US2257595A - Paint for simulating wood grain - Google Patents

Description

Patented Sept. 30, 1941 OFFICE PAINT FOR. SIMULATING WOOD GRAIN Edwin W. Danielson, Dunellen, N. J.

No Drawing. Application October 19, 1938, Serial No. 235,779

9Claims.

This invention relates to paint, and more particularly paints, enamels, and the like, for producing a simulation of the grain of wood. Al- .though representations of grained wood, particularly the graining of the richer or more attractive hard woods such as oak, walnut, mahogany --and' the like are often desired for decorative purposes (as on articles or surfaces of metal or of less costly wood), the procedures heretofore usually employed to obtain the eflect have been relatively costly and have required special skill or complex apparatus.

One such procedure, for instance, has been to cover the surface flrstif a wood surface, after it has been preliminarily sealed-with an undercoat of a flat pigmented paint, usually embodying an ochre color. There is next applied a socalled graining compound, of wash consistency, containing the desired darker-colored pigment.

While the graining compound is still wet and fluid, a graining tool is worked over the surface, to wipe ofl part' of the compound for attainment of the desired eifect. There is thus involved not only a succession of treatments and a careful control of the consistency of the graining compound, but also special skill in operating the graining tool, which is usually a rocker-like implement having a peculiar surface configuration of rubber ribs, and must be used with a particular rocking and rubbing motion that requires care and long practice in order to obtain satisfactory results. Y

Another method is of a photographic nature, wherein the grained aspect of a master hardwood surface is photographed, and the photographed impression then transferred by a printing or quasi-printing process. 'It will be manifest that this procedure requires complex apparatus, suitable only for manufacturing establishments, and is limited in application to flat or relatively simple surfaces which can be subjected to the operation of the printing-on devices.

An important object, therefore, of the present invention is to provide a paint, preferably of the character of an enamel, which can be applied by anyone, and without any special skill, to obtain a strikingly realistic representation of a grained wood surface which has been varnished or'otherwise finished in the usuahmanner for fine woods; and more particularly, to provide a paint which, when simply applied with a brush of the usual sort, automatically forms or presents a series of dark and light bands or lines, of random size and shade, in close simulation of the natural grain of a large variety of woods. A furthere object is to provide such paints which can be readily packaged, stored, transported, and sold to the general public, for use by them to obtain the desired eflecti. e., handled and marketed like any simple household paint, varnish or enamel.

Other objects are: to provide brushing paint for obtaining a simulation of the grain of wood, wherein the character and color of the finish-'- as to represent light and dark oak, walnut, mahogany, and so forth-can be readily selected or-predetermined in the course of manufacture, as by simple variation in the proportions of certain ingredients; and to provide such a point, which is relatively quick drying, but easy to apply with a brush, and which can be thinned or diluted with any of the usual thinners employed for household paints and enamels.

To these and other ends, an important feature of the invention resides in the discovery that if a mixture of a vehicle and a metal powder, for example a very flne copper powder, is provided wherein the metal will not leaf or float when the paint is applied, and if the mixture has incorporated in it a coloring material (such as a hard asphalt) which is preferably of the soluble rather than the pigment type, the resulting paint will produce a remarkable simulation of the grain of wood, merely upon a simple brushing application. It is believed that for this result advantage is taken of a characteristic of metal powders heretofore usually considered a disadvantage, namely "streaking within the paint fllm-- streaking being believed to be occasioned by the position which the particles or flakes assume in the film (it being understood that the position of the particles governs their light reflection).

or at least to present a definite metallic appear ance with the metal particles, at surfaces of the applied paint. Thus almost without exceptionone exception being in certain paints of aluminum powder and bright pigment, wherein leafing the vehicle or remainder of the paint until the actual time of use. In the present invention,

however, the arrangement is such that the metal powder is positively prevented from leafing. for example by suitable preliminary treatment to destroy leafing.

According to the presently preferred meth of carrying out the invention, the metal'powder, preferably a very fine copper powder, is first mixed with a quantity of a vehicle, preferably the principal body-forming or film-forming ingredient, such as an alkyd resin solution, and the thorough mixture of the powder and vehicle is given an aging treatment, which may include moderate heating for a short period of time. Thereafter other suitable ingredients of the paint, including coloring matter-conveniently 'in the form ofan asphalt varnish or the likefurther film-forming vehicles, thinning ingredients and driers, are added and the entire composition thoroughly mixed in accordance with the practice for making ordinary enamels and house paints.

The resulting product, which may be packaged in cans, and if desired, stored for any length of time without detrimental results, can then be efifectlvely used in the simple manner hereinbefore described, to obtain an attractive and accurate representation 01' grained wood. Ordinarily, all that is necessary is to brush a single coat of the paint on the surface to be covered, andthe mere act of'brushing so disposes or arranges the paint that it naturally presents a striking simulation of wood graining, in the direction of the brush strokes.

. No special skill is required, other than to stroke the brush in the direction in which it is desired that the grain shall run. By reason, I believe, of the cooperation between the colored vehicle (preferably having a transparent, translucent or quasi-transparent nature) and the fine, mobile, non-ieafing copper powder beneath the surface of the vehicle, the naturally varying or random application at various points'across the end of the brush is suillcient to produce bands, lines and streaks which are of pleasantly random width, shade and tone, which may include minute flecks or ripples, and which may blend into each other along their edges in some degree,- so asto provide a surprisingly exact representation of natural wood grain. Furthermore, the resultingcoating includesa striking simulation of the subtle iridescence or sheen that characterizes the lighter areas or bands of a properly finished and polished hard wood surface; but there is no metallic or semimetallic appearance such as is presented by prior types ofpaint contain! metal-powder.

Curves, loops and'other common conflurations of grain can be readily obtained, merely by varying the direction of brush stroke, or by working back or in convergent or divergent directions all cial composition containing it, be not mixed with in a manner easily apparent to the veriest navice. Furthermore, the grained eflect is usually facilitated by employing a relatively wide brush, a practice which in turn speeds up the application of the paint and makes its use even more attractive both to the general public and to workers in the painting and decorating trades.

Although application with a brush is most convenient for the average user, it will be appreciated that under some circumstances, for

example in certain manufacturing processes, it

may be more expeditious to apply the paint by spraying, as at one station in a finishing procedure, and then while the paint is wet, to 80 over it rapidly with a brush to obtain the desired grained effect. For either type of application, however, the paint should preferably have the same essential brushing characteristics, including a viscosity suitable for brushing, and a long enough drying time (unlike rapid-drying lacquers and spray paints) so that there is no immediate thickening or setting to impede ready application or re-working with a brush.

The paint, particularly when made in accordance with preferred examples herein set forth, has excellent covering power so that a single coat is usually suflicient; it being understood that raw wood or other relatively porous surfaces require a preliminary sealing coatconveniently, any flat or sealing paint or varnish, such as used preliminarily to the application of ordinary enamels or the like. If desired, however, the preliminary sealing coat may satisfactorily be the same paint, of the present invention, as is used for the finishing or decorating coat.

By way of specific example, a particularly good enamel or paint of the type described has been made by using a fine copper powder and an alkyd resin vehicle, such as the alkyd resin solution called "No. 2 Beckosol." which is manufactured by Reichhold Chemicals Inc. (formerly Beck, Koller & Company, Inc.) and which is understood to consist of alkyd resin, modified with phenol and oil-extended: this specific resin solu-' tion being further described as of the drying type, medium long in oil, and being composed of 50% solid resin and 50% mineral spirits, proportioned by weight. The copper powder is preliminarily mixed with a small quantity of the alkyd solution, say in proportion of four pounds of copper per gallon of solution, and the mixture is then g preferably aged-for example, by heating for about 15 to 30 minutes at a moderate temperature, e. g., about 100 C. as attained over a steam bath. After the aging treatment, which is believed to contribute effectively to the suppression or destruction of leafing, the remaining ingredients of the paint, including the suitable coloring material, are incorporated with the aged mixture.

Particularly good coloring effects, in close resemblance of natural wood finishes, are obtained by the inclusion of an asphalt varnish, preferably made of Gilsom'te (sometimes called uintahite). A satisfactory Gilsonite varnish can be prepared by melting 540 pounds of Gilsonite in 200 pounds of linseed oil at 400 F. and thinning with 100 gallons of mineral spirits. The remaining ingredients of the paint may conveniently comprise a further quantity of film-forming vehicle such as the same alkyd resin solution, and

also thinning material of the characterof mineral spirits or solvent naphtha (the latter being often desirable to prevent. precipitation of the alkyd resin), together with a small proportion of drier (such as cobalt naphthenate) as is commonly included in varnishes and enamels.

Following the procedure Just described, for instance, light oak graining enamel paint can be prepared with ingredients having the following proportions in the finished product:

Copper powder pounds-- 75 Gilsonite varnishgallons- 17 No. 2 Beckosol do 55 Mineral spirits do 14 Solvent naphtha do 13 Liquid driers do 1 Similarly, a mahogany grainlng enamel paint can be prepared with the following proportion of ingredients:

Copper powder ..pounds-.. Gilsonite varnish "gallons" 54% No. 2 Beckoso do 24 Mineral spirits -do 6 Solvent naphtha do 14 Liquid driers do 1% In addition to providing the pleasing and attractive simulation of wood grain as hereinabove described, these paints are of satisfactory brush ing consistency, dry with convenient rapidity (say four hours or so), and have a high gloss and I excellent covering power, as well as abrasion reerai, the lighter colors are obtained by using alarge percentage of bronze powder relative to the amount of Gilsonite varnish, and the darker efiects vice versa: and the amounts of the remaining constituents of the vehicle may conveniently vary inversely with the amount of Gilsonite varnish, which itself contains both a thinner and film-forming agents. viz., linseed oil and Gilsonite. Using the stated ingredients, the foregoing formulae represent approximate limits of a range of proportions presently preferred for best results.

It seems best that the metal powder be extremely fine. For instance, I have obtained excellent results with a fine copper powder known as #350 Copper Flake," made by Metals Disintegrating Company, Inc., thisbeing a powder of which about 99 or more will pass 325 mesh, and which in a water covering test (where the powder is spread out on a water surface into a compact, single flake layer) will cover about 4500 square centimeters per gram. It will be understood that a less fine powder may be used, e. g., another available copper powder of which substantially all will pass 325 mesh, but which in the water test will not cover more than about 2500 square centimeters per gram; however, with such or coarser material the results.

are substantially less satisfactory than with the finer gradesi. e., the latter seem to produce a smoother surface and a definitely more pleasing and natural graining effect in the paint composition of the invention.

- In some cases, other kinds of bronze powder can be employed, such as powders of brass, alloys of copper (including so-called gold powders) and the like. In general, powders of warm color, e. g., red, orange, yellow and similar paint embodying the listed ingredients may body,

warm tints, are most suitable; but some good reresults have been obtained with aluminum powder, conveniently of the very finest or so-called "lining grade. Thus a non-leafing mixture containing Gilsonite asphalt. clear alkyd resin solution, and extremely fine aluminum powder, in proportions by volume of these and other ingredients generally corresponding to the specific examples set forth above, can be brushed out to produce a good simulation of weathered oak. It will be appreciated that in some cases, mixtures of metal powders may be used; for instance, where copper powder alone makes the resulting paint too red for best representation of some woods, a quantity of the fine aluminum powder (which has a bluish-white color) may be effectively included.

It will be appreciated that the nature and quantity of the coloring material may vary considerably in accordance with the particular color or tone of wood which it is sought to simulate. A wide variation, for instance, of the quantity of Gilsonite varnish is indicated in the examples previously set forth, and, of course, such material can be incorporated in other ways than with the specific varnish hereinabove described. For example, the asphalt 'can be prepared by a cold cut". procedure (which seems to give better results in paints which include substantial quantitles of aluminum powder): thus, pounds of Gilsonite are dissolved cold in 10 gallons of solvent naphtha and 15 gallons of mineral spirits are then added. The resulting solution may conveniently be used in'proportions generally similar to the Gilsonite linseed varnish described above. but since the cold cut preparation is thinner in it is preferable that the ultimate paint contain less additional thinner and more of the film-forming vehicle, such as the alkyd resin solution.

Although Gilsonite is at present preferred because of its availability, cleanliness, drying and film-producing properties, and ready adaptability to solution or mixture with other ingredients, other asphalts may be used. In general, asphaltites, of which Gilsonite is one, are preferable. "asphaltite" being a generic term for hard native or natural asphalts, which are peculiarly well adapted for use in paints of this character. With a number of petroleum asphalts tested, the paint likewise has good color and graining effect, but petroleum asphalts are usually relatively soft, and tend to make the applied film somewhat soft or tacky. Substituting pigments of the ordinary type in lieu of asphalt, has generally been found unsatisfactory, in that attempts to do so (with correspondingly substantial quantities of pigment) have failed to produce a paint having a good resemblance of wood grain on brushing; possible explanations being that pigments apparently lack the infinite variation in obscuring or coloring power relative to the metal, which sults with alkyd resin solutions, since these permit efiicient destruction of leafing and afford an especially accurate simulation of finished wood upon direct brushing application; and I have found the drying types of such resins, medium long in oil, to be particularly adaptable for the present invention, having good compatibility with the soluble color, good miscibility with thinners, and a drying rate and viscosity thatare conducive to easy brushing. It will be appreciated that extremely rapid-drying lacquers and like vehicles, while desirable in spray paints, are preferably avoided where good brushing capability is important, as in the present paint; and ready miscibility with common thinners is valuable not only for the manufacturer but also to make the paint fool-proof for the household user, who, even regardless of directions, will customarily attempt thinning with turpentine, mineral spirits, gasoline and the like. Among others, "Rezyl 807-1 (hereafter identified) provides a vehicle notably well adapted for such thinning.

In place of Beckosol No. 2, already mentioned, a similarly excellent graining paint can be made with the same manufacturers Beckosol" No. 1 (which is identical, but lighter in color), and very good results have also been obtained with each of a number of other alkyd resin solutions (generally similar to Beckosol No. 1 and No. 2 in physical characteristics), such as the following:

Duraplex C-45 manufactured by The Resinous Products and Chemical Co. Inc.;

"2466 Glyptal Solution manufactured by General Electric Company (this product, however, being somewhat too soft for some uses) Rezyl 880-1 and also "Rezyl 807-71, made by American Cyanimid & Chemical Corporation.

"No. 1319 Beckosol (also made by Reichhold Chemicals Inc.) is fairly useful, this being a nonphenolic plastic resin solution, which air dries with moderate rapidity, and which is of a long-oil tvpe understood to contain 67% of solid nonphenolic plastic resin and 33% of mineral spirits, proportioned by weight; but like 2466 Glyptal, the film is rather soft.

In some cases, other film-forming materials may be used in lieu of the alkyd resin vehicles described above, although in general not so efiectively or efficiently. For instance, although leaflng can be destroyed by the simple, brief heataging treatment in Beckosol No. 2 (or the like) heretofore described, or often merely by permitting the preliminary mixture of metal powder and alkyd resin solution to stand for about 24 hours, a more extensive or rigorous treatment is necessary with other common materials such'as ester-gum, rosin or phenolic varnishes. Thus to destrov leafing in ordinary rosin varnish, a preliminary mixture of the letter with the metal powder should be heated for, say, an hour at 100 C. and then allowed to stand for about 48 hours; and similarly extended treatments seem necessary with the other materials just mentioned.

'Morecver, some of these other vehicles seem to have a tendency to interfere with such adjustment of the metal powder or coloring agent or both, in the applied film, as is desirable for best grain-simulating results; thus a standard phenolic varnish has been found to have a decided tendency toward leaflng, and some long-oil alhd resin vehicles, when used in the described compositions, have given the applied paint a cloudy appearance-in either case, necessitating longrepeated brushing over, in order to obtain an appearance comparable to that achieved upon a single brushing application of the described alkyd resin paints.

It will be appreciated that other treatments than the specific aging steps described, can be used t destroy leafing. Thus, particularly in the case of fine aluminum powder, an excellent destruction of leaiing is achieved by making a paste with the powder and the alkyd resin solut on, and running the paste through a paint grinding mill.

Considerable variation is also possible in the other ingredients of the paint. For example, the small percentage of liquid drier is merely added t facilitate drying in the usual manner and is preferred in most cases. The preferred charac teristics of the thinning portion of the paint are that it should be compatible or miscible with the other ingredients, e. g., the film-forming vehicle and the color, should not impair the brushing characteristics of the paint, as by hastening its drying time, and should not counteract the nonleafing condition of the metal powder. In general, the quantity of thinning ingredient may vary substantially, although their total amount is preferably substantially less than that generally included in spraying paints, and is conveniently no more than necessary to make the composition sufficiently fluid for ready brushing. For instance, in the specific formulae hereinabove set forth, a very substantial increase in the amount of thinner, particularly mineral spiritssay twice as much-may result in a tendency toward leafing of the metal powder. Other thinning materials may be used than mineral spirits-for example, the better grades of turpentine-and as previously explained, solvent naphthe is of special advantage in an alkyd resin vehicle, by virtue of its solvent action on the resin.

It will now be appreciated by those skilled in the art that .the vehicle, including its thinning and likewise its film-forming and solvent ingredients, may be readily selected in accordance with known r easily ascertained properties of such materials; the preferred characteristics being suitable drying time and viscosity for brushing, a non-leafing character or a susceptib lity to treatment (such as aging) for destruction of leafing, compatibility with the coloring ingredient (such as asphalt), clarity rather than turbidity or heavy cloudiness (particularly in combination with the coloring agent), and for best results, an avoidance of such suspension or near-floating of the metal particles as might interfere with clearly apparent streaking or the latter in the applied paint.

In conclusion it should be seen that the present invention provides a new paint, which can be easily applied or worked with a brush to obtain a striking and realistic simulation of grained wood, i. e. wood which has a distinct grain and which has been varnished and polished or has otherwise received a desirable and attractive finish. The paint, moreover, may conveniently be of the nature of an enamel, relatively foolproof in the hands of inexperienced persons, and providing a hard, durable and high gloss finish when dry. a

It will be understood that the invention is not limited to the specific compositions and arrangements herein described, but may be carried out in other ways without departure from its spirit as defined by the following claims.

Iclaim:

l. A paint for simulating wood grain upon brushing, comprising a non-leaflng mixture of metal powder in flake form with a mutually soluble coloring agent and vehicle cooperating to provide free, clearly-apparent streaking of the metal powder, all of the metal powder in the paint being adapted to remain beneath th surface of the vehicle in the film formed when the paint is applied.

2. A paint for simulating wood grain upon brushing, comprising a non-leaflng mixture of a metal powder in flake form, a coloring ingredient and a vehicle, said vehicle and coloring ingredient being soluble one in another to provide free streaking of the metal powder, and said powder and ingredient being respectively adapted, in color, to cooperate in providing wood-simulating color, all of the metal powder in the paint being adapted to remain beneath the surface of the vehicle in the film formed when the paint is applied.

3. A paint for simulating wood grain upon brushing, comprising a non-leafing mixture of metal powder in flake form with a vehicle and a coloring agent soluble therein. all of the metal powder in the paint being adapted to remain beneath the surface of the vehicle in the film formed when the paint is applied.

4. A paint for simulating wood grain upon brushing, comprising a non-leaflng mixture of a vehicle, asphalt for coloring the same, and metal powder in flake form cooperating in color, with the asphalt, to provide a wood-simulating color, all of the metal powder in the paint being adapted to remain beneath the surface of the vehicle in the fllm formed when the paint is applied.

5. A paint for simulating wood grain upon brushing, comprising a non-leafing mixture of metal powder in flake form and a vehicle containing asphaltite and adapted to provide free streaking of the metal powder, all of the metal powder in the paint being adapted to remain beneath the surface of the vehicle in the film formed when the paint is applied.

6. A paint for simulating wood grain upon brushing, comprising a non-leafing mixture of metal powder in flake form having a fineness not substantially less than 4500 sq. cm. per gram in water covering test, Gilsonite asphalt, and a vehicle including alkyd resin solution of drying type.

7. A paint described in claim 6 wherein the metal powder is copper powder and is included in proportion of about to pound per gallon of the remainder of the mixture, and wherein the said remainder pf the mixture contains the asphalt in proportion of about 0.4 to 1.5 pounds per gallon.

8. A paint for simulating wood grain upon brushing, comprising a non-leafing mixture of copper powder in flake form, Gilsonite asphalt, a drying type alkyd resin, and thinning material including mineral spirits.

9. A paint for simulating wood grain upon bushing, comprising metal powder in flake form having a fineness not substantially less than 4500 sq. cm. per gram in water covering test, coloring material of transparent type adapted to reveal metallic sheen of a metal flake uniformly and adapted to impart wood-simulating color, and a vehicle, said metal powder being associated in non-leafing condition in the vehicle, and said vehicle being adapted to provide free streaking of the metal powder upon brushing the paint, all of the metal powder in the paint being adapted to remain beneath the surface of the vehicle in the fllm formed when the paint is applied.

EDWIN W. DANIEL-SON,

CERTIFICATE or CORRECTION. Patent No. 2,257,595. September 50, 19m. EDWIN w. DANIELSON.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 72, for "confiurations" read "configurations- 1 page 14., first eo-lumn, line 66, for the word "letter" read --1at ter-; page 5, second column, line 29, claim 9, for "bushing" read --brushing--; and that the said Letters Patent should be read with this correction therein that the same may conform to.the record of the case in the Patent Office.

Signed and sealed this 25th day of November, A. D. 19M.

Henry Van Arsdale (S Acting Commissioner of Patents.