PU FLOORING PRODUCTION FOR A SPORTS FIELD

Abstract

The invention relates to a method for producing a polyurethane flooring (129) for a sports field (136), the method comprising: providing (502) reactive components for producing polyurethane, the reactive components comprising an A component (902) being a polyol mixture and a B component (904) being an isocyanate mixture and water (914), the B component comprising: 2,2 Methylendiphenyldiisocyanate (922); diphenylmethane-2,4-diisocyanate (924); diphenylmethane-4,4-diisocyanate (926); and isocyanate prepolymer (932); mixing (504) the reactive components for generating a liquid polyurethane reaction mixture (129); applying (506) the polyurethane reaction mixture (128) to a ground (103) of the sports field before chemical reactions in the reaction mixture have generated a solid polyurethane foam, the polyurethane foam after its solidification to be used as the polyurethane flooring.

Claims

1. A method for producing a polyurethane flooring (129) for a sports field (136), the method comprising: providing (502) reactive components for producing polyurethane, the reactive components comprising an A component (902) being a polyol mixture and a B component (904) being an isocyanate mixture and water (914), the B component comprising: 2,2 Methylendiphenyldiisocyanate (922); diphenylmethane-2,4-diisocyanate (924); diphenylmethane-4,4-diisocyanate (926); and isocyanate prepolymer (932); mixing (504) the reactive components for generating a liquid polyurethane reaction mixture (129); applying (506) the polyurethane reaction mixture (128) to a ground (103) of the sports field before chemical reactions in the reaction mixture have generated a solid polyurethane foam, the polyurethane foam after its solidification to be used as the polyurethane flooring.

2. The method of claim 1, the amount of the water and the amount of the -2,2-Methylendiphenyldiisocyanate (922) being chosen such that one hour after the mixing of the reactive components, more than 60% of the water has reacted to CO2 and more than 50% of the NCO groups of component B have reacted with hydroxyl groups of the polyol of the component B into the solid polyurethane foam.

3. The method of any one of the preceding claims, the water (914) being added in an amount of 0.1-1.5% by weight of the A component, in particular in an amount of 0.4%-0.6% by weight of the A component.

4. The method of any one of the preceding claims, the water (914) being added to the reaction mixture as an ingredient of the A component.

5. The method of any one of the preceding claims, the water (914) being added to the reaction mixture and/or to the A component in a free, non-zeolitbound form.

6. The method of any one of the preceding claims, further comprising: adding a molecular sieve material to the A component to adsorb and remove any moisture from the A component; optionally, if the water (914) is added to the reaction mixture as an ingredient of the A component, adding the water (914) after the moisture was removed from the A component.

7. The method of claim 6, the molecular sieve material being a first zeolite.

8. The method of any one of the previous claims, the B component (904) comprising a mixture of monomers (922-926) and polymers (932) respectively comprising one or more NCO groups, the polyol (906) of the A component comprising one or more OH groups, the NCO groups in the B component and the OH groups in the polyol of the A component having an NCO/OH molar ratio in the range of 1.14:1 to 1.18:1, in particular in the range of 1.15:1 to 1.17:1.

9. The method of any one of the previous claims, further comprising: adding a catalyst for catalyzing a polyaddition reaction of the polyol and the B component, the catalyst being added to the reaction mixture in an amount that catalyzes the generation of the solid polyurethane foam at a speed that prevents the generation of the solid polyurethane foam before at least 30 minutes has lapsed since the generation of the reaction mixture.

10. The method of any one of the preceding claims, further comprising: adding a second zeolite to the reaction mixture, the second zeolite being soaked with the water and being adapted to desorb at least 20% of the water to the reaction mixture within 60 minutes after creation of the reaction mixture.

11. The method of claim 10, further comprising: acquiring a temperature of the ground (103) of the sports field; wherein the amount of the second zeolite depends on the measured ambient temperature, wherein the higher the temperature, the higher the amount of the second zeolite with its adsorbed water that is added to the reaction mixture.

12. The method of any one of the previous claims, further comprising generating the B component by: creating an MDI premix (940) comprising: 2,2 Methylendiphenyldiisocyanate (922) in an amount of 0.3%-7% by weight of the MDI premix, preferably in an amount of 4%-7% by weight of the MDI premix; diphenylmethane-2,4-diisocyanate (924) in an amount of 10%-35% by weight of the MDI premix; diphenylmethane-4,4-diisocyanate (926) in an amount of 10%-45% by weight of the premix; and MDI-polymers (930) consisting of two or more of said diisocyanate monomers (922, 924, 926) in an amount of 0%-30% by weight of the MDI premix; mixing the MDI premix 940 and a premix polyol (930) for letting the MDI premix components and the premix polyol 930 generate the B component, the B component comprising: an aromatic isocyanate prepolymer (932); and unreacted educts of the premix and the premix polyol.

13. The method of any one of the previous claims, the NCO content of the B component being between 1.5% and 18% by weight of the B component.

14. The method of claim 13, the NCO content of the B component being between 9% and 14%, e.g. 10% by weight of the B component.

15. The method of any one of the previous claims, further comprising: using an MDI premix (940), the premix comprising a mixture of isocyanate monomers (922-926) for generating the isocyanate prepolymer (932), the MDI premix comprising the 2,2 Methylendiphenyldiisocyanate (922) in an amount of 0.3 to 7% by weight of the MDI premix, preferably in an amount of 4%-7% by weight of the MDI premix.

16. The method of any one of the previous claims, wherein the polyol (906) of the A component has a viscosity of 2500 to 3500 mPas/25 C.

17. The method of any one of the previous claims, wherein the ground is made of concrete, soil or wood and wherein the reaction mixture is applied to the ground (103) directly in the absence of an adhesive layer.

18. The method of any one of the previous claims, wherein the application of the reaction mixture to the ground (103) comprises: applying a first lane (144) of the reaction mixture to the ground; before the foam of the first lane has solidified, applying a second lane (146) of the reaction mixture (128) to the ground such that a side edge of the second lane is in contact with a side edge of the first lane.

19. The method of any of the previous claims, wherein the reaction mixture is applied to the ground by a vehicle (100) or by an apparatus (101) carried by a user (102), the method further comprising: automatically determining the position and/or the speed of the vehicle or apparatus used for applying the reaction mixture to the ground; and automatically adjusting the type and/or quantity of reactive components mixed together to generate the reaction mixture in dependence on the position and the speed of the vehicle or the user (102) carrying the apparatus.

20. The method according to any one of the previous claims, further comprising: applying, after the applied polyurethane foam has solidified or hardened, a sealing coating (127), the sealing coating preferentially covering multiple lanes (144, 146, 148) of the polyurethane ground, thereby skipping any operation for gluing adjacent lanes to each other.

21. A system for producing a polyurethane flooring (128) for a sports field (136), the system comprising: an A component (902) being a polyol mixture; a B component (904) being an isocyanate mixture and comprising: 2,2 Methylendiphenyldiisocyanate (922); diphenylmethane-2,4-diisocyanate (924); diphenylmethane-4,4-diisocyanate (926); and isocyanate prepolymer (932); water (914), the water and the B-component being stored in different containers; a mixer for mixing (504) the A component, the B component and the water for generating a liquid polyurethane reaction mixture; and a nozzle (124) coupled to the mixer for applying (506) the polyurethane reaction mixture (128) to a ground (103) of the sports field before chemical reactions in the reaction mixture have generated a solid polyurethane foam, the polyurethane foam after its solidification to be used as the polyurethane flooring.

22. A portable apparatus (101) comprising the system of claim 21.

23. A vehicle (100) comprising the system of claim 21.

24. A polyurethane flooring (129) of a sports field (136) manufactured by a method according to any one of the previous claims 1-20.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0105] In the following embodiments of the invention are explained in greater detail, by way of example only, making reference to the drawings in which:

[0106] FIG. 1 depicts the application of in-situ generated PU foam on a sport field ground;

[0107] FIG. 2 depicts an athletic track comprising multiple lanes;

[0108] FIG. 3 depicts the automatic intermixing of adjacent PU foam lanes;

[0109] FIG. 4 depicts three fresh PU foam lanes;

[0110] FIG. 5 depicts a paving machine that applies PU foam on the ground;

[0111] FIG. 6 is a flowchart of a method of generating a PU-based flooring of a sports ground;

[0112] FIG. 7 depicts the gellation reaction for generating PU;

[0113] FIG. 8 depicts the blowing reaction for generating CO2 as the blowing agent; and

DETAILED DESCRIPTION

[0114] FIG. 1 depicts the application of in-situ generated PU reaction mixture 128 on a sport field ground 103. A user 102 carries a portable apparatus 101 comprising a reaction tank 154 with a mixer 156 that is coupled to a nozzle 124 via a duct. The system comprises a first container 160 with a B component and a second container 162 for the A component. In the depicted example, the A component comprises an exactly defined amount of water, while all other substances of the A component may have been dried in a pre-processing step with the help of a first zeolite. The amount of water and the type and amount of polyol and isocyanates are chosen such that a sufficient amount of CO2 is continuously generated in a blowing reaction for boosting the generation of the PU foam. Optionally, the reaction mixture comprises a second zeolite with absorbed water for boosting the blowing reaction in case the ambient temperature is high. The first and second containers can be coupled directly to the mixer 156 or can be coupled indirectly to the mixer via the reaction tank 154. In other examples, the first and second containers may simply be transport containers which are not coupled to the reaction tank and are merely used for transporting the reactants and for filling the reactants into the reaction tank. The viscosity of the PU reaction mixture 128 generated by the blowing reaction and the gellation reaction that happen in parallel may depend on the specific composition of the reaction mixture in the reaction tank 154. Preferentially, the viscosity is low enough to allow self-levelling of the viscous liquid PU reaction mixture or PU foam 128 into a plane PU foam layer that slowly solidifies into a foamed PU based flooring 129 of a sport field. Thus, uneven ground surfaces, damaged areas and hollows in the ground are filled by the PU foam and an even PU foam layer is generated that solidifies after some hours to form the PU based, elastic flooring of the sport field. However, the viscosity should be high enough to retain the CO2 bubbles to allow the PU foam to build.

[0115] The PU foam is allowed to dry and solidify completely. Depending on the temperature and other weather conditions, complete solidification is typically accomplished within 1 to 15 hours after the mixing of the reactive components, e.g. between 6 to 10 hours after the mixing of the reactive components.

[0116] The water can be contained in a separate container or can be part of the A component contained in the second container. The A component, the B component and the water may be provided in a step 502 of a method shown in FIG. 6. For example, said substances can be provided by a user who adds said substances to the first or second containers or who adds said substances directly in the reaction container.

[0117] In step 504 the mixer mixes all components of the reaction mixture, i.e., all reactive components for producing polyurethane foam and optionally one or more of the additives and/or filler materials mentioned above. By mixing the A component, the B component and the water, chemical reactions, in particular a gellation reaction that generates PU polymers and a blowing reaction that generates CO2 as a blowing agent are triggered which in effect result in the generation of PU foam.

[0118] The composition of the reaction mixture, in particular the amount of water and the MDI monomers in the B component are chosen such that the formation of CO2 is performed at the same time as the urethane polymerization (gellation) is occurring. The carbon dioxide is generated by reacting isocyanate with the water.

[0119] When the mixer has mixed the reaction mixture homogeneously, the reaction mixture starts generating PU polymers and CO2 gas bubbles and is referred to as PU liquid or liquid PU reaction mixture although the chemical reactions for generating the PU foam may immediately start and may immediately generate some CO2 bubbles. The PU reaction mixture is transported from the mixer to a nozzle 124 and is applied directly on the floor of a sport field. The user 102 may apply multiple lanes of the PU reaction mixture to generate the PU flooring for a larger area. Preferentially, the PU reaction mixture is applied on an outdoor ground, but it is also possible to apply the method for generating indoor sport field floorings. In solidified and dried state, the PU foam 129 is used as the polyurethane flooring of the sport field.

[0120] Optionally, the solidified PU layer 129 can be coated with a protective and water repellent layer 127 (coating), e.g. for increasing the resistance of the flooring to heat, UV light, rain, fungi and other factors (see FIG. 1b) and/or to give the flooring a desired color.

[0121] FIG. 4 shows one embodiment of a PU flooring of a sport field comprising multiple lanes and FIG. 3 depicts the automatic intermixing of adjacent PU foam lanes. The ground 103 to be applied with a polyurethane flooring is a rectangular sports field 136 with a length 138 and a width 140. The ground 103 may be prepared, e.g. concreted and/or leveled, or unprepared. The user 102 may use a portable apparatus 101 as shown in FIG. 1a or a vehicle 100 as shown in FIG. 5 for applying a lane of the liquid foam 128 having a width 142 which is smaller than the width 140 of the sports ground 136. Therefore, the PU reaction mixture is applied to the ground 103 in lanes 144, 146, 148, wherein adjacent lanes 144, 146, 148 are in contact with each other. The foam of a second lane 146 which is applied after the foam of a first lane 144 immediately intermixes with and generates a coherent mass with the foam of the first lane 144 (see FIG. 3) so that a side edge 150 of the first lane 144 is in contact with the side edge 152 of the second lane 146. The side edge 130 would contact the side edge of lane 148 once said lane is applied on the ground.

[0122] In case a vehicle is used, the vehicle may comprise a levelling unit 126 and an injection unit 126. The levelling unit is wider in shape than the injection unit 124 so that the levelling unit 126 can smooth the transition from the first lane 144 to the second lane 146.

[0123] FIG. 2 schematically shows a second embodiment of a method for applying foam for a polyurethane flooring to a ground 103 of an athletic track comprising multiple lanes. In this embodiment, the sport field is an oval track field. The user with the apparatus 101 or with the vehicle 100 moves around the field applying the PU reaction mixture 128 that slowly starts to foam. The second lane 146 connects at the starting point of the first lane 144, whereby the apparatus or vehicle moves radially inwards so that the path of motion of the apparatus 100 is spiral.

[0124] Independently from the geometry in which the reaction mixture is applied to the ground, the foam/mixture of the first lane 144 should be in a liquid state when applied the adjacent second lane 146. If the foam 128 of the first and the second lanes 144, 146 are both liquid respectively not cured, the foam of both lanes 144, 146 is mixed up in the contact zone and/or bond firmly together to improve a continuous polyurethane flooring. Furthermore, the user 102 can use a levelling unit 126 of the vehicle or a mechanical tool to smooth the PU foam to produce an even and smooth surface 129.

[0125] Therefore, the method comprises applying the foam of the second lane 146 before the foam of the first lane 144 solidifies (is cured). Especially in hot, dry climate conditions and floorings with large expansions it is important to start applying the second lane shortly, preferentially within 30 minutes or one hour after having generated the first lane, to prevent that the curing process may have started before the second lane is applied to the ground 103.

[0126] To avoid an early curing process, the components of the reaction mixture used for generating the PU foam and the process parameters of the mixing process can be customized to the environmental conditions.

[0127] Distributing various sensors 132 at different positions of the ground may have the advantage that the environmental data of an unfavorably positioned sensor 132 can be compensated for. For example, one sensor can be positioned in shadow so that the temperature of this sensor is lower than the temperature of the remaining ground. For example, the mixture can be customized such that the process parameters enable the deposition of the foam using the worst measured environmental conditions of the sensors. For example the highest measured temperature. Alternatively, a map of the environmental data may be created and the mixture and the process parameters are customized continuously on the basis of this map and the current position of the apparatus 100.

[0128] Furthermore, additional environmental data may be taken into account, for example a weather forecast, a time of the day or the relative humidity. Due to the weather forecast and the time of day a rising of the temperatures during the process may by predicted in order to adapt the mixture and the process parameters to the rising temperatures. For example, additional environmental data may be received from a meteorological service.

[0129] The environmental data may be measured at the beginning of the process or continuously in order to adjust the mixture and the process parameters continuously to the environmental data. The environmental data may be stored to a memory of the control unit 134. The stored data may be used to improve the prediction of temperatures or to control the current mixing process.

[0130] In a further embodiment, the position and/or the speed of the apparatus 100 may be determined by additional sensors. By this information, the control unit 134 may calculate the time between applying the first and the second lanes, calculate the required curing time and adapt the mixture and the process parameters of the foam.

[0131] FIG. 5 depicts a system 100 in the form of a paving machine that applies PU reaction mixture 128 on the ground as depicted in FIG. 1. The PU reaction mixture 128 consists essentially of two reactive components, A B component and an A component that may in addition comprise a defined amount of water as a further reactive component. Depending on the desired properties of the flooring, various polyurethane forming ingredients, for example chemical additives, compressed air or other additives may be added. The composition and amount of the reactive components and the additives, e.g. catalysts and/or a second zeolite soaked with additional water to compensate high temperatures, may influence the speed of PU polymer generation and/or the speed of CO2 production as well as mechanical properties of the flooring, the resistance to climate conditions, the water absorbency, the viscosity of the PU foam, the stability of the PU foam, the curing time, the color or other characteristics of the flooring.

[0132] For example, the additives may comprise emulsifiers and/or foam stabilizers, e.g. high sheer resistant silicone foam stabilizers. Catalysts might be used to moderately enhance the reactivity of the mixture between the NCO terminal prepolymer and/or the polymeric isocyanate on one hand and the polyol of the A component. Moreover, pigments and UV stabilizers might be used.

[0133] The system 100 comprises tanks 160, 162 for the basic materials of the polyurethane, wherein the first tank 160 contains the B component and the second tank 162 contains the A component and the defined amount of water. Both tanks 160, 162 are connected with ducts 108, 110 to a mixing unit 156 in which the components are mixed to a foam 128 for the polyurethane flooring. Each duct 108, 110 comprises a valve 112, 114 for dosing the amount of polyol respectively isocyanate which flows from the respective tank 160, 162 to the mixing unit 156. The ducts 108, 110 may comprise a supply unit, for example a pump. In the example depicted in FIG. 5, the apparatus is a vehicle, but the portable apparatus depicted in FIG. 1a could likewise comprise the same or functionally equivalent components as described for the vehicle of FIG. 5.

[0134] Alternatively, the system 100 can comprise a further tank 116 comprising the defined amount of water for the blowing reaction and/or comprising various polyurethane forming ingredients. The further tank 116 is connected with a duct 118 to the mixing unit 156. The duct comprises a valve 120. The system 100 may comprise various tanks for various additives depending on the desired number of additives to be added to the foam 128 for the polyurethane flooring.

[0135] The mixing unit 156 comprises means for producing a reaction mixture for generating polyurethane foam. The mixing unit 106 is connected with a duct 122 to an application unit 124 which is configured for applying the reaction mixture 128 to a ground 103. The application unit 124 may comprise a various number of nozzles for applying the mixture 128 to the ground 103. The nozzles may be spaced out evenly over the entire width of the application unit 124. Alternatively, there may be a single nozzle or a bundle of nozzles and a user may have to smoothly move the nozzle from one side to the other to evenly spread the PU foam over the ground (see FIG. 1a).

[0136] Furthermore, the system 100 comprises a levelling unit 126 for levelling and smoothing the applied mixture 128. The levelling unit 126 may be a scraper, which is located in a drive direction 130 of the apparatus 100 behind the injection unit 124. The levelling unit 126 is configured for smoothing the surface 129 of the applied foam and or for taking up excess foam.

[0137] The vehicle comprises a driving unit 131 for driving the apparatus 100 in the drive direction 130.

[0138] Furthermore, a sensor 132 for measuring environmental conditions may be provided as part of the vehicle 100. The sensor 132 may be configured for measuring the air temperature, the ground temperature, the relative humidity or other climate conditions. Various sensors for determining various environmental data may be provided.

[0139] The valves 112, 114, 120, the mixing unit 156, the application unit 124, the levelling unit 126, the drive unit and the sensor 132 are connected to a control unit 134. The control unit 134 is configured for receiving environmental data measured by the sensor 132 and to control the valves 112, 114, 120, the mixing unit 106, the application unit 124, the drive unit 131 and the levelling unit 126 depending on the received environmental data.

[0140] The environmental data are measured by the sensor 132 and sent to the control unit 134. The control unit 134 controls the valves 112, 114, 120 so that the desired mixture of polyol, isocyanate, water and additives is mixed. Furthermore, the amount of zeolite-bound water and/or the amount of catalysts or other process parameters can be adjusted by controlling the mixing unit 156.

[0141] Furthermore, the control unit may take into account the geometry of the ground, the planned path, respectively the length of each lane 144, 146, 148, the thickness of the polyurethane flooring and the speed of the system 100 (vehicle or portable apparatus) into the process of determination the mixture 128 in order to ensure that the foam of a first lane 144 is not cured before the foam of the second lane 146 is applied and/or to ensure that a sufficient amount of PU foam is applied to reach the desired minimum thickness and elasticity of the PU flooring.

[0142] In the described embodiment, the sensor 132 is attached to the system 100 so that the environmental conditions are measured at the position of the apparatus 100. Therefore, the mixture and the process parameters can be adapted continuously to the current conditions so that a constant curing time of the PU foam generated from the applied mixture 128 can be achieved.

[0143] Alternatively or in addition, stationary sensors can be used. Stationary sensors can be positioned at various positions of the ground 103 in order to achieve the environmental conditions in advance in order to customize the mixture of the foam to these conditions. In these embodiments, the sensors 132 may be connected to the control unit 134 by any wireless connection, for example a radio connection or a WLAN-connection, whereby the sensor 132 comprises a transmitter and the control unit 134 comprises a receiver.

[0144] FIG. 6 is a flowchart of a method of generating a PU-based flooring of a sports ground. The reactants, i.e., at least a polyol, an isocyanate and water and optionally one or more additives are provided in step 502, e.g. by filling the reactants into different containers 160, 162. The reactants and optionally one or more additives are added and distributed to the different containers such that the substances in each of the containers basically do not react with each other. Then, in step 504, an automated mixing device or a mechanical mixer operated by a human is used for mixing the reactants for triggering one or more chemical reactions, e.g. the gellation reaction and the blowing reaction to generate PU polymers that are foamed by the blowing agent CO2. The PU reaction mixture for chemically generating the PU foam is applied to the ground of a sport field.

[0145] After applying the polyurethane reaction mixture to the ground, the ground is optionally smoothed and leveled to a predetermined roughness and level. In some examples, the viscosity of the PU foam is small enough to allow self-levelling. After the smoothing and levelling process, the polyurethane foam cures. Optionally, the solidified, cured PU layer is coated with a further, protective layer 127. A separate step to anneal edges of two adjacent lanes to each other is not necessary.

[0146] Again, the application may be performed fully automatically as described for example for FIG. 5 or can be performed semi-automatically by a user 102 using a portable PU foam application apparatus.

[0147] FIG. 7 depicts the gellation reaction for generating PU. In order to produce polyurethane, a polyaddition reaction is performed. In this type of chemical reaction, the isocyanate monomers and the prepolymer in the B component contain reacting end groups. Specifically, a diisocyanate (OCNRNCO) is reacted with the polyol of the A component represented here as a diol (HOROH). The first step of this reaction results in the chemical linking of the two molecules leaving a reactive alcohol (OH) on one side and a reactive isocyanate (NCO) on the other. These groups react further with other monomers to form a larger, longer molecule. This is typically a rapid process which yields high molecular weight materials. Embodiments of the invention may allow selecting the type and amount of the reactive components and/or catalysts such that the reaction (gellation reaction) that generates the PU polymers is retarded. The reaction is retarded such that basically the PU polymer foam is built and solid after one or more hours, e.g. 1 to 10 hours after the mixing of the reactive components.

[0148] FIG. 8 depicts the blowing reaction for generating CO2 as the blowing agent. The reaction to generate carbon dioxide involves water reacting with an isocyanate first forming an unstable carbamic acid, which then decomposes into carbon dioxide and an amine. The amine reacts with more isocyanate to give a substituted urea. Water has a very low molecular weight, so even though the weight percent of water may be small, the molar proportion of water may be high and considerable amounts of urea produced. The urea is not very soluble in the reaction mixture.

[0149] As water is present in the reaction mixture, the isocyanate reacts with water to form an urea linkage and carbon dioxide gas and the resulting polymer contains both urethane and urea linkages. This reaction is referred to as the blowing reaction.

[0150] FIG. 9 illustrates the composition of the reaction mixture for generating PU foam according to some embodiments of the invention. In the depicted embodiments, the water is added to the reaction mixture as an ingredient of the A component 902.

[0151] In the following, four examples RM1-RM4 for a reaction mixture RM comprising different amounts (specified in parts by weight) of an A component 902 and a B component 904 will be given:

TABLE-US-00001 Hydroxyl number of polyol of A NCO parts by parts by component [mg NCO index weight A weight B KOH/g A content of B of component component component] component RM RM1 100 80 96.24-109.74 10% 1.16 RM2 100 95 96.24-109.74 10% 1.16 RM3 100 60 96.24-109.74 14% 1.16 RM4 100 68 96.24-109.74 14% 1.16

[0152] For example, the polyol 906 may have a hydroxyl number of 155-180 mg KOH/g polyol 906. As the polyol has a share of the A component of about 54% by weight in the depicted example, the hydroxyl number of the complete A component is diluted/reduced in accordance with the share of the polyol in the A component.

[0153] Thus, according to the first example RM1, the isocyanate index of 1.16 is obtained by mixing 100 parts by weight of the A component whose polyol 906 has a hydroxyl number in a range of 155-180 mg KOH/g mg KOH/g with 80 parts by weight of the B component having an NCO-content of 10% for generating the reaction mixture.

[0154] According to embodiments, the polyol 906 of the A component 902 is a polyetherpolyols or a polyesterpolyol. The polyol can be branched. The polyol can be a primary hydroxyl terminated diol. For example, the polyol 906 can have a molecular weight of 1000-4000 Dalton, e.g. 1190 Dalton. The polyol 906 preferentially has a viscosity of 2500-3500 mPas/25 C. According to some examples, the polyol has an acid value of up to 3 and/or a density of 1.0 g/cm.sup.3. The acid value (or neutralization number) is the mass of potassium hydroxide (KOH) in milligrams that is required to neutralize one gram of the chemical substance. The acid value is a measure of the amount of carboxylic acid groups in a chemical compound, such as a fatty acid, or in a mixture of compounds. The polyol 906 can be, for example, a polyetherpolyols, e.g. polypropyleneglycol. Polyetherpolyols may be manufactured e.g. from propylenoxide and may have the advantage of generating a PU with good coherence properties. Alternatively, the polyol can be a polyesterpolyol which may have the advantage of generating a PU with good adhesion properties (to the non-PU ground). The polyol can also be a mixture of polyester-polyols and polyether polyols having the advantage of a good compromise between adherence and coherence capabilities of the generated PU foam.

[0155] In the following, the A component will be described in greater detail for embodiments of the invention, whereby the % values are % by weight of the A component: [0156] 54% polyol 906, e.g. a polyethylene; according to embodiments, the polyol 906 of the A component is a polyether polyol or a polyester polyol or a mixture thereof. It has a hydroxyl number of 155-180 mg KOH/g/g polyol; [0157] 31% filling material 908, e.g. calcium carbonate; [0158] 7.6% extender 910, e.g. castor oil; [0159] 0.5% water 914; preferably, the water is added in a very precise amount by drying the other ingredients of the A component, e.g. with a first zeolite, and then adding the defined water in free form and/or bound to a second zeolite; [0160] 7.4% further substances 912, e.g.: [0161] 4.5% inorganic and/or organic pigments 916, e.g. iron oxide pigments, titandioxide, etc; [0162] 2,4% of further substances 918, e.g. 0.001% catalyst of the PU polyaddition reaction, e.g. Di-n-octyltinneodecanoat, 0.14% surfactants and emulsifiers, remnants of the first zeolite used for drying the A component before adding the water.

[0163] According to embodiments, the A component in addition comprises 0.5-2% of a second zeolite soaked with water (the amount of filler material is adapted accordingly). To prohibit an absorption of the additional water bound to the second zeolite by the first zeolite, the first zeolite is either removed from the A component after the drying process or is deactivated. Alternatively, the first zeolite is a zeolite that absorbs water much slower than the second zeolite desorbs the water and that also absorbs the water slower than the speed of the desorbed water reacting with the B component to CO2. The second zeolite may be added to the reaction mixture immediately before the PU reaction mixture is applied on the ground. Thus, the time will not suffice for the first zeolite to absorb the additional water that is provided by the second zeolite.

[0164] Surfactants and emulsifiers are used to emulsify the liquid components, regulate foam cell size, and stabilize the cell structure to prevent collapse and surface defects of the PU foam. Rigid foam surfactants are designed to produce very fine cells and closed cell structures. Flexible foam surfactants are designed to stabilize the reaction mass while at the same time maximizing open cell content to prevent the foam from shrinking. Thus, the reaction mixture that is used for generating the PU foam may in fact comprise a significant portion of additional substances for modifying the viscosity and foam bubble properties, for colorizing the foam, for acting as a filler or for other technical purposes.

[0165] According to embodiments, the B component 904 is created by reacting about 40 parts by weight of an MDI premix 940 with about 60 parts by weight of a premix polyol 930. The premix polyol may be a polyetherpolyols. For example, the premix polyol may have a molecular weight of about 2000 Dalton and a hydroxyl number in the range of 30-160 mg KOH/g polyol, e.g. 55 mg KOH/g. In some example embodiments, the premix polyol 930 and the polyol 906 of the A component can be of the same type.

[0166] According to embodiments, the MDI premix 940 for generating the B component comprises, before the premix polyol is added for generating the prepolymer: [0167] 0.3-7% by weight of the MDI premix: 2,2-Methylendiphenyldiisocyanate 922, preferably in an amount of 4%-7% by weight of the MDI premix; [0168] 10-35% by weight of the MDI premix: Diphenylmethane-2,4-diisocyanate 924; [0169] 10-45% by weight of the MDI premix: Diphenylmethane-4,4-diisocyanate 926; [0170] 0-30% by weight of the MDI premix: an MDI polymer 928 created by reacting two or more of the monomers 922-926 with each other.

[0171] By adding and mixing the premix polyol 930 to the MDI premix, at least a fraction of the totality of the educts 922-930 will react into a prepolymer 932, in this case an aromatic isocyanate prepolymer. The prepolymer is comparatively viscous and has a retarded reactivity in respect to polyols compared to standard prepolymers used in PU generation reactions.

[0172] After the reaction of the premix polyol and the MDI monomers and the MDI polymer has reached equilibrium, the resulting solution can be used as the B component. The B component 904 comprises a mixture of unreacted educts 920 (MDI monomers 922, 924, 926, optionally an MDI polymer 928 and the premix polyol 930) and the prepolymer 932 as the reaction product of the chemical reactions that takes place in the premix upon adding the premix polyol. Typically, about 62% by weight of the B component consists of the prepolymer 932 and about 38% by weight of the B component consists of the unreacted educts 920.

[0173] Thus, in effect, according to embodiments, the B component comprises: [0174] 0.1-2.8% by weight of the B-component: 2,2-Methylendiphenyldiisocyanate 922; [0175] 10-20% by weight of the B-component: Diphenylmethane-2,4-diisocyanate 924; [0176] 10-25% by weight of the B-component: Diphenylmethane-4,4-diisocyanate 926; [0177] 0-16% by weight of the B-component: an MDI polymer 928 created by reacting two or more of the monomers 922-926 with each other. [0178] 62% by weight of the B-component: aromatic isocyanate-prepolymer, e.g. (1,2-Propanediol, polymer with 1-isocyanato-2-(4-isocyanatophenyl)methylbenzene, 1,1-methylenebis 4-isocyanatobenzene, methyloxirane and oxirane)

[0179] The B component has, according to some examples, has a viscosity of 3200 mPas/25 C. In some examples, the isocyanate has a density of 1.15 g/cm3.