WO2000039212A1

WO2000039212A1 - Biodegradable polymer materials or ternary polymer mixtures on a polysaccharide or polysaccharide derivative basis

Info

Publication number: WO2000039212A1
Application number: PCT/IB1999/001866
Authority: WO
Inventors: Jürgen LOERCKS; Harald Schmidt; Ralf Timmermann; Wolfgang Schulz-Schlitte; Michael Voigt
Original assignee: Bio-Tec Biologische Naturverpackungen Gmbh & Co. Kg; Bayer Aktiengesellschaft
Priority date: 1998-12-23
Filing date: 1999-11-23
Publication date: 2000-07-06
Also published as: AU1070900A

Abstract

The invention relates to a biodegradable polymer material which is characterized by at least one polysaccharide and/or polysaccharide derivative and at least two other polymers of different crystallinity which are not fully miscible. At least one of the polymer components is preferably of high crystallinity. Moreover, the polysaccharide or polysaccharide derivative is at least almost homogeneously miscible with at least one of the two additional polymer components.

Description

Biodegradable polymer materials or ternary polymer mixtures based on polysaccharide or polysaccharide derivative

The present invention relates to a biodegradable, polymeric material or a ternary polymer mixture consisting of at least one polysaccharide or derivative thereof, such as starch or thermoplastic starch, and at least two other polymers with different crystallinity, as well as a method for producing a biodegradable polymeric material or a ternary polymer mixture and uses of the biodegradable material and the ternary polymer mixtures containing a polysaccharide or a derivative thereof, such as starch, a starch derivative, such as thermoplastic starch or a cellulose derivative.

Biopolymers based on renewable raw materials for the

Manufacture of biodegradable materials (BAW) are largely based on starch, such as in particular thermoplastic starch, starch derivatives, cellulose derivatives or more generally on polysaccharides, as well as polymer mixtures from the polysaccharides mentioned and other degradable polymer components such as polylactic acid, polyvinyl alcohol , Polycaprolactone, tailor-made copolyesters from aliphatic diols and aliphatic and aromatic dicarboxylic acids as well as degradable polyester amides, which are used, for example, with thermoplastic starch in the anhydrous melt

Ester reactions and / or as polymer combinations form new degradable polymer materials with a high proportion of renewable raw materials. Other natural additives are additives and plasticizers, such as glycerin and its derivatives, hexavalent sugar alcohols such as sorbitol and its derivatives and other materials suitable as plasticizers or plasticizers.

Polysaccharides or starch, starch derivatives and cellulose derivatives are known from a number of publications which have been modified in such a way or are present in suitable polymer mixtures that they are suitable for processing in the plastics processing industry. For example, EP-A 118 240 and EP 0 304 401 describe the production of destructurized starch and use, inter alia, in EP 032 802, EP 408 503, EP 409 789, WO91 / 02024 and WO92 / 19680 Destructured starch in polymer blends. The list of publications in which the use of destructurized starch in suitable polymer mixtures is described can be continued as desired.

Furthermore, for example, US Pat. Nos. 3,922,239, 5,011,637, DE 501 889 and EP-A 0 244 206 describe, among other things, cellulose esters and / or reaction or mixed products of cellulose derivatives with lactones, triacetin, etc. , which in turn are suitable for thermoplastic processing in the plastics processing industry.

EP 397 819 defines for the first time a process for the production of thermoplastic starch or TPS for short, as well as what is known under the new starch material, thermoplastic

Starch - TPS - is to be understood, and what are the serious differences, especially in plastic processing technology, from the destructured starch that has been known for a long time. The thermoplastic starch is produced with the aid of a swelling or plasticizing agent, not only without adding water, but rather using dry or dried starch and / or starch, which is dried by degassing during processing in the extrusion process during the melting phase. Starches contain 14% water, potato starch and even 18% natural moisture as balancing moisture.

If a starch with more than 5% moisture is plasticized or gelatinized under pressure and temperature, a destructurized starch always results, whereby the process of producing the starch is endothermic.

In contrast, the manufacturing process of the thermoplastic starch is an exothermic process. The essentially water-free (<5%) native starch is homogenized in an extrusion process with an additive or plasticizer (eg glycerin, glycerol acetate, sorbitol), which lowers the melting temperature of the starch and by adding mechanical energy and Heat melted in a temperature range of 120 - 220 ° C. The thermoplastic starch is free of crystalline components, at least the crystalline components in TPS are less than 5%, while the crystalline components remain very low. The process parameters produce a permanent rearrangement of the molecular structure to thermoplastic starch, which practically no longer comprises any crystalline components and, unlike destructured starch, no longer recrystallizes.

In the production of polymer mixtures based on, for example, starch, such as destructured or thermoplastic Starch and starch derivatives are used as phase mediators for the homogenization of the hydrophilic and polar starch polymer phase and the hydrophobic and non-polar, further polymer phase, which are either added or are preferably produced in situ (for example by transesterification) during the preparation of the polymer mixture.

As phase mediators, i.a. Block copolymers used, among others are described in detail in WO 91/16375, EP 0 539 544, US 5 280 055 and EP 0 596 437. These publications also disclose polymer mixtures of the TPS with, for example, cellulose derivatives, aliphatic polyesters, such as PCL, PHB, PHVB, PLA and PVOH.

The intermolecular compounding of these different polymers takes place under defined temperature and shear conditions to processable granules. These thermoplastic blends are technologically produced by coupling the phase interfaces between the less compatible polymers so that the distribution structure of the disperse phase is achieved during processing through the optimal processing window (temperature and shear conditions).

The twin-screw extruders used, for example, for compounding are preferably co-rotating twin-screw extruders with tightly intermeshing screw profiles and have individually temperature-controlled kneading zones. For the compounding or production of starch / polymer blends, twin-screw extruders are used, preferably with eight chambers or zones, which can optionally be expanded to ten zones and have, for example, the following structure: Extruder design: For example, co-rotating twin-screw extruder

Screw length process length = 32-40 / D

Screw diameter D-45

Screw speed = 230 rpm

Throughput = 50-65 kg / h

Nozzle, diameter = 3 mm

Nozzle, number = 4 pieces

Zone 1 compression with degassing feed zone temp. 60 ° C gradual melting pressure - bar of the mixture (native like glycerin)

Zone 2 same as Zone 1 mixing and plasticizing temp. 140 ° C pressure> 1 bar water content 4 - 15%

Zone 3 same as 1 plastification temp. 180 ° C pressure> 1 bar water content 4 - 15% Zone 4 same as 1 plastification temp. 185 ° C pressure> 1 bar water content 4 - 15%

Zone 5 (optional if necessary degassing, water removal thermoplastic strength temp. 160 ° C required pressure vacuum 0.7 bar water content <1%

Zone 6 (sidefeeder, dosing dosing of additional polymers of the additional PolyTemp. 200 ° C mere such as pressure> 1 bar PCL)

Zone 7 transition homogenization and if necessary

Compression transesterification reaction zone temp. 200 ° C pressure> 1 bar water content <1%

Zone 8 discharge zone, if necessary, homogenization and, if necessary, evaporation of transesterification water of reaction temp. 205 - 210 ° C

Pressure> 1 bar

Water content <1% Outside the extrusion system: cooling and conditioning of the strands, if necessary taking up 0.3 - 4% water as a plasticizer in a water bath, strand granulation and bagging.

The above-mentioned extrusion conditions for the production of mixtures based on starch, such as thermoplastic starch (including zone 5) are essentially based on the example of a starch / PCL (polycaprolactone) polymer mixture. Of course, the processing or extrusion conditions change with different polymer blends. The example given above is only intended to explain how polymer mixtures are produced in the prior art which are based on starch, such as destructured or thermoplastic starch.

With all the polymers or polymer mixtures containing starch or based on starch described in the prior art, it is assumed that the native starch is first converted using a largely low-molecular plasticizer or swelling agent. Using the example given above, the destructured or thermoplastic starch is produced, for example, in zones 1 to 4. Only then, if appropriate, are further components mixed with the modified starch thus produced purely physically or also partially chemically, with mixing in the example given above An esterification or a transesterification reaction takes place between the PCL and the TPS, whereby the homogenization also includes a chemical reaction. As additives and plasticizers that lower the melting temperature of the starch and the solubility parameter has been, as mentioned, low molecular weight additives, including DMSO, butanediol, glycerol, ethylene glycol, propylene glycol, diglyceride, diglycol ether, formamide, DMF, dimethyl urea, dirnethylacetamide, N-methylacetamide, polyalkene oxide, glycerol mono- or - Diacetate, sorbitol, sorbitol ester and citric acid are proposed and used.

PVOH, EVOH and their derivatives as well as urea and urea derivatives are occasionally used.

When using starch derivatives, cellulose derivatives or generally polysaccharides and / or polysaccharide derivatives for the production of polymer mixtures with further polymer components, the procedure is similar, however, temperature controls adapted to the biopolymers or derivatives used and the other polymers are to be selected. The above example of a starch / polymer mixture is only for better understanding and is in no way intended to limit the present invention.

It has now been found, completely surprisingly, that shaped bodies with a layer-like structure and significantly increased stability against

Environmental influences can be produced if polysaccharides or derivatives thereof, such as in particular starch, starch derivatives or cellulose derivatives, are mixed and processed with a mixture of at least two biodegradable high molecular weight polymers. It is advantageous if one of the polymer components has a high crystallinity, such as, for example, aliphatic, biodegradable polyesters, such as polycaprolactone, polylactide or succinic acid. The effect of the significantly increased stability against environmental influences arises from the fact that at least two biodegradable polymers are mixed in the melt with the polysaccharide or the derivative thereof, for example with the starch, such as preferably thermoplastic starch, which, for example, is not completely miscible, but instead only partially compatible with each other.

As a result, a layer-like structure of these mixtures of the polysaccharide and / or the derivative thereof with at least two other biodegradable polymers is obtained during processing.

This layer structure ensures that the property advantages of the individual components of this mixture can be advantageously combined with one another.

In addition to the partial compatibility of the polymers with one another, there may be greater compatibility of the individual polymer components with the polysaccharide, such as the starch or the thermoplastic starch, so that the starch or thermoplastic starch is preferably present in one of the at least two added polymers.

For example, the water absorption of mixtures of biodegradable polyester amides and the polysaccharides, such as starch or thermoplastic starch, can be significantly reduced if one or more aliphatic polyesters, such as polylactide, polycaprolactone or succinic acid ester, are used as the third mixture component. Polycaprolactone is preferably used. This makes it possible, for example, to produce moldings with a longer service life against the action of moist ingredients.

These mixtures according to the invention of at least one polysaccharide or derivatives thereof, such as, for example, starch or thermoplastic starch and at least two other biodegradable polymers, also have advantages in the following properties: for example gas barrier against oxygen and water vapor, gas barrier against flavoring agents or higher temperature stability.

Films produced according to the invention have the diverse requirements that are placed on food packaging.

Conventional multilayer films with special properties are known in the prior art and can usually be produced in a complex manner by coextrusion of different polymers or by lamination or lamination or vapor deposition of individual polymer layers (for example, one extruder per layer during coextrusion) .

In contrast, the mixtures according to the invention allow the production of multilayered shaped bodies by simple processing from an aggregate. The mixture can be obtained either by simply mixing the various polymer granules with subsequent processing or by prior compounding of the individual components. This eliminates the need for multi-layer extrusion, such as coextrusion. Polysaccharides or derivatives thereof are generally suitable for producing the mixtures proposed according to the invention, for example the materials mentioned below:

Gums: Arabicum = Acacia gum, tragacanth, carragenan, furcelaran, ghatti, guar, locust bean, psyllium, quince, tamarind-karaya gum;

Plant extracts: Agar = extract Gelidium sp., Alginate = block copolymer from beta-D-mannuronic acid and alfa-L-guluronic acid, arabinogalactan, pectin;

Fermentation products: dextran, xanthan, curdlan, scleroglucan;

Bacterial extracts: yeast glucan, pullulan, Zanflo-10, Zanflo-21: Reg.Mark Kelco Division, Merck & Co., Inc., PS-7: Azotobacter indicus, Bacterium alginate: Azotobacter vinelandii,

as well as other starches such as grain, tapioca, potato, wheat, rice, etc.;

Celluloses and cellulose derivatives, such as carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and also methyl ether of pectin, hydroxypropyl alginates;

modified starches;

Shellfish extracts, chitin and chitosan.

The above list is by no means exhaustive, and other derivatives of the above-mentioned polysaccharides are also suitable for reacting with lactones, lactams and / or suitable carboxylic acids in accordance with the present invention. The following derivatives are particularly suitable: Formates, acetates, butyrates, propionates or generally esters, ethers, alkyl ethers such as, for example, ethyl cellulose, methyl cellulose etc. and carboxymethyl derivatives such as hydroxyalkyl ether, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose. It is essential that the derivative or derivatives are soluble in lactones.

As is known, there are a large number of polysaccharides which are already being used in large quantities or are being used. The following are examples of this, which are used industrially in large quantities:

Corn starch, potato starch, corn sugar, agar, Arabic gum, guar, pectin, carboxymethyl cellulose and xanthan, to name just a few examples.

Polysaccharide acetate (diacetate), formate,

-butyrate and -proprionate, such as cellulose acetate (diacetate), -formate and -butyrate, where the degree of substitution should be at least about 1.5, but should not be higher than about 2.6. Suitable lactones or other reaction partners for the polysaccharide are, in particular, caprolactone, dilactide and diglicidyl lactone (2-glycolic acid), corresponding to lactams, such as, for example, caprolactam or carboxylic acids, such as, in particular, formic acid.

The following polymers are particularly suitable for mixing with the suitable polysaccharides or polysaccharide derivatives mentioned: Aliphatic and partially aromatic polyester

A) linear bifunctional alcohols, such as, for example, ethylene glycol, hexadiol or preferably butanediol and / or optionally cycloaliphatic, bifunctional alcohols, such as, for example, cyclohexanedimethanol and additionally optionally small amounts of higher-functionality alcohols, such as, for example, 1, 2, 3-propanetriol or neopenthyl glycol, and also from linear bifunctional acids, such as, for example, succinic acid or adipic acid and / or optionally cycloaliphatic bifunctional acids, such as, for example, cyclohexanedicarboxylic acid and / or optionally aromatic bifunctional acids, such as, for example, terephthalic acid or isophthalic acid or naphthalenedicarboxylic acid and additionally optionally small amounts of higher-functional acids or such as trimellitic acid

B) from acid- and alcohol-functionalized building blocks, for example hydroxybutyric acid or hydroxyvaleric acid or their derivatives, for example ε-caprolactone,

or a mixture or a copolymer of A and B,

the aromatic acids making up no more than 50% by weight, based on all acids.

The acids can also be used in the form of derivatives, such as acid chlorides or esters;

Aliphatic polyester urethanes C) an ester fraction from linear bifunctional alcohols, such as, for example, ethylene glycol, butanediol, hexanediol, preferably butanediol and / or optionally cycloaliphatic bifunctional alcohols, such as, for example, cyclohexanedimethanol and additionally optionally small amounts of higher-functional alcohols, such as, for example, 1, 2, 3-propanetriol or Neopentyl glycol and from linear bifunctional acids, such as, for example, succinic acid or adiphic acid and / or optionally cycloaliphatic and / or aromatic bifunctional acids, such as, for example, cyclohexanedicarboxylic acid and terephthalic acid and, if appropriate, small amounts of higher-functional acids, such as trimellitic acid or

D) an ester fraction from acid- and alcohol-functionalized building blocks, for example hydroxybutyric acid and hydroxyvaleric acid, or their derivatives, for example ε-caprolactone,

or a mixture or a copolymer of C) and D), and

E) from the reaction product of C) and / or D) with aliphatic and / or cycloaliphatic bifunctional and additionally optionally higher-functional isocyanates, for example tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, optionally additionally with linear and / or cycloaliphatic bifunctional and / or higher functional groups Alcohols, for example ethylene glycol, butanediol, hexanediol, neopentyl glycol, cyclohexanedimethanol, wherein the ester fraction C) and / or D) is at least 75% by weight, based on the sum of C), D) and E.

Aliphatic-aromatic polymer carbonates

F) an ester fraction from linear bifunctional alcohols, such as, for example, ethylene glycol, butanediol, hexanediol, preferably butanediol and / or cycloaliphatic bifunctional alcohols, such as, for example, cyclohexanedimethanol and additionally optionally small amounts of higher-functional alcohols, such as, for example, 1,2,3-propanetriol or neopentyl glycol and from linear bifunctional acids, such as, for example, succinic acid or adipic acid and / or optionally cycloaliphatic bifunctional acids, such as, for example, cyclohexanedicarboxylic acid and additionally optionally small amounts of higher-functional acids, such as, for example, trimellitic acid or

G) from an ester fraction from acid- and alcohol-functionalized building blocks, for example hydroxybutyric acid or hydroxyvaleric acid or their derivatives, for example ε-caprolactone,

or a mixture or a copolymer of F) and G) and

H) a carbon portion which is produced from aromatic bifunctional phenols, preferably bisphenol A and carbonate donors, for example phosgene,

wherein the ester fraction F) and / or G) is at least 70% by weight, based on the sum of F), G) and H);

Aliphatic polyester amides I) an ester fraction from linear and / or cycloaliphatic bifunctional alcohols, such as, for example, ethylene glycol, hexanediol, butanediol, preferably butanediol, cyclohexanedimethanol, and additionally, if appropriate, small amounts of higher-functional alcohols, for example 1,2,3-propanetriol or neopentyl glycol, and from linear and / or cycloaliphatic bifunctional acids, for example succinic acid, adipic acids, cyclohexanedicarboxylic acid,

preferably adipic acid and additionally optionally small amounts of higher functional acids, e.g. Trimellitic acid, or

K) from an ester fraction from acid- and alcohol-functionalized building blocks, for example hydroxybutyric acid, or hydroxyvaleric acid, or their derivatives, for example ε-caprolactone,

or a mixture or a copolymer of I) and K), and

L) an amide portion of linear and / or cycloaliphatic bifunctional and additionally optionally small amounts of higher functional amines, e.g. tetramethylene diamine, hexamethylene diamine, isophorone diamine, as well as from linear and / or cycloaliphatic bifunctional and additionally optionally small amounts of higher functional acids, e.g. Succinic acid or adipic acid, or

M) from an amide portion of acid- and amine-functionalized building blocks, preferably W-laurolactam and particularly preferably ε-caprolactam,

or a mixture of L) and M) as an amide component, wherein the ester content I) and / or K) is at least 20% by weight, based on the sum of I), K), L) and M).

In connection with polyester amides, reference is made in particular to EP-A 0 641 817, which relates to the production and use of thermoplastically processable and biodegradable aliphatic polyester amides. This European patent application proposes for the synthesis according to the invention of polyester amides, in particular monomers, from the following groups:

Dialcohols such as ethylene glycol, 1,4-butanediol, 1,3-propanediol,

1, 6-hexanediol, diethylene glycol and others and / or dicarboxylic acid such as oxalic acid, succinic acid, adipic acid and others. also in the form of their respective esters (methyl, ethyl, etc.), and / or hydroxycarboxylic acids and lactones, such as caprolactone and others.

and / or amino alcohols such as ethanolamine, propanolamine etc. and / or cyclic lactams such as ε-caprolactam or laurolactam etc.

and / or w-aminocarboxylic acids such as aminocaproic acid etc. and / or mixtures (1: 1 salts) of dicarboxylic acids such as adipic acid, succinic acid etc. and diamines such as hexamethylenediamine, diaminobutane etc.

Likewise, both hydroxyl- or acid-terminated polyesters with molecular weights between 200 and 10,000 can be used as the ester-forming component.

The production conditions of the polymers or polymer mixtures described above can be dispensed with, since their production is best known from the prior art, such as, for example, PolyesteramJ.de from the aforementioned EP 0 641 817. In connection with compostable polyester urethanes, reference is also made to EP 539 975, which is why a description of their production processes can also be dispensed with here. It should only be mentioned that polyester urethane materials described in EP 539 975 are used in the examples described below.

Also to be mentioned are aliphatic polyesters, such as polycaprolactone, polylactic acid, polyhydroxybutyric acid, polyhydroxybenzoic acid, polyhydroxybutyric acid / hydroxivaleric acid copolymers and mixtures thereof.

Statistical copolyesters of aliphatic and aromatic dicarboxylic acids with a proportion, for example of approximately 35-55 mol, are also suitable for mixing with the polysaccharides, such as starch, such as in particular TPS. % with an aromatic acid, such as, for example, terephthalic acid, polyalcylene terephthalates and polyethylene terephthalates, for example, having been found to be suitable copolyesters for mixing with TPS.

The proportions by weight of the polysaccharides or their derivatives, such as starch or thermoplastic starch and the at least two other biodegradable plastics, can be varied within a wide range.

The proportion of polysaccharide or the derivative can vary between 5 and 90% by weight. The content of a mixture of at least two other biodegradable polymers is between 10 and 95% by weight. The mixing ratio of the different biodegradable polymers can be set freely depending on the requirements. Using native starch and thermoplastic starch, some examples of polymer mixtures proposed according to the invention are to be mentioned, which are listed in the table below.

Legend :

Starch = native potato starch dried 3.5% H20: Plasticizer la - lf Bayer Polymer according to the list below.

² TPS = thermoplastic starch = starch + plasticizer <0.1%

H20, water content by degassing, analogous to EP 0 397 819

³ PLA (Polylactic acid resin) = Mitsui Toatsu Chemicals LACEA

H 100 MFR 13 190 ° C 2.16 kg;

Polyamide 1 = Bayer BAK 1095 polyester amide MFI 2.5 150 ° C

2.16 kg;

⁵ polyester 1 = BASF ZK 242/108 copolyester of aliphatic diols and aliphatic / aromatic dicarboxylic acids MVR 3.0 at 190 ° C / 2.16 kg;

^δ PCL (polycaprolactone) = Union Carbide Tone Polymer P-787

MFI 1.0 125 ° C 44 psi g / lOmin;

⁷ extrusion equipment = Werner & Pfleiderer ZSK 40;

MFI 150 ° C, 10 kg

For the preparation of the mixtures, the individual components, ie the polysaccharide or derivative thereof, such as the starch or thermoplastic starch and the two further polymer components, can be metered into a mixing unit, such as a kneader or extruder, or the components can be added before Enter into the mixing unit to be compounded. Mixing or kneading in the extruder is carried out in accordance with generally customary process conditions, such as those used in plastics processing. manufacturing industry are known for mixing or compounding polymers. It is essential that a melt that is as homogeneous as possible is produced without, however, choosing an excessively high temperature in order to avoid any decomposition of the at least three polymer components.

According to an embodiment variant of the present invention, it is possible first to mix the polysaccharide with one further polymer component in the sense of a compounder before this compound is then mixed with the second, further polymer component in an extruder to form the ternary polymer mixture. Mixing between the polysaccharide, such as, for example, the starch or, in particular, the thermoplastic starch with the one further polymer can take place in accordance with WO97 / 48764, where, for example, starch or a starch derivative with an aliphatic polyester, a copolyester with aliphatic and aromatic blocks Polyester amide, a polyester urethane, a polyethylene oxide, a polymer or a poly glycol and / or mixtures thereof is mixed at a water content of <5% by weight, preferably <1% by weight, so that a largely homogeneous mixture of Starch with which another polymer is formed. This is possible because the low water content enables the starch or the starch derivative to react with the hydrophobic polymer in situ, which on the one hand modifies the starch into a thermoplastic starch and on the other hand creates a phase mediator which allows the starch or starch to be mixed as homogeneously as possible of the starch derivative with the other polymer. This process technology described in WO97 / 48764 can of course be transferred to other polysaccharides or derivatives thereof, so that the content of the W097 / 48764 is to be regarded as an integral part of the present patent application.

The starch / polymer mixture compounded in this way is then subsequently mixed with the second further polymer, the miscibility between the compound and the additional further polymer being only partial so that the layer-like structure desired according to the invention is achieved in the molded article or extrudate to be produced can be.

Of course, the miscibility between the polysaccharide and the one other polymer component can also be achieved by adding a corresponding phase mediator which enables at least partial miscibility at the phase boundary of the two polymers. For example, this phase mediator can have two blocks, one block being soluble or miscible in the polysaccharide and the second block being correspondingly soluble in the further polymer component or miscible with it. This phase mediator can of course also be added if the polysaccharide or the derivative thereof and the at least two further polymer components are admixed to a mixing unit such as an extruder or kneader without prior compounding, ie the phase mediator is effective when the at least three components mentioned are mixed. Thus, the miscibility of the polysaccharide with one of the two further polymer components can be adjusted by a suitable choice of the phase mediator, while the miscibility with the other of the two further polymer components is only insufficient. Of course, it is possible to add further additives and aggregates either in a pre-compounding of one or the other component or to add them directly into the mixing unit, which are any suitable plasticizers, plasticizers, fillers, degassing aids, mold release additives, etc. can.

The advantage of the present invention is that the melt produced in this way can be processed to a quasi single-layer film, for example by bubble extrusion, slot extrusion, etc. However, the properties of the film produced correspond to those of a multilayer film, such as has been produced by coextrusion.

This effect is to be illustrated with reference to FIG. 1, in which a cross section through a film produced according to the invention is shown schematically in FIG. The film shown in cross section in FIG. 1 is one made from thermoplastic starch, polyester amide and polycaprolactone, corresponding to Example 1 from the table above. The individual layers correspond to the different mixture components and alternate irregularly. Partial compatibility can be recognized by the black dots, i.e. at these points, the proportions of a mixed component are distributed in a second mixed component.

Injection molded parts, extrudates and foils produced by means of polymer mixtures proposed according to the invention, in addition to relatively good material properties, have excellent biodegradability due to the multilayer structure, which is why they are able to make a significant contribution to the acute waste problem. For example, foils are made made from a polymer mixture proposed according to the invention, excellently suitable for a wide variety of applications in agriculture, for example for covering fields, films of this type can either be composted after they have been used or else plowed into the ground in the field. Such polymer mixtures are also suitable for the production of composting bags, composting waste containers, etc. Furthermore, containers and bottles, for example, can be produced from the polymer mixture proposed according to the invention by means of blow molding.

The degradation rate and the physical properties can be influenced by the selection of the polymer components.

However, the polymer mixtures according to the invention are also suitable for the production of textile products, for example for the production of fibers, monofilaments, flat structures, such as fabrics, felts, nonwovens, so-called backsheets, textile composites, flakes, wadding, and also linear structures, such as for example threads, yarns, ropes, lines etc. In particular, it has been shown in practice that the polymer mixtures according to the invention are suitable for the production of hygiene articles such as diapers, bandages, incontinence products and bed liners.

The fibers according to the invention are also suitable for producing filter materials, such as cigarette filters in particular.

The majority of the polymer mixtures proposed according to the invention, such as in particular containing cellulose derivatives, starch derivatives and / or thermoplastic starch and a copoly- Esters or and / or a polyester amide and / or a polyester urethane are also suitable as an adhesive or can also be used as coatings, for example for the impregnation of textile fabrics.

Another application of the polymer mixtures according to the invention, based on a polysaccharide or a derivative thereof, such as starch or thermoplastic starch, is the production of flexible packaging, consisting of paper and a film made from the material according to the invention, by calendering the paper with the film laminated at an elevated temperature. This combination of paper and bioplastic film is easily printable, biodegradable and suitable for the production of flexible packaging in the food and non-food sectors.

High-quality wallpapers, so-called vinyl wallpapers, are produced by coating with a PVC plastisol in a screen printing or gravure printing process. The emissions and environmental problems of products containing PVC are well known. Blown or flat films can be produced from the polymer mixtures according to the invention in a layer thickness of 80-120 μm customary for wallpaper coating, which coating may optionally contain fillers and other additives which are bonded to the wallpaper paper by heat sealing in a calendering tool and then be printed several times, as is known.

The significantly improved material properties of the polymer mixtures according to the invention, in particular with regard to high dimensional stability, even under changing climatic conditions, result in applications which in the past were reserved for other high-quality materials. This in particular This is because these newly developed materials according to the invention are biodegradable if the milieu and the environmental conditions offer appropriate conditions. Another application is the production of maneuver and practice ammunition in the weir area, which in the past was made from plastics that cause corresponding pollution after use, as it is known that they cannot be collected or can only be insufficiently collected. It is therefore advantageous if these maneuver and practice ammunition can be produced from the biodegradable materials according to the invention.

Again from the weir area, so-called drive-over aids and folding roads are known, which are used in a variety of ways in addition to the military but also in civilian areas, in order to make impassable areas accessible. Folding roads are usually made from metal materials, rarely from plastic. Theoretically, folding roads should be resumed after the exercise or use, but this is not done in practice because the folding roads are distorted after heavy traffic, especially heavy trucks and armored vehicles, and are therefore unusable for further use. In order to reduce the environmental impact in this case as well, folding lines are advantageously produced from the proposed, high-strength, biodegradable materials.

Claims

claims

1. Biodegradable polymeric material, characterized by at least one polysaccharide and / or a derivative of a polysaccharide and at least two other polymers with different crystallinity, which are not completely miscible with one another.

2. Material, in particular according to claim 1, characterized in that at least one of the polymer components has a high crystallinity.

3. Material, in particular according to one of claims 1 or 2, characterized in that the polysaccharide or derivative thereof is at least almost homogeneously miscible with at least one of the at least two further polymer components.

4. Material, in particular according to one of claims 1 to 3, characterized in that the mixture contains at least starch, modified starch, such as destructurized starch or thermoplastic starch, a starch derivative and / or a cellulose derivative.

5. Material, in particular according to one of claims 1 to 4, characterized in that the ternary polymer mixture contains at least one polysaccharide or derivative thereof, selected from the list below:

Gums: Arabicum = Acacia gum, tragacanth, carragenan, furcelaran, ghatti, guar, locust bean, psyllium, quince, tamarind-karaya gum; Plant extracts: Agar = extract Gelidium sp., Alginate = block copolymer from beta-D-mannuronic acid and alfa-L-guluronic acid, arabinogalactan, pectin;

Fermentation products: dextran, xanthan, curdlan, scleroglucan;

as well as other starches such as grain, tapioca, potato, wheat, rice, etc.;

modified starches;

Shellfish extracts, chitin and chitosan;

Reaction products of polysaccharides or their derivatives, such as, in particular, the materials mentioned above with lactones, lactams and / or suitable carboxylic acids, such as, in particular, formates, acetates, potyrates, propionates or generally esters, ethers, alkyl ethers, such as, for example, ethyl cellulose, methyl cellulose, etc. and carboxymethyl derivatives such as hydroxyalcyl ether, carboxymethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose.

6. Material, in particular according to one of claims 1 to 5, characterized in that the further polymers are selected from the list below: Aliphatic and partially aromatic polyester

A) linear bifunctional alcohols, such as, for example, ethylene glycol, hexadiol or, preferably, butanediol and / or optionally cycloaliphatic, bifunctional alcohols, such as, for example, cyclohexanedimethanol and additionally optionally small amounts of higher-functional alcohols, such as, for example, 1, 2, 3-propanetriol or neopenthyl glycol, and from linear bifunctional acids, such as, for example, succinic acid or adipic acid and / or optionally cycloaliphatic bifunctional acids, such as, for example, cyclohexanedicarboxylic acid and / or optionally aromatic bifunctional acids, such as, for example, terephthalic acid or isophthalic acid or naphthalenedicarboxylic acid and, if appropriate, small amounts of higher-functional acids or, for example, trimfunctional acids or such as trimethylene acids

or a mixture or a copolymer of A and B,

the aromatic acids making up no more than 50% by weight, based on all acids.

Aliphatic polyester urethanes

C) an ester fraction from linear bifunctional alcohols, such as, for example, ethylene glycol, butanediol, hexanediol, preferably butanediol, and / or optionally cycloaliphatic bifunctional alcohols, such as, for example, cyclohexanedimethanol and additionally optionally small amounts of higher functional alcohols, such as, for example, 1,2, 3-propanetriol or neopentyl glycol, and from linear bifunctional acids, such as, for example, succinic acid or adiphic acid and / or optionally cycloaliphatic and / or aromatic bifunctional acids, such as, for example, cyclohexanedicarboxylic acid and terephthalic acid and additionally, if appropriate, small amounts of higher-functional acids, such as trimellitic acid or

or a mixture or a copolymer of C) and D), and

E) from the reaction product of C) and / or D) with aliphatic and / or cycloaliphatic bifunctional and additionally optionally higher-functional isocyanates, e.g. Tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, optionally additionally with linear and / or cycloaliphatic bifunctional and / or higher-functional alcohols, e.g. Ethylene glycol, butanediol, hexanediol, neopentyl glycol, cyclohexanedimethanol,

wherein the ester fraction C) and / or D) is at least 75% by weight, based on the sum of C), D) and E. Aliphatic-aromatic polymer carbonates

F) an ester fraction from linear bifunctional alcohols, such as, for example, ethylene glycol, butanediol, hexanediol, preferably butanediol and / or cycloaliphatic bifunctional alcohols, such as, for example, cyclohexanedimethanol and, if appropriate, small amounts of higher-functional alcohols, such as, for example, 1,2,3-propanetriol or neopentyl glycol and from linear bifunctional acids, such as, for example, succinic acid or adipic acid and / or optionally cycloaliphatic bifunctional acids, such as, for example, cyclohexanedicarboxylic acid and additionally optionally small amounts of higher functional acids, such as, for example, trimellitic acid or

or a mixture or a copolymer of F) and G) and

Aliphatic polyester amides

I) an ester fraction from linear and / or cycloaliphatic bifunctional alcohols, such as, for example, lenglycol, hexanediol, butanediol, preferably butanediol, cyclohexanedimethanol, and additionally optionally small amounts of higher-functional alcohols, for example 1,2,3-propanetriol or neopentyl glycol, and also of linear and / or cycloaliphatic bifunctional acids, for example succinic acid, adipic acids, cyclohexanedicarboxylic acid,

or a mixture or a copolymer of I) and K), and

L) an amide component of linear and / or cycloaliphatic bifunctional and additionally optionally small

Amounts of higher functional amines, e.g. tetramethylene diamine, hexamethylene diamine, isophorone diamine, as well as from linear and / or cycloaliphatic bifunctional and additionally optionally small amounts of highly functional acids, e.g. Succinic acid or adipic acid, or

M) from an amide portion of acid- and amine-functionalized building blocks, preferably W-larin lactam and particularly preferably ε-caprolactam,

or a mixture of L) and M) as an amide component, wherein

the ester content I) and / or K) is at least 10% by weight, based on the sum of I), K), L) and M).

7. Material, in particular according to one of claims 1 to 6, characterized by at least one polysaccharide or derivative thereof, a polyester amide and by at least one aliphatic polyester.

8. Material, in particular according to one of claims 1 to 7, characterized in that the polymer mixture contains at least one phase mediator to improve the miscibility of the polysaccharide or the derivative thereof with at least one of the further polymer components.

9. Material, in particular according to claim 8, characterized in that the phase mediator is obtainable by substantially water-free mixing of the polysaccharide or derivative thereof with the at least one further polymer in an at least almost water-free environment, such as preferably with a water content of <1 wt. %.

10. Material, in particular according to one of claims 1 to 9, characterized in that at least one of the further polymer components is an aliphatic polyester, such as e.g. a polylactide, polycaprolactone or succinic acid ester.

11. Material, in particular according to one of claims 1 to 10, characterized in that the proportion of the polysaccharide is from 5 to 90% by weight and the proportion of the at least two further, biodegradable polymers is between 10 and 95% by weight.

12. Material, in particular according to one of claims 1 to 11, characterized in that at least thermoplastic starch is present as the polysaccharide.

13. A process for producing a biodegradable material or an at least ternary polymer mixture, thereby characterized in that at least one polysaccharide or a derivative thereof and at least two further biodegradable polymers with different crystallinity are metered into a mixing unit, melted therein and mixed to form a mixture that is as homogeneous as possible.

14. The method, in particular according to claim 13, characterized in that the mixing takes place in an extruder or kneader.

15. The method, in particular according to one of claims 13 or 14, characterized in that the at least one polysaccharide or derivative thereof is first mixed or compounded with at least one further polymer component and then at least one second further polymer is added in the mixing unit and in the melt is mixed.

16. The method, in particular according to one of claims 13 to 15, characterized in that first the polysaccharide or derivative thereof is mixed with at least one of the other polymers in a largely water-free atmosphere, preferably at a water content of <1% by weight, and then the the largely homogeneous mixture thus produced is additionally mixed with at least one second further polymer in the melt.

17. The method, in particular according to one of claims 13 to 16, characterized in that when the polysaccharide or derivative thereof and the at least two further polymer components are fed to the mixing unit, at least one phase mediator is added, which is the compatibility between the polysaccharide and at least one of the others Polymer components increased.

18. Use of the material according to one of claims 1 to 12 for the production of moldings or extrudates, such as fibers, foils, flat structures, such as fabrics, felts, nonwovens, etc.

19. Use of the materials according to one of claims 1 to 12 for the manufacture of textile products, such as fibers, threads,

Yarns, ropes, lines, etc.

20. Use of the materials according to one of claims 1 to 12 for the manufacture of packaging materials, such as films in particular.