EP3119604A1

EP3119604A1 - Multi-layered plastic film with separation effect

Info

Publication number: EP3119604A1
Application number: EP15712056.9A
Authority: EP
Inventors: Ingrid SEBALD; Werner Schmidt; Felix Grimm
Original assignee: Infiana Germany GmbH and Co KG
Current assignee: Loparex Germany GmbH and Co KG
Priority date: 2014-03-21
Filing date: 2015-03-19
Publication date: 2017-01-25
Also published as: LT3119603T; RU2685651C2; HUE057921T2; CA2942703A1; RU2016136847A; US20170015478A1; JP6500033B2; CA2942692C; EP3119603B1; CN106132701A; SI3119603T1; PT3119603T; RU2016136848A; HRP20220369T1; WO2015139844A1; DK3119603T3; RU2016136846A3; CN106132701B; JP2017511288A; CN106103087B

Abstract

The invention relates to an at least monoaxially stretched, multi-layered plastic film with a separation effect and a total thickness ≤ 18 μητι, preferably ≤ 12 μηη, which has on at least one surface, an at least partial embossing.

Description

Multilayer plastic film with release effect

The present invention relates to an at least monoaxially stretched, multilayer plastic film having a release effect and a total thickness <18 pm, preferably <12 μιτι having at least one surface at least partial embossing, and the use of the plastic film according to the invention as a packaging material, preferably for individually packaged hygiene products or incontinence products.

It is known that release-release plastic films are used for many applications, such as protective and / or release films for adhesive products used in technical fields such as construction, furniture or packaging. Separating-effect plastic films are also preferably used in the hygiene sector for packaging adhesive articles, preferably self-adhesive articles, preferably for single use. As such sanitary articles as panty liners or sanitary napkins, but also incontinence articles are increasingly being individually packaged, the demand for packaging material is increasing. Since not only such a packaging material, but also the protective and release films used elsewhere are hardly recyclable and thus can not be reused, an attempt is being made to a greater extent to use as little fossil resources as possible for these polymer materials. This means that as little as possible derived from fossil raw materials polymers are to be used for the production of corresponding plastic films, but without the indispensable quality requirements of such plastic films, in particular at their mechanical properties whose release effect, barrier properties and other necessary physical properties must be compromised.

In order to save polymer material in the production of the plastic film, it is initially obvious to reduce the total layer thickness of such a multilayer plastic film. As a result, however, usually a sometimes drastic reduction of the mechanical properties of such a plastic film, such. whose tensile strength, their tear propagation resistance and optionally their puncture resistance is associated, not only their handling during further processing of the plastic film is impaired to the final product, but also the shelf life of a corresponding packaging can be adversely affected. Thus, such a possibility for saving material is associated with not insignificant risks. In addition, difficulties can also occur in the release finish of plastic films with a total layer thickness of 20 pm.

Object of the present invention was therefore to provide a plastic film with release effect available, despite having a reduction in the total thickness of the plastic film to less than 20 pm excellent mechanical properties, in particular for trouble-free handling and further processing, in addition to an excellent release effect.

This object is achieved by providing an at least monoaxially stretched, multilayer plastic film having a release effect and a total thickness of <18 μm, preferably <12 μm, in particular from 5 μm to <12 μm, which has at least one partial embossing on at least one surface. The multilayer plastic film according to the invention is characterized in that it has at least one uniaxial stretching in the machine direction of at least 1: 2, preferably from 1: 3 to 1: 5.

Optionally, the plastic film of the invention may also be biaxially oriented, d. H. also have a cross-machine direction stretching of 1: 2 to 1: 3.5. In a biaxial stretching, i. In both machine direction and cross machine direction stretching, the draw ratio in these two directions may be different, with machine direction stretching preferably higher than the machine direction.

The plastic film according to the invention is multi-layered, preferably at least three-layered, particularly preferably at least five-layered. In further preferred embodiments, the plastic film according to the invention can have 7 to 11 layers.

The multilayer plastic film according to the invention preferably comprises a layer sequence of the polymer layers:

(a) an optionally sealable or optionally provided with a release coating layer (a) as an outer layer,

if necessary, (b) a primer layer (b),

(c) a layer (c), optionally with barrier effect,

optionally (d) a primer layer (d),

(e) an optionally sealable layer (e) as the outer layer. The layers of the plastic film according to the invention are preferably made of thermoplastic polymers selected from the group comprising polyolefins, polyamides, polyesters, biodegradable polymers, copolymers of at least two monomers of said polymers and mixtures of at least two of said polymers.

Preferably, the plastic film according to the invention consists of at least 50 wt .-%, more preferably from at least 70 wt .-% polyolefins, olefin copolymers or mixtures thereof, with the exception of cyclo-olefins or cyclo-olefin copolymers or mixtures thereof.

Preferably, the layers (a) and (e) and optionally layer (c) of the multilayer film of the invention are based, identically or differently, on polyolefins and olefin copolymers of α, β-unsaturated olefins having 2-8, preferably 2-3, carbon atoms, preferably selected from the group comprising polyethylenes (PE) - in particular low density polyethylenes between 0.86 and 0.93 g / cm ³ (LDPE), linear low density polyethylenes between 0.86 and 0.94 g / cm ³ (LLDPE ) containing in addition to ethylene as comonomer one or more α-olefins having more than 2 carbon atoms, medium density polyethylenes between 0.926 and 0.94 g / cm ³ (MDPE), high density polyethylenes between 0.94 and 0.97 g / cm ³ (HDPE) or ethylene copolymers with an α-olefin having 4 or more carbon atoms (mPE); Polypropylene (PP), polyisobutylene (PI), polybutylene (PB) or ethylene-propylene copolymers with preferably 1-10 mol% of ethylene (EPC). Particular preference may be given to using mixtures of at least one PE and at least one PP, preferably a mixture of LDPE, MDPE or LLDPE or a mixture of LLDPE and / or MDPE and / or PP, wherein the proportion of MDPE or PP in the mixture is in each case 5% by weight 80% by weight, based on the total weight of the mixture.

The layers (a) and (e) may also be applied to olefin / vinylcarboxylic acid copolymers or olefin / vinyl esters such as ethylene-acrylic acid copolymers (EAA), their esters such as (EMA), ethylene-methacrylic acid copolymers (EMAA), their esters such as (EMMA), ethylene-vinyl acetate copolymers having preferably 60-99 mol .-% ethylene (EVA) or mixtures of in each case at least two of the abovementioned polymer types.

In a further embodiment, at least layer (e) may be based on at least one polyester or at least one copolyester, which is preferably selected from the group comprising polyethylene terephthalates (PET, c-PET, a-PET) and copolymers such as CoPET, PBT and CoPBT). By "PET" is meant polyethylene terephthalates prepared by polycondensation of ethylene glycol and terephthalic acid. Furthermore, amorphous PET (a-PET) and crystalline PET (c-PET) can be used. "CoPET" refers to copolyesters which, in addition to ethylene glycol and terephthalic acid, may contain other monomers, such as, for example, branched or aromatic diols. "CoPBT" refers to polybutylene terephthalates. Preferably, the polyester or copolyester used has an intrinsic viscosity of preferably from 0.1 to 2.0 dl / g, more preferably from 0.3 to 1.5 dl / g, in particular from 0.6 to 1.0 dl / g with the methods for determining the intrinsic viscosity being known to the person skilled in the art. A detailed description of suitable PET and PBT can be found in Kunststoffhandbuch Volume 3/1 - Engineering Thermoplastics: - Polycarbonates, Polyacetals, polyesters, cellulose esters; Carl Hanser Verlag, 1992, the contents of which are incorporated by reference.

In another embodiment, at least layer (e) may be based on at least one biodegradable polymer. Suitable biodegradable thermoplastic polymers may be at least one biodegradable polymer selected from the group comprising lactic acid homopolymers and copolymers, preferably polylactides, more preferably DL-lactide, L-lactide and D-lactide, polyhydroxyalkanoates, cellulose, cellulose derivatives, thermoplastic starch, polyesters, preferably polycaprolactones, polyethers, at least partially hydrolyzed polyvinyl acetates, ethylene-vinyl alcohol copolymers and copolymers of at least two monomers of said polymers are used.

In a preferred embodiment, the multilayer film according to the invention has at least one layer (c) with a barrier effect. The skilled worker is aware of suitable polymers with which a barrier effect, in particular against gas or aroma loss, against migration of low molecular weight fractions and / or against taste or odor impairment, or against moisture and / or against oils and fats can be achieved.

Accordingly, the layer (c) is based with a barrier effect against gases, preferably against O 2, H 2 O vapor or flavor loss, against migration of low molecular weight fractions and / or against taste or odor on at least one thermoplastic polymer selected from the group comprising ethylene-vinyl alcohol Copolymers, polyvinyl alcohols, polyvinylidene chlorides, vinylidene chloride copolymers, polyethers Polyamide block copolymers and blends of the polymers with ethylene-vinyl acetate copolymers. Preferred vinylidene chloride copolymers have a proportion of vinylidene chloride of 80% or more. Ethylene-vinyl alcohol copolymers are particularly preferred.

According to a further preferred embodiment, layer (c) achieves a barrier action against moisture and / or oils and fats, which is preferably based on a thermoplastic, aliphatic or (partially) aromatic polyamide or copolyamide or mixtures thereof.

As polyamides (PA) or copolyamides (CoPA) it is possible to use at least one layer (c) preferably aliphatic or (partially) aromatic polyamides, preferably having a melting point in the range from 160 to 240 ° C, more preferably from 170 to 220 ° C become. Preferred are aliphatic polyamides, wherein at least one polyamide or copolyamide selected from the group comprising PA 6, PA 12, PA 6,6, PA 6,12, PA 6 / 6,6, PA 6,6 / 6, or partially aromatic polyamides such PA6T and PA6I was used. Preference is also given to using polyamides with isophoronediamine units. A detailed description of polyamides and copolyamides can be found in Kunststoff-Handbuch Volume VI, Polyamides, Carl Hanser Verlag Munich, 1966; and Melvin I. Kohan, Nylon Plastics Handbook, Carl Hanser Verlag Munich, 1995, the contents of which are fully incorporated by reference.

As already mentioned, in particular for the production of the layer (c) homo- and / or copolyamides selected from the group comprising thermoplastic, aliphatic, partially aromatic and aromatic homo- or copolyamides with Isophorone diamine units are used. These homo- or copolyamides with isophorone diamine units can be prepared from further aliphatic and / or cycloaliphatic diamines having 2-10 carbon atoms, such as hexamethylenediamine and / or aromatic diamines having 6-10 carbon atoms, such as p-phenylenediamine, and aliphatic or aromatic dicarboxylic acids having 6-14 Carbon atoms such as adipic acid, terephthalic acid or isophthalic acid. Furthermore, homo- or copolyamides can be prepared with isophorone diamine units from lactams with 4-10 carbon atoms such as ε-caprolactam. Isophoronediamine may preferably be used as at least one diamine component for the preparation of homopolymers and / or copolyamides, so that the homo- and / or copolyamides which are preferably suitable for the preparation of the layer (c) comprise isophoronediamine units. Homo- and / or copolyamides with isophoronediamine units which are used according to the invention are particularly preferably copolyamides formed from ε-caprolactam, isophoronediamine and an aromatic dicarboxylic acid, preferably isophthalic acid.

In a preferred embodiment, the proportion of isophoronediamine units and isophthalic acid units in the polyamide component of the layer (c) is at least 1 to 10% by weight, particularly preferably 2 to 6% by weight, based on the total weight of the polyamide -Component.

The thermoplastic polyesters listed above for the preparation of the layer (e) can also be used for the preparation of the layer (c). With the aid of layer (c) as a barrier layer, the appropriate choice of suitable polymers, the inventive multilayer plastic film having a significantly reduced oxygen permeability according to DIN 53380-3, which up to 10.00 cm ³ / (m ² d bar) at 23 ° C and 50% r. F. may be. The oxygen permeability of the multilayer plastic film according to the invention can be up to 8 cm ³ / (m ² d bar), preferably at most 7 or 6 cm ³ / (m ² d bar), more preferably at most 5, 4 or 3 cm ³ / (m ² d bar), more preferably at most 2, 1 or 0.5 cm ³ / (m ² d bar), most preferably at most 0.4, 0.3 or 0.2 cm ³ / (m ² d bar), and in particular not more than 0.1, 0.09 or 0.08 cm ³ / (m ² d bar) (each at 23 ° C and 50% RH).

With the aid of the layer (c) as a barrier layer, the water vapor permeability of the multilayer plastic film according to the invention can also be reduced to at most the above-mentioned values for the oxygen permeability by appropriate selection of suitable polymers, the water vapor permeability being determined according to DIN ISO 53,122.

If the layer (c) acts as a barrier layer (c), it is preferably connected via adhesion promoter layers (b) and (d) to the layers adjacent thereto.

Suitable thermoplastic polymers which can be used as adhesion promoter materials are known to the person skilled in the art. The adhesion promoter layers (b) and (d) are preferably based, identically or differently, on a preferably modified polyolefin and / or olefin copolymer, preferably selected from the group comprising carboxyl groups or cyclic anhydride groups modified polyethylenes, polypropylenes, in particular maleic anhydride group-modified polyethylenes, polypropylenes and ethylene-vinyl acetate copolymers. Preference is given to maleic anhydride-modified PE, COOH-modified PE, carboxy-modified copolymers of ethylene-vinyl acetate, or of ethylene (meth) acrylate or anhydride-modified ethylene-vinyl acetate copolymers and a polymer blend containing at least two of the abovementioned polymers. Copolymers modified with maleic anhydride are particularly preferred.

In a further particularly preferred embodiment, the multilayer plastic film according to the invention comprises more than one layer (c) and comprises the following layer sequence:

(A) a possibly heat-sealable, optionally multi-layered layer (a) preferably composed of at least one thermoplastic olefin homo- or copolymers or mixtures thereof, which may be configured with a release layer as the outer layer.

(b) a primer layer (b),

(c) a layer (c) preferably composed of at least one homo- and / or copolyamide,

(b) optionally a further adhesion promoter layer (b),

(c) another layer (c) preferably composed of at least one

Homo- and / or copolyamide, or ethylene vinyl alcohol copolymers,

(d) a further adhesion promoter layer (d), (E) an optionally heat-sealable outer layer (s) composed of at least one thermoplastic olefin homo- or copolymers or mixtures thereof.

The layers (c), the same or different, are based on homopolymers, copolymers or mixtures of polymers as described above, particularly preferably on polyamides or ethylene-vinyl alcohol copolymers. This also applies to the other layers.

The layers of the multilayer plastic film according to the invention may each contain the same or different additives selected from the group consisting of antioxidants, antiblocking agents, antifogging agents, antistatic agents, antimicrobial agents, light stabilizers, UV absorbers, UV filters, dyes, color pigments, stabilizers, preferably heat stabilizers, Process stabilizers and UV and / or light stabilizers, preferably based on at least one sterically hindered amine (HALS), processing aids, flame retardants, nucleating agents, crystallizing agents, preferably nucleating agents, lubricants, optical brighteners, plasticizers, silanes, spacers, fillers, such as CaCO3, silicates, peel additives, seal additives, waxes, wetting agents, surface-active compounds, preferably surfactants, and dispersants.

The layers of the plastic film according to the invention may contain at least 0.01-30% by weight, preferably at least 0.1-20% by weight, based in each case on the total weight of a single layer of at least one of the abovementioned additives. The plastic film according to the invention not only has an at least monoaxial stretching, but is also embossed. As a result, at least one surface layer of the plastic film according to the invention has at least one specific area of the surface layer, preferably of layer (a), an embossed structure, particularly preferably the entire surface of the layer, preferably of layer (a).

This embossing structure of the release film according to the invention is preferably based on a recurring, regularly or irregularly arranged pattern. The embossed structure may be a continuous embossed structure such as e.g. a continuous groove structure to a plurality of preferably recurring single embossed structures or a regularly recurring, but in itself arbitrary embossing structure in each case according to the embossing roll used, act.

According to one embodiment, each embossing pattern may be based on a plurality of preferably recurring single embossing patterns. These respective individual embossing structures may preferably be based on a structure with embossing recesses (grooves) which have more or less pronounced embossing elevations, such as webs, through which the embossing height of the film as sum of embossing elevation and thickness of unembossed stretched film - measured according to DIN 53370 2006 - is defined. According to the respective geometry of the elevations of a preferably recurring single embossing structure, a multiplicity of in each case different, preferably recurring, individual embossed structures may result, for example, preferably serpentine, serrated, hexagonal, diamond-shaped, diamond-shaped, parallelogram-shaped, honeycomb-shaped, circular, point-shaped, star-shaped, linen-shaped, net-shaped, polygonal, preferably triangular, quadrilateral, particularly preferably rectangular and square, pentagonal, hexagonal, pentagonal and octagonal, wire-shaped, elliptical, oval and latticed designed patterns, which can also overlap at least two patterns. The embossing elevations may each preferably have a length of up to one centimeter, more preferably a length of 0.001 mm to 10 mm. The proportion of elevations in the total length of the embossed structure ?? with depressions may preferably be <75%, more preferably from 5% to 60% and most preferably from 10% to 50%. Preferably, the elevations are arranged at regular or alternating recurring intervals. The elevations of the individual embossed structures may also preferably have a curvature, ie a convex and / or concave structure.

In a further preferred embodiment, the embossing structure has recurring units of arbitrarily arranged embossing recesses and embossing elevations. The embossing elevations of the embossed structure should preferably be <75%, particularly preferably <50%, based on the entire embossed surface of the plastic film according to the invention.

Preferably, the embossment elevation of the optionally uniform embossing elevations of the plastic film according to the invention is> 5 pm measured according to DIN 53370 2006. The embossing of the embossed structure of the plastic film according to the invention is determined according to DIN 53370 2006 by a mechanical scanning of the surface. In this case, the embossing surveys are measured at least 10 points in a line evenly distributed over the width of the sample, taking care that the scanner does not compress the embossed structure of the plastic film, and the average formed, of which the thickness of the corresponding stretched, unembossed plastic film is deducted. ,

In a further preferred embodiment, the multilayer plastic film of the invention has an asymmetric embossing structure, i. an embossed structure which is continuous throughout the film and imprints both the top and bottom of the film so that they are no longer flat, but the extent of embossing is different on the two sides of the film. In the following, the side of the film, on which the embossing tool acts or has acted, is referred to as the upper side of the film. The film underside of the film can therefore have a weaker embossing (negative form).

By embossing the multilayer plastic film of the invention, it is possible not only to achieve a release effect of the plastic film according to the invention, but also surprisingly to reduce the shrinkage of the stretched, embossed film drastically by more than 50% compared to a corresponding stretched, unembossed film. The stretched and embossed film of the present invention also has excellent tensile strength, good to very good tear propagation performance and excellent puncture resistance. The multilayer plastic film according to the invention may also have a release coating on one of its surface layers to improve its release effect. Preferably, the release coating is based on a cured polysiloxane coating with which the multilayer plastic film according to the invention can be finished prior to stretching or after stretching or after stretching and embossing. The release effect generating release coating and embossing is essentially the entire surface, preferably at least one in Masch inin direction extending strip or partial area, preferably as Rapportgenauer horizontal stripes before.

For the purposes of the present invention, the term "polysiloxane" refers to compounds whose polymer chains are built up alternately from silicon and oxygen atoms. A polysiloxane is based on n recurring siloxane units (- [Si (R2) -O] -) _n , which are each independently disubstituted with two organic radicals R, where R is preferably each R or OR ¹ and R is each a Alkyl radical or an aryl radical. Preferably, the cured polysiloxane coating is based on a recurring dialkylsiloxane unit or on a repeating alkylaryl-siloxane unit. Depending on how many Si-O bonds a single siloxane unit, in each case based on a tetravalent silicon atom, these units can be in terminal monofunctional siloxanes (M) with a Si-O bond, difunctional siloxanes (D) with distinguish two Si-O bonds, trifunctional siloxanes (T) with three Si-O bonds, and tetrafunctional siloxanes (Q) with four Si-O bonds. The polysiloxane coating according to the invention preferably has a crosslinked ring-shaped or chain-like, particularly preferably crosslinked, chain-like structure which comprises (D), (T), and / or (Q) units linked to a two- or three-dimensional network. The number n of repeating siloxane units [Si (R ₂ ) -O] -) _n in the polysiloxane chain is referred to as the degree of polymerization of the polysiloxane.

The cured polysiloxane coating of the plastic film of the invention is preferably based on at least one cured, i. crosslinked polysiloxane selected from the group comprising addition-crosslinked, preferably metal-catalyzed addition-crosslinked, condensation-crosslinked, radically crosslinked and / or cationically crosslinked polysiloxanes.

Particularly preferably, the polysiloxane coating is based on at least one cured polysiloxane, which has been cured by thermal curing and / or under the action of UV radiation. The polysiloxane coating is preferably based on at least one cured polysiloxane selected from the group comprising polydialkylsiloxanes, preferably polydimethylsiloxanes, and polyalkylaryl siloxanes, preferably polymethylphenylsiloxanes, which are each cured. Thermally cured polysiloxanes can be obtained by thermal hydrosilylation of silane-functional polysiloxanes having at least one carbon Double bond can be obtained. UV curing preferably takes place after stretching of the film according to the invention, whereas thermal curing is preferably carried out after stretching and after embossing.

In principle, the production of the plastic film according to the invention can be carried out by any known production method, for example by extrusion or by coextrusion. Both individual layers and also all layers of the plastic film according to the invention can be produced by extrusion, in particular by blown film extrusion and / or flat film extrusion (cast extrusion), or preferably coextrusion, in particular blown film coextrusion and / or flat film co-extrusion. Extrusion (cast-co-extrusion) can be formed, the latter being preferred. It should be noted that in the case of a doping of the layer (a) or further layers with additives, these are used by mixing, if necessary as a masterbatch, with the polymer component or components of the respective layer for processing. This mixing can be done dry in granules / powder or granules / granules form. However, it is also possible to add the additive to the molten polymer component (s) of the respective layer, preferably by metering in an extruder used for the extrusion of the respective layer.

According to the coextrusion process known per se, the melts corresponding to the individual layers of the film according to the invention are simultaneously and jointly coextruded through a round die or a flat die, the resulting film is removed for solidification on one or more rolls and the stretched film is heat-set.

Biaxial stretching (orientation) can be performed sequentially or simultaneously. The sequential stretching is generally performed sequentially with the successive biaxial stretching, first being stretched longitudinally (in the machine direction) and transverse (perpendicular to the machine direction), being preferred. In a film production after a flat film extrusion with subsequent monoaxial or biaxial stretching, the polymer or the Polymer mixture of the individual layers compressed and liquefied in an extruder, wherein the optionally added additives may already be contained in the polymer or in the polymer mixture. The melts are then simultaneously pressed through a flat die, and the extruded multilayer film is drawn off on one or more draw-off rolls at a temperature of 10 to 100 ° C, preferably 10 to 50 ° C, where it cools and solidifies.

The multilayer plastic film according to the invention is then stretched either only longitudinally or longitudinally and transversely to the extrusion direction, which leads to an orientation of the molecular chains. The longitudinal stretching is preferably carried out at a temperature of 70 to 130 ° C, preferably 80 to 110 ° C, advantageously with the help of two according to the desired stretching ratio different fast-running rollers and optionally additional transverse stretching preferably at a temperature of 120 to 180 ° C with the aid a corresponding clip frame. You can set the desired transverse stretching conditions. Stretching only in the machine direction is preferred according to the invention.

The stretching of the film is preferably followed by its heat-setting (heat treatment), the film being kept at a temperature of 100 to 160 ° C. for about 0.1 to 10 seconds. Subsequently, the film can optionally be equipped after intermediate storage with an optional release coating and then embossed or equipped with an optional release coating after embossing. It is also possible to provide the extruded multilayer plastic film with the optional release coating before stretching. The embossing of the plastic film according to the invention with an embossing structure which is only one-sided or entirely continuous can be effected by an embossing process with the aid of a patterning or embossing calender comprising a screen applicator in-line or off-line. This calender preferably has rollers arranged opposite one another in the vertical direction at a certain distance, rotating in opposite directions, the separating film to be provided with an asymmetric embossing structure being fed to the rollers and passed through the nip forming the gap width and being variably adjustable. The raster rolling mill preferably comprises a first roller with a comparatively hard surface, particularly preferably a steel roller, and a second roller which has a comparatively less hard surface and is preferably formed of an elastic material, particularly preferably of rubber or hard rubber.

The harder of the two rollers bears in negative form the einzufrägende in the plastic film pattern (embossing roller). The roller opposite this second roller preferably serves as a counter-pressure roller or pressure roller and presses the to be provided with a pattern or embossed pattern plastic film against the first embossing roller. The embossing of the plastic film is preferably carried out at elevated temperature, therefore, the plastic film passes through the off-line embossing first a heating mill, then optionally takes place irradiation with infrared light before the actual embossing process described above takes place. After embossing, the plastic film optionally passes through a cooling mill for cooling. The creation of the negative form of the structure to be embossed takes place according to the methods known and customary to the person skilled in the art, wherein specific processes may be particularly advantageous depending on the structure and materials. Basically, the structures on the embossing roll can either have a continuous structure or but be formed as an interrupted structure (sequence of individual embossed structures), whereby a combination of both structures is possible. The respective structures on the embossing roller can have a wide variety of geometric shapes, depending on the intended (asymmetrical) structure of the plastic film.

Another object of the present invention is the use of the plastic film according to the invention as a removable release film or protective film, preferably for adhesive articles of any kind, particularly preferably for self-adhesive articles of any kind.

The use of the plastic film according to the invention as a removable packaging and / or protective film for self-adhesive labels or adhesive tapes of any kind, in particular in the construction industry, is a further subject of the present invention.

This also applies to the use of the plastic film according to the invention as a removable, flexible packaging and / or protective film for hygiene articles, preferably individually packaged, optionally folded, self-adhesive panty liners, sanitary napkins or incontinence articles.

The detachable, flexible packaging material according to the invention preferably has the advantage that it can be used to produce packages that can be opened and disposed of with low noise, in particular for individually packaged hygiene products. The noise development is <60 [db] measured as the equivalent continuous sound level L _eq [db]. To determine the equivalent continuous sound level, a film sample in the size of DIN A5 on each longitudinal side is fixed centrally and horizontally by means of a stapler. One of the staplers is not movable while the other can be moved to generate noise by continuously upsetting and stretching the film sample on an eccentric path. The rotational speed of the eccentric drive during the measurement is 36 min ^-1 . As a noise emission parameter, the equivalent continuous sound level L _eq [db] is determined with the aid of a sound recording device which is at a distance of 30 cm from the middle of the broad side of the DIN A5 film sample for the duration of The film sample should not be damaged during stretching and compression, using a measuring device from Brüel & Kjaer, 2250- L, for 30 seconds.

Another object of the invention is also a flexible packaging material made of a plastic film according to the invention for individually packaged, stickable articles, preferably for self-adhesive articles for single use.

Likewise, another object of the present invention is a sanitary or hygienic product provided with the plastic film of the invention as a removable release or protective film.

Furthermore, an object of the present invention is also a flexible packaging material made of a plastic film according to the invention for individually packaged, self-adhesive hygiene articles or incontinence articles. Method of shrinkage measurement

The measurement of the shrinkage takes place according to DIN 5543/4. For this reason, 10 samples each of 100 mm × 100 mm each with a marked running direction in the machine direction or transversely to the machine direction are left in a high-boiling oil bath at 90 ° C. for 3 min, the mean value of the change in length in the MD or in the CD from the respective 10 th Samples averaged and the respective change indicated as% shrinkage.

The following examples and comparative examples serve to illustrate the invention, but are not to be construed as limiting.

I. Chemical characterization of the raw materials used

Table I

Density MFR

(° C / kg)

LDPE 0.923 0.75 (190 / 2.16)

LLDPE 0.921 0.9 (190 / 2.16)

MDPE 0.935 1, 4 (190 / 2.16)

PP 0.90 0.95 (230 / 2.16)

Copolyamide from 1, 13 5 (235 / 2.16)

Isophorone diamine /

isophthalic /

ε-caprolactam with

about 5 mol%

isophoronediamine

(IPDI copolyamide)

HV = PE with MSA 0.91 2.6 (190 / 2.16)

modified

Chalk masterbatch made of LDPE with 70% by weight CaC0 ₃

Dye masterbatch of LDPE with 70 wt .-% Ti0 ₂ II. Production of the Kunstofffilien (B1 / B2) according to the invention and of the plastic films (V1 V2) according to comparative experiment

Each of the multilayer plastic films having the compositions shown in Table II was prepared by coextrusion onto a blown film coextrusion unit initially with a total layer thickness of 40 μm. After spreading the film tube, it was fed to a roll stretching machine and stretched by a factor of 1: 4 in the longitudinal direction so that the resulting total film thickness of 10 m resulted. After stretching on a stamping calender, the plastic films B1 or B2 according to the invention were provided with microembossing (embossing elevation) of about 5 .mu.m and the physical and shrinkage behavior indicated in Table IV below was determined and indicated by the comparative and inventive plastic films ,

III. Construction of the plastic films

All subsequent% data are each wt%.

111.1 Examples B1 / Comparative Example C1

(3-layer, total layer thickness 10 μηη)

Table II

Layer structure Raw materials B1 Raw materials V1

Layer (a) 30% MDPE 30% MDPE

Layer thickness 2.5 μητι 49.5% LDPE 49.5% LDPE

20% chalk 20% chalk

0.5% additive 0.5% additive

Layer (c) 48.4% MDPE 48.4% MDPE

Layer thickness 5 μηι 33.3% PP 33.3% PP

13.3% LDPE 13.3% LDPE

4% dye 4% dye

1% additive 1% additive

Layer (s) 30% MDPE 30% MDPE

Layer thickness 2.5 μηη 49.5% LDPE 49.5% LDPE

20% chalk 20% chalk

0.5% additive 0.5% additive unembossed + stretched + embossed +

stretched + II 1.2 Example B2I Comparative Example V2

(5-layer, total layer thickness 10 pm)

Table III

Layer structure Raw materials B2 Raw materials V2

Layer (a) 54% MDPE 54% MDPE

Layer thickness 2.9 pm 20% LDPE 20% LDPE

15% chalk 15% chalk

10% dye 10% dye

1% additive 1% additive

Adhesive layer (b)

100% HV 100% HV layer thickness 0.85 pm

Layer (c) 100% 100%

Layer thickness 2.5 μm IPDI copolyamide IPDI copolyamide

Adhesive layer (d)

100% HV 100% HV layer thickness 0.85 μιη

Layer (s) 54% MDPE 54% MDPE

Layer thickness 2.9 μητι 20% LDPE 20% LDPE

15% chalk 15% chalk

10% dye 10% dye

1% additive 1% additive uncoated + stretched + embossed + stretched + Table IV

Example 1 Comparative Example 1 (3-layer)

Example 2 / Comparative Example 2 (5-layer)

Claims

claims

1. An at least monoaxially stretched, at least 50 wt .-% consisting of polyolefins, multilayer plastic film having a release effect and a total thickness <18 pm, preferably <12 pm, which has at least one surface at least partial embossing.

2. A plastic film according to claim 1, characterized in that it has a stretching in the machine direction of at least 1: 2, preferably of at least 1: 5.

3. A plastic film according to one of claims 1 or 2, characterized in that the release effect of the plastic film on the at least partial embossing is based on at least one surface, wherein the embossment elevation of the at least partial embossing> 5 pm measured according to DIN 53370 2006.

4. A plastic film according to claim 1 to 3, characterized in that the plastic film has a release coating, preferably of cured polysiloxane, on at least one of its surfaces.

5. A plastic film according to any one of the preceding claims, characterized in that the plastic film has a shrinkage of at least 50% lower than a corresponding unembossed, stretched plastic film.

6. A plastic film according to any one of the preceding claims, characterized in that the release effect producing release coating and / or embossing substantially over the entire surface, preferably except for at least one machine direction stripes, or partial area, preferably as Rapportgenauer horizontal strip of the sheet-like plastic film.

7. A plastic film according to any one of the preceding claims, characterized in that the plastic film consists of at least 70 wt .-% of polyolefins, preferably from C2-C8 olefin polymers, more preferably from C2-C3 olefin polymers, their mixtures or their copolymers.

8. A plastic film according to one of the preceding claims, characterized in that the polyethylenes are LDPE, MDPE, LLDPE or a mixture of at least two of said PE.

9. A plastic film according to one of the preceding claims, characterized in that at least one layer of the plastic film is based on a mixture of at least one PE and a PP, preferably a mixture of an LLDPE and / or MDPE and / or PP.

10. A plastic film according to one of the preceding claims, characterized in that the film has a barrier layer, preferably at least one barrier layer against gases, particularly preferably against O 2, H 2 O steam and / or gaseous flavors, against migration of low molecular weight, organic compounds and / or taste or odor impairment and / or against moisture and / or fats and / or oils.

11. A plastic film according to any one of the preceding claims, characterized in that the barrier layer of ethylene A / inyl alcohol copolymers, polyvinyl alcohols, polyamides, polyesters and / or polyether-polyamide block copolymers is constructed.

12. A use of a plastic film according to any one of claims 1 to 11 as a release or protective film.

13. A use of a plastic film according to any one of claims 1 to 11 as a removable packaging and / or protective film for preferably self-adhesive articles of any kind, preferably for self-adhesive labels, toiletries, preferably individually packaged, self-adhesive panty liners, sanitary napkins or incontinence.

14. A use of a plastic film according to any one of claims 1 to 11 as a carrier layer for adhesive tapes of any kind, preferably in roll form.

15. A use of a plastic film according to any one of claims 1 to 11 as a low-noise, optionally removable packaging material for individually packaged hygiene articles or incontinence products.

16. A flexible packaging material made of a plastic film according to one of claims 1 to 11, preferably for individually packaged, adhesive articles, preferably for self-adhesive articles for single use.

17. A flexible packaging material made of a plastic film according to one of claims 1 to 11 for individually packaged, self-adhesive hygiene articles or incontinence articles.