NZ625147B2 - Repair method for road surfacings, in particular for open-pored asphalts - Google Patents

Abstract

The present disclosure relates to a method for repairing the surface layers for roads, paths and other traffic areas, in which a polymeric material is applied in an amount of at least 20 g/m2 to the damaged place, a first polyurethane reaction mixture (can contain additives) is applied in an amount of at least 80 g/m2 to the polymeric material and a mixture containing mineral aggregate and a second polyurethane reaction mixture is applied to the first polyurethane mixture and allowed to cure. The present disclosure further relates to a repair kit for repairing surface layers for roads, paths and other traffic areas. of at least 80 g/m2 to the polymeric material and a mixture containing mineral aggregate and a second polyurethane reaction mixture is applied to the first polyurethane mixture and allowed to cure. The present disclosure further relates to a repair kit for repairing surface layers for roads, paths and other traffic areas.

Description

PF 72503 Repair method for road surfacings, in particular for ored asphalts The present invention relates to a process for repairing top layers for roads, tracks, and other areas used by traffic, by applying an amount of at least 20 g/m2 of a polymeric material to the damaged site, applying an amount of at least 80 g/m2 of a first polyurethane reaction mixture to the polymeric material, and applying, to the first polyurethane reaction mixture, a mixture comprising mineral ate and a second polyurethane reaction mixture, and allowing the material to harden. The present invention further relates to a repair kit for repairing top layers for roads, tracks, and other areas used by traffic.

Heavy traffic, or the effects of ring, often cause(s) defects in road surfacing systems, examples being binder loss and potholes. if the ion is to avoid complete tion of the top layer, another possibility is to repair the defects by filling. The usual method for this is what is known as the hot-mix method using bitumen-bound mineral aggregates, or what is known as the ix method, using t-containing or emulsified bitumen and mineral aggregates. There are also approaches that use plastics-based mixtures with mineral aggregates.

In this context, CA 2236499 describes a resistant top layer for roads for the resurfacing of concrete, asphalt, brick, one, tile, and wood, based on polyurethanes. It is also le here to use dissolved, bitumen-based primers.

JP 02088802 bes a repair mixture for roads, where a polyurethane-based primer is d to the damaged site and a mixture of mineral aggregates and polyurethane prepolymer at maximum packing density is applied to said primer and the material is cured with steam.

The known processes have disadvantages due to a restricted lifetime caused by inadequate on.

Open—pore asphalts are used increasingly frequently in order to reduce noise, and they also have very good drainage performance; accumulation of water on the ~surface can therefore be avoided and, by way of example, the risk of aquapianing can be reduced.

However, said open-pore asphalts are very expensive and generally have lifetimes of only about 10 years. Unfortunately, there is at t only an inadequate range of ilities for the repair of defective top layers of open-pore asphalt, since known open-pore repair materials have only limited adhesion on open-pore asphalts. lf repair materials are used that are not open-pore, road noise increases, and water can 40 accumulate on the surface.

It was therefore an object 'of the present invention to provide a process for repairing top PF 72503 layers for roads, tracks, and other areas used by traffic which gives excellent adhesion to the substrate material and can be d out simply and rapidly. A particular object of the present invention was to provide a s for ing ore asphalt which provides very good adhesion values and has no effect on drainage capability or the reduction of road noise.

Said object is achieved via a process for repairing top layers for roads, tracks, and other areas used by traffic, by applying an amount of at least 20 g/m2 of a polymeric material to the damaged site, applying an amount of at least 80 g/m2 of a first , 1O polyurethane reaction mixture to the polymeric material, and applying, to the first ethane reaction mixture, a mixture comprising at least one mineral aggregate and a second polyurethane reaction mixture, and allowing the material to harden.

Polymeric material used preferably comprises a polymeric material with number- average molar mass of at least 500 g/mol, particularly ably of at least 1000 g/mol.

This polymeric material has groups and structures that adhere to rock and/or bitumen, for example acid groups, isocyanate groups, ester groups, acrylate groups, methyl methacrylate groups, phenol groups, phosphate groups, amide groups, epoxy groups, silane groups, soluble bitumen fractions, hydrophobic alkyl groups as side chains or in the main chain, modified fatty acid ester groups, fatty acid derivative groups, hydrophobic polyol groups, or amphiphilic structures, for example structures composed of alkyl chains with C-chain length greater than 4, and of hydrophilic or ionic terminal groups. It is particularly preferable that the polymeric material has urea groups and/or urethane groups, optionally alongside the groups that adhere to rock and/or bitumen. it is preferable that the polymeric materials used have been ved in a suitable solvent. Suitable solvents are lly those which not only have te properties for ving the polymeric material but also function as solvent or swelling agent for bitumen and evaporate sufficiently rapidly, and do not lead to any lasting damage to 3O the asphalt ing surfacing. Examples of these solvents are xylene, toluene, trichloroethene, solvent a, ed naphtha, enzene, oils, gasoline, diesel, acetone, methyl ethyl ketone, and also chlorinated andlor fluorinated solvents, where these can be used individually or in the form of mixtures.

The polymeric materials that can be used in the invention can also be used in the form of reaction mixtures, where the polymeric materials by way of example are produced only after application to the site requiring repair. lsocyanate-containing reaction mixtures can serve as examples of a class of ric materials of this type. These reaction mixtures, too, can comprise solvents.

Materials of this type are known and are described by way of example in Waterborne & Solvent Based Surface Coating Resins and Their Applications: Polyurethanes. Wiley, PF 72503 1998, lSBN 0471978868, 9780471978862. it is able to use single-component polyurethanes or acrylate-modified bitumen solutions. These are available commercially by way of example with trade names Mastertop P 690 and Mastertop P 691.

The amount applied of the polymeric material is preferably at least 20 glmz, with preference from 30 to 300 g/m2, and with particular preference from 50 to 200 g/m2, based in each case on the pure ric material, and ignoring, by way of example, solvents optionally comprised.

As an alternative to the application of polymeric material to the damaged site, the surface of the site requiring repair can be activated by flame treatment. This can be achieved by using burners conventionally used on building sites, and must be d out immediately prior to the application of the polyurethane reaction mixture. However, this is ered to be a less useful alternative because open flames should be avoided on building sites, the underlying layers of bitumen are subjected to l damage, and this reduces long-term stability, the method cannot be used with open- pore asphalts without destroying the al, and it is impossible to monitor the duration and uniformity of the flame treatment, and ensure that these are correct and quality assurance ore becomes almost impossible.

Mineral aggregate used here can comprise any le mineral aggregate. However, a factor that should be taken into account is that rock particles used by way of e have grain sizes that give them adequate resistance to impact fracture and adequate resistance to polishing. Another advantageous factor is a high tion of advantageous grain shape. For abovementioned reasons the types of rock or mineral materials used should preferably have high hardness, an example being greywacke, quartz, granite, or diabase. in certain cases here the mineral material can be used by way of example rain rock les with a flow ient of less than 30 s in the 3O form of sand, or else fine-grain rock particles with a flow coefficient of more than 35 s ground'rock, known as broken material. Mineral aggregate used particularly preferably comprises rock particles composed mainly of broken particles. Mineral aggregate selected ably comprises rock particles with suitable particle size distribution based on the specifications used in bituminous road construction, and varying with the intended use. For the specific case of open-pore asphalt, the intention is to use exclusively or almost exclusively a single class of rock particle with uniform grain size. it is preferable that the particle—size distribution curve ranges of the mineral aggregate are from O to 32 mm, with particular preference from 1 to 16 mm, and in particular from 40 2 to 11 mm. The proportion by mass of mineral aggregate with grain sizes smaller than 0.063 mm here is preferably smaller than 15% by mass, and the tion by mass of mineral aggregate with grain sizes r than, 16 mm is preferably smaller than or PF 72503 equal to 10% by mass. Particle-size distribution curves are to be based on the relevant European standard DlN EN 13108.

It is preferable that the t top layer is an asphalt top layer, with particular ence an open-pore asphalt top layer, and that the mixture comprising mineral ate and a second polyurethane on mixture cures to give an open-pore al. To this end, the size distribution of the particles of the mineral aggregate can correspond to the size distribution of the mineral aggregate usually used for producing open-pore asphalt, so that pores can form. For the filling of flat defective sites in the 1O substrate it is also possible to use classes of grain size that are r than those normally ed for new open-pore asphalt. In particular, the largest grain diameter used should be smaller than the depth of the defective site, so that a relatively stable three-dimensional network is achieved even in the case of flat defects, where the depth of the defect is smaller than the particle-size distribution curve. The blend of the repair ‘15 material, or the particle-size distribution curve, must be kept sufficiently narrow to achieve a cavity content of at least 10% by volume, ably at least 15% by volume, particularly preferably at least 20% by volume, and in particular at least 25% by volume, based on the pure mineral material t binders.

The first and the second polyurethane material can be identical or ent. “identical” here means that the same polyurethane-forming substances, such as isocyanates, relatively high-molecular—weight compounds having groups reactive toward isocyanates, and optionally chain extenders, are used in the same ratio to one another in each case. in the event that various other additives are also used, the polyurethanes are nevertheless considered for the purposes of the invention to be identical.

The first and the second polyurethane reaction mixture here are preferably identical.

A polyurethane reaction mixture is a mixture composed of compounds having 3O isocyanate groups and compounds having groups ve toward isocyanates, where the reaction conversion, based on the isocyanate groups used for the preparation of the polyurethane reaction mixture, is preferably smaller than 90%, ularly preferably smaller than 75%, and in particular r than 50%. The compounds having groups reactive toward isocyanates here comprise not only high-molecular— weight compounds, such as polyether— and polyesterols, but also low-molecular—weight compounds, such as glycerol, glycol, and also water. If the reaction conversion, based on the isocyanate group, is greater than 90%, the term polyurethane is used below. A polyurethane reaction mixture'here can also comprise further reaction mixtures for the production of polymers. Examples of further reaction mixtures that can be used for the 40 production of rs are reaction mixtures for the production of epoxides, of acrylates, or of polyester . The proportion of further on mixtures for the production of polymers here is preferably less than 50% by weight, based on the total PF 72503 weight of the polyurethane reaction mixture. It is particularly preferable that the polyurethane reaction mixture comprises no further reaction mixtures for the production of polymers.

The polyurethane reaction mixture can involve what are known as moisture-curing systems. These se isocyanate prepolymers which form polyurethanes or polyureas via addition of water or via ty, mainly by forming urea groups.

It is able to use what are known as two-component s for the production of the polyurethane reaction mixture. For this, an isocyanate ent comprising nds comprising isocyanate groups, and a polyol component comprising compounds having groups reactive toward isocyanates are mixed in tative proportions such that the isocyanate index is in the range from 40 to 300, preferably from 60 to 200, and particularly preferably from 80 to 150.

For the purposes of the present ion, isocyanate index here means the stoichiometric ratio of isocyanate groups to groups reactive toward isocyanate, multiplied by 100. Groups reactive toward isocyanate here means any of the groups which are comprised in the reaction mixture and which are reactive toward isocyanate, and this includes chemical blowing agents, but not the isocyanate group itself.

The polyurethane reaction e is preferably obtained by mixing of a) isocyanates with b) relatively high-molecular—weight compounds having at least two hydrogen atoms reactive toward isocyanate, and also optionally 0) chain extenders and/or crosslinking agents, cl) catalysts, and e) other additives. Compounds particularly preferably used as ents a) and b), and also ally c) to e) are those which lead to a hydrophobic polyurethane reaction mixture and to a hydrophobic ethane. 3O isocyanates a) that can be used are in principle any of the emperature-liquid isocyanates, mixtures and prepolymers having at least two isocyanate groups.

Aromatic isocyanates are preferably used, particularly isomers of tolylene diisocyanate (TDI) and of diphenylmethane diisocyanate (MDI), in particular mixtures ed of MDI and of enylene polymethylene polyisocyanates (crude MDI). The isocyanates can also have been modified, for example by incorporating isocyanurate groups and carbodiimide groups, and in particular by incorporating urethane groups.

The last-mentioned compounds are prepared via reaction of isocyanates with a substoichiometric amount of compounds having at least two active hydrogen atoms and are usually termed NCO prepolymers. Their NCO content is mostly in the range 40 from 2 to 32% by weight. The isocyanates a) preferably comprise crude MDI, with resultant increase in the stability of the polyurethane obtained.

PF 72503 A disadvantage with the use of aromatic isocyanates is the inadequate colorfastness of the polyurethanes produced therefrom. Marked yellowing of the polyurethanes mostly occurs over the course of time. In ations of the inventive process where high colorfastness is important, it is therefore preferable to use es comprising aliphatic isocyanates and ic isocyanates. it is particularly preferable to use exclusively aliphatic isocyanates. In one particular embodiment, an overlayer composed of polyurethane based on an aliphatic isocyanate can be used, in order to protect the top layer based on aromatic isocyanate from yellowing. The overlayer here can also comprise mineral aggregate. Preferred representative compounds are hexamethylene yanate (HDI) and isophorone diisocyanate (lPDl).- e the aliphatic isocyanates have high volatility, they are mostly used in the form of their reaction products, in particular in the form of biurets, allophanates, or isocyanurates. The aliphatic compounds can se be reacted and used with any of the conceivable polyols, in particular those listed under b), to give prepolymers.

The relatively high-molecular-weight nds b) used having at least two hydrogen atoms reactive toward nate are preferably nds which have hydroxy groups or amino groups as group reactive toward isocyanate. It is preferable to use polyhydric alcohols, since the amino groups are highly reactive and the reaction mixture therefore has to be processed rapidly. Amino groups moreover led to formation of urea groups, which in turn harden to give a rather brittle polyurethane.

The relatively high-molecular-weight, polyhydric alcohols used can by way of example be polyethers or polyesters. Further compounds having at least two hydrogen atoms reactive toward isocyanate groups can be used together with the compounds mentioned. Polyether alcohols are preferred by virtue of their high hydrolysis ance. These are prepared by conventional and known processes, mostly via an addition reaction of alkylene oxides onto H-functional starter nces. The functionality of the polyether alcohols used concomitantly is ably at least 3 and their hydroxy number is preferably at least 400 mg KOH/g, preferably at least 600 mg KOH/g, in particular in the range from 600 to 1000 mg KOH/g. They are prepared conventionally via reaction of at least trifunctional starter substances with alkylene oxides. r substances that can be used are preferably alcohols having at least three y groups in the molecule, examples being glycerol, trimethylolpropane, pentaerythritol, ol, and sucrose. Propylene oxide is preferably used as alkylene oxide.

Inventive reaction mixtures preferably comprise compounds having hydrophobic groups. These particularly preferably e hydroxy-functionalized compounds having 40 hydrophobic groups. These hydrophobic groups have hydrocarbon groups preferably having more than 6, particularly ably more than 8, and fewer than 100, and in particular more than 1 O and fewer than 50, carbon atoms. The compounds having PF 72503 hydrophobic groups can be used as separate component or as constituent of one of components a) to e), for preparation of the reaction mixture. The hydroxy-functionaiized ‘ hydrophobic compounds preferably involve compounds b) which comply with the definition of the relatively high-molecular—weight compounds having at least two hydrogen atoms reactive toward isocyanates. Component b) here can cdmprise hydroxy—functionalized hydrophobic compounds or preferably be composed thereof.

The hydroxy-functionalized hydrophobic nd used is preferably a y- functionalized compound known in oleochemistry, or a polyol known in oleochemistry.

A number of hydroxy-functional compounds that can be used are known in emistry. Examples are castor oil, oils modified using hydroxy groups, e.g. grapeseed oil, black cumin oil, pumpkin seed oil, borage seed oil, soybean oil, wheatgerm oil, rapeseed oil, er oil, peanut oil, apricot seed oil, pistachio oil, almond oil, olive oil, macadamia nut oil, avocado oii, sea buckthorn oil, sesame oil, hazelnut oil, evening primrose oil, wild rose oil, hemp oil, thistle oil, walnut oil, fatty acid esters modified using hydroxy groups and based on myristoleic acid, palmitoleic acid, oleic acid, vaccenic acid, petroseiinic acid, gadoieic acid, erucic acid, nervonic acid, iinoleic acid, nic acid, stearidonic acid, arachidonic acid, timnodonic acid, clupanodonic acid, or cerevonic acid. It is preferable here to use castor oil and its reaction products with ne oxides or with -formaldehyde resins. The last- named nds are marketed by way of example by Bayer AG as Desmophen® 1 150.

Another group of polyols which are known in oleochemistry and whose use is preferred can be obtained via pening of epoxidized fatty acid esters with simultaneous reaction with alcohols and ally Subsequent further transesterification reactions. incorporation of hydroxy groups into oils and fats occurs primarily via epoxidization of the olefinic double bond comprised in these products, followed by reaction of the 3O resultant epoxy groups with a mono— or polyhydric alcohol. The product here of the epoxy ring is a hydroxy group or, in the case of polyhydric alcohols, a ure having a relatively high number of OH . Since oils and fats are mostly glycerol esters, parallel transesterification reactions proceed with the abovementioned reactions. The molar mass of the resultant compounds is preferably in the range from 500 to 1500 g/mol. These products are supplied by way of example by Cognis and Altropoi.

In one particularly preferred embodiment of the inventive process, the relatively high- molecular—weight nds b) having at least two hydrogen atoms reactive toward isocyanate comprise at least one polyol known in oleochemistry and at least one 40 phenol-modified aromatic hydrocarbon resin, in ular one -coumarone resin.

Polyurethane reaction mixtures based on said component b) have a level of hydrophobic properties which is sufficiently high that in principle they can even be PF 72503 hardened under water, or installed during rainfall.

The phenol-modified aromatic hydrocarbon resins used having a terminal phenol group are preferably phenol-modified indene-coumarone resins, and particularly preferably rial mixtures of aromatic hydrocarbon resins. These products are commercially available and are supplied by way of example by RUtgers VFT AG as NOVARES®.

The OH content of the phenol-modified aromatic hydrocarbon , in ular the phenol-modified indene—coumarone resins, is mostly from 0.5 to 5.0% by weight.

The polyol known from oleochemistry and the phenol-modified aromatic hydrocarbon resin, in particular the indene—coumarone resin, are preferably used in a ratio by weight of from 100:1 to 100:50.

Preparation of an inventive ethane on mixture can use a chain er c).

However, the chain er c) can be omitted here. However, the addition of chain extenders, crosslinking , or else optionally a mixture of these can prove successful for modification of mechanical properties, e.g. hardness. 2O lf low—molecular-weight chain extenders and/or crosslinking agents 6) are used, the preparation of polyurethanes can use known chain extenders. These are preferably low-molecular-weight compounds having groups reactive toward isocyanates whose molar mass is from 62 to 400 g/mol, examples being glycerol, trimethylolpropane, known glycol derivatives, butanediol, and diamines. Other possible low-molecular- weight chain extenders and/or crosslinking agents are given by way of e in stoffhandbuch, Band 7, Polyurethane" [Plastics Handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition 1993, chapter 3.2 and 3.3.2.

The polyurethanes used can in principle be prepared t the presence of catalysts d). Catalysts d) can be used concomitantly to e hardening. The catalysts d) selected should preferably be those that maximize on time. It is thus possible that the ethane reaction mixture s liquid for a long period. These catalysts are known to the person skilled in the art. it is also possible in principle, as described, to work entirely without catalyst.

Other conventional constituents can be added to the polyurethane reaction mixture, examples being conventional additives e). These comprise by way of example conventional fillers. The fillers used are preferably the conventional, organic and inorganic fillers, reinforcing agents, and weighting agents known per se. Individual 40 examples that may be mentioned are: inorganic fillers, such as silicatic minerals, e.g. phyllosilicates, such as antigorite, serpentine, hornblendes, amphiboles, chrysotile, metal oxides, such as , aluminum oxides, titanium oxides, and iron oxides, metal PF 72503 salts, such as chalk, barite, and inorganic pigments, such as cadmium sulfide, zinc sulfide, and also glass. it is preferable to use kaolin (China clay), aluminum silicate, and coprecipitates composed of barium sulfate and aluminum silicate, and also natural and synthetic fibrous minerals, such as wollastonite, metal fibers of various lengths, and in particular glass fibers of various lengths, which may optionally have been coated with a size. es of c fillers that can be used are: carbon black, melamine, rosin, cyclopentadienyl resins, and graft polymers, and also ose fibers, polyamide fibers, polyacrylonitrile fibers, polyurethane fibers, polyester fibers based on aromatic and/or aliphatic dicarboxylic esters, and in ular carbon fibers.

If the abovementioned inorganic fillers are used as additives e), their mineral substance constitution preferably differs from that of the mineral aggregates, and they are ignored when determining the grain size distribution of the mineral aggregate.

The inorganic and organic fillers can be used individually or in the form of a mixture, and their amounts comprised in the reaction mixture are ably from 0.5 to 50% by , particularly ably from 1 to 40% by weight, based on the weight of components a) to e).

The polyurethane reaction mixture should also comprise dryers, such as zeolites.

These are preferably added, prior to preparation of the ive reaction mixture, to the compounds b) having at least two hydrogen atoms reactive toward nate, or to the component which comprises the compounds b) having at least two hydrogen atoms reactive toward isocyanate. Addition of the dryers avoids any increase in the concentration of water in the components or in the reaction e, and/or results in tion, in the raw als of the ation, of any water present, and thus avoids formation of foamed polyurethane. Additions preferred for water adsorption are aluminosilicates, ed from the group of the sodium aluminosilicates, potassium aluminosilicates, calcium aluminosilicates, cesium aluminosilicates, barium aluminosilicates, magnesium aluminosilicates, strontium aluminosilicates, sodium aluminophosphates, potassium aluminophosphates, calcium aluminophosphates, and mixtures thereof. It is particularly preferable to use mixtures of sodium aluminosilicates, potassium aluminosilicates, and calcium aluminosilicates in castor oil as carrier substance. Said dryers are not counted as part of the “mineral aggregate”.

To improve the long-term stability of the inventive top layers, it is moreover advantageous to add agents to r attack by microorganisms. Addition of UV ' stabilizers is also ageous, in order to avoid embrittlement of the moldings. These additives are known, and examples are given in "Kunststoffhandbuch, Band 7, 40 Polyurethane" [Plastics Handbook, volume 7, Polyurethanes], Carl Hanser Verlag, 3rd edition 1993, chapter 3.4.

PF 72503 The additives E) can moreover comprise conventional coupling agents, ably based on silanes. Coupling agents used particularly preferably se one or more hydroxy— or alkoxyaminosilane compounds of the general formula (I) Writs—(Hi. in which X is mutually independently OH, CH3 or OlCH2]pCH3; Y is [CH2]t, or [CH2]rNH[CH2]s; R and R’ is hydrogen or [CH2]tCH3; t is from 0 to 10; n is from 1 to 3; p is from 0 to 5; m is 4 minus n, and r and s are mutually independently from 1 to 10. 1O Preferred coupling agent of this type are described by way of example in WC 201 0/043644. it is preferable that the components 0), d), and e) are added to the compounds having at least two hydrogen atoms reactive toward isocyanate groups. This blend is often referred to in industry as polyol component.

The ratio in which the isocyanates are combined with the compounds having at least two hydrogen atoms reactive toward isocyanate groups should preferably be such that a stoichiometric excess of nate groups is present.

In one preferred embodiment of the invention, polyurethane reaction mixtures are used which lead to hydrophobic, substantially t polyurethanes. A polyurethane is termed compact polyurethane if it is substantially free from gas inclusions. The y of a compact ethane is preferably greater than 0.8 g/cm3, ularly preferably greater than 0.9 glcm3, and in particular greater than 1.0 g/cm3.

The weight ratio here of polyurethane reaction e to mineral aggregate is preferably n 2 : 98 and 15 : 85, particularly preferably between 3 : 97 and 10 : 90, and in particular between 4 : 96 and 8 : 92.

An inventive mixture comprising l aggregate and a second polyurethane reaction mixture can also comprise further additions alongside polyurethane reaction mixture and mineral aggregate. The additions preferably se als which inhibit flow of the binder away from the mineral aggregate. Examples of possible such additions are organic fibers, such as cellulose fibers, or inorganic auxiliaries with thixotropic effect, for example fumed silica, an example being Aerosil® from Evonik. Said auxiliaries with thixotropic effect are not d as part of the mineral material. it is moreover possible to add polymers which are nowadays used in the bitumen—based systems used. These are especially neoprenes, styrene-butadiene—styrene block 40 copolymers, or a e of these, or else any of the other known rubbers and their PF 72503 es. The additions can either be added directly to the mineral e in the form of powder or pellets or else dispersed in one of the polyurethane components. It is moreover possible to use reactive additions to render the polyurethane mixture thixotropic in situ. By way of example, mono— or polyfunctional amines can be used in proportions of a few percent in the polyol mixture to provide thixotropic properties, examples being polyetherolamines, e.g. Jeffamine Huntsman or polyetheramines from BASF, diethyltoluenediamine, for example DETDA 80, alkylated ene- diphenylenediamines, such as Lonzacure® M-CDA, ure® M-DEA or Lonzacure® M-DIPA, or else a mixture of these agents having thixotropic effect.

The preparation of the ive mixture comprises mineral aggregate and a second polyurethane reaction mixture is not subject to any restriction. By way of example, it can be prepared in mixers to which the mineral aggregate is introduced, and the starting components for the preparation of the polyurethane reaction mixture can, for example, be introduced by spraying. Additions to be added here are preferably optionally added to the mixture at the respective advantageous juncture. By way of example, therefore, these may be in solution or dispersion in one of the components of the reaction mixture, for example in one of components a) to e), and may be added with these to the mixture. The additions can also be separately added to the mixture.

By way of example, cellulose fibers can be added at a juncture such that these are t in homogeneous dispersion in the mixture for the production of top layers, but are not irreversibly damaged by the mixing procedure. The inventive mixture here for the production of top layers can by way of example be produced by the s described in DE 38. It is likewise possible, for example, to begin by ing the ethane reaction mixture and then to mix this with the mineral aggregate and optionally with the further additions. in another embodiment, the mineral aggregate can optionally first be mixed with some of the components of the reaction mixture, for example with components b) and, if present, 0) to e), and then the ents not yet present, for example component a), can be added in a mixer. The proportion of the second polyurethane reaction mixture is preferably from 1 to 10% by mass, particularly preferably from 2 to 8% by mass, and in particular from 3 to 6% by mass, based on the total weight of mineral aggregate and of second polyurethane reaction e. it is preferable that the site requiring repair in the top layer is cleaned prior to application of the polymeric material. This can be achieved by way of example by sweeping or blowing. it is equally possible to use a low-pressure or ressure wash to clean the site requiring repair, but in that case it should appear visually dry prior to application of the polymeric material. Residual moisture ented by moisture in the deeper ers of the open-pore material is not problematic. Once the polymeric 40 material has been d, it is preferable that any t t is allowed to escape, for example by evaporation. in the event that the polymeric material has been d in the form of a reaction mixture, the first polymeric material can be applied PF 72503 directly, or preferably the reaction to form the polymeric material is allowed to d to an extent such that the average molar mass of the polymeric material is preferably at least 500 g/moi.

An amount of at least 80 g/m2, preferably from 100 g/m2 to 1000 g/m2, and particularly preferably from 120 to 500 g/m2, of the first ethane reaction mixture is then d to the polymeric material.

The mixture comprising l aggregate and a second polyurethane on mixture is d to the first polyurethane reaction mixture or to the polyurethane obtained via complete reaction of the first polyurethane reaction mixture. it is able that the mixture comprising mineral aggregate and a second polyurethane reaction mixture is applied while the first polyurethane reaction mixture has not yet reached its gelling time or cobwebbing time. The gelling time here is the juncture at which the storage modulus is greater than the loss modulus in gical measurement at room temperature. For the purposes of this ion, an approximation to the g time isdetermined by way of the cobwebbing time. For this, a wooden bar is repeatedly placed on the surface of the polyurethane reaction mixture. The cobwebbing time has been reached as soon as removal of the wooden bar from the surface results in fiber formation.

Once the mixture of the invention for producing top layers has been applied, this is smoothed to the level of the surrounding road surfacing. It can then also be d with scattered sand, preferably when there is no involvement of an open-pore asphalt subject to acoustic requirements. Prior to the scattering process, the mixture can optionally be carefully compacted, in order to achieve intermeshing of the mineral substances, for example by gentle tamping or by using a lightweight road roller conventionally used in road construction. Any depression below the surrounding road surfacing is to be avoided. 3O The resultant repair material is then d to harden, optionally with use of heat. it polyurethane material used comprises a moisture-curing material, it is also possible to use steam for the curing process.

The invention further provides a repair kit for repairing top layers for roads, tracks, and other areas used by c, comprising a polymeric material, optionally a first polyurethane reaction mixture, and a second polyurethane reaction mixture, and also optionally further additions and mineral aggregate.

The various sublayers can be d by operatives manually, by spraying, rolling, or 40 spreading. Application by machinery is equally possible, via adaptation of finishers, of automated spray ent, and of other necessary equipment.

PF 72503 The process of the invention for repairing top layers for roads, tracks, and other areas used by traffic leads to a asting renewal of the top layer, since very strong adhesion develops between the asphalt and the repair material used. Areas used by traffic here comprise all of the areas used by traffic which have bound top layers, for example taxiways and take-off and g runways at airports, and also sidewalks or cycleways. A possible use here is indeed for repairing open—pore asphalt, where the repair in turn forms an open-pore element which is not inferior to the previous top layer, in particular to the previous open—pore asphalt top layer, either in terms of sound- deadening or in terms of drainage capability. When the repaired site is compared with conventional repair mixtures it also ts high frost resistance and low susceptibility to ion of udinal grooves, and is more rapidly available to carry traffic at usual speeds, since the desired skid resistance is present ly after ing. The skid resistance of the repair mixture of the invention can moreover be adjusted prior to the final ing of the repair mixture, for example by covering the surface with scattered sand or scattered rock—derived material. Finally, the color and lightness of the ed site can be adapted via colorant ons or via selection of the coloring of the mineral material used so as to be precisely appropriate to the surrounding material.

Examples will be used below to illustrate the invention.

Examples Polyol component: Elastopave 6551/102, comprising a castor-oil-based hydroxy- functional oleochemical component, trifunctional chain extender, reactive amine to e thixothropic properties, and antifoam lsocyanate: Polymeric diisocyanatodiphenylmethane (PMDl) Primer1: Mastertop P 691 from BASF; -component polyurethane adhesion promoter in solvent Primer 2: Mastertop P 690 from BASF; polyacrylate—bitumen-based single- component adhesion primer Preparation of polyurethane reaction mixture and repair mixture 100 parts by weight of the polyol component of the Elastopave 6551/102 system were mixed intimately with 83.7 parts by weight of isocyanate to give a polyurethane reaction mixture. 5% by weight of said polyurethane reaction mixture are mixed with 95% by weight of 2/4 diabase to give a repair mixture. The repair mixture of comparative example 5 comprised 8% by weight of polyurethane reaction mixture and 92% by weight of 2/4 diabase. 40 The adhesion experiments used sample sheets made of AC 16 BS asphalt binder material with dimensions 320 x 260 x 50 mm. in the first step, the asphalt sheets were optionally coated with primer in accordance with the table. After air-drying, a second PF 72503 sublayer of binder is optionally applied, and then immediately coated with the repair mixture to a height of 1 cm and subjected to slight mechanical compression. After the hardening s, test specimens were produced by Using a 5 cm hollow drill, and these were used to determine the adhesion of the repair mixture on the asphalt binder material by a method based on TP Asphalt StB T81, but with a ram diameter of 47.5 mm, differing from that in the test specification mentioned. The table collates the amounts used of primer, and also the results of on ement. The value stated here in relation to the determination of adhesion was determined by taking the average from 4 test specimens.

PF 72503 Table Repal‘r mixture:, Weight per Weight per Adhesion umtarea, unit area of. proportion of' Experiment 1st primer 2nd primer of primer1 primer2 polyurethane reaction [9 m/ 2] [g mf 21 mixture -- No - 5% adhesion Polyurethane Comparison on - 5% 168 mixture Polyurethane Inventive Primer 2 reaction 144 144 example 1 mixture Primer 2 and ethane reaction Inventive mixture (in - 5% 144 0.8 example 2 each case 50% by POIYUFethane Inventive Primer 2 on 5% 156 276 example 3 mixture.

I”Oil/urethane inventive Primeri on 5% 132 144 m examPle 4 mixture The examples show that particularly high adhesion of the repair mixture on the asphalt binder material is obtained by using primers with a polymeric material and with a polyurethane reaction mixture.

PF 72503

Claims (11)

Patent claims
1. A process for repairing top layers for roads, tracks, and other areas used by traffic, by applying an amount of at least 20 g/m2 of a polymeric material to the damaged site, applying an amount of at least 80 g/m2 of a first polyurethane reaction mixture to the polymeric material, and applying, to the first polyurethane reaction mixture, a e comprising at least one mineral aggregate and a second polyurethane reaction mixture, and allowing the material to harden.
2. 10 The process according to claim 1, wherein the the top layers are open-pore asphalt top , and the mixture comprising mineral aggregate and a second ' polyurethane reaction mixture hardens to give an open-pore material.
3. The process according to claim 1 or 2, wherein the first polyurethane reaction 15 mixture has not yet reached its cobWebbing time when the mixture comprising mineral ate mineral material and a second polyurethane reaction mixture is applied.
4. The process ing to any of claims 1 to 3, n the polymeric material has 20 groups that adhere to rock and/or to bitumen.
5. The process according to claim 4, wherein the polymeric material has polyurea bonds and/or polyurethane bonds.
6. 25 The s according to any of claims 1 to 5, wherein the first polyurethane reaction mixture and the second polyurethane reaction mixture is obtainable by mixing of a) isocyanates with 30 b) compounds having at least two hydrogen atoms reactive toward isocyanate, and also optionally 0) chain ers and/or crosslinking agents, d) sts, and e) other additives, where the starting materials for the production of the first polyurethane reaction e and for the second polyurethane reaction mixture can be identical or ent.
7. 40 The process according to claim 6, wherein the compound b) having at least two hydrogen atoms reactive toward isocyanate comprises a hydroxy-functional compound having hydrophobic groups.
8. The process according to claim 7, wherein the hydroxy-functional compound having hydrophobic groups comprises a hydroxy-functional compound known in emistry.
9. The process according to claim 7 or 8, wherein the compound b) having at least two en atoms reactive toward nate comprises a hydroxy—functional compound known in oleochemistry and a phenol—modified aromatic hydrocarbon resin.
10. 10 10. The process according to any of claims 1 to 9, wherein the proportion of the ethane reaction mixture is from 2 to 10% by weight, based on the total weight of the mixture.
11. 11. A process according to claim 1, substantially as herein described with reference 15 to any one of the accompanying examples thereof.