DE10042328A1 - Composite film useful for e.g. wall coverings, advertizing material and labels, comprises a white biaxially oriented polyester film with a base layer comprising a thermoplastic polyester and a cycloolefin copolymer - Google Patents

Abstract

Composite film comprises at least two films including a white mono- or multi- layer biaxially oriented polyester film (I) that comprises: (1) an ultraviolet (UV) stabilizer; and (2) a base layer comprising a thermoplastic polyester and a cycloolefin copolymer (COC). An Independent claim is also included for a process for producing the composite film, which comprises bonding the component films together by (1) lamination (optionally with an intermediate adhesive layer); or (2) melt extrusion.

Description

The present invention relates to a composite film consisting of at least two films I and II, where film I is a single- or multilayer white, UV-stabilized, is biaxially oriented polyester film which has at least one layer which has a Contains polyester and a cycloolefin copolymer (COC). The invention further relates to a Process for producing the composite film and its use.

Composite films are known in the prior art. Transparent laminates or Compounds are described, for example, in DE-A 33 00 411 and DE-A 26 44 209 described.

White, biaxially oriented polyester films are also known.

DE-A 23 53 347 describes a process for producing one or more layered, milky polyester film described, which is characterized that a mixture of particles of a linear polyester and 3 to 27 wt .-% a homopolymer or copolymer of ethylene or propylene, which Extruded mixture as a film, quenching the film and stretching it vertically mutually biaxially oriented directions and heat-set the film. A disadvantage of the method is that it is incurred during the production of the film Regenerate (essentially a mixture of polyester raw material and ethylene or Propylene copolymer) can no longer be used, otherwise the film discolored or turns yellow. The process is therefore uneconomical. In addition, the Foil high roughness and has a very matt appearance (very low Gloss), which is undesirable for many applications.  

EP-A 0 300 060 describes a single-layer polyester film which, apart from Polyethylene terephthalate still 3 to 40 wt .-% of a crystalline propylene polymer and contains 0.001 to 3% by weight of a surfactant. The surfaces active substance causes the number of vacuoles in the film to increase and at the same time their size decreases to the desired extent. This will make a higher one Opacity and a lower density of the film achieved. The disadvantage here is that that Regenerate accumulating in the production of the film (essentially a mixture of Polyester raw material and propylene homopolymer) can no longer be used because otherwise the film turns yellow. The process is therefore uneconomical. In addition, the film has high roughness and is therefore very matt Appearance (very low gloss), which is undesirable for many applications.

EP-A 0 360 201 describes an at least two-layer polyester film which has a base layer with fine vacuoles, the density of which is between 0.4 and 1.3 kg / dm ³ and at least one cover layer, the density of which is greater than 1. 3 kg / dm ³ . The vacuoles are created by adding 4 to 30% by weight of a crystalline propylene polymer and then biaxially stretching the film. The additional cover layer improves the producibility of the film (no streaking on the surface of the film), the surface tension is increased and the roughness of the laminated surface can be reduced. It is also disadvantageous here that the regrind obtained in the production of the film (essentially a mixture of polyester raw material and propylene homopolymer) can no longer be used, since otherwise the film is discolored yellow. The process is therefore uneconomical. In addition, the films listed in the examples have high roughness and thus have a matt appearance (low gloss), which is undesirable for many applications.

EP-A 0 795 399 describes an at least two-layer polyester film which has a base layer with fine vacuoles, the density of which is between 0.4 and 1.3 kg / dm ³ and has at least one cover layer whose density is greater than 1. 3 kg / dm ³ . The vacuoles are created by adding 5 to 45% by weight of a thermoplastic polymer to the polyester raw material of the base layer and then biaxially stretching the film. Polypropylene, polyethylene, polymethylpentene, polystyrene or polycarbonate are mentioned as thermoplastic polymers, polypropylene being the preferred thermoplastic polymer. The additional cover layer improves the producibility of the film (no streaking on the surface of the film), the surface tension is increased and the roughness of the laminated surface can be adapted to the respective requirements. A further modification of the film in the base layer and / or in the outer layers with white pigments (usually TiO ₂ ) and / or with optical brighteners enables the film properties to be adapted to the respective application requirements. However, it is also disadvantageous here that the regenerate produced in the production of the film (essentially a mixture of polyester raw material and the additive raw material) can no longer be used, since otherwise the color of the film is changed indefinitely, which is undesirable for many applications , The process is therefore uneconomical. In addition, the films listed in the examples have high roughness and thus have a matt appearance (low gloss), which is undesirable for many applications.

DE-A 195 40 277 describes a single-layer or multilayer polyester film which has a base layer with fine vacuoles, the density of which is between 0.6 and 1.3 kg / dm ³ , and has a birefringence in the plane which ranges from -0.02 to 0.04. The vacuoles are generated by adding 3 to 40% by weight of a thermoplastic resin to the polyester raw material of the base layer and then biaxially stretching the film. Thermoplastic resins include polypropylene, polyethylene, polymethyl-pentene, cyclic olefin polymers, polyacrylic resins, polystyrene or polycarbonate, polypropylene and polystyrene being preferred raw materials. By adhering to the specified limits for the birefringence of the film, the claimed film is distinguished in particular by good tear strength and good isotropy properties. The disadvantage remains that the regrind produced in the production of the film can no longer be used, since otherwise the color of the film is changed indefinitely, which is undesirable for many applications. The process is therefore uneconomical. In addition, the films listed in the examples have high roughness and thus have a matt appearance (low gloss), which is undesirable for many applications.

The object of the present invention was therefore a composite film to provide, which are particularly characterized by a high gloss and by a improved manufacturability, d. H. low manufacturing costs, distinguished and the above also has a high UV stability without the above to have adverse properties. In particular, it should be ensured that the regenerate that is inherent in the manufacturing process of film I in one Concentration of preferably 10 to 70 wt .-%, based on the total weight of the Foil I, can be used again without losing the physical properties properties of the film according to the invention are significantly negatively affected. In particular, the addition of regenerated material should not cause any discolouration or Yellowing of the film I or the composite film occur.

High UV stability means that the films are exposed to sunlight or other UV Radiation is not damaged or only extremely little, so that the films are suitable for Outdoor applications and / or critical indoor applications are suitable. In particular should the films not yellow after several years of outdoor use, no ver show brittleness or cracking on the surface and also no deterioration of mechanical properties. High UV stability therefore means that the film absorbs UV light and only lets light through in the visible range.

The object is achieved by a composite film consisting of at least two films I and II exists, where film I is a white, UV-stabilized, biaxially oriented polyester film, which has at least one base layer, which is a polyester and a cycloo Contains lefin copolymer (COC). The concentration of the COC is preferably from 2 to  60% by weight, based on the weight of the base layer. The glass transition temperature of the cycloolefin copolymer (COC) is preferably in the range from 70 to 270 ° C. and the film I contains at least one UV stabilizer as a light stabilizer. The Film I according to the invention can be either single-layer or multi-layer, wherein the multilayer embodiment has a base layer and at least one Cover layer comprises. The composite film according to the invention contains at least that film I according to the invention and a film II. Film II can be a standard thermoplastic film, a polyolefin film, paper, aluminum, a polyamide film and / or the film I according to the invention. In principle, all foils are suitable as foil II together with, a film I to composite films with the Eigen invention lead.

Under a white, biaxially oriented polyester film (film I) in the sense of the present the invention is understood to be a film which has a degree of whiteness of more than 70%, preferably of more than 75% and particularly preferably of more than 80%. Furthermore, the opacity of the film is more than 55%, preferably more than 60% and particularly preferably more than 65%.

To achieve the desired degree of whiteness of the film I, the proportion of the Cycloolefin copolymers (COC) in the base layer may be greater than 2% by weight. Is the Cycloolefin copolymer (COC) content, on the other hand, is greater than 60% by weight, so there is Danger that the film can no longer be produced economically because it is under Circumstances that can no longer be reliably drawn under certain circumstances.

It is further preferred that the glass transition temperature of the used Cycloolefin copolymer (COC) is greater than 70 ° C. Otherwise (with a glass transition temperature of less than 70 ° C) the raw material mixture may be more difficult to process (more difficult to extrude), the desired whiteness is below Under certain circumstances no longer reached and the regrind used leads to a film that may have an increased yellowing. On the other hand is the glass transition temperature  of the selected cycloolefin copolymer (COC) greater than 270 ° C, so the raw material mixture in the extruder may no longer be sufficient disperse homogeneously. This would then have a film with inhomogeneous properties result.

In the preferred embodiment of the film I according to the invention Glass transition temperature of the COCs used in a range from 90 to 250 ° C and in the particularly preferred embodiment in a range from 110 to 220 ° C.

Surprisingly, it was found that the addition of a cycloolefinco polymeric (COC) in the manner described above a white, opaque, glossy film I can be produced.

According to the amount and type of cycloolefin copolymer (COC) added can the whiteness and the opacity of the film I and thus the composite film exactly adjusted and adapted to the respective requirements. Through this It is possible to measure on other common whitening and opaque additives largely to do without. Furthermore, it was surprising that the surface roughness ity of the film I much lower and thus the gloss of the film I much higher than comparable films according to the prior art. Was surprising moreover the additional effect that the regenerate is not like the polymer Additives according to the prior art, tending to yellow discoloration.

All of the features described were unpredictable. This is all the more because z. B. COCs largely become the preferred polyester polyethylene terephthalate are incompatible, but are known to have similar stretch ratios and stretch temperatures are oriented, such as polyethylene terephthalate. The specialist would have expects that under the production conditions according to the invention no white, opaque Foil with high gloss can be produced.  

In particular in the preferred and the particularly preferred embodiments film I is characterized by high UV protection, high / or. through a particularly high degree of whiteness and a high / or. due to a particularly high opacity from, the color change of the film due to the addition of regeneration extremely small remains.

The film I according to the invention contains at least one UV stabilizer as light protective agent, preferably directly using the so-called masterbatch technology is metered during film production, the amount of UV stabilizer in the range between 0.01 and 5% by weight, based on the weight of the finished layer, lies, wherein the base layer and / or the cover layers and / or the intermediate layers can be equipped with a UV stabilizer. Mixtures can also be used various UV stabilizers can be used.

Light, especially the ultraviolet portion of solar radiation, i.e. H. of the waves length range from 280 to 400 nm, induced by thermoplastics, such as. B. polyesters, Degradation processes, as a result of which not only the visual appearance changes occurring color change or yellowing changes, but by which also extreme mechanical-physical properties of the films made of thermoplastics be adversely affected.

The prevention of these photooxidative degradation processes is of considerable importance technical and economic importance, otherwise the application is possible of numerous thermoplastics are drastically restricted.

Polyethylene terephthalates, for example, start below 360 nm UV Absorb light, its absorption increases considerably below 320 nm and is very pronounced below 300 nm. The maximum absorption is in the range between 280 and 300 nm.  

In the presence of oxygen there are mainly chain cleavages, but none Networking observed. Carbon monoxide, carbon dioxide and carboxylic acids are the quantitatively predominant photo-oxidation products. In addition to the direct Photolysis of the ester groups still need to consider oxidation reactions that also lead to the formation of carbon dioxide via peroxide radicals to have.

The photooxidation of polyethylene terephthalates can also be done via hydrogen cleavage in the α-position of the ester groups to form hydroperoxides and their decomposition products as well as the associated chain splits (H. Day, D. M. Wiles: J. Appl. Polym. Sci 16, 1972, page 203).

UV stabilizers, d. H. UV absorbers as light stabilizers are chemical compounds applications in the physical and chemical processes of light-induced Degradation can intervene. Soot and other pigments can partially Effect sun protection. However, these substances are for brightly colored or even Transparent films are unsuitable because they lead to discoloration or color changes.

Suitable UV stabilizers as light stabilizers are UV stabilizers which at least 70%, preferably 80%, particularly preferably 90%, of the UV light in the Wavelength range from 180 nm to 380 nm, preferably 280 to 350 nm, absorb. These are particularly suitable if they are in the temperature range are thermally stable from approx. 260 to 300 ° C, d. H. do not decompose into fission products and do not lead to outgassing. Suitable UV stabilizers are light stabilizers therefore, for example, 2-hydroxybenzophenones, 2-hydroxybenzotriazoles, nickelorgani cal compounds, salicylic acid esters, cinnamic acid ester derivatives, resorcinol monobenzoa te, oxalic acid anilides, hydroxybenzoic acid esters, benzoxazinones, sterically hindered Amines and triazines, the 2-hydroxybenzotriazoles, the benzoxazinones and the Triazines are particularly preferred.  

It was completely surprising that the combination of the invention was used COC plus UV stabilizers to usable films I with excellent properties led. One would probably have tried first, a certain UV stability over one Achieving oxidation stabilizer, however, would have found that the Film quickly turns yellow.

In view of the fact that UV stabilizers which absorb the UV light and thus offer protection are known from the literature, the person skilled in the art would have used commercially available UV stabilizers. He would have noticed that

• - The UV stabilizer has a lack of thermal stability and at Temperatures between 200 and 240 ° C decomposed or outgassed in fission products
• - Large amounts (approx. 10 to 15% by weight) of UV stabilizer are incorporated so that the UV light is really effectively absorbed and the film is not is damaged.

At these high concentrations, film I is already yellow after production. Furthermore, the mechanical properties are negatively affected. When stretching the film I, unusual problems such as arise

• - Demolition due to lack of strength, d. H. E-module;
• - nozzle deposits, which leads to profile fluctuations;
• - Roller deposits from the UV stabilizer, which affects the optical properties (poor cloudiness, adhesive defect, inhomogeneous Surface) leads;
• - Deposits in stretching and fixing frames "dripping onto the film.

It was therefore surprising that excellent UV protection is achieved even at low concentrations of the UV stabilizers according to the invention. It is also advantageous that

• - The yellowness index of film I compared to a non-stabilized film in Frame of measurement accuracy does not change;
• - no outgassing, no nozzle deposits, no frame evaporation adjust, which makes the film I excellent optics and excellent Profile and excellent flatness .;
• - The UV-stabilized film I due to its excellent stretchability distinguished, so that they are reliable and stable on so-called »high speed film lines «up to speeds of 420 m / min can be manufactured.

This makes film I and therefore the composite film also economically profitable, especially since that Regenerate the film I can be used again without negatively affecting the yellowness index of the film influence.

In a very particularly preferred embodiment, the film I according to the invention contains 0.01% by weight to 5.0% by weight of 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) oxy phenol of the formula

or 0.01% to 5.0% by weight of 2,2-methylene-bis (6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) - phenol of the formula

In a further embodiment, mixtures of these two UV Stabilizers or mixtures of these UV stabilizers with other UV Stabilizers are used, the total concentration of light stabilizers is preferably between 0.1 and 5.0 wt .-%, based on the weight of the finished layer, particularly preferably in the range from 0.5 to 3.0% by weight.

The film I to be used according to the invention has one or more layers. Single-layer embodiments are like the COC-containing described below Layer built up. Multi-layer embodiments are at least two-layer and always include the COC-containing layer and at least one additional layer, the COC-containing layer being the base layer, but also the intermediate layer or can form the cover layers of the multilayer film I. In a preferred one In one embodiment, the COC-containing layer also forms the base layer of film I. at least one, preferably with cover layers on both sides, where appropriate additional intermediate layers may be present on one or both sides, wherein individual or all layers can be equipped with UV stabilizers. The Layer structure of the film is then z. B. A-B-C, where B is the base layer and A and C the Are cover layers that can be the same or different. In another preferred embodiment, the COC-containing layer also forms an intermediate layer of a multilayer film I. Further embodiments with COC-containing Interlayers are built up of five layers and have COC-containing ones Base layer with COC-containing intermediate layers on both sides. In another version the COC-containing layer can form in addition to the base layer on one or both sides Form cover layers on the base or intermediate layers. The base layer is for the purposes of the present invention, that layer which is preferably 50% to 100%,  in particular 70 to 90% of the total film thickness I. The top layers are the layers that form the outer layers of film I.

The COC-containing layer (preferably the base layer) of film I contains one thermoplastic polyester, preferably a polyester homopolymer, a COC and optionally further additives in effective amounts. In general this layer preferably contains at least 20% by weight, preferably 40 to 98% by weight, in particular 70 to 98% by weight of thermoplastic polyester, based on the weight of the layer. This base layer preferably also contains the UV Stabilizer in the specified amounts.

Suitable thermoplastic polyesters for the base layer of film I are preferred Polyester made of ethylene glycol and terephthalic acid (= polyethylene terephthalate, PET) Ethylene glycol and naphthalene-2,6-dicarboxylic acid (= polyethylene-2,6-naphthalate, PEN), from 1,4-bis-hydroximethyl-cyclohexane and terephthalic acid (= poly-1,4-cyclohexane dimethylene terephthalate, PCDT) and from ethylene glycol, naphthalene-2,6-dicarboxylic acid and biphenyl-4,4'-dicarboxylic acid (= polyethylene-2,6-naphthalate bibenzoate, PENBB). Polyesters which are at least 90 mol% preferred at least 95 mol%, from ethylene glycol and terephthalic acid units or from Ethylene glycol and naphthalene-2,6-dicarboxylic acid units exist. The remaining Monomer units come from other aliphatic, cycloaliphatic or aromatic diols or dicarboxylic acids, such as z. B. in layer A (A = top layer 1) or layer C (C = top layer 2) of a multilayer film ABC (B = base layer) can occur.

Suitable other aliphatic diols are, for example, diethylene glycol, triethylene glycol, aliphatic glycols of the general formula HO- (CH ₂ ) _n -OH, where n represents an integer from 3 to 6 (in particular propane-1,3-diol, butane-1, 4-diol, pentane-1,5-diol and hexane-1,6-diol) or branched aliphatic glycols with up to 6 carbon atoms. Of the cycloaliphatic diols, cyclohexanediols (in particular cyclohexane-1,4-diol) may be mentioned. Suitable other aromatic diols correspond, for example, to the formula HO-C ₆ H ₄ -XC ₆ H ₄ -OH, where X is -CH ₂ -, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -O -, -S- or -SO ₂ - stands. In addition, bisphenols of the formula HO-C ₆ H ₄ -C ₆ H ₄ -OH are also very suitable.

Other aromatic dicarboxylic acids are preferably benzenedicarboxylic acids, naphthalene dicarboxylic acids (for example naphthalene-1,4- or -1,6-dicarboxylic acid), biphenyl-x, x'-dicarboxylic acids (in particular biphenyl-4,4'-dicarboxylic acid), diphenylacetylene-x, x '-dicarboxylic acids (especially diphenylacetylene-4,4'-dicarboxylic acid) or stilbene-x, x'-dicarboxylic acids. Of the cycloaliphatic dicarboxylic acids, cyclohexanedicarboxylic acids (in particular cyclohexane-1,4-dicarboxylic acid) should be mentioned. Of the aliphatic dicarboxylic acids, the (C ₃ -C ₁₉ ) alkanedioic acids are particularly suitable, it being possible for the alkane portion to be straight-chain or branched.

The preparation of the polyesters to be used according to the invention can, for. B. after Transesterification procedures are carried out. One starts from dicarboxylic acid esters and diols from that with the usual transesterification catalysts, such as zinc, calcium, lithium, Magnesium and manganese salts are implemented. The intermediates are then in the presence of common polycondensation catalysts such as antimony trioxide or titanium salts, polycondensed. The production can be just as good after Direct esterification process in the presence of polycondensation catalysts respectively. Here one starts directly from the dicarboxylic acids and the diols.

According to the invention, the COC-containing layer or the film I contains single-layer Embodiments of a cycloolefin copolymer (COC) in an amount of preferred at least 2.0% by weight, in particular 4 to 50% by weight and particularly preferably 6 to 40% by weight based on the weight of the layer equipped with COC or on the weight of the film I in single-layer embodiments. It is very advantageous for the present invention when the cycloolefin copolymer used  (COC) with the thermoplastic polyester, e.g. B. polyethylene terephthalate, not is compatible and does not form a homogeneous mixture with it.

Cycloolefin polymers are generally homopolymers or copolymers which contain polymerized cycloolefin units and optionally acyclic olefins as comonomers. Particularly suitable for the present invention are cycloolefin polymers which polymerized 0.1 to 100% by weight, preferably 10 to 99% by weight, particularly preferably 50-95% by weight, in each case based on the total mass of the cycloolefin polymer Contain cycloolefin units. In particular, polymers which are composed of the monomers of the cyclic olefins of the formulas I, II, III, IV, V or VI are preferred:

In these formulas, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ^{8 are,} independently of one another, the same or different and represent a hydrogen atom or a C ₁ -C ₃₀ hydrocarbon radical; or two or more of the radicals R ¹ to R ⁸ are cyclically linked, the same radicals in the different formulas having the same or different meaning. C ₁ -C ₃₀ hydrocarbon radicals are preferably linear or branched C ₁ -C ₈ alkyl radicals, C ₆ -C ₁₈ aryl radicals, C ₇ -C ₂₀ alkylene aryl radicals or cyclic C ₃ -C ₂₀ alkyl radicals or acyclic C ₂ -C ₂₀ alkenyl groups.

Optionally, the cycloolefin polymers according to the invention can contain 0 to 45% by weight, based on the total mass of the cycloolefin polymer, of polymerized units of at least one monocyclic olefin of the formula VII:

Here n is a number from 2 to 10.  

The cycloolefin polymers can optionally contain 0 to 99% by weight, based on the total mass of the cycloolefin polymer, of polymerized units of an acyclic olefin of the formula VIII:

Here R ⁹ , R ¹⁰ , R ¹¹ and R ^{12 are,} independently of one another, the same or different and denote a hydrogen atom or C ₁ -C ₁₀ hydrocarbon radical, preferably a C ₁ -C ₈ alkyl radical or C ₆ -C ₁₄ aryl radical.

Also suitable in principle are cycloolefin polymers which are ring-opening Polymerization of at least one of the monomers of the formulas I to VI and closing hydrogenation can be obtained.

Cycloolefin homopolymers are composed of a monomer of the formulas I-VI. These cycloolefin polymers are less for the purposes of the present invention suitable. For the purposes of the present invention, cycloolefinco in particular polymers (GOC) suitable which contain at least one cycloolefin of the formulas I to VI and comonomer included. Preferred comonomers are the acyclic olefins Formula VIII. In the foregoing and in the following, these are according to the invention usable cycloolefin copolymers called COC. Here are as acyclic Preferred olefins of the formula VIII are those which have 2 to 20 C atoms, ins special unbranched acyclic olefins with 2 to 10 carbon atoms, for example Ethylene, propylene and / or butylene. The proportion of polymerized acyclic units Olefins of the formula VIII are up to 99% by weight, preferably 5 to 80% by weight, particularly preferably 10 to 60 wt .-%, based on the total weight of the respective cycloolefin copolymer.  

Among the cycloolefin copolymers, those which are particularly preferred polymerized units of polycyclic olefins with a norbornene structure, especially preferably contain norbornene, 5-methyl-norbornene or tetracyclododecene. Suitable monomers are also dimethyl octahydronaphthalene and cyclopentene. Cycloolefin copolymers (COC) which polymerized are also particularly preferred Contain units of acyclic olefins, especially ethylene. Again special preferred are norbornene / ethylene and tetracyclododecene / ethylene copolymers, which Contain 5 to 80 wt .-%, preferably 10 to 60 wt .-% of acyclic olefin (based on the weight of the copolymer).

The cycloolefin polymers described generally have a glass transition temperatures between -20 ° C and 400 ° C. Are preferred for the invention Cycloolefin copolymers (COC) can be used which have a glass transition temperature of greater than 70 ° C, preferably greater than 90 ° C and in particular greater than 110 ° C exhibit. The viscosity number (decalin, 135 ° C, DIN 53 728) is expedient between 0.1 and 200 ml / g, preferably between 50 and 150 ml / g.

The cycloolefin copolymers (COC) are produced by a heterogeneous process or homogeneous catalysis with organometallic compounds and is in a variety described by documents. Suitable catalyst systems based on Mixed catalysts made of titanium or vanadium compounds in connection with Aluminum organyls are described in DD 109 224, DD 237 070 and EP-A-0 156 464 described. EP-A-0 283 164, EP-A-0 407 870, EP-A-0 485 893 and EP-A-0 503 422 describe the production of cycloolefin copolymer (COC) with catalysts based on soluble metallocene complexes. To the writings mentioned above Manufacturing process of cycloolefin copolymers described is hereby expressly referred.

The cycloolefin copolymers are incorporated into film I either as pure granules or as granulated concentrates (masterbatch) by premixing the polyester granules or powder with the cycloolefin copolymer (COC) or the cycloolefin copolymer (COC) masterbatch and then feeding them to the extruder. The components are mixed further in the extruder and heated to processing temperature. It is expedient for the process according to the invention that the extrusion temperature is above the glass transition temperature T _{g of} the cycloolefin copolymer (COC), generally at least 5 ° C., preferably 10 to 180 ° C., in particular 15 to 150 ° C., above the glass transition temperature of the cycloolefin co-polymer (COC).

In principle, for the intermediate layers and for the outer layers of film I same polymers are used as for the base layer. Preferably, the Cover layers made of a mixture of polymers, a copolymer or a Homopolymers consist of ethylene-2,6-naphthalate units and / or ethylene terephthalate units included. Up to 30 mol% of the polymers can be made from others Comonomers (e.g. ethylene isophthalate units) exist.

The base layer and the other layers of film I can additionally be conventional Contain additives such as stabilizers, antiblocking agents and other fillers. you will be Expediently the polymer or the polymer mixture before melting added. Phosphorus compounds such as Phosphoric acid or phosphoric acid ester used.

Typical antiblocking agents (also referred to as pigments in this context) are inorganic and / or organic particles, for example calcium carbonate, amorphous silica, talc, magnesium carbonate, barium carbonate, calcium sulfate, Ba rium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, aluminum oxide, Lithium fluoride, calcium, barium, zinc or manganese salts of the used Dicarboxylic acids, carbon black, titanium dioxide, kaolin or cross-linked polymer particles, e.g. B. Polystyrene or acrylate particles.  

Mixtures of two or more different ones can also be used as additives Antiblocking agents or mixtures of antiblocking agents of the same composition, but different particle sizes can be selected. The particles can Polymers of the individual layers of film I in the respective advantageous concentrations trations, e.g. B. as a glycolic dispersion during the polycondensation or over Masterbatches are added during extrusion. Have proven to be particularly suitable Pigment concentrations of 0 to 25 wt .-% proven (based on the weight of the equipped layer). A detailed description of suitable antiblocking agents can be found, for example, in EP-A-0 602 964.

To improve the whiteness of the film I, the base layer or the others Layers of film I contain a further pigmentation. Here it turned out to be proven particularly favorable as additional additives barium sulfate in a grain size of 0.3-0.8 µm, preferably 0.4-0.7 µm, or titanium dioxide in a grain size of 0.05-0.3 µm. This gives the film a brilliant, white appearance. The particle concentration of barium sulfate is 1 to 25% by weight, preferably above 1 to 20% by weight, and very preferably 1 to 15% by weight, based on the weight of the layers equipped with it.

The total thickness of the film 1 can vary within wide limits and depends according to the intended use. The preferred embodiments of the Foil I have total thicknesses of 4 to 400 μm, 8 to 300 μm, in particular 10 to 300 microns, are particularly preferred. The thickness of any, if any Intermediate layers are generally 0.5 to 15 μm, independently of one another, intermediate layer thicknesses of 1 to 10 μm, in particular 1 to 8 μm, are preferred are. The values given relate to an intermediate layer. The The thickness of the cover layers is chosen and lies independently of the other layers preferably in the range from 0.1 to 10 μm, in particular 0.2 to 5 μm, preferably 0.3 up to 2 µm, covering layers applied on both sides with respect to thickness and Composition can be the same or different. The thickness of the base layer  results accordingly from the difference between the total thickness of the film I and the thickness of the applied top and intermediate layers and can therefore be analogous to that Total thickness vary within wide limits.

The film I according to the invention is produced in accordance with the known method Extrusion or coextrusion processes.

Within the scope of this process, the individual layers are processed in such a way extrusions corresponding to film I are extruded through a flat die or are co-extruded, the film I thus obtained for solidification on one or more Rolls is pulled off, the film I then biaxially stretched (oriented), the Biaxially stretched film I heat-set and optionally on the treatment provided surface layer is corona or flame treated.

Biaxial stretching is generally carried out sequentially. Doing so preferably only in the longitudinal direction (i.e. in the machine direction, = MD direction) and then in the transverse direction (i.e. perpendicular to the machine direction, = TD direction) stretched. This leads to an orientation of the molecular chains. Stretching in The longitudinal direction is preferably carried out with the help of two in accordance with the desired Stretch ratio of rolls running at different speeds. Used for cross stretching generally a corresponding tenter frame.

A simultaneous, i.e. H. simultaneous stretching of the film I in both directions (MD direction and TD direction) with the help of a suitable one Clip frame has not proven to be useful. That is, this stretch can lead to a film that is too low in whiteness and too low in opacity having.

The temperature at which the drawing is carried out can be in a relative vary widely and depends on the desired properties of the  Slide I. In general, the longitudinal stretching at 80 to 130 ° C and the transverse stretching at 90 to 150 ° C. The longitudinal stretch ratio is generally in Range from 2.5: 1 to 6: 1, preferably from 3: 1 to 5.5: 1. The transverse stretching ratio is generally in the range from 3.0: 1 to 5.0: 1, preferably from 3.5: 1 to 4.5: 1.

In the subsequent heat setting, the film I is about 0.1 to 10 s at a Temperature kept from about 150 to 250 ° C. Then the film I in the usual Way wrapped up.

To set other desired properties, the film I can chemically be treated as well as corona or flame treated. The treatment intensity should be chosen so that the surface tension of the film I in is generally over 45 mN / m.

The film I is preferably coated on at least one of its surfaces, so that the coating on the finished film I has a thickness of approximately 5 to 100 nm, preferably 20 to 70 nm, in particular 30 to 50 nm. The coating is preferably applied in line, ie during the film production process, expediently before transverse stretching. Application by means of the so-called "reverse gravure-roll coating" method is particularly preferred, in which the coatings can be applied extremely homogeneously in the layer thicknesses mentioned. The coatings are preferably applied as solutions, suspensions or dispersions, particularly preferably as an aqueous solution, suspension or dispersion. The coatings mentioned give the film surface an additional function, for example. The film 1 is thereby sealable, printable, metallizable, sterilizable, antistatic or they improve z. B. the aroma barrier or allow adhesion to materials that would otherwise not adhere to the film surface (z. B. photographic emulsions). Examples of substances / compositions that add additional functionality are:
Acrylates such as z. B. are described in WO 94/13476, ethyl vinyl alcohols, PVDC, water glass (Na ₂ SiO ₄ ), hydrophilic polyesters (5-Na-sulfoisophthalic acid-containing PET / IPA polyesters as described, for example, in EP-A-0 144 878, US-A-4,252,885 or EP-A-0 296 620, vinyl acetates as described, for example, in WO 94/13481, polyvinyl acetates, polyurethanes, alkali metal or alkaline earth metal salts of C ₁₀ -C ₁₈ fatty acids, Butadiene copolymers with acrylonitrile or methyl methacrylate, methacrylic acid, acrylic acid, their esters or silanes The substances / compositions which give the additional functionality can the usual additives, such as antiblocking agents, pH stabilizers in amounts of preferably 0.05% by weight % to 5% by weight, preferably 0.1% to 3% by weight,% by weight in each case based on the weight of the coating composition (for example solution, emulsion, dispersion) ,

The substances / compositions mentioned are a dilute solution, emulsion or dispersion preferably as an aqueous solution, emulsion or dispersion on a or both film surfaces are applied, and then the solvent volatilized. If the coatings are applied inline before the transverse stretching, Usually the thermal treatment in the transverse stretching and subsequent is sufficient Heat fixation to volatilize the solvent and the coating too dry. The dried coatings then have layer thicknesses of 5 to 100 nm, preferably 20 to 70 nm, in particular 30 to 50 nm.

In the case of the film I according to the invention, there may be a on one surface side Heat sealing lacquer or a heat sealing layer applied.

The other surface side is optionally coated with SiO _x , aluminum or Al ₂ O _x . The thickness of this coating is generally in the range from 10 to 8000 nm, preferably 30 to 4000 nm. The other surface can also be printed according to the prior art.

A good barrier against oxygen, ie a low oxygen permeability, is achieved, for example, if the stoichiometric factor of SiO _x is x = 1.2 to 1.9. If x is greater than 2.0, the locking effect deteriorates.

The SiO _x coating can be carried out, for example, by electron beam evaporation or by conventional evaporation in a high vacuum, as in a conventional metallization.

In electron beam evaporation, silicon dioxide (SiO ₂ ), which is in the form of granules or pieces, is caused to glow and evaporate by means of a guided electron beam, which happens in a very short time due to the high energy of the beams.

With conventional vapor deposition in a high vacuum, the SiO _{2 is brought} to a high temperature in a melting tank. The temperature is around 1400 ° C. In both methods, the SiO ₂ sublimes and condenses on the film surface - depending on the O ₂ content of the atmosphere - as SiO _x .

Evaporation of the film surface with SiO _x results in a transparent layer with good adhesion to the polar surface. In a preferred embodiment, the surface can be corona-treated before vapor deposition.

It can be seen that the coating already - without the SiO _x layer being protected - significantly reduces the oxygen permeability.

It also shows that the SiO _x layer in the composite, ie when it is covered by a second film, has an oxygen permeability which is reduced again by a factor of 5 to 10.

The barrier layer serves as a gas, in particular oxygen or aroma barrier and preferably has an oxygen permeability of <15 cm ³ / (m ² .24 h.bar).

The total thickness of the composite film according to the invention, which is at least one film I according to the invention and a film II can be combined within Limits vary and depend on the application. They preferred composite films according to the invention have a thickness in the range from 8 to 1200 μm, in particular from 10 to 1000 μm, particularly preferably from 20 to 800 μm.

The film II of the composite film according to the invention can be a thermoplastic film and / or a standard thermoplastic film z. B. a transparent or white pigmented PET film and / or a polyolefin film z. B. a biaxially oriented PP film or an unoriented PE film and / or an aluminum film and / or paper and / or the film I according to the invention. This second film is preferably applied to the side of film I which has additional functionality (SiO _x coating, corona and / or flame treatment and / or adhesion promoter and / or copolyester, aluminum or Al ₂ O _x coating and / or Printing inks, to name just a few), but can also be applied to the film side, which has no functionality.

The film II can have one or more layers and, like film I, can have a UV Stabilizer contained in the concentrations specified for film I. Furthermore, Film II has been oriented by stretching and can have a sealing layer. The second film can with or without adhesive with film I according to the invention be connected.

The thickness of this second film is preferably between 4 and 700 microns.

The composite films can be made by known methods, e.g. B. by one another kidney or lamination of foils I and II, with or without intervening Adhesive layer obtained by z. B. between to 30 ° C to 90 ° C. passes through tempered rollers.

The composite films according to the invention can consist of several identical or different ones  Foils are constructed and are then z. B. depending on the structure of the films I and II 2 to 10 layers.

However, it is also possible, for example, to coat the film II by in-line coating (Melt extrusion) onto the existing film I.

When using adhesives, these are applied to a film surface of film I and / or film II by known methods, in particular by applying solutions or dispersions in water or organic solvents. The solutions usually have an adhesive concentration of 5.0 to 40.0% by weight in order to give an amount of adhesive of preferably 0.5 to 10.0 g / m ² on the film I and / or II.

Adhesives made from thermoplastic have proven to be particularly useful Resins such as cellulose esters and ethers, alkyl and acrylic esters, polyamides, Polyurethanes or polyesters, or from thermosetting resins, such as epoxy resins, Urea / formaldehyde, phenyl / formaldehyde or melamine / formaldehyde resins, or made of synthetic rubbers.

Suitable solvents for the adhesive are e.g. B. hydrocarbons such as ligroin and toluene, esters such as ethyl acetate, or ketones such as acetone and methyl ethyl ketone.

A particular advantage of the composite film according to the invention is expressed by a high degree of whiteness and high opacity in combination with high UV Stability. The whiteness of the composite film is more than 70%, preferably more than 75% and particularly preferably more than 80%. The opacity of the invention according composite film is more than 55%, preferably more than 60% and particularly preferably more than 65%. The gloss of the composite film according to the invention is more more than 50, preferably more than 70 and particularly preferably more than 90.  

Another particular advantage of the composite film according to the invention is that the regrind that is inherent in the production of the film I in one concent tration of about 10 to 70 wt .-%, based on the total weight of the film I again can be used without affecting the physical properties of the film I or the composite film are significantly negatively affected. In particular through the regenerate (essentially from polyester raw material and cycloolefinco polymeric (COC) consisting) the film does not change in color undefined, which in the white films according to the prior art.

In addition, the manufacturing cost of film I is comparable to that conventional transparent films according to the prior art. The other processing and use properties of film I remain in essentially unchanged or even improved.

The composite film according to the invention is very well suited for interior paneling, for stand construction and articles, for protective coverings of machines and Vehicles and other molded articles and for packaging light and / or air-sensitive food and beverages. It is also excellent for use in industrial areas, e.g. B. for decorative applications, in Exhibition stand construction, as shadow mats, in the manufacture of stamping foils or as Label film, suitable to name just a few possible applications. in the The composite film is particularly suitable for those applications in which a high UV stability is required.

The processing and winding behavior of film I, especially on high-speed ones Machines (winder, metallizing, printing and laminating machines) is pronounced Good. The coefficient of friction of the film is a measure of the processing behavior is less than 0.6. In addition to a good thickness profile, the winding behavior is one excellent flatness and a low coefficient of friction are crucial due to the Roughness of the film I influenced. It has been found that the winding of the  Foil I is particularly good when the other properties are retained average roughness is in a range from approx. 50 to 250 nm. The roughness can be u. a. by varying the COC concentration and the process parameters in the Set the manufacturing process in the specified range.

The table below (Table 1) summarizes the most important properties of film I. together again.  

The following measured values were used to characterize the raw materials and the foils used:

measurement methods

DIN = German Institute for Standardization
ISO = International Organization for Standardization
ASTM = American Society for Testing and Materials

SV (standard viscosity)

The standard viscosity SV (DCE) is based on DIN 53726 in dichloroacetic acid measured.

The intrinsic viscosity (IV) is calculated from the standard viscosity as follows

IV (DCE) = 6.67.10 ^-4 SV (DCE) + 0.118

friction

The friction was determined according to DIN 53 375. The sliding friction number was 14 days measured after production.

surface tension

The surface tension was measured using the so-called ink method (DIN 53364) certainly.

roughness

The roughness R _{a of} the film was determined according to DIN 4768 with a cut-off of 0.25 mm.

Whiteness and opacity

The degree of whiteness and the opacity are determined using the electrical "ELREPHO" remission photometer from Zeiss, Oberkochem (DE), standard illuminant  C, 2 ° normal observer. The opacity is determined according to DIN 53146. The whiteness is defined as WG = RY + 3RZ - 3RX. WG = whiteness, RY, RZ, RX = ent speaking reflection factors when using the Y, Z and X color measurement filter. As A white barium sulfate compact (DIN 5033, part 9) is used as standard. A detailed description is e.g. B. in Hansl Loos "color measurement", Verlag Profession and Schule, Itzehoe (1989).

Light transmission

The light transmittance is measured based on ASTM-D 1033-77.

shine

The gloss was determined in accordance with DIN 67530. The reflector value was measured as optical parameter for the surface of a film. Based on the standards ASTM-D 523-78 and ISO 2813 the angle of incidence was set at 60 °. A beam of light hits at the set angle of incidence on the flat test surface and is from this reflected or scattered. Those striking the photoelectronic receiver Light rays are displayed as a proportional electrical quantity. The reading is dimensionless and must be specified with the angle of incidence.

Glass transition temperature

The glass transition temperature T _g was determined on the basis of film samples with the aid of DSC (Differential Scanning Calorimetry) (DIN 73765). The device DSC 1090 from DuPont was used. The heating rate was 20 K / min and the initial weight was about 12 mg. The glass transition T _{g was} determined in the first heating process. The samples often showed enthalpy relaxation (a peak) at the beginning of the step-shaped glass transition. The T _g was the temperature at which the step-like change in heat capacity - regardless of the peak-shaped enthalpy relaxation - reached half its height in the first heating process. In all cases, only a single glass transition stage was observed in the thermogram when it was first heated up.

Weathering, UV stability

The UV stability is tested according to the test specification ISO 4892 as follows
Test device: Atlas Ci 65 Weather Ometer
Test conditions: ISO 4892, ie artificial weathering
Irradiation time: 1000 hours (per side)
Irradiation: 0.5 W / m ² , 340 nm
Temperature. 63 ° C
Relative humidity: 50%
Xenon lamp: inner and outer filter made of borosilicate
Irradiation cycles: 102 minutes of UV light, then 18 minutes of UV light with water spraying the samples, then again 102 minutes of UV light, etc.

The following examples serve to explain the invention in more detail:

example 1 Slide I

Polyethylene terephthalate chips (produced by the transesterification process with Mn as the transesterification catalyst, Mn concentration: 100 ppm) were dried at 150 ° C. to a residual moisture content of below 100 ppm and fed to the extruder for the base layer B. In addition, chips made of cycloolefin copolymer (COC) from Ticona, Germany, ®Topas 6015 (COC consisting of 2-norbornene and ethylene, see also W. Hatke: Films made of COC, Kunststoffe 87 (1997) 1, pp. 58-62 ) with a glass transition temperature T _g of about 160 ° C also fed to the extruder for the base layer B. The proportion of the cycloolefin copolymer (COC) in the base layer was 10% by weight. In addition, 1.0% by weight of the UV stabilizer 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) oxyphenol (®Tinuvin 1577 from Ciba-Geigy , Basel, Switzerland) via masterbatch technology (Masterbatch 2). Tinuvin 1577 has a melting point of 149 ° C and is thermally stable up to approx. 330 ° C.

It was made by extrusion and subsequent gradual orientation in longitudinal and Transversely, a white, opaque single-layer film with a total thickness of 23 microns manufactured

Base layer B, mixture of:
85.0% by weight of polyethylene terephthalate homopolymer with an SV value of 800
10.0% by weight of cycloolefin copolymer (COC) from Ticona, ®Topas 6015
5.0% by weight of masterbatch 2 which, in addition to RT49 (from Kosa, Germany), contains 20% by weight of ®Tinuvin 1577 (Ciba Geigy, Switzerland)

The manufacturing conditions in the individual process steps were:
extrusion:
Base layer temperature: 280 ° C
Take-off roller temperature: 30 ° C
Longitudinal stretching:
Temperature: 80-125 ° C
Longitudinal stretch ratio: 4.2
Transverse stretching:
Temperature: 80-135 ° C
Lateral stretch ratio: 4.0
fixation:
Temperature: 230 ° C
duration:
3 s

After the longitudinal stretching, the film is coated on both sides with an aqueous dispersion by means of the “reverse gravure-roll coating” method. In addition to water, the dispersion contains 4.2% by weight of hydrophilic polyester (5-Na-sulfoisophthalic acid-containing PET / IPA polyester, SP41®, Ticona, USA), 0.15% by weight of colloidal silicon dioxide (Nalco 1060®, Deutsche Nalco Chemie, Germany) as an antiblocking agent and 0.15% by weight ammonium carbonate (Merck, Germany) as a pH buffer (all% by weight based on the weight of the dispersion). The wet application weight is 2 g / m ² per coated side. After the transverse stretching, the calculated thickness of the coating is 40 nm.

The film had the required good properties and shows the desired one Handling and the desired processing behavior. The properties achieved Films I produced in this way are summarized in Table 2.

Example 2 Slide I

According to coextrusion technology, a 23 µm thick multilayer film with the layer sequence ABA is produced, where B is the base layer and A is the cover layers. The base layer B is 21 µm thick and the two outer layers which cover the base layer are each 1 µm thick. Polyethylene terephthalate chips (produced by the transesterification process with Mn as transesterification catalyst, Mn concentration: 100 ppm) were dried at 150 ° C. to a residual moisture content of below 100 ppm and fed to the extruder for the base layer B. In addition, chips made of cycloolefin copolymer (COC) from Ticona: ®Topas 6015 (COC consisting of 2-norbornene and ethylene, see also W. Hatke: Films made of COC, Kunststoffe 87 (1997) 1, pp. 58-62) a glass transition temperature T _g of 160 ° C also fed to the extruder for the base layer B. The proportion of the cycloolefin copolymer (COC) in the base layer was 10% by weight. In addition, 1.0% by weight of the UV stabilizer 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyl) oxyphenol (®Tinuvin 1577 from Ciba-Geigy , Basel, Switzerland) via masterbatch technology (Masterbatch 2).

The 1 µm thick cover layers contain 88% polyester (RT49, Kosa, German country) and 7% of a masterbatch 1 that contains 10,000 ppm silicon in addition to polyester contains dioxide (®Sylobloc, Grace., Germany) and 5% of a masterbatch 2 that contains 20% by weight of Tinuvin 1577® (Ciba Geigy, Switzerland) in addition to polyester.

It was made by coextrusion and subsequent gradual orientation in longitudinal and Transversely, a white, opaque three-layer film with a total thickness of 23 microns manufactured  

Base layer B, mixture of:
85.0% by weight of polyethylene terephthalate homopolymer (RT49, Kosa, Germany)
10.0% by weight of cycloolefin copolymer (COC) from Ticona, ®Topas 6015
5.0% by weight of masterbatch 2, which in addition to RT49 (Kosa, Germany) contains 20% by weight of Tinuvin 1577® (Ciba Geigy, Switzerland)

The manufacturing conditions in the individual process steps were:
extrusion:
Base and top layer temperatures: 280 ° C
Take-off roller temperature: 30 ° C
Longitudinal stretching:
Temperature: 80-125 ° C
Longitudinal stretch ratio: 4.2
Transverse stretching:
Temperature: 80-135 ° C
Lateral stretch ratio: 4.0
fixation:
Temperature: 230 ° C
duration:
3 s

After the longitudinal stretching, the film is coated on both sides with an aqueous dispersion by means of the “reverse gravure-roll coating” method. In addition to water, the dispersion contains 4.2% by weight of hydrophilic polyester (5-Na-sulfoisophthalic acid-containing PET / IPA polyester, SP41®, Ticona, USA), 0.15% by weight of colloidal silicon dioxide (Nalco 1060®, Deutsche Nalco Chemistry, Germany) as an antiblocking agent and 0.15% by weight ammonium carbonate (Merck, Germany) as a pH buffer. The wet application weight is 2 g / m ² per coated side. After the transverse stretching, the calculated thickness of the coating is 40 nm.

The film had the required good properties and shows the desired one Handling and the desired processing behavior.

Example 3 Slide I

In comparison to Example 2, 50% by weight of regenerate was now in the base layer added. The concentration of the cycloolefin copolymer (COC) in the The film produced was again 10% by weight and that of the UV stabilizer was 1.0% by weight. %. The process parameters were not changed compared to Example 2. It the yellowing of the film was observed visually. Table 2 shows that hardly any Yellowing of the film has become visible.

Base layer B, mixture of:
40.0% by weight of polyethylene terephthalate homopolymer (RT49, Kosa, Germany)
50.0% by weight regenerate (90% by weight polyester + 10% by weight Topas 6015)
5.0% by weight cycloolefin copolymer (COC) from Ticona, ®Topas 6015
5.0% by weight of masterbatch 2, which in addition to RT49 (Kosa, Germany) contains 20% by weight of Tinuvin 1577® (Ciba Geigy, Switzerland)

Cover layers: As in example 2.

After the longitudinal stretching, the film is coated on both sides with an aqueous dispersion by means of the “reverse gravure-roll coating” method. In addition to water, the dispersion contains 4.2% by weight of hydrophilic polyester (5-Na-sulfoisophthalic acid-containing PET / IPA polyester, SP41®, Ticona, USA), 0.15% by weight of colloidal silicon dioxide (Nalco 1060®, Deutsche Nalco Chemistry, Germany) as an antiblocking agent and 0.15% by weight ammonium carbonate (Merck, Germany) as a pH buffer. The wet application weight is 2 g / m ² per coated side. After the transverse stretching, the calculated thickness of the coating is 40 nm.

Example 4 Slide I

Example 1 is repeated. In contrast to Example 1, the film is not coated after the longitudinal stretching. A surface layer of the longitudinally and transversely stretched film is vaporized with SiO _x on an electron beam system from Leybold, Germany, the SiO _x layer (x = 1.6) having a thickness of 50 nm.

Example 5 Slide I

Example 2 is repeated. In modification of Example 2, the film is after Longitudinal stretch not coated. A surface layer of lengthways and crossways stretched film is steamed with aluminum (steaming system from Leybold, Germany).

Comparative Example 1 Slide I

Example 1 from DE-A 23 53 347 was reworked to a thickness of 23 μm. In a modification of the example, an additional 50% by weight of regrind was processed. Table 2 shows that a clear yellowing of the film has become visible. In addition, the roughness of the film is too high for many applications and the gloss for too many applications too low. The film is not UV stable.

Base layer B, mixture of:
47.5% by weight polyethylene terephthalate homopolymer with an SV value of 800
50.0% by weight self-regenerated material (95% by weight polyester + 5% by weight polypropylene)
2.5% by weight polypropylene

Example 6 composite film

The film I from Example 1 is coated on one coated side with a polyurethane adhesive, so that the adhesive layer formed weighs 0.5 g / m ² . Then a 40 μm thick film II made of low-density polyethylene, which is equipped with 2.0% by weight of Tinuvin 1577, is laminated onto the film I from example 1 coated with polyurethane adhesive (anchoring agent).

Example 7 composite film

The film I from Example 2 is coated on one coated side with a polyurethane adhesive, so that the adhesive layer formed weighs 0.5 g / m ² . Then a 23 μm thick film II made of PET, which is biaxially oriented and contains 1.5% by weight of Tinuvin 1577 (®Hostaphan RUVK 23 from Mitsubishi Polyester Film GmbH), is applied to the film I coated with polyurethane adhesive (anchoring agent) Example 2 laminated.

Example 8 composite film

The film I from Example 4 is coated on the side coated with SiO _x with a polyurethane adhesive, so that the adhesive layer formed weighs 0.5 g / m ² . Then a 23 μm thick film II made of PET, which is biaxially oriented and contains 1.5% by weight of Tinuvin 1577 (®Hostaphan RUVK 23 from Mitsubishi Polyester Film GmbH), is placed on the film I coated with polyurethane adhesive (anchoring agent) laminated from example 4.

Example 9 composite film

The film I from Example 5 is coated on the aluminum-coated side with a polyurethane adhesive, so that the adhesive layer formed weighs 0.5 g / m ² . Then white paper with a thickness of 80 μm is laminated onto the film I from Example 5 coated with polyurethane adhesive (anchoring agent).

Comparative Example 2 composite film

The film I from comparative example 1 is coated on one side with a polyurethane adhesive, so that the adhesive layer formed weighs 0.5 g / m ² . A 40 μm thick film II made of low-density polyethylene is then laminated onto the film I from comparative example 1 coated with polyurethane adhesive (anchoring agent).

The properties achieved of composite films produced in this way are shown in Table 3 shown.

All prepared according to Examples 1 to 9 and Comparative Examples 1 and 2 Sheets or composites were weathered 1000 hours per side with Atlas Ci 65 Weather Ometer exposed.

The films and composites produced according to Examples 1 to 9 according to the invention show hardly any difference after weathering compared to unweathered foils or Connected. The mechanical properties are compared to unweathered films or connected unchanged.

In contrast, the films and composites of Comparative Examples 1 and 2 showed after 1000 Hours of weathering with Atlas Ci 65 Weather Ometer on the cracks and surfaces Embrittlement. A precise property profile - especially that mechanical properties - could therefore no longer be measured on these samples become. In addition, the film and the composite showed a visually clearly visible Yellowing.  

Claims (26)

1. Composite film consisting of at least 2 films I and II, characterized in that film I is a single-layer or multilayer, white, at least one UV stabilizer-containing, biaxially oriented polyester film which has at least one base layer (B) which is a thermoplastic Contains polyester and a cycloolefin copoly mer (COC). 2. Composite film according to claim 1, characterized in that the film I further Has cover and / or intermediate layers. 3. Composite film according to claim 1 or 2, characterized in that the film I has a layer structure A-B-C, the outer layers A and C being equal to or are different. 4. Composite film according to one or more of claims 1 to 3, characterized characterized in that the thermoplastic polyester of the film I ethylene glycol and Terephthalic acid units or ethylene glycol and naphthalene-2,6-dicarboxylic acid units Contains units. 5. Composite film according to one or more of claims 1 to 4, characterized characterized in that the thermoplastic polyester of film I is Polyethylene terephthalate is. 6. Composite film according to one or more of claims 1 to 5, characterized characterized in that the layers of film I finished with the COC  COC from 2 to 60% by weight, preferably from 4 to 50% by weight, in particular from 6 to 40% by weight, based in each case on the weight of the layers provided with it, contain. 7. Composite film according to one or more of claims 1 to 6, characterized characterized in that the COC of film I polynorbornene, tetracyclododecene, Polydimethyloctahydronaphthalene, polycyclopentene or poly (5-methyl) norbornene contains. 8. Composite film according to one or more of claims 1 to 7, characterized characterized in that the COC of film I as a copolymer ethylene, propylene and / or butylene, preferably ethylene. 9. Composite film according to one or more of claims 1 to 8, characterized characterized in that the COC of film I is a norbornene / ethylene or a Tetracyclododecene / ethylene copolymer is. 10. Composite film according to one or more of claims 1 to 9, characterized characterized in that the COC of film I has a glass transition temperature of 70 to 270 ° C, preferably 90 to 250 ° C, in particular from 110 to 220 ° C. 11. Composite film according to one or more of claims 1 to 10, characterized characterized in that the film I has a whiteness of greater than 70%, preferably greater 75%, in particular greater than 80%.   12. Composite film according to one or more of claims 1 to 11, characterized characterized in that the film I has an opacity of greater than 55%, preferably greater 60%, in particular greater than 65%. 13. Composite film according to one or more of claims 1 to 12, characterized characterized in that the film I has a gloss of greater than 50, preferably greater than 70, in particular greater than 90. 14. Composite film according to one or more of claims 1 to 13, characterized characterized in that as UV stabilizers for the film I 2-hydroxbenzotriazoles, Benzoxazinones or triazines or mixtures of these UV stabilizers or Mixtures of these UV stabilizers can be used with others. 15. Composite film according to one or more of claims 1 to 14, characterized characterized in that as UV stabilizers for the film I 2- (4,6-diphenyl-1,3,5- triazin-2-yl) -5- (hexyl) oxyphenol or 2,2'-methylene-bis-6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol or mixtures of these UV stabilizers or Mixtures of these UV stabilizers can be used with others. 16. Composite film according to one or more of claims 1 to 15, characterized characterized in that the film I the UV stabilizer from 0.01 to 5% by weight, based on the weight of the layers equipped with it. 17. Composite film according to one or more of claims 1 to 16, characterized characterized in that the film I additionally conventional additives such as antiblocking agents, Contains pigments, stabilizers or lubricants.   18. Composite film according to one or more of claims 1 to 17, characterized characterized in that the film I is functionally coated at least on one side. 19. Composite film according to one or more of claims 1 to 18, characterized characterized in that the film II is a thermoplastic film and / or a polyolefin film and / or an aluminum film and / or paper and / or the Slide I acts. 20. Composite film according to one or more of claims 1 to 19, characterized characterized in that the film II is a thermoplastic film and / or a polyolefin film and / or an aluminum film and / or paper and / or the Slide I acts. 21. Composite film according to one or more of claims 1 to 20, characterized characterized in that they have a whiteness of greater than 70%, preferably greater than 75%, in particular greater than 80%. 22. Composite film according to one or more of claims 1 to 21, characterized characterized in that they have an opacity of more than 55%, preferably more than 60%, in particular more than 65%. 23. Composite film according to one or more of claims 1 to 22, characterized characterized that they have a gloss of more than 50, preferably more than 70, in particular more than 90. 24. A method for producing a composite film according to one or more of the Claims 1 to 23, characterized in that the films I and II through  Laminating or laminating one on top of the other, with or without an intermediate layer Adhesive layer, or connected by melt extrusion. 25. Use of a composite film according to one or more of claims 1 to 23 for the production of moldings. 26. Shaped body produced using a composite film according to one or several of claims 1 to 23.