Ballast and process for the production of ballast

Abstract

The present invention relates to ballast which have a high stability and a long service life and to a process for the production of ballast. These ballast are suitable for railway track laying and road construction and dike systems used for example in costal protection. These ballast comprise ballast stones and polyurethane foams based on a reaction mixture of selected polyisocyanates and selected compounds with isocyanate-reactive groups.

Description

Claims

1. A process for the production of ballast for railway track laying and road construction and dike systems, comprising: 1) spreading ballast stones out to form ballast,and2) applying a polyurethane foam forming reaction mixture between the spread out ballast stones, in which the polyurethane foam forming reaction mixture comprises the reaction product of: a) one or more isocyanate compounds selected from the group consisting of (I) polyisocyanates having an NCO group content of 28 to 50 wt. % and (II) NCO prepolymers having an NCO group content of 10 to 48 wt. %, in which the NCO prepolymers comprise the reaction product of one or more polyisocyanates having an NCO group content of 28 to 50 wt. %, with a hydroxyl group containing compound selected from the group consisting of one or more polyetherpolyols having a hydroxyl number of 6 to 112, one or more polyoxyalkylenediols having a hydroxyl number of 113 to 1100, one or more alkylenediols having a hydroxyl number of 645 to 1850 and mixtures thereof;withb) at least one polyol component comprising one or more polyetherpolyols having a hydroxyl number of 6 to 112 and a functionality of 1.8 to 8;in the presence ofc) 0 to 26% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more chain extenders having a hydroxyl number or an amine number of 245 to 1850 and a functionality of 1.8 to 8;d) 0.05 to 5% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more blowing agents;e) 0 to 5% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more catalysts;f) 0 to 50% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more fillers;andg) 0 to 25% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more auxiliary substances and/or additives;wherein the isocyanate index of the polyurethane foam forming reaction mixture ranges from 70 to 130.

2. The process of claim 1, wherein e) said catalysts have primary and/or secondary hydroxyl and/or amino groups.

3. Ballast comprising a polyurethane foam and ballast stones, wherein the polyurethane foam which is located between the ballast stones comprises the reaction product of: a) one or more isocyanate compounds selected from the group consisting of (I) polyisocyanates having an NCO group content of 28 to 50 wt. % and (II) NCO prepolymers having an NCO group content of 10 to 48 wt. %, in which the NCO prepolymers comprise the reaction product of one or more polyisocyanates having an NCO group content of 28 to 50 wt. %, with a hydroxyl group containing compound selected from the group consisting of one or more polyetherpolyols having a hydroxyl number of 6 to 112, one or more polyoxyalkylenediols having a hydroxyl number of 113 to 1100, one or more alkylenediols having a hydroxyl number of 645 to 1850 and mixtures thereof;withb) at least one polyol component comprising one or more polyetherpolyols having a hydroxyl number of 6 to 112 and a functionality of 1.8 to 8;in the presence ofc) 0 to 26% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more chain extenders having a hydroxyl number or an amine number of 245 to 1850 and a functionality of 1.8 to 8;d) 0.05 to 5% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more blowing agents;e) 0 to 5% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more catalysts;f) 0 to 50% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more fillers;andg) 0 to 25% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more auxiliary substances and/or additives;wherein the isocyanate index of the polyurethane foam forming reaction mixture ranges from 70 to 130.

4. The ballast of claim 3, wherein the polyurethane foam has a free-rise density of 20 to 800 kg/m3, a compression force (at 10% compression) of at least 10.0 N, a compression hardness (at 10% compression) of at least 1.0 kPa, a tensile strength of at least 0.1 MPa and a compression set (CS; 40%; 25° C.; 5 min) of no more than 0.01%.

5. A process for the production of railway tracks and road construction and dike systems, comprising a ballast which comprises a polyurethane foam and ballast stones wherein the polyurethane foam comprises the reaction product of: a) one or more isocyanate compounds selected from the group consisting of (I) polyisocyanates having an NCO group content of 28 to 50 wt. % and (II) NCO prepolymers having an NCO group content of 10 to 48 wt. %, in which the NCO prepolymers comprise the reaction product of one or more polyisocyanates having an NCO group content of 28 to 50 wt. %, with a hydroxyl group containing compound selected from the group consisting of one or more polyetherpolyols having a hydroxyl number of 6 to 112, one or more polyoxyalkylenediols having a hydroxyl number of 113 to 1100, one or more alkylenediols having a hydroxyl number of 645 to 1850 and mixtures thereof;withb) at least one polyol component comprising one or more polyetherpolyols having a hydroxyl number of 6 to 112 and a functionality of 1.8 to 8;in the presence ofc) 0 to 26% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more chain extenders having a hydroxyl number or an amine number of 245 to 1850 and a functionality of 1.8 to 8;d) 0.05 to 5% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more blowing agents;e) 0 to 5% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more catalysts;f) 0 to 50% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more fillers;andg) 0 to 25% by weight, based on 100% by weight of the sum of reaction components b) through g), of one or more auxiliary substances and/or additives;wherein the isocyanate index of the polyurethane foam forming reaction mixture ranges from 70 to 130.