WO1999050346A1

WO1999050346A1 - Biodegradable packaging material, method for producing same and its use

Info

Publication number: WO1999050346A1
Application number: PCT/EP1999/002220
Authority: WO
Inventors: Andreas Gerhard Baar
Original assignee: Apack AG für Biologische Verpackungen
Priority date: 1998-03-31
Filing date: 1999-03-31
Publication date: 1999-10-07
Also published as: JP2002509969A; NO20004891D0; DE19980541D2; CA2324575A1; NO20004891L; DE19814373A1; DE19814373C2; KR20010074465A; PL343178A1; EP1070099A1; AU3522199A

Abstract

The invention relates to a biodegradable packaging material, containing: (a) between 45 and 72 wt.% starch, (b) between 18 and 45 wt.% cellulosic fibres, (c) between 0.2 and 10 wt.% fatty separating agent, (d) between 0.05 and 3.0 wt.% emulsifier and (e) between 2 and 15 wt.% water. The invention also relates to a method for producing such a material and to its use for packaging objects, especially food.

Description

BIODEGRADABLE MATERIAL FOR PACKAGING, METHOD FOR THE PRODUCTION AND USE THEREOF

The invention relates to a biodegradable material for packaging, a method for producing such a material and its use for packaging objects, in particular foodstuffs.

Nowadays, the prevention, reduction and disposal of waste is one of the greatest environmentally relevant problems. This is particularly evident in molded articles such as cups, plates, cups, bowls, boxes and other containers, which are used, for example, for packaging food and used in fast food restaurants. For example, Food, especially those intended for immediate consumption, are often sold in voluminous packaging. Although such molded articles are relatively light, they increase the amount and volume of long-lasting, solid waste after their use when they are disposed of. As a result, these moldings, due to their considerable volume, strain the waste containers or the landfills. Furthermore, they are easily blown away by the wind. Such moldings are thrown away outdoors after the ones in it

ERSATZBI_Aπ (RULE 26) contained food, they often mess up the landscape for years.

Many of the previously used materials for the production of the above-mentioned shaped bodies are made from non-renewable raw materials, which continues to represent a strong ecological burden.

As is clear from the circumstances set out above, there is a great need for a material which can be used for moldings, in particular packaging, which is produced from predominantly renewable raw materials and is rapidly biodegradable.

The present invention is therefore based on the object of providing a material which is produced from predominantly renewable raw materials and is rapidly biodegradable.

According to the invention, this is achieved by a biodegradable material for packaging, which is characterized in that it comprises the following components:

(a) 45 to 72% by weight starch,

(b) 18 to 45% by weight of cellulose-containing fibers,

(c) 0.2 to 10% by weight of a fatty release agent,

(d) 0.05 to 3.0 wt% emulsifier and

(e) 2 to 15% by weight of water, the amounts in% by weight in each case relating to the biodegradable material.

The material according to the invention thus has starch as the main components, and cellulose-containing fibers and, as secondary components, a fatty release agent, an emulsifier and water. Furthermore, the inventive

ERSATZB.LATT (RULE 26) Packing materials contain additional additives, for example fillers, such as chalk, kaolin, talc, gypsum, alumina, titanium dioxide or aluminum oxide, fluxes, such as magnesium carbonate, magnesium hydrogen carbonate, sodium hydroxide solution and ammonium hydroxide, and also color pigments and food colors. However, the material according to the invention can also consist only of the specified components (a) to (e), ie there are no further constituents in the material according to the invention, except for those which are present in components (a) to (e) as customary accompanying substances , eg impurities in the starch.

In the material according to the invention, the starch and the cellulose-containing fibers form a starch-fiber composite which contains the fatty release agent, the emulsifier and the water, this starch-fiber composite being formed by gelatinizing the starch. This means that at least part of the starch can be present in the material according to the invention as gelatinized starch, it having proven to be advantageous if the largest part or all of the starch in the material according to the invention, and thus in the starch-fiber composite, as gelatinized starch is present. The expression "gelatinized starch" indicates that this is made from native starch or from chemically and / or physically modified starch by first heating it in the presence of water and then cooling it, if necessary. The fat-containing release agent, the emulsifier and the water can be evenly distributed in the starch-fiber composite.

The material according to the invention can be produced from a dough which has the above-mentioned components (a) to (d) in the ratio desired in the material according to the invention, but the water content being greater than 15% by weight. This dough is e.g. filled in a closed baking pan and thus brought into the desired shape and then baked. Through the baking, part of the water escapes as water vapor with a strong increase in pressure, as a result of which a material according to the invention is obtained. The water vapor escapes from the through specially designed openings

ERSATZBI_Aπ (RULE 26) Baking pan. The material according to the invention thus produced is removed from the baking mold after baking.

The starch present in the material according to the invention can originate from natural starch, chemically and / or physically modified starch and mixtures thereof. Examples of the natural starch present in the material according to the invention are potato, maize, rice and wheat starch and other starches obtained from vegetable materials, potato starch being preferred since it can be obtained economically in large quantities on the one hand and materials according to the invention on the other hand with particularly good material properties. Furthermore, the potato starch has a large swelling volume, which gives high-viscosity paste, and good adhesive properties.

The starch is present in the material according to the invention in an amount of 45 to 72% by weight, preferably 58 to 66% by weight and particularly preferably 64 to 66% by weight, in each case based on the material according to the invention. With these amounts of starch in the material according to the invention, a mechanically particularly stable starch-fiber composite and a very rapid biodegradability are achieved.

The material according to the invention contains cellulose-containing fibers which, together with the starch which is also present, form the starch-fiber composite described in more detail above, which represents the basic structure of the material according to the invention. The expression “cellulose-containing fibers” indicates fibers of any kind which contain cellulose or consist of cellulose. In a preferred embodiment, the cellulose-containing fibers are cellulose fibers, ie fibers that can be obtained from cellulose. Cellulose is a name for the fine-fiber mass obtained from the digestion of wood or other fibrous plants and consisting predominantly of cellulose. The term “fibers” used in the present application indicates fine, thin structures which are limited in length, the length being greater than the width. They can be present as individual fibers or as a bundle of fibers. Such fibers can be produced in a manner known to the person skilled in the art, it having turned out to be particularly favorable if the fiber production takes place in such a way that the cellulose-containing material is broken up, for example by means of a hammer mill.

In a preferred embodiment of the material according to the invention, the length of the cellulose-containing fibers is in the range from 0.1 to 3.0 mm; the width of the cellulose-containing fiber can preferably be in the range from 0.01 to 0.06 mm.

The amount of cellulose-containing fibers in the material according to the invention is 18 to 45% by weight, preferably 20 to 30% by weight, particularly preferably 21 to 24% by weight and very particularly preferably approximately 24% by weight, in each case based on the material according to the invention. These amounts of cellulose-containing fiber in the material according to the invention particularly advantageously enable good mechanical stability and excellent biodegradability of the material according to the invention.

The ratio of starch to fiber in the material according to the invention can be adjusted so that it is 1: 1 to 4: .1, preferably 3: 1 to 2.5: 1, e.g. approx. 2.7: 1.

As has already been explained above, the material according to the invention has a fatty release agent which is present in an amount of 0.2 to 10% by weight, based on the material. The amount of the fat-containing release agent is preferably 0.2 to 2.5% by weight and particularly preferably 0.6 to 1.3% by weight, in each case based on the material according to the invention. The term “fat-containing release agent” encompasses compositions of any kind which have one or more different fats and which facilitate the separation of the material according to the invention after baking from the baking mold. Fats are triglycerides, ie esters of glycerin, the three hydroxyl groups of which are esterified by fatty acids. The fatty acids in a fat molecule can be the same or different. The fat can be synthetic or naturally occurring fat, such as vegetable or animal fat. The fat can also be partially or fully hardened, with fully hardened fats having excellent storage stability and not becoming rancid. Furthermore, it is advantageous if the fat-containing release agent has good storage stability and a high release force and is physiologically harmless. It is also advantageous if the melting point of the fat is above room temperature (approx. 18 ° C.), for example at 40 ° C. or higher, since this improves the water repellency of the material according to the invention.

In a preferred embodiment of the fat-containing agent used in the material according to the invention, it mainly contains fat. The amount of fat in the fat-containing agent is advantageously at least 90% by weight, preferably at least 94.5% by weight and particularly preferably at least 98% by weight, based in each case on the fat-containing agent. The fat-containing agent can also consist entirely of fat.

In addition to the fat or fats, the fat-containing release agent can contain small amounts of other components, e.g. Oil, wax, which should not be fats, or lecithin.

The fat-containing agent preferably has the following composition, the percentages by weight relating to the fat-containing agent: approximately 64.5% by weight of vegetable fat, approximately 30.0% by weight of animal fat and approximately 5.5% by weight of one

ERSATZBI_ATT (RULE 26) Mixture of lecithin and a wax, preferably beeswax. This fatty agent is characterized by excellent storage stability, good separation and physiological harmlessness. It is therefore ideally suited for an agent according to the invention.

Surprisingly, it has now been found that these fatty release agents, in particular in the amounts used, have no negative effect on the structural properties of the material according to the invention. The excellent mechanical stability of the material for packaging is not adversely affected. Furthermore, the odor properties of the material, in spite of these high amounts of fat which are introduced into the material according to the invention by the fatty release agent, are not adversely affected, i.e. the packaging material does not smell unpleasant even after prolonged storage. Furthermore, greasing of the baking mold used to produce the material according to the invention is not necessary, and yet the material can be easily removed from the baking mold. This makes it possible to save the greasing of the baking mold with a liquid release agent that is otherwise necessary for the production of biodegradable materials for packaging, which on the one hand makes the production more economical and on the other hand does not cause the baking mold to become encrusted with the liquid release agent. Furthermore, it has been found that the above-mentioned fat-containing release agent also ensures that the material according to the invention is water-repellent.

As already explained above, an emulsifier is present in the material according to the invention. The term "emulsifier" includes compounds of any kind that are amphiphilic, i.e. have a lipophilic and a hydrophilic group in the molecule, but the emulsifier is not fat. Conveniently the emulsifier has a melting point greater than room temperature, e.g. approx. 40 ° C or higher. The emulsifier has the effect that the fatty release agent also present in the material according to the invention is homogeneously distributed therein. Furthermore, it has

ERSATZB.LATT (RULE 26) proven to be favorable, especially when the material according to the invention is used as packaging for food, that the emulsifier is approved under food law. The emulsifier is preferably a mono- or diglyceride of fatty acids which is esterified with a carboxylic acid such as citric acid, mono- and diacetyltartaric acid, lactic acid or acetic acid and tartaric acid. These emulsifiers are summarized under EEC number 472. The expression "fatty acids" is a common term in the field of fats, so that the person skilled in the art knows which fatty acids can be used. The emulsifier can also be a fatty alcohol ether sulfate, a fatty alcohol sulfate, preferably each with a higher fatty alcohol (from 12 C atoms), an alkali metal salt of a higher fatty acid (fatty acid with 12 or more carbon atoms), for example sodium stearate. The emulsifier can also be a mixture of two or more of the above emulsifiers.

The amount of emulsifier in the material according to the invention is 0.2 to 3.0% by weight, preferably 0.05 to 0.8% by weight and particularly preferably 0.2 to 0.4% by weight, in each case based on the material according to the invention. It was surprising that even small amounts of fat-containing agent can be introduced homogeneously into the material according to the invention with such small amounts.

Surprisingly, the emulsifier makes the material according to the invention even more water-repellent. Furthermore, the release effect can also be improved with the emulsifier, i.e. the material according to the invention can be removed from the baking mold even more easily after baking the dough on which the material according to the invention is based.

Furthermore, water is present in the material according to the invention in an amount of 2 to 15% by weight, preferably 6 to 12% by weight, in each case based on the material according to the invention. Preferred materials according to the invention are given in Table 1 below.

Table 1: Composition of materials according to the invention (in% by weight)

Raw material type Z1 22 Z3 Z4 Z5 Z6 Z7 Z8 Z9 Z10 Z11

Strength 65.5 65.4 65.1 64.8 64.4 65.1 64.8 64.5 64.2 62.9 59.5

Fiber 24 24 24 24 24 23 23 23 23 22 21

Fat 0.2 0.3 0.6 0.9 1.3 1.6 1.9 2.2 2.5 4.8 9.2

Emulsifier 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

Water 10 10 10 10 10 10 10 10 10 10 10

Raw material type Z12 Z13 Z14 Z15 Z16 Z17 Z18 Z19 Z20 Z21 Z22

Strength 65.75 65.5 65.2 64.8 64.3 64.9 64.5 64.1 63.7 61.6 57.1

Fiber 24 24 24 24 24 23 23 23 23 22 21

Fat 0.2 0.3 0.6 0.9 1.3 1.6 1.9 2.2 2.5 4.8 8.9

Emulsifier 0.05 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 1.6 3.0

Water 10 10 10 10 10 10 10 10 10 10 10

Starch: potato starch

Chamfer pulp fiber

Fat: mixture of 64.5% by weight vegetable fat, 30% by weight animal fat and 5.5% by weight

Lecithin and beeswax emulsifier: citric acid monoglyceride

10

The material according to the invention is characterized by a large number of advantages. On the one hand, it has high mechanical stability, which is still very high even with small thicknesses (wall thicknesses) of the material of approx. 2 mm. This outstanding mechanical stability is achieved in particular through the high proportion of cellulose-containing fibers of up to 45% by weight. At the same time, the flexibility of the material according to the invention is very high, which is particularly surprising since cooled starch is very brittle. Furthermore, the material according to the invention is resistant to cold water for up to 1 hour. Furthermore, articles made from the material according to the invention, e.g. a vessel and an associated lid are glued together by moistening with water, the two objects adhering very well to one another. Furthermore, the material according to the invention according to DIN 54900 is almost completely biodegradable within 28 days. In addition, the material according to the invention is stable in storage for a long time, i.e. no change in the material according to the invention occurs during storage. Furthermore, the material consists predominantly of biologically occurring raw materials and can therefore be called "biological" material. Finally, the material according to the invention does not have to be adjusted to a certain water content by a special conditioning step.

Thus, the material according to the invention can best be used as a material for shaped articles (i.e. bodies having a specific shape) of any kind, e.g. as disposable tableware, as fast food packaging (container for hamburgers and french fries), as packaging, e.g. for foods such as dry, moist, pasty, fried foods. After a biodegradable barrier layer has been applied to the material according to the invention, it can then be used to hold liquid foods, such as hot drinks and soups.

The shaped body can take any shape, for example the shape of a bowl, a plate, a cup, a plate. More examples 11

Shaped bodies that can be produced with the material according to the invention are shown in FIGS. 1 to 4.

Furthermore, the shaped body can have the shape of an urn, as is used for cremations, or the shape of a rocket, as is used for fireworks.

The present invention further relates to a method for producing a material for packaging, in particular as described above, in which a bakeable mass is first produced by using 7 to 22% by weight of cellulose-containing fibers and 18 to 36% by weight of starch , 0.1 to 4.6% by weight of fat-containing separating agent, 0.1 to 1.5% by weight of emulsifier and 50 to 60% by weight of water, in each case based on the bakable mass, and then the bakeable Mass is baked to form a shaped body.

The term "bakeable mass" refers to masses of any kind that are baked, i.e. can be foamed by water vapor. The bakable mass used in the process according to the invention can be referred to as a soft, semi-solid dough.

After baking, a product (material) can be obtained which has the following composition:

(a) 45 to 72% by weight starch,

(b) 18 to 45% by weight of cellulose-containing fibers,

(c) 0.2 to 10% by weight of a fatty release agent,

(d) 0.05 to 3.0 wt% emulsifier and

(e) 2 to 15 wt% water.

It can therefore be the material according to the invention for packaging described in more detail above. It is therefore advantageous if in 12

processes according to the invention for the starch, the cellulose-containing fibers, the fatty release agent and the emulsifier, the constituents used above in connection with the material according to the invention are used.

A quantity of starch preferably used in the process according to the invention is 30 to 32% by weight, based on the bakable mass.

In a preferred embodiment of the process according to the invention, the amount of cellulose-containing fiber is 10 to 12% by weight, based on the baked mass.

The fat-containing release agent in the bakable composition is preferably 0.1 to 1.2% by weight, 0.3 to 0.6% by weight being particularly preferred.

The preferred amount of the emulsifier used in the bac-capable composition in the process according to the invention is 0.03 to 0.4% by weight, particularly preferably 0.1 to 0.2% by weight.

In the process according to the invention, the water can preferably be present in the bakeable mass in an amount of 54 to 58% by weight.

In the method according to the invention, it is preferred to use the cellulose-containing fibers in the form of a non-woven fabric. For this purpose, the cellulose-containing fibers are first processed into a non-woven fabric in the usual way. A cellulose-containing fiber fleece can be produced, for example, by pulp webs being broken up (fibered) with a hammer mill, individual fibers being obtained. These single pulp fibers are then processed into a nonwoven fabric, as is customary, for example, in the hygiene industry for the production of cotton wool for sanitary napkins. For the further steps of the method according to the invention, the nonwoven fabric can be spread out flat, for example on a conveyor belt. On this on the 13

Then, the remaining components (a) and (c) to (e) are applied to the nonwoven fabric. The conveyor belt can serve to transport the nonwoven fabric to the points at which the other components are added.

In a preferred embodiment of the process according to the invention, the starch comprises a part of native starch and a part of cooking starch (starch which has been heated (boiled) in water). The favorable ratio of native starch to cooking starch is in the range from 1.0: 1 to 4.0: 1, preferably 2.5: 1 to 3.5: 1, particularly preferably approximately 3: 1. The cooking starch can cover the entire range Water content of the dough as well as the emulsifier, which contain fatty agents and possibly other additives. The native starch and the chemically and / or physically modified cooking starch can be added separately to the cellulose-containing fibers.

For the separate addition of the native starch and the cooking starch, it has proven to be particularly advantageous to proceed as follows: In a kettle, a mixture is produced by adding the water, the fatty agent, the emulsifier, possibly other additives and part of the starch added as a native starch and heated for 10 minutes to 1 hour, preferably 20 minutes to 40 minutes, at a temperature of 60 ° C to 80 ° C, preferably 64 ° C to 68 ° C. By heating the starchy mixture in the kettle, the native starch that was originally added is converted into gelatinized starch (cooking starch). Ultimately, this means that the cellulose-containing fibers are mixed both with the gelatinized starch in the form of the mixture explained above and with the native starch, namely the remaining part of the total starch.

First the cooking starch and then the native starch can be added to the cellulosic fibers. You can also add the native starch first and then the cooking starch. Are the cellulose-containing ones 14

Fibers in the form of a non-woven fabric, e.g. on a conveyor belt, before, then the above-described mixture comprising the cooking starch can be applied to the nonwoven fabric, whereby a two-layer structure is obtained, to which the native starch is then applied, e.g. by trickling or scattering. Surprisingly, it has now been found that this procedure ensures an exact composition in small volume elements which can then be easily processed into the bakable mass.

After the above components have been combined, they are mixed. The components can be mixed in a conventional manner, for example by kneading with a kneader, such as a continuous kneader. Kneading can result in a volume reduction of approx. 7: 1 because the fibers have a very low density. Kneading is made much easier by specifying the exact composition in small volume elements.

The baked mass obtained is then baked. For this purpose, the bakable mass is placed (dosed) in a baking mold and preferably for 1 minute to 3 minutes and particularly preferably for 1.5 minutes at a temperature of 100 ° C. to 300 ° C., preferably 150 °, for 0.5 minutes to 15 minutes C to 220 ° C and particularly preferably 190 ° C to 200 ° C heated in a closed baking pan. The baking pan is designed depending on the shape of the desired end product, for example in the form of a bowl. The baking mold can be formed by at least two baking plates, i.e. an upper and a lower baking plate, which are accommodated in a bactaange, the inner surface of the baking plates being kept spaced apart in a closed, locked state of the baking mold to form a mold cavity and the mold cavity being held by the mold baked mass is filled. The baking pan has specially shaped evaporation openings for discharging the water vapor. A plurality of baking tongs can also be used for the simultaneous production of a plurality of shaped bodies. 15

The batchable mass can be dosed into the baking mold using compressed air, screw conveyors, pumps or by applying a vacuum, the use of compressed air being preferred. Dosing can take place at a temperature up to 80 ° C.

Such baking devices are based on the waffle baking technology known per se.

When baking the bacl-capable mass, the water contained in this mass is removed, the baking process advantageously being designed so that the residual water content in the material obtained after baking is less than 5% by weight. By removing the water, the mass is foamed and the starch contained in the mass is gelatinized, as a result of which the material according to the invention described above can be obtained with the starch-fiber composite. Through storage or normal use, the material according to the invention can absorb water from the environment, so that the water content is ultimately 5 to 15% by weight, preferably 6 to 12% by weight, based on the baked material.

The process according to the invention has a number of advantages: the special composition of the bakable mass significantly improves the flow properties of the baking mass used in the process according to the invention, so that it is possible to meter the intrinsically highly viscous bakable mass precisely by metering pumps. This makes it possible to carry out the method according to the invention continuously. It is also not necessary to grease the baking pan. All moldings which are produced by the process according to the invention could be produced quickly, inexpensively and with excellent material properties with regard to dimensional stability, breaking strength and elasticity, structural density and surface quality. Due to the special composition, the material according to the invention is already immediately after baking with a 16

Water content of less than 5% by weight is so exceptionally stable that it can be processed or used immediately.

Brief description of the figures:

1 to 4 show exemplary embodiments of moldings which can be produced using the material according to the invention.

Fig. 1 shows a molded packaging body 1 with base and lid part 2, 3, which are connected by a hinge 4 and e.g. suitable for the lockable intake of food, even when warm. Due to its high elasticity, the hinge 4 made from the material according to the invention can be opened and closed several times. This is all the more astonishing since starch-based materials are usually extremely brittle and break easily.

2 shows a molded body 1 in the form of a half-shell, which can also be connected to a corresponding counter-molded body to form a completely closed package. The shell-shaped molded body 1 has a multiplicity of cylindrical section-shaped depressions 5, these being subdivided with one another into a longer section 6 and a shorter section 7, and this arrangement is repeated symmetrically, divided by a central web 8 on the other side of the molded body. Lateral "feet" 9 increase the dimensional stability and improve the support and stackability of the molded package. Such a packaging tray can be used, for example, to hold ballpoint pens, lipsticks, cosmetic articles, pencils, writing utensils, or also in pharmacy, for example, to hold packaging tubes. 17

3 and 4 show relatively deep packaging body 1, as e.g. can be used as a flower pot, seed bowl or for other packaging or wrapping purposes.

The following examples illustrate the invention.

Examples 1 to 22: Preparation of materials according to the invention

Baked masses (doughs), the composition of which are given in Table 2, were produced as follows:

The stated amounts of water, emulsifier, fatty agent and the portion of native potato starch specified as cooking starch in Table 2 were combined in a kettle and heated with stirring at about 65 ° C. for about 30 minutes. Cooking starch was thus obtained which still contained the emulsifier and the fatty agent.

A cellulose fiber fleece was produced in a conventional manner from cellulose fibers which had a length of 0.1 mm to 3.0 mm and a width of 0.01 to 0.06 mm.

The cellulose fiber fleece was then spread out flat. Then the cooking starch described above was first applied to this cellulose fiber fleece, so that a cooking starch layer comprising emulsifier and fatty agent is formed on the cellulose fiber fleece. The amount of native starch given in Table 2 was then sprinkled over the cooking starch layer. The composition thus obtained was subsequently introduced into a kneader and kneaded therein thoroughly to mix the ingredients, thereby obtaining a bakable mass (dough). 18th

The dough was then placed in a baking pan and baked at about 195 ° C for about 90 seconds.

In this way, materials according to the invention were obtained which were produced from largely renewable raw materials and were rapidly biodegradable. These materials also had high mechanical stability with a wall thickness of approx. 2 mm and good flexibility at the same time and were resistant to cold water for up to 1 hour.

Table 2: Composition of bakeable masts (in% by weight)

Tue

Type of raw material Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex. 10 11

Native 23 23 23 23 23 23 23 23 23 23 22 Strength

Cooking strength 8 8 8 8 8 8 8 8 8 8 8

Fiber 11 11 11 11 11 11 11 11 11 11 11

Fat 0.1 0.2 0.3 0.5 0.6 0.8 0.9 1.1 1.2 2.4 4.6 m emulsifier 0.2 0.2 0.2 0.2 0.2 0.2 0, 2 0.2 0.2 0.2 0.2

Water 57.7 57.6 57.5 57.3 57.2 57.0 56.9 56.7 56.6 55.4 54.2

09 Type of raw material Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. 12 13 14 15 16 17 18 19 20 21 22 f Native 23 23 23 23 23 23 23 23 23 23 23 22 Thickness m Cooking strength 8 8 8 8 8 8 8 8 8 8 8 O m fiber 11 11 11 11 11 11 11 11 11 11 11 r fat 0.1 0.2 0.3 0.5 0.6 0.8 0.9 1 , 1 1, 2 2.4 4.6

N> emulsifier 0.03 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.8 1.5

Water 57.87 57.75 57.6 57.35 57.2 56.95 56.8 56.55 56.4 54.8 52.9

Native starch: native potato starch

Cooking starch: Potato starch warmed in water and then cooled

Fiber: pulp

Lecithin and beeswax o emulsifier: citric acid monoglyceride

© o

Claims

20 claims

1. Biodegradable packaging material comprising:

(a) 45 to 72% by weight starch,

(b) 18 to 45% by weight of cellulose-containing fibers,

(c) 0.2 to 10% by weight of a fatty release agent,

(d) 0.05 to 3.0 wt% emulsifier and

(e) 2 to 15 wt% water.

2. Material according to claim 1, characterized in that the starch is potato starch, corn starch, another vegetable starch or a Gemscih different starches.

3. Material according to claim 1 or 2, characterized in that the starch is present in an amount of 58 to 66 wt .-%, based on the material.

4. Material according to one of claims 1 to 3, characterized in that the cellulose-containing fibers are cellulose fibers. 21

5. Material according to one of claims 1 to 4, characterized in that the cellulose-containing fibers have a length in the range of 0.1 mm to 3.0 mm.

6. Material according to any one of claims 1 to 5, characterized in that the cellulose-containing fibers have a width in the range from 0.01 mm to 0.06 mm.

7. Material according to one of claims 1 to 6, characterized in that the cellulose-containing fibers are present in an amount of 20 to 30 wt .-%, based on the material.

8. Material according to one of claims 1 to 7, characterized in that the fatty release agent is present in an amount of 0.2 to 2.5 wt .-%, based on the material.

9. Material according to one of claims 1 to 8, characterized in that the fatty agent predominantly has fat.

10. Material according to one of claims 1 to 9, characterized in that the fatty release agent further comprises at least one component selected from oil, wax and lecithin.

11. Material according to any one of claims 1 to 10, characterized in that the emulsifier is a mono- or diglyceride of fatty acids which is esterified with a carboxylic acid, a fatty alcohol ether sulfate, a fatty alcohol sulfate or an alkali metal salt of a higher fatty acid.

12. Material according to claim 11, characterized in that the carboxylic acid is citric acid, mono- and diacetyltartaric acid, tartaric acid, lactic acid or acetic acid and tartaric acid. 22

13. Material according to one of claims 1 to 12, characterized in that the emulsifier is present in an amount of 0.05 to 0.8 wt .-%, based on the material.

14. Material according to one of claims 1 to 13, characterized in that the water is present in an amount of 6 to 12 wt .-%, based on the material.

15. A process for producing a biodegradable material for packaging, in which a bakeable mass is produced by 7 to 22% by weight of cellulose-containing fibers, 18 to 36% by weight starch, 0.1 to 4.6% by weight. % fat-containing release agent and 0.03 to 1.5% by weight of emulsifier and 50 to 60% by weight of water, in each case based on the bakable mass, are mixed and then the bakeable mass is baked to form a shaped body.

16. The method according to claim 15, characterized in that the cellulose-containing fibers are used in the form of a nonwoven fabric.

17. The method according to any one of claims 15 or 16, characterized in that the starch comprises native starch and cooking starch.

18. The method according to claim 17, characterized in that the ratio of native starch to cooking starch is in the range from 1: 1 to 4: 1.

19. The method according to any one of claims 15 to 18, characterized in that the native starch and the cooking starch are added separately to the cellulose-containing fibers. 23

20. The method according to claim 19, characterized in that the cooking starch contains the fatty release agent and / or the emulsifier.

21. The method according to claim 19 or 20, characterized in that first the cooking starch and then the native starch are added to the cellulose-containing fiber.

22. The method according to any one of claims 15 to 21, characterized in that the baking is carried out at a temperature of 100 ° C to 300 ° C.

23. The method according to any one of claims 15 to 22, characterized in that the baking is carried out for 0.5 minutes to 15 minutes.

24. The method according to any one of claims 15 to 23, characterized in that the baking takes place in a closed form under pressure increase due to the evaporation of water.

25. The method according to any one of claims 15 to 24, characterized in that the mixing is carried out by kneading.

26. Use of the material according to one of claims 1 to 14 as packaging material.

CHANGED REQUIREMENTS

[Received at the International Office on August 17, 1999 (August 17, 1999); original claims 1, 9 and 15 amended; all other claims unchanged (3 pages)]

1. Biodegradable packaging material comprising:

(a) 45 to 72% by weight of starch, (b) 18 to 45% by weight of cellulose-containing fibers,

(c) 0.2 to 10% by weight of a fatty release agent with a triglyceride content of at least 90% by weight,

(d) 0.05 to 3.0 wt% emulsifier and

(e) 2 to 15 wt% water.

2. Material according to claim 1, characterized in that the starch is potato starch, corn starch, another vegetable starch or a mixture of different starches.

4. Material according to one of claims 1 to 3, characterized in that the cellulose-containing fibers are cellulose fibers.

6. Material according to any one of claims 1 to 5, characterized in that the cellulosic fibers have a width in the range from 0.01 mm to 0.06 mm.

8. Material according to one of claims 1 to 7, characterized in that the fatty release agent is present in an amount of 0.2 to 2.5 wt .-%, based on the material. 25th

9. Material according to one of claims 1 to 8, characterized in that the fat-containing releasing agent has a triglyceride content of at least 94.5% by weight, preferably of at least 98% by weight.

12. Material according to claim 11, characterized in that the carboxylic acid is citric acid, mono- and diacetyl tartaric acid, tartaric acid, lactic acid or acetic acid and tartaric acid.

13. Material according to one of claims 1 to 12, characterized in that the emulsifier is present in an amount of 0.05 to 0.8% by weight, based on the material.

15. A process for producing a biodegradable material for packaging, in which a bakeable mass is produced by 7 to 22% by weight of cellulose-containing fibers, 18 to 36% by weight starch, 0.1 to 4.6% by weight. % fatty release agent with a triglyceride content of at least 90% by weight and 0.03 to 1.5% by weight emulsifier and 50 to 60% by weight water, in each case based on the bakeable mass, and then the baking mass Formation of a shaped body is baked.

18. Process according to claim 17, characterized in that the ratio of native starch to cooking starch is in the range from 1: 1 to 4: 1.

19. The method according to any one of claims 15 to 18, characterized in that the native starch and the cooking starch are added separately to the cellulose-containing fibers.

21. The method according spoke 19 or 20, characterized in that first the cooking starch and then the native starch are added to the cellulose-containing fiber.