EP2958875A1 - Porous masses or moulded bodies consisting of inorganic polymers and production thereof - Google Patents

Abstract

Disclosed is a method for producing a porous mass or a porous moulded body consisting of an inorganic polymer, according to which water glass is tempered using specific amounts of a carbonate, thus allowing the addition of various other materials. Disclosed are also porous masses and moulded bodies which can be obtained by means of the method and the use of said masses and moulded bodies.

Description

 Porous masses or shaped bodies of inorganic polymers

 and their production

Area of Expertise

The present invention relates to a process for the preparation of porous masses and moldings of inorganic polymers, as well as masses and moldings obtained in this process and their use, e.g. in the construction industry and foundry auxiliary bodies.

background

Inorganic polymers are known. Thus, a reaction between water glass, ie sodium silicate, and metakaolin (Al ₂ Si ₂ O ₇ ) is often referred to in the literature as geopolymerization. Geopolymerisation is based on the formation of polymeric structures between oxygen, silicon and aluminum. Are reacted with water glass with metakaolin with admixture of sodium or potassium hydroxide as an activator; the optimum pH of this reaction is in the range of pH 13-14. According to J. Davidovits in "GEOPOLYMERS Inorganic polymeric novel materials", Journal of Thermal Analysis, Vol. 37 (1991), pp. 1633-1656 Reaction of an OH-catalyzed polycondensation of SiOH and AlOH groups to a mixed silyl ether (SiOAl) with elimination of water This reaction is characterized by its long duration of several hours to days and is usually accelerated at elevated temperatures (80-160 ° C) The three-dimensional network formed consists of covalent -Si-O-Si and -O-Si-O-Al-O bonds in the form of Si and Al tetrahedra, which are linked to each other via four oxygen atoms. The bond lengths between silicon and oxygen (Si-O: 1.63 Å) and aluminum-oxygen (Al-O: 1.73 Å) are almost the same length, and there are virtually no -O-Al-O-Al-O bonds (Löwenstein Rule), so every aluminum tetrahedron (A10 ₄ ^" M *) mostly surrounded by four SiCV tetrahedra. The production of foams with geopolymers is considered possible, but very difficult. This makes it difficult to use the known geopolymers for insulation materials.

However, insulating materials are gaining importance due to the shortage of oil supplies available worldwide and the need to reduce CCVE emissions. Much of the required oil is used for heating. Therefore, house insulation can save enormous quantities of oil. Currently, however, it is mostly insulated with organic materials such as foamed polystyrene, which is flammable and impermeable to water. With bad house ventilation, this quickly leads to mold growth and in case of fire, melting and dripping polystyrene obstructs an evacuation of the inhabitants. In addition, polystyrene itself is made from petroleum.

There are a number of documents dealing with the foaming of inorganic substances and other applications of inorganic substances.

Thus, from DE-OS 23 23 488 a process for the preparation of foam or compacts is known, with which one carries out the solidification of inorganic substances in the presence of boron phosphate and polyhydroxylated organic compounds. It should be used as aqueous solutions mixtures of alkali metal silicates and urea formaldehydes. The reaction product of boric acid and phosphoric acid (boron phosphate) should work well in inorganic-organic systems and by slow hydrolysis, a solidification of the silica in a glass of water in the desired manner.

From EP 1 241 131 Al the use of polymeric aluminum phosphate as a means for controlling the setting, in particular curing of plaster is known, wherein the polymeric aluminum phosphate is to have a certain P: Al-Mo Iverhältnis, by tempering a certain ratio of the different forms B and A is to be set, the amorphous material content between 15% to 70%, the particle size distribution D ₀ 0.1 μιη to 100 μπι, the water-soluble fraction should be greater than 2% _. and the content of A1 ₄ (P ₄ O ₁₂ ) _{3 should be} greater than 1%. It is mentioned that polymeric aluminum phosphate should be used in the form of an anhydrous suspension, and as a liquid. For this suspension, the water-soluble lower alcohols, copolymers of ethylene oxide / propylene oxide, the block polymers of ethylene oxide, propylene oxide, mono- and dimethylene glycol, alkyl ethers, in particular triethylene glycol alkyl ethers and Dipropylenglycolalkylether to be used.

From DE 28 13 473 C3 a method for producing an expanded material based on alkali silicate from a mixture of at least one alkali metal silicate and at least one pore-forming agent in the form of aluminum or silicon and active and optionally inactive materials is known, wherein the expansion in the presence of a methyl ester and / or propylene carbonate to be carried out. The methyl ester should be formed in situ during the expansion.

From DE 36 17 129 AI solid silicate-based foams are known, wherein silicate solutions using gases without external heat supply by chemical reaction of an added gas generating system should be foamable to place foams. As foaming gases are proposed to aqueous silicate solutions, inert or reactive gases, in particular oxygen, carbon dioxide, nitrogen, ammonia, hydrogen or nitrous oxide. Oxygen for foaming is said to be produced with hydrogen peroxide which is unstable in the alkaline media prevailing there and by catalysts, for example chromium (VI) compounds, manganese dioxide or permanganate, salts of transition metals, activated carbon, pumice powder or other high specificity powder substances Surface is to be decomposed to produce oxygen. In addition, the production of CO _{2 is} discussed by isocyanates, the production of nitrogen from ammonium compounds, etc. For curing the silicate foams, hydrolyzable organic esters, sodium fluorosilicate, potassium fluorosilicate, calcium fluorosilicate, potassium fluoroborate, calcium fluoroborate, calcium fluorotitanate, polyvalent metal salts, weak acids, organic borates, alkoxy esters of polyvalent metals, carboxylic esters of polyvalent metals, binary organic salts, cements capable of silicating, Nat - Riumaluminat, aluminum and iron phosphates, zinc borate, metal oxides, alkali hydrogen carbonate, alkali metal hydrogen phosphates or mixtures thereof proposed. Framework-forming substances are hydraulic materials such as cements, gypsum, polyisocyanates or water-dispersible scaffold-forming synthetic resins. The possibility of a thermal aftertreatment is discussed. From DE 40 40 180 AI a molding compound or consisting of several parts compilation of the components for producing a solid foam product is known, with an inorganic stone-forming component, a water-containing second component which causes the curing reaction of the stone-forming component in the alkaline region, as well as with a foam-forming component, wherein the addition of a surface-active, amphiphilic substance is proposed in an amount sufficient to influence the pore structure or strength.

From DE 32 46 619 an at least partially made of foam inorganic moldings based on alkali metal silicate is known, which is formed by casting and curing by heating from water-containing molding materials and indeed from an oxide mixture with contents of amorphous Si0 ₂ and alumina, silica, alkali metal silicate solutions, optionally Alkali hydroxide, possibly in aqueous solution and optionally fillers and foaming agent. Likewise mentioned is a maturing or waiting time between molding and possible formation of the molding by heating. As fillers inorganic substances in ground or distributed form are discussed, for example ground minerals, basalts, clays, feldspars, mica flour, glass flour, quartz sand, quartz flour, bauxite flour, alumina hydrate, alumina waste, bauxite or corundum industry, ashes, slags, fiber materials and other inert non-water-soluble mineral and possibly organic minerals. For foamable molding compositions light fillers such as pumice, vermiculite or perlite are given as preferred.

From DE-OS 36 17 129 the foaming of aqueous silicate solutions with gases is known.

From DE 197 17 330 Al, the use of inorganic foams consisting of silica and / or alumina, a hardener of alkali water glass and a blowing agent of hydrogen peroxide for producing a housing for installing a sanitary equipment components is known, consisting of combined into a ready-to-install installation group pipe strands Absperrrorgangen, rule bodies and / or monitoring operations exist. From DE 197 06 492 Al a brick for statically resilient masonry as a homogeneous solid brick with open-cell structure is known. A very low Scherbenrohdichte should lead to a lower thermal conductivity. At the same time to be effected by the nature of a blended in the production of foam and the stabilizer used, that forms a stable framework at the pore boundaries, which allows relatively high compressive strengths, including in surfactant foam slip is to be mixed, the surfactant should contain silica as a stabilizer.

EP 0 148 280 B1 discloses hydrous, curable molding compositions of inorganic constituents in a flowable or pressable distribution with optionally contained fractions of fillers.

Low-sodium silicate foams are known from DE 10 2005 051 513 AI, for which a dispersion of Si0 ₂ particles with a surfactant and a blowing agent at temperatures below 50 ° C mixed and the mixture at a temperature between 60 ° C and 100 ° C. or is foamed under pressure release. A sintering can then take place in the range of 200 ° C to 500 ° C.

From DE 10 2008 058 664 Al an automatically foaming and hardening mineral foam is known, is liberated for foaming oxygen by catalytic decomposition of hydrogen peroxide.

From DD 296 676 A5 an inorganic foam body is known, which are formed from at least partially open-cell, foamed by heating and cured mixture of alkali water glass and a filler from the group alumina, silica, alumina cement, rock flour and graphite or mixtures and have a certain density should. The exemplified mixtures must be heated.

From DE 100 29 869 AI a fiber-free, non-combustible foamed insulation and fire protection material based on inorganic materials is known, which has a content of 5 to 20 wt .-% swellable phyllosilicate, 30 to 80 wt .-% silicate rods, 10 bis 40% by weight of colloidal silica, alumina and / or alkali silicate, 0.05 to 10% by weight of aluminum sulfate and 0 to 15% by weight of a hydrophobing agent.

DE 101 41 777 A1 discloses an inorganic foam based on an aluminosilicate with a molar ratio Si0 ₂ : Al ₂ O ₃ of 20: 1 to 1: 1, which has a density of less than 25 g / l. Hydrocarbons, alcohols, ketones and esters are mentioned as blowing agents.

From DE 196 16 263 Al a process for the preparation of aerogels and xerogels is known. In this case, the gel precursor should be treated with a C0 ₂ soluble, aprotic solvent. The preferred solvent is propylene carbonate, which is to be mixed with inorganic gels, organometallic compounds, etc. The mixture should be mixed with a solvent, for example propylene carbonate, water and acid, preferably hydrochloric acid, to produce a transparent gel after one to two days.

From DE 196 28 553 Cl a foam for fire protection and / or insulating purposes is described, which arises from a solution containing Al (H ₂ P0 ₄ ) ₃ and water, and a mixture of MgO mica, aluminum hydroxide and Mn0. ₂ and from a foaming agent with H ₂ 0 ₂ and water. It is stated that inorganic fillers and as processing aids, inter alia, polyacrylic acid esters, polyurethanes, polyvinyl alcohol, polyethylene are usable.

From the essay "water glass ester molding material for cast iron" by H. Glaß in foundry practice 1-2 / 2006, pages 22 to 26 is the use of a molding material system with quartz sand, sodium silicate as binder liquid and glycerol ester of acetic acid, which may be in the form of mono-, di- or triacetate, known as the hardener component The amount of hardener should be about 1/10 of the amount of binder.

From the article "Mechanism of geopolymerization and factors influencing its development: a review" by D. Khale and R. Chaudary in J. Mater. Be. (2007) 42: 729-746, geopolymers are known, reactions of the geopolycondensation, in particular the orthosialation and the Alkalipolysialatbildung and the reaction of Ortho (Sialat- Siloxo) to polysialate-siloxane compounds. It is also discussed that the most important factor for the compression strength of products is the pH. The effect of phosphate salts in delaying gel solidification is discussed.

Further, from "GEOLOPOLYMERS Inorganic polymeric new materials" by J. Davidovits in Journal of Thermal Analysis, Vol. 37 (1991), pages 1633 to 1656 it is known that certain inorganic substances can polycondensate at temperatures below 100 ° C.

Reference may also be made to: Andree Barg, Dissertation, Paderborn 2004; Anja Buchwald, What are Geopolymers? Concrete Plant and Precast Technology (BFT) 72 (2006), 42 - 49; Radnai, T., May, P. M., Hefter, G. and Sipos, P. (1998) Structure of aqueous sodium alu- minate Solutions: A Solution X-ray diffraction study. Journal of Physical Chemistry A, 102 (40). pp. 7841-7850;

James Murray, Davis King, Oil's tipping point has passed, Nature 481 (2012), 433-435; Ivan Sumirat, Y. Ando, S. Shimamura, Theoretical Consideration of the Effect of Porousity on Thermal Conductivity of Porous Materials, J. of Porous Materials, 13 (2006), 439-443; J. Davidovits, J. Mater. Educ. 16, (1994), 91-137; H. Rahier, B. van Meie, J. Wastiels, X. Wu: Low-temperature synthesized aluminosilicate glasses, Part I: Low-temperature reaction stoichiometry and structure of a model compound. J. Material Science, 31 (1996), 71-79; H. Rahier, B. van Meie, J. Wastiels, Low-Temperature Synthesized aluminosilicate glasses, Part II: Rheological transformation during low-temperature and high-temperature properties of a model compound. J. Material Science, 31 (1996), 80-85; H. Rahier, W. Simns, B. van Meie, M. Briesemans, Low-Temperature Synthesized Aluminosilicate Glasses, Part III. Influence of the Composition of the Silicate Solution on Production, Structure and Properties, J. Material Science, 32 (1997) , 2237 - 2247; WD Nicoll, AF Smith, Stability of Dilute Alkaline Solutions of Hydrogen Peroxides, Industrial and Engineering Chemistry, 47 (1955), 2548-2554; E. Rönsch, A. Porzel, Chemical modification and investigation possibilities of water glass solutions as a binder for foundry mold materials, foundry technology 27 (1988), 348-351; KJD MacKenzie, IWM Brown, RH Meinhold, Outstanding Problems in the Kaolinite Mullite Reaction Sequence Investigated by ²⁹ Si and ²⁷ Al Solid-state Nuclear Magnetic Resonance: I, Metakaolinite, J. Am.Ceram. Soc. 68, (1985), 293-297; Puyam S. Singh, Mark Trigg, Iko Burgar, Timothy Bastow, Geopolymer formation process at room temperature studied by Si and AI MAS-NMR, Materials Science and Engineering A 396 (2005), 392 - 402; Zhongqi He, C. Wayne Honeycutt, Baoshan Xing, Richard W. McDowel, Perry J. Pellechia, Tiequan Zhang, Solid State Fourier Transform and ³¹ P nuclear magnetic resonance spectral features of phosphate compounds, Soil Science 172 (2007), 501 - 515; S.-P. Szua, LC Klein, M. Greenblatt, Effect of precursors on the structure of phosphosilicate gels: ²⁹ Si and 3 ¹ P MAS-NMR study, J. Non-Cryst. Solids 143 (1992), 21-30; H. Maekawa, T. Maekawa, K. Kawamura and T. Yokokawa, The structural groups of alkali silicates glasses deterministic mined from ²⁹ Si MAS NMR, J. Non-Cryst. Solids 127 (1991), 53-64.

EP 2 433 919 A1 describes a hardener composition for controlling the setting behavior of an alkali metal silicate binder. Mention should also be made of EP 0 495 336 B1, EP 0 324 968 A1, WO 89/02878 A1, JP 57063370 A, ZA 8802627 A, EP 0 455 582 A, DE 32 46 602 A1, US Pat 4 642 137 A, US Pat. No. 4,983,218 A, GB 1 283 301 A, GB 1 429 803 A, WO 95/15229 A, DE 2 856 267 A1, EP 0 641 748 A1, DE 697 34 315 T2, GB 1 429 804 A and EP 0 495 336 Bl.

However, improvements in product properties and their manufacture are still desirable.

It is desirable to be able to show mineral alternatives to the non-mineral and mineral construction and insulation materials used today. It is also desirable to open up new uses.

It is desirable that the starting materials or components used to prepare an inorganic polymer are sufficiently stable on storage, recyclability is ensured and little to no safety requirements are to be considered during processing. The polymer should preferably be easy to prepare without heating. Furthermore, it is desirable to achieve a sufficiently rapid hardening, in particular a hardening which is so fast that, on the one hand, a good processability is ensured, ie the reacting mass is still applied as desired, blocked, cast, can be spun, etc., on the other hand, but also the time to hardening does not take too long. It is further desirable, when using the inorganic polymer as the substance to be applied, to be able to ensure a good substrate adhesion to a specific, possibly even or different substrates, eg concrete walls, existing plaster layers, iron-galvanized surfaces, etc. The porosity of the polymer should be reduced during production be easily adjustable to allow a wide range of applications. The finished polymer should be free of nail, grindable, sawable, and so on. Further, the material should be fungicidal and acid resistant, incombustible and / or refractory and / or temperature and / or UV resistant.

The object of the present invention is to provide a process for producing a porous mass or a porous shaped body which fulfills at least some of the properties described above. A further object is to provide a porous mass or a porous shaped body which has at least some of the properties described above.

The object is achieved by the method defined in the claims and the products defined in the claims. Description of the figures

Fig. 1 shows the light absorption based on the reference case of the transmitted light in

 Air. Fig. 2 shows Al-MAS NMR spectra of meta-silicate used (metakaol and a polymer obtained

Fig. 3 shows an Si-MAS NMR spectrum of a polymer obtained. Fig. 4 shows a ³¹ P NMR spectrum of NasP ₃ Oi ₀ and a polymer obtained

Fig. 5 shows the dependence of the pressure stability in MPa (A) and the thermal conductivity in W / mK (♦) on the porosity Fig. 6 shows the dependence of the viscosity of different surcharges

Fig. 7 shows a photomicrograph of a obtained porous product

Fig. 8 shows a surface photograph of a sample body

9 shows a light microscope photograph of a sample body at magnification x500 shows a light microscope photograph of a sample body at magnification x200

Detailed description of the invention

In the method according to the invention, a first composition (hereinafter composition a)) is brought into contact with a second composition (in the following composition b)) for a polycondensation.

Composition a) is an aqueous composition containing sodium and / or potassium waterglass dissolved in water.

Water glasses are usually made of sand and Na or K carbonate. They consist of water-soluble silicates whose negative charge is compensated by monovalent countercations (M ⁺ ).

It is possible to use a sodium water glass (sometimes called soda water glass) or a mixture of different sodium water glasses. In addition, a potassium water glass (sometimes referred to as potassium water glass) or a mixture of different potassium water glasses can be used. The use of one or more potassium water glasses is preferred over the use of one or more sodium water glasses, as often higher pressure stability can be achieved. According to one embodiment, a mixture of sodium and potassium water glass, such as 90:10 to 10:90 mixture, for example a 50:50 (based on total weight of dissolved water glass) mixture or a 90:10 mixture is used.

Water glasses are characterized by their s-value, which indicates the mass ratio Si0 ₂ / M ₂ 0 (M = alkali metal); the smaller the s value, the more alkali metals are present. Water glasses with different s values are commercially available.

They are e.g. Water glasses with s values in the range of 0.7 to 8 known. For the present invention preferably water glasses with an s value of 1, 3-5 are used.

As Kali water glasses come for the invention, for. those with an s value of 1.3 - 4.5, preferably 1.3 - 3.5 or 1.3 - 2.5 in question.

As soda water glasses come for the invention, for. those with an s value of 2 - 5 in question, preferably 3 - 4.5.

According to one embodiment, a mixture of water glasses is used in which the proportion of water glass with an s value of 1.3 to 5 is at least 90%, based on the total amount of water glass dissolved in composition a).

By using a mixture of potassium and soda waterglass, surprisingly, the crack resistance and the shrinkage behavior of the product could be improved. The use of potassium water glass usually has a favorable effect on the pressure stability of the product.

Aqueous solutions of water glasses are viscous. Sodium water glasses usually lead to a higher viscosity than potash water glasses with the same Si0 ₂ content (s value). The viscosity and the viscosity of the composition a) can be varied by the type and amount of waterglass or waterglasses used and, if appropriate, the use of further components, for example such that without or before the addition of a surfactant a value of 10-1000 mPa.s ( 25 ° C) is achieved. If the composition contains a) no methylsiconate, a viscosity value (measured without surfactant at 25.degree. C.) of 20-350 mPa.s, for example, can be favorable. The viscosity is measured with a rotary viscometer with a barrel-shaped spindle at 25 ° C (Brookfield viscometer DV-II + Pro with standard spindle RV 06). Without methyl sulphate (and without or before the addition of surfactants), the viscosity according to another embodiment is 50-250 mPa s or 80-150 mPa s.

For the preparation of the composition a), e.g. of commercial water glass solutions having a solids content of 30 - 48 wt .-% are assumed.

Water glasses can also be characterized by their structural properties with respect to existing silicon groups:

The s value of a water glass determines the chemical constitution of the silicate. At an s value of s = 1, the silicate has on average a negative charge. Theoretically, the s value can drop to 0.25. The formula of such a potassium silicate would be K _f SiO), ie a fourfold negatively charged silicon / oxygen tetrahedron. This functional group is referred to below as Q ₀ . If such a Q ₀ group forms an Si-O-Si bond by condensation, a Qi group is formed. There is exactly one O-Si group attached to the central silicon atom. The suffix thus refers to the number of bridging oxygen atoms that bind to this silicon atom. Accordingly, a central silicate group with two bonds to silicon atoms is called a Q ₂ -, with three bonds a Q ₃ - and with four bonds a Q4 group. The Q ₄ group no longer carries a negative charge and is neutral.

Thus, the different silicon groups can be characterized as follows:

Q ₀ : monosilicate

Q _j : end group Q ₂ : middle group

Q ₃ : branching group

Q ₄ : crosslinking group

N / A

 Q

The Si-OR group stands here as a placeholder for a further branching of the Si-O-Si skeleton. The Q ₄ group, which is not shown, no longer has a negative charge but consists only of Si (OR) ₄ groups which can no longer react in the sense of a polycondensation reaction.

To determine the percentages of Q ₀ to Q ₄ in a given waterglass, ²⁹ Si MAS NMR spectra can be used. In the context of the present invention and all embodiments described herein, water glasses with the following characterization are preferred:

Preferred range Qj: 2-6%

Preferred range Q ₂ : 10-25%

Preferred range Q ₃ : 15-25%

Preferred range Q ₄ : 45-70%, wherein the area of those peaks which is assigned to a specific silicon group Q (i) is related to the sum of the area of all Si NMR signals (= 100%). In addition, it has been found to be essential for the present invention that the pH of the composition a) at 25 ° C is at least 12 (measured with pH meter); preferably, the pH is in the range of 12 to 13.5. By using the carbonate hardener (I), the pH is abruptly lowered in the polycondensation. In order that the pH in the reaction does not noticeably drop below 10, a minimum pH of 12 is required for the composition a). Usually, the pH in the reaction will fall by about 1 - 1.5 units. The inventors have surprisingly found that no foam forms, ie no porous product is obtained when the pH falls below 10.

In view of high strength, uniform pore distribution and smallest possible pores, the pH of composition a) is preferably not substantially above 13.5.

Due to the alkaline pH, composition a) is resistant to Piizbesiedelung and relatively acid-stable, which has a good shelf life.

The composition b) contains, in addition to water, at least one water-soluble or water-miscible (preferably water-soluble) hardener, the hardener being selected from carbonates of the general formula (I)

wherein R and R are independently selected from Ci _-6 alkyl (preferably C _1-4 alkyl, more preferably Ci _-2 alkyl) or R and R with the group

form a 5-membered ring which is optionally mono- or polysubstituted by substituents selected from Ci. ₂ alkyl and C _1-2 alkyl substituted with one or more OH. 5-ring hardeners are preferred over open-chain carbonates. The C _1-6 (preferably particularly preferably C 1 _-2 ) alkyl radicals may be independently optionally substituted with one or more OH groups, which may improve the water solubility of the hardener.

Suitable examples of curing agents are dimethyl carbonate, propylene carbonate, butylene carbonate (e.g., 1,2-butylene carbonate), glycerin carbonate, and ethylene carbonate.

The first three mentioned compounds are low-viscosity, water-like liquids that are easy to dose. Ethylene carbonate is a glassy, readily water-soluble solid. Particularly preferred is propylene carbonate and glycerin carbonate; since the latter is relatively expensive, propylene carbonate is preferred from an economic point of view.

The compounds mentioned show different Hydrolyseeigenschaften: ethylene, butylene, glycerol and propylene carbonate are five-membered systems and are hydrolyzed at a pH of about 12 instantly, so in a few seconds, while the hydrolysis of dimethyl carbonate with a few minutes, typically until about half an hour, takes much longer. This influences the reaction time in the process according to the invention.

The amount of added hardener determines in the product not only the number of cross-links, but also the hardness of the product. The pore size and porosity can also be influenced by the choice of hardener and hardness.

Since the hardener affects both pore size and product hardness, it may be advantageous to use mixtures of different hardeners, especially if large pores (size of 2 to 8 mm in diameter) are desired with high hardness. For example, a mixture of ethylene and propylene carbonate could be used. In addition to methanol and 1, 2-propanediol arise as additional reaction products only water-soluble alkali metal carbonates. Upon reaction of water glass with the mentioned carbonates, in particular ethylene and propylene carbonate, only small amounts of glycol or 1,2-propanediol (C ₃ H ₇ (OH) ₂ ) and water-soluble sodium carbonate (Na ₂ C0 ₃ ) or potassium carbonate (K ₂ C0 ₃ ) formed. It is important for the invention that per mole of propylene carbonate two moles of alkali metal cations are caught and at the same time two moles of protons are released, which set the polycondensation in motion and catalyze:

C ₃ H ₇ C0 ₃ + 2 H ₂ O ⁺ 2 M ⁺ C ₃ H ₇ (OH) ₂ + Na ₂ C0 ₃ + 2 ⁺ M ⁺ = K ⁺ or Na ⁺

All reaction products can be almost completely dissolved out of the porous polymer with water. Sodium and potassium carbonate were identified by their IR spectra and 1,2-propanediol by IR and H-MAS NMR spectra.

Since the pH of the mixture, as mentioned above, should not noticeably fall below pH 10, the amount of hardener can not be increased arbitrarily. At the same time, another limitation of the reaction mixture comes into play:

 Hardener addition in the form of composition b) always means a dilution of the reaction mixture. An approach should not be diluted indefinitely, because otherwise the foam collapses too quickly. If there is too much hardener, however, the product gets stuck too fast and can not foam properly.

As explained above, the amount of hardener used and the amount of water in composition b) have a decisive influence on the product. The inventors of the present invention have found that the following conditions must be satisfied in order to obtain porous products having good strength:

(A) The amount of carbonate used in g (m _c ) is m _stö to xm _stö (B) The amount of water in composition b) is chosen so that the law applies

 x 100%> 25%

G _a + Gb

In conditions (A) and (B):

rristö = stoichiometrically required amount of carbonate in g and is calculated as m _stö = ( _{MW C} / _{MgM 2} O) * (m _WG / (1 + s)) (1) MGc = molecular weight of the carbonate used

MGM ₂ O ⁼ molecular weight of M ₂ 0 from dissolved water glass (composition a)) with M = Na or K.

mwG ⁼ amount of dissolved water glass in g in the composition a)

s = mass ratio Si0 ₂ / M ₂ 0 of the waterglass used in composition a) If a mixture of 2 or more waterglasses is used, m _st ö = m m _stö (i), where m _stö (i) is the equation (1) for each water glass (i) is the amount of carbonate calculated with the respective s (i) value.

x = 0.35 when using dissolved Na water glass in composition a) and x = 0.45 when using dissolved K water glass in composition a)

and

x = 0.35 * y a + 0.45 * yi using a mixture of dissolved Na waterglass and dissolved K waterglass in composition a), wherein

yNa = weight fraction of Na water glass based on total amount of dissolved water glass calculated according to:

(Amount in g of the dissolved Na water glass) / (total amount in g of dissolved water glass) yic = weight fraction of K water glass relative to total amount of dissolved water glass, where y _Na + y _K = 1,

when using a mixture of carbonates: MGc = Σ (MGc (i) * m (i))

with MGc (i) = molecular weight of carbonate (i)

m (i) = weight fraction of carbonate (i) based on total amount of used

 Carbonathärtern

where m (i) = 1. An example of a calculation of m _stö is as follows:

For 18 g of sodium silicate with a solids content of 34.5% and s = 3.3, so m _s te for propylene carbonate is calculated to be 2.38 g. For 40 g of _{sodium silicate} , m _stö for propylene carbonate increases to 5.28 g.

When using the carbonates (I) as a curing agent is based on a two-stage reaction: in the first stage, which runs fast and is fired after a few minutes, implementation of organic carbonate, and then a gradual drying and optionally a residual curing with C0 ₂ from the Air.

It should be noted that during such a drying process by C0 ₂ from the air bonds can be formed with elimination of water and that the resulting water emerges from the product. This reaction can last between hours and days, in typical situations the initially higher humidity remains stable for one to three days depending on the size, shape and hardness of the formed body, even though water is still being dispensed, indicating that during this time as well Curing by chemical bonding of alkali cations in the substance occurs while thereafter water is released substantially due to physical drying.

In addition to the above essential components of the compositions a) and b), these may also contain one or more optional constituents with which the reaction and / or the properties of the products can be further influenced.

It has been found that the use of a substance (or a substance mixture) which is present dissolved in composition b) and generates decomposition of O ₂ gas promotes foaming and thus pore formation in the product.

Examples of suitable substances ("gas source", "0 ₂ -Gas supplier") are H ₂ 0 ₂ , urea Ή ₂ 0 ₂ adducts, percarbonates (especially alkali metal percarbonates), perborates (especially alkali metal perborates) and ammonium peroxydisulfate ((NH ₄ ) ₂ S. ₂ 0 ₈ ). From large-scale shear view is H ₂ 0 ₂ preferred because it is commercially available as a solution and easy to dose.

When a gas source is present in composition b), composition a) is preferably added to a gas source activator. A gas source activator will effect or catalyze the release of O ₂ gas by chemical reaction of the gas source substance or the gas source mixture. For example, potassium iodide, CoCl ₂ , KMnO ₄ , MnO ₄ , CuSO ₄ , FeSO ₄ , N 1 SO ₄ and / or AgNO ₃ can be used as activator for activation of the gas source.

CoCl are preferred as activator KI, KMn0 _{4, 2} and a 2: 1 mixture of KMn0 ₄ and KI, and particularly preferably CoCl _{2 was} used.

The amount of 0 ₂ gas supplier is not particularly limited, and is for H ₂ 0 _2, preferably 0 to 10, preferably 2 to 6% by weight based on the composition a).

The amount of e.g. Perborate or percarbonate may be calculated according to the following principles:

• 1 mol of H ₂ 0 ₂ releases Vi mol 0 ₂

• Mass 0 ₂ (mo ₂ ) results

m ₀₂ =% H ₂ 0 ₂ »mges ♦ (MG02 / MGH202) ^♦ 5 ♦ VJOO

with m _ges = composition a) in g

% H ₂ O ₂ = weight H ₂ 0 ₂ based on composition a)

• alkali metal percarbonate 2 M ₂ C0 ₃ ^■ 3 H ₂ 0 _2: 1 mole is _^3/2 mol 0 ₂ free

• m _PC . _^3/2 * ₍₀₂ MG / MG _PC) =% H ₂ 0 ₂ * m * _{ges (02} MG / MG _H 202) * Vi * Άοο

Amount of percarbonate in g

Molecular weight percarbonate gives m = _PC% H ₂ 0 ₂ * m * _ges (MGP _C / MG _H2 o) * V * V _{3 100}

• alkali metal perborate M ₂ H4B 0g _2: 1 mol 1 mol of 0 ₂ free

• m * _PB (mgO2 MG _PB) =% H ₂ 0 ₂ * m * s _ge (MG02 MGH202) * i * 100 MPB = the amount of perborate in g

MGPB = molecular weight perborate gives: m = _PB% H ₂ 0 ₂ · m _ge s * (MW _PB / _H MG 202) 00 * ^ * i

The amount of activator is not particularly limited, and is preferably 0 to 0.5, more preferably 0.005 to 0.5 wt%, and more preferably 0.002 to 0.2 wt%, based on the composition a).

Hydrogen peroxide decomposes in the alkaline medium, so that typically after about 30 minutes at the prevailing conditions according to the invention (such as room temperature) almost complete decomposition of hydrogen peroxide results.

This can be further accelerated by the additional use of the activator.

As sufficient for a decomposition of hydrogen peroxide within a few minutes, for example, potassium iodide, possibly in conjunction with KMn0 ₄ in an amount of 20 to 200 mg per 100 g of composition a) has been found to be sufficient. Especially in H ₂ 0 ₂ decomposition in homogeneous solution (ie without solids in composition a) and b)), the pore formation is uniform. The formation of small pores is made possible. The viscosity of the reaction mixture increases as the pores become smaller. In addition, it is sufficient to use a lower amount of activator than in any of the previously described methods. The polycondensate material thus obtains better properties because the activator will affect the polycondensation and its side effects less. In even lower amounts, CoCl ₂ * 6H 0 as a decomposition activator of eg H ₂ 0 ₂ are used. For example, about 10 μΐ per 100 g of composition a). - 100 μΐ a 4.8 g / 10 mL H ₂ 0 CoCl * 6H ₂ 0 solution used. This is about 5 -5 0 mg per 100 g of composition a) (= 2 * 10 ^"4 molar.) In the decomposition of H ₂ 0 ₂ in a closed system, pressures of several bars are produced in the foam product. The mixture is therefore excellent suitable for foaming under pressure of complicated structures This is a special field of use of the invention.

The composition a) may optionally also contain one or more solid components homogeneously distributed in the composition. Suitable substances are kaolin, metakaolin, Si0 ₂ , perlite, disperse silicic acids, dolomite, CaC0 ₃ , A1 ₂ 0 ₃ and water glass powder. These substances can be used to increase the viscosity of the composition a), for example if a higher value is desired than is achieved with the dissolved water glass. It has also been found that these solids increase the resistance of the products to cracking and reduce cure shrinkage. The solids should be mixed in as a powder, preferably with an average particle size of not more than 1 mm, more preferably not more than 100 μm.

According to one embodiment, metakaolin is used (preferred particle size <20 μπι). According to another embodiment, a mixture of metakaolin and kaolin is used.

A mixture of water glass and metasilicate is, depending on the content of metasilicate, stable over weeks, so that the corresponding components have a sufficiently long storage time. The liquids are also easy to dose and mix, which can also happen automatically. This ensures, among other things, the production of foam bricks among other foamed products of consistently high quality.

Metakaolin is a sodium aluminum silicate and can formally be considered as a condensation product of aluminum hydroxide and silica. If, in addition to silicon, aluminum is also present in the structure, products of considerably greater hardness result. The inventors suspect that the aluminum centers in the framework carry a net negative charge.

The conversion ratio of sodium silicate to metakaolin is preferably carried out in a stoichiometric ratio of about 1: 1. It is believed that then forms a covalent, three-dimensional network of highest stability. In addition, all sodium atoms are used to saturate the aluminum cations. Thereafter, water glass could be reacted with metakaolin in a weight ratio of 242 g to 258 g. There are also Si: Al ratios of 2: 1 and 3: 1, and other conditions possible, even not even ratios. A weight ratio of water glass to metasilicate of 100: 1 to 100: 25 is preferred (more preferably 100: 5 to 100: 25) because such mixtures are readily pourable. However, an even higher proportion of metasilicate led to crumbly and too dry mixtures and is therefore not preferred, in particular for the production of porous shaped articles.

Since the incorporation of aluminum tetrahedra requires the grid to charge balance, appropriate cations, such as alkali cations must be incorporated into the scaffold. This probably leads to ionic bonding of monovalent metal cations from the water glass, provided that aluminum is incorporated. The metasilicate would then act not only as a component to build a covalent network but also as a hardener at the same time. That insofar water glass cures in a mixture with metakaolin also without further curing agent, although this may take a long time, is so far understandable and in the production of multicomponent systems for producing inorganic polymers of the invention in this regard, the storage time for the starting materials of the inorganic polymer to be formed to be observed.

To further increase the compressive strength of the porous products, composition a) may also include fibers (eg with a fiber thickness of <10 μm and a length of 1-10 mm) such as glass fibers, rock wool, basalt fibers and cellulose fibers and / or glass beads (eg with 1-3 mm diameter), styrofoam beads (eg 1-3 mm in diameter) and pumice particles. Their quantity is not particularly limited; it amounts to one Embodiment 0 wt .-% and according to another embodiment, a suitable amount is> 0 to 10 wt .-% based on composition a).

The use of phosphates in composition a) has a favorable effect on the compressive strength of the product and can also reduce the shrinkage during the drying process. The products obtained also show good anti-rust properties.

Mono-, di-, tri- or polyphosphates can be used, preferably di-, tri- and / or polyphosphates of sodium and / or aluminum. It is believed that in addition to silicate and aluminate and polyphosphates can be incorporated into the Si-O-Al skeleton of an inorganic polymer of the invention. This would be particularly advantageous because in the polycondensation of water glass as well as metasilicate, the molecules involved in each case have only two docking sites and thus in principle without the preferred phosphates linear polymers are formed. If, however, a phosphate such as trisodium phosphate (Na ₃ P0 ₄ ), tetrasodium diphosphate or pentasodium triphosphate or metaphosphates with silicates and aluminates brought to the polycondensation, branching in the chains can occur here.

This is due to the structure of the phosphates, cf. z. B. Trisodium phosphate (Na ₃ P0 ₄ ):

O II

Na ⁺ OP-0-Na ⁺

 I

Na ⁺ Ό

The connection tetrasodium for example, has four docking points, that Na ⁺ 0 ^- Group: OO

 II II

Na ⁺ OP-0-PO-Na ⁺

 I i

Na ⁺ Ό O ^" Na ⁺

A higher number of docking sites also results from trisodium phosphate and pentasodium triphosphate:

0 OO

 II II II

Na ⁺ OP-0-PO-PO Na ⁺

 1 I I

Na ⁺ Ό O ^" O ^' Na ⁺

Na ⁺

It can thus be formed three-dimensional space scaffoldings. The amount of the phosphates is not particularly limited, but is preferably 0 to 3 wt .-%, more preferably 0 to 1 wt .-% based on composition a), according to another embodiment> 0 to 3 wt .-%.

If very small bubbles and / or an overall larger and more stable foam volume is desired, it is advantageous to add a surfactant, i. one

Surfactant. Diphenyloxide sulfates, alkane and alkylbenzenesulfonates, alkylnaphthalenesulfonates, olefinsulfonates, alkyl ether sulfonates, alkyl sulfates, alkyl ether sulfates, alpha-sulfofatty acid esters, acylaminoalkanesulfonates, acylisothionates, alkyl ether carboxylates, N-acyl sarcosinates, alkyl and alkyl ether phosphates may be mentioned as anionic surfactants. Nonionic surfactants which may be mentioned are alkylphenol polyglycol ethers, fatty alcohol polyglycol ethers, fatty acid polyglycol ethers, fatty acid alkanolamides, EO / PO block copolymers, amine oxides, glycerin fatty acid esters, sorbitan esters and alkylpolyglucosides. As catonic surfactants, mention may be made of alkyltriammonium salts, alkylbenzyldimethylammonium salts and alkylpyridinium salts. The use of nonionic surfactants is preferred. The addition of PEG also proves to be advantageous because the foaming process is more uniform than without addition and the foam in turn gets more stable. It should be mentioned that with PEG addition it is also possible to completely dispense with other surfactants. The amount of the surfactants is not particularly limited, but is preferably 0 to 0.8% by weight, more preferably 0.3 to 0.6% by weight, based on the composition a).

Another optional component of composition a) are polyvalent metal oxides, preferably one or more selected from ZnO, TiO ₂ , MnO, PbO, PbO ₂ , Fe ₂ O ₃ , FeO, Fe ₃ O ₄ , ZrO ₂ , Cr ₂ O ₃ , CuO, BaO, SrO, BeO, CaO and MgO, preferred are oxides of divalent metals such as MgO, BeO, SrO, BaO, PbO, CuO, CaO, ZnO and MnO.

The addition of metal oxide is particularly advantageous when Metakaolin is used, which produces long chains in the polycondensation with water glass, which carry negative charges when incorporating an Al ³⁺ - atom. Depending on the water glass, sodium or potassium cations act as countercharges.

If metal oxides are added to the reaction mixture, a cation exchange can take place here. It is believed that oxides of polyvalent metals, e.g. can serve as a bridge between two negatively charged aluminum atoms and help build a three-dimensional network framework. It should be noted, of course, that the metal oxide admixtures are not problematic in the case of a later recycling required and that, if necessary, restrictions in terms of processability could occur without safety requirements.

Per se, trivalent or tetravalent ions such as Fe ³⁺ , Cr ³⁺ , Zr ⁴⁺ or Ti ^{4+ are also} usable as oxide and / or sulfate. However, a cluster-like arrangement of three or more aluminum atoms is considered unlikely, so that no advantage can be expected from such higher-valent ions.

Particularly advantageous is the addition of metal oxides whose metals form stable ie sparingly soluble carbonates. In the reaction with organic carbonates as hardeners, inorganic carbonates such as potash and soda are formed. If CaO, SrO, BaO, PbO, MgO or ZnO are added, a later blooming of soda and potash can be avoided and at the same time the hardness and stability of the products can be increased. The amounts of metal oxides are not particularly limited and are preferably 0 to 5 wt .-% based on composition a), according to another embodiment> 0 to 5 wt .-%.

The use of alkyl siliconeates (preferably C _1-6 alkyl siliconeates, more preferably C _1-6 alkyl siliconeates, such as methyl siliconeate) in composition a) is also possible and advantageous when water-impermeable foam or the like is desired. Thus, composite materials of water-permeable and water-impermeable foam can also be readily prepared by appropriate stratification of reaction mixtures, optionally carrying out the reaction of components with or without Alkylsilikonat successively.

It has been found, moreover, that by using methyl siliconate the otherwise very rapid reactions of e.g. Systems can be delayed with propylene carbonate. Mention may be made herein as methyl siliconeate e.g. Potassium methylsiliconate, e.g. Rhodorsil Siliconate 51 T from Rhodia. However, the delay can be helpful in order to allow extensive foaming and thus low density.

The amount of alkyl siliconates is not particularly limited, and is preferably 0 to 10% by weight, more preferably 0.1 to 5% by weight, based on the composition a).

In order to increase the strength of the products, it is also possible to add alkali metal and / or alkaline earth metal sulfates, preferably barium, calcium and / or lithium sulfate. Their amount is not particularly limited and is preferably 0 to 2 wt .-% (according to one embodiment> 0 to 2 wt .-%) based on composition a).

Of course, organic or inorganic pigments can also be added to the composition a) if dyed products are desired.

In step c) of the process according to the invention, the compositions a) and b) are brought into contact in order to allow the polycondensation to proceed. Unless additional solids such as pigments and others are present in compositions a) and b), a homogeneous fluid will be able to be reacted. This is beneficial because with it the polycondensation reaction can also take place from a homogeneous solution. The complex stirring of suspensions can thus be omitted as a rule. This allows, for example, the use of corresponding suburban construction of spray cans, spray guns, etc., especially since the components are not only faster curable, but also incombustible. The fact that, as can be seen from the above, toxic or harmful chemicals do not need to be used, thereby also allow use in indoor or indoor. It should be noted, however, that solid bodies which solidify from a homogeneous solution tend to be more severe in shrinkage. Insofar as dimensional stability during hardening is not absolutely necessary, this is not critical. Otherwise, the shrinkage can be reduced or avoided altogether if the polycondensation takes place in a suspension.

For the reaction no external heat supply is necessary. Depending on the components and quantities used, a foam is formed within seconds to minutes, which solidifies. The final strength is achieved by storage at room temperature for a few days.

If, in addition to water glass and hardener (I), other ingredients are used, an exemplary sequence of the process according to the invention is as follows:

(1) Provide a water glass solution

(2) Optionally adding an activator solution (eg CoCl ₂ solution)

 (3) Optionally adding solids such as e.g. Metakaolin and homogeneous distribution by stirring

(4) Optionally adding oxide of a polyvalent metal such as ZnO, TiO ₂

 (5) Optionally, adding a surfactant, e.g. a nonionic surfactant and optionally a phosphate

 Obtained is a stable solution or suspension A.

 (6) Provide a carbonate hardener solution

(7) Optionally adding from a gas source such as H ₂ 0 ₂ to the carbonate hardener solution (8) adding the carbonate hardener solution to the solution or suspension A, optionally with stirring.

The foaming can be done in a mold. The solidified porous body is then removed from the mold.

The foaming may take place in a cavity, e.g. Well, done and the foamed and solidified product remain therein.

The foaming can take place outside of a mold and the solidified mass afterwards be brought into a specific shape by machining such as sawing, grinding etc.

The products obtained by the process according to the invention are solidified foams (also referred to herein as porous masses or porous shaped bodies), which are distinguished by both high strength and good thermal insulation properties. In addition, they show a high temperature resistance.

The products may have closed and / or open pores. While products made using a gas source such as H ₂ O ₂ show predominantly closed pores, products made without a gas source show a mostly open pore system.

By controlling the process parameters (e.g., surfactant usage, hardener selection and amount), pores of different sizes can be produced; e.g. can average pore diameter of 40 - 300 μπι, in particular 60 to 140 μπι, or 70 - 90 μηι, can be achieved.

The percentage pore area PF can be determined as described below and fulfills the following condition for the products according to the invention:

0.5 <P _F <1 The porosity of the products obtained is also controllable via the process parameters and is preferably 40-95%, more preferably 50-92%, most preferably 65-85%, each determined by the method described below. A porosity in excess of 95% means reduced strength at the same time and is therefore undesirable for some uses.

The density of the products obtained is preferably 0.05-0.5 g / cm ³ , more preferably 0.1-0.4 g / cm ³ , determined by the method described below.

Determination of the percentage pore size

A reaction mixture (i.e., composition a) + b) was mixed) immediately after being placed in contact with a glass plate to form a hardened mass which was removed from the glass plate after curing. With the flat side (i.e., the side hardened in contact with the glass plate) of the cured sample up, the sample was placed under a light microscope and, with lateral illumination at 100-200x, a flat sample side image was taken. The pores of the sample were then recognizable on the flat surface. We calculated (1) the total area of the sample (corresponding to length x width of the image) and (2) measured the area of all pores visible on the image. The percentage pore area was calculated according to the following equation

Total area of all pores in the picture

 P = x l00%

 Total area of the image

Determination of porosity

A specimen in the form of a cuboid with edge lengths of 6 × 3.5 × 3.5 cm was produced and dried to constant weight at room temperature. The body was weighed (G in _vor g) and then 1 h in aqueous soapy water (10 drops commercial). completely rinsed with distilled water), the vessel being closed with a lid.

Subsequently, the sample body was removed from the vessel and weighed again after draining, whereby G _naC higher ng was determined. The porosity P was determined according to equation (2):

Gafter "Gvorher

 P = x l 00 (%) (2)

Body volume · density using 73.5 cm ³ for the body volume and 1 g / cm ³ for the density, so that equation (2a) is obtained:

Gafter "Gvorher

 P = x l00 (%) (2a)

 73.5

Determination of density

To determine the density, the volume and weight of a rectangular sample were determined and the density was calculated as the weight / volume.

Determination of thermal conductivity

For the determination of the thermal conductivity, test specimens of thickness 3.5 cm together with a reference body of equal thickness and a thermal conductivity of 0.0354 W / mK (available from IRMM Institute for Reference Materials and Measurements, Geel, Belgium) were left for 1 h Place a hot plate at a constant 80 ° C and then measure with a thermal imager in the dark. The measured surface temperature (as a measure of the thermal conductivity) of the sample body is used to determine the thermal conductivity of the sample body with the aid of the reference body. Determination of compressive strength

The compressive strength of the samples was measured on a Zwick Zwick Zwick tester. For this purpose, the compressive forces (in N) were recorded graphically over the deformation section. The maximum pressure reached was related to the surface of the sample and expressed as N / mm (= MPa).

The product obtained by the process of the invention has a variety of uses. It can be used as heat or cold insulation material, in particular in building construction, in industrial construction, in furnace construction and / or in thermal insulation.

It can foam or foam elements, especially water-repellent foam bricks, components for tunneling, plasters, pipes and / or pontoon stones are produced. With sufficient open cell foam, fuel such as ethanol can be included in the polymer product, allowing its use as a fuel storage, such as in rechauds or the like. The inclusion of ethanol in the foam bricks and thus their use as metered fuel may be advantageous for rechauds, chimneys and the like. The use as rock wool, for rapid prototyping (rapid production of sample components), computer-assisted molds, but also as a room coolant, especially as a means that acts room cooling through water absorption and Abgab, and the production of composite materials (eg with at least one water-barrier and a water-permeable layer) may be mentioned. From the above, the applicability also results as a passive room humidifier.

It should also be mentioned that a use of the material according to the invention can also be used as impact sound insulation, as cladding or facing of visible surfaces, for screeds, for the production of pipes, products can be used for fire protection purposes (this fire protection material is acid-resistant, mineral and light) for internal and external insulation purposes, in particular as internal and external insulation, as a fire-resistant door foam and / or as a filler for the shipment of dangerous goods such as acids, where it offers special advantages by its optionally provided with generation absorbency. The absorbency in particular according to open-pored Foams according to the present invention also allow the use of granules of such inventively prepared material as a binder in oil spills.

It is possible to produce finished elements such as walls, ceilings, cladding panels, sound insulation walls, fire walls according to the invention and / or produce pore concrete-like stones, which can also be adjusted in strength and at the same time have a higher acid resistance than aerated concrete. For building purposes can be advantageously exploited that glass fibers, fiberglass structures, carbon fibers and structures that can form a polymeric compound can be used. It can achieve such high strengths of more than 30 N / mm ² and in particular produce components that can be used simultaneously thanks to their high strength for insulation and reinforcement. It is particularly advantageous that the material can optionally be repaired without losing its positive properties such as strength and durability. It should be mentioned that, where appropriate, curing can also take place under water, which offers significant advantages in special applications.

The material can also be used as a porcelain adhesive, core insulator in bricks for prefabricated elements such as walls, ceilings, cladding panels, noise barriers, fire walls, etc.

If granules or very fine powders are to be produced, foam can optionally also be produced in a spray tower. This may make it possible to produce a lightweight filler with great mechanical stability. The pulverulent or finely ground material body are suitable as a fire-extinguishing agent at high temperatures and it is also possible to use a fast-foaming, fine-pored variant for the production of fire barriers in area fires such as forest fires, where the very large increase in volume is just as beneficial as the fact that less combustible material must be removed in case of fire. The use as a fire barrier is also advantageous because the material of the present invention not only has high heat resistance and a high melting point, but the material does not constitute hazardous waste even after passing through a fire. That this is also in conventional use in residential real estate and the like is advantageous, may be mentioned. Moreover, it should be emphasized that in addition to the use in large pieces such as for finished parts, the use of a foam according to the invention, for example as a product from a spray tower and / or in ground or, as granules in shredded form in question, such as a filler for lightweight concrete, for plasters, in particular silicate plasters, as a substitute for polystyrene, for example in bricks, ie for use as a filler to improve the heat-insulating properties of bricks and the like or other formwork or building materials. A powder, ground or shredded foam of the invention can also be used as an additive for concrete, wherein the concrete with the filler according to the invention gains resistance to acid attack. A suitably equipped concrete is particularly used in bridge construction, road construction, for sewer pipes, etc. It should be mentioned that ground or shredded silicate foam or powder can be used as a fill prior to floor laying between beams, for example in old building renovation, and in the case of fire-fighting with stainless steel pipe between pipe and chimney wall.

The products are acid-resistant, fungus-resistant, heat-resistant up to typically 1,600 ° C; They are also sawed and / or sanded, can be milled and nailed without causing cracking.

Another use is also the use as a catalyst support. So it would be e.g. possible to foam metal nitrates with. The metal nitrates will react with the liberated during polymer formation alkali metal carbonates to metal carbonates and these can be reacted at high temperatures to catalytically active metal oxides. This results in good catalysts.

The use of lead oxides, ie PbO and Pb0 ₂ allowed because of the high stability of the final product, the (preferred) unfoamed pouring of radioactive waste for permanent storage. This energy is far cheaper than the previously practiced glazing.

The heat resistance and dimensional stability up to about 1,600 ° C makes the products applicable for the furnace construction, but also in the area of fire protection, etc. The foam blocks also show a high stability against pressure and shear forces, what their use for earth- Quake-proof buildings allowed. The stability can be increased by the addition of fiber materials. Because they can not only be sawed, sanded and / or drilled, but also that nails can be hammered without cracking, the products are very easy to process. With appropriate foaming the densities are so low that pontoon blocks can be built and it is also the use of acid-stable for the production of vessels, containers and pipes possible, such as catch basins and the like. The addition of alkyl siliconates also allows use in the soil area. It is readily possible to combine compositions a) and b) from spray cans or the like and thus to use for foaming, for example, cavities such as boreholes.

The material according to the invention also has a very good adhesion, which is better on walls than plaster. Also on iron carriers and galvanized surfaces, the material adheres very well. The use of phosphates also results in anti-rust properties. The high temperature resistance and the fact that the mixtures can be spun well, also allows the production of refractory stone wool.

A product can easily be dyed with color pigments.

Due to the fast reaction speed, the system is well suited for rapid prototyping. In such an application, the viscosity is typically chosen to be so low that the components can be deployed well controlled from a reservation. If the products are to be used for passive room cooling in such a way that the finished materials absorb water and extract water from the environment when they evaporate, the products can be designed with algae-inhibiting means if the products are to be arranged visibly.

The products of inorganic polymer obtained according to the invention contain no combustible constituents (unless incombustible organic materials such as cellulose fibers were mixed in) and are thus completely recyclable. In contrast to known polymeric reactions, the reaction claimed here proceeds with a decrease in pH. As a catalyst of the polycondensation serve, unlike conventional, protons, not hydroxyl anions. The corresponding reactions proceed much faster than with conventional polycondensation and can take place at room temperature. The general problem in the production of inorganic foams, namely the too long time until hardening can thus be avoided.

With the method according to the invention, a framework which is sufficiently stable at elevated temperatures can be produced. A scaffold stability should be readily above 650 ° C, typically even up to 1600 ° C given, because in the final product neither - as in Portlandzement- water, nor - as in air mortar calcium carbonate is included, so that at higher temperatures neither escaping Water still escaping carbon dioxide can destroy the structures.

It should be noted that the porosity of the final product via various parameters of the method according to the invention, e.g. Hardeners, additives, ratio of water glass / metakaolin, quantities can be adjusted so that materials of different density can be produced. Pores of the products can be adjusted in the range of a few μπι to cm. This is advantageous because the insulating effect of insulators is based on the inclusion of air in the form of small bubbles, which is why all known thermal insulation materials are highly porous.

Non-mineral thermal insulation materials such as polystyrene, polyurethane and wool, but also rock wool, usually have a total porosity of at least 45%. In practice, values of 60 to 90% and in extreme cases (in aerogels) up to 99%. A high porosity allows a high gas permeability, but unfortunately always reduces the mechanical strength of the material.

Responsible for the heat flow are solid state conduction, convection and radiation. All three parameters show a different influence depending on the temperature. In insulating materials air convection should be avoided in any case. Pore diameters of <1 mm are desirable in order to achieve the lowest possible heat flow, because the free path of air molecules at room temperature is 68 nm. In general, the lighter the material and the smaller the pores, the better the material can absorb heat. Important is a uniform pore distribution. Stones with a small, even pore distribution should be optimally insulated. A uniform pore distribution is in particular to produce from homogeneous solution.

The reaction mixture of the invention may also be spun to give wool-like materials; the mixture of compositions a) and b) can be applied as a plaster before curing, in particular as a heat-insulating plaster, and it is possible to use the mixture in rapid prototyping.

Due to the special thermal stability up to 1600 ° C, use of the compositions according to the invention is also possible in foundry technology.

The casting of metals is a primary molding process in which molten metal is poured into a mold to form a casting according to the mold. The production of castings, especially of large and complex castings, involves considerable problems. The liquid, hot metal must namely fill the hollow body completely, so that no voids and the like arise. But it must be ensured that even if the hot, liquid metal cools and therefore a reduction in volume occurs, there is still enough material available to ensure even when contraction of the hot material still a complete filling. For this reason, reservoir volumes are provided, into which additional liquid hot metal is poured, which flows in the course of the filling of the hollow body and during the material cooling in the hollow body. Care must also be taken to allow air to escape if necessary.

The hot metal now not only leads to a sudden warming of the coming into contact with the metal materials, but also exerts due to the high density of the metal at the same time high forces, which must withstand the locally strongly heated material even with inflow. Moreover, it is advantageous if just in feeders, sprues, etc., the heat dissipation from the metal into the volume of the molding material is low. Otherwise, if the heat flow is too great, proper flow of the material into the hollow body shape can not be ensured. For this Reason, it is precisely in the reservoirs for liquid metal, which are referred to as enhancers, but optionally also in other places, advantageous to use a material that is insulating.

As a foundry auxiliary body for purposes of the present application u.a. understood feeders, runners to the actually auszuformenden cavity, cores, which are provided in a mold, in turn there to form cavities and etc. To Eingusssystemen also includes so-called refractive cores, sprue-run-gate systems, such as channels for the sprue, funnel for pouring , Gates for distribution of the liquid metal in the cavity of the mold, etc. These individual parts may optionally be composed, so need not necessarily be made in one piece in mold making. In addition, there are other Gießereihilfskörper example Eingussfilter for einzugießende metal to filter out existing dirt, etc. there.

It is known to use water glass in mold making. For example, it is pointed out in DE 10 2007 031 376 A1 that water-glass-containing binders can be used for bonding the foundry sand used for mold making, wherein it is mentioned that the casting mold can be produced using the waterglass / ester process.

Due to their high temperature resistance, their strength and their good recyclability, the compositions / shaped bodies produced according to the invention are outstandingly suitable for foundry auxiliary bodies. It is in principle possible to make the foundry auxiliary body so that it withstands high Eingusskräften. The foundry auxiliary body in this case has the composition according to the invention in at least one area that has been flown during the casting process.

Just inside, very fine-pored or compact body surfaces are desired for contact with molten metal, which can be realized with the method according to the invention. Such surfaces can be realized for example by lining with non-foamed or less foamed material; Since the material combines very well in multi-stage production, these possibilities are opened up. In principle, additions, as can be seen from the above, possible. That in addition to smaller casting auxiliary bodies such as pouring funnels, feeders, etc., larger auxiliary bodies can also be produced, for example hollow containers. Forms themselves, which may even be reinforced accordingly, such as carbon nanotubes, glass fibers, etc., should be mentioned.

The high heat resistance of the compositions / moldings obtained according to the invention allows the use also with high-melting alloys. It is of great advantage that the foundry auxiliary body is subject to only a small change in size, can be produced without cracks and still has a sufficiently high mechanical stability even in the heat; In addition, the foundry aids are characterized by good insulating properties and resistance to mineral acid attack. It should be noted, however, that when the riser or the like is to be designed as an exothermic foundry auxiliary body, to be incorporated into the combustible substances, a resistance to mineral acids is not given, because the exothermically reacting additives then also react with the mineral acids.

It is possible that the foundry auxiliary body is formed entirely from inventive composition with or without additives, fiber reinforcements and / or aggregates. In this case, there may be exceptions with respect to at most one or more of the elements filter areas, in particular sprue filter areas, in particular coarse and / or open-cell, foamed, inserted and / or integrally connected filter areas, connecting areas for connection to one of other elements of a casting mold and / or or other foundry auxiliary bodies, covers, areas for exothermic reactions.

It is possible to provide in particular filter areas. Pouring filters serve to filter out coarse impurities from the liquid metal to be cast. This is possible with the material according to the invention, if this is made open porous with large pores by appropriate control of the manufacturing process. This in turn can e.g. done by instead of a small pores-forming foam under pressure, a pressure-free foaming takes place. The corresponding areas can then form the bottom of a sprue or be inserted into such.

It should be mentioned that a foundry auxiliary body is preferably selected from one of the riser (also called feeder), sprue system, sprue, cast iron funnel and inlet system. According to one embodiment, the foundry auxiliary body is characterized in that material with a pore size <3 mm, preferably <2 mm, is present in at least one area. Preferably, the foundry auxiliary body has a density of less than 0.4 kg / l.

According to one embodiment, the foundry auxiliary body is characterized in that, with the exception of one or more elements selected from filter areas (eg Eingussfilterbereiche, especially coarse and / or porous, foamed, inlaid and / or integrally connected filter areas), connecting areas (for connecting to a selected from other elements, a casting mold and / or other foundry auxiliary bodies and covers) and regions for exothermic reactions, formed entirely of the composition according to the invention.

For the production of foundry auxiliary bodies such as e.g. Feeders are preferably used Kaliwassergläser, and more preferably a mixture of 2 different potash water glasses with different water content, for example, a mixture of 20 wt .-% potassium water glass with s = 2.2 and 80 wt .-% potassium silicate with s = 1.35. The use of potassium silicate has particular advantages in terms of curing time and the time to solidification, which in turn is able to influence the bubble size.

It is preferred to add solids, more preferably kaolin and metakaolin in admixture. Metakaolin is chemically bound and thus changes the strength. Kaolin, on the other hand, primarily changes the viscosity before the reaction and prevents shrinkage. This can therefore be provided for a lower shrinkage and be influenced with the viscosity of the components foaming and reaction. The weight mixing ratio kaolin / metakaolin is preferably from 1: 9 to 9: 1, more preferably from 2: 8 to 8: 2, and most preferably 1: 1. It should also be noted that it is also possible to use kaolin alone, however, a mixture of kaolin and metakaolin is preferred in terms of achievable pore sizes. Some embodiments of the present invention are summarized below:

A process for producing a porous mass or a porous shaped body of inorganic polymer, comprising

 a) providing an aqueous composition containing sodium and / or potassium waterglass dissolved in water, the composition having a pH of at least 12

 b) providing a composition comprising

 (i) water, wherein the amount of water is chosen so that applies

 x 100%> 25%

G _a + Gb

G _a = weight of composition provided in a) in g

G _b = weight of composition provided in b) in g

 mwG = amount of dissolved water glass in g in the composition provided in a)

 and

 (ii) at least one water-soluble or water-miscible hardener, wherein the hardener is selected from carbonates of the general formula (I)

O

R'-OCOR ² (I) wherein R ¹ and R ^{2 are} independently selected from optionally substituted with one or more OH groups Ci _-6 alkyl or R ¹

and R ² with the group _e i _NEN form 5-membered ring which is optionally mono- or polysubstituted by substituents selected from _{C] -2} alkyl and Ci _-2 alkyl substituted with one or more OH; and wherein the amount of carbonate used mc in g from m _stö to x * m _stö

 with x = 0.35 when using dissolved Na waterglass in a) and

 x = 0.45 when using dissolved K-water glass in a)

 and

 x = 0.35 * yNa + 0.45 * yi using a mixture of dissolved Na waterglass and dissolved K waterglass in a), where

yNa ⁼ weight fraction of Na water glass relative to the total amount of dissolved water glass calculated according to:

(Amount in g of dissolved Na water glass) / (total amount in g of dissolved water glass)

y = weight fraction of K water glass based on the total amount of dissolved

Water glass,

where y _Na + y _K = 1,

where m _s tö is calculated according to the following equation (1): m _stö = (MG _C / MGM ₂ O) * (m _WG / (1 + s)) (1) _where m _stö = stoichiometrically required amount of carbonate in g

MGc ⁼ molecular weight of the carbonate used

MGM ₂ O ⁼ molecular weight of M ₂ 0 of dissolved water glass in which M = Na or K

niwG ⁼ amount of dissolved water glass in g in the composition provided in a)

s = mass ratio Si0 ₂ / M ₂ 0 of the water glass used in a) and wherein when using a mixture of 2 or more water glasses and m _stö (i) is the amount of carbonate calculated according to equation (1) for each water glass (i) with the respective s (i) value;

and wherein when using carbonate mixtures see for MG _C in equation (1)

Z (MG _c (i) * m (i)) (3)

 is used

 with MGc (i) = molecular weight of carbonate (i)

 m (i) = weight fraction of carbonate (i) based on total amount of carbonate hardeners used

 where Σ m (i) = 1

 and

 c) contacting the aqueous compositions provided in step a) and b) without heat supply to achieve a polycondensation.

The method according to item 1, wherein the composition provided in b) additionally contains at least one substance in dissolved form, which releases 0 ₂ by decomposition.

A method according to item 2, wherein the releasing substance at decomposition 0 ₂ is selected from H ₂ 0 ₂ , urea-H ₂ 0 ₂ -Addukten, ammonium peroxydisulfate (NH.t) ₂ S ₂ 0 ₈ , percarbonates, perborates and mixtures thereof.

A method according to item 3, wherein the releasing substance at decomposition 0 ₂ is selected from H ₂ 0 ₂ , alkali metal perborates, alkali metal percarbonates and mixtures thereof.

Method according to one of the items 2-4, wherein the releasing substance at decomposition 0 ₂ H ₂ 0 ₂ , which is used in an amount of 2 to 10 wt .-% based on composition a).

Method according to one of the items 2 to 5, wherein the composition provided in a) additionally contains at least one dissolved or suspended activator for the 0 ₂ release, the activity of which can be increased by addition of alkali metal hydroxide. The method of item 6, wherein the activator is selected from KI, CoCl ₂ , KMnO _4j MnO ₄ , CuSO ₄ , FeSO, NiSO ₄ , AgNO ₃ , and mixtures of 2 or more of the above. The method of item 7, wherein the activator is selected from KI, KMnO _4j CoCl ₂ and a 2: 1 mixture of KMnO ₄ and KI. Method according to one of the items 6 to 8, wherein the activator is used in an amount of 0 to 0.5 wt .-% based on composition a). Method according to one of the preceding points, wherein the composition provided in a) also contains one or more solid components selected from kaolin, metakaolin, Si0 ₂ , perlites, disperse silicas, dolomite, CaC0 ₃ , A1 ₂ 0 ₃ and water glass powder homogeneously distributed , The method of item 10, wherein the composition provided in a) contains metakaolin. The method of item 11, wherein the weight ratio of dissolved waterglass to metakaolin is 100: 1 to 100: 25. A method according to any one of the preceding claims, wherein the composition provided in a) further comprises one or more components homogeneously distributed among glass fibers, rock wool, basalt fibers, cellulose fibers, pumice, glass beads and polystyrene beads. The method according to item 13, wherein the fibers or particles in composition a) are present in an amount of 0 to 10% by weight, based on composition a). A method according to any preceding item, wherein the composition provided in a) further comprises one or more polyvalent metal oxides. Process according to item 15, wherein the oxides are one or more selected from ZnO, TiO ₂ , MnO, PbO, PbO ₂ , Fe ₂ O ₃ , FeO, Fe ₃ O _4> ZrO ₂ , Cr ₂ O ₃ , CuO, BaO, SrO, BeO, MgO and CaO. A method according to item 15 or 16, which is an oxide of divalent metals or mixtures thereof. A method according to item 15 to 17, wherein the oxides are contained in an amount of 0 to 5 wt .-% based on composition a). A process according to any preceding item, wherein the composition provided in a) further comprises one or more sulfates selected from alkali sulfates and alkaline earth sulfates. The method of item 19, wherein the sulfates are present in an amount of 0 to 5 wt .-% based on composition a). Method according to one of the preceding points, wherein the composition provided in a) also contains one or more surface-active substances. The method of item 21, wherein one or more nonionic surfactants are used. The method according to item 21 or 22, wherein the surfactants are present in an amount of 0 to 0.8 wt .-% based on composition a). Method according to one of the preceding points, wherein the composition provided in a) also contains one or more phosphates selected from mono-, di-, tri- and polyphosphates. The method of item 24, wherein the phosphate is selected from di-, tri- or polyphosphates of sodium or aluminum and mixtures of 2 or more thereof. Method according to item 24 or 25, wherein the phosphates are present in an amount of 0 to 3 wt .-% based on composition a). A method according to any preceding item, wherein the composition provided in a) further comprises one or more alkyl silicone agents. Process according to item 27, wherein the alkyl silicone agents are present in an amount of 0 to 10% by weight, based on composition a). A method according to any preceding item, wherein the curing agent is at least one of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate and glycerin carbonate. Method according to one of the preceding points, wherein the dissolved water glass in the composition provided in a) is potassium water glass or a 50:50 mixture of sodium water glass and potassium water glass. Method according to one of the preceding points, wherein the dissolved water glass in the composition provided in a) is at least one water glass, in which:

Q ₂ : 10 - 25%

Q ₃ : 15 - 25%

Q ₄ : 45-70% wherein the area of those peaks which is assigned to a specific silicon group Q (i) is related to the sum of the area of all Si NMR signals (= 100%). Method according to one of the preceding points, wherein the dissolved water glass in the composition provided in a) is a mixture of water glasses and the proportion of water glass with an s value of 1, 3 to 5 at least is at least 90% based on the total amount of dissolved water glass. Method according to one of the preceding points, wherein composition a) also contains an organic pigment. Porous mass or shaped article obtainable by the method according to one of the items 1 to 33. Porous mass or shaped body of polycondensed sodium and / or potassium water glass, characterized in that the pores are homogeneously distributed, the porosity is 40 to 95%. Porous mass or shaped article according to item 35, wherein the porosity is 65 to 85%. Porous mass or shaped article according to any one of items 34 to 36, wherein the density of the mass / the shaped body is 0.05 to 0.5 g / cm. Porous mass or shaped article according to one of the points 34 to 37, wherein the percentage pore area PF calculated as (area of all pores on a light microscope image) / (total area of the optical microscope image) applies:

0.5 <P _F <1. Use of the porous mass or of the porous shaped body according to any one of items 34 to 38 as insulating material, foam, for foundry auxiliary body, material for fire and noise barriers, cavities ejector, catalyst support, material for thin-layer or column chromatography or rapid prototyping. Foundry auxiliary body, which has a porous mass according to one of the points 34 to 38 in at least one area flowed during the casting process. 41. Foundry waist according to item 40, which is a feeder, sprue, runner, sprue system, inlet system or core.

42. Composite material, characterized in that a part thereof consists of a porous mass according to one of the points 34 to 38.

The invention will now be described by way of example and with reference to the figures, but is in no way limited thereto.

Experimental part Chemicals used:

Sodium water glass: s = 3.3, s _mo iar = 3.4, Roth Co. (Karlsruhe, D), aqueous solution with 34.5% solids content (Na7561)

Sodium water glass 38/40: s = 3.3, s _m0 iar = 3.4, Woellner (Ludwigshafen, D), aqueous solution with 36% solids content (Na38 / 40)

Potassium water glass Betol 5020T: s = 1.35, s _m0 iar = 2.2, Fa. Woellner (Ludwigshafen, D), aqueous solution with 48% solids content (K5020)

Potassium water glass Betolin K35: s = 2.2, s _mo iar = 3.4, Fa. Woellner (Ludwigshafen, D), aqueous solution with 35% solids content (K35)

Potassium water glass K42: s = 1.9, s _mo iar = 2.9, Fa. Woellner (Ludwigshafen, D), aqueous solution with 40% solids content (K42)

The structural characterization of the used water glasses with ²⁹ Si-MAS-NMR (carried out as described below) is shown in Table 1: Table 1

Metakaolin: MetaStar 501, Fa. Lehmann and Voss (Hamburg, D)

Pentasodium triphosphate (Na ₅ P ₃ Oio): white, odorless solid having a molecular weight of 367.86 g / mol and a density of 2.52 g / cm ³ , from Roth (Karlsruhe, D); Solubility in water at 25 ° C 145 g / L Propylene carbonate (hardener): specific gravity of 1.21 g / cm ³ . Solubility in water 240 g / L; from Merck (Darmstadt, Germany)

Glycerol carbonate (hardener): specific gravity of 1.40 g / cm ³ ; miscible with water; from company AB CR GmbH (Karlsruhe, D.)

Hydrogen peroxide (oxygen source): from Merck, Darmstadt, 35% solution of sodium perborate (oxygen source): from Fluka (Buchs, CH) cobalt chloride CoCl ₂ × 6H ₂ O (activator): Merck, Darmstadt

Triton BG-10 (non-ionic surfactant): Dow Chemical (Midland, USA) Zinc oxide and titanium oxide: Merck (Darmstadt).

Rhodoesil® Siliconate R 51T: Methylsiliconate, Fa. Rhodia (Freiburg, D) (R 51 T) Lithopix S2: solid water glass, Fa. Tschimmer Sc Black GmbH & Co. KG (Lahnstein, D)

Sipernat: solid silicic acid

The following standard solutions were produced:

Cobalt solution: 4.8 g CoCl ₂ * 6H ₂ 0, dissolved in 10 mL H ₂ O (2 * 10 ^'2 mol).

KMnCVKI suspension: 0.6 g KMn0 ₄ + 0.3 g KI in 10 mL H ₂ 0

Triphosphate solution: 13g pentasodium triphosphate dissolved in 100 mL water.

Surfactant solution A: 1 g of Triton BG-10 is dissolved with 13 g of pentasodium triphosphate in 100 ml of water.

Surfactant solution B: 20 g Triton BG-10 is dissolved in 100 mL water. Perborate solution: Dissolve 0.9 g of sodium perborate in 100 mL of water.

Examples 1 - 10

To 5 ml of water was added 100 μΐ cobalt solution. Then, with gentle shaking, 1 to 3 drops of water glass solution (using the commercial aqueous solution of the water glass first mentioned in Table 2 in the respective Example from above to below) was added. The solution was deep blue and clear. To this solution were added sequentially the solids shown in Table 2 for the respective example from top to bottom, optionally water and finally 5mL surfactant solution B. The resulting mixture was stirred at 400 rpm for 10 minutes. Then a clear solution of propylene carbonate (hardener) and 30% H ₂ 0 ₂ solution (amounts see Table 2) was added rapidly with stirring. The mixture then foamed within 15 seconds and was pourable for 20-40 seconds. It was poured into a mold (24x12x6 = 1728 cm ³ ), hardened quickly and could be removed from the mold after 10-20 minutes. The final hardness was reached after 6-8 days.

In Example 10, instead of the cobalt solution, the KMnO ₄ I suspension was used and this was mixed in at the end with surfactant solution B.

The details regarding chemicals used and their amounts (in g) and properties of the products obtained are shown in Table 2. The pH of the waterglass mixture (composition a) before addition of the hardener) was in all examples between 12 and 12.5; Viscosities are given in Table 2.

Table 2

The viscosity of the waterglass composition a) was measured before addition of the surfactant.

Figs. 9 and 10 show light micrographs of the product of Example 4 with 500x (Fig. 9) and 200x (Fig. 10) magnification, respectively. Example 1 1

 Suspension A:

 Dissolve 10 l of cobalt solution in 600 g of water, 26 g of sodium waterglass 7561 (34.5% solids), 14 g of metakaolin, 3 mL of surfactant solution A and 10 mL of triphosphate solution A. Solution B:

500 H ₂ 0 ₂ , 2.0 mL propylene carbonate and 9.5 mL water.

Suspension A and solution B were mixed and poured into a mold. A specimen with a density of 0.3 g / ml and a thermal conductivity of 0.05 W / mK was obtained. The porosity of the specimen was determined to be 68%, and the strength to 0.1 N / mm.

The density, thermal conductivity, porosity and strength were determined using the measuring methods described above.

Investigations on the mechanism

In the reaction, first, the light absorptions of reaction mixtures as shown in FIG. 1 were considered.

Fig. 1 shows the light absorption based on the reference case of the transmitted light in air. In each case 20 mL sodium waterglass were mixed with - in Fig. 1 from left to right: 15 mL, 20 mL and 25 mL water and 2.2 mL propylene carbonate, shaken briefly and then the transmitted light curve was recorded. The transmitted light curve provides information about the course of the reaction. The light absorptions indicate that two fundamentally different reactions occur, both of which appear to lead to the polycondensation of the water glasses.

Without wishing to be bound by it, the inventors proceed from the following reaction sequence:

Native water glass does not polycondensate because the negatively charged silyl anions repel each other. In the case of the polycondensation reaction presented here, an organic carbonate, which regulates the pH, is rapidly and uniformly mixed in as a starter the mixture abruptly humiliated. The organic carbonate (as well as C0 ₂ ) forms soda or potash with water glass. This "consumption" of sodium or potassium ions leads to a discharge of the negative, repulsive silyl groups, and the colloidal solution of the silicates in the water glass approaches its isoelectric point (the first pKs of orthosilicic acid is pKS] = 9.84). The result is an accelerated condensation of the silicic acid, which takes only a few minutes and leads to a plastillin mass that hardens slowly on drying.The further hardening does not require C0 ₂ from the air, rather the dehydration alone causes the equilibrium to increase Polycondensation of silyl groups shifted.

From Fig. 1 it can be seen that the polycondensation has expired within a few minutes and can be controlled by the water content of the mixture.

Although the reaction is exothermic, the specimen does not heat above 27 ° C. During the reaction, the body solidifies, but remains plastillin. Only in the next four to six days, the final hardness is reached. Experiments by the inventors have shown that this process can not be accelerated by an additional C0 ₂ addition.

Spectroscopic investigations

For further investigation, MAS NMR spectra were recorded. In NMR spectroscopic measurements in solids, undesirable line broadening generally occurs. This line broadening is caused by anisotropic interactions between the atomic nuclei of the sample, which do not stochastically average, in contrast to NMR spectroscopic measurements in solution. This line broadening can be reduced by measuring under the Magic Angle-Spinning (MAS) condition. To do this, the sample is rotated at speeds of up to 70 kHz around an axis that is tilted 54.74 ° (the "magic angle") with respect to the external magnetic field orientation, and this angle causes all dipolar interactions to be averaged and so on The sharp NMR signals of Al, Si, and P nuclei allow an exact structure assignment. In the present invention, an Advaiice 500 DSX 500WB from Bruker (Billerica, USA) was used at room temperature with a 4 mm Zr0 ₂ rotor and the rotation speed of 9 or 10 kHz; The following irradiation frequencies were used: JH: 500.20 MHz, ²⁹ Si: 99.36176 MHz, ²⁷ A1: 130.336560 MHz, ³¹ P: 202.484646 MHz. It was worked with single pulse program, with the following pulse times: 45-degree pulse at Ή, ²⁷ A1 and ²⁹ Si with a pulse duration of 2 μ5βο and at ³¹ P a 30-degree pulse with a pulse duration of also 2 μ8εα as decay times were chosen: ²⁷ A1: 0.5 and 0.6 sec, 2 ⁹ Si: 6 sec, ³¹ P: 25 sec.

Figure 2 shows the Al-MAS NMR spectra of the metakaolin used ("metasilicate") and the polymer obtained in Example 11. Both spectra show maxima at 7, 35 and 62 ppm, the signal at 7 ppm can be octahedrally coordinated al ³⁺ atom are assigned to the signal at 35 ppm belongs to a five-coordinate al ³⁺ -... atom to which a free -OH group binds as a ligand in the sixth Metakaolinspektrum this is the largest signal spectrum, the polymer has its greatest Signal at 62 ppm This shift is characteristic of a four-coordinate Al ³⁺ atom that carries a single overall negative charge, which is typical for a geopolymer spectrum. AI-MAS NMR spectra are evidence of incomplete geopolymerization Aluminum atoms are partially incorporated as negatively charged tetrahedra in the polymer, but it can also be seen from the spectra that part of the metakaolin has not reacted, even the unreacted Metakaolin shares are important for polymer stability because it is believed that possible cracking can be stopped at these particles.

The Si-MAS NMR spectra (Figure 3) are also very informative to assess the binding ratio in a polymer. A shift in the range of -70.0 to -72.0 ppm indicates monosilicates with four negative charges. The range of -77.5 to -80.7 ppm is typical of a silyl end group carrying three negative charges. The shift range from -80.0 to -82.3 ppm represents a mid-group in cyclo-trisilicates with two negative charges, and the range from -88.0 to -90.5 ppm represents the corresponding middle group of a linear chain. A branching group with a single negative charge shows a shift from -92.6 to -98.5 ppm and a broad signal down to -108 ppm is typical of a crosslinking group that no longer carries a negative charge.

The more intense the signals are at shifts above -90 ppm, the more the silicon polymer is cross-linked.

In the Si-MAS NMR spectrum of the polymer, the maxima are now at shifts of -87, -92 and -99 ppm. They thus indicate doubly negatively charged middle groups, simply negatively charged branching groups, and neutral branching groups. The spectrum is typical of a highly branched geopolymer.

Fig. 4 shows the ³¹ P NMR spectrum of the polymer of Example 11.

The pentasodium triphosphate used shows shifts of 1.3, -2.4, -4.6 and -7.1 ppm in the ³¹ P NMR spectrum.

These signals can not be seen in the polymer (see FIG. 4). It is therefore believed that the triphosphate was fully incorporated into the silicon / aluminum oxygen framework. An assignment of the individual signals is difficult. The signal at -2.7 ppm is the typical signal of a monophosphate group that might have been formed by hydrolysis during the reaction. The other two signals indicate phosphorus in di- and triphosphate groups, which carries no negative charge, that is covalently incorporated into the Si-0 scaffold.

Studies on pressure stability. Porosity and thermal conductivity

The methods described above for measuring pressure stability, thermal conductivity and porosity were used.

The dependence between the amount of water glass used and the pressure stability achieved as well as the thermal conductivity was investigated. For this, in Example 1 described above, the amount of water glass used (34.5% solution of Na water glass with s = 3.3) and the amount of metakaolin varies. With increasing water glass content, the pressure stability and thermal conductivity also increased.

Then, porosity and thermal conductivity were examined. Porous bodies insulate better because air is a good insulator. As shown in Fig. 5, heat conductivity (♦) and compressive strength (■) in the product do not depend linearly on porosity. These properties are important when using the products of the invention as Dämmmaterialien.

It can also be seen in FIG. 5 that, with a porosity of more than 50%, a further increase in the weighing capacity is no longer to be observed, but the stability of the test specimens is further reduced.

Viscosity studies of the water glass composition

The viscosities were measured using an aqueous glass-water mixture consisting of 15 g Bentol 5020T and 300 g Betolin K35, depending on the additives metakaolin, quartz powder (Si0 ₂ ), Lithopix S2 and perlite. The result is shown in FIG. As can be seen from FIG. 6, the viscosity of the waterglass solution (composition a)) can be varied, for example via the addition of different solid additives and their amount, and adjusted to the desired value.

Example 12

In a next experiment, a sodium water amount (7561) of 24 g and a metakaolin amount of 6 g was used, and 16 mL of surfactant solution A were added. As solution B, a mixture of 2.4 mL propylene carbonate in 4 mL water and 400 H ₂ O _{2 was} used. The specimen showed a thermal conductivity of 0.035 W / mK, a density of 0.19 g / cm ^J and a compression strength of 0.18 N / mm.

Fig. 7 shows a photomicrograph of the sample body of Example 12 obtained by pouring the reaction mixture onto a glass plate, allowed to set and removal from the glass plate. The picture shows the flat surface (previously in contact with the glass plate). Example 13

Example 12 was repeated, but the amount of water glass increased to 30 g, and 2g ZnO, 7g Metakaolin and 15 mL of surfactant solution A used. It was cured with a mixture of 3.3 ml of propylene carbonate and 0.4 ml of H ₂ 0 ₂ . The specimen had a thermal conductivity of 0.056 W / mK, a compressive strength of 1.04 N / mm ² and a density of 0.32 g / cm ^{3 .}

Example 14 ( ^" experiment with perborate instead of LLOV)

Example 12 was repeated, increasing the amount of water glass to 40 g. It was hardened with 4.4 mL propylene carbonate, but instead of H ₂ O ₂ solution, aqueous sodium perborate (0.9 g in 10 mL H ₂ O) was added. This gave a specimen with a density of 0.21 g / ml, a thermal conductivity of 0.048 W / mK and a compressive strength of 0.19 N / mm ² .

Example 15 (Experiment without glass source)

With the same formulation as Example 12, but without hydrogen peroxide, but with an increased phosphate content (9 mL phosphate solution in addition), a sample body with a density of 0.39 g / mL, heat conductivity of 0.085 W / mK and compressive strength of 1.37 N / mm ² . The specimen shrank slightly during the reaction and on drying.

Example 16

Example 12 was repeated with 24 g of sodium waterglass, 16 mL of surfactant solution, ₂ g of ZnO and 6 g of metakaolin in suspension A. The mixture was cured with 2.6 mL of propylene carbonate mixed with 200 H ₂ O ₂ (35%) and 4 mL water (Solution B). The density of the sample body was 0.28 g / mL ³ . The surface image in FIG. 8 shows that the pores obtained are self-contained and uniformly distributed. The body shrank when drying by less than 1 mm over a length of 6 cm. The density was 0.28 g / mL.

Comparative Examples Examples 1-10 were repeated, but the pH of composition a) (water glass composition) was lowered to <12 by addition of concentrated H ₃ PO ₄ . The mixture solidified in each case before the hardening solution could be added. Upon drying, the product disintegrated into powder.

Examples 1-10 were repeated, but the viscosity of the waterglass composition was lowered by adding more water to <10 mPas. It came within the usual time for the invention only to an education opaque body; Upon further drying, the specimen shrank markedly and, upon complete drying, disintegrated to a powder.

Claims

A process for producing a porous mass or a porous shaped body of inorganic polymer, comprising

 a) providing an aqueous composition containing sodium and / or potassium waterglass dissolved in water, the composition having a pH of at least 12

 b) providing a composition comprising

 (i) water, wherein the amount of water is chosen so that applies

 x 100%> 25%

G _a + Gb

G _a = weight of composition provided in a) in g

G _b = weight of composition provided in b) in g

 mwG = amount of dissolved water glass in g in the composition provided in a)

 and

 (ii) at least one water-soluble or water-miscible hardener,

 wherein the curing agent is selected from carbonates of the general formula

(I) wherein R ¹ and R ^{2 are} independently selected from optionally substituted with one or more OH groups substituted Ci _-6 alkyl or R ¹

O and R ² with the group _ 0 J C_ 0 _ form _a 5 gii _ec ring ring, which is optionally mono- or polysubstituted by substituents selected from Ci _-2 alkyl and Ci _-2 alkyl substituted with one or several OH; and wherein the amount of carbonate used is mc in g from m _stö to x * m _st ö

 with x = 0.35 when using dissolved Na waterglass in a) and

 x = 0.45 when using dissolved K waterglass in a)

 and

 x = 0.35 * yNa + 0.45 * ys when using a mixture of dissolved Na waterglass and dissolved K waterglass in a), where

yNa ⁼ weight fraction of Na water glass based on total amount of dissolved water glass calculated according to:

(Amount in g of dissolved Na water glass) / (total amount in g of dissolved water glass)

yjc = weight fraction of K water glass based on the total amount of dissolved

Water glass,

where y _Na + y _K = 1,

where m _{stö is calculated} according to the following equation (1): ms »= (MG _C / MGM ₂ O) * (m _WG / O + s)) (1) with mstö ⁼ stoichiometrically required amount of carbonate in g

 MGc = molecular weight of the carbonate used

MGM ₂ O ⁼ molecular weight of M ₂ 0 of dissolved water glass in which M = Na or K

MLG - Amount of dissolved water glass in g in the composition provided in a)

s = mass ratio Si0 ₂ / M ₂ 0 of the waterglass used in a) and where m _stö = Σ mstöO) (2) when using a mixture of 2 or more waterglasses, and m _stö (i) for each according to equation (1) Water glass (i) calculated Amount of carbonate is;

and wherein when using carbonate mixtures for MG _C in equation

Z (MG _c (i) * m (i)) (3) is used

 with MGc (i) = molecular weight of carbonate (i)

 m (i) = weight fraction of carbonate (i) based on total amount of carbonate hardeners used

 where Σ m (i) = 1

 and

 c) contacting the aqueous compositions provided in step a) and b) without heat supply to achieve a polycondensation.

2. The method of claim 1, wherein the composition provided in (b) additionally contains at least one substance in dissolved form, which releases by decomposition 0 ₂ .

3. The method of claim 2, wherein the releasing in case of decomposition 0 ₂ substance is selected from H ₂ 0 _2, urea-H2C> 2 adducts of ammonium peroxydisulfate (NH4) ₂ S ₂ 08, percarbonates, perborates and mixtures thereof.

4. The method according to claim 2 or 3, wherein the composition provided in a) additionally contains at least one dissolved or suspended activator for the 0 ₂ - release whose activity can be increased by the addition of alkali metal hydroxide.

The process of claim 4, wherein the activator is selected from KI, CoCl ₂ , KMnO _4, MnO ₄ , CuSO, FeSo ₄ , NiSO ₄ , AgNO ₃ , and mixtures of 2 or more of the above.

6. The method according to any one of the preceding claims, wherein the composition provided in a) also one or more solid components selected from kaolin, metakaolin, Si0 ₂ , perlites, disperse silicas, dolomite, CaC0 ₃ , A1 ₂ 0 ₃ and water glass powder, homogeneous contains distributed.

The method of claim 6, wherein the composition provided in a) contains metakaolin and the weight ratio of dissolved water glass to metakaolin is 100: 1 to 100: 25.

A process according to any one of the preceding claims, wherein the composition provided in a) also contains one or more components homogeneously distributed among glass fibers, rock wool, basalt fibers, cellulose fibers, pumice, glass beads and polystyrene beads.

A process according to any one of the preceding claims, wherein the composition provided in a) further comprises one or more polyvalent metal oxides.

10. The process according to claim 9, wherein the oxides are one or more selected from ZnO, TiO ₂ , MnO, PbO, PbO ₂ , Fe ₂ O ₃ , FeO, Fe ₃ O _4> ZrO ₂ , Cr ₂ O ₃ , CuO, BaO, SrO, BeO and MgO.

1 1. A method according to any one of the preceding claims, wherein the composition provided in a) further comprises one or more sulfates selected from alkali sulfates and alkaline earth sulfates.

12. The method according to any one of the preceding claims, wherein the composition provided in a) also contains one or more surface-active substances.

13. The method of claim 12, wherein one or more nonionic surfactants are used.

14. The method according to any one of the preceding claims, wherein the composition provided in a) also contains one or more phosphates selected from mono-, di-, tri- and polyphosphates.

15. The method of claim 14, wherein the phosphate is selected from di-, tri- or polyphosphates of sodium or aluminum and mixtures of 2 or more thereof.

16. The method according to any one of the preceding claims, wherein the composition provided in a) also contains one or more alkyl siliconates.

17. The method according to any one of the preceding claims, wherein the curing agent is at least one of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, and glycerol carbonate.

A process according to any one of the preceding claims, wherein the dissolved waterglass in the composition provided in (a) is potassium waterglass or a 50:50 mixture of sodium silicate and potassium waterglass.

19. The method according to any one of the preceding claims, wherein it is the dissolved water glass in the composition provided in a) is a mixture of water glasses and the proportion of water glass having an s value of 1.3 to 5 at least 90% based on the total amount of dissolved water glass is.

20. Porous mass or shaped article obtainable by the process according to one of claims 1 to 19.

21. Porous mass or shaped body of polycondensed sodium and / or potassium water glass, characterized in that the pores are homogeneously distributed and the porosity is 40 to 95%.

22. Porous mass or molded article according to claim 21, wherein the porosity is 65 to 85%.

23. Porous mass or shaped body according to any one of claims 20 to 22, wherein the density is 0.05 to 0.5 g / cm ³ .

24. Use of the porous mass or the porous shaped body according to one of claims 20 to 22 as an insulating material, foam, for foundry auxiliary body, ejection means for cavities, catalyst support, material for thin-layer or column chromatography or rapid prototyping.

25. Foundry auxiliary body, which has a porous mass according to one of claims 20 to 23 in at least one area flowed during the casting process.

26. Composite material, characterized in that a part thereof consists of a porous mass according to one of claims 20 to 23.