US2747997A - Decoration of cellulosic, metal and vitreous surfaces - Google Patents

Description

May 29, 1956 J. G. SMiTH ET AL 2,747,997

DECORATION OF CELLULOSIC. METAL AND VITREOUS SURFACES Filed Oct. 1, 1952 LIGHT EXPOSURE zozozoxg 305.1507

LIGHT SENSITIVE POLYMER- FLUORESCENT P/GMENT SUPPORT (GLASS) JAMES 6 SMITH EARL SUNOEEN INVENTORS M i I United States Patent signors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jerse Application October 1, 1952', Serial No. 312,478

1 claim. (Gl. 95 -7 This invention relates to photographic processes for the formation or" images on various surfaces by means of pigmented light-sensitive polymeric compositions.

In various manufacturing processes it is desirable from time to time to form a pigmented design on selected areas of a product which design is securely bonded to the product. For example, in the production of patterns and templates it is customary to form a design of a product on a thin metal or other support to serve as a guide in preparing the final product. Photographic methods are especially suitable for such work particularly since much hand work is dispensed with. In the past, various light-sensitive compositions have been employed for the decoration of surfaces such as pigmented glue, albumen, and syntheticresin compositions. In general, such compositions have been found to be lacking partly due to their inherently low light-sensitivity, poor stabili ty, etc. For example, dichroma'te'd glue compositions require high intensity and duration of exposure to light to obtain the best results and such compositions are notoriously unstable. A process involving the use of a dichrornate sensitized mixture of gelatin and a synthetic resin is disclosed in U. S. Patent 2,472,128. This process is characterized by producing direct positive images by exposure of the composition to light followed by removal of the exposed regions from the supportcarrying the sensitive layer. In spite of the advantages of the process difficulty of reproducibility in the process and low resolving power have limited the usefulness of the process.

We have discovered that pigmented compositions containing certain polymers which are inherently lightsensitive and which can be sensitized to increase their speed, are especially efficacious for decorative purposes such as those set forth in detail in the following examples.

The figures of the accompanying. drawings illustrate our invention and show in greatly enlarged cross-sectional view the appearance of a typical light-sensitive element at various stages in the production of a design on a vitreous surface.

The pigmented compositions of the invention contain in addition to pigments, synthetic polymers having combined polymeric units containing groups of structurein which R is an aryl group as above mentioned.

Particularly efficacious polymers under the above general formulas are the polyvinyl alcohol esters of cinnamic acids such as cinnamic acid and m-nitrocinnamic acid.

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These polymers contain combined polmeric units of structure.

in which R is an aryl group' as above. The" polymers are preferably made by reacting polyvinyl alcohol with cinnamoyl halides as described in the Minsk U. S. patent application Serial No. 207,052 filed January 20, 1952. For example, the polymer obtained by substantially fully ester-ifyil'rg. polyvinyl alcohol with cinnamoyl chloride and containing about mole percent or combined vinyl cinnamat'e groups is particularly useful in our invention. Similarly useful polymers having groups of the formula immediately above in which R is an alkyl group are obtained by reacting polyvinyl alcohol with the desired saturated aliphatic acid halide such as crotonyl chloride to obtain an ester of polyvinyl alcohol.

Useful pol mers having structures falling under the two first-mentioned general formulas above are polymers such as those obtained by reacting polymers containing ac'etyl groups with aromatic aldehydes as disclosed in the Unruh et a l. U. S. patent applicatio Serial Nos. 246,- 515, 2465 16, and 246,517 filed September 1 3, 1951,- now U. S. Patents 2,716,102, 2,716,097, and 2,706,725 respectively. A typical polymer of this type is that obtained by ace'tylatirig polystyrene and condensing the acetyl groups of the resultant polymer with ben'z'aldehyde, am: saldehyde, etc. in a Claisen-Schmidt reaction to obtain a vinyl Benzalaeetophenene polymer having pdlyi'iieri units of structure Similarly, vinylmethylketone polymers condensed with aromatic aldehydes to obtain polymers having the units (CH2'-CH-)n' OCH=CHR are very useful in our invention.

Other polymers contemplated for use in the lightsensitive pigmented compositions are those disclosed in the Allen et al. U. S. Patent 2,566,302 granted September 4, 1951. These resins are made by cinnamoylating sty rene polymers with, for example, cinnamoyl chloride in a Friedel-Crafts reaction.

In addition to containing the polymeric constituents above mentioned the pigmented compositions preferably but not necessarily contain a light-sensitizing agent such as nitro compounds, triphenylmethane dyes, anthrones, quinones, or ketones such as disclosed in the Minsk et al. U. S. patent application Serial No. 148,684 filed March 9, 1950, now U. S. Patent 2,610,120, granted September 9, 1952, and- Serial Nos. 207,048-51 filed January 20,- 1951,- now U. S. Patents 2,690,966, 2,670,285, 2,670,286, and 2,670,287 respectively, e. g. picramide, 1,2-benzanthraquinone, crystal violet carbinol base, or 4,4'- tetramethyldiarrlinodiphenylketone.

The pigment components of the composition will vary according to the requirements of the particular process under consideration as will be seen from consideration of the examples following, illustrating various uses for the pigmented polymeric composition. In general, thepigment used has a color contrasting with the background of the product on which the decoration is to be formed.

The general procedure of decorating the various surfaces is also illustrated in the examples following and includes coating-and drying the light-sensitive compost tion on the desired surface, exposing the coatings preferably under a design to render the coating insoluble in organic solvents only in the region of exposure, followed by removal of the unexposed portion of the coating with an organic solvent leaving a pigmented design on the surface. Of course, designs of the pigmented polymeric compositions applied to a surface by hand or through stencils can be insolubilized by exposure to light and the solvent treating step is therefore not required to obtain an insoluble design on the given surface.

The following examples illustrate our invention.

Example 1 This example illustrates the preparation of pigmented images on a glass support particularly in a process of making a fluorescent screen of use in television systems.

Three fluorescent pigmented dopes were prepared by milling 20 grams of three difierent inorganic fluorescent pigments into 100 cc. of a dope containing 20% of polyvinyl cinnamate (polyvinyl alcohol substantially 100% esterified with cinnarnoyl chloride) in ethylene glycol monomethyl ether acetate. The dopes were each sensitized with 4,4-tetramethyldiaminodiphenyl ketone. The first dope containing zinc phosphate as the fluorescent pigment which fluoresces red when excited, was sprayed on to a glass surface, dried and exposed to a screen having light transmitting apertures such as a perforate plate or half-tone screen, for minutes at 3 feet from a 35-ampere MacBeth white flame carbon are, developed in a tank containing a solvent mixture of xylene and ethylene glycol monomethyl ether acetate (4:1), dried and swabbed with a cotton tuft saturated with isopropyl alcohol to remove excess pigment.

The second dope containing zinc sulfide which fluoresces blue when excited, was sprayed over the first image, dried and the resultant coating exposed through the same apertured screen at a difi'erent angle in order to insolubilize the coating in a different region of the glass surface. Following this the element was developed with solvent and cleaned to remove excess pigment as mentioned above. The third dope containing zinc orthosilicate which fluoresces green when excited, was sprayed over the first two images on the glass surface and exposed through the same screen at a new angle after which the soluble region of the coating was removed as above described leaving three adjacent polymeric images each consisting of a fluorescent pigment and insoluble polymer occupying different areas of the glass surface. As is apparent, the process is partic ularly adapted to forming such fluorescent images which are fired to burn off the polymer and sinter the phosphors onto surfaces of vacuum tubes or other elements of use in the transmission and reception of color television broadcasts. It has been found that, e. g., polyvinyl cinnamate burns away more quickly and completely than gelatin or polyvinyl alcohol media. Except in those cases where it may be desirable to produce only one pigmented polymeric image having fluorescent properties on a given support, our process may be used to form a multiplicity of fluorescent pigmented images on supports such as glass.

The procedure just described for forming fluorescent pigmented polymeric images on a support is illustrated in part in the accompanying drawings wherein Stage A shows the sensitive element including a glass support carrying a sensitive layer of a mixture of the light-sensitive polymer such as polyvinyl cinnamate and fluorescent pigment, being exposed to light under a screen 13 having light-transmitting apertures 14 such as a perforated metal plate. As shown, the exposing rays impinge on area 12; of layer 11 and thereby render the polymer in the layer in that area insoluble in organic solvents. When the element is treated with organic solvents in which the unexposed areas of layer 11 are soluble the result is to remove those areas from the glass support leaving a relief image 15 containing insoluble polymer and fluorescent pigment on the support as shown in Stage B. As mentioned in this example the element of Stage B can then be re-coated Example 2 This example illustrates the preparation of pigmented images on cellulosic surfaces.

Ultramarine Blue pigment (3.75 gms.) was milled into 100 cc. of a 7.5% solution of polyvinyl cinnamate in ethylene glycol monomethyl ether acetate and the lightsensitivityof the composition was increased by the addition of picramide. The composition was then coated on to a paper support, exposed for 1 minute at 4 feet from a Eli-ampere white flame arc, and developed with methyl ethyl ketone to remove the pigmented composition from the unexposed regions and excess pigment was removed by swabbing with a cotton swab saturated with isopropyl alcohol. The result was to obtain a blue image on the paper surface.

Example 3 Example 4 This example illustrates a method for the preparation of a pigmented image on a metal support particularly suitable for template use.

A 1,2-benzanthraquinone sensitized 7.5% polyvinyl cinnamate dope in a mixture of toluene and ethylene glycol monomethyl ether acetate (5:3) was pigmented with 5 grams of Prussian blue pigment per 100 cc. of solution. The resulting dope was coated on to a clean aluminum sheet and after drying was exposed for 1 /2 minutes at 4 feet from a 35-ampere white flame arc. The exposed coating was then developed as described in the above examples to obtain a blue pigmented image on the aluminum sheet.

Example 5 This example illustrates the application of our invention to the preparation of metal images on vitreous surfaces for use in electrical work.

7 /2 grams of silver oxalate and 5 grams of lead sulfide were pigmented into cc. of a 1,2-benzanthraquinone sensitized 7.5% polyvinyl cinnamate dope in a mixture of ethylene glycol monomethyl ether acetate and toluene (3:5). This composition was then sprayed on to a porcelain disk and after drying exposed for 1 /2 minutes at 18 inches from a 35-ampere white flame carbon arc, the coating developed with solvent as in the previous examples and dried. Thereafter the disk was fired until a metal image was obtained, a temperature of 1150" F. being suitable for this purpose.

What we claim is:

A composition for use in forming a fluorescent image on a surface, comprising a mixture of a member of the class consisting of zinc phosphate, zinc sulfide and zinc orthosilicate and a light-sensitive substantially fully esterified cinnamic acid ester of polyvinyl alcohol.

References Cited in the file of this patent UNITED STATES PATENTS 6 Reppe et a1 May 31, 1938 Ellis Mar. 26, 1940 Staehle June 7, 1949 Minsk et a1. Sept. 9, 1952 FOREIGN PATENTS Great Britain June 2, 1921 Great Britain Oct. 30, 1942

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