DE202017006503U1 - Multilayer films containing rigid cycoolefin polymers and flexible polymers and their use - Google Patents

Abstract

Multilayer film containing at least three layers in which at least one inner layer contains a polymer having a glass transition temperature of less than or equal to 30 ° C and in which at least two further layers contain a cycloolefin polymer having a glass transition temperature greater than 30 ° C.

Description

The present invention relates to multilayer films of rigid cycloolefin polymers and of flexible polymers, in particular of flexible cycloolefin polymers.

Cycloolefin polymers have been known for years. Typical representatives of these polymers are derived from norbornene and ethylene. Most of these polymers are amorphous, characterized by excellent transparency and are used for the production of films, optical components and containers of all kinds.

Amorphous cycloolefin polymers often have glass transition temperatures greater than 30 ° C and have no crystalline domains. This can be determined, for example, by means of differential scanning calorimetry (DSC), in that no phase transitions from solid to liquid (melting transitions) can be recognized in the DSC diagrams. Moldings of these polymers are characterized by high moduli of elasticity and tensile strengths, by low elongation at break and low opacities or high transparency.

Another group of cycloolefin polymers is one of the thermoplastic elastomers. Typical representatives of these polymers are also derived here from norbornene and ethylene, but have compared to the amorphous cycloolefin polymers lower levels of norbornene (or other polycyclic olefins) derived structural units or higher levels of ethylene-derived structural units. These polymers are semi-crystalline and shaped articles of these polymers can look transparent or cloudy. Elastomeric cycloolefin polymers can be used to make films and containers of all kinds.

It has also been proposed to combine cycloolefin polymers with other polyolefins, for example with polyethylene or with polypropylene.

It is well known that important properties of polymers can be altered by alloying polymers with other polymers.

Numerous examples are known in the patent literature in which polyolefins such as polyethylene or polyethylene are blended with additions of cycloolefin polymers to modify certain properties of the polyolefins.

Examples of such polymer blends can be found, for example, in US Pat DD 214 137 . DD 214 623 . JP 01/318052 A . JP 03/122148 A . US 4,990,559 A . DE 102 42 730 A1 and EP 566 988 A1 ,

Also films containing a plurality of cycloolefin polymers are already known. So revealed DE 10 2008 051 399 A1 Films comprising at least one layer of a first and a second cycloolefin copolymer or containing at least two layers, one of which contains at least one first cycloolefin copolymer and a further at least one second cycloolefin copolymer. The first cycloolefin copolymer has a glass transition temperature of at least 65 ° C and an elongation at break of less than 10%, and the second cycloolefin copolymer has a glass transition temperature between 25 and 35 ° C and an elongation at break of at least 10%.

Furthermore, from the EP 844 077 A2 multilayer biaxially oriented films of cycloolefinic polymers known. These contain at least one base layer and at least one cover layer, wherein the base layer is composed essentially of a cycloolefin polymer and the cover layer of at least two cycloolefin polymers having different glass transition temperatures. By adding a cycloolefin polymer having an increased glass point, a film with a rough surface can be produced during stretching.

The range of cycloolefin polymers can be categorized into three categories in terms of film properties.

Films of cycloolefin polymers with glass transition temperatures of more than 100 ° C are very stiff. Such films generally have high moduli of elasticity of, for example, more than 2000 MPa, in particular between 2500 and 3000 MPa, and exhibit low elongation at break of about 1 to 2%. This can lead to problems in the production and processing, as for example, a tearing of the film web only below Compliance with certain boundary conditions is to be avoided. However, these cycloolefin polymers are necessary if increased temperature loads of the films, for example of more than 90 ° C to be tolerated.

Films of Cylcoolefinpolymeren with glass transition temperatures between 30 ° C and 100 ° C can be handled much easier. However, these are only marginally less rigid, usually have moduli of elasticity between 1500 and 2500 MPa and show elongations at break of> 5%.

Films of a Cycloolefinpolymeren with glass transition temperatures of less than 30 ° C have very high elongation at break and impact resistance and are therefore easy to process.

Mixtures of elastomeric cycloolefin polymers and of amorphous cycloolefin polymers are already known from the prior art. So describes WO 2011/129869 A1 Mixtures of amorphous cycloolefin polymers and partially crystalline, elastomeric norbornene-ethylene copolymers with increased toughness. The proportion of amorphous cycloolefin polymer is 60 to 99% by weight, and the content of norbornene ethylene elastomer is 40 to 1% by weight.

DE 20 2016 001 500 also discloses blends of amorphous cycloolefin polymers or partially crystalline polyethylenes or polypropylenes and partially crystalline, elastomeric cycloolefin polymers. The proportion of amorphous cycloolefin polymer or semicrystalline PE or PP in the mixture is 1 to 55 wt.% And the proportion of cyclolefin polymer elastomer in the mixture is 99 to 45 wt.%.

US 2012/0021151 A and US 2012/0003410 A1 describe transparent and flexible products containing partially crystalline cycloolefin elastomers as well as tubes and tubes made of them for use in the medical sector. These references also contain references to the use of mixtures of partially crystalline cycloolefin elastomers and of amorphous cycloolefin copolymers having higher glass transition temperatures.

Multi-layer films containing cycloolefin polymers can be used, for example, in medical diagnostics, for example in "lab-on-a-chip" devices. These films can be used, for example, as thermoforming films or as films for covering cavities.

The use of cycloolefin polymers in films is advantageous in several respects. Thus, cycloolefin polymers have a low content of migratable and migrating substances, have a high barrier to water and other polar substances, and have in most cases a high transparency. In addition, several types with different glass stages are available, which can be adapted to the application purpose produced films.

Multi-layer films have now been discovered which cover a wide range of softening points and have excellent mechanical properties. They are ideal for applications where high pressures and high temperatures are required. For example, for performing PCR cycles pressures up to a few bar and temperatures of at least 100 ° C can be tolerated.

These films are characterized by high temperature resistance and good mechanical properties. In addition, they can be processed easily.

The adaptation of mechanical properties of the films is required for their processing and use. For example, films with a certain degree of impact strength or elongation at break are frequently needed. To cover the cavities in microfluidic systems, the foils used for this purpose must meet various requirements (cf. Y. Temiz et al. "Lab-on-a-chip devices: how to close and plug the lab" in Microelectronic Engineering 132 (2015) 156-175 ).

It has now been found that by suitable combination of the above-described types of cycloolefin polymers in a multi-layer construction it is possible to produce films with high temperature resistance and at the same time good flexibility and rigidity. In this case, symmetrical and asymmetric multilayer films can be produced.

The present invention relates to multilayer films comprising at least three layers in which at least one inner layer contains a polymer having a glass transition temperature of less than or equal to 30 ° C. and in which at least two further layers contain a cycloolefin polymer having a glass transition temperature greater than 30 ° C.

The cycloolefin polymers used according to the invention are polymers known per se. These may be polymers derived from one monomer or from two or more different monomers.

The cycloolefin polymers used according to the invention can be prepared by ring-opening or in particular by ring-holding polymerization, preferably by ring-retaining copolymerization of cyclic olefins, such as norbornene, with non-cyclic olefins, such as alpha-olefins, in particular ethylene.

The choice of the catalysts can be used to control, in a manner known per se, whether the olefinic ring of the cyclic monomer is retained or opened during the polymerization. Examples of methods of ring-opening polymerization of cycloolefins can be found in EP 0 827 975 A2 , Examples of catalysts that are mainly used in ring-holding polymerization are metallocene catalysts. An overview of possible chemical structures of the polymers derived from cycloolefins can be found, for example, in Pure Appl. Chem., Vol. 77, no. 5, pp. 801-814 (2005).

Within the scope of this description, the term "cycloolefin polymer" also refers to those polymers which have been subjected to hydrogenation after the polymerization in order to reduce any remaining double bonds.

The cycloolefin polymers used according to the invention are thermoplastics which are frequently distinguished by an extraordinarily high transparency.

The glass transition temperature (hereinafter also referred to as "T _g ") of the cycloolefin polymers can be adjusted by the skilled person in a conventional manner by selecting the type and amount of monomers, for example the type and amount of cyclic and non-cyclic monomers. For example, of norbornene-ethylene copolymers, it is known that the higher the norbornene component in the copolymer, the higher the glass transition temperature. The same applies to combinations of other cyclic monomers with non-cyclic monomers.

For the purposes of the present description, glass transition temperature is to be understood as the temperature determined according to ISO 11373 using the differential scanning calorimetry (DSC) method, the heating rate being 10 K / minute.

worin

• n 0 oder 1 bedeutet,
• m 0 oder eine positive ganze Zahl ist, insbesondere 0 oder 1,
• R¹, R², R³, R⁴, R⁵ und R⁶ unabhängig voneinander Wasserstoff, Halogen, Alkyl, Cycloalkyl, Aryl oder Alkoxy bedeuten,
• R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵ und R¹⁶ unabhängig voneinander Wasserstoff oder Alkyl bedeuten,
• R¹⁷, R¹⁸, R¹⁹ und R²⁰ unabhängig voneinander Wasserstoff, Halogen oder Alkyl bedeuten, wobei
• R¹⁷ und R¹⁹ auch aneinander gebunden sein können, derart dass sie einen einfachen Ring oder ein Ringsystem mit mehreren Ringen bilden, wobei der Ring oder die Ringe gesättigt oder ungesättigt sein können, und
• R²¹ und R²² unabhängig voneinander Wasserstoff oder Alkyl bedeuten.

In a preferred embodiment of the multilayer film of the invention, cycloolefin copolymers are used which are derived from the ring-retaining copolymerization of at least one cycloolefin of the general formula (I) with at least one alpha-olefin of the formula (II)

wherein

• n is 0 or 1,
• m is 0 or a positive integer, in particular 0 or 1,
• R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ independently of one another denote hydrogen, halogen, alkyl, cycloalkyl, aryl or alkoxy,
• R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ independently of one another are hydrogen or alkyl,
• R ¹⁷ , R ¹⁸ , R ¹⁹ and R ^{20 are} independently hydrogen, halogen or alkyl, wherein
• R ¹⁷ and R ^{19 may} also be bonded to each other to form a single ring or a multi-ring ring system, which ring or rings may be saturated or unsaturated, and
• R ²¹ and R ^{22 are} independently hydrogen or alkyl.

In a particularly preferred embodiment, cycloolefin copolymers derived from compounds of formulas I and II wherein n is 0, m is 0 or 1, R ²¹ and R ^{22 are} both hydrogen or R ^{21 is} hydrogen, R ^{22 is} alkyl having one is up to eight carbon atoms, and R ¹ , R ² , R ⁵ to R ⁸ and R ¹⁵ to R ^{20 are} hydrogen.

In a most preferred embodiment, cycloolefin copolymers derived from compounds of formulas I and II wherein the compound of formula I is norbornene or tetracyclododecene and the compound of formula II is ethylene.

Very particular preference is given to using cycloolefin copolymers of the type defined above, the copolymerization of which has been carried out in the presence of a metallocene catalyst.

Preferred types of cycloolefin copolymers are disclosed in U.S.P. DE 102 42 730 A1 described. Very particular preference is given to using the types ^Topas® 6013, ^Topas® 6015, ^Topas® 5013, ^Topas® 8007 and ^Topas® E-140 (Topas Advanced Polymers GmbH, Frankfurt am Main) as cycloolefin copolymers.

The preparation of the cycloolefin copolymers preferably used according to the invention takes place under ring-retaining polymerization, ie. the bi- or polycyclic structure of the monomer units used are retained during the polymerization. Examples of catalysts are titanocene, zirconocene or hafnocene catalysts, which are usually used in combination with aluminoxanes as co-catalysts. This method of preparation has already been described many times, for example in the patent document mentioned above.

Typical examples of cycloolefin copolymers are copolymers of norbornene or tretracyclododecene with ethylene. Such polymers are commercially available, for example under the tradename APEL ^®, ARTON ^® or TOPAS ^®.

Further examples are cycloolefin polymers derived from ring-opening polymerization of cyclopentadiene or norbornene. Such polymers are also commercially available, for example under the tradename ZEONEX ^® or ZEONOR ^®.

Cycloolefin copolymers which are derived from the above-described monomers of the formulas I and II are preferably used, these monomers I: II having been employed in a molar ratio of 95: 5 to 5:95 and optionally still having small amounts of structural units, for example bis to 10 mole percent, based on the total amount of monomer, derived from other monomers such as propylene, pentene, hexene, cyclohexene and / or styrene.

Particular preference is given to using cycloolefin copolymers which consist essentially of norbornene and ethylene, and which may also contain small amounts, e.g. up to 5% by weight, based on the total amount of monomers, of structural units derived from other monomers, such as propylene, pentene, hexene, cyclohexene and / or styrene.

Further particularly preferably used cycloolefin polymers have a melt flow index between 0.3 to 4 g / 10 minutes, measured at a temperature of 230 ° C under a load of 2.16 kg.

In addition to the obligatory cycloolefin polymer and the partially crystalline alpha-olefin polymer, the polymer blend may optionally contain conventional additives. The total amount of these additives is usually up to 5 wt.%, Based on the total mixture, preferably up to 2 wt.%.

The film-forming polymers which form the layers of the multilayer film according to the invention may contain additives, also called adjuvants or additives. These are substances that are added to the polymer in small amounts in order to achieve or improve certain properties, for example, to achieve a positive effect on production, storage, processing or product properties before, during and after the use phase.

The additives may be processing aids, such as oils or waxes, or additives which impart a particular function to the polymer or multilayer film of the present invention, such as plasticizers, UV stabilizers, matting agents, preservatives, biocides, antioxidants, antistatics, Flame retardants, reinforcing agents, fillers, pigments or dyes.

The proportion of such additives in the multilayer film according to the invention is typically less than 10% by weight of the weight of this film.

In the multilayer films according to the invention cycloolefin polymers having glass transition temperatures greater than 30 ° C are used, preferably with glass transition temperatures between 40 and 210 ° C, and most preferably between 60 and 190 ° C.

In a preferred embodiment of the multilayer films of the present invention, at least one of the inner layers contains a cycloolefin polymer having a glass transition temperature less than or equal to 30 ° C, preferably from -40 to + 10 ° C, and most preferably from -20 ° C to + 10 ° C.

The multilayer films according to the invention contain at least three layers, of which at least two contain cycloolefin polymers.

For the purposes of this description, layers comprising cycloolefin polymers are layers whose proportion of cycloolefin polymer, based on the total amount of this layer, of at least 70% by weight of cycloolefin polymer, preferably at least 80% by weight of cycloolefin polymer and in particular at least 95% Wt .-% of cycloolefin polymer is. Mixtures of cycloolefin polymers can also be used in these layers.

At least one of the inner layers of the multilayer film according to the invention contains a polymer having a glass transition temperature of less than or equal to 30 ° C.

For the purposes of this description, layers comprising a polymer are layers whose proportion of this polymer, based on the total amount of this layer, is at least 70% by weight of this polymer, preferably at least 80% by weight of this polymer and in particular at least 95% by weight of this polymer. In these layers, mixtures of polymers with glass transition temperatures of less than or equal to 30 ° C can be used

The polymer with a glass transition temperature of less than or equal to 30 ° C. can be any desired chemical polymer classes. These polymers are commonly referred to as elastomers or as thermoplastic elastomers.

Examples of elastomers are rubbers such as styrene-butadiene rubber (SBR), polybutadiene rubber (BR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene-propylene-diene rubber (EPDM) and silicone rubber (SI). ,

Examples of thermoplastic elastomers are thermoplastic elastomeric polyesters (TPE-E), thermoplastic elastomeric polyamides (TPE-A), thermoplastic elastomeric polyolefins (TPE-O), in particular PP / EPDM, thermoplastic elastomeric polyurethanes (TPE-PU), styrene block copolymers, such as SBS, SEBS, SEPS, SEEPS and MBS, or especially thermoplastic elastomeric cycloolefin copolymers. The latter are, in particular, copolymers derived from cyclic or polycyclic olefins and from ethylene, the glass transition temperature being less than or equal to 30 ° C., in particular from -40 to + 10 ° C.

The multilayer films according to the invention typically have three, five, seven or nine layers. At least one of the layers of these multilayer films, which is not a cover layer, is also referred to as "inner layer" in this specification. At least one of the inner layers contains a polymer having a glass transition temperature less than or equal to 30 ° C or a mixture of such polymers.

The multilayer films according to the invention preferably contain an inner central layer and above and below this inner layer other layers follow, of which at least two contain cycloolefin polymers, in particular cycloolefin copolymers, or mixtures of cycloolefin polymers.

The multilayer films of the invention preferably have two cover layers of cycloolefin polymer having a glass transition temperature between 30 and 210 ° C, in particular between 60 and 120 ° C.

The multilayer films of the invention may be constructed symmetrically or asymmetrically. In the context of this description, a symmetrical structure is to be understood as meaning that the layer sequence above and below the inner layer is symmetrical. Other layer sequences are therefore an asymmetric structure.

In a preferred embodiment, the multilayer film according to the invention contains in at least one inner layer a partially crystalline cycloolefin polymer having a glass transition temperature of less than or equal to 30 ° C.

In a further preferred embodiment, the multilayer film according to the invention contains in at least two further layers a cycloolefin polymer having a glass transition temperature of greater than 60 ° C.

A preferred embodiment relates to multilayer films having three, five or seven layers.

Particularly preferred are multilayer films whose entire layers contain cycloolefin polymers.

Very particular preference is given to multilayer films in which the film-forming polymers in the layers are cycloolefin polymers or mixtures of different cycloolefin polymers.

Another preferred multilayer film contains in at least one of the inner layers 45 to 100 wt.% Of a partially crystalline cycloolefin copolymer having a glass transition temperature of less than or equal to 30 ° C, which was prepared by ring-retaining copolymerization of one or more polycyclic olefin monomers with ethylene and optionally further therewith copolymerizable ethylenically unsaturated comonomers.

Preferably used partially crystalline cycloolefin copolymers have a glass transition temperature of -20 ° C to + 10 ° C and a crystallite melting temperature of 60 ° C to 110 ° C.

For the purposes of the present description, crystallite melting temperature is to be understood as the temperature determined according to ISO 11373 using the differential scanning calorimetry (DSC) method, the heating rate being 10 K / minute.

Further preferably used partially crystalline cycloolefin copolymers have a degree of crystallinity, determined by DSC measurements, of less than or equal to 40%.

Of the preferred multilayer films described above, particular preference is given to those in which at least one of the inner layers comprises a blend of from 45 to 99% by weight of a partially crystalline cycloolefin copolymer having a glass transition temperature of less than or equal to 30 ° C. and from 55 to 19% by weight amorphous cycloolefin copolymers having a glass transition temperature of greater than 30 ° C, in particular greater than 60 ° C, wherein the Cycololefin copolymers were prepared by Ringerhaltende copolymerization of one or more polycyclic olefin monomers with ethylene and optionally further copolymerizable ethylenically unsaturated comonomers ,

Of these multilayer films, those in which the cycloolefin copolymer is prepared by ring copolymerization of ethylene, a polycyclic olefin monomer and optionally a C ₃ -C ₈ alpha-olefin are most preferred.

worin R₁, R₂, R₃, R₄, R₅, R₆, R₇ und R₈ gleich oder verschieden sind und ein Wasserstoffatom oder einen C₁-C₈-Alkylrest bedeuten, wobei gleiche Reste in den verschiedenen Formeln einen unterschiedliche Bedeutung haben können.The polycyclic olefin monomer is in particular selected from the group of the monomers of the formulas I to VI

wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R _{8 are the} same or different and represent a hydrogen atom or a C ₁ -C ₈ alkyl radical, wherein the same radicals in the various formulas one may have different meanings.

Of these multilayer films, those in which the cycloolefin copolymer is prepared by ring copolymerization of ethylene and norbornene are most preferred.

By suitably combining the above-described types of cycloolefin polymer in a multi-layer construction, it is possible to combine various requirements. In this case, symmetrical and asymmetric multilayer films can be produced. It is possible to produce the individual layers both from a polymer component and by blending two or more polymers.

• • Fünfschichtfolie mit einer inneren Schicht aus Polypropylen und auf jeder Seite jeweils zwei Schichten aus einem Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur zwischen 60 und 190 °C
• • Fünfschichtfolie mit einer inneren Schicht aus Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur von weniger als 10 °C und auf jeder Seite jeweils zwei Schichten aus einem Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur zwischen 60 und 190 °C
• • Fünfschichtfolie mit einer inneren Schicht aus Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur zwischen 60 und 190 °C, und auf jeder Seite an die innere Schicht direkt anschließend zwei Schichten aus einem Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur von weniger als 10 °C und auf jeder Seite an diese zwei Schichten direkt anschließend jeweils eine Schicht aus einem Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur zwischen 60 und 190 °C
• • Fünfschichtfolie mit einer inneren Schicht aus einem Blend aus Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur zwischen 60 und 190 °C und aus Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur von weniger als 10 °C, und auf jeder Seite an die innere Schicht direkt anschließend jeweils eine Schicht aus einem Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur von weniger als 10 °C und auf jeder Seite an diese zwei Schichten direkt anschließend jeweils eine Schicht aus einem Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur zwischen 60 und 190 °C
• • Fünfschichtfolie mit einer inneren Schicht aus einem Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur von weniger als 10 °C, und auf jeder Seite an die innere Schicht direkt anschließend jeweils eine Schicht aus einem Blend aus Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur von weniger als 10 °C und aus Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur zwischen 60 und 190 °C und auf jeder Seite an diese zwei Schichten direkt anschließend jeweils eine Schicht aus einem Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur zwischen 60 und 190 °C
• • Dreischichtfolie mit einer inneren Schicht aus Polypropylen und auf jeder Seite jeweils einer Schichten aus einem Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur zwischen 60 und 190 °C
• • Dreischichtfolie mit einer inneren Schicht aus Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur von weniger als 10 °C und auf jeder Seite jeweils eine Schicht aus einem Norbornen-Ethylen-Copolymer mit einer Glasübergangstemperatur zwischen 60 und 190 °C

Examples of preferred multilayer films are

• • Five-layer film with an inner layer of polypropylene and on each side two layers of a norbornene-ethylene copolymer with a glass transition temperature between 60 and 190 ° C
• Five-layer film with an inner layer of norbornene-ethylene copolymer with a glass transition temperature of less than 10 ° C and on each side two layers of a norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C.
• Five-layer film with an inner layer of norbornene-ethylene copolymer with a glass transition temperature between 60 and 190 ° C, and on each side of the inner layer directly two layers of a norbornene-ethylene copolymer with a glass transition temperature of less than 10 ° C. and on each side of these two layers directly followed by a respective layer of a norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C.
• Five-layer film with an inner layer of a blend of norbornene-ethylene copolymer with a glass transition temperature between 60 and 190 ° C and norbornene-ethylene copolymer with a glass transition temperature of less than 10 ° C, and on each side of the inner layer directly then in each case one layer of a norbornene-ethylene copolymer having a glass transition temperature of less than 10 ° C and on each side of these two layers directly followed by a respective layer of a norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C.
• Five-layer film with an inner layer of a norbornene-ethylene copolymer with a glass transition temperature of less than 10 ° C., and on each side of the inner layer directly followed by a layer of a blend of norbornene-ethylene copolymer with a glass transition temperature of less as a 10 ° C and norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C and on each side of these two layers directly followed by a layer of a norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C.
• • Three-layer film with an inner layer of polypropylene and on each side of each one layers of a norbornene-ethylene copolymer with a glass transition temperature between 60 and 190 ° C.
• Three-layer film with an inner layer of norbornene-ethylene copolymer with a glass transition temperature of less than 10 ° C and on each side a layer of a norbornene-ethylene copolymer with a glass transition temperature between 60 and 190 ° C.

• 8007 = TOPAS^®8007
• 6013 = TOPAS^®6013
• E-140 = TOPAS^®E140
• PP = Polypropylen

Specific and preferred examples of multilayer films having the above construction can be constructed from norbornene-ethylene copolymers of the following topaz types / polypropylene, using the following terminology:

• 8007 = TOPAS ^® 8007
• 6013 = TOPAS ^® 6013
• E140 = TOPAS ^® E140
• PP = polypropylene

• 8007 / 8007 / PP / 8007 / 8007
• 8007 / 8007 / E-140 / 8007 / 8007
• 8007 / E-140 / 6013 / E-140 / 8007
• 8007 / E-140 / Blend 6013 und E-140 / E-140 / 8007
• 8007 / Blend 6013 und E-140 / E-140 / Blend 6013 und E-140 / 8007

Examples of five-layer films:

• 8007/8007 / PP / 8007/8007
• 8007/8007 / E-140/8007/8007
• 8007 / E-140/6013 / E-140/8007
• 8007 / E-140 / Blend 6013 and E-140 / E-140/8007
• 8007 / Blend 6013 and E-140 / E-140 / Blend 6013 and E-140/8007

A comparative film with the structure 8007/8007/6013/8007/8007 proved to be brittle and vulnerable to breakage during processing.

• 8007 / PP / 8007
• 8007 / E-140 / 8007
• 8007 / Blend 6013 und E-140 / 8007

Examples of three-layer films:

• 8007 / PP / 8007
• 8007 / E-140/8007
• 8007 / Blend 6013 and E-140/8007

The films can be prepared by known methods, for example on a cast or blown film line.

The multilayer films of the invention can be used in particular in devices for medical diagnostics. For this purpose, the multilayer films can be used as thermoforming films. These films typically have thicknesses of at least 100 μm, preferably between 0.1 to 1 mm.

The multilayer films according to the invention can also be used to cover cavities. For this purpose, the films on one or both sides of a shaped body with built-in recesses, preferably a plastic molding, are applied, and thus form with this the cavity (s).

The coverage of the cavities in microfluidic systems must meet various requirements which are known to the person skilled in the art (cf. the above-mentioned article by Temiz et al.).

For the multilayer films according to the invention, sealing on plastic surfaces, in particular on cycloolefin polymer surfaces, with the aid of a laser, offers thermal sealing or sealing using process aids, such as, for example, a solvent.

Good experience in the field of sealing of cycloolefin polymer-based label films has been made e.g. made with limes.

For sealing surfaces to other plastics such as e.g. Poly (methyl methacrylate) or polycarbonate, UV-curable adhesive systems can be used.

Cycloolefin polymer shaped bodies are preferably sealed with the multilayer films according to the invention.

The invention also relates to the use of the above-described multilayer films in devices for medical diagnostics. For this purpose, the multilayer film is preferably used as a thermoforming film.

In a further preferred embodiment, the multilayer film is used for covering cavities.

In a further preferred embodiment, the multilayer film is bonded to plastic surfaces by sealing, especially on cycloolefin polymer surfaces.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DD 214137 [0008]
• DD 214623 [0008]
• JP 1318052 A [0008]
• JP 3122148 A [0008]
• US 4990559 A [0008]
• DE 10242730 A1 [0008, 0036]
• EP 566988 A1 [0008]
• DE 102008051399 A1 [0009]
• EP 844077 A2 [0010]
• WO 2011/129869 A1 [0015]
• DE 202016001500 [0016]
• US 2012/0021151 A [0017]
• US 2012/0003410 A1 [0017]
• EP 0827975 A2 [0027]

Cited non-patent literature

• Y. Temiz et al. "Lab-on-a-chip devices: how to close and plug the lab" in Microelectronic Engineering 132 (2015) 156-175 [0022]

Claims (19)

Multilayer film containing at least three layers in which at least one inner layer contains a polymer having a glass transition temperature of less than or equal to 30 ° C and in which at least two further layers contain a cycloolefin polymer having a glass transition temperature greater than 30 ° C. Multi-layer film after Claim 1 , characterized in that at least one inner layer contains a partially crystalline Cycloolefinpolymer having a glass transition temperature of less than or equal to 30 ° C. Multilayer film after at least one of Claims 1 to 2 , characterized in that at least two further layers containing a cycloolefin polymer having a glass transition temperature of greater than 60 ° C. Multilayer film after at least one of Claims 1 to 3 , characterized in that it comprises three, five or seven layers. Multilayer film after at least one of Claims 1 to 4 , characterized in that all layers contain cycloolefin polymers. Multi-layer film after Claim 5 , characterized in that the film-forming polymers in the layers are cycloolefin polymers or mixtures of different cycloolefin polymers. Multilayer film after at least one of Claims 1 to 6 , characterized in that at least one of the inner layers contains from 45 to 100% by weight of a partially crystalline cycloolefin copolymer having a glass transition temperature less than or equal to 30 ° C, prepared by ring copolymerization of one or more polycyclic olefin monomers with ethylene and optionally further therewith copolymerizable ethylenically unsaturated comonomers. Multi-layer film after Claim 7 , characterized in that at least one of the inner layers, a blend of 45 to 99 wt.% Of a partially crystalline cycloolefin copolymer having a glass transition temperature of less than or equal to 30 ° C and from 55 to 19 wt.% Of an amorphous cycloolefin copolymer having a glass transition temperature of greater than 60 ° C, wherein the Cycololefin copolymers were prepared by ring-retaining copolymerization of one or more polycyclic olefin monomers with ethylene and optionally further copolymerizable ethylenically unsaturated comonomers. Multilayer film after at least one of Claims 1 to 8th , characterized in that cycloolefin copolymer is prepared by ring-retaining copolymerization of ethylene, a polycyclic olefin monomer and optionally a C ₃ -C ₈ alpha-olefin. Multi-layer film after Claim 9 , characterized in that the polycyclic olefin monomer is selected from the group of monomers of formulas I to VI

wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R _{8 are the} same or different and represent a hydrogen atom or a C ₁ -C ₈ alkyl radical, wherein the same radicals in the various formulas one may have different meanings. Multi-layer film after Claim 9 , characterized in that the cycloolefin copolymer is prepared by ring-retaining copolymerization of ethylene and norbornene. Multi-layer film after Claim 7 , characterized in that the partially crystalline cycloolefin copolymer has a glass transition temperature of -20 ° C to + 10 ° C and a crystallite melting temperature of 60 ° C to 110 ° C. Multi-layer film after Claim 7 , characterized in that the partially crystalline cycloolefin copolymer has a degree of crystallinity determined by DSC measurements of less than or equal to 40%. Multilayer film after at least one of Claims 1 to 13 characterized in that they have the following structure: • five-layer film with an inner layer of polypropylene and on each side two layers of a norbornene-ethylene copolymer with a glass transition temperature between 60 and 190 ° C; or • five-layer film with an inner layer of norbornene-ethylene copolymer having a glass transition temperature of less than 10 ° C and on each side two layers of a norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C; or • five-layer film with an inner layer of norbornene-ethylene copolymer having a glass transition temperature of between 60 and 190 ° C, and two layers of a norbornene-ethylene copolymer with a glass transition temperature of less than 10 ° on each side of the inner layer C and on each side of these two layers directly followed by a respective layer of a norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C; or • five-layer film with an inner layer of a blend of norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C and norbornene-ethylene copolymer with a glass transition temperature of less than 10 ° C, and on each side to the inner layer directly afterwards in each case one layer of a norbornene-ethylene copolymer with a glass transition temperature of less than 10 ° C and on each side of these two layers directly followed by a layer of a norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C. ; or • five-layer film with an inner layer of a norbornene-ethylene copolymer. with a glass transition temperature of less than 10 ° C, and on each side of the inner layer directly followed by a layer of a blend of norbornene-ethylene copolymer having a glass transition temperature of less than 10 ° C and norbornene-ethylene copolymer with a Glass transition temperature between 60 and 190 ° C and on each side of these two layers directly followed by a layer of a norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C; or • three-layer film with an inner layer of polypropylene and on each side of each of a layer of a norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C; or • Three-layer film with an inner layer of norbornene-ethylene copolymer having a glass transition temperature of less than 10 ° C and on each side in each case a layer of a norbornene-ethylene copolymer having a glass transition temperature between 60 and 190 ° C. Use of the multilayer film after at least one of Claims 1 to 14 in devices for medical diagnostics Use after Claim 15 , characterized in that the multi-layer film is used as a thermoforming film. Use after Claim 15 , characterized in that the multi-layer film is used for covering cavities. Use after Claim 15 , characterized in that the multi-layer film is sealed by sealing with plastic surfaces, in particular cycloolefin polymer surfaces.