US2607729A - Textile treating compounds - Google Patents

Description

Patented Aug. 19, 1952 TEXTILE TREATING COMPOUNDS William L. Dills, Wilmington, Del., assignor to E. I. du Pont de Nemours & Company, Wilmington, DeL, a corporation of Delaware No Drawing. Application June 24, 1950,

Serial No. 170,265

8 Claims.

This invention relates to novel titanium-antimony compositions useful in treating organic substances, especially textile materials, in order to impart valuable properties thereto. More particularly it relates to the production and use of a novel composition comprising titanium and antimony, useful for rendering textile materials flame-resistant.

The various textiles, such as rayon and cotton goods, present an appreciable fire hazard due to the ease with which they may be ignited. This is particularly true in clothing such as lightweight rayon dress goods or in heavier fabrics having a pile finish. The finer pile fabrics are often made by brushing regenerated cellulosic textiles, e. g., woven or knitted viscose goods, and these are particularly hazardous due to the ease with which a flame may spread over the pile material. The dangers have been brought to the attention of the public by the many disasters in recent years resulting from the increased use of fabrics having such high susceptibility to flamepropagation. ActiOn has been taken by the American Association of Textile Chemists and Colorists, which has developed a testing method to' determine the flashor flame-resistance-of textile fabrics. In such a test a rectangle of treated cloth measuring 2" x 6" must be heated for fifteen minutes at 105 C. and then cooled in a desiccator over calcium chloride. The resulting dried cloth will have a moisture content of less than 0.3 under such conditions. The cooled cloth must then be removed from the desiccator, supported on a screen held at a 45 angle, and touched with a /2" flame for one second. To pass the test, pile goods must not show material flashing, even after laundering. Flat or non-pile goods may be tested similarly, but the flame in this instance is applied to goods suspended in a vertical position, and the goods must not continue to burn after the flame is removed.

Various compounds have been added to, or incorporated in fabrics to attempt to render them fireor fiameproof. The most widely employed process comprises coating the textile simultaneously with a chlorinated resin or chlorinated paraffin and an inorganic oxidic material. Such compositions have been used especially to render tarpaulin tenting material fiameproofand for like military applications. Such a method, however, substantially changes the character of the goods because the coating is of substantial thickness and the textile loses its flexibility. Too, although the coating is relatively water-resistant and thus durable to laundering, it is not resistant to the solvents used in dry-cleaning but is dissolved thereby. Hence, fabrics so treated are not satisfactory for general clothing purposes and are not even acceptable for work clothing. In addition, it has been suggested that fabrics be treated with an inorganic salt such as a chloride of titanium, tin or antimony, dissolved either in water or in non-aqueous solvents like toluene, ethyl acetate, etc. Fabrics have also been contacted with ammonium sulfamate, alone or in conjunction with soluble salts, e. g., borates and the like. However, none of these prior art processes has given products which at the same time meet the above-referred-to AATCC test for flashor flame-resistance, are dry-cleaningand laundering-resistant and give a product having consumer appeal.

More recently it has been proposed to apply a combined solution of antimony and titanium to textile materials; such a method is outlined and claimed in co-pending application Serial No. 724,242, filed January 24, 1947 by F. W. Lane and myself, which has issued as U. S. Patent No. 2,570,566, dated October 9, 1951. The fabric is immersed in the antimony-titanium solution; after a short lag period, the fabric is treated with an alkaline neutralizing agent, such as ammonium hydroxide or sodium carbonate, and then rinsed or washed to remove any loosely-held inorganic oxides and salts. Upon drying, it is ready for use as a flame-resistant textile. This method has shown great promise, since it provides clothing, drapery, curtain, and industrial fabrics of greater consumer appeal, and having a flameresistance which is durable both to laundering and to dry-cleaning. Most important, of course, is the fact that it makes economically possible the obtention of clothing material which passes the rigid AATCC fire-resistance test and implements practically the enforcement of fire prevention laws such as that enacted in California.

It is among the objects of this invention to substantially improve upon the operations recited in the above-mentioned Lane and Dills application and to provide the textile trade with a flameretarding composition comprisin titanium and antimony in more concentrated form. Another object is to provide a composition which is soluble in an aqueous medium but which may exist as a solid or powdery material and be transported in relatively inexpensive containers. A further object is to provide to the textile-finishing industry an anhydrous reagent which may be transported from its point of manufacture to the consumer at decreased shipping charges. Other obchloride of antimony, e. g., SbCls, as may be illustrated in part by the hypothetical equation:

3TiCl4+Sb2O3- 3TiOCl2+2SbCl3 This reaction takes place with the generationol heat. The product is dry, and will be substantially devoid of visible fumes when there is no excess of anhydrous TiCh therein. In the event that one uses an excess of titanium tetrachloride, a fuming substance results which may be used as such, if suitable packaging and other precautions are taken. However, if it is desired to eliminate the fumes, this may readily be done by the addi- Y tion of sufficient water to convert the excess TiCli to an oxychloride, e. g.

In a preferred embodiment of my invention, I react titanium tetrachloride with antimony oxide, using approximately three mols .of TiCh for each mol of SbzOc in accordance with the first equation given above. This ratio :of

titanium to antimony has been found quite satisfactory in the flameproofing of fabrics, particularly cellulosic fabrics made of rayon and cot ton yarns. The product has been found quite soluble in water or water containing an acid such as hydrochloric, acetic, chloracetic or other similar reagents useful in maintainingtitanium and antimony chlorides in solution in a dilute aqueous medium.

When one stirs antimony oxidev into titanium tetrachloride, spontaneous reaction may or may not. take place, depending on the purity of the reagents and their freedom from moisture as well as the temperature of the suspension. I find it convenient to mix the two reagents under conditions which will give a uni-formcomposition prior to the beginning of the reaction. In other words, I prefer .to mix the two in the absence of water and while keeping the temperature low, and then initiate the, reaction by adding. a trace of water. catalytic in its behaviour; or it is also possible that the water-addition generates heat and raises the temperature to the point where the reaction itself starts and spreads.

My method of preparing these solid flame-retarding compositions is subject to considerable variation without departing from the spirit of the invention The product may vary in composition over a considerable range without becoming liquid or even tacky. A free-flowing powder having a variable ratio of titanium to antimony is therefore possible, depending on the amount of each ingredient employed. The. use of amounts of titanium tetrachloride in excess of that shown inv the hereinbefore-mentioned equation, e. g.,'four mols of TiCli for each mol of SbzOc, will result in a reaction product contai'ni'ng residual 'IiCli. Upon subsidence of the reaction and exposure of the mass toth'e moist atmosphere, a funding product'is thus obtained. However, if desired, this visible smoke or fume may be avoided by adding to the reaction mass a limited amount of water so as to convert the residual tetrachloride to an oxychloride suchas TiOCl'z. This use of a quantity of water The latter may be stoichiometrically equivalent to the excess TiCll present should not be confused with the utilization of a small or trace amount to catalyze or accelerate reaction between the titanium chloride and antimony oxide as above disclosed. The product resulting after the addition of water to react with an excess of one mol of TiCl4 will contain approximately two atoms of titanium per atom of antimony and will be a dry powder which is free of visible fumes and which may be transported like other powders in simple drums or bags.

The solid fiameproofing product of this invention may also be modified by using a larger proportion of antimony oxide, in which event the antimony content will be greater than that provided by the previously mentioned reaction For instance, equimolar proportions of the reactants may be employed, according to the equation The antimony will be present either as unconverted oxide, as the normal chloride or as a basic chloride, depending on the conditions of reaction between the titanium tetrachloride and theantimony reagent. Such a product will dissolve in dilute acid, e. g., 20% HCl, to give a clear solution which may be used directly in the treatment of inflammable textile fabrics, or may befurther diluted with water or modified in other ways depending on the wishes of the consumer.

To a clearer understanding of my invention, the following specific examples are given, it being understood that they are merely illustrative and are not to be taken as limiting the scope of my invention:

Example 1 One hundred parts by Weight of antimony oxide were slurried in 190 parts by weight of anhydrous titanium tetrachloride and after a uniform suspension was obtained, water was added in a dropwise manner until reaction set in. Heat was generated and fumes appeared above the reacting mixture. After the initial reaction had subsided, 18 parts by weight of water were slowly added with agitation to the solid reaction product. Fuming ceased and the final'prodnot was a dry, powdery material.

This dry mixture of titanium and antimony chlorides was found to dissolve readily in water acidulated with 20 HCl, and a very concentrated solution could be thus prepared. A por-' a 15 minute lag period,'imme'r'sed in a saturated The fabric wasfinally thoroughly scrubbed with soapy water,

sodium carbonate solution.

rinsed, dried; and a portion tested by the AATCC test "(dried in a proper desiccator, supported at a 45 angle and touched for 1 second with a -inch flame). No flashing occurred on the pile surface. Another portion of the treated material was subjected. to chemical analysis and found to contain 7.5% 'I'iOa and 7.0% SbzOa;

gem-#29 wer jslurifiediin 205 "parts "weight of Ti C li whileithelatter was being stirred and'maintain'ed at, allow" temperature by, water jacket cooling. N'o" reaction" took place during the mixing, but when a uniform suspension was obtained, water was added dropwise toira'ise; the temperature and initiatethe'reaction. Dense fumes were evolved in'the-moist'air andthe reaction'was vigorous, continuing for about '15' minutes. Twenty eight parts-byweightof water were then added dropwise with stirring, converting the excess of TiCl4 to an oxychloride, in which condition it became substantially non-fuming. Stirring was continued until the mixture was ,free of any lumps, and the sqlidproduct wasthentested for solubility. It wasfou'nd to leave Someih's'olubleresidue when treated with HC1 but to dissolve completelyin 'I-ICl. --The solid analy zed 25.9% TiO2,33.6% SbzOs, and 42.1% H01;

The product of this example, like that of-Example'I,-was=found to be a-valuable fiameproofing compound for rendering inflammable textile materialssuch as rayon and cotton goods fireresistant. v r l As, disclosedaboveand illustrated in theexample's, I have outlined amethod for'producing solidcompositions useful in the treatment 'jof textiles to reduce fire hazards. soluble-Yin water or acidulated Water or the like, e. "g'.,' a 10% or 20% HCl solution, solutionsof sulfuric acid, acetic or chloracetic acids, propionic acid, other water-soluble acids, etc. The exact chemistry of the reaction between antimony oxide and titanium tetrachloride is unknown but is believed to follow one or more of the following equations:

One may observe that the process is flexible in that a considerable variation in the ratio between antimony and titanium is possible and the reaction yields a mixture of a chloride and one or more oxychlorides. For reasons of simplicity, I use the term chloride to include both the normal chloride and the oxychloride or basic chloride, as for example TiOC12 or SbOCl, and it is understood that the extent of the reaction between the two reagents and the chemical composition of the reaction products is not a fundamental of my invention. I regard my invention as a means of preparing a solid material which will readily dissolve in an aqueous system and which is useful as a treating agent for inflamable textile goods to render them fire-resistant. A close examination of the equations given above will show that it is possible to produce solid compositions comprising chlorides of titanium and antimony in which the ratio of antimony to titanium may be as great as two and as low as one-half.

In the examples, I have shown the reaction taking place in the absence of a diluent or solvent. It is naturally essential to avoid contact with a substantial amount of water in order to produce a dry, powdery material; but excess TiCl-i may be consumed by reaction with an equivalent amount of H20. The reaction may be aided and accelerated by the application of a small amount of heat. Additionally, the process These solids are a can be. carried out. the-presence of. anonganicsolvent such as benzene, toluene, or cycle hexane, and it. should vbeunderstood. thati'such a modification .comes within. the'scope ofathis in vention. The '.:.avoidance of "such additional reagents :is-generally recommended, however; for economy .as well as for minimizing operational complications. y ..'.r:::.:-;

The solid,'.soluble concentrates of thisinvention form aqueous. solutions which. are. particularly effective. for treating filamentstmdfilms comprising fmaterials which reactchemically with them "toimpart tov suchfilaments and filmsdesired name-resistance characteristics. Thus, while after-treatment of .polyacrylom'trile yarn with these flame-proofing. compositions is relatively ineffective, excellent results; .are. ob.- tained by after-treatment of acrylonitrilelpoly mers containing reactive functional groups, such as. hydroxyl groups, carboxylgroups, and groups which hydrolyze to the'seunder the after-treat-- menti..conditions;.. v :Someofthe more successful methods of modi-. fying polyacrylonitrile so that films andpfilaments. can be, flame-proofed; with .the compositions. of. this invention are: -(-1) partial hydrolysis to provide amide or carboxylic: groups, (2) .:use of acrylonitrile, 'co-polymer ...containingc, "such groups as hydroxyLcarboxyl, -anhydrides, amides, lactones,,esters, and amines,--andl(3) incorpora-r 'tionofmaterials containing such groups as ,thfise into fibers by impregnation or by inclusionin the spinning compositions. Many of, these techniques are applicable to other fibers, and particularly the third treatment could be applied to any synthetic fiber.

I claim as my invention '1. A solid dry aqueous-media-soluble composition for rendering inflammable textile materials flame-resistant which consists in a reaction mixture of titanium oxychloride with a compound of antimony selected from the group consisting of a basic and normal chloride, the atom ratio of antimony to titanium in said composition being not more than two and not less than one-half.

2. Dry, powdery flame-retarding composition, useful for the treatment of inflammable textile materials and soluble in an aqueous system, which consists in titanium oxychloride and antimony chloride, the atom ratio of antimony to titanium in said composition being not more than two and not less than one-half.

3. A process for the preparation of a soluble. solid flame-retarding composition of matter which comprises mixing in the dry state, antimony oxide with titanium tetrachloride, incorporating a small amount of water therein, and thereby converting the tetrachloride to an oxychloride and the antimony oxide to a chloride, and employin therein such ratio of reactants that the resulting composition contains an atom ratio of antimony to titanium of not more than 2 and not less than one-half.

4. A process for the preparation of solid flameretarding compositions of matter soluble in aqueous media, which comprises mixing in the dry state antimony oxide with titanium tetrachloride, and adding a small quantity of water thereto, the amount of the reagents being so selected that the product will comprise .an oxychloride of titamum and a normal chloride of antimony, with its atom ratio of antimony to titanium being not more than 2 and not less than one-half.

5. A process for the production of a solid, flameretarding reagent comprising chlorides of titanium. and antimonyso'lub'le. in aqueous media which comprises mixing together inthe .dry state antimony oxide and titanium tetrachloride. .adding enough water to the mixture to convert any unreaoted titanium tetrachloride :to titanium oxychioride, and employing said reactants insuch proportion that th'esolid product obtained will contain an atom ratio of antimony to titanium of .not :more than 2 and not less than one-half. 5.6; A process for the production of .the solid flamzeretarding reagent: comprising an. oxychlorideoftitanium' and antimony chloride soluble in aqueous media which comprises mixing together in: fthedry state for reaction antimony oxide and titanium tetrachloride, employing an atom ratio of antimony to titanium in the reaction mixture of :notimore than two norless than one-half, and theniniti-ating areaction between the compounds admixed by adding water .dropwise thereto.

7. A process for the production of a solid flameretarding reagent comprising an oxychloride of titanium and antimony trichloride' soluble in aqueous media which comprises reactingttogether antimony trioxide and titanium tetrachloride by mixing said compounds in the dry state and adding a small amount of water to the mixture, em-

water'to the reaction product to convert any un reacted titanium tetrachloride to titanium oxy' chloride.

- 8; A method tor producing a dry solid aqueous- WILLIAM L. BILLS.

REFERENCES CITED The following references are of record'in the fileof this patent: UNITED STATES PATENTS Number Name Date 723,088 'Warr Mar. 17, 1903. 2,395,922 Timmons Mar. 5, 1946 2,416,447 Laughlin et al. Feb. 25, 1947 2,427,997 White Sept. 23,194 2,461,302 Truhlar et a1. Feb. 8, 1949 2,570,566

Lane et a l 001?. 9, 1951 OTHER REFERENCES 7 Industrial and Engineering Chemistry, Vol. 42, No.13, Mar. 1950, pgs. 440-444, vby Gulledge and Seidel. Ephraim: Inorganic Chemistry, Nordeman Pub. Co., Inc., N. Y., 1943, pgs. 747 and 755-756.

Claims (1)

1. 2. DRY, POWDERY FLAME-RETARDING COMPOSITION, USEFUL FOR THE TREATMENT OF INFLAMMABLE TEXTILE MATERIALS AND SOLUBLE IN AN AQUEOUS SYSTEM, WHICH CONSISTS IN TITANIUM OXYCHLORIDE AND ANTIMONY CHLORIDE, THE ATOM RATIO OF ANTIMONY TO TITANIUM IN SAID COMPOSITION BEING NOT MORE THAN TWO AND NOT LESS THAN ONE-HALF.