US1569056A - Colored patent leather and process of making the same - Google Patents

Description

1m. 12 1926. l 1,569,056v

W. C. WELCH COLORED PATENT LEATHER AND PROCESS 0Fl MAKING THE SAME Filed July e, 1925 2 sheets-sheet 1 ngz f3 )e Y l /f fd /d f l Jan. 12 1926. 1,569,056

w. c. WELCH COLORED PATENT LEATHER AND PROCESS MAKING THE SAME Filed July 1925 2 sheets-sheet 2 ZP/WV'' Z d'vaby @w dal@ of its manufacture, and wherein Figure 1 is Patented Jan. l2, 1926.

UNITED STATES PATENT oFFlcE. I

WILLIAM C. WELCH, OF NEWTON, MASSACHUSETTS, ASSIGNOR TO SNYDER WELCH PROCESS CORPORATION, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSA- CH'USETTS.

COLORED PATENT LEATHER AND PROCESS OF'MAKING THE SAME. i

Application tiled July 8, 1925.

To atl whom it may concern:

Be it known that I, WILLIAM C. WELCH, a citizen of the United States, residing at Newton, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Colored Patent Leather and Processes of Making the Same; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

'Ihis invention relates to colored patent leather and to a method of making the same.

In general the invention has for an object to produce a novel colored patent leather possessing a distinctively novel and highly attractive appearance which is extremely durable and which is sufficiently elastic to enable it to be successfully manufactured into shoes without any more cracking than with ordinary high-grade patent leather. The colored patent leather possesses flexibility and will not peel or deteriorate under severe conditions of usage.

A further object of the invention is to provide a novel, economical and practical method of making colored patent leather.

With these objects in view, the invention consists in the colored patent leather and in the method and novel steps thereof hereinafter described and particularly pointed out in the claims at the end of the specification.

The drawings illustrate the preferred form of the colored patent leather and also some of the steps inthe preferred method a plan view of a frame showing a side of leather stretched therein; Fig. 2 is a front elevation of a portion of one of the ovens preferably used for baking the leather in producing the present colored patent leather; Fig. 3 is a sectional view of a portion of the side shown in Fig. 1, illustrating the partially completed leather in a condition preparatory to the application Aof the coloring material; Fig. 4 is a view similar to Fig'. 3 illustrating ,the manner in which the coloring material is preferably applied; Fig. 5gg-is a similar View illustrating the preferred manner in which the excess of coloring material is removed; Fig.- 6 is a similar view illustrating the polishing or burnishing Serial No. A12,173.

operation; Fig. 7 is a view similar to Fig.'3, illustrating the completely finished colored patent leather; and Fig. 8 is an enlarged section illustrating the formation of the several layers of material comprising the present colored patent leather.

Prior to the present invention no satisi factory colored patent leather has been produced. A certain amount of so-called pigment finished leather has been heretofore produced in Awhich pigments have been incorporated into a paint vehicle and the rehas been unsatisfactory, the pigmentk operating to some extent to shorten or destroy the elasticity of the coating, and the coating having a tendency to peel and crack.

In accordance with the present invention a colored patent leather is produced having a novel and highly attractiveappearance and which may properly be described as having the appearance of a continuous sheetA of the coloring material itself. For example, if the coloring material be silver or bronze, then the finished colored patent leather has the appearance of a sheet of the silver or bronze, and when this material is made up into shoes, particularly into ladies slippers, the slippers or .shoes have the apand further- Y pearance of slippers made of the p ure colorl ing material in sheet form.

Referring to the drawing, the tanned leather, preferably in the form of the tanned side 10 in the condition in which it is received from the tanner is first stretched and secured in an open wooden frame 12 by means of .toggle strings 13 secured-to the i different marginal portions o f the side and which are tacked to the frame. After the hide has been thus stretched and secured in the frame, it has applied to it, two and preferably three coatings or layers 20, 21, 22, of

a material comprising preferably j apanners varnishA prepared in a particular way asis -l time in which the second finishing coat of coat, and which is brushed onto the leather and the coating dried, either in the sunlight or by -means of artificial drying exactly as is practiced `in the production of the best grades of patent leather. After the daub coat has been dried, the second so-called first finishing coat 21 is brushed onto the leather While the latter remains in a tightly stretched condition in the frame, and this first finishing coat 21 may comprise a linseed oil varnish of the composition and prepared in accordance with the standard practice in producing the best grade of patent leather, and which preferably contains pigment corresponding to or harmonizing with the final color to be applied to the leather. After this first finishing coat has been applied, the coated leather stretched in the frame is placed within the usual form of baking oven 30 at present employed in the manufacture of patent leather, and the leather and coatings baked until the coatings become hard, preferably at a temperature of 140 F. The leather is then removed from the oven, then rubbed down with pumice, and a second finishing coat 22 of japanners varnish applied. This second finishing coat 22 preferably comprises a linseed oil varnish prepared in accordance with the methods at present practiced in preparing the second finishing coat f o'r the production of high-grade patent leather', and is preferably thinned to a less specific gravity of 23 Baum,\and after it has been applied, the leather and frame is returned to the oven and baked. Instead of baking the leather at this stage of the process for the` period at present used in the manufacture of ordinary patent leather, it

should be baked for a lesser time, so that the varnished surface of the leather may quite soft and capable of holding the color to be applied. For example, if the second finishing coat or layer 22 is ordinarily baked, depending upon the particular varnish used, at an average' temperature of 150 F. for twenty hours, then it is desirable to cut down the time of baking to from 9-10 hours. trolled by cutting down the heat and baking for a longer period than 10 hours.

With the, exception of the diminished the varnished material is-baked, the procedure thus far and the materials employed may and preferably will comprise those at present known and used by the patent leather manufacturers in this country in the production of'high-grade patent leather,

or in other Words, in the reduction of al `the oven, placed upon the horses 1n a subgrade of patent leather which may be suc- The baking may be con-` cessfully utilized in the manufacture of shoes without excessive cracking and which enables shoes when worn to last for relatively long periods of time.

The leather stretched in the wooden frame and having the upper varnished layer- 22 incompletely baked, is withdrawn from the oven one piece at a time and laced on a pair of horses or other supporting member in a substantially horizontal position. The color material in powdered form, which may comprise a metallic owder, dry igment, or dyes in powdered form accor ing to the color which it is desired that the patent vleather should assume, is applied over the tacky .surface of the finished leather. It is desirable to apply an excess powder so that the whole piece may be completely covered, forming a relatively thick layer 3l. In applying the powder, a swab of soft cloth, or a soft brush may be used with advantage, and in order to prevent a streaky appearance in the finished colored patent leather, it is essential for the most satisfactory results that this powdeit` be spread or distributed over the surface of the tacky varnish in a manner such as to prevent the bursh, cloth, or other device from contacting with the stick surface ofthe varnish. As represented in ig.- 4, the preferred manner in which the color material is ap lied comprises the application of a mass or eap 32 of the# owdered color material upon the surface o the tacky varnish, and t en the distribution of the material into a relatively thick layer by the brush 34 or cloth, the

operator pushing the pile or powdered material over the varnished surface in advance of the brush or cloth, so that at no time is the brush; brought into direct contact with the sticky varnish. After the powdered color has thus been thoroughly spread, it is well to go over the iece of leather again with the brush, applylng a very slight pressure. These details in the operation of applying a layer of powdered color to the lncompletely aked and tacky surface of the ulpper varnish la er 22, are necessary in or er that the pow er may beforced into sufficient contact with "the tacky varnish surface, so that during the subsequent baking operation it may be securely alixed andy stantially horizontal position and the excess color carefully and thoroughly removed. It is desirable to remove all of the excess possible with va vacuum having a brush attachment as this enables the unattached color to be recovered and used overagain, and in passing the brush over the surface of the leather in the manner illustrated in Fig. 5, the suction not only operates to suck up and withdraw from the surface of the leather all of the loose unattached particles of the powdered color, but also the brushing action over the entire surface of the leather operates to loosen a great deal of the" excess material so that there remains upon the surface a very thin layer 38 comprising practically a skin or smear of the color, and all particles of which are firmly anchored in the baked surface of the varnish. The leather in this condition presents an opaque and a dull appearance, and it is desirable that the surface of the leather be burnished to completely blend the particles of the powdered color and to impart to the surface a shiny appearance, the extent of the shine depending upon, to some extent, the character of the powdered color. This may be done by means of a soft cloth in the manner illustrated in Fig. 6.

After the powdered color has been ithusi applied, baked; and preferably burnished, then a layer 36 of transparent japanners varnish is applied over` the surface of the powdered color and the wooden framewith the leather therein is again placed in the oven and baked unt the surface coating of varnish has hardene and preferably for the first three hours of baking at a temperature not higher than 110 F. and thereafter at approximately 150o F. until the varnish has become sufliciently dry. This result is ordinarily obtained after a total drying of about twenty hours. After this final baking operation, the leather is withdrawn from the oven and placed in the sunlight for a final drying, exactly as in the ordinary process for producing a high-grade black patent leather. The final transparent varnish is preferably a very light varnish having a gravity of approximately 52 Baume at 98o F. Such a light varnish is particularly to be employed when the powdered color comprises dyes, pigments or metallic powders of the lighter shades, such as silver. When some of the darker shades of coloring material are employed, a varnish somewhat heavier should be used to impart suflicient luster to the product. Care should l be taken in the application of this last varnish coating, as it 1s desirable that it should be applied lightly without bearing on the brus any more than is necessary.

In applying the final varnish coating, care should be taken, in order to secure the best result, to prevent contamination of the supply of varnish with the coloring material and inorder to prevent this contamination I have found by experiment that this final varnish coatingv may be applied by means of standard spraying apparatus adapted to spray the varnish over the color. The varnished coating produced by the spraying method noty only i's uncontaminated by the color but also when applied produces a very clear and transparent film entirely free from cloud effects which areapt to be produced by islodgment of color particles in brushing. i

A simple method for applying the final varnish coating and reducing to a minimum the liability of contamination of the final varnish coating with color consists in dipping the requisite quantity of varnish from the supply and pouring the same "onto the leather. over the color. The varnish thus applied to the color may be spread by brushing and the brush is never dipped in the supply of varnish. After six sides have been brushed in this manner, the operator quickly rinses his brush` in a pail of clean naphtha and the brush is in a condition to be used again. lMost all of the naphtha in which the brush is rinsed may, at the end of a days run, be poured ofl' and utilized again.

The present colored patent leather, it will be observed, is preferably made as to the major portion of the coatings thereof, exactly and of the same materials, as a highgrade black patent leather, so that the final product has imparted to it by these coatings, comprising either the first two or the first three coatings accordingly as the proccess is operated upon two coating or three coating work, thosecharacteristics of elasticity, toughness, vdurability and strength so necessary in a patent leather to permit the manufacture therefrom of shoes. As is well known, patent leather when made into shoes is subjected to strains accompanying the pull of the leather over the last which are so great that unless the varnish or japanned coatings are properly prepared and applied and baked upon the leather in a careful manner within predetermined temperature vwill Acrack during the manufacture of the shoes. As above stated, the present colored patent leather possesses these desirable characteristics of elasticity, durability and strength, and furthermore the powdered color is applied between lthe upper and next ower japanned coatings in such a manner as to enable a definite bond to be established y between the upper and surface coating and the next lower coatin between the individual particles of t e powdered color. Furthermore, in accordance with the preferred process, the excess and in fact all of the powdered color which may be removed by energetic brushingvis removed, thus leavto decrease the liexibility or elasticity of the finished product so that the vcompleted patent leather may be successfully made 1nto shoes or any other wearing apparel or other articles desired.

The coatin material for the daub coat and for the nishing coat, or coats, preferably comprises a special apannerslinseed oil boiled in a careful manner and cut with naphtha, in accordance `with the standard practice in producing japanners varnish fused for producing high grade patent leather. The details of the manufacture of this material are well known. The coatings on the-leather 4produced by such ma# terial are exceedingly elastic and durable and the thin body of powdered color, comprising individual particles anchored in and baked between superimposed layers of coating produced from these special ja anners varnishes, operates to impart to t e final product an appearance to the eye of acontinuous sheet of the color material and at the same time the porosity and thinness of the color layer enables the adjacent coatings to thoroughly bond togetherv to provide a unitary structure of coating capable of Vwithstanding severe usage for long periods of time without cracking or peeling, an advantage which is directly due to the character of the color layer and the character of the coatings and the fact that during the baking" operation the leather is stretched 1n an open frame, affording an opportumty for the heat to pass upwardly through the leather and to blend and bond the coatings to ether.

he present colored patent leather is preferably formed by finishing in the manner above described the rainedslde of the leather and in the finishe product the grain is clearly visible, because. of the fact that the burnishing operation performed upon the body of coloring material operates to bring out to some extent the a1n, and as a result the transparent varnish film over the coloring material serves to emphasize the grained appearance of the colored powdered layer and to impart lustre to the product. f

The finished colored patent leather made i in accordance with the preferred process above described may be readily distinguished in appearance from leather to which a thin film of paint has been applied, 1n that the particles of color in the resent product under a magnifying glass impart the appearance of very .fine stipplmg, a striking characteristic whlch 1s entirely absent from a paint film. Of course the present product being a true patent leather possesses durability and workability not possessed by the painted leathers `of the prior art.

While it is vpreferred to apply three; coats to the leather before the application thereto .of the powdered color, nevertheless for 'some purposes it may be advantageous to operate upon the two coat system in applying two coats of japanners varnish to the-leather. Also, in some instances, it may be desirable to utilize cellulose derivatives in connection with the linseed oil base of the varnish coatings, in accordance with the standard practice in the manufacture of japanners varnish for patent leather work. ln some instances it may be desirable to omit the final protectiveY layer 36, although I prefer to employ it as a protection against the tarnishing and deleterious eli'ect of exposing the color layer 33 to the weather.

As usedthroughout the specification and claims, the term japanners varnish is intended to define those standard varnishes used in the patent leather trade to lproduce elastic, tough, and durable coatings, capable of being used in the manufacture of shoes.

While the preferred embodiments of the invention have been illustrated and described, it is to be understood that the invention may'be embodied in other forms within the scope of the following claims. i

Having thus described Y the invention, what lis claimedis:

1.In the `method of making colored patent leather, the steps comprising applying to the` leather successive coatings of )apanners varnish to form patent leather,

and applying and firmly afixing in the surface of one of said coatings a thin layer of powdered color to impart to the patent leather the general appearanceof a continuous sheet of the color.

2. The method of making colored ypatent leather, which consists in applying japanners varnish to the leather to form patent in astretched condition in said frame, and l applying and of powdered color in the surface of the underlying of-two` of said baked coatings and before the application of the upper of said coatings.

4. The method of making colored patent leather, which consists in stretching the leather in van open frame, Vapplying and firmly aflixing a thin layer baking successive coatings of japanners varnishl to form patent leather, stopping the baking of the last applied coatingjto render the surface of the varnish adhesive, applying a thin layer of powdered color over the adhesive varnish, baking theleather thus coated to firmly anchor the color in the varnish, and finally applying and baking a thin layer of transparent japanners varnish over said layer of color.

5. The method of making colored patent leather, which consists in stretching the leather in an open frame, applying and baking successive coatings of japanners varnish to form patent leather, stopping the baking of the last applied coating to render the sur face of the varnish adhesive, applying a very thin layer of powdered color overthe adhesive varnish, baking the leather thus coated to -lirmly anchor the color in the varnish.

6. The method of making colored patent leather, which consists in stretching the leather in an open frame, applying and baking successive coatings of japanners varnishV to form patent leather, stopping the baking of the last applied coatin to render the surface of the varnish ad' esive, completely covering the adhesive varnish with an excess of the powdered color, baking the leather inl this condition, removing the excess color and leaving upon the leather a Very thin layer of the powdered color, the particles of which are firmly anchored in the baked varnish.

7. The method of making colored patent leather, which' consists in stretching the leather in an open frame, applying and baking successive coatings of japanners varnish to form ordinary patent leather, stopping the baking of the last applied coating to render the surface ofthe varnish adhesive, completely covering the adhesive varnish with an excess of the powdered color, baking the leather in this condition, removing the excess color and leaving upon the leather a very thin layer of the powdered color, the particles of which are firmly anchored' in the baked varnish, and thereafter applying and baking a layerof transparent japanners varnish over said Vlayer of color.

8. The method of making colored patent leather, which consists in stretching the leather in an open frame, applying and baking successive coatings of japanners varnish to form patent leather, stopping the baking of the last applied coating to render the surface of the`varnish adhesive, completely covering theadhesive varnish with an excess of dry powdered color, baking the leather in this condition, removing the excess color and leaving a ver are anchored in the baked varnish, then thin layer.. of the color, the individual particles of which burnishing said color layer, and thereafter applying and baking a layer of transparent japanners` varnish over the layer of color. 9. The method of making colored patent leather, which consists in applying to the leather successive baked coatings of japanners varnish to form patent leather, terminating the baking of the last applied coat to render the varnish adhesive, forming a thin layer of powdered color upon said adhesive varnish surface, then applying a layer of transparent varnishy without contaminating it by powdered color and subsequently baking the leather.

10. -As a new article of manufacture, a colored patent leather comprising ordinary patent leather having a thin layer of powdered color firmly affixed on the surface of the coating and a transparent protective layer covering the color layer.

11. As a newl article of manufacture, a colored patent leather comprising leather provided with a plurality of superposed hardened coatings of japanners varnish, and a thin layer of color between two of the varnish coatings.

12. As a new article of manufacture, a colored patent leather comprising leather having the grained vsurface thereof provided with a plurality of baked coatings of japanners varnish conforming to the grain, a thin layer of powdered color firmly affixed in the surface of one of the varnish coatings and conforming to some extent to the grain,

'and a thin coating of baked japanners varnish over the color.

13. As a new article of manufacture, a colored patent leather comprising ordinary patent leather having a thin layer of color firmly afl'ixed in the upper surface thereof, and a layer of baked transparent japanners varnish covering said color layer and being itself free from contamination by the color.

14,. vA colored patent leather comprising leather having a plurality of superposed baked coatings of japanners varnish, and a layer of color between two of said coatings and comprising small particles imparting to the surface .the general appearance of a continuous sheet of the color but presenting under a magnifying glass a characteristic stippled appearance lof the largev number of individual particles of color.

15. The steps in the herein described method, which consist in applying to patent leather having anv adhesive surface, an excess of powdered color, baking the leather with the excess of color thereon, and thereafter removing the excess of color by i.

suction.

16. The steps in the herein described method, which consist in applying to patent leather having an adhesive surface of an incompletely baked coat of japanners varnish, l

an excess of powdered color, baking the leather, removing the excess, and then applying by spraying a thin layer of colorless japann'ers varnish.

17. The 'steps in the herein described method, which consist in applying to patent leather having an adhesive surface of an incompletely baked coat of japanners varnish, an excess of powdered color, baking the leather, removing the excess, and then applying by spraying a thin layer of colorless ]apanners varnish and baking the leather.

18. As a new article ofmanufacture, a

colored patent leather comprising ordinary patent leather having a thin layer of` powdered color firmly aiixed in the surface thereof, and comprising small particles, impartingto the surface the general appearance of a continuous sheet of the color but presenting under a magnifying glass a characteristic stippled appearance of a large number of individual particles of color.

In testimony whereof I have signed `my name to this specification.

WILLIAM C. WELCH.

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