contrast to Example 1, the sheet comprises no UV stabilizer. The polyethylene terephthalate employed, the extrusion parameters, the process parameters and the temperatures are chosen as in Example 1.
10 The transparent, amorphous, three-layered sheet produced has the following set of properties:
- Layer build-up : A-B-A
- Thickness of the base layer : 3.5 mm - Thickness of the covering layers : 0.25 mm each ~ - Total thickness : 4 mm - Surface gloss 1st side : 189(measurement angle 20~) 2nd side : 185 - Light transmission : 93.8%
- Clarity : 100%
- Clouding : 0.8%
- Surface defects perm2 : none (specks, orange peel, bubbles and the like) - Charpy impact strength an : nofracture - Izod notched impact strength ak : 4.6 kJ/m2 - Cold forming properties : good, no defects - Crystallinity : 0%
- Density : 1.33 g/cm3 After weathering for 1000 hours per side with the Atlas Ci 65 Weather Ometer, the PET sheet has the following properties:
- Total thickness : 4 mm - Surface gloss 1st side : 98 CA 02262~43 1999-01-29 (measurement angle 20~) 2nd side : 95 - Light transmission : 79.5%
- Clarity : 81.2%
- Clouding : 7.8%
- Total discoloration ~E : 3.41 - Darkdiscoloration ~L : -0.29 - Red-green discoloration ~A : -0.87 - Blue-yellow discoloration ~B : +3.29 - Surface defects : embrittlement (cracks, embrittlement) - YellowvalueY : 17 CA 02262~43 1999-01-29
The thickness of the scratch-resistant coating is in general between 1 and 50 ~m.
The amorphous sheet according to the invention, which comprises a 15 crystallizable thermoplastic, such as, for example, PET, as the main - constituent, has outstanding mechanical and optical properties. Thus, when the impact strength an according to Charpy (measured in accordance with ISG 179/1 D) is measured on the sheet, preferably no fracture occurs.
Furthermore, the notched impact strength ak according to Izod (measured 20 in accordance with ISO 1 80/1A) of the plate is preferably in the range of 2.0 to 8.0 kJ/m2, particularly preferably in the range from 4.0 to 6.0 kJ/m2.
The distinctness of image of the sheet, which is also called clarity and is determined at an angle of less than 2.5~ (ASTM D 1003), is preferably 25 more than 95%, and particularly preferably more than 96%.
The surface gloss, measured in accordance with DIN 67530 (measurement angle 20~), is greater than 110, preferably greater than 120; the light transmission, measured in accordance with ASTM D 1003, is more than 30 80%, preferably more than 84%; and the clouding of the sheet, measured in accordance with ASTM D 1003 is less than 15%, preferably less than 1 1 %.
Weathering tests have shown that even after 5 to 7 years of exterior use, CA 02262~43 1999-01-29 the UV-stabilized sheet according to the invention shows no visible yellowing and no visible loss of gloss, as well as no visible surface defects.
Furthermore, the sheet according to the invention is poorly flammable and 5 produces non-burning drips with very little evolution of smoke, so that it is also particularly suitable for interior applications and in exhibition construction.
The sheet according to the invention furthermore can recycled without 10 problems, without pollution of the environment and without loss in the mechanical properties, which means that it is suitable, for example, for the production of short-lived advertising signs or other advertising articles.
Outstanding and economical thermoforming properties (heat forming and 15 vacuum forming properties) have in addition completely unexpectedly been ~ found. Surprisingly, in contrast to polycarbonate sheets, it is not necessary to predry the sheet according to the invention before thermoforming. For example, polycarbonate sheets must be predried at about 1 25~C for 3 to 50 hours before thermoforming, depending on the sheet thickness.
Furthermore, the sheet according to the invention can be obtained withvery low thermoforming cycle times and at low temperatures during the thermoforming. On the basis of these properties, shaped articles can be produced economically and with a high productivity from the sheet 25 according to the invention on customary thermoforming machines.
The production of the multilayered, transparent, amorphous sheet according to the invention, which has been treated with one or more additives if appropriate, can be carried out, for example, by the coextrusion 30 process known per se in an extrusion line.
In this case, an extruder for plasticizing and producing the core layer and a further extruder per covering layer are each connected to a coextruder adapter. The adapter is constructed such that the melts which form the CA 02262~43 1999-01-29 covering layers and, if appropriate, are UV-stabilized are applied as thin layers adhesively to the melt of the core layer. The multilayered melt strand thus produced is then shaped in the downstream die and sized, polished and cooled in the polishing stack, before the sheet is cut to size.
The process for the production of the sheets according to the invention is described generally below.
If necessary, the thermoplastic polymer can be dried before the 1 0 coextrusion.
Drying can expediently be carried out at temperatures in the range from 110 to 1 90~C over a period of 1 to 7 hours. The main drier is associated with the main extruder, and, per covering layer, one drier is associated with one coextruder.
- Thereafter, the thermoplastics for the core layer(s) and the top layer(s) are melted in the main extruder and in the coextruders. The temperature of the melt is preferably in the range from 230 to 330~C, it then being possible for the temperature of the melt to be established essentially both by the temperature of the extruder and by the residence time of the melt in the extruder.
If polyethylene terephthalate, which is preferred according to the invention as the thermoplastic, is used, drying is usually carried out at 160 to 1 80~C
for 4 to 6 hours and the temperature of the melt is established in the range from 250 to 320~C.
If an additive, such as a UV stabilizer and/or an antioxidant, is used, these can already be metered in by the manufacturer of the raw material or can be metered into the extruder during sheet production.
Addition of additives via masterbatch technology is particularly preferred. In this case, the additives are dispersed completely in a solid carrier material.
Possible carrier materials are certain resins, the thermoplastic itself or else other polymers which are sufficiently compatible with the thermoplastic.
CA 02262~43 1999-01-29 It is important that the particle size and bulk density of the masterbatch are similar to the particle size and bulk density of the thermoplastic, so that homogeneous distribution and thus a homogeneous effect of the additives, such as, for example, stabilization to UV and hydrolysis, can be achieved.
As already stated, the main extruder for production of the core layer and the coextruder or coextruders are connected to a coextruder adapter such that the melts forming the covering layers are applied as thin layers adhesively to the melt of the core layer. The multilayered melt strand thus 10 produced is shaped in a die connected to the line. This die is preferably a slot die.
The multilayered melt strand shaped by a slot die is then sized by polishing calender rolls, i.e. cooled intensively and polished. The calender rolls used 15 can be arranged, for example, in an 1-, F-, L- or S-shape.
The material can then be aftercooled on a roller conveyor, trimmed to size at the edges, cut to length and stacked.
20 The thickness of the resulting sheet is essentially determined by the take-off, which is positioned at the end of the cooling zone, by the cooling (polishing) rolls coupled to this in terms of speed, and by the conveying speed of the extruder on the one hand and the distance between the rolls on the other hand.
Both single-screw and twin-screw extruders can be employed as the extruder.
The slot die preferably comprises the dismountable die body, the lips and 30 the restrictor bar for flow regulation via the width. For this, the restrictor bar can be bent by tension and pressure screws. The thickness is set by adjusting the lips. It is important to ensure that the multilayered melt strand and the lip have a uniform temperature, since otherwise the melt strand flows out in different thicknesses via the different flow paths.
CA 02262~43 1999-01-29 The sizing die, i.e. the polishing calender, gives the melt strand the shape and the dimensions. This is effected by freezing to below the glass transition temperature by means of cooling and polishing. Shaping should no longer take place in this state, since otherwise surface defects would 5 form because of the cooling which has taken place. For this reason, the calender rolls are preferably driven jointly. The temperature of the calender rolls must be lower than the crystallite melting temperature in order to avoid sticking of the melt strand. The melt strand preferably leaves the slot die with a temperature of 240 to 300~C. The first polishing/cooling roll has a 10 temperature between 50~C and 80~C, depending on the output and sheet thickness. The second, somewhat cooler, roll cools the second or other surface.
To obtain a uniform thickness in the range from 1 to 20 mm, with good 15 optical properties, it is essential for the temperature of the first polishing roll ~ to be 50 to 80~C.
While the sizing device freezes the surfaces of the sheet as smoothly as possible and cools the profile to the extent that it is dimensionally stable, 20 the aftercooling device lowers the temperature of the sheet to virtually room temperature. Aftercooling can take place on a roller board.
The speed of the take-off should be coordinated precisely with the speed of the calender rolls in order to avoid defects and variations in thickness.
As additional devices, the extrusion line for production of the sheetsaccording to the invention can comprise a separating saw as a device for cutting to length, the edge trimmer, the stacking unit and a control station.
The edge or margin trimmer is advantageous, since under certain 30 circumstances the thickness in the margin region may be nonuniform. The thickness and visual properties of the sheet are measured at the control station.
As a result of the surprisingly large number of excellent properties, the CA 02262~43 1999-01-29 transparent, amorphous sheet according to the invention is outstandingly suitable for a large number of various uses, for example for interior paneling, for exhibition construction and exhibition articles, as displays, for signs, in the illumination sector, in shopfitting and shelf construction, as 5 advertising articles, as menu stands, as basketball backboards, as room dividers, as aquaria, as information boards, as brochure and newspaper stands, and also for extemal applications, such as, for example, greenhouses, roofing, exterior paneling, coverings, for applications in the building sector, illuminated advertising profiles, balcony paneling and 10 skylights.
The invention is illustrated in more detail in the following with the aid of embodiment examples, without being limited by these.
15 Measurement of the individual properties is carried out here in accordance ~ with the following standards or methods.
Measurement methods 20 Surface gloss:
The surface gloss is determined at a measurement angle of 20~ in accordance with DIN 67530. The reflector value is measured as the optical parameter for the surface of a sheet. In accordance with the standards ASTM-D 523-78 and ISO 2813 the angle of incidence was set at 20~.
25 Under the angle of incidence set, a ray of light strikes the flat test surface and is reflected or scattered by this. The rays of light incident on the photoelectronic receiver are indicated as a proportional electrical value.
The measurement value is dimensionless and must be stated together with the angle of incidence.
Light transmission:
Light transmission is to be understood as meaning the ratio of the total light allowed through to the amount of incident light.
CA 02262~43 1999-01-29 The light transmission is measured with a "Hazegard plus" measuring instrument in accordance with ASTM D 1003.
Clouding and clarity:
5 Clouding is the percentage content of light allowed through which deviates from the incident light bundle on average by more than 2.5~. The distinctness of image is determined at an angle of less than 2.5~.
The clouding and the clarity are measured with the "Hazegard plus"
10 measuring instrument in accordance with ASTM D 1003.
Surface defects:
The surface defects are determined visually.
15 Charpy impact strength an:
This value is determined in accordance with ISO 179/1 D.
Izod impact strength ak:
The Izod notched impact strength or resistance ak is measured in 20 accordance with ISO 180/1A.
Density:
The density is determined in accordance with DIN 53479.
25 SV (DCA), IV (DCA):
The standard viscosity SV (DCA) is measured in dichloroacetic acid in accordance with DIN 53728.
The intrinsic viscosity (IV) is calculated as follows from the standard 30 viscosity (SV) IV (DCA) = 6.67 x 10-4 SV (DCA) + 0.118 CA 02262~43 l999-0l-29 Thermal properties:
The thermal properties, such as crystallite melting point Tml crystallization temperature range Tc, after-(cold)crystallization temperature TCC and glass transition temperature Tg are measured by means of differential scanning 5 calorimetry (DSC) at a heating-up rate of 10~C/minute.
Molecular weight, polydispersity:
The molecular weights Mw and Mn and the resulting polydispersity MW/Mn are measured by means of gel pemmeation chromatography (GPC).
Weathering (both sides), UV stability:
The UV stability is tested as follows in accordance with test specification Test apparatus : Atlas Ci 65 Weather Ometer - Test conditions : ISO4892, i.e. simulated weathering Irradiation time : 1000 hours (per side) Irradiation : 0.5 W/m2, 340 nm Temperature : 63~C
20 Relative atmospheric humidity : 50 %
Xenon lamp : internal and external filter of borosilicate Irradiation cycles : 102 minutes UV light, then 18 minutes UV light with spraying of the specimens with water, then 102 minutes UV light again and so on.
Change in color:
The change in color of the specimens after simulated weathering is 30 measured with a spectrophotometer in accordance with DIN 5033.
The symbols have the following meanings:
~L: Difference in lightness +~L: The specimen is lighter than the standard CA 02262~43 1999-01-29 -~L: The specimen is darker than the standard ~A: Difference in the red-green range +~A: The specimen is redder than the standard -~A: The specimen is greener than the standard QB: Difference in the blue-yellow range +~B: The specimen is yellower than the standard -~B: The specimen is bluer than the standard ~E: Total change in color ~E = (~L2 + ~A2 + ~B2)1\2 The greater the numerical deviation from the standard, the greater the 15 difference in color.
~ Numerical values of < 0.3 are negligible and mean that no significant change in color exists.
Yellow value:
20 The yellow value Y is the deviation from colorlessness in the direction of yellow and is measured in accordance with DIN 6167. Yellow value Y
values of < 5 are not visually detectable.
In the following examples and comparison examples, the sheets are in 25 each case transparent sheets of different thickness produced on the extrusion line described.
Example 1:
A 4 mm thick, multilayered, transparent, amorphous polyethylene 30 terephthalate sheet having the layer sequence A-B-A is produced by the coextrusion process described, B representing the core layer and A the covering layer. The core layer B is 3.5 mm thick and the two covering layers, which coat the core layer, are each 250 ~Jm thick.
CA 02262~43 1999-01-29 The polyethylene terephthalate employed for the base layer B has the following properties:
SV (DCA) 1100 IV (DCA) : 0.85 dl/g Density : 1.38 g/cm3 Crystallinity : 44 %
Crystallite melting pointTm : 245~C
Crystallization temperature range Tc : 82~C to 245~C
After-(cold)crystallization temperature TCC : 152~C
Polydispersity MV~/Mn : 2.02 Glass transition temperature : 82~C
The covering layers A comprise polyethylene terephthalate, as the main - constituent, and 3.0% by weight of the UV stabilizer 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol (t~)Tinuvin 1577 from Ciba-Geigy) .
Tinuvin 1577 has a melting point of 140~C and is stable to heat up to about 330~C.
To ensure a homogeneous distribution, 3.0% by weight of the UV stabilizer is incorporated into the polyethylene terephthalate directly by the manufacturer of the raw material.
The polyethylene terephthalate from which the covering layers are produced has a standard viscosity SV (DCA) of 1010, which corresponds to an intrinsic viscosity IV (DCA) of 0.79 dl/g. The moisture content is < 0.2% and the density (DIN 53479) is 1.41 g/cm3. The crystallinity is 59%, the crystallite melting point, according to DSC measurements, being 259~C. The crystallization temperature range Tc is between 83~C and 258~C, the after-crystallization temperature (also the cold crystallization temperature) TCC being 144~C. The polydispersity MW/Mn of the polyethylene terephthalate is 2.14. The glass transition temperature is 83~C.
CA 02262~43 1999-01-29 Before the coextrusion, the polyethylene terephthalate for the core layer and the UV-stabilized polyethylene terephthalate for the covering layers are each dried in a dryer at 1 70~C for 5 hours and then coextruded through 5 a slot die onto a polishing calender, the rolls of which are arranged in a S-shape, and polished to form a three-layered sheet 4 mm thick.
The extrusion temperature of the main extruder for the core layer is 282~C.
The extrusion temperatures of the two coextruders for the covering layers are 294~C. The first calender roll has a temperature of 65~C and the subsequent rolls each have a temperature of 58~C. The speed of the take-off is 4.2 m/minute.
After the aftercooling, the three-layered transparent sheet is trimmed at the 15 edges with separating saws, cut to length and stacked.
The transparent, amorphous, three-layered PET sheet obtained has the following set of properties - Layer build-up : A-B-A
- Total thickness : 4 mm - Thickness of the core layer : 3.5 mm - Thickness of the covering layer : 0.25 mm each - Surface gloss 1 st side : 185 (measurement angle 20~) 2nd side : 183 - Light transmission : 93.6%
- Clarity : 100%
- Clouding : 0.7%
- Surface defects perm2 : none (specks, orange peel, bubbles and the like) - Charpy impact strength an : no fracture - Izod notched impact strength ak : good, no defects - Crystallinity : 0%
CA 02262~43 1999-01-29 - Density : 1.33 g/cm3 After weathering for 1000 hours per side with the Atlas Ci 65 Weather Ometer, the PET sheet has the following properties:
- Total thickness : 4 mm - Surface gloss 1 st side : 166 (measurement angle 20~) 2nd side : 164 - Light transmission : 91 .1 %
- Clarity : 100%
- Clouding : 1.2%
- Total discoloration ~E : 0.22 - Dark discoloration ~L : -0.18 - Red-green discoloration ~A : -0.08 - Blue-yellowdiscoloration ~B : 0.10 ~ - Surface defects : none (cracks, embrittlement) - Yellowvalue Y : 4 20 Example 2:
A transparent, three-layered PET sheet 4 mm thick is prepared analogously to Example 1.
The core layer B is composed of 50% of the polyethylene terephthalate from Example 1 and 50% of recycled sheet from Example 1.
The transparent PET sheet obtained has the following properties profile:
- Total thickness : 4 mm - Surface gloss 1 st side : 172 (measurement angle 20~) 2nd side : 170 - Light transmission : 92.1%
- Clarity : 99.8%
- Clouding : 2.0%
- Surface defects perm2 : none CA 02262~43 1999-01-29 (specks, orange peel, bubbles and the like) - Charpyimpact strength an : no fracture - Izod notched impact strength ak : 4.6 kJ/m2 - Cold forming properties : good, no defects - Crystallinity : 0%
- Density : 133 g/cm3 After weathering for 1000 hours with the Atlas Ci 65 Weather Ometer, the PET sheet has the following properties:
- Total thickness : 4 mm - Surface gloss 1st side : 158 (measurement angle 20~) 2nd side : 154 - Light transmission : 91.1%
- Clarity : 99.4%
~ - Clouding : 2.9%
- Total discoloration ~E : 0.24 - Dark discoloration ~L : -0.19 - Red-green discoloration~A : -0.08 - Blue-yellow discoloration ~B : 0.12 - Surface defects : none - Yellowvalue Y : 4 Example 3:
25 A three-layered, transparent, amorphous sheet 6 mm thick is produced analogously to Example 1.
The covering layers comprise 3.5% by weight of the UV stabilizer 2,2'-methylene-bis-(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethyl-30 butyl)phenol ((~)Tinuvin 360 from Ciba-Geigy), based on the weight of the thermoplastic of the covering layers.
Tinuvin 360 has a melting point of 195~C and is stable to heat up to about 250~C .
CA 02262~43 1999-01-29 As in Example 1, 3.5% by weight of the UV stabilizer is incorporated directly into the polyethylene terephthalate by the manufacturer of the raw material.
5 The first calender roll has a temperature of 59~C and the subsequent rolls have a temperature of 51 ~C. The speed of the take-off is 2.5 m/minute.
The transparent PET sheet obtained has the following properties profile:
- Layer build-up : A-B-A
- Thickness of the covering layers : 0.4 mm each - Thickness of the core layer : 5.2 mm - Total thickness : 6 mm - Surface gloss 1st side : 165 (measurement angle 20~) 2nd side : 163 ~ - Light transmission : 89.1%
- Clarity : 99.6%
- Clouding : 2.4%
- Surface defects per m2 : none (specks, orange peel, bubbles and the like) - Charpy impact strength an : no fracture - Izod notched impact strength ak : 4.9 kJ/m2 - Cold forming properties : good, no defects - Crystallinity : o%
- Density : 1.33 g/cm3 After weathering for 1000 hours per side with the Atlas Ci 65 Weather Ometer, the PET sheet has the following properties:
- Thickness : 6 mm - Surface gloss 1st side : 151 (measurement angle 20~) 2nd side : 150 - Light transmission : 88.3%
- Clarity 99 5%
CA 02262~43 1999-01-29 . _ .
- Clouding : 3.1 %
Total discoloration ,~E : 0.56 - Dark discoloration ~L : -0.21 - Red-green discoloration ~A : -0.11 - Blue-yellow discoloration ~B : +0.51 - Surface defects : none (cracks, embrittlement) - Yellowvalue Y : 5 10 Example 4:
A three-layered, transparent PET sheet is produced analogously to Example 1. As in Example 3, the covering layers comprise 3.5% by weight of Tinuvin 360 as a UV stabilizer, based on the weight of the thermoplastic of the covering layer, which has been incorporated directly by the 15 manufacturer of the raw material.
~ The polyethylene terephthalate employed for the core layer has the following properties:
- SV (DCA) : 3173 - IV (DCA) : 2.23 dl/g - Density : 1.34 g/cm3 - Crystallinity : 112%
- Crystallite melting pointTm : 240~C
- Crystallization temperature range Tc : 82~C to 240~C
- After-(cold)crystallization temperature TCC : 156~C
Polydispersity MW/Mn 3.66 - Glasstransition temperature : 82~C
Mw : 204 660 g/mol - Mn : 55 952 g/mol The polyethylene terephthalate for the covering layers is the same as in Example 1. The extrusion temperature is 274~C. The first calender roll has a temperature of 50~C and the subsequent rolls have a temperature of CA 02262~43 1999-01-29 45~C. The speed of the take-off and of the calender rolls is 2.4 m/minute.
The sheet produced has the following properties profile:
- Layer build-up : A-B-A
- Thickness of the covering layers : 0.4 mm each - Thickness of the core layer : 5.2 mm - Total thickness : 6 mm - Surface gloss 1st side : 162 (measurement angle 20~) 2nd side : 159 - Light transmission : 89.3%
- Clarity : 99.3%
- Clouding : 2.2%
- Surface defects perm2 : none (specks, orange peel, bubbles and the like) - Charpy impact strength an : no fracture ~ - Izod notched impact strength ak : 5.1 kJ/m2 - Cold forming properties : good, no defects - Crystallinity : o%
- Density : 1.33 g/cm3 After weathering for 1000 hours with the Atlas Ci 65 Weather Ometer, the PET sheet has the following properties:
- Thickness : 6 mm - Surface gloss 1st side : 150 (measurement angle 20~) 2nd side : 149 - Light transmission : 86.2%
- Clarity : 99.1 %
- Clouding : 3.2%
- Total discoloration ~E : 0.47 - Dark discoloration ~L : -0.18 - Red-green discoloration aA : -0.09 - Blue-yellowdiscoloration ~B : +0.42 - Surface defects : none CA 02262~43 1999-01-29 (cracks, embrittlement) - YellowvalueY : 5 Comparison example:
5 A transparent, amorphous sheet is produced analogously to Example 1. In contrast to Example 1, the sheet comprises no UV stabilizer. The polyethylene terephthalate employed, the extrusion parameters, the process parameters and the temperatures are chosen as in Example 1.
10 The transparent, amorphous, three-layered sheet produced has the following set of properties:
- Layer build-up : A-B-A
- Thickness of the base layer : 3.5 mm - Thickness of the covering layers : 0.25 mm each ~ - Total thickness : 4 mm - Surface gloss 1st side : 189(measurement angle 20~) 2nd side : 185 - Light transmission : 93.8%
- Clarity : 100%
- Clouding : 0.8%
- Surface defects perm2 : none (specks, orange peel, bubbles and the like) - Charpy impact strength an : nofracture - Izod notched impact strength ak : 4.6 kJ/m2 - Cold forming properties : good, no defects - Crystallinity : 0%
- Density : 1.33 g/cm3 After weathering for 1000 hours per side with the Atlas Ci 65 Weather Ometer, the PET sheet has the following properties:
- Total thickness : 4 mm - Surface gloss 1st side : 98 CA 02262~43 1999-01-29 (measurement angle 20~) 2nd side : 95 - Light transmission : 79.5%
- Clarity : 81.2%
- Clouding : 7.8%
- Total discoloration ~E : 3.41 - Darkdiscoloration ~L : -0.29 - Red-green discoloration ~A : -0.87 - Blue-yellow discoloration ~B : +3.29 - Surface defects : embrittlement (cracks, embrittlement) - YellowvalueY : 17 CA 02262~43 1999-01-29
Claims (35)
1. A multilayered, transparent, amorphous sheet having a thickness in the range from 1 to 20 mm, which comprises a crystallizable thermoplastic as the main constituent, wherein the sheet has a multilayered build-up of at least one core layer and at least one covering layer, the standard viscosity of the thermoplastic contained in the core layer being greater than the standard viscosity of the thermoplastic contained in the covering layer.
2. The sheet as claimed in claim 1, wherein the standard viscosity of the thermoplastic of the core layer, of which it comprises at least one, is in the range from 800 to 5000 and that of the thermoplastic of the covering layer, of which it comprises at least one, is in the range from 500 to 4500.
3. The sheet as claimed in claim 1 or 2, wherein the sheet has two covering layers and a core layer lying between the covering layers.
4. The sheet as claimed in one of the preceding claims, wherein at least one of the core and/or covering layer(s) is treated with at least one UV stabilizer.
5. The sheet as claimed in claim 4, wherein the concentration of the UV stabilizer in a layer is 0.01 to 8% by weight, based on the weight of the thermoplastic of the layer comprising the UV stabilizer.
6. The sheet as claimed in claim 4 or 5, wherein the concentration of the UV stabilizer in the core layer, of which it comprises at least one, is 0.01 to 1% by weight, based on the weight of the thermoplastic of the core layer comprising the UV stabilizer.
7. The sheet as claimed in one of claims 4 to 6, wherein the UV
stabilizer is chosen from 2-hydroxybenzotriazoles, triazines and mixtures thereof.
stabilizer is chosen from 2-hydroxybenzotriazoles, triazines and mixtures thereof.
8. The sheet as claimed in claim 7, wherein the UV stabilizer is chosen from 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyl)oxyphenol and 2,2'-methylenebis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethyl-butyl)phenol.
9. The sheet as claimed in one of the preceding claims, wherein at least one of the core and/or covering layers is treated with at least one antioxidant.
10. The sheet as claimed in claim 9, wherein the antioxidant is present in a concentration of 0.1 to 6% by weight, based on the weight of the thermoplastic of the layer treated with this.
11. The sheet as claimed in claim 9 or 10, wherein the antioxidant, of which it comprises at least one, is chosen from sterically hindered phenols, secondary aromatic amines, phosphites, phosphonites, thioethers, carbodiimides and zinc dibutyldithiocarbamate.
12. The sheet as claimed in claim 11, wherein the antioxidant is 2-[2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxa-phosphepin-6-yl]oxy)-ethyl]ethanamine and/or tris(2,4-di-tert-butylphenyl) phosphite.
13. The sheet as claimed in one of the preceding claims, wherein the crystallizable thermoplastic is chosen from a polyalkylene terephthalate with a C1 to C12-alkylene radical, a polyalkylene naphthalate with a C1 to C12-alkylene radical, a cycloolefin polymer and a cycloolefin copolymer.
14. The sheet as claimed in claim 13, wherein the alkylene radical is ethylene or butylene.
15. The sheet as claimed in claim 13, wherein the thermoplastic is polyethylene terephthalate.
16. The sheet as claimed in any of claims 13 to 15, wherein the thermoplastic is recycled material of the thermoplastic.
17. The sheet as claimed in one of the preceding claims, wherein the thermoplastic has a crystallite melting point, measured by DSC with a heating-up rate of 10°C/minute, in the range from 220 to 280°C.
18. The sheet as claimed in one of the preceding claims, wherein the thermoplastic has a crystallization temperature, measured by DSC with a heating-up rate of 10 °C/minute, in the range from 75 to 280°C.
19. The sheet as claimed in one of the preceding claims, wherein the thermoplastic employed has a crystallinity which is in the range from 5 to 65.
20. The sheet as claimed in one of the preceding claims, wherein the thermoplastic employed has a cold (after-)crystallization temperature T CC
in a range from 120 to 158°C.
in a range from 120 to 158°C.
21. The sheet as claimed in one of the preceding claims, wherein the sheet has a surface gloss, measured in accordance with DIN 67530 (measurement angle 20°), of greater than 110.
22. The sheet as claimed in one of the preceding claims, wherein the sheet has a light transmission, measured in accordance with ASTM D
1003, of more than 80%.
1003, of more than 80%.
23. The sheet as claimed in to one of the preceding claims, wherein the clouding of the sheet, measured in accordance with ASTM D 1003, is less than 15%.
24. The sheet as claimed in one of the preceding claims, wherein no fracture occurs during measurement of the Charpy impact strength a n, measured in accordance with ISO 179/1D.
25. The sheet as claimed in one of the preceding claims, wherein the sheet has an Izod notched impact strength a k, measured in accordance with ISO 180/1A, in the range from 2.0 to 8.0 kJ/m2.
26. The sheet as claimed in one of the preceding claims, wherein the sheet has a distinctness of image which, measured in accordance with ASTM D 1003 at an angle of less than 2.5°, is more than 95%.
27. The sheet as claimed in one of the preceding claims, wherein the sheet has a scratch-resistant coating on at least one side.
28. The sheet as claimed in claim 27, wherein the scratch-resistant coating comprises silicon and/or acrylic.
29. A process for the production of a multilayered, transparent, amorphous sheet as claimed in one of the preceding claims, wherein the thermoplastic for the core layer, of which it comprises at least one, is a main extruder, and the thermoplastic for the covering layer, of which it comprises at least one, are melted in a coextruder, the melts are layered one on top of the other and the layers brought together are shaped through a die and then sized, polished and cooled in a polishing stack having at least two rolls, the temperature of the first roll of the polishing stack being in a range from 50 to 80°C.
30. The process as claimed in claim 29, wherein at least one additive is melted together with the thermoplastic of the layer to be treated with the additive.
31. The process as claimed in claim 29 or 30, wherein the thermoplastic is a polyalkylene terephthalate or polyalkylene naphthalate.
32. The process as claimed in claim 31, wherein the polyalkylene terephthalate or polyalkylene naphthalate is dried at 160 to 180°C for 4 to 6 hours before the extrusion.
33. The process as claimed in either of claims 31 and 32, wherein the temperature of the polyalkylene terephthalate or polyalkylene naphthalate melt is in the range from 250 to 320°C.
34. The process as claimed in one of claims 29 to 33, wherein the additive, of which at least one is present, is added via masterbatch technology.
35. The use of a multilayered, transparent, amorphous sheet as claimed in one of the preceding claims for the exterior and interior sector.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19630597A DE19630597A1 (en) | 1996-07-31 | 1996-07-31 | Multi-layer sheet made of a crystallizable thermoplastic, process for its production and use |
| DE19630597.7 | 1996-07-31 | ||
| PCT/EP1997/003856 WO1998005496A1 (en) | 1996-07-31 | 1997-07-18 | Multilayered crystallizable thermoplastic plate, process for its production and use thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2262543A1 true CA2262543A1 (en) | 1998-02-12 |
Family
ID=7801198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002262543A Abandoned CA2262543A1 (en) | 1996-07-31 | 1997-07-18 | Multilayered crystallizable thermoplastic plate, process for its production and use thereof |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0915756A1 (en) |
| AU (1) | AU4010997A (en) |
| CA (1) | CA2262543A1 (en) |
| DE (1) | DE19630597A1 (en) |
| WO (1) | WO1998005496A1 (en) |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3213315C2 (en) * | 1982-04-08 | 1986-10-09 | GAO Gesellschaft für Automation und Organisation mbH, 8000 München | Process for the production of a multi-layer identification card |
| JPS5976226A (en) * | 1982-10-26 | 1984-05-01 | Kohjin Co Ltd | Polyester-laminated film and its manufacture |
| US4737389A (en) * | 1986-01-31 | 1988-04-12 | Amoco Corporation | Dual ovenable frozen food tray/cookware formed from a lainate containing a polymer that is crystallizable at use temperature |
| US5292471A (en) * | 1990-12-13 | 1994-03-08 | Toray Industries, Inc. | Process for forming a polyester film |
| DE4214383C2 (en) * | 1992-04-30 | 1996-08-14 | Inventa Ag | Coextruded multilayer polymer tube |
| DE69323751T2 (en) * | 1992-07-07 | 1999-07-01 | Continental Pet Technologies, Inc., Florence, Ky. | METHOD FOR SHAPING A MULTILAYERED PREFORMING AND CONTAINER WITH A LOW CRYSTALINE INSIDE LAYER |
| JP3329606B2 (en) * | 1994-12-08 | 2002-09-30 | カネボウ株式会社 | Polyester sheet excellent in slipperiness and molded product thereof |
| JP3251794B2 (en) * | 1994-12-09 | 2002-01-28 | カネボウ株式会社 | Thermoformed polyester container with excellent slipperiness |
-
1996
- 1996-07-31 DE DE19630597A patent/DE19630597A1/en not_active Withdrawn
-
1997
- 1997-07-18 AU AU40109/97A patent/AU4010997A/en not_active Abandoned
- 1997-07-18 EP EP97937502A patent/EP0915756A1/en not_active Withdrawn
- 1997-07-18 WO PCT/EP1997/003856 patent/WO1998005496A1/en not_active Application Discontinuation
- 1997-07-18 CA CA002262543A patent/CA2262543A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| EP0915756A1 (en) | 1999-05-19 |
| WO1998005496A1 (en) | 1998-02-12 |
| AU4010997A (en) | 1998-02-25 |
| DE19630597A1 (en) | 1998-02-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| ES2258779T3 (en) | INTERMEDIATE LAYER OF THERMOPLASTIC FILM. | |
| US6423170B1 (en) | Thermoplastic interlayer film | |
| RU2169158C2 (en) | Method of manufacturing transparent amorphous plate from crystallizable thermoplastic, and plate manufactured by this method | |
| US6902818B2 (en) | Transparent, UV resistant, thermoformable film made from crystallizable thermoplastics, its use and process for its production | |
| US6277474B1 (en) | Amorphous, transparently dyed plate of a crystallisable thermoplastic, process for its production and its use | |
| US10008617B2 (en) | Co-extruded multi-layer polyester films having hydrolytic stability and improved delamination resistance | |
| TW379241B (en) | Polyethylene terephthalate sheet of improved stability to hydrolysis,a process for its production and its use | |
| MXPA97009367A (en) | Amorfa lamina color of a crystallized thermoplastic | |
| KR19990022066A (en) | Amorphous coloring sheet of crystallizable thermoplastic resin | |
| CA2228364A1 (en) | Amorphous, transparent sheet of a crystallisable thermoplastic having high standard viscosity | |
| CA2262543A1 (en) | Multilayered crystallizable thermoplastic plate, process for its production and use thereof | |
| CA2262534A1 (en) | Multilayered coloured plate made of a crystallising thermoplastic material, process for producing the same and its use | |
| CA2261716A1 (en) | Multilayered, transparent coloured plate made of a crystallising thermoplastic material, process for producing the same and its use | |
| MX2007008853A (en) | Translucent uv permeable panel exhibiting ir reflecting properties. | |
| MXPA99001183A (en) | Multilayered crystallizable thermoplastic plate, process for its production and use thereof | |
| JP3904262B2 (en) | Laminate | |
| MXPA99001149A (en) | Multilayered, transparent coloured plate made of a crystallising thermoplastic material, process for producing the same and its use | |
| MXPA99001150A (en) | Multilayered coloured plate made of a crystallising thermoplastic material, process for producing the same and its use | |
| MXPA98000940A (en) | Lamina amorfa transparent of a crystallized thermoplastic with a normal viscosity a | |
| KR20180121000A (en) | Polyester film for back sheet of solar cell and solar cell module comprising the same | |
| WO1998050222A1 (en) | Amorphous plate with a structured surface |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |