US2052886A - Treatment of various materials for rendering them impermeable and fireproof - Google Patents

Description

Patented Sept. 1, 1936 UNITED STATES PATENT, orrice TREATMENT OF VARIOUS RENDERING THEM llVlP FIBEPROOF Yvonne Aimee Raymonde Leroy,

France, assignm- MATEBIALS FOR ERMEABLE AND Asniereo, Brick Trust Limited,

London, England, a. British company No Drawing. Application May 14, 1934, Serial No. 725,592. In France May 1e, 19::

1 (Cl. iii-sci or potassium silicate, aluminium acetate, fluosilicate etc., baths of sulphonated oils, lubricating substances of vegetable or animal origin, liquefied by heat, fatty matters, organic acids rich in carbon and their ethers etc., which processes have for their object to coat the surface of the pasteboards, papers orfabrics with a layer which penetrates more or less deeply into the interior and which, forming a slight protective film, prevents the water from moistening their surfaces.

Each of these processes has a perfectly definite object and imparts to the paper, pasteboard or fabric which has been subjected to it, special qualities either of impermeability to water, or resistance to fatty bodies or of protection against slightly acid bodies, and satisfying in general one or the other of these objects, while not one satisfies all of them togetherwhich facts are all known.

These processes, however, in addition to their high cost, have the defect that they cannot be applied indiscriminately with a view to imparting any form of protection whatever, and that they each necessitate a list of a few classes or products appropriate to them and without which they are not effective. Some of them even necessitate the use of fairly high temperatures lying between and centigrade, making a strict supervision necessary and running the risk of the heat exceeding the safety line beyond the degree at which cellulose, entirely dehydrated and having undergone too strong a desiccation, commences to carbonize or to lose its fibrous texture;all these facts are also known.

It is known in particular that there exist numerous processes for the impregnation of pasteboards, papers or fibrous materials, which proc esses usually employ paraflins, hydrocarbons, tars, alums or the like, depositing upon one of the sides or sometimes upon the two sides of the paper, pasteboard or jute sack to be waterproofed,'an insulating film;-it is sometimes even necessary specially to prepare the surface of the paper or of the pasteboard, in order that the impregnating material may in consequence adhere to it, and for this reason certain processes mention the use of hydrolizing salts and of paraflins melted and the material to be treated subsequently being passed under calenders heater to high temperatures, etc.

The present process is not satisfied with simply covering one side or the different sides of the product to be protected, but it penetrates into the interior of the cells, surrounding all the capillary shaped bodies, modifying their internal texture,

by the application and the fixing of an impregnat- 10 ing and fireproofing material.

The modifications which it efiects in the papers, pasteboards, or the like, are the absolutely direct results of the said process and the changes which it causes the materials treated to undergo are due 15 to its.own effect which is manifested in the different stages intended for the improvement of the material treated, thus permitting novel applications and novel industrial uses.

The present invention has therefore for its object a process for imparting to any paper, pasteboard or fabric, as also to all fibrous or woody material, treated according to the method disclosed below, qualities of impermeability to water, alcohols, hydrocarbons, humidity, acids. fatty bodies, butters, dairy products, greases, soft soaps, fertilizers, superphosphates, efllorescent, hydroscopic or humid products, fresh fish, meats etc., and even to certain aeriform bodies.

Furthermore, it transforms the composition of the paper, pasteboard, fabric or any other woody material in such manner that this becomes the base of a fireproof product which, under the action of heat arising from the combustion of gas or vapours, will carbonize without fire or flame being able to develop therefrom, or to extend or be transmitted, this even being extinguished for want of combustible elements.

The present process of impregnation and fireprooflng is applicable to all paper, pasteboard, fabric, fibrous or woody material, either at the outset or in the course of its manufacture or at the completion of this manufacture, whether the material obtained is glued or not glued, whether it is in sheets, in reels or transformed into manufactured objects such as boxes, containers, bottles, pots, tubes, various receptacles of any shape whatever, carpets, cords, strings, tapestry, sacks etc.

Furthermore the papers, pasteboards, or the like, treated by the present method and subjected to stamping, folding or other mechanical operations no longer break and do not crack at the part stamped which will remain impermeable.

The present invention adds to all the qualities disclosed above, both from the point of view of resistance to water, greases, and to salts, as well i as of resistance to the transmission of fire or flames, the following qualifications:which are only given by way of example and are not restrictive: a

lstThose ,of being able to be obtained by the use of chemical products of current sale on the market and the extremely low price of the said products.

2nd-Those of being able to be applied, for papers or pasteboards in particular, by the utilization of a very simple apparatus interposed between the rollers of the machines previously installed, and before passing under the finishing calenders. e

3rd--Those of substituting for certain baths at present employed for the initial manufacture of volatile solvents.

5th--Finally, those of only utilizing temperatures in the neighbourhood of 50 centigrade, which will have no influence upon the hydrated composition of the material employed.

Other characteristics will be seen from the following description in which there will be described not only the various manipulations necessitated by the reaction, impregnating or fireproofing baths, but the apparatus which will be used for the application of the process forming the object of the present invention and the principles of its application.

To carry the invention out in practice, according to one example as applied to the treatment of paper, the paper is caused to pass from the roller or reel from which it unwinds, into the first bath.

This first bath consists of an aqueous solution obtained from a combination formed by a metallic' carbonate such as sodium carbonate with a fatty acid such as stearate acid, which is saponifled by said metallic carbonate.

On leaving this first bath, the paper passes under or between rollers which force out the solution in excess and returns the liquid thus recovered into the initial bath.

The fibres are thus impregnated with an emul sion of alkaline salts of fatty acids.

The paper then passes into the second bath constituted by an aqueous solution of zinc sulphate of a more or less high percentage according to the qualities aimed at.

On leaving this second bath, the material passes under or between rollers which press out the solution in excess and return this excess into its vat.

The fibres are thus impregnated with the resulting stearate of zinc, insoluble in water, alerhol or ether, which is formed by the double decomposition between the sulphate of zinc and the sodium stearate, both in aqueous solution; the fibres are thus made non-wettable in the ordinary sense.

The paper, pasteboard or fabric then passes into the third bath constituted by an aqueous fireproof and non-oxidizing solution of 10% of salts comprising: 1% of hydrated sodium borate, 5% of sodium phosphate, 2%, of ammonium phosphate, 1.5% sodium tungstate, and 0.5% 'of phosphorus oxychloride.

' The fireproof qualities of this solution which I constitutes one of the remarkable features of the presentinvention, considerably diminish the infiammability of the organic bodies, since they oppose the propagation of fire and burning or combustion. I

The proportions indicated may, of course, vary to a great extent without thereby departing from the scope of the invention.

phosphate PO(OC2H5) and this be then mixed with the first solution, and in the same way the result would be better still if the zinc ethyl in ethereal solution were added to the phosphorus oxychloride, which would give rise to chloride of tretrethyl phosphonium, but prices asked for by the makers of chemical products for zinc ethyl make the use of this product prohibitive as an anti-oxygen.

In the present invention, the sodium tungstate is utilized to compensatefor the ammoniacal losses which the heat of the calenders might occasion, although these latter are kept at very low temperatures, varying between 30 and 75 centigrade, with a mean of 50 centigrade;- furthermore, care is taken to add to this solution of borated phosphatotungstate, a small quantity of gelatine which will serve as a support to the internal impregnation of the fibres and to the protective coating whiclrwill prevent the action of the oxygen of the air on flame, fire or combustion, with which protective coating the fibres will be covered on leaving the third bath.

The material then passes under rollers which press out the fireproofing and anti-oxidizing liquor in excess and carry it back to its vat.

Continuing its cycle of manufacture, the material passes into the fourth bathcomprising an aqueous solution of oxide of methylene which will render insoluble the colloidal support which it has taken up in the preceding fireproofing bath;- rollers will compress it at the exit from the' bath, and the excess of the methanal solution will be returned to its original vat.

The bath or baths which follow will be simple washings, at ordinary temperature in water to which is added a small quantity of phosphorus oxychloride or chlorine or calcic salts, and the material again compressed will be dried, calendered and glazed and it may thenbe given all the usual decorations, g'raining, or the like; it is then placed on reels, in sheets or inpieces and supplied to the trade.

For ease in carrying out the operation of impregnation and fireproofing, the vats filled with solutions kept at the most suitable temperature may be replaced by pistols or other apparatus spraying or atomizing the said solutions, the final washing taking place between sprayers. The

drying may also be facilitated by the use of vacuum or hot air,-in the same way, that each impregnating vat may be followed by heated calenders, dehydrating more or less on its passage the material under treatment, which will improve its absorbent qualities when passing into the following bath.

The concentrations of the solutions above described may vary according to the nature of the cellulose constituting the papers or pasteboards, of the threads which constitute the fabrics, and of the vegetable fibres used in the manufacture of the cords, and in general of any texture, textile fabric or ligneous material treated or to be treated, and minimum time of steeping, of moistening in the baths or of spraying or atomizing by compressed air pistols. On the other hand, if it is desired simply to treat cords, fibres or ligneous materials not wound on drums or reels, it is sufficient to plunge them into the above-mentioned baths.

To obtain less resistant qualities, the papers, pasteboards, fabrics or other ligneous materials, may be subjected to much more ordinary treatments by replacing the metallic stearate mentioned by any other metallic stearate, and the colloidal product serving as a support for the fireproof material by any other product furnishing a ,gel adapted to be made insoluble in the course of the subsequent fireproofing operations.

Pasteboards, papers or fabrics, once treated by the above-disclosed process, are entirely modified in their composition and have acquired as a consequence of the said treatment, remarkable qualities of impermeability which will permit their use in particular for packing and the despatch of merchandise, of humid products, fatty matters, soft soaps, roasted coffee, fertilizers, salts, chemical products, fresh fish, materials likely to soil, diary products etc.

Thus, it is possible to impregnate receptacles intended to contain hot liquids, coffee, punch, grog, and in general, all hot drinks, whereas this is impossible with receptacles impregnated with parafiin, or bodies melting between 45 and 63 C.,

The remarkable resistance to acids will permit in particular the manufacture of special objects in. impregnated paper (mittens, gloves, coats, overalls, smocks, gauntlets, etc.) intended for the protection against gaseous bodies of the personnel composing the cleaning corps charged with disinfecting places contaminated by projections of dichlorethyl sulphide, or the like, the said articles of clothing thus constituted, being of little value,may be destroyed or buried when the work is over, without having to fear the accidents which take place during the cleaning of the special articles of clothing actually provided or used, and composed generally of oiled or rubbered cloth, the seams of which must be made impermeable by special varnishes, and the cost of which is somewhat high;the closing of refuges or shelters for the protection of the civil population against gases,-the covering or roofing of places to be protected or to be camouflaged by papers thus treated, etc., in a word, all the protection so difiicult and dangerous against discharges of dichlorethyl sulphide will be ensured by papers thus treated which, once contaminated, will be destroyed,-their low prime 5 cost enabling their cleaning to be dispensed with and the dangers resulting from this delicate operation thus avoided.

The present invention consequently permits of obtaining a more complete and durable impermeability of papers, pasteboards, fabrics or ligneous materials, in particular in the use of packages for dairy products, humid, acid, efliorescent, and hygroscopic products, etc. than with the processes at present known.

The present invention permits of adding to this said novel process of waterproofing-fireproofing qualities obtained by novel processes which by their anti-oxygen form will insulate or oppose any development of fire, of flames, or of combustion.

The present invention is very economical both from the point of view of the price of the initial materials used as from that of the cost of the plant permitting the said impregnation and fireproofing.

The said invention by the mixture, reactions or combinations of the bodies employed for protection against humidity, acids, water, fatty bodies, etc. ensures to the materials thus treated, an impermeability superior to that known hitherto in the field of the protection of products having an absorbent character.

The present invention by the mixture, reactions of combinations of the products employed for fireproofing the materials treated, ensures to them a protection superior to any hitherto known in the field of protection against fire.

The present invention permits of transforming by its application, the bodies treated into new products, having novel qualities, novel uses and absolutely novel applications in all departments of industry.

Naturally, the shapes, details and materials of the invention may be varied without interfering with its principle, and that it is in no way limited to the methods of execution described, which have only been selected by way of example.

What I claim and desire to secure by Letters Patent of the United States is:-

A process for treating fibrous materials to render them impervious to liquids and fireproof, which comprises impregnating the material with zinc stearate by treating said fibrous materials successively with sodium stearate and zinc sulphate, then treating the material thus impregnated at 30-75" C., with a fireproofing solution prepared by mixing together a solution comprising an alkali tungstate, borate and phosphate with a solution obtained by mixing aqueous ammonia with phosphorous oxychloride, then treating said material with a solution of gelatine, and finally hardening the said gelatine by treatment with formalin.

YVONNE AIMEE RAYMONDE LEROY.