Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Antihalation or filter layer containing
Reexamination Certificate
2003-02-03
2004-06-01
Schilling, Richard L. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Antihalation or filter layer containing
C430S523000, C430S538000
Reexamination Certificate
active
06743573
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the use of light stable pigments incorporated in an aqueous coating for photographic supports utilized in silver halide black and white photographic display elements, preferably black and white paper. These papers are typically used in advertising, portraiture, fine art, and restoration applications.
BACKGROUND OF THE INVENTION
Fiber-based photographic papers are typically coated with baryta to obtain a smooth high-reflectance surface as a base for light sensitive photographic layers. In order to provide warm tone, cream colored paper supports, yellow and red colored pigments are incorporated in either the paper base fibers or more typically in the baryta layer.
Often warm tone tinted papers exposed to normal room light conditions fade with time. When this occurs, the aesthetic properties associated with creamy colored papers are lost. Therefore, it is desired to provide a black and white silver halide photographic display material which does not fade after long-term exposure to light.
SUMMARY OF THE INVENTION
This invention relates to a black and white silver halide photographic display element comprising a support and a layer on top of said support comprising baryta and a yellow pigment represented by Formula I
wherein each of R
1
, R
2
, and R
5
independently represents a halogen atom, or a substituted or unsubstituted alkyl, alkenyl, aryl, aralkyl, cycloalkyl, alkoxy, or alkyl amino group of 1 to 8 carbon atoms, or a substituted or unsubstituted aminocarbonyl, alkoxycarbonyl or alkylthio group of 2 to 10 carbon atoms, or a substituted or unsubstituted alkylsulfonyl, arylsulfonyl or sulfamoyl group of 1 to 8 carbon atoms, or a nitro, amino, acetamido, hydroxy, cyano, carboxy, carboxylate, sulfonic acid, or sulfonate group, additionally pairs of R
1
or R
2
may represent the non-metallic atoms necessary to complete a substituted or unsubstituted ring system containing at least one 5- or 6-membered heterocyclic or carbocylic fused ring; and n, m, and r are independently 0 to 5.
Colorimetric testing indicated that typical yellow pigments degrade significantly under room light conditions. This invention relates to the use of yellow pigments that offer long-term light stability when incorporated in baryta coatings for photographic fiber base papers. This invention provides a baryta layer that will not fade under long-term exposure to light. Therefore, the support material maintains its intended “creamy” color.
DETAILED DESCRIPTION OF THE INVENTION
The photographic elements of the invention are silver halide black and white photographic display elements and more preferably silver halide black and white papers. Most preferably they are professional quality papers where the tone of the support is particularly important. Examples of current papers which could suitably incorporate the improved baryta layer described hereafter include KODAK POLYMAX Fine Art Paper.
The black and white elements of the invention comprise a support. The support may be made of any suitable material as known to those skilled in the art. Preferably the support is comprised of cellulose paper fibers. In order to achieve a highly reflective photographic surface for the light sensitive photographic emulsions, a layer comprising baryta layer is applied on top of the support. The phrase “on top of the support” means between the support and the imaging layers. There may be other layers in between the baryta layer and the support such as adhesion layers or barrier layers. There may also be additional layers between the baryta layer and the imaging layers.
Baryta refers to barium sulfate, a highly reflective white pigment. The binder for the barium sulfate is typically, but not exclusively gelatin. Other coating aids, surfactants, colorants, optical brighteners, and inorganic or organic cross-linking agents may be employed to support the manufacturing operations and provide for physical and aesthetic properties specific for product requirements. A typical baryta layer is comprised of 70-95% by dry weight barium sulfate, and 5-30% gelatin. These layers are applied to a photographically inert paper base and typically range from 10 to 60 grams per square meter in coverage.
The baryta layer utilized in the invention also comprises a yellow pigment represented by Formula I
R
1
, R
2
, and R
5
are substituents. Preferably each of R
1
, R
2
, and R
5
independently represents a halogen atom, or a substituted or unsubstituted alkyl, alkenyl, aryl, aralkyl, cycloalkyl, alkoxy, or alkylamino group of 1 to 8 carbon atoms; or a substituted or unsubstituted aminocarbonyl, alkoxycarbonyl or alkylthio group of 2 to 10 carbon atoms; or a substituted or unsubstituted alkylsulfonyl, arylsulfonyl or sulfamoyl group of 1 to 8 carbon atoms; or a nitro, amino, acetamido, hydroxy, cyano, carboxy, carboxylate, sulfonic acid, or sulfonate group. Additionally pairs of R
1
or R
2
may represent the non-metallic atoms necessary to complete a substituted or unsubstituted ring system containing at least one 5- or 6-membered heterocyclic or carbocylic fused ring.
Examples of unsubstituted alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, octyl, 2-ethylhexyl, and the like. Cycloalkyl groups can be cyclopentyl, cyclohexyl, 4-methylcyclohexyl, and the like. Alkenyl groups can be vinyl, 1-propenyl, 1-butenyl, 2-butenyl, and the like. Aryl groups can be phenyl, naphthyl, styryl, and the like. Aralkyl groups can be benzyl, phenethyl, and the like. Particularly useful substituents for these groups include halogen, alkoxy, acyl, alkoxycarbonyl, aminocarbonyl, carbonamido, carboxy, sulfamoyl, sulfonamido, sulfo, nitro, and the like.
Preferably each R
1
, R
2
, and R
5
independently represents a halogen atom or an alkoxycarbonyl or alkyl group. In one suitable embodiment each R
1
and R
2
independently represents a halogen atom or an alkoxycarbonyl group. It is preferred that R
1
and R
2
are the same and that n=m. R
5
, when present, is preferably alkyl or halogen.
n, m, and r are independently 0 to 5, and more preferably n and m are 1 to 5 in order to provide a pigment with improved properties. In a preferred embodiment n and m are 1 or 2. In one embodiment r is 0. In one preferred embodiment, R
1
and R
2
are methoxycarbonyl (CO
2
Me) and r is 0.
Examples of suitable pigments include the following, with Inventive Pigment 1 being most preferred.
The pigments can be used in any amount which provides the appropriate color aim. In one suitable embodiment a lay down of 1 to 10 mgs per square meter may be utilized. The disazo pigments described herein for use in the invention materials are well known yellow pigments (see GB 2,356,866 and U.S. Pat. No. 5,559,216) and their method of preparation is well known to those skilled in the art. The pigments have excellent qualities for use as inks and colorants, such as transparency, and color strength. In this application, the Formula I pigments exhibit excellent light stability and fastness as compared with other pigments used in the commercial trade.
Combinations of pigments of Formula I may be used. Further, the pigments of Formula I may be used alone or in combination with other pigments to produce the desired tinting color for the support material. Any companion pigments may be used, but a red colored pigment is preferred. Especially preferred is the combination of Inventive Pigment 1 with Flexonyl Red
Pigments are colorants which are considered to be effectively insoluble in the application medium, and many such compounds are well known and in wide commercial use. It is common practice to provide pigment compositions in the form of finely divided dispersions, which may be produced by well-known methods such as ball milling, media milling, or by the methods disclosed in U.S. Pat. Nos. 5,026,427 and 5,310,778 incorporated herein by reference.
Unless otherwise specifically stated, substituent groups which may be substituted on molecules herein include any groups, whether substituted or unsubstituted, whic
Helber Margaret J.
Southby David T.
Vogt Charles H.
Meeks Roberts Sarah
Schilling Richard L.
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