NO118852B - - Google Patents

Description

Process for the production of polymeric adducts suitable as flame retardants for textile materials.

The present invention relates to cross-linked, liquid or solid adducts, which contain phosphorus, nitrogen and bromine in the form of stable chemical components, and which are particularly suitable for use as flame retardants for organic textiles.

Another invention by the same inventor relates to various polymers capable of being produced by condensation and/or esterification reactions comprising tetrakis-(hydroxymethyl)phosphonium chloride

((HOCH2)4PCl, which is abbreviated to THPC in the following) and/or tris(hydroxymethyl)phosphine oxide ((HOCH2)3PO, abbreviated to THPO), whose methylol-phosphorus groups (i.e. PCH2OH ) has the ability to (1) be condensed with a compound capable of condensing with formaldehyde and (2) to be esterified with an esterifying agent capable of esterifying methanol.

The term "phosphorus compounds" is used in the following only with reference to compounds of the group THPO, THPC and other salts, or their derivatives containing several methylol-phosphorus groups.

Adducts capable of being produced by condensation and/or esterification of the phosphorus compounds can be produced in the form of cross-linked polymers or thermosetting resins. In the following, these adducts are referred to by the expression "methylol-phosphorus" adducts, polymers or resins, and they are characterized by having structural units containing phosphorus atoms in radicals of the group (-CH0)4PC1 and (-CH2)3PO.

Methylol phosphoralkyds are prepared by esterifying at least one of the phosphorus compounds with at least one polycarboxylic acid or an ester-forming derivative. Phenolic methylol phosphorus polymers are prepared by condensing at least one of the phosphorus compounds with at least one phenolic compound.

The methylol-phosphorus resins can be reacted to form additional compounds. For example a further polymerizable adduct prepared from THPC and a nitrilo compound such as melamine can be reacted with a phenolic compound such as bromohydroquinone to give a methylol-phosphorus polymer containing chemically bonded residues of melamine and bromohydroquinone. Also a further polymerizable adduct of THPO can be reacted, e.g. a polycarboxylic acid ester-forming derivative such as phthalic anhydride to give a methylol-phosphorus polymer containing chemically bonded residues of melamine and phthalic acid. Certain nitrogen-containing methylol phosphorous adducts, which are hereinafter referred to as "nitrilo" methylol phosphorous adducts, are particularly useful as flame retardants for textiles. These adducts can be used to impregnate textiles and exist in the textile as a partially formed thermosetting resin or fully formed cross-linked polymer; e.g. the cross-linked polymer can be formed by impregnating the textile with an aqueous solution or dispersion of polymer-forming reactants, causing the reactants to react in situ until the insoluble polymer is produced. The nitrilo-methylol phosphorus adducts can be prepared by condensing at least one of the phosphorus compounds, by elimination of water, with at least one organic nitrogen compound having a molecular weight of not more than about 800, and contains at least one trivalent nitrogen atom and several reactive groups which are H and/or CH2OH group-bonded to trivalent nitrogen atoms. These organic nitrogen compounds are hereinafter referred to as "nitrogen compounds". The methods for the production of nitrilomethylol-phosphorus adducts and always their use as flame retardants for textiles are more fully described in the inventor's British patent 761 985, TJ. S. patent 2 772/188 and Norwegian patent 88 957. The nitrilomethylol phosphorus polymers can be completely reacted to form cross-linked phosphorus and nitrogen containing polymers having structural units each containing a phosphorus atom in a radical such as (-CH2)4PC1 and (-CH2)3PO, bound to at least two trivalent nitrogen atoms of divalent groups such as alkylene groups e.g. -CH2- and ether groups, e.g. -CR2OCR2-, where R is a hydrogen atom or alkyl radical.

Although the nitrilomethylol-phosphorus polymers are particularly good textile flame retardants, an agent which could induce the same degree of flame resistance with a smaller amount by weight of the agent would be strongly desired.

An object of the present invention is to provide a resin-like, flame-retardant impregnating agent which retains the beneficial effects of the nitrilo-methylol-phosphorus adducts in that it causes only a small reduction of the desired textile properties such as grip, sensitivity, tear strength and the like , while at the same time imparting to them an absolutely greater degree of flame resistance per part resin-like impregnating agent.

Until now, the effectiveness as a flame retardant of the nitrilomethylol-phosphorus adducts (magnitude of flame resistance reported per unit weight of impregnating agent) seemed essentially to be completely dependent on the conditions and total amounts of nitrogen and phosphorus in the adducts. The presence or absence of halogen appeared to have little, if any, effect on this efficiency, e.g. a nitrilo-methylol-phosphorus adduct containing approx. 1 to 12 percent chlorine showed essentially the same effectiveness as a similar but essentially halogen-free adduct.

It is now recognized that nitrilomethylol-phosphorus adducts within certain ranges of nitrogen and phosphorus content and conditions, and also containing a certain amount of fixed bromine are, with respect to weight, more effective flame retardants than similar adducts, whose composition only differs in the absence of the bromine.

In accordance with the present invention, the aforementioned adducts are now produced by reacting a phosphorus-containing compound with a nitrogen-containing compound and a bromine-containing compound and continuing the reaction until essentially all reaction participants are combined and form a homogeneous polymer and characteristic of the method is that the phosphorus-containing compound is a polymethylol derivative of phosphonium chloride, phosphonium oxide or one of their salts and the nitrogen-containing compound has a molecular weight below 800 and contains trivalent nitrogen and several reactive groups, which are hydrogen atoms and/or methylol groups and/or terminally unsaturated alkylene radicals, all of which are bound to a trivalent nitrogen atom, and that the bromine-containing compound is a polyfunctional compound that has the ability to condense with formaldehyde and/or esterify methanol and contains bromine bound to carbon, and that the reaction participants are selected such that they comprise at least 1 .0 percent phosphorus ti lpresent in a phosphonium radical and for each part of phosphorus 0.5 to 20 parts of nitrogen in the nitrogenous compound and 0.3 to 15 parts of bromine bound to carbon, and that the reaction is preferably carried out in the presence of a lower aliphatic aldehyde, e.g. formaldehyde.

Compounds with the ability to condense with formaldehyde or esterify with methanol are designated in the following description with the term "Methylol-reactive compounds". In the definition before and in the following part of the present presentation and subsequent claims, all indications regarding parts and percentages are related to weight.

The reaction participants from which bromine-containing nitrilomethylol-phosphorus adducts are produced can be monomers and/or polymeric adducts. For example the initial reaction mixture (i.e. the mixture of the reaction participants) may contain

(1) THPC, melamine and 2,4-dibromohydroquinone, and (2) an additional polymerizable THPC urea polymer and 2,3-dibromosuccinic acid (the phosphorus compound is pre-reacted with the nitrogen compound), (3) THPO and a partial brominated diallylmelamine (the nitrogen compound is pre-reacted with the bromine compound), (4) an additional polymerizable THPO-2,4-dibromohydroquinone polymer and an additional polymerizable melamine THPC-2,3-dibromosuccinic acid polymer (a phosphorus compound pre-reacted with a bromine compound, and a nitrogen compound pre-reacted with a phosphorus compound and a bromine compound (5) a bromine derivative of THPC or THPO and THPC and melamine or methylolmelamine, or any other combination of these or other suitable reactants, and in all cases the amounts are so chosen for to provide the specified quantities and ratios for phosphorus, nitrogen and bromine.

The bromine-containing nitrilomethylol-phosphorus adducts according to the present invention can be produced in the form of liquid or solid polymers. When completely reacted, the adducts are homogeneous, cross-linked polymers characterized by a particularly high resistance to combustion and the property of imparting a particularly high flame resistance to other materials. In liquid form, they are soluble or dispersible in water and can be converted into solid form either by heating to a moderately elevated temperature, or by reaction with ammonia at temperatures below approx. 30° C. In their insoluble, solid form, they are highly resistant to attack by dilute acids, bases and organic solvents. These polymers are generally applicable for any purpose where cross-linked polymers are usable, e.g. in the production of molded synthetic plastic articles such as buttons, containers and electrical insulators, synthetic coatings such as paints and varnishes, adhesives and impregnation agents, e.g. for textiles, ropes and paper.

Textiles impregnated with a liquid containing nitrilomethylol-phosphorus-resin-forming materials are preferably dried by heating them to approx. 60 to 125°C for 2 to 15 minutes (low temperatures take longer) to evaporate any volatile material. Insolubility of ni-tvilomethylol phosphor resin-forming materials can be induced by heating textiles containing them to a temperature of approx. 125 to 170° C for approx. 2 to 15 minutes (low temperatures — longer time), or by reacting the resin-forming materials in situ in the fabric with ammonia, preferably by the process described in U.S. Pat. patent No. 2,772,188.

The nitrilomethylol-phosphorus adducts containing bromine are particularly suitable for use as flame retardants when impregnating organic textiles. These adducts can be advantageously used in the treatment of vegetable textile materials such as cotton wool, flax, linen and ramie, chemically modified vegetable textile materials such as cyano-tylated, carboxymethylated and aminoethylated cottons, semi-synthetic cellulose textiles such as viscose or acetate rayons , and protein-containing textiles such as these and wool. These textile materials can be suitably processed in the form of loose fibres, yarns, threads or fabrics. The adducts can be formed before application or can be produced in situ in the textile. The textiles can be impregnated with the new adducts in any form, alone or in conjunction with other textile fire-proofing, creasing-proofing and other textile treatment agents, or in connection with a textile lubricant, water-repellent or other textile treatment agents.

A useful process for the preparation of bromine-containing nitrilomethylol phosphorus adducts consists of condensing at least one phosphorus compound which can be dissolved in an aqueous solution of sodium carbonate to give a solution THPO (ie THPC, THPO, or mixtures thereof) with at least one organic nitrogen compound (ie, an organic nitrogen compound having a molecular weight of less than 800 and containing multiple nitrilo N-bonded hydrogen atoms or methylol groups) containing sufficient bromine atoms bonded to carbon atoms to give from about 0.5 to 10 parts bromine per part nitrogen, and use of the reaction participants in such quantities that they

the mixed reaction participants contain

at least approx. 1 percent phosphorus present in the phosphorus compounds, and continuation of the reaction until essentially all the reaction participants are bound together.

The molar ratios of such phosphorus compounds to such nitrogen compounds, which give mixtures of the reactants in the amounts indicated, vary greatly depending on (a) the amount of phosphorus, nitrogen and bromine present in the reactants and desired in the adduct, and (b) the amount of methylol-reactive functional groups contained in the nitrogen compound. However, by knowing the structures of the reaction participants, the desired molar ratios of the reaction participants can be calculated, or a simple series of trial reactions can be carried out under the desired reaction conditions for the same purpose. The reaction participants can be assumed to be bound together by means of their respective functional groups as follows:

Another applicable method for producing the nitrilomethylol-phosphorus adducts containing bromine comprises the condensation of at least one further polymerizable nitrilomethylol-phosphorus adduct still containing several of the methylol-phosphorus groups originally in the parent phosphorus compound, with at least one further polymerizable methylol-phosphorus compound also containing several methylol-phosphorus groups, but in addition several bromine atoms bound to the carbon atoms, using the desired conditions of the reaction participants. When the textiles or similar materials are impregnated, the textile is advantageously impregnated with the further polymerizable adducts and the adducts are then reacted in situ.

In a further method, the bromine-containing nitrilo-methylol-phosphorus adducts can be prepared by condensing bromine derivatives of THPC or THPO with nitrilo compounds (e.g. melamine, methylolmelamine or carbamide). When the textiles or similar materials are impregnated, the textile is advantageously impregnated with the monomers which are reacted in situ.

The phosphorus compounds which can be used in the method according to the invention include THPC, THPO and compounds derived from each of them which contain several methylol-phosphorus groups from the parent compounds. These derivatives can be obtained by reacting THPC, THPO or a mixture of these with a suitable compound until some, but not all, of the methylol-phosphorus groups in THPC or THPO have reacted. The phosphorus compounds can be monomers in which several methylol-phosphorus groups are bound to a single phosphorus atom or further polymerisable polymers, preferably oligomers in which some or all of several methylol-phosphorus groups are bound to different phosphorus atoms in the polymeric molecules.

Although the phosphonium salts are usually derived from phosphonium chloride, other phosphonium salts can also be used, e.g. the analog phosphate

or of phosphonium salts of acids other than hydrochloric acid, acetic acid or phosphoric acid. Bromomethyl derivatives of the phosphorus compounds, such as where R means CH2Br or CH,OH, are particularly suitable phosphorus compounds for use in the present process. It is recognized that new compounds are produced by partial halogenation of phosphorus compounds such as THPC, THPO and mixtures of these with hydrobromic or hydrochloric acids until some, but not all, of the OH parts in the PCH2OH groups are replaced by halogen atoms. The partial halides thus prepared are compounds of the group

where R means CH2OH or CH2X the radical I and X means a bromine or chlorine atom. Such compounds contain halomethyl- and me-

tyrol groups as well as phosphine oxide or phosphonium chloride and are useful in some applications, e.g. in the manufacture of

lubricating oil additives, insecticides and in the reactions when it is desired to connect phosphorus and halogen with methylol-reactive compounds. Suitable halogenating agents which can be used to prepare these compounds include hydrobromic acid, phosphorus pentachloride, phosphorus pentabromide, phosphorus trichloride and phosphorus tribromide. The reaction can be carried out in the usual way using usual apparatus, solvents and catalysts, where desired. Preferably, the phosphorus compound is brominated only until the resulting compounds contain both PCH2Br and at least two PCH,OH groups.

Other suitable phosphorus compounds can be prepared by partial reaction of THPO, THPC or other salt with an analogous organic nitrilo compound containing only one H atom or CH,OH group bonded to a trivalent nitrogen atom. Examples of such nitrilo compounds include open-chain polyamines such as N,N,N'-trimethyl-ethylenediamine, alicyclic amines such as N-butyl-cyclohexylamine, aromatic amines such as mesitylene and pyrrole, aliphatic amines such as diethanolamine, amides such as N-allyl-acryl- amide, amino acids N-methylglycine, and the analogs of any such nitrilo compound containing one or more bromine atoms attached to another carbon atom.

Examples of suitable polyfunctional methylol-reactive compounds capable of condensing with formaldehyde include polyamines such as ethylenediamine and tetramethylenepentamine, alicyclic amines such as cyclohexylamine, cyclopentamine and methylolated cyclohexylamines, aromatic amines such as phenylamine and phenyldlamine, imines such as ethyleneimine and polymers of ethyleneimine, amido compounds such as melamine, guanidine, carbamide, and alkylated and methylated homologs, analogs, amides such as acrylamide and cyanamide, amino acids such as glycine, lysine, and arginine, and bromo analogs of any such organic nitrilo compound. These compounds can, when appropriate, be used as polyfunctional nitrogen compounds, reactants for partial reaction with THPC or THPO to give phosphorus compounds containing nitrilo group, and as methylol-reactive compounds containing bromine for the preparation of nitrilomethylol-phosphorus adducts containing bromine.

Examples of polyfunctional methylol-reactive compounds that will condense with formaldehyde also include phenols, naphthols, and halogen and/or carbon-substituted phenols and naphthols, such as phenol, itself, vinylphenol, resorcinol, catechol, hydroquinone, phloroglucinol, p-tertiary amyl -phenol, allylphenol, ortho-bromophenol, bromohydroquinone and 2,4-dibromo-l-naphthol. Any of these compounds can be partially reacted with THPO, THPC or other salts, and their derivatives to give a monomeric or polymeric aromatic compound which, if it contains more than one methylol-phosphorus group, is suitable as a phosphorus compound for use in the process according to the invention.

Examples of polyfunctional methylol-reactive compounds that will esterify methyl alcohol include saturated aliphatic polycarboxylic acids such as oxalic, malonic, methylsuccinic, malic, tartaric and citric acids, unsaturated aliphatic polycarboxylic acids such as maleic, itaconic and aconitic, alicyclic polycarboxylic acids such as abietin -, homoabietinic and hexahydrophthalic acids, aromatic polycarboxylic acids such as phthalic-benzene-tricarboxylic-, diphenyl- and "chlorendic"- (Ullman 1954, V, p. 486 840) acids, polycarboxylic acid anhydrides such as succinic, maleic- , phthalic and chlorine anhydrides and polycarboxylic acid halides such as the oxalyl, succinyl and phthalyl halides. Any of these esterifying agents can be partially reacted with THPO, THPC and other salts, or their derivatives to give monomeric or polymeric compounds which, if they contain at least two methylol phosphorus groups, are suitable phosphorus compounds for use in the process of the invention.

Particularly suitable nitrogen compounds (suitable either as a polyfunctional methylol reacting compound used in the preparation of a nitrilomethylol phosphorus polymer containing bromine, or as a compound in which THPO, THPC or another salt, or derivative, is reacted to give a phosphorus compound containing a nitrilo group) are the derivatives of N-alkenylated melamines containing at least one bromine atom bound to a carbon atom and at least two reactive groups which can be H or CH2OH bound to a trivalent nitrogen atom.

The N-alkenylmelamines are compounds of the formula where R is hydrogen or a methylol, alkyl or alkenyl radical, and at least one R is an alkenyl radical. Alkenylated melamines in which the alkenyl radicals are terminally unsaturated radicals of from 2 to 6 carbon atoms are preferred and those in which the alkenyl radicals are terminally unsaturated allyl radicals are particularly preferred. Examples of suitable N-alkenylated melamines include melamines in which from 1 to 5 of the N-bonded hydrogen atoms have been replaced by allyl radicals, metallyl radicals and 4-pentenyl radicals, and the methylol derivatives of such alkenylated melamines.

For example certain N-alkenylated melamines containing at least one bromine atom attached to a carbon atom and at least 2 members of the group H and CH„OH can be prepared by brominating a suitable N-alkenylated melamine (i.e. one containing at least two members of the group , H and CH2OH bound to the nitrogen atoms). Such melamine derivatives can be brominated using usual methods and apparatus for the bromination of N-alkenylamino compounds, e.g. by dissolving the amino compound in an organic solvent, and then adding the stoichiometric amount of bromine. Examples of such derivatives include N,N-bis(2,3-dibromopropyl)melamine and 1,2-dibromopropionamide.

The addition products of N-alkenylated melamines containing at least two members of the group H and CH2OH bonded to trivalent nitrogen atoms, and a bromine-containing polyhalo C, , carbon hydrogen containing at least two atoms of the group Cl and Br bonded to the same carbon atom are also suitable for use in the present invention.

New adducts of N-alkenylated melamines are prepared by an additional reaction between at least one compound of polymerizable N-alkenylated melamine, with a polyhalocarbon hydrogen with reactivity by addition of an olefin, and, if desired, a lower aliphatic aldehyde. These addition reactions can be induced by a catalyst of the Friedel-Crafts type or by a free radical reaction inducer, and the latter is preferred. The reaction can be carried out in an aqueous, water-soluble or water-insoluble, organic, liquid reaction medium. The adducts are liquid or solid monomers or polymers, and the latter are particularly useful, especially when they are produced in the form of an aqueous emulsion, as fire retardants for textiles. The polyhalocarbon hydrogen

should be able to enter into the reaction illustrated by

compounds with the formula

where X means an atom of the group bromine and chlorine, and Y means an atom of the group bromine, chlorine, and hydrogen is preferred. Any aldehyde capable of forming an amino ester resin is suitable, but formaldehyde is preferred.

Where the adducts contain bromine and are derived from an N-alkenylated melamine containing at least two H or CH2OH groups bound to a trivalent nitrogen atom, they are particularly suitable for use in the method according to the invention.

Other bromine-containing nitrogen compounds which are suitable are polymeric adducts prepared from an aliphatic acrylamide containing at least one group of the formula

and which has at least two reactive groups, which can be H and/or CH2OH groups, bound to trivalent nitrogen atoms, and (as before) a polycarbon-hydrogen containing bromine and containing at least two atoms of the group, bromine and chlorine, bonded to the same carbon atom. New adducts are produced by an addition reaction between at least one compound of the formula where R is a hydrogen atom, an alkyl radical, a methylol radical or a radical of the formula

and a polyhalocarbon hydrogen as defined above, and, if desired, a lower aliphatic aldehyde. Preferably, polyhalocarbon hydrogen and the aldehyde reaction participants specified above are used.

These additional reactions can be induced by a catalyst of the Friedel-Crafts type or preferably by a free radical reaction inducer. The reaction can be carried out in an aqueous liquid, a water-soluble or, rather, water-insoluble organic liquid reaction medium. The adducts are liquid or solid polymeric compounds, and are particularly useful when prepared in the form of an aqueous emulsion, as textile fire retardants.

Free radical reaction initiators which can be used to initiate the aforementioned additional reactions include essentially any compound which is believed to be decomposed to give free radicals under the influence of heat, light or almost elemental particles formed during the reaction, e.g. e.g. peroxides such as dibenzoyl peroxide, di-tertiary butyl peroxide and hydrogen peroxide, alkali metal persulfates, benzoyl hydroperoxide, cumene hydroperoxide and other hydroperoxides, azo compounds such as 2,2'-bisazoisobutyronitrile and ketones in connection with actinic light. Peroxides are preferably used, and water-soluble peroxides are preferred when the reaction is carried out in an aqueous medium.

Preferred polymeric N-alkenylated melamine or aliphatic acrylamide-polyhalocarbon hydrogen adducts are prepared by reaction with a polyhalomethane of the formula CX 2 Y 2 in which X represents bromine or chlorine atoms and Y represents bromine, chlorine or hydrogen atoms, e.g. compounds of the formula; CBr4, CBr.^Cl, CBr2Cl9, CBr3H, CBr2H2, CC14, CClgH and CCl2H2.~Polyhalomethanes containing at least two bromine atoms, e.g. CBr4, CBr3Cl, CBr2Cl2 and CBrCl3 are particularly suitable.

In reactions between bromine-containing polymeric N-alkenylated melamine or aliphatic acrylamide-polyhalogen carbon hydrogen adducts and THPC, THPO, other salts or their derivatives, to produce a nitrilo group and a phosphorus compound containing bromine, the amount of the reaction participants can be greatly varied, and the reaction can is carried out in the presence or absence of catalysts and/or solvents, although an aqueous reaction medium and the absence of a catalyst is preferred. The polymeric adducts can be isolated by usual methods for isolating polymers, unless the raw adduct mixture is to be used in and of itself, without further purification, e.g. in an aqueous emulsion.

These polymeric adducts, especially those containing relatively large amounts of bromine, are particularly useful as reaction participants from which nitrilomethylol phosphortextile flame retardants containing bromine are prepared. A particularly effective method for treating textiles with such polymers comprises impregnating the textile with (1) an emulsion capable of being produced by reacting a polyhalomethane and an N-alkenylated melamine or an aliphatic acrylamide in the presence of a free radical reaction initiator in a aqueous emulsion containing the reactants, water and a small but effective amount of an emulsifier, and also with (2) an aqueous solution or emulsion of a monomeric phosphorus compound capable of dissolving in aqueous sodium carbonate to give solutions of THPO and/or a phosphorus compound derivative with a high nitrogen and phosphorus content containing a nitrilo group and heated from such impregnated textile to a moderately elevated temperature to give nitrilomethylol phosphorus polymer containing bromine in situ in the textile.

The following examples are given for the purpose of further illustrating the invention. All parts and percentages refer to weight.

In the examples, the flame resistance of the different resin-impregnated substances is compared using the "strip flame test" method. With this method, a fabric strip is supported, which is approx. half an inch wide and approx. 3 inches long, at one end so that the strip extends in some direction between 0 to 180 to a vertical azimuth. The unsupported end of the strip is ignited by bringing it into contact with a flame until the fabric begins to burn. As soon as the substance is ignited, the ignition flame is removed. The flammability of the substances is compared on the basis that when supported and ignited in this way, the substances have a far greater tendency to burn when they extend straight down and ignite at the bottom. Untreated cellulosic fabric will fail at 0 degrees (ie will burn when supported vertically and ignited at the top). A highly flame resistant fabric will pass 180° (ie will not burn even when supported vertically and ignited at the bottom). And, a relatively flame-resistant material will not fail except in some position between about 90 and 180° (ie when supported somewhat obliquely so that the flame develops at least somewhat upwards). In cases where the substance passes 180°, note the number of seconds it continues to burn after the ignition flame is removed, and the most flame-resistant substance will only burn for a few seconds.

Example 1:

A polymeric adduct of a polyhalomethane and an N-alkenylated melamine.

10.4 parts of N,N'-diallylmelamine are dissolved in 83.0 parts of water containing 20 parts (37 per cent) of formaldehyde, 0.6 parts of polyvinyl alcohol and 1.2 parts of NaHCO 3 . The resulting dispersion, which had a pH of 8.0, was heated and stirred to aid in the dissolution of the diallyl melamine. When the temperature reached 80°C, 27.0 parts of CHBr 3 were added and an emulsion was formed. 0.6 parts of K 2 S 2 O 8 were added as a catalyst, after which the pH dropped to 7.0, so that a further 1.2 parts of NaHCO 3 were added. The emulsion was stirred for 1 hour, while the temperature was maintained at 80-83°C to give a milky, white, free-flowing, stable emulsion consisting of a polymer adduct containing nitrogen and bromine dispersed in an aqueous medium having a pH between 7 and 8.

Example 2:

A nitrilomethylol phosphorus adduct containing bromine produced in situ on a textile and comparison of its flame-retardant properties with those of the preparation according to e.g. 1

A sample of 225 gr. twill was immersed in the emulsion prepared according to example 1, and the wet absorption was 64.2%. The sample was dried for 6 minutes at 100° C., ripened for 6 minutes at 140° C., rinsed in water and dried, after which the resin absorption was 7.0% .This sample only passed the 45° flame test.

Another sample 225 gr. twill was treated with an aqueous solution containing 25 parts of the emulsion prepared in Example 1 and 75 parts of a THPC resin-forming reaction mixture (containing 15.7 percent THPC, 10.0 percent water-soluble methylolmelamine, 10.0 percent carbamide and 3.0% triethanolamine), and the wet absorption was 66.3%. After drying for 6 minutes at 100° C, ripening for 6 minutes at 140° C, rinsing in water and drying, the resin absorption was 16.9%. The test passed the 180° strip flame test and also the match test.

Example 3:

A nitrilomethylol phosphorus adduct containing bromine prepared from a brominated diallylmelamine, THPC and methylolmelamine.

A brominated diallylmelamine was prepared by dissolving 10.3 parts diallylmelamine in 50 parts glacial acetic acid and slowly adding a solution of 16 parts bromine in 50 parts glacial acetic acid. After cooling the resulting solution, a heavy, white precipitate formed, which was filtered off and washed with acetone. About. 20 parts of a crystalline brominated diallylmelamine, which melts above 230°C (under decomposition) were prepared. A neutral aqueous solution of the brominated diallylmelamine was prepared by dissolving 10 parts of the above compound in 20 parts of an aqueous 37% formaldehyde solution and neutralizing with sodium carbonate. A textile impregnating solution was prepared by mixing this solution of diallylmelamine with a solution of 38 parts THPC, 24 parts water-soluble methylolmelamine, 24 parts carbamide and 6 parts triethanolamine in 150 parts water.

Samples of a 225 gr. cotton twill and of 240 gr. bromo wool satin was immersed in the aforementioned textile treatment solution, and then dried for 6 min. at 90° C., ripened for 16 minutes at 140° C., washed and dried. The impregnated samples, which contained

18 and 10 percent resin respectively, passed

the strip flame test at 180° with approx. 1 more

2 seconds afterflame.

Example 4:

A polymeric adduct of a polyhalogen methane and an aliphatic acrylamide. (a) Prepared in organic solution.

7.1 parts of acrylamide and 27.1 parts of bromoform were dissolved in 100 parts of dioxane and heated with stirring to 80° C, after which 0.5 parts of benzoyl peroxide were added and the heating and stirring continued for 6 hours at 80-85° C, and a bottom-fall was formed. The precipitate was filtered off and washed with acetone to give 9 parts of a dry white powder polymer adduct containing bromine. The adduct was insoluble in water.

(b) Prepared in aqueous emulsion.

7.1 parts of acrylamide were dissolved in 50 parts of water containing 0.6 parts of polyvinyl alcohol

hol, 15.2 parts of bromoform were added below

stirring so as to form an emulsion which

was heated to 70° C. when 0.6 parts of potassium persulfate were added. The heating and stirring are continued for 1 hour at approx. 80°C

to give a viscous solution which became completely

in a large volume of alcohol with stirring.

A tough mass was formed and was first washed with fresh alcohol and then with acetone.

After drying in a vacuum oven for 4 hours

obtained 9.0 parts of an amorphous, polymeric

adduct.

Example 5:

A bromine-containing nitrilomethylol phosphorus adduct prepared from a polymer

adduct of a polyhalomethane

and an aliphatic acrylamide.

A polymeric addition product was produced in an aqueous emulsion by the method

described in Example 4 (b) using

7.1 parts acrylamide, 50 parts water, 0.6 parts

polyvinylalcophtol, 27 parts bromoform and

0.6 parts potassium persulfate. The product was a

cloudy, somewhat viscous solution.

A textile impregnating liquid was prepared by mixing 25 parts of the above

solution with 75 parts of an aqueous

THPC resin-forming solution (15.7

% THPC, 10 % Pesloom HP, 10 % carbamide and 2.5 % triethanolamine).

A sample of a 225 gr. cotton twill became

immersed in the above liquid, matured in wood

heating for approx. 6 minutes at 140° C,

washed and dried. The fabric, which had been impregnated with a homogeneous nitrilomethylol-phosphorus polymer containing bromine, showed a

distinct resistance to burning.

Claims (5)

1. Procedure for the production of polymeric adducts, suitable for use as flame retardants for textile materials, consisting of reacting a phosphorus-containing compound with a nitrogen-containing compound and a bromine-containing compound and continuing the reaction until substantially all the reaction participants are combined to form a homogeneous polymer, characterized in that the phosphorus-containing compound is a polymethylol derivative of phosphonium chloride, phosphonium oxide or one of its salts, and the nitrogen-containing compound has a molecular weight below 800 and contains trivalent nitrogen and several reactive groups, which are hydrogen atoms and/or methylol groups and/or terminally unsaturated alkenyl radicals, all of which are bound to a trivalent nitrogen atom, and that the bromine-containing compound is a polyfunctional compound which has the ability to condense with formaldehyde and/or esterify methanol and contains bromine bound to carbon, and that the reaction participants are selected in such a way that they comprise at least 1.0 percent by weight of phosphorus present in a phosphonium radical, and for each part of phosphorus 0.5 to 20 parts of nitrogen in the nitrogen-containing compound and 0.3 to 15 parts of bromine bound to carbon, and that the reaction is preferably carried out in the presence of a lower aliphatic aldehyde, e.g. formaldehyde. 2. Method according to claim 1, characterized in that the bromine-containing compound is a polyhalogen carbon containing 1 or 2 carbon atoms and 2 or more halogen atoms (which are bromine atoms, or bromine and chlorine atoms). 3. Method according to claim 2, characterized in that the bromine-containing compound is bromoform. 4. Method according to any of the preceding claims, characterized in that a polymeric adduct is first formed by reacting the nitrogen-containing compound with the bromine-containing compound, and preferably also with a lower aliphatic aldehyde, after which the resulting polymeric adduct is reacted with the phosphorus compound. 5. Method according to any of the preceding claims, characterized in that the nitrogen-containing compound is melamine or a melamine derivative, preferably diallylmelamine, or acrylonitrile or a derivative of acrylonitrile.