US1900131A - Rugous coating composition and process of making same - Google Patents

Description

25 lacquer, but baking involves an Patented Mar.

UNITED, 'ST'AITESIPIATENT OFFICE A rum: 3.

COMPANY, OF NEW YORK, 11'. Y., A CORPORATION OF VIRGINIA BUG OUB COATING COMPOSITION AND PROCESS OF MAKING SAME Ne Drawing. 7

This invention relates to a liquid coating composition containing a binder preferably of the cellulose ester type, such as nitrocellulose 'or acetyl cellulose, and also containing ground wood or wood flour, preferably of spray-projecting fineness coatings formed by the application of sprayingof 'sueh composition preferably having the property of drying rapidly at room temperature to form a 10 textured rugous. surface.

The vehicle of the coating composition as stated is preferably of the cellulose ester type such, for example, as a solution in appropriate solvents of low viscosity nitrocellulose,

a plasticizer and a resin. A lacquer vehicle of this character forms the carrier for the ground wood material essential in forming the textured rugous surface. Instead of using lacquers or similar rapidly drying com- '20 positions, I may in some cases employ a quic drying o1l varnish. When the latter is used the acceleration of drying by mild baking 1s not precluded. Likewise, if desired, baking may be resorted to in the case of the cellulose additional step with loss of time. and labor expense and I preferably, as indicated, employ a very rapid drying vehicle in order that the textured surface may be produced in the quickest possible time at a minimumof labor cost..

, Ground wood or wood flour varies in particle size, some being quite coarse and others "very fine. The ground wood obtalned from soft Woods such as poplar, pine, spruce, fir,

36 and the like, which is ordinarily employed as afiller in molding compositions, lmeoleum, and the like, may be used in carrying out the present invention. Also it is possible to employ ground wood prepared from hard woods.

40 Cedar dust likewise may be employed in some cases.

In the preferred form of the invention it is an object to employ the ground wood in a state of palpabilit or coarseness adequate to secure a texture surface of a decidedly I Application filed November 20, 1929. Serial No. 408,662.

rugous character but, on the other hand, of a particle size not exceeding spray-projecting fineness, since 1 preferably apply my composition by means of a spray-gun. The latter implement has become thoroughly standardized and its orifices and connecting tubes are of such character that coarse particles will not pass therethrough. I have found, however, particles of ground wood of soft wood origin seemingly of a size which would clog the spray nozzles will pass through these relatively tiny orifices and be projected in the spray upon the surface which is to be coated, forming a rugous coating of a decorative textured character.

R001, 01' EAST ORANGE, NEW JERSEY, ASSIGNOB. TO CHADELOIID CHEMICAL Y There is, however, a limit to the fineness of the ground wood which I prefer to employ, since the use of ground wood in the form of an impalpable powder tends to give merely a dull surface of a non-rugous character. While I do not avoid the employment of ground wood containing a percentage of tiny particles which, if separated, wouldyield an impalpable powder, nevertheless I find it highly advantageous to employ a screened mixture of the ground wood from which the impalpable particles have been removed,

likewise the coarse particles of spray-clogging dimensions. In this way I secure a texture-producing ingredient of spray-projecting fineness largely free from impalpable wood powder. In other words, I prefer to employ ground wood in the form of a palpable powder largely free from impalpable material.

The wood flour of soft wood origin preferably is entirely free from bark or dirt in discoloring proportion in order that the coating may be pigmented by colors, lakes or pigments, or-the wood flour itself dyed to yield, when desired, coatings of desirable tone or tint. Insome cases the wood flour may be dyed and the vehicle itself may carry another color with the object of securing some contrast between the rugous wood particles of the coating and the binder.

Another possible decorative effect is that secured by spraying the composition on surfaces which are held vertically and allowing a certain slippage or downward movement to take place resulting in slight separations into ridgelike formations or elevated areas intermediate which is an area occupied by the vehicle alone perhaps dotted with a few particles of the ground wood; such effect being to give a more emphatic texture to the surface, which oftentimes is desirable.- The formations, or sliprugae, obtained in this manner serve as demarcation or aggregation areas which viewed from a distance of a few feet afford to the eye a textured appearance of high decorative value. In this manner I may treat the interior walls of buildings to form textured surfaces. For example, the composition may be applied to plaster which has been well sized andafter the spray coating has dried the textured effect described will be found well-developed.

Such a textured surface oftentimes may be improved in vigor or depth by applying a coating of a clear composition such as clear lacquer or varnish, preferably the former.'

The second coat or supercoat may be tinted in any desired manner by colors, lakes, pigments, and so forth.

A further feature of my invention is the proportioning of ground wood to binder. In a lacquer vehicle composed of nitrocellulose, plasticizer, resin and solvents in about normal proportions, I find a proportion of about one part of wood flo'ur of said spray-projecting fineness to two parts of solid contents of the vehicle is suitable. This ratio varies somewhat with the different kinds of wood particles. It may be as high as one part of wood flour to one part of Vehicle solids in certain cases. 1

The following will serve to illustrate my invention:

Ewample 1 Percent .6 second nitrocellulose 5.4 ester gum 2 dibutyl phthalate 30 ethyl acetate 2 ethyl alcohol 22 butyl acetate 25 toluol 7 spruce flour I may use any suitable plasticizer, such as castor oil, tricresyl phosphate, alkyl' ether of a polyglycol, and so forth. I prefer to use nitrocellulose of low viscosity since wood flour naturally produces a viscous mixture. The use of high viscosity nitrocellulose would tend to give too viscous a mixture for application. In this respect the resins and plasticizers are of value in giving high solid content of the vehicle without increasing the viscosity very much.

I prefer to 'use a wood flour the particles of which have a substantially definite size. In the above example the flour was passed through a 30 mesh screen and the larger particles discarded, these being of spray-clogging size. The smaller particles were then removed by means of a 120 mesh screen and these were discarded. That. is, the flour was of such particle size that all passed through a 30 mesh screen but was retained by a 120 mesh screen.

If desired the more impalpable particles may not be separated. However, since they do not assist in the attainment of a textured surface and absorb a certain portion of the vehicle, I prefer to separate them as described.

I may use any wood fiour of soft wood origin. Also, I may use a wood flour of hard wood origin, such as oak, gum, maple, and so forth. If the spruce flour in the above example is replaced by the same amount of hard wood flour, there is less absorption of the binder by the flour and a coating having more gloss is obtained. To get the same dullness of surface using a hardwood flour, the proportion of the latter must be increased. Thus in Example 1, I may use as much,as 14 per cent of hardwood flour and obtain a sprayprojecting composition which produces a highly desirable textured quality when applied. To avoid the disadvantage of the greater settling of hardwood flour due to its higher density, I may use a mixture of two or more forms of wood flour.

A particular advantage of the composition designated Example l'is its film-building ability. On a vertical surface a film can be built up in one application the thickness of which greatly exceeds that which is possible with the ordinary sprayed coating. The ordinary sprayed coating runs off a vertical surface if a very heavy film is applied, but with the composition here described a quite heavy coat is permissible. Another advantage of this type of composition is its very great covering power. For example, one coat applied to a piece of bare wood produces a uniform color which completely hides the grain configuration of the wood underneath.

If a very heavy film of the composition designated Example 1 is applied to a vertical, more or less impervious surface, some downward sliding of the film occurs producing table ivory-was passed smooth areas. as described above is facilitated by lower vissegregated ridges bounded by substantially The formation of slip-rugae cosity of the mixture. For example, if I add an extra 20 per cent of a solvent mixture to Example 1 and spray a heavy coat on a vertical surface, there is a very noticeable forma-' tion of irregular ridges or slip-rugae which produces a very desirable texture-contrast.

Example 2 Per cent I 6 second nitrocellulose 3 ester gum 2 dibutyl phthalate 25"; ethyl acetate 28 butyl acetate 2 butyl alcohol 26 toluol 8 ground vegetable ivory screen and thev larger particles of sprayclogging dimensions were discarded. Ground vegetable ivory contains a certain amount of to the shell. This is not brown particles due pigment is used in the objectionable if a lacquer to modify the color.

Since vegetable ivory is of greater density than wood flour and therefore has a greater tendency to settle out of the mixture, it is well to use a mixture of wood flour and vegetable ivory. Thus I may use a mixture consisting of equal parts of wood flour and ound vegetable ivory. This mixture settles much more slowly than the vegetable ivory alone. Also the composition containing this mixture has very desirable sprayprojecting qualities. 1

. Example 3 Per cent 5 second nitrocellulose 3 dammar 1 castor oil 1 dibutyl phthalate 3O ethyl acetate 2 ethyl alcohol 22 butyl acetate 30 toluol 6 cedar dust This mixture is of very desirable sprayprojecting consistency and when sprayed it produces by means of one coat a rich brown textured coating without the use of a pigment. However, a pigment may be used if wool, cotton 'linters,

desired to modify the color. The cedar dust used in this example was passed through a 30 mesh screen and all the larger particles were discarded. The more or less impalpable particles may or may not be removed.- A certain percentage-of these particles is desirable for their tinting qualities, although they are of no advantage in producing the textured effect.

By use of this composition it is possible to obtain a finish on bare wood or sized plaster, or other more or less rigid surfaces,

by one coat due to the high covering (hiding) power of the cedar dust.

Example. 4 Per cent 6 second nitrocellulose 2 castor oil 1 dibutyl phthalate 30 ethyl acetate 2 ethyl alcohol 24 butyl acetate 30"- toluol 5 cork dust This composition is also of excellent sprayprojecting character and produces a dark brown textured coating without the use of any pigment. The corkdust'which I used was of the commercial grade used in the linoleum industry. It was screened to 30 mesh size without separating the more impalpable par ticles.

E wample 5 Per cent 7 3 5 A second nitrocellulose 4 rosin ester 1 dibutyl phthalate 3O ethyl acetate 2 ethyl alcohol 18- blltyl acetate 30 toluol 6 wood flour 4 gold bronze This is a mixture of good spray-projecting qualities and produces a textured finish which is a combination of the eflects given by the other examples and that of the gold bronze.

Clipped hair, shredded asbestos, mineral cotton flock and silk flock, when used alone are much more diflicult to convert to spray-projecting comminution. Mixed with a lacquer the fibres normally tend to mat together somewhat so that the mixture cannot be as readily applied by spra -gun or brush. However, used in admixture with a palpable material of the requisite spray-projecting type they greatly assist the latter in forming a textured surface. Thus I may use 20 per cent of finely shredded asbestos and 80 per cent of wood flour in-a lacquer, as set forth above, and obtain a composition of good texturing qualities.

In any of the aboveexamples I may add a,

coloring agent such as pigment or dye to give any desired shade. Thus in Example 1, I may add Prussian blue, sayt per cent, and produce a blue texturing material which gives the desiredcolor and textured coating by means of one coat. That is, I may give bare wood or other surfaces a textured and suitably colored coating in one application.

I may also use the compositions listed above as undercoats over which to apply a coating of lacquer enamel, varnish enamel, clear shellac or any other clear coating composition.

For example, the composition designated Example 1, may be applied to a surface and dried, giving a rough textured coating. This rough coating is then sprayed with a lacquer, for example, the following:

Per cent 6 tnitrocelulose 3 ester gum 8 gold bronze 83 thinner The applied lacquer is thus used to give the colored effect upon the rough textured surface which is an undercoat.

In the foregoing I have indicated the possibility when treating vertical surfaces to secure slip-rugae. This result, however, can be secured only when a thin solution is used of adequate sagging properties. Under normal conditions the lacquer containing the ground wood or similar material can be applied as a coat of a fairly uniform character so far as concealing or hiding power is concerned. A very surprising result is obtained by using the product of the present inventlon as a one-coat finish in that complete coverage and hiding of the under surface is obtained by the application of a single coat. In the or-- dinary nitrocellulose lacquer pigmentation, especially in the lighter shades, cannot be carried to such a degree that a single coat will properly conceal or hide the under surface. In the present invention by the employment of wood fibres and the like, acting somewhat similar to blotting paper, I am able to build up by a single sprayed application a one-coat finish which provides full concealment of the surface without dripping of the lacquer vehicle. I therefore. disclose the process of application which comprises spraying a lacquer containing a drip-arrester whereby a covered surface adapted as a complete finish is secured in a single coat. In other words, a one-coat rugous sprayed finish completely concealing the surface beneath results.

WVhat I claim is 1. A liquid coating composition containing palpable ground wood of substantially soft wood origin and of spray-projecting fineness; said coating composition rapidly drying on exposure at room temperature to form a textured rugous surface.

2. A liquid coating composition containing palpable ground Wood of substantially soft wood origin and of spray-projecting fineness; said coating composition rapidly drying on exposure at room temperature on a vertical surface to form a textured finish containing slip-rugae.

3. A decorative nitrocellulose wall lacquer containing palpable ground wood of soft wood origin and of spray-projecting fineness; said lacquer drying to a rugous surface.

4. A decorative wall lacquer containing palpable ground wood of soft wood origin and of spray-projecting fineness; said lacquer drying to a rugous surface.

5. An article of manufacture carrying a finish of a rugous character containing ground wood of spray-projecting fineness held in position by a binding agent and supercoated with a lacquer.

6. A rugous drying lacquer carrying as a pigment cedar sawdust of between 20 and 120 mesh.

7. A rugous drying lacquer carrying as a pigment cedar sawdust not exceeding about 20 mesh.

8. A rugous drying lacquer carrying as a pigment cedar sawdust not exceeding spraydelivering coarseness.

9. In a one-coat spraying lacquer a textureforming agent comprising a non-caking freespraying component of pulverized wood.

10. The process which consists in screenlng pulverized wood to remove chips and coarse particles and then incorporating the screened product in a nitrocellulose lacquer of low viscosity in proportion to give a spray-projecting coating composition capable of forming in one application a rugous coatlng adequate to completely conceal the supporting surface.

11. Rugous-forming lacquer finishes containing low viscosity nitrocellulose and palpable ground wood of spray-projecting fineness.

12. Rugous-forming lacquers containing a cellulose pigment.

13. An article of manufacture carrying a rugous film adherent thereto. said film com prising a fibrous rugosifier of spray-deliver- 1