US1784804A - Variegated floor covering and method of making same - Google Patents

Description

Dec. 9, 1930; c. ELLIS 1,784,804

VARIGATED FLOOR COVERING AND METHOD OF MAKING SAME Filed Dec. 5, 192

COLOR VAMEGATED TREAD. I

FLEX\BLE SHEET SUPPORT Qwuawto'z 'CRRLETON E LUS.

Patented Dec. 9, 1930 FF! C E GA R-LETON ELLIS, F MONTCLAIR, NEW JERSEY, ASSIGNOR '1'0 ELLIS-FOSTER COMPANY,

' A COR-PQRATION OF NEW JERSEY VARIEGATED FLOOR COVERING AND METHOD OF MAKING SAME Application filed December 3, 1926.

This invention relates to floor coverings containing a cellulose ether or ester as the primary or essential plastic and binding agent, and relates particularly to floor coverings containing nitrocellulose.

The drawing shows a cross section through one form of a floor covering made in accordance with the present invention.

In the preferred form of the invention a plastic tread composition is applied to a supporting Web or fabric. Such a support or backing preferably paper or sheets of pulp material, but in some cases, and for more ex pensive products, cloth, burlap, and the like, may be utilized.

The paper material does not need .to be prepared from high grade expensive fibre, but may be made from ground wood, with perhaps some addition of sulphite fibre, and the like, to add strength. Various cheap fibres may be employed since the paper backing is practically concealed, being in contact with the floor. The paper may be dyed in difierent colors, if desired, so as to correspond in tone with that of the tread composition, or may be of any other shade. Preferably such paper is rendered water resistant. This does not mean that it is necessarily absolutely waterproofing, but a sufficient amount of a waterproofing agent, preferably is present. to preclude disintegration in case the floor becomes wet or when the floor covering is used in a damp locality that absorption of moisture will not cause any undue swelling of the paper backing with consequent distortion or buckling.

In some cases asphalt-saturated paper of a grade known as felt may be employed. This saturated felt is highly water resistant, but has the disadvantage when white or delicately tinted floor coverings are desired, of soiling the tread composition or throwing it ofi shade. This is due to small particles of Serial No. 152,520.

erings, I preferably do not employ a paper backing saturated with black materials.

A suitable paper for backing purposes made from ground wood and sulphite pulp carries some rosin size to give strength and wax particles preferably introduced into the paper by adding dispersions or emulsions of paraffin wax or other waxes to the pulp in the beater engine. In this way a wax-sized paper is obtained, which although containing but'a small amount of wax, say from 1 to 5 per cent, is quite water resistant. Paper appropriate for the foregoing purpose is described in U. S. Patents Nos. 1,607,517-8-9 and 1,607,- 552 all of November 16, 1926.

Thin paper preferably is used for the backing, and in order to avoid splitting of laminations, enough rosin size or other binder should be present to cause the fibres to adhere tightly. Papers of the kraft type are useful when waterp-roofed in the manner aforesaid. I prefer'to use a thin paper-for several reasons. In the first place the paper itself does not afford any great amount of cushioning effect and I preferably rely on the tread composition applied to the paper to obtain such a cushioning quality. In the second place a heavy paper, unless saturated with some material like asphalt or pitch, is prone toexpand when in a moist place and cause buckling. A paper which is only thick or stifi enough to be passed through the sheeting rolls and, receive a layer of tread composition is satisfactory and does notintroduce any objectionable amount of paper stock into the product.

While I have thus stated the preferred form of the invention, I do not wish to be limited to the employment of such thin paper, but may use thick papers as occasion requires and may employ saturated felt as conditions warrant.

Preferably the paper has a rough texture or open surface, for example, showing marks of screens or felts employed in making the. paper, preferably being uncalendered or only lightly calendered and preferably beingfree from oily substances or such a quantity of waxes as would serve to repel the nitrocellulose tread composition and prevent proper i adherence. It is important that thepaper backing does not at any time peel away from the tread. Nitrocellulose does not adhere Well to surfaces oiled with, for example, mineral oil.- It does not adhere .well to a waxed surface, but by employing a wax .emulsion in making the-paper, but having the latter possess a fairly'rough surface, adequate adherence of the tread composition results.

The repellent effect of nitrocellulose on wax is recognized, and I believe the employment by me of waxed paper to which a nitrocellulose composition will actually adhere constitutes a novel feature in the floor covering industry.

A suitable paper may be made from ground wood-and sulphite p'ulp as aforesaid, having a thickness of about mm. and containing 2 or? per cent of rosin size, and from 1 to 5 per cent of wax size.

The pa er may carry various fireproofing salts or su stances having a fireproofing and waterproofing effect, as for example, bydrated calcium sulphate, some of the highly chlorinated compounds of benzol or naph thalene, chlorinated petroleum asphalt, and the like. Any substances to go into the paper for fireproofing or for other reasons should not have a harmful effect on nitrocellulose. For example, the latter is affected by alkaline substances and therefore it is not desirable to have-any condition of alkalinity which will have an objectionable effect on the nitrocellulose contacting with the paper surface.

As a floor covering should rest fiat on the floor and as thick paper is liable to curl, the employment not only of thin paper, but of paper impregnated with substances which render it more flexible or pliable, or which absorb moisture and keep the paper from becoming bone dry sometimes are desirable. Salts such as calcium chloride or magnesium chloride are hygroscopic and also have some fireproofing qualities. Glycerine and glycol likewise may be employed for such special result. The paper-may be impregnated with resins which do not have any objectionable discoloring effect on the tread material and which afford more waterproof products. In some cases certain vegetable oils, and the like, maybe introduced into the paper structure.

The tread composition may be applied to thepaper backing in various Ways. but I prefer applying itowith the aid of sheeting rolls. These are of the type used in milling rubber and for calendering purposes. Preferably differential rolls are employed, that is, one roll runs slightly faster than the other. These sheeting rolls may be set to feed the paper horizontally through them or their position may be altered so the paper feeds vertic-ally down through the rolls or other angles of feed may be employed.

The composition employed for sheeting preferably is of a putty-like consistency, or

.tread' surface.

even slightly stiffer than putty. When a mass of it is squeezed in the hand preferably liquid should not exude nor should it stick very readily to the hands. Preferably it should be as dry as i's-consistent with applying it to the sheet of paper in a smooth layer. Such a putty-like product when made according to the preferred form of the invention has nitrocellulose as the primary cementing or binding agent, incorporated with plasticizer and filling material preferably of a fibrous character.

Antacid materials may also be present and in many cases I prefer to employ a certain proportion of volatile solvent, as will be more fully hereinafter set forth. 'The sheet of paper is'fed through the rolls and while it progresses the plastic tread material' is placed on the paper. before the rolls and as. paper and plastic pass therethrough,

the tread composition is squeezed tightly into contact with the paper and thus orms the Such tread surface may be further rolled or calendered while still plastic to smooth the surface, or to disturb it in order to give texture, all depending on the character of the surface finish desired.

In some cases it is possible to extrude a sheet of the tread composition and permit'it to fall on a traveling sheet of paper, the. latter serving as a backing either temporary or permanent. In other cases, especially when .a high proportion of binder is present, it-is possible to eliminate the paper backing entirely.

Floor coverings of the linoleum type as made today, have a smooth surface. This gives a severe kitchen-like effect and limits the applications of linoleum to a very considerable degree. On the other hand, roughfinished textured effects would afford a type of floor covering of muchgreater artistic possibilities than the harsh smooth and even glossy surfaces of the present day linoleum, congoleum, and so forth.

A suitably textured floor covering may be made from nitrocellulose, as will be hereinafter more fully described.

Light colored effects have an important field of application. A pure white floor covering is desired because of its sanitary appearance. Rubber, boiled oils, and resins such 'as are employed in present day floor coverings make it diflicult to obtain a pure white. Using nitrocellulose, it is possible to obtain a practically pure white tread. Having such a pure color, it is then possible to add various tints and obtain new effects, for example, soft green, rose, pastel shades, and the like, which are not obtainable if the ground color is not pure white. This, if coupled with the aforesaid textured efi'ect, enables floor rugs to be ance, may be used in the home, or in hospitals,

made, which because of their'artistic appearnr w) public buildings and the likein a widespread manner.

The procedure therefore overcomes the kitchen-like severity of ordinary linoleum and yields new decorative effects of great possibilities.

Having obtained a white or light-colored background it becomes possible to introduce into the sheeting small masses of other and more intense colors and thus obtain mottled or variegated color effects. This result may be obtained by adding small particles of colored tread composition to the mass of the main tread composition as it is passing through the sheeting rolls. A better procedure is to sheet the main tread composition on the paper backing and as it emerges from the sheeting rolls to scatter small masses of colored tread composition over the moist surface and allow the sheet to pass through a second set of rolls, thereby rolling the colored masses into the tread and squeezing such masses over the surface to distribute them in a variegated manner. Thus. innumerable i'nulti-colored or polychrome efiects may be obtained.

If desired, instead of using two sets of rolls there may be a plurality of rolls and different colored masses added between the different rolls, all while the light-colored ground mass of the tread is sufiiciently moist and, Plastic.

Using a white ground, for example, and

adding small particles of green. plastic composition,

will give a'product with a white background and splotches or streaks of green. in a similar manner white and rose, or white and black combinations may be secured.

The addition of such supplemental colors is not as well carried out on a single set of rolls, that is, conducting the operation of sheeting and coloring all on one set of rolls as by the use of auxiliary rolls. There is a greater tendency when using a single set of rolls in getting some of the coloring compositions so much mixed in with the main tread composition that the latter becomes simply discolored and the well defined mottled effects desired are not produced in the same satisfactory manner. Purity of the ground tone color is highly important and the present invention makes it possible to secure technical results of the character specified through the availability of such pure ground colored tread composition.

In some cases also it is proposed to extrude onto a light-colored tread composition tiny streams of composition of a stronger color and cause the sheeting to pass through a second set of rolls, whereby the extruded material is impressed into the main tread composition. This enables stripes of color to be obtained. If the extruding tubes are given a lateral movement while the sheeted material is fed forward, the stripes will have an undulating character.

Again, it is possible to reverse the color effect and to apply lighter colored material in small proportion to a dark pigment.

. In making the plastic composition I may employ nitrocellulose of high viscosity or of low viscosity, or may use mixtures of these. Also, it is possible to use scrap celluloid and other nitrocellulose waste or products which may not'be'suited for other purposes,'as for example, to make smokeless powder. Since a floor covering contains nitrocellulose distributed through a large amount of filler, and since it is possible to have in such filler an abundance of antacid material such as zinc oxide, chalk, magnesium oxide, magnesium carbonate, and the like, nitrocellulose that might be considered dangerous if used in some directions is available for making floor coverings. There is therefore an outlet for low grade cellulose for the present purpose. Nitrated wood and other analogous nitrocelluloses may be used in whole or in part. Preferably I employ celluloid nitrocellulose, or what is termed celluloid cotton as the binding agent. This has great toughness and a viscosity which is desirable in some sheeting operations. The viscosity reckoned in terms of lacquer viscosity is approximately 25. or seconds, or may be higher, for example, seconds. Nitrocellulosehaving a-viscosity of 4 or 5 seconds also may, be used.

With the celluloid cotton or nitrocellulose 1 preferably employ a plasticizer such as dibutyl or diamyl phthalate, acetin, triphenyl and tricresyl phosphates. The tricresyl I phosphate is especially desirable as a plasticizer because of its tendency to gender nitrocellulose slow burning. By incorporating a s uflicient amount of the tricresyl phosphate along with a substantial proportion of mineral tiller and possibly using some chlorinated hydrocarbon to saturate the paper backing a relatively and notably fire resistant .fioor covering may be obtained.

Ill)

Castor. oil or rapeseed oil, preferably of I the blown type, sometimes may be added to the composition to yield greater flexibility.

A floor covering or rug which flattens effectively is obtained desirably by incorporation with the celluloid cotton or other nitrocellulose of a quantity of an appropriate resin, one which 18 compat ble with nitrocellulose. A series of resins have been described by main copending applications,

as for example, in Serial Nos. 149,528, 150,387, 142,532 and 144,647. Appropriate resins are those made'b-y reacting glycerine or glycol with various crystalline organic acids or anhydrides such as phthalic, or succinic and with a free fatty acid of glyceride oils, as for example, the fatty "acid of cotton seed oil. In application, Serial -No. 142,532, compositions are claimed which inters and protecting resins, particularly those of the oil acid type. In application, Serial No. 144,647, the claims are directed to resins and process of making such resins by the use of distilled or heat treated fatty acids. In Serial'No. 149,528, the claims are directed to floor coverings including nitrocellulose tread layers containing wax as well as print ed designs or figured coatings of that char- ,acter, and also burnished coatings. In Serial No. 150,387 the claims are directed to 'the use of wax paper cores or otherwise waterproofed paper cores containing or carrying nitrocellulose tread, particularly the sheeted tread, and also to processes of sheeting such compositions upon the stated paper cores.

The glycol resins of this character are quite soft-and have some plasticizing effect.

Most natural resins shorten the life of nitrocellulose coatings, whereas, the resins aforesaid act aspreservatives. However, I do not wish to exclude additions of natural resins or of various natural resins which have been modified by chemical treatment, as for example, rosin ester.

The above resins which have the compatible properties noted may be added in considerable proportion to assist in obtaining a non-curling rug. By employing a goodly proportion of plasticizing material and soft compatible synthetic resin, the desired flattening effect may be secured.

As pigment there may be used for white sheeting such substances as lithopone, zinc oxide, white lead sublimed lead, lead sulphate, barytes, chalk, and the like. Titanoxv is also astrong white, but is not wholly a pure white, and in'some cases has been observed to have an action on nitrocellulose. Some of the pigments have an antacid effect which is desirable. Colors or pigments are added to tint as desired.

Certain mineral substances such as calclum sulphate containing the maximum.

amount of water of hydration are desirable as fillers because they tend to reduce the infiammability in a very marked way.

In addition to the mineral antacids I may use organic antacids such as urea or amines.

The character of the fibrous material employed as filler is important as on this to a certain extent depends the strength and flexibility of the tread and its cushioning ef-- fect. Asbestos fibre, \ground wood, sulphite pulp, and the like, may be used, according to the character of the floor covering desired. When a cream colored finish or darker effect is wanted, ground cork of a fineness passing say 60-80 mesh is useful.

For a white textured effect a considerable proportion of cotton flock, linters, bleached sulphite pulp, and the like, may be used.

The greater the proportion of material such as cotton flock, employed, the more textured, as a rule, will be the surface. In pass ing through the rolls the cotton flock gathers to some extent and sets irregularly, giving a wavy, rippled or flow-marked surface or what may be termed in some cases, an elephants hide effect.

Suflicient nitrocellulose and pigment to fill in around the fibres of such textured surface and not afford crevices for dirt to lodge in is desirable as floor coverings even of the textured type should have a surface capable of being cleaned readily.

A solvent frequently is required in rendering the nitrocellulose com osition sufliciently plastic to be smoothly or adequately sheeted and such solvents may be those which are known as high-boiling in the lacquer industry, as for example, primary and secondary butyl and amyl alcohol and their acetates,

diacetone, alcohol, ethyl-lactate, butyl propionate, and so forth. Using these high-boilwith some of the high boiling solvents. This is sometimes advantageous in securing a good sheetin effect. Methyl acetone also may be used, li ewise, methyl and ethyl acetate. Isop ropyl acetate is not as powerful a solvent, but may be used to advantage as it is fairly cheap. Associated with the nitrocellulose solvents may be various diluents for the sake of cheapness, as for example, benzol and toluol, light petroleum benzine, monochlorobenzol, and the like.

However, the employment of such cheap hi hly volatile solvents brings with it the difiiculty that the masses of material on hand in the workroom dry out too quickly, besides giving off a large amount of vapors which pollute the air. To obtain a workable com position which remains plastic for an indefinite period, I introduce a small amount of a mineral wax, as for example, ceresin or paraffin wax. This gives to the composition two very useful qualities. In the first place, it does not dry out quickly at room temperature, but remains plastic 'and workable for a relaout very quickly at temperatures above. say,

F. Thus, it becomes possible to dry and sheet the composition very rapidly. This is not true with some of the high boiling solvents mentioned, these requiring more protracted heating, and even so, the odor sometimes is retained ina thick composition for a long time and may be identified even after the finished rugs have been kept for or shellac wax, may be added, in some cases.

Hot calendering enables a more polished surfaceto be obtained when desired.

Sometimes it is desirable to have the solvent employed in the plastic material of low inflammability and in such cases I may intro duce non-inflammable solvents, as for example, carbontetrachloride or trichlorethylene. The latter is preferable to the former because it is less likely to become acid and also because it may be usedfor dilution of a nitrocellulose solvent'mixture to greater advanta e.

lin order to secure a non-inflammable plastic a solvent for nitrocellulose should be used which is not too highly inflammable. Acetone and methyl acetate are less suited than ethyl acetate, isop'ropyl. acetate, and some. of the higher esters. Mixtures of isopropyl acetate or isobutyl acetate with trichlorethylene, when incorporated with nitrocellulose, filler, plasticizer and'tricresyl phosphate, with or without a synthetic resin or preservative solid, will be found to possess very little, if any, tendency. to inflame on bringing, for example, a lighted match, near a mass of the material. If a flame is held in contact with the material for a sufficient length of timethe solids themselves may take fire, but the rateof combustion. is comparatively slow and the fire hazard therefore is greatly reduced. Incorporation of wax in such a composition greatly reduces the tendency to evolution of vapors and this is desirable not. only from the standpoint of fire hazard, but because the mass of material for sheeting is maintained in a state of uniform plasticity over a considerable'period.

In'some cases chlorinated ethylene,,that is, ethylenedichloride, or Dutch liquid, may be used to reduce 'infiammability.

While the desirability of using a volatile solvent, that is, quick-drying, after the completion of sheeting has been emphasized,.it should be understood that I do not exclude sheeting with hot rolls without solvents, but.

with suflicient plasticizer and/or resin to obtain an adequate softening effect. Such hot sheeting cannot be carried'out very satisfactorily with ordinary asphalt-saturated felt because the temperature of sheeting is usually higher than the melting point of the saturating material and the latter is therefore squeezed out of the felt between the rolls.

There are cases also when water emulsions of nitrocellulose and plasticizer may be employed, using for example, bentonite as an emulsifying agent. a

When it is not appropriate to produce a tread of suflicient thickness in one sheeting operation, a tread may be formed, dried and a second layer of tread composition shected on the first, so that there is obtained one tread layer superposed on another. This procedure may be repeated, if desired, to obtain a plurality of tread layers.

On the other hand, it is also feasible to sheet first on one side of the paper support and then to sheet the other side. In this way treads opposed to one another are obtained and rugs or runners may be made in this manner which are reversible. When one side has been worn out the rug isreversed and a fresh tread surface becomes available. These opposed tread layers may, if desired, be of different colors.

- One form of the invention is that in which the rugs, runners,'or other forms of floor covering take for shipment. To prepare for transportation the floor covering is rolled so that the flexible sheeting support of paper backing is on the inside, while the tread compositionfaces outwardly, that is, a cross section of the roll would show the tread of each spiral or convolution facing outwardly, while the paper support would be facing inwardly.

-This, of course, applies to products having the tread on only one side of the paper backing. By rolling in this manner the tread surface is maintained in a state of extension, a condition which is highly desirable, especi'ally in the case ofsurfa-ces of the textured character described. Rolling such rugs with thetread facing inwardly places the tread surface under compression and tends to affect its textured character. Hence,- one form of the invention is concerned with a floor covering in roll form comprising a flexible sheeted support carrying a nitrocellulose tread composition, as for example, one having a textured surface; said roll having the tread composition facing outwardly, whereby the tread face is maintained in a state of extension.

In accordance with the foregoing there may be obtained a floor covering such as a rug, runner, or strips, latter being intended to be laid in parallel, e. g., to cover a floor stand exposure to such contact with water as is likely under reasonable service conditions;

paper waterproofed paper, waxed paper,

Wax-sized paper, and the like, carrying a nitrocellulose tread composition adapted for underfoot usage; such floor covering preferably having an ornamental surface secured by the use of pleasing'colors, variegated colors, textured finish, andthe like.

A textured effect such as is obtained b embossing a design by means of rolls is not as satisfactory as the method of destroying the smooth continuity of the surface to obtain an irregular reflection of light by sheeting material containing fibrous masses which are somewhat lumpy and which on passing through the sheeting rolls form the rough surface noted. The employment of emboss ing rolls, however, is not precluded in some cases. I

In one form of the invention, a volatile solvent, or water, is present in the plastic tread composition and after sheeting this on a support, the product is rapidly heated to cause bubbles or pores to form. When this has progressed sufficiently the sheet may be re-rolled to smooth out the surface somewhat. A more cushiony effect is obtained in this way. The combined effect of this with aresilient filler such as Wood flour or ground cork is advantageous from the cushioning standpoint.

Another filling material which may be used to good advantage in making a more fire resistant product is vegetable ivory waste. This material inthe form of fine fragments or dust is a by-product of the manufacture of buttons, and the like. It does not have the same combustibility as, for example, wood flour. Being very light in color it is used to good advantage in making white floor cover ing or light-colored and variegated products.

, waterproofing agents.

When paper is used as the backing material, in addition to impregnating it with ammonium phosphate and incorporating, for example,-paraflin wax as a waterproofing agent, I may also use chlorinated naphthalene such as the tetra or penta chloride of naphthalene, perchlorinated benzol, chlorinated asphalt, and the like, as sizing or These chlorinated compounds confer fireproof qualities as well as acting as waterproofing agents. In addition, chlorinated naphthalene, and the hke, may be incorporated in the tread composition as a polishing agent and also to depress combustibility.

A feature of my invention is the employment of mineral salts containing water of;

crystallization or hydration. A salt which is suitable for the purpose is finely-ground or precipitated calcium sulphate containing 2' molecules water. If plaster of Paris, that is, calcined calcium sulphate, is moistened with water, ,it gives up morejthan 2 molecules water and this perhydrated' sulphate is a useful filler to employ in making tread compositions. In order to obtain fire resistance to a high degree I preferably employ a sub.- stantial proportion of the perhydrated calcium sulphate.

In some cases nitrocellulose, as for example, celluloid stock, may be used wet with water. This avoids drying the nitrocellulose prior to use and enables it to be stored safely and to be handled with a considerable degree of impunity. In using such material, if desired, a portion of the water may be absorbed by mixing calcined calcium sulphate, e. g., plaster of Paris, when this hydrated Water is absorbed from the nitrocellulose and dries it to the extent corresponding to the amount of plaster of Paris added. It is important to avoid mixing the plaster of Paris in such a manner that the nitrocellulose mass becomes heated to an objectionable degree due to the reaction of hydration.

When wet nitrocellulose is employed and all the water is notabsorbed by'a dehydrating filler, the nitrocellulose may be converted into a kind of an emulsionwith plasticizer and posslbly a solvent such as butyl acetate or amyl acetate not miscible with water. Ad'- dltional water may be added if desiredin order that a putty-like material results when the bulky filler is added. In other words, the water serves to replace a volatile solvent in whole or 1n part, to produce the puttylike sheeting composition.

When triphenyl or tricresyl phosphate is used as a plasticizer for nitrocellulose in tread compositions which are white or lightcolored, the employment of zinc oxide or cer- I colored or pure white tread. Plasticizers which do not have anydiscoloring action or pigments and antacids which do not have a sapomfying action on triphenyl phosphate or tricresyl phosphate may be used. form of the invention I contemplate for example,'tricresyl phosphate as the principal plasticizer with pigments, fillers or antacids inert or innocuous thereto. Likewise, when synthetic ,resins such as those of the gelpceride type mentioned above are employ preferably a basic pigment is avoid- In one using,

ed which will saponify the resin and cause hardening or brittleness. Hence I prefer to employ pigments, fillers and antacids substantially free from destructive or harden ing action on these resins.

From the foregoing it will appear that I preferably employ in tread compositions containing nitrocellulose with both syntheticresins and plasticizing agents, a type of pigment, fillers and antacids which are inert with respect to such essential substances, or, at least, have no objectionable action. Just as I prefer to employ a synthetic resin compatible with nitrocellulose, so I prefer to employ pigments, fillers and antacids which are compatible with nitrocellulose, synthetic used. 5 parts of paraffin wax also were'incoreluding paper.

porated to renderthe composition: slow drying at room temperature.

- The materials were thoroughly incorporated, makin a white putty, which was sheeted on varlous forms of backing, in-

After sheeting the -moist sheeted product was dried at about C. The solvent was rapidly removed at this temperature.

A textured efiect' of a very marked type was obtained by forming fragments of tread composition still plastic but dried out somewhat and applying such fragments helter skelter to a freshly sheeted surface, then passing through rolls. The somewhat harder lumps of the drier tread composition im-- parted a notable texture to the surface in this manner.

' Another tread composition was made from 500 parts by weight of nitrocellulose, dry" weight, (moistened with denatured alcoh 665 parts'plasticizer, 400 parts acetone, and 300 parts benzol. Thenitrocellulose was allowed to soak over night in the solvents and plasticizers and thoroughly mixed the following morning in a Werner-Pfleiderer mixer. There was added 750 parts cork dust,

mesh, 750 partslithopone, 50 partschrome green. The'composition also included 12 A; partsceresin wax. Finally, 200 parts each of acetone and benzol were. added to obtain a more plastic putty. v

Large sheets of blotting paper, manilla paper and saturated felt base were sheeted with this composition and dried at about 45 C. When drying had progressed sufiiciently a second'sheeting of material was applied to the first. Good surfaces were obtained. Some of the samples were placed in a hydraulic press .in contact with a polished sheet of metal and were pressed for five minutes at 500 to 1000 lbs. pressure, the press being heated by steam at 20 lbs. pressure. This gave a very smooth surface.

In the foregoing formula it should be noted that the plasticizer is dibutyl phthalate, or a mixture of this substance and tricresyl phosphate. Or, if more fireproof results are desired, the plasticizer may be entirely tricresyl phosphate.

Variegated results are obtained, for example, by sheeting the light-colored composition set forth above and applying to the surface at irregular distances small portions of the green composition set forth in the second formula. In this manner atwo-color or mottled and streaked effect is secured.

In the form of the invention shown in the drawing, a floor covering is shown in cross section, the flexible sheet support being shown at '1, with the adherent, color variegated tread at 2. I

Still another composition was prepared from:

7 Parts by Q weight Celluloid nitrocellulose 400 Denatured alcohol 160 Tricresylphosphate 612 Acetone r 320 Benzol 240 Paraifin wax 20 Urea 4 Cottonseed fatty acid phthalio glyceride resin dissolved in an equal weight of Volatile solvent (200 parts actual resin) After thorough incorporation the following fillers were added:

Parts Cotton flock Finely-divided vegetable ivory 400 Per-hydratedcaloium sulphate L00 Lithopone 200 This produced a white mix. A good yellow tone was obtained by adding 20 parts were obtained with saturated felt as a cushioning support.

A- lossysmooth finish was obtained by pressing the dry sheeted product between polished metal plates in a hydraulic press at Water.

1000 lbs. pressure per squarefinch and ata temperature corresponding to 20 lbs. steam pressure. In one case blotting paper was saturatedwith a solution made from 1 part by weight diam'monium hydrogen phosphate in 2 parts The paper then was dried and some of the last mentioned tread composition .was sheeted thereon to form a floor covering product. This material could: not be ignited by the flame of a match. 1

Finally I wish: to emphasize the feature that in the preferred =for'mof the invention the plastic material when prepared for sheeting is not self-supporting in thin layers of the thickness of the intended tread. This is likewise true after sheeting and before elimination of volatile solvents. Drying, however, causes. a cementation of the-sheeted mass and strengthening of the tread. The

paper or other support so needful therefore to carry the tread layer in its freshly sheeted condition becomes less important after drying. The ratio of thickness of the tread support to the tread itself varies according to requirements. On the one hand thin kraft paper may carry a. thick tread (double-' sheeted) or thick saturated felt may; have merely a veneer of the cellulose ester plastlc. The ratio thus may be greatly varied.

; The employment of highly volatile sol} vents permits the sheeting operation totake place without artificial heat, hence may be carried out at room "temperature; Blistering, due to the evoliition 'of water vapors from th e fillers. an dthe like in hot rolling as well as other objectionablefeaturs of hot rolls, is avoided:

Using felt saturated with soft pitch or a sphalt to give pliability makes hot'rollingin sheeting on a veneer o'fnitrocellulos'e tread composition amatter of great practical difii- Gu lty, On the other hand the employment calendering.

the latter being present in substantial quantity, and in pressing into the sheeted surface fragments of plastic tread composition of another color; whereby a color-variegated finish results.

.- 5. Saturated felt veneered on one side with a multi-colored tread composition com rising nitrocellulose, a synthetic resin and a Her.

6. A floor covering comprising a flexible sheeting support carrying a nitrocellulose tread composition, and having rolled in hard, plastic, multi-colored fragments yielding a textured effect.

7. A process of making a floor covering comprising sheeting a nitrocellulose tread composition upon a backin "and rolling thereinto hard,.plastic, multi-colored fragments whereby a textured effect is obtained.

8. ,A floorcovering comprising a flexible sheeting support carrying a baked nitrocellulose tread composition, imparting to the surface a glossy, smooth finish. 9. In the process of making floor covers ings comprising a nitrocellulose tread composition sheeted upon a flexible paper back ing, the .step of hot pressing the sheeted material to give the treadcomposition a smooth, glossy finish.

10. In the manufacture of floor coverings consisting of a support carrying a tread ve neer containing nitrocellulose,-the step which comprises sheeting a solvent containing nitrocellulose plastic composition onto the tread support, drying and subsequently hot 'OARLETON Ennis.

of hi'ghly volatile solvents anchored at room temperaturein a-tread. composition by war; and readily released at slightly higher temperatures enables such veneer to.be applied qi1ickly-and-cheaply.--

vents and "wax a remarkably adherent tread results even to a paper backing containing a very considerable proportion "of wax wateriproofing.

What I claim is .1. As a" floor cbverin'ga waterproofed flexible'sheetingsupport carrying a'she'eted nitrocellulose tread composition of color-variegated surface; P

2. 'As a floor covering a flexible paper support carrying a sheeted nitrocellulose tread composition of multi-colored surface.

3. As a floor covering a flexible wax-containing paper support carryin a nitrocellusurface. y I

- lose tread composition of co or-variegated Also, I wish to note that a

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