US789249A - Enamel leather and process of making same. - Google Patents

Description

NITEDV STATES Patented May 9,1905.

PATENT ()FFICE.

WILLIAM W. ADAMS, JR., OF PHILADELPHIA, AND HARRY C. MoKAY, OF ESSINGTON, PENNSYLVANIA, ASSIGNORS, BY MESNE ASSIGNMENTS, TO AMERICAN PATENT KID COMPANY, A CORPORATION OF NEW JERSEY.

ENAMEL LEATHER AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 789,249, dated May 9, 1905.

Application filed December 29,1900. Serial No. 41.453.

To all whom, it may concern:

Be it known that we, WILLIAM W. ADAMs, J r., residing at Philadelphia, and HARRY C. MGKAY, residing at Essington, Delaware county, Pennsylvania, citizens of the United States, have invented certain new and useful Improvements in Enamel Leather and Processes of Making the Same, of which the following is a full, clear, and exact description, referencebeing had to the accompanying drawings, forming a part of this specification.

Our invention relates to the manufacture of enamel and patent leathers; and it consists of a new and improved process or method of making such leathers and of a new product as the result thereof.

It relates specifically to that class of such leathers in which the enameling is applied to the grain side of the skin and without any previous buffing thereof, and not to that class in which the enameling is applied to the flesh side or to the grain side, which has been rendered soft and porous by buffing. Hence our process is applicable particularly to the manufacture of enamel and patent leathers from goatskins and other light leathers on which it is not desirable to apply the enamelilng to the flesh side nor to buff the grain SIC e.

Our improved process comprises two essential stepsnamely, the degreasing or extractingof all natural and applied grease from the tanned skin to be enameled, followed by the application thereto of a preparatory varnish composed of a drying-oil, specifically, boiled linseed-oil and a pyroxylin carrier thereof, which will be absorbed into and on the skin tissues through and below the exterior hard grain-surface of the tanned skin.

An additional step in our process, which though not essential in all cases, as hereinafter stated, is frequently desirable, is the compacting and smoothing of the grain-surface prior to the application of the preparatory varnish before mentioned.

In carrying out our process the tanned skins prepared to the point where they would otherwise be surface-finished in any of the various known ways to make them merchantable are treated as follows: The natural and applied grease in the tanned skins or leather is completely extracted, for which purpose any of the well-known degreasing processes may be employed-such, for example, as that in which a naphtha solvent is used a suitable one being described in United States Letters Patent to W. W. Adams, Jr. Nos. 685,551 and 685,552, both dated October 29, 1901. This degreasing step is the first in our process and is absolutely essential to enable the preparatory varnish, hereinafter described, to penetrate the grain side below the surface and to adhere to the fibers thereof. The next step in the process, which may, however, be employed before degreasing the tanned skin as aforesaid, is a smoothing and compacting of the grain, which may be done in any suitable way long familiar to tanners and curriersfor example, by repeated manual application of a slicker with force over the surface or mechanically by giving the skin the usual first treatment under the glass roller of a glazing-machine as though the tanned skin was to be made into glazed kid, in which case a usual seasoning, such as a blood season, should be applied. This smoothing and compacting step is not, however, essential in all cases, as some skins naturally have and some tannages give a low smooth grain; but for the greater varieties of tanned goatskins such smoothing and compacting will be very desirable for the production of perfectly smooth-surfaced enamel and patent leathers of this class. The next step in the process is the application to a tanned skin degreased, as first stated, and preferably in most cases with the fibers of its grain side compacted, as aforesaid, of a preparatory varnish composed of a pyroxylin solution and boiled linseed-oil, dissolved in a solvent. of both, such as amyl acetate. This solution must have considerable fluidity, so as to be applied to the skin by a brush or sponge. It

will be absorbed by the fibrous structure of the grain side without producing an enamel coating. Such effects are obtained by a mixture having such properties, resulting from boiling linseed-oil to the consistency of fresh mucilage, thinning one quart of this with an equal bulk of amyl acetate or sufficient to give it a consistency of 31 Baum, and then adding a pyroxylin solution consisting of one pound of guncotton in eight quarts of amyl acetate, and for a pigment and drier adding to every three gallons of this mixture a solution of one and one-half ounces of nigrosin in one quart of methyl alcohol. Such a composition has great penetrating power. It will be absorbed almost instantly by the skin so prepared, penetrating the exterior grain-surface and enveloping and adhering to the fibers composing the whole epidermis or grain side of the skin, and forms a preliminary coating so thin and transparent as to be scarcely perceptible, but so effective for our purpose that the usual exterior enamel commonly applied in making patent-leather adheres so firmly thereto that a peeling or separation thereof after drying becomes impossible. The remaining steps in the manufacture of our enamel and patent leathers are as follows, v'iz.: The tanned skins having been degreased, as aforesaid, and the grain smoothed or compacted, if need be, and then placed on the usual stretching-frames, are treated on the grain side by the preparatory varnish above referred to, dried in the sun or in an oven, and finally treated while still on the frame by the application thereto of any well-known exterior enamel or varnish commonly applied in making enamel and patent leathers.

In a separate application for patent filed by one of usHarry C. McKayon December 29, 1900, Serial No. 41,461, (on which Letters Patent N 0. 704,082 were issued, dated July 8, 1902,) is described a specific preparatory varnish of the character described, and hence adapted to be used with great utility in the carrying out of our new process.

Our invention in the process and in the resultant leather produced difiers entirely as to both from the process and product described in the United States patent to Field, No. 627,493, dated June 27, 1899, and equally so from the process and product described in the United States patents to VVolfl', Nos. 632,162 and 632,163, both datedAugust 29, 1899. In neither of these prior processes is the tanned skin prepared by subjection to either of our preparatory steps, and in the former of them the preparatory varnish employed is a solution of a pyroxylin compound with a nondrying oil, while in the Wolff process there is applied a preparatory varnish or enamel directly to the grain-surface of goatskin or kid-leather which will not be absorbed by Said surface, but will form an adherent flexible coating thereupon. Our process, however, is radically different from both of these in the two essential particulars which distinguish it, since, first, we prepare the tanned skin to deprive it of its oil-resistant grease and make it more absorbent, and, second, we employ a preparatory varnish of the character described which will penetrate the grain side and envelop and adhere to the fibers composing the same. It is our experience that goatskins and kid-leather finally enameled on the grain side, especially when not previously buffed or roughened, will when submitted to a treatment by our process, as described, preliminary to the application of any usual external enamel coating possess great flexibility and unusual freedom from crackingand peeling.

The enameled leather which is the product of our new process is exactly like other kidleather in respect of its flesh side; but as to the grain side of the skin it differs therefrom in having the entire fibrous structure thereof enveloped by the preparatory varnish which forms a flexible film-like covering of the fibers, attaching itself thereto with remarkable adherence and at the same time being so thin and transparent in character as scarcely to be perceptible, and hence not hiding the external grain texture of the skin and with the advantage that frequently we are able to make an excellent enamel leather with but a single outside coating of the usual exterior enamel commonly employed, showing through the same the contour of the natural grain of the skin.

Having thus described our invention, what we claim as new, and desire to secure by Letters Patent, is-

1. An improved process of preparing unbufied tanned skins for enameling with the usual surface enamels, which consists in first extracting from the skin its contained natural and applied grease, then applying to the unbuffed grain sideof the skin the described pyroxylin solution and boiled linseed-oil dissolved in a solvent of both, whereby a thin, transparent and flexible coating is formed upon and adheres to the fibrous structure constituting the grain side of the skin.

2. An improved process of enameling unbuffed tanned skins, which consists in compacting and smoothing the unbuffed grain side thereof, then extracting the natural and applied grease from the skin, then applying the described pyroxylin and boiled linseed-oil solution whereby an adhering, thin, flexible and transparent coating is formed upon the grain side, and, after drying, finally applying upon said grain side any usual exterior surface enamel.

3. As a new article of manufacture, enameled leather composed of tanned skin from which the natural and applied grease has been extracted, and having upon and throughout IIO- the fibrous structure constituting its grain side, a thin, flexible and transparent coating resulting from the employment of a pyroxylin solution with linseed-oil, of the character described, said coating penetrating the fibrous structure of the unbuffed grain side of the skin and forming a homogeneous union therewith, and an exterior adherent surface enamel superposed thereon.

In testimony whereof we have hereunto affixed our signatures this 26th day of December, A. D. 1900.

WILLIAM W. ADAMS, JR. HARRY O. MoKAY.

Witnesses:

ANDREW V. GRoUPE, H. T. FENTON.