Polaroid Corporation

Irena Y Bronstein-Bonte

Lloyd D Taylor

Derek H Barton

Edward P Lindholm

Edwin H Land

Alan B Fischer

Richard J Murphy

Novel photovoltaic cell systems, particularly silicon cells, for converting electromagnetic radiation into electric energy, wherein a luminescent medium or reagent which will absorb radiation at the shorter wavelengths, e.g. the UV, and emit it at longer wavelengths is disposed between the light source and the cell to increase its efficiency, the essence of the invention being the use of a class of anthracene dimer derivatives known in the literature as lepidopterenes as the luminescent medium or reagent. The structural formula for the lepidopterenes is shown in FIG. 1.

Photovoltaic cell

Optical filter agents and photographic products and processes using same are disclosed. The optical filter agents are pH-sensitive hydrazone compounds conforming to the following structural formula: ##STR1## where R is any group which can provide a double bond for conjugation with the ##STR2## portion of the compound to provide light-absorbing capability or color for the agent at a pH above its pKa, X is a substituent of R providing at least one electron-withdrawing group and each R' can be defined as any substituent that does not impair the light-absorbing capacity of the compound at a pH above the pKa thereof. The pH-sensitive optical filter agents have a highly colored light-absorbing form at a pH above the pKa and are substantially non-absorbing at a pH below the pKa. The pH-sensitive optical filter agents are useful in photographic film units and processes for the protection of photoexposed photosensitive elements against the occurrence of fogging during in-light development.

Optical filter agents and photographic products and processes containing

Copolymeric mordant materials containing recurring units according to the following formula are disclosed: ##STR1## In such copolymers, each of R.sup.1, R.sup.2 and R.sup.3 can independently be alkyl; substituted-alkyl; cycloalkyl; aryl; aralkyl; alkaryl; or at least two of R.sup.1, R.sup.2 and R.sup.3, together with the quaternary nitrogen atom to which they are bonded, can complete a saturated or unsaturated, substituted or unsubstituted nitrogen-containing heterocyclic ring; X is an anion; each R.sup.4 is alkyl of from 1 to 6 carbon atoms; R.sup.5 is a divalent alkylene of from 1 to 8 carbon atoms; R.sup.6 is hydrogen, amino, phenyl or alkyl of from 1 to 4 carbon atoms; R.sup.7 is hydrogen or methyl; and m is an integer 1 or 2. The molar ratio of a:b can range from about 0.1:1 to about 10:1, e.g., about 0.3:1 to about 3:1. The copolymeric mordant materials can be utilized as image-receiving layers in photographic products and processes of the diffusion transfer type. The mordants are especially adapted to the production of dye images exhibiting favorable maximum density (D.sub.max) and rates of dye transfer properties.

Copolymeric mordants and photographic products and processes containing

Polymeric optical filter agents and products and processes using same are disclosed. The polymeric optical filter agents are pH-sensitive materials comprising a polymeric backbone having a plurality of pendant moieties of the formula (I). ##STR1## wherein X is ##STR2## and R is alkyl, aryl, alkaryl or aralkyl; A is hydrogen, alkyl or the radical ##STR3## where each of Y.sup.1, Y.sup.2 and Y.sup.3 is hydrogen or an electron-withdrawing group; and each Z.sup.1, Z.sup.2 and Z.sup.3 is hydrogen or an electron-withdrawing group; with the proviso that, when each of Z.sup.1, Z.sup.2 and Z.sup.3 is hydrogen, said A is a radical ##STR4## wherein at least one of said Y.sup.1, Y.sup.2 and Y.sup.3 groups comprises an electron-withdrawing group. These agents upon contact with alkali are converted from a substantially non-light absorbing form to a highly colored light-absorbing form useful in photographic products.

Polymeric pH-sensitive optical filter agents and articles including same

Image-receiving elements for use in photographic diffusion transfer products and processes and including a unitary image-receiving and decolorizing layer are disclosed. The unitary image-receiving and decolorizing layer comprises a mixture of gelatin, an organic monobasic or polybasic acid or anhydride and a copolymeric mordant comprising recurring units from a vinylpyridine and from a copolymerizable vinylbenzyl quaternary ammonium salt. The image-receiving elements can be used in diffusion transfer products and processes for the provision of color images which appear satisfactorily to emerge from a white background and which exhibit desirable densitometric characteristics.

Image-receiving element with unitary image-receiving and decolorizing

Polymeric optical filter agents and photographic products and processes using same are disclosed. The polymeric optical filter agents are pH-sensitive optical filter agents comprising polymeric backbone units having the following hydrazone moiety: ##STR1## where R is a group which can provide a double bond for conjugation with the ##STR2## portion of the moiety to provide light-absorbing capability for the agent at a pH above its pKa, and X represents a substituent of R providing at least one electron-withdrawing group. The polymeric pH-sensitive optical filter agents have a highly colored light-absorbing form at a pH above the pKa and are substantially non-absorbing at a pH below the pKa. The polymeric optical filter agents are useful in photographic film units and processes for the protection of photoexposed photosenstive elements against the occurence of fogging during in-light development.

Polymeric pH-sensitive optical filter agents having hydrazone moieties

Copolymeric mordant materials containing recurring units according to the following formula are disclosed: ##STR1## In such copolymers, each of R.sup.1, R.sup.2 and R.sup.3 can independently be alkyl; substituted alkyl; cycloalkyl; aryl; aralkyl; alkaryl; or at least two of R.sup.1, R.sup.2 and R.sup.3, together with the quaternary nitrogen atom to which they are bonded, can complete a saturated or unsaturated, substituted or unsubstituted nitrogen-containing heterocyclic ring; and X is an anion. The molar ratio of a:b can range from about 0.1:1 to about 10:1, e.g., about 0.3:1 to about 3:1. The copolymeric mordant materials can be utilized as image-receiving layers and in photographic products and processes of the diffusion transfer type. The mordants are especially adapted to the production of dye images free of objectionable haze, yellowing or related image defects.

Copolymeric mordants

A process for preparing a solution of a copolymer of a vinylpyridine and an ethylenically-unsaturated copolymerizable vinylbenzyl quaternary salt is disclosed. The process comprises polymerizing, in the presence of a polymerization medium comprising water and a lower alcohol, a vinylpyridine and a copolymerizable vinylbenzyl quaternary ammonium salt having the formula ##STR1## wherein each of R.sup.1, R.sup.2 and R.sup.3 is independently alkyl; substituted alkyl; cycloalkyl; aryl; aralkyl; alkaryl, or at least two of R.sup.1, R.sup.2 and R.sup.3 together with the quaternary nitrogen atom to which they are bonded complete a saturated or unsaturated, substituted or unsubstituted nitrogen-containing heterocyclic ring. The process provides the desired copolymer in the form of a clear solution useful in the formation of polymeric coatings or layers utilized as image-receiving layers in photographic products and processes.

Process for preparing cationic polymers

Copolymeric mordants and photographic products and processes utilizing

Optical filter agents and photographic products and processes using same are disclosed. The optical filter agents are pH-sensitive hydrazone compounds conforming to the following structural formula: ##STR1## where R is any group which can provide a double bond for conjugation with the ##STR2## portion of the compound to provide light-absorbing capability or color for the agent at a pH above its pKa, X is a substituent of R providing at least one electron-withdrawing group and each R' can be defined as any substituent that does not impair the light-absorbing capacity of the compound at a pH above the pKa thereof. The pH-sensitive optical filter agents have a highly colored light-absorbing form at a pH above the pKa and are substantially non-absorbing at a pH below the pKa. The pH-sensitive optical filter agents are useful in photographic film units and processes for the protection of photoexposed photosensitive elements against the occurence of fogging during in-light development.

Diffusion transfer films and processes are disclosed wherein the processing composition includes a light-reflecting pigment and an optical filter agent, and the image-receiving layer carries over it a layer containing a substantially non-diffusible agent adapted to decolorize optical filter agent immediately adjacent the interface between said processing composition and said decolorizing layer.

Image-receiving elements

Polymeric optical filter agents and photographic products and processes using same are disclosed. The polymeric optical filter agents are pH-sensitive optical filter agents comprising polymeric backbone units having the following hydrazone moiety: ##STR1## where R is a group which can provide a double bond for conjugation with the ##STR2## portion of the moiety to provide light-absorbing capability for the agent at a pH above its pKa, and X represents a substituent of R providing at least one electron-withdrawing group. The polymeric pH-sensitive optical filter agents have a highly colored light-absorbing form at a pH above the pKa and are substantially non-absorbing at a pH below the pKa. The polymeric optical filter agents are useful in photographic film units and processes for the protection of photoexposed photosensitive elements against the occurence of fogging during in-light development.

Polymeric optical filter agents and photographic products and processes

Photographic film units and photographic products using an acetal of a hydroxylated polymer and a formyl benzyl quaternary salt(s) as a mordant for diffusible dye image-providing materials.

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Newton, MA, United States of America

Irena Y Bronstein-Bonte