IE40270B1

IE40270B1 - Organic-inorganic plastics and a process for producing them

Info

Publication number: IE40270B1
Application number: IE2463/74A
Authority: IE
Original assignee: Bayer Ag
Priority date: 1973-11-30
Filing date: 1974-11-29
Publication date: 1979-04-25
Also published as: LU71390A1; FR2253053B1; BE822759A; ATA954974A; JPS5087193A; JPS5530530B2; IT1023378B; DE2359610C3; DE2359610B2; AU7581074A; AT335750B; DE2359610A1; NL7415638A; IE40270L; DD118103A5; FR2253053A1; GB1450240A; BR7410036A; ES432429A1

Abstract

1450240 Modified polyisocyanate/aqueous silicate reaction products BAYER AG 27 Nov 1974 [30 Nov 1973] 51299/74 Heading C3R Flexible polymeric materials are obtained by mixing (a) 30-70 wt. per cent of a compound having at least 2 reactive H atoms, of molecular weight 400-6000 and glass transition temperature below 10‹ C., (b) 10-30 wt. per cent of a polyisocyanate and (c) 20-60 wt. per cent of an aqueous alkali metal or ammonium silicate solution of 30-70 wt. per cent solids content. Preferably (a) and/or (b) contains a hydrophilic group, and these two are preferably mixed first to give a prepolymer. The products are usually foams, and conventional blowing agents and other polyurethane foam additives and fillers may also be added. In Examples 150 p.b.w. (total) of a mixture of a polyoxypropylene polyol/TDI prepolymer which may be sulphonated with SO 3 , with 20-60 p.b.w. (usually 50) of a crude polyphenyl polymethylene polyisocyanate modified with a polyoxyethylenated butanol is mixed with 30-50 p.b.w. of CCl 3 F, and this mixture combined with one containing 100-200 p.b.w. of 44% aqueous sodium silicate (Na 2 O : SiO 2 , 1 : 2), 0À5-2 p.b.w. of Et 3 N, optionally 1À5-3 p.b.w. of an emulsifier or silicone foam stabilizer and, in Examples 2-4, and 15-17, 50-200 p.b.w. of cement; in Examples 20-26 a one-shot process is carried out using 100 p.b.w. of polypropylene glycol 10 p.b.w. of TDI and 60 p.b.w. of an unmodified and/or sulphonated or polyglycol-modified polyphenyl polymethylene polyisocyanate with CFCl 3 and waterglass and optional triethylamine and silicone in quantities as above. Reference has been directed by the Comptroller to Specification 1,186,771. [GB1450240A]

Description

402T0 This invention relates to organic-inorganic plastics and a process for producing them.

Klastomers based on polyisocyanates and polyols are known. They are mainly produced as foams and have 5 a wide variety of uses. It is also known how the properties of the elastomers may be adapted to their intended purpose by varying the formulations of the reaction mixtures. Thus, for example, the hardness, resistance to compression and elasticity may be con-lO trolled within a wide range.

The fire characteristics of the polyurethane elastomers are in many cases still unsatisfactory.

This applies particularly to open-cell light-weight foams owing to their unfavourable surface/mass ratio. 15 Many attempts have been made in the past to improve the fire characteristics of these foams, for example by adding halogen and/or phosphorus compounds or by means of particular structural features, such as thermolabile bonds which when exposed to fire cause the foam to melt and - 2 - 40270 thereby drastically roihu't* tin* surf.uv. Kui'lIkuhumo, antimony oom|Rumds, lor example, and Inorganic sails and fillers, such as calcium carbonate, bariuni sulphate or zinc borate, may be added. 5 Such additions to the elastomer formulations often do in fact reduce the flammability or even cause spontaneous extinction of a small ignited test sample. However, in large test samples or in the sort of fire which would occur in practice, they are often unsatis-factory because of the high temperatures which occur. The main disadvantage of inorganic fillers is that they do not contribute to the advantageous properties of the products, but merely "dilute" the organic matrix. Furthermore, they frequently act as wicks which may even 15 promote the spread of fire.

Another difficulty when adding inorganic materials and especially those which are very hard and therefore abrasive lies in the conventional techniques for producing foams. The high pressure piston pumps normally 20 used cannot deliver viscous products which contain fillers or only with great difficulty and not in exact amounts. Moreover, additional mixing apparatus are necessary to cffect homogeneous distribution of the fillers in the polyol. 25 According to an earlier proposal of the present Applicants, hard inorganic-organic plastics having high strength, dimensional stability to heat and flame resistance are obtained when liquid prepolymer ionomers which still contain reactive groups are homogeneously 30 mixed with aqueous alkali metal silicate solutions and the resulting sol is left to react to form a xerosol. The liquid prepolymer ionomers used are, in particular, - 3 - j o a 7 o polyisocyanatos.

According to another earlier proposal of the present Applicants, it is possible to use prepolymers which instead of the ionic modification carry a hydro-5 philie, non-ionic group. The proportion of prepolymer to water glass may vary within wide limits.

Hard moulded products, coatings and, in particular, foams may be obtained according to these earlier proposals. In these materials, the hardness 10 Is often above Shore D 50. If the elastic properties are particularly emphasized in this connection it must be remembered that the elasticity under discussion is the impact elasticity of a material which is basically hard.

^ In the course of further development of these earlier proposals, it has now surprisingly been found that, under ccrtain con<l i t i nns, polyisocyanates und alkali metal or ammonium silicate solutions may even be used to produce flexible oroducts, in other words 2o products which, for example, have a Shore hardness A of from 40 to 95 and an elongation at break of from lOO to 800 combined with high elasticity. These flexible products have excellent fire characteristics even as foams and, moreover, they may easily be prepared as liquid components 25 in the conventional manner.

The present invention therefore relates to a process for producing flexible inorganic-organic plastics which have a low calorific value and improved fire characteristics by reacting a mixture which comprises ■jO compounds containing Zerewittinoff-active hydrogen atoms, polyisocyanates, aqueous alkali metal or ammonium silicate solutions and, optionally, other auxiliary agents and additives, in particular blowing agents, flame-rota riling - 4 - 4 0 2 TO agents which contain halogen and water-binding fillers.

The present invention provides a process for the production of an organic-inorganic plastic which comprises reacting together! (a) from 30 to 70%, by weight, of one or more compounds which contain at least two Zerewittinoff-active hydrogen atoms, have an average molecular weight of from 400 to 6000 and a glass temperature of below 10°c. (b) from lO to 30%, by weight, of one or more polyisocyanates; and (c) from 20 to 60%, by weight, of an aqueous solution containing from 30 to 70'i, by weight, of an alkali metal or ammonium silicate and in which components (a) and (b) may be used in the form of a reaction product of the two components.

It is preferred that the compounds in component (a) have an average molecular weight of from lOOO to 6000 and a glass temperature below -20°C.

The following proportions, by weight, of the compounds in the mixture are particularly preferred: (a) from 45 to 70 pcrcent, by weight, (b) from 10 to 30 percent, by weight, (c) from 20 to 45 pcrcent, by weight.

Within these proportions, exceptionally soft and highly elastic products are obtained.

Particularly preferred are the reaction mixtures in which at least one of the compounds (a) and/or (b) or the reaction product of (a) and (b) contains at least I ,) :i 7 <» a proportion of hydrophilic groups, which may be either ionic or non-ionic. Furthermore, component (a) should preferably be liquid at 50°C and have a glass temperature of below 10°C, preferably below 5 -20°C, and an average molecular weight of from 1500 to 5000.

The addition of small quantities (from 0.5 to 5%) of aqueous alkali metal silicate solutions to foam formulations is known (U.S. Patent No.3,634,342). Such lO small quantities act as additives and have little influence on the properties of the basic formulations. The foams obtained should be capable of softening in water/alcohol mixtures, but the fire characteristics are not affected. It is explicitly emphasised in 15 the said Specification that the reaction gets out of control if tin? quantity of si I lea to .nMcd is mora t li.in '>% , based on the basic formulation.

In the present invention, on the other hand, the alkali metal or ammonium silicate solution is 20 a major component. The silicate proportion, based on the dry substance, is at least 10%, but preferably from 20 to 40%. This means that formation of the polymer takes place in the presence of a large excess of water. In contrast to what would have been expected, 25 this large excess of water has no undesirable effect.

It causes neither unwanted branching nor crosslinking reactions nor premature chain breaking. This important feature which is decisive for the properties of the products is presumably connected with the diphasic 30 structure both of the reaction mixture whilst this is still liquid and of the end product. - 6 - 4 0 2 7 0 It is distinctly surprising that even with an alkali metal or ammonium silicate content of 60% it is still possible to obtain elastomeric products in spite of the silicate structure which is formed.

One particular advantage of the products according to the present invention is that they may also contain substantial quantities of flame-retarding agents which contain phosphorus and/or halogen without acid or toxic fumes being produced when the products are heated or exposed to fire. The only requirement which must be observed is that the number of potential acid equivalents introduced with the flame-retarding agent must not exceed the number of basic equivalents in the alkali metal or ammonium silicate solution. If water glass is used as silicate component in an elastomer which has been treated, for example, with polychloro-paraffin and tris-bromoethyl phosphate, it is found that after pyrolysis the chlorine is present as sodium chloride, the bromine as sodium bromide and phosphorus as sodium phosphate.

This means that in the event of fire an equivalent quantity of carbon dioxide is liberated by the flame-retarding agent.

The starting components used for preparing the elastomers according to the present invention are known.

Compounds which contain at least two Zerewittinoff-active hydrogen atoms (component (a)) are compounds having a molecular weight of from 400 to 6000 which contain at least two hydrogen atoms which are reactive with isocyanates. Apart from compounds which contain amino-, thiol- or carboxyl groups, the compounds of this type are preferably polyhydroxyl compounds, in particular compounds which contain from 2 to 8 hydroxyl groups, <10 2 7 0 especially those, having a molecular weight of from lOOO to 6000, e.g. polyesters, polyethers, polythioethers, polyacetals, polycarbonates and polyester amides containing at least 2, generally from 2 to 8, but preferably from 2 to 4 hydroxyl groups, of the type known for the production of homogeneous and cellular polyurethanes.

The polyesters containing hydroxyl groups which may be used for this purpose are, e.g. reaction products of polyhydric alcohols, preferably dihydrlc alcohols, with the optional addition of trihydric alcohols, and polybasic, preferably dibasic carboxylic acids. Instead of the free polycarboxylic acids, the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols or mixtures thereof may be used for producing thd polyesters. The polycarboxylic acids may be aliphatic, cycloaliphalic, aromatic and/or heterocyclic and may be substituted, e.g. with halogen atoms, and/or be unsaturated. The following are examples: succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid, phthalic acid anhydride, tetrahydrophthalic acid anhydride, hexahydrophthalic acid anhydride, tetra-chlorophthalic acid anhydride, endomethylene tetrahydrophthalic acid anhydride, glutaric acid anhydride, maleic acid, maleic acid anhydride, fumaric acid, dimeric and trimeric fatty acids, such as oleic acid, optionally mixed with monomeric fatty acids, dimethyl terephthalate and bis-glycol terephthalate. Suitable polyhydric 40270 alcohols arc, e.g. ethylene glycol, propylene-1,2-and -1,3-glycol, butylene-1,4- and -2,3-glycol, hexane-1,6-diol, octane-1,8-diol, neopentyl glycol, cyclohexane dimethanol, (1,4-bis-hydroxyraethyl cyclo-5 hexane), 2-methyl-propane-l,3-dlol, glycerol, tri- methylol propane, hexane-1,2,6-triol, butane-1,2,4-triol, trimethylolethane, pentaerythritol, quinitol, mannitol and sorbitol, methyl glycoside, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene lO glycols, dipropylene glycol, polypropylene glycols, dibutylene glycol and polybutylene glycols. The polyesters may contain a proportion of carboxyl end groups. Polyesters of lactones, such as c-caprolactone, or hydroxyearboxylie acids, e.g. w-hydroxycaproic acid, 15 may also be used.

The polyethers suitable for the process according to the present invention, which contain at least two, generally from 2 to 8 and preferably 2 or^3 hydroxyl groups, are also known and may be prepared, e.g. 20 by the polymerisation of epoxides, such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, • styrene oxide or epichlorohydrin, each with itself, e.g. in the presence of BF-j, or by the addition of these epoxides, optionally as mixtures or successively, to 25 starting components which contain reactive hydrogen atoms, such as water, alcohols or amines, e.g. ethylene glycol, propylene-1,3-glycol or -1,2-glycol, trimethyl-olpropane, 4,4'-dihydroxy-diphenylpropane, aniline, ammonia, ethanolamine or ethylene diamine. Sucrose poly-30 ethers as described, e.g. in German Auslegeschrift Nos. 1,176,358 and 1,064,938 may also be used according to the 40270 present invention. in many cases it is preferred to use polyethers which contain predominantly primary OH-groups (up to 90 percent, by weight, based on all the OH-groups present in the polyether). Polyethers modified with vinyl 5 polymers of the type which may be obtained, e.g. by polymerising styrene or acrylonitrile in the presence of polyethers (U.S. Patent Nos. 3,383,351; 3,304,273; 3,523,093 and 3,110,695 and German Patent No.1,152,536) and polybutadienes which contain OH-groups or COOH-groups lO are also suitable.

Among the polythioethers should be mentioned particularly the condensation products of thiodiglycol with itself and/or with other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or amino alcohols. 15 The products obtained are polythio mixed ethers, polythin-ether esters or polythioether ester amides, depending on the co-components used.

Suitable, polyacetals are, e.g. the compounds which may bo prepared from glycols, such as diethylene glycol, 20 triethylenc glycol, 4,4'-dioxethoxy-diphenyldimethylmethane and hexanodiol, and formaldehyde. Polyacetals suitable for the purpose of the present invention may also be obtained by the polymerisation of cyclic acetals.

The polycarbonates containing hydroxyl groups which 25 may be used are also known, e.g. those which may be obtained by reacting diols, such as propane-1,3-diol, butane-1,4-diol and/or hexane-1,6-diol, diethylene glycol, triethylene glycol or tetraethylene glycol, with diaryl carbonates, e.g. diphenyl carbonate, or phosgene. 30 The polyester amides and polyamides which may be used include, e.g. the predominantly linear condensates which may be obtained from polybasic saturated and unsaturated carboxylic acids or their anhydrides and - 10 - 40270 polyvalent saturated and unsaturated amino alcohols, diamines, polyamines and mixtures thereof.

Polyhydroxyl compounds which already contain urethane or urea groups and modified or unmodified natural polyols, such as castor oil, carbohydrates or starch, may also be used. Addition products of alkylene oxides with phenol/formaldehyde resins or with urea/ formaldehyde resins may also be used according to the present invention.

To ensure the flexible character of the products of the process, polyether polyols and polyester polyols having molecular weights of from lOOO to 6000 which contain flexible chains and have an average functionality of from 2.1 to 3 are preferred.

Representatives of these compounds which are to be used according to the present invention have been described, e.g. in High Polymers, Volume XVI, "Polyurethanes, Chemistry and Technology", published by Saunders and Frisch, Interscience Publishers, New York/London, Volume I (1062), pages 32 to 42 and pages 44 lo 54, and Volume II (1964), pages 5 to 6 and 198 to 199, and in Kunststoff-llandbuch. Volume VII (1966), Vieweg-Hochtlen, Carl-Hanser-Verlag, Munich, e.g. on pages 45 to 71.

The compounds which may be used as component (b) according to the present invention may be aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic polyisocyanates, e.g. those described by W. Siefken in Justus I.iebigs Annalen der Chemie, 562, pages 75 to 136§ for example ethylene diisocyanate, tetramethylene-1,4-diisocyanatc, hexamethylene-1,6-diisocyanate, dodecane-1,12-diisoocyanatc, cyclobutane-l,3-diisocyanate, cyclohcxano- 40270 1,3- and 1,4-diisocyanate and mixtures of these isomers; l-isocyanato-3,3,5-trimethyl-5-isocyanato-methyl-cyclohexane (German AS No.1,202,785), hexnhydro-tolylene-2,4- and -2,<»-diisocynnnto and mixtures of 5 these isomers, hexahydrophenylene-1,3- and/or -1,4-diiso-cyanate, per-hydrodiphenylmethane-2,4 *- and/or -4,4*-diisocyanate, phenylene-1,3- and -1,4-diisocyanate, tolylene-2,4- and -2,6-diisocyanate and mixtures of these isomers; diphenylmethane-2,4and/or -4,4'-diisocyanate, 10 naphthylene-1,5- diisocyanate, triphenylmethane-4,4 *,4"-tri-isocyanate, polyphenylpolymethylene polyisocyanate which may be obtained by aniline-formaldehyde condensation following by phosgenation and which have been described, e.g. in Dritish Patent Specification Nos. 874,430 and 848,671 j perch lor ina ted aryl polyisocyanates as described, e.g. in German Auslegeschrift No.1,157,601; polyisocyanates which contain carbodiimide groups as described in German Patent No.1,092,007; the diisocyanates described in U.S. Patent No.3,492,330; polyisocyanates which contain 20 allophanate groups as described, e.g. in British Patent Specification No. 994,890 in Belqian Patent No. 761,626 and in published Dutch Patent Application No.7,102,524; polyisocyanates which contain isocyanurate groups as described, e.g. in German Patent Nos.1,022,789; 1,222,067 and 1,027,394 and in German Offenlegungsschrift Nos. 1,929,034 and 2,004,048; polyisocyanates which contain urethane groups as described, e.g. in Belgian Patent No. 752,261 or in U.S. Patent No.3,394,164; polyisocyanates which contain acylated urea groups according to German . Patent No. 1,230,778; polyisGcyanates which contain biuret - 12 - 40270 groups, ns described, c.q. in German Patent No. 1,101,394 in British Patent Specificntion No. 880050 and in French Patent No. 7,017,514; polyisocyanates prepalred by telomcrisation reactions as described, e.g. in ttolqlnn Patent No. 723,640; polyisocyanates which contain ester groups, such as those mentioned, e.g. in British Patent Specification Nos. 965,474 and 1,072,956 in U.S. Patent No. 3,567,763 and in German Patent No. 1,231,688; and reaction products of the above-mentioned isocyanates with acetals according to German Patent No. 1,072,385.

The distillation residues which are obtained from the commercial production of isocyanates and which still contain isocyanate groups may also be used, optionally dissolved in one or more of the above-mentioned polyisocyanates. Mixtures of the above-mentioned polyisocyanates may also be used.

It is generally particularly preferred to use commercially readily available polyisocyanates, such as tolylene-2,4- and -2,6-diisocyanate and mixtures of these isomers ("TDI"), polyphenyl-polymethylene polyisocyanates which are obtained by aniline-formaldehyde condensation followed by phosgenation ("crude MDI") and polyisocyanates which contain carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups or biuret groups ("modified polyisocyanates").

The polyisocyanates which may be used as component (b) also include reaction products of the above-mentioned isocyanates with low molecular weight glycols, amino alcohols and diamines. These modification components are in most eases only used in minor quantities, e.g. 1 40270 mol to from 3 to 20 mols of isocyanate.

It is particularly preferred to use components (a) and (b) which contain a (potential) ionic or a non-ionic hydrophilic group. By "potential ionic groups" 5 are meant groups which are converted into ionic groups by alkali metal silicate solutions, in particular sulphonic acid, carboxylic acid, anhydride, betain, sultain and phosphinic acid groups and phenolic OH-groups. lO The following are examples of ionic groups: -N-, -S-(+), -P-( + ), COO(-), -SO,(-), I I | (-) (-) (-) -o-so3 , ~p \ (-) -so2-n -so2, -co-n1 -co-, o 0 -C0-li~'-S02~, -CO-CII-CO, -CO-CH (_,-S02-, -C0-Cn<_>-CN, -Ar-0(_) IS Components (a) and (b) may, of course, also contain two or more of the above-mentioned groups. Moreover, ampholytes which contain an anionic and a cationic group in one and the same molecule or symploxes which contain anionic and cationic products 20 both at the same time may also be present.

Non-ionic hydrophilic groups are, in particular, hydrophilic oligoether or polyether groups and excess Oil-groups which under the reaction conditions will not react or react only incompletely with NCO-groups, as 25 well as, for example, amide groups and urea groups. - 14 - 40270 The introduction of such potentially ionic or non-ionic groups is known to those skilled in the art. Particularly preferred are polyethers or polyether esters which have been prepared at least partly from ethylene oxide; polyesters which contain di-, tri-, tetra- or octa-ethylene glycol; and isocyanates which have been modified by reaction with monofunctional, di- t functional or trifunctional, oligo- or poly-ethylene oxides.

Cationic polyethers and polyesters are prepared in particular, by using those glycols, amino alcohols or polyamines which contain tertiary amino groups and/or sulphide groups as initiators or components for the synthesis, and they are then converted into quaternary salts either immediately thereafter or in the course of the reaction to form the elastomers. Anionic products are prepared in a corresponding mannner, e.g. by using aminocarboxylic acids and/or amino sulphonic acids in the preparation of the polyesters or polyethers. Hydroxycarboxylic acids, such as dimethylolpropionic acid, polycarboxylic acids, such as citric acid, ethylene diaminotetracarboxylic acid, trimellitic acid and hydroxysulphonic acids are also suitable.

The modifying components mentioned are also suitable for ionic or hydrophilic-non-ionic modification of isocyanates by prepolymer or semi-prepolymer formation.

The compounds used for the isocyanate modification are, in particular, also monofunctional compounds, such as ethoxylated monohydric alcohols, dialkylaminopropanol and monoaminocarboxylic acids and sulphonic acids. Component (a) may be reacted with component (b) to form a prepolymer, before it is mixed with the silicate solution, 40270 in a separate reaction stage. This conversion to prepolymer need by no means be completed before the second stage is carried out. Such a reaction to an isocyanate prepolymer is particularly indicated if the Zerewittinoff-active groups of component (a) have only a low reactivity, as for example in the case of secondary OH-groups, SH-groups or COOH-groups, and if a high proportion of alkali metal silicate solution is used, but it is also indicated if, for example, the evolution of heat in the reaction should be prevented as far as possible and if the high viscosity of the prepolymers compared with that of the starting components is not a disadvantage. When preparing the prepolymers, it is advantageous to include a component which contains hydrophilic groups so that dispersion is facilitated when the silicate solution is added. Suitable additives are compounds which contain ionic or non-ionic hydrophilic groups, e.g. the modifying components mentioned above.

• If desired, however, the prepolymer may be modified subsequently with hydrophilic groups, e.g. by sulphonation or other known methods of the type which have been described, e.g. for the preparation of polyurethane (*) ionomers By "aqueous solutions of alkali metal silicates" (component (c)) are meant the solutions of sodium silicate and/or potassium silicate in water which are commonly known as "water glass". Crude commercial solutions which may in addition contain substances, such as calcium silicate, magnesium silicate, borates and aluminates, may also be used. The proportion of Na^O and/or l<20:Si02 is not critical and may vary within the (*) See, e.g. German OS No. 1,770,068 and D. Dietrich and H. Reiff, Angew. makromol. Chemie 2§ (1972), page 85 and the literature references given therein. - 16 - 40270 usual limits, but is preferably between 4 and 0.2. If the water content of the synthetic resin initially obtained by the reaction with the pre-polymer ionomer is of minor importance, either because it has no undesirable effect or because it may easily be removed by drying, then neutral sodium silicate may quite well be used, which may be prepared as from 25 to 35% solutions. It is preferred, however, to use from 32 to 54% silicate solutions, and these may be obtained at the viscosity of below 500 Poises necessary for problem-free working only if they are sufficiently alkaline. Ammonium silicate solutions may also be used, but are less preferred. The solutions may be true solutions or colloidal solutions.

The choice of concentration of the alkali metal or ammonium silicate solution depends above all on the end product desired. Compact materials or materials with closed cells are preferably prepared with concentrated silicate solutions which may, if necessary, bo adjusted to a lower viscosity by the addition of alkali metal hydroxide. In this way from 40 to 70% solutions may be prepared. On the other hand, to produce open-celled, light-weight foams, it is preferred to use silicate solutions having concentrations of from 20 to 40% in order to obtain low densities. Also when finely divided inorganic fillers are used in substantial quantities it is preferred to use silicate solutions having concentrations of from 20 to 45%.

Preparation of the organic-inorganic elastomers according to the present invention is in the simplest 40270 case carried out by mixing the three components (a), (b) and (c) (one-shot process) to form an emulsion whose degree of subdivision, as well as chemical constitution depends, in particular, on the nature and number of the hydrophilic groups contained in it and on the amount of energy expended for mixing the components (in particular in the case of products which are not hydrophilically modified). As mentioned above, however, the reaction product of (a) and (b) may be mixed with component (c) (prepolymer process). In fact, any method of mixing may be employed, for example (a) and (b) may be mixed and then added to (c) either before, during or immediately after the reaction» The mixing process results primarily in the formation of a finely divided stable emulsion in which the organic component is the external phase. The emulsion subsequently hardens to form the elastomer. Due to the alkaline silicate phase which has a strong catalytic action, hardening in most cases takes place spontaneously at from 0 to 20°C with the evolution of heat. Hardening is then substantially completed within from 1 to 5 minutes. In the case of less reactive isocyanates and especially when using masked isocyanates, among which are also included the amine-amides, hardening may take a longer time and require higher temperatures. Due to the spontaneous evolution of heat and rapid hardening, the process according to the present invention is particularly suitable for producing foams of various types.

According to the present invention, readily volatile organic substances are often used as blowing agents. Suitable organic blowing agents are, e.g. _ 18 _ acetone, ethyl acetate, methanol, ethanol, halogenated alkanes, such as methylene chloride, chloroform, ethylidene chloride, vinylidene chloride, monofluoro-trichloromethane, chlorodifluoromethane and dichloro-5 difluoromethane, butane, hexane, heptane or diethyl ether. Compounds which decompose at temperatures above room temperature with liberation of gases, for example nitrogen, e.g. azo compounds, such as azoisobutyric acid nitrile, may also act as blowing agents. Other 10 examples of blowing agents and details of methods of using blowing agents mayb e found in Kunststoff-Hand-buch. Volume VII (1966), Vieweg-Hochtlen, Carl Hanser-Vcrlag, Munich, e.g. on pages 108-109, 453 to 455 and •>i)7 to 5IO. 15 Catalysts are also often used according to the present invention. The catalysts used may be known, e.g. tertiary amines, such as triethylamine, tributylamine, N-methyl-morpholine, N-ethyl-morpholine, N-cocomorpholine, N,N,N',Ntetramethylethylenediamine, 1,4-diaza-bicyclo-20 (2,2,2)-octane, N-methyl-N'-dimethylaminoethylpiperazine, N,N-dimethyl benzylamine, bis-(N,N-diethylaminoethyl)-adipatc, N,N-diethyl benzylamine, pentamethyl diethylene-triamine, N,N-dimethyl-cyclohexylamine, N,N,N",N'-tetra-methyl-1,3-butanediamine, N ,N-dimethyl-f$-phenyl ethylamine, 25 1,2-dimethyl imidazole and 2-methyl imidazole.

Tertiary amines containing hydrogen atoms which are reactive with isocyanate groups are, e.g. triethanol-amine, triisopropanolamine, N-methyldiethanolamine, N-ethyl-diethanolamine and N,N-dimethylethanolamine and 30 the reaction products thereof with alkylene oxides, such as propylene oxide and/or ethylene oxide. - 19 - 40270 Silaamines containing carbon-silicon bonds as described, e.g. in German Patent No.1,229,290 may also be used as catalysts, e.g. 2,2,4-trimethyl-2-sila-morpholine and 1,3-diethylaminomethyl-tetramethyl-di-siloxane.

Bases which contain nitrogen, such as tetraalkyl ammonium hydroxides, alkali metal hydroxides, such as sodium hydroxide, alkali metal phenoxides, such as sodium phenoxido, and alkali metal alcoholates, such as sodium mcthoxidc, may also be used as catalysts. Hexahydro-triazoncs are also suitable catalysts.

According to the present invention, organic metal compounds may also be used as catalysts, particularly organic tin compounds.

The organic tin compounds used are preferably tin(II) salts of carboxylic acids, such as tin(lI)-acetAte, tin(II)-octoate, tin(Il)-ethyl hexoate and tin(II)-laurate, and the dialkyl tin salts of carboxylic acids, such as dibutyl tin diacetate, dibutyl tin dilaurate, dibutyl tin maleate or dioctyl tin diacetate.

Other representatives of catalysts which may be used according to the present invention and details of the action of the catalysts are described in Kunststoff-Ilandbuch, Volume VII (1966) , Vieweg and Hochtlen, Carl-llanser-Verlag, Munich, e.g. on pages 96 to 102.

The catalysts are generally used in a quantity of between O.OOl and 10 percent, by weight, based on the quantity of compounds having a molecular weight of from 400 to 6000 which contain at least two hydrogen atoms capable of reacting with isocyanates.

Surface-active additives (emulsifiers and foam stabilisers) may also be used according to the present invention. Suitable emulsifiers are, e.g. the sodium salts of ricinoleic sulphonates or of fatty acids or salts of " 20 ~ •10 2 7 0 fatty acids with amines, such as oleic acid diethyl-amine or stearic acid diethanolamine. Alkali metal or ammonium salts of sulphonic acids, such as dodecyl benzene sulphonic acid or dinaphthyl methane disulphonic acid, or of fatty acids, such as ricinoleic acid, or of polymeric fatty acids may also be used as surface-active additives.

ThW foam stabilisers used are mainly water-soluble polyether siloxanes. The compounds generally have a pojLydimethyl siloxane group attached to a copolymer of ethylene oxide and propylene oxide. Foam stabilisers of this type have been described, e.g. in U.S. Patent No.2,764,565.

According to the present invention, reaction retarders, e.g. substances which are acid in reaction, such as hydrochloric acid or organic acid halides, known cell regulators, such as paraffins, or fatty alcohols or dimethyl polysiloxanes, pigments, dyes, known flame-retarding agents, such as tris-chloroethyl phosphate or ammonium phosphate and polyphosphate, stabilisers against ageing and weathering, plasticisers and fungistatic and bacteriostatic substances and fillers, such as barium sulphate, kieselguhr, carbon black or whiting, may also be used.

Other examples of surface-active additives, foam stabilisers, cell regulators, reaction retarders, stabilisers, flame-retarding substances, plasticisers, dyes and fillers and fungistatic and bacteriostatic substances which may also be used according to the present invention and details concerning their use and mode of - 21 ~ J 0 2 7 0 action are described in Kunststoff-Handbuch, Volume VI (1966), Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich, p.«|, on pagcn lo3 to 113.

Accord i ikj |o i lie pri'Mcnl I iivcnl Ion , i lie 5 rcactants arc rcactcd together by the known one-step process, prepolymer process or semi-prepolymer process, often using mechanical devices, such as those described in U.S. Patent No.2,764,565. Details concerning processing apparatus which may also be used according lO to the present invention may be found in Kunststoff-Handbuch, Volume VI (1966), Vieweg and Hochtlen, Carl-Hanser-Verlag, e.g. on pages 121 to 205.

Hardening of the alkali metal or ammonium silicate phase is carried out by the carbon dioxide liberated 15 in the reaction. If this quantity is not enough then additional known silicate hardeners may be added, e.g. esters, anhydrides and halides of carboxylic acids, carbonic acid or sulphonic acids, ammonium salts and the conventional inorganic hardeners, such as aluminium 20 salts, magnesium salts or zinc salts. Hardening may, however, also be effected by the carbon dioxide from the atmosphere.

Preparation of the elastomers according to the present invention is carried out by techniques which 25 are basically already known, especially those used for producing cast or foamed polyurethanes. The process may be carried out discontinuously or continuously. Preferably, the components are continuously mixed in a mixing chamber with a short residence time by the tech-30 nique conventionally used for producing polyurethane foams, - 22 ~ 40270 » and the mixture is then hardened and shaped at the same time. For this purpose, the liquid or pasty mixture may, for example, be poured into moulds, applied to surfaces or used to fill cavities, joints or cracks. t The continuous production of plate ^oods is also possible, e.g. by the so-called double conveyor belt technique. in eases where the continuous organic matrix is thermoplastically deformable as a result of suitable choice of the starting components, the primary emulsion may first be hardened and made up into shavings, granulates or powders which may subsequently be thermoplastically deformed in known manner, e.g. by means of extruders, injection moulding machines or calender rollers, and they may be formed up, e.g. using blowing agents. Semi-finished goods, such as panels or sections, may also be produced which may subsequently be thermoplastically foamed up, e.g. using blowing agents. Foams may, of course, also be produced with the aid of inert gases, particularly air. For example, one of the components may first be foamed up with air and then added to the others. Furthermore, the components may be mixed, for example with the aid of compressed air, so that a foam is formed directly and this is then moulded and hardened at the same time.

The water in the mixture may also take over the function of blowing agent, especially if mixing of the properties is carried out under pressure at temperatures alxjve l(Xi°C so that when the material leaves the apparatus the pressure is released and foaming sets in.

Finely divided metal powders, e.g. calcium, - 23 - 40270 magnesium, aluminium or zinc powder, may also act as blowing agents due to the hydrogen evolved in the presence of the alkali metal or ammonium silicate solution, and these metnl powders at the same time have a hardening and strengthening effect. 5 Production of the foams in accordance with the present invention is basically carried out by mixing the above-described reactants in one or more stages in a discontinuously or continuously operating mixing apparatus and then leaving the resulting mixture to foam lO up and harden, usually outside the mixing apparatus in moulds or on suitable supports. The required reaction temperature of between O and 200°C/ preferably from 50 to 160°C, may be obtained either by heating one or more of the reactants before the mixing process or by heating 15 the mixing apparatus itrelf or by heating the reaction mixture after the components have been mixed. Combinations of these or other methods may, of course, also be used for adjusting the reaction temperature. In most cases, sufficient heat is evolved in the reaction to 20 enable the reaction temperature to rise above 100°C after the onset of the reaction or of foaming.

For any given formulation of components, the properties of the resulting foams, e.g. their density in the moist state, depend to some extent on the 25 details of the mixing process, e.g. the form and speed of the stirrer, the form of the mixing chambers, as well as the selected reaction temperature when foaming is started. This density may vary between 0.02 and 1.3 g/cm3. The moist, fresh foam in most cases has densities of - 24 - \ t 40270 between 0.11 and 0.8 g/cm"*. The dried foams may have closcd or open cells. They are in most oases substantially open-celled and have densities between 0.01 and 1.1 g/cm3. 5 Due to the behaviour of the reaction mixture, there are numerous possible uses for the process according to the present invention and hence numerous fields of i application, some of which will be outlined below. The | possibility of either leaving the water in the hardened mixture as a desirable constituent in the foam or to protect the foam against loss of water by suitable application of coatings or laminates or of removing the water partly or completely by suitable drying processes, e.g. in a heating cupboard or with hot air, IR heating, ultra-sound or high-frequency, may be selected from case to case according to the desired technical application.

The reaction mixture which contains blowing agent may bo spread-coated on hot or cold supports or supports exposed to IR or HF radiation or after passing 2q through the mixing apparatus the mixture may be sprayed on these supports with the aid of compressed air or by the airless spraying process. It may then foam up and harden on these supports to form a filling or insulating or moisture-proofing coating. The foam reaction mixture 25 may also be forced, cast or injection-moulded into cold or heated moulds, which may be relief moulds, solid moulds or hollow moulds, and they may then be left to harden in these moulds optionally under pressure at room temperature or temperatures up to 200°C, optionally 20 using a centrifugal casting process.

I - 25 " 4 (12 70 At this stage, reinforcing elements may well be added if desired. These may be inorganic and/or organic, e.g. metal wires, fibres, fleeces, foams, woven fabrics or supporting structures. These may be incorporated, e.g. by the fibrous web impregnation process or by processes in which, for example, reaction mixtures and reinforcing fibres are together applied to the mould, e.g. by means of spray apparatus. The moulded products obtainable in this way may be used as building elements, e.g. in the form of foamed or unfoamed sandwich elements which may either be used directly or may first be laminated with metal, glass or plastics. The advantageous fire characteristics in the moist or dry state is an advantage when the products are used in this form. However, the products may also be used as hollow bodies, e.g. as containers for goods which must be kept moist or cool, or as filter materials or exchangers, as catalyst carriers or carriers of other active substances, as decoration elements, furniture components and cavity fillings. They may also be used as heavy-duty lubricants and coolants or as carriers for such substances, e.g. in metal extrusion presses.

The water in the elastomers has a very advantageous effect in the event of fire because its evaporation uses up a lot of energy and the products therefore remain "cold" for a long time. Self-ignition is prevented when large foam blocks are produced. The water in the finished elastomers is normally in the form of silicic acid hydrate. A more powerful chemical bond may be ~ 26 ~ I •10 2 71) obtained by adding water-binding fillers. Particularly suitable fillers for this process are, in particular, hydraulic cements, anhydrite, gypsum and quick-lime, but also, e.g. silica gel, diatomaceous 5 earth or clay. It is particularly surprising that even the addition of these water-binding fillers does not spoil the elastomeric character of the materials according to the present invention. The inexpensive filled foams of polyols, isocyanates, water glass and lO fillers obtained in this way are eminently suitable particularly for use as shock-absorbing materials, .e.g. safety padding, such as crash pads.

The products of the process may be used in the conventional fields for compact or cellular elastomers, 15 soft foams and semi-rigid foams, especially in cases where they are required to meet high standards of fire resistance. This applies particularly to the foains thus the products obtainable by the process according to the present invention are particularly suitable 20 for producing upholstery materials, matresses, elastic supports, car seats, damping materials, shock-absorbers and sound-damping insulations, as well as for protection against heat and cold.

The following Examples illustrate the invention: 25 Preparation of the starting materials (I) lOOO g of a linear polypropylene glycol having a molecular weight of 2000 which has been started on 1,2-propylene glycol and 174 g (1 mol) of tolylene diisocyanate (isomeric mixtures 80:20) 30 are stirred together for 2.5 hours at 80°C. » ~ 27 " 270 The resulting prepolymer has an NCO-content of 3.7% and a viscosity of 3825 cP at 25°C. .1124 g of this prepolymer are mixed with 32 g . of sulphur trioxide in the course of 4.5 hours with stirring at 40°C to 50°C. To provide the sulphur trioxide, 65% oleum is heated and the sulphur trioxide which is evolved is passed over the prepolymer. Sulphur content 1.09%, viscosity: 20 OOO cP. lOOO g of a branched polypropylene glycol ether having a molecular weight of 3000 which has been started on trimethylolpropane are reacted with tolylene diisocyanate as under (I).

Viscosity: 10 OOO cP at 25°C. 1137 g of prepolymer (II) are mixed with 30 g of sulphur trioxide as described under (I).

Sulphur content : 1.13%.

Viscosity: 50 OOO cP. 2000 g of a mixed polyether (alkoxylated (ethylene oxide :propylene oxide = 20:80 percent, by weight)trimethylolpropane/1,2-propylene glycol mixture) (OH-number 42) are reacted with 261 g of tolylene diisocyanate as under (I) .

Viscosity: 6 100 cP at 25°C. 2162 g of the prepolymer are mixed with 24 g of sulphur trioxide as described under (I).

Sulphur content: 0.47*. 40270 (V) 2OOO g of a polypropylene glycol which has been started on trimethylolpropane and contains 17 percent, by weight, of polyethylene glycol end groups(OH-number 28} are reacted with 174 g of tolylene diisocyanate as under (I).

Viscosity: 7 500 cP at 25°C. 2082 g of the prepolymer (V) are mixed with 23 g of sulphur trioxide as described under (I).

Sulphur content: 0.38%.

Viscosity: above 100 OOO cP at 25°C.

(VII) The dinuclear content is distilled out of a * crude phosgenation product of aniline/forroaldehvde condensate until the distillation residue has a viscosity of 400 cP at 25°C. The resulting 15 product is sulphonated to a sulphur content of 1% by mixing it with sulphur trioxide as described under (I).

Viscosity: 1 300 cP at 25°C.

(VIII) 1000 g of a crude phosgenation product of an 20 aniline/formaldehyde condensate which has an NCO-content of 31.4% and a viscosity of 100 cP is diluted with 200 g of 1,2-dichloroethane, 71.5 g of a 33% solution of sulphur trioxide in 1,2-dichloroethane are then added at room 25 temperature in the course of 4 5 minutes. Dichloro- ethane is then distilled off under vacuum.

Sulphur content: 0.67%.

Viscosity: 200 cP at 25°C.

(VI) lO - 29 - 40370 (IX) lh k'i »> t* .1 1 yd hy I imh' ««xMc w 11 li .) im> I <m-ii I .i r wcltjht ol 12<m> which liaii l>i*on started on nbutanol are melted in a 100-litre vessel at ' 80°C. 80 kg of a crude commercial phosgenation ® product of an aniline/formaldehyde condensate which has an NCO-content of 31% and a viscosity of 400 cP are added all at once with stirring and cooling and the mixture is then stirred for a further 5 hours at 80°C. A non-ionic-hydrophil-lO ically modified isocyanate is obtained which has an NCO-content of 24.6% and a viscosity of 1500 cP (25°C) .

(X) A trifunctional polypropylene glycol ether which has been started on trimethylolpropane 15 and contains 17% of polyethylene glycol end groups (primary OH-groups); OH-number 28.

(XI) Tolylene diisocyanate (2,4/2,6-isomeric mixture, ratio 80:20).

(XII) Unsulphonated (VII). 20 EXAMPLE 1; 100 g of (I) and 50 g of (IX) are mixed with 30 g of T (trichlorofluoromethane). A mixture of 100 g of 44% W (sodium water glass) Na20:Si02=l:2), 2 g of K (catalyst-striethylamine) and 3 g of M (50% aqueous 25 mersolat solution K 30; sodium salt of a sulphochlor- inated paraffin mixture) is rapidly added and the mixture is vigorously stirred for 15 seconds. It is then poured " 30 " 4027O i out into a paper mould. The foaming process sets in after 27 seconds and is completed after 38 seconds. The resulting foam has coarse pores and is moderately elastic.

EXAMPLE 2: 100 9 of (ID 50 9 of (IX) Component 1 30 g of T 150 g of H according to Example 1 2 g of triethylamlne component 2 3 g of M according to Example 1 50 g of quick-setting cement Component 1 and component 2 are vigorously stirred together for 15 seconds and the resulting thick emulsion 15 is poured into a paper mould. The foam process begins after 33 scconds and is completed after 52 seconds. The resulting foam has a medium pore size and is elastic.

EXAMPLE 3: component 1 lOO g of (III) 20 50 g of (IX) 50 g of T 180 g of W according to Example 1 2 g of triethylamine 3 g of M according to Example 1 70 g of quick-setting cement component 2 - 31 - 40270 lo Preparation of the foam according to Example 2. Onset of foaming: after 4 5 seconds, end of foaming: after 77 seconds, pore size: medium, t elasticity: moderate.

EXAMPLE 4: o o g of (111) 50 g of (IX) component 1 40 g of T 200 g of W according to Example 1 2 g of triethylamino 3 g of M according to Example 1 lOO g of quick- setting cement component 2 Preparation of the foam according to Example 2. 15 Onset of foaming: after 73 seconds, end of foaming: after 130 seconds, por* size: medium coarse, elasticity: moderate.

The tough foam is suitable for use as filling 2<) fo.im, e.g. in motorcar safely parts. After drying, about 6()'A of the foam consists of inorganic substnnce and the foam consequently has a high resistance to fire.

The fire resistance may be even further improved 2 5 by the addition of from lO to 40 g of polychloro- paraffins or tris-chloroethylphosphate. 32 40270 EXAMPLE 5; 50 g of (II) 50 g of (III) 50 g of . (IX) 30 g of T component 1 10 150 g of W according to Example 1 2 g of triethylamlne 1.5 g of M according to Example 1^ ► component 2 Preparation of the foam according to Example 2. Onset of foaming: after 45 seconds, end of foaming: after 62 seconds, pore size: medium, elasticity: good immediately after preparation of the foam, moderate after drying. 15 20 25 EXAMPLE 6: 130 g of (III) 20 g of (IX) 30 g of T component 1 150 g of W according to Example 1 3 g of triethylamlne , component 2 Preparation of the foam according to Example 2. Onset of foaming: after 36 seconds, end of foaming: after 70 seconds, pore size: medium, elasticity: moderate.

EXAMPLE 7: 90 g of (VI) 60 g of (IX) 40 g of T component 1 - 33 - 40270 100 g of W according to Example 1 1 g of triethylamlne 1.5 g of M according to Example J component 2 Stirring time Onset of foaming: end of foaming: pore size: elasticity: lO 14 seconds, after 30 seconds, after 43 seconds, coarse, good immediately after preparation of the foam, moderate after drying.

EXAMPLE 8: 90 g of (VI) 60 g of (IX) 40 g of T 1 component 1 lOO g of W according to Example 1 0.5 g of triethylamine component 2 I Preparation of the foam according to Example 2. Pore size very coarse, elasticity: very good. 2o EXAMPLE 9: 120 g of (IV) ] 30 g of (IX) f component 1 35 g of T lOO g of W according to Example 1] 25 2 g of triethylamine /component 2 1.5 g of M according to Example l) - - 40270 preparation of the foam according to Example 2. Stirring-time: 13 seconds, Onset of foaming: after 45 seconds. end of foaming: pore size: elasticity: after 75 seconds, very coarse, moderate-good. lO Examples lO to 19 are shovm in the following Table 1. The foam is prepared as described in Example 2. The figures given in the Table refer to "quantity in g" unless otherwise indicated. 35 TABLE 1 O (0 -4 O Example 1 10 f 11 12 13 14 15 f 1 16 17 , 18 19 (IV) 120 (V) 60 70 70 70 90 90 90 (VI) 90 90 30 20 20 | 20 i (VII) < i 20 50 (VIII) 60 (IX) 60 30 60 60 60 60 60 40 10 T 40 35 30 40 45 50 50 50 . 50 50 w 100 100 100 100 150 150 150 150 150 150 Triethylamine 1 2 0.5 1 1 0.5 0.5 Quick-setting cement 100 200 100 Silicocell 7200 (1) 0.5 0.5 0.5 0.8 0.8 0.8 0.8 1 0.8 1.2 Stirring time (in sec.) 13 13 15 15 15 15 20 20 18 20 TABLE 1 (Contd.) f f Example 10 11 12 r I 13 ! 14 15 16 i f i 17 18 ! 19 Onset of foaming (after seconds) 35 40 28 26 i 30 33 34 45 44 48 End of foaming (after seconds) 48 80 35 50 62 68 67 78 70 68 Pore size coarse fine medium fine fine fine fine fine medium fine Elasticity very good moderate; tough very good good good medium good medium medium very good good I EXAMPLES 20 to 26: Preparation by the one-shot-process. The components indicated are added together shortly before they are mixed. The stirring time is 15 seconds.

The figures given in Table 2 below also represent "quantity in g" unless otherwise indicated.

TABLE 2 Example (X) (XI) (VII) (XII) (IX) T w Triethylamine Silicocell 7200 Onset of foaming (after sec.) jEnd of foaming I(after sec.) Pore size Elasticity (1) 20 100 10 50 10 50 150 0.5 0.8 24 36 medium very good 21 100 10 25 25 10 40 150 25 39 fine-medium good 22 100 10 50 10 35 150 35 47 fine-medium good-very good 23 100 10 60 35 150 35 44 fine-medium medium 24 100 10 50 10 35 200 35 47 fine-medium medium 25 100 10 60 35 150 5 35 47 fine good-very good ! 26 ! 100 10 60 35 200 5 38 52 fine good-very good commercial foam stabilisers based on polysiloxane-polyalkylene glycol copolymers (ICI). r 40 270 The density and compression resistance were determined in some of ihe soft foams prepared in the previous examples.

Example r • • I i Density ! kg/m3 1 . Compression resistance according to DIN 53 577 (KPa) i 2 157 36.4 4 i 212 - 5 177 - 6 154 : - 8 lOO ; - 11 lOO - 12 80 11.6 13 51 - 16 94 6.0 18 62 10.8 l«> 60 9.0 20 48 - 21 67 - 22 67 - 23 72 - 25 58 - 26 84 - - 39 - 40270

Claims

CLAIMSi-

1. A process for the production of an organic-inorganic plastic which comprises reacting together: (a) from 30 to 70%, by weight, of one or more compounds 5 which contain at least two Zerewittinoff-active hydrogen atoms, have an average molecular weight of from 400 to 6000 and a glass temperature of below 10°C; (b) from lO to 30%, by weight, of one or more lO polyisocyanates; and (c) from 20 to 60%, by weight, of an aqueous solution containing from 30 to 70%, by weight, of an alkal'i metal or ammonium silicate 15 20 25 and in which components (a) and (b) may be used in the form of a reaction product of the two components.

2. A process as claimed in claim 1 in which the compounds in component (a) have an average molecular weight of from lOOO to 6000 and a glass temperature below -20°C.

3. A process as claimed in claim 1 or claim 2 in which one or more blowing agents are used so that a foam is produced.

4. A process as claimed in any of claims 1 to 3 in which one or more flame retarding agents which contain halogen are used. - 40 - 40270

5. A process as claimed in any of claims 1 to 4 in which one or more water binding fillers are used.

6. A process as claimed in any of claims 1 to 5 5 in which components (a) and/or (b) contain at least one hydrophilic ionic group, or a group capable of ion formation with alkali metal or ammonium silicate or non-ionic hydrophilic group.

7. A process as claimed in any of claims 1 to lO 6 in which from 45 to 70S of component (a); from lO to 30% of component (b); and from 20 to 45% of component (c) are used and component (a) has an average molecular weight of 15 from 1500 to 5OOO and a glass temperature of below -20°C.

8. A process as claimed in claim 1 substantially as herein described.

9. A process as claimed in claim 1 substantially as herein described with reference to any one of the 20 „ , Examples.

10. Organic-inorganic plastics when produced by a process as claimed in any of claims 1 to 9. F.R.KELLY & CO., Agents for the Applicants. ~ 41 ~