Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/52—Compositions containing diazo compounds as photosensitive substances
  • G03C1/61—Compositions containing diazo compounds as photosensitive substances with non-macromolecular additives

Definitions

• a thermally developable diazotype copying material is manu- 3064049 1 1,1962 C m e a [91 x factured which comprises a supporting sheet and a light-sensi- 5398 1 196 96 75 x tive copying layer coated on said supporting sheet, said layer 4 1 I a1 4 91 consisting of a water soluble light-sensitive diazo compound,a 5991 6/ l 0 euge ouer et I water soluble heat fugitive acidic salt (base generating agent) 2239'704 4/1941 de et "96/9l x and a water insoluble coupler.
• the present invention is concerned with thermally developable diazotype copying materials having features which are represented particularly by the markedly improved color developing ability and shelf life, which are manufactured by forming, on the supporting sheet, a light-sensitive layer containing a light-sensitive diazo compound, a base generating agent consisting of a water soluble heat fugitive acidic salt and a coupler, or by the provision of a light-sensitive layer containing said respective components and additional agent for lowering the melting point of said coupler.
• the first-mentioned copying materials had the shortcoming that, during storage, the base generating agent became dispersed and was transferred into the supporting sheet even at normal temperature, resulting in a reduction in the developing ability (or color developing ability). Accordingly, when prior art copying materials which had undergone such degenerating changes of the copying layers were exposed to actinic light under originals and were then subjected to heat development, the result of their development was often found to be poor in quality so that it was impossible to obtain prints having a satisfactory image density. This shortcoming of the prior art copying materials was compensated for either by increasing the base generating agent content of the light-sensitive layer or by conducting the development at a temperature slightly higher than the proper development temperature for these copying materials.
• the secondmentioned prior art copying materials carrying a light-sensitive layer consisting of fine particle components had the shortcoming that the coupling velocity (or the color developing velocity) of the light-sensitive diazo compound and the coupler contained in the light-sensitive layer was somewhat smaller than that of said first-mentioned copying materials having their light-sensitive layers made with a water-soluble light-sensitive component, and involved a difficulty in forming a clear image on the print.
• the primary object of the present invention to eliminate the aforesaid shortcomings of the prior art and to provide thermally developable diazotype copying materials having superior copying ability, by forming a light-sensitive layer with the principal components consisting of a combination of a water soluble light-sensitive diazo compound, a water insoluble coupler with or without an agent for lowering the melting point of said coupler, and a base generating agent consisting of a water soluble heat fugitive acidic salt.
• Another object of the present invention is to provide thermally developable diazotype copying materials which permit the color development at an increased velocity during the development process and which permit the formation of clear images on the prints and which are of a markedly improved shelf life.
• the water soluble light-sensitive diazo compounds which are used in the present invention are double salts of zinc chlorides or cadmium chlorides and the compounds which include, for example:
• the water insoluble couplers which are used in the present invention include, for example, 2,3-dihydroxy-naphthalene, 2,3-dihydroxy-6-sulfonamide-naphthalene, 2,3-dihydroxy-6- dihydroxyethyl sulfonamide-naphthalene, l-carboxy-2,3- dihydroxy-naphthalene, 1 ,4-dichloro-2 ,3-dihydroxynaphthalene, and 3,3'-dihydroxy-Z-naphthanilide. These water insoluble couplers are used in the form of fine particles or powder.
• the water soluble heat fugitive acidic salts include, for example, such water soluble salts which are the compounds formed with the substances of the following two groups: (1) water soluble heat fugitive acids which are represented, for example, by halogenoacetic acids such as monochloroacetic acid, dichloroacetic acid and trichloroacetic acid; derivatives of acetic acid, such as cyanoacetic acid and halogenomalonic acid such as dichloromalonic acid, and (2) alkali metals such as sodium and potassium, or basic components such as ammonia, ethanolamine and isopropylamine.
• these salts are added to said diazo compound in an amount preferably ranging from 4 parts by weight to 7 parts by weight per part by weight of such a diazo compound.
• the agents for lowering the melting points of the couplers include guanidine-tartaric acid salt (having a melting point of 164 C.) and the derivatives of guanidine which include, for example:
• Said agents further include acid amides such as acetamide (melting point being 82 C.), acrylamide (melting point being 85 C.), propionamide (melting point being 79 C.), butylamide (melting point being 116 C.) and malonamide (melting point being C.).
• acid amides such as acetamide (melting point being 82 C.), acrylamide (melting point being 85 C.), propionamide (melting point being 79 C.), butylamide (melting point being 116 C.) and malonamide (melting point being C.).
• the aforesaid agents for lowering the melting points of the couplers are invariable water soluble.
• the present invention is concerned, therefore, with copying materials which are formed by providing, on a supporting sheet such as paper, precoated paper and plastic foil, a lightsensitive layer which consists of an appropriate combination of the aforesaid respective components constituting a lightsensitive layer.
• Said one example of the present invention is represented by a thermally developable diazotype copying material having a structure wherein a supporting sheet carries thereon a light-sensitive layer containing the following three components, i.e., one of the aforesaid diazo compounds, one of the aforesaid couplers and one of the aforesaid water soluble salts.
• This coping material is featured by an extremely increased development velocity which is displayed when the exposed copying material is subjected to the development process, as compared with conventional copying materials. This difference can be explained by the following facts.
• the conventional copying materials employing, as the base generating agent in general, a nitrogen-bearing compound such as urea or the derivatives thereof present impaired color developing ability at the time of heat development for the reasons that have been stated previously, with the result that the obtained prints do not have a satisfactory color density.
• the base generating agent of the present invention employs a water soluble heat fugitive acidic salt such as monochloroacetic acid, dichloracetic acid and trichloroacetic acid, so that the color development velocity of the copying material of the present invention containing such a base generating agent increases, and accordingly, a print bearing a satisfactory image density is obtained.
• an intermediate layer consisting of a waxlike substance for being interposed between the light-sensitive diazo compound and the coupler.
• the formation of such an intermediate layer will impair satisfactory coupling between the light-sensitive diazo compound and the coupler at the time of the heat treatment, resulting in a marked deterioration in the color development of the obtained image on the print.
• the occurrence of the aforesaid premature coupling phenomenon is arrested by the particular use ofthe water insoluble couplers.
• these water insoluble couplers By virtue of the use of these water insoluble couplers, there hardly takes place a coupling between the light-sensitive diazo compounds and the couplers at normal temperature even where the water soluble heat fugitive acidic salts have undergone decomposition to some extent, so that, as a result, there occurs no impairment of the color development in the image formed on the print obtained.
• the coupler gains its coupling activity for the first time from the heat development, and the coupler is allowed, by this heat treatment, to be united with the water soluble light-sensitive diazo compound to quickly form a dye image.
• the adoption of the water insoluble couplers in the present invention thus contributes to the provision of thermally developable copying materials which are of superior color developing ability and an improved shelf life.
• the copying materials may be made by first applying a coupler onto the supporting sheet and then applying a mixture ofa diazo compound and a water soluble heat fugitive acidic salt to the resulting first layer to form a light-sensitive layer on the supporting sheet.
• the light-sensitive layer may be formed by applying a mixture of the aforesaid three components onto the supporting sheet.
• the former copying material of the present invention which carries a light-sensitive layer consisting of the aforesaid two layers, i.e., a first layer of coupler and a second layer consisting of said mixture is somewhat superior in shelf life to the latter copying material which is a single layer type.
• the water insoluble coupler is provided in the form of a solution such that the coupler is dispersed in a vinyl acetate emulsion.
• the aforesaid series of agents adapted for lowering the melting point of the couplers are provided as one of the components constituting the lightsensitive layer in order to further improve the color developing ability of the coping materials during the development process.
• the inclusion, in the light-sensitive layer, of a water soluble agent, such as guanidine, its derivatives and acid amides, adapted for lowering the melting point of the coupler jointly with the other components constituting the light-sensitive layer, or the inclusion of such an agent in the layer of the aforesaid water insoluble coupler leads to a markedly lowered eutectic point of the water insoluble coupler by virtue of the multiplying action effected by the coupler and the agent, with the result that the velocity of coupling (or the color development velocity) between the light-sensitive diazo compound and the coupler at the time of heat development is further increased, leading to an improved color developing ability as well as the materialization of high density images on the prints obtained.
• a water soluble agent such as guanidine, its derivatives and acid amides
• This improved color developing ability of copying materials permits a reduction in the contacting time of the heated rollers.
• This reduced contacting time of the heated rollers leads to the advantages that not only the manufacture of copying apparatuses is economized by the simplified developing mechanism which is incorporated in such apparatuses, but also the production of copying apparatuses of compact size becomes possible.
• the agent for lowering the melting point of the coupler be admixed to the coupler inan amount which is represented by the eutectic ratio by weight. Ordinarily, however, the agent is added in an amount ranging from 0.14 parts by weight to 0.25 parts by weight per part by weight of the coupler used.
• the present invention is concerned with thermally developable diazotype copying materials which thoroughly satisfy various requirements, such as the instantaneously effected coupling at a low temperature and the improved shelf life, which are demanded of thermally developable diazotype copying materials.
• a comparison of shelf life between the copying material of the present invention and a conventional copying material was conducted by subjecting these two copying materials to coercive ageing by preserving them under the conditions consisting of a temperature which was 50 C. and a relative humidity which was 20 percent. More specifically, these two copying materials which have undergone coercive ageing for a predetermined period of time were exposed and developed in a manner as described above. It was confirmed that the copying material of the present invention showed an improved shelf life which was two to three times longer than that of the conventional copying material.
• the light-sensitive solution (A) containing a light-sensitive diazo compound was admixed with the solution (B) prepared by dispersing a water insoluble coupler in a vinyl acetate emulsion which was then thoroughly dispersed in said solution (A).
• the resulting light-sensitive solution was applied to a supporting sheet and was dried, and thus, a thermally developable diazotype copying material was obtained.
• This copying material showed a shelf life which was in the order similar to that of the copying material of the present invention obtained in Example 1.
• the image density of the present example was 15 to 20 percent superior to that of the latter. Furthermore, the shelf life of the product of this example was measured by means of a coercive ageing in a manner similar to that described in Example l. [t was noted that the inclusion of an agent for lowering the melting point of the coupler in the light-sensitive layer gave rise to no adverse effect.
• EXAMPLE 6 Water 100 cc. 2,3-dihydtoxy-6-sulfonamide-naphthalene 3.5 g. Vinyl acetate cmulsion (content: 50%) 4.0 g. Fine particles nt'silicu (grain size: l-S microns) 2.0 g. Aminoguanidine (hydrochloride) 0.5 g.
• a thermally developable diazotype copying material having on one surface of a supporting member a light-sensitive layer comprising a binder resin having dispersed therein a diazonium compound, an azo coupling compound, a base generating agent, an acidic stabilizer and a compound for lowering the melting point of said azo compound, in which a.
• said diazonium compound is a water-soluble, light-sensitive, diazonium compound selected from the group consisting of zinc chloride and cadmium chloride double salts of p-dimethyl-aminobenzene diazonium chloride, pdiethyl-aminobenzene diazonium chloride, p-methylhydroxyethyl-aminobenzene diazonium chloride and pethylhydroxyethyl-aminobenzene diazonium chloride;
• said base generating agent is a water-soluble, heat-fugitive, acidic salt selected from the group consisting of a1- kali metal salts, ammonium salts, ethanolamine salts and isopropylamine salts of halogenoacetic acids, cyanoacetic acid and halogenomalonic acids;
• said azo coupling compound is a water-insoluble azo coupling compound uniformly dispersed in said layer in the form of fine particles, said compound being selected from the group consisting of 2,3-dihydroxy-naphthalene, 2,3-dihydroxy-fi-sulfonamide-naphthalene, 2,3-dihydroxy-G-dihydroxyethyl sulfonamide-naphthalene, l-carboxy- 2,3-dihydroxy naphthalene, l,4-dichloro-2,3-dihydroxy naphthalene and 3,3-dihydroxy-Z-naphthanilide; and
• said compound for lowering the melting point of said azo coupling compound is a water-soluble compound selected from the group consisting of guanidine-tartaric acid salt, aminoguanidine-hydrochloric acid salt, cyanoguanidine, ethylbiguanide-hydrochloric acid salt, dimethylbiguanide-h drochloric acid salt, 3-methoxy benzoguanldtne, -butyl-3-nitroguanrdine, Z-guanyl phthalic acid amide, acetamide, acrylamide, propionamide, butylamide and malonamide, the amount of said compound for lowering the melting point being in the range of 0.14 to 0.25 part by weight per one part by weight of said azo coupling compound and forming a eutectic with the azo coupling compound.
• a thermally developable diazotype copying material having on one surface of a supporting sheet a two-layer light-sensitive coating comprising a diazonium compound, an azo coupling compound, a base generating agent, an acidic stabilizer and a compound for lowering the melting point of said azo coupling compound, in which a.
• the first layer consists of a binder resin containing a water-insoluble azo coupling compound uniformly dispersed in said binder resin in the form of fine particles and a compound for lowering the melting point of said azo coupling compound
• said azo coupling compound being selected from the group consisting of 2,3-dihydroxy-naphthalene, 2,3-dihydroxy-naphthalene-6-sulfonamide-naphthalene, 2,3-dihydroxy-6-dihydroxyethyl-sulfonamide-naphthalene, l-carboxy-2,3-dihydroxynaphthalene, l,4-dichloro-2,3-dihydroxy-naphthalene and 3,3'-dihydroxy-2-naphthanilide; and said compound for lowering the melting point of said azo coupling compound being selected from the group consisting of guanidine-tartaric acid salt, amino-guanidine-hydrochloric acid salt, cyanoguanidine,
• said diazonium compound being selected from the group

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• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• General Physics & Mathematics (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)

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Cited By (12)

Citations (19)

• 0
  • NL NL136527D patent/NL136527C/xx active
• 1967
  • 1967-10-26 US US678183A patent/US3642483A/en not_active Expired - Lifetime
  • 1967-11-06 GB GB50443/67A patent/GB1212358A/en not_active Expired
  • 1967-11-06 NL NL6715040A patent/NL6715040A/xx unknown
  • 1967-11-07 DE DE1597625A patent/DE1597625B2/de active Pending

Patent Citations (22)

Non-Patent Citations (2)

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