CA2172020A1 - Impregnating agents for flameproof finishing and their use - Google Patents

Abstract

A halogen-free impregnating agent for improving the flame resistance of a foamedplastic, textile or nonwoven fabric, comprising an aqueous solution containing asurface active agent and the reaction product of a) 1 molar amount of an allumimum compound, b) 2 to 5 molar amounts of a phosphorous-contaning acid, c) 0 to 9 molar amounts of a boron-containing acid, and d) 2 to 9 molar amounts of ammonia or an amine.

Description

Le A 30 972-Foreign Countries/Le/ngb/S~ l 7 2 0 2 0 Impre~natin~ A~ents for Flameproof Finishin~ and their Use The present invention relates to impregn~ting agents for flameproof fini~hin~ and their use for the surface impregnation of foamed plastics, textiles, nonwoven fabrics and lightweight materials.

As a fundamental strategy for the reduction of fire risks and serious consequences of fire, combustible foamed plastics for example are so finished with conventional commercial flameproofing agents that the conventional utility of the end product is preserved but the flammability and the behavior in fire is modified in the desired way.

Individual solutions must be worked out by the foamed plastics manufacturer according to the m~mlf~cturing process, service temperature conditions and re-quirements for flameproofing, since the use of the flameproofing agents in the initial formulation naturally considerably impairs the proce.s~in~ properties and the overall properties of the complete products and makes appropliate adjustments necessary. With the increased safety requirement and by reason of ~luloly regulations, the requirements for flameproofing are also increasing considerably.

Particularly effective flameproofing agents for plastics are as a rule halogen-cont~ining For example tetrabromobisphenol A is recommended as a flame-proofing agent for thermoplastics by various suppliers (e.g. the Great Lakes Company). Antimony compounds, as for example antimony trioxide, act synergistically in combination with halogen compounds in flameproofing, so that such combinations are frequently used (see e.g. Proceedings of the Flame Retardants 94 Conference, Interscience Communications, ISBN 0 9516320 5 1).

Halogen and antimony compounds are, however, undesirable for ecological reasons, which is why efforts are increasingly being made to use halogen-free flameproofing agents. Owing to the relatively low effectiveness and the lack of synergy, however, distinctly higher quantities must be used, as a result of which 30 the negative effects of the foamed plastic appear in turn to an increased extent.

Also, in many uses of the foamed plastics, for example in wall covering, only one side or surface is exposed to the flame attack, so that it would suff1ce to flameproof-finish this surface appropriately.

Le A 30 972-Forei~n Countries 2 ~ 7 2 0 2 0 _ -- 2 In principle, the enormous expenditure which has been described for the incorporation of flameproofing agents in the starting components of the foamed plastics could be avoided if the surfaces of the materials to be protected could be so finished that during the exposure to fire a sufficient resistance to fire is 5 established or the appropfiate use-related fire tests are passed. It is naturally required in this connection that the rem~ining physical properties demanded of the corresponding prefabricated part are not or only very little influenced. Of special advantage for the reasons given would also be a halogen-free and ecologically acceptable surface impregnation.

In DE-A 42 11 762 foamed plastic profiles are described that contain in their cavities intumescent formers of in.~ ting layers for the case of fire. The foamed plastics described there are used for fire protection sealing. If open-cell, flexible polyurethane foams are used in this connection, the pores must be closed with the in~ tin~-layer-formers in order for them to be impermeable to flue gases and to constitute effective fire-protection seals. At the same time the elasticity of the foamed plastics is completely restricted so that they cannot be used for example in the upholstery sector.

Gels and gel-formers based on alllmimlm phosphate are known in principle from a number of patent specifications, of which DE-A 40 23 310, DE-A 42 26 044 and DE-A 43 07 631 may be mentioned by way of example. These gels have been developed especially for use in fire-protection glasswork.

In DE-A 38 08 275, fire-protection elements are described that are manufactured by impregnation of flexible foamed plastics. However, the impregnated foamed plastics are only flexible and elastic in the moist state; they cure on drying, as a result of which the foamed plastic part becomes hard and inflexible. These impregnations cannot therefore be used in the upholstery sector.

In DE-A 43 07 631 it is proposed to use the gel-formers described, for further application, apart from fire-protection glasswork, also for the impregnation of flexible foamed plastics. In this case also, however, the drying leads to an undesirable hardening of the foamed plastics.

Le A 30 972-Foreign Countries 2 1 7 2 0 2 0 The object is therefore to provide agents that allow the flameproof fini~hing, especially of flexible foamed plastics, without the properties, in particular the flexibility, of the foamed plastic end-products being adversely affected.

The invention provides impregn~ting agents for the halogen-free flameproof 5 finishing of surfaces of foamed plastics, textiles and nonwoven fabrics, characterized in that the agents contain aqueous solutions of surface-active agents and reaction products from 1 mol of an alllmimlm compound with 2 to 5 mols of a phosphorus-con~ining acid, O to 9 mols of a boron-cont~ining acid and 2 to 9 mols of ammonia and/or an amine.

10 For spray application the impregn~ting agents preferably have concentrations between 10 and 50 wt.%. The concentration to be set depends not only on the particular application method but also on the desired final viscosity according to the application.

Those aluminum compounds are preferred which can yield alumim~m phosphates 15 by reaction with a phosphoric acid, e.g. alumimlm oxides, hydrous oxides, . hydroxides and carbonates. Alllminllm hydroxide Al(0H)3, which optionally contains water of cryst~lli7~tion, is particularly preferred.

Possible phosphorus-cont~ining acids are preferably e.g. ortho-, meta-, pyro- and polyphosphoric acids, as well as phosphonic and phosphinic acids. Orthophos-20 phoric acid H3PO4 is particularly preferred. Relative to 1 atom equivalent of alu-minum in the alllmimlm compound, particularly 2.5 to 3.5, especially 2.9 to 3.1,mols of phosphorus-cont~ining acid are used.

Possible boron-cont~ining acids are preferably orthoboric acid and other boron acids or boron compounds that can change into orthoboric acid under the influence 25 of water, e.g. boron oxides. Orthoboric acid H3BO3 is particularly preferred.Particularly preferably, relative to 1 atom-equivalent of alllminum in the aluminum compound, 1 to 4, in particular 1 to 3, mols of boron-cont~inin~ acid or a precursor thereof are used.

In addition to ammonia, usable as amines are primary and secondary hydroxy-30 alkylamines, the alkyl groups of which have 2-6 carbon atoms, as for example Le A 30 972-Forei~n Countries 2 ~ 7 2 0 2 0 ._ -- 4 --monoethanolamine, diethanolamine and triethanolamine, and furthermore poly-alkylenepolyamines, piperazines and morpholines.

Particularly preferred as amines are hydroxyalkylamines, especially reaction products of ammonia or amines with alkylene oxides. As well as ammonia, there 5 may be mentioned as amines for example hydrazine, hydroxylamine, optionally cyclic aliphatic, aromatic and heterocyclic amines and polyamines with up to 7 Natoms and up to 20 C atoms, such as ethylenediamine, propylenediamine, piperazine and morpholine. Alkylene oxides that may be mentioned for example are ethylene oxide, propylene oxide and their mixtures. Hydroxyalkylamines and 10 polyhydroxyalkylamines (such as diethanolamine, triethanolamine and e.g. mono-to tetrahydroxyalkyl alkylene diamines, such as di-hydroxyethylethylenediamine) as well as polyether groups cont~ining hydroxyalkylamines are also possible.
Monoethanolamine is preferred. Relative to 1 atom equivalent all~minum in the aluminllm compound, particularly 3 to 7 mols alkanolamine are used. The boron-15 cont~ining acid, if present, and the alkanolamine are particularly used in the molarratio 1:2. A part of the alkanolamines being used can optionally be replaced by ammonia, ethylene~i~mine or other volatile amines, wherein, however, preferably no more than 50 mol % of the alkanolamines are substituted. Preferred alkyl and alkylene radicals have up to 4 carbon atoms.

20 The reaction products used and their process of manufacture are described in detail in DE-A 40 23 310, DE-A 41 26 702, DE-A 42 26 044, DE-A 43 07 631 and DE-A 42 36 936.

The reaction products preferably have a molar Al:B:P:N ratio of 1: (1.2-1.8):(2.3-3.7):(2.3-3.7).

25 For the prepal~lion of the aqueous solutions the reaction products can be used directly, or optionally in appropliate dilution with water.

The aqueous solutions preferably contain 0.1 to 5 wt.% of surface-active agents, as for example ionic and nonionic emulsifiers, surfactants and soaps.

As typical examples of the surface-active substances there may be mentioned:
30 sodium and ammonium salts of dodecylbenzenesulphonic acid and of lauryl-Le A 30 972-Foreign Countries ~ 1 7 2 0 2 0 sulphonic acid as well as sulphates of stearylamine and laurylamine and reactionproducts of nonylphenols with several mols of ethylene oxide.

The surface-active agents bring about a uniform wetting of the surface or of thecell struts of the foamed plastic, the elasticity of the flexible foamed plastics being 5 influenced only a little or not at all.

Surprisingly, the surface-active agents turn out to be advantageous even during the flaming, probably because a uniform, fine-porous and rigid intumescent foam is formed, which provides effective protection against the further effect of flame.
Particularly preferred surface-active agents are water-soluble polyether poly-10 siloxanes, which are frequently used as foam stabilizers in the manufacture of polyurethane foams. The structure of these compounds is generally such that a copolymer of ethylene oxide and propylene oxide is connected to a poly-dimethylsiloxane group. Such polysiloxane polyethers are described e.g. in US
Patent Specifications 2 834 748 and 3 629 308.

The polyether polysiloxanes are preferably used in amounts of 0.01 to 2.0 wt.%, preferably 0.1 to 1 wt.%, relative to impregn~ting agent.

The impregn~ting agents according to the invention can preferably also contain, in addition to water, water-soluble organic solvents, for example isopropanol, acetone, etc. The concomitant use of these solvents is advantageous when the 20 impregn~ting agent is used on molded parts, since these molded foamed plastics contain, as a result of their manufacture, release agent on the surface. The solvents partially dissolve these release agents and permit the wetting of the foamed plastic with the formulations. The water-soluble organic solvents are preferably present in an amount of 1 to 50 wt.%, particularly of 5 to 30 wt.%, 25 relative to impregn~ting agent.

Formulations of the impregn~ting agents according to the invention can also contain latices or polymer dispersions. Suitable materials for this purpose are above all film-forming aqueous polymer dispersions which on mixing with the aqueous dispersions do not lead to coagulation. These include for example 30 aqueous ethylene-vinyl acetate dispersions with solids contents of up to 60 wt.%

2 t 72020 and polyurethane dispersions with solids contents of up to 50 wt.% (for example Impranil types from Bayer AG).
The impregnating agent/dispersion mixtures can contain 1 to 70 wt.% of aqueous dispersions mentioned above;
preferably a content of 10 to 50 wt.% is maintained.
The mixtures yield particularly flexible films which have a particularly small effect on the elasticity of the foamed plastics.
In a preferred specific embodiment, the impregnating agents additionally contain aqueous colloidal silica sols.
The conventional commercial silica sols used preferably have a concentration range of 10 to 50 wt.% at a pH value of 7 to 8. These aqueous silica sols are used in an amount of preferably 20 to 60 wt.%, relative to the impregnating agent.
Preferably the impregnating agent contains 5 to 50 wt.% of silica sol colloidally dispersed therein.
Further fillers and additives preferably can be added to the impregnating agents according to the invention.
Fillers that may be mentioned are rock dust, chalk powder, silicates, gypsum powder and powdery flameproofing agents, as for example aluminum hydroxide, magnesium hydroxide and borates, such as calcium or zinc borate.
The impregnating agents according to the invention can be used as they are, as aqueous solutions. The aqueous solution can also, however, be subjected to a drying stage and the remaining solid, after pulverization, can be dispersed in an organic solvent, as for example alcohols, glycols, volatile alkanes or aromatics or water. In this manner, organic dispersions or pastes, according to concentration, can be manufactured that can be of advantage in some fields of application.
The surfaces of foamed plastics, in particular molded flexible foams, textiles and nonwoven fabrics, can be impregnated flameproof with the impregnating agents according to the invention, so that they are flameproof finished. In particular, foamed plastics with solid or microcellular surface can be flameproof finished with the impregnating agents according to the invention.
The following may be mentioned as foamed plastics that are impregnated flameproof on the surface by the process according to the invention:

- 6a -Le A 30 972-Forei~n Countries 2 t 7 2 0 2 0 - reversible compressible elastic foamed plastics, preferably polyurethane flexible foams based on polyetherpolyol or polyesterpolyol, as have been used for years for the manufacture of mattresses and seat cushions - latex foamed plastics of natural or synthetic rubber, polyolefin foamed plastics, cellulose foamed plastics, natural sponges and other polymeric foamed plastics - hydrophilic elastic foamed plastics, as for example cellulose foams or hydrophilic elastic polyurethane foams, as are described for example in US
4 051 081.

10 The following may be mentioned as further materials that are impregn~ted flame-proof by the process according to the invention:

- mineral wool, rock wool, glass wool and fleeces thereof, as are fequently used for example for thermal insulation and other insulation - fleeces, nonwoven fabrics, woven fabrics and knitted fabrics of natural and polymeric fibers.

Impregnation is carried out by dipping, spraying or similar known impregn~tin~
techniques. In this connection the impregn~ting liquid must be so metered out that it penetrates into the surface of the foamed plastics only to a depth of not more than 2 cm and only the cell struts or the foamed plastics or fibers are coated with 20 the impregn~tin~ agents. The pores of the foamed plastic must not be closed with the impregn~ting agents in the course of treatment.

Elastic polyurethane foams manufactured by the so-called reaction injection molding (RIM) process usually contain on the surface, as a consequence of the process, residues of mold-release agents. These molded foamed plastics are pref-25 erably impregn~ted with impregn~ting agents which, in addition, contain water-soluble organic solvents, as for example isopropanol.

Seating furniture or automobile seats are manufactured particularly efficiently by sucking elastic textile upholstery fabrics flush into a mold by applying a vacuum, so that the textiles assume the surface contour of the mold. Thereafter liquid Le A 30 972-Foreign Countries 2 t 7 2 0 2 0 _ -- 8 --polyurethane mixture is introduced into the mold, as a result of which a strong bond is produced between foamed plastic and cover. The textile is frequently l~min~ted with a thin film of nonwoven fabric or expanded sheet to the so-called"interliner", in order to produce a particularly strong bond between the textile and 5 the polyurethane foam. The upholstery fabric or the expanded sheet l~nnin~ted on can preferably be impregnated with the impregn~ting agent according to the invention before the foamed plastic reaction mixture is fed in. Flameproofed seats or upholstered furniture are thus obtained in one operation.

Closed-cell foamed plastics also can be flameproof-finished with the impregn~ting 10 agents according to the invention. In this connection the surface of the foamed plastic that can come into contact with the flames in the event of fire is coated with the agents.

Closed-cell foamed plastics are for example rigid polyurethane foams, poly-isocyanurate foams, polystyrene foams and other polymeric foams. Such foamed 15 plastics are used for thermal insulation in many fields.

After the impregnation drying takes place at room tempe~ e or, for the acceler-ation of the drying process, preferably at elevated temperature. According to the temperature resistance of the foamed plastics, textiles or nonwoven fabrics, temperatures distinctly above 100C can be used during the drying.

20 During fl~ming the impregnated liquids, with small volume increase, develop asolid ceramic-like layer, which by thermal insulation protects the polymeric material from further flame access. A further advantage is the small amount of smoke generated during the flaming even in the case of foamed plastics which, asis well known, tend to generate extraordinarily intense smoke in case of fire, as is 25 true for example for polyurethane foams.

The invention will be further explained in the following illustrative examples, wherein all parts are by weight unless otherwise expressed.

Le A 30 972-Foreign Countries 2 1 7 2 0 2 0 g Example 1 Preparation of the reaction product a) Alumimlm phosphate solution 107 parts of hydrargillite (technical alllmin-lm hydroxide) were added to 477 parts of 85 % of orthophosphoric acid and 115 parts of water and stirred for 4 hours at 100 to 110C. The aluminum phosphate solution obtained is used for the reaction with boric acid-ethanolamine solution.
b) Boric acid-ethanolamine solution 116 parts of boric acid are added in portions with stirring to 251 parts of ethanolamine and 3.7 parts of water at 85C. A clear boric acid-ethanolarnine solution is obtained, which is reacted with the al-lmim-m phosphate solution.
c) Reaction product 212 parts of the boric acid-ethanolamine solution according to lb) are charged to a stirred pot and mixed with stirring with 244 parts of alumim-m phosphate solution according to la). The solution thus obtained is used for the plep~lion of the impregn~tin~ agents.
Exam~le 2 Preparation of Impregn~tin~ Agent A

100 parts of the solution prepared according to Example lc) are mixed with 100 parts of water and 2 parts of a conventional commercial polysiloxane polyether (Stabilizer OS 22 from Bayer AG). This low-viscosity solution was used as "Impregn~ting Agent A" in the following examples of application.

Le A 30 972-Foreign Countries 2 1 7 2 0 2 0 Example 3 Plepala~ion of Impregnating Agent B

50 parts of water and 20 parts of isoplopalol are added to 100 parts of the solution plepared according to Example lc). Thereafter 2 parts of a conventional5 commercial polysiloxane polyether (Stabilizer OS 20 from Bayer AG) are admixed. This solution was used as "Impregn~ting Agent B" in the following examples of application.

ExamPle 4 Plepal~ion of Impregnating Agent C

100 parts of the solution prepared according to Example lc) were mixed with 100 parts of a 30 % aqueous silica sol (Levasil~ 300/30 from Bayer AG). There~ler 2 parts of a conventional commercial polysiloxane polyether (Stabilizer OS 22 ofthe Bayer AG Company) were admixed. This solution was used as "Impregnatin~
Agent C" in the following examples of application.

15 Example 5 Application A 100 x 19 x 0.5 cm strip of a polyether-based polyurethane flexible foam with abulk density of 20 kg/m3 was intensively sprayed from both sides with "Impre~n~tin~ Agent A". Thereafter drying at 90C overnight (about 14 hours) 20 was carried out. After drying, the foamed plastic showed a weight increase of100 g. The impregnated foamed plastic strip remained elastic even after the impregnation and after compression had an unchanged recovery capacity.

The impregnated foamed plastic was subjected to the flammability test according to DIN 4102, part 1, wherein it was given the classification B 1 (flame-retardant).
25 During the flamin~ only very little smoke generation was noticeable. Before the impregnation the foamed plastic had a very easy flammability and the foamed plastic burnt with a very sooty flame with intense smoke generation.

Le A 30 972-Foreign Countries 2 1 7 2 0 2 0 ~ 1 1 -Example 6 Application On two 30 cm x 30 cm x 8 cm pieces of a polyether-based polyurethane flexible foam with a bulk density of 20 kg/m3, the "Impregn~ting Agent A" was applied by 5 brush to one edge and one surface of each. After drying (S hours, 60C, air-circ~ ting oven), each foamed plastic piece had a weight increase of 50 g as a result of the impregnation. The foamed-plastic cushions remained permanently elastic, even after impregnation.

For the simulation of an upholstered seat, the two impregnated foamed plastic 10 pieces were positioned at an angle of 90 so that the coated surfaces and edges abutted and represented seat and backrest. In imitation of the paper pad test according to DIN 54 341, a ball of newspaper of about 50 g was laid in the anglebetween "backrest" and "seat" and ignited. In this test the flame died completely after about 8 mim1tes; the lateral edges were not reached by the flame front.

15 Example 7 Application On a molded foam seat of flexible polyurethane foam of bulk density 45 kg/m3, the "Impregn~ting Agent B" was applied with a spray gun to the seat surface.
After drying, the increase in weight of the seat amounted to 15 %. The surface 20 was wetted uniformly and after the impregnation the seat had the same seating comfort.

On flaming the seat surface with a Bunsen burner for 3 minutes the molded foam seat did not inflame. Rather, a local incrustation at the flarned places was observed, so that the foam did not continue to burn, also after removal of the 25 flame.

~e A 30 972-Foreign Countries 2 1 7 2 0 2 0 Example 8 (Comparative test for Example 7) Application The molded foam seat used in Example 7 was sprayed with a solution consisting of the reaction product lc) and water in the ratio 1:1. In the course of this trial a 5 part of the impregn~tin~ liquid formed beads by water repellency. The impregnation was not uniform, as a result of which hardened places appeared on the surface which impaired the seating comfort.

On flaming with a Bunsen burner, the flarne penetrated after about 1 minute and resulted in continued combustion of the foamed plastic even after removal of the10 flame.

Example 9 Application A polystyrene particle foam sheet, 30 cm x 30 cm x 1 cm, was coated on one half of the surface with the "Impregn~ting Agent B". The thickness of the coating 15 after drying amounted to 1 mm.

On flaming of the sheet with a Bunsen burner at full flame for 20 seconds, only a local incrustation of the surface was observed, the back of the foamed plastic remaining undamaged.

If the surface of the untreated part of the sheet was approached with the flame,20 however, the foamed plastic melted through on the first contact and dripped away, burning.

Example 10 Application An "endless" glass-fiber veil, 20 cm wide and 1 mm thick, was impregn~ted with 25 the "Impregnating Agent A" by dipping and thereafter dried. A flexible bandage, about 1 mm thick, was obtained.

Le A 30 972-Forei~n Countries ~ 1 7 2 0 2 `~ - 13 -The bandage so obtained was wound in 2 layers a round a paçl~ging container of polystyrene foam as used for the impact and transport protection of glass bottles.
The wall thickness of the container was 1.5 cm.

The wrapped container was flamed with a Bunsen burner at full flame and the 5 internal temperature measured with a thermometer during the flaming. After 10 mimltes flaming the internal temperature in this test was 40C, while after 21 minutes 80C was reached.

Such paç~gings are suitable for the transport of temperature-sensitive goods, for example as parlr~ging for ~mmllnition 10 Example 11 Application A 40 cm x 40 cm x 10 cm polyurethane rigid foam slab with a bulk density of 30 kg/m3 was coated on both sides with the "Impregn~ting Agent C". A 400 cm x 400 cm x 1 mm steel sheet was applied flush to each of the two coated sides 15 and this composite structure dried at 90C for 1 hour.

A steel sheet/rigid foam sandwich structure was obtained with a 1 mm thick bonding layer of the dried mass of the "Impregn~ting Agent C". Similar sandwich elements are used in the construction sector as in~ ting curtain facades.

The element produced according to Example 11 was installed in a wall opening in 20 a small-fire furnace according to DrN 4102 and flamed according to the standard temperature curve. After 90 min~ltes, on the side of the element remote from thefire, at the center of the element, a temperature difference of 110C was measured.

Example 12 Application 25 The "Impregn~ting agent A" was charged to a trough. A 20 cm x 20 cm sheet, 1 cm thick, of a hydrophilic rigid foamed plastic according to DE 24 41 843 was laid on the surface of the impregnating agent solution. After about 10 min~ltes the Le A 30 972-Foreign Countries 2 1 7 2 0 2 0 foamed plastic sheet, as a result of its hydrophilic character and the suction pressure, had become saturated with the "Impregn~ting Agent A". The sheet was then dried and had gained 10 times its own weight.

This sheet was flamed on one side with a Bunsen burner at full flame for 5 5 mim~tes. After the end of the fl~ming the back of the foamed plastic was still nd~nn~ed and the temperature on the side remote from the flame opposite the tip of the flame cone had risen to 60C.

Example 13 Application 10 A polyurethane flexible foam with a bulk density of 16 kg/m3 and with dimensions 7 x 21 x 1.7 cm was impregnated with a mixture of 30 parts of Impregn~tin~ Agent "A" and 10 parts of a 50 wt.% aqueous ethylene vinyl acetate dispersion (Vimapas EU 25 from the Wacker Chemie Company). After drying for more than 1 hour at 90C, the foamed plastic showed a weight increase of 13 %.

15 This impregnated foamed plastic was flamed for 3 minutes with a Bunsen burner at full flame at a distance of 4 cm.

During the flaming a ceramized foam developed, which prevented the passage of flame. The back of the foam remained intact. No ~lelbullling occurred.

It will be understood that the specification and examples are illustrative but not 20 limitative of the present invention and that other embodiments within the spirit and scope of the invention will suggest themselves to those skilled in the art.

Claims (12)

1. A halogen-free impregnating agent for improving the flame resistance of a foamed plastic, textile or nonwoven fabric, comprising an aqueous solution containing a surface active agent and the reaction product of a) 1 molar amount of an aluminum compound, b) 2 to 5 molar amounts of a phosphorous-containing acid, c) 0 to 9 molar amounts of a boron-containing acid, and d) 2 to 9 molar amounts of ammonia or an amine.

2. An impregnating agent according to claim 1, wherein the surface active agent comprises a water-soluble polysiloxane polyether present in about 0.1 to 5 wt.% relative to the reaction product.

3. An impregnating agent according to claim 1, wherein the aluminum compound comprises at least one member selected from the group consisting of a hydroxide, oxide, hydrous oxide and carbonate of aluminum.

4. An impregnating agent according to claim 1, wherein the phosphorus-containing acid comprises at least one member selected from the group consisting of ortho-phosphoric acid, meta-phosphoric acid, pyro-phosphoric acid, a polyphosphoric acid, a phosphonic acid and a phosphinic acid.

5. An impregnating agent according to claim 1, wherein boron-containing acid comprises at least one of orthoboric acid and a boron oxide.

6. An impregnating agent according to claim 1, wherein (d) comprises an alkanolamine.

7. An impregnating agent according to claim 1, further containing about 1 to 50 wt.% of a water-soluble organic solvent.

8. An impregnating agent according to claim 1, further containing about 10 to 50 wt.% of a film-forming polymer dispersed therein.

9. An impregnating agent according to claim 1, further containing 5 to 50 wt.% of silica sol colloidally dispersed therein.

10. An impregnating agent according to claim 3, wherein the surface active agent comprises a water-soluble polysiloxane polyether present in about 1 to 5 wt.% relative to the reaction product, the phosphorous containing acid comprises at least one member selected from the group consisting of ortho-phosphoric acid, meta-phosphoric acid, a phosphoric acid and a phosphinic acid, the boron containing acid comprises at least one of orthoboric acid and a boron oxide, (d) comprises an alkanolamine, the solution further containing about 5 to 30 wt.% of a water-soluble organic solvent and dispersed therein about 10 to 50 wt.% of at least one of an ethylene-vinyl acetate copolymer and a polyurethane, and silica sol.

11. A method for increasing the flame resistance of a foamed plastic, textile or nonwoven fabric which comprises applying thereto an amount effective therefor of a composition according to any one of claims 1 to 10.

12. A flame resistant foamed plastic textile or nonwoven fabric produced by the process of claim 11.