DE19962019A1 - Low-permeability multi layer film useful as a packaging material comprises a layer of vinylcyclohexane polymer and a layer of thermoplastic polymer - Google Patents

Abstract

Multi layer film comprises at least one layer comprising a vinylcyclohexane polymer (I), other than atactic polyvinylcyclohexane, and at least one layer comprising a thermoplastic polymer (II).

Description

The invention relates to a multilayer film comprising a layer comprising a Vinylcyclohexane based polymer or mixtures thereof and at least one contains another layer. The multilayer film is characterized by a high Water vapor barrier effect and a low oxygen permeability.

A material that is used for packaging everyday items, Household items, food, various items, semiconductor devices genes, medicine tablets, etc. requires many functional properties, such as B. transparency, moisture impermeability, oxygen barrier, hot you Gelability, vacuum and air formability as well as hand formability. Such under Different requirements are not sufficient in all cases individual polymer layer, so that multilayer films that are covered by the Laminating polymer resin films of various chemical compositions have been widely used. In addition to using such Laminates for films there are other areas of application for such laminates, especially in the manufacture of bottles, oxygen-absorbing Ver packaging material (EP-A 787 764), containers (e.g. medical infusion containers JP-A 10 081 795, cold storage bags for cell cultures, antimicrobial laminated tube containers JP-A 10 146 924) and the like.

Multi-layer film packaging is already known. In EP-A 450 247 Multi-layer films described as packaging material, the z. B. film layers Have polyester, polyethylene and polyvinyl chloride.

EP-A 477 797 describes biaxially oriented polyolefin sealable on both sides layer films with a base layer made of propylene polymers and outer layers sealable olefin polymers (ethylene-propylene copolymer) with good optical properties Properties (transparency and gloss). However, propylene polymers can  due to the partially crystalline nature of the polymer only within close processing limit thermoforming.

EP-A 693 369 describes an oriented polyolefin multilayer film made of a poly olefinic base layer and at least one sealable top layer. The Cover layer is made of a sealable polymer from aliphatic α-olefins and an amorphous polymer. Atactic polystyrene and atactic polyvinylcyclo Hexane is listed in a variety of amorphous polymers. The more Layered film according to EP-A 693 369 is characterized by good gloss, low turbidity low coefficient of friction and low surface roughness.

Films made from polystyrene or polystyrene copolymers are known in the art. Such films are easily thermoformable. The monomers used are inexpensive value bulk chemicals. Films made from styrene-containing polymers, however, show no special barrier effect against water vapor and are therefore not suitable for the packaging of moisture-sensitive goods (H. Klein, Permeability of polystyrene film, Kunststoffe (1976), 66 (3), 151-156). The complete hydrogenation of polystyrene produces a polyvinylcyclohexane, which is a has significantly improved water vapor barrier. This also slightly thermoform bare film shows no special oxygen barrier.

The object of the present invention was to provide a multilayer film to be provided with a water vapor barrier layer containing a vinylcyclohexane based polymer or mixtures thereof and at least one further layer, which is characterized by low oxygen permeability and good printability draws while maintaining the properties relevant to films such as good processing processability of the polymers used (no speck formation), thermoformability, sufficient mechanical properties and, if necessary, transparency. Depending on the use of the polymer for the second or further layers have the Multilayer films have good sterilizability.  

It has now been found that a multilayer film which is a layer of one Vinylcyclohexane based polymers or mixtures thereof and at least contains another layer which has the desired requirements.

The invention relates to multilayer films comprising at least two Layers, characterized in that at least one layer is a vinyl cyclo contains hexane-based polymer (A), except atactic polyvinylcyclo hexane, and at least one further layer containing a thermoplastic Polymer (B) or a mixture thereof.

The multilayer film preferably consists of 2 to 10, particularly preferably 2 to 10 6, in particular from 2, 3 or 4 layers.

The thickness of the overall film can vary widely depending on the application. It is in generally 0.01 to 1.5 mm, preferably 0.05 to 1.3 mm and in particular 0.05 to 1 mm.

In the case of use as a flexible container, the thickness can also be up to 7 mm, preferably up to 5 mm.

The multilayer film according to the invention can furthermore have one or more Layers e.g. B. a paper or metal layer.

Polymer A

Polymers based on vinylcyclohexane include homopolymers of vinyl cyclohexane and copolymers or block copolymers of vinylcyclohexane and understood other copolymers.

Preferred as a homo- or copolymer is a vinylcyclohexane-based polymer with the recurring structural unit of the formula (I)

in which
R ¹ and R ^{2 are} independently hydrogen or C ₁ -C ₆ alkyl, preferably C ₁ -C ₄ alkyl and
R ³ and R ⁴ independently of one another for hydrogen or for C ₁ -C ₆ alkyl, preferably C ₁ -C ₄ alkyl, in particular methyl and / or ethyl, or R ³ and R ⁴ together for alkylene, preferably C ₃ - or C ₄ alkylene (fused-on 5- or 6-membered cycloaliphatic ring),
R ^{5 represents} hydrogen or C ₁ -C ₆ alkyl, preferably C ₁ -C ₄ alkyl,
R ¹ , R ² and R ⁵ independently of one another in particular represent hydrogen or methyl.

As comonomers in the polymerization of the starting polymer, (optionally substituted polystyrene) are preferably used and also incorporated into the polymer: olefins with generally 2 to 10 carbon atoms, such as, for example and preferably, ethylene, propylene, isoprene, isobutylene, butadiene, isoprene and / or butadiene, C ₁ -C ₈ - preferably C ₁ -C ₄ - alkyl esters of acrylic or methacrylic acid, unsaturated cycloaliphatic carbons, for. Example, cyclopentadiene, cyclohexadiene, optionally sub-substituted norbornene, dicyclopentadiene, dihydrocyclopentadiene, optionally substituted tetracyclododecenes, nuclear-alkylated styrenes, α-methylstyrene, divinyl benzene, vinyl acids, and vinyl cyanide nitrate such as vinyl cyanide of these monomers. The polymers can generally contain up to 60% by weight, preferably up to 50% by weight, particularly preferably up to 40% by weight, of comonomers (based on the polymer). The polymers can very particularly preferably contain 1 to 30% by weight of comonomers.

The vinylcyclohexane (co) polymers generally have absolute molecular weights M _w weight average of 1,000-10,000,000, preferably 60,000-1,000,000, very particularly preferably 70,000-600,000, determined by light scattering.

The vinylylohexane-based polymers can be iso- as well as syndiotacic available at the table. A group of particularly suitable polymers are those described Vinylcyelohexane-based polymers in syndiotactic form, preferably with a syndiotactic diad content of 50.1 to 74%, in particular from 52 to 70% (see WO 99/32528).

The polymers can have a linear chain structure as well as Units have branching points (e.g. graft copolymers). The branch supply centers include e.g. B. star-shaped or branched polymers. The fiction polymers according to the invention can have other geometric forms of the primary, secondary, Tertiary, optionally quaternary polymer structures have what is called their helix, Double helix, leaflet etc. or mixtures of these structures.

Both random and block-like poly can be used as copolymers merisate can be used.

Block copolymers include di-blocks, tri-blocks, multi-blocks and star-shaped Block copolymers.  

The vinylcyclohexane based (co) polymers are made by: Derivatives of styrene with the corresponding monomers radical, anionic, cationically, or polymerized by metal complex initiators or catalysts and then the whole or part of the unsaturated aromatic bonds wise hydrogenated (see, for example, WO 94/21694, EP-A 322 731).

A block copolymer with at least three blocks is preferably used which contains at least one hard block and at least one soft block, the hard block having at least 50, preferably 60, particularly preferably 65% by weight repeating units of the general formula (II),

wherein
R ¹ and R ² independently of one another are hydrogen or C ₁ -C ₆ -alkyl, preferably C ₁ -C ₄ -alkyl,
R ³ for hydrogen or for C ₁ -C ₆ alkyl, preferably C ₁ -C ₄ alkyl, in particular methyl and / or ethyl, or for fused alkylene, preferably C ₃ - or C ₄ alkylene (fused 5- or 6-membered cycloaliphatic ring),
p represents an integer from 0.1 to 5, preferably 0.1 to 3,
contains
and the soft block
100-50 wt .-%, preferably 95-70 wt .-% repeating units based on straight-chain or branched C ₂ -C ₁₄ alkylene, preferably C ₂ -C ₈ alkylene and
0-50 wt .-%, preferably 5-30 wt .-% repeating units of the general formula (II) contains.

The repeating units in the soft block can be statistical, alternating or gradient be distributed.

The repeating units according to formula (II) in the hard and soft block can thus probably be the same as well as different. A hard block and a soft block can itself in turn contain different repeating units according to formula (II).

The hard blocks of the block copolymers which can be used according to the invention as polymer component A) may contain a maximum of 35% by weight of further repeating units which are based on customary, optionally substituted olefinic comonomers, preferably cyclohexadiene, norbornene, dicyclopentadiene, dihydrocyclopentadiene, substituted by C ₁ -C ₄ -alkyl. Tetracyclododecene, vinyl ester, vinyl ether, vinyl acetate, maleic acid derivatives and (meth) acrylic acid derivatives are based.

The suitable block copolymer can optionally contain further soft blocks of repeating units based on saturated, optionally substituted by C ₁ -C ₄ alkyl, aliphatic hydrocarbon chains with 2 to 10, preferably 2 to 5 carbon atoms and their isomer form.

The proportion of hard blocks (based on the total polymer) is generally NEN 65 to 97 wt .-%, preferably 75 to 95 wt .-% and the proportion of soft Blocks 3 to 35% by weight, preferably 5 to 25% by weight.  

The block copolymer that can be used generally has molecular weights (numbers medium) from 5,000-1,000,000; preferably from 50,000-500,000, especially before 80,000-200,000 determined by gel permeation chromatography, calibrated with Polystyrene standard. The molecular weight (number average) of the hard blocks is in generally 650-970,000, preferably 6,500-480,000, particularly preferred 10,000-190,000. The molecular weight of the soft blocks is generally 150-350,000, preferably from 1,500-170,000, particularly preferred 2,400-70,000. The block copolymer can have hard or soft blocks contain different molecular weights.

The linkage of the chain building blocks can besides the stereoregular head-tail Link have a small proportion of head-to-head linkage. The Co polymers can be linear or branched through centers. You can also have a star-shaped structure. Are preferred in the context of this invention linear block copolymers.

The block copolymer can have different block structures, and the end blocks can be a hard or soft block independently of one another. For example, they can be structured as follows:
A ¹ - (B ⁱ -A ⁱ ) _n ;
B ¹ - (A ⁱ -B ⁱ ) _n ;
(A ⁱ -B ⁱ ) _n ;
where A for a hard block, B for a soft block,
n ≧ 1, preferably for 1, 2, 3, 4 and
i for an integer between 1 and n (1 ≦ i ≦ n)
stand.

The hard and soft blocks in the block copolymer are generally together the incompatible. This incompatibility leads to phase separation in microscopy extent.

The polymer component which can be used as component A) is preferably prepared such that vinyl aromatic monomers of the general formula (III) for the hard blocks and conjugated dienes of the general formula (IV) and, if appropriate, vinyl aromatic monomers of the general formula ( III) for the soft blocks

wherein
R ¹ , R ² , R ³ and p have the meaning given above and
R ⁴ to R ^{7 are} independently hydrogen, C ₁ -C ₄ alkyl, preferably methyl,
converted to a prepolymer and then hydrogenated the carbon-carbon double bonds of the prepolymer in the presence of a homogeneous or heterogeneous catalyst.

The monomers of the formula (III) can be used for the hard and soft block of the Pre polymers can be both the same and different. A hard block and a soft  block can have different repeating units based on monomers of the Contain formula (III).

Suitable comonomers can in the polymerization is preferably used and englobed in the hard blocks: in each case optionally C ₁ -C ₄ alkyl substi tuiertes cyclohexadiene, vinylcyclohexane, vinylcyclohexene, norbornene, dicyclo pentadiene, dihydrocyclopentadiene, tetracyclododecene, ring-alkylated styrenes, α- methyl styrene, divinylbenzene , Vinyl esters, vinyl ethers, vinyl acetate, maleic acid derivatives and (meth) acrylic acid derivatives, etc. or a mixture thereof.

The prepolymer can be processed by a living polymerization process such as e.g. Legs living anionic polymerization or living radical polymerization getting produced. Such polymerization methods are common in polymer chemistry common knowledge. Living anionic polymerization is particularly suitable process by alkali metals or by alkali metal alkyl compound such as Methyl lithium and butyllithium can be initiated. Suitable solvents for such polymerization are hydrocarbons such. B. cyclohexane, hexane, Pentane, benzene, toluene, etc. and ethers such as. B. diethyl ether, methyl tert-butyl ether, Tetrahydrofuran.

Various block structures are accessible through a living polymerization process. In the case of anionic polymerization in a hydrocarbon medium such as cyclohexane or benzene, there is no chain termination and no chain transfer with the exclusion of active impurities such as water, oxygen, carbon dioxide, etc. Block copolymers with specific block segments can be produced by sequential addition of monomer or monomer mixture. For example, a styrene-isoprene or butadiene diblock copolymer can be prepared by adding the styrene monomer after complete polymerization of diene. The chain structure is denoted in the present invention by the symbol (I) _m - (S) _n or (B) _m - (S) _n or simplified by IS or BS. m, n mean degree of polymerization in the respective blocks.

In addition, it is known that block copolymers can be produced with a mixed block (“ver smeared” block boundary) by using the favorable cross-polymerization parameters and starting the polymerization in a monomer mixture. For example, styrene / butadiene diblock copolymer with a diene-rich mixing block can be produced as a soft block by initiation in a mixture of styrene and butadiene in a hydrocarbon medium. The polymer chain contains a diene-rich soft block, a transition phase with increasing styrene incorporation rate and a styrene block that ends the chain. The chain structure is denoted by the symbol (I ^{I / S} ) _m - (S) _n or (B ^{B / S} ) _m - (S) _n or simplified by I ^IS S or B ^BS S, where I ^IS and B ^BS each represent the isoprene-rich and butadiene-rich soft block. The corresponding hydrogenated products are referred to as H- ^IS S or HB ^BS S.

By combining the above two procedures, multi-block copolymers can be made with both mixed and certain soft blocks. Examples are Triblock SI ^IS S, I ^IS SI and Pentablock S (I ^IS S) ₂ , (I ^IS S) ₂ I. The symbols are self-explanatory. The corresponding hydrogenated products are referred to as H-SI ^IS S, HI ^IS SI or HS (I ^IS S) ₂ , H- (I ^IS ) ₂ I.

Control of the molecular weight in anionic polymerization is possible by varying the monomer / initiator ratio. The theoretical molecular weight can be calculated using the following equation:

Other factors such as solvents, co-solvents and cocatalysts can also if it affects the chain structure sensitively. Hydrocarbons like. e.g. B. Cyclohexane, toluene or benzene are in the present invention as a solution preferred for the polymerization, because in such solvents block copoly mer can be formed with mixing block and the diene monomer preferred to that  polymerized highly elastic 1,4-polydiene. An oxygen or nitrogenous one Cosolvents such as B. tetrahydrofuran, dimethoxyethane or N, N, N ', N'-tetramethy ethylenediamine causes a statistical polymerization and at the same time a before preferred 1,2-polymerization of conjugated dienes. In contrast, it does Alkali metal alcoholate such. B. lithium tert-butoxide is also a statistical poly merisation, but has little influence on the 1,2- / 1,4-ratio of diene polymer tion. The microstructure of the soft blocks in prepolymer is crucial for that Microstructure of the soft blocks in the corresponding hydrogenated block copolymer. So z. B. a poly-1,4-butadiene block when hydrogenated to a polyethylene Segment that can crystallize. The hydrogenation product of poly-1,2-butadiene has too high a glass temperature and is therefore not elastic. The hydrogenation of poly Butadiene block with suitable 1.2 / 1.4 ratios can be an elastic poly (ethy len-co-butylene) segment. Isoprene is a comonomer for the soft block 1,4-Polymerization preferred because of an alternating poly (ethylene-propylene) elasto merblock results after hydrogenation.

Temperature, pressure and monomer concentration are far for the polymerization uncritical. Preferred temperature, pressure and monomer concentration for the Polymerization ranges from -60 ° C to 130 ° C, particularly preferably 20 ° C to 100 ° C, 0.8 to 6 bar and 5 to 30 wt .-% (based on the sum of monomer and amount of solvent).

The process for producing the block copolymers is carried out either with or without, but preferably without, a work-up between the polymerization and hydrogenation stages for isolating the prepolymer. Any workup can be carried out by known methods such as precipitation in a non-solvent such. B. C ₁ -C ₄ alcohol and C ₃ -C ₆ - ketone, evaporation extrusion or stripping, etc. In this case, the prepolymer is redissolved in a solvent for hydrogenation. Without working up, the prepolymer solution can be hydrogenated directly - optionally after chain termination and optionally with the same inert solvent as in the polymerization or with another inert solvent. In this case, a saturated hydrocarbon such as. B. cyclohexane, hexane or mixtures thereof are particularly preferred as solvents for the process.

The vinylcyclohexane-based copolymers or homopolymers are produced by radical derivatives of styrene with the corresponding monomers, anionic, cationic, or by metal complex initiators or catalysts polymerized and the unsaturated aromatic bonds are then complete dig or partially hydrogenated (see, for example, WO 94/21694, EP-A 322 731).

The hydrogenation of the prepolymers is carried out according to generally known methods leads (e.g. WO 94/02 720, WO 96/34 895, EP-A-322 731). WO 94/21694 describes a process for the complete hydrogenation of alkenyl aromatic polymers and poly (alkenyl aromatic) / polydiene block copolymers by heterogeneous catalysts lysis.

A large number of known hydrogenation catalysts can be used as catalysts. Preferred metal catalysts are mentioned, for example, in WO 94/21 694 or WO 96/34 896. Any catalyst known for hydrogenation reaction can be used as the catalyst. Catalysts with a large surface area (for example 100-600 m ² / g) and a small average pore diameter (for example 20-500 Å) are suitable. Furthermore, catalysts with a small surface area (e.g. <10 m ² / g) and large average pore diameters are suitable, which are characterized by the fact that 98% of the pore volume has pores with pore diameters greater than 600 Å (e.g. approx 1000-4000 Å) (see e.g. US-A 5,654,253, US-A 5,612,422, JP-A 03076706). In particular, Raney nickel, nickel on silicon dioxide or silicon dioxide / aluminum oxide, nickel on carbon as a support and / or noble metal catalysts, for. B. Pt, Ru, Rh, Pd used.

The polymer concentrations, based on the total weight of solvent and Polymer are generally 80 to 1, preferably 50 to 10, in particular 40 up to 15% by weight.  

The hydrogenation is generally carried out at temperatures between 0 and 500 ° C. preferably between 20 and 250 ° C, especially between 60 and 200 ° C leads.

The customary solvents that can be used for hydrogenation reactions are examples described in DE-AS 11 31 885.

The reaction is generally preferred at pressures from 1 bar to 1000 bar 20 to 300 bar, in particular 40 to 200 bar, carried out.

The process generally leads to a virtually complete hydrogenation of the aromatic units and optionally of dop in the main chain fur ties. As a rule, the degree of hydrogenation is higher than 97%, particularly preferred higher than 99%. The degree of hydrogenation can be determined, for example, by NMR or UV Determine spectroscopy.

The amount of catalyst used depends on the procedure. The Ver Driving can be carried out continuously, semi-continuously or discontinuously become.

The ratio of catalyst to prepolymer is discontinuous, for example process generally 0.3-0.001, preferably 0.2-0.005, especially before increases 0.15-0.01.

The invention further relates to a method for producing the invention ß film according to the known extrusion process. It is featured here that the polymer is added to a screw conveyor via a metering device siert, heated and melted and extruded as a melt through a flat die becomes. The melt film is drawn off via a roller system and the film is added if necessary one after the other or simultaneously in the longitudinal and / or transverse direction  or oriented without tempering (in the longitudinal direction using high-speed rollers, in the transverse direction z. B. with the help of a tenter frame), heat-set, corona or flame treated and finally wound up. It has proven to be convenient that Take-off roller or rollers corresponding to the glass transition temperature of the polymer perieren.

The layer containing the polyvinylcyclohexane-based polymer can besides the vinylcyclohexane-based polymer contains another polar polymer For the purposes of the present invention, polar polymers are preferably made chooses from the group consisting of polycarbonate, polyacetal, polyamide, polyester, Polyurethane, acrylate or methacrylate polymers or mixtures thereof.

The layer preferably contains 0.05 to 8% by weight of a polar polymer or one Mixture based on the total amount of polymer in this layer, be 0.1 to 6% by weight of a polar polymer or one are particularly preferred Mix of this.

The second and optionally further layers generally contain one Polymer or a mixture of polymers selected from at least one of the Group of polyolefins, polyamides, polycarbonates, polyurethanes and polyesters.

Suitable polyamides are known homopolyamides, copolyamides and mixtures of these polyamides. These can be partially crystalline and / or amorphous polyamides.

As partially crystalline polyamides are polyamide-6, polyamide-6,6, mixtures and ent speaking copolymers of these components. Keep coming Semi-crystalline polyamides into consideration, the acid component in whole or in part is selected from at least one acid from the group consisting of terephthalate acid, isophthalic acid, suberic acid, sebacic acid, azelaic acid, adipic acid, cyclo hexanedicarboxylic acid, the diamine component of which is wholly or partly selected from m- and / or p-xylylenediamine, hexamethylenediamine, 2,2,4-trimethylhexa  methylenediamine, 2,2,4-trimethylhexamethylenediamine and isophoronediamine and whose composition is known in principle.

In addition, polyamides are to be mentioned, which consist entirely or partially of lactams with 7 to 12 carbon atoms in the ring, optionally with the use of one or more of the above-mentioned starting components.

Particularly preferred partially crystalline polyamides are polyamide 6 and polyamide 6,6 and their mixtures. Known products can be used as amorphous polyamides become. They are obtained by polycondensation of diamines, preferably selected from ethylenediamine, hexamethylenediamine, decamethylenediamine, 2,2,4- and / or 2,4,4-trimethylhexamethylene diamine, m- and / or p-xylylene diamine, bis- (4-aminocyclohexyl) methane, bis (4-aminocyclohexyl) propane, 3,3'-dimethyl- 4,4'-diamino-dicyclohexylmethane, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, 2,5- and / or 2,6-bis (aminomethyl) norbornane and / or 1,4-diaminomethylcyclo hexane or mixtures thereof with dicarboxylic acids, preferably selected from Oxalic acid, adipic acid, azelaic acid, decanedicarboxylic acid, heptadecanedicarbon acid, 2,2,4- and / or 2,4,4-trimethyladipic acid, isophthalic acid and terephthalate acid or mixtures thereof.

Copolymers that are obtained by polycondensation of several monomers which are suitable, further copolymers, such as with the addition of amino carboxylic acids -Aminocaproic acid, -Aminoundecansäure or -Aminolaurinsäure or their Lac tamen, are made.

Particularly suitable amorphous polyamides are those made from Isophthalic acid, hexamethylenediamine and other diamines such as 4,4'-diaminodi cyclohexylmethane, isophoronediamine, 2,2,4- and / or 2,4,4-trimethylhexamethylene diamine, 2,5- and / or 2,6-bis (aminomethyl) norbornene; or from isophthalic acid, 4,4'-diaminodicyclohexylmethane and caprolactam; or from isophthalic acid, 3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane and laurolactam; or from Tereph  thalic acid and the mixture of isomers of 2,2,4- and / or 2,4,4-trimethylhexamethy lendiamine.

Instead of the pure 4,4'-diaminodicyclohexylmethane, it is also possible to use mixtures of the positionally isomeric diaminodicyclohexalmethanes which are composed of one another
70 to 99 mol% of the 4,4'-diamino isomer
1 to 30 mol% of the 2,4'-diamino isomer
0 to 2 mol% of the 2,2'-diamino isomer
if appropriate, correspondingly more highly condensed diamines obtained by hydrogenating technical-grade diaminodiphenylmethane. Up to 30% of the isophthalic acid can be replaced by terephthalic acid.

Polyamide-6, polyamide-6,6, polyamide-8, -10, -11 and -12 are preferred. Especially polyamide-6 and polyamide-6,6 are preferred.

The polyamides preferably have a relative viscosity (measured on a 1 wt .-% Solution in m-cresol at 25 ° C) from 2 to 5, particularly preferably from 2.5 to 4 on.

Preferred polyalkylene terephthalates can be derived from terephthalic acid (or its reactive derivatives) and aliphatic or cycloaliphatic diols with 2 produce up to 10 carbon atoms using known methods (plastic manual, Vol. VIII, pp. 695 ff, Karl-Hanser-Verlag, Munich 1973).

Preferred polyalkylene terephthalates contain at least 80, preferably 90 mol%, based on the dicarboxylic acid component, terephthalic acid residues and min at least 80, preferably at least 90 mol%, based on the diol component, Diols selected from the group consisting of ethylene glycol, propylene glycol, 1,4- Butanediol, cyclohexane-1,4-dimethanol or mixtures thereof.  

In addition to terephthalic acid esters, the preferred polyalkylene terephthalates can contain up to 20 mol%, preferably up to 10 mol% of other aromatic dicarboxylic acids with 8 contain up to 14 carbon atoms or aliphatic dicarboxylic acids with 4 to 12 carbon atoms, such as residues of phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, 4,4'-diphe nyldicarboxylic acid, succinic, adipic, sebacic acid, azelaic acid, cyclohexane diacid acid.

The preferred polyalkylene terephthalates can in addition to the above. Diols up to 20 mol%, preferably up to 10 mol%, other aliphatic diols with 3 to 12 C- Contain atoms or cycloaliphatic diols with 6 to 21 carbon atoms, for example and preferably residues of 1,3-propanediol, 2-1,3-propanediol, neopentylglycol, Pentanediol-1,5, hexanediol-1,6,3-methylpentanediol-2,4,2-methylpentanediol-2,4,2,2,4- Trimethylpentanediol-1,3 and -1,6,2-ethylhexanediol-1,3, 2,2-diethylpropanediol-1,3, Hexanediol-2,5, 1,4-di- (β-hydroxyethoxy) benzene, 2,2-bis (4-hydroxycyclohexyl) - propane, 2,4-dihydroxy-1,1,3,3-tetramethyl-cyclobutane, 2,2-bis (3-β-hydroxyethoxy phenyl) propane and 2,2-bis (4-hydroxypropoxyphenyl) propane (DE-A 24 07 674, 24 07 776 and 27 15 932).

The polyalkylene terephthalates can be 3- or 4- by incorporating relatively small amounts quality alcohols or 3- or 4-basic carboxylic acid, such as z. B. in DE-A 19 00 270 and US-A 3,692,744 are branched. examples for preferred branching agents are trimesic acid, trimellitic acid, trimethylolethane and propane and pentaerythritol.

It is advisable to use no more than 1 mole% of the branching agent, based on the Acid component to use.

Polyalkylene terephthalates which consist solely of terephthalic acid and Ethylene glycol, propylene glycol or 1,4-butanediol or their copolymers with 1,4-  Dicyclohexanedimethanol are built up and mixtures of these polyalkylene tereph thalate.

The polyalkylene terephthalates generally have an intrinsic viscosity of approx. 0.4 to 1.5 dl / g, preferably 0.5 to 1.3 dl / g, each measured in phenol / o-dichloro benzene (1: 1 parts by weight) at 25 ° C.

Polyesters are described for example in EP-A 774490.

Polyolefins in the sense of the invention are polyethylene, polypropylene, poly-1-butene and polymethylpentene, which polymerizes small amounts of non-conjugated dienes can contain. Polyolefins are known and in Roempp's chemistry dictionary and in the literature cited there. Polypropylene is preferred.

Polycarbonates in the sense of the invention are those as described, for example, in EP-A 640 655 are described.

Preferred aromatic polycarbonates are polycarbonates based on 2,2-bis (4-hydroxyphenyl) propane or one of the others in EP-A 640 655 as preferred called diphenols. Those based on 2,2-bis- (4-hy droxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane or 1,1-bis (4- hydroxyphenyl) -3,3,5-trimethylcyclohexane or mixtures of 2,2-bis- (4-hydroxy phenyl) propane and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane.

Polycarbonates based on bisphenol A are very particularly preferred.

The aromatic polycarbonates generally have average molecular weights M _w of approximately 10,000 to 200,000, preferably 20,000 to 80,000 (determined by gel chromatography after prior calibration).

The multilayer films according to the invention can be used widely, for example wise as blister packs, blister packs. Packing material.

Blister packs and blister packs are used, for example, for medicines medium, household goods, food products, snacks, cookies, teabag packaging etc. used.

The multilayer film according to the invention can be produced by customary for Films known processing techniques, for example by coextrusion, pressing molding, dry lamination, wet lamination, vacuum lamination etc.

Other articles can also be made from the multilayer film according to the invention produce, e.g. B. flexible containers such as flexible bags, laminate tubes, cups, Cardboard boxes, composite cans, inner bags for storage vessels for storage products containing flavorings (e.g. food, non-alcoholic drinks, Cosmetics).

Additives

The multilayer film according to the invention can have additives added to it Polymers or polymer mixtures used for film production before or be added during processing. The aim of such an additive is the ease of processing or an improvement in the properties of the End product. Important groups of additives are antiblocking agents, thermal or Oxidation stabilizers, antistatic agents, bio-stabilizers, colorants, lubricants, Light stabilizers, optical brighteners, additives to improve printability u. a.

Suitable antiblocking agents are inorganic additives such as silicon dioxide, Calcium carbonate, magnesium silicate, aluminum silicate, calcium phosphate and the same and / or incompatible organic polymers such as polyamides, polyesters,  Polyurethanes, polycarbonates etc. The effective amount of antiblocking agent is in the Range from 0.1 to 2% by weight, preferably 0.1 to 0.5% by weight. The middle part Chen size is between 1 and 6 microns, especially 2 and 5 microns, with particles a spherical shape are particularly suitable.

All common thermal stabilizers can be used as stabilizers. in the generally sterically hindered phenols, phosphorus compounds and lactone derivatives either alone or as binary or ternary mixtures men. Ternary mixtures, in particular of Igranox 1010, are particularly preferred (Phenol component), Irgafos P-EPQ (phosphorus compound) and HP 136 (lactone derivative) from CIBA Specialty Chemicals, Basel, Switzerland.

Preferred antistatic agents are alkali alkane sulfonates, polyether-modified, ie ethoxylated and / or propoxylated polydiorganosiloxanes (polydialkylsiloxanes, polyalkylphenylsiloxanes etc.) and / or the essentially straight-chain and saturated aliphatic, tertiary amines with an aliphatic radical with 10 to 20 carbon atoms -Hydroxy- (C ₁ -C ₄ ) alkyl groups are substituted, N, N-bis (2-hydroxyethyl) alkylamines having 10 to 20 carbon atoms, preferably 12 to 18 carbon atoms, being particularly suitable in the alkyl radical. The effective amount of antistatic is in the range of 0.05 to 0.3% by weight.

Dyes and pigments that are more inorganic are suitable as colorants or can be organic in nature. Examples are titanium dioxide, carbon black, oxides and / or Mixed oxides of chromium, nickel, iron, azo pigments and phthalocyanines.

Lubricants are hydrocarbons such as paraffin oils, waxes (e.g. polyethylene and Polypropylene waxes), higher alcohols and carboxylic acids, carboxylic acid esters and -amides, glycerides, higher aliphatic acid amides, higher aliphatic acid esters and polydimethylsiloxanes. The effective amount of lubricant is in the range from 0.01 to 4% by weight, particularly preferably 0.25 to 1% by weight.  

Light stabilizers are additives that protect films from exposure to light Zen. Different classes are distinguished depending on the mechanism of action. With foils usually find hydroperoxide decomposers (metal complexes, sulfur-containing orga African compounds), quenchers (e.g. nickel complexes containing sulfide groups phenols), radical scavengers (e.g. sterically hindered amines) and less often UV Absorbers (e.g. hydroxybenzophenones, hydroxyphenybenzotriazoles) application. The effective amount of light stabilizer is between 0.01 and 3% by weight, in particular preferably 0.5 and 2 wt .-%.

Optical brighteners are additives that are absorbed by blue waves length ranges caused yellowish appearance of some plastic films (blue balance). Examples are triazine-phenycoumarins, benzotriazole-phenyl coumarins and benzooxazoles. The effective amount is between 0.041 and 0.1% by weight, particularly preferably 0.01 and 0.05% by weight.

Low molecular weight resins can be added to further improve the desired physical properties (e.g. film stiffness, shrinkage behavior, optics, water vapor permeability). Compatible hydrocarbon resins are low molecular weight polymers whose molecular weight M _w (weight average) is generally in a range from 300 to 8,000, preferably 400 to 5,000, particularly preferably 500 to 2,000. The proportion of the resin is in a range of 1 to 30% by weight, preferably 2 to 30% by weight. Koh hydrogen resins are preferred.

The printability of the cover film can be improved by the polarity of the upper area is increased in a suitable manner. This can be done through a corona treatment or by adding organic or inorganic additives. As an orga niche additives are polymers such as polypropylene or polyethylene as homo- or copolymers, polyesters, polyamides, polycarbonate, polyacetals, polyurethanes, Acrylate or methacrylate polymers or mixtures thereof. Prefers  the layer contains 0.05 to 8% by weight. Titanium are suitable as inorganic pigments dioxide, barium sulfate, calcium sulfate, calcium carbonate or barium sulfate.

The films according to the invention can be used to improve the adhesion to films or containers made of thermoplastic polymer sealing layers applied the. Depending on the application, the sealing layers must be adapted. As a mate rialien for sealing layers can z. B. ethylene and propylene polymers with ver different proportions of polar groups as they result from the copolymerization e.g. B. are available with vinyl acetate, acrylate monomers or polymers based of copolymers of ethylene or propylene with alpha-olefins and polar mono be used. Grafted (e.g. maleic anhydride) Ethylene and propylene copolymers can be used as sealing layers. The Sealing temperatures can be achieved by choosing the right composition put.

For some packaged food preservation applications, it is necessary to use oxygen absorbents (e.g., NaHCO ₃ , Na ₂ CO _3, or other carbonates and bicarbonates) in conjunction with agents that generate or emit carbon dioxide.

Multi-layer films can also oxygenators (such as peroxides, in particular Barium peroxide and calcium peroxides) z. B. for packaging live fish and Shellfish (e.g. JP 07-289 114, EP-A 905 086) included.

Multi-layer films can by coextrusion of the polymers used or by separate production of the individual polymer films with a subsequent one Laminating step can be produced by generally known methods.

The multilayer films can be used in a variety of ways, e.g. B. as a blister pack, Food packaging and packaging of electronic items.

The following examples are intended to illustrate the invention:

Examples example 1 Synthesis of the polyvinylcyclohexane based polymer

The autoclave is flushed with inert gas (nitrogen). The polymer solution used (see Table 1) is a filter SBF-101-S16 (Loeffler, Filter-Tech nik, Nettersheim, Germany) filtered and together with the catalyst in the Autoclave given (Table 1). After closing it is protected several times gas, then hydrogen. After relaxing, the respective Hydrogen pressure adjusted and with stirring to the appropriate reaction temperature heated temperature. The reaction pressure is after the onset of hydrogen uptake kept constant. The reaction time is defined from heating up the batch up to the time when the hydrogen uptake approaches its saturation value.

After the hydrogenation has ended, the polymer solution is filtered through a pressure filter which is covered with a Teflon fabric (B43-MU10, from Dr. M. Männendorf, Switzerland). The product solution is then filtered through a 0.2 µm Teflon filter (Pall Filtertechnik, Dreieich, Germany). The polymer solution is stabilized with Irganox XP 420 FF (CIBA Specialty Chemicals, Basel, Switzerland) and filtered again with the 0.2 µm filter mentioned. The polymer solution is then freed from the solvent at 240 ° C., the melt is filtered through a 20 μm filter and the product is processed into granules. Neither aromatic nor olefinic carbon-carbon double bonds can be detected using ¹ H NMR spectroscopy.

Table 1

Hydrogenation of polystyrene

Example 2 Production of a two-layer film by coextrusion 1st layer of syndiotactic amorphous polyvinylcyclohexane (Example 1) 2nd layer of polyamide 6

Two-layer A-B films are made by coextrusion with a total thickness of Made 200 microns. The base layer B has a thickness of 100 microns and the deck layer A has a thickness of 50 µm. The base layer is made of polyamide 6 (Durethan ™ B 40, Bayer AG, Leverkusen, Germany) and the top layer of amorphous syn diotactic polyvinylcyclohexane (see Example 1).

The system for producing the coextrusion film consists of two extruders, a coextrusion adapter, a slot die, a casting roll, a cooling roll and a take-off and film winding device. The melt of material A is processed by the following extruder:
Manufacturer: Reifenhäuser GmbH, Troisdorf, Germany
Screw ∅: 50 mm
Screw length: 33 D
Mass temperature: 280 ° C

The melt of material B is processed by the following extruder:
Manufacturer: Stork Plastics Machinery BV, Hengelo, The Netherlands
Screw ∅: 45 mm
Screw length: 25 D.
Mass temperature: 280 ° C

Both extruders are controlled independently of one another. To adjust the mitt The layer thicknesses are given with a gravimetric Dosing system fed to the extruders. The melts are in coextrusion adapters from the company Reifenhäuser merged and via the wide slot nozzle from the company Reifenhäuser on the rotating and tempered casting roller (manufacturer: Reifenhäuser) brought. Then the already solidified melt through the opposite rotating cooling roller (manufacturer: Reifenhäuser) cooled and off the trigger direction fed to the film winder.

Comparative Example 1 non-oriented polystyrene monofilm

Polystyrene 158K (BASF, Ludwigshafen, Germany), with a weight average molecular weight M _w , = 260,400, a density ρ = 1, 05 g.cm ^-3 , a glass transition temperature T _g = 100 ° C and a melt index of MFR = 27, 4 g / 10 min., Is at a melt temperature (nozzle) of 250 ° C with a Göttfert single-screw extruder (30 mm screw diameter, screw length 25D) via a flat film nozzle (220 mm lip width, gap width adjustable between 0.01-0, 6 mm) extruded. The temperature of the casting roll is 90 ° C. A 50 μm thick, clearly transparent film is obtained, which has a take-off speed of 7.3 m / min. is wound up.

Table 2 contains the gas and water vapor permeabilities determined on the monolayer or multilayer film. A multilayer film structure as shown in Example 2 on a polyvinylcyclohexane / polyamide 6 two-layer film composite also increases the gas barrier and gives the polyvinylcyclohexane-based film system, in addition to the high water vapor barrier effect, a high oxygen barrier property.

The following measurement methods were used to characterize the raw materials and foils used:

Melt flow index MFR

The melt flow index was determined in accordance with DIN ISO 1133 with a Meltflixer LT SWO Polymertechnik GmbH at 280 ° C under a weight of 2.16 kg measured.

Molecular weight M _w

The weight average molecular weight M _w , which is given in the description of the games and in the claims, indicates the weight average molecular weight. A two-detector gel permeation chromatography is used to determine it (0.5% by weight solution, solvent tetrahydrofuran, 25 ° C., polystyrene standard). The detection is carried out by means of UV absorption spectroscopy at 254 nm and by means of differential refractometry of the fractions. The calibration is carried out using several polystyrene standards of known molecular weights.

Glass transition temperature T _g

Injection molded standard bodies (flat bars 80 × 10 × 4 mm) of the samples were measured using DMA (Dynamic-Mechanical Analysis) examined. The complex thrust mo dul determined depending on the temperature at a measuring frequency of 1 Hz. Measuring device: RDA-II from Rheometric Scientific, Inc., Piscataw, N.J., USA.

Water vapor permeability WDD

The water vapor permeability WDD of the samples was determined as a function of the water vapor permeability. In the case of film samples with a water vapor permeability <1 gd ^-1 m ² based on DIN 53 122, Part 1, the determination according to the gravimetric method, with water vapor permeability <1 gd ^-1 .m ^-2 was based on DIN 53 122, Part 2 made the determination by the electrolysis method.

Gas permeabilities O ₂ , N ₂ , CO ₂

The gas permeabilities for O ₂ , N ₂ and CO ₂ are determined in accordance with DIN 53 380, Part 1 by gas-tight clamping of the respective film pattern in a permeation chamber. In one part of the chamber, the gas to be measured (measuring gas) is fed in at a defined pressure, in the other evacuated part of the chamber, the gas part permeating through the film sample is registered with the aid of a capacitive pressure sensor. Test conditions are 1000 mbar sample gas, 23 ° C and 0% relative air humidity.

Claims (13)

1. Multi-layer films comprising at least two layers, characterized in that at least one layer contains a vinylcyclohexane-based polymer (A), with the exception of atactic polyvinylcyclohexane, and at least one further layer containing a thermoplastic polymer (B) or a mixture thereof. 2. Multi-layer film according to claim 1 containing 2 to 10 layers. 3. Multi-layer film according to claim 1 and 2 containing 2 to 6 layers. 4. A multilayer film according to claims 1 to 3, wherein the thickness of the overall film is up to 7 mm. 5. multilayer film according to claim 1 to 4, wherein the thickness of the total film 0.001 to 1.5 mm. 6. Multi-layer film according to one or more of the preceding claims che, where the vinylcyclohexane-based polymer A) is a homopolymer, Copolymer or block copolymer. 7. Multi-layer film according to one or more of the preceding claims, containing as polymer A) a vinylcyclohexane-based polymer with the recurring structural unit of the formula (I)
in which
R ¹ and R ² independently of one another represent hydrogen or C ₁ -C ₆ alkyl and
R ³ and R ^{4 are} independently hydrogen or C ₁ -C ₆ alkyl, or R ³ and R ⁴ together are alkylene,
R ^{5 represents} hydrogen or C ₁ -C ₆ alkyl and
where comonomers selected from the group consisting of olefins, C ₁ -C ₈ alkyl esters of acrylic or methacrylic acid, unsaturated cyclo aliphatic hydrocarbons, substituted tetracyclododecenes, nucleus alkylated styrenes, α-methylstyrene, divinylbenzene, vinyl esters, vinyl acids, vinyl ethers, vinyl acetate, Vinyl cyanide maleic anhydride and mixtures of these monomers can be added to the polymerization and copolymerized. 8. A multilayer film according to claim 1 containing as polymer A) a block copolymer with at least three blocks, which contains at least one hard block and at least one soft block, the hard block having at least 50% by weight of repeat units of the general formula (II),
wherein
R ¹ and R ² independently of one another denote hydrogen or C ₁ -C ₆ alkyl,
R ^{3 represents} hydrogen or C ₁ -C ₆ alkyl or fused alkylene,
p represents an integer from 0.1 to 5,
contains
and the soft block
Contains 100-50 wt .-% repeating units based on straight-chain or branched C ₂ -C ₁₄ alkylene and
0-50% by weight repeating units of the general formula (II)
contains. 9. multilayer film according to one or more of the preceding claims che, containing as polymer B at least one polymer selected from the group Group of polyamides, polycarbonates, polyolefins, polyurethanes and poly ester. 10. Multi-layer film according to one or more of the preceding claims che, wherein the polymer (A) containing layer up to 8 wt .-% of a can contain further polar polymers or a mixture thereof. 11. Multi-layer film according to one or more of the preceding claims che, wherein the polar polymers are selected from the group of poly  amides, polycarbonates, polyolefins, polyurethanes, polyesters and mixtures from here. 12. Multi-layer film according to one or more of the preceding claims che, the layers additionally containing conventional additives. 13. Multi-layer film according to claim 12, containing at least one additive selected from the group of antiblocking agents, thermal or oxidation states bilisators, antistatic agents, biostabilizers, colorants, lubricants, light protective agents, optical brighteners, additives to improve the printability speed.