Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Patent
1995-12-14
1997-07-15
Gorr, Rachel
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
524791, 524839, 524847, 4283124, 4283126, 264 453, 523142, 523220, 521122, C08K 334
Patent
active
056484216
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This Invention relates to an isocyanate/polyol casting resin and to its use as a binder for granular material for the production of open-cell moldings.
2. Discussion of Related Art
Open-cell moldings, for example of pebbles, are known. Thus, paving sets which allow rain to pass through are described in the Journal "ADAC Motorwelt", No. 2, 1993, pages 6, 7 and 8. In particular, there is a report there on a "filter set" made up of small pebbles which, in the same way as a sponge, allows rainwater to trickle through exactly where it falls. It is suitable not only for car parks but also for footpaths and bicycle paths.
Open-cell moldings of thermoset polyurethane are also known as a binder for a gravel-sand mixture. Thus, EP 468 608 describes a drainage element for lining wells. It consists essentially of 20 to 30 parts by weight of a defined aggregate and 1 part by weight of a polyurethane-based binder. Filter gravel with a particle size of 1 to 4 mm is used as the aggregate. Curing takes place at 80.degree. C. in the presence of a catalyst. The disadvantage is that grains of sand smaller than 1 mm in diameter have to be removed. In addition, curing at 80.degree. C. is too laborious and hence too uneconomical. Finally, the polyurethane binder is not evenly distributed. A particularly harmful aspect is that "nests" of unwetted fines are formed to the detriment of strength.
WO 92/18702 describes liquid-permeable elements which are produced by joining several unsupported segments with a cast elastomer. The segments consist of a mixture of gravel, polyurethane and casting resin. The grain fraction consists of particles 2 to 8 mm and 2 to 4 mm in diameter. The binder makes up 5% by weight.
In their prospectus entitled "Ecofilter", the Laubag company describes a pressure-resistant unsupported gravel filter produced from a polyurethane binder and a quartz sand mixture with a particle size of 1 to 4 mm. It is distinguished by the following advantages: high permeability to water, long-life well column, excellent filter effect, suitable to a depth of 200 m and high mechanical strength, more particularly high impact strength. Nothing is said about the production of the gravel filter or, in particular, about the polyurethane binder used.
DE 40 23 005 describes a polyurethane system which is suitable, for example, for filter construction, for fitting glass in window frames and for the production of sandwich elements. The polyol component contains 15 to 100% by weight of polyol, 0 to 85% by weight of filler, 0 to 5% by weight of a drying agent, such as zeolite, 0 to 2% by weight of thickener, 0 to 2% by weight of other auxiliaries, for example dyes or catalysts, and 1 to 10% by weight of a thixotropicizing agent of a mixture of polyamidoamine with a low molecular weight polyfunctional amine.
Starting out from this prior art, the problem addressed by the invention was to provide a binder for granular material which would provide for the safe and simple production of open-cell moldings of high mechanical strength which, in particular, are non-toxic.
SUMMARY OF THE INVENTION
The solution provided by the invention is defined in the claims and lies essentially in the choice of a certain isocyanate/polyol casting resin based on the following components: in the casting resin in such concentrations that, within 10 minutes of mixing, it flows downwards a) by at least 15 cm at 25.degree. C. and b) by at most 3, preferably 2 and, more preferably, 1 cm, but by at least 0.6 and preferably by at least 0.3 cm at 130.degree. C. In this way, the viscosity of the reactive resin on the one hand is so low when it is stirred at room temperature that granular material is thoroughly wetted and, on the other hand, is so high in the event of an increase in temperature without stirring that a film in the vertical position does not flow downwards. A thermoset polyurethane is formed on curing of the resin.
DETAILED DESCRIPTION OF THE INVENTION
Basically, any polyols of the type already know
REFERENCES:
patent: 3965051 (1976-06-01), Markusch et al.
"ADAC Motorwelt", No. 2, 1993, pp. 6, 7, and 8. Feb., 1993.
Kohlstadt Hans-Peter
Plutniok Claudia
Schlingloff Nicole
Thiele Lothar
Gorr Rachel
Henkel Kommanditgesellschaft auf Aktien
Jaeschke Wayne C.
Ortiz Daniel S.
Wood John Daniel
LandOfFree
Isocyanate/polyol casting resin does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Isocyanate/polyol casting resin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Isocyanate/polyol casting resin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1492917