US3666402A - Compositions and method for flame-proofing cellulosic materials while simultaneously imparting wrinkle resistance,and articles thereby produced - Google Patents

Abstract

FIRE RESISTANCE AND WRINKLE RESISTANCE ARE IMPARTED TO CELLULOSIC MATERIALS BY TREATMENT WITH N,N'',N" -TRIALLYL PHOSPHORIC TRIAMIDE WITHOUT ADVERSELY AFFECTING OTHER PROPETIES OF THE CELLULOSIC MATERIALS. THE TREATING COMPOSITIONS AND THE TREATED ARTICLE ARE ALSO DISCLOSED.

Description

t as e Int. Cl. D06m 13/44 US. Cl. 8-4161 8 Claims ABSTRACT OF THE DISCLOSURE Fire resistance and wrinkle resistance are imparted to cellulosic materials by treatment with N,N',N-triallyl phosphoric triamide without adversely affecting other properties of the cellulosic materials. The treating compositions and the treated article are also disclosed.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to wash-durable single step aqueous bath treatment for cellulosic textiles which renders them fire and wrinkle resistant.

Description of the prior art It is known that flame resistant properties can be imparted to cellulosic materials (textile fabrics) by treatment with phosphorus containing compounds. Organic phosphorus compounds containing functional groups capa ble of chemically reacting with the cellulose are used When it is desired that the flame resistant properties be durable to a number of laundering cycles. See for example Guth, U.S. 3,421,923, issued Ian. 14, 1969; Reeves et al., US. 2,809,941, issued Oct. 15, 1957; Glade et al., US. 2,828; 228, issued Mar. 25, 1958; Chance et al., US. 3,403,044, issued Sept. 24, 1968; and Reeves et al., US. 3,276,897, issued Oct. 4, 1966. It is also known that introduction of nitrogen in a phosphorus-containing flame retardant has a synergistic efifect. See Tesoro et al., Textile Research Journal, 1969, pp. 180490 who show N-hydroxymethyl-3 (dialkylphosphono)propionamide (NMPA) as a cellulose flame retardant. Also see Beninate et al., American Dye stuff Reporter, Dec. 2, 1968, pp. 74-77, showing tetrakis (hydroxymethyl) phosphonium hydroxide in equilibrium with the tris (hydroxymethyl) phosphine. cured with ammonia to introduce nitrogen. The textile materials are impregnated usually with aqueous solutions containing the organic phosphorous compounds, dried and then subjected to conditions which insolubilize the flame retardant in situ. While such an impregnation materially improves the properties of the heavier fabrics, it is often difiicult to obtain the desired degree of flame resistance in the lighter weight fabrics without adversely altering other properties of the fabric. For example, it is often difficult to impart fire resistance to fabrics of less than about 7 ounces per yard nted May 30, 1972 without causing an undesirable increase in the stiffness of the fabric. It is also difficult to impart to any fabric an appreciable increase in both wrinkle resistance and flame resistance. In order to obtain both flame resistance and wrinkle resistance, the textile material was usually treated successively with a flame retardant and then with a compound capable of imparting wrinkle resistant properties. A single treatment process to impart both flame retardancy and wrinkle resistance has been long sought after in the art.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved method for treating textile fabrics so as to improve their flame resistance to a greater degree than prior art flame retardancy methods at equal add on levels. A second object is to simultaneously impart wrinkle resistant and flame resistant properties to cellulosic textiles without materially increasing the fabric stiffness. Another object is to provide textile treating composition comprising a compound containing both phosphorus and nitrogen by which both the wrinkle resistance and the flame resistance of a textile can be enhanced by a single treatment. An additional object is to provide treated cellulosic textile mate rials which are both flame and wrinkle resistant at low add on levels. The present invention comprises treating a textile material with a solution containing N,N',N"-triallylphosphoric triamide, drying to remove excess solvent, and then either curing at elevated temperatures in the presence of a catalyst or irradiating in with a radioactive source material to produce a wrinkle resistant and flame resistant textile fabric.

DETAILED DESCRIPTION OF THE INVENTION AND DESCRIPTION OF THE PREFERRED EMBODIMENTS Textile materials which may be modified include those derived from cellulosic materials such as cotton, linen, rayon, jute, ramie, paper and the like. Blends of these with synthetic fabrics are also very suitable. The N,N',N"-triallylphosphoric triamide is prepared by reacting phosphorus oxychloride with allylarnine in a non-aqueous solvent in the presence of a tertiary amine to react with the liberated hy rochl ric a id-v Thev prefer-red. mo e atio of th the allylamine and the tertiary ami e t pho p r Y- chloride is 3 to 1. Higher ratios can be used although no a van age ha be n f und to g n Any inert non-aqueous solvent can be used. Suitable solvents include the ether type such as diethyl ether or dioxane and the hydrocarbon type such as hexane, here zene, toluene, etc. The, tertiary amine functions as an HCI acceptor and can be any trialkyl, alkyl-aryl, or heterocyclic type. Examples of trialkyl amines are triethyl amine, tripropyl amine, and tributyl amine. Examples of alkyl-aryl type are diethyl-phenyl amine, Examples of heterocyclic type are pyridine and pyrrole.

The reaction between the phosphorous oxychloride and allyl-amine is exothermic and generally it has been found. to be desirable to control the reaction temperature below C. and preferably between 5 -25 C. The temperature new 3 control of the reaction may be conveniently carried out by utilizing a relatively slow addition rate for the reactants or by cooling the reaction mixture.

The HCl which is liberated during reaction reacts with the tertiary amine to form the HCl salt which precipitates during reaction and is easily removed from the reaction by filtration. The desired N,N',N"-triallylphosphoric triamide is recovered by removal of the solvent and excess reactants by any siutable means such as vacuum distillation.

Following reaction the N,N,N"-triallylphosphoric tri amide can be formulated into the desired treating composition. Any suitable formulation can be used, for example, an emulsion or solution, with aqueous solution being generally preferred. The treating solution can be applied to the fabric by dipping, spraying, rolling, padding or the like techniques, as are known to those skilled in the art. Following the application of the treating formulation so as to impregnate the textile material, the excess of the formulation can be removed by squeezing, centrifuging, pressing, or other similar operations. The material can, if desired, be dried and is then cured by holding the treated textile material for several minutes at high temperatures or for several hours at lower temperatures, or in the presence of a radioactive source of several minutes.

In formulating the textle treating composition the NQNQN"-triallylphosphoric triamide is included in the formulation in amounts within the range of 1 to 50 percent by weight of the composition and preferably in amounts within the range of to percent by weight of the total composition. Additionally, it has been found to be desirable to also include in the treating composition a catalyst capable of initiating a free radical polymerization by itself or in the presence of an activator such as a reducing agent. Such redox systems are described in Fundamental Principles of Polymerization, DAlelio, Gaetano F., John Wiley & Son, New York, 1950. Such catalyst is desirably contained in the composition in amounts within the range of about 0.] to about 20 percent by weight of the formulation and preferably in amounts within the range of about 0.5 to 10 percent by weight of the treating composition.

Suitable compounds which can be used as the catalyst include hydrogen peroxide; persulfates such as ammonium, sodium or potassium; hydroperoxides such as t-butyl hydroperoxide, cumene hydroperoxide; diacylperoxides such as benzoyl peroxide, acetyl peroxides; di-alkyl per oxides such as di-t--butyl peroxide and dicumyl peroxides; peresters such as t-butyl peroxyacetate, t-butyl peroxybenzoate; and peracids such as performic or peracetic.

The remainder of the textile treating composition is comprised of solvent and wetting agent, the latter being optional. Suitable solvents include water, hexane, benzene, ethyl alcohol, methyl alcohol, and any others which do not react with the N,N,N"triallylphosphoric triamide. Wetting agents such as Triton X100 which is an ethylene oxide-alkyl phenol adduct can be incorporated in the treating composition in amounts ranging up to 5 weight percent, preferably 0.5 to 1 weight percent.

The textile treating formulations are applied so as to provide in the textile material an add-on desirably within the range of about 1 to 20 percent by weight of the textile material and preferably within the range of about 5 to 15 percent by weight after the treated fabric has been cured. The term add-on" refers to the flame retardant which has reacted with the textile material; that is, the modifying agent which remains as an integral chemical part of the material after curing and. washing to remove any unreacted excess. The amount of add-on. is given in percent by weight based. on the original dry Weight of the textile material.

The curing of the treated textile material is carried out in one embodiment by holding the material at temperatures between about room temperature, i.e., about 25 C., and about 250 C. for a period of time sufficient to permit the reaction between the textile material and the N,N',N"-triallylphosphoric triamide to take place. This period of time can range from several hours at room temperature to several minutes at elevated temperatures. Desirably the curing is carried out at temperatures within the range of about to 250 C. and preferably at temperatures within the range of about to 180 C. At these temperatures, curing times of from 15 to 30 minutes are typical. An alternative embodiment is irradiating the cellulosic textile material which has been. cuntacted with a solution or emulsion of N,l\l' .N"-triallylphosphoric triamide with a radioactive material such as cobalt. In this embodiment the free radical catalyst is unnecessary since the radiation acts the pclymeriza tion agent.

It is believed that the N,N,N"-triallyelphosphoric triamide and the cellulosic material react through the olefinic double bonds and the C--H linkages respectively, resulting in cross-linkage of the cellulosic material and the imparting of wrinkle resistance thereby.

The following examples illustrate several embodiments of the invention, but are not to be considered limiting.

EXAMPLE 1 171 grams (3.0 moles) of allyl amine, 309 grams (3.05 moles) of triethylamine, and 1600 mls. of ether were placed in a Pyrex glass reaction vessel. The vessel was flushed with nitrogen and the contents cooled to about 5 C. Thereafter 153.4 grams (1.0 mole) of phosphorous oxychloride were added dropwise over a two hour period. The temperature of the ractiou mixture was not allowed to go above 25 C. After the addition. of the phosphorus oxychloride the reaction mixture was stirred at ambient temperature for 2 hours and then filtered to remove the precipitated triethylamine-HCl salt. The liltrate was stirred for about 16 hours at ambient tempera ture with 20'grams of decolorizing charcoal and then filtered to remove the latter. The filtrate was then vacuum distilled to remove the ether solvent and excess reactants as overhead and the desired product, N,l l',i l"-trialiylphosphoric triamide (192 grams), was recovered as dis tillation bottoms. The isolated product was found to greater than 95 percent pure by elemental and Nlvllt analyses.

EXAMPLE II A textile treating bath was made by combining '20 parts of N,N,N"-triallylphosphoric triamide prepared in Example I and two parts of tertiary butyl hydroperoxide as a free radical catalyst with sufficient Water to a total of 100 parts of treating solution. Swatches of bleached, desized, mercerized cotton print cloth weighing 4 ounces per yard were then padded through this solution and a wet pick-up on the fabric of 100 percent was obtained. After drying, the treated fabrics were then cured for 15 minutes at C. and then washed under hot water to remove unreacted compound.

Similar treats were made in which the textile treating solution was refluxed for 4 hours prior to treating the fabrics. This was done to initiate a low degree of polynr erization. All the treated fabrics were tested for fire re sistance by the AATCC vertical flame test method (34 1970) and for wrinkle resistance by the AATCC wrinkle recovery angle method (Monsanto) (66-1968). These are standard tests used by the cotton industry, The resu are given in Table l.

TABLE 1 Wrinkle Cure conditions Wt. Vertical recovery I percent test, char angle Temp dry leng (W+F) Experiment Treating solution Time add-on inches deg.

Untreated cotton A N of: heat treated 15 minutes 165 6. B d 165 6. 5 4. 5 C g do 165 7. 6 4. 5 D Heat treated- 165 8. 3 4. 7 E do 165 8.8 4.9 F do. 165 8. 5 3. 9 G. do. 165 9. 1 3. 8 H o- 165 10. 5 3. 6 I do 1 hour 165 14. 2 2. 7 J Not heat treated 16 hours 125 12. 3 3. 5

1 20 wt. percent N,N',N"-

2 5.5 inch charlength allowable for 4 oz. per yard of cotton.

3 Burned entire length.

It can beseen that the add-ons obtained by the nonheat treated solution ranged from 6 to 7.5 percent by weight of the untreated fabric. The fabrics containing 6.5

and 7.5 weight percent add-ons passed the vertical flame test as the char lengths obtained were 4.5 inches. A char length of 5.5 inches is allowable by the test for cotton of this weight. Untreated cotton is consumed in the vertical flame test. Slightly higher add-ons were obtained in the range of 8.5'to 10.5 weight percent when the treating solution washeat treated prior to impregnation of the fabrics. All of the treated fabric in this add-on range passed the vertical flame test. The flame resistance obtained at this level of add-on (7 weight percent) is considered quite good for the lightweight cotton being tested since add-ons in the range of to weight percent are usual- 1y required to give this degree of flame resistance for fabrics of comparable weight when prior art phosphorous flame retardants are used. There was no detectable difference between the hand of the treated fabrics and the hand of the untreated fabric.

It can also be seen from Table 1 that the fabrics containing add-ons in the range of 9 to 10.5 weight percent had wrinkle resistant properties as the dry wrinkle recovery values were 240 to 250 (W-l-F) as compared to about 190 for untreated cotton.

EXAMPLE III The procedure of Example II was repeated with the exception that longer curing times were used. In one case the treated fabric was cured for 1 hour at 165 C. and this resulted in an add-on of 14.2 Weight percent (Table 1). The treated fabric passed the vertical flame test and had a wrinkle recovery angle of 271. Curing at longer times (18 hours) at lower temperatures (125) resulted in an add-on of 12.3 Weight percent. The treated fabric passed the vertical flame test and had a wrinkle recovery value of 276.

EXAMPLE IV A textile treating bath Was made by combining 20 parts of N,N,N-triallylphosphoric triamide prepared in Example I with sufficient water to make a total of 100 parts of treating solution. Swatches of untreated cotton fabric used in Example II were padded through this solution and a wet pick-up on the fabric of 100% was obtained. After drying the fabrics were then cured at room temperature by being exposed to a cobalt 60 radiation source with an effective exposure dose rate of 250,000 roentgens per hour. After irradiation the fabrics were washed under hot water to remove unreacted N,N,N" triallylphosphoric tri'amide.

Dry add-ons of 1.5, 2.3 and 4.0 weight percent were obtained after the treated fabrics were exposed to irradiation dosages of 0.25, 1.0 and 4.0 megarads, respectively. This example shows that N,N',N"-triallylphosphoric triamide can be reacted with cotton using ionizing radiation as the free radical initiator and that the extent of reaction with cotton is related to the irradiation dosage.

Textile fabrics treated to impart flame resistant propertriallylphosphoric triamide, 2 wt. percent t-butyl hydroperoxlde.

ties normally require high add-ons (15 percent or higher) which usually increase the stiffness of the fabric with no improvement in the wrinkle resistant properties of the fabric. Tesoro et al., supra, at page 182, required a 17.1% add-on of NMPA to achieve a degree of fire retardancy (6.8 inch char length) which does not even pass the AATCC vertical flame test which only allows 5.5 inches of char length for 4 ounces per yard fabric. Our flame retardant passed this test with only 6.5 weight percent add on (Table 1) and so appears to be markedly superior than NMPA in flame retardancy. A two step process consisting of treatment of the fabric with a flame retardant and then with a compound capable of imparting wrinkle resistance is usually required when a fabric containing both properties is desired.

' In the present invention a textile fabric is treated with one compound in a single step to produce a treated fabric having improved wrinkle resistant and fire resistant prop erties with no increase in stiffness of the fabric. The addon required to impart these properties is also exceptionally low.

Although the invention has been described with great specificity, various modifications should become readily apparent to those skilled in the art without departing from the spirit and Scope of the invention.

We claim:

1. A process for simultaneously imparting wrinkle resistance and flame retardance to cellulosic textile materials comprising applying the composition comprising from 1 to 50 weight percent N,N',N-triallylphosphoric triamide, 0.1 to 20 weight percent free radical catalyst, 0 to 5 weight percent wetting agent, and the remainder solvent to said materials, heating the material at from about 25 C. to about 250 C for a time sufficient to permit cross-linking.

2. The process of claim 1 wherein the material is heated at a temperature of from about 150 to about 180 C. for from 15 minutes to one hour.

3. The process of claim 1 further including the step of drying the material at 25-100 C. for from about 5 to about 30 minutes so as to remove excess solvent prior to he ti g h mat ri l.

4. The Process of claim 1 further including the step of heating the composition for 1 to 4 hours at to C. prior to applying it to said cellulosic textile material so as to p lym rize the omposition t a low de 5. A process for rendering cellulosic textile material's resistant to fire and wrinkles comprising (a) contacting the material with a solution of an emul sion of N,N',N"-triallylphosphoric triamide,

(b) removing excess solution or emulsion,

(c) heating the material containing the N,N,l l"-tri allylphosphoric triamide for a time sufficient to chemically react the material with the N,N',N"-triallylphosphoric tn'amide,

(d) thereafter washing to remove any unreacted MN,

N-triallylphosphoric triamide, and

(e) thereafter drying the treated material.

6. The process of claim 4 further including the step of heating the solution or emulsion of N,N',N"-triallyiphosphoric triarnide in the presence of a free radical polymerization catalyst for a period of time sutficient to induce partial polymerization prior to the contacting or step (a).

7. A process for rendering cellulosic textile materials resistant to fire and wrinkles comprising (a) contacting the material with a solution or an emulsion of N,N,N-triallylphosphoric triamide,

(b) removing excess solution or emulsion,

(c) irradiating the material containing the N,N',N-

triallylphosphoric triamide with a radioactive source material for a time sufficient to chemically react the material with the N,N',N"-triallylphosphoric triamide,

(d) thereafter washing to remove any unreacted N,N,

N"-triallylphosphoric triamide, and

(e) thereafter drying the treated material.

8. A wrinkle resistant, flame resistant article compris- References Cited Chemical Abstracts, 1963, vol, 58, p. 1485(h).

GEORGE F. LESMES, Primary Examiner I. R. MILLER, Assistant Examiner US. Cl. X.R.

8-1i6 P, 120, DIG l2; 106-15 FP; i1793.3l, I36; 204--l59.22, 160.1; 2528.l; 26080 PS, 606.5 P, DIG. 24