DE2031160C3 - Process for impregnating foams with polrethanes - Google Patents

Description

The present invention relates to a process for the production of novel foams with improved properties through impregnation.

Have foams with a low density mechanical properties that make them unsuitable for many technical applications. You correspond in tensile strength. Tear resistance, fire behavior, light stability and hardness often do not meet the requirements which are placed on you in technical applications. That’s why there has been no lack of attempts by impregnation the mechanical properties of elastic foams with low density to improve. The American patent 29 55 056 describes a method for improvement the mechanical properties of lightweight foams by impregnation with solutions of curable polyurethanes. The process allows the production of foams with improved mechanical properties, however, has the major disadvantage that organic solvents are used that are difficult to handle from a procedural point of view, as they are often flammable or light are flammable and emit explosive gas mixtures with air and are not physiologically harmless. Furthermore, the so impregnated foams have the disadvantage that by using the organic Solvent initially an undesirable swelling takes place, after which on evaporation of the solvent often a shrunk foam with a bonded cell structure is left behind.

It has now been found that the mechanical properties as well as light fastness and fire behavior of open-cell foams with low density can be improved significantly if they impregnated with aqueous dispersions of hard or elastic and soft adjusted polyurethane plastics will. For the process, such polyurethane dispersions come into question, the in anhydrous homogeneous form a hardness of at least 5, preferably 40 degrees of hardness according to Shore A (DIN 53 505) and a maximum pendulum hardness (DIN 53 157) of 240, preferably a Shore D hardness (DIN 53 505) to 90. The film-forming polyurethane dispersions can be used as plasticizing segments predominantly linear polyhydroxy compounds from the Group of linear polyesters of aliphatic or aromatic dicarboxylic acids and aliphatic diols, Corresponding polycarbonates, polythioethers of thiodiglycol, polypropylene glycols, polybutylene glycols, polyethylene oxides, Contain polyacetals of formaldehyde from aliphatic diols.

The process has considerable advantages:

A) The impregnation with the aqueous polyurethane dispersions is carried out at room temperature while curing can be carried out at any higher temperature.

B) Since the carrier of the dispersion is water, neither flammable nor co-formed during the curing process Air is an explosive gas mixture, so that work in explosion-proof devices is not necessary is. There is also no physiological hazard.

C) The method has a very wide range of variation. Depending on the structure of the dispersion, i. H. depending on the degree of hardness of the polyurethane plastic in homogeneous form, others can, starting from open-pored, flexible foams Soft, elastic foams with gradually graduated, higher hardness, but; iueh semi-hard and hard foams can be obtained. Soft elastic foams can also be used with improved spring characteristic in force defor Exercise diagram through insert / elastic muscle liner delivering polyurethane dispersions cihal

will be.

D) Impregnate the soft polyurethane foams by the process according to the invention produced hard foams are so tough and abrasion-resistant that they can with the in the woodworking industry tools, i.e. planed, milled, sanded or can be pierced.

E) Due to the impregnation, the open-cell structure of the foams is retained and when the as The foam used as the starting material is so hydrophilic that it is present in the aqueous polyurethane dispersion swells, even cell expansion occurs, i.e. there is a dimensional growth of the Foam in the three dimensions of the room, which makes the porosity even greater becomes, with a completely open-celled space in the new space created by the swelling process Structure and arrangement of materials even when using very large amounts by weight of the inventive Impregnating agents is achieved.

F) The polyurethane latex to be used adheres without containing reactive groups and without that additional adhesion promoters must be used, extremely firmly on the foam. The addition of crosslinking agents or vulcanizing agents is not absolutely necessary because the resulting film on the foam surface does not stick.

G) The preferred cationic or anionic aqueous polyurethane dispersions can be due to a more or less pronounced electrolyte sensitivity during the impregnation process be precipitated in a targeted manner coagulating in the foam without there is some adhesion of the cells. This variant of the impregnation allows the The latex serum can largely be seen to be mechanically squeezed out as water during the impregnation process, a technically particularly simple procedure for foam modification results and also thermal energy for evaporation of the water can be saved to a large extent can.

H) The aqueous polyurethane dispersions used for impregnation have a surprisingly high compatibility with aqueous solutions of compounds capable of aminoplast and / or phenoplast formation, such as. B. urea, thiourea, methylenediurea, dicyandiamide, melamine, guanidine, hexamethylenetetramine, phenol, bis-phenol A, the mono- or polymethylol compounds of the above-mentioned compounds and aligomeric polycondensates of these methylol compounds, the methylol compounds of hexamethylenediurea, methylol compounds such as those of the hydrazodicarbonamides . B. obtained from bischlorkohlensäijestern of butanediol by reaction with ammonia in a known manner. The aforementioned compounds can even be dissolved in the dispersions directly without coagulation and even with the addition of carbonyl compounds such as / Ii. Formaldehyde, acetaldehyde, crotonaldehyde. Isobu lyraldenyd. Chloral hydrate can be used for impregnation. As a result, an extraordinary variety in the variation of the modification of foams according to the invention can be carried out, in particular the flame resistance of the cellular foams can be improved to a surprisingly high degree and, if desired, the dispersion used itself can be chemically modified as a result of its reactivity with the added compounds .
1) The impregnation in particular with

ίο cationic or anionic polyurethane dispersions Open-celled, elastic or semi-rigid modified foams obtained are optimal substrates to use according to the procedures of German patents 19 11 644, 19 11 643,

is 19 11 645 and 19 11 180 a variety of inputs and

Multi-component reactions at the phase interfaces of these modified by impregnation To carry out foams so that the most diverse solids are spatially oriented and are ordered cell-like under strong three-dimensional growth phenomena. A A particular advantage of the impregnation according to the invention is the resulting variability of the feasible interfacial reactions.

2s More cationic despite the very different structure or anionic impregnating agents can be used in these so impregnated foams, preferably with impregnated elastic polyurethane foams, the most diverse types of reaction organic or inorganic chemistry within the meaning of the aforementioned German Carry out patent applications. Swelling processes are thereby caused by the formation of solids ongoing reactions irreversibly fixed and ever

Is according to the type of reaction carried out and the swelling reactant or solvent Up to 400% volume enlargement with complete retention of the open pores through the resulting solids fixed.

^ o J) As a result of their excellent adhesion the preferred ionomeric polyurethane latices are excellent when used for impregnation Fixatives and adhesion promoters for pigments, dyes, fillers, silicas, Aluminum oxide, graphite, titanium dioxide, red phosphorus, biocidal and bactericidal compounds, powdery polyoxymethylene, polythic formaldehyde, paraformaldehyde, powdery polymethylol compounds of urea, dicyandiamide ^ and

so melamine, urea, ammonium phosphate, calcium

umphosphate, deodorant, blood clotting inhibiting agents, various metal powders such as aluminum, copper, iron, zinc or use manganese.

ss K) The method according to the invention also enables Surprisingly, the production of lightfast, open-cell foams from light-sensitive foams yellowing cellular substrates. Polyurethane displacements are preferred here

(«Ι used on the basis of aliphatic,

cycloaliphatic, araliphatic polyisocyanates are produced, e.g. B. preferably hexamethylene diisocyanate. Trimethyl hexamethylene diisocyanate, diisocyanatomethyl eyclobutane. Isophorondiisocy

<··· anal, m- and p-xylylene diisocyanate, diisoeyanatoly-

sinester etc.

I.) The method according to the invention makes it possible when applied to polviirethanflockcn oiler

Polyurethane foam waste with simultaneous shaping at moderate or higher Pressure the production of cellular molded parts, sheet goods, elastic or semi-hard to hard Objects of various geometric shapes, with those mentioned under G), H) and J) Improvements can be made.

M) Finally, the process according to the invention enables In an interesting process variant, the use of very unstable aqueous polyurethane dispersions or cationic or anionic polyurethane dispersions that do not exist in water. This is made possible by the direct production of the aqueous polyurethane dispersions even in the presence of Cellular foam flakes or sheets in which the short-lived dispersions are instantaneously as firmly adhering, film-forming coagulates. With this variant of the procedure the number of polyurethane dispersions that can be used, some of which are very difficult to handle, is extraordinary expanded.

N) Depending on the structure of the dispersed polyurethanes, in particular depending on the content of ionic groups, the hydrophilicity and lyophobicity of the foams can be adjusted as desired.

The invention relates to a method for impregnating foams with polyurethanes, thereby characterized in that the foams with aqueous dispersions of such polyurethanes impregnated, which in homogeneous, fully reacted form at least a Shore A hardness (DIN 53 505) of 5, preferably of 40, at most a pendulum hardness (DIN 53 157) of 240, preferably a Shore D hardness (DIN 53 505) to 90.

According to the invention, aqueous dispersions of such polyurethanes are used as impregnating agents which, in homogeneous form, have at least a Shore A hardness of 5 and a maximum pendulum hardness of 240 exhibit. The range between these sizes is often given in Shore D degrees. It goes without saying that the entire Shore D range is within those given above Limits.

The polyurethane dispersions suitable for the process according to the invention are known per se Made from higher molecular weight compounds with reactive hydrogen atoms with a molecular weight from 300 to 20,000, polyisocyanates and any chain extenders to be used made with reactive hydrogen atoms.

As compounds with reactive hydrogen atoms with a molecular weight of 300-20,000, Polyisocyanates and any chain-lengthening agents to be used with reactive Hydrogen atoms are all known and commonly used components. Examples are in Belgian patents 6 53 223, 6 69 954 and 6 73 432 and in the German Auslegcschrifi 10 67 678 included. The proportions used can vary widely in a manner known per se Limits vary depending on whether soft, flexible or flexible elastic or very hard and thermoplastic plastics are to be produced.

Examples of the production of aqueous polytire

than dispersions can be found in the official publications 10 97 678, 11 87 012, Π 84 94b, 11 78 586. 11 79 363, in the disclosure documents 17 70 068, 19 39 911, 19 43 975, in Belgian patents 6 53 223, 6 58 026, 6 69 954.6 73 432. 7 27 923 and 6 88 299, in the English patent 8 83 568, in French patents 1108 785 and 14 10 546 and in the American patents 31 78 310 and 34 10 817.

For the method according to the invention are particular Emulsifier-free dispersions are suitable, in particular emulsifier-free dispersions of polyurethane ionomers. especially of anionic polyurethanes with sulfonate and carboxylate groups as well cationic polyurethanes with quaternary ammonium groups are preferred.

Be the production of dispersions of polyurethanes with anionic groups, the pre-adduct containing isocyanate groups is generally used in organic solution reacted with the anionic component. Water added and the organic Solvent distilled off. But it can also be proceeded the other way around, by adding water that the contains anionic component, is presented, and then the isocyanate group-containing pre-adduct is entered. Anionic components suitable for incorporation are, for example, the alkali salts of Amino acids like taurine. Methyl taurine, 6-aminocaproic acid, glycine, sulfanilic acid. Diaminobenzoic acid. Ornithine, lysine, 1: 1 adducts of sultones such as propane sultone or butane sultone with diamines such as Ethylenediamine, hydrazine or 1,6-hexamethylenediamine.

For the production of cationic polyurethane dispersions suitable starting components are, for. B. in the German Offenlegungsschrift 15 95 602 contained. in the generally the polyurethane polymer is in organic solution, e.g. B. in acetone, tetrahydrofuran or Built up methylene chloride and simultaneously or subsequently converted into an ionomer. After mixing the organic solvent is (partially) distilled off with water to form a dispersion.

The introduction of the ionic centers, in particular the quaternary ammonium group, can take place in various ways Be done, e.g. B. in that components are used at least proportionally to build up the polyurethanes which already contain a salt-like group or a group capable of salt formation, e.g. B. (poly) alcohols, (Poly) isocyanates with quaternary ammonium groups and / or tertiary basic nitrogen atoms.

You can also use the quaternary ammonium group generate in the course of the polyurethane build-up, as this z. B. in German Offenlegungsschrift 14 95 693 and in the German Auslegeschrift 13 00 275 is detailed.

Another method for the preparation of cationic polyurethane dispersions is that from compounds with at least 2 primary or secondary amino groups, polyisocyanates and optionally Polyhydroxy compounds are built up, which free primary and / or secondary Have amino groups that have a neutralizing effect before or during mixing with water Acids and / or more than equivalent amounts of alkylating agents into ammonium groups will.

You can also use nonionic polyurethanes, which for example, high molecular weight in organic solution or also in the melt can be present through

Cationic addition or condensation reactions or modify it anionically. So you can, for example, polyurethanes, which unsaturated C = C double bonds have by adding compounds which at least one capable of addition reactions -OH-, -SH-, -NHR-, -SCI-Gruppc and another group capable of salt formation, e.g. B.

(R = H or alkyl),

OH

- S, —Ρ, —COOH, -SO ₃ H, —Ρ

O R

or have a corresponding salt group to modify them to polyelectrolytes.

Conversely, polyurethane polyelectrolytes can also be produced by adding compounds which contain at least one unsaturated C =C double bond and at least one of the above-mentioned groups or groups capable of salt formation to nonionic polyurethane polymers. The reaction can be carried out via reactive groups of the polyurethane polymer, for example —OH—, —SH—. —Only, —SCl groups take place or by a radical reaction which can be triggered by conventional radical formers such as peroxides, azo compounds or also thermally or by exposure to UV light, X-rays, γ rays, or iron rays. Examples of modifying agents are unsaturated acids such as acrylic acid, crotonic acid, maleic acid and fumaric acid. Tetrahydrophthalic acid, itaconic acid, citraconic acid, mesaconic acid, vinyl sulfonic acid. Propene (l) sulfonic acid (1) and its salts can be considered.

Ionic modifications can be carried out particularly easily by condensation reactions like them are known in principle from the chemistry of aminoplasts and phenoplasts. Are particularly suitable Aminomethylation and sulfomethylation reactions on polyurethanes which advantageously in addition to Urethane groups also contain other —NH or —NHj groups substituted by an acid radical.

Of course, combined methods can also be used. So you can, for example Acrylamide via a methylene bridge by condensation with an aminocarboxylic acid or sulfonic acid Modify ionically and either add the product to a nonionic polyurethane or add to a diamine and then uses this as a chain extender when building up the polyurethane. One Another production possibility for ionomeric polyurethanes to be used according to the invention is that Sulphonation of aromatically bound NCO groups having polyurethane prepolymers with z. B. Sulfuric acid and / or oleum, which also makes water dispersibility possible (cf. 19 39911). It is evident that that A person skilled in the art has a wealth of possibilities available to build up polyurethane ionomers, which result this modification through self-dispersion or solubility in water as well as through particularly strong distinguish intermolecular interaction.

It is according to the invention. preferred to increase the lightfastness dispersions of such polyurethane monomers to use that on the basis of I lexamethylene diisocyanal, isophorone diisocyanate

and / or m- and p-xylylene diisocyanai produced have been.

The presence of an organic solvent when mixing the polyurethane with water under Formation of a dispersion is not a requirement. Provided that the polyurethane mass at the time of their mixing with water be: the working temperature is stirrable or machine processable, can be applied to the Presence of a solvent can be largely or even completely dispensed with. After a special one Preferred and extremely economical processes are polyurethane dispersions free through polycondensation of oligourethane electrolytes with reactive end groups with formaldehyde (donors) produced in an aqueous two-phase system. This is where appropriate methylol groups having oligourethane electrolyte preferably in the form of the melt by simply mixing with water dispersed. This process, by which dispersions which are well suited according to the invention are prepared is described in detail in Belgian patent 7,30543. After a special one Preferred processes here are oligourethane propolymers with terminal isocyanate groups (approx. 0.8-10% NCO) reacted with urea or another aminoplastbildcenden compound, the so formed over formadehyde at least bifunctional prepolymers according to one of the literature known or ionically modified by the methods described above and dispersed by mixing with water. Formaldehyde or such releasing compounds are before, during or after the Dispersion added.

The polycondensation to high molecular weight polyurethane is usually at least partially in the Dispersion carried out by thermal aftertreatment and / or lowering the pH. The so precondensedc Polyurethane dispersion is then used to impregnate foam. However, it is also possible to use the Polycondensation only occurs on the substrate during and / or after drying Effect of heat or storage at room temperature.

Polyurethane dispersions particularly suitable for fire protection impregnation are those made from oligourethane prepolymers containing terminal biuret groups by formaldehyde polycondensation have been manufactured. The condensation with the concomitant use of further urea becomes advantageous. Melamine, dicyandiamide, benzoguanamine, which practical act as a "chain extender". Instead or in addition, you can also Aminoplast or phenoplast precondensates are used. Additionally or instead of the Formaldehyde can also be higher aldehydes and their acetals, z. B. chloroacetaldehyde and chloral as carbonyl components can be used.

It is therefore preferred according to the invention that the impregnation is carried out in the presence of carbonyl compounds. preferably formaldehyde. Chloral hydrate. Acetaldehyde. Isobutyraldehyde, crotonaldehyde and / or for Aminoplast- or phenoplast-capable compounds or solutions of these compounds are preferred Urea. Thiourea, methylenediurea. Urotro-

pin code. Dicyandiamide, melamine and their methylolation products is carried out.

Cationic dispersions which are more than 5% in the solids, preferably 7-20%, contain nitrogen. To generate ionic groups, it is particularly advantageous at least proportionally Phosphoric acid used as a salt former.

Additional fire protection effects can be achieved by incorporating suitable fillers can be achieved in the dispersions, e.g. B. Polymethylene urea, antimony compounds, red phosphorus and other flame-retardant fillers.

Fire protection with aqueous polyurethane dispersions has the following advantages:

1) The foam recipes do not need to be changed will; in particular, there is no deterioration in the mechanical properties of the foam by adding flame retardants.

2) The fire protection can be targeted at particularly endangered steliums, e.g. B. applied to the surface or to certain parts of the surface will. (It is well known that even so-called non-flammable foams are often intolerable strong, if only brief, surface erosion.)

3) Introduced fillers are removed from the polyurethane by the tough elastic coating Dispersion firmly anchored. No dust formation occurs even with vibrating mechanical loads on.

4) The flame retardant is applied from the aqueous phase, so it occurs during the impregnation process itself does not pose an increased risk of fire. A flame retardant impregnation can therefore itself Successful during a fire that has already broken out a

All elastic foams, such as soft ones, are generally suitable for the process Polyvinyl chloride foams, latex foams and natural sponges. In particular, are in favor of the procedure Suitable for polyurethane foams.

The polyurethane foams suitable for the process are produced using the isocyanate polyaddition process from compounds with several active hydrogen atoms, in particular hydroxyl and / or Compounds containing carboxyl groups and polyisocyanates, if appropriate with use of water, activators, emulsifiers, foam stabilizers and other additives for a long time technical scale manufactured R. V i e w e g, A. Hoch ti en, Kunststoff-Handbuch, Volume VlI, Polyurethane, Hanser-Verlag Manschen 1966).

Polyurethane foams are preferably made by mixing liquid components, wherein the starting materials to be reacted with one another are either mixed together at the same time or initially from a polyhydroxyl compound such as polyalkylene glycol ethers or hydroxyl groups containing polyesters with an excess of polyisocyanate a pre-adduct containing NCO groups which is then converted into the foam in a second operation with water will.

Any desired polyisocyanates can be used for the production of the polyurethane foams, such as z. B. hexamethylene diisocyanate. Xylylene diisocyanate,

Phenylene diisocyanates, tolylene diisocyanates, chlorophenyl diisocyanates. Diphenylmethane-4,4'-diisocyanate, naphthylene-1,5-diisocyanate, triphenylmethane-4,4'-4 "-triisocyanate, Xylylene; \, <x'-diisothiocyanate. Farther Diners and trimers of isocyanates and diisocyanals, biuret polyisocyanates, semicarbazides are suitable Urea, allophanate or acylated biuret polyisocyanates, as well as adducts of polyisocyanates with alcohols containing free NCO groups, such as Triniethylolpropane, glycerol, hexantrial-1,2,6 or glycol, or to low molecular weight polyesters, such as Castor oil, also reaction products of the above isocyanates with acetals according to the German patent 10 72 385 and the isocyanates mentioned in German patents 10 22 789 and 10 27 394, where any mixtures can of course also be used. 2,4- and 2,6-tolylene diisocyanate are particularly preferred as well as any mixtures of these isomers and those produced by aniline-formaldehyde condensation and subsequent phosgenation used polyphenyl-polymethylene polyisocyanates.

Suitable polyhydroxy polyethers are, in particular, those with a molecular weight range of 200-5000. the These compounds are preferably prepared by reacting alkylene oxides or alkylene oxide mixtures with suitable starter molecules. Preferred alkylene oxides are ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide and 1,4-butylene oxide. Suitable starter molecules are any preferred having at least 2 active hydrogen atoms low molecular weight compounds such. B. water, ethylene glycol, 1,2-,! 3-propanediol, glycerine, trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol, sorbitol, cane sugar, Polyhydroxybenzenes, polyhydroxynaphthalenes, polyhydroxyanthracenes, poly (hydroxyaryl) alkanes, etc. Adducts of alkylene oxides with hydroxyl groups containing phenolic resins such. B. Novolak and similar compounds are also suitable. As further suitable for reaction with alkylene oxides Starter molecules are also primary di- and polyamines such as. B. ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine Diaminobenzenes, triaminobenzenes and secondary di- and polyamines such as N, N'-dimethylethylenediamine, Ν, Ν'-dimethylpropylenediamine, N, N'-dimethyldiaminobenzenes, Ν, Ν ', Ν' '- Trimethyltriaminobenzo-Ie and similar compounds called. The polyhydroxypolyethers can also be used in a mixture with the monomeric organic starter molecules.

Suitable polyhydroxy polyesters are in particular those which have a hydroxy equivalent weight of 100 to 3000 have, under hydroxy equivalent weight the amount of polyester is to be understood in grams, the one mole of hydroxyl groups contains. The polyhydroxypolyester is produced by reacting Polycarboxylic acids or their anhydrides with polyvalent hydroxyl compounds. Suitable polycarboxylic acids are z. B. oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid. Phthalic acid, terephthalic acid and dimerized fatty acids. Appropriate polyvalent polyhydroxyl compounds are z. B. ethylene glycol, diethylene glycol, Triethylene glycol, polyethylene glycols, propylene glycol, Dipropylene glycol, polypropylene glycols, 1,4-butanediol, Butane (2) diol-1,4, glycerine, trimethylolpropane, pentaerythritol, castor oil, hydroquinone, 4,4-dihydroxydiphenyl methane and 4,4-dihydroxydiphenylpropane. Preferred are used in the manufacture of the polyhydroxy polyester

Dicarboxylic acids brought to reaction with divalent hydroxy compounds. Also tri- or polycarboxylic acids as well as higher polyhydroxy compounds can be used in the production of the polyhydroxyl polyesters may be added. The one to be used for the foam production if necessary The amount of tertiary amine generally varies between about 0.001 and 10% by weight, based on the Amount of polyol and depends on the molecular weight and structure of the polyol component, the amine and of the isocyanate. The tertiary amines can optionally contain active hydrogen atoms.

Typical tertiary amines which are practically non-reactive with isocyanate groups include

Triethylamine, tributylamine, N-methyl-morpholine,

N-ethylmorpholine, N-cocomorpholine,

Ν, Ν, Ν'-N'-tetramethylethylenediamine,

1,4-diaza-bicyclo- (2,2,2) -octane,

N-methyl-N'-dimethylamino-ethyl-piperazine,

Bis - [(2-N, N-dimethylamino) ethyl] ether,

Ν, Ν-dimethylbenzylamine,

Bis (N, N-diethylaminoethyl) adipate,

N.N-diethylbenzylemine, pentamethyldiethylenetriamine,

Ν, Ν-dimethylcyclohexylamine,

N, N, N ', N'-Tetramethyl-1,3-butanediamine,

N.N-dimethyl / J-phenylethylamine,

i, 2-dimethylimidazole, 2-methylimidazole,

as well as silaamines with carbon-silicon bonds, such as those in German patent specification 12 29 290 are described; Examples include 2,2,4-trimethyl-2-silamorpholine, 1,3-diethylaminomethyltetramethyidisiioxane.

Typical tertiary amines that contain active hydrogen atoms that are reactive with isocyanate groups, are z. B. triethanolamine, triisopropanolamine, N-methyl-diethanolamine, N-ethyl-diethanolamine, dimethylethanolamine, and their reaction products with alkylene oxides, such as propylene oxide and / or ethylene oxide.

Instead of the amines, nitrogenous bases such as tetraalkylammonium hydroxides, as well as alkalis, Alkali phenolets or alcoholates, such as, for example, sodium methylate as well as hexahydrotriazines as Catalysts are used.

As additional catalysts to accelerate the Isocyanate-polyol reaction, especially to accelerate the polyether-polyol-isocyanate reaction organic metal compounds, in particular organic tin compounds, can still be used.

Particularly noteworthy tin compounds are the stannous acylates, such as tin (II) octoate, tin (II) ethylhexoate, Tin (II) versatate, tin (ii) acetate and tin (II) laurate or the dialkyltin salts of carboxylic acids, such as. B. Dibutyl tin diacetate, dibutyl tin dilaurate, dibutyl tin maleate or dioctyl tin diacetate.

Water or liquefied halocarbon compounds, alone or in combination, are used as the blowing agent used together The liquefied halocarbon compounds are saturated, aliphatic, at least partially halogenated hydrocarbons that are at or below the temperature of the Evaporate the foam. Preferred compounds are water and halogenated hydrocarbons such as Methylene chloride, chloroform, trichlorofluoromethane, dichlorodifluoromethane and others. Regulation additives pore size and cell structure or emulsifiers can also be used in small amounts

although their presence in some cases is not necessary. Furthermore, fillers can be used in the same way in the production of foam be present such as dyes or plasticizers.

A preferred method according to the invention is that foams are used that are 0.1 to 10% by weight of polyelectrolytes, preferably salts of inorganic or organic acids of elements the first, second and third main group of the periodic table, or ammonium oxalate, oxalic acid and that the impregnation process is carried out with immediate coagulation of the dispersion will.

The preparation of d: r polyurethane foams can by the known one-shot, or Semiprepolymer- Propolymer method at room temperature or elevated temperature effected. In this case, mechanical devices, such as those described in French patent 10 74 712, are advantageously used.

The implementation of the method according to the invention is simple. The open-pored, soft foam or sponge is z. B. loaded by compressing and then releasing the pressure in the aqueous polyurethane dispersion with impregnating solution, the excess amount squeezed off and the impregnated foam in Temperaluren above room temperature, preferably above 100 ⁰ C cured. The curing time depends on the curing temperature and is shorter, the higher the temperature. It is also possible to make the impregnation continuous; for this purpose, the foam in the aqueous polyurethane dispersion is squeezed together by means of rollers and the excess amount of impregnating solution outside the solution is again squeezed off by means of rollers. The impregnated foam then passes through an oven to harden. Both in the batchwise and in the continuous process it is possible to increase the amount of polyurethane plastic which is deposited in and on the foam structure by repeated pressing and relaxation processes in the impregnating solution.

Another variant of the method according to the invention is such that the organic Solution, e.g. B. acetone produced and only a little water containing solution of the dispersible polyurethane containing cationic or anionic groups on water-impregnated polyurethane foams comes to action, with very unstable dispersions produced in situ and used Impregnation according to the invention can be used. This variant of the method according to the invention can be particularly advantageous on foam flakes or flaked cellular polyurethane waste be performed.

According to a further variant of the method, the impregnation is optionally carried out directly with shaping on foam flakes and their deformation and sticking under normal pressure or increased pressure executed, with elastic or hard moldings, sheet goods or continuously cylindrical highly elastic rolls can be produced.

The impregnation solution can be applied to the foam not only by dipping, but also by spraying be applied. This method has the advantage that, for example, in molded parts by local Treatment so obtained zones of different hardness

can be. This can be done in a simpler way Manufacture wise parts with different suspension behavior. Another advantage of the spray process is that even complexly shaped contours that are made from soft foam sheets, according to the process according to the invention can be solidified.

The foams produced by the process according to the invention are suitable for all areas of application for which soft, semi-hard and hard foams have long been used, such as, for. B. in the field of upholstery element production, mattress production, heat insulation, sound insulation, textile coating, packaging and the production of structural elements. The new Verfahrensprodukie may subsequent to their preparation selbstverständ lent also be further customized, by being deformed, pressed, welded or air-drying with solutions or dispersions paints, z. B. based on polyisocyanates and polyhydroxyl compounds overpainted or coated.

The foams according to the invention, in particular the open-cell, swellable, highly elastic polyurethane foams are also eminently suitable for use as cellular substrates (Matrices) for carrying out the phase boundary reactions in the form of single and / or multi-component reactions, as described in German patents 19 11 644, 19 11 645, 19 11 180, 19 11 643 will. Thereby the swelling processes and through reactions proceeding with the formation of solids Increased volume of the matrix achieved, which remain irreversibly fixed.

The following examples serve to explain the process according to the invention in more detail.

example 1

The soft polyether-polyurethane foam used in this example was made in the following way:

100 parts by weight of a polyether composed of propylene oxide and ethylene oxide, in the production of which trimethylolpropane and 1,2-propylene glycol (1: 1) were used as starters (OH number 49), 2.7 parts by weight of water, 1.0 wt. Parts of a polyether polysiloxane, 0.2 part by weight of triethylenediamine and 0.2 part by weight of a tin (II) salt of 2-ethylcaproic acid are mixed with one another. 36.3 parts by weight of tolylene diisocyanate (80% 2,4- and 20% 2,6-isomer) are added to this mixture and mixed well with a high-speed stirrer. After a start time of 10 seconds, foam formation begins, and a white, flexible polyurethane foam is formed which is open-pored, has a density of 38 kg / m ¹ and a compressive strength (DIN 53 577) at 40% compression of 56 p / cm ² .

The polyurethane latex used was produced in the following way:

250 g of polypropylene glycol ether (OH number 56) are reacted with 224 g of tolylene diisocyanate (2,4-2,6 isomer ratio 65:35) at 80 ° C. for two hours. After cooling to 70 ° C, the reaction mixture is mixed with 104 g of neopentyl glycol in 200 ml acetone and kept for 30 hours at 6O ⁰ C. Then 700 ml of acetone are added. After adding a mixture of 50 ml of water, 7.5 g of ethylenediamine, 15.3 1,3-propane sultone and 70 g of 10% potassium hydroxide solution, 840 ml of water are stirred in. After the acetone has been distilled off, a stable dispersion with a solids content of 40% remains. The dispersion dries to give a film with a Shore D hardness of 45 degrees.

A cuboid of the foam produced above with the dimensions 8 cm × 5 cm (= 320 cm ') is impregnated with the polyurethane dispersion and pressed out with repeated repetition of pressing and releasing. The moist, impregnated foam is then dried and cured ^{at 105 ° C. for 30 minutes.}

ίο You get a high quality soft foam with good physical properties, the density of which is SSkg'ii ', and thus compared to the Starting material has gained 46.28% in weight. The compressive strength of the according to the invention

. -, Ben process after-treated foam is now at 135 p / cm ² (at 40% compression - measured according to DIN 53 577). Storing the impregnated foam in water and gasoline for 1.5 hours does not change the hardness of the foam.

^: ° Example 2

A cuboid of the foam produced in Example 1 with the dimensions 10x10x5 cm (= 500 cm ¹ ) is impregnated with a polyurethane dispersion by pressing it out several times and relaxing it, which was produced in the following way:

88 g ethylene glycol phthalic acid polycster (OH number 159) and 124.3 g of ethylene glycol phthalic acid polyester (OH number 282) are placed in a water jet for 30 minutes.

dehydrated in vacuo at 12O ⁰ C and reacted with 90.5 g of 1,6-hexanediisoeyanate for 2 hours. The viscous prepolymer is dissolved in 700 ml of acetone, and a solution of 9.5 g of potassium lysine in 80 ml of water is added. Then 425 ml of water are stirred in and the acetone

js distilled off. The 40% strength latex obtained provides films with a Shore D hardness of 50.

After the damp, impregnated foam has been pressed out, it is heated to 130 ° C for 15 minutes dried and hardened. You get a high quality

4c term semi-rigid foam with good physical properties, the density of which is 65 kg / m ' , and which has thus increased 683% in weight compared to the starting material. The compressive strength of the post-treated according to the method according to the invention

4S foam is now 875 p / cm ² (at 40% compression - measured according to DIN 53 577). Storing the impregnated foam in water and gasoline for 1.5 hours does not change the hardness of the foam.

Example 3

By mixing 100 parts by weight of a polyether started on glycerine, the 55 percent by weight propylene oxide and 45 percent by weight ethylene

ss oxide contains (hydroxyl number 56) with 4.0 parts by weight of water, 1.0 part by weight of a polyether polysiloxane, 0.4 parts by weight of Ν, Ν ', Ν''- pentamethyl diethylenetriamine, 035 wt. Parts of a tin (II) salt of 2-ethylcaproic acid and 513 parts by weight of toluylene diisocyanate

<«, (65% 2,4- and 35% 2,6-isomer) an open-pore, flexible polyurethane foam with good physical properties is obtained, which has a ^{density of 29 kg / m 5} and a compressive strength (DIN 53 577) of 40 % Compression of 73 p / cm ² .

a) A cuboid of this foam with the dimensions 5 χ 5 χ 3 cm (= 75 cm ') is pressed out several times and relaxed with the in

Example 2 described polyurethane dispersion impregnated. After pressing out the moist Foam is dried and cured the same for 15 minutes at 100 ° C. You get one semi-rigid foam with good physical properties, the density of which is now 87 kg / m ' and which now has a compressive strength (at 40% compression - measured according to DIN 53 577) of 1330 p / cm-.

b) An identical cuboid, as described above (Example 3a), was "impregnated" even more frequently by repeated pressing and releasing than in Example 3a), and the moist foam was dried and cured for 30 minutes at 150.degree an open-pore rigid foam with good physical properties is obtained under these conditions, the ^{density of which is 151 kg / m 3} and a compressive strength (at 40% compression - measured according to DJN 53 577) of 10 320 p / cm ² .

Example 4

An open-pored, soft polyester foam is produced by mixing the following components.

100 parts by weight of slightly branched polyester from adipic acid, diethylene glycol and trimethylolpropane (Molecular weight 2500, OH number 60)

2.4 parts by weight of water

4.2 parts by weight sodium castor oil sulfonate (50% by weight Wasfer)

1.5 parts by weight of benzylated hydroxydiphenyl, the

is ethoxylated

1.4 parts by weight of N, N-dimethylbenzylamine
0.1 part by weight of paraffin oil
55 parts by weight of tolylene diisocyanate (65% 2,4- and

35% 2,6 isomer).

The foam has good physical properties, a ^{density of 25 kg / m 3} and a compressive strength (at 40% compression - measured in accordance with DIN 53 577) of 115 p / cm ² .

A cuboid of this foam with the dimensions 5 × 5 × ³ cm (= 75 cm 3) is impregnated with the polyurethane dispersion described in Example 2 by repeatedly squeezing it out and releasing the pressure. After pressing, the moist foam is ^{dried at 130 °} C. for 40 minutes and cured. A hard, open-cell foam with good physical properties is obtained, the density of which is 150 kg / m ³ and a compressive strength (at 40% compression - measured according to DIN 53 577) of 7360 p / cm ² .

Example 5

A cuboid of the foam produced in example 1 with the dimensions 10x10x5cm (= 500cm ') is loaded by repeatedly soaking and relaxing with a polyurethane dispersion, which on the following Way was made:

212.5 g ethylene glycol-phthalic acid-adipic acid polyester (molar ratio of phthalic acid to adipic acid 1: 1, OH number 66) after dewatering at 120 "C with 248 g of tolylene diisocyanal (2,4: 2,6-isomeric complex ratio 65:35) reacted for 2 hours at 80 "C and then with 120 g of diethylene glycol in 300 ml Acetone reacted for 10 hours at 50-60 ° C. The viscous prepolymer is then dissolved in 700 ml of acetone and

with a solution of 50 ml of water, 3.7 g of ethylenediamine, 7.6 g of propane sultone and 35 g of 10% aqueous potassium hydroxide solution offset. After stirring in 450 ml of water, the

s acetone distilled off. The 45.8% latex obtained is stable and can be used directly to impregnate flexible polyurethane foams.

The hardness of the film is 55 ° Shore D.

After pressing out the damp foam

ίο is it dried for 5 minutes at 15O ^{0 C?} and hardened. The result is a high-quality, semi-rigid foam with good physical properties, the ^{density of which is 63 kg / m 3} , and which has thus increased in weight by 67.5% compared to the starting material. The compressive strength of the foam post-treated by the process according to the invention is now 1185 p / cm ² (at 40% compression - measured in accordance with DIN 53 577): compared to the starting material, the aftertreatment according to the invention gives the density by a factor of 1.65 (63 compared to 38 kg / m ³ ) and the compressive strength has increased by a factor of 21.2 (1185 compared to 56 p / cm ² ).

La game 6

A soft, open-pored polyether foam is produced by mixing the following components:

100 parts by weight of branched polypropylene oxide-polyethylene oxide-polyether based on tri

methylolpropane and hexanetriol with 67% terminal primary OH groups (OH number 35)
2.5 parts by weight of water

is 0.3 part by weight of triethylenediamine

41.4 parts by weight of an isocyanate containing urethane groups, which was obtained as follows:
By reacting 79 parts by weight of a mixture of 70% by weight of tri-

methylolpropane and 30% by weight of 1,3-butanediol with 921 parts by weight of a tolylene diisocyanate isomer mixture from 65% 2,4-diisocyanatotoluene and 35% 2,6-diisocyanatotoluene

at 80-100 ⁰ C and subsequent removal of the unreacted diisocyanate by distillation is an isocyanate group-containing

ν Polyurethane with approx. 17% by weight NCO

Groups received. 40 parts by weight of this, present as a solid resin Product are with 60 parts by weight of toluene diisocyanate isomeric

ss mixed (80% 2,4 and 20% 2,6 isomes

res) solved; the clear solution obtained has an NCO content of 35.5% and a viscosity of 14OcP at 25 ° C.

do The foam is highly elastic, has good physical properties, a ^{density of 43 kg / m 1} and a compressive strength (at 40% compression - measured according to DIN 53 577) of 4 p / cm '.

A cuboid of this foam with the dimensions

r-v gen 5 χ 5 χ 3 cm (= 75 cm ') is repeated once with the in Example 2 described polyurethane dispersion impregnated, the excess latex by squeezing removed and the damp foam for 30 minutes

B09 62S / 137

105 ° C. dried and cured A soft foam with good physical properties is obtained, which has a ^{density of 53 kg / m 3} and whose compressive strength (at 40% compression - measured according to DIN 53 577) has risen to 160 p / cn r.

Example 7

A soft, elastic polyurethane foam is produced by mixing the following components.

100 parts by weight of branched polypropylene oxide-polyethylene oxide-polyether based on trimethyiolpropane and hexanetriol with 67% terminal primary OH groups (OH number35)

3.0 parts by weight of water

0.5 part by weight of N, N ', N "-Pentamethyl diethylen-

triamine

55 parts by weight of crude diphenylmethane diisocyanate, which is obtained by condensation of aniline with formaldehyde and subsequent phosgenation (viscosity 20OcP at 25 ° C, NCO content 32%).

The foam has good physical properties, has a density of 64 kg / m ^J, and has a compression hardness (at 40% compression - measured according to DIN 53577) of 105 p / cm *.

A cuboid of this foam with the dimensions 5 × 5 × 2.8 cm (= 70 cm ³ ) is impregnated once with the polyurethane dispersion described in Example 2. After the excess dispersion has been squeezed off, the moist foam is dried and cured in a drying cabinet at 120 ° C. for 15 minutes. A soft to semi-hard foam with high hardness is obtained, which has a ^{density of 84 kg / m 3} and whose compressive strength (at 40% compression - measured according to DIN 53 577) is 590 p / cm ² .

Example 8

A polyurethane dispersion is prepared according to the following procedure.

250 g of 1,6-hexanediol-phthalic acid polyester (OH number 56) are reacted at 120 ° C. for 2 hours with 172 g of tolylene diisocyanate (2,4-2,6 isomer ratio 65/35) at 80 ° C. after dehydration and then reacted with 63 g of 1,4-butanediol in 250 ml of acetone at 60 ⁰ C for reaction. After a reaction time of 10 hours, the prepolymer is taken up in 600 ml of acetone and an aqueous solution of 7.52 g of ethylenediamine, 15.2 g of propane sultone and 5.0 g of sodium hydroxide in 100 ml of water is added. When the reaction has ended, 630 ml of water are stirred in and the acetone is distilled off. The 40% latex dries to form hard films with a Shore D hardness of 50 °.

a) A cuboid of the polyether urethane foams produced according to Example 1 with the dimensions 10 × 10 × 5 cm (= 500 cm ³ ) is impregnated with the above polyurethane dispersion by pressing it out twice and releasing it. After squeezing off the excess dispersion of the wet foam is 10 minutes and cured at 12O ⁰ C dried. The result is a semi-rigid foam with good properties phyikalischen, whose density is now 82 kg / m ^J is and which has a compression hardness (at 40 ¥ u compression - measured according to DIN 53577) of nanmehr 1135 p / cm ²

b) The experiment described under a) was repeated, but the extrusion and relaxation process was repeated five times. The damp, impregnated foam is used for removal the excess amount of dispersion

ίο squeezed off and at 130 ⁰ C for 30 minutes

dried and cured A hard, tough foam with good physical properties is obtained, the ^{density of which is 185 kg / m 3} and a compressive strength (at

is 40% compression - measured according to DIN 53 577) of now 7375 p / cm ² .

Example 9

For comparison purposes, a polyurethane dispersion was prepared according to the following procedure.

g of polypropylene glycol ether (OH number 56) are ^{reacted with 40 g of toluene diisocyanate (2,4-2,6 isomer ratio as 65:35) at HO 0} C for 2 hours, dissolved in ml of acetone and treated with an aqueous solution of 50 ml of water, 4.7 g of ethylenediamine, 9.5 g of propane sultone and 4.4 g of potassium hydroxide were added. Then 1260 ml of water are stirred in at 50 ^° C. and the acetone is distilled off in a water jet vacuum. The latex obtained is 22% and dries to give films with a Shore Α hardness of 40 °.

A cuboid of the soft polyurethane foam produced according to Example 1 with the dimensions

Is 10 × 10 × 5 cm (= 500 cm ³ ) was impregnated with the polyurethane dispersion by repeatedly squeezing it out and releasing the pressure, the excess of the dispersion was squeezed off and the moist foam was ^{dried at 130 °} C. for 20 minutes and cured. A flexible foam is obtained which now has a density of 46 kg / m ³ and whose compressive strength has increased to only 63 p / cm ² . The compression hardness was therefore not increased in this case.

The comparative example shows that for the production of foams, according to the invention Process with higher hardness the composition of the polyurethane dispersion is crucial Meaning is.

Example 10

a) A cuboid of commercially available synthetic latex foam with the dimensions 10 χ 10 χ 5 cm (= 500 cm ³ ) and a compressive strength (at 66% compression - measured according to DIN 53 577) of 224 p / cm ² (density 84 kg / m ³ ) is impregnated with the polyurethane dispersion described in Example 8 by pressing out and releasing the pressure twice. After squeezing off the excess dispersion is

do the moist foam is ^{dried for 15 minutes at 130 °} C. and cured. A soft foam with good physical properties is obtained, the density of which is now 114 g / m 'and a compressive strength (at 66%

hs compression - measured according to DIN 53 577) by

now has 2850 p / cm ² .

b) The experiment described under a) was repeated, where however: h the compression and relaxation

operation was repeated six times. The impregnated wet foam was squeezed to remove the excess amount of polyurethane dispersion and 30 minutes at 150 ⁰ C dried and cured The result is a semi-hard foam having good physical properties, whose density is now 168 kg / m ^J is and which has a compression hardness (at 66% compression - measured according to DIN 53 577) of now 10,000 p / cm ²

c) The experiment described under a) was repeated, but this time! the squeezing and relaxing process was repeated ten times. The impregnated wet foam was squeezed to remove the excess amount of dispersion and dried for 30 minutes at ¹ .60 ° C and cured. A hard foam with good physical properties was obtained, which had a ^{density of 329 kg / m 3} and a compressive strength (at 66% compression - measured according to DIN 53 577) of 28,500 p / cm ² .

Example U

a) A cuboid of a natural sponge with the dimensions 10 χ 10 χ 5 cm (= 500 cm ³ ), with a density of 19 kg / m ³ and a compressive strength (at 45% compression - measured according to DIN 53 577) of 160 p / cm ² is impregnated with the polyurethane dispersion described in Example 8 by pressing out and releasing the pressure twice, the excess amount of dispersion is squeezed off and the moist foam is dried and cured ^{at 130 ° C. for 10 minutes.} The result is a flexible foam of higher hardness with good physical properties, the ^{density of which is 28 kg / m 3} and which now has a compressive strength (at 45% compression - measured according to DIN 53 577) of 260 p / cm ² .

b) If the experiment described under a) is repeated, but the foam was pressed six times in the polyurethane dispersion, relaxed, squeezed and then ^{dried and cured for 15 minutes at 150 °} C., a foam is obtained which now has a density of 78 kg / m ³ and a compressive strength (at 45% compression - measured according to DIN 53 577) of 4000 p / cm ² .

Example 12

The anionic polyurethane latex used in this example was prepared in the following way:

Parts by weight of adipic acid-hexanediol-neopentyl glycol polyester with an OH number of 65 (molar ratio of the components: 30:22:12) are dehydrated for 30 minutes in a water jet vacuum at 120 ° C. and reacted with 30 parts by weight of hexamethylene diisocyanate for two hours. The viscous prepolymer is dissolved acetone at 60 ⁰ C in 700 parts by volume and a solution of 3.8 parts by weight of ethylenediamine, 7.6 parts by weight of 1,3-propane sultone and 35 parts by weight of a 10 % strength aqueous potassium hydroxide solution in 50 parts by volume of water is added. After a short stirring time, 310 parts by volume of water are stirred in and the acetone is distilled off in a water jet vacuum at Torr. The acetone-free, stable latex obtained has a solids content of approx. 41% by weight. The polyurethane ionomer has a Shore A hardness of 60.

A cuboid of the foam used for impregnation in Example 1 with the dimensions 30 × 15 × 5 cm (= 2250 cm ³ ) (= 83.3 parts by weight) is, as described in Example 1, with 205 parts by weight of the Above-mentioned anionic polyurethane dispersion impregnated, pressed out, impregnated again and then

ίο only lightly stripped of non-adherent latex, with a total of about 202 parts by weight of the aqueous latex being drawn onto the foam. The foam pretreated in this way is dried ^{at 105 ° C. in vacuo.} The result is a high-quality, completely tack-free, soft, open-pored and very elastic foam (= 166 parts by weight), the density of which is about 76 kg / m ³ and which has now increased by about 100% by weight compared to the starting material and nevertheless remained completely open-celled and tack-free. The elastic foam modified in this way shows no color change even after months of storage in the light and is pure white, while the foam used for impregnation yellows in sunlight within 10 days and takes on a yellow-brownish color.

If the foam used in this example is replaced by foams which, according to the in Example 1 given recipe are produced but as polyhydroxyl component polyesters from adipic acid and diethylene glycol, polythioether of thiodiglycol, polyacetals from triethylene glycol and formaldehyde, Polycarbonates made from triethylene glycol, copolymers made from tetrahydrofuran and propylene oxide (1: 1) or Contain polypropylene glycols with OH numbers from 45 to 60, so are again in the impregnation obtained completely tack-free, elastic, soft foams with excellent lightfastness.

Example 13

The procedure is exactly as described in Example 12, using the cuboids described there in each case Dimensions and adds in each case to 205 parts by weight of the anionic polyurethane dispersion used in Example 12 the following additives in aqueous solution to:

a) 32 parts by weight of urea in 50 parts by weight of water,

b) 32 parts by weight of thiourea in 70 parts by weight of water,

c) 16 parts by weight of urea, 16 parts by weight of urotropin in 60 parts by weight of water,

d) 18 parts by weight of urea, 14 parts by weight of monomethylolurea in 32 parts by weight of water,

e) 32 parts by weight of N-methylol-dicyandiamide in 60 Parts by weight of water,

f) 32 parts by weight of dicyandiamidine in 55 parts by weight of water,

g) 16 parts by weight of phenol and 16 parts by weight of dimethylolurea in 60 parts by weight of water,

h) 32 parts by weight of ammonium oxalate in 100 parts by weight of water (65 ° C.).

The foams are each impregnated with the specified mixtures and the impregnated foams are dried as described in Example 12. The completely (15) open-cell, elastic foams described under A) to H) are obtained, the weight of which has increased by about 138% compared to the starting material, which have a density of about 88 kg / m ¹ , the additives are completely dust-free

and have the following improved properties compared to the starting material:

A) Urea content fixed in a dust-free manner: 16.2% by weight, lightfast, self-extinguishing.

B) Dust-free fixed thiourea content: 16.2 % By weight, lightfast, self-extinguishing.

C) Urea content fixed without dust: 8.1% by weight, urotropine content: 8.1% by weight, lightfast, self-extinguishing.

D) Urea-formaldehyde condensates fixed without dust: 16.2% by weight, lightfast, self-extinguishing.

E) Dust-free fixed methylol dicyandiamide condensates: 16.2% by weight, lightfast, self-extinguishing.

F) Dust-free fixed dicyandiamidine content: 16.2 % By weight, lightfast, self-extinguishing.

G) Part of urea-phenol-formaldehyde condensates fixed in a dust-free manner: 16.2% by weight, self-extinguishing foam.

H) Dust-free fixed ammonium oxaht content: 16.2% by weight, lightfast, the foam burns with it smokeless flame.

The foam used as the starting material for the impregnation, on the other hand, differs from the Examples A) to H) are not lightfast and burns with strong and extremely strong development of smoke gas Surface fire.

Example 14

The procedure is exactly as in Example 13 and 205 is used in each case when carrying out the impregnation Parts by weight of the anionic polyurethane latex used the following additives in aqueous suspension or solution to:

a) 32 parts by weight of titanium dioxide in 70 parts by weight of water.

b) 32 parts by weight of the strongly herbicidally active 2-chloro-4,6-bis-ethylamino-s-triazine in 60 parts by weight Water.

c) 16 parts by weight of aluminum oxide, 16 parts by weight of silicon dioxide in 80 parts by weight of water and 2 Parts by weight of aluminum sulfate.

d) 32 parts by weight of paraformaldehyde in 60 parts by weight of water.

e) 32 parts by weight of graphite powder in 70 parts by weight of water.

f) 32 parts by weight of a mixture of potassium nitrate and sec. Ammonium phosphate in 50 parts by weight of water.

g) 32 parts by weight of copper powder in 70 parts by weight of water.

h) 32 parts by weight of aluminum powder in 70 parts by weight of water.

i) 32 parts by weight of copper phthalocyanine in 60 parts by weight of water.

Although the additives a) to i) used differ in their adhesive properties when conventional adhesive agents are used such as natural rubber latex, glue, polyacrylates etc. differ greatly and only a minor one Have adhesive strength, in all cases a) to i) after the impregnation and drying of the foams Completely dust-free fixation of the additives is achieved, the additives in the modified Foam to about 16.2% by weight are fixed. The foams obtained have a density of about 88 kg / m 'and are open / elligical and adhesive.

Example 15

Proceed exactly as in Example 12, using the anionic polyurethane dispersion described there for impregnation, but using foam in the form of foam flakes (83 parts by weight) with a cross section of approx. 5 mm and impregnating them with 205 Parts by weight of the polyurethane dispersion. The impregnated foam flakes are filled into a cylindrical shape (cross section = 9 cm) which contains a steel sieve as the base plate.A pressure of approx. 500 Torr is exerted on the flake material by means of a displaceable stamp ⁰ C and receives after the

■ ^ demoulding a rubber elastic roller that is completely is free of klcb, corresponds to a homogeneously foamed molding, has a density of about 74 kg / m ' and an excellent shock absorbing material for storing sensitive optical and electrical Represents measuring instruments.

Example 16

The anionic polyurethane latex used in this example was prepared in the following way:

88 parts by weight of ethylene glycol phthalic acid polyester (OH number 159) and 124.3 parts by weight of ethylene glycol phthalic acid polyester (OH number 282) are dewatered for 30 minutes in a water jet vacuum at 120 ° C and 2 Reacted hours with 90.5 parts by weight 1,6-hexane diisocyanate. The tough prepolymer is made in 700 parts by volume Dissolved acetone and mixed with a solution of 9.5 parts by weight of potassium lysinate in 80 parts by volume of water. Then 425 parts by volume of water are stirred in and the acetone is distilled off. The 40% strength latex obtained provides films with a Shore D hardness of 50.

A cuboid of the foam used for impregnation in Example 1 with the dimensions 30 × 15 × 5 cm (= 2250 cm ³ ), (= 83.3 parts by weight) is loaded with 205 parts by weight of the abovementioned anionic polyurethane dispersion and dried at 115 ° C in a vacuum cabinet. A high-quality, semi-rigid foam (= 166 parts by weight) is obtained, which is completely tack-free and open-celled and has a high level of lightfastness. Volume weight: 76 kg / m '.

Example 17

The cationic used in this example

so polyurethane latex was prepared in the following manner: 500 g (0.298 mol) of adipic acid-hexanediol-Neopentylglykolpolyesters (molar ratio 30:22:12), and 56 g (0.342 mol) of N-butyldiethanolamine be at 8O ⁰ C with 161 g (0 , 96 mol) 1,6-hexamethylene diisocyanate and heated to 130-140 ° for 30 minutes. It is then reacted with 38 g (0.64 mol) of urea at 125-146 ° C. for 30 minutes. The melt, which has been cooled to 96 ° C., is then successively converted into a solution of 20 g of 85% phosphoric acid in 100 ecm of water

do within 4 minutes, 600 ecm of water at 90 ° C within 8 minutes, 100 g of 30% aqueous formaldehyde solution within 5 minutes and 500 ecm of water at 90 ° C within 15 minutes added.

r, s 1.9 kg of a 38% polyurethane dispersion are obtained. Ford cup viscosity (D 8): 5.2 seconds.

Homogeneous films obtained from the latex have a Shorc D hardness of 15.

200 parts by weight of this latex are used to impregnate the cuboid described in Example 12. After drying in vacuum at 11O ⁰ C a tack-free, highly elastic foam is obtained (= 166 parts by weight), the density is about 76 kg / m ¹ and the now compared with the starting material is about 100 wt .-% gained weight has, yet it is completely open-celled and non-sticky and has a high level of light resistance compared to the foam used for impregnation.

Example 18

The cationic polyurethane latex used in this example was prepared in the following manner. represents:

500 g (0.291 mol) of a phthalic acid-adipic acid-ethylene glycol polyester (molar ratio 1: 1: 2.3), 30 g of N-methyl-diethanolamine and 33 g of urea are mixed with 140 g of 1,6-hexamethylene diisocyanate at 80.degree and stirred at 130-150 ° C for 30 minutes. After adding 14 g of chloroacetamide in 30 ecm of glycol monomethyl ether acetate, the mixture is kept at 134 ° C. for 30 minutes. To the cooled to 105 ⁰ C melt, a solution of 6 g of acetic acid in 150 cc of water at 90 ⁰ C in 25 minutes, 129 cc of 30% aqueous formaldehyde solution in 16 minutes and 950 cc of water at 90 ⁰ C in 23 minutes added. The cooled dispersion is adjusted to pH 4 with 33 g of a 30% strength tartaric acid solution.

1.9 kg of a 38% strength latex are obtained. Ford cup viscosity (D 6): 11 seconds. Obtained from the latex homogeneous films have a Shore D hardness of 24.

200 parts by weight of this kaiionischen polyurethane latex are used to impregnate the cuboid described in Example 12. After drying in vacuum at 120 ⁰ C to obtain a tack-free, light-fast, modified semi-rigid foam (= 166 parts by weight), which has increased compared to the starting material to about 100 wt .-%, is totally open-celled, and a density of 74 kg / m ³ .

Example 19

The cationic polyurethane latex used in this example was prepared in the following manner:

750 g (0.285 mol) of adipic acid diethylene glycol polyester, 30 g of N-methyldiethanolamine and 33 g of urea are mixed with 134 g of 1,6-hexamethylene diisocyanate at 84 ° C. and the mixture is stirred at 130-137 ° C. for 30 minutes. After adding 12 g of chloroacetamide, the mixture is stirred at 136-144 ° C. for 30 minutes. Derauf 90 ⁰ C cooled melt are successively added a solution of 10.5 g of acetic acid in 120 cc of water, 120 cc of 30% aqueous formaldehyde solution, 1000 cc of water at 90 ° C and 45 cc of 30% aqueous solution of tartaric acid was added. The latex is then cooled

2.2 kg of a 44% strength polyurethane latex are obtained, Ford cup viscosity (D 8): 41 seconds. From the Homogeneous films obtained from latex have a Shore A hardness of 40.

200 parts by weight of this cationic polyurethane latex are used to impregnate the cuboid described in Example 12. After drying in vacuo at 115 ° C, a non-tacky, lightfast, elastic foam (= 159 parts by weight) is obtained, which has increased by about 98% by weight compared to the starting maicrial, is completely open-cell and has a density of approx. 73 kg / m ^! owns.

,. B e i s ρ i e I 20

The cationic polyurethane latex used in Example 12 (100 parts by weight) is 100 parts by weight Brought water to a solids content of approx. 22% by weight.

ίο A cuboid as in example 1 for impregnation foam used with the dimensions 30 cm χ 15 cm χ 5 cm (= 2250 cm ') (= 83.3 parts by weight) is impregnated in a first phase with 80 parts by weight of a 2% ammonium oxalate solution and im

ι vacuum dried. The dried cuboid contains after drying 1.92% by weight ammonium oxalate. 200 parts by weight of the cationic dispersion with a Solids content of 22% by weight are used for the impregnation, as described in Example 12. By The polyelectrolytes, which are finely distributed in the foam, are cationic, which are sensitive to electrolytes Polyurethane dispersion precipitated coagulating shortly after impregnation of the foam, see above that 120 parts by weight of water can be squeezed out as a latex serum

2s and the subsequent drying in a vacuum takes place quickly. A lightfast, elastic, open-cell, completely tack-free foam is obtained, the density of which is about 48 kg / m ¹ and has increased by 28% by weight compared to the starting material.

If in this example ammonium oxalate is replaced by guanidine oxalate, oxalic acid, phosphoric acid, ammonium chloride, Potassium nitrate, sec. Ammonium phosphate, colloidal silica, or zinc chloride, so will be as im

In the case of the addition of ammonium oxalate, the coagulating c Precipitation accelerated so that the latex serum can be easily squeezed out shortly after impregnation, see above that even relatively dilute latex solutions with solids contents of only 5% by weight are used can.

Example 21

The cationic polyurethane latex used in this example is prepared in the following way:

4.S In a 500-liter stirred tank 26 kg of a 70% Polythioäthers of thiodiglycol and 30% of OH number 77 heated hexanediol-1,6 with 53 kg of tolylene diisocyanate (mixture of isomers 65:35) at 8O ⁰ C and 30 Leave at this temperature for minutes. After cooling

<, <> to 50 ° C successively 32 liters of acetone, 10.4 kg of diethylene glycol in 13 minutes, 10.4 kg of 1,4-butanediol in 30 minutes and a solution of 7.8 kg of N-methyl diethanolamine in 51, 2 liters of acetone added in 25 minutes. After about 80 minutes, the viscosity is 100 poise. At this point in time 1.26 kg of dimethyl sulfate and 0.54 kg of 1 _v 3-dimethyl-4,6-bis-chloromethylbenzene in 2.8 liters of acetone and then 622 liters of acetone are stirred in one after the other. The mixture is stirred at 50.degree Hieraul has achieved a sample with a viscosity of 150 to 200 poise

Ui are successively a solution of 1.35 kg of 85% phosphoric acid and 1.1 kg of triethyl phosphate in 6.4 liters of water and 116 liters. Lonenaustauschei added over a purified water, the water is 2, f l / min. Then the acetone is stirred in

distilled off in vacuo. 220 liters of 50% strength are obtained Polyurethane latex.

Shore hardness of the homogeneous films produced from this approx. D 90.

If you impregnate an elastic polyurethane foam with this latex under the conditions of Example 12, so an open-celled semi-rigid foam is obtained, which even with an increase in weight of over 120% compared to the foam used for impregnation completely open-celled and is tack-free. In the same way, waste foam by impregnation in the manufacture of the above Latex can be refined in situ as follows:

83 parts by weight of flocculated foam waste with a diameter of 4 to 6 mm, which were produced from waste from industrial block foaming, are mixed with 100 parts by weight of toilet water, 1.35 parts by weight of 85% phosphoric acid and 1.1 Contains parts by weight of triethyl phosphate, impregnated and the flakes intimately mixed. This mixture is homogeneously impregnated with 227 parts by weight of the acetone solution described in this example after quaternization with dimethyl sulfate and!, S-dimethyl- ^ ö-bis-chloromethylbenzene, the latex being formed in the cellular substrate. The foam flakes are compacted under slight pressure in the cylindrical shape described in Example 15. It is dried in a vacuum oven and acetone and water are removed through the porous steel sieve of the cylindrical shape. After removal from the mold to obtain a semi-rigid, cylindrical, open-cell moldings with a Raumgev, maybe from about 75 kg / m ^J.

Example 22

The cationic polyurethane latüx used in this example was prepared in the following manner:

8000 parts by weight of a polyester with an OH number of 64 and a water content of less than 0.3% made from phthalic acid, adipic acid and ethylene glycol (molar ratio 1: 1: 2.2) are mixed with 2160 parts by weight of tolylene diisocyanate (isomer mixture 65 : 35) 90 minutes at 100 ⁰ C implemented. 3950 parts by volume of acetone (water content 0.24%), 800 parts by weight of N-methyldiethanolamine and then 3500 parts by weight of acetone are added successively to the viscous pre-adduct, and the mixture is stirred at 50 ° C. until the viscosity is 20 Poise is. A solution of 244 parts by weight of 1,3-dimethyl-4,6-bis-chloromethylbenzene in 790 parts by volume of acetone and then 3500 parts by volume of acetone are then added. After a viscosity of 40 poise has been reached, 8 parts by weight of dibutylamine in 126 parts by volume of acetone, 277 parts by weight of 85% strength phosphoric acid and 106 parts by weight of triethyl phosphate in 1000 parts by volume of water and 14,000 parts by volume are successively added . -Parts of water are stirred in. After the acetone has been distilled off, a 52% opaque, viscous, colloidal polyurethane solution is obtained.

Is impregnated with this latex under the conditions of Example 12 an elastic polyurethane foam and hardens in vacuo at 80 ⁰ C, an open cell semi-rigid foam is obtained which is totally open-celled, even with a weight gain of 130% over that used to impregnate foam and tack-free and is an excellent filter material for cleaning air or mineral oils containing suspended matter.

Example 23

This example shows the advantageous use of the polyurethane foams impregnated according to the invention as matrices for carrying out interfacial reactions according to the procedure of German patents 19 11644, 19 11643,

ίο 19 11 645 and 19 11 180.

Elastic foams modified by impregnation according to Example 12 ^{and having a density of 74 kg / m 3} and dimensions 30 cm × 15 cm × 5 cm (= 2250 cm ³ ) (= 166 parts by weight) are loaded with the following reactive mixtures, the Foams swell extremely strongly:

a) 83 parts by weight of tris (isocyanatohexylbiuret), dissolved in 140 parts by volume of acetone,

b) 83 parts by weight of benzoquinone, dissolved in 160 parts by volume of ethyl alcohol,

c) 83 parts by weight of bisphenol A, eaten in 145 parts by weight of acetone and 2 parts by weight of 50% strength aqueous sodium hydroxide solution,

d) 83 parts by weight of methylene chloride and 0.8 parts by weight of tin II-octoate,

e) 83 parts by weight of urea in 200 parts by weight of ethyl alcohol.

The highly swollen matrices treated in this way are in the case of a) and b) gassed with 30 parts by weight of ammonia in a cylindrical reactor in the absence of oxygen, in the case of c), d) and e) in a similar reactor with exclusion of oxygen Treated 120 parts by weight of gaseous formaldehyde. One gassed such that the measured inside the cuboid temperature does not exceed 6O ⁰ C. Open-celled, hard combination foams are obtained in which the resulting solids are completely open-celled

^ have been arranged. The following spatial growth was irreversibly fixed by the solids formed during the reaction:

A) Lightfast hard foam, irreversibly fixed increase in volume 110% by volume, based on the impregnated foam used.

B) Graphite-like, high-temperature-resistant foam, irreversibly fixed increase in volume: 120% by volume.

C) Open-celled rigid foam modified with phenoplasts, irreversibly fixed increase in volume: 98 V0I.-0/0.

D) Open-cell, polyoxymethylene-modified rigid foam with high antibacterial effectiveness, irreversible fixed increase in volume: 105 V0I.-0/0.

E) Open-cell, flame-resistant rigid foam modified with urea-formaldehyde condensates, irreversibly fixed volume scale 102% by volume, in each case based on the initial volume of 2250 cm ^{3 of} the matrix used for the phase interface reaction.

Claims (7)

Patent claims: 1. A process for impregnating foams with polyurethanes, characterized in that the foams are impregnated with aqueous dispersions of polyurethanes which, in homogeneous, fully reacted form, have at least a Shore A hardness (DIN 53 505) of 5, preferably 40 , and at most a pendulum hardness (DIN 53 157) of 240, preferably a Shore D hardness (DIN 53 505) of up to 90. 2. The method according to claim 1, characterized in that that dispersions of polyurethane ionomers based on hexamethylene diisocyanate, Isophorone diisocyanate and / or m- and p-xylylene diisocyanate have been produced, used. 3. The method according to claim 1 and 2, characterized in that foams are impregnated, the 0.1 to 10 wt.% of polyelectrolytes, preferably salts of inorganic or organic acids of Elements of the first, second and third main group of the periodic table, or ammonium oxalate, Contain oxalic acid and that the 2s impregnation process with immediate coagulation the dispersion carries out. 4. The method according to claim 1 to 3, characterized in that the impregnation in Presence of carbonyl compounds, preferably formaldehyde, chloral hydrate, acetaldehyde, isobutyraldehyde, Crotonaldehyde and / or compounds capable of aminoplast or phenoplast formation or solutions of these compounds, preferably urea, thiourea, methylenediurea, uro- * s tropine. Dicyandiamide, melamine and their methylolysis products. 5. The method according to claim 1 to 4, characterized in that the impregnation agent together with pigments, fillers, herbicides, bio-silk or hemostatic additives on the Foams fixed. 6. The method according to claim 1 to 5, characterized in that one foam flakes with Impregnated with diameters of 2 - 30 mm and the impregnation and drying, if necessary, in molds takes place using heat and pressure. 7. Use of elastic foams impregnated according to Claims 1 to 6 as a matrix zen for carrying out interfacial reactions in the form of single and / or multi-component reactions, whereby by swelling processes and by reactions proceeding with the formation of solids an irreversible increase in volume of the s_s die takes place.