DE2714006A1 - MOLDING - Google Patents

Description

It is known from various starting materials such as wood chips, waste materials, molding sand or gravel with
Polyisocyanates as binders to produce moldings. However, these starting materials are very irregularly shaped structures, so that they either require a relatively large amount of binder for complete surface coverage by the binder or due to a certain absorbency, or only partially
the binder are provided. As a result, the molded bodies obtained have a rather inhomogeneous structure, so that they have some homogeneity-related quality features.

Le A 17 900

8U9841 / 0078

27U006

Male, e.g. uniform or optimally developed strength is missing.

It is also known to use hollow glass spheres, for example, as a filler for plastics. Here are these either incorporated into the pre-formed plastics, e.g. thermoplastics, or the liquid synthetic resins, e.g. polyester resins or epoxy resins added before curing, these synthetic resins in order to cure through, must be very carefully homogenized with the necessary hardeners, e.g. peroxides or amines. Such Plastics filled with hollow glass spheres usually contain less than 50% by weight of inorganic filler.

Because of the possible shortage of organic raw materials and the risk of fire in humans To reduce living and working areas, there is a need for materials that are easy to process, have good mechanical and thermal properties and are largely composed of inorganic material. In the manufacture and processing of the sought-after materials, z. B. the use of peroxides and physiologically questionable amines or relatively volatile, i.e. ecologically questionable, compounds be avoided.

The DOS 2 357 931 describes the binding of organic or inorganic, foamed, porous or massive, uniformly or irregularly shaped particles due to polyisocyanates.

Le A 17 900 - 2 -

809841/0078

27U006

This method can be used when using non-volatile Polyisocyanates partially solve the above-mentioned problems due to their curability due to the ingress of moisture, However, it also leads to relatively inhomogeneous parts and is in terms of the amount of binder required unsatisfactory because foamed, porous particles are either relatively large and therefore relatively Provide inhomogeneous molded parts or the porosity of the particles favors the absorption of the binder. In addition, the use of massive inorganic particles impairs the manufacture more easily and therefore well manageable, material-saving and, if necessary, heat-insulating molded parts.

There is therefore a requirement for heat-resistant and possibly fire-resistant materials or

Molded parts that can be produced by uncomplicated processes, i.e. from storage-stable, cold-deformable premixes as far as possible and that do not contain any volatile substances, peroxides or physiologically harmful hardeners and that have mechanical properties as isotropic as possible at liter weights of less than 1000 grams, with the organic material content below 30 wt. -% should be.

Surprisingly, these requirements can be met with mixtures which consist of more than 50 % by weight of inorganic hollow spheres with a bulk density of less than 900 g / l, grain diameters of less than 1 mm, and less than 50% by weight of non-volatile, liquid polyisocyanates,

Le A 17 900 - 3 -

ο ο μ / η η τ β

6 27U006

in which the hollow beads are coated with the polyisocyanate. These mixtures are made after the addition of phosphoric acid and / or phosphates and optionally water and other auxiliaries and then molded at room temperature and access of atmospheric moisture and / or heating, optionally under pressure, to temperatures of up to Cured at 35O ° C.

Accordingly, the present process for the production of molded parts with largely isotropic properties, Weights per liter under 1000 grams and largely inorganic in character from cold-deformable raw materials with safe handling, characterized in that the starting material used is mixtures of 70-97 % By weight of inorganic hollow spheres with a bulk density of less than 900 g / l and grain diameter of less than 1 mm, 1-20 % By weight phosphoric acids and / or phosphates and 2-29% by weight polyisocyanate with a boiling point of more than 150.degree used at 1 Torr and this optionally deformed after the addition of water and other auxiliaries and then at room temperature and ingress of air humidity and / or by heating, optionally under pressure, hardening.

Inorganic hollow spheres are understood to be those which consist of more than 95% by weight of inorganic material. They have a bulk density of less than 900 g / l, preferably 200 - 600 g / l. The grain diameter is less than 1 mm *, preferably between 3 and 500 microns. The hollow pearls can be used as a sieved fraction with a narrow grain size distribution, but preferably unfractionated with a broad grain size distribution. Preferred

Le A 17 900 - 4 -

/ 0078

271A0Q6

are hollow beads in spherical shape that are not or only slightly porous. If you make a 50% suspension of the hollow spheres in distilled water, this suspension should not have a pH value above 7 after 24 hours. The pH is preferably between 6 and 7.

Hollow beads that meet these requirements are known and are commercially available. They are made of silica or quartz, from clays, from glasses, preferably from, optionally iron-containing, aluminosilicates. They have for example the following chemical composition:

Silica as SiO ₂ = SO - 65%

Alumina as Al ₃ O ₃ = 20 - 35%

Iron oxide as Fe ₃ O ₃ = 2 - 15%

Calcium as CaO = 0.1-0.9%

Magnesium as MgO = 0.5 - 4% alkaline 1 Na ₂ O +

Components j K ₂ O = 0.3 - 5%

Such pearls can, especially after careful drying, e.g. by heating to 150 - 250 C with surprisingly, the polyisocyanates to be used according to the invention in the absence of air or moisture Almost unlimited storable mixtures can be processed, i.e. apparently occur during storage Even when using e.g. aluminosilicate beads, there is no catalytic effect that could lead to a premature change in consistency the mix.

Le A 17 900 - 5 -

809841/0078

27U006

These mixtures contain 70-97% by weight of the hollow beads, preferably 75-97% by weight and can also contain auxiliaries such as pigments, lubricants or fillers not present in hollow spherical form, provided that they contain the do not adversely affect the required storage stability to be taken into account.

All phosphoric acids, but preferably the purely inorganic types, are suitable as phosphoric acid such as ortho-, meta-, pyro- or polyphosphoric acid. The acids can be used in anhydrous form or as a water-containing material or aqueous solution. It must be regarded as surprising that the presence of phosphoric acids in the molding composition or mixture their hardening behavior does not adversely affect or even prevent hardening.

The phosphates are the metal phosphates of the acids mentioned above, preferably the (earth) alkali metal phosphates, be they primary, secondary or tertiary, such as primary. Sodium phosphate, sec. Potassium phosphate, sodium metaphosphate, Na or calcium polyphosphate. Inorganic ammonium phosphates are of particular interest e.g. primary and secondary ammonium phosphate and especially ammonium polyphosphate, as they are easily accessible and do not introduce any additional metal ions into the material. The phosphoric acid or phosphates are obtained on the total mixture, used in amounts of 1-20, preferably 1-10 wt .-%.

Le A 17 900 - 6 -

809841/0078

The special role of the phosphoric acids to be used according to the process, or phosphates consists in the fact that they surprisingly without the setting process caused by the isocyanate to affect the molding compound at relatively low temperatures, in the event of fire temperatures above e.g. 35O ° C ensure the cohesion of the molded body. While without using the phosphorus compound through the decomposition of the organic binder or its burn-off at 350 C the bond is lost Surprisingly, very little by 1 - 3 wt .-%, based on the total mixture, built-in phosphates or Amounts of phosphoric acid ensure that once the organic bond is only lost at temperatures above 35O ° C goes, on the other hand, even in the course of the complete burn-off of the organic bond at approx. 800 C a stable bond is maintained.

Of course, elemental phosphorus can also be used as a phosphoric acid generator, z. B. powdered red phosphorus can be used.

Surprisingly, the effect described here is only caused by phosphoric acid or phosphates, while silicates, borates or enamel frits are not usable Bring results.

In this respect, both on the part of the curing options and, rarely, of the performance properties of the cured moldings the excellent application technology of the three-component system: inorganic hollow bead,

Le A 17 900 - 7 -

8098A1 / 0078

Ao 27U006

Phosphoric acid (generator), polyisocyanate as surprising and are considered technically advantageous.

The polyisocyanates are contained in the mixtures in amounts of 2-29% by weight, preferably 3-25% by weight. Here it is important that mixtures which contain the polyisocyanates in amounts between about 6 and 2% by weight, lead to moldings that are classified in fire class A 2 according to DIN 4102 and are therefore of particular technical nature Are interested.

In order to be able to handle the mixtures safely, the polyisocyanates to be used according to the invention should be non-volatile and should accordingly have boiling points above 150.degree own at 1 torr. These can be pure polyisocyanates or polyisocyanate mixtures. Preferably Such polyisocyanates or mixtures have average molecular weights above 300.

In order to be able to shape the mixtures well, it is not always necessary, but it is advantageous if the Applied polyisocyanates are liquid at room temperature because the mixtures have a certain inherent tack have good cohesion, e.g. can also be inserted into joints, as a raw molding a good cohesion and can adapt well to complicated shapes.

Polyisocyanates that are non-volatile and therefore considered safe are to be considered have at least 2 isocyanate groups in the molecule, but they can also be tri-, tetra- and be more functional.

Le A 17 900 - 8 -

8U9841 / 0078

_ΛΛ 27U006

It is preferred to use polyisocyanates which can be obtained by phosgenation of aniline-formaldehyde condensates and by distilling off or by extracting volatile constituents to give reaction components of the above low volatility have been refined. Such polyisocyanates are commercially available. It is about generally by-products of the production of pure diphenylmethane diisocyanate, which in addition to this diisocyanate Contain proportions of multinuclear polyisocyanates. It has been shown that just such technical polyisocyanate mixtures of the type described can be used particularly well according to the process, which are at room temperature are liquid and have a high proportion of such highly condensed polyisocyanates with a three- and multi-core character contain.

In addition to this preferred group of polyisocyanates, there are of course other aromatic, araliphatic ones and aliphatic polyisocyanates which meet the requirement of non-volatility. these are especially those that are liquid at room temperature and have molecular weights above 300, preferably above 400.

To these polyisocyanates, which can be at least bifunctional, but also tri-, tetra- and higher-functional, also include those polyisocyanates which have a more complex composition and are obtained if one dioder higher functional isocyanates, e.g. to allophanes, biurets and carbodiimides or by cyclization, e.g. to isocyanurates, to polyisocyanates with increased molecular weight

Le A 17 9OO - 9 -

8U9841 / 0078

27U006

converts and in particular those more complex polyisocyanates that are obtained when at least bifunctional Isocyanates with, based on the polyisocyanate groups contained in the polyisocyanate used, stoichiometric converts insufficient amounts of compounds containing at least two isocyanate-reactive groups have, so that higher molecular weight addition compounds are formed, which in turn at least contain two isocyanate groups per molecule. Such higher molecular weight NCO-functional compounds are standard technology and are often referred to as NCO prepolymers.

Compounds which can be used for the formation of such NCO prepolymers contain at least two isocyanate-reactive compounds Have groupings, compounds with Zerewitinoff-active hydrogen atoms are in principle suitable. In addition to such compounds with amino groups, they are particularly suitable for use according to the invention Polyhydroxy compounds, in particular compounds containing two to eight hydroxyl groups, especially those from a molecular weight of 800 to 10,000, preferably 1,000 to 6,000, e.g. at least two, usually 2 up to 8, but preferably 2 to 4, hydroxyl-containing polyesters, polyethers, polythioethers, polyacetals, Polycarbonates and polyester amides, such as those used for the production of homogeneous and cellular polyurethanes are known per se.

The possible polyesters containing hydroxyl groups are, for example, reaction products of polyvalent, preferably dihydric, and optionally additionally trihydric alcohols with polyhydric, preferably di-

Le A 17 900 - 10 -

80 98 A1 / 0078

43 27H006

valued. Carboxylic acids. Instead of the free polycarboxylic acids, the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols or their mixtures are used to produce the polyester. The polycarboxylic acids can aliphatic cycloaliphatic ^ aromatic and / or heterocyclic in nature and optionally substituted and / or unsaturated, for example by halogenate be.

Examples include: succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, Phthalic acid, isophthalic acid, trimellitic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, glutaric anhydride. Maleic acid, maleic anhydride, fumaric acid, dimeric and trimeric fatty acids such as oleic acid, optionally mixed with monomeric fatty acids, dimethyl terephthalate and bis-glycol terephthalate. The polyhydric alcohols include, for example, ethylene glycol, propylene glycol (1,2) and - (1,3), butylene glycol (1,4) and - (2,3), hexanediol- (1,6), octanediol- (1,8), neopentyl glycol, cyclohexanedimethanol (1,4-bis-hydroxymethylcyclohexane), 2-methyl-1,3-propanediol, glycerol, trimethylolpropane , Hexanetriol (1,2,6), butanetriol (1,2,4), trimethylol ethane. Pentaerythritol, quinitol, mannitol and sorbitol, Methyl glycoside, also diethylene glycol, triethylene glycol, Tetraethylene glycol, polyethylene glycols, dipropylene glycol, Polypropylene glycols, dibutylene glycol and polybutylene glycols in question. The polyesters can have a proportion of terminal carboxyl groups. Also made of polyester Lactones, e.g. ε-caprolactone or hydroxycarboxylic acids, e.g. ω-hydroxycaproic acid, can be used.

Le A 17 900 - 11 -

809841/0078

27H0Ü6

The polyethers which can be used according to the invention and which have at least two, generally two to eight, preferably two to three, hydroxyl groups are also such

of the type known per se and are, for example, with themselves, for example in the presence of BF _3, or by addition of these epoxides, optionally as mixtures or successively, to starting components containing, by polymerizing epoxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin reactive hydrogen atoms such as water, alcohols, ammonia or amines, for example ethylene glycol, propylene glycol (1,3) or - (1,2), trimethylolpropane, 4,4'-dihydroxydiphenylpropane, aniline, ethanolamine or ethylenediamine. Sucrose polyethers, as described, for example, in German Auslegeschriften 1,176,358 and 1,064,938, are also suitable according to the invention. Often those polyethers are preferred which predominantly (up to 90% by weight, based on all OH groups present in the polyether) have primary OH groups. Modified by vinyl polyethers, such as for example, by polymerizing styrene and acrylonitrile in the presence of polyethers formed (US Patents 3,383,351, 3,304,273, 3,523,093, 3,110,695, German Patent 1,152,536) are also suitable, as well Polybutadienes containing OH groups.

Among the polythioethers are in particular the condensation products of thiodiglycol with itself and / or with other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or amino alcohols. Ever according to the co-components, the products are polythio mixed ethers, polythio ether esters or polythio ether ester amides.

Le A 17 900 - 12 -

8098 4 1/0078

27U006

The polyacetals used are, for example, those from glycols, such as diethylene glycol, triethylene glycol, 4,4'-dioxäthoxydiphenyldimethylmethane, hexanediol and formaldehyde possible connections in question. Polyacetals suitable according to the invention can also be prepared by polymerizing cyclic acetals.

Polycarbonates containing hydroxyl groups are those of the type known per se, e.g. by reacting diols such as propanediol (1,3), butanediol (1,4) and / or hexanediol (1,6), diethylene glycol, Triethylene glycol or tetraethylene glycol can be produced with diaryl carbonates, e.g. diphenyl carbonate, or phosgene.

The polyester amides and polyamides include, for example obtained from polyvalent saturated and unsaturated carboxylic acids or their anhydrides and polyvalent saturated and unsaturated amino alcohols, diamines, polyamines and their mixtures, predominantly linear condensates.

Also already containing urethane or urea groups Polyhydroxy compounds and, if appropriate, modified natural polyols, such as castor oil, carbohydrates or starch, can be used. Addition products of alkylene oxides with phenol-formaldehyde resins or also of urea-formaldehyde resins can be used according to the invention.

Le A 17 9OO - 13 -

8U9841 / 0078

27U006

Representatives of these compounds to be used according to the invention are, for example, in High Polymers, Vol. XVI, "Polyurethanes, Chemistry and Technology" written by Saunders-Frisch, Interscience Publishers, New York, London, Volume I, 1962, pages 32-42 and pages 44-54 and Volume II, 1964, pages 5-6 and 198-199, as well as in the Kunststoff-Handbuch, Volume VII, Vieweg-Höchtlen, Carl-Hanser-Verlag, Munich, 1966, e.g. on pages 45-71.

Mixtures of the abovementioned compounds with at least two opposite isocyanates can of course be used reactive hydrogen atoms with a molecular weight from 400 - 10,000, e.g. mixtures of polyethers and polyesters, can be used.

As starting components optionally to be used according to the invention there are also compounds with at least two isocyanate-reactive hydrogen atoms with a molecular weight of 32-4OO in question. In this case too, this is understood to mean hydroxyl groups and / or compounds containing amino groups and / or thiol groups and / or carboxyl groups, preferably Compounds containing hydroxyl groups and / or amino groups, which are used as chain extenders or crosslinking agents to serve. These compounds generally have 2 to 8 isocyanate-reactive compounds Hydrogen atoms, preferably 2 or 3 reactive Hydrogen atoms.

Le A 17 900 - 14 _

809841/0078

Examples of such compounds include: ethylene glycol, propylene glycol (1,2) and - (1,3), butylene glycol (1,4) and - (2,3), pentanediol (1,5), hexanediol (1,6), octanediol- (1,8), neopentylglycol, 1,4-bishydroxymethyl-cyclohexane, 2-methyl-1,3-propanediol, glycerine, trimethylolprpane, hexanetriol- (1,2,6), trimethylolethane. Pentaerythritol, quinitol, mannitol and sorbitol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycols with a molecular weight of up to 400, dipylene glycol, polypropylene glycols with a molecular weight of up to 400, dibutylene glycol, polybutylene glycol, polybutylene glycol, polybutylene glycol, 4,4'-dihydroxypropylene, 4,4'-dihydroxylene glycol with a molecular weight of up to 400 hydroquinone, ethanolamine, diethanolamine, triethanolamine, 3-aminopropanol, ethylenediamine, 1,3-diaminopropane, 1-mercapto-3-aminopropane, 4-hydroxy- or -amino-phthalic acid, succinic acid, adipic acid, hydrazine, Ν, Ν'-dinethylhydrazine , 4,4'-diaminodiphenylmethane, toluenedianiine, methylenebis-chloroaniline, methylene-bis-anthranilic acid ester, diaminobenzoic acid ester and the isomeric chlorophenylene diamine.

In this case too, mixtures of different compounds containing at least two isocyanate-reactive hydrogen atoms with a molecular weight of 32-400 can be used.

With the help of this NCO prepolymer technique, Conversion of volatile polyisocyanates into modified polyisocyanates that meet the requirements outlined suffice with regard to non-volatility.

Le A 17 900 - 15 -

809841/0078

27U006

Polyisocyanates, which are suitable for the preparation of such complex polyisocyanates with greatly reduced volatility, are aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates, as they are, for. B. by W. Siefken in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136, are described, for example ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclobutane-1, 3-diisocyanate, cyclohexane-1,3- and -1,4-disocyanate and any mixtures of these isomers, i-isocyanato ^^. S-tri inethyl-5-isocyanatomethyl-cyclohexane (DAS 1 202 735, American patent 3 401 190 ), 2,4- and 2,6-nexahydrotoluylene diisocyanate and any mixtures of these isomers, hexahydro-1,3- and / or -4,4-phenylene diisocyanate, perhydro-2,4 · and / or -4,4 '-diphenylmethane diisocyanate, 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-tolylene diisocyanate and any mixtures of these isomers, diphenylmethane-2,4 ¹ - and / or -4,4 ^l -diisocyanate , Naphthylene-1,5-diisocyanate, triphenylmethane-4,4 ¹ , 4 "-triisocyanate, PoIyphenyl-polymethylene-polyisocyanate, as obtained by aniline-formaldehyde condensation and subsequent phosgenation and eg in British patents 874 430 and 848 671, m- and p-isocyanatophenylsulfonyl isocyanates according to American patent 3 454 606, perchlorinated aryl polyisocyanates, as described, for example, in German Auslegeschrift 1 157 601 (American patent 3 277 138; are described, polyisocyanates containing carbodiimide groups, as described in German Patent 1 092 007 (American Patent 3 152 162)

Le A 17 900 - 16 -

80 98A1 / 0078

27U006

are described, diisocyanates, as described in US Pat. No. 3,492,330, polyisocyanates containing allophanate groups, as described, for example, in British Pat. No. 994,890, Belgian Pat. No. 761,626 and the published Dutch Pat as described, for example, in the American patent 3 001 973, in the German patents 1 022 789, 1 222 067 and 1 027 394 as well as in the German laid-open specifications 1 929 034 and 2 004 048, polyisocyanates containing urethane groups, as described in cB Belgian patent 752 261 or American patent 3 394 164, polyisocyanates containing acylated urea groups according to German patent 1 230 778, polyisocyanates containing biuret groups, such as those described, for example, in German patent 1 101 394 (American patents 3 124 605 and 3 201 3 72) described as well as in British Patent 889,050, polyisocyanates prepared by telomerization reactions as described in United States Patent Specification 3,654,106, for example, estergruppen containing polyisocyanates as described, for example, in British Patents 965,474 and 1,072,956, in American patent 3,567,763 and German patent 1,231,688 , reaction products of the above-mentioned isocyanates with acetals according to German patent 1,072,385, polyisocyanates containing polymeric fatty acid residues according to American patent 3,455,883.

It is also possible to use the isocyanate group-containing distillation residues obtained in the technical production of isocyanates, optionally dissolved in one or more

Le A 17 900 - 17 -

809841/0078

27H006

of the aforementioned polyisocyanates to be used. It is also possible to use any desired mixtures of the aforementioned polyisocyanates .

As a rule, the technically easily accessible polyisocyanates, e.g. 2,4- and 2,6-tolylene diisocyanate, are particularly preferred and any mixtures of these isomers ("TDI"), polyphenyl-polymethylene-polyisocyanates, such as those produced by aniline-formaldehyde condensation and subsequent phosgenation are produced ("raw MDI") and carbodiimide groups, urethane groups, Allophanate groups, isocyanurate groups, urea groups ater polyisocyanates containing biuret groups ("modified Polyisocyanates ").

The mixtures to be used according to the method of inorganic hollow beads, phosphoric acid or phosphates and Non-volatile polyisocyanates are cured when moisture in the form of water or steam is exposed. It is surprising that, in contrast to other casting resin systems, the substance acting as a hardener, namely the water, in the mixture, develops a fully satisfactory effect even if it is in the binder is not homogeneously distributed. If, for example, water or aqueous phosphoric acid is added to the mixture, a simple brief mixing by means of a mixing drum or a stirrer is sufficient for hardening, with the the isocyanate normally immiscible water is in no way homogeneously distributed in the overall mixture.

Le A 17 900 - 18 -

809841/0078

The hardening is also surprisingly insensitive to the amount of water used. In addition to the simple access of air humidity or water vapor, e.g. when storing the preformed mixture at room temperature, amounts of water from 0.1 to 20% by weight and higher can be used to carry out the hardening on the total mixture used. Preferably, 0.5 to 10% by weight of water is added to the mixture added to the deformation process. However, it is also possible to cure moldings produced anhydrous in water vapor.

Furthermore, it is surprising that the CO- formed during the curing brought about by the reaction of the water with the polyisocyanate, even at relatively high levels, e.g. 20 wt .-% lying polyisocyanate content, even when working under the press at about 150 ° C, the molding obtained does not explode or damage. The tendency, Some polyisocyanates foam up when reacting with moisture, seems to be the one obtainable according to the process Also not to adversely affect molded bodies.

The further auxiliaries to be considered according to the process can either be added to the mixture of inorganic hollow beads and non-volatile polyisocyanates or such as phosphoric acid with the optionally used water are added to the mixture immediately before the shaping process.

Le A 17 900 - 19 -

809841/0078

27U006

The latter case occurs when the auxiliaries are substances that react with the isocyanates. Emulsifiers, water repellants, pigments such as TiO , carbon black, chromium oxides, iron oxides, dyes, fluxes such as fluorspar, borates, organic or inorganic halogen compounds, metal powders, alkali or alkaline earth silicates, calcium sulfates, cements or other fillers other than Hollow spherical shape, for example in the form of powders with massive particles, the grain size of which should also be below 1 mm. The amounts of these auxiliaries are preferably such that the weight limits to be complied with according to the process for the content of hollow beads, phosphoric acid and polyisocyanate in the molded mixture are not violated, that is, that the molded mixture contains at least 70% by weight of inorganic hollow beads, at least 1% phosphoric acid and Contains at least 2% polyisocyanate.

Furthermore, the following are understood as aids: activators or modifiers for steering or acceleration the isocyanate curing reaction, such as alkali metal alcoholates or carboxylates, e.g. sodium acetate, tin octoate, iron acetylacetonate, amine activators known in polyurethane chemistry, such as tertiary amines, such as triethylamine, tributylamine, N-methyl-morpholine, N-ethyl-morpholine, N-cocomorpholine, N, N, N ', N · -Tetramethy1-ethylenediamine, 1,4-Diaza-bicyclo- (2,2,2) -octane, N-Methy1-N'-dimethy1-

Le A 17 900 - 20 -

8Ü9841 / 0078

27U006

aminoethyl-piperazine, Ν, Ν-dimethylbenzylamine, bis- (N, N-diethylamlnoäthyD-adipate, Ν, Ν-diethylbenzylamine, pentamethyldiethylenetriamine, N ^ -dimethylcyclohexylamine, N, N, N ¹ , N'-tetramethyl-I, 3- butanediamine, N, N-dimethyl-β-phenylethylamine, 1,2-dimethylimidazole, 2-methylimidazole, Mannich bases known per se from secondary amines, such as dimethylamine, and aldehydes, preferably formaldehyde, or ketones such as acetone, methyl ethyl ketone or cyclohexanone, are also used as catalysts Phenols such as phenol, nonylphenol or bisphenol in question.

Hydrogen atoms active towards isocyanate groups tertiary amines as catalysts are e.g. triethanolamine, triisopropanolamine, N-methyldiethanolamine, ΝΑ thy 1-diethanolamine, Ν, Ν-dimethyl-ethanolamine, as well as their Reaction products with alkylene oxides, such as propylene oxide and / or ethylene oxide.

Of the activators, those of particular interest are those that are not very volatile and physiologically largely are harmless, e.g. alkanolamines or N-alkylalkanolamines, in particular triethanolamine and its oxyalkylation products and oxyalkylation products of ethylene or Propylenediamine.

While the usual amine activators are used in amounts of 0.01 to 3% by weight, based on isocyanate for triethanolamine, for example, as a weakly effective activator, it is advisable to use amounts of 0.5-10, preferably 1-5% by weight, based on isocyanate, to be used if strong acceleration effects are achieved want.

Le A 17 900 - 21 -

809841/0078

27U006

Such compounds are also used as auxiliaries understood, which serve as plasticizers or elasticizing reactants for the isocyanate can. Such compounds correspond to the compounds that are already known as compounds with at least two Zerewitinoffactive Hydrogen atoms in the preparation of any prepolymers to be used on page 5 were listed. Here, too, polyhydroxy compounds of the type mentioned are preferred to pull.

The mixtures according to the method are preferably initially prepared without the addition of phosphoric acid or phosphate using customary methods, e.g. by tumbling, spraying in mixing drums, special mixers or kneading units, Kneading screws, etc. These mixtures can be stored if activating substances are excluded very good, e.g. for the preferred hollow bead types with a weakly acidic reaction in water, if the Hollow beads have been dried beforehand at an elevated temperature of around 150 - 250 C. Of course, moisture is excluded necessary, e.g. by storing in appropriately equipped silos or containers or in sheet metal drums Can be soldered or in welded, polyolefin-coated aluminum foil packs. Do you want one fresh Process the mixture to be prepared immediately, protective measures are not necessary, as a freshly prepared mixture Can be used for several hours even after the addition of water, provided that temperatures below 25 ° C are maintained will. Of course, this processing latitude is

Le A 17 900 - 22 -

809841/0078

27U006

lower when using accelerators. The phosphoric acid or phosphates are expediently, if appropriate dissolved in water, added immediately before processing. Polyphosphate is preferred to the mixture added in powder form as a solid.

The mixtures, which may contain accelerators, can be cold-worked without further addition of water by tamping, rolling, pressing, extruding, shaking in, blowing in, etc. at room temperature or elevated temperatures harden by exposure to air humidity or water vapor. When working at elevated temperatures, e.g. between 50 and 180 ° C or when adding the mixtures The use of water is of course recommended in closed molds. The hardening is temperature-dependent and is also dependent on the geometry of the molded part and the thermal conductivity at a given temperature of the molded part. Accordingly, curing times can range from a few seconds to about 24 hours and more appear. Because even with parts that were manufactured at elevated temperatures, e.g. in the press, still Post-reactions are possible, the strength of the molded part generally somewhat improved in storage. Hardened at room temperature and / or by humidity Depending on the geometry, parts may only reach their final strength after approx. 30 days, similar to concrete parts.

A particular advantage of the method according to the invention

is the possibility of cold deformation of the previously prepared mixtures, while the hardening then optionally takes place is carried out at an elevated temperature. So

Le A 17 900 - 23 -

809841/0078

26 27U006

is a special procedure for the production of moldings with a particularly low density, thereby characterized in that the mixture optionally containing water and further auxiliaries according to the invention Hollow beads, phosphoric acid and polyisocyanates are first converted into the form of preforms and these Preforms are then used to produce the final molding.

These e.g. extruded preforms have the shape of cylinders with diameters of approx. 1 - 10 mm or from small tubes, hemispheres, tube half-shells or twisted ribbons with similar diameters and are then filled in the form of smaller fragments or continuously in forms, e.g. a plate form, and compacted there under low pressure and then hardened. The density of sheet goods produced in this way can be 50 - 200 kg / m lower than sheet goods made directly from the mixture.

Another interesting processing variant is characterized in that the mixture, optionally containing water and other auxiliaries, is passed through a piston or screw injection molding machine or other conveying units, in which the mixture can even be produced itself, at temperatures between 0 and approx ⁰ C, preferably 15 and 60 ° C, is injected or pressed into a closed mold,

Le A 17 900 - 24 -

80 98A 1/0078

ΖΊ- 27Η006

which either immediately after filling or previously to temperatures between 100 and 250, are preferred 120 and 180 ° C, is heated. Leave that way moldings can be produced from the mixtures according to the invention in short cycle times.

The simplest way of processing the mixtures, possibly water, accelerators and other auxiliaries may contain is tamping, pouring or blowing into a mold and then allowing it to harden optionally under pressure and heating. The production of sheet goods on presses is interesting Temperatures between 100 and 250 ° C., preferably 120 to 180 ° C., and pressures from 0.5 to about 50 kp / cm.

Of course, internal or, preferably, external release agents can be used in the production of molded parts Find. In addition, the introduction of reinforcing elements in the molded parts in the form of metal or Consider non-metal rods, wires, fibers, fabrics, fleeces and knitted fabrics.

The mixtures or molded parts obtainable therefrom can be used for insulation purposes, e.g. in the form of pipe half-shells or building blocks and plates are used as binders for pumice, expanded glass and expanded clay or organic Foam particles, as mortar or as articles of daily use, components, cover panels, acoustic panels, for production of wall elements, filters, sandwich constructions with the help of various cover surfaces, these cover surfaces e.g. in the production of

Le A 17 900 - 25 -

809841/0078

^SE 27H006

Press plates can be applied in one operation. The molded parts can be used as a carrier for fragrance and biological Active ingredients are used as floating bodies, filling or joint filling material, as plaster or coatings for rigid substrates, as a fire-retardant and insulating filling or sealing compound for structural cable and pipe penetrations or doors and safes, as screeds, as material for furniture production or semi-finished products for further processing mostly by machining processes. The moldings are also after thermal stress Stable above 35O ° C when stored in water.

The hardened molded parts can be sawn, nailed, screwed or glued. You can use hydraulic Binders or with organic layer formers based on latices, dispersions, solutions, pastes or melt coated. They can be enamelled or painted after appropriate pre-treatment galvanize or laminate, due to the low coefficient of thermal expansion in the area of brick the molded body must be paid attention to the correct dimensioning and selection of the outer layers. as Adhesion promoters are often used, for example, when lamination with metals or wood and other cover layers Polyolefins or copolymers of olefins with e.g. vinyl acetate, acrylates and / or (meth) acrylic acid have proven their worth, which result in a good bond during the pressing process. Of course, adhesives based on epoxies have also proven themselves or, for example, polyvinyl acetate dispersions have been found to be suitable.

Le A 17 900 - 26 -

8Ü98A1 / 0078

27ΊΑ006

In the following, the method is to be explained by way of example. The parts and percentages shown are on based on weight.

Hollow spheres are closed as inorganic hollow spheres Walls are used that have, for example, the following composition or properties:

Silica as SiO = 55 - 60% Alumina as Al-O, = 25 - 30% Iron oxide as Fe-O ^ = 4 - 10% Calcium as CaO = 0.2 - 0.6% Magnesium as MgO = 1 - 2% Alkaline η Na ₃ O + = 0.5 - 4% Components.) K-O

Shape: small, hollow glass spheres Color: light gray

Specific weight: 0.6 Bulk weight: 4OO g / l Fineness: 10 - 250 microns Average grain size: 1OO microns

15% under 50 microns 20% over 125 microns

Wall thickness: approx. 10% of the diameter. Melting point: 1200 ° C Hardness: Mohs scale 5

A 50% slurry of the hollow spheres in distilled water has one at room temperature after 24 hours pH 6.3.

Le A 17 9OO

- 27 -

H0Π HL 1/0078

3 ο

The polyisocyanate is exemplified at room temperature liquid polyisocyanate is used, which is technically produced by phosgenation of aniline-formaldehyde condensates and distilling off the volatile constituents and part of the DLphenylmethane diisocyanate formed will. Accordingly, it is a polyisocyanate from the sump of industrial production or distillation of diphenylmethane diisocyanates. The polyisocyanate used, in addition to diphenylmethane diisocyanate complex multinuclear isocyanates are also included, is characterized as follows:

Isocyanate content: hydrolyzable chlorine: total chlorine:
Viscosity at 25 ° C: sediment:

30 - 32% 0.3% or less 0.8% or less 400 + 50 cP max. 1%

Density d

Viscosity at 2OC:

Flash point:

Boiling point:

1.235 g / cm ^J 580 + 100 cP above 200 ° C

over 170 ⁰ C at 1 Torr

A closed propeller mixer is used to produce the mixture, so that mixtures can also be excluded can be carried out by humidity.

The percentages in the following examples are always Weight percent unless otherwise stated.

Le A 17 900

- 28 -

H i) iJ a 4 1/0 Ü 7 8

27U006

example 1 Preparation of a storage-stable premix

The hollow spheres are dried at 150 ° C. for 24 hours. Then you put them in the mixer filled with dried air and start the mixing propeller. to 92.5 parts of the beads are now metered in 7.5 parts of the polyisocyanate in about 5 minutes. After another 5 Minutes the mixture is homogeneous; under the microscope it can be seen that all hollow spheres contain the polyisocyanate are coated. The mixture is placed in polyethylene-lined metal drums with exclusion of atmospheric moisture filled, the drums are hermetically sealed.

The freshly made premix feels like moist earth. You let yourself go by pressing and pounding deform without, for example, a shaped ball disintegrating again. The appearance is also very similar when you prepare mixtures that contain not 7.5 but between 3 and 15% polyisocyanate.

When lying in the air, the character of the non-compacted mixtures changes; they are getting less sticky, clump together and no longer deformable after approx. 24 hours.

In the closed drums, the premix retains its consistency for at least three months; still after

Le A 17 9OO - 29 -

8U98A1 / 0078

27U006

The premixes can be deformed for 5 months. A sample is then taken from the drum and if it leaves it in the air, the change in properties described above takes place again.

This premix is now mixed with the additives listed in the table below and without additives and then the specified amount of water is mixed in using a high-speed mixing drum will.

A prism shape is then filled from the mixture. The prisms are compacted by hand using a tamper and then hardened at 70 ° C for 24 hours. To For a further 7 days, the strengths are checked using a test device such as that used for concrete tests, certainly. The values obtained are given in the table.

Some of the prisms are heated to 450 Ω for 30 minutes in a gas-fired oven and in an electric oven. This shows a clear superiority of the phosphorus-containing additives over all other additives im Test were. It is surprising to find that those produced with the use of ammonium polyphosphate Test specimens have improved strengths.

Le A 17 9OO - 30 -

809841/0078

• J

σ: I. C. LJ CC ■ CE I. * - "'S. O O

Premix

Na-silicate basic Na-silicate neutral borax

Anncnioipolyphosphate Anncnivi ^ hosphate sec.

2)

water

Parts parts parts parts parts parts parts parts parts

Raise weight kg / m
Compressive strength kg / cm ²
Flexural strength kp / αη

Tabel

40

40

40

40

10

20th

10

505 503 478 482 493 446 450 430 482

40 37 26 36 50 49 50 47 49

11 13 8 9 13 12 11 11 13

Comments / burning test, furnace, 45QOC η

destroyed or disintegrated

disintegrate

no more residual strength

no more residual strength

severe cracking

Samples received, strong bond

1) 2)

Type X 1301 from Bayer-Rickmann dissolved in water

CD O CD

Example 2 Manufacture of moldings

A mixture of the hollow beads and, based on hollow beads, 5% by weight of ammonium polyphosphate powder and one A predetermined amount of polyisocyanate is mixed with a predetermined amount of water in a drum mixer for about 3 minutes mixed.

The mixture is then introduced into a plate form to form a 4 cm thick plate, which is tamped with a small tamper is compacted by hand.

The plate produced in this way is then cured at a predetermined temperature in a hot air cabinet, with the curing time can be between hours and days. Then from the plate in different places and Test specimens with the dimensions 4 χ 4 χ 16 cm cut out in different cutting directions and checked for compressive strength and flexural strength investigated. The strength values of the are within the error limits test specimens produced on a plate, regardless of the cutting direction. In detail, the following Values summarized in tabular form receive:

Table A-C shows the relationship between the mechanical values for different water additions the curing temperature. In connection with A-C, Table D clarifies the relationships between quantity

Le A 17 900 - 32 -

8 (19841/0078

³⁶ 27U006

of the polyisocyanate used and mechanical values.

It is clear that there is a wide range of tolerances with regard to the amount of water that can be used. on the other hand shows the great influence of temperature. Nevertheless, it should be noted here that at least one at room temperature the compressive strengths obtainable at 70 ° C can also be achieved if the curing time is long enough measures.

To test the behavior on exposure to flame, all of the individual test variations are obtained Test body in the middle of a Bunsen burner flame for approx. 60 minutes exposed. Here, the test prisms are not destroyed, but essentially keep theirs Shape. On the other hand, similar test pieces that differ from the previous ones only in that in them the ammonium polyphosphate was replaced by a further proportion of hollow pearls when exposed to a flame as before, more or less completely destroyed, because the organic bond burns out and the hollow pearls be detached at the point of exposure to the flame and trickle out of the composite like sand.

The hardening properties of the mixtures according to the process are shown in Table E for room temperature. The hardening is determined with the needle device based on DIN 1164 . It turns out that with triethanolamine as an easily manageable accelerator, the hardening times can be roughly halved.

Le A 17 900 - 33 -

809841/0078

³⁶ 27H006

Example 3

This effect is also observed in compression tests, which are shown in Table F. For this purpose, the freshly prepared mixture of hollow beads and polyisocyanate, containing 3.5% by weight of ammonium polyphosphate powder, is stirred with a little water and optionally dissolved accelerator (triethanolamine), then shaken in a plate shape and pressed under low pressure at elevated temperature. It can be seen that the hardening proceeds, as expected, starting from the heated press rams towards the center of the plate. However, sufficient hardening in the middle of the plate depends on the temperature reached there or the reaction speed at this temperature, ie on the thermal conductivity of the plate material. The resulting relatively long minimum pressing time can be significantly reduced by adding accelerators, with the mechanical values even increasing. The plates are not destroyed if the Bunsen burner is used for 1 hour.

Is placed in the plate form, a polyethylene-coated aluminum foil so that the Polyäthylenfläche is turned to a plate material and covers the plate also from top, is obtained in a pressing process, for example according to Test F, e, an Al-coated press plate (sandwich) with good adhesion between the sheet material and the top layer.

The same procedure can be used with a polyester fabric, since it is coated on one side with an ethylene-acrylic acid copolymer.

Le A 17 900 - 34 -

809841/007

27H006

If a polyamide fleece is introduced into the mold in an analogous procedure, a plate is obtained which is provided with a textile layer on one or both sides and is suitable as wall cladding.

If you put a veneer wood foil in the form of the plate, on top of it an approx. 0.3 mm thick foil made of polyethylene, which is modified by the addition of an ethylene-acrylic acid copolymer, then overlaid with the mixture according to the invention according to experiment F, b or F, f, a veneer-coated one is obtained in one pressing process Press plate which is suitable as a semi-finished product for the manufacture of furniture.

Example 4 Manufacture of compression molded molded bodies

A mixture of 100 parts of the hollow beads and 15 parts of the polyisocyanate is made in a propeller mixer and 10 parts of ammonium polyphosphate. Then in the same mixer a solution of 0.5 Parts of triethanolamine in 3 parts of water are added.

The freshly made mixture is put into a screw injection molding machine at an operating temperature of approx. 20 ° C and placed in a silicone-based release agent equipped steel plate shape, which is heated to 150 ° C. It is removed from the mold after 3 minutes. The received

Le A 17 900 - 35 -

8Ü98A1 / 0078

38 27H006

Plate (10 χ 10 χ 3 cm) has a weight of approx. 150 grams. It holds a 120-minute flame exposure with a Bunsen burner stood without destruction.

Example 5 Manufacture of moldings from preforms

A mixture stored for 5 weeks according to Example 1 is removed from the pack and mixed with 10% by weight of a 30% aqueous solution of sec. Ammonium phosphate mixed. Now the mixture is passed through a steel sieve with square Holes with an edge length of 0.9 mm pressed. This creates strands that loosen up with each other To have cohesion, but as such retained their shape. These strands are now loosely into a shape filled and compacted by a slight pressure to form an approx. 20 cm thick plate.

This is cured at 80 ° C. overnight. The resulting The board has a compressive strength of approx. 7 kp / cm and a volume weight of only 300 kg / m. An analogue made Plate, however, in which only half the amount of polyisocyanate was used, had a volume weight of 300 kg / cm a compressive strength of 4.4 kp / cm. Since it meets the requirements of fire class A 1 according to DIN 41O2, it can be used particularly well for insulation purposes.

Le A 17 900 - 36 -

8U98A1 / 0078

P ft

Table A.

mixture

% Content of poly! Socyanate

I. additive U) % Water CD
O ■ «J hardening temperature <£> I. CO
* ~ Curing time d - days «^ O Volume weight O
-J kg / m ³

7.5

0 2.5 5 room temperature

8th Days "

0 compressive strength kp / m2 (DIN 1164)

0 flexural strength kp / m ² (DIN 1164)

WMnne passage number (plate 30 χ 30 cm) W / Km

thermal expansion coefficient o _c -1

422 416 28.8 27.6

7.5 10 12.5 15

15th

9.0

9.6

410 410 402 420 423 30.2 29.8 27.8 28.6 30.8 29.5 9.8 10.1 11.2 10.3 10.2 9.8

CD O (D

VO

mixture

% Content of polyisocyanate

additive
% Water

Curing temperature

OO ■ Curing time O I.
IjJ h - hours cc W.
OO cc I. Volume weight kg / mJ ">»
O 0 compressive strength O kp / m ² (DIN 1164)

Tabel

2.5

7.5

12.5 15

25th

0 flexural strength kp / πΓ (DIN 1164)

Heat transfer coefficient (plate 30 χ 30 cm) W / Km

thermal expansion coefficient o _c -1

429 428 423 425 420 416 415

38.9 41.0 33.7 35.6 37.1 35.6 33.3 29.9

17.0 12.9 9.6 11.9 13.2 11.2 11.1 10.0

0.1

(D

Table C.

«J

VD

mixture

% Content of polyisocyanate

7.5-

Addition% water

Curing temperature C

O 2.5 5

150 ^BC

7.5 10 12.5 15 25

UJ

Hardening time h - hours

Volume weight kg / m ³

9 compressive strength kp / m ² (DIN 1164)

<ί flexural strength kp / πΓ (DIN 1164)

Heat transmission s ζ ah1 (plate 30 χ 30 cm) W / Km

thermal expansion coefficient o _c -1

410 408

400 400 395 406

46.0 49.8 50.0 39.3 48.2 46.3 40.6 53.5

22.3 21.1 19.2 18.2 18.2 19.9 18.6 20.2

7.9

-10

-6

OO (Ti

r mixture _i _ % Content of polyisocyanate ^ _ additive , P ^ % Water f
(D ^ Λ Curing temperature * ^ «J O Curing time G -JI
3D ^, h - hours / day - days O
I. Volume weight kg / m ³ £ f breaking strength
kp / nr (DIN 1164) / ^ Flexural strength

Thermal transmittance (plate 30 χ 30 cm) W / Km

thermal expansion coefficient

Table D.

7.5 7.5 10

10

20 20

7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 20 150

20 20 70 150

60 150

8 days 12 days 4 days 30 days 24 h 24 h 24 h 24 h 392 432 428 410 452 422 475 460 13.3 29.1 25.9 39.8 47.8 72.7 72.8 98.0 6.2 11.9 9.9 10.8 18.2 26.2 22.9 40.5

O CD CD

Table E.

mixture % Content of polyisocyanate

Addition% water

a 7.5

7.5

b 7.5

7.5

c
7.5

7.5

O (O OO

% Triethanolamine based on polyisocyanate

Temperature C

Start of hardening after minutes (DIN 1164)

End of hardening after hours (DIN 1164

20th

360

10

20th

170

150

CD O CD

tr ¹
(D mixture
% Content of polyisocyanate T a b e lie F. 7 *
_k
-J additive
% Water a b 900 3 7.5 3 3

OO to Plate thickness ο I. cm cc OC Pressing temperature O Press pressure σ bar • ο co Minimum pressing time Minutes

% Triethanolamine

related on polyisocyanate

4 4 1 50 1 50 10 10

20 20

JZf compressive strength (DIN 1164)

kp / m2 28.3 50.9

l6 bi

tensile strength ²

(DIN 1164)

Volume weight kg / m3

9.8 15.2 416 428 20 7.5 7.5 7.5

150 150

10 10

25 10

125.4 72.5

52.0 28.3

428

10

10

10

27U006

Example 6

To demonstrate the particularly favorable performance behavior of the inventive, if appropriate Experiments A, B and C and the comparative experiments are those containing further additives D and E carried out.

A: 97 parts of the hollow beads are mixed well with 3 parts of polyisocyanate and 3 parts of ammonium polyphosphate. Then 10 parts of water are added, the mixture is mixed thoroughly and the resulting deformable material is tamped Put the mass into prismatic shapes and harden overnight at 70 ° C. A stable molding is obtained with firm, smooth surface.

B: Like Α »but instead of ammonium polyphosphate equal amounts of sec. Ammonium phosphate used and added to the water to be mixed. Man receives a stable molded body with smooth, solid surfaces.

C: Like A # but instead of ammonium polyphosphate equal amounts of orthophosphoric acid are used and added to the water to be mixed.

D: As A, but the ammonium polyphosphate is omitted. A stable, smooth molding with solid surfaces is obtained.

Le A 17 900 - 43 -

809841/0078

E: As C, but the polyisocyanate is omitted. A molding which is very weak is obtained with soft, crumbly surfaces.

If the moldings are heated in an oven at 450 ° C. for 30 minutes, the patterns according to A, B and C are true blackened, but still stable and virtually unchanged in shape. Pattern D is except for a small one Core area completely crumbled. Pattern E is contour stable but moderately firm, i.e. it crumbles during use.

If the moldings A - E are left to stand in the air in a normal room climate, the patterns also change E not noticeable. At E, the surfaces become increasingly crumbly, the molded body tends to disintegrate.

If the shaped bodies are placed in water, only pattern E begins to crumble, while A-D remain stable.

Le A 17 900 - 44 -

tt 0 Π Π Λ 1/0078

Claims (5)

Claims 1. Formable molding compounds consisting of 70-97% by weight inorganic hollow spheres with a bulk density of less than 900 g / l and grain diameters of less than 1 mm, 1-20 Wt .-% phosphoric acids and / or phosphates with 2-29 wt .-% polyisocyanate with a boiling point of more than 150 ° C at 1 torr are coated. 2. A process for the production of molded parts with largely isotropic properties, liter weights of less than 1000 grams, from cold-formable molding compositions according to claim 1, characterized in that mixtures of 70-97% by weight of inorganic hollow spheres with a bulk density of less than 900 g / l, grain diameters below 1 mm, 1-2O wt .-% phosphoric acid and / or phosphates and 2-29 wt .-% polyisocyanate with a boiling point of more than 150 ⁰ C at 1 Torr, and this optionally after the addition of water and deformed further aids and hardened at room temperature and ingress of atmospheric moisture or heating, if necessary under pressure. 3. The method according to claim 2, characterized in that serving as the starting material molding compound by means of a conveyor device into a closed mold and in this at temperatures between 100 and 25O ° C hardens. Le A 17 900 - 45 - P 0 Q B A 1/0 0 7 8 ORIGINAL INSPECTED 27U006 4. The method according to claim 2, characterized in that one from the serving as the starting material molding compound first produces preforms, then these transferred into a mold and hardened there, if necessary after compaction. 5. The method according to claim 1 to 4, characterized in that ammonium phosphates are used as phosphates. Le A 17 900 - 46 - Hi: ■: / * 1/01) 7 8