Process for producing a mainly inorganic foam, and thus produced

Details Process for producing a mainly inorganic foam, and thus produced Process for producing a mainly inorganic foam, and thus produced

1996-09-24

1998-06-30

Dudash, Diana

Compositions: ceramic

Ceramic compositions

Pore-forming

106601, 252 62, 4283122, C04B 2834, C04B 3802, C04B 3810, B32B 326

Patent

active

057733767

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to a process for producing an inorganic solid foamed mass or molded part with a density of preferably more than 0.15 g/cm.sup.3 which comprises mixing a first component, which comprises a phosphate solution and a hardener, with a second component comprising a foaming agent. The two components may be mixed themselves, and may contain additional additives. The invention includes not only the process of mixing, but also the resulting foamed products.
For the thermal insulation, for example of furnaces, temperature resistant light bricks, fibrous materials or inorganic foams are used. The disadvantage of the light bricks is their brittleness. The weakness of the fibermats is, besides the common environmental problems of fibers, their low stability, which can lead in the case of certain applications to a disintegration of the mats. The inorganic foams, however, are mostly based on water glass or glass and often possess due to the melting point of glass, relatively low application temperatures. It is the aim of this invention to describe an environmentally sound, multi-purpose applicable insulating material also useable for high temperatures.
Such foams are known amongst others from U.S. Pat. No. 3,148,996, where to an aqueous acidic solution of a metal phosphate finely powdered calcium silicate (wollastonite) is added and where after five minutes of ripening time, before hardening of the mass occurs, through stirring of solid calcium carbonate as foaming agent into the mass a foam is produced.
In U.S. Pat. No. 3,330,675 instead of calcium silicate a basic compound is used. To an aluminum phosphate solution equivalent amounts of a basic compound and a gas forming as foaming agent acting compound are added.
In DOS 27 56 198 on the basis of metal phosphate and powdered calcium carbonate a foam with a specific weight below 0.15 g/cm.sup.3 is described Here an equivalent ratio of the metal valences to he protons of the phosphate groups of 0.65 to 0.95 is used and mainly highly viscous, already precured metal phosphate solutions are used, in which the solid carbonate is to be stirred.
A continuous process for the production of a foam with low specific weight, which is filled into moulds, is described in DD 205 429. Here an acidified metal phosphate solution, which can contain fillers, a suspension of a bivalent metal carbonate, is mixed continuously in a two component spraying gun and the mass is blown with a gaseous pressure medium into moulds or spaces to be filled.
In none of the mentioned patents a foaming mass on the basis of phosphates with adjustable hardening characteristics or with as far as possible independently adjustable working parameters like starting time, rising time and setting time, etc. as defineable for a polyurethane foam, is described. The invention, as described in the claims, particularly points out the subject matter how to overcome these disadvantages and to describe a foaming and solidifying inorganic mass, in which as decisive advantage the density can be adjusted in wide ranges and the working parameters of above can be adjusted largely possible independently from one another.
Important for the homogeneity of the foam is in the case of fast reacting components, the rapidly obtainable regularity in the distribution of hardener and foaming agent in the acidic component. The addition of these compounds can usually occur in two ways; as powdered solid matter or as suspension in water. A solution in water is only possible in the case of alkali- or ammonium carbonates or hydrocarbonates.
The addition of solid matter, to be stirred in causes, (especially in the case of large amounts and possible mixing times of only some seconds) due to the reactions on the surfaces of the solid matter, that during the mixing process locally different concentrations arise and thus different cross-linking reactions occur. A fast, homogeneous, strongly stoichiometric reaction, is necessary for a fast foam hardening, and is especially necessary for the entire foam amount also in the c

REFERENCES:
patent: Re33366 (1990-10-01), Barrall
patent: 3141857 (1964-07-01), Sommer
patent: 3150988 (1964-09-01), Dess et al.
patent: 3598618 (1971-08-01), Fuji et al.
patent: 4124365 (1978-11-01), Williams et al.
patent: 4171985 (1979-10-01), Motoki et al.
patent: 4207113 (1980-06-01), Yoshino et al.
patent: 4226908 (1980-10-01), Yoshino et al.
patent: 4724242 (1988-02-01), Vassileff

Affiliated with

Also associated with

Rating

Process for producing a mainly inorganic foam, and thus produced does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for producing a mainly inorganic foam, and thus produced, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for producing a mainly inorganic foam, and thus produced will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1858974