US2330251A - Fireproofing textile materials - Google Patents

Description

' Patented Sept. 28, 1943 FIREPROOFING TEXTILE MATERIALS William Ivan Taylor, Henry Charles Olpin, and Kenneth Ronald House, Spondon, near Derby, England, assignors to Celanese Corporation of America, a corporation of Delaware No Drawing. Application June at, 1940, Serial No. 342,504. In Great Britain July 28, 1939 ZClaims.

This invention relates to improvements in proofing and in particular to a method of fireproofing yarns, fibres, fabrics and other products having a basis of cellulose acetate or other organic derivative of cellulose.

Materials of the kind referred to above are considerably less inflammable than cotton so that the question of fire-proofing them does not normally arise. For certain applications, however, for instance in the production of theatre curtains and the like and of rugs containing such materials,-it is desirable still further to improve their resistance to fire. This has proved dimcult, primarily since most of the known fireproofing agents for fabrics are substantially lacking in affinity for organic derivatives of cellulose.

We have found that materials of the kind referred to above can be given a high degree of resistance to fire by causing them to absorb a halogenated ester of phosphorus such as tri- (monochlorethyl) phosphate from a dispersion of the ester in water or other liquid which is without substantial swelling action on the materials under the conditions of treatment.

This fire-proofing treatment does not adversely affect the mechanical properties of the materials. It can be carried out simultaneously with dyeing, or can be applied to dyed materials without causing bleeding of the dyeings.

The invention may be illustrated with reference to the fire-proofing of cellulose acetate yarn of heavy denier, e. g. denier of about 5000 or more, such as is used for the pile of rugs. Such yarn or rugs or carpets containing it can be rendered substantially-fire-proof by treatment with an aqueous dispersion of tri-(monochlorethyl) phosphate or like halogenated ester of phosphorus together with a suitable dispersing agent. The treatment is preferably carried out so that the amount of the ester deposited in or on the yarn is from -10%. This can be efiected in a treatment lasting between 3 and 5 hours at a temperature between '75 and 80 C. Temperatures in excess of about 78 C. tend to cause delustring. On the other hand, at lower temperatures, for example from 20 or 30 up to 50 or 60 C., the operation takes considerably longer.

In baths of the kind referred to above the cellulose derivative materials may be dyed simultaneously with the fire-proofing treatment by means of dispersed insoluble dyes..

The following examples illustrate the invention:

Example 1 A cellulose acetate yarn of denier about 25,000 is immersed in hank form in a bath of the following composition, the parts being by weight:

- Parts Tri-(nionochlorethyl) phosphate 1 A sulphation product of oleyl alcohol sold as Cyclanone C. A." 1.5 Pine 0.5 Water 200 By pine oil is meant an oil obtainable from pine-trees and of which the essential constituents are terpene alcohols, principally aand B- terpineols.

The volume of the bath is such that the amount of tri- (monochlorethyl) phosphate present is between 20 and 30% on the weight of the yarn.

The yarn is kept in the bath at a temperature between '70 and C. until it has absorbed about 5% of the tri-(monochlorethyl) phosphate. It is then removed and dried without washing.

Example 2 Parts Tri-(monochlorethyl) phosphate 1 Turkey red oil 2 Soap 0.3 Water 300 and the temperature of the bath is maintained at 78-80- C. In this way the yarn is delustred simultaneously with fire-proofing.

The process of the invention has considerable advantages over the introduction of fire-proofing agents into the spinning solution from which the textile materials are made as well as over the application of the fire-proofing agent in solution. In the first case the fire-proofing agents are very readily removed during the subsequent dyeing operation. In the second case the solvents used to dissolve the fire-proofing agent are apt to stiffen the materials treated or otherwise adversely aifect their physical properties and/or to cause bleeding oi dyes applied before fireproofing. The retention of the mechanical properties of the materials when treated according to the invention is of special importance when the materials comprise voluminous yarns such as can be made, for instance, by passing an ordinary yarn through crimping rollers, by highly twisting the yarn first in one direction and then in the opposite direction to produce a crimp, and/ or by spinning flat filament yarn with a content of a plasticiser, e. g. para-dichlorbenzene and crinkling the material by a hot aqueous treatment, if desired after converting it into yarn containing staple fibres, as described in U. S. application S. No. 83,274, filed J1me 3, 1936. The hot aqueous treatment may be the fire-proofing treatment of the invention and/or may be effected so as to modify the lustre of the material. Such voluminous yarns and/or cabled yarns made therefrom are of special utility in the production of rugs, carpets and other pile fabrics. The present invention is of particular importance in connection with the treatment of such yarns and fab IlCS.

A further advantage of materials fire-proofed according to the present invention is that the fire-proofing is resistant to dry cleaning operations involving the use of liquids such as petrol, ligroin, carbon tetrachloride and perchlorethylene. Naturally such operations reduce the fireproof properties of the material to some extent but a valuable degree of resistance to fire is retained in the materials of the invention even after several normal dry cleaning operations with any of the liquids specified above.

Instead of tri-(monochlorethyl) phosphate other halogenated alkyl esters of phosphoric acid may be employed, for example tri-(monochlorbutyl) phosphate, the corresponding tribrom esters and aryl and aralkyl esters of phosphorus, halogenated, for example chlorinated, in the and nucleus. Other esters of phosphorus though in general less effective as fire-proofing agents, can be applied by similar methods. Among these mention may be made of tributyl phosphate, tricresyl phosphate, triphenyl phosphate, triethyl glycol phosphate and ethyl glycol-dicresyl phosphate.

Although it is in general preferable to apply the fire-proofing agent indispersion in an aqueout medium suitable non-aqueous media may be employed instead, for example organic fire-proofing agents, such as triphenyl phosphate, which are insoluble in petroleum hydrocarbons can be applied in the form of a dispersion in such hydro-;

. nitrocellulose acetate.

chlorethyl) phosphate, a dispersing agent, pine carbons, and dyeing can also be effected simultaneously with the application of the dispersed fire-proofing agent in a non-aqueous non-solvent therefor. Thus, for example, water-insoluble azo dyes, water-insoluble dyestuffs of the nitro-diarylamine series, water-insoluble indigoid dyestufls and water-insoluble dyes of the amino-anthraquinone series, for example 1:4-diamino-anthraquinone, 1-amino-4-oxyanthraquinone, 1:4- di-(methylamino) anthraquinone and 1:4 di- (ethanolamino) -5:8dioxy-anthraquinone can be applied in a mixture of benzene or a liquid paraffin hydrocarbon and a carboxylic ester such as ethyl acetate as described in British Patent No. 460,575, the fire-proofing agent being dispersed in this mixture.

The invention has been described with particular reference to the fire-proofing and coloration of materials having a basis of cellulose acetate, but materials composed of or containing other derivatives of cellulose, for example cellulose propionate, cellulose butyrate, cellulose acetate-pro pionate, cellulose acetate-butyrate, ethyl and benzyl cellulose, can also be treated according to the invention. The materials treated may also comprise mixed organic-inorganic esters such as The process of the invention however does not purport to render materials of nitrocellulose non-inflammable nor is the term fire-proofing even when used of very much less inflammable materials such as cellulose acetate to be regarded as necessarily involving a complete removal from the materials of the capacity to burn.

Having described our invention, what we desire to secure by Letters Patent is: v

1. Process for fire-proofing textile materials having a basis of an organic derivative of cellulose, which comprises impregnating the material with from 5 to 10%, based on the weight of the textile material, of a halogenated alkyl ester of phosphorus by immersing said material in a bath containing a halogenated alkyl ester of phosphorus, a dispersing agent. pine oil and water.

2. Process for fire-proofing textile materials having a basis of cellulose acetate, which comprises impregnating the material with from 5 to 10%, based on the weight of the textile material, of tri-(monochlorethyl) phosphate by immersing aid material in a bath containing tri-(monooil and water for from 3 to 5 hours at a tem-' perature between to C.

WILLIAM IVAN TAYLOR. HENRY CHARLES OLPIN. KENNE'I'H RONALD HOUSE.