Petersen, Harro (Frankenthal, DT)
Fuchs, Friedrich (Kirchheim, DT)
Scharwaechter, Peter (Ludwigshafen, DT)

05/479893

08/12/1975

06/17/1974

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BASF Aktiengesellschaft

558/83

106/18.140, 558/172, 558/159, 987/160

C07F9/40; D06M13/288; C07F9/00; D06M13/00; C07F9/40

260/937,932,938,970

Sutto, Anton H.

Raymond, Richard L.

Johnston, Keil, Thompson & Shurtleff

We claim

1. A substance of the formula: ##EQU27## in which R¹, R², R³ and R⁴ are identical or different and are alkyl of one to five carbon atoms,

2. A substance as set forth in claim 1 wherein R¹, R³ and R⁴ are unsubstituted alkyl of 1 or 2 carbon atoms, R² is hydrogen, methylol or alkoxymethyl of 1 to 3 carbon atoms, A is linear alkylene of 3 or 5 carbon atoms and X is alkylene of 2 to 4 carbon atoms or alkylene of 2 to 4 carbon atoms containing 1 ether group.

3. A substance as set forth in claim 1 having the formula: ##EQU30##

4. A substance as set forth in claim 1 having the formula: ##EQU31##

5. A substance as set forth in claim 1 having the formula: ##EQU32##

6. A substance as set forth in claim 1 having the formula: ##EQU33##

7. A substance as set forth in claim 1 having the formula: ##EQU34##

8. A substance as set forth in claim 1 having the formula: ##EQU35##

9. A substance as set forth in claim 1 having the formula: ##EQU36##

10. A substance as set forth in claim 1 having the formula: ##EQU37##

11. A substance as set forth in claim 1 having the formula: ##EQU38##

12. A substance as set forth in claim 1 having the formula: ##EQU39##

13. A substance as set forth in claim 1 having the formula: ##EQU40##

14. A substance as set forth in claim 1 having the formula: ##EQU41##

15. A substance as set forth in claim 1 having the formula: ##EQU42##

16. A substance as set forth in claim 1 having the formula: ##EQU43##

The invention relates to certain alkyl esters of N-(dialkylphosphonoalkyl)-carbamic acids, to their use as flameproofing agents for textiles and also to a method of manufacturing them.

It is known that combustible fibrous material, particularly such as contains or consists of cellulose, can be treated with organic substances containing phosphorus to make them flameproof. Tetrahydroxymethylphosphonium chloride (THPC) used in common with aminoplastics and trisaziridinylphosphine oxide (APO) have become particularly well known for this purpose. Both have serious disadvantages. THPC tends to be an odor nuisance, and APO is difficult to handle because of its toxicity.

N-monomethylol and N-dimethylol compounds of dialkyl esters of carbamoylalkanephosphoric acids are known from Belgian Pat. Nos. 647,376 and 713,511. They are recommended therein as flameproofing agents for cellulose. It has been found however that finishes obtained therewith exhibit inadequate resistance to treatments with chlorine. A process for the wash-resistant flameproofing of cellulosic fibrous material is described in German Laid-Open Specification (DOS) No. 1,930,308 according to which the monomethylol or dimethylol compounds of dialkoxyphosphonomonoalkyl carbamates are used as nitrogeneous phosphorus compounds.

These have the disadvantage that they cause stiffening and yellowing.

There are only a very limited number of prior art textile flameproofing agents which are useful in practice; the present invention therefore has as an object the provision of novel outstanding flameproofing agents for textiles.

The invention comprises a flameproofing agent for textiles in which a dialkylphosphonoalkyl ester group is attached to the nitrogen atom of a carbamic acid ester, a process for the production of the same and the use of the same. The substances according to the invention have the general formula: ##EQU1## in which R ¹ , R ² , R ³ and R ⁴ are alkyl of one to five carbon atoms, R ³ and R ⁴ may also be halogenated and particularly chlorinated alkyl or together may be alkylene of two to three carbon atoms, R ² may also be hydrogen, methylol or alkoxymethyl of one to three carbon atoms in the alkoxy, A is linear or branched alkylene of two to eight carbon atoms of which at least two are situated in the chain linking nitrogen and phosphorus and R ¹ may also be a radical of the formula: ##EQU2## or ##EQU3## in which X is linear or branched alkylene of two to eight carbon atoms which may be interrupted by oxygen atoms and R ² , R ³ and R ⁴ have the above meanings.

Particular industrial significance attaches to those substances of the formula (I) in which R ¹ , R ³ and R ⁴ are unsubstituted alkyl preferably of one or two carbon atoms, R ² is hydrogen, methylol or alkoxymethyl of one to three carbon atoms and particularly one carbon atom in the alkoxy, A is linear alkylene of three or four and particularly of three carbon atoms and X is alkylene of two to four carbon atoms which may contain an ether group.

Preferred examples of substances of the formula (I) are: ##EQU4##

Other suitable examples of substances of the formula (I) are: ##EQU5##

The substances of the formula (I) may be prepared according to the process of the invention by reacting a dialkyl ester of phosphorus acid of the formula (IV): ##EQU6## with an olefinically unsaturated carbamic acid ester of the formula (V) or (VI): ##EQU7## in which R ¹ to R ⁴ have the meanings given in formula (I), X has the meanings given in formulae (II) and (III) and R ⁵ , R ⁶ and R ⁷ are hydrogen or alkyl of one or two carbon atoms, D is an alkylene of one to three carbon atoms and n = zero or 1, and the sum of the carbon atoms of D, R ⁵ , R ⁶ and R ⁷ is a maximum of 6, or the formula (VII): ##EQU8## in which R ² , R ⁵ , R ⁶ , R ⁷ , D and n have the same meanings as in formulae (V) and (VI) and R ⁸ , R ⁹ , R ¹⁰ , E and m (if desired, but preferably not, independently thereof) have the same meaning as R ⁵ , R ⁶ , R ⁷ , D and n, and the total number of carbon atoms in E, R ⁸ , R ⁹ and R ¹⁰ like that of D, R ⁵ , R ⁶ and R ⁷ is no more than 6, in the presence of an organic peroxide as catalyst, by heating the mixture to the decomposition temperature of the peroxide, if desired methlolating the product formed with formaldehyde and if desired acetalizing the methylol groups thus introduced with an alkanol of one to three carbon atoms.

In this process it has proved to be suitable to use the dialkyl ester of phosphorous acid (formula (IV)) in excess, for example in from 1.5 to 5 times the molar amount based on the starting material (V). Secondary reactions are suppressed and the yields are improved in this way.

Examples of suitable starting compounds of the formula (V) are substances of the following structures: ##EQU9##

Examples of suitable substances of formula (VI) are: ##EQU10##

Examples of suitable substances of formula (VII) are: ##EQU11##

Any organic peroxide may be used as the catalyst. Examples are ditertiary-butyl peroxide and dibenzoyl peroxide.

The catalyst is conveniently used in an amount of from 0.1 to 10 percent based on the weight of the reaction mixture.

The starting materials (IV) and (V), (VI) or (VII) are generally reacted by simple mixing, adding the catalyst and heating the mixture. The reaction temperature depends on the type of peroxide and may easily be ascertained by preliminary experiment. As a rule it is within the range from 90° to 180°C. The reaction is usually over in thirty to ninety minutes. The reaction may be carried out in the presence of an inert solvent. The products obtained may if desired by reacted by a conventional method in an alkaline medium with formaldehyde to form the corresponding methylol compounds. These may then be acetalized by a conventional method in the presence of an acid catalyst with an alkanol of one to three carbon atoms. The optional steps of methylolation and acetalization may for example be carried out as follows:

For methylolation the substance obtained by reaction of the components (IV) and (V), (VI) or (VII) is mixed with formaldehyde in a molar ratio corresponding to the desired degree of methylolation. A basic substance, for example an alkali metal hydroxide, is added to the mixture until the pH is from 8 to 11 and preferably from 9 to 10. After the exothermic reaction is over the methylol compound formed is neutralized.

For acetalization it has proved to be suitable to dissolve the methylol compound in the alkanol provided for the acetalization, to add to the solution a catalytic amount of an acid and preferably of a strong acid, to heat the mixture until the acetalization reaction is over and then to neutralize the product. The excess alkanol may then be removed by distillation.

The substance of formula (I) may be used with very good results as a flameproofing agent for textile material and particularly for textile material which contains or consists of natural or regenerated cellulose. It has proved to be advantageous to add an aminoplast-forming substance to the finishing liquor to achive a finish which is durable to laundering. Suitable aminoplast-forming substances include all methylol and alkoxymethyl compounds of acyclic and cyclic ureas, for example of urea, thiourea, ethylenurea, propylenurea, glyoxalmonoureine, triazinones and urones, of monocarbamic acid dicarbamic esters, cyanamide and dicyanamide and also aminotriazines and preferably the methylol and methoxymethyl compounds of melamine. In the case of compounds of formula (I) in which the radical R ² is a methylol or alkoxymethyl group a reaction with the hydroxyl groups of the cellulose is achieved in known manner but in this case also a combination with an aminoplast-forming substance gives improved durability to washing.

The textile material to be treated is impregnated with a dispersion or solution of one or more substances of formula (I) with or without one or more aminoplast-forming substances and then reaction is carried out in the presence of at least one acid and/or potentially acid catalyst. It is preferred to use the substance of formula (I) and if desired the aminoplast-forming substances in the form of aqueous impregnation liquors. The concentration of substance of formula (I) in the liquor is generally from 250 to 600 g/liter. The amount of any aminoplast-forming substance which it is necessary to add is generally from 50 to 260 g/liter.

The amount of flameproofing agent (I) applied to the fiber should be from 25 to 55 percent and preferably from 28 to 50 percent. The flameproofing effect is thus retained even after the loss of some of the finish in numerous washings. The critical limits below which the flameproofing effect is substantially lost are at about 20 percent of flameproofing agent based on the weight of fiber (in the case of cellulosic fibers). The amount of aminoplast-forming substance applied to the fiber may be from 0 to 25 percent and preferably from 10 to 20 percent by weight.

It is preferred to use a padding mangle for the impregnation. The impregnated material is freed from excess impregnating liquor in known manner by sequeezing. The impregnated fibrous material may be dried and then heated in the presence of an acid or potentially acid catalyst at a temperature of up to 200°C and preferably at from 130° to 170°C. The reaction is generally over in from one minute to six minutes under these conditions.

Acid or potentially acid catalysts for finishing with N-alkoxymethyl compounds are known and commonly used. Examples are inorganic or organic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, boric acid and oxalic acid and salts which have an acid reaction or which form acids during use for example by the action of heat and/or hydrolysis, for example ammonium and amine salts, magnesium chloride, zinc chloride and zinc nitrate. Particularly good flameproofing effects are achieved when monoammonium or diammonium phosphate is used. The reaction of the substances of formula (I) and if desired of the aminoplast-forming substances with the textile material is carried out, as already stated, in the presence of these catalysts. This may be effected by applying the catalysts, preferably in the form of aqueous solutions, to the material to be finished before or after the impregnation of the same. It is preferable however to introduce the catalyst direct into the impregnating liquor containing the substance of formula (I). Concentrations of catalyst of from 1 to 40 g/liter have generally proved to be suitable.

It is also possible to use together with the substances of formula (I) and with any aminoplast-forming substances other finishing agents, for example nitrogen-free hydroxymethyl or alkoxymethyl compounds, polyethylene glycol formals and compounds containing epoxy groups, as for example glycol diglycidol ethers. It is also possible to use conventional water-repellent, softening, levelling, wetting or other finishing agents. Examples of water-repellent agents are the known paraffin wax emulsions containing aluminum or zirconium and also silicon-containing preparations and perfluorated aliphatic compounds. Examples of softeners are oxyethylation products of higher fatty acids, fatty alcohols and fatty acid amides, high molecular weight polyglycol ethers and their esters, higher fatty acids, fatty alcohol sulfonates, stearyl-N,N-ethylenurea and stearylamidomethylpyridinium chloride. Examples of levelling agents are watersoluble salts of acid esters of polybasic acids with ethylene oxide or propylene oxide adducts of long-chain oxyalkylatable base materials. Examples of wetting agents are salts of alkylnaphthalenesulfonic acids, the alkali metal salts of sulfonated dioctyl succinate and the adducts of alkylene oxides to fatty alcohols, alkylphenol, fatty amines and the like. "Other finishing agents" include for example cellulose ethers or esters and alginates, and also solutions or dispersions of synthetic polymers, for example of polyethylene, polyamides, oxyethylated polyamides, polyvinyl esters, polyvinyl alcohols, polyacrylic acid or esters or amides thereof and the corresponding polymethacrylic compounds, polyvinyl propionate, polyvinylpyrrolidone, copolymers, for example those of acrylic or methacrylic esters and at least 20 percent by weight of acrylic and/or methacrylic acid, of vinyl chloride and acrylic esters, of butadiene and styrene or acrylonitrile or of α-dichloroethylene, β-chloroalkylacrylic esters or vinyl-β-ethyl ether and acrylamide or the amides of crotonic or maleic acid or of N-methylolmethacrylamide and other polymerizable compounds.

After the reaction with the substances of formula (I) and if desired with aminoplast-forming substances the textile material has an excellent flameproofing substances the textile material has an excellent flameproofing which is very resistant to hydrolysis and washing. The treated material may be washing, rinsed and dried by conventional methods.

The following Examples illustrate the invention. The parts and percentages specified are by weight. Parts by weight bear the same relationship to parts by volume as the kilogram to the liter.

EXAMPLE 1 ##EQU12##

A mixture consisting of 115 parts of methyl N-allylcarbamate and 110 parts of dimethyl phosphite and 10 parts of ditertiarybutyl peroxide are dripped within 1 hour into 110 parts of dimethyl phosphite at 150° to 160°C. After the exothermic reaction is over the whole is stirred for half an hour at 165°C, excess dimethyl phosphite is removed in vacuo and 214 parts (95 percent of theory) of a clear viscous oil (methyl N-(3-dimethylphosphonopropyl)-carbamate) is obtained.

C ₇ h ₁₆ no ₅ o (225)

c% h% n% p% ______________________________________ calculated: 37.2 7.1 6.2 13.8 found: 36.5 7.5 6.3 14.2 ______________________________________

EXAMPLE 2 ##EQU13##

A mixture of 225 parts of methyl N-(3-dimethyl-phosphonopropyl)-carbamate and 75 parts of 40 percent formaldehyde solution is brought to pH 9.0 with 5N caustic soda solution. The temperature rises to 50°C; the whole is stirred for 1 hour at from 45° to 55°C. 331 parts of a clear viscous oil is obtained having a content of free formaldehyde of 3.2 percent and of combined formaldehyde of 6.6 percent. The degree of methylolation is 61 percent.

EXAMPLE 3 ##EQU14##

A mixture consisting of 115 parts of methyl N-allylcarbamate and 138 parts of diethyl phosphite and also 10 parts of ditertiarybutyl peroxide are dripped within 1 hour into 138 parts of diethyl phosphite at 160°C. The product is worke up as in Example 1. 248 parts (94 percent of theory) of a clear viscous oil (methyl N-(3-diethylphosphonopropyl)-carbamate) is obtained.

C ₉ h ₂₀ no ₅ p(253)

c% h% n% p% ______________________________________ calculated: 42.8 7.9 5.5 12.3 found: 42.9 8.3 5.4 12.2 . ______________________________________

EXAMPLE 4 ##EQU15##

A mixture consisting of 129 parts of ethyl N-allylcarbamate and 110 parts of dimethyl phosphite and also 10 parts of ditertiarybutyl peroxide are dripped during 1 hour into 110 parts of dimethyl phosphite at 150° to 160°C. The reaction mixture is worked up as described in Example 1. 230 parts (96 percent of theory) of a clear and viscous oil (ethyl N-(3-dimethylphosphonopropyl)-carbamate) is obtained.

C ₈ h ₁₈ no ₅ p (239)

c% h% n% p% ______________________________________ calculated: 40.1 7.5 5.9 13.0 found: 40.0 7.8 5.5 13.2 . ______________________________________

EXAMPLE 5 ##EQU16##

A mixture of 129 parts of ethyl N-allylcarbamate, 138 parts of diethyl phosphite and 10 parts of ditertiary-butyl peroxide is dripped within 1 hour into 138 parts of diethyl phosphite at 160°C. The reaction mixture is worked up as described in Example 1. 253 parts (95 percent of theory) of a clear and viscous oil (ethyl N-(3-diethylphosphonopropyl)-carbamate) is obtained.

C ₁₀ h ₂₂ no ₅ p (267)

c% h% n% p% ______________________________________ calculated: 45.0 8.25 5.25 11.6 found: 44.8 8.7 5.1 12.0 . ______________________________________

EXAMPLE 6 ##EQU17##

129 parts of methyl methallylcarbamate and 10 parts of ditertiary-butyl peroxide is dripped within 1 hour at 160°C into 220 parts of dimethyl phosphite. After the exothermic reaction is over the whole is stirred for another half an hour at 165°C, excess dimethyl phosphite is removed in vacuo and 234 parts (94 percent of theory) of a clear viscous oil is obtained (methyl N-(3-dimethyl-phosphono-2-methylpropyl)-carbamate).

C ₈ h ₁₈ no ₅ p (239)

c% h% n% p% ______________________________________ calculated: 40.1 7.5 5.8 13.0 found: 39.7 7.7 5.5 12.3 . ______________________________________

EXAMPLE 7 ##EQU18##

A mixture of 239 parts of methyl N-(3-dimethylphosphono-2-methylpropyl)-carbamate and 75 parts of 40 percent aqueous formaldehyde solution is adjusted to pH 9.0 with 5N caustic soda solution. The temperature rises to 50°C. The whole is stirred at this temperature for 1 hour. 344 parts of a clear viscous oil is obtained having a content of free formaldehyde of 4.3 percent and of combined formaldehyde of 5.2 percent. The degree of methylolation is 59.5 percent.

EXAMPLE 8 ##EQU19##

A mixture consisting of 272 parts of diethylene glycol N,N'-diallylbiscarbamate, 220 parts of dimethyl phosphite and 25 parts by volume of ditertiary-butyl peroxide are dripped into 220 parts of dimethylphosphite at 165°C within 1 hour. The whole is stirred for another fifteen minutes at 165°C. The reaction mixture is worked up as described in Example 1. 480 parts (96 percent of theory) of a clear viscous oil is obtained (diethylene glycol N,N'-di-(3-dimethylphosphonopropyl)-biscarbamate).

C ₁₆ h ₃₄ n ₂ o ₁₁ p ₂ (492)

c% h% n% p% ______________________________________ calculated: 38.9 6.9 5.7 12.6 found: 38.0 6.9 5.3 12.0 . ______________________________________

EXAMPLE 9 ##EQU20##

A mixture of 492 parts of diethylene glycol N,N'-di-(3-dimethylphosphonopropyl)-biscarbamate (the compound from Example 8) and 165 parts of 40 percent aqueous formaldehyde solution is adjusted to pH 9 with 5N caustic soda solution.

The temperature rises to 50°C and the whole is stirred for one hour at this temperature.

732 parts of a clear viscous oil is obtained having a content of free formaldehyde of 4.0 percent and of combined formaldehyde of 5.1 percent. The degree of methylolation is 62 percent.

EXAMPLE 10 ##EQU21##

A mixture of 141 parts of allyl N-allylcarbamate and 15 parts of ditertiary-butyl peroxide is dripped at 110°C into 440 parts of dimethyl phosphite. The whole is allowed to react for half an hour at 160°C and is then concentrated in vacuo. 342 parts (95 percent of theory) of a clear viscous oil (3-dimethylphosphonopropyl ester of N-(3-dimethyl-phosphonopropyl)-carbamic acid) is obtained.

C ₁₁ h ₂₅ no ₈ p ₂ (381)

c% h% n% p% ______________________________________ calculated: 36.8 6.9 3.9 17.2 found: 36.1 7.1 4.0 17.2 ______________________________________

EXAMPLE 11 ##EQU22##

A mixture of 361 parts of the 3-dimethylphosphonopropyl ester of N-(3-dimethylphosphonopropyl)-carbamic acid from Example 10 and 82.5 parts of 40 percent aqueous formaldehyde solution is adjusted to pH 9 with 5 N caustic soda solution and brought to reaction for two hours at 50°C. The whole is then cooled, dissolved in 500 parts of methanol, adjusted to pH 3 to 4 with hydrochloric acid and heated for thirty minutes under reflux. After cooling, the whole is neutralized with 5N caustic soda solution and concentrated in vacuo.

431 parts of a clear viscous oil is obtained having a total formaldehyde content of 5.8 percent and a phosphorus content of 14.9 percent (calculated: 15.3 percent).

EXAMPLE 12

Cotton twill weighing about 176 g per square meter is padded on a pad mangle with an aqueous liquor containing per liter 420 parts of the compound from Example 2: ##EQU23## 150 parts of hexamethylolmelamine pentamethyl ether and 20 parts of monoammonium phosphate to a wet pickup of 100 percent, dried at 100°C and condensed for five minutes at 170°C. The cloth is washed at 70°C for two minutes with 5 parts of soda per liter of water to remove unreacted material. After having been rinsed with hot water at 70°C the cloth is dried.

The cotton twill thus finished is given the vertical flame test according to DIN 53,906. It exhibits a flameproofing effect which remains intact after fifty washings at 95°C.

In the following Tables, the following abbreviations are used:

Uc = untreated cloth

Aa = after application

10W (30W, 50W) = after having been washed at 95°C with 1.5 g/liter of a commercial detergent 10 (30, 50) times

Bt = burned through

Treated cloth UC AA 10W 30W 50W ______________________________________ test time in seconds 6 6 6 6 6 burning time in seconds 21 0 0 0 0 glow time in seconds 65 0 0 0 0 tear length in mm BT 95 110 110 110 load in grams 50 50 50 50 ______________________________________

EXAMPLE 13

Cotton twill having a weight of about 176 g per square meter is finished by the method of application described in Example 12 with an aqueous liquor containing per liter 400 parts of the compound from Example 7: ##EQU24## 200 parts of hexamethylolmelamine pentamethyl ether and 20 parts of monoammonium phosphate.

The cotton twill finished in this way is given the vertical flame test according to DIN 53,906. It shows a good flame-proofing effect which is retained even after the cloth has been washed 50 times at 95°C:

Treated cloth UC AA 10W 30W 50W ______________________________________ test time (seconds) 6 6 6 6 6 burning time (seconds) 21 0 0 0 0 glow time (secons) 65 0 0 0 tear length (mm) BT 90 100 105 105 load (g) 50 50 50 50 ______________________________________

EXAMPLE 14

Cotton twill having a weight of about 176 g per square meter is finished by the method of application described in Example 12 with an aqueous liquor containing per liter 500 parts of the compound from Example 9: ##EQU25## 150 parts of hexamethylolmelamine pentamethyl ether and 20 parts of 45 percent aqueous phosphoric acid.

The cotton twill finished in this way is treated in the vertical flame test according to DIN 53,906. It shows a good flameproofing effect which is intact after fifty washings at 95°C.

______________________________________ Treated cloth UC AA 10W 30W 50W ______________________________________ test time (seconds) 6 6 6 6 6 burning time (seconds) 21 0 0 0 0 glow time (seconds) 65 0 0 0 0 tear length (mm) BT 100 100 100 90 load (g) 50 50 50 50 ______________________________________

EXAMPLE 15

Cotton twill weighing about 176 g per square meter is finished by the method of Example 10 in an aqueous liquor which contains per liter 285 parts of the compound from Example 11: ##EQU26## 115 parts of hexamethylolmelamine pentamethyl ether and 20 parts of monoammonium phosphate.

The cloth finished in this way exhibits a good flameproofing effect in the vertical flame test according to DIN 53,906 and this is intact after 50 washings at the boil.

______________________________________ Treated cloth UC AA 10W 30W 50W ______________________________________ test time in seconds 6 6 6 6 6 burning time in seconds 21 0 0 0 0 glow time in seconds 65 0 0 0 0 tear length in mm BT 94 90 95 120 load in grams 50 50 50 50 ______________________________________