USRE23757E

USRE23757E - Complementary color blending

Info

Publication number: USRE23757E
Authority: US
Priority date: 1948-09-30
Publication date: 1953-12-22
Also published as: US2604414A; USRE23722E; US2642404A; GB676696A

Description

Dec. 22, 1953 R. E. PIKE Re. 23,757

COMPLEMENTARY COLOR BLENDING Original Filed Sept. 30, 1948 FIG.2.

RED M MAROON PURPLE CHROMA YELLOW HUE BLUE GREEN YELLOW YELLOW GREEN IN V EN TOR.

Ralph E. Pike BY A TTORNE Y.

refine specification;

Reissued Dec. 22, 1953 Pout de Nemours a Company, W

Del,- a corporation of Delaware Original-No. 2,842,404, dated June 18,1953, Serial No. 247,957, September 24, 1951, which is a division of Serial No. 51,883, September 30, 1948, now Patent No. 2,604,414, dated July 22, 1952. Application for reissue September 30, 1958, Se-

' rial No. scam 1': Claims. (01. zoo-Q16). v Hatter enclosed in heavy brackets I: 1 appears in the original patent but forms no part of this l This invention relates to lacquers and synthetic enamels and particularly to such coating compositions which possess a translucent metallic appearance and which are currently popular for v automobile finishing.

A customary requirement for coating compositions is opacity'in relatively thin films, a property commonly referred to as hiding power. Although desirable in some of its aspects, this opacity limits the appearance of a fllm of coating composi- 'tion to the colors reflected from its surface. In the past few years, coating compositions which have a transparent appearance and relatively-low hiding power, but which possess a desirable depth, luster, and metallic appearance, have been very popular, particularly as automobile finishes. In this case depth does not involve intensity as in the term "deep color. Rather, it

A coating composition described as being 'metallic in appearance possesses the following char-- acteristics, to some degree, simultaneously: (1)

An appearance of depth or distance in the film, (2) An ability to change color depending on the nature and direction of the illuminating source,

(3) The ability to high light, or attract attention, to changes in contour of the finished article (for instance; body design of automobiles), and

(4) a multi-color or polychromatic effect on flat surfaces. Thus, it is common in the coating composition industry to refer to overall metallic effect rather than to attempt to identify the specific quality that is present or absent. Since no composition is known which possesses a maximum of all four characteristics, useful coating compositions are selected on the basis of the most favorable combination of those characteristics.

In the description of this'invention the terms for the qualities of color will be based upon the deilnitions given in the Munsell Book of Color by A. H. Munseli. Hue" is the name of a color, as red or green-the first characteristic that the matter prlnted'in italics indicates the additions made by reissue.

. 2 eye detects. Value" is the amount of light in a color; how light or dark it is, or how nearly white or black it is. "Chroma is the strength of the color; how strong (intense) or weak (gray) it 18. I

By the term "complementary pigment and related expressions, as used herein, is meant a pigment or group of pigments which will substantially neutralize the color of the prime pigment to a true gray or to a, grayish base of the same hue I as that that desired in the final color.

I U. 8. Patents 2,140,745; 2,335,760; and 2,384,579 describe means of accomplishing some degree of transparency in. nitrocellulose lacquer and synthetic enamel compositions. Essentially these methods retain the principal pigment in a state of very fine division so that its transparent properties may be utilized, in conjunction with aluminum flakes, to produce the above-mentioned desirable metallic appearance. U. B.

' Patent 2,140,745 covers the process of flushing" pigments from the wet pulp stage directly into uniform dispersion in lacquers without the intermediate steps of drying and pulverizing the pigment. While applicable to some degree with all pigments, the process is most useful with those ordinarily manufactured by chemical precipitation from water solution. U. S. Patents 2,335,760 and 2,384,579 prepare iron oxide pigments capable of being flushed into lacquer or enamel vehicles so that the very small primary particles of the pigment do'not agglomerate to any marked extent and so that the nature of the particles is not substantially changed from their freshly-precipitated condition. Thus, durable, lightfast and relatively inexpensive pigments of comparatively high transparency and low hiding power are made available for use as the principal, or so-called prime pigment in lacquers and synthetic enamels for outdoor exposure. In low concentrations these colloidal hydrated or hydrous ferric oxides impart an amber tinge to the filmforming component of the coating compositions. In higher concentrations, the color is a translucent go1d,- brown, or reddish brown. In the actual use of the iron oxides, it has been necessary and desirable to add to the iron oxide base composition closely controlled amounts of selected relatively opaque tinting or toning pigments, suitably dispersed in a useful vehicle, to

impart opacity or hiding power, at the same time i 3 coloring the composition to the desired hue. Small quantities or selected flaked aluminum pig- 'ment added to this mixture increase the "value or lightness of the color and provide the metallic I toiore available.

the coating composition is overcome by the comparatively poor outdoor durability-of 'the shading pigments, which in most cases are notably inferior to hydrous iron oxide in color-iastness, chalk-resistance, and general resistance to film deterioration. For instance, excessive amounts 01 phthalocyanine blue and green pigments, while dull red chalk or bronze under normal exposure conditions. Excessive amounts of aluminum flake cause dulling and aluminum chalking. Carbon black and lamp black pigments, of the low tinting strength type required to maintain low aluminum concentration, show early dulling and chalking on exposure.

In order to obtain maximum freedom from aluminum mottling or flooding (heterogeneous pigment pattern in the applied film) in practical metallic enamel formulations, a minimum concentration of aluminum in the enamel is essential. Unfortunately, brightness and lightness increase with aluminum content, and the bright colors are currently the most popular ones for articles commonly finished with "metallic" colors. These bright colors can be made by any of the following methods.

A. Use of high aluminum concentration resulting in severe flooding or mottling tendencies and early dulling on exposure. B. Use of a combination of aluminum and non-chalking opaque white pigments, which invariably results in a sacrifice in metallic appearance over alternate A.

C. Use of a maximum of low tinting strength,

transparent type pigment and a minimum of strong toning pigments, by the complementary blendin principles as described in this invention.

It has been desirable to prepare enamels and lacquers with a greater variety of hues, improved metallic appearance, and improved outdoor durabiiity, using the iron oxides of U. S. Patents 2,335,760 and 2,384,579. It has also been desirable to accomplish essentially the same results by finding and using, as additives to or substitutes for the hydrous iron oxides, prime pigments which possess the desirable properties of transparency, low, tinting strength, and good durability, capable of being tinted to the desired hue with relatively minor quantities of lighti'ast toning pigments that are strong (high in chroma), relatively opaque, high in tinting strength, and that preferably but not necessarily.

possess good durability in enamel films.

Accordingly ,the purpose of this invention is to provide improved synthetic, enamels and lacquers which are durable, lustrous, translucent and metallic in appearance. A further object is to make new durable, relatively inexpensive colored coating compositions, suitable for finishing automobile exteriors, which possess metallic efiect to an unusual degree. Another object is to make durable gray lacquers or enamels without the use of black or white pigments. Still another object is to make a pigmented composition of a specific hue using a pigment of that hue or an equivalent blend of more-than one pigment in only minor portions with respect to the total pigment present. An additional object of this invention is to provide a method of using the desirable properties of hydrated iron oxide pigments in enamels and lacquers possessing better durability and a wider variety of hues than here- Other objects will appear as the invention is described.

There are no known pigments which individually impart all the desired properties discussed above.to a synthetic resin metallic enamel, but

by selecting pigments according to the new procedure of the present invention, pigments which otherwise are undesirable can be combined to produce brilliant, durable beautiful metallic finishes which are substantially non-chalking,

' and non-fading.

The objects of this invention are accomplished fundamentally by using the hydrous iron oxide pigments described'in U. S. Patents 2,335,760 and 2,384,579 in combination with one transparent pigment, or a blend of two transparent pigments, relatively complementary to the iron pigment so that the yellow nature f the latter is substantially neutralized to a true gray or to a grayish base of the same hue as that desired in the final color. Then a tinting pigment of that hue, but of higher chroma, or an equivalent blend of two or more pigments, is added to adjust the color of the product to the desired strength, or chroma. A preferred modiflcation is to select the "neutralizing pigment (or pigments) in such a way that it (or one of them) can be used in excess of the required neutralizing" quantity to produce the desired color. This method reduces the number of pigments required and simplifies the application of this invention to commercial enamel manufacture. Finally, the value or lightness is adjusted by adding flaked aluminum pigment. The resulting composition possesses simultaneously the desired hue, chroma, and value along with the most favorable combination of the four characteristics of a metallic enamel; depth, apparent color change, high lighting, and polychromatic eifect. While the above description is based on hydrous iron oxide pigments, the same principle is applicable to other prime pigment bases, as will be explained later.

In the attached drawing, Figure 1 shows the three dimensional diagrammatical concept of color characteristics. The vertical axis is value (from black to white), the horizontal axis is chroma (from neutral gray at the center to stronger color away from the center) and the radial or angular location on any given value plane is hue. Figure 2 is a vertical view of the same system, a two dimensional view showing only hue and chroma, the qualities most important in persing methods, or in some cases by the processes of U. S. Patents 2,140,745 and 2,384,579.

5 TABLE 1 Pigment key v Description H drous iron'Oxide Note 1) (U. S. P. 2,384,579). La ke oi Diehloro-isodsbensanthrone on Barium Rosinate.

' Phthalocyonine Blue. 1

Phthalocyanine Green. Chromium Tetrahydroxide (Guignets Green). Lightiast Nickel Am Salt, the nickel complex of, the

azo dye obtained by coupling diazotised parachloraniline with zgihgfirioxysquin line-Lithosol 36D ,390, (U s P 2 in Mineral Spirits) Coarse Aluminum Flake (75% in Mineral Spirits) otos 1, 3). Fine Aluminum Flake (05% in Mineral Spirits) (Note Meziium Particle Size Channel Carbon Black. Lamp Black. Ferrite Yellow Orange. Synthetic Red Iron Oxide. M 7" r i 2is' nide) 0 us 0 c errocya Precipitated Hydrous Iron Oxide (Water-Wet) (Note 1) .2 5,760). Vat Thieindigzid Dyestufl-Indo Maroon.

Nora 1.--In all the enamel composi tions {It tligag t fi ent sonapgmen so s l b'i' n BEE? fir? c n further be described as an "Extra Fine lfii i minnni1 inning Paste (non gegiingzg; l:

h ub tantiall no a es are as ar as d i i fiet r :nd subs tantially all of the ifi kes are less than 1 di meter. 10 -i lig ment 8 can further be described as a NOTE "Standard Aluminum Paste (leafing)," in which about 40% of the total surface area. is composed of flakes with r r than 'mlcrons. a ii r rf if riis pigment is a lake of dichloro-isodibenzment #1 in the principle of this invention, butbeing different in hue and chroma, they produce different families of colors when substituted for pigment #1. Pigmentlfi is similar to 1 but is prepared according to U. 'S.Patent 2,335,760. In the claims the term hydrous iron oxide is intended to refer to pigments substantially equivalent to those prepared according to either of the patents just mentioned above.

Pigments

2, 3 and 4 are transparent tinting or toning pigments possessing high tinting strength, high chroma, lightfastness. and reasonably good outdoor durability.

A durable transparent metallic neutral gray without black or white pigment will serve as a fundamental example of an automotive enamel of this invention. In this caseit is desired to neutralize the hue and chroma of pigment 1, yet retain a preponderant proportion of pigment l in the finished enamel in order to utilize its transparencyand durability to an optimum degree. Figure 3 is a graphical representation of the pigmentation. Since there is no known pigment completely complementary to pigment 1. proportions of 2 and 4 are blended to produce an intermediate hue 18, which is substantially complementary to 1. Then blend '18 and pigment l are blended in the proper proportions to producel9, a neutral gray possessing substantially no hue or chroma. Pigment 3 might be substituted for pigment 4. A blend of 2 and 3, complementary to 1, would have a higher chroma than blend 18 and would require larger proportions of pigment 1 to produce a neutral gray. The enamel thus produced would greater transparency, less hiding power, and a different metallic effect than the same color gray enamel made with pigments 1, 2 and 4. In either case, a small amount of a naked aluminum pigment is added. This lightens thecolor to the desiredvalue and contributes represented by the point 20 on Figure 4. To ar-,

rlve'at this hue and chroma, pigments 2 and 3 are blended in proportions yielding blend 21 which is complementary to pigment 1. Blend 21 and pigment 1 are mixed in proportions yielding blend 22 which is on an extension of a straight line connecting 2 and 20, so that by adding pigment 2 to blend 22 in small increments color 20 is approached and reached.

While the theory of producing a durable gray and a grayish blue metallic enamel have been explained above, the invention will be more completely understood from the examples listed in Table 2, in which the parts are by weight. The examples are largely shown in tabular form for convenience of comparison. The column or-row headings are identified as follows:

Complementary Blend. is blend of pigments to produce an improved metallic enamel 01 a desired color by this invention.

Conventional Blends I and II are alternative blends of conventional pigments commonly used in metallic-enamels of the same color as the corresponding Complementary enamel. Two alternatives are given for comparative purposes. For instance, color #13 Gray is substantially the same color in its three modifications, namely: Complementary, Conventional I, and Conventional II.

P/B is a designation for the ratio of total pigments to solid vehicle by weight. This refers to the final enamel produced, using the pigment blends in the table. Variations in P/B ratio occur because each pigment is dispersed (or ground) separately with small quantities oi liquld vehicle to produce a mill base. For commercial production reasons, mill bases do not necessarily have the same P/B ratio.

The following formula represents a typical baking enamel vehicle for all of the tabulated pigmentations in which the parts are by weight:

49% linseed oil-China-wood oil glyceryl The thinner or solvent content of the final enamel is variable because it is common practice to prepare enamels at a uniform viscosity says:

enamels was 37 seconds :4 seconds in a Parlin 8 An example a finished synthetic resin enamel typical of those intended in this invention, using the above air drying vehicle as a basis, is as follows. The parts are by weisht. The pismentation is taken from Complementary Color A,

# viscosity cup at 25 C. A suitable baking 5 Gray. at Table 2: schedule for these products applied to metal substrates was 1 hour at 225 F. Pigment The following formula is a typical air drying Pigment Vmet 0'24? vehicle for illustrating all of the tabulated pigfigment 2-167 mentations in which the parts are by weight: ment Aluminum L228 49% linseed oil-China-wood oil glyceryl 19% linseed oii-China-wood oil glyceryl phthalate resin 24.52! V phthalate resin, (solid) -5 52% linseed oil glyceryl phthalate resin 2.701 linseed v y yl Dhthfllate resin 50% soyaoil-China-wood oil pentaerythri- (solid) 2.82 1 ml phthalate resin 6.599 509610 oil-ch a-wo d 011 p y 33% China-wood oil phenolformaldehyde ritol phthalate resin (solid) 6.88 varnish (solid) 0.392 33% China-wood oil phenolformaldehyde Drier solution (16% lead) 0.654 varnish (solid) 0.41 Drier solution (3% manganese) 0.436 Drier solution (16% lead) 0.68 20 Drier solution (2% cobalt) 0.872 Drier solution (3% manganese) 0.46 Hydrocarbon solvent (volatile) 59.723 Drier solution (2% cobalt) 0.91 Hydrocarbon solvent (volatile) 62.25 100.000

100 no In all 01' the 8 basic colors of Table 2 (A-H). the Complementary modification possessed better The final volatile solvent content varied as deapplication properties, metallic appearance, or scribed under the baking vehicle. The viscosity outdoor durability, than the two corresponding of the air drying enamels was the same as for Conventional enamels. In substantially all inbaking flstances, the Complementary modification was TABLE 2 METALLIC ENAMEL COMPOSITIONS Complementary Blend C n nti l Bl d I Conventional Blend II a 0 or Pigment Pigment Pigment o No Color i No. Color :2; N- color 225 211 Black.-- so (10 Black 1a (A) Gray 35111 I Blue 93/1) I g "iii'lifdfifiifiii: (1 Almifiiifihi" es (10 Black 18 $3 1 3 2:]: y 2 (1mm ii; $355113: 12 12; 11513233: m 7) Aluminum 64 (7 Aluminum l 1m 100 (3 Blue i7 (4) Green 37 k 0 Green omym- 0.41100 0.6/1! Egg @Efkf 11.6 100 5'21? i5 v a (D) Blue-Gray..." 8.21100 53 100 0.61100 s o r y 84/100 31mm Yellow 8 8.811(1) (F) Brown as/mo 59 mm 8 143 100 100 G G v 8 9512? 61 r 3 15-555; f 8.7/100 (1 Aluminum 23 (3 Aluminum.

55 Blue v (H) 113/10" I g 10.0 9.81 00 l Black i 1 (8 Aluminum.. 23 100 sans? enamels no black or white pigments were used.

the aluminum pigment content was lower, with one exception, and'the pigment content was predominantly pigments 1. or 6 or a combination 5 thereof. so that the resulting enamels were superior in application properties, durability and metallic appearance.

The cellulose nitrate in this composition'is the conventional lacquer type, a viscosity of about 6 seconds in Formula Cora. T. M.

n-soi-ss. c. I

Brown lacquer J 01 Table [21 this TABLE 3 Com me Blend Nitrocellulose Oomplemen Blends mm pk uer' Res in ltnamel m mm Com Pigment Pigment P/B P/B Ratio Ratio No. Color Percent No Color Percent 8 Maroon #3 '8 4. (J) Brown 8.76l100.. 5 Gm 5.4 12.5/i00 to 100.0 mac 8% 52 a; m ti aroon.- ue -r s; Blue 4.8 9-- 2) Violet 5.1 8 Aluminum 4.5 8) Al nm 3.1 1(110 10.1.0

68.9 11.1 (11) 1 7 Jilin-l t:

, (16) Yellow 50.2 24) cm 12.4 (M) Gray 8.56I1GL- 3) Blue 12.7

(17) Maroon 19.5 (8) Aluminum 5.2

liXLO (5) Green 65.9 (N) [Dark Gra 16) Yellow 18.3

Gray Green 115/100 17) Maroon.. 3.0 4) men 1.1

. 8) Aluminum 11. l

- 1(XLO 81.4 (0) Green 9.11100-.- g;g

The following are examples of the application of this invention to nitrocellulose or lacquer-type compositions. For direct comparison, the pig- 'mentation of synthetic resin enamels 01' substantially the same color as the'first two lacquers is shown. In all compositions black and white pigments are absent. and the pigment combinations are based on the principles of this inven-- tion. It is to be understood that in the lacquers, as in the synthetic resin enamels, all pigments had been previously dispersed in a suitable vehicle (usually nitrocellulose for the lacquers) by methods known to the art.

In Table 3, the Synthetic Resin Enamels may be made with either a baking or an air dry vehicle.

.A suitable vehicle for the lacquers in Table 3 has the following analysis, by weight: g

- v Per cent Cellulose nitrate 17.6 50% cocoanut oil glyceryl phthalate resin 8.8 Dibutyl phthalate 3.6

vehicle had the following composition, by

weight:

Per cent Pigment 16, Yellow 1.4 Pigment 4, Green 0.2 Pigment 17, Maroon 0.2 Pigment 8, Aluminum 1.0

Cellulose nitrate 17.1

In the claims the term "preponderant as applied to the transparent prime pigment means that it is present in amount greater than any other single pigment. The term transparent pigmen refers to a pigment which when dispersed in an organic vehicle has low hiding power and transparency as distinguished from a relatively opaque pigment with relatively high hiding power. In the former case the transparency oi the pigment allows the light to reach the aluminum particles giving the film a high metal- 'lic brilliance whereas an opaque pigment would mask the reflection giving a dull, lifeless film.

The aluminum powders used in the compositions of the present invention are widely available commercially in the form of mineral spirit pastes. They are made in leaflng and non-leafing grades and also in fine grades called lining pastes or coarser grades called "standard" pastes. Any grade may be used, but the standard" grade which is considerably coarser than the "linings grade imparts a much greater brilliance to enamel films giving them an unusual apparent depth. For this reason the standard" grade of aluminum paste is preferred in both cellulose derivative and synthetic resin enamels of this invention where a maximum degree of reflection is desired.

The proportions of pigments may vary to give a large assortment of colors and effects; but in the preferred embodiment of the invention, the prime transparent pigment (A) of the claims may vary between 25% and 85.7% by weight of the total pigment in synthetic resin enamels and between 11% and 84% for cellulose derivative lacquers.

. The relatively transparent complementary pigments (B) and tinting pigment (C) of the claims may vary in the preferred embodiment from 11% to 45% combined in synthetic resin enamels and from 4.7% to 44.6% in cellulose derivative enamels.

The aluminum powder (D) of the claims may vary from 3.1% to 30% in synthetic resin enamels and .from. 4.5% to 36.4% in cellulose derivative lacquers.

The principles of pigmentation for coating compositions with a metallic appearance disclosed in this invention are applicable to all types of film-forming materials including, (1) all types of alkyd resins made from any combination of a polyhydric alcohol and a polybasic acid, unmodified or modified with non-drying oils, semi-drying oils, or drying oils such as coconut oil, soya oil, and linseed oil, respectively; (2) cellulose derivative film-forming agents; (3) vinyl type materials such as vinyl, acrylic, and allyl resins; (4) urea-formaldehyde type resins; (5) melamine formaldehyde resins; (6) phenol formaldehyde resins and oleoresinous compositions prepared therefrom; and (7) miscellaneous film-forming materials such as silicone resins.

The principles of pigmentation of this invention pertain also to durable, lightfast, transparent, low tinting strength, low hiding pigments other than the prime pigments which are shown as examples of the type most useful, namely, the hydrous iron oxides #1 and #16, the yellow #6, and the green #5, which contribute predominantly to the transparency and outdoor durability of the products. [Tinting] Transparent tinting and toning pigments other than violet #2, blue #3, green #4 and maroon #17 will be found useful in the practice of invention; and those listed are used to set forth the invention without limiting its scope.

Aluminum flake pigments 7 (extra fine), 8 (coarse) and 9 (fine) listed in Table 1 each contribute to a different degree to the metallic appearance of a finished enamel. Pigment 8 (coarse) is preferred where the most brilliant metallic appearance is required. Pigment 9 (fine) gives a less brillant effect and #7 yields the least brilliance of the three listed, although even enamels prepared from the latter are attractive and useful products.

It is obvious to one skilled in the a t that use- 12 ful coating compositions can be made within the scope of this invention using other prime or transparent base pigments, other tinting pigments, and other grades of aluminum pastes, resulting in the improvements set forth previously, although those used in this disclosure are currently preferred because the rmulting colors are at present the most popular where metallic enamels are largely usedautomobiles and certain other commercial articles.

The advantages of the enamels of this invention over conventional metallic coating compositions are depth, high-lighting of colors, ap-

parent color change when viewed from different directions or under different light. and polychromatic appearance; and, in addition to these, a marked improvement in outdoor durability over conventional metallic enamels in gloss retention, color retention, and general film integrity, including freedom from bronzing, chalking, checking, and cracking. The application properties and resistance to aluminum mottling of the metallic enamels of this invention are equal to, or better than, the duller and less brilliant conventional metallic enamels and are far superior to convenapplication, Serial No. 51,883, now Patent 2,604,-

I claim:

1. A coating composition adapted to yield a tough. durable finish having a metallic appear ance of great depth and brilliance, comprising a vehicle and pigment, said pigment consisting of (A) the nickel complex of the azo dye obtained by coupling diazotized parachloraniline with 2,4- dihydroxyquinoline; (B) transparent pigment substantially complementary in color to the said (A) pigment in amount to yield a gray when mixed separately therewith; (C) at least one colored tinting pigment and (D) finely divided flake aluminum metal.

2. The composition of claim 1 in which the aluminum flake is relatively coarse and about 40% of the total aluminum surface area is composed of fiakes with a diameter larger than 20 microns.

3. The composition of claim 1 in which the pigment (A) is present in amount between 11% and 85.7% by weight of the total pigment; complementary pigment (B) and tinting pigment (C) combined are present in amount between 4.7% and 45%; and aluminum fiake powder (D) is present in amount between 3.1% and 36.4%.

4. The composition of claim 1 in .which the vehicle contains a synthetic resin and the pigments are present in amount as follows:

(A) 25% to 85.7% by weight (8) and (C) 11% to 45% (D) 3.1% to.30%

5. The composition of claim 1 in which the vehicle is a nitrocellulose lacquer and the pigments are present in amount as follows:

(A) 11% to 84% by weight (13) and (C) 4.7% to 44.6% (D) 4.5% to 36.4%

6. The composition of claim 1 in which the pigment (B) is composed of a plurality of pigments, the resulting shade of which is substantially complementary to pigment A).

'7. Thecomposition of claim 1 in which the pigment (B) is composed of a plurality of pigments, one of which is in excess of the amount necessary to produce a color complementary to pigment (A), the said excess being pigment (C).

8. A process of preparing coating compositions adapted to produce tough, durable finishes having a metallic appearance of great depth and brilliance, which comprises blending A) a relatively transparent pigmented composition, the pigment portion of which consists essentially of the nickel complex of the azo dye obtained by coupling diazotized parachloraniline with 2,4- dihydroxyquinoline; with (B) a transparent pigmented composition in which the pigment is substantially complementary in color to the pigment of (A); tinting the resulting blend with (C) a colored, pigmented composition and adding (D) flake aluminum metal.

9. The process of claim 8 in which the aluminum flake is relatively coarse and about 40% of the total aluminum surface area is composed of 2 r ment (B) comprises phthalocyanine blue.

16. The process of claim 8 in which the pigment (B) comprises phthalocyanine green.

17. The process of claim 8 in which the pigment (B) is vat thioindigoid dyestufi-indo maroon.

RALPH E. PIKE.

No references cited.