EP3221388A1

EP3221388A1 - Flexible, thermally stable and simultaneously transparent bio-based film based on poly(lactic acid), formulation for producing the film and use of said film

Info

Publication number: EP3221388A1
Application number: EP15786978.5A
Authority: EP
Inventors: Kerstin KLINGEBERG; Bernhard MÜSSIG
Original assignee: Tesa SE
Current assignee: Tesa SE
Priority date: 2014-11-18
Filing date: 2015-10-29
Publication date: 2017-09-27
Also published as: US20190085214A1; DE102014223470A1; WO2016078889A1; CN107001777A

Abstract

The invention relates to a bio-based film comprising a composition based on poly(lactic acid), said composition containing the following components: (a) at least one bio-based co-polymer based on at least one lactic acid derivative; (b) at least one plasticizer comprising at least one compound which contains at least one ester group, excluding dimeric and polymeric esters of lactic acid; (c) at least one nucleation agent; and (d) optional additives.

Description

Flexible, thermally stable and at the same time transparent bio-based film based on polylactic acid, a formulation for the production of the film as well as their

use

The present invention relates to a bio-based film having improved properties such as thermal stability, degree of crystallization, softness and transparency and their use as a support for sheet-like pressure-sensitive adhesives such as cable ties and cable winding tapes. Furthermore, the invention relates to a formulation A and a formulation B each comprising at least one polymer based on lactic acid, at least one plasticizer and at least one nucleating agent and a method for producing the film according to the invention from at least one of the formulations A and / or B.

Many formulations with polylactic acid (PLA) and films based on polylactic acid-containing polyesters are already known. However, the films produced from the formulations or the known films lack thermal stability, which has the highest priority inter alia for the coating with an adhesive and for applications as a carrier in adhesive tapes or cable winding tapes for the automotive sector. The lack of softness was often compensated in the known formulations by blending with a biodegradable polyester such as polyethylene terephthalate (PET).

In the prior art (DE 10 2007 038 473 A1), the softness of films based on polylactic acid (PLA) is achieved inter alia by admixing long-chain plasticizers such as polyglycols, thus reducing migration of the plasticizer. Other compositions based on polylactic acid (US 2009/031 151 1 A1) include, as nucleating agents, organic compounds, such as aliphatic carboxylic acid amides having at least one amide bond, preferably ethylenebiscarboxamide, in order to achieve the thermal stability of three-dimensional molded articles produced therefrom. Another relevant point when using lactic acid and its derivatives as starting material for the production of polyesters is the increase in the crystallization of polylactic acid in such a composition. Thus, US 2012/0184672 A1 describes a PLA resin composition with a plasticizer, in particular a carboxylic ester, and as an additive wax or a mineral filler such as talc, wherein the composition is substantially free of organic nucleating agents. Such PLA-based compositions are used to make films (US 2006/093791 A1) achieving a heat of fusion of 10 J / g. However, blending with these non-bio-based materials will lose both biobasedness and transparency. Furthermore, the thermal stability of PLA-based compositions and the moldings obtainable therefrom, such as supports, films and adhesive tapes, achieved so far in the prior art is insufficient. In particular, this is not sufficient for applications of said moldings in the automotive sector and for applications with adhesives, in particular pressure-sensitive adhesives. Furthermore, a migration of the plasticizers contained therein still takes place and the flexibility of the achievable sheet-like moldings, in particular films, is still unsatisfactory, without at the same time accepting restrictions in the respective other properties such as, for example, transparency.

It is therefore an object of the present invention to provide a bio-based film which has very good optical and mechanical properties. An essential object of the present invention is to provide a film having improved properties such as degree of crystallization, thermal stability, softness and transparency. A further object of the invention is to provide a film with very good optical and mechanical properties, in which there is no migration, in particular no outdiffusion, of the plasticizer containing it. It is a further object of the invention to provide a formulation from which the described film can be produced, without limitation in the mechanical and optical properties, in particular degree of crystallinity, thermal stability, softness and transparency. And object of the invention is to provide a process for the preparation of the formulations and the film.

By adding at least one plasticizer and at least one nucleating agent with special processing of the components, the resulting material, in particular the film, both the brittleness taken and the thermal stability can be improved while maintaining the required transparency. The use of plasticizers and nucleating agents leads to a synergistic effect, which on the one hand reduces the stiffness and brittleness of the film and, on the other hand, improves the thermal stability of the film by means of a special process control. At the same time, the disturbing crackling, which is known, for example, in BO-PLA films, is avoided.

Through the use of plasticizers, in the polylactic acid-based composition of the present invention, the glass transition temperature (TG) is lowered, whereby ultimately the brightener and stiffness of the formulation and film of the invention are taken. The film has a higher elongation and a lower power consumption. The problem of the migration of the often low molecular weight plasticizer molecules to the surface, which, for example, considerably complicates the anchoring with an adhesive, is solved by the invention by the combined use of nucleating agents and plasticizers according to the invention. Thereby, the crystallization temperature is shifted to higher temperatures, which leads to greater crystallinity and higher thermal stability of the formulation and film according to the invention, and at the same time migration of the plasticizers is prevented.

This inventive combination of plasticizer and nucleating agent in suitable proportions and the treatment with heat, in particular by hot rolling and / or stretching of the film according to the invention, a special synergistic effect occurs. It can be observed a greater degree of crystallization than with each additive alone. In addition, the degree of crystallization can reach a value greater than the sum of the individual values. In addition, not only migration is prevented, but also a constant transparency maintained.

The solution of the objects is described by the subject matters of the independent claims and moreover in concrete form in the subclaims as well as in detail in the description.

The first object of the invention is a bio-based film comprising a composition based on polylactic acid containing the following components

(a) at least one bio-based (co) polymer, in particular (co) polyester, based on at least one lactic acid derivative, in particular a monomer and / or dimer of lactic acid,

(B) at least one plasticizer comprising at least one ester group-containing compound, except dimeric and polymeric esters of lactic acid, and at least one nucleating agent, in particular with a mean particle diameter of less than or equal to 2 μm, and

optional additives.

Furthermore, the invention provides that the film according to the invention comprises the respective components in a proportion, based on the total content of the composition (ad 1 00 wt .-%), of

(a) greater than or equal to 75% by weight to less than or equal to 98.9% by weight, greater than or equal to 80% by weight to less than or equal to 97% by weight, preferably greater than or equal to 85% by weight to less than or equal to 95% by weight %, particularly preferably greater than or equal to 87% by weight to less than or equal to 90% by weight, of at least one bio-based (co) polymer, in particular (co) polyester, based on at least one lactic acid derivative, in particular one Monomer and / or dimer of lactic acid,

(b) greater than or equal to 1% by weight to less than or equal to 20% by weight, greater than or equal to 5% by weight to less than or equal to 15% by weight, preferably greater than or equal to 1% by weight to less than or equal to 13% by weight. %, more preferably 12 wt .-%, of the at least one plasticizer and

(c) greater than or equal to 0.1% by weight to less than or equal to 5% by weight, preferably from 0.5% by weight to 3% by weight, particularly preferably greater than or equal to 0.5% by weight to less than or equal to 1, 5 wt .-%, of the at least one nucleating agent, in particular having a mean particle diameter of greater than or equal to 0.5 μηη to less than or equal to 5 μηη, preferably less than or equal to 2 μηη, greater than or equal to 0.5 μηη to less than or equal to 3 μηη, greater than or equal to 0.7 μηη to less than or equal to 2.5 μηη, more preferably greater than or equal to 1 μηη to less than or equal to 2 μηι, and

(d) greater than or equal to 0 wt% to less than or equal to 20 wt%, preferably greater than or equal to 0 wt% to less than or equal to 1-5 wt%, more preferably greater than or equal to 0.5 wt% to less equal to 1 0 wt .-%, of additives.

In particular, the film according to the invention has a TG of less than or equal to 120 ° C. preferably a TG of less than or equal to 1 10 ° C.

Furthermore, the film according to the invention has a softness, measured at the elongation at break (according to ISO 527), of greater than or equal to 3% to less than or equal to 300%. The softness is the deformability of the film. The ductility of a material can be described by its strength, plasticity and elasticity. A film with an elongation at break of 3% or 300% has an extension of the film by 3% or 300% of its original length, said extension after breakage has occurred Sample is preserved. The film according to the invention preferably has an elongation at break of greater than or equal to 30% to less than or equal to 300%, greater than or equal to 50% to less than or equal to 280%, preferably greater than or equal to 100% to less than or equal to 250%. The data on the elongation at break of the film according to the invention can relate to stretched films. Thus, for example, a breaking elongation of greater than or equal to 30% to less than or equal to 300%, greater than or equal to 50% to less than or equal to 280%, preferably greater than or equal to 100% to less than or equal to 250%, can refer to stretched films as well as non-stretched films. Therefore, another object of the invention is a film which at a temperature above a TG, particularly suitably greater than or equal to 90 ° C to less than or equal to 120 ° C, even better equal to 90 ° C to less than or equal to 1 10 ° C, by a factor λ of greater than or equal to 1 to less than or equal to 7, particularly suitably greater than or equal to 2 to less than or equal to 6, preferably greater than or equal to 5 to less than or equal to 6, in particular in the longitudinal direction was stretched.

A stretch ratio of 1: 6 indicates that a section of 6 m length of the stretched film is formed from a section of the film of, for example, 1 m in length. Often, the draw ratio is also referred to as the quotient of the line speed before drawing and the line speed after drawing. The numbers used below refer to the stretching. The stretching takes place without the width of the primary film substantially decreasing, solely at the expense of the thickness of the film.

In particular, the film has a thermal stability, measured as shrinkage (according to DI N 53377), of greater than or equal to 0% to less than or equal to 5%, preferably greater than or equal to 0% to less than or equal to 3%, more preferably greater than or equal to 1% to less than or equal to 4%.

The film preferably has a degree of crystallinity, measured as heat of fusion (according to DIN EN ISO 1 1357-3), of greater than or equal to 30 J / g to less than or equal to 50 J / g, preferably greater than or equal to 35 J / g to less than or equal to 50 J / g, more preferably greater than or equal to 40 J / g to less than or equal to 50 J / g.

In particular, no migration of the compounds contained occurs in the film of the invention, in particular no migration of the plasticizers comprising esters of di- and / or tricarboxylic acids having at least one alkyl radical on the at least one ester group selected from Ci to C2o-alkylene comprising methyl, ethyl -, propyl, butyl, hexyl, nonyl, dodecyl and octydecyl radicals, preferably comprising esters of citric acid and adipic acid, particularly preferably alkyl citrates such as tributyl citrate, triethyl citrate and Acetyltributylcitrat and / or adipic acid esters such as diethylhexyl adipate (Dioctyladipat) used.

Particularly preferred is a stretched by a factor λ = 1 film comprising the formulation A, preferably prepared from Formulation B, a high elongation at break of greater than or equal to 250%. Such a film additionally preferably has a high thermal stability, measured by shrinkage at 120 ° C. of less than or equal to 5%. In particular, when stretched by a factor λ of greater than or equal to 5 to less than or equal to 6, a high strength is achieved. According to a further aspect of the invention, the film according to the invention has a high transparency of greater than or equal to 80% to less than or equal to 100%, preferably greater than or equal to 85% to less than or equal to 98%, preferably greater than or equal to 90% to less than or equal to 97%, measured by transmission at a wavelength of greater than or equal to 400 nm to less than or equal to 800 nm, preferably greater than or equal to 600 nm to less than or equal to 800 nm. In addition, no migration of the compounds contained in these films, in particular the plasticizer.

This high transparency is achieved, since esters of a di- and / or tricarboxylic acid are used essentially as plasticizers, as explained in more detail below. The film of the invention may have a layer thickness of greater than or equal to 5 μηη to less than or equal to 500 μηη, preferably greater than or equal to 5 μηη to less than or equal to 50 μηη, greater than or equal to 10 μηη to less than or equal to 40 μηη, more preferably greater than or equal to 15 μηη to less than or equal to 30 μηη , Several films of different layer thicknesses can be arranged one above the other in the form of several layers. Thus, it may be advantageous for the stability and / or flexibility of the film according to the invention to combine film layers of different layer thickness (for example 5 μm, 10 μm, 15 μm, 20 μm, 30 μm and 40 μm) from at least two layers to form a film. In particular, films of different layer thickness can be combined with different degrees of stretching. Thus, a film has a layer thickness of greater than or equal to 10 μηη, greater than or equal to 15 μηη, greater than or equal to 20 μηη greater than or equal to 25 μηη to less than or equal to 30 μηη, less than or equal to 35 μηη, less than or equal to 40 μηη a degree of stretching with a factor λ greater than or equal to 1 , 2, 3, 4, 5, 6 to less than or equal to 7.

Another object of the invention is a formulation A, in particular a formulation B, containing polylactic acid comprising the following components at least one biobased (co) polymer, in particular (co) polyester, based on at least one lactic acid derivative, in particular a monomer and / or dimer of lactic acid,

at least one plasticizer comprising at least one ester group-containing compound, with the exception of dimeric and polymeric esters of lactic acid,

at least one nucleating agent, in particular with a mean particle diameter of less than or equal to 2 μm, and

optional additives.

Preferably, the components of the formulation A according to the invention, in particular the formulation B according to the invention, are each present in a proportion, based on the total content of the composition (ad 100% by weight), of

(b) greater than or equal to 1% by weight to less than or equal to 20% by weight, greater than or equal to 5% by weight to less than or equal to 15% by weight, preferably greater than or equal to 1% by weight to less than or equal to 13% by weight. %, more preferably 12 wt .-%, of the at least one plasticizer

(c) greater than or equal to 0.1% by weight to less than or equal to 5% by weight, preferably from 0.5% to 3% by weight, more preferably greater than or equal to 0.5% by weight to less than or equal to 1, 5 wt .-%, of the at least one nucleating agent, in particular having a mean particle diameter of greater than or equal to 0.5 μηη to less than or equal to 5 μηη, preferably less than or equal to 2 μηη, greater than or equal to 0.5 μηη to less than or equal to 3 μηη, greater than or equal to 0.7 μηη to less than or equal to 2.5 μηη, more preferably greater than or equal to 1, 0 μηη to less than or equal to 2 μηη, and

(d) greater than or equal to 0% by weight to less than or equal to 15% by weight of additives.

In a particular embodiment of formulation A, in particular formulation B, the components are each present in a proportion, based on the total content of the composition (ad 100 wt .-%), of

(A) greater than or equal to 86 wt .-% to less than or equal to 88.5 wt .-% of the at least one bio-based (co) polymer, in particular (co) polyester, based on at least one lactic acid derivative, in particular a monomer and / or dimer of lactic acid, (b) greater than or equal to 1 1% by weight to less than or equal to 13% by weight of the at least one plasticizer,

(c) greater than or equal to 0.5% by weight to less than or equal to 1.5% by weight of the at least one nucleating agent, and

(d) greater than or equal to 0 wt% to less than or equal to 15 wt%, preferably less than or equal to 10 wt%, of additives.

A particular synergistic effect of the components contained in the formulation A, in particular formulation B and thus in the film according to the invention, was found when the at least one inventive (a) polyester based on lactic acid with a fraction of less than or equal to 87 wt .-%, the Plasticizer at a level of 12% by weight and the nucleating agent at 1% by weight of the total content of the composition. Additives may be added if necessary, in which case the proportion of (a) at least one polyester is reduced accordingly. When combined with one or more other polyesters, the proportion of (a) is adjusted accordingly to the at least one lactic acid-based polymer.

According to a further aspect of the invention, the formulation A and the formulation B, in particular the film according to the invention obtainable from the formulation A, comprise at least (a) a bio-based (co) polymer, in particular polyester, containing at least one lactic acid derivative as at least one monomer and / or dimer which is selected from L (S) -lactic acid, D (R) -lactic acid, (S, S) -lactide, (R, R) -lactide, (meso) -lactide and mixtures of at least two of the mentioned compounds. In particular, polymers such as poly (L) -lactide and copolymer such as poly (D, L) -lactide and poly (L) -lactide-co- (D, L) -lactide are preferred.

The lactic acid is a hydroxycarboxylic acid having a carboxy group and a hydroxy group. It can be present in different isomers, L (S) -lactic acid and D (R) -lactic acid, which are understood as monomers for the purposes of the invention. D-lactic acid is described as levorotatory and L-lactic acid as dextrorotatory lactic acid. R is a synonym for D and S is a synonym for L. Racemate are mixtures of both isomers with a ratio of 1: 1.

The lactide is a cyclic diester of lactic acid and is understood in the context of the invention as a dimer of lactic acid. Similar to the monomers, dimers can also be present as different isomers (S, S) -lactide, (R, R) -lactide and (meso) -lactide. The lactide of L-lactic acid (synonym = (S) -lactic acid) has an (S, S) -configuration, so it lies as (S, S) - Lactide before, and the lactide of D-lactic acid (synonym = (R) -lactic acid) has an (R, R) - configuration, is thus present as (R, R) -Lactide. The (meso) lactide consists of an L- and D-lactic acid and is therefore an (R, S) -lactide and has two asymmetric centers of opposite configuration R and S.

Polymers according to the invention which are used both in the film and in the formulations A and B are preferably polyesters and comprise homopolymers of one of the abovementioned lactic acid derivatives and copolymers of at least two of said lactic acid derivatives or mixtures of homopolymers and copolymers , Lactic acid-based homopolymers are, for example, polyesters of L-lactic acid such as poly (L) -lactide and racemate D, L-lactic acid such as poly (D, L) -lactide. Copolymers are, for example, polyesters of L-lactide with D-lactide such as poly (L) -lactide-co- (D) -lactide or L-lactide with D, L-lactide such as poly (L) -lactide-co- (D , L) lactide. In particular, preferred as lactic acid-based polymers are compounds such as poly (L) -lactide and copolymers such as poly (D, L) -lactide and poly (L) -lactide-co- (D, L) -lactide. In the copolymers, the ratios of the at least two monomers to each other can vary from 30: 1 to 1:30.

By using lactic acid derivatives in the formulations A and B, bio-based films are obtained, which are preferably biodegradable according to DIN EN 13432. For the purposes of the present invention, bio-based means that the compound designated as such is based on renewable raw materials and has been produced exclusively from them. Thus, bio-based feedstocks are compounds such as monomers, dimers, polymers, plasticizers, and nucleating agents that are not crude oil based. Thus, cracked crude monomers that were subsequently optionally fermented are not considered bio-based.

In a particular embodiment, the copolymer of lactic acid as a (b) second monomer may be selected from the group comprising (i) aliphatic and aromatic mono- / di-carboxylic acids such as valeric acid (butylcarboxylic acid), succinic acid, malic acid, adipic acid, Maleic acid, alpha-, beta-hydroxy acids, terephthalic acid, lactic acid, glycolic acid, butyric acid (beta), hydroxyvaleric acid, mevalonic acid and / or (ii) alkyl-containing alpha, omega-diols comprising 1, 2-1, 3-1, 4-alkyl-diols comprising ethyl, propyl, butyl, preferably 1, 4-butanediol, 1, 3-propanediol and mixtures of at least two of said compounds.

Possible copolymers of lactic acid include, for example, poly (L) -lactide-co-glycolide and poly (D, L) -lactide-co-glycolide. By copolymerization of lactic acid with a Glycolsäurelactid, the degradation of the polyester in the film can be controlled, since the degradation of the polyester is slowed by glycolic acid. By the mixing ratio of the two acids or their lactones, the desired degradation or the lifetime of the film and the formulation B described below for the production of the film according to the invention can be adjusted accordingly.

Particularly preferred are those polyesters which contain bio-based monomers and / or are biodegradable according to DIN EN 13432. Of course, mixtures of several such polyesters are suitable.

The films according to the invention, in particular the corresponding formulations A and B, preferably contain at least one biobased polyester as homopolymer of polylactic acid (PLA). For example Compostable ^® of Cereplast, ECOPOND PLA 873 of Kingfa, Bio-Flex ^® A4100 CL from FKuR, FT1 minima, all Ingeo products from NatureWorks, Kareline ^® Plast Hill, all Nature plastic products and PLA of RTP. Bio-Flex from FKuR Kunststoff GmbH, Biocylce from Klöckner Pentaplast GmbH & Co. KG, Biofront from Teijin Chemicals Ltd., Biopearls from Biopearls, Biophan from Treofan Germany GmbH & Co. KG, Ceramis from Alcan Packaging Kreuzlingen GmbH, Earthfirst from Sidaplax VOF , Ecodear of Toray Industries, Inc., Ecovio of BASF SE, Evlon of Bi-Ax International Inc., Fozeas of Mitsubishi Chemical Corporation, Ingeo of NatureWorks LLC, Lacea of Mitsui Chemicals, Puralct of Purac, Terramac of Unitika Ltd.

If necessary, one or more other polymers may be used in addition to a polyester based on polylactic acid. Possible polymers include polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyamide (PA), polyurethane (PU), polybutyl succinate (PBS), polyhydroxyalkanoate, polylactic acid (PLA) and their copolymers, scPLA, PPLA, polycaprolactone and starch , As a second component, formulation A according to the invention and film (b) according to the invention comprise at least one plasticizer comprising at least one ester group-containing compound, with the exception of dimeric and polymeric esters of lactic acid. Thus, another aspect of the invention is formulation A, especially formulation B, wherein (b) the at least one plasticizer is an ester of a di or tri carboxylic acid comprising (i) aliphatic saturated or unsaturated and (ii) aromatic saturated or unsaturated di- and tri-carboxylic acid esters. Preference is given to using bio-based plasticizers based on carboxylic acid esters. By using the plasticizer according to the invention, in particular by the esters of carboxylic acids, the integration of the plasticizer in the polyester, preferably in the polylactic acid, improved. Particularly preferably, the plasticizer has a molecular weight Mw of 100 to 10,000, 100 to 1, 000, 200 to 800, preferably 250 to 500. Preferably, the plasticizer is a short-chain plasticizer. Especially such plasticizers allow the described synergistic effect between plasticizer and nucleating agent, whereby the improved thermal stability, good transparency achieved while preventing migration of the plasticizers.

Dicarboxylic and tricarboxylic acids in the context of the invention include acids having two or three COOH groups and a hydrocarbon radical having greater than or equal to 2 to less than 40 C atoms, preferably greater than or equal to 2 to less than or equal to 20 C atoms, particularly preferably greater than or equal to 2 less than 12 C atoms. These may be branched saturated, unbranched saturated, and branched unsaturated or unbranched unsaturated. Examples of unbranched saturated dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid and azelaic acid. Examples of tricarboxylic acids are the aliphatic citric acid, trimesic acid, the aromatic trimellitic acid and the aromatic hemimellitic acid.

The esters of the respective acids are reacted with mono-, di- or trihydric aliphatic saturated alcohols having greater than or equal to 2 to less than 40 carbon atoms, preferably greater than or equal to 2 to less than or equal to 20 carbon atoms, more preferably greater than or equal to 2 to less than or equal to 6 C atoms formed.

The esters of di- and / or tricarboxylic acids preferably comprise at least one alkyl radical on the at least one ester group selected from C 1 to C 20 -alkylene, including methyl, ethyl, propyl, butyl, hexyl, nonyl, dodecyl and Octydecyl residues.

Preferably, esters of citric acid and adipic acid, preferably citric acid alkyl esters such as tributyl citrate, triethyl citrate and acetyltributyl citrate and / or adipic acid esters such as diethylhexyl adipate (dioctyl adipate) are used. These plasticizers have no negative influence on the transparency of the film. In particular, these plasticizers do not diffuse from the film according to the invention and / or formulation B. Preference is given to using those plasticizers which have no negative influence on the biodegradability of formulation A and the film according to the invention obtainable therefrom. The at least one plasticizer is preferably biodegradable alone or in combination with (a) the at least one polymer, (c) at least one nucleating agent and / or the optional additives of formulation A according to DIN EN 13432.

As a third component, formulation A according to the invention comprises at least (c) a nucleating agent which is simultaneously a nucleating accelerator, comprising in particular natural, bio-based and / or synthetic waxes, mineral fillers and bio-based fillers.

As the nucleating agent may be selected talc, chalk, carbon black, graphite, calcium or zinc stearate, poly-D-lactic acid, N, N'ethylen-bis-12-hydroxystearamid, polyglycolic acid, sodium phenyl phosphinate, alumina, silica and preferably talc. All waxes include ester group-containing compounds such as fatty acid esters and fatty alcohols with long-chain aliphatic alcohols and long-chain aliphatic carboxylic acids, free or unbound ketones, free or unbound alcohols, free or unbound fatty acids and saturated and unsaturated hydrocarbon compounds, and amide group-containing compounds ,

Natural waxes include those waxes that can be taken from nature, including vegetable and animal waxes. Examples of animal waxes are spermaceti and beeswax, and for vegetable waxes sugar cane wax or carnauba wax of the wax palm. In particular, the mixture of stearic stearic and palmitic acid is derived mainly from vegetable palm oil or animal fats. Stearin and derivatives thereof, preferably amide group-containing stearin derivatives such as ethylene-bis-stearamide are preferred because it is biodegradable. The jojoba oil is an example of a liquid wax. The natural waxes also include so-called earth waxes, such as the ozokerite, which consists essentially of hydrocarbons.

Bio-based waxes are those that are prepared synthetically by methods known to those skilled in the art, but using bio-based starting materials for the purposes of the invention. For example, polyethylene and copolymers thereof can be synthesized entirely from bio-based monomers. Synthetic waxes are also those that are of natural origin, but for the Application chemically modified. For example, a soy wax can be produced by hydrogenating soy.

Particularly suitable mineral fillers are silicas (spherical, acicular or irregular, such as fumed silicas), calcium carbonates, zinc oxides, titanium dioxides, aluminum oxides, aluminum hydroxides or aluminum oxide hydroxides, magnesium hydroxides, magnesium, zinc or calcium oxides. Carbonates / sulphates comprising chalk, dolomite, barite; Oxides / hydroxides such as quartz flour and silicates comprising clay, loam, talc, mica, kaolin, Neuburg Siliceous Earth.

As bio-based or organic fillers it is possible in particular to use both vegetable and animal raw materials, if appropriate also in combination with one another. The organic fillers are very preferably finely divided, in particular in the form of fibers, shot, dust or flour. Preferred vegetable organic fillers are renewable raw materials (renewable organic materials), in particular wood, cork, hemp, flax, grass, reeds, straw, hay, cereals, maize, nuts or constituents of the abovementioned materials, such as shells (for example nut shells), Cores, awns or the like. In particular, wood flours, cork flours, cereal flours, corn flours and / or potato flours are used without wishing to be unnecessarily limited by the list in the inventive teaching. Particularly suitable animal organic fillers are bones, chitin (for example, crayfish, insect armor), hair, bristles and horn, and in particular in finely divided (ground) form. Preference is given to using cellulose powders such as wood flour as filler, starch-plasticized or non-plasticized with plasticizers such as glycerol or sorbitol, starch derivatives, cereals and / or cellulose derivatives.

Preferred nucleating agents are ethylene-bis-stearamide from the group of waxes and talc from the group of mineral fillers. The inventive formulation A preferably comprises (c) the at least one nucleating agent comprising wax and / or mineral fillers having an average particle diameter of greater than or equal to 0.5 μm to less than or equal to 5 μm, preferably less than or equal to 2 μm, preferably greater than or equal 0.5 μηη to less than or equal to 3 μηη, greater than or equal to 0.7 μηη to less than or equal to 2.5 μηη, more preferably greater than or equal to 1, 0 μηη to less than or equal to 2 μηη.

The nucleating agent also has an influence on the transparency of the film obtainable from the formulation A and / or B. If you want high transparency, the middle one should be Particle diameter at greater than or equal to 0.05 μηη are less than or equal to 2 μηη, preferably 0.05 to less than or equal to 0.2 μηη.

Where necessary, the film of the invention may comprise additives and / or (d) additives may be added to Formulation A and / or Formulation B. Additives include antiblocking agents, dyes, optical brighteners, antistatic agents, antifoggants, lubricants, UV absorbers, fillers, peel and / or seal additives, antioxidants and / or processing aids. The respective additives can already be incorporated into Formulation A or only in Formulation B. Furthermore, the at least one additive may be contained in one or more film layers or films in the film structure according to the invention.

Possible additives are listed below by way of example, the skilled person being familiar with the selection and function of the respective additives and the influence on the properties of the film.

(1) Acid scavenger for increasing the hydrolytic stability. This procedure is especially preferred for polyesters having a high starting acid number. Particularly preferred acid-scavengers are compounds selected from the group consisting of bisoxazoline, polyoxazoline, carbodiimide, polymeric carbodiimide, dicaprolactam, polymeric caprolactam, bisoxazine and polyoxazine.

(2) Lubricants, such as preferably long-chain fatty acids (for example stearic acid or behenic acid), their salts (for example calcium or zinc stearate) or montan waxes (mixtures of straight-chain, saturated carboxylic acids with chain lengths of 28 to 32 carbon atoms) or salts thereof with (alkaline) alkali metals, preferably Ca-montanate and / or sodium montanate) and low molecular weight polyethylene or polypropylene waxes,

(3) fillers such as glass fibers,

(4) UV stabilizers such as various substituted resorcinols, salicylates, benzotriazoles and benzophenones, preferably organic phosphatins such as tetrakis (2,4-di-tert-butylphenyl) biphenylene diphosphonite and / or

(5) Colorants such as dyes and inorganic pigments such as ultramarine blue, iron oxide, zinc sulfide and / or titanium dioxide, further organic pigments such as phthalocyanines, quinacridones, perylenes and dyes such as anthraquinones are added as colorants. Preferred embodiments of the formulation A according to the invention, in particular the formulation B according to the invention, for the production of the film according to the invention comprise: Formulation A-1 (total content of the composition ad 100% by weight)

(a) PLA comprising poly (L) -lactide, poly (D, L) -lactide and / or poly (L) -lactide-co- (D) -lactide, preferably poly (L) -lactide and / or poly ( L) -lactide-co- (D) -actide, with a proportion of greater than or equal to 75% by weight, optionally 60% by weight, to less than or equal to 98.9% by weight, greater than or equal to 80% by weight to less than or equal to 97% by weight, preferably greater than or equal to 85% by weight to less than or equal to 95% by weight, particularly preferably greater than or equal to 87% by weight to less than or equal to 90% by weight

(b) citric acid ester as a plasticizer, preferably tributyl citrate, triethyl citrate and / or acetyltributyl citrate in a proportion of greater than or equal to 1% by weight to less than or equal to 20% by weight, greater than or equal to 5% by weight to less than or equal to 15% by weight preferably greater than or equal to 1 1% by weight to less than or equal to 13% by weight, particularly preferably 12% by weight

(C) As a nucleating agent according to a first alternative ethylene-bis-stearamide or after a second alternative talc in each case with a proportion of greater than or equal to 0.1% by weight to less than or equal to 5 wt .-%, preferably greater than 0.5 wt % to less than or equal to 3% by weight, particularly preferably greater than or equal to 0.5% by weight to less than or equal to 1.5% by weight

Formulation A-2 (total content of the composition ad 100% by weight)

(b) citric acid ester as a plasticizer, preferably tributyl citrate, triethyl citrate and / or acetyltributyl citrate in a proportion of greater than or equal to 1% by weight to less than or equal to 20% by weight, greater than or equal to 5% by weight to less than or equal to 15% by weight preferably greater than or equal to 1 1% by weight to less than or equal to 13% by weight, particularly preferably 12% by weight (c) as nucleating agent according to a first alternative ethylene-bis-stearamide or, according to a second alternative, talc of greater than or equal 0, 5 μηη to less than or equal to 5 μηη, preferably less than or equal to 2 μηη, preferably greater than or equal to 0.5 μηη to less than or equal to 3 μηη, greater than or equal to 0.7 μηη to less than or equal to 2.5 μηη, more preferably greater than or equal to 1, 0 μηη to less than or equal to 2 μηη and with a proportion of greater than or equal to 0.1% by weight to less than or equal to 5% by weight, preferably greater than or equal to 0.5% by weight to less than or equal to 3% by weight, more preferably greater than or equal to 0.5 wt .-% to less than or equal

1, 5 wt .-% Formulation A-3 (total content of the composition ad 100% by weight)

(a) PLA comprising poly (L) -lactide, poly (D, L) -lactide and / or poly (L) -lactide-co- (D) -lactide, preferably poly (L) -lactide and / or poly ( L) -lactide-co- (D) -actide, with a proportion of greater than or equal to 77% by weight, optionally 65% by weight, to less than or equal to 98.5% by weight, greater than or equal to 80% by weight to less than or equal to 97% by weight, preferably greater than or equal to 85% by weight to less than or equal to 95% by weight, particularly preferably greater than or equal to 87% by weight to less than or equal to 90% by weight

(c) As nucleating agent according to a first alternative, ethylene-bis-stearamide or, according to a second alternative, talc of less than or equal to 2 μηη, preferably greater than or equal to 0.5 μηη to less than or equal to 3 μηη, greater than or equal to 0.7 μηη to less than or equal to 2, 5 μηη, and with a proportion of greater than or equal to 0.5 wt .-% to less than or equal to 3 wt .-%, more preferably greater than equal to 0.5 wt .-% to less than or equal to 1, 5 wt .-%

Formulation A-4 (total content of composition ad 100% by weight)

(a) PLA comprising poly (L) -lactide, poly (D, L) -lactide and / or poly (L) -lactide-co- (D) -lactide, preferably poly (L) -lactide and / or poly ( L) -lactide-co- (D) -actide, with a proportion of greater than or equal to 80% by weight, optionally 65% by weight, to less than or equal to 94.9% by weight, greater than or equal to 80% by weight to less than or equal to 97% by weight, preferably greater than or equal to 85% by weight to less than or equal to 95% by weight, particularly preferably greater than or equal to 87% by weight to less than or equal to 90% by weight

(b) citric acid ester, preferably tributyl citrate, triethyl citrate and / or acetyltributyl citrate, having a content of greater than or equal to 5% by weight to less than or equal to 15% by weight, preferably greater than or equal to 1% by weight to less than or equal to 13% by weight. %, more preferably 12% by weight

(C) As a nucleating agent for a first alternative ethylene-bis-stearamide or for a second alternative talc, each having a particle diameter of greater than or equal to 0.5 μηη to less than or equal to 5 μηη, preferably less than or equal to 2 μηη, preferably greater than or equal to 0.5 μηη to less than or equal to 3 μηη, greater than or equal to 0.7 μηη to less than or equal to 2.5 μηη, more preferably greater than or equal to 1 μηη to less than or equal to 2 μηη and containing greater than or equal to 0.1% by weight to less than or equal to 5 wt .-%, preferably greater than or equal to 0.5 wt .-% to less than or equal to 3 wt .-%, particularly preferably greater than 0.5

Wt .-% to less than or equal to 1, 5 wt .-% Formulation A-5 (total content of composition ad 100% by weight)

(a) PLA comprising poly (L) -lactide, poly (D, L) -lactide and / or poly (L) -lactide-co- (D) -lactide, preferably poly (L) -lactide and / or poly ( L) -lactide-co- (D) -actide, having a proportion of greater than or equal to 82% by weight, optionally 67% by weight, to less than or equal to 88.9% by weight, greater than or equal to 80% by weight to less than or equal to 97% by weight, preferably greater than or equal to 85% by weight to less than or equal to 95% by weight, particularly preferably greater than or equal to 87% by weight to less than or equal to 90% by weight

(b) Citric acid esters, preferably tributyl citrate, triethyl citrate and / or acetyltributyl citrate, having a content of greater than or equal to 1 1% by weight to less than or equal to 13% by weight, particularly preferably 12% by weight, as the plasticizer.

(C) As a nucleating agent for a first alternative ethylene-bis-stearamide or for a second alternative talc, each having a particle diameter of greater than or equal to 0.5 μηη to less than or equal to 5 μηη, preferably less than or equal to 2 μηη, preferably greater than or equal to 0.5 μηη to less than or equal to 3 μηη, greater than or equal to 0.7 μηη to less than or equal to 2.5 μηη, more preferably greater than or equal to 1 μηη to less than or equal to 2 μηη and containing greater than or equal to 0.1% by weight to less than or equal to 5% by weight, preferably greater than or equal to 0.5% by weight to less than or equal to 3% by weight, particularly preferably greater than or equal to 0.5% by weight to less than or equal to 1.5% by weight

Formulation A-6 (total content of the composition ad 100% by weight)

(a) PLA preferably poly (D, L) -lactide and / or poly (L) -lactide-co- (D) -lactide, with a content of greater than or equal to 85.5 wt .-%, optionally 70, 5 wt %, to less than or equal to 88.5% by weight

(B) Citric acid esters as the plasticizer, preferably tributyl citrate, triethyl citrate and / or acetyltributyl citrate with a content of greater than or equal to 1 1 wt .-% to less than or equal to 13 wt .-%, particularly preferably 12 wt .-%.

(C) As a nucleating agent according to a first alternative ethylene-bis-stearamide or after a second alternative talc each having a particle diameter of less than or equal to 2 μηη and with a proportion of greater than or equal to 0.5 wt .-% to less than or equal to 1, 5 wt .-%

The compositions of the formulations A-1 to A-6 contain no information on the optional additives, since these are added only when required in desired amounts of greater than or equal to 0 wt .-% to less than 15 wt .-%. When additives are added, the proportion of (a) at least one bio-based polymer is correspondingly reduced in respective formulations. The details of Formulations A-1 to A-6 apply mutatis mutandis to Formulations B-1, B-2, B-3, B-4, B-5 and B-6. The function of a nucleant is to decrease the surface free energy in favor of nucleation and thereby initiate crystallization at higher temperatures after / during cooling. Thus, the use of the nucleating agents according to the invention, preferably ethylene-bis-stearamide or talc, leads to an increase of the nucleation by 5 to 10 times and an increased crystallization by 2 to 6 times. The function of a plasticizer is to increase the mobility of the polymer chains and thus to increase the crystallization rate by reducing the energy required for the folding of the polymer chains during crystallization. The inventive combination of the nucleating agent and the plasticizer, the effects are not only summed, but have a synergistic effect.

Talc alone does not significantly increase the crystallization of PLA. However, if talc or ethylene-bis-stearamide is used in combination with a plasticizer, preferably tributyl citrate, triethyl citrate and / or acetyltributyl citrate, this leads to a marked improvement in the crystallization of PLA.

At the same time, by means of this synergistic effect, the plasticizer used is firmly anchored in the formulation B and / or the film according to the invention, in particular by a multiplicity of hydrogen bond bonds between the ester groups of the plasticizers and the ester groups of the at least one (a) polymer and preferably (c) the at least one amide group and / or hydroxy group of the at least one nucleating agent. The invention likewise provides a process for the production of the film according to the invention, as well as film obtained by the process in which

in the first step, a formulation A is prepared by mixing, in particular to obtain a homogeneous distribution of the plasticizer in the formulation of

(a) at least one biobased, preferably biodegradable (co) polymer, in particular (co) polyester, based on at least one lactic acid derivative, in particular a monomer and / or dimer of lactic acid,

(b) at least one plasticizer comprising at least one ester group-containing compound, with the exception of dimeric and polymeric esters of lactic acid,

(c) at least one nucleating agent, and

(d) optional additives, wherein the order of mixing is immaterial. The (a) polymer, or other aforementioned compound may be presented and the further components blended.

- In a further step, a formulation B is prepared by supplying heat, preferably up to a processing temperature of greater than or equal to 170 ° C to less than 190 ° C, particularly preferably from 180 ° C, in particular melts in the extruder, preferably twin-screw extruder, preferably with homogeneously distributed plasticizer in Formulation A, optionally adding at least one additive and

- In a subsequent step, the film is formed, in particular by extrusion, preferably by means of a single-screw extruder.

According to a further object of the invention is in the process according to the invention

in the further step, the formulation B is obtained by melting the formulation A, in particular in the twin-screw extruder, optionally adding at least one additive,

optionally, in a next step, the recovered formulation B cooled, in particular in a water bath, and

- Formed in a subsequent step, the film. In a preferred embodiment, in the method according to the invention

in a further step the molten formulation B, and optionally cooled formulation B, granulated, optionally at least one additive added before or after cooling and

- In a subsequent step, the film formed from the granules of the formulation B, preferably by (a) supply of heat, preferably up to one

Processing temperature of 170 ° C to 190 ° C, more preferably 180 ° C, especially melting in the extruder and optionally adding at least one additive, in particular single-screw extruder, (b) extrusion of the heated formulation B, in particular the melt by means of a slot die, (c) molding the film and optionally (d) cooling, in particular on a cooling roll, preferably at a temperature of greater than or equal to 20 ° C to less than or equal to 60 ° C, preferably 40 ° C.

Another object of the invention is a film prepared by the described method. Preferably, this film is additionally stretched, as explained below.

In the process according to the invention, in a subsequent step, the film according to the invention obtained from the formulation A and / or B is preferred at a temperature above the Tg, more suitably greater than or equal to 90 ° C to less than or equal to 120 ° C, even better greater than or equal to 90 ° C to less than or equal to 1 10 ° C, especially in a stretching unit, by a factor λ greater than or equal to 1 less than or equal to 7 , Particularly suitable greater than or equal to 1 to less than 6, preferably greater than or equal to 5 to less than 6, stretched in the longitudinal direction.

Another object of the invention is a formulation B obtainable by the process according to the invention, wherein the formulation B has a thermal stability, measured as shrinkage (according to DIN 53377), of greater than or equal to 0% to less than or equal to 5%. The formulation B preferably has a shrinkage of greater than or equal to 0% to less than or equal to 3%, particularly preferably greater than or equal to 1% to less than or equal to 3%. In particular, a film comprising formulation B and prepared from formulation B has the same thermal stability, measured as shrinkage (according to DI N 53377), of greater than or equal to 0% to less than or equal to 5%, preferably greater than or equal to 0% to less than or equal to 3%, more preferably greater than or equal to 1% to less than or equal to 3%.

Formulation B of the invention preferably has a degree of crystallinity, measured as heat of fusion (according to DIN EN ISO 1 1357-3), of greater than or equal to 30 J / g to less than or equal to 50 J / g, preferably greater than or equal to 35 J / g to less than or equal to 50 J / g, more preferably greater than or equal to 40 J / g to less than or equal to 50 J / g. In particular, a film comprising Formulation B and prepared from Formulation B has the same degree of crystallinity, measured as heat of fusion (according to DIN EN ISO 1 1357-3), of greater than or equal to 30 J / g to less than or equal to 50 J / g, preferably greater than or equal to 35 J / g to less than or equal to 50 J / g, more preferably greater than or equal to 40 J / g to less than or equal to 50 J / g. In a further embodiment of the formulation B according to the invention, no migration of the compounds containing, in particular the plasticizer occurs. In particular, in a film comprising formulation B and prepared from formulation B, no migration of the compounds containing them, in particular the plasticizers comprising esters of di- and / or tricarboxylic acids, comprises at least one alkyl radical on the at least one ester group selected from C 1 to C 20 -alkylene Methyl, ethyl, propyl, butyl, hexyl, nonyl, dodecyl and octadecyl radicals, preferably esters of citric acid and adipic acid, preferably citric acid alkyl esters such as tributyl citrate, triethyl citrate and acetyltributyl citrate and / or adipic acid esters such as diethylhexyl adipate (dioctyl adipate), on. Another object of the invention is the use of the formulation B comprising in the form of bulk material comprising briquettes, granules, extrudates, pellets, grains and powders, or in the form of banderoles, strands of material, by the meter, blocks, cylinders and / or plates for the manufacture of supports in the form of:

(a) surface elements comprising spun, woven and / or fused surface elements such as nonwovens, films, fabrics, mesh fabrics, nets, textiles and textile tapes and / or

(b) fibrous structures comprising spun, woven and / or fused fibers, yarns, braids, knits and filaments, and

Surface elements comprising fiber structures according to. Another object of the invention is a sheet-like pressure-sensitive adhesive comprising the film according to the invention and at least one adhesive in the form of at least one layer, preferably a bio-based, preferably biodegradable, PSA.

Suitable adhesives are described in WO 2013/060624 A1, WO 2012/126773 A1, EP 2 647 682 A1 or WO 2014/154479 A1.

Biobased means made from renewable raw materials.

Biodegradable polymers is a name for natural and synthetic polymers that have plastic-like properties (impact strength, thermoplastizability), but in contrast to conventional plastics from a variety of microorganisms in biologically active environment (compost, digested sludge, soil, wastewater) are degraded; This does not necessarily happen under normal household conditions (composting in the garden). A definition of biodegradability can be found in the European standards DIN EN 13432 (biodegradation of packaging) and DIN EN 14995 (compostability of plastics).

In order to produce an adhesive tape from the film, all known adhesive systems can be used. In addition to natural or synthetic rubber-based adhesives, it is possible in particular to use silicone adhesives and also polyacrylate adhesives, preferably an acrylate hot melt pressure-sensitive adhesive. Because of their particular suitability as adhesive for winding tapes of automotive cable harnesses in terms of Foggingfreiheit and the excellent compatibility with PVC and PVC-free wire insulation solvent-free acrylate Hotmeltmassen are preferable, as described in DE 198 07 752 A1 and DE 100 1 1 788 A1 are described in more detail.

The application weight preferably moves in the range between 15 and 200 g / m ² , more preferably 30 to 120 g / m ² (corresponds approximately to a thickness of 15 to 200 μm, more preferably 30 to 120 μm). The adhesive is preferably a pressure-sensitive adhesive, that is to say an adhesive which, even under relatively weak pressure, permits a permanent connection with almost all adhesive reasons and can be removed from the primer again after use essentially without residue. A PSA is permanently tacky at room temperature, so it has a sufficiently low viscosity and a high tackiness, so that it already occupies the surface of the respective Klebegrunds at low pressure. The adhesiveness of the adhesive is based on its adhesive properties and the removability on their cohesive properties. An adhesive which is suitable on acrylate hotmelt basis, which has a K value of at least 20, in particular greater than 30 (measured in each case in 1 wt .-% solution in toluene, 25 ° C), obtainable by concentrating a solution of such Mass to a hotmelt processable system.

The K value (according to FIKENTSCHER) is a measure of the average molecular size of highly polymeric substances. The viscosity of polymers is determined by a capillary viscometer in accordance with DIN EN ISO 1628-1: 2009.

For measurement, one percent (1 g / 100 ml) of toluene polymer solutions are prepared at 25 ° C and measured using the corresponding DIN Ubbelohde viscometer according to ISO 3105: 1994, Table B.9.

The concentration can take place in suitably equipped boilers or extruders, in particular in the concomitant degassing, a degassing extruder is preferred.

Such an adhesive is set forth in DE 43 13 008 C2. These acrylate masses produced in this way are completely removed from the solvent in an intermediate step.

In addition, additional volatile components are removed. After coating from the melt, these materials have only low levels of volatile components. Thus, all claimed in the above-mentioned patent monomers / formulations can be adopted.

The solution of the composition may contain from 5 to 80% by weight, in particular from 30 to 70% by weight, of solvent.

Commercially available solvents are preferably used, in particular low-boiling hydrocarbons, ketones, alcohols and / or esters.

Further preferably, single-screw, twin-screw or multi-screw extruders with one or in particular two or more Ent''ga-lungs-units are used. In the adhesive based on Acrylathotmelt-based benzoin derivatives may be copolymerized, such as benzoin acrylate or benzoin methacrylate, acrylic acid or methacrylic acid ester. Such benzoin derivatives are described in EP 0 578 151 A. The acrylate-based adhesive can be UV-crosslinked. Other types of crosslinking are also possible, for example electron beam crosslinking. In a further preferred embodiment, the self-adhesive compositions employed are copolymers of (meth) ^_, acrylic acid and acrylamides esters thereof having 1 to 25 carbon atoms, maleic, fumaric and / or itaconic acid and / or their esters, substituted (meth) maleic anhydride and other vinyl compounds, such as vinyl esters, in particular vinyl acetate, vinyl alcohols and / or vinyl ethers used.

The residual solvent content should be below 1 wt .-% be carrying ^i.

An adhesive which is particularly suitable is an acrylate hot melt pressure-sensitive adhesive, such as that supplied by BASF under the name acResin, in particular acResin A 260 UV. This adhesive with a low K value obtains its application-oriented properties through a final radiation-induced crosslinking.

Preferably, the adhesive is applied over the entire surface of the carrier.

The adhesive may be applied in the longitudinal direction of the adhesive tape in the form of a strip which has a smaller width than the carrier material of the adhesive tape.

The coated strip has, in an advantageous embodiment, a width of 10 to 80% of the width of the carrier material. Particularly preferably, the use of strips with a coating of 20 to 50% of the width of the carrier material.

Depending on the application, it is also possible for a plurality of parallel strips of the adhesive to be coated on the carrier material.

The position of the strip on the carrier is freely selectable, with an arrangement directly on one of the edges of the carrier being preferred.

Furthermore, two adhesive strips may be provided, namely an adhesive strip on the upper side of the carrier material and an adhesive strip on the underside of the

Support material, wherein the two adhesive strips are preferably arranged on the opposite longitudinal edges. According to a variant, the two

Adhesive strips arranged on one and the same longitudinal edge.

Preferably, the adhesive strip (s) respectively terminate flush with the one or more

Longitudinal edges of the carrier material from. At least one strip of covering may be provided on the adhesive coating of the backing which extends in the longitudinal direction of the adhesive tape and which covers between 20% and 90% of the adhesive coating.

Preferably, the strip covers a total of between 50% and 80% of the adhesive coating. The degree of coverage is selected depending on the application and the diameter of the cable set.

The percentages given refer to the width of the strips of the covering in relation to the width of the carrier. According to a preferred embodiment of the invention, exactly one strip of the covering is present on the adhesive coating.

The position of the strip on the adhesive coating is arbitrary, with an arrangement directly on one of the longitudinal edges of the carrier is preferred. In this way, an adhesive strip extending in the longitudinal direction of the adhesive tape results, which terminates with the other longitudinal edge of the carrier.

If the adhesive tape is used to encase a cable harness by guiding the adhesive tape around the cable harness in a helical movement, the cladding of the cable harness can be made so that the adhesive of the adhesive tape is glued only to the adhesive tape itself while the product is not coated with any adhesive Touch comes. The thus-sheathed wire harness has a very high flexibility due to the lack of fixation of the cables by any adhesive. Thus, its bending ability during installation - especially in narrow passages or sharp turns - significantly increased. If a certain fixation of the adhesive tape on the material is desired, the sheath can be made such that the adhesive strip is glued to a part on the tape itself and to another part on the estate.

According to another advantageous embodiment, the strip is applied centrally on the adhesive coating, resulting in two adhesive strips extending on the longitudinal edges of the carrier in the longitudinal direction of the adhesive tape.

For the safe and economical application of the adhesive tape in said helical movement around the cable harness and against the sliding of the resulting protective sheath, the two adhesive strips respectively present at the longitudinal edges of the adhesive tape are advantageous, especially if one which is usually narrower than the second one is considered Fixation aid serves and the second, wider strip than closure serves. In this way, the tape is glued to the cable so that the cable set is secured against slipping and yet flexible design.

In addition, there are embodiments in which more than one strip of the cover are applied to the adhesive coating. If only a strip is mentioned, the expert reads in mind that quite a few strips can cover the adhesive coating at the same time.

The production and processing of the adhesives can be carried out from solution, dispersion and from the melt. Preferred production and processing methods are carried out from solution as well as from the melt. Particularly preferred is the production of the adhesive from the melt, in particular batch or continuous processes can be used. Particularly advantageous is the continuous production of the PSAs by means of an extruder.

The adhesives produced in this way can then be applied to the carrier by the generally known methods. When processed from the melt, these can be application methods via a nozzle or a calender.

In solution processes, coatings with doctor blades, knives or nozzles are known, to name just a few.

It is also possible to transfer the adhesive from an anti-adhesive carrier cloth or release liner to the carrier composite. Finally, the adhesive tape may comprise a covering material with which the one or two adhesive layers are covered until use. Also suitable as cover materials are all the materials detailed above.

Preferably, however, a non-linting material is used, such as a plastic film or a well-glued, long-fiber paper.

On the back of the adhesive tape, a backside lacquer can be applied to favorably influence the unwinding properties of the adhesive tape wound on the Archimedean spiral. This backcoat can be equipped with silicone or fluorosilicone compounds as well as with Polyvinylstearylcarbamat, Polyethyleniminstearylcarbamid or fluoroorganic compounds as abhesive substances. Optionally, there is a foam coating on the back of the adhesive tape under the backcoat or alternatively. The adhesive tape according to the invention can be made available in fixed lengths such as, for example, by the meter or else as endless goods on rolls (Archimedean spiral). For use in the latter case, then a variable cutting to length by knives, scissors or dispenser u.ä. possible or a manual processing without tools.

Furthermore, the adhesive tape may have one or more lines of weakness substantially at right angles to the direction of travel, so that the adhesive tape is easier to tear by hand. In order to allow a particularly simple work for the user, the weakening lines are aligned at right angles to the direction of the adhesive tape and / or arranged at regular intervals.

The adhesive tape can be cut particularly easily if the weakening lines are configured in the form of perforations.

It can be achieved in this way edges between the individual sections, which are very lint-free, so an undesirable fraying is avoided.

Particularly advantageously, the lines of weakness can be produced discontinuously with flat punches or transverse perforating wheels and continuously using rotary systems such as spiked rollers or punching rollers, optionally with the use of a counter roll (Vulkollanwalze), which form the counter wheel during cutting.

Other options are controlled intermittent cutting technologies such as the use of lasers, ultrasound, high pressure water jets, etc. As in laser or ultrasonic cutting a portion of the energy introduced as heat in the substrate, can be in the cutting area, the fibers merge, so that a disturbing Fringing is largely avoided and you get edge sharp cutting edges. The latter methods are also suitable for obtaining special cutting edge geometries, for example concave or convex shaped cutting edges.

The height of the sting or knife on the punching rollers is preferably 150% of the thickness of the adhesive tape.

The hole-to-web ratio at the perforation, how many millimeters hold the material together ("bridge"), how many millimeters are severed, determines how easy it is to break down the fibers of the substrate in particular. how lint-free the tear-off edge is to be obtained.

Preferably, the web width is about 2 mm and the cutting width between the webs about 10 mm, that is, it alternate 2 mm wide webs with 10 mm incisions. The hole-land ratio is accordingly preferably 2:10.

With this weakening of the material, a sufficiently low tearing force can be achieved. If a low flammability of the described adhesive tape is desired, it can be achieved by adding flame retardants to the carrier and / or the adhesive. These may be bromoorganic compounds, if necessary with synergists such as antimony trioxide, but in view of the freedom from halogens of the adhesive, red phosphorus, organophosphorus, mineral or intumescent compounds such as ammonium polyphosphate alone or in combination with synergists are preferably used.

According to a preferred embodiment, the width of the adhesive tape is between 9 and 38 mm.

For the purposes of this invention, the general term "adhesive tape" encompasses all flat structures such as films or film sections which are expanded in two dimensions, tapes of extended length and limited width, strip sections and the like, and ultimately also diecuts or labels.

Furthermore, it is advantageous for sheathing elongated material such as in particular cable harnesses suitable in motor vehicles, wherein the adhesive tape can be guided in a helical line around the elongated Good or the elongated material can be wrapped in the axial direction of the tape.

Finally, the concept of the invention also includes an elongated product encased with an adhesive tape according to the invention. Preferably, the elongated product is a harness. Due to the excellent suitability of the adhesive tape, it can be used in a sheathing, which consists of a covering, in which at least in an edge region of the covering the self-adhesive tape is present, which is glued to the covering, that the tape over one of Longitudinal edges of the covering extends, and preferably in a narrow compared to the width of the covering edge region.

Such a product as well as optimized embodiments thereof are disclosed in EP 1 312 097 A1. Further developments are shown in EP 1 300 452 A2, DE 102 29 527 A1 and WO 2006 108 871 A1, for which the adhesive tape according to the invention is likewise very well suited. Likewise, the adhesive tape according to the invention can be used in a method as disclosed in EP 1 367 608 A2.

Finally, EP 1 315 781 A1 and DE 103 29 994 A1 describe embodiments of adhesive tapes as are also possible for the adhesive tape according to the invention. Finally, the concept of the invention also includes an elongated product encased with an adhesive tape according to the invention. Preferably, the elongated product is a harness, more preferably in an automobile.

The invention further provides for the use of the film according to the invention as a carrier, carrier in adhesive tapes and / or cable winding tapes, carriers in cable tapes according to LV 312, carriers for adhesive, carriers for PSAs, carriers in articles for marking articles and components, in particular in motor vehicles and for the marking of electrical devices, carriers in multilayer labels and diecuts, in multilayer laser-inscribable labels and diecuts, transfer material, a transfer film or release liner, OLEDs, in adhesive tapes as cover material, cover film, transfer material and / or release liner.

In the case of the use according to the invention, preference is given to using a carrier which has a high softness, high thermal stability, an outstanding degree of crystallization and in which there is no migration of the compounds containing, in particular the plasticizer. In the use according to the invention, preference is given to using a carrier comprising the formulation A and obtainable by the process according to the invention.

A particular object of the present invention is the outstanding suitability of the film according to the invention for adhesives and PSAs, in particular the combination of the inventive film with a bio-based PSA, as mentioned above.

Another object of the invention is a film structure or a film assembly comprising at least one film according to the invention. The at least one film is preferably produced from formulation A and / or B according to the process of the invention. The respective films may vary in their crystallization degree, thermal stability and softness properties in ranges defined herein. Furthermore, the combined films can have different layer thicknesses of greater than or equal to 5 μm to less than or equal to 500 μm, preferably greater than or equal to 5 μm to less than or equal to 50 μm, greater than or equal to 10 μm to less than or equal to 40 μm, particularly preferably greater than or equal to 15 μm to less than or equal to 30 μm μηη. Several films of different layer thicknesses can be arranged one above the other in the form of several layers. Thus, it may be advantageous for the stability and / or flexibility of the film arrangement according to the invention films different layer thickness (for example, 5 μηη, 10 μηη, 15 μηη, 20 microns, 30 μηη and / or 40 microns) to combine. In particular, films of different layer thickness can be combined with different degrees of stretching. Thus, a film has a layer thickness of greater than or equal to 10 μηη, greater than or equal to 15 μηη, greater than or equal to 20 μηη greater than or equal to 25 μηη to less than or equal to 30, less than or equal to 35, less than or equal to 40 μηη a degree of stretching with a factor λ greater than or equal to 1.2 , 3, 4, 5, 6 to less than or equal to 7 and provide a film arrangement of, for example, 2, 3, 4, or 5 film layers.

Thus, a film arrangement is conceivable in which in the case of several, in particular 3, 4 or 5, layers, at least one of the exposed (arranged outside) layers has a higher thermal stability, whereas the inner layers have a lower thermal stability in comparison thereto. It is also conceivable that one or both exposed layers have a lower softness (lower proportion of plasticizers), but the inner film layers, on the other hand, have a higher softness (higher proportion of plasticizers) for better flexibility. By the amount of nucleating agent films of different degrees of crystallization can be generated, which can be combined in the film assembly.

Examples

Glass transition temperatures TG

Glass transition temperatures TG were determined by dynamic mechanical analysis (DMA); The following procedures were chosen: Glass transition temperatures were determined by means of temperature sweep. All information in this document refers to the results of these measurements, unless otherwise specified. The DMA makes use of the fact that the properties of viscoelastic materials in the case of sinusoidal mechanical stress depend on the frequency of the stress (ie the time) as well as on the temperature.

All DMA process guides:

Meter: Rheometric Scientific RDA III; Measuring head: spring-loaded with normal force; Temperature control: heating chamber; Measuring geometry: parallel plate arrangement, sample thickness 1 (± 0.1) mm; Sample diameter 25 mm (to prepare a 1 mm thick sample, 5 layers (200 μηη each) of the adhesive tape to be tested were laminated on top of each other, as the PET support does not significantly contribute to the theological properties, its presence can be neglected). The films produced in this way, in addition to high transparency, no migration and a high proportion of renewable raw materials (up to 99%). Furthermore, a high elongation (> 250% at λ = 1), high strength (at λ = 5-6) and high thermal stability (shrinkage at 120 ° C <5%) can be achieved.

Molecular weight Mw

The determination of the average molecular weight Mw and the polydispersity D was carried out by means of gel permeation chromatography (GPC). The eluent used was THF containing 0.1% by volume of trifluoroacetic acid. The measurement was carried out at 25 ° C. PSS-SDV, 5 μm, 10 ³ Å, ID 8.0 mm × 50 mm was used as precolumn. For separation, the columns PSS-SDV, 5 μηι, 10 ³ Ä, 10 ⁵ Ä and 10 ⁶ Ä were used with each ID 8.0 mm ^χ 300 mm. The sample concentration was 4 g / l, the flow rate 1, 0 ml per minute. It was measured against PMMA standards.

The weight average molecular weight M _w is determined by gel permeation chromatography (GPC). The eluent used is THF with 0.1% by volume of trifluoroacetic acid. The measurement takes place at 25 ° C. The precolumn used is PSS-SDV, 5 μ, 10 ³ A, ID 8.0 mm × 50 mm. For separation, the columns PSS-SDV, 5 μ, 10 ³ and 10 ⁵ and 10 ⁶ , each with ID 8.0 mm x 300 mm are used. The sample concentration is 4 g / l, the flow rate is 1, 0 ml per minute. It is measured against PMMA standards, (μ = μηη, 1 λ = 10 ^"10 m).

Example of the process for preparing a formulation B:

NatureWorks Ingeo 4032D PLA granules were melted in a twin-screw extruder at a temperature of 180 ° C. In this case, the plasticizer triethyl citrate (name Citrofol AI from Jungsbunzlauer) in a concentration of 1 wt .-% to 20 wt .-%, particularly well 1 1 wt .-% to 13 wt .-%, specifically 12 wt .-%, and the nucleating agent in a concentration of 0.1 wt .-% to 5 wt .-%, more preferably 0.5 wt .-% to 3 wt .-%, specifically 2 wt .-%, incorporated into the PLA. The thus obtained strand of material (Formulation B) was cooled in a water bath and granulated (Formulation B).

Example of the method for producing a film according to the invention:

Formulation B is melted at temperatures of 170 to 190 ° C, especially and selected here 180 ° C, in a single screw extruder and formed using a slot die and on a chill roll at temperatures of 20 to 60 ° C, particularly suitable and selected here 40 ° C, cooled. Subsequently, the film at Temperaturn above the Tg, particularly suitable 90 to 120 ° C, even better and here selected 1 10 ° C in the stretching unit by factors between λ = 1 and λ = 7, particularly suitably stretched between λ = 1 or λ = 5 to 6 (h selected 5.5) in the longitudinal direction.

Properties of films according to the invention

Claims

claims

A bio-based film comprising a composition based on polylactic acid containing the following components

(a) at least one biobased (co) polymer based on at least one lactic acid derivative,

(B) at least one plasticizer comprising at least one ester group-containing compound, except dimeric and polymeric esters of lactic acid, and

(c) at least one nucleating agent and

(d) optional additives.

A film according to claim 1, characterized in that the components are each present in a proportion, based on the total content of the composition to

(a) greater than or equal to 75% by weight to less than or equal to 98.9% by weight of the at least one bio-based (co) polymer based on at least one lactic acid derivative,

(b) greater than or equal to 1% by weight to less than or equal to 20% by weight of the at least one plasticizer and

(c) greater than or equal to 0.1% by weight to less than or equal to 5% by weight of the at least one nucleating agent, and

(d) greater than or equal to 0% by weight to less than or equal to 20% by weight of additives.

A film according to claim 1 or 2, characterized in that it has a transparency of greater than or equal to 80% to less than or equal to 100%, measured by transmission at a wavelength of greater than or equal to 400 nm to less than or equal to 800 nm.

Film according to one of claims 1 to 3, characterized in that it has a thermal stability, measured as shrinkage according to DIN 53377, of greater than or equal to 0% to less than or equal to 5%.

Film according to one of claims 1 to 4, characterized in that it has a softness, measured at the elongation at break (according to ISO 527) of greater than or equal to 3% to less than or equal to 300%.

A process for producing a film according to any one of claims 1 to 5, in which in the first step, a formulation A is prepared by mixing

(a) at least one bio-based (co) polymer based on at least one lactic acid derivative,

(c) at least one nucleating agent,

- In a further step, a formulation B is prepared by supplying heat and

- In a subsequent step, the film is formed. A method according to claim 6, characterized in that

in the further step, the formulation B is obtained by melting the formulation A,

in a next step optionally the recovered formulation B is cooled and

- In the subsequent step, the film is formed.

A method according to claim 6 or 7, characterized in that

- In a further step, the molten formulation B is granulated and

- In a subsequent step, the film is formed from the granules of Formulation B.

Method according to one of claims 6 to 8, characterized in that

- In a subsequent step, the recovered film is stretched at a temperature above the TG by a factor λ of greater than or equal to 1 to less than 7 in the longitudinal direction.

Film produced by the process according to one of claims 6 to 9.

Formulation A containing polylactic acid comprising the following components

(c) at least one nucleating agent and (d) optional additives.

Formulation A according to claim 10, characterized in that the components are each present in a proportion based on the total content of the composition to

(a) greater than or equal to 75% by weight, optionally 60% by weight, to less than or equal to 98.9% by weight of the at least one bio-based (co) polymer based on at least one lactic acid derivative,

Formulation A according to any one of claims 1 1 or 12, characterized in that

(a) the at least one lactic acid derivative of the at least one bio-based (co) polyester is a monomer and / or dimer selected from L (S) -lactic acid, D (R) -lactic acid, (S, S) -lactide, (R, R) -lactide and (meso) -lactide and mixtures of at least two of said compounds.

Formulation A according to one of claims 1 1 to 13, characterized in that

(b) the at least one plasticizer is an ester of a di or tri carboxylic acid comprising (i) aliphatic saturated or unsaturated and (ii) aromatic saturated or unsaturated di- and tri-carboxylic acid esters.

Formulation A according to any one of claims 1 1 to 14, characterized in that

(c) the at least one nucleating agent is simultaneously a nucleating promoter comprising waxes, mineral fillers and / or bio-based fillers.

Formulation A according to any one of claims 1 1 to 15, characterized in that (c) the at least one nucleating agent comprising wax, mineral and / or bio-based fillers has an average particle diameter of greater than or equal to 0.5 μηη to less than or equal to 5 μηη.

Formulation B obtainable by the process according to any one of claims 6 to 9, characterized in that it has a thermal stability, measured as shrinkage (according to DIN 53377), of greater than or equal to 0% to less than or equal to 5%.

18. Formulation B obtainable by the process according to one of claims 6 to 9 or according to claim 16, characterized in that it has a degree of crystallinity, measured as heat of fusion (according to DIN EN ISO 1 1357-3) of greater than or equal to 30 J / g equal to 50 J / g.

19. Use of the formulation B according to claim 17 or 18 comprising in the form of bulk material comprising granules, extrudates, pellets, grains and powders, or in the form of bands, material strands, by the meter, blocks and / or plates for the production of carriers in the form of

(b) fibrous structures comprising spun, woven and / or fused fibers, yarns, braids, knitted fabrics and filaments, and

Surface elements comprising fiber structures according to.

20. A sheet-like pressure-sensitive adhesive comprising at least one film according to any one of claims 1 to 5 or film obtainable by a process according to any one of claims 6 to 10, and at least one adhesive.

21. Use of the film according to any one of claims 1 to 5, comprising a formulation A according to any one of claims 1 to 16 and / or obtainable by a process according to any one of claims 6 to 9 and use of the film according to claim 10, as a carrier, carrier in Adhesive tapes and / or cable wrapping tapes, carriers in cable tapes in accordance with LV 312, carriers for adhesives, carriers for pressure-sensitive adhesives, carriers in articles for marking articles and components, carriers in multilayer labels and diecuts, in multilayer laser-inscribable labels and diecuts, transfer material, a transfer film or Releaseliner, OLEDs, in adhesive tapes as cover material, cover film, transfer material and / or release liner.