US1957179A - Coating material - Google Patents

Description

May 1, 1934. K. A. MILAR COATING MATERIAL Filed May 25. 1931 MHz/ 6772;??? Kari 5% MtZar 2 W 1% ?atentecl May 1, 19 34 I STAKE AENT OFFICE This invention relates to improvements in tiles and chemical changes such that, when the coating material. cement is allowed to cool during the nights, it

Heretofore, difi'iculty has been experienced in is unfit for application thereafter. providin suitable protective coatings for metal One object of my invention is to provide a 5 surfaces such as the side and end walls, underdurable and efiicient coating material, such as 6 frames and other parts of railway cars. If ordicar cement, particularly adapted for application nary paints are employed, it is generally necesto metal surfaces and which comprises an assary to apply at least three coats, particularly on phaltic base and undissolved fibrous matter, any vertical walls where the tendency is for the which coating material will always be of sufiil0 thin coating material to run down. Some progcient fluid or semi-fluid consistency within the Q ress has been made in providing what are known normal range of atmospheric temperatures in as car cements, which generally embody an the temperate zone as to eliminate the necessity asphaltic base and some undissoived free fibrous of heat at time of application, will retain the material such as asbestos fiber. Such cements fibrous matter properly in suspension and perembodying undissolved fibrous matter possess the mit of uniform application of the coating mate- 7Q advantage of greater thickness or density and rial to the surfaces by spraying. hence have required fewer coats. However, such A further object of my invention is to provide previously known car cements have not been ena protective coating material having an asphaltic tirely satisfactory because of the difficulty eX- base and containing undissolved fibrous matter perienced in keeping the same in a proper 0010- in suspension, which material retains its pre- 75 dition of fluidity under normal temperature determined consistency within the normal range ranges in the United States and temperate zone of atmospheric temperatures so that the coating to permit of proper and eiiicient application to material may be transported and handled withthe metal surfaces. As well known, it is cusout any special precautions as regards temperatomary to apply the protective coatings to the ture, and sprayed and atomized through a spray 8!) metal car surfaces in car building plants and gun for application to the surfaces. railroad shops, which are always more or less Other objects of the invention will more clearly open to atmosphere so that, particularly in cold appear from the description and claims herein- Weather, heat has generally been employed to after following.

a condition the cement for application. Prior to In the drawing forming a part of this specificamy invention, the customary manner of applytion, Figure 1 is a schematic or diagrammatic ing such so-called cements has been by means view, illustrating conventionally suitable apparaof trowels or stiff brushes, which obviously intus for mixing or compounding my improved volves the use of excessive amounts of the matecoating material. Figure 2 is an elevational view I 35 rial, increases labor cost of application, and unof suitable apparatus for spraying the coating even application of the material. material, and Figure 3 is a sectional view of a To some extent, eiiorts have been made to apspray nozzle suitable for use in spraying my ply car cements having an asphaltic base and improved coating material.

fibrous material therein by spr y bu this In carrying out my invention, I provide a coat- 40 method also has resulted in other difficulties. ing material which preferably combines a petro- The undissolved 01 free fibers in such cements leum asphalt such as roofing black asphalt, gilheretofore emp y frequently Cause clogging of sonite, a saponifiable or oxidizable oil such as the 11 p y gun a d, unless the Cement is blown soya bean oil, preferably both long and heated at time of application, the same frequenth t b t fiber d d rk pigment such 7 45 1y becomes s thick or Solid a to p v t applias dry carbon black and volatile oil, such as cation by spraying and atomizing. If heating b nZin of the ceme t material is p y her di In order that the coating material may be of ficulties arise in actual practice. If the usual the proper consistency when applied and permit class of operators are instructed to heat the car of the carrying out of my improved method of 50 cement, it frequ y pp that S u h application, the material is prepared in the folheat will be applied that the cement becomes lowing manner. The roofing black asphalt, which so thin or fluid as to allow the fibrous content is a petroleum asphalt and may be obtained comto settle in the barrels or tanks and, also, heatmercially, is first heated until liquefied, whereing of the cement as commonly carried out at upon it is then cut with a hydro-carbon volatile 55 car building plants results in driving ofi volathinner, such as benzine, suliiciently so that, upon cooling to a normal atmospheric temperature condition, the thinned asphalt will remain in a liquid or semi-fluid condition and or" such density that it will retain fibrous matter such as asbestos fiber in suspension, as hereinafter described.

The gilsonite, also obtainable as a commercial product, is likewise heated with a small quantity of saponifiable or oxidizable oil until it liquefies and fuses with the oil and is then similarly cut with a volatile oil, such as benzine, so that it also will retain a liquid or semi-fluid consistency when allowed to cool to normal atmospheric temperatures and of sufficient density to maintain the fibrous matter in suspension, as hereinafter described.

The saponifiable or oxidizable oil, such as blown soya bean oil, the volatile oil, such as benzine, and the pigment, such as dry carbon black, are all ordinary commercial products requiring no special treatment and are mixed with the cut asphalt and gilsonite, as hereinafter described. Asbestos fiber is likewise obtainable commercially and in what is known as short and long fibers, quantities of both of which are preferably used in my improved coating material.

The improved coating material is preferably compounded in the following proportions by weight:

Per cent Petroleum asphalt 20-35 Gilsonite 8-20 Oxidizable oil '7-1'7 Volatile oil 25-40 Fibrous matter 10-30 Pigment 0- 4 For average conditions, I have found a most satisfactory coating material comprised of the following proportions by weight, namely:

Per cent Petroleum asphalt 2'7 Gilsonite 12 Blown soya bean oil 10 Benzine 34 Asbestos fiber 16 Dry carbon black 1 In preparing and compounding the coating material, the petroleum asphalt and gilsonite are first prepared in the manner hereinbefore set forth and are then placed in a mixer, such as indicated conventionally at 10 in the drawing. To the mixture of cut asphalt and gilsonite is then added the rest of the saponifiable or oxidizable oil and pigment, after which is added and thoroughly whipped into the mixture the fibrous matter, all of this mixing being done at ordinary temperatures. From the mixer 10 the batch is then transferred to an agitator, as indicated conventionally at 11 in the drawing, where the mixture is thoroughly agitated also at normal temperatures. After agitating, the mixture is then placed in barrels or other suitable containers 12 for shipment, the mixture, however, after leaving the agitator and before being deposited in barrels being passed through a screen, indicated conventionally at 13, for the purpose about to be described. In this connection, due to the consistency of the asphalt and gilsonite, prepared as hereinbefore set forth, it will be understood that the fibrous matter, such as asbestos fiber, will be thoroughly and uniformly distributed throughout the batch by the foregoing mixing and agitating steps and will remain in suspension due to the consistency of the material.

Asbestos fiber, as ordinarily carried in stock, is

considered or assumed to be dry, but because of its hydroscopic qualities will absorb a certain amount of moisture from the atmosphere, which moisture to a more or less extent is always present even though the asbestos fiber has all the appearance of being dry. The moisture so absorbed by the asbestos fiber results in small lumps or wads of the fiber being formed, which are exceedingly difiicult and practically impossible to break up, after once formed, by any mixing or agitating process. Because of the lumps or wads so formed in the asbestos fiber (which remains undissolved and in suspension in the other materials), I pass the mixture through the screen 13 before delivering into the barrels and so design the mesh of the screen 13 that it will strain out or hold back any of said lumps or wads of the asbestos fiber that would be too big to freely pass through the nozzle of the spray gun used in applying the coating material, and hence insure that the coating material or cement, as it is placed in the barrels for shipment, is of such consistency and, particularly, the asbestos fiber in such size particles, that the material may be readily passed through the nozzle of the spray gun and atomized.

After being placed in the barrels or other suitable form of containers, the material will be shipped to the car building plants or railroad shops, no special precautions being necessary to maintain the desired consistency of the material. Where the material is to be applied, the following is a suitable apparatus that may be employed. The material is first placed in a pressure tank, indicated at 14, which may be mounted on wheels 15 to facilitate its movement from one place to another. The material may be entered through opening 16, which will then be closed. Extending down into the tank 14 to near the bottom thereof is a discharge pipe 17, through which the material is delivered, the same being controlled by valve 18, passing through another screen 19 (interposed in the line for the purposes hereinafter described) and thence through flexible pipe 20 to the spray gun 21. A control valve at the nozzle is indicated at 22. Air under pressure is supplied to the pressure tank 14 from any suitable source, as, for instance, the usual air line 23, through coupling 24, to a Y-25, from one branch of which leads a flexible pipe 26 to the tank 14, said pipe line having a control valve 27 included therein. Preferably, between the control valve 27 and the tank 14, is interposed a branch pipe 28 communicating with a gauge 29 and safety valve 30. From the other branch of the Y-25 leads a flexible pipe 31 to the spray gun 21, said pipe having also included therein a control valve 32 adjacent the nozzle.

The spray gun, as shown, preferably comprises a casing 33, having an apertured bushing 34 threaded into the outer end thereof, the aperture 35 being tapered outwardly as shown in Figure 3. The material supply line 20 terminates in a nozzle 36 within the casing 33, said nozzle projecting partially within the tapered aperture 35. The air supply line 31 delivers the air into a chamber 3'? within the casing 33 around the nozzle 36 so that, as the material is forced under pressure through the nozzle and through the bushing, the supply of air, also under pressure, will effectively atomize the material as it leaves the gun.

Referring to the screen 19, which is interposed in the delivery line from the pressure tank, the same is provided to catch or hold back any foreign matter that may inadvertently become mixed with the coating material, such as pieces of wood, it being not unusual for chips from the barrels to become mixed with the material when the barrels are opened.

With my improved coating material, it is obvious that the same may be shipped and handled at ordinary temperatures; the fiber remains in suspension; no heat is required during application within the normal range of atmospheric temperatures; and, because of the normal liquid or semiliquid condition of the material and the elimination of lumps or wads of the asbestos, the material may be economically and easily applied by the spray gun method, thus insuring uniform application with minimum labor costs.

The coating material compounded as hereinbefore described, will dry out with a tough but not brittle film; the body or consistency of the material is such that, when applied, it will not run but will remain where deposited; will not become brittle or friable even under extreme low temperatures nor become runny or tacky under high atmospheric temperatures; and, when dried out or oxidized, the body of the material retains the desirable elasticity and ductility so as to prevent cracking or checking under vibration or bending Within reasonable limits of the metal surface to which applied.

Although I have herein described the preferred composition of my improved coating material and method of compounding the same, nevertheless all changes and modifications are contemplated that come within the scope of the appended claims.

I claim:

1. A coating material compound including the following substances, thoroughly mixed, and in approximately the following proportions by weight, namely: petroleum asphalt 27%; gilsonite 12%; blown bean oil 10%; asbestos fiber 16%; pigment 1%; and benzine 34%, the mixture being of substantially liquid consistency and the fiber remaining in suspension therein within normal atmospheric temperature ranges.

2. A coating material compound including: petroleum asphalt and gilsonite both pre-cut with a volatile hydrocarbon thinner to a substantially liquid consistency within normal atmospheric temperature ranges, the quantity of the petroleum asphalt being materially greater than that of the gilsonite; blown bean oil, the quantity of the latter being less than the quantity of the petroleum asphalt and gilsonite; and asbestos fiber, all the ingredients being thoroughly mixed and the mixture being of substantially liquid consistency and the fiber remaining in suspension therein within normal atmospheric temperature ranges.

KARL A. MILAR.

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