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...
Reexamination Certificate
2002-08-30
2004-03-30
Niland, Patrick (Department: 1714)
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...
C427S372200, C427S385500, C524S589000, C524S590000, C524S591000, C524S837000, C524S838000, C524S839000, C524S840000, C524S044000, C524S021000, C524S049000, C524S052000, C524S085000
Reexamination Certificate
active
06713554
ABSTRACT:
The present invention relates to compositions for the manufacture of organo-mineral products, products obtained therefrom and their use.
Methods for the manufacture of porous (foamed) and non-porous organo-mineral products by the conversion of polyisocyanates and aqueous alkali silicate solutions (water glasses) are known, for example, from DE-A-177 03 84, DE-A-246 08 34 and EP-B-0 000 579. In these instances, alkali water-glasses with a different solid-substance content and different ratio of Me
2
O/SiO
2
(Me: alkali metal) are preferably used.
Organo-mineral products characterized by a high mechanical strength are described in EP-B-0 167 002. Polyisocyanate in an aqueous alkaline solution containing SiO
2
is induced into trimerization by the addition of a defined quantity of a polyisocyanate trimerization catalyst.
Initially, the NCO/water-glass reaction is largely suppressed, so that a quantity of gaseous CO
2
, controllable by the formulation, is produced, which is optimally used for the reaction with the water glass. During the reaction, two interwoven polymer structures are simultaneously formed, so that there is a dense high-strength network in the organo-mineral product produced.
In the first stage of the reaction, a proportion of the polyisocyanate reacts with the water to form polycarbamide, with the separation of gaseous CO
2
. The CO
2
produced in situ reacts instantaneously with the Me
2
O component of the water-glass solution to form Me
2
CO
3
×H
2
O. By the bonding of the Me
2
O from the water-glass solution, the SiO
2
component is induced to form polysilicic acid. Considerable quantities of heat are released in the reaction, so that, in the next stage, a particular further proportion of the polyisocyanate can take part in the trimerization reaction. Initially trimerized products for their part at least partly undergo further trimerization, so that a branched high-molecular structure can be formed.
A similar concept is applied in mining and tunnelling to stabilize coal and rock, as well as in the construction industry in general to stabilize and consolidate stone and brickwork, as in the preservation of old structures, for example, and is described in EP-B-0 167 003.
For application purposes, it is in most cases desirable in practice to process two-component systems, consisting of a water-glass component (component A) and an isocyanate component (component B), wherein the catalyst can be added either to component A or component B. On the one hand, the catalyst should be chemically compatible with the component concerned, and on the other there should be an even dispersion of the catalyst in the component.
In the isocyanate component, the stable dispersion/solution of a catalyst presents no problem, provided moisture is strictly excluded whilst working. Heterocyclically substituted ethers which can be stably dispersed in the isocyanate component are described in EP-B-0 636 154. In practice, however, this is only possible in closed systems, such as in spray cans or with cartridge methods.
The catalyst is therefore generally added to the water-glass component. Whereas, in the isocyanate component, stable dispersion of the catalyst presents no problem, provided the exclusion of moisture is ensured, in the water-glass component, on the other hand, it is impossible to prevent floating or hydrolysis of the catalyst in the highly alkaline solution, so that the catalyst can be added only shortly before the components are mixed, or must be carefully redispersed in the water-glass component shortly before being brought together with the other components.
It has been observed that the tendency towards dehomegenization can be reduced if antimony trioxide is added to the mixture (EP-B-0 167 002+003). Even this, of course, does not produce a dispersion which can be stored for months. Using the dispersing agents, solubilizers, stabilizers, emulsifiers, wetting agents, surfactants or polyols has not yielded a completely satisfactory result, either.
Catalysts used in the past have been amine catalysts common in polyurethane chemistry, such as tertiary amines, tertiary amino-alcohols or polyamines. Besides these, the trimerization catalysts known from EP-B-0 167 002 and EP-B-0 167 003 are also used: these are similarly tertiary amine catalysts or Mannich bases. Metallo-organic compounds, such as dibutyl tin laurate, are described in EP-B-0 016 262. With the tertiary amines and Mannich bases customarily used as catalysts in the past, even when polymers have been used on the isocyanate side, mechanically strong, but relatively brittle, hard products have in fact been obtained, in which the properties of the product are difficult to control.
The invention is consequently based on the problem of producing new organo-mineral products which exhibit the desired properties, are cheap and can be manufactured in a simplified manner.
This problem has been solved by the surprising discovery that primary amino-alcohols can be stably dissolved as catalysts in the water-glass components, at the same time resulting in organo-mineral products with the desired properties. This is surprising, insofar as primary amino-alcohols are hardly used in polyurethane chemistry, since undesirable effects, such as “swelling” of the reaction mixture, often occur as a result of the extremely high reaction rate. The controllability of the desired product-properties also decreases as the reaction rate increases. It is all the more surprising, because the use of primary amino-alcohols not only solves the long-standing problem of the stable dispersibility of the catalyst in the water-glass component, but also opens up the way to organo-mineral products with specific properties/characteristics. With the tertiary amines and Mannich bases which have customarily been used as catalysts in the past, even when polymers have been used on the isocyanate side, mechanically strong, but relatively brittle, hard products have in fact been obtained. With the existing invention, it has now become possible to produce organo-mineral products which are not only characterized by a high mechanical strength, but in addition also by outstanding elastic properties, whereby a high mechanical load carrying capacity is obtained.
The subject of the present invention is consequently a compositions comprising a component (A) containing an aqueous alkali silicate solution and a primary alcohol as a catalyst, and a component (B) containing a polyisocyanate.
The subject of the present invention is further an organo-mineral product, essentially from the conversion of polyisocyanates and aqueous alkali silicate solutions, in the presence of a primary amino-alcohol as a catalyst.
The subject of the present invention is also the use of an organo-mineral product as a building material, coating material, sealant or insulating material, or as a cement or adhesive.
The essential constituents of the reaction mixture for the manufacture of organo-mineral products are an aqueous water-glass solution, a polyisocyanate and a primary amino-alcohol as catalyst.
The catalysts according to the invention preferably exhibit the following general formula:
in which R
1
and R
2
, independently of each other, represent a hydrogen atom, a hydroxyl or methyl group, and m, n and p, independently of each other, have the value zero or a whole number from 1 to 20, preferably 1 to 10, and especially 1 to 4, with the condition that they cannot all be zero.
Catalysts in which n=1, 2 or 3, m=1 and p≧0 are preferable used.
The aforementioned catalysts can be used individually or as a mixture.
In the composition of the water-glass solution which is customary and is preferably used according to the invention, the molar ratio of catalyst to NCO groups is 2 to 150, and preferably 8 to 40 mmol catalyst per mole of NCO. The molar ratio of the catalyst to SiO
2
is preferably 5 to 100 mmol catalyst per mole of SiO
2
. The molar ratio of catalyst to Me
2
O is preferably 5 to 100 mmol catalyst per mole of Me
2
O.
Organo-mineral products with particularly f
Fosroc International Limited
Niland Patrick
Nixon & Vanderhye P.C.
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