Organic compounds -- part of the class 532-570 series – Organic compounds – Fatty compounds having an acid moiety which contains the...
Reexamination Certificate
1998-03-05
2001-01-23
Carr, Deborah D. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Fatty compounds having an acid moiety which contains the...
C554S223000, C560S166000
Reexamination Certificate
active
06177578
ABSTRACT:
BACKGROUND OF THE INVENTION
Much of the black on white photographic industry depends on the use of silver salts, e.g. mixed halides, as the active agent. One characteristic of the silver process is its high photosensitivity achieved through amplification; however, this benefit is realized at some sacrifice to resolution. Further, images of high acuity and density require liquid chemical processing with inherent process limitations and environmental drawbacks. In contrast, polyacetylene-based, “processless” films are imaged solely by the application of one or more simple physical means, such as by exposure to ionizing radiation which provides instantaneous imprinting at 1000 lines/mm, or higher resolution, at a high density. Alternatively, a first simple physical means of exposure to thermal radiation can cause latent-image formation by the deactivation of the polyacetylene imaging component. The final image can then be developed by a second simple physical means of exposure to ionizing radiation. In both cases, not only does this mode of imaging reduce the time for obtaining an imaged product, but also it avoids safety and environmental problems associated with chemical development, eliminates the cost of such processing and increases the quality and efficiency of imaging.
Notwithstanding the benefits of polyacetylenic films, the majority of diacetylenic compounds which are capable of color development produce blue, purple, magenta, and red coloration; yellow being less common and pure permanent black being virtually unknown. Further complicating the issue of a chosen color development is the widely varying photosensitivity of the individual color producing diacetylenes.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a polyacetylenic-based film which is imageable to a black or neutral near black color in high density.
Another object of the invention is to provide a photosensitive, thermochromic polyacetylenic film which is imageable to a black or near black color by exposure to ionizing radiation and heat.
Still another object is to provide economic and commercially feasible processes for the production of such black or neutral near black imageable films suitable for use in recording media.
These and/or other objects may be readily gleaned from a review of the following description and disclosure of the present invention.
BRIEF DESCRIPTION OF THE INVENTION
The polyacetylene compounds of the present invention contain the conjugated chemical group (—C═C—)
n
. (generally, where n=2 to 6, preferably 2 to 4 and more preferably 2) and generally exist in an ordered state as in crystals or in an oriented monolayer. These crystalline or oriented polyacetylenes are capable of intermolecular alignment which is provided through specific chemical ions, atoms or groups attached to the polyacetylene moiety and are capable of undergoing solid state polymerization to polyacetylene polymers (generally, by way of 1,4 addition-type reactions) by exposure of the monomeric polyacetylene compounds to ionizing radiation. These chemical ions, atoms or groups provide molecular alignment in the crystal structure so that only a small atomic motion within the polyacetylene unit is required to effect polymerization.
It is now discovered that intermixtures or discrete integral layers of certain imageable polyacetylene metal salts or mixtures of a metal salt and a non-metal salt polyacetylenic compound which form images in complementary colors after polymerization (e.g. blue-yellow, magenta-green, cyan-red, etc.), are capable of producing a permanent black or neutral near black image color upon exposure of mixtures containing these polyacetylenic components to ionizing radiation followed by heat. In preferred embodiments, the black image color is produced by first exposing the intermixture or discrete layers to ionizing radiation followed by a second step which exposes the intermixture or layers to thermal radiation. In a more preferred embodiment, a single metal salt of a polyacetylene carboxylic acid may be used to generate the permanent black or near black image color.
In other preferred embodiments, the black image color may be produced after a first thermal radiation step is used to inactivate certain portions of polyacetylenic compounds in a mixture, a second step of exposure to ionizing radiation, followed by a third step of exposure to heat or thermal radiation. Using this method, the black image color which is formed after the second thermal radiation step will appear in combination with a colorless or white area which is formed by inactivating a portion of the mixture with a first thermal radiation step, thus highlighting the black image color produced.
In other preferred embodiments according to the present invention the permanent black or near black image color is produced by the complementary colors blue and yellow.
Compositions according to the present invention may be used to produce high resolution laser scanning film, to produce high resolution images in laser printing applications and to produce continuous tone photographic images, among numerous other uses.
DETAILED DESCRIPTION OF THE INVENTION
The following definitions will be used throughout the specification in order to describe the present invention.
The term “permanent black or near black image color” as employed herein refers to an image which appears black or near black and which is non-reversible, i.e., it is not further imageable to another color. The desired result which is obtained by the implementation of the present invention is the production of a permenant black or near black image color, preferably in the shape or form of a design. It is also contemplated, however, that the black image color may appear as a background surrounding a light colored, colorless or even white image in the form of a design.
The term “imageable” is used throughout the description of the present invention to describe a composition, film, mixture, laminate, etc. which contains polyacetylene compounds which, upon exposure to ionizing radiation, will produce a color image. The terms “photochromic”, “photosensitive thermochromic” and “thermochromic” are subsets of the term imageable and relate generally to the type of energy or radiation which may be used to produce a color or image from the polyacetylene compounds according to the present invention. For example, a photochromic compound is a compound which produces an image color using an effective amount of ionizing radiation and/or visible light (i.e., in a concentration and for a duration of time) to produce the image color. A photosensitive thermochromic compound is a compound which may produce such an image color using effective amounts of ionizing radiation and/or visible light and heat. A thermochromic compound is a compound which produces a color image by exposing the compound to effective amounts of heat, i.e., an amount of heat which is effective to produce an image color. Polyacetylene compounds according to the present invention preferably are thermochromic, i.e., they produce the black or near black image after exposing the compound to heat. In many instances, according to the present invention, the black or near-black image is produced by first exposing the polyacetylenic compound(s) to effective amounts of ionizing radiation (which term includes visible light) followed by a second heat step.
The term “ionizing radiation” is used throughout the specification to describe energy in any form (other than thermal or heat energy) to which polyacetylenic compounds according to the present invention are exposed in a first step (the second step being a heat step) in order to generate the permanent black or near black image colors of the present invention. In general, the term ionizing radiation embraces all forms of radiation other than thermal radiation which may be used in a first step in producing the final black or near black image. Ionizing radiation generally is energy in the form of radiation having an effective wavelength below about 400 nm. Source
Lewis David F.
Varma Sangya S.
Carr Deborah D.
Goldberg Jules E.
ISP Investments Inc.
Katz Walter
Maue Marilyn J.
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