Technicolor related patent on dyes - 1972 -US 3835781 A
You can download full patent from google patents , I copied the most important parts.
DYE COLOR INDEX NUMBER Pontamine Fast Red 8 BLX 28160 Pontamine Fast Orange 40265 Fast Red S Conc. 15620 Congo Red 48X 22120 Pontacyl Carmine 6B Extra Conc. 18055 Pontacyl Scarlet R Conc. 23910 Pontacyl Rubine R Extra Conc. l4720 Acid Magenta 0 42685 Pontamine Fast Yellow RL 29025 Metanil Yellow WS [3065 Anthracene Yellow GR 13290 Erie Yellow F Conc. 40000 Acid Green SN Extra 44090 Acid Green 42095 Ink Blue R 42755 Pontamine Fast Blue 3RLP 27925 Pontamine Fast Gray 34l70 Alizarine Fast Brown G 667l0 Perlamine Fast Brown 3 GL l04l0 Pontamine Black ULR 30235 Diamond Acid Black SAS 27270 -Continued DYE COLOR lNDEX NUMBER* Acid Black L 20470 "Colour Index" 2nd Edition, by The Society of Dyers And Colourists (and) The American Association of Textile Chemists and Colorists.
As is well known in wash-off relief dye transfer processes, while the amount of dye transferred to the reception coating is proportional to the thickness of the gelatin matrix image, the absorption of acid dyes to the gelatin image is controlled by the amount of acetic acid in the dye bath. However, the acetic acid tolerance of acid dyes varies substantially; some dyes require considerable acetic acid before precipitation occurs, while others are precipitated by very small concentrations of acetic acid. Precipitation also varies with concentration of the dye solution. Since acetic acid controls the absorption of the dye by the gelatin, it is desirable to extend the range or tolerance of the dyes for acetic acid over a range in concentrations of dye and acid solutions. Bufiering solutions such as are widely used in electrometric titrometer and pH determinations provide a ready means for increasing the tolerance of acid dye solutions for acetic acid. The use of such buffer solutions and higher concentrations of acetic acid in the dye solutions increases the absorption of dye by a given thickness of gelatine relief image which, in turn, increases the density of dye transferred to the reception coating. Buffer solutions contain mixtures of a weak acid and its salt or a weak base and its salt.
A common buffer is an aqueous solution of acetic acid and sodium acetate. Acid salts of polybasic acids such as sodium orthophosphate are also highly useful buffers in combination in solution with boric acid or borax. Buffered acid dye solutions suitable for the present method, prepared as suggested by Colton and Thomson, Photo Technique, November 1940, 54-58,
The above buffered dye solutions produce low density or contrast on the imbibition print coating. If greater dye contrast or dye density is desired to 200 mls. of 5 percent acetic acid should be added to the dye solutions depending upon the desired density of dye image. If it is desired to store the dye solutions about 10 mls. of formalin should be added to each liter of dye solution to increase the shelf life thereof.
As previously mentioned, mixtures of water soluble acid dyes may be used in the present process to form dye images of innumerable variety of colors and hues. The process is also useful for producing dichroic dye images, i.e., images varying from one color in the lower densities to a different color in the higher densities such as, for example, from yellow-to-red with one and the same dyed matrix. Dye baths containing mixtures of dyes suitable for obtaining dichroic yellow-to-red images are as follows:
Pontachrome BSW (Cl 14835) 0.30 grns Pontacyl Rubine R (CI 14720 I 00 grns Metanil Yellow WS (Cl l3065) l.30 grns Potassium citrate 30 to 60 grns Water (100 F) to l liter The longer the matrix is in the dye bath the more pronounced is the dichroic effect. Increasing the amount of citrate increases the clarity'of the transferred dye image.
An alternate dye bath for dichroic images is:
Pontacyl Rubine R (Cl 14720) 1.75 gms Metanil Yellow WS (Cl 13065) l.75 gms Glacial acetic acid l0.0 ml
Water to 1 liter The reception paper to which the dye images are transferred by imbibition contact with the dyed matrix is commercially available as Eastman Kodak Dye Transfer Paper which is a gelatine-coated white paper containing an acid dye mordant in the colloid coating. In lieu of the manufactured dyetransfer paper an alternate reception can be prepared by fixing-out unexposed and undeveloped photographic paper in a new hardening fixing bath. The photographic paper may be any except those with a rough surface. Double weight papers are preferred. After fixation and thoroughly washing the paper, the gelatin layer of the former emulsion coating on the paper is mordanted to increase the rate of dye transfer and to minimize lateral diffusion of transferred dye with the resultant loss of dye image sharpness. Suitable mordants for water soluble acid dyes are the oxides and hydroxides of heavy metals such as iron, chromium, copper, tin and aluminum. Since the mordant must be colorless to avoid adulterating the dye color, and must also be capable of being deposited in a gelatin coating on paper or film, one of the most commonly used mordants for acid dyes is aluminum hydroxide, which may be prepared as follows:
(A) Aluminum sulfate 200 grams Water to 1 liter (B) Sodium carbonate, anhy. grams Water to 1 liter (B) is added to (A) with vigorous stirring to redissolve the precipitate first formed. The fixed and washed photographic paper is bathed in the mordanting solution for 5 minutes, washed for 5 minutes in running water, then bathed for 5 minutes in a 5 percent aqueous solution of sodium acetate .and then again washed for 5 minutes. The mordanted and buffered transfer paper may then be used immediately or it may be dried and stored for future use.
Reception materials to which the dye images may be transferred byimbibition contact with dyed matrices include white and colored paper, sheet film, glass, metal such as, for example, aluminum and porcelain, pottery and stoneware. The reception materials should be provided with a layer of gelatin or other natural or synthetic hydroxyl-containing, film-forming colloid which also contains a mordant for water soluble acid dyes. Suitable water-permeable colloids useful as reception layers include agar-agar, albumin, zein, collodion, polyvinyl alcohol, partially hydrolyzed polyvinyl acetate and hydrophilic copolymers thereof with ethylenically unsaturated monomers such as ethylene, vinyl chloride, etc.; polyvinyl acetals, e.g., the acetal of polyvinyl alcohol with acetaldehyde or benzaldehyde; or water soluble or hydrophilic cellulose derivatives. Suitable hydrophilic or water permeable colloids of the above types are described in US. Pat. Nos. 2,397,866, 2,286,215, 2,276,323, 2,276,322, 2,211,323 and 2,110,491.
Mordants suitable for fixing the acid dyes transferred to the water permeable colloid coatings on the reception materials include the metallic oxides and hydroxides previously described and also the polymeric polyamines and polymeric amides prepared as described in US. Pat. Nos. 2,753,263, 2,585,583 and 2,495,255 and the copolymeric' mordants described in US. Pat. No. 2,839,401.
The present invention is particularly useful in providing a process for testing, exhibiting, and comparing the color, saturation, and hue characteristics of water soluble dyes useful in dye transfer imbibition processes for forming dye images from black-and-white photographic record images. In such processes the dye images are formed in reception coatings of gelatin or other water permeable colloids by transfer of dyes thereto in aqueous dispersion form and subsequently drying the reception coatings. It is well known that the color imparted by dyes to wet gelatin or other colloid coatings nearly always changes upon drying. Generally speaking, the reds tend to become bluer and the blues tend to become greener. Also, almost all dyes exhibit the peculiarity of appearing to be mixed with red upon decreasing the concentration of the dye solution or density of the dye image. Thus a dye imbibition print in a gelatin coating may be purple, for example, in the highlights, but appears as pure red in the shadows or higher dye concentration areas. In the case of a cyan blue imbibition print in gelatin the shadows show less of a greenish tinge. In like manner a yellow imbibition print appears orange in the shadows or areas of highest dye densities.
If the lowest density area, i.e., area 2 in FIG. 4, is colored, however, weakly, the dye solution is diluted with 25 percent by volume of water
the most dense area represents the color of dye transferred from a matrix dye density 23 times the area of color on the print. Any bathochromic shift (towards the red) or hypsochromic shift (towards the blue) of the dye images will probably be apparent in a dye density range as large as 1 to 23.
a. Increasing the cross exposure of the matrix step wedge to, say, factor 4 instead of factor 2. b. Increasing the developer composition to increase the thickness of the gelatin image on the matrix. c. Increasing the acetic acid concentration in the rinse bath[s]. d. Increasing the length of time of transferr
Index of Textile Chemists and Colorists:
DYE COLOR INDEX NUMBER Pontamine Fast Red 8 BLX 28160 Pontamine Fast Orange 40265 Fast Red S. Conc. 15620 Congo Red 4BX 22120 Pontacyl Carmine 68 Extra Conc. 18055 Pontacyl Scarlet R Conc. 23910 Pontacyl Rubine R Extra Conc. 14720 Acid Magenta 0 42685 Pontamine Fast Yellow RL 29025 Metanil Yellow WS 13065 Anthracene Yellow GR 13290 Erie Yellow F Conc. 40000 Acid Green SN Extra 44090 Acid Green 42095 Ink Blue R 42755 Pontamine Fast Blue 3RLP 27925 Pontamine Fast Gray 34170 Alizarine Fast Brown G 66710 Perlamine Fast Brown 3GL 10410 Pontamine Black ULR 30235 Diamond Acid Black SAS 27270 Acid Black L 20470
I looked at the patent.
It really clearly has to do with color printing, so fits here. But it is mainly about testing dye concentrations and matrix exposures when making dye transfer prints starting from b/w negatives, i.e., trichromy.
Process for exhibiting and evaluating the effects of variation in dye concentration on the saturation and hue of dyes useful in color photography, dye imbibition transfer processes. The process comprises preparing a crossed step wedge on a dye transfer matrix film, dyeing the processed matrix in a given transfer dye solution, and transferring the crossed step wedge dye images to a reception material. The density, saturation and hue of any individual step of the transferred dye images is referenced to any other step of the positive dye wedge by relative exposure indicia in each step. The crossed step wedge dye positive serves as a relative exposure guide for producing positive color prints from non-color negatives using imbibition dye transfer processes.
There's forest, and there's individual trees.
SUMMARY OF THE INVENTION
An object of this invention is to provide a method for producing colored photographic reproductions of non-colored originals.
A further object of this invention is to provide an improved dye transfer method for producing two or more differently colored photographic reproductions of the same non-colored original.
A still further object of this invention is to provide a photographic dye transfer method for preparing a graduated step wedge showing the variation in saturation and hue of a given transfer dye with known variation in exposure of the imbibition matrix.
Still another object of the present invention is to provide a method for producing colored photographs by dye transfer processes using a graduated step wedge of the dyes to determine the exposure of the imbibition matrix required to produce the desired color.
This invention has as another prime object to provide a method for testing and exhibiting the color, hue and saturation characteristics of dyes useful in dye imbibition transfer processes.
Cheers - Andy C
16mm Cine, 35mm, 120, 5x4 & 7x5.