Abstract: A rewritable thermal recording medium of this invention uses a recording material which reversibly changes between an equilibrium state and a quasi-equilibrium state different in color condition from the equilibrium state when a predetermined heat treatment is performed. This rewritable thermal recording medium includes a substrate and a recording layer formed on the substrate. The recording layer has a first region containing a first recording material which takes on lighter color in quasi-equilibrium than in equilibrium, and a second region containing a second recording material which takes on darker color in quasi-equilibrium than in equilibrium.

Abstract: A black donor for use in a laser addressable thermal transfer system, wherein the black donor comprises a substrate having coated thereon at least one black color layer comprising a binder and colorants. The colorants include a non-infrared absorbing black dye or pigment and about 10% to about 50% of a carbon black pigment, based on the total weight of the colorants in the black color layer.

Abstract: The speed at which a thermosensitive recording medium is scanned with a laser beam is selected to be 5 m/s or higher to increase the temperature of a thermosensitive layer of the thermosensitive recording medium for recording a gradation image thereon with high sensitivity. A sharp temperature gradient is produced along the thickness of the thermosensitive layer, so that a density gradient along the thickness of the thermosensitive layer is developed, therefore, a high-quality image can be recorded without producing any density irregularities caused by thickness irregularities of the thermosensitive layer.

Abstract: A reversible heat-sensitive recording medium has a substrate where a reversible heat-sensitive recording layer and a protective layer are successively formed on top of it. The reversible heat-sensitive recording layer is formed by a reversible heat-sensitive recording material including a leuco dye and a color developing/reducing agent. The color developing/reducing agent is a combination of two kinds of color developing/reducing agents, one with a high color developing ability and the other with high image preservation and stabilization capabilities. The two agents are combined at a ratio between 1:4 to 4:1. Thus a reversible heat-sensitive recording material with a fine color developing ability and high image preservation and stabilization capabilities can be obtained.

Abstract: A thermal transfer film is provided. The thermal transfer film having a support layer, light absorbing layer and a transfer layer further includes an insulating layer between the support layer and the light absorbing layer. The reverse transmission of heat is minimized, thereby improving the thermal energy transmission efficiency from the light absorbing layer to the transfer layer and performing a transfer process efficiently. Therefore, the quality of an image is enhanced.

Abstract: A thermally processable imaging element is disclosed having a protective coat overlying at least one thermographic or photothermographic imaging layer containing an organic silver salt and a thermally activated reducing agent for silver ion. The protective coat includes a film-forming binder comprised of a water dispersible polymer containing hydroxy pendant groups and, to reduce low density spots visible after thermal processing, a combination of anionic, non-ionic and fluorocarbon moiety containing surfactants satisfying formula defined selection criteria.

Abstract: A method of forming an image comprising imagewise-exposing a thermal recording element to heat, the element comprising a support having thereon a thermally-sensitive layer comprising particles containing a colorant, the particles having a particle size between about 1 and about 25 .mu.m suspended in a matrix, the layer having an optical density no higher than about 0.5, the heating thereby causing the colorant to spread out from the particles into the matrix, thus increasing the optical density in the imagewise-exposed areas.

Abstract: A thermal transfer donor element is provided which comprises a support, a light-to-heat conversion layer, an interlayer, and a thermal transfer layer. When the above donor element is brought into contact with a receptor and imagewise irradiated, an image is obtained which is free from contamination by the light-to-heat conversion layer. The construction and process of this invention is useful in making colored images including applications such as color proofs and color filter elements.

Abstract: A reversible thermosensitive recording material which includes a recording layer including a resin, an electron donating coloring agent and an electron accepting coloring developer and in which an image is reversibly formed and erased by appropriately heating and cooling the recording layer, wherein the resin includes a resin crosslinked with the isocyanate compound. The reversible thermosensitive recording material has good image recording/erasing ability, and good durability.

Abstract: A silver halide color photographic film element and more particularly a color motion picture projection film element is provided comprising a transparent thermoplastic film support having a subbing layer unit, coated thereon at least one color forming hydrophilic layer and protective layer, characterized in that at least said subbing layer unit comprises at least one light-stabilizer, preferably absorbing ultraviolet radiation, and at least one chemical compound having reducing properties.

Abstract: A (photo)thermographic material is provided, capable of being used to produce a lithographic printing plate, comprising a support, a hydrophobic thermosensitive layer and a hydrophilic surface adjoining the hydrophobic thermosensitive layer, the thermosensitive layer containing an ingredient A, for example a substantially light-insensitive organic silver salt, which upon negative or positive image-wise heating reacts with at least one other ingredient B, for example a reducing agent therefor, in thermal working relationship therewith, producing a moiety which changes the adhesion between the thermosensitive layer and an adjoining hydrophilic surface to an extent such that negative or positive image-wise separation of the hydrophobic thermosensitive layer from the adjoining hydrophilic surface is enabled.

Abstract: The present invention provides a heat mode recording material comprising on a flexible support having an oleophilic surface (i) a recording layer containing a light-to-heat converting substance capable of converting radiation into heat and (ii) an oleophobic surface layer, wherein said oleophobic surface layer and said recording layer may be the same layer, characterized in that the kinetic coefficient of friction (.mu..sub.k) of said material when sliding one side of said material over the other side of said material is not more than 2.6.

Abstract: A method of coating an optical recording layer on a transparent grooved substrate is disclosed. The recording layer is coated from a mixture of a primary and a secondary solvent. The solvent mixture provides a wide range of conformalities for optical recording layers.

Abstract: Novel thermally imageable monochrome product compositions, elements, and processes are disclosed herein. These compositions and elements characteristically have high contrast and fast imaging speeds. The thermally imageable compositions of this invention comprise (a) at least one near IR-absorbing dye having the structure given in the specification; (b) at least one HABI compound; (c) at least one leuco dye; (d) at least one acid-generating compound; and (e) a polymeric binder. Optionally at least one UV stabilizer and/or at least one inhibitor of color formation can also be present. These compositions have the propensity for affording, upon imaging, highly colored images having high optical density values. At the same time, background color is low in preferred compositions even after extensive exposure to ambient light. These compositions are imagewise exposed to near IR radiation from a laser or other device to effect color formation (i.e., generation of an image).

Abstract: A reversible thermosensitive composition including a coloring agent and a developer and capable of assuming a colored state and a discolored state depending upon the thermal hysteresis thereof. The developer is a phenol compound represented by the formula: ##STR1## wherein R.sup.1 and R.sup.3 represent, independently from each other, a substituted or non-substituted hydrocarbon group, R.sup.2 represents a substituted or non-substituted aliphatic hydrocarbon group having at least two carbon atoms, with the proviso that the total number of carbon atoms of R.sup.1, R.sup.2 and R.sup.3 is at least 8, X and Y represent, independently from each other, a divalent group having a nitrogen atom or an oxygen atom and r is an integer of between 1 and 3.

Abstract: A method is disclosed, and a corresponding thermal imaging medium for use with it, for the formation of an improved heat mode image comprising (A) exposing information-wise to laser radiation a thermal imaging medium comprising (1) a transparent support, (2) an image recording layer containing a hydrophilic binder, a substance capable of converting laser radiation into heat, and a dispersion of a hydrophobic polymer capable of undergoing thermocoagulation by the action of heat and having a built-in UV-absorber. A heat mode image with high density and improved resistance to physical damage is obtained.

Abstract: A laser addressable thermal imaging element comprising a bleachable photothermal converting dye in association with a heat-sensitive imaging medium, and a photoreducing agent for said dye, said photoreducing agent bleaching said dye on laser address of the element. The imaging element may be in the form of a colorant transfer system, a peel-apart system, a phototackification system or a unimolecular thermal fragmentation system. Also provided is a method of crosslinking a resin by leaser irradiation, which is useful in the production of colored images.

Abstract: A reversible thermosensitive composition including a coloring agent and a developer and capable of assuming a colored state and a discolored state depending upon the thermal hysteresis thereof. The developer is a phenol compound represented by the formula: ##STR1## wherein R.sup.1 represents a substituted or non-substituted divalent hydrocarbon group having at least two carbon atoms, R.sup.2 represents a substituted or non-substituted hydrocarbon group, X and Y represent, independently from each other, a divalent group having a hetero atom and r is an integer of between 1 and 3. A reversible thermosensitive recording medium includes a support and a thermosensitive layer including the above composition.

Abstract: A laser-induced thermal imaging system having a donor element and a receptor element. The donor element includes a substrate on which is coated transfer material that includes: a binder including a hydroxylic resin; a fluorocarbon additive; a cationic infrared absorbing dye; a dihydropyridine latent crosslinking agent; and a dispersible material. The receptor element comprises a texturized surface.

Abstract: Provided is a method for making a lithographic printing plate according to which the area of a silver thin film of non-image area of a lithographic printing plate material comprising a support, at least a hydrophilic layer on the support and a silver thin film on the hydrophilic layer is exposed by laser beams to be fused and/or decomposed by heat transformed from laser energy thereby to disclose the hydrophilic layer.

Abstract: According to the present invention there is provided a heat mode imaging element comprising in the order given:i) a lithographic base having a hydrophilic surface,ii) a layer comprising a metal and/or a metallic derivative capable of being ablated by actinic radiation andiii) a hydrophobic layercharacterized in that the hydrophobic layer is a cross-linked layer.

Abstract: Compositions for making structured color images comprising (a) a soluble pigment precursor which can be transformed to an insoluble pigment by means of chemical, thermal, photolytic or radiation-induced method, and (b) a binder polymer or prepolymer, or a positive or negative resist-type resin which can be structured by crosslinking, polymerization or depolymerization by applying heat or electromagnetic irradiation. The compositions can be applied to optical and thermal recording, printing, and the production of color filters for Liquid Crystal Displays, with high accuracy, high transparency and high stability.

Abstract: A cyan dye-donor element for thermal dye transfer comprising a support having thereon a dye layer comprising a mixture of cyan dyes dispersed in a polymeric binder, at least one of the cyan dyes having the formula: ##STR1## and at least one of the other of the dyes having the formula: ##STR2##

Abstract: According to the present invention an element comprising a layer on a glass support characterised in that: (i) the thickness of said glass support is less than 1.2 mm, (ii) said glass support has a failure stress (under tensile stress) equal to or higher than 5.times.10.sup.7 Pa and (iii) the sides in the longitudinal direction have a rounded border with a radius in the order of magnitude of half of the thickness of the glass support.

Abstract: According to the present invention there is provided a thermosensitive imaging element for obtaining a lithographic printing plate comprising on a hydrophilic surface of a support a layer comprising an organic metallic salt and in the same or an adjacent layer an organic reducing agent and a compound capable of converting light into heat, said organic metallic salt being reducible on heating by said reducing agent to an ink-accepting compound or to a compound which can react with a hydrophobizing agent to an ink-accepting compound, characterized in that said layer comprising an organic metallic salt comprises a hydrophobic binder in an amount between 0.00 g/m.sup.2 and 0.25 g/m.sup.2 and a hydrophilic binder in an amount between 0.00 g/m.sup.2 and 5.00 g/m.sup.2.

Abstract: An assemblage for forming a lithographic printing plate is disclosed. The assemblage contains a receiver support with a rough hydrophilic surface; a layer containing a poly(cyanoacrylate) binder; and a donor support. When the assemblage is exposed with a high intensity laser beam, the binder is transferred to the hydrophilic surface of the receiver support to produce a lithographic printing plate. The transfer requires relatively low exposure and no post processing is necessary.

Abstract: Novel thermally imageable monochrome product compositions, elements, and processes are disclosed herein. These compositions and elements characteristically have high contrast and fast imaging speeds. The thermally imageable compositions of this invention comprise (a) at least one hexaarylbiimidazole (HABI) compound, (b) at least one leuco dye, (c) at least one acid-generating compound, (d) a polymeric binder, (e) optionally at least one UV stabilizer and/or at least one inhibitor of color formation, and, in certain embodiments, (f) at least one near IR-absorbing dye. These compositions have the propensity for affording, upon thermal imaging, highly colored images having high optical density values. At the same time, background color is low in preferred compositions even after extensive exposure to ambient light. These compositions can be imagewise heated to effect color formation (i.e.

Abstract: A black thermal transfer sheet comprises a substrate film and a black dye layer formed on one surface of the substrate film. The die layer comprises dye and a binder. The dye comprises a first dye and a second dye respectively expressed by the following formulae (1) and (2): ##STR1## (where, "R.sup.1 " and "R.sup.2 " represent a substitutional or non-substitutional alkyl group, etc., "R.sup.3 " represents a hydrogen atom, etc., "R.sup.4 " represents a substitutional or non-substitutional alkyl group, etc., and "R.sup.5 " represents a substitutional or non-substitutional aminocarbonyl group, etc.; and "n" represents an integer of 1 or 2); and ##STR2## (where, "R.sup.1 ", "R.sup.2 ", "R.sup.3 " and "n" represent the same definitions as those in the formula (1), and "R.sup.6 " and "R.sup.7 " represent a substitutional or non-substitutional alkyl group, etc.).

Abstract: An image forming material is disclosed which comprises a support and provided thereon, an image forming layer and an image protective layer in that order, the image forming layer containing a colorant and a first binder resin, and the image protective layer containing fine particles in an amount of 2 to 150 mg/M.sup.2 and a second binder resin and having a thickness of 0.03 to 1.0 .mu.m, wherein an image is formed by exposing the material to a high density energy light to reduce adhesion between the image forming layer and the support and then removing the image forming layer at exposed portions.

Abstract: A color reproduction method is described using laser addressable thermal transfer donor elements which may be used to image both color proofing films and printing plates. Matched proofs and plates may be generated by direct digital address since identical transfer media are used in the respective imaging processes. In addition, each plate bears a resin image of a color that matches the color of the ink that will be used with that plate thus providing a convenient means of identification. In other words, the identity of each plate (i.e. whether it bears the y, m, c or k separation image) is immediately apparent by visual inspection, thus removing any risk of confusion and any need to provide individual plates with identification marks.

Abstract: An imaging method is provided that includes a tetraarylpolymethine dye, and bleaching this dye by bringing the dye into contact with a 4-alkyl or 4-unsubstituted 1,4-dihydropyridine derivative.

Abstract: Photosensitive donor elements, assemblages, and associated processes are described for use in a laser-induced thermal transfer process, said elements comprising in the order listed a support; a photohardenable layer comprising a binder, at least one photohardenable component, and an initiator; optionally a barrier layer; optionally a coversheet; at least one ejection layer comprising a first polymer having a decomposition temperature T.sub.1 ; at least one top layer having an outer surface and comprising (i) a second polymer having a decomposition temperature T.sub.2 and (ii) an imageable component. For photomask fabrication applications, the imageable component is preferably black. Assemblages made with these donor elements are useful for fabrication of photomasks on various photohardenable materials, including flexographic printing plates and photoresists.

Abstract: According to the present invention there is provided a method for preparing a hydrophilic surface of an aluminum lithographic base comprising the steps of roughening and anodizing a side of an aluminum foil and sealing said side of the aluminum foil with hot water within a temperature range from 70.degree. C. to 100.degree. C. for at least 5 seconds and rinsing said side of the aluminum foil with water characterized in that between said hot water treatment and said rinsing said side of the aluminum foil is treated with an aqueous silicate solution within a temperature range from 70.degree. C. to 100.degree. C. for at least 5 seconds.

Abstract: A cyan dye-donor element for thermal dye transfer comprising a support having thereon a dye layer comprising a mixture of cyan dyes dispersed in a polymeric binder, at least one of the cyan dyes having the formula: ##STR1## and at least one of the other of the dyes having the formula: ##STR2##

Abstract: Donor elements, assemblages, and associated processes are described for use in a laser-induced thermal transfer process, said elements comprising in the order listed (a) at least one flexible ejection layer comprising a first polymer having a decomposition temperature T.sub.1 and characteristic glass transition temperatures of T.sub.g.sup.0 and T.sub.g.sup.1 for unplasticized and plasticized polymer samples, respectively, wherein the tensile modulus of the flexible ejection layer(s) structure is less than or equal to 2.5 Gigapascals; (b) at least one heating layer; (c) at least one transfer layer comprising (i) a second polymer having a decomposition temperature T.sub.2, wherein T.sub.2 .gtoreq.(T.sub.1 +100.degree. C.

Abstract: A process for forming an image on a transparent or translucent substrate comprising the steps of providing an imageable element comprising a transparent or translucent glass or polymeric film having a coating of a black metal on one surface thereof, directing radiation in an imagewise distributed pattern at said black metal layer with sufficient intensity to substantially increase the light transmissivity of the medium in the irradiated region in an imagewise distributed pattern, said element having no layers comprising a thermally activated gas-generating composition. The image comprises residual black metal on the film base, and may be used for overhead transparencies, contact negatives/positives, and the like.

Abstract: An image receiving sheet having a support sheet, an intermediate layer and an image receiving layer, wherein the intermediate layer comprises a polymer and a plasticizer having at least one ester bonds and molecular weight of 700 to 3,000. Otherwise, an image receiving sheet having a support sheet and an image receiving layer wherein the image receiving layer comprises a polymer and the plasticizer. A heat sensitive ink sheet has a heat sensitive ink layer which is formed of a heat sensitive ink material comprising colored pigment and thermoplastic resin such as amorphous organic polymer. An image forming method is conducted by using the heat sensitive ink sheet and one of the image receiving sheets by area gradation by the use of a thermal head or laser beam.

Abstract: A laser-exposed thermal recording element comprising a support having thereon a pigment layer comprising a pigment dispersed in a polymeric binder, the pigment absorbing at the wavelength of a laser used to expose the element, wherein the pigment comprises the formula:Cu.sub.2-x M.sub.x (OH).sub.y R.sub.z :M'.sub.wwherein:M is at least one metal atom,M' is at least one alkali metal,R is at least one anion,w is between 0 and 2,x is between 0 and 1.5,y and z are selected to maintain charge neutrality, with the proviso that w, x and z cannot all be 0.

Abstract: A substantially non-photosensitive recording material comprising a thermosensitive element comprising a substantially light-insensitive organic silver salt, an organic reducing agent therefor in thermal working relationship therewith and a binder, on a support, characterized in that the thermosensitive element further comprises in reactive association with the light-insensitive organic silver salt and the organic reducing agent a 1,2,4-triazole compound with at least one of the nitrogen atoms having a hydrogen atom and none of the carbon atoms being part of a thione-group, said compound not being annulated with an aromatic ring system; and a thermal image recording process therefor.

Abstract: A method of making a color filter array on a first substrate having an array of pixels, comprising the steps of: depositing and patterning a photoresist layer on the substrate layer to form selected openings over pixels in the array; providing a plurality of two or more transferable colorant layers on a second substrate and positioning such transferable layers in transferable relationship with the first substrate; simultaneously transferring the colorant materials from the plurality of transferable colorant layers to the photoresist layer on the first substrate; and removing the patterned photoresist layer leaving behind the colorant materials in the position of the openings over the selected pixels.

Abstract: The present invention provides a negative-working image recording material which can be used as a lithographic printing plate for so-called direct plate making process comprising directly making plate from digital signal such as computer signal. A novel negative-working image recording material is provided, comprising a high-molecular compound having a weight-average molecular weight of from 5,000 to 400,000 and a repeating unit represented by the following general formula (I), and a substance which absorbs light to generate heat: ##STR1## wherein R.sup.1 represents a hydrogen atom, a halogen atom, a cyano group (--CN) or an alkyl group; R.sup.2 represents an alkyl group, an aralkyl group or an aromatic ring group; L.sup.1 represents a single bond or a phenylene group; L.sup.2 represents an alkylene group, an alkenylene group or an aromatic ring group; X represents a single bond, --O--, --OCO--, --COO--, --CONR.sup.3 --, --CONR.sup.3 CO--, --CONR.sup.3 SO.sub.2 --, --NR.sup.3 --, --NR.sup.3 CO--, --NR.sup.

Abstract: A thermal transfer donor element is provided which comprises a support, a light-to-heat conversion layer, an interlayer, and a thermal transfer layer. When the above donor element is brought into contact with a receptor and imagewise irradiated, an image is obtained which is free from contamination by the light-to-heat conversion layer. The construction and process of this invention is useful in making colored images including applications such as color proofs and color filter elements.

Abstract: A method for forming a lithographic printing plate requiring no fountain solution, which comprises the steps of irradiating a lithographic printing plate precursor requiring no fountain solution comprising a support having a layer for converting a laser beam to heat (first layer) and a layer having an ink-repellent surface (second layer) provided thereon in this order with the laser beam absorbable by the first layer to conduct image exposure, pressing an adhesive sheet layer on the second layer, the sheet having a surface layer adhesive to a surface of the second layer, and thereafter separating the adhesive sheet, thereby forming an image which makes it possible to perform printing requiring no fountain solution.

Abstract: A process for making a flexographic printing plate from a flexographic element having an infrared ablatable layer capable of being selectively removed by a laser beam is described.

Abstract: A dye-donor or recording element comprising a support having thereon a dye layer comprising a yellow dye in a polymeric binder, the dye having the formula: ##STR1## wherein: R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each independently represents hydrogen, halogen, hydroxy, nitro, a substituted or unsubstituted alkyl or alkoxy group of from 1 to about 6 carbon atoms, a substituted or unsubstituted phenyl group, an alkylazo group, or an arylazo group;or any two adjacent R.sup.1, R.sup.2, R.sup.3 and R.sup.4 groups may be taken together with the phenyl ring to which they are attached to form a fused ring system; andZ.sup.1 and Z.sup.2 each independently represents hydrogen or a moiety having a Hammet Sigma (meta) Constant greater than 0.3, such as cyano, esterified carboxy, amide, benzoxazole, alkylsulfonyl, arylsulfonyl; or may be taken together to form a group having a Hammer Sigma (meta) Constant greater than 0.3.

Abstract: An optical recording medium including a substrate having thereon a recording layer containing a dye precursor, a color developer reactable with the dye precursor to develop a color, and a light absorbent for converting light to heat, characterized in that the color developer is at least one compound of Formula (1):(R--NH (C.dbd.S) NH)n--Z (1)(wherein R denotes a substituted or unsubstituted alkyl, cycloalkyl, aryl, aralkyl, or alkenyl. n is an integer of 2 or more, and Z denotes a group having a valence of 2 or more.). The optical recording medium is superior in heat resistance and plasticizer resistance of the recorded image, heat resistance of background, water resistance, and moisture resistance.).

Abstract: A thermosensitive reversible color-developing and disappearing agent includes an aromatic compound having at least one group of the formula, --SO.sub.2 NHCXNH--, wherein X.dbd.O or S atom, and at least one straight chain alkyl group with 11 or more carbon atoms, and is reactive with a dye precursor in a thermosensitive recording material to thereby record colored images on the recording material upon heating imagewise, and make the colored images disappear upon heating to a temperature lower than the colored image-forming temperature.

Abstract: A production method of an ink-oozing plate for stamp having open cells, in which the production steps and the apparatus are simple, and an ink-oozing plate for stamp which can provide a sharp impress image and is conveniently used, that is, to provide a production method of a stamping plate in which a stamping plate can easily be produced with a small flashlight irradiating energy, including such a method as using a heat transfer sheet coated with a heat transfer substance which generates heat by irradiating with infrared rays and can be transferred, irradiating with infrared rays while pressing a stamp material, and coating an impress image copy with a liquid substance containing water, and thus coming to complete the production method of the ink-oozing plate for stamp of the present invention.

Abstract: A thermal transfer sheet is provided which can eliminate the need to use any apparatus, such as equipment for vapor deposition, and to provide any anchor layer for vapor deposition and can provide a good print having high brightness even on paper having low smoothness. The thermal transfer sheet comprises: a substrate sheet; and a hot-melt ink layer provided on at least one surface of the substrate sheet, the hot-melt layer containing a metallic powder having such a particle geometry that the shape is tabular, the diameter is from 8 to 20 .mu.m and the thickness is from 0.01 to 5 .mu.m.

Abstract: Dye-donor element for thermal dye transfer comprising at least one magenta dye having extremely low side absorption in the blue and red regions of the spectrum, said dye corresponding to the general formula (I) : ##STR1## wherein R.sup.1 is H, (cyclo)alkyl, or aryl; X represents the atoms completing a heterocycle; Z is an electron-withdrawing group; Y is an electron-withdrawing group or --N(R.sup.2)R.sup.3 ; R.sup.2 and R.sup.3 together represent the atoms completing a heterocycle; or R.sup.2 and R.sup.3 together represent .dbd.C(R.sup.4)R.sup.5, or each of R.sup.2 and R.sup.3 represents (same or different) (cyclo) alkyl, aryl, or an electron-withdrawing group; each of R.sup.4 and R.sup.5 (same or different) represents H, (cyclo)alkyl, aryl, a heterocycle, SO.sub.2 R.sup.6, COR.sup.6, CSR.sup.6, POR.sup.6 R.sup.7, OR.sup.8, NR.sup.8 R.sup.9, SR.sup.8, or R.sup.4 and R.sup.5 together represent the atoms completing an aliphatic ring or a heterocycle, each of R.sup.6 and R.sup.