Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Cellular products or processes of preparing a cellular...
Reexamination Certificate
2001-02-20
2004-03-16
Cooney, Jr., John M. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Cellular products or processes of preparing a cellular...
C521S100000, C521S101000, C521S104000, C521S105000, C521S106000, C521S107000, C521S109100, C521S123000, C521S124000, C521S128000, C521S172000, C521S173000, C521S174000
Reexamination Certificate
active
06706774
ABSTRACT:
BACKGROUND INFORMATION AND PRIOR ART
Intumescing polyurethane foams for fire protection purposes have been known for many years and are used as stuffing for seats in aircraft, trains and buses, as well as in the furniture industry, but also as blocking material for closing off openings, breaches, pipe and cable leadthroughs in walls, floors and ceilings, particularly in firewalls, and joint tapes, in order to prevent the spread of fire through these openings or joints. For the production of such intumescing foams, there is essentially the method of subsequently impregnating the foam by fulling in additives, that is, incorporating chemically intumescing additives, mainly based on phosphates, melamine, carbon-supplying substances and the like during the production of the foam, as well as incorporating swelling graphite during the preparation of the foam, optionally with the use of additional additives.
For example, the EP 0 400 402 describes fire-protection elements based on polyurethane foam materials, which contain swelling graphite, phosphorous-containing polyols, borates and/or ethylenediamine salts and optionally are equipped additionally and conventionally to be anti-inflammatory and/or contain conventional anti-inflammatory additives, fillers or auxiliary materials. These fire protection elements are used as construction materials, in that the polyurethane foam is cured and, from the cured material, the construction element is developed in the respectively desired shape, so that these separation elements can be assembled on site from individual pieces, optionally using adhesives, and installed. The foam materials obtained have a bulk density of more than 200 kg/m
3
.
These and all other known foam systems for preventive fire protection are machine-manufactured molded parts or blocks of the foam cut to size, which must be incorporated as finished molded parts at the building site. This means that appropriate blocks must be kept in storage or corresponding costs arise for the adaptation.
From the DE-A 38 28 544 and the EP 0 192 888, high resilient, flame-protected polyurethane foams for upholstery purposes are already known which, to improve their flame protection properties, contain expanding graphite and other additives for producing an intumescing crust, in order to achieve insulation by these means and to retard the rate of burning. Normally, these polyester foams have a bulk density of less than 100 kg/m
3
(mostly about 50 kg/m
3
) and is produced on a large industrial scale according to the REM method (Reaction Injection Mode). However, they do not have the fire resistance endurance of two hours at an installed depth of 100 mm, which is required for pipe and cable leadthroughs.
OBJECT OF THE INVENTION
The object of the present invention is to provide an intumescing foam system, which can be processed at the building site without the use of machinery and with a high foam yield (at a density of less than 200 kg/m
3
) and provides a fire protection foam of increased fire resistance endurance.
SUMMARY OF THE INVENTION
This objective is accomplished by the two-component on-site foam system of claim
1
. The dependent claims relate to preferred embodiments of this object as well as to the use of this two-component on-site foam system for filling openings and cable and pipe leadthroughs in walls, floors and/or ceilings of buildings with foam for the purpose of fire protection.
Surprisingly, it has turned out that, by reacting a polyol component, which contains at least one polyester polyol, at least one aminopolyol, at least one halogen-containing, preferably brominated polyol, at least one acid-forming agent, expanding graphite and at least one ash crust stabilizer, with a polyisocyanate component in a molar ratio of isocyanate groups to hydroxyl groups of more than 1:1, a foam system is obtained which, in the event of a fire, does not intumesce or does so only a little and, at the same time, forms a stable ash crust, which is not removed during the fire. In this way, it is possible to achieve an ASTM 814 fire resistance endurance of 3 hours at an installed depth of 100 mm without additional auxiliary materials and to do this with a two-component on-site foam system, which is formed at the building site by introducing the mixed components into the opening that is to be closed off.
The invention therefore relates to a two-component on-site foam system for producing an intumescing fire protection foam with a density of less than 200 kg/M
3
and an increased fire resistance endurance with a polyol component (A), which contains at least one polyol, one catalyst for the reaction between the polyol and the polyisocyanate, water or a blowing agent based on a compressed or liquefied gas as foam-forming agent and at least one intumescing material based on an acid-forming agent, a carbon-supplying compound and a gas-forming agent, and a polyisocyanate component (B), which contains at least one polyisocyanate, wherein the polyol component (A) contains at least one polyester polyol, at least one aminopolyol, at least one halogen-containing polyol, at least one acid-forming agent, expanding graphite and at least one ash crust stabilizer, the quantitative ratios of the polyols to the polyisocyanates being matched so that, when the polyol component (A) is mixed with the polyisocyanate component (B) as specified, the molar ratio of isocyanate groups of the polyisocyanate to the hydroxyl groups of the polyol (NCO: OH ratio) is larger than 1:1.
In accordance with a preferred embodiment of the invention, the polyol component (A) contains 3 to 40 percent by weight and preferably 5 to 30 percent by weight of polyester polyol, 3 to 50 percent by weight and preferably 5 to 20 percent by weight of aminopolyol, 5 to 20 percent by weight and preferably 10 to 15 percent of a halogen-containing, preferably brominated polyol, 5 to 30 percent by weight and preferably 10 to 20 percent by weight of an acid forming agent, 1 to 20 percent by weight and preferably 2 to 10 percent by weight of a carbon-supplying compound, 1 to 10 percent by weight and preferably 5 to 8 percent by weight of at least one melamine compound as gas-forming agent and 10 to 40 percent by weight of expanding graphite.
Preferably, a polyester polyol is used with a functionality of 1.5 to 5 and a hydroxyl number of 100 to 700. The aminopolyol preferably has a functionality of 2 to 5 and a hydroxyl number of 200 to 700, while the halogen-containing, preferably brominated polyol preferably has a functionality of 2 to 5 and a hydroxyl number of 100 to 500, while the polyisocyanate component (B) advantageously contains a polyisocyanate with a functionality of more than 2 and an NCO content of 20 to 40 percent. Such polyols are known to those skilled in the art and are commercially obtainable.
The polyisocyanate component (B) contains, as polyisocyanate, materials usually used for polyurethane foams, such as aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic polyisocyanates, particularly 4,4′-methylenedi(phenyl isocyanate), toluylene diisocyanate, isopropyl diisocyanate, hexamethylene diisocyanate or one of the customary isocyanate prepolymers.
The polyol component (A) may additionally containing diether polyols, hydroxyl-terminated polybutadiene and/or polyethylene glycol.
Pursuant to the invention, a salt or an ester of an inorganic, non-volatile acid, selected from sulfuric acid, phosphoric acid or boric acid, is used as acid-forming agent. Particularly preferred acid-forming agents are ammonium phosphate, ammonium polyphosphate, diamine phosphates, esters of phosphoric acid with polyols, such as pentaerythritol, melamine phosphates, such as melamine orthophosphate, dimelamine orthophosphate, dimelamine pyrophosphate or melamine polyphosphate, boric acid salts, such as melamine borate, and/or borate esters.
The polyol component (A) preferably contains 1 to 20 percent by weight and especially 2.5 to 10 percent by weight of the ash crust stabilizer, for which purpose preferably a particulate metal from the group, comp
Förg Christian
Heimpel Franz
Lieberth Wolfgang
Münzenberger Herbert
Rump Stefan
Cooney Jr. John M.
Hilti Aktiengesellschaft
Sidley Austin Brown & Wood LLP
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