US2723899A - Wood stains containing a flavanone azo dye - Google Patents

Description

United States Patent Ofiice WOOD STAINS CONTAINING A FLAVANONE AZO DYE Harry A. Toulmin, Jr., Dayton, Ohio, assignor to Chadeloid Corporation, Dayton, liio No Drawing. Application May 29, 1953, Serial No. 358,554

'6 Claims; (Cl. 8-6.5)

This invention relates to stains, especially stains for use on wood and to compositions for use in staining wood articles and the like, as well as methods for staining such articles.

The art of wood staining in the past has made use of dyes which were dissolved or dispersed solvents and the like diluents so as to make thesame applicable for applying as a spray, dip, or by brush. The water soluble' stains generally consisted of an aqueous solution of an" aniline dye, and were applied by brushing the same onto the wood surface to be stained. Such water stains, how ever, exhibit the very undesirable effect of raising the grain of the wood. This raising of the grain necessitates that the surface be sanded or otherwise treated to render it smooth. The grain raising effect of such water soluble stains also makes it necessary to apply a sealer coating such as shellac to the stained wood in order to stiffen the fibers of the wood so that the surface can be uniformly sanded. When an open grain wood is used, it is necessary, after the sanding operation, to apply a filler to the surface over which is then applied a varnish, lacquer or other desired coating. 7

The non-aqueous stains, for example, oil stains and spirit stains, and which generally 'consist of an'aniline dye or aniline dye base dissolvedin an organic solvent such as a hydrocarbon or alcohol, have been extensively used and have certain advantages over water stains. They also have certain undesirable features.- The use of hydrocarbons, such as benzol, toluol or other petroleum distillates that are highly volatile when applied to the surface to be treated tends-t leave the pores of the wood- They are also dangerous the solvents of the varnish or lacquer will penetrate into the stain and cause the color to bleed into thefinish coat. Theuse of hydrocarbon solvents also is undesirable from the standpointv of fire hazard and the effect thevolatile solvent may have on the operator applying the stain.

The spirit stains are not as useful as the water stains because they are subject to the disadvantage that such. stains-do not penetrate into the wood stains and they further lack permanency of color and tend to fade in. use, similar as the oil. type stains. Spirit stains are also subject to. the bleeding effect, and in manyinstances, also produce the undesirable grain raising upon application to the wood surface.

In accordance with the present invention, I have discovered that. by combining citrus flavanone derivatives, for example, hesperetin or naringenin found in citrus pulp and citrus waste, with'aniline or aniline bases, and

Thisapplication of shellac or the like is necessary, otherwisedispersing the resultant dye in water solution that this new combination provides an excellent wood stain composition With unexpected results. This citrus-aniline dye compound can be readily fixed in the cellulose pores of the wood as it is derived from cellulose and is compatible with it.

It may be applied as a hot or cold solution to the wood. A hot aqueous solution of such citrus-azo dyes as derived from these citrus fiavanone's obtained from citrus wastes, being derived from a cellulose source, forms a stain which is completely compatible with the wood so that a highly desirable stain effect is produced with complete dispersion of uniform character'and deep penetration. 1

The aqueous staining solutions of this invention which comprise the aforementioned citrus-azo dye are preferably applied as a hot aqueous solution, although it is also efifectivevas a wood stain when applied as a'cold solution.- Hot aqueous solutions of such dyes when applied penetrate into the wood and the solvent evaporates before the grain of the wood is caused to raise;

Upon cooling, the dye is set in the Wood and forms a smooth uniformly stained wood surface which requires nosanding orother treatment to produce a desirable surface upon'which a finish coating of varnish or lacquer may be applied; 1

v disadvantages, may be: entirely eliminated.

A typical formula of naringenin is as follows;

The combination: citrus-azo dyes which are utilized informing the-'wood" staining compositionof "this inventionare exemplified bythe following compounds which are illustrated graphicallyas follows: A

Coupling aniline with naringenin, e. g., recovered from grapefruit waste, as described results in the production,

of an azo dye having the probable structural formula:

Patented Nov. 15, 1955' the production of an azo dye having the probable structural formula:

In accordance with the present invention, I have found that these azo dyestufls can be obtained by coupling a diazotized aromatic amino compound, preferably one containing at least one substituted benzene nucleus or a naphthalene nucleus, with a polyhydroxy flavanone, for example naringenin, eriodictyol or hesperetin, such as derived from citrus waste products. The resultant dyestuffs, which are water soluble, are of particular value in compounding wood stains.

The object of coupling into a new compound of the naringenin and hesperetin with a diazotized aromatic amino compound to produce a carrier on which the dye compound may be fixed in suitable colors of the browns, yellows, and reds of varying hues and shades.

These citrus dyes are soluble in methanol to a limited degree and are very slightly soluble in Carbitol Cellusolve. They are insoluble in hydrocarbons, esters and higher alcohols. Higher temperatures do not increase solubility in solvents.

Therefore, the advantage lies in the fact that with the dyes being insoluble in the customary solvents, it is possible to provide a rapidly volatizing organic solvent in which the dye is substantially insoluble; and to provide a wood stain that, when it is once applied, is not subject to injury by the hydrocarbons, esters, alcohols, etc. The water solution of the dye, therefore, maintains its integrity despite the association with it in application of rapidly volatizing organic solvents or in use with glycols, ethers, alcohols and the benzene series of hydrocarbons.

These dyes stained the wood well, with good clarity and non-bleeding into succeeding coats. The darker dyes are more soluble than the red dyes. The darker dyes can be made in as high as a ten ounce solution as contrasted with the usual two ounce solution in the lighter dyes.

Illustrative of the method of producing the diazo dyes for use in preparing aqueous wood stains is as follows:

Example I 1. To a slurry comprising 0.1 mol of aniline in water is added 0.25 mol of hydrochloric acid. The mixture is diluted with water and cooled'to a temperature of between about -15 C.

While maintaining the temperature of the mixture" at about 10 C., there is added slowly over a period of about 10 to 15 minutes a 0.1 mol sodium nitrite. The mixture is stirred slowly while maintaining the temperature at about 10 C. for one-half an hour.

2. To effect the coupling reaction, a solution containing 0.1 mol of hesperetin dispersed in an aqueous solution containing 0.3 mol of sodium hydroxide is employed. The mixture is diluted with water and cooled to between and C. Thereafter, the diazo of (1) is stirred into the mixture over a minute period while maintaining the temperature at about 10-15" C. and the pH of the solution above 9. After stirring the mixture for half an hour more the dyestulf is isolated by adjusting the pH of the solution to neutral with dilute hydrochloric and adding a salt, i. e., sodium chloride or sodium sulfate, until the dye precipitates from the solution. Thereafter, the mixture is filtered to recover the dyestuff.

Example II In this example, aniline is diazotized in the usual manner and coupled with naringenin (or a mixture of naringenin and hesperetin) as the flavanone substance.

Example III Variations of naringenin azo dyestuffs are made by carrying out the coupling as described in Example I employing other amines or amino compounds in place of aniline, such as l-naphthamine 4 sulphonic acid, 2 amino 8 naphthol sulfonic acid and p-nitroaniline.

Example IV Similarly variations of hesperetin azo dyestutfs are prepared by effecting a coupling action as described in Example I utilizing instead of aniline, other amino compounds such as l-naphthalene 4-sulfonic acid, Z-amino- S-naphthol 6-sulfonic acid.

The invention broadly includes the preparation of wood staining compositions comprising a water-soluble azo dyestuff containing the grouping AN=NB in which A represents the residue of an aromatic amino compound and B is a flavanone derivative of citrus wastes as described above. N is nitrogen.

Varied shades of color may be produced with the citrus azo dyestuffs, depending on the particular amine and flavanone used in compounding the dyestuff.

The following examples are exemplary of the specific wood staining compositions in accordance with the present invention:

Example V A wood stain is prepared by dissolving the product of Example I in water to form a 5% solution. The resulting stain may be applied to wood by brushing or spraying.

Example VI To a gallon of water is added one ounce of the dyestuffs prepared as described in Example I.

Example VII Suitable amounts of the dyestuffs, as described in Examples III and IV, are dissolved in water to provide a staining composition having the desired strength.

The amount of dye utilized in a given case depends upon the particular dye employed, and its degree of concentration, and, of course, the depth of color required for the particular stain.

Additional solvent and vehicle ingredients may be added to the chosen citrus-azo dye (as described in the patent to Bush No. 2,000,121 of May 7, 1935) to secure the particular properties desired in the final composition. In choosing such additional solvents or diluents or other vehicles, several factors should be kept in mind. The solvents or diluents or additional vehicles utilized should preferably be inexpensive enough to make them commercially practicable for the use in hand. They should be solvents of or miscible with the dye dissolved in the penetrant vehicle component, and should be of such nature as to penetrate the wood and carry the dye into the wood. Further, the composition should desirably include a water eliminant in order to give the composition properties of resistance to moisture retention. Further, the combination of solvents or diluents or vehicles should be such that the final composition exhibits a proper evaporation curve to dispel both the diethylene-glycol monoethyl ether or other penetrant vehicle and any moisture present from the wood surface.

As illustrative of ingredients that may be utilized in order to increase the rapidity of drying and setting of the composition, the aliphatic alcohols, such as methyl alcohol, ketones, such as acetone, and the esters of the aliphat c alcohols, particularly the fatty acid esters of such but such materials as these esters are slower drying and cost more, and, therefore, are not as valuable in general in compositions of the present character as are the hydrocarbon substances, such as toluol. Both the aliphatic alcohols and similar ingredients and the hydrocarbon distillates, and similar ingredients aid in the penetration and evaporation and other desirable effects above mentioned.

A modified wood staining composition may be made using composite solvents, such as follows, the parts being by weight:

Parts Diethylene-glycol mono-ether 1-5 Methyl alcohol 8-10 Toluol 4-6 This composition may be utilized with, for example, from 2 to 3 ounces of the particular citrus-azo dye to one gallon of the composite solvent. Diethylene-glycol mono-ethyl ether is a particularly good penetrant vehicle component since these desirable citrus-azo dyes are soluble in this substance. Mono butyl ether of diethylene glycol may also be used for this purpose.

While for the production of stain compositions, par ticularly for treating wood surfaces, the compositions hereinabove described may be utilized, other additional ingredients may be added to the composition for particular purposes. For example, fillers, such as silex, or oil paste fillers, may be mixed with the new stain composition to make a combination stain and filler.

A combination citrus-azo dye stain and filler having a transparent color that is fast to light may, accordingly, be produced under this disclosure, whereas this result has never heretofore been possible.

In addition, the citrus-azo dye stains produced in accordance with this disclosure, or the stain bases, may be added to or incorporated with cellulose ester or ether solutions and lacquers, as well as other lacquers, particularly those containing solvents of the nature of alcohols and hydrocarbons. In this way, color dipping lacquers, the color of which is fast, may be produced. Various types of nitrocellulose compositions may, for example, be combined with the stain bases or compositions of the present invention.

In accordance with the present invention, it is possible for the first time to utilize such water soluble azo dyes made by coupling a fiavanone derivative, such as naringenin, eriodictyol or hesperidin with aniline or other suitable diazotizing amino compound to form a water soluble dye which yields, upon dispersion in an aqueous vehicle, a wood stain which is substantially fast to light, and exhibits non-fading, non-grain raising properties. A wood stain also is provided which, when properly compounded and applied as described, ates not bleed through'lacquer or varnish top finishing coats. Thus, the use of intermediate sealing coats is not necessary. Where desired, of

course, intermediate sealing coats of suitable type may be employed.

This application relates to applicants prior application Serial Number 277,921 filed March 21, 1952.

It will be understood that While there have been described herein certain specific embodiments of this invention, it is not intended thereby to have it limited to or circumscribed by the specific details given in view of the fact that this invention is susceptible to various modifications and changes which come within the spirit of this disclosure and the scope of the appended claims.

I claim:

l. A wood staining composition comprising an azo dye in which the coupling component is chosen from the group consisting of naringenin, hesperetin and eriodictyol, and comprising a volatilizable organic solvent chosen from the group consisting of methyl alcohol and lower aliphatic alcohol esters and ethers.

2. A wood staining composition as in claim 1, in which the azo dye consists of diazotized aniline coupled with a component chosen from the group consisting of narin genin, hesperetin, and eriodictyol.

3. A wood staining composition comprising an azo dye in which the coupling component is chosen from the group consisting of naringenin, hesperetin and eriodictyol, and comprising a filler and a volatilizable organic solvent chosen from the group consisting of methyl alcohol, and lower aliphatic alcohol esters and ethers.

4. A wood staining composition comprising an azo dye in which the coupling component is naringenin, and said composition containing a volatilizable organic solvent chosen from the group consisting of methyl alcohol and lower aliphatic alcohol esters and ethers.

5. A wood staining composition comprising an azo dye in which the coupling component is hesperetin, and said composition containing a volatilizable organic solvent chosen from the group consisting of methyl alcohol and lower aliphatic alcohol esters and ethers.

6. A wood staining composition comprising an azo dye in which the coupling component is eriodictyol, and said composition containing organic solvent chosen from the group consisting of methyl alcohol and lower aliphatic alcohol esters and ethers.

References Cited in the file of this patent UNITED STATES PATENTS 901,096 Hall Oct. 13, 1908 1,106,781 Chapin Aug. 11, 1914 1,977,345 Moore Oct. 16, 1934 2,000,120 Bush May 7, 1935 2,105,984 Moore Jan. 18, 1939 OTHER REFERENCES Perkin, Jour. Chem. Soc., vol. 73 (1898) pp. 666-674.

Claims (1)

1. A WOOD STAINING COMPOSITION COMPRISING AN AZO DYE IN WHICH THE COUPLING COMPONENT IS CHOSEN FROM THE GROUP CONSISTING OF NARINGENIN, HESPERETIN AND ERIODICTYOL, AND COMPRISING A VOLATILIZABLE ORGANIC SOLVENT CHOSEN FROM THE GROUP CONSISTING OF METHYL ALCOHOL AND LOWER ALIPHATIC ALCOHOL ESTERS AND ETHERS.