 Spectral photosensitive dyes for photothermal graphic elements
专利摘要:
The present invention (a) photosensitive silver halides; (b) a non-photosensitive reducing silver source; (c) reducing agents for silver ions; (d) binders; And (e) Provided is a thermodegradable photothermal element comprising a support having at least one photosensitive image forming layer comprising a compound having a central nucleus of formula (I) in an amount that is photosensitive to the spectrum. Where Z is S, O, Se or NR 3 ; R 1 and R 2 represent alkyl groups having 1 to 20 carbon atoms other than carboxy-substituted alkyl; R 3 is H or an alkyl group; X and Y are thioalkyl groups having 1 to 20 carbon atoms; n is 0 to 4; m is 0 to 4; the sum of m and n is at least 1; D 1 to D 7 each independently represent a methine group, and adjacent methine groups selected from D 2 , D 3 , D 4 , D 5 and D 6 may form a cyclic group; p is 0 or 1; A − is an anion. 公开号:KR19990007902A 申请号:KR1019970707425 申请日:1996-02-29 公开日:1999-01-25 发明作者:제임스 알. 밀러；브라이언 씨. 윌렛트；도린 씨. 린치；베키 제이. 쿰메쓰 申请人:캐씨알.샘스；이메이션코포레이션； IPC主号:
专利说明:
Spectral Photosensitive Dyes for Photothermal Graphic Elements Background of the Invention Silver halide-containing photothermal graphic elements (ie heat-developing elements) that are treated by heat without liquid development have been known in the art for many years. These elements are also known as dry silver compositions or emulsions and generally include (a) a photosensitive compound that, when irradiated, generates silver atoms; (b) a non-photosensitive reducing silver source; (c) silver ions such as silver ion reducing agents (ie, developers) in non-photosensitive reducing silver sources; And (d) a support coated with a binder. The photosensitive compound is generally a photographic silver halide, which should be catalytically approximated for a non-photosensitive reducing silver source. Catalytic proximity allows optical nuclei to act as catalysts in the reduction of reducible silver sources when sunlight is exposed to light or exposed to light to generate silver atoms (also known as silver grains, silver clusters or silver nuclei). This requires a close physical relationship between these two materials. It has long been known that silver atoms (Ag 0 ) are catalysts for the reduction of silver ions, and that photosensitive silver halides can be catalytically approximated in a variety of ways with non-photosensitive reducing silver sources. Silver halides, for example, may be partially substituted by adding a halogen containing source to the reducing silver source (see, eg, US Pat. No. 3,457,075); Silver halides and reducing silver sources can be prepared in situ by simultaneously precipitation (see, eg, US Pat. No. 3,839,049). Silver halides can also be prepared outside the reaction system and added to organic silver salts. The addition of silver halide particles to photothermal graphics materials is disclosed in Research Disclosure, June 1978, section 17029. The art also reports that when silver halides are manufactured outside the reaction system, the experimenter can more precisely control the composition and size of the particles, giving more limited properties to the photothermal elements and giving better homeostasis than techniques in the reaction system. It became. Non-photosensitive reducing silver sources are compounds containing silver ions. Typically, the preferred non-photosensitive reducing silver source is a silver salt of long chain aliphatic carboxylic acid having 10 to 30 carbon atoms. Salts of behenic acid or mixtures of acids with similar molecular weights are generally used. Salts of other organic acids or other organic compounds, such as silver imidazolates, have been proposed. US 4,260,677 discloses the use of complexes of inorganic or organic silver salts as a non-photosensitive reducing silver source. In both optical and photothermal emulsions, the exposure of photographic silver halides to light produces small clusters of silver atoms (Ag 0 ). Imagewise distribution of such clusters is known in the art as latent images. Such latent images are generally invisible by conventional means. Therefore, the photosensitive emulsion must be further processed to form a visible image. This visualization is realized by the reduction of silver ions catalytically close to silver halide particles having silver atom clusters (ie latent images). This forms a black and white image. In the optical graphics element, the silver halide is reduced to form a black and white image. In photothermal graphics elements, the photosensitive silver source is reduced to form a visible black and white image, with most of the silver halides remaining as silver halides and not being reduced. The reducing agent for organic silver salts, often also referred to as developer in photothermal graphics elements, may be any compound capable of reducing silver ions to metallic silver, preferably any organic compound. At elevated temperatures, in the presence of a latent image, a non-photosensitive reducing silver source (eg, silver behenate) is reduced by a reducing agent for silver ions. As a result, a negative black and white image of a silver element is formed. Conventional optical graphic developers such as methyl gallate, hydroquinone, substituted-hydroquinone, techol, pyrogallol, ascorbic acid and ascorbic acid derivatives are useful, but they are easy to form highly reactive photothermal graphics formulations and Fogs can be formed during coating. Thus hindered phenolic developers (ie, reducing agents) have long been preferred. Since the visible image in the black and white photothermal element is typically formed entirely by the silver element (Ag 0 ), it is not easy to reduce the amount of silver in the emulsion without reducing the maximum image density. However, reducing the amount of silver is often desirable to reduce the cost of raw materials used in the emulsion and / or to improve performance. For example, toning agents may be incorporated to improve the silver color tone of photothermal graphical elements, as described in US Pat. Nos. 3,846,136, 3,994,732 and 4,021,249. Another way to increase the maximum image density in emulsions for optical and photothermal graphics without increasing the amount of silver in the emulsion layer is to incorporate dye-forming or salt-releasing compounds in the emulsion. In image formation, the dye formation or dye emitting compound is oxidized and the dye and reduced silver image are formed in the exposed area at the same time. In this way, dye-enhanced black and white silver images can be formed. Dye-enhanced black and white silver image forming elements and methods are described in US Pat. No. 5,185,231. Imaging techniques have long been recognized as clearly different from the techniques of optical graphics in the field of photothermal imaging. The element for photothermal graphics differs significantly from conventional silver halide photographic elements that require wet processing. In photothermal image elements, the visible image is formed by heat generated by the reaction of a developer incorporated in the element. Heat is essential for development and generally requires temperatures above 100 ° C. In contrast, conventional wet processing optical graphic image forming elements must be processed in an aqueous processing bath (e.g., development and fixed bath) to form a visible image, and development is typically performed at milder temperatures (e.g., 30-50 ° C). To perform. In photothermal elements, only a small amount of silver halide is used to capture light and other forms of silver (eg silver behenic acid) are used to form the image by heat. Thus silver halides are worn as catalysts for the development of non-photosensitive reducing silver sources. In contrast, conventional wet processed black and white optical graphics elements use only one type of silver, which itself converts into a silver image upon development. In addition, photothermal elements require an amount of silver halide per unit area as small as 1/100 of the amount used in conventional wet treated silver halides. Photothermal graphics systems use non-photosensitive silver salts, such as silver behenate, which participate with the developer in shaping the latent image. In contrast, optical graphics systems do not use non-photosensitive silver salts directly in the image forming process. As a result, the image in the photothermal graphic element is mainly produced by the reduction of the non-photosensitive silver source (silver behenic acid) while the image in the black and white element of the optical graphic is mainly produced by silver halide. In photothermal elements, all system chemistry is incorporated into the element itself. For example, a photothermal graphic element incorporates a developer (ie, a reducing agent for a non-photosensitive reducible silver source) into the element, but a conventional optical graphic element does not. Incorporating the developer into the photothermal graphics element can increase fog formation when coating the photothermal graphics emulsion. Even in so-called instant optical graphics, developer chemistry is physically separated from the photosensitive silver halide until development is desired. Many efforts have been made to manufacture and fabricate photothermal graphics elements that minimize fog formation during aging after coating, storage and processing. Likewise, in photothermal elements, unexposed silver halides remain inherent after development, and the elements must stabilize for further development. In contrast, silver halides should be removed from the optical graphics element after development to prevent further image formation (ie, fixing step). Binders in photothermal elements may vary and many binders are effective for making such elements. In contrast, optical graphics elements are almost limited to hydrophilic colloidal binders such as gelatin. Because photothermal graphics elements require heat treatment, different considerations arise in their fabrication and use and pose completely different problems. In addition, the effects of additives (e.g. stabilizers, anti-fog agents, speed accelerators, photosensitizers, ultra-sensitizers, etc.) that can directly affect the image forming process are determined by whether they are incorporated into the photothermal or element. Can be changed accordingly. Because of these and other differences, conventional halogen halides may exhibit completely different behavior in photochromic elements, where the chemistry of which additives exhibit specific effects are latent is much more complex. For example, it is common to produce various types of fog when antifog agents for silver halide systems are incorporated into photothermal elements. Differences between photothermal graphics and optical graphics elements are described in Imaging Processes and Materials (Neblett's Eighth Edition); J. Sturge et al. Ed; Van Nostrand Reinhold: New York, 1989; Chapter 9 and in Unconventional Imaging Processes; E. Brinckman et al. Ed; he Focal Press: London and New York: 1978; 74-75 pages] It is well known that many cyanines and related dyes can impart spectral sensitivity to gelatinous silver halide elements. The wavelength of maximum sensitivity is a function of the dye wavelength of maximum light absorption. Many of these dyes provide spectral sensitivity in the photothermal graphics media, but often dye sensitization is inefficient and it is not possible to transfer the performance of the dye in the gelatinous silver halide element to the photothermal element. Emulsion preparation procedures and the chemical environment of the photothermal elements are much coarser than those of the colloidal silver halide elements. When fatty acids and fatty acid salts are present in large surface areas, surface deposition of the photosensitive dye on the silver halide surface is limited and the photosensitive dye can be removed from the surface of the silver halide particles. The above problems are exacerbated if the pressure, temperature, pH and solubility change significantly during the preparation of the photothermal graphics formulation. Thus, the photosensitization of dyes that perform well in gelatinous silver halide elements is often inefficient in photothermal graphics formulations. In general, merocyanine dyes have been found to be superior to cyanine dyes in photothermal graphics formulations, as disclosed, for example, in British Patent 1,325,312 and US Patent 3,719,495. Attempts to impart photosensitivity at the red end of the spectrum have resulted in somewhat varied results. In particular, attempts to impart photosensitivity to photothermal graphics elements at the red end and in the vicinity of infrared light using cyanine dyes have resulted in inconsistencies with the performance of the dyes in conventional colloidal silver halide elements. Therefore, those skilled in the art are working to modify the merocyanine to achieve the desired level of performance. However, there are few merocyanines capable of absorbing wavelengths larger than 750 nm, and it is not clear whether dyes absorbing such wavelengths can impart photosensitivity to photothermal elements. Recently, as a source for the output of image data electrically stored on a photosensitive film or paper, a relatively high power semiconductor light source, in particular a laser diode emitting in the red and near infrared region of the electromagnetic spectrum, is commercially available and is becoming more and more widespread. This increases the need for high quality image forming articles having photosensitivity in the near infrared region, and the need to provide photosensitivity to photothermal graphic elements in harmony with such exposed light sources. In particular, it must be matched with a source emanating from a wavelength in the range of 780 to 850 nm, which is close to the extremes of the photosensitive dye industry. Such articles are prominently used in laser scanning. Although spectral photosensitive dyes for photothermal graphics elements currently absorbing the 780-850 nm wavelength range are known, dyes with improved storage stability, sensitivity, contrast and low Dmin are still required in photothermal graphics. U.S. Patents 5,108,662 and 4,975,221 and J. R. J.R. Lenhard [J. Phys. Chem. 1993, 97, 8269-8280, describe spectral photosensitized photographic elements over infrared light using heptamethine spectral photosensitive dyes of various structures. These patents all disclose heptametin dyes in which one of the aromatic rings in the dye molecular structure can be substituted with one or more thioalkyl groups (eg, thiomethyl). Typically at least one thiomethyl substituent is present at position 5 of the fused phenyl ring of the dye. Neither of these patents specifically refers to photothermal elements, but both refer to US Pat. No. 4,619,892, which describes a multilayer infrared photosensitive optical graphic element and mentions a hue photothermal graphical multilayer infrared photosensitive element. British Patent 425,417 discloses an optical graphic element spectrally photosensitive with a carboxycyanine dye, including a benzothiazole heptametin dye substituted with various groups including alkoxy and thioalkyl (e.g., dyes 6 and 7 of BP 425,417). . These dyes are disclosed for use in optical graphics systems. Summary of the Invention The present invention provides a thermally developable photothermal graphic element that can provide high luminous flux, high resolution, stable high density images, and excellent sharpness. The thermally developable photothermal graphic element of the present invention (a) photosensitive silver halides; (b) a non-photosensitive reducing silver source; (c) reducing agents for silver ions; (d) binders; And (e) a support having at least one photosensitive image forming layer comprising a compound having a central nucleus of formula (I) in an amount that is photosensitive to the spectrum. Where Z is S, O, Se or NR 3 ; R 1 and R 2 represent an alkyl group having 1 to 20 carbon atoms other than carboxy-substituted alkyl, preferably an alkyl group having 1 to 8 carbon atoms, most preferably an ethyl group; R 3 is H or an alkyl group (preferably an alkyl group having 1 to 4 carbon atoms, most preferably a methyl or ethyl group); X and Y are thioalkyl groups having 1 to 20 carbon atoms; n is 0 to 4; m is 0 to 4; the sum of m and n is at least 1, preferably 1, 2, 3, or 4; D 1 to D 7 each independently represent a methine group, and adjacent methine groups selected from D 2 , D 3 , D 4 , D 5 and D 6 may form a cyclic group; p is 0 or 1; A − is an anion. It is preferable that the compound which photosensitizes the spectrum has a central nucleus of following formula (II). Where X is independently a thioalkyl group having 1 to 20 carbon atoms; D 1 to D 7 each independently represent a methine group, and adjacent methine groups selected from D 2 , D 3 , D 4 , D 5 and D 6 may form a cyclic group; n is independently 0, 1 or 2, and the sum of all n is 1 or more, preferably 1, 2, 3 or 4; R 1 and R 2 represent an alkyl group having 1 to 20 carbon atoms other than carboxy-substituted alkyl, preferably an alkyl group having 1 to 8 carbon atoms, most preferably an ethyl group; A − is an anion. Anions include, but are not limited to, those known in the art, such as, but not limited to, I, Br, Cl, ClO 4 , paratoluenesulfonate, PECHS, acid anions, solubility functional anions (eg perfluorinated alkylsulfonyl metes and amides), and the like. Any of the common anions used in dye chemistry is useful. It is most preferable that the compound which is exposed to the spectrum has a central nucleus of the formula (III). Where X is independently a thioalkyl group having 1 to 20 carbon atoms; n is independently 0, 1 or 2, and the sum of all n is 1 or more; R 1 and R 2 represent an alkyl group having 1 to 20 carbon atoms other than carboxy-substituted alkyl, preferably an alkyl group having 1 to 8 carbon atoms, most preferably an ethyl group; A − is an anion. The nucleus of the above-described structural formulas may have additional substituents such as carboxy, sulfoxy, alkyl, alkoxy and the like, which are generally known in the cyanine dye technique. It has been found that the immobilized thioalkyl substituted cyanine dyes having the core of formula (I), (II) or (III) have unexpected properties which are particularly advantageous both in the spectral amplification and fabrication of photothermal graphic image forming elements. Specifically, the dyes provide the elements of the present invention with high luminous flux (ie, photosensitivity), excellent contrast, improved Dmin, and low fog formation. In addition, in the fabrication of photothermal elements, the use of these dyes extends the shelf life of the coating emulsions, resulting in less sensitivity changes in the emulsion when coating after a period of time. Surprisingly, the rates, Dmin, fog formation and contrast provided by thioalkyl substituted dyes having a core of formula (I), (II) or (III) have similar structures but are provided by unfixed dyes and immobilized dyes having no thioalkyl groups Much better than speed and contrast. This is especially true when the dye is used in combination with a superphotosensitive compound. Photothermal graphical elements used in the present invention are preferably exposed to or simultaneously with image-wise exposure for about 1 second to about 2 minutes under substantially water free conditions at temperatures of about 80 ° C. to about 250 ° C. (176 ° F. to 482 ° F.) When thermally developed later, a black and white silver image is obtained. The reducing agent for the non-photosensitive silver source can be any conventional optical graphics developer such as methyl gallate, hydroquinone, substituted hydroquinone, catechol, pyrogallol, ascorbic acid and ascorbic acid derivatives. However, it is preferred that the reducing agent is a hindered phenol developer. Reducing agents may also include compounds that can be optionally oxidized to form or release dyes. Preferred dye forming materials are leuco dyes. The present invention also provides a method of forming a visible image by first exposing the photothermal graphic elements of the invention described herein above to electromagnetic radiation and then heating. Photothermal elements of the invention can be used to produce monochrome monochrome or full color images. The photothermal graphics elements of the present invention are, for example, in conventional black and white or color photography, in electronically generated black and white or color hardcopy recordings, in the graphic arts area (e.g., photographers), in digital processing and in digital radiation light. It can be used for graphic image formation. The elements of the present invention provide a high luminous flux, provide a strongly absorbing black and white or color image, and provide a dry and rapid process. As used herein, heating in substantially water free conditions means heating to a temperature of 80 ° C to 250 ° C. The term substantially free of water means that the reaction system is in equilibrium with water in the air and that no water is specifically or actually supplied to the urea from the outside to induce or promote the reaction. These conditions are T.H. James, T.H. James, The Theory of the Photographic Process, 4th edition, Macmillan 1977, p. 374. As used herein, the term photothermal graphic element means a structure comprising one or more photothermal graphics emulsion layers and any support, top coating layer, image receiving layer, blocking layer, antihalation layer, sublayer or avalanche layer, and the like, Emulsion layer means one layer of a photothermal graphic element containing a non-photosensitive, reducing silver source and photosensitive silver halide, and the spectral ultraviolet region means a spectral region of about 400 nm or less, preferably about 100 nm to about 400 nm. . More preferred spectral ultraviolet regions range from about 190 nm to about 400 nm. The term short wavelength visible region of the spectrum means a spectral range of about 400 nm to about 450 nm, the infrared region of the spectrum means about 750 nm to about 1400 nm, and the visible region of the spectrum means about 400 nm to about 750 nm. Meaning, the red region of the spectrum means about 640 nm to about 750 nm. Preferred red regions of the spectrum are about 650 nm to about 700 nm. As is known in the art, substituents are not only acceptable, but are often preferred and substitutions of thioalkyl substituted sensitizing dye compounds used in the present invention are envisaged. When the general structure is represented as a compound having a central nucleus of a given formula, any substituent or atom represented in the formula that does not change the binding structure of the formula unless the substituent is stated to be excluded (eg, carboxy-substituted alkyl In the formula). For example, where there is a polymethine chain immobilized between two defined benzothiazole groups, the substituents may be located on the chain, on the ring in the chain, or on the benzothiazole group, but the conjugation of the chain Can be changed and the atoms shown in the chain or in the benzothiazole group cannot be substituted. When representing a general structure as a general formula, it does not specifically allow substitution of such a wide range of structures, but only ordinary substituents recognized by those skilled in the art as equivalent or advantageous properties (e.g., absorption wavelength shift, solubility change, molecular stabilization, etc.). It is. To simplify the discussion and citation of specific substituents, the terms groups and moieties are used to distinguish between chemical species that may be substituted and chemical species that may not be substituted. Thus, when describing substituents using the term group or aryl group, such substituents include the use of additional substituents in addition to the literal definition of the base group. When describing substituents using the term moiety, only unsubstituted groups are included. For example, an alkyl group may be a pure hydrocarbon alkyl group such as methyl, ethyl, propyl, t-butyl, cyclohexyl, iso-octyl, octadecyl and the like, as well as alkyl substituents containing substituents known in the art, such as hydroxyl, Alkoxy, phenyl, halogen atoms (F, Cl, Br and I), cyano, nitro, amino, carboxy and the like. For example, alkyl groups include ether groups (eg, CH 3 -CH 2 -CH 2 -O-CH 2- ), haloalkyl, nitroalkyl, carboxyalkyl, hydroxyalkyl, sulfoalkyl, and the like. On the other hand, the alkyl moiety is limited to containing only pure hydrocarbon alkyl chains such as methyl, ethyl, propyl, t-butyl, cyclohexyl, iso-octyl, octadecyl and the like. Substituents that react with active ingredients, such as very strong electrophilic or oxidative substituents, are of course not excluded by those skilled in the art because they are not inert or harmless. Other aspects, advantages and advantages of the invention will be apparent from the description, the examples, and the claims. The present invention relates to cured and uncured thioalkyl substituted cyanine dyes and their use as spectral sensitive dyes in photothermal graphical elements. Dyes having a core of formula (I), (II) or (III) are particularly effective photosensitizers for photothermal graphics elements, giving surprisingly good photosensitivity to the red and near infrared regions and excellent Dmin and fog levels when compared to cyanine dyes having other similar structures. see. The stability provided by using such dyes also greatly extends shelf life stability. In many cases, it has been found that the compounds of the present invention impart twice or more greater photosensitivity than those obtained using similar compounds having no thioalkyl groups. The dyes are particularly useful for photosensitizing photothermal graphics elements in the range from 720 to 900 nm, more particularly in the range from 780 to 850 nm, to provide photothermal elements that are well coordinated with a source emanating from the region, for example an infrared emitting diode (IRED). . Preferred dyes are hecametine cyanine dyes which are well known and are described in the literature, for example in Hamer, Cyanine Dyes and Related Compounds, Interscience 1964, as compounds and near infrared spectral photosensitizers for conventional photographic silver halide emulsions. . Synthesis of heptmethine cyanine is described, for example, in Fisher and Hamer [J. Chem. Soc. 1933, 189. For the existence and synthesis of dyes according to the present invention, see the aforementioned US Pat. Nos. 5,108,662 and 4,975,221 and Research Disclosure, September 1, 1978, Section 17363. The preparation of infrared absorbing dyes typically requires the presence of long chains (eg, heptamethine chains) in the color system. However, when the long chain increases, a decrease in dye stability occurs incidentally. Processing by incorporating tetrahydronaphthyl groups into the polymethine chain of the cyanine dye having two benzothiazole groups has been found to increase spectral photosensitivity and shelf life in coated films compared to similarly stored unfixed dyes. . Surprisingly, adding thioalkyl groups to at least one of two aromatic groups (e.g., benzothiazole groups) provides not only improved Dmin, fog formation and improved shelf life, but also photosensitivity compared to dyes lacking these properties. This has also been found to increase. Compounds having a core of formula (I), (II) or (III) represent such dyes. As demonstrated in the examples below, we have succeeded in applying the technique to photothermal graphics elements. Compounds having Formula (I), (II) or (III) can be incorporated into photothermal emulsions as spectral photosensitizers in conventional manner. Generally, the concentration of the compound having the core of formula (I), (II) or (III) will be from 2 x 10 -8 to 4 x 10 -2 moles of photosensitive dye per mole of silver in the emulsion. It is found that the practice of the present invention can surprisingly provide a high degree of photosensitivity that is almost equivalent to the photosensitivity provided by the increased amounts in small amounts. This is particularly unexpected and once again pointed out as the difference between photography and photothermal because one or more of the aforementioned references suggesting the use of thioalkyl substituted infrared dyes at high concentrations degrades spectral photosensitivity in the infrared. A preferred range in the practice of the invention is a narrow range of 2 x 10 -5 to 1 x 10 -3 moles of photosensitive dye per mole of silver, with a photosensitive dye of 5 x 10 -5 to 8 x 10 -4 per mole of silver The narrow range of moles is most preferred. Representative spectral photosensitive compounds (dyes 1, 2, 3 and 4) useful in the present invention are shown below. These are presented as examples and are not intended to be limiting. Photosensitive silver halides As noted above, the present invention includes photosensitive silver halides. The photosensitive silver halide may be any photosensitive silver halide such as silver bromide, silver iodide, silver chloride, silver bromoiodide, silver chromobromoiodide, silver chlorobromide and the like. The photosensitive silver halide may be added to the emulsion in any manner so long as it is located catalytically close to the organic silver compound serving as a reducing silver source. Silver halides may be in any photosensitive form, including but not limited to tetragon, octahedron, tetrahedron, tetragonal, tetrahedron, other polyhedron, and the like, on which crystals can be epitaxially grown. Silver halide granules can have a constant halide yield and can have varying halide content, such as, for example, the ratio of silver bromide and silver iodide is constantly changing, or a separation with a separated core having one halide ratio and a different halide ratio. It may be of the core-shell type with a shell. Silver halide granules useful for photothermal graphics elements and methods for making such materials are described in US Pat. No. 5,382,504. Particular preference is given to core-shell silver halide granules having an iridium doped core. Iridium doped core-shell granules of this type are described in US patent application Ser. No. 08 / 239,984, filed May 9, 1994. Silver halides may be prepared outside the reaction system (ie, formed in advance) and mixed with organic silver salts in the binder prior to use in preparing the coating solution. Silver halides may be previously formed according to any method, for example, US Pat. No. 3,839,049. For example, it is effective to blend silver halides and organic silver salts using homogenizers for extended periods of time. This type of material is often called a preformed emulsion. Methods of making such silver halides and organic silver salts and the manner of blending them are described in Research Disclosure, June 1978, 17029; US Patents 3,700,458 and 4.076,539; And Japanese Patent Application Nos. 13224/74, 42529/76, and 17216/75. The invention is preferably carried out using preformed silver halide granules of less than 0.10 nm in infrared photosensitive photothermal graphical elements. The number average particle size of the granules is preferably 0.01 to 0.09 nm. It is also preferable to use iridium doped silver halide granules and iridium doped core-shell silver halide granules as disclosed in the aforementioned U.S. Patent Application Serial Nos. 08 / 072,153 and 08 / 239,984. When preformed silver halide emulsions are used in the elements of the invention, they may or may not be washed to remove soluble salts. When washing, the soluble salts can be removed by cold-condensation and filtration or the emulsion can be coagulated washed by the procedures described in US Pat. Nos. 2,618,556, 2,614,928, 2,565,418, 3,241,969 and 2,489,341. It is also effective to use an in situ process, ie a process in which a halogen containing compound is added to the organic silver salt to partially convert the silver of the organic silver salt into silver halide. The photosensitive silver halide silver used in the present invention is in the range of about 0.005 mol to about 0.5 mol, preferably about 0.01 mol to about 0.15 mol, more preferably 0.03 mol to 0.12 mol per mole of non-photosensitive reducing silver salt or as another parameter. It can be used in the range of 0.5 to 15% by weight of the emulsion (photosensitive layer), preferably in the range of 1 to 10% by weight of the emulsion layer. The silver halide halide used in the present invention may be chemically photosensitive in a manner similar to that used to photosensitive conventional wet processed silver halide photographic materials or state-of-the-art thermally developable photothermal graphics elements. For example, using chemical photosensitizers, such as sulfur, selenium, tellurium, and the like, or compounds containing gold, platinum, palladium, ruthenium, rhodium, iridium, etc., reducing agents, for example tin halides, and the like, or combinations thereof It can be chemically exposed. Detailed procedures are provided by T.H. James's Theory of the Photographic Process, 4th edition, chapter 5, pages 149-169. Suitable chemical photosensitization procedures can also be found in Shepard, US Pat. No. 1,623,499, Waller, US Pat. No. 2,399,083, McVeigh, US Pat. No. 3,297,447, and Dunn, US Pat. No. 3,297,446. It is disclosed in the call. Supersensitive In order to increase the speed of the photothermal graphic element to the highest level and further improve the photosensitivity, a superphotosensitive agent is often used. Any superphotosensitive agent that increases photosensitivity can be used. For example, infrared photosensitive agents described in US patent application Ser. No. 08 / 091,000 (filed Jul. 13, 1993) are preferred and include heteroaromatic mercapto compounds or heteroaromatic disulfide compounds of the formula: Ar-S-M Ar-S-S-Ar In the formula, M represents a hydrogen atom or an alkali metal atom. In the above-mentioned superphotoresist, Ar represents a heteroaromatic ring or a fused heteroaromatic ring containing at least one of nitrogen, sulfur, oxygen, selenium or tellurium atoms. Heteroaromatic rings are benzimidazole, naphthymidazole, benzothiazole, naphthothiazole, benzoxazole, naphthazole, benzo selenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole Preference is given to tetrazole, triazine, pyrimidine, pyridazine, pyrazine, pyridine, purine, quinoline or quinazolinone. However, other heteroaromatic rings may be included within the scope of the present invention. The heteroaromatic ring may also contain substituents, examples of preferred substituents being halogen (eg Br and Cl), hydroxy, amino, carboxy, alkyl (eg one or more, preferably one to four carbon atoms). And alkoxy (eg, having one or more, preferably 1 to 4 carbon atoms). Preferred superphotosensitive agents are mercapto-substituted benzimidazoles, benzoxazoles and benzothiazoles, such as 5-methyl-2-mercaptobenzimidazoles, 2-mercaptobenzimidazoles, 2-mercaptobenzoxazoles, 2-mercaptobenzothiazole and 2-mercapto-5-methylbenzimidazole. Other mercapto-substituted, heteroaromatic compounds that can be used as superphotoresist include 6-ethoxy-2-mercaptobenzothiazole, 2,2'-dithiobis- (benzothiazole), 3-mercapto-1 , 2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2-mercaptoimidazole, 1-ethyl-2-mercaptobenzimidazole, 2-mercaptoquinoline, 8-mer Captopurine, 2-mercapto-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol, 2,3,5,6-tetrachloro-4-pyridinethiol, 4-amino-6 -Hydroxy-2-mercaptopyrimidine monohydrate, 2-amino-5-mercapto-1,3,4-thiadiazole, 3-amino-5-mercapto-1,2,4-triazole , 4-hydroxy-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-diamino-2-mercaptopyrimidine, 2-mercapto-4-methylpyrimidine hydrochloride 3 Mercapto-5-phenyl-1,2,4-triazole, 2-mercapto-4-phenyloxazole. Most preferred photosensitizers are 2-mercaptobenzimidazole, 2-mercapto-5-methylbenzimidazole, 2-mercaptobenzothiazole and 2-mercaptobenzoxazole. Superphotoresists are generally used in amounts of at least 0.001 moles of photosensitizer per mole of silver in the emulsion layer. A range of 0.001 to 1.0 mole of compound per mole of silver is conventional, and 0.01 to 0.3 mole of compound per mole of silver is preferred. Non-photosensitive reducing silver source The present invention includes a non-photosensitive reducing silver source. The non-photosensitive reducing silver source that may be used in the present invention may be any compound containing a source of reducing silver ions. Preference is given to silver salts which are relatively stable to light and which form silver images when heated to 80 ° C. or higher in the presence of an exposed photocatalyst (eg silver halide) and a reducing agent. Preference is given to silver salts of organic acids, in particular silver salts of long chain fatty carboxylic acids. The chain typically contains 10 to 30, preferably 15 to 28 carbon atoms. Suitable organic silver salts include silver salts of organic compounds having carboxyl groups. Examples of the above include silver salts of cycloaliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Examples of silver salts of aliphatic carboxylic acids include silver behenic acid, silver stearate, silver oleate, silver laurate, silver caprate, silver myristate, silver palmitate, silver malate, silver fumarate, silver tartarate, silver Furoate, silver linoleate, silver butyrate, silver camphorate and mixtures thereof and the like. Silver salts that can be substituted with halogen atoms or hydroxyl groups can also be used effectively. Preferred examples of silver salts of aromatic carboxylic acids and other carboxyl group-containing compounds include silver benzoates, silver substituted benzoates, such as silver 3,5-dihydroxybenzoate, silver o-methyl-benzoate, silver m -Methylbenzoate, silver p-methylbenzoate, silver 2,4-dichloro-benzoate, silver acetamidobenzoate, silver p-phenylbenzoate, etc., silver gallate, silver tannate, silver phthalate, silver tere Phthalates, silver salicylates, silver phenylacetates, silver pyromellilates, silver salts of 3-carboxymethyl-4-methyl-4-thiazoline-2-thione as described in US Pat. No. 3,785,830; And silver salts of aliphatic carboxylic acids containing thioether groups as described in US Pat. No. 3,330,663. Silver salts of compounds containing mercapto or thion groups and derivatives thereof can also be used. Preferred examples of such compounds include silver salts of 3-mercapto-4-phenyl-1,2,4-triazole, silver salts of 2-mercaptobenzimidazole, silver salts of 2-mercapto-5-aminothiadiazole, Silver salt of 2- (2-ethylglycolamido) benzothiazole, silver salt of thioglycolic acid, such as silver salt of S-alkylthioglycolic acid, wherein the alkyl group has from 12 to 22 carbon atoms, dithiocarboxyl Acid silver, for example silver salt of dithioacetic acid, silver salt of thioamide, silver salt of 5-carboxy-1-methyl-2-phenyl-4-thiopyridine, silver salt of mercaptotriazine, 2-mercaptobenzoxazole Silver salts, silver salts as described in US Pat. No. 4,123,274, for example silver salts of 1,2,4-mercaptothiazole derivatives, for example, 3-amino-5-benzylthio-1,2,4-thia Silver salts of sol and silver salts of thion compounds, for example silver salts of 3- (2-carboxyethyl) -4-methyl-4-thiazoline-2-thione as disclosed in US Pat. No. 3,201,678 It includes. In addition, the silver salt of the compound containing an imino group can be used. Preferred examples of this compound include silver salts of benzotriazole and its substituted derivatives, such as silver methylbenzotriazole and silver 5-chlorobenzotriazole, such as 1,2,4- as disclosed in US Pat. No. 4,220,709. Silver salt of triazole or 1-H-tetrazole; And silver salts of imidazole and imidazole derivatives. Silver salts of acetylene can also be used. Silver acetylides are described in US Pat. Nos. 4,761,361 and 4,775,613. It turns out that it is convenient to use van soap. A preferred example of silver half soap is an equimolar blend of silver behenic acid and behenic acid, which is about 14.5% by weight silver solids in the blend and is prepared by precipitation from a commercially available aqueous sodium salt solution of behenic acid. The transparent sheet element produced on the transparent film backing requires a transparent coating. To this end, behenic acid containing less than about 15% free behenic acid and about 22% silver is analyzed to use complete soaps. The methods used to prepare silver soap emulsions are well known in the art and include Research Disclosure, April 1983, section 22812, Research Disclosure, October 1983, 23419, and US Pat. No. 3,985,565. Is disclosed. Silver halides and non-photosensitive reducing silver sources that determine the starting point for development should be catalytically approximated. That is, the response must be related. Catalytically approximate or associated reactions mean that they must be present in the same layer, in adjacent layers or in layers separated from each other by intermediate layers having a thickness of less than 1 μm. The silver halide and the non-photosensitive reducing silver source are preferably present in the same layer. Fluorescent silver sources generally comprise about 5 to about 70 weight percent of the emulsion layer. It is preferably present at about 10 to about 50% by weight of the emulsion layer. Reducing Agents for Non-Photosensitive Reducing Silver Sources When used in black and white photothermal elements, the reducing agent for organic silver salts may be any compound capable of reducing silver ions to metallic silver, preferably organic compounds. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful but hindered bisphenol reducing agents are preferred. A wide range of reducing agents have been disclosed with dry silver systems, including amidoxime, such as phenylamidoxin, 2-thienylamidoxim and p-phenoxy-phenylamidoxime; Azines such as 4-hydroxy-3,5-dimethoxybenzaldehydeazine; Blends of aliphatic carboxylic acid aryl hydrazine and ascorbic acid, such as 2,2'-bis (hydroxymethyl) propionyl-β-phenylhydrazide in combination with ascorbic acid; Blends of polyhydroxybenzenes and hydroxylamines; Redoxtones and / or hydrazines such as hydroquinone and bis (ethoxyethyl) hydroxylamine, piperidinohexose riductone or formyl-4-methylphenylhydrazine; Hydroxyamic acid, such as phenylhydroxyamic acid, p-hydroxyphenylhydroxylamine acid and o-alaninehydroxyamic acid; Combinations of azine and sulfonamidophenols, such as p-benzenesulfonamidophenol or 2,6-dichloro-4-benzenesulfonamidophenol and phenothiazine; α-cyanophenylacetic acid derivatives such as ethyl α-cyano-2-methylphenyl-acetate, ethyl α-cyano-phenylacetate; Combinations of bis-o-naphthol and 1,3-dihydroxybenzene derivatives, such as 2,4-dihydroxybenzophenone or 2,4-dihydroxyacetophenone; 5-pyrazolone, such as 3-methyl-1-phenyl-5-pyrazolone; Redoxtones such as dimethylaminohexose deducton, anhydrodihydroaminohexose deducton and anhydrodihydro-piperidone-hexose deductone; Sulfonamidophenol reducing agents such as 2,6-dichloro-4-benzene-sulfonamidophenol and p-benzenesulfonamidophenol; Indan-1,3-dione, such as 2-phenylindan-1,3-dione; Chroman, for example 2,2-dimethyl-7-t-butyl-6-hydroxy-chroman; 1,4-dihydropyridine, for example 2,6-dimethoxy-3,5-dicarbethoxy-1,4-dihydropyridine; Ascorbic acid derivatives such as 1-ascorbyl palmitate ascorbyl stearate, unsaturated aldehydes and ketones; Particular 1,3-indanedione and 3-pyrazolidone (phenidone) are included. A hindered bisphenol developer is a compound that contains only one hydroxy group in a given phenyl ring and one or more additional substituents in the olso position to the hydroxy group. This is different from conventional photographic developers that contain two hydroxy groups (eg hydroquinones) in the same phenyl ring. The hindered phenol developer may contain one or more hydroxy groups located at different phenyl rings. The hindered phenol developer is, for example, vinaphthol (i.e. dihydroxyvinaphthyl), biphenol (i.e. dihydroxybiphenyl), bis (hydroxynaphthyl) methane, bis (hydroxyphenyl) Methane, hindered phenols and naphthol. Non-limiting examples include bis-o-naphthol, such as 2,2'-dihydroxy-1-binafyl, 6,6'-dibromo-2,2'-dihydroxy-1,1'-ratio Naphthyl and bis (2-hydroxy-1-naphthyl) methane. See column 6, lines 12-13 of US Pat. No. 5,262,295, which is incorporated herein by reference for further compounds. Non-limiting examples of biphenols include 2,2'-dihydroxy-3,3'-di-t-butyl-5,5-dimethylbiphenyl; 2,2'-dihydroxy-3,3 ', 5,5'-tetra-t-butylbiphenyl; 2,2'-dihydroxy-3,3'-di-t-butyl-5,5'-dichlorobiphenyl; 2- (2-hydroxy-3-t-butyl-5-methylphenyl) -4-methyl-6-n-hexylphenol; 4,4'-dihydroxy-3,3 ', 5,5'-tetra-t-butylbiphenyl; And 4,4'-dihydroxy-3,3 ', 5,5'-tetramethylbiphenyl. Non-limiting examples of bis (hydroxynaphthyl) methane include 2,2'-methylene-bis (2-methyl-1-naphthol) methane. See column 6, lines 14-16 of US Pat. No. 5,262,295, which is incorporated herein by reference for further compounds. Bis (hydroxyphenyl) methane Non-limiting examples include bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane (CAO-5); 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane (Permanax (trade name) or Nonox (trade name)); 1,1'-bis (3,5-tetra-t-butyl-4-hydroxy) methane; 2,2-bis (4-hydroxy-3-methylphenyl) -propane; 4,4-ethylidene-bis (2-t-butyl-6-methylphenol); And 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane. See column 6, line 8 of US Pat. No. 5,262,295, which is incorporated herein by reference for further compounds. Non-limiting examples of sterically hindered phenols include 2,6-di-t-butylphenol; 2,6-di-t-butyl-4-methylphenol; 2,4-di-t-butylphenol; 2,6-dichlorophenol; 2,6-dimethylphenol; And 2-t-butyl-6-methylphenol. See column 6, lines 17-20 of US Pat. No. 5,262,295, which is incorporated herein by reference for further compounds. The reducing agent should be present at 1 to 10% by weight of the image forming layer. In a multilayer element, a slightly higher amount of about 2-15% may be desirable if the reducing agent is added to a layer other than the emulsion layer. Binder Photosensitive silver halides, non-photosensitive reducing silver sources, reducing agents and any other additives used in the present invention are generally added to one or more binders. The binder (s) that can be used in the present invention can be used individually or in combination with each other. The binder is preferably selected from natural and synthetic resins that are polar enough to retain other components in the polymeric material, such as a solution or suspension. Representative hydrophilic binders are transparent or translucent hydrophilic colloids. Examples of hydrophilic binders include proteins such as natural substances such as gelatin, gelatin derivatives, cellulose derivatives, and the like; Photosaccharides such as starch, Arabic gum, pullulan, dextrin and the like; And water soluble polyvinyl compounds such as synthetic polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, acrylamide polymers and the like. Another example of a hydrophilic binder is a vinyl compound dispersed in latex form that is used for the purpose of increasing the dimensional stability of an optical graphic element. Examples of representative hydrophobic binders are polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, cellulose acetate, polyolefins, polyesters, polystyrenes, polyacrylonitrile, polycarbonates, methacrylates, copolymers, maleic anhydride ester aerials Copolymers, butadiene-styrene copolymers, and the like. Particular preference is given to polyvinyl acetals such as polyvinyl butyral and polyvinyl formal and vinyl polymers such as polyvinyl acetate and polyvinyl chloride. The binder may be hydrophilic or hydrophobic but is preferably hydrophobic in the silver containing layer. Optionally such polymers can be used in two or more combinations. The binder is preferably used at a level of about 30 to 90% by weight of the emulsion layer, more preferably at a level of about 45 to 85% by weight. If the portion and activity of the reducing agent for the non-photosensitive reducing source of silver requires a particular development time and temperature, the binder must be able to withstand such conditions. In general, the binder preferably does not decompose or damage its structure at 121 ° C. (250 ° F.) for 60 seconds and more preferably does not decompose or damage its structure at 177 ° C. (350 ° F.) for 60 seconds. The polymeric binder is used in an amount sufficient to retain the components dispersed therein, that is, in an amount within a range effective for acting as a binder. Effective ranges may be appropriately determined by those skilled in the art. Photothermal Graphic Formulations Formulations for the photothermal emulsion layer may be binders, photosensitive silver halides, non-photosensitive reducing silver sources, reducing agents for non-photosensitive reducing silver sources, and optional additives such as inerts such as toluene, 2-butanone, or tetrahydrofuran. It can be prepared by dissolving and dispersing in a solvent. It is highly desirable to use toners or derivatives thereof that improve the image but is not essential to the elements of the present invention. The toner may be present in an amount of about 0.01 to 10% by weight of the emulsion layer, with about 0.1 to 10% by weight being preferred. Toner is disclosed in U.S. Patent No. 3,080,254; Compounds well known in photothermal graphics techniques, as shown in 3,847,612 and 4,123,282. Examples of toners include phthalimide and N-hydroxyphthalimide; Cyclic imides such as succinimide, pyrazolin-5-one, quinazolinone, 1-phenylurazol, 3-phenyl-2-pyrazolin-5-one and 2,4-thiazolidinedione; Naphthalimide, such as N-hydroxy-1,8-naphthalimide; Cobalt complexes, such as cobalt hexamine trifluoroacetate; Mercaptans such as 3-mercapto-1,2,4-triazole, 2,4-dimercapto-pyrimidine, 3-mercapto-4,5-diphenyl-1,2,4-triazole and 2,5-dimercapto-1,3,4-thiadiazole; N- (aminomethyl) aryldicarbodiimide, such as (N, N-dimethyl-aminomethyl) phthalimide, and N- (dimethylaminomethyl) naphthalene-2,3-dicarboximide; Combinations of blocked pyrazoles, isotyuronium derivatives and certain photobleaching agents, for example N, N'-hexamethylene-bis (1-carbamoyl-3,5-dimethylpyrazole), 1,8- (3, 6-diazaoctane) bis (isothiuronium) -trifluoroacetate and 2- (tribromomethylsulfonyl benzothiazole); Merocyanine dyes such as 3-ethyl-5-[(3-ethyl-2-benzothiazolinylidene) -1-methyl-ethylidene] -2-thio-2,4-o-azolidinedione; Phthalazinone, phthalazinone derivatives, or metal salts or derivatives thereof such as 4- (1-naphthyl) phthalazinone, 6-crophthalazinone, 5,7-dimethoxyphthalazinone and 2,3 -Dihydro-1,4-phthalazinedione; A combination of phthalazine and one or more phthalic acid derivatives, such as phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride, quinazolinedione, benzoxazine or naphthoxazine derivatives; Rhodium complexes, such as ammonium hexachlororodate (III), rhodium bromide, rhodium nitrate and potassium hexachlororodate (III), which act not only as a shade adjuster but also as a source of halides for silver halide formulations; Inorganic peroxides and persulfates, such as ammonium peroxydisulfate and hydrogen peroxide; Benzoxazine-2,4-dione, for example 1,3-benzoxazine-2,4-dione, 8-methyl-1,3-benzoxazine-2,4-dione and 6-nitro-1,3 Benzoxazine-2,4-dione; Pyrimidine and asim-triazines such as 2,4-dihydroxypyrimidine, 2-hydroxy-4-amino-pyrimidine and azauracil; And tetraazapentalene derivatives such as 3,6-dimercapto-1,4-diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene and 1,4-di- (o-chloro Phenyl) -3,6-dimercapto-1H, 4H-2,3a, 5,6a-tetraazapentalene. Photothermal elements used in the present invention can also be protected from fog generation and can also be stabilized against loss of photosensitivity during storage. While not essential to the practice of the present invention, it may be advantageous to add mercury (II) salts as antifog agents to the emulsion layer (s). Preferred mercury (II) salts for this use are mercury acetate and mercury bromide. Other suitable antifogging agents and stabilizers that can be used alone or in combination include the tazolium salts described in US Pat. No. 2,131,038 and US Pat. No. 2,694,716; Azaindenes described in US Pat. No. 2,886,437; Trazaindoligins described in US Pat. No. 2,444,605; Mercury salts described in US Pat. No. 2,728,663; Urasols described in US Pat. No. 3,287,135; Sulfocatechol described in US Pat. No. 3,235,652; Oximes described in permanent patent 623,448; Polyvalent metal salts described in US Pat. No. 2,839,405; Thiuronium salts described in US Pat. No. 3,220,839; And the palladium, platinum and gold salts described in US Pat. Nos. 2.566,263 and 2,597,915. Stabilizer precursor compounds capable of releasing stabilizers upon application of heat during development can also be used in combination with stabilizers of the present invention. Such precursor compounds are described, for example, in US Pat. Nos. 5,158,866, 5,175,081, 5,298,390, and 5,300,420. Photothermal graphical elements of the invention include plasticizers and lubricants such as polyalcohols and diols of the type described in US Pat. No. 2,960,404; Fatty acids or esters, such as those described in US Pat. Nos. 2,588,765 and 3,121,060; And silicone resins such as those described in British Patent 955,061. Photothermal graphical elements containing an emulsion layer described herein may contain glossing agents such as starch, titanium dioxide, zinc oxide, silica and polymeric beads including beads of the type described in US Pat. Nos. 2,992,101 and 2,701,245. have. Emulsions according to the present invention are soluble salts, such as chloride, nitrate, evaporated metal layers, for example ionic polymers as described in US Pat. Nos. 2,861,056 and 3,206,312 or insoluble inorganics such as those described in US Pat. It can be used in photothermal graphics elements containing an antistatic layer or conductive layer, such as a layer comprising a salt. The photothermal graphics element may also contain a conductive base layer to reduce the electrostatic effect and to improve transport through the processing apparatus. Such layers are described in US Pat. No. 5,310,640. The photothermal elements of the invention may consist of one or more layers on a support. The single layer element should contain silver halides, non-photosensitive reducing silver sources, reducing agents, binders and toners for the non-photosensitive reducing silver sources, accumulator dyes, coating aids and other additives. The bilayer structure should contain a silver halide and a non-photosensitive reducing silver source in one emulsion layer and some of the other components in the second or both layers. Also possible are two-layer structures comprising a single emulsion layer coating containing all components and protective topcoats. Multicolor photothermal graphics The silver element may contain the bilayer structure set for each color tone or may contain all components in a single layer as described in US Pat. No. 4,708,928. A protective layer, preferably comprising a polymeric material, may also be present in the photothermal elements of the invention. Polymers for the protective layer can be selected from natural and synthetic polymers such as gelatin, polyvinyl alcohol, polyacrylic acid, sulfonated polystyrene and the like. The polymer may optionally be blended with a defense aid such as silica. The photothermal emulsions used in the present invention may be coated with a variety of coating procedures including wire wound rod coating, dip coating, air knife coating, curtain coating, or extrusion coating using a hopper of the type described in US Pat. No. 2,681,294. have. Optionally, two or more layers are described in US Pat. 5,340,613; And simultaneously by the procedure described in British Patent 837,095. Typical wet thickness of the emulsion layer may be about 10 to 150 μm and the layer may be dried in pressurized air at a temperature of about 20 to 100 ° C. By selecting the layer thickness, it is desirable that the maximum image density measured using a color filter complementary to the dye color in the MacBeth Color Densitometer Model TD 504 is greater than 0.2, and it is in the range of 0.5 to 4.5. More preferred. The photothermal graphics element according to the invention may contain an accumulation dye and an antihalation dye. The dye may be incorporated into the photothermal emulsion layer as an accumulator dye by known techniques. The dye may also be incorporated into the anti-halation layer according to techniques known as anti-halation backing layers, anti-halation base layers or overcoatings. The photothermal graphics element of the invention contains an antihalation coating on a support opposite the side on which the emulsion and top coating are coated. Anti-halation dyes and accutence dyes useful in the present invention are disclosed in US Pat. Nos. 5,135,842, 5,226,452, 5,314,795 and 5,380,635. The developing conditions will vary depending on the structure used but will typically include heating the photothermal graphics element in a condition that is substantially free of water at the same time or after exposure to an image image unit at a suitably elevated temperature. Thus, the latent image obtained after exposure is generally sufficient for a period of time at a moderately elevated temperature of about 80 ° C. to about 250 ° C. (176 ° F. to 482 ° F.), preferably about 100 ° C. to about 200 ° C. (212 ° F. to 392 ° F.) By heating the urea for about 1 second to about 2 minutes. When used for black and white elements, black and white silver images are obtained. When used for monochromatic or full color elements, dye images are obtained simultaneously with the formation of black and white images. Heating can be performed by typical heating means such as a heat generator using an oven, hot plate, iron, hot roller, carbon or titanium white and the like. In some cases, the imaged element is sufficient to enhance and improve the stability of the latent image, but insufficient to produce a visible image, but not sufficient time to produce a visible image after application to the first heating step of a time and temperature. It can be applied to two heating stages. This method and its advantages are described in US Pat. No. 5,279,928. Support Photothermal emulsions used in the present invention can be coated on a variety of supports. The support or substrate can be selected from a wide range of materials depending on the image forming conditions. The support may be transparent or at least translucent. Representative supports include polyester films, polyester films with sublayers (e.g. polyethylene terephthalate or polyethylene naphthalate), cellulose acetate films, cellulose ester films, polyvinyl acetal films, polyolefinic films (e.g. polyethylene or polypropylene or Blends thereof), polycarbonate films and associated or dendritic materials and glass paper. Typically, flexible supports are used and in particular polymer film supports which can be partially acetylated or coated with a polymer sublayer or primer. Particularly preferred polyesters are polyethylene terephthalate and polyethylene naphthalate. It is also possible to use a support having a back heat-resistant layer in a photothermal graphic image forming system as shown in US Pat. No. 4,374,921. Use as a photomask The low absorption of the photothermal graphics element in the non-imaging region in the range of 350 to 450 nm facilitates the use of the photothermal graphics element in the course of subsequent exposure of ultraviolet or short wavelength visible photosensitive imageable media. For example, visualizing an optical thermal element with interference line radiation and subsequent development results in a visible image. The developed photothermal elements absorb ultraviolet or short wavelength visible lines without visible images. The developed element can then be used as a mask to be placed between an ultraviolet or short wavelength visible energy source and an ultraviolet or short wavelength visible photosensitive image forming medium, for example a photopolymer, diazo compound or photoresist. This process is particularly useful when the image forming medium comprises a printing plate and the photothermal graphics element functions as an image fixing film. The objects and advantages of the invention will now be illustrated by the following examples, but the specific materials or amounts thereof and other conditions and details mentioned in these examples should not be construed as unduly limiting the invention. All materials used in the examples below are readily available from reputable commercial vendors such as Aldrich Chemical Co., Milwaukee, Wisconsin. All percentages are by weight unless otherwise indicated. The following additional terms and materials were used. Acryloid (trade name) A-21 is a poly (methyl methacrylate) polymer available from Rohm and Haas, Philadelphia, Pennsylvania. Butvar B-79 is a poly (vinyl butyral) resin available from Monsanto Company, St. Louis, Missouri. CAB 171-15S and CAB 381-20 are cellulose acetate butyrate polymers available from Eastman Chemical Co., Kingsport, Tennessee. CBBA is 2- (4-chlorobenzoyl) benzoic acid. MEK is methyl ethyl ketone (2-butanone). MMBI is 5-methyl-2-mercaptobenzimidazole. It is a superphotosensitive agent. 4-MPA is 4-methylphthalic acid. Nonox (brand name) is 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,3,5-trimethylhexane [CAS RN = 7292-14-0] and Saint Jean Photochemical of Quebec Love Inc. (St, Jean Photo Chemicals, Inc.) can be obtained. Non-photosensitive reducing is a hindered phenolic reducing agent (ie developer) for a source. Also known as Permanax (trade name) WSO. PET is polyethylene terephthalate. PHZ is phthalazine. PHP is pyridinium hydrobromide perbromide. TCPAN is tetrachlorophthalic anhydride. TCPA is tetrachlorophthalic acid. THDI is Desmodur (trade name) N-100 which is a bugue hexamethylene diisocyanate available from Miles Chemical Corporation. Fog inhibitor 1 (AR-1) has the following structure. Fluorinated terpolymer A (FT-A) has the following random polymer structure in which m is 7, n is 2 and p is 1. Methods of making fluorinated terpolymer A are described in US Pat. No. 5,380,644. Anti-halation dye-1 (AH Dye-1) has the following structure. The preparation of this compound is described in Example 1f of US Pat. No. 5,380,635. Vinyl sulfone-1 (VS-1) is disclosed in European Patent Application Publication No. 0 600 589 A2 and has the following structure. The following dyes were used. Dye 1 to 4 are dyes of the present invention. Dye-C-1 to Dye-C-4 are comparative dyes. The following comparative dyes were evaluated. Dye-C-1 is a fixed comparative dye having methoxy (CH 3 O-) at the position of the thiomethyl (CH 3 S-) group. Dye-C-2 is a fixed comparative dye with hydrogen (H-) at the position of the thiomethyl (CH 3 S-) group. Dye-C-3 is a fixed comparative dye having a carboxyalkyl group at the ethyl group position and a hydrogen (H-) group at the position of the thiomethyl (CH 3 S-) group. Dye-C-4 is a comparative dye that has an unfixed chain and has a hydrogen (H-) group in place of a thiomethyl (CH 3 S-) group. Iridium-doped core-shells contain potassium bromide and potassium iodide in the first solution (solution A) with 30 g of phthalated gelatin dissolved in 1500 ml of deionized water maintained at 34 ° C. One second solution (solution B) and a third solution (solution C), which is an aqueous solution with 1.4 to 1.8 mol of silver nitric acid per liter, were added simultaneously. pAg, Research Disclosure No. 17643, US Pat. No. 3,415,650; 3,872,954; And maintained at a constant value using a pAg feedback control loop as disclosed in US Pat. No. 3,821,002. After adding some of the transferred silver nitrate, the second halide solution (solution B) is replaced with solution D containing potassium bromide and iridium salt (2 x 10 -5 mol Ir / mol halide) and solution C is Substituted with E. By way of example, the procedure for the preparation of one mole of emulsion is shown below. Solution A was prepared at 32 ° C. as follows. Gelatin30 g Deionized water1500 ml 0.1 M KBr6 ml Adjust ph to 5.0 with 3 N HNO 3 Solution B was prepared at 25 ° C. as follows. KBr27.4 g KI3.3 g Deionized water275.0 g Solution C was prepared at 25 ° C. as follows. AgNO 3 42.5 g Deionized water364.0 g Solutions B and C were sprayed into Solution A for 9.5 minutes. Solution D was prepared at 25 ° C. as follows. KBr179.g K 2 IrCl 6 0.010 g Deionized water812.g Solution E was prepared at 25 ° C. as follows. AgNO 3 127 g Deionized water1090.g Solutions D and E were sprayed into Solution A over 28.5 minutes. The emulsion was washed with water and desalted. The average granule size, measured by scanning electron microscopy (SEM), was 0.045 μm. Iridium doped preformed silver halide / silver organic salt dispersion: A silver halide / silver organic salt dispersion was prepared as described below. This material is also called a silver soap dispersion or emulsion. I. Ingredients 1.0.1 moles of preformed silver halide emulsion at a concentration of 700 g / mol in 1.25 L of H 2 O at 42 ° C. 2.89.18 g NaOH in 1.50 L H 2 O 3.364.8 g of AgNO 3 in 2.5 L of H 2 O 4. 118 g of humpco-type 9718 fatty acid (available from Witco Co., Memphis, Tte.) 5. 570 g Hulk type 9022 fatty acid (available from Witco Company, Memphis, Tte.) 6. H 2 O 50 ㎖ in concentrated HNO 3 19 ㎖ II. reaction 1. Dissolve components 4 and 5 in 13 L of H 2 O at 80 ° C. and mix for 15 minutes. 2. Add component 2 to Step 1 at 80 ° C. and mix for 5 minutes to form a dispersion. 3. Add component 6 to the dispersion at 80 ° C. and cool the dispersion to 55 ° C. and stir for 25 minutes. 4. Add ingredient 1 to the dispersion at 55 ° C. and mix for 5 minutes. 5. Add ingredient 3 to the dispersion at 55 ° C. and mix for 10 minutes. 6. Wash until the wash water has a resistance of 20,000 ohms / cm 2. 7. Dry at 45 ° C. for 72 hours. Homogenization of Preformed Soap (Homogenate): The preformed silver fatty acid salt homogenate is homogenized in solvent and Butvar B-79 poly (vinyl butyral) with 209 g of the preformed soap prepared previously according to the following procedure. To make it. 1. Add 780 g of 2-butanone and 209 g of preformed soap to Butvar B-79. 2. Mix the dispersion for 10 minutes and hold at 45 ° F. overnight. 3. Homogenize at 6000 psi. 4. Homogenize again at 6000 psi. Preparation of photothermal elements: 507 g of preformed soap homogenate were stirred at 55 ° F. for 15 minutes and 3.9 ml of pyridinium hydrobromide perbromide (PHP) solution (prepared by dissolving 1.35 g of PHP in 12 g of methanol) was added. After stirring for 2 hours 5.2 ml of calcium bromide solution (prepared by dissolving 1.0 g of CaBr 2 in 8.00 g of methanol) was added. After stirring for 30 minutes 117 g of Butvar B-79 poly (vinyl butyral) was added. After stirring for an additional 30 minutes, 27.3 g of Permanax (trade name) WSO were added and the dispersion was stirred for an additional 15 minutes. Then 2.73 g of anti-fog AF-1 was added and stirred for 15 minutes. Then 1.39 g of THDI in 12.3 g of 2-butanone were added and the dispersion was stirred for an additional 15 minutes and then heated at 70 ° C. for 15 minutes. 100 g of test samples were taken from this dispersion. For each of these samples: a) 0.0061 to 0.010 g of the photosensitizer dye for 1 molar concentration level (hereinafter designated 1X) or 0.0008 to 0.001 g for 1/10 molar concentration level (hereinafter referred to as 1 / 10X). The solution containing was added. This amount was varied to maintain an equivalent molar concentration among the various dyes b) 0.47 g CBBA and c) 0.043 g MGBI 2.6 g so MMBI. The samples were then mixed at 70 ° F. for 1.0 hour and then 0.368 g of PHZ and 0.123 g of TCPA were added and mixed with each other for an additional 15 minutes before coating. The top coating solution was prepared by mixing the following materials at room temperature. matteramount 2-butanone512.0 g Methanol61.0 g CAB 171-15S48.0 g 4-MPA2.08 g FT-A (16% solid solution in 2-butanone)3.3 g Acryloid A-21 Resin1.9 g Vinyl sulfone-1 (VS-1)0.5 g The sample was then coated under infrared safety light. Photothermal emulsion and topcoating formulations were coated onto a 7 mil (176 μm) blue polyethylene terephthalate support with an antihalation back coating containing AH Dye-1 in CAB 381-20 resin. Double knife coating was used. The device consists of two tandem knife coated plates. Cut into lengths suitable for the volume of the solution using the support, lift the hinged knife and fix it in place on the coater bed. Then lower the knife and lock it in place. The height of the knife was adjusted with a wedge adjusted with a screw handle and measured with an electronic gauge. Knife 1 is raised by the interval corresponding to the sum of the thickness of the support and the desired wet thickness of the emulsion layer (layer 1). Knife No. 2 is raised to the same height as the sum of the desired support thickness, the desired wet thickness of the emulsion layer (layer 1) and the desired wet thickness of the top coating layer (layer 2). A photothermal emulsion layer was coated with a wet thickness of 3.7 mils (94 μm) on the support. Topcoating was coated on the photothermal graphics line with a wet thickness of 5.3 mils (135 μm) on the support. This photothermal element was dried at 79.4 ° C. (175 ° F.) for 4 minutes. Photometer and Thermal Stability Measurements: The coated and dried photothermal graphical elements were cut into 3.8 cm x 20.3 cm (1.5 inch x 8 inch) strips and exposed to a photometer incorporating a 809 nm, 150 kV laser diode. After exposure, an image was obtained by heating the film strip for 15 seconds at 124 ° C. (° F.). The obtained image is then evaluated on a custom-made computer scanned densitometer and considered to be compared to the measurements obtained from commercially available densitometers. Photometer results include Dmin, Dhi, Velocity-2, Velocity-3, Average vs-1, Average vs-3 and Dmax. Dmin is the density value of the unexposed areas after development. The average of the eight lowest density values on the exposed side of the reference point. Dhi is the density value corresponding to an exposure at 1.40 LogE that is greater than an exposure equal to 0.20 greater than Dmin. E is exposure and the unit is ergs / cm 2. Rate-2 is Log 1 / E + 4, which is required to achieve a density 1.00 greater than Dmin. This is Log 1 / E + 4, which is required to obtain a density of 2.90 greater than the speed -3dms Dmin. E is exposure and the unit is ergs / cm 2. Rate-3 is important for evaluating the exposure response of a photothermal element to a high intensity light source. AC-1 (1 on average) is the slope of the line that meets the density points 0.60 and 2.00 greater than Dmin. AC-3 (3 vs mean) is the slope of the line that meets the density points 2.40 and 2.90 greater than Dmin. Dmax sms The highest density value on the exposed surface of the reference point. Example 1 Example 1 compares Dye-2 and Dye-C-4, and a photothermal emulsion containing a photosensitive dye having a thiomethyl group (CH 3 S-) on each benzothiazole ring is used on the benzothiazole ring. It demonstrates that it provides a photothermal graphic element with higher speed, higher contrast and lower Dmin compared to similar dyes without thiomethyl groups (CH 3 S-). Dye-2 represents the dye of the present invention. Dye-C-4 represents a comparative dye. (Triangle | delta) shows the improvement of the dye of this invention with respect to the comparative dye (C-4). densitycompoundDminDhiSpeed-2Speed-3AC-1AC-3 1XDye-C-40.252---1.270.754.732.14 1XDye-20.229---1.461.075.373.19 △ -0.023 0.190.320.641.05 Example 2 Example 2 compares Dye-1 and Dye-4 with Dye-C-2 and a photosensitive dye having two thiomethyl groups (CH 3 S-) on each benzothiazole ring and having a fixed chain. The photothermal emulsions contain photothermal elements with higher rates, higher contrast and lower Dmin compared to similar dyes with fixed chains but without thiomethyl groups (CH 3 S-) on the benzothiazole ring. Prove it. Dye-1 and Dye-4 represent dyes of the invention. Dye-C-2 represents a comparative dye. (Triangle | delta) shows the improvement of each dye of this invention with respect to the comparative dye (C-2). densitycompoundDminDhiSpeed-2Speed-3AC-1AC-3 1XDye-C-20.274---1.390.864.332.41 1XDye-10.247---1.961.576.113.00 △ -0.027 0.579.711.780.59 1XDye-40.2313.691.891.375.582.22 * Worse value for comparison. Example 3 Example 3 compares Dye-1 and Dye-C-3 and shows a photothermal emulsion containing a photosensitive dye having two thiomethyl groups (CH 3 S-) on the benzothiazole ring and having a fixed chain. It provides a photothermal graphical element with a higher rate, higher contrast and lower Dmin compared to similar dyes having a fixed chain and having an alkylcarboxyl group but no thiomethyl group (CH 3 S-) on the benzothiazole ring. Prove it. Dye-1 represents the dye of the present invention. Dye-C-3 represents a comparative dye. Δ represents an improvement of each dye of the present invention over the comparative dye. densitycompoundDminDhiSpeed-2Speed-3AC-1AC-3 1XDye-C-30.2753.51.831.204.411.74 1XDye-10.2473.652.021.525.802.14 △ -0.028 0.190.321.390.40 Example 4-5 Examples 4 and 5 once again compare Dye-1 and Dye-C-3 and contain a photosensitive dye having two thiomethyl groups (CH 3 S-) on the benzothiazole ring and having a fixed chain One photothermal emulsion is comparable to a similar dye having a fixed chain and alkylcarboxyl group but no thiomethyl group (CH 3 S-) on the benzothiazole ring even when using 1/10 molar molar concentration (1 / 10X). It demonstrates that it provides a photothermal graphic element with higher speed, higher contrast and lower Dmin. Dye-1 represents the dye of the present invention. Dye-C-3 represents a comparative dye. Example 4 densitycompoundDminDhiSpeed-2Speed-3AC-1AC-3 1XDye-C-30.2563.611.891.294.631.98 1XDye-10.2413.752.101.625.672.41 1 / 10XDye-10.2353.512.051.455.561.74 Example 5 densitycompoundDminDhiSpeed-2Speed-3AC-1AC-3 1 / 10XDye-C-20.233---1.551.014.572.24 1XDye-10.2603.631.851.304.922.14 1 / 10XDye-10.2283.851.981.566.173.03 Example 6 Example 6 compares Dye-3 and Dye-C-3 and once again contains a photosensitive dye having two thiomethyl groups (CH 3 S-) on each benzothiazole ring and having a fixed chain Photothermal elements with higher rates, higher contrast and lower Dmin compared to similar dyes with photochromic emulsions having fixed chain and alkyl carboxy groups but no thiomethyl groups (CH 3 S-) on the benzothiazole ring Prove that. Dye-3 represents the dye of the present invention. Dye-C-3 represents a comparative dye. (Triangle | delta) shows the improvement of the dye of this invention with respect to the comparative dye. densitycompoundDminDhiSpeed-2Speed-3AC-1AC-3 1XDye-C-30.2753.581.831.204.411.74 1XDye-30.2613.601.891.355.282.03 △ -0.014 0.060.150.870.29 Example 7 Example 7 compares Dye-1 and Dye-C-3 and photothermal graphics containing a photosensitive dye having two thiomethyl groups (CH 3 S-) on each benzothiazole ring and having a fixed chain It demonstrates that emulsions provide photothermal elements with longer storage stability (storage life) compared to similar dyes with immobilized chain and alkylcarboxyl groups but without thiomethyl groups (CH 3 S-) on the benzothiazole ring. . Again higher rates, high contrast and low Dmin were obtained using the dyes of the present invention. Dye-1 represents the dye of the present invention. Dye-C-3 represents a comparative dye. (Triangle | delta) shows the characteristic change with respect to the comparative dye (C-3) and the dye of this invention. densitycompoundConditionDminDhiSpeed-2Speed-3AC-1AC-3 1XDye-C-3Initiation Point Sensitivity0.2383.451.731.134.001.79 1XDye-C-3After 25 hours storage at 55 ℉0.2923.611.751.214.532.01 △ 0.054 0.020.080.530.22 1XDye-1Initiation Point Sensitivity0.2303.671.941.505.132.77 1XDye-1After 25 hours storage at 55 ℉0.2443.881.981.625.513.93 △ 0.0143 0.040.120.381.16 Example 8 Example 8 compares Dye-1 and Dye-C-3 and photothermal graphics containing a photosensitive dye having two thiomethyl groups (CH 3 S-) on each benzothiazole ring and having a fixed chain It demonstrates that emulsions provide photothermal elements that can withstand higher drying conditions compared to similar dyes with fixed chains and alkylcarboxyl groups but without thiomethyl groups (CH 3 S-) on the benzothiazole ring. Again higher rates, high contrast and low Dmin were obtained using the dyes of the present invention. Dye-1 represents the dye of the present invention. Dye-C-3 represents a comparative dye. (Triangle | delta) shows the characteristic change with respect to the comparative dye (C-3) and the dye of this invention. densitycompoundConditionDminDhiSpeed-2Speed-3AC-1AC-3 1XDye-C-3175 ° F / 4 min Dry-Standard0.2273.681.821.305.182.12 1XDye-C-3205 ℉ / 4 minutes drying0.220---1.43---2.82--- △ -0.007 -0.38 -2.361 / 10XDye-1175 ° F / 4 min Dry-Standard0.2123.851.861.545.635.14 1 / 10XDye-1205 ℉ / 4 minutes drying0.209---1.631.054.181.94 △ -0.003 -0.23-0.49-1.45-3.20 Example 9 Example 9 provides a further comparison of thioalkyl and alkoxy substituents on the benzothiazole ring and demonstrates the unique advantages provided by thioalkyl substitution. It also demonstrates further improvements obtained by incorporating superphotoresists into photothermal elements with dyes containing thioalkyl groups. Photothermal elements were prepared, coated and dried as described above. Four dyes were compared. Samples 9-1 to 9-10 were prepared for comparison. Sample 9-1 contains dye C-3 at 1 × level with 5-methyl-2-mercaptobenzimidazole as superphotosensitive agent. Sample 9-2 contains dye 1 at 1 × level with 5-methyl-2-mercaptobenzimidazole as a superphotosensitive agent. Sample 9-3 contains dye 1 at a 1 / 10X level with 5-methyl-2-mercaptobenzimidazole as a superphotosensitive agent. Sample 9-4 contains dye C-2 at 1 × level with 5-methyl-2-mercaptobenzimidazole as superphotosensitive agent. Sample 9-5 contains dye C-2 at 1/10 × level with 5-methyl-2-mercaptobenzimidazole as a superphotosensitive agent. Sample 9-6 contains dye C-1 at 1 × level with 5-methyl-2-mercaptobenzimidazole as superphotosensitive agent. Sample 9-7 contains dye 1 at a 1 / 10X level with 5-methyl-2-mercaptobenzimidazole as a superphotosensitive agent. Samples 9-8 contain dye 1 at 1 × level without superphotoresist. Sample 9-9 contains dye C-2 at IX levels without superphotoresist. Samples 9-10 contain dye C-1 at IX levels without superphotoresist. The data presented below demonstrate that using a smaller amount (1 / 10X) of the dye of the present invention is superior to the use of a large amount of dye having the same structure but no thioalkyl group. Samples 9-9 and 9-10 were measured due to too slow luminous flux even with 150 GHz laser diodes in which the dyes containing no thioalkyl groups on the thibenzothiazole ring were used in the examples under the image forming and processing conditions described above. It proves that it provides a photothermal graphic element that cannot be done. ExampledyesDminDhiSpeed-2Speed-3AC-1AC-3Dmax 9-1Dye-C-3 1X0.2453.911.761.284.882.803.97 9-2Dye-1 1X0.2403.391.921.536.013.044.02 9-3Dye-1 1 / 10X0.2213.911.841.435.493.043.97 9-4Dye-C-2 1X0.242*1.06*4.42*2.95 9-5Dye-C-2 1 / 10X0.225*0.84***1.96 9-6Dye-C-1 1X0.247*1.340.794.202.163.35 9-7Dye-C-1 1 / 10X0.230*1.19*4.08*3.15 9-8Dye-1 1X0.233*1.390.874.972.223.49 9-9C-2 1X＠＠＠＠＠＠＠ 9-10C-1 1X＠＠＠＠＠＠＠ * Too small to measure. 늦 luminous flux too late to measure Reasonable modifications and variations are possible in light of the above teachings without departing from the spirit or scope of the invention as defined in the claims.
权利要求:
Claims (23) [1" claim-type="Currently amended] (a) photosensitive silver halides; (b) a non-photosensitive reducing silver source; (c) reducing agents for silver ions; (d) binders; And (e) A thermally developable photothermal element comprising a support having at least one photosensitive image forming layer comprising a compound having a central nucleus of the formula: Where X is independently a thioalkyl group having 1 to 20 carbon atoms, n is independently 0, 1 or 2, and the sum of all n is 1 or more; R 1 and R 2 represent alkyl groups having 1 to 20 carbon atoms other than carboxy-substituted alkyl; A − is an anion. [2" claim-type="Currently amended] The photothermal element according to claim 1, wherein the silver halide is silver bromide, silver chloride, silver iodide, silver chlorobromide, silver bromo iodide, silver chlorobromo iodide, or a mixture thereof. [3" claim-type="Currently amended] The photothermal element of claim 1, wherein the reducing silver source comprises a silver salt of a fatty acid. [4" claim-type="Currently amended] The photothermal element of claim 3, wherein the non-photosensitive reducing source of silver comprises a silver salt of C 1 to C 30 carboxylic acids. [5" claim-type="Currently amended] The photothermal graphical element of claim 4, wherein the non-photosensitive silver source comprises silver behenic acid. [6" claim-type="Currently amended] The photothermal element of claim 20, wherein at least two adjacent methine groups selected from D 2 , D 3 , D 4 , D 5, and D 6 form a carbocyclic ring structure. [7" claim-type="Currently amended] The photothermal element of claim 20, wherein the carbocyclic ring structure comprises a tetrahydronaphthyl group. [8" claim-type="Currently amended] The photothermal element of claim 1, wherein the binder is a hydrophobic polymer binder. [9" claim-type="Currently amended] The photothermal element of claim 8, wherein the binder is selected from the group consisting of polyvinylbutyral, cellulose acetate butyrate, cellulose acetate propionate, and vinyl resin. [10" claim-type="Currently amended] The photothermal element of claim 1, wherein the binder is hydrophobic and each n is 1 or 2. [11" claim-type="Currently amended] The photothermal element of claim 1, wherein the reducing agent is sterically hindered phenol. [12" claim-type="Currently amended] 12. The photothermal element of claim 11, wherein the hindered phenol is selected from the group consisting of vinaphthol, biphenol, bis (hydroxy-naphthyl) methane, bis (hydroxyphenyl) methane, hindered phenol and naphthol . [13" claim-type="Currently amended] 13. The photothermal graphic element of claim 12 wherein the hindered phenol is bis (hydroxyphenyl) methane. [14" claim-type="Currently amended] The photothermal element of claim 1, wherein R 1 and R 2 have from 1 to 8 carbon atoms. [15" claim-type="Currently amended] The photothermal element of claim 14, wherein R 1 and R 2 represent an ethyl group. [16" claim-type="Currently amended] The photothermal element of claim 1, wherein each X substituent independently comprises a thioalkyl group having 1 to 20 carbon atoms, wherein each n is 1 or 2. 6. [17" claim-type="Currently amended] The photothermal element of claim 1, wherein the concentration of the compound photosensitive to the spectrum is in the range of 2 × 10 −8 to 4 × 10 −2 moles of dye per mole of silver in the emulsion layer. [18" claim-type="Currently amended] 16. A photosensitive agent according to claim 1 or 15, wherein each image forming layer has a photosensitizer, the superphotoresist being an aromatic, heterocyclic mercapto or disulfide compound, mercapto-substituted benzimidazole, mercapto-substituted benzoxazole and mercapto Photothermal graphics element selected from the group consisting of substituted benzothiazoles. [19" claim-type="Currently amended] 19. The photothermal element of claim 18, wherein each n is 1 or 2. [20" claim-type="Currently amended] (a) photosensitive silver halides; (b) a non-photosensitive reducing silver source; (c) reducing agents for silver ions; (d) binders; And (e) a compound having a central nucleus of the formula A thermally developable photothermal graphic element comprising a support having at least one photosensitive image forming layer comprising a. Where X is independently a thioalkyl group having 1 to 20 carbon atoms; D 1 to D 7 each independently represent a methine group, and adjacent methine groups selected from D 2 , D 3 , D 4 , D 5 and D 6 may form a cyclic group; n is independently 0, 1 or 2, and the sum of all n is 1 or more; R 1 and R 2 represent alkyl groups having 1 to 20 carbon atoms other than carboxy-substituted alkyl; A − is an anion. [21" claim-type="Currently amended] (a) photosensitive silver halides; (b) a non-photosensitive reducing silver source; (c) reducing agents for silver ions; (d) binders; And (e) a compound having a central nucleus of the formula A thermally developable photothermal graphic element comprising a support having at least one photosensitive image forming layer comprising a. Where Z is S, O, Se or NR 3 ; R 1 and R 2 represent alkyl groups having 1 to 20 carbon atoms other than carboxy-substituted alkyl; R 3 is H or an alkyl group; X and Y are thioalkyl groups having 1 to 20 carbon atoms; n is 0 to 4; m is 0 to 4; the sum of m and n is at least 1; D 1 to D 7 each independently represent a methine group, and adjacent methine groups selected from D 2 , D 3 , D 4 , D 5 and D 6 may form a cyclic group; p is 0 or 1; A − is an anion. [22" claim-type="Currently amended] 22. The photothermal element of claim 21, wherein said compound is a dye having one of the formulas: [23" claim-type="Currently amended] 22. The photothermal graphic element of claim 20 or 21 having a superphotosensitive agent in the image forming layer.
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同族专利:
公开号 | 公开日 EP0821811B1|2002-06-19| JPH11504127A|1999-04-06| EP0821811A1|1998-02-04| DE69621924T3|2006-07-27| AU5090696A|1996-11-07| DE69621924D1|2002-07-25| US5541054B1|1998-11-17| WO1996033442A1|1996-10-24| JP3720369B2|2005-11-24| DE69621924T2|2003-01-02| EP0821811B2|2006-01-25| US5541054A|1996-07-30|
引用文献:
公开号 | 申请日 | 公开日 | 申请人 | 专利标题
法律状态:
1995-04-20|Priority to US8/425,860 1995-04-20|Priority to US08425860 1996-02-29|Application filed by 캐씨알.샘스, 이메이션코포레이션 1999-01-25|Publication of KR19990007902A 2003-03-10|First worldwide family litigation filed
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申请号 | 申请日 | 专利标题 US8/425,860|1995-04-20| US08425860|US5541054B1|1995-04-20|1995-04-20|Spectral sensitizing dyes for photothermographic elements| 相关专利
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