US3331147A - Edge finishing shoe outer bottoms - Google Patents

Description

July 18, 1967 c. ISAACSON 3,331,147

EDGE FINISHING SHOE OUTER BOTTOMS Filed July 25, 1964 1] 106 [08 705 3 J04 516 10825 1 d 1 6 105 11.2 7/5 5 z- W1 A 1/0 Inventor Calvin Zsaacson By his flfzorney United States Patent 3,331,147 EDGE FINISHING SHOE OUTER BOTTOMS Calvin Isaacson, Wellesley, Mass., assignor to United Shoe Machinery Corporation, Flemington, N..I., a corporation of New Jersey Filed July 23, 1964, Ser. No. 384,726 Claims. (Cl. 36--25) ABSTRACT OF THE DISCLOSURE The invention is directed to edge finished shoe outer bottoms, and a method for producing them. In finished form the edges of the bottoms are trimmed and support a sizing and a coating including a polyurethane composition.

The present invention relates to edge finishing shoe outer bottoms, and more specifically shoe outer bottoms which are fibrous in nature.

When used in this paper the terminology shoe outer bottom has reference to an outsole, sole, heel, welt, lift, platform and similar other parts, whose edges or edge surfaces are exposed in a finished shoe or other footwear. Of these parts, outsoles are the most prominently involved and accordingly they will be most often referred to throughout. In referring to the shoe outer bottom as fibrous or fibrous in nature it is intended that there be included those of leather and various composite materials in which fibrous fillers are bonded by various resins, adhesives and the like.

Edge finishing of shoe outer bottoms, for instance an outsole, may be carried out prior to or after the incorporation into a shoe assembly or a finished shoe.

Edge finishing generally includes the basic operations of edge trimming and edge coating. Edge trimming involves contouring or shaping the outsole, etc. in outline by use of cutting tools, such as knives, etc. Edge coating then involves the application of a coating(s) which may also be referred to as a finish(es), to the edge surface exposed or otherwise provided as a result of edge trimming. Edge trimming may be single or multi-step in nature. For instance, a first cutting step, or rough rounding may be carried out to be followed by a second, or later, smooth rounding, and, as well an abrading step or steps may be used. Edge coating may also be single or multi-step in nature, and, generally is the latter. Decorative or protective edge coatings may be applied in a single pass, or in a number of passes. In addition, drying, curing, setting and similar other steps such as burnishing and the like may also be practiced as part of the edge coating operation.

In the case of shoe outer bottoms, which are of a fibrous nature, for instance leather, finished edges obtained from following conventional edge finishing procedures, have been the subject of continuing complaints. The most frequent complaint is that the finish coatings, generally waxes, lacquers, varnishes, mixtures of the preceding, etc., lack sufiicient adherence to or adhesion with shoe outer bottom edge surfaces to which they are applied. The coatings crack away or are Worn ofi all too easily with normal shoe wearing. In this regard it should be noted that normal wearing is actually quite a severe test. It involves continued flexing of the shoe, and as well the shoe bottom, accompanied often with exposure to dampness, saline and other stringent environmental conditions.

Lack of sufiicient adherence between edge coatings and shoe outer bottom edge surfaces, which is obtained by conventional practices, is in many instances due to failure to obtain a cleanly cut edge surface from the edge trimming operation. The edge surface obtained is made up of or presents or includes fibers of uneven lengths with some of the fibers laid over. The effect is a rough edge surface on or to which it is difllcult to obtain an edge coating which is continuous in nature, which adheres continuously to the edge surface, and which itself presents a smooth surface. The coating obtained is then prone to exhibit lower adherence or adhesion and is more prone to being abraded off than one which would be obtained if the coating is initially applied to an even edge surface. The alternative, and which is an unattractive one, is to use greater amounts of coating material and greater care in the application of the same.

In instances where conventional practices provide a clean cut surface as a result of edge trimming, failure to obtain desired adherence between coatings and edge surfaces is frequently the result however. This may be attributed to the failure to obtain sufiicient penetration by the coatings through or beyond the edge surfaces of the bottoms to which the coatings are applied, when conventional practices are followed.

It is an object of this invention to provide an improved method for edge finishing shoe outer bottoms which are fibrous in nature.

It is another object of this invention to provide a shoe outer bottom of a fibrous nature, which exhibits an improved edge finish and edge surface finish appearance.

Other objects of this invention will come in evidence in the discussion which follows.

The objects of this invention may be attained in edge finished shoe outer bottoms which are fibrous in nature by following a multi-step edge finishing method. The method involves as a first step, (a) introducing a liquid, aqueous sizing into edge portions of shoe outer bottoms, so that it penetrates beyond the edge surfaces and into portions of the bottom which are to remain part of the bottom after edge trimming is carried out. In the second step (b) trimming of the edges or edge portions is carried out while the edges are in moist or wet condition to a depth beyond that where trimming is carried out, due to the presence of the sizing. In the third step (c) with the trimmed edge or edge portions in moist or wet condition, due to the presence of the sizing in liquid condition, an edge coating including a moisture-curing polyurethane composition is applied in liquid form to the trimmed edge.

The following drawings are included for the purpose of illustrating the invention in which:

FIG. 1 is a perspective view showing an unattached shoe outsole which is fibrous in nature being subjected to edge finishing;

FIG. 2 is another perspective view showing an unattached shoe outsole which is fibrous in nature being subjected to edge finishing;

FIG. 3 is a perspective view with parts broken and in section showing a shoe including outer bottom parts some of which are fibrous in nature being subjected to edge finishing; and

FIG. 4 is another perspective view with parts broken and in section showing a shoe including outer bottom parts which are fibrous in nature being subjected to edge finishing.

The first step carried out in the practice of this invention, that of introducing an aqueous, liquid sizing into the edge surface of a shoe outer bottom, is designed to facilitate both the edge trimming and edge coating operations which are to follow. In order that improvements available from practice of the invention may be obtained a number of functions are demanded as a result of carryout this step.

Initially, the application of the sizing should be such that the sizing impregnates the fibers at the shoe outer bottom edges. In doing so though, it should penetrate beyond that portion of the fibers, or those fibers, located at the immediate edge surfaces, and into portions of the fibers, and fibers which are to remain as part of the bottom after trimming is carried out. This is for the purpose of improving coating application and penetration conditions. When the bottom is such that trimming is to be carried out to some depth this may require that considerable penetration be obtained, and, to obtain that more than one application of sizing may be necessary.

The sizing as applied should be capable of swelling the fibers. In swollen condition, the fibers project outward and cleaner trimming can be accomplished. Later, on drying the previously swollen fibers retract or constrict to form a more even surface edge which contributes to the obtaining of an improved edge finish and/ or finish appearance.

The sizing should also serve as a lubricant for the trimming operation, particularly where knives or similar cutting objects are to be used for trimming.

As mentioned above, the sizing should be such that it facilitates penetration of the edge coating into the fibers. With good penetration by the coating, secure bonding and/ or coating is facilitated. Further, in this respect the sizing and the coating should be compatible in nature. To provide for internal and uniform curing of the edge coating which includes as a major constituent a moisturecuring polyurethane, the sizing is aqueous in nature.

In order that these various functions may be obtained,

the sizing includes a size material having lubricating qualities at least when it is in moistened condition, which is in an aqueous or water medium.

Various size materials may be used as the bases for the sizings used in practicing this invention, These may include starches, caseins, soy protein, gelatine, animal glue, gums, dextrines, cellulosic esters, rosins, as well as synthetic polymeric materials such as polyvinyl alcohol, polyvinyl chloride, polyvinyl esters and others.

A particular group of sizings which are preferred in practice of this invention are those which rely on synthetic polymeric materials as size materials, the materials being present in a particular form. These are the synthetic latices which are stable colloidal dispersions of thermoplastic synthetic polymeric materials which are present as finely divided, discrete particles in water. They are generally produced by emulsion type polymerizations using methods which are well appreciated. Typical of such latices are those produced from the following monomers.

(a) Styrenes, methyl substituted styrenes, mixtures of the preceding as well as mixtures including other monomers such as butadiene, acrylonitrile, etc.

(b) Vinyl chloride, vinyl acetate and vinylidene chloride, mixtures of the preceding, and mixtures including as other monomers acrylonitrile, butyraldehyde, methylmethacrylate, butadiene, isobutylene, maleic esters such as diethyl maleate and dibutyl maleate, etc.

(c) Acrylonitrile, and mixtures of the same with butadiene, isobutylene, vinylidene chloride, chloroprene, maleic esters, etc.

(d) Acrylates such as methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, isobutyl methacrylate, 2-ethyl hexyl methacrylate, mixtures of the preceding, and mixtures including as well styrene, acrylonitrile, acrylic acid, butadiene and vinyl acetate.

(e) Butadiene, particularly the 1,3 dienes, mixtures thereof and with styrene, Z-methyl styrene, ethyl acryiate, vinyl napthaline, etc,

(f) Chloroprene and other halogen-Z-butadienes such as the various chloroprenes, mixtures of the foregoing as well as with styrene, acrylonitrile, etc.

The aqueous sizings based on synthetic polymeric materials may also include plasticizers such as dioctyl phthalate, tricresyl phosphate, etc. for the polymeric materials. Various other additive materials may also be present such as humectants exemplified by glycerine, sorbitol, etc., as well as lubricants which may be illustrated by waxy partial esters, such as sorbitan and mannitan mno ammonium salts such as stearyl dimethyl benzyl ammonium chloride, ethylene oxide condensates of hexitan monostearates, etc.

The amount of size materials, or solids, which may be present in the liquid, aqueous medium may range on the order of 1% to 10% by weight based on total weight of the total sizing. Preferred amounts may range on the a order of 2% to 5% by weight size material based on the total sizing.

Application of the sizing to the edges or edge surfaces of the shoe outer bottom may be carried out by any convenient procedure. This would include spraying, swab bing, brushing or soaking, etc. Application of the sizing is generally carried out immediately prior to the final trimming step, that is smooth rounding and/or abrading. Except in the extraordinary case, this is sufiicient to insure that the edge surface presented at the time of coating will be even, with the fibers presented there trim-med evenly and smoothly, and at the same time.

that the edge surface or edge portions will be at least moist due to the presence of sizing there.

The second step carried out in practiciug this invention is edge trimming. The step of actual edge trimming is carried out using expedients which are known such as rotating knives, etc. In addition however, it is prescribed that in practicing the present invention that edge trimming be carried out while the sizing contained in the fibers or leather is in moist or liquid condition, as manifest by the leather or fibers being in a moist, wet, or damp condition.

The edge coating for use in practice of the present invention is based on a moisture-curing polyurethane composition. In its initial state, that is adapted for application, it is an isocyanate-containing or -terminated prepolymer which is moisture-curable and capable of solvation. Moisture-curable indicates that the prepolymer, and more specifically the free isocyanate groups contained in the same, have the capacity .to react with water, either in vapor or liquid state to effect curing to a flexible, solid state. The moisture required for reaction maybe provided by the atmosphere or from a separate source of moisture or water.

The isocyanate-terminated prepolymer which may be used may be any of those basedon polyols or polyfunctional hydroxyl compounds, and preferably mixtures of the same. Examples of these include polyethylene glycol, polybutylene glycols and trimethylol propane. Polyesters which may :be used as high molecular weight diols include pentane diol, dihydroxy castor oil derivatives, neopentyl glycol and polypropylene glycols. Alternate trials may include trimethylol ethane, castor oil, hexane triol and polyoxy propylene adducts of either hexane triol or glycerine.

The polyols are reacted with a polyfunctional isocyanate such as a toluene diisocyanate to obtain an isocyanate terminated prepolymer which is moisture-curable.

A variation of this procedure involves reacting the polyol with a blocked isocyanate. In this variation the prepolymer is resistant to moisture-curing at room temperature until such time that the block which may be a phenol, thiophenol or the like, is driven off or disposed of and the isocyanate'reactivityrestored by application of heat.

The prepolymer is dissolved in a solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketonc, xylene, Cellosolve acetate and the like to provide a moisture-curable polyurethane based edge coating which is capable of convenient application to shoe outer bottom edge surfaces. The amount of prepolymer to solvent may range on the order of 30% to 70% by weight with preference ranging 45% to 55% by Weight based on total weight of coating to be applied.

Various additives may be included in the coating. Examples of these include fiatting agents as well as agents which provide high gloss in the coating which finally results. An important class of materials which may be considered additives are pigments and colorants. It is recommended that the additives be as moisture-free as possible when included.

The coating is applied in liquid form to a shoe outer bottom edge and becomes tack-free when the solvent evaporates. The film or coating deposited as a result then continues to cure to the desired condition, i.e., continuous etc., by reacting with moisture conveniently obtained from the atmosphere, as well as the moisture retained in the outer bottom as a result of the preceding sizing application.

It bears noting that the reaction of the isocyanate terminated prepolymer with water or moisture, produces carbon dioxide which diffuses slowly from the coating and into the atmosphere as the coating cures. The coating applied, or rather coating which may also be described as a film or film-coating, developed on deposition from the solvent should be thin enough for the carbon dioxide to escape. Bubble-free finish coatings, or finish coatings exhibiting a smooth outer surface, generally may be cast up to 20 mils in thickness.

The moisture-curable coating may be applied to the edge surfaces in any convenient manner, such as spraying, brushing, rolling, doctoring, etc. It is applied to the trimmed edge surfaces while the latter are in moist condition, the same being caused by the presence of sizing, and, in instances to be described later, the presence of an intermediate color coating. There may be instances where the amount of moisture present in or on the trimmed edge may be considered too great to facilitate obtaining best results in the urethane coating and in those instances drying of an incomplete nature, forced or otherwise may be carried out at the edge prior to application of the prepolymer solution. Drying and curing of the coating can be forced if desired but in such a case care should be taken so that the rate of drying or curing will not adversely affect the appearance and physical properties which bear on obtaining a continuous coating having good adhesion with the edge to which it is applied.

As indicated previously, it may be the more convenient practice in particular instances to include or apply an intermediate color coating. This is applied after trimming and prior to applying the moisture-curing polyurethane type coating to the trimmed shoe outer bottom edge. One reason for this expedient would be to avoid the difiiculty, previously noted, which may be met in introducing pigments or colorants into the polyurethane prepolymer. The intermediate coating may be considered an extension of the sizing, and for that matter the sizing itself, as pre viously described may include pigments and colorants. To return however, the intermediate coating may differ from the sizing, as previously described, in that it may contain a higher concentration of solids, for instance on the order of 35 to 55 weight percent and preferably 40 to 45 weight percent each determined on the total weight of the coating. Neither is there reason to require of the intermediate coating that it have the capacity, nor include agents contributing to it the capacity to provide lubrication and similarly facilitate the trimming operation. Otherwise, the intermediate coating should be aqueous in nature and it may be and preferably is based on synthetic latices of the type described for use in the sizings.

Application of the intermediate coatings to the trimmed edges may be by convenient means including spraying, brushing, rolling, doctoring, etc. Incomplete drying, as previously described, may be carried out on this coating prior to application of the moisture-curing polyurethane finish coating.

Reference will now be made to the drawings wherein various embodiments of the invention are shown and will be described.

The embodiment of the invention shown in FIG. 1 is directed to edge finishing an unattached outsole 10 which is fibrous in nature, specifically leather. As shown there, the outsole 10, defined in outline by edge 12 is in a contoured condition of such nature as to indicate that it has been previously subjected to a shaping and cutting operation, such as dinking-out using equipment not shown. The condition of edge surface 12a as a result of the preceding shaping is shown in the heel area 16 where a multiplicity of fibers 18 project out to uneven lengths.

Using positioning expedients, not shown, the outsole 10 is directed through a progression of edge finishing operations. In the first of these, the rough edge surface 12a is advanced through a spray 20 of aqueous sizing in liquid condition, directed under pressure from a spray nozzle 22. This serves to provide a wet edge surface portion 12b. The sizing penetrates into fibers 18 and into the fibrous outsole 10 to a point or depth beyond that to which trimming is to take place. The desired wetting penetration is indicated in exaggerated fashion by the darkened area 24 on the top surface 26 of the outsole 10. While maintaining this wet condition, or to state it differently, while sizing 20 is maintained in liquid condition, the edge surface portion 12b is directed against a fine cutting or trimming wheel 28, rotationally driven by a spindle 30, the latter being connected to a power source, not shown. The result obtained is a smooth edge surface portion 120, which is wet by sizing or contains sizing in liquid condition. The wetted edge surface portion 120 is then advanced through a spray 32 of liquid coating which includes a moisture-curable polyurethane composition, the same being directed under pressure from a spray nozzle 34. This results in a surface portion 12d which includes a coating of moisture-curable polyurethane that hardens on drying and curing to a continuous smooth outer, finish surface and appearance.

A second embodiment of the invention is shown in FIG. 2. Again an unattached sole 40 is directed through a series of edge finishing operations. In this embodiment an abrading operation is included. A spray 42 of sizing is directed onto an edge surface 44 from which a multiplicity of fibers 45 project. Specifically spraying is carried out at edge surface portion 44a, from a spray nozzle 46 to produce welted edge surface portion 44b. The extent of penetration of sizing into the outsole 40 is indicated by the darkened area 47 on the top surface 48 of outsole 40. Then, fine cutting or trimming is performed by a cutter head 50 rotated by a spindle 52 to produce the edge surface portion 440. While the sizing is still present in liquid form, the edge surface 44, more specifically, surface portion 440, is advanced against an abrading Wheel 56 rotated by a spindle 58. The result is a smooth edge surface portion 44d which is then advanced through a spray 60 of moisture-curable polyurethane composition in liquid solvated form directed from a spray nozzle 62. The spray 60 penetrates the surface portion 44d and sets up on drying and curing to a continuous coating having a smooth outer finish surface as indicated at edge surface portion 44a.

The embodiment of the invention shown in FIG. 3 illustrates the present invention being practiced on an assembled shoe stationed on a last 72. The shoe 70 includes an upper 74 assembled with a shoe outer bottom 76 including a welt 78, an outsole 80 both of which are fibrous in nature, as indicated by fibers 81, a heel 82 and block 83. As shown, the outsole 80 is in rough-rounded condition, the same previously performed, see scallop cuts 84 outlining outsole surface portion 80:: indicating this. The welt 78 is shown in the same condition as indicated by the presence of scalloping 86 at welt portion 78a. Welt portion 78a and outsole edge surface portion 80a are advanced through a spray 88 of aqueous sizing in liquid condition, directed from a spray nozzle 90. The spray 88 wets and penetrates to provide wetted surface portions 78b and 80b. These surface portions are then advanced into contact with a cutting wheel 92 which is rotated on a spindle 94. The result is wetted, smooth surface portions 78c and 800. The latter are then advanced through a spray 96 of moisture-curable polyurethane in liquid, solvated condition directed from a spray nozzle 98. The results obtained on drying and moisture-curing or set up are strongly adherent, continuous finish coated portions 78d and 80d each of which presents a smooth outer surface appearance.

The embodiment of the invention shown in FIG. 4 also illustrates the present invention in connection with an assembled shoe 100. Shoe 100 is stationed on a last 102. A shoe upper 104 is combined with a shoe outer bottom 106, the latter including a welt 108, an outsole 110, a heel 112 and heel block 113 all of which are fibrous in nature as indicated by presence of fibers 114, and with the first two in rough rounded condition. This is indicated at portions 108a, 110a, 112a and 113a. The first treatment involves applying a spray 115 of liquid sizing from spray nozzle 116 to obtain wetted surface portions 108b, 110b, 1121: and 113b. These surface portions are then advanced against a cutting wheel 118 rotated on a spindle 120. The result is wetted, smooth edge surface portions as indicated at 1080 and 110s. In this condition the surface portions are advanced through a spray 122 of intermediate color coating material in liquid condition, directed from spray nozzle 124. The color coating material is based on an aqueous latex of a thermoplastic synthetic polymeric material. The result then obtained is an intermediate color coated edge surface portion 108d and 110d which may then be partially or incompletely dried as desired. The intermediate color coated surface portions 103d and 110d are then advanced through a spray 126 of finish coating material which includes a moisture-curable polyurethane composition in liquid, solvated form. Spray 126 emerges from a spray nozzle 128 to develop as coated surface portions Se and 1102. With drying and curing a strongly adherent, continuous, finish coated edge surface portion again referred to as 108a and 1102 are obtained, each presenting a smooth, outer surface and surface appearance.

The following example is provided for the purpose of further illustrating the invention. When parts are mentioned, unless otherwise defined, parts by weight are intended.

Example A synthetic latex is prepared by copolymerizing 390 ml. of ethyl acrylate and 50 ml. of acrylonitrile in a polymerizing medium which includes 550 ml. of water, 15.2 ml. of a fatty alcohol triethanolamine sulfate, 0.7 ml. of an alkyl phenyl polyethylene glycol ether and 28 ml. (1.0% solution) of ammonium sulfate solution. The 40 percent solids acrylic latex which is obtained is then formulated as (A) a Sizing and (B) an Intermediate Color Coating.

(A) Sizing: The latex obtained above is diluted with water to 4% solids.

(B) Intermediate Color Coating: The latex obtained above is adapted to include 0.2% by weight of pigment grade Carbon Black (Benney and Smith Micron X).

A moisture-curing polyurethane prepolymer is produced by reacting 1.0 mol. polypropylene glycol, 1.0 mol. 1,3-butane diol, 2.0 mol. of trimethylol propane and 8.0 mol. of 80-20 mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate. A portion of the moisture-curing polyurethane obtained is mixed under anhydrous conditions with 0.4% by weight of the carbon black. This is then dissolved in a 50:50 mixture of xylene and Cellosolve acetate to give a 50% by weight solution. For convenience this solution is referred to as (C) Pigmented Final Coating. Another portion of the moisture-curing polyurethane, but without the pigment, is similarly solvated. For convenience this solution is referred to as (D) Clear Final Coating.

A number of shoe assemblies including attached, previously rough rounded leather outsoles are sprayed at the outsole edges with (A) Sizing. The sizing penetrates to a distance of about 0.20 inch. The outsoles are then smooth rounded to remove about 0.15 inch off the edge. The shoes are immediately divided into two groups and the following procedure carried out within 5.0 minutes.

The first group (I) of shoes are subjected to spraying by the (B) Intermediate Color Coating,followed by an incomplete drying under an air. blast at a temperature of about 700F., followed by a spray application of the (D) Clear Finish Coat. After drying, it is noted that the polyurethane coatings are about 0.0006 inch in thickness, are continuous in nature, and have smooth outer finish appearances.

The second group (II) of shoes are sprayed directly with the (C) Pigmented Final Coating. After drying the polyurethane film coatings obtained are noted to be 0.0013

inch in thickness, are continuous in nature and exhibit smooth outer finish appearances.

The shoes of groups (I) and (II) are subjected to wearing and abrasion tests. Their performances are compared with shoes whose outsoles have conventional edge finishes, i.e., wax-pigment finishes. The performance of finishes on the outsoles of the shoes from both groups (I) and (II) show far superior properties of resistance to cracking, peeling, abrasion to those having conventional finishes. In addition the finishes on the outsoles of the shoes of both groups (I) and .(II) are non-marking. Further than that the finishes obtained on the outsoles of groups (I) and (II) shoes do not deteriorate when exposed to temperatures above 350 F. and below 35 F. for extended periods of time (on the order of 60 days).

It will thus be seen that the objects set forth above,-.

among those made apparent from the preceding description, are efiiciently attained, and since certain changes may be carried out in the above edge finishing method and in shoe outer bottoms obtained from practice of that method, without departing tion, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure States is:

1. A method for edge finishing shoe outer bottoms which are fibrous in nature, the method comprising the steps of (a) providing edge portions of .the shoe outer bottom in at least moist condition by introducing an; aqueous, liquid sizing into edge. portions of the shoe outer bottom, the sizing penetrating beyond edge portions which.

remain as part of said bottom after edge. trimming is carried out, and, while the edge portions are in at least moist condition (b) trimming the edge portions of the shoe outer bottom and (c) applying a liquid coating including a moisture-curing polyurethane composition to the trimmed edge surfaces, the said coating being compatible with the sizing.

2. A method for edge finishing shoe outer bottoms according to claim 1 wherein the sizing is an aqueous dispersion of thermoplastic synthetic polymeric material.

3. A method for edge finishing shoe outer bottoms according .to claim 2 wherein the thermoplastic synthetic polymeric material is based .on an acrylic latex.

4. A method for edge finishing shoe outer bottoms which are fibrous in nature, the method comprising the steps of (a) providing edge portions of a shoe outer bottom in atleast moist condition by introducing an aqueous liquid sizing into the edge portions of the shoe outer bottom, the sizing penetrating beyond the edge .portions which remain as part of said bottom after edge trimming are waterproof and I from the scope of the invenby Letters Patent of the United is carried out and while the edge portions of the shoe outer bottom are in at least moist condition (b) trimming said edge portions of the shoe outer bottom (c) applying an aqueous, liquid intermediate coating and a liquid finish coating including a moisture-curing polyurethane composition to the trimmed edge surfaces, the said coatings being compatible with each other and the sizing.

5. A method for edge finishing shoe outer bottoms according to claim 4 wherein the sizing is an aqueous dispersion of thermoplastic synthetic polymeric material.

6. A method for edge finishing shoe outer bottoms according to claim 4 wherein the intermediate coating is an aqueous dispersion of thermoplastic synthetic polymeric material.

7. A shoe having an outer bottom which is fibrous in nature with an edge exhibiting an improved finish, the edge including a first coating penetrating an edge portion of said bottom and comprising an aqueous liquid sizing in moist condition, a portion of said edge being trimmed away and leaving a portion of said edge including said liquid sizing subsequent to trimming and a second coating comprising a moisture-curing polyurethane compatible with the sizing.

8. A shoe outer bottom which is fibrous in nature with an edge exhibiting an improved finish, the edge including a first coating penetrating an edge portion of said bottom and comprising an aqueous liquid sizing in moist condition, a portion of said edge being trimmed away and leaving a portion of said edge including said liquid sizing subsequent to trimming and a second coating comprising a moisture-curing polyurethane compatible with the sizing.

9. A shoe having an outer bottom which is fibrous in nature with the edge exhibiting an improved finish, the edge including a first coating penetrating an edge portion of said bottom and comprising an aqueous liquid sizing in moist condition, a portion of said edge being trimmed away and leaving a portion of said edge including said liquid sizing subsequent to trimming, an intermediate coating comprising coloring material in aqueous liquid and an edge coating comprising a moisture-curing polyurethane, the said coatings being compatible with each other.

10. A shoe outer bottom which is fibrous in nature with an edge exhibiting an improved finish, the edge including a first coating penetrating an edge portion of said bottom and comprising an aqueous liquid sizing in moist condition, a portion of said edge being trimmed away and leaving a portion of said edge including said liquid sizing subsequent to trimming, an intermediate coating comprising coloring material in aqueous liquid and an edge coating comprising a moisture-curing polyurethane, the said coatings being compatible with each other.

References Cited UNITED STATES PATENTS 1,961,318 6/1934 White 12142 2,051,374 8/1934 Frost 12-142 2,058,454 10/1936 Hopkins l2-146 X 2,852,413 9/1958 Tischbein 117139 X 2,884,336 4/1959 Loshaek et a1. 11711 JORDAN FRANKLIN, Primary Examiner. H. H. HUNTER, Assistant Examiner.

Claims (1)

1. 7. A SHOE HAVING AN OUTER BOTTOM WHICH IS FIBROUS IN NATURE WITH AN EDGE EXHIBITING AN IMPROVED FINISH, THE EDGE INCLUDING A FIRST COATING PENETRATING AN EDGE PORTION OF SAID BOTTOM AND COMPRISING AN AQUEOUS LIQUID SIZING IN MOIST CONDITION, A PORTION OF SAID EDGE BEING TRIMMED AWAY AND LEAVING A PORTION OF SAID EDGE INCLUDING SAID LIQUID SIZING SUBSEQUENT TO TRIMMING AND A SECOND COATING COMPRISING A MOISTURE-CURING POLYURETHANE COMPATIBLE WITH THE SIZING.

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