US2427997A - Flame resistant fabric material - Google Patents

Description

- February 1939, for duck, cotton,

Patented Scpb23, 1947 OFFICE 2,421,991 FLAME RESISTANT Fannie MATERIAL Clarence B. White, Montclair, N. J.

Serial No. 8 Claims. '(Cl. 117-437) This invention relates, generally, to improvements in the art of imparting fire resistance to cellulosic fibers and fabrics, as well as other relatively inflammable fibers and fabrics, while si-, -mu1taneously rendering the fibers and fabrics thus protiessed, resistant to the action of weathering and attack by bacteria and fungoid agencies, usually described under the collective title of mildew, and the invention relates, more particularly, to product, and to the process of preparing the same and the material with which the processing is effected. This application is a continuation-in-part of ap Serial No. 457,- 226, filed September 3, 1942, for Flameproofing of textiles and method of making the same.

The material to be treated of most common occurrence and commercial importance is cotton duck, cotton sheeting, cotton camouflage and other types of netting, and the various types of cotton clothing fabric such as drills and twills and poplins. At present commercially acceptable grades of fire resistance must meet the requirements of Federal specification CCC-D MG, fire, water and as amended by sup- (tentative) 2fl2. Procweather resistance, and plementary specification essed material the requirements of the above specified specifications may be considered as "fireproofed within the meaning of this invention.

Material processed as fireproof.which will meet the requirements of specifications 746 and 242, noted above, has hitherto beenprepared by the application of a fire resistant paint formula in which ground pigments of various types are suspended in a halogenated organic material which serves as a base and as a carrier for the essential pigments. These pigment solids are preferably mixed or ground with the halogenated carrier material (almost universally a chlorinated compound), and then deposited in and on the fabric, the chlorinated material serving as a, base or carrier, usually known as a vehicle.

fire resistance produced by the appaint meets the of the aforesaid specifications, a very heavy is an indispensable prerequisite, the heavy loading producing the defect of tackiness at normal temperatures and objectionable stiffness when subiected to the usual winter temperature of the temperate zone, which stiffness is accentuated greatly when subiected to arctic temperatures.

No Drawing. Application January 7, 1944,

While the degree of stiffness may be materially modified by the addition of relatively large amounts of plasticizing media. the addition of plasticizing media greatly increases the degree of tackiness. Another objection, vital in many cases, lies in of the soft fire resistant paint to croc off, selling any article with which come in contact, a defect which renders fabrics processed with such fire resistant paints unavailable for clothing,

, chair or seat covers, and affects adversely their that will substantially comply with usefulness for tentage and awning purposes, largely for the reason that they will soil any fabric which comes in contact with them, and

having a soft tacky surface such processed fabrics attract dirt and grime and quickly become unsightly, although still retaining their fire resisting characteristics.

The present invention does not make use of a fire resisting paint composition, but instead employs materials that are introduced into the fabric, fiber or structure to be fire proofed in the form of solutions, which are then insolubilized on and within the fibers of the cellulcsic structure. These materials may be introduced into the fabric either in the form of aqueous solutions of the salts of the metals and compounds to be employed, or, where feasible in solutions of the desired compounds in aliphatic, aromatic or chlorinated hydrocarbons, the hydrocarbon in this latter case being first removed by evaporation, and the residual metallic compound being then insolubilized (as to water) by means of appropriate precipitants, usually compounds of the alkali metals. or ammonia, such as the carbonates and hydroxides of the alkali metals.

The principal object of the present invention is to provide a novel fire resistant textile fabric material with the use of a minimum amount of loading, 1. e., reducing the effective loading from 40 to percent of loading ordinarily required in the case of fire reslstant texle fabric heretofore known.

Another object of the present invention is to provide a novel fireresistant textile fabric or similar material which will not crock nor will the fire resistant material rub off as in the case of paint-coated fabrics heretofore commonly used, whereby the material of this invention is adaptable for use for clothing, awnings, furniture, etc.

Another object of the present invention is to provide a novel fire resistant textile fabric or similar material that is not tacky and is further not stiff at low temperatures but possesses a de- 3 e 4- gree of flexibility approximating that of the uncarbonate and antimony chloride, is next passed treated fabric. through a solution of sodium carbonate, prefer- A still further object of the present invention ably warm, which solution immediately decomis to provide a flame resistant fabricpr similar poses the'impregnated antimony chloride with material preferably employing antimony trioxide 5 the formation of antimony oxide.

\ V the, antimony group, antimony, bismuth and inhibiting characteristics. Because of the cost as the flame resistant ingredient thereof and also 1 The compounds of the antimony group [anti- It has long been known that the chlorides of the chlorides of these metals, show marked flame of the group that can be considered of commercial may. therefore. be selected as a commercially importance. The chemical characteristics of practicable type. but representative oiflthe men'- o is an invariable constituent of all cellulosic strucwere possible to impregnate a cellulosic cent of the entire fabric and element antimony, antimony chloride is quite e soluble in alcohol and most hydrocarbon solvents,

ric can be impregnated with a solution of anti- 4o Anfl'monymcmmde m the which. m tum, at once destroys the fabric. evolution of carbon dioxide, as follows:

Applicant has discovered that if the fabric 2SbCla+3Na=CO:- Sb:0a+6NaCl-l-3CO:

is first impregnated with a carbonate or acetate Antimony trioxide is inert insofar as the fabric or other weak salt of a metal of thealkali ou be emcemedsuch impregnating compound while. g; If the fabric destined to be impregnated with mprgnate the fabric thus prepared with a s1u then be safely impregnated with an organic soludon of antimony m m a hydrocarboh sob tion of antimony trichloride. Under theseconre resistant possesses an impregnation of carsodium chloride n c n dioxide.

solution of antimony trichloride addition to carbon dioxide.

ing, nothing remains but of the solvents.

carbonate solution (aqueous) or other equivalent carbonate. Second,

Third, the

the fabric is dried. (Usually on cans.) dried fabric is impregnated with a in an organic solvent.

' Fourth, the fabric impregnated with antimony trichloride is solvent being volatilized.

" Fifth,

dried, the organic the dried fabric impregnated with antimony trichloride is now passed through a warm sodium carbonate, which solution in dissolving the sodium carbonate already incorporated with the fabric (first step), decomposes present as a result of the third and fourth steps, forming insoluble antimony trioxide, sodium chloride and solution of Sixth, the thus processed fabric is now washed with water, which treatment removes the residual sodium carbonate, sodium chloride, and after drya fabric impregnated with antimony oxide which is now flame proofed. The fabric will not now support flame, but combustion can still be propagated through the fabric, but without flame effect.

The following will serve as an example of a working process.

First, the fabric or cellulosicstructure to be fireproofed is padded (that is, passed through a dye bath and squeezed through rollers or-nips") with a, hot carbonate (or equivalent carbonate) temperature near boiling, sodium carbonate being per cent of the whole.

Second, the fabric is dried on cans.

LThird, the dried, thus processed fabric is impregnated with a per cent solution of antimony chloride in an organic solvent, which may be a. petroleum or coal tar solvent or alcohol.

Fourth, the antimony impregnated fabric is dried on cans.

Fifth, the dried fabric (fourth step) is padded with a 10 per cent solution of sodium carbonate, warm but not hot.

Sixth, the processed fabric is washed and dried.

The processed fabric has now been flameproofed, but the treatment herein proposed does not prevent the propagation of nameless comthe application Thus, the fabric will glow, and the zone of combustion will creep, although actual flaming is no prevention of glowing" or the propagation of a creeping area of flameless combustion requires an additional treatment.

Certain organic compounds, principal among which may be named chlorinated paraffin, tricresyl phosphate, tri-phenyl phosphate, polymers of vinyl resiri and various phenolic compounds will prevent the propagation of a zone of creeping combustion but will not, in themselves, prevent flame propagation. A combination of the two media will result in the production of a flreproofed fabric which will not only not support flame propagation but creeping or glowing propagation of a zone of combustion as well.

These compounds may be added to the fabric processed as above by means of a separate and distinct operation, or they may be incorporated with the solution of antimony chloride in organic In the former case the fabric, processed as above described, is passed through a solution of chlorinated paraffin, tricresyl phosphate, triphenyl phosphate, separately or a combination of after which the solvent may be removed by evaporation. On the other hand, the simultaneous application of the flame and "glow" inhibiting compounds would be effected as follows:

First, the fabric is incorporated wit a carbonate of the alkali metals.

Second, the fabric is dried.

Third, the dried fabric is impregnated with a solution of antimony trichloride (15%) and chlorinated paraflin (20%) with cresyl phosphate (6%) in an aromatic or aliphatic hydrocarbon solvent, the usual proportion of this solvent being 50 per cent of the whole mixture, although this proportion is susceptible of variation'according to circumstances,

Fourth, the fabric is now dried with the'evaporation of the solvent as an incident. The dried fabric will now contain the sodium carbonate base, antimony chloride and the glow resistant hydrocarbon compounds, such as chlorinated paraffln, tricresyl phosphate, or whatever media may have been selected.

Fifth, the dried fabric now containing carbonate of soda (base), antimony chloride, glow resisting hydrocarbon compounds is now passed through a warm, though preferably not hot, 10 per cent solution of sodium carbonate, squeezed through rolls and washed and dried over cans, or other methods of drying. This procedure has the effect of removing all carbonate of soda while converting the antimony chloride into antimony oxide, while the glow inhibiting hydrocarbons are not changed.

What is claimed is:

1. The method of producing a fire resistant textile fabric comprising impregnating a fabric with sodium carbonate solution, drying the fabric, impregn'ating the dried fabric with a solution of antimony trichloride in an organic solvent, the presence of residual sodium carbonate in the fabric preventing any hydrochloric acid resulting from hydrolysis of the antimony trichloride from attacking the fabric, drying the thus impregnated fabric, passing the fabric through a warm solution of sodium carbonate thereby precipitating insoluble antimony trioxide throughout the interstices of the fabric, washing the fabric with water to remove residual sodium carbonate, drying the fabric, thereafter passing the fabric through a solution of chlorinated paramn and then again drying the fabric.

2. The method of producing a fire resistant textile fabric comprising impregnating the fabric with a of an alkali metal, drying the fabric, impregnating the dried fabric with a solution of antimony trichloride and chlorinated paraffin in an organic solvent, drying the fabric, and passing the same through a warm solution of sodium carbonate, squeezing, washing, and drying the fabric.

3. The method of producing a fire resistant fabric material comprising impregnating the material with an aqueous solution of an alkali metal carbonate, drying the material, impregnating the dried material with an organic solution of antimony trichloride, the presence of residual sodium carbonate in the fabric preventing any hydrochloric acid resulting from turdrolysis of the antimony trichloride from attacking the fabric, again drying the material, passing the dried material through an aqueous solution of an alkali carbonate, washing the material to remove residual alkali carbonate, drying the material and passing the same through a solution of chlorione or more of these ingredients, nated paraifin capable of rendering the fabric the inclusion of tri-' resistant to creeping combustion and again drying the fabric. 1

4. The method of producing a fire resistant textile fabric comprising impregnating the fabric with a carbonate of an alkali metal, drying the fabric, impregnating the dried fabric with a solution of anti fabric, impregnating the dried fabric with a solution of antimony trichloride in an organic solparaflin subsequent with sodium carbonate.

8. The method of producing a fire resistant textile fabric comprising impregnating the fabric 7. The method of fabric comprising passing sodium carbonate of approximate- 1y 10% concentration, drying the fabric, im-

eth

Number American 32, No. 14. p

and again drying the fabric.

0d of employing antimony trichloride same.

-CLARENCE B.- Wm I REFERENCES CITED The following references are file of this patent:

UNITED STATES PATENTS of record in the Name Date Arent Aug. 23, 1921 McCuiioch June 16, 1936 Clayton Oct. 20, 1942 Dreyfus Apr. 7, 1936 OTHER REFERENCES Dyestuffs Reporter, ages 297 to 301.

July 5, 1943, vol.