EP1996765A1

EP1996765A1 - Method for fixing traffic routes

Info

Publication number: EP1996765A1
Application number: EP07726737A
Authority: EP
Inventors: Joachim Roser; Helmut Tesch; Hans Ulrich Schmidt; Andrea Eisenhardt; Johann Leitner; Hans-Jürgen Reese
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2006-03-15
Filing date: 2007-03-09
Publication date: 2008-12-03
Also published as: JP2009530515A; US20090095820A1; WO2007104710A1; KR20080106549A; CN101400857A

Abstract

The invention relates to a method for fixing traffic routes, which is characterised in that at least one plastic material is applied to the surface and/or to the inside of the traffic route.

Description

Method for fixing traffic routes

description

The invention relates to a method for fixing traffic routes, preferably railway lines, roads and unpaved roads.

Roads, such as railway tracks, roads and unpaved roads, consist to a large extent of loose particles. For example, railway lines usually have a potty bed. Unpaved roads and paths have mostly loose sand or dust on their surface. It is often necessary to fix these particles. In railway lines loose gravel stones can be whirled up and thus lead to problems. In particular, fast-moving trains, such as ICE trains swirl the stones below each other so that the subsoil is damaged. This is because the track beds in many countries are not as deep as in Germany. Lowering, however, would involve an additional cost.

Another problem is the attachment of unpaved roads and paths. These are mostly covered with dust, sand or gravel. When driving on it may come to a dust whirling up or throwing stones. This leads to a burden on the environment and also to pollution of the vehicles, which in turn can lead to their increased wear. Flying stones can also cause injuries to passers-by. In addition, there is a heavy load on the unpaved roads. In particular, it can lead to the formation of ruts. This is undesirable because deep ruts can cause damage to the vehicles and accumulate water in the ruts, resulting in damage to the paths.

Another problem is the repair and attachment of roads. Even paved roads are subject to wear, which can lead to a relaxation of the materials used for road construction. Here a complete repair is often expensive and time consuming.

From the prior art, a number of ways are known to secure such traffic routes. In the field of railroad track fastening, ballast bonding technology has become an established technology. The bonding serves to prevent the ballast flight, the stabilization of the track bed and the securing of the operating tracks in track construction work. In this method, the track ballast is usually first applied to the ballast bed. Subsequently, the ballast is then wetted in a spray process with a self-curing adhesive. As an adhesive is often used epoxy, but also acrylates and polyurethanes are used. Thus, WO 2004/079094 describes the attachment of rock fillings, such as railway embankments, by gluing these with plastics and installing an insert inside the rock fillets.

DE 197 29 348 describes a method for producing a closed, drainable ballast in track construction. In this case, the upper layer of the ballast is covered with a cavity filling the filling layer. The filling compound can also be applied as a layer up to 10 cm high on the ballast. Bulk material with a particle size of 1 to 16 mm, the particles of which are covered with an adhesive film, is used as the filling material. As adhesives, for example, epoxy resins or polyurethanes are used.

DE 198 1 1 838 describes a method and apparatus for solidifying ballast beds. A liquid hardening mass is injected into the ballast bed. The consolidation compound may also be a polyurethane. A similar process is also described in US 4156440.

In CH 595512 a method for stabilization and vibration damping of railway lines is described in which a foamable polyurethane mixture is introduced into the track bed, where it hardens to foam.

The attachment of loose soil by applying plastics is known. So it is known to attach loose rock formations with plastics, for example in mining or for the attachment of surfaces. In this case, different plastics can be used, for example polyesters, polyacrylates or polyurethanes.

DE 197 03 980 describes the use of biodegradable plastics for fixing soil. Here, a planting of the soil is to be achieved by this is stabilized. For the stabilization of unpaved roads, however, the decomposition of the plastic layer should just be avoided.

No. 3,719,050 describes the stabilization of soils using polyurethane prepolymers. These prepolymers should preferably be water repellent. The curing takes place by means of water. This results in a foaming of the polyurethane, which is disadvantageous for the attachment of unpaved paths. Furthermore, the polyureas formed in the reaction of the prepolymers with water are not hydrophobic, so that they offer no protection against water and can also be hydrolytically decomposed.

The task was to safely secure traffic routes and avoid so that it comes to a whirling up of particles. Furthermore, the wear on the routes are reduced. The attachment should be possible by a simple process and not cause environmental problems. The traffic routes should continue to be equipped so that the attack by water is minimized.

The object could surprisingly be solved by the fact that there is a hydrophobic polyurethane on the surface and / or inside the guideway.

The subject matter of the invention is a method for fastening driveways, characterized in that at least one plastic, in particular a hydrophobic polyurethane, is brought onto the surface and / or into the interior of the driveway.

In many applications, both in track tracks and on unpaved roads and paths and also in the repair of roads, the application of the hydrophobic polyurethane on the surface of the traffic route is sufficient. The application of the polyurethane can be accomplished in the simplest case by applying the liquid feed components of the polyurethane by spraying or by pouring onto the driveway, where they harden to polyurethane. Preference is given to spraying, as less material is consumed. The spraying can be done by vehicles or manually.

In a particular embodiment of the method according to the invention, in particular for thicker layers of loose particles, the plastic is introduced into the layer. This embodiment is preferably used in tracks.

This can be done, for example, by wetting the particles, in the case of ballast of the ballast, with the liquid feed components of the plastic in a mixer and spreading the wetted particles on the roadway where the feed components cure to polyurethane.

The loose stones are preferably gravel, as commonly used for the production of track beds. The size of the gravel stones depends on the load on the tracks. Usually, the size of the ballast stones is approximately between 30 and 70 mm. They are preferably made of hard rock, such as basalt.

As a mixer for mixing the ballast stones with the starting components of the plastic, in principle, all types of mixers can be used with which a substantially complete wetting of the ballast stones with the liquid starting components of the plastic is possible. Mixers have proven particularly suitable which consist of an open container, for example a drum, which is preferably provided with internals. For mixing, either the drum can be rotated or the internals moved. Such mixers are known and used for example in the construction industry for the production of concrete mixtures.

For applying the mixture to the surface to be fixed, it may be advantageous to attach the mixer to a vehicle, for example a tractor, a front loader, a truck or a rail vehicle. In this embodiment of the method according to the invention, the mixture can each be transported to the place where it is to be applied. After emptying the mixer, if necessary, the mixture can be distributed manually, for example by raking, to achieve the desired structure.

In one embodiment of the method according to the invention, the mixture of the stones is carried out continuously with the liquid starting components of the plastic. For this purpose, the stones and the liquid starting components of the plastic are continuously lent into the mixer and the wetted stones are discharged continuously. In this procedure, care must be taken that the starting materials remain in the mixer for so long that sufficient wetting of the stones can take place. Conveniently, such a mixing device can be moved along the track bed to be fastened at such a speed that the stones wetted with the liquid starting components of the plastic are discharged from the mixer in an amount as needed. It is also possible to operate the continuous mixing device stationary and to transport the wetted stones discharged from the mixer to the desired location.

In a further embodiment of the continuous embodiment of the method according to the invention, the mixer may be a rotating drum into which stones are continuously introduced. This drum is equipped with nozzles that continuously distribute the starting components of the plastic on the stones. The rotation of the drum ensures good mixing of plastic and stones. Through an opening at the end of the drum plastic / stone composites are then continuously discharged. The rotating drum can be horizontal, but also inclined at different angles to promote the discharge.

In a further embodiment of the continuous process, the stones are transported continuously on a conveyor belt which is driven through a tunnel. This has openings through which the starting materials of the plastic are continuously discharged onto the stones. At the end of the conveyor belt, the wetted stones fall onto the track or into an open drum, which discharges the composite onto the track at an adjustable conveying speed. Preferably, the entire ballast bed is attached to the plastic. It is also possible to fix only the upper layer of the ballast bed, preferably up to 20 cm, with the plastic. In this embodiment as well, either the ballast bed can first be heaped up without plastic and then the liquid starting components of the plastic are applied or initially only a part of the ballast bed is poured and, as described above, a layer of stones mixed with the liquid starting components of the plastic become.

Polyurethanes, epoxy resins, unsaturated polyester resins, acrylates and methacrylates can be used as plastics.

In a preferred embodiment of the invention, hydrophobic, substantially compact polyurethanes are used as plastics.

The following can be said of the hydrophobic polyurethanes which are preferably used.

As structural components of the hydrophobic polyurethanes, compounds with free isocyanate groups and compounds with groups which are reactive with isocyanate groups are understood in general terms. Groups which are reactive with isocyanate groups are usually hydroxyl groups or amino groups. Preference is given to hydroxyl groups, since the amino groups are very reactive and therefore the reaction mixture must be processed rapidly. The products formed by the reaction of these structural components are generally referred to below as polyurethanes.

When applying the structural components for the hydrophobic polyurethanes, it is not necessary for the top layer of the unpaved road or the stones of the track bed to be dry. Surprisingly, even in the presence of wet stones, it is possible to obtain good adhesion between the polyurethane and the bricks. The curing of the hydrophobic polyurethane can be done even under water, as well as puddles on the unpaved roads do not significantly affect the deployment of the polyurethane.

As polyisocyanates, it is possible in principle to use all liquid polyisocyanates, mixtures and prepolymers having at least two isocyanate groups which are liquid at room temperature.

Aromatic polyisocyanates are preferably used, particularly preferably isomers of tolylene diisocyanate (TDI) and of diphenylmethane diisocyanate (MDI), in particular mixtures of MDI and polyphenylene polymethylene polyisocyanates (crude MDI). The polyisocyanates may also be modified, for example by the incorporation of isocyanurate groups and in particular by the incorporation of Urethane groups. The latter compounds are prepared by reacting polyisocyanates with a deficit of compounds having at least two active hydrogen atoms and commonly referred to as NCO prepolymers. Their NCO content is usually in the range between 2 and 29 wt .-%.

A disadvantage of the use of aromatic polyisocyanates is the insufficient color stability of the polyurethanes produced therefrom. In most cases, over time, yellowing of the polyurethanes occurs. In applications of the process according to the invention, in which high color stability is important, the use of aliphatic polyisocyanates is therefore preferred. Preferred representatives are hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI). Due to the high volatility of aliphatic polyisocyanates, these are usually used in the form of their reaction products, in particular as biurets, allophanates or isocyanurates.

As compounds having at least two isocyanate-reactive hydrogen atoms, polyfunctional alcohols, so-called polyols, or, less preferably, polyfunctional amines, are generally used.

The hydrophobicity of the polyurethanes used can be brought about in particular by addition of hydroxyl-functional oleochemical components to at least one of the starting components of the polyurethane system, preferably to the polyol component.

A number of hydroxyl functional oleochemical components are known which can be used. Examples are castor oil, hydroxyl group-modified oils such as grapeseed oil, black cumin oil, pumpkin seed oil, borage seed oil, soybean oil, wheat germ oil, rapeseed oil, sunflower oil, peanut oil, apricot kernel oil, pistachio kernel oil, almond oil, olive oil, macadamia nut oil, avocado oil, sea buckthorn oil, sesame oil, hazelnut oil, evening primrose oil, wild rose oil , Hemp oil, thistle oil, walnut oil, hydroxyl-modified fatty acid esters based on myristoleic, palmitoleic, oleic, vaccenic, petroselinic, gadoleic, erucic, nervonic, linoleic, linolenic, stearidonic, arachidonic, timnonic, clondanoic, cervonic The castor oil and its reaction products with alkylene oxides or ketone-formaldehyde resins are preferably used here. The latter compounds are, for example, sold by Bayer AG under the name Desmophen ^® 1150.

A further preferred group of oleochemical polyols can be obtained by ring opening of epoxidized fatty acid esters with simultaneous reaction with alcohols and optionally following further transesterification reactions. The incorporation of hydroxyl groups in oils and fats is carried out mainly by Epoxidation of the olefinic double bond contained in these products followed by reaction of the epoxide groups formed with a monohydric or polyhydric alcohol. In this case, the epoxide ring becomes a hydroxyl group or, in the case of polyfunctional alcohols, a structure with a higher number of OH groups. Since oils and fats are usually glycerol esters, parallel transesterification reactions take place in the reactions mentioned above. The compounds thus obtained preferably have a molecular weight in the range between 500 and 1500 g / mol. Such products are offered for example by the company Henkel.

In a particularly preferred embodiment of the process according to the invention, a compact polyurethane is used which can be prepared by reacting polyisocyanates with compounds having at least two isocyanate-reactive hydrogen atoms, characterized in that the compounds having at least two reactive hydrogen atoms are at least one fatty chemical. a polyol and at least one phenol-modified aromatic hydrocarbon resin, in particular an indene coumarone resin. These polyurethanes and their structural components have such a high hydrophobicity that they can in principle be cured even under water.

As phenol-modified aromatic hydrocarbon resins having a terminal phenol group, preference is given to using phenol-modified indene-coumarone resins, more preferably technical mixtures of aromatic hydrocarbon resins, in particular those containing as essential constituent compounds of the general formula (I)

with n from 2 to 28 included. Such products are commercially available and are offered for example by Rutgers VFT AG under the trade name NOVARES ^®.

The phenol-modified aromatic hydrocarbon resins, in particular the phenol-modified indene-coumarone resins, usually have an OH content between 0.5 and 5.0 wt .-% on.

Preferably, the fat chemical polyol and the phenol-modified aromatic hydrocarbon resin, especially the indene-coumarone resin, are used in a weight ratio of 100: 1 to 100: 50. Together with the compounds mentioned further compounds having at least two active hydrogen atoms can be used. Due to their high hydrolysis resistance, polyether alcohols are preferred. These are prepared by customary and known processes, usually by addition of alkylene oxides to H-functional starter substances. The co-used polyether alcohols preferably have a functionality of at least 3 and a hydroxyl value of at least 400 mgKOH / g, preferably at least 600 mgKOH / g, in particular in the range of 400 to 1000 mgKOH / g. They are prepared in the usual way by reaction of at least trifunctional starting substances with alkylene oxides. Starting substances which may be used are preferably alcohols having at least three hydroxyl groups in the molecule, for example glycerol, trimethylolpropane, pentaerythritol, sorbitol, sucrose. The alkylene oxide used is preferably propylene oxide.

Other customary constituents may be added to the reaction mixture, for example catalysts and customary auxiliaries and additives. In particular, desiccants, for example zeolites, should be added to the reaction mixture in order to avoid the accumulation of water in the components and thus foaming of the polyurethanes. The addition of these substances is preferably carried out to the compounds having at least two hydrogen atoms reactive with isocyanate groups. This blend is often referred to in the art as a polyol component. To improve the long-term stability of composites, it is also advantageous to add anti-microbial agents. In addition, the addition of UV stabilizers is advantageous in order to avoid embrittlement of the moldings.

The polyurethanes used can in principle be prepared without the presence of catalysts. To improve the curing catalysts can be used. As catalysts should preferably be selected those which cause the longest possible reaction time. This makes it possible for the reaction mixture to remain liquid for a long time. In principle, as described, it is possible to work without a catalyst.

The combination of the polyisocyanates with the compounds having at least two isocyanate-reactive hydrogen atoms should take place in such a ratio that a stoichiometric excess of isocyanate groups, preferably of at least 5%, in particular in the range between 5 and 60% is present.

The preferably used hydrophobic polyurethanes are characterized by a particularly good processability. Thus, these polyurethanes show a particularly good adhesion, especially on moist substrates such as wet rock, in particular granite gravel. The curing of the polyurethanes is practically compact despite the presence of water. The compact polyurethanes used show a completely compact curing even with thin layers. Thus, the polyurethanes preferably used are ideal for securing traffic routes. The bond between rock or sand and polyurethane is very strong. Furthermore, in particular when very hydrophobic polyurethanes are used, there is practically no hydrolytic degradation of the polyurethanes and thus a very long shelf life of the traffic routes fastened by the process according to the invention.

To carry out the process according to the invention, the polyisocyanates are preferably mixed with the compounds having at least two active hydrogen atoms and this mixture is mixed with the stones. In principle, both starting components of the polyurethane could be separately added to the stones and mixed together with them. In this case, however, uneven mixing and thus inadequate mechanical properties of the polyurethane can occur.

The mixing of the starting components of the polyurethane can be carried out in a known manner. In the simplest case, the components in the desired ratio in a vessel, such as a bucket, given mixed by simple stirring and then mixed in the mixing device with the stones. It is also possible to mix the starting components of the polyurethane in a mixing organ customary in polyurethane chemistry, for example a mixing head, and to bring this mixture into contact with the stones.

The attachment of traffic routes with the hydrophobic polyurethanes has a number of advantages.

The attachment has a longer service life, requires less repair effort and leads to a higher road safety than other plastics for this purpose. Due to their hydrophobicity frost damage is significantly suppressed, and there is no noticeable hydrolytic degradation. Rainwater drains from the paved roads according to the method of the invention.

The polyurethanes do not cause any ecological problems, so in principle you can fix not only road surfaces but also forest roads with these polyurethanes. Optionally, according to the inventive method also unpaved roads or slopes, such as runways and airstrips for aircraft, are coated. There, stirring up dust can cause damage to the engines. The attachment of ballast beds with the hydrophobic polyurethanes leads to time and cost savings on trains, as the trains can travel at regular speed, without causing damage.

Compared to lowering the track bed, the process is significantly cheaper because the adhesive can be applied directly to the ballast stones.

The hydrophobic system can, in contrast to the plastics used so far, also be processed in the rain and on damp substrates. This results in a not insignificant economic advantage, since waiting periods in wet weather omitted.

Despite the hardness of the bond, the water permeability of ballast beds treated according to the invention is fully retained owing to the punctiform bonding of the stones. This prevents the risk of leaching even in heavy rainfall. Washouts and frost damage are thus effectively prevented, especially the washing out is even lower with a hydrophobic PU system than with a non-hydrophobic plastic.

With the described mixing of the stones with the liquid starting components of the plastic has the advantage of a single process step, which in turn increases the efficiency of the process.

Claims

claims

1. A method for securing driveways, characterized in that on the surface and / or in the interior of the guideway at least one plastic, is brought.

2. The method according to claim 1, characterized in that the infrastructure is an unpaved road.

3. The method according to claim 1, characterized in that the track is the gravel bed of a track.

4. The method according to claim 1, characterized in that the plastic is a hydrophobic polyurethane.

5. The method according to claim 1, characterized in that the plastic is a hydrophobic polyurethane, which was prepared using aromatic polyisocyanates cyanates.

6. The method according to claim 1, characterized in that the plastic is a hydrophobic polyurethane, which was prepared using aliphatic polyisocyanates cyanates.

7. The method according to claim 1, characterized in that the plastic is applied to the surface of the traffic route.

8. The method according to claim 1, characterized in that the plastic is introduced into the interior of the traffic route.

9. The method according to claim 1, characterized in that the loose stones of the traffic route mixed with the liquid starting components of the plastic in a mixer and this mixture is applied to the traffic route.