EP0953032A1

EP0953032A1 - Method of protecting soil surfaces

Info

Publication number: EP0953032A1
Application number: EP98901947A
Authority: EP
Inventors: Wolfgang Ritter; Christian Priebe
Original assignee: Cognis Deutschland GmbH and Co KG
Current assignee: BASF Personal Care and Nutrition GmbH
Priority date: 1997-01-16
Filing date: 1998-01-07
Publication date: 1999-11-03
Also published as: DE19701325A1; WO1998031770A1

Abstract

The invention concerns a method of covering, securing and, if necessary, sealing soil or soil regions with polymer films which are watertight or water-repellant for a predeterminable amount of time. According to the invention, these polymer films are to be formed in situ on the regions to be covered in that the soil surface in question is first provided with a primer containing solids which are water-insoluble but swell and form a film on contact with water. The polymer film with increased watertightness is then produced as a cover layer on this primer in that previously formed polymer substances are applied in the form of melts, solutions, emulsions and/or dispersions of film-forming and optionally hardening polymer compounds and/or by the application of, in particular light- or UV-hardenable, monomers and/or corresponding macromers, with subsequent hardening. The method is used for covering areas of ground used for agricultural or forestry purposes, and also for forming permanent protective layers, in particular against the undesired ingress of water, for example, in the landscaping and protection of landfill sites and areas of water.

Description

Procedures for securing ground areas

The use of sheet-like plastic tarpaulins to protect the soil both on the surface of the soil and - in special areas of application - in lower-lying areas of the earth is currently being implemented to a large extent in the areas of agriculture and forestry as well as in more technical areas of application. Examples of the last-mentioned technical fields of application are, for example, the formation of landfill rooms or dumps with a permanently solid water-impermeable underlayer, as well as the surface covering of those landfill areas that are to be insulated against the ingress of rainwater. However, in the construction and regulation of standing and / or flowing water areas in private and commercial areas, corresponding floor seals with plastic films are of great practical importance today. The temporary cover with prefabricated plastic films is used today to a large extent to cover agricultural areas after the application of seeds, e.g. to protect against wind and / or water erosion, at least for the period in which sufficient soil consolidation through plant roots is not yet ensured. However, further goals with such a film cover are also sought, particularly in the agricultural sector. Thus, at least in the early phase of plant growth, the film cover can be used to control the microclimate on the soil surface in the sense of growth-promoting climatic conditions. Sunshine on films containing black pigments, for example, heats the surface area near the surface and preserves this microclimate situation for comparatively longer periods of time. For further advantages and disadvantages of the field of work mentioned here, reference can be made to the relevant specialist knowledge become. The following points are only taken as examples:

Prefabricated plastic films restrict the use of potentially suitable synthetic plastics to the classes that are suitable for large-scale film production. In particular, these are polyolefins. Large-scale plastic sheets require sufficient mechanical strengthening against wind influences. Even a short-term potentiation of these wind forces, e.g. in the context of a thunderstorm, the large-area protective sheets can be torn off. When covering irrigated cultural areas with preformed plastic sheets, care must be taken to ensure that the covered soil surface can be sufficiently moistened by natural and / or artificial irrigation. The sealing of the ground against water penetration - for example in the landfill area or in the area of standing or flowing water - requires the reliable and permanent welding of the plastic sheets lying next to each other in the area affected by the water. Basically, the following applies: The flat plastic film with only limited elasticity can only adapt to more complicated spatial shapes of the area to be covered to a limited extent, so that in practice there are always smaller or larger cavities between the covered floor surface and the plastic tarpaulin, which can trigger secondary faults.

The teaching of the invention described in the following is based on the task of showing a new way with which numerous restrictions of the technology which is common today for protecting soil surfaces in the field of agriculture and forestry can be better overcome. At the same time, however, it should also be possible to use the new technology in the previously described more technical areas of application and to make it easier here. The principle of the technical solution described in the following in the sense of the teaching according to the invention is thereby characterized by the overarching idea of the "in situ formation" of a polymer film of increased water resistance on the surface to be covered. In important embodiments, this can involve the in-situ formation of an at least largely water-resistant polymer film. The solution according to the invention provides that the plastic material ultimately forming the cover layer is formed in an intermediate step. to be applied, as it were, as a "liquid tarpaulin" and to be solidified as a water-repellent cover layer in the space shape that forms.

With the implementation of this concept, a multifaceted optimization and adaptation of the soil protection technology involved here is possible in a previously unknown form. The selection of the plastic used in each individual case is no longer restricted to those plastic classes that can be processed into polymer films using today's technology. The film cover on the way over the liquid tarpaulin can be designed to be limited in time and / or space and / or unlimited. Details of this are given in the description of the invention below. The type and thickness of the film cover can be optimally adapted to the stresses to be expected in the respective specific area of application.

The following applies to the technical realization of the advantages and concepts given here only in part in the sense of the teaching according to the invention:

Subject of the invention

In a first embodiment, the subject matter of the invention is a method for covering, fastening and, if appropriate, sealing soil with water-repellent polymer films, this method being characterized in that the areas to be covered are first of all equipped with a primer containing water-insoluble, but swelling and filming solids upon ingress of water and subsequently as a top layer, the water-repellent polymer film by applying melts, solutions, emulsions and / or dispersions of prefabricated filming and optionally curing polymer compounds and / or by applying in particular light- or UV-curable monomers and / or corresponding macromers with subsequent curing in situ generated.

In further embodiments, the invention relates to the use of this method to cover agricultural or forestry soil areas, and preferably to protect the soil surface for a limited period of time, in particular during the early growth phase of plant material against uncontrolled desired wind and / or water erosion as well as for other promotion of plant growth.

The teaching according to the invention further relates to the use of the previously described method for forming permanent protective layers, in particular against unwanted water penetration e.g. in the creation and protection of landfill areas, bodies of water and the like.

Details of the teaching according to the invention

The technical solution to the concept described at the outset for the teaching according to the invention is primarily mastered by the following combination of features:

The in situ formation of the water-repellent protective film by means of the intermediate formation of the liquid tarpaulin provides for the floor areas to be covered to be provided with multiple layers. Before the application or formation of the water-repellent polymer film, the earth areas to be covered are first equipped with a primer. A variety of feedstocks can be considered as valuable materials for the formation of this primer. The same applies here to the group of suitable auxiliaries that these are at least partially, preferably at least predominantly water-insoluble, but swelling and filming solids when exposed to water. These solids are applied in sufficient quantities, preferably in finely divided application form, either as a free-flowing solid and / or in the form of a water-containing, swollen material to the soil surfaces to be treated. These primers are capable of filming according to the definition according to the invention. In direct contact with the surface of the floor, a filmed and at least temporarily water-swollen primer layer is formed, which prevents direct contact of the subsequently applied polymeric top layer of increased water resistance with the surface of the floor. The advantages of this measure include: The polymer cover layer applied in the form of the "liquid tarpaulin" in the next step meets a closed surface, which prevents the flowable form of this liquid tarpaulin from penetrating into the structure of the floor surface. The amount of polymer to be applied as a water-repellent cover layer can thus be reduced to the minimum required in the individual case and thus optimized. In preferred and in the Following the described embodiments of the invention, the material layer of the primer is accessible to material degradation through natural degradation processes, but not - or not to a comparable extent - the material layer of the water-repellent polymeric top layer. The polymeric top layer solidified after application to the primer thus detaches from the adhesive bond to the floor surface to the extent that the primer layer is subject to degradation through natural degradation processes. The periods of time occurring in practice are largely controllable in the sense of the teaching according to the invention. Provided there is sufficient water resistance in the top layer, this will ultimately also make it easier to remove the water-insoluble polymer top layer from the surface of the floor as soon as it is no longer required here.

The importance of the primer layer is multifaceted and multifunctional, in particular in the area of the use of the teaching according to the invention in the agricultural and forestry sector and in landscape protection. Accordingly, the details of the formation and configuration of this primer layer are first discussed below.

Preferred basic components in the primer are water-swelling solids of natural origin, which are available on a large scale as finely divided material - in particular in powder form. Appropriate raw materials of plant origin are particularly suitable here. Examples include polysaccharides, polypeptides, wood constituents such as lignin and lignin derivatives as well as derivatives of the aforementioned valuable substances of natural origin. At least partially water-insoluble, but water-swellable, components of the type described, which have a certain adhesive effect - as water-containing, swollen but also as a re-dried product - can be particularly suitable. In practice, the primer applied to the floor surface therefore fulfills a partial condition, namely sufficient consolidation of loose or erosion-prone floor surfaces against the effects of wind and / or water. As will be explained in more detail below, the primer can also be applied over the entire area if considerations for sufficient moistening make a partially spatially open structure of the subsequent top layer of increased water resistance desirable. The binder or adhesive function of the primer provides substantial help in the area of work mentioned here. Accordingly, this first application layer is sometimes referred to below as "adhesive" in the sense of the teaching according to the invention.

Adhesives of plant origin which are particularly suitable according to the invention are essentially water-insoluble, but water-swellable protein fractions which have apparently not been proposed for the purpose of soil consolidation. The following applies in particular:

Feedstocks which are particularly suitable according to the invention for the primer are at least a predominant proportion of finely divided grinding products from the grinding of grain and / or legumes containing protein fractions of the type required here. Corresponding ground products from the grinding of wheat can be of particular importance.

Today's knowledge of cereals and cereal products provides extensive information on the different substance classes of cereal grains of different origins, especially based on wheat, rye, barley, oats, rice, millet, corn and the like. Reference is made, for example, to Belitz, Grosch "Textbook of Food Chemistry" 4th edition, 1992, pages 611-627. In addition to water, the grain contains especially starch and other carbohydrates, proteins, lipids, raw fibers and minerals. About 70 to 80 percent of the grain forms the flour body and the aleurone layer enveloping it. Fruit and seed husks enclose this nutrient tissue and the seedling. The protein content of conventional cereals is in the range from about 10 to 12% by weight.

Works by T.B. Osborne at the beginning of this century differentiated - depending on the solubility of the respective fraction - in particular four different protein fractions: the water-soluble albumins, the globulins soluble in saline solution, the prolamines soluble in highly concentrated aqueous ethanol and the gluteline remaining in the residue.

The grinding products of cereal grains or legumes, which predominantly contain prolamines and / or gluteline, are particularly suitable for use in the context of the teaching according to the invention. can be separated from grain as fine-grained dry ground products. Protein fractions containing prolamine and glutelin are no longer water-soluble, but are water-swellable and filmable in the case of the feed materials of this type preferred according to the invention.

As previously indicated, corresponding protein fractions based on the grain of wheat are the particularly preferred adhesives in the sense of the inventive method. The relevant technical language refers to the prolamine fraction of the wheat grain as gliadin and the higher molecular weight glutelin fraction as glutenin. Fine-grain, in particular powdery, in particular powdery, at least largely water-insoluble, but water-swellable wheat protein fractions are large-scale commercial products which have hitherto been used, for example, in the food and animal feed sectors. Due to their viscoelastic properties - pronounced elasticity and elasticity of the water-containing material - they also serve as binding and extrusion aids in this area.

In contrast, the teaching according to the invention provides for the sum of the specific properties of the protein fractions of plant origin concerned here to be used for the completely different field of primers in the course of finishing soil surfaces with essentially water-insoluble polymer films. The multifunctionality of this primer or adhesive can then be used in important areas of the teaching according to the invention. A number of mechanical / physical properties - very fine particles, rapid water absorption, thus development of the adhesive function and filmability - combine with structure-related secondary effects in the context of plant growth: the adhesive based on plant protein in the sense of the invention is at the same time valuable nitrogen fertilizer to promote the growth of microorganisms and thus to promote plant growth.

Basic materials designed according to the invention for the primer can be applied to the floor surfaces to be equipped in one or more stages. It is possible to apply these primers with an adhesive effect, in particular in the form of the dry product, based on the vegetable protein. bring, for example by sprinkling and / or by blowing the dry powder onto the surface to be treated. The filmed state of the primer layer can be formed here by subsequent irrigation. However, wet application of water-based preparation forms to the ground to be consolidated is also possible. For example, the adhesive can be stirred into an excess amount of water. To stabilize the swollen adhesive in the excess water, auxiliary substances with a stabilizing effect are expediently used. Suitable are the water-soluble and / or water-swelling protective colloids known to those skilled in the art, for example based on polyvinyl alcohol, starch, starch degradation products and / or derivatives of the substance classes mentioned here. In the sense of the action according to the invention, it may be expedient to use corresponding protective colloids of natural origin in order in this way to additionally limit the entry of synthetic chemistry into the surface of the soil and not to hinder plant growth. The stabilization of very finely divided polymeric substances with the aid of auxiliaries based on surfactants and / or on the basis of such protective colloids, in particular those related to natural substances, is general specialist knowledge to which reference can be made in the present context.

The implementation of this working step of the method according to the invention is, as already mentioned at the outset, not restricted to the use or the sole use of these adhesives based on vegetable proteins. Together with these proteins and / or instead of this class of substances, not only the above-mentioned organic water-swellable and film-forming components are suitable, but also the use or concomitant use of inorganic fine-particle inorganic materials that swell in particular when exposed to water. Appropriate input materials of natural and / or synthetic origin are suitable. Bentonite, clays and the like may be mentioned here merely by way of example.

The amounts of primer material to be applied in each case are determined by the soil structures specified in the respective case and the climatic origin, which is also natural and can be expected in the period of use. It has been shown that even with very small amounts of high-quality adhesive in the sense of the inventive action, a considerable Solidification and filming of the soil surface can be triggered. Application amounts of the primer in the range of at least 5 g / m ² , preferably at least up to 20 g / m ² and in particular at least 25 or 30 to 50 g / m ² are particularly suitable. Upper limits for the application of this primer layer are approximately 500 g / m ² , with lower application quantities being preferred, which are, for example, a maximum of 300 to 400 or 450 g / m ² . Application quantities in the range from approximately 50 to 250 and in particular in the range from approximately 100 to 200 g / m ² can be particularly suitable. These figures relate consistently to the dry powdery form of the primer and of course also depend to a certain extent on the specific density of the material used.

The formation of the binder effect through water absorption and filming is then in turn determined by the respective natural conditions. If the surface of the soil to be solidified is sufficiently damp or wet, then an additional application of water is not necessary. However, if the surface to be consolidated is dry, subsequent artificial irrigation of the coated soil surface can trigger the binder function. In the context of a special embodiment, it is also possible, however, to swell a still substantially dry layer of the primer applied to the bottom surface by subsequently applying the further class of substances forming the polymer film with increased water resistance in the form of aqueous emulsions and / or dispersions and filming the primer layer to enter the amount of water required in this material of the first application layer.

In a particular embodiment, the invention provides that, together with the valuable materials of the primer material and in particular the protein-based adhesives, additional auxiliaries are introduced into the soil to be covered and solidified. This additional addition of auxiliaries can take place simultaneously with the application of the primer in the sense of the teaching according to the invention, but it is also possible to apply the auxiliaries beforehand and / or subsequently to the floor surface. Auxiliaries include both components for promoting plant growth and components for promoting the effect of surface consolidation or the influencing of the physical nature of the surface consolidated by the primer. dress. Suitable additives are thus, for example, nutrients for plant growth, but in particular auxiliaries of the type of plasticizers for the adhesive layer formed. Examples include: glycerin, sorbitol, urea and ammonium salts. However, other film-forming polymer compounds which are known in particular from the field of soil stabilization can also be considered. But other components for controlling the physical properties of the surface strength of the floor can also be considered here. The teaching according to the invention provides in particular for the use of the elements which are described in a number of previously published property rights of the applicant, to which reference is expressly made here and the content of which is hereby also made the subject of the teaching according to the invention. Reference is made to the disclosure of DE-A 43 24 474, DE-A 44 28 269 and DE-A 195 48 314. The two publications mentioned first describe water-based and adhesion-promoting adhesives for finishing floor surfaces based on esters of polyvinyl alcohol with C 1 -C Monocarboxylic acids and / or their mixtures with higher monocarboxylic acids, if desired with the use of components which harden when exposed to air, in order to increase the water resistance of the impregnating composition as biologically compatible adhesive components. The last-mentioned publication by the applicant modifies this method of surface consolidation of soil at risk of erosion in that the soil impregnation is developed in several stages to intensify the surface consolidation and an aqueous preparation is used at least in the first impregnation stage, the biologically compatible wetting agents for accelerating and / or intensifying the soil wetting contains with aqueous phase. Preferred wetting agents are surface-active compounds with HLB values of at least 7, preferably equal to or greater than 8, the use of corresponding nonionic wetting agents or wetting aids with HLB values in the range from 10 to 18 being particularly preferred. A particularly suitable class of biologically compatible wetting agents of this type are the alkyl (poly) glycosides, which are also known in the art as APG compounds. For the formation of the primer layer in the sense of the teaching according to the invention, use can additionally be made of all these elements or work instructions.

As described at the outset, the multilayer of the tarpaulin, which is designed in situ according to the invention, is an essential determining element for technical action. On the layer of the priming material is now applied in a separate step, the material for forming the polymeric top layer of increased water resistance. The primary closure of the floor surface provided by the primer layer according to the invention creates diverse and improved possibilities for the concrete design of this work step. Without the interposition of the primer layer according to the invention, to implement the principle of the liquid tarpaulin, for example, highly concentrated polymer dispersions - solids contents of approximately 50% by weight with viscosities greater than 5,000 mPas - would have to be applied to the substrate to be coated. However, the handling of such highly concentrated viscous polymer dispersions has considerable price consequences as well as handling disadvantages. In particular, however, the direct, permanent contact between the floor surface and the water-repellent polymer protective layer is the imperative consequence. The teaching according to the invention not only enables the separation between the floor surface and the water-repellent polymer substance - in particular triggered by natural degradation mechanisms on the adhesive substances of the primer layer - the sealing function of the primer or adhesive layer enables the use of the subsequent polymer substances in the form of highly mobile and easy-to-handle liquid phases. Suitable are on the one hand melting of the selected polymers, but also corresponding solutions in solvents, but above all the form of sufficiently mobile emulsions and / or dispersions, the polymer material in the form of very finely divided particles capable of filming, especially in an aqueous base, emulsifying as a liquid phase or is dispersed. Reference can be made to the general specialist knowledge of such polymer preparations, in particular in the form of aqueous emulsions or dispersions.

Basically, two embodiments are again to be defined here, which according to the invention can be used separately or in combination with one another. In a first embodiment, the polymer compounds are pre-formed in the desired molecular weight range and are only applied to the pretreated floor surface in one of the flowable forms shown. In a second embodiment, precursors of the polymer compounds ultimately required - and thus in particular corresponding monomeric and / or macromeric building blocks or elements - are linked to the Primed surface applied. In a manner known per se, the reaction of the monomers or macromers to the desired higher molecular weights is then triggered in situ, usually by using reaction-promoting systems, after the top layer has been formed. Here, too, reference can be made to the general specialist knowledge.

Suitable reactive systems are, in particular, light- or UV-curable monomers or macromers. However, other reactive systems can also be used here, as described, for example, in the aforementioned DE-A-44 28 269. Here, for example, it is proposed to use fatty acids, fatty alcohols and / or their at least largely water-insoluble esters, ethers and / or salts as stabilizers to increase the water resistance of soil impregnations based on polyvinyl acetate and comparable esters of polyvinyl alcohol use with lower monocarboxylic acids.

The choice of the type of polymer to be used in the individual case of this essentially water-resistant and water-insoluble cover layer is largely determined by the specific requirements imposed in the respective application. Here is an essential element for the technical progress to be set with the teaching according to the invention compared to the prior art.

The following list gives examples of potential representatives from the field of polymer compounds or reactive feedstocks for the in situ formation of the polymer substances, which are characterized by high or even permanent water resistance. Emulsion polymers of vinyl monomers, in particular PE emulsions, PVC emulsions, styrene / butadiene copolymers, block copolymers of styrene, polyacrylate and poly methacrylate copolymers, polyvinyl acetate-co-ethylene, polyvinyl acetate-co-, for example, are suitable here.

Vinyl laurate, poiyisobutylene and the like. Emulsion polymers of dienes such as butadiene, isoprene, chloroprene, latex, etc. are also suitable, but polyurethane dispersions which can be nonreactive or reactive, for example with NCO groups, are also suitable. Further examples of suitable polymer substances are alkyd resins with a low fat content, epoxy resins which are in particular cationic and cationic / light-cured or of the 2K type are hardened with dicarboxylic acids or bismercapto compounds, as well as polyurea and polysiloxanes. Suitable other classes for the formation of the non-degradable or controlled degradable cover layer are polysulfides or polyfatty acrylates.

In another embodiment, the teaching according to the invention provides that the resistance of the polymeric cover layer to the influence of water and other climatic conditions and, in particular, to natural degradation processes is controllably adjusted. In this embodiment, the water-repellent function is ensured in the primary phase after the polymer cover layer has been formed. Due to the nature and selection of the polymer substance, the at least partial degradation of this cover layer is then made possible at the same time in a subsequent secondary phase, in particular through natural degradation processes. Examples of the structure of such cover layers are, for example, polyvinyl acetate copolymers with high contents of vinyl acetate, which are, for example, at least 50% by weight and in particular at least 70% by weight, in each case based on the copolymer. Another example of such secondarily degradable polymer types are fat-modified alkyd resins with a high fat content, which here is preferably at least 40% by weight and preferably at least 50% by weight fat. Reference can be made here to the relevant specialist knowledge of such primarily water-repellent or even water-resistant polymer compounds, which are then subject to degradation due to aging processes.

The application quantities of these polymer components or their precursors can be controlled in the ranges previously specified for the application quantities of the insert components for forming the primer layer. Reference is hereby made to these numerical values given in detail. The proportions on the one hand of primer and on the other hand polymeric top layer materials to be applied according to the invention can be the same or different. The individual case determines the adaptation to the specified requirements of the floor surface to be coated and the requirements for the service life and functionality of the finished multi-layer coatings in practical use.

The following differing circumstances immediately illuminate here: Should the method according to the invention be used for training purposes? Fertilize permanent protective layers, especially against unwanted water penetration, for example in the installation and / or protection in the landfill area, when equipping water bodies and the like, then the water-impermeable polymer protective layer is designed in an optimized manner in terms of type and quantity so that the functionality of the seal over the required long periods of use are ensured. In particular, polymer types that are resistant to microbial degradation processes should be selected. The protective layers are applied in a closed cover and can, if desired - in relation to the water-impermeable polymer layer - also be made in one layer or in multiple layers.

On the other hand, if the method according to the invention is used in the field of agriculture and / or forestry to cover areas of earth on which plant growth is to be promoted, then only the temporary functionality of the tarpaulin is required here. The type of water-repellent polymer compounds to be used here does not therefore have to meet the stability criteria of the previously mentioned working range. This affects the formation of the water-insoluble polymeric cover film by type and quantity. In addition, as already mentioned at the beginning, provision can be made here to provide targeted vacancies in the formation of the cover foils in order to allow or allow water to enter the area of plant growth. It is immediately understandable that here there is complete freedom to the extent and shape of the corresponding foil models.

The use of initially impermeable and in situ formed film cover layers can be of interest especially for the last-mentioned working area, which is partially or entirely accessible to a partial degradation mechanism with the formation of a porous and in particular microporous film structure or also to the time-controlled complete degradation. Here, living conditions adapted to the respective plant progress can be created for the different phases of the plant growth to be protected according to the invention.

Other auxiliaries can also be used together with the film-forming cover layer polymers in the sense of the invention. To be mentioned here, in addition to plasticizers, in particular structure formers, where fibrous structure formers - for example corresponding materials of plant origin - can prove to be particularly suitable. Another example of auxiliaries of the type to be provided here are pigments which control the energy absorption when the sun is shining into the film and thus into the covered soil area and thus enable the formation of the microclimate in the immediate growth area of the plant.

B e i s p i e l e

In the examples below, the formation of the primer in the sense of the definition according to the invention is first described in various embodiments, examples 1a to f. The following examples then show selected specific work instructions for applying the liquid tarpaulin and converting it into a polymer film that is mechanically and water-resistant in the sense of the top layer defined according to the invention.

The protein glue used to form the primer layer in Example 1 is a protein glue of natural origin, which is powdery in the dry state and obtained from wheat by wet grinding. In all examples, the material sold under the protected trade name "VITEN de ble" by ROQUETTE GmbH, Frankfurt, FRG, is used, which has a raw protein content of 75 to 80% by weight and a moisture content of approx. 8% .-% contains a residual starch content of about 10 wt .-% together with minerals and fatty substances.

When added to water, this wheat-based protein glue quickly absorbs about twice its own weight in water. A viscoelastic material capable of filming is formed on the basis of the two comparatively high molecular protein fractions glutenin and gliadin.

Example 1 a

A plastic bowl with the following dimensions: 26 cm x 32 cm x 20 cm (length, width, depth) is filled with sand with a maximum grain diameter of 2 mm. The surface of the sand filling is leveled and 4.2 g (corresponding to 50 g / m ² ) of the dry wheat protein powder are evenly sprinkled on with a sieve (mesh size 400 micrometers). Then 166 ml of water - corresponding to 2 l / m ² - are sprayed evenly onto the surface of the sand equipped with the protein adhesive using a spray bottle. After drying, a hard, brittle and detachable 3 to 6 mm thick material layer is obtained, which withstands a loading pressure of 100 N / cm ² .

Example 1 b

The test field is prepared as described in Example 1a. With the help of the sieve, 16.6 g of the protein glue based on wheat - corresponding to 200 g / m ² - is applied. Then, as in Example 1, by adding water in the amount corresponding to Example 1, the material layer containing protein glue is soaked and glued.

After drying, a hard, brittle and easily removable, 3 to 6 mm thick layer is obtained, which withstands a loading pressure of 292 N / cm ² .

Example 1 c

According to Example 1 a prepared sand surface is sprinkled homogeneously with the sieve 16.6 g (corresponding to 200 g / m ² ) of the protein glue in dry form. The subsequent moistening is carried out with a 10% glycerol / water solution in an amount of 166 ml (corresponding to 2 l / m ² ).

After drying, a flexible, soft, adaptable and easily removable, 3 to 6 mm thick top layer is obtained, which withstands a pressure of up to 142 N / cm ² .

Example 1 d

The acc. Example 1 a prepared sand surface is equipped with the dry protein glue in an amount of 41.6 g (corresponding to 500 g / m ² ) by discharge through the sieve. Subsequently, a thin liquid polyvinyl acetate dispersion ("Wormalit PM 4265", Cordes, solids content 49.3%; viscosity 750 mPas) in an amount of 84.4 g - corresponding to 1014 g / m ² aqueous dispersion or 500 g / m2 solid - applied evenly.

After drying, a 3 to 6 mm thick, very hard top layer forms, which can be easily detached from the sand underneath. Example 1 e

According to Example 1 a pretreated sand surface, 16.6 g of the protein glue (corresponding to 200 g / m ² ) are applied. A 10% by weight glycerol / water solution is then applied in an amount of 166 ml (corresponding to 2 l / m ² ). After drying, 166 g of the following mixture are applied: 28.6 g Terracontrol SC 823 (57.5% by weight polyvinyl acetate dispersion, commercial product from the applicant), 2.9 g triacetin and 134.2 g water. This corresponds to an order of 200 g / m ^{2 of} polyvinyl acetate.

After drying, you get a 3 to 4 mm thick, very hard layer that is flexible and adaptable to the surface. It withstands a maximum load pressure of 1,183 N / cm ² .

Example 1 f

According to Example 1 a prepared sand surface, 16.6 g calcium lignin sulfonate - corresponding to 200 g / m ² - (commercial product "Collex XM / XB 120" from Ligno Tech GmbH) is applied with the aid of the sieve. Then 166 g of a 10% by weight polyvinyl acetate dispersion (commercial product 'Terracontrol SC 823 "diluted to 10% by weight with water) are applied using a spray bottle. The amount applied corresponds to a coating with 200 g / m ^{2 of} polyvinyl acetate.

After drying, a very hard, 7 to 11 mm thick layer is obtained.

Example 2

According to Example 1 a equipped sand surface after drying, 33.2 g of an aqueous polyacrylate dispersion (commercial product "Acronal 80 D" from BASF with a solids content of 50% by weight) are applied. This corresponds to an order of 200 g / m ² polyacrylate solid.

When this aqueous dispersion dries up, the polymer portion films into a closed, solid and watertight cover layer, and the multi-layer cover layer formed can easily be lifted off the sand. Example 3

According to Example 1 c finished sand surface after drying the primer layer 16.6 g of a mixture of 70 wt .-% tripropylene glycol diacrylate, 29 wt .-% ethylhexyl acrylate and 1 wt .-% of a UV photoinitiator of the benzophenone type (commercial product "Darocor 4665" from Merck) with a squirt bottle. The sand surface thus equipped is exposed to the action of the midday sun. The formation of a polyacrylate layer can be seen after about 1 hour.

The primer layer based on the wheat protein and the polyacrylate layer stick together and form a soft, flexible, easily removable film with a thickness of 3 to 4 mm.

Example 4

The acc. Example 1 c equipped sand surface, 41.5 g of a 70% by weight solution of an aliphatic urethane diacrylate (commercial product "Photomer 6210" from the applicant) in tripropylene glycol diacrylate are subsequently applied using a spray bottle. The solution contains 2% by weight of the benzophenone-type UV photoinitiator as a starter. Example 3. The amount of polymer-forming solid applied corresponds to the conversion of 500 g / m ² . Here, too, the polymerization and solidification of the waterproof cover layer is brought about by the action of sunlight.

A flexible, hard and easily removable layer with a total thickness of 3 to 5 mm is obtained.

Example 5

According to Example 1c, the sand surface is prepared with the protein adhesive. Using a spray device, 16.6 g (corresponding to 200 g / m ² ) of a mixture of 15.9 g Edenol D 81 (soybean oil epoxy commercial product from the applicant) and 0.7 g Cyracure UVI 6990 (triarylsulfonium hexafluorophosphate salt in 50% Propylene carbonate, commercial product from Union Carbide) sprayed on finely. The area is exposed to a UV light lamp for 7 minutes. After curing, a 3 to 6 mm thick flexible cover layer is obtained. Example 6

According to Example 1c, the sand surface is prepared with the protein adhesive. Using a spray device, 16.6 g (corresponding to 200 g / m ² ) of a mixture of 15.9 g of Rütapox EPD-TP (reaction product of trimethylopropane with epichlorohydrin, commercial product from Bakelite) and 0.7 g of Cyracure UVI 6990 (triarylsulfonium -Hexafluorophosphate salt in 50% propylene carbonate, commercial product from Union Carbide) sprayed on finely. The area is exposed to a UV light lamp for 7 minutes. After curing, a 3 to 6 mm thick top layer is obtained.

Claims

Expectations

1. A method for covering, fastening and, if desired, sealing of soil with water-repellent polymer films, characterized in that the areas to be covered are initially equipped with a primer containing water-insoluble but swelling and filming solids and then as a top layer the polymer film with increased water resistance by application of melts, solutions, emulsions and / or dispersions of prefabricated filming and optionally curing polymer compounds and / or by applying in particular light- or UV-curable monomers and / or corresponding macromers and subsequent curing in situ.

2. The method according to claim 1, characterized in that in the primer water-swelling solids of natural origin such as polysaccharides, polypeptides, lignin and / or their derivatives, but in particular proteins of plant origin are used, which in their dry form are preferably formed as finely divided powders .

3. The method according to claims 1 and 2, characterized in that for the at least predominant proportion protein fractions of the specified type containing finely divided ground products from the grinding of grain and / or legumes are used as a primer.

4. Process according to Claims 1 to 3, characterized in that fine-grained ground products from the wet grinding of cereals and in particular corresponding fractions from the grinding of wheat are predominantly used as the protein of plant origin, which contains prolamine and / or gluteline.

5. Process according to Claims 1 to 4, characterized in that proteins of plant origin largely freed from starch are used in powder form to form the primer of starch components and are either initially applied as a dry product to the ground surface to be solidified. brought and then filmed here by applying water and / or applied directly as water-containing material, in which case the use of water-containing preparations is preferred which contain the protein-based swellable material together with biodegradable protective colloids.

6. The method according to claims 1 to 5, characterized in that the solids forming the primer are applied in amounts - based on free-flowing dry product - from 5 to 500 g / m ² , with amounts of at least 30 to 50 g / m ² at a upper application limit in the range of 300 to 400 g / m ^{2 are} preferred.

7. The method according to claims 1 to 6, characterized in that together with the primer-forming water-swelling and filming solids - before, at the same time with and / or subsequently to their application to the surface to be fastened - further auxiliaries such as plasticizers, other water-soluble and / or swellable polymer compounds of natural and / or synthetic origin, structure formers based in particular on fibers of natural and / or synthetic origin, but if desired also nutrients for plant growth can be applied.

8. The method according to claims 1 to 7, characterized in that in the formation of the primer as an additional polymer component of synthetic origin, polymer compounds based on polyvinyl acetate and / or propionate and / or based on copolymers of these lower vinyl esters with vinyl esters of higher fatty acids, especially vinyl laurate, are used, the application amounts of these further components of the primer layer in relation to the swellable protein being in the range from 90:10 to 10:90, but preferably not significantly exceeding the proportion of protein primer and in particular being less.

9. The method according to claims 1 to 8, characterized in that the polymer-based cover layers of synthetic origin with predetermined resistance to and / or with timed degradation through natural degradation processes.

10. The method according to claims 1 to 9, characterized in that the polymer-based cover layers of synthetic origin by applying aqueous emulsions and / or dispersions of preformed polymeric films such as emulsion polymers of vinyl monomers and / or dienes, polyurethane dispersions, alkyd resin -Dispersions, corresponding preparations of polysulfides or polyfatty acrylates, or by applying in particular light-curing monomers and / or macromers, such as UV acrylics, polyurethane acrylates and / or epoxy formers.

11. The method according to claims 1 to 10, characterized in that the film-forming top layer polymers further auxiliaries such as plasticizers, structure formers, in particular in fiber form and / or pigments for controlling the microclimate in the upper soil region are added.

12. The method according to claims 1 to 11, characterized in that the in situ formed top layers of increased water resistance to the pre-formed primer layer in amounts of 5 to 500 g / m ² , preferably in amounts of at least 10 to 50 g / m ² with further preferred Upper limits of the top coat application in the range of 300 to 400 g / m ^{2 are} applied.

13. Application of the method according to claims 1 to 12 for covering agricultural or forestry soil areas, preferably for the temporary protection of the soil surface, especially during the early growth phase of plant material.

14. Application of the method according to claims 1 to 12 for the formation of permanent protective layers, in particular against unwanted water penetration, e.g. in the creation and protection of landfill areas and surface waters.