US1412898A - Manufacture of paints - Google Patents

Description

I pass this mixture HENRY SELLMAN, 01F BRQOKLYN, NEW YORK.

MANUFACTURE EPAHWTS.

lilo Drawing.

T 0 all whom it may concern:

Be it known that l, HENRY SELLMAN, residing at 337 LincolnRoad, inthe borough of Brooklyn, county of Kings, city and State of New York, a citizen of the United States of America, have invented certain new and useful Improvements in the Manufacture of process resulting directly in a finished article of commerce. I

The object ofmy invent1on 1s to provide a simple, direct and eflicient means of treat ing the materials involved in such a manner as to produce a superior quahty of paint at a distinct economy in the cost of manufacture, in material used, and elimination of loss by damage to the ingredients caused by other difliculties connected with all known processes of paint making.

The common practice in this field 1s to first make a preliminary mixture of pigment and vehicle in a tub fitted with mechanically operated mixing blades, then to through a grinder or mill in which it is compressed and worked between two abrading surfaces. After having been sufficiently ground, the resulting paste is diluted to the desired extent by further addition of vehicle and finely mixed in a separate mixing apparatus, when this is carried out on a manufacturing scale, it generally requires several hours to pass a batch of paint through these three d1 st1nct and heretofore apparently necessary operations. During'all this time the preparation 18 sub ject to evaporation, accumulatlon of dust from the work-room, and, equally deleterious oxidation of the product by direct exposure to the atmospheric air, a loss from these sources amounting to two per cent of a batch being considered normal in ordinary factory practice.

Furthermore, if a finely ground product is desired the abrading surfaces of the stones in the grinding mill must be set so close to gether that a great amount of heat is produced during the operation, serlously endangering, and occasionally damaging the paint. The mills are therefore generally Specification of Letters Patent. Patented Aplfi 1L8, 1922..

Application filed. March 8, 1921. Serial No. 450,542.

water cooled, and require much careful attention. The abrading surfaces in such mills do not remain long in the perfect condition required for good work, and must be frequently redressed, but this is an expensive and difiicult operation. At best, these mills require constant and skilled attention to insure satisfactory work. a

On the other hand it is well-known that many vehicles found in paint have highly objectionable odors which are entirely -uncontrolled in the common methods of manufacture. Yet another disadvantage inheres in these methods, namely; large quantities of a1r are worked into the product during the operations. Ordinarily, this is not very detrimental, except for its drying effect on, thepaint, but in some cases where any oxidation whatever is highly injurious, it is found that air bubbles have become so thoroughly distributed throughout the ground mixture that they cannot well be eliminated from the final product. It is, therefore, another object of this invention to employ the possibilities of my process to entirely prevent. oxidation of the paint.

The present process hereinafter to be more specifically described is performed by introducing the requisite pigment and vehicle into a container together with a large num-' ber of movable reducing bodies, the action of the latter upon the interposed materials upon rotation of the container eventually producing a thoroughly ground mixture of pigment with thevehicle. T 0 this mixture is added whatever amount of vehicle is necessary to make a finished paint, the contamer belng agaln revolved for a few minutes toinsure homogeneity of the product. The result is a finished article of commerce unless it is desired to further treat the ma- ,terial by staining it to match some specialice - vehicle through said valve.

and

the turpentine and henzine order. llt was, therefore, the necessary practice first to mix and grind the igment with/the heavier and more viscid Oll, then later to dilute the ground paste with the lighter oils.

Returning again to the present process, -ll prefer to do the mixing and grinding of the pigment to a paste with a light and quick flowing oil, or, if the correct proportion of light oil is not suficient to make the paste as fluent as desired, a mixture of light, and heavy oils may be used. When this operation is complete, the paste is-diluted with the heavy oil in the mill, the whole process having been accomplished in an airtight container, as will now be more definitely pointed out.

While my process is not limited in application to any particular form of container, in

practice, if prefer to use the a aratus described in United States Patent 0. 1,363,620 granted to me December 28, 1920, the said apparatus consisting of a metalcylinder ordinarily furnished'with a lining of abrasion resistant material. The cylinder is provided with'a charge. opening having a suitable cover, an air vent with a vent plug, and a discharge opening having a valve located opposite to the charge opening, there being also means for rotating the cylinder. The latter is supplied with a little less than half its content of movable reducing bodies, which are' preferably, egg shaped flint pebbles, but may also be metallic balls or slu lgs.

hen a charge of dry pigment is introduced, together with' just enough vehicle to form a slow flowing paste when ground and mixed. This done, the cylinder is caused to revolve in the manner usual with ball mills, the length of time for this operation depending on the conditions involved and result desired. Ordinarily, a run of two to three hours is sufficient to producea fine. smooth paste, but coarse or hard pigments require more time. Under equal conditions, governed chiefly by the size of container, speed at which it is rotated, amount quality of pigment and vehicle, and quantity of reducing bodies, equal grinding and mixing results are always attained in equal time. When the paste is finished, and the vehicle is to be added in order to make the paste into a paint of proper density, it may be introduced through any of the various openings in the container, but I prefer to stop the cylinder with the discharge valve on top, and'then to pour in the In order to mix the fresh vehicle with the paste, the cylinder is run again from three to live minutes, after which the apparatus is stopped with the discharge valve in its lowest position, when the finished paint may be drawn oil". This last operation takes care of itself 11,411 gene in ordinary cases where the paint is of comparatively light density, but occasionally it -may be so viscous and thick that its own weight is insuflicient to cause it to drain out through the discharge valve. Tn such cases,

ll am able to force outthe grou nd'mass by and seriously afiect its quality. Tn such par ticular cases it is necessary to connect a vacuum pump to the mentioned discharge valve when the same is in its upper osition and completely remove all the air in t e mill. When the desired point of exhaustion is attained, the valve isclosed and the pump removed, and the usual operation of mixing and grinding may be carried on in vacuo. Naturally, the design of the valve which would be suitable for connection with 1 a vacuum pump does not form a feature of the present invention, and the details of the same are therefore left for a later application.

.llilowever, the absence of air'or any actual gas in the mill is neither necessary nor required as far as the presence of such bodies would exert a mechanical pressure upon the contents but the divisible qualities of all gases into practically misroscopic colloidally suspended bubbles is one of the chief things which it is sou ht to prevent by the removal of the gases. t is even more true that this removal of the air is intended as a preventive of the mentioned filming or oxidation of the mill contents by the atmospheric oxygen, and, furthermore, any gas would partially cushion the blows and grinding action of the reducing bodies in the mill. Hence there are three deleterious effects prevented by removal of the air from the mill drum, and it is one of the novel features of my process to remove the air for these reasons.

It is also evident that no odor or loss by evaporation can occur in the practice of my process, owing to the fact 1; at the entire operation is performed within a practically sealed container, the very limited quantity of air enclosed. with the grinding charge causing such a small amount of oxidation as to be negligible in ordinary cases. And if even this small oxidation is objectionable, it is merely necessary to remove the contained air to eliminate this slight trouble.

lit is likewise true, that so little heat is generated by the work going on within the apparatus, that in no case has it ever been known to injuriously aflect the paint, even Mill Hit

in prolonged runs with very unsatisfactory pigments, and it is therefore, not only safe,

but very common to leave the apparatus attention whatever when in in combustible media, the whole product being a more or less combustible colloidal solution.

No skilled labor is required to operate a mill when using my herein described process, except for weighing and proportioning the in redients for a grinding charge.

aving thus fully described my invention, I claim:

1. The process of manufacturing paint by simultaneously introducing a charge of pigment and vehicle into a rotatable drum rovided with freely movable reducing bo ies, revolving said drum for a prolonged period, then introducing an additional quantity of vehicle and again resuming rotation of said drum until the contained mixture is homogeneous, and finally withdrawing the product from the drum.

The process of paint making which consists in placing a quantity of pigment and vehicle in a revoluble drum containing a number of movable reducing bodies, exhausting the residual air from said drum, and rotating said drum with its contents in vacuo.

.3. The rocess of paint making which consists in p acing a quantity of pigment and volatile combustible vehicle in a rotary drum containing mechanical reducing bodies and revolving said drum for a prolonged period.

4. The process of paint making which consists in introducing a charge of pigment and volatile vehicle into a drum containing reducing bodies rotating the drum for a time introducing a quantity of non volatile vehicle into said drum, resuming the operation of the latter, and finally withdrawing the product from the drum.

5. The process of paint manufacture consisting in the introduction of a charge of pigment and oxidizable vehicle into a drum containing a number of mechanical reducing bodies, the rotation of said drum for a period, the stopping of said drum and addition of a quantity of vehicle to the contained mixture, the resumption of rotation of said drum for a second period, and finally the withdrawal of the product from said drum.

6. The process of paint manufacture consisting in placing a charge of pigment and vehicle simultaneously in a rotatable drum, revolving said drum for a period of time, stopping the same and adding a quantity of volatile vehicle, again revolving said drum for a period, and finally discharging the contents.

7. The process of paint manufacture consisting in agitating a quantity of pigment with a mixture of oxidizable and volatile vehicle in a closed container, stopping said agitation, introducing a second mixture of vehicle into said container, again agitatin said container and enclosed contents, an finally withdrawing the finished product therefrom.

8. The process of paint manufacture which consists in placing a quantity of pigment and vehicle in a drum, removing deleterious gases from said drum revolving the drum fo a prolonged period, then introducing an additional quantity of vehicle into the drum, resuming the agitation of the drum contents and finally withdrawing the resulting mixture.

9. The process of paint manufacture which consists in simultaneously introducing a quantity of pigment and volatile combustible vehicle into a revoluble drum containing free reducing bodies and revolving said drum to comminute and mix the introduced materials. .7

10. The process of paint manufacture which consists in placing a quantity of pigment with a mixture of volatile and oxidizable vehicles in a closaiole drum containing free reducing bodies, and rotating thedrum to reduce the introduced materials to a smooth mixture.

Signed at 132 Nassau Street, in the borough of Manhattan, county of New York, city and State of New York this 7th day of March,

HENRY SELLMAN. Witnesses:

EDWARD CHILSTRAM, Asnan Jameson.