JPH1073901A - Photothermographic recording material containing infrared sensitizing dye - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording material containing a photo-addressable, thermally developable element which can be coated with an aqueous medium and has high infrared sensitivity and excellent image forming property by having an infrared sensitivity smaller than a specified value, and providing a dye satisfying a specified test. SOLUTION: This recording material has an infrared sensitivity smaller than 80j/m<2> , and a dye satisfies the following test. Namely, the exposure required by a recording material A formed of a polyester support body of 100μm thickness to which a photo-addressable thermally deformable element containing the dye and a compound represented by the formula is imparted is >90% of the exposure required by a recording material B manufactured in the same manner as the recording material A except omitting the compound of the formula. The exposures of the recording materials A, B are required to provide an optical density in the exposed part higher than the non-exposed part by about 0.5 when they are exposed to an infrared ray to which they are sensitive, and heated to 105 deg.C for 15 seconds by a heat source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photothermographic recording material comprising a photosensitive silver halide spectrally sensitized with a specific dye and a recording method therefor.

[0002]

BACKGROUND OF THE INVENTION Thermal imaging or thermography is a recording method in which an image is formed by the use of image-wise regulated thermal energy.

[0003] Three types of thermography are known: 1. Directly visible image patterns by image-wise heating of recording materials containing objects that change color or optical density by chemical or physical methods. Formation by excessive heat.

[0004] 2. Image-wise transfer of components required for chemical or physical methods to effect a change in color or optical density on the receiver element.

[0005] 3. Dye transfer printing by heat in which a visible image pattern is formed by transfer of a colored species from an imagewise heated donor element to a receiver element.

[0006] Type 1 thermographic materials are useful for photothermographic imaging in the presence of photosensitizers which can catalyze the thermographic process after exposure to ultraviolet, visible or infrared light or cause a change in color or optical density associated therewith. And sex.

[0007] An example of a photothermographic material is the so-called "dry silver" photographic material of the 3M Company,
They were written by DA Morgan in "Handbook of Imaging S
cience ", edited by AR Diamond, p. 43, Marcel Dekker
Published, 1991.

The most widely used radiation-sensitive salt in such materials is silver halide, which is an organic silver salt such that the species formed upon exposure can catalyze the thermal imaging process. Must be in contact with the salt. Silver halide requires spectral sensitization using a dye to extend its sensitivity range into the infrared region of actinic radiation.

Various benzoxazole, benzothiazole and benzoselenazole cyanine spectral sensitizers have been used in infrared-photosensitive photothermographic materials based on organic silver salt / silver halide / reducing agent systems. No. 4,835,096 discloses a compound of the general formula:

[0010]

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Wherein R ₁ represents a lower alkyl group having 1 to 5 carbon atoms and X ⁻ represents an anion. A photothermographic element comprising a dye as a sensitizer is disclosed. JN03-163440A,
At least one compound of formula (I)

[0012]

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Wherein Z ₁ and Z ₂ are each S, O or Se, R ₁ ＝ H, alkyl, alkoxy,
R ₂ = carboxyalkyl or — (CH ₂ ) _n COOH, n = 1 to 4 and X = Cl, Br or I]. No. 5,441,866 preferably discloses a hydrophobic binder, a supersensitizer and a central nucleus of spectral sensitization amount:

[0014]

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[Wherein R ¹ is (CH ₂ ) _n having ¹ to 20 carbon atoms]
Represents a COO ^- group or an alkyl group having 1 to 20 carbon atoms,
And n is an integer from 1 to 20] and discloses a heat developable photothermographic element comprising an infrared dye-absorbing dye, and EP-A 616 014
Can be used in combination with supersensitizers such as 2-mercaptobenzimidazoles, metal chelators and pyridine, pyrimidine and triazine derivatives wherein the two nitrogen atoms of the cyanine chromophore have at least 5 carbon atoms. A heptamethine cyanine dye is disclosed that has a 5-carboxylalkyl substituent comprising an alkyl chain. The detailed description of all these patents and embodiments of the invention are limited to photoaddressable thermally developable elements coated from non-aqueous media.

These patents have no indication as to the application of the specific invention described therein to photothermographic recording materials comprising photoaddressable thermally developable elements coated from an aqueous medium. .

This means that a substantially light-insensitive organic silver salt coated from a non-aqueous medium, a light-sensitive silver halide and an organic silver salt which are in close catalytic association with said organic silver salt. Reflecting standard teachings on such photothermographic materials based on reducing agents. However, for economic, safety and morphological reasons, it is desirable to coat such materials from aqueous media.

Manufacturing methods according to standard teachings are very inefficient, require investment in explosion-prevention process and solvent recovery basic equipment and energy consumption in several drying steps, and Unhealthy. Accordingly, it is desirable to develop alternative material technologies that replace coatings from solvent media with coatings from aqueous media.

However, our work on the spectral sensitization of photothermographic materials based on an organic silver salt / silver halide / reducing agent system coated from an aqueous medium is based on a study of the material coated from an aqueous medium. Could not be easily applied to speculation.

In addition, all of the infrared-spectral sensitizers disclosed for spectral sensitization of such photothermographic materials require from 3 to 50 mol / mol of spectral sensitizer to exhibit acceptable spectral sensitization. Requires the presence of a concentration of a supersensitizer. The presence of such large amounts of additional components is disadvantageous both from an economic point of view and from the danger of disturbance to the functional components.

[0021]

OBJECTS OF THE INVENTION It is a first object of the present invention to provide a photothermographic recording material comprising a photoaddressable thermally developable element having high infrared sensitivity and excellent imaging properties coatable from an aqueous medium. It is to provide.

A second object of the present invention is to provide an infrared spectral sensitizer capable of effectively sensitizing a photoaddressable thermally developable element in the absence of a supersensitizer. That is.

Further objects and advantages of the present invention will become clear from the description hereinafter.

[0024]

SUMMARY OF THE INVENTION In accordance with the present invention, a support, and a substantially light-insensitive organic silver salt, a reducing agent therefor in thermal relationship therewith, a dye, spectrally sensitized to a wavelength of> 700 nm and A photosensitive silver halide in catalytic association with the substantially light-insensitive organic silver salt; and a water-soluble binder, a water-dispersible binder or a water-soluble binder and a water-dispersible binder. A photothermographic recording material comprising a photoaddressable thermally developable element containing a mixture with the photothermographic recording material, wherein the photothermographic recording material has an infrared sensitivity of less than 80 J / m ² and There is provided a photothermographic recording material characterized in that the dye satisfies the following test: prepared as described herein and the dye and formula

[0025]

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Exposure required by photothermographic recording material A consisting of a 100 μm thick polyester support provided with a photoaddressable heat developable element containing the corresponding compound was omitted. Is> 90% of the exposure required by photothermographic recording material B produced as described for photothermographic recording material A, except that the exposure of materials A and B is sensitive The optical density in the exposed portion is 0.5 times higher than the unexposed portion when exposed to infrared light and heated to 105 ° C. for 15 seconds with the heat source while contacting the polyester support with the heat source. What you need to get.

According to the present invention, (i) the substantially light-insensitive organic silver salt, photosensitive silver halide spectrally sensitized to infrared light with the dye, the reducing agent, and the water-soluble Producing one or more aqueous dispersions containing a binder, a water-dispersible binder or a mixture of a water-soluble binder and a water-dispersible binder, and (ii) the one or more aqueous dispersions. Also provided is a method of making the photothermographic recording material described above, comprising the step of coating the liquid on a support.

The term infrared for the purposes of the present invention is 7
It means light having a wavelength in the range from 00 nm to 1000 μm.

[0029] Preferred embodiments of the invention are disclosed in the claims.

[0030]

DETAILED DESCRIPTION OF THE INVENTION

Aqueous The term aqueous for the purposes of the present invention refers to water and water-miscible organic solvents such as alcohols such as methanol, ethanol, 2-propanol, butanol, iso-amyl alcohol, octanol, cetyl alcohol and the like; glycerols, For example, ethylene glycol, glycerin; N-methylpyrrolidone; methoxypropanol; and mixtures with ketones such as 2-propanone and 2-butanone.

Infrared-Spectral Sensitizing Dye According to the present invention, the photoaddressable thermally developable element comprises a dye that satisfies the following test: manufactured as described in the specification. And the dye and formula

[0032]

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The exposure required by the photothermographic recording material A consisting of a 100 μm thick polyester support provided with a photoaddressable heat developable element containing the corresponding compound was omitted. Is> 90% of the exposure required by photothermographic recording material B produced as described for photothermographic recording material A, except that the exposure of materials A and B is sensitive The optical density in the exposed portion is 0.5 times higher than the unexposed portion when exposed to infrared light and heated to 105 ° C. for 15 seconds with the heat source while contacting the polyester support with the heat source. What you need to get.

2,2'-disulfo-4,4'-bis [2-
The dilithium salt of {4,6-bis (2-oxy-naphtho)}-triazino] -aminostilbene was selected as supersensitizer for the above test, because the present applicant has Patent application title: Effective superchromic for photothermographic recording materials comprising a photoaddressable thermally developable element coated from an aqueous medium as disclosed in a European patent application and as seen from comparative examples This is because it is a sensitizer.

The photoaddressable thermally developable element used in the above test is prepared as follows: i) A stabilized aqueous solution of finely divided silver behenate with the following components: A coating dispersion is prepared by adding to the dispersion with stirring at a pH of 6.5: * an amount corresponding to 8 mol% of 3- (3 mol% with respect to silver behenate in the dispersion as an aqueous solution having a pH of 4 Triphenyl-phosphonium) propionic acid bromide, followed by stirring for at least 10 minutes.

[0036]

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2,2'-disulfo-4,4'-
Bilithium salt of bis [2- {4,6-bis (2-oxy-naphtho)}-triazino] -aminostilbene * Dye as solution or dispersion in water and / or methanol, followed by at least 15 minutes Agitation; * a weight of film-forming non-protein binder equal to silver behenate in an aqueous solution or dispersion having a pH of 4; and * an amount of 40 mol% with respect to silver behenate as aqueous solution. 3- (3 ', 4'-dihydroxyphenyl) propionic acid: ii) The dispersion is then coated on a subbed 100 μm thick polyethylene terephthalate support and dried to give about 4.5 g / m ² . The coating weight of silver behenate is given.

In a preferred embodiment of the invention, the photothermographic recording material has an infrared sensitivity of less than 20 J / m ² and in a particularly preferred embodiment of the invention, the photothermographic recording material has a red color of less than 8 J / m ^2. Has external sensitivity.

In a preferred embodiment of the photothermographic recording material of the present invention, the dye is a merocyanine dye, and in a further preferred embodiment of the photothermographic material of the present invention, the dye is a heptamethine cyanine dye.

In a particularly preferred embodiment of the photothermographic recording material of the present invention, the general formula (I) optionally having a charge-compensating anion:

[0041]

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Wherein Z ¹ and Z ² independently represent S, O or Se, and R ¹ and R ¹⁷ each independently represent at least one fluorine, chlorine, bromine, iodine or aryl oxy -, alkoxy -, - (C = O) - alkyl, - (S = O) -R ' or - (SO ₂₎ -R' is alkyl which may be substituted with a group, where R is alkoxy , aryloxy, amino or substituted amino group and R 'is hydroxy, mercapto, alkoxy, aryloxy, amino or substituted amino ^{group, R 2, R 3, R} 4, R 5, R 13 , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently hydrogen, chlorine, bromine, fluorine or keto-, sulfo-, carboxy-, ester-, sulfonamido-, amido-, dialkylamino-, nitro-, cyano − Alkyl -, alkenyl -, heteroaryl - aromatic, aryl -, alkoxy - or aryloxy - group, which groups may be substituted, or R ² together with R ^3, R ³ is together with R ^4, R ⁴ together with R ^5, R ¹³ together with R ^14, R ¹⁴ is and R ¹⁵ together with R ¹⁵ together with R ¹⁶ And each may independently constitute an atom necessary for completing an optionally substituted benzene ring;
⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently hydrogen, an alkyl group, a substituted alkyl group, an alkoxy group, an aryloxy group, a thioalkyl group, a thioaryl group, chlorine, fluorine , Bromine, iodine, a disubstituted amino group, wherein the substituents may comprise the atoms necessary to complete a 5- or 6-ring heterocyclic ring, or R ⁶ is with R ⁸ , R ⁸ is with R ¹⁰ , R ¹⁰ is with R ¹² , R ⁷ is with R ⁹ and R ⁹ is with R ¹¹ Together, they may form the atoms necessary to complete a 5- or 6-ring atom, which may be independently substituted, and R ¹ may be R ⁶ Together with R ¹² is R ¹⁷
And each may be independently substituted with 5-
Or an atom necessary for completing a heterocyclic ring having 6 or more ring atoms]. − (C =
R) in the O) -R group or-(S = O) -R 'and-(S
If the R ′ group in the O ₂ ) —R ′ group represents a substituted amino group, this includes all possible substituents of the amino group;
Whereby -NH- (C = O) -R " , - NH- (SO 2)
-R ", - NH- (S = O) -R", - N - -CN, -N - -
(C = O) -R ", - N - - (SO 2) -R", - N - - (SO)
-R "and -N ^-- CN groups, where R" is an optionally substituted alkyl or aryl group.

In a particularly preferred embodiment of the present invention, the dye is of the formula

[0044]

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Corresponds to

In a further particularly preferred embodiment of the present invention, the dye is of the formula

[0047]

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Corresponds to

In yet another particularly preferred embodiment of the present invention,
The dye is of the formula

[0050]

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Corresponds to

In yet another particularly preferred embodiment of the present invention,
The dye is of the formula

[0053]

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Corresponds to

Suitable infrared-sensitizing dyes to be used according to the invention are:

[0056]

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[0057]

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[0058]

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[0059]

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[0060]

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[0061]

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[0062]

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SENSI 01 was synthesized as described in Example 1 of the present invention. Embodiment 1 of the present invention
Synthesis techniques and FM Hamer, "The Cy
anine Dyes and Related Compounds ", Interscience Pu
Other infrared-sensitizing dyes according to the invention can be synthesized using synthetic techniques similar to those described in Blishers, Nwe York (1964).

The sensitivity of the photothermographic recording material comprising the infrared-sensitizing dye used according to the invention depends on the choice of the infrared-sensitizing dye, its concentration, the method of adding the infrared-sensitizing dye and the photothermography. It will depend on the exact composition of the recording material.

Photoaddressable Thermally Developable Element The photoaddressable thermally developable element used in accordance with the present invention is a substantially light-insensitive organic silver salt, in catalytic association with it. A light-sensitive silver halide and a substantially light-insensitive organic silver salt and an organic reducing agent in thermal relation with a water-soluble or water-dispersible binder. This element comprises a silver halide grain catalytically associated with a substantially light-insensitive organic silver salt, and optionally a silver halide grain optionally associated with a supersensitizer. And a layer system having other components active in the thermal development step or stabilization before or after development in the same layer or another layer, provided that the The organic reducing agent and, if present, the toning agent is in a thermal working relationship with the substantially light-insensitive organic silver salt, i.e., the reducing agent and, if present, the toning agent during the thermal development step. It is capable of diffusing into substantially light-insensitive organic silver salts.

Substantially Light-Insensitive Organic Silver Salts Suitable substantially light-insensitive organic silver salts for use in accordance with the present invention include organic carboxylic acids, especially aliphatic carbon chains having at least 12 carbon atoms. Silver salts of aliphatic carboxylic acids,
For example, silver laurate, silver palmitate, silver stearate, silver hydroxystearate, silver oleate and silver behenate, also referred to as "silver soap"; U.S. Pat. No. 4,504,5
Silver dodecyl sulfonate described in No. 75; and silver di- (2-ethylhexyl) -sulfosuccinate described in EP-A 227 141. For example, modified aliphatic carboxylic acids having a thioether group described in British Patent No. 1,111,492 and British Patent No. 1,111,492.
Other organic silver salts described in U.S. Pat. No. 439,478, such as silver benzoate and silver phthalazinone, may also be used to produce thermally developable silver images. Also included are silver imidazolates and the substantially light-insensitive inorganic or organic silver salt complexes described in U.S. Patent No. 4,260,677.

Light-sensitive silver halide The light-sensitive silver halide used in accordance with the present invention can be used within a range of 0.1 to 35 mol% of a substantially light-insensitive organic silver salt; A range of 20 mol% is preferred and 1 to 12 mol% is particularly preferred.

Silver halide includes, for example, silver bromide, silver iodide,
Any of photosensitive silver halides such as silver chloride, silver bromoiodide, silver chlorobromoiodide, silver chlorobromide and the like may be used. The silver halide may be in shapes including, but not limited to, photosensitive cubes, orthorhombic, tubular, tetrahedral, octahedral, etc., and having epitaxial growth of crystals thereon. May be.

The silver halide used according to the present invention may be used without modification. However, it can be used as a compound containing chemical sensitizers such as sulfur, selenium, tellurium, or gold, platinum, palladium, iron, ruthenium,
Chemical sensitization may be carried out using a compound containing rhodium or iridium, for example, a reducing agent such as tin halide, or a combination thereof. See TH James, "The Theory of the Photographi
c Process ", Fourth Edition, Macmillan Publishing C
o., Inc., New York (1977), Chapter 5, pages 149 to
169.

According to a preferred embodiment used in accordance with the present invention, the photosensitive silver halide grains are non-aggregating and substantially light-insensitive in a photoaddressable thermally developable element. Are uniformly distributed on and between the particles of the organic silver salt of which at least 80% of the particles have a diameter of < 40 nm as measured by transmission electron microscopy.

Emulsions of Organic Silver Salts and Photosensitive Silver Halides According to the method used according to the invention, a suspension of substantially light-insensitive organic silver salt particles is an aqueous solution of an organic carboxylic acid or a salt thereof. Or by simultaneous metered addition of a suspension and an aqueous solution of a silver salt to an aqueous liquid,
The metered addition of the aqueous solution or suspension of the organic carboxylic acid or its salt and / or the aqueous solution of the silver salt is adjusted by the concentration of silver ions or the concentration of silver salt anions in the aqueous liquid.

The silver halide can be added to the photoaddressable thermally developable element in such a way that it is placed in catalytic proximity to a substantially light-insensitive organic silver salt. A separately prepared, ie, not in-situ, or "pre-made" silver halide and a substantially light-insensitive organic silver salt are mixed in a binder prior to use to produce a coating solution. You can do it,
It is also effective to mix both of them over a long period of time. Further, a halogen-containing compound is added to the organic silver salt to partially convert the substantially light-insensitive organic silver salt to silver halide as disclosed in U.S. Pat. No. 3,457,075. It is also effective to use a method comprising:

According to another preferred embodiment for use in accordance with the invention, the aqueous emulsion of substantially light-insensitive organic silver salt particles comprises at least one aqueous emulsion of one or more halides or polyhalide anions. There is provided a method for producing a photothermographic recording material, further comprising the step of producing photosensitive silver halide grains by reacting with a species of onium salt.

The aqueous emulsion of an organic silver salt optionally containing light-sensitive silver halide is, according to the invention, prepared from particles of an organic silver salt optionally containing light-sensitive silver halide, Ball milling in the presence of a nonionic or anionic surfactant or a mixture of nonionic and anionic surfactants, e.g.
It can also be prepared by dispersion using any dispersion technique known to those skilled in the art, such as dispersion in a collision mill (rotor-star mixer), dispersion in a microfluidizer, and the like. . For example, a combination of a dispersing technique using a first technique for producing a preliminary dispersion and a second technique for producing a fine dispersion may be used.

According to the present invention, an aqueous dispersion of substantially light-insensitive organic silver salt particles is reacted with at least one onium salt having a halogenated or polyhalogenated anion. By doing so, photosensitive silver halide grains are produced. The onium cation used according to the invention may be polymeric or non-polymeric. Non-polymeric onium salts suitable for the partial conversion of substantially light-insensitive organic silver salt grains to the light-sensitive silver halide used in accordance with the present invention are: PC01 = 3- (Triphenyl-phosphonium) propionic acid bromide perbromide PC02 = 3- (triphenyl-phosphonium) propionic acid bromide PC03 = 3- (triphenyl-phosphonium) propionic acid iodide.

The onium salt is present in an amount between 0.1 and 35 mol% with respect to the amount of substantially light-insensitive organic silver salt, preferably between 0.5 and 20 mol%. And amounts between 1 and 12 mol% are particularly preferred.

Organic Reducing Agent for Photoaddressable Thermally Developable Element Coated from Aqueous Medium Substantially light-non-photosensitive in a photoaddressable thermally developable element coated from an aqueous medium Suitable organic reducing agents for the reduction of sensitive organic heavy metal salts are O, N or C
And an organic compound containing at least one active hydrogen atom bonded to Particularly suitable organic reducing agents for the reduction of substantially light-insensitive organic silver salts in such photoaddressable thermally atomizable elements are at least 3
Unsubstituted 6-membered aromatic or heteroaromatic ring compounds having one substituent, one of those substituents being a hydroxy group on the first carbon atom and Are hydroxy or amino-groups substituted on the second carbon atom, wherein three or five ring atoms have been removed from the first carbon atom of the compound in a conjugated double bond system, Wherein (i) the third substituent may be part of a fused carbocyclic or heterocyclic ring system, and (ii) the third or another substituent is an aryl group wherein the aryl group is hydroxy- Is not an aryl- or oxo-aryl- group substituted with a thiol- or amino-group, and (iii) a third or another substituent is a group wherein the second substituent is an amino group. Is non-sulfo-
It is an electron withdrawing group.

Particularly preferred reducing agents are substituted catechols or substituted hydroquinones, and 3- (3 ',
4'-dihydroxyphenyl) -propionic acid, 3 ',
Particularly preferred are 4'-dihydroxy-butyrophenone, methyl gallate, ethyl gallate and 1,5-dihydroxy-naphthalene.

Addition of Reducing Agent During the thermal development step, the reducing agent is present in such a way that it can diffuse into the substantially light-insensitive particles of the organic silver salt and the reduction of the organic silver salt can take place. There must be.

Auxiliary reducing agents The above reducing agents, which are considered to be the main or main reducing agents, may be used together with so-called auxiliary reducing agents. Auxiliary reducing agents that may be used in conjunction with the above main reducing agents are, for example, the sulfonyl hydrazide reducing agents disclosed in U.S. Pat. No. 5,464,738, such as those disclosed in U.S. Pat. No. 5,496,695. Trityl hydrazides and formyl-
Phenyl-hydrazides, and organic reducing metal salts,
For example, U.S. Patent Nos. 3,496,946 and 3,54.
No. 7,648, stannous stearate.

Water-Dispersible and Water-Soluble Binders According to the invention, the photoaddressable thermally developable element comprises a water-soluble binder, a water-dispersible binder or a water-soluble binder and a water-dispersible binder. A binder comprising a mixture with the binder. An important precondition in the choice of binder and binder-mixture is the ability to form a continuous layer with the other components in which they are present.

The water-dispersible binder is a water-insoluble polymer, such as a water-insoluble cellulose derivative, a polymer derived from an α, β-ethylenically unsaturated compound, such as polyvinyl chloride, post-chlorinated. Polyvinyl chloride, copolymer of vinyl chloride and vinylidene chloride, copolymer of vinyl chloride and vinyl acetate, polyvinyl acetate and partially hydrolyzed polyvinyl acetate, polyvinyl alcohol, repeating vinyl alcohol Is a polyvinyl acetal produced from polyvinyl alcohol as a starting material which may be reacted with an aldehyde, preferably polyvinyl butyral, a copolymer of acrylonitrile and acrylamide, polyacrylic esters, polymethacrylic esters, polystyrene And polyethylene or a mixture thereof Door can be. A particularly suitable polyvinyl butyral containing a small amount of vinyl alcohol units is sold under the trade name BUTVAR B79 of Monsanto USA and provides good adhesion to paper and properly primed polyester supports. No clear cut transition between polymer dispersion and polymer solution in the case of very small polymer particles resulting in relatively small particles of dissolved polymer and relatively large particles in the dispersion It should be noted.

Suitable water-soluble polymers used according to the invention are polyvinyl alcohol, polyacrylamide, polyacrylic acid, polymethacrylic acid, polyethylene glycol, proteins such as gelatin and modified gelatin such as phthaloyl gelatin, polysaccharides For example, starch, gum arabic and dextran and water-soluble cellulose derivatives.

To improve the layer-forming properties of the water-soluble and water-dispersible polymers, a plasticizer can be added to the polymer, a water-miscible solvent can be added to the dispersion medium, and Mixtures of water-soluble polymers, mixtures of water-dispersible polymers, or mixtures of water-soluble and water-dispersible polymers may be used.

The binder to organic silver salt weight ratio The binder to organic silver salt weight ratio is preferably in the range of 0.2 to 6 and the thickness of the photoaddressable thermally developable element. The length is preferably in the range of 1 to 50 μm.

Thermal Solvents The binders or mixtures thereof described above are treated with waxes which improve the rate of redox-reaction at elevated temperatures, ie “thermal solvents”, also called “thermal solvents” or “thermosolvents”. (heat solv
ents) ".

The term “thermal solvent” in the context of the present invention refers to a region in the recording layer which is solid at temperatures below 50 ° C. but is heated and / or for at least one redox-reactant. For example, a non-hydrolyzable organic substance that becomes a plasticizer at a temperature of 60 ° C. or more in a liquid solvent, such as a reducing agent for an organic silver salt.

Toning Agent To obtain a pure black image tone at relatively high densities and a pure gray at relatively low densities, the photoaddressable thermally developable element is preferably an organic silver salt and a reducing agent. It contains a so-called toning agent known from thermography or photothermography in admixture with the agent.

Suitable toning agents are disclosed in US Pat. No. 4,082,90.
Succinimides and phthalimides and phthalazinones within the general formula described in No. 1. See also the toning agents described in U.S. Pat. Nos. 3,074,809, 3,446,648 and 3,844,797. Other particularly useful toning agents are disclosed in British Patent No. 1,43.
No. 9,478 and U.S. Pat. No. 3,951,660, which are heterocyclic toning compounds of benzoxazinedione or naphthoxazinedione.

Toner compounds particularly suitable for use in combination with the polyhydroxybenzene reducing agent are described in US Pat. No. 3,951,660, 3,4-dihydro-2,4-dioxo-1, 3,2H-benzoxazine.

Stabilizers and Antifoggants Stabilizers and antifoggants can be included in the photothermographic materials of this invention to obtain improved shelf life and fog reduction. Examples of suitable stabilizers and antifoggants and their precursors, which can be used alone or in combination, include US Pat.
Thiazolium salts described in 1,038 and 2,694,716, azaindenes described in U.S. Pat. Nos. 2,886,437 and 2,444,605; U.S. Pat. 287,135; urazoles described in U.S. Pat. No. 3,235,652; UK patent 623,4.
Oximes described in No. 48; US Pat.
Thyuronium salts described in US Pat. No. 20,839; US Pat. Nos. 2,566,263 and 2,597,915
, Platinum and gold salts described in US Pat. No. 3,700,457; tetrazolyl-thio-compounds described in US Pat. No. 3,700,457; US Pat. Nos. 4,404,390 and 4,351,896. A mesoionic 1,2,4-triazolium-3-thiolate stabilizer precursor described in EP-A 600 587; a tribromomethyl ketone compound described in EP-A 600 587; an isocyanate described in EP-A 600 586 Combinations of nates with halogenated compounds; vinylsulfone and β-halosulfone compounds described in EP-A 600 589; and Chapter 9 of "ImagingProcesses and Materials,
Neblette's 8th edition ", D. Kloosterboer, J.S.
turge, edited by V. Walworth and A. Shepp, p. 279, V
an Nostrand (1989); in Research Disclosure 17029, J
l2_systemmessage [1978] = _strdup ("The compounds mentioned in this regard are included in the references cited in all of these articles.");

Surfactants According to the present invention, a water-dispersible binder such as a polymer latex is prepared in an aqueous medium for preparing a dispersion of substantially light-insensitive organic silver salt particles in an aqueous medium. A nonionic, cationic or anionic surfactant may be used to disperse the surfactant. In a preferred embodiment of the invention, the surfactant is a sulfonate, such as an alkyl, aryl, alkaryl or aralkyl sulfonate, and the alkyl and alkaryl sulfonates, such as MERSOLAT ^™ H, the sodium salt of an alkyl sulfonate from Bayer, USTRAVON ^™ W, the sodium salt of arylsulfonates from Ciba-Geigy, is particularly preferred.

Other Additives In addition to these components, the photoaddressable thermally developable element may contain other additives, such as free fatty acids, surfactants, antistatic agents, such as F ₃ C (CF ₂ ) ₆ CONH (CH
₂ CH ₂ O) —H as in non-ionic antistatic agents containing fluorocarbon groups, silicone oils such as BAYSI
LICONE OE1 A (trade name of Bayer AG, Germany), UV absorbing compounds, white light reflecting and / or UV reflecting pigments, silica, colloidal silica, fine polymer particles [eg those of poly (methyl methacrylate)] and / or Optionally, a lightening agent may be contained.

Antihalation Dye According to a preferred embodiment of the present invention, the photothermographic recording material also comprises an antihalation or acutance dye that absorbs light transmitted through the photosensitive layer and thereby prevents its reflection. Such dyes can be added in the photoaddressable thermally developable element or in other layers comprising the photothermographic recording material of the present invention. The antihalation dye may be bleached by heat during the heat development step or may be photo-bleached so that it can be removed after the heat development step and it may be contained in a layer that can be removed after the exposure step. Antihalation dyes suitable for use with infrared are EP
-A 377 961 and 652 473, EP-B 1
01 646 and 102 781, and U.S. Patent Nos. 4,581,325 and 5,380,635.

Support The support for the photothermographic recording material used according to the present invention may be transparent, translucent or opaque,
It may have, for example, a white light reflecting surface and is preferably, for example, paper, polyethylene coated paper, or a transparent resin film, for example made from cellulose esters, for example cellulose triacetate, corona and flame treated polypropylene, polystyrene , Polymethacrylates, polycarbonates or polyesters, such as British Patent 1,293,676, British Patent 1,441,304 and British Patent 1,454,95.
No. 6, it may be a thin flexible support made from polyethylene terephthalate or polyethylene naphthalate. For example, there are paper-based substrates that may contain a white reflective pigment, which may optionally be applied in an intermediate layer between the recording material and the paper-based substrate.

The support may be in the form of a sheet, ribbon or web, and may be subbed if necessary to improve adhesion with the upper heat-sensitive recording layer. A resin composition in which the support is made opaque, such as a pigment and / or
Alternatively, it may be made from polyethylene terephthalate, which is opaque by micropores and / or coated with an opaque pigment-binder layer, and may be a so-called synthetic paper or paper-like film, Information on various supports can be found in EP 194.
Nos. 106 and 234 563 and U.S. Pat. Nos. 3,944,699, 4,187,113, 4,7.
Nos. 80,402 and 5,059,579. If a transparent base is used, the base may be colorless or colored, for example having a blue color.

One or more backing layers may be provided to control physical properties such as curl or electrostatic properties.

Protective Layer According to a preferred embodiment of the photothermographic recording material according to the invention, in order to avoid local deformation of the photoaddressable thermally developable element, to improve its abrasion resistance and to thermally develop it. A protective layer is applied to the photo-addressable thermally developable element to prevent its direct contact with the components of the device used for the application.

The protective layer preferably comprises a binder, which may be solvent soluble (hydrophobic), solvent dispersible, water soluble (hydrophilic) or water dispersible. Among the hydrophobic binders, particular preference is given to cellulose acetate butyrate, polymethyl methacrylate and polycarbonates as described, for example, in EP-A 614 769.
Suitable hydrophilic binders are, for example, gelatin, polyvinyl alcohol, cellulose derivatives or other polysaccharides, hydroxyethylcellulose, hydroxypropylcellulose, etc .; curable binders are preferred and polyvinyl alcohol is particularly preferred.

The protective layer of the photothermographic recording material used according to the invention may be crosslinked. The cross-linking can be performed using a cross-linking agent for a protective layer described in, for example, WO 95/12495, for example, tetraalkoxysilanes, polyisocyanates, zirconates, titanates, melamine resins, and the like.
Tetraalkoxysilanes such as tetramethyl orthosilicate and tetraethyl orthosilicate are preferred.

The protective layer used according to the invention may further comprise in the binder at least one solid lubricant having a melting point below 150 ° C. and at least one liquid lubricant, wherein the lubricant At least one is a phosphoric acid derivative, another dissolved lubricating substance and / or a particulate substance which may optionally protrude from the outermost layer, such as talc particles. Examples of suitable lubricating substances are surfactants, liquid lubricants, solid lubricants which do not melt during the thermal development of the recording material, solid lubricants which melt during the thermal development of the recording material (heat-meltable) or mixtures thereof. It is. Lubricants can be applied with or without a polymeric binder.

Such a protective layer is described in WO 94/1119.
8 may include particulate matter, such as talc particles, which may optionally protrude from the outermost layer. Other additives, such as colloidal particles, such as colloidal silica, may be added into the protective layer.

Antistatic Layer In a preferred embodiment of the recording material of the present invention, an antistatic layer is provided on the outermost layer on the side of the support on which the photoaddressable thermally developable element is not coated. Applied. A suitable antistatic layer is EP-A 44
Nos. 4,326,534,006 and 644,456; U.S. Pat. Nos. 5,364,752 and 5,472,832; and DOS 4,125,758.

Coating The coating of any layer of the photothermographic recording material of the present invention may be, for example, a Modern Coating and Drying T
echnology, Edward D. Cohen and Edgar B. Gutoff
Editing, (1992) VCH Publishers Inc. 220 East 23rd Str
eet, Suite 909, New York, NY 10010, USA.

Photothermographic Recording Method The photothermographic recording materials used according to the invention are prepared using infrared light of a wavelength of> 700 nm, for example with infrared wavelength lasers or with infrared-laser diodes which emit, for example, at 780 nm, 830 nm or 850 nm. Exposure can be by using an image obtained by pixel-wise exposure, or by direct exposure to the object itself or an image therefrom using suitable irradiation with infrared radiation.

For the thermal development of the image-wise exposed photothermographic recording material used according to the present invention, any type capable of uniformly heating the recording material to the development temperature in a time acceptable for the application. , Such as contact heating, irradiation heating, and microwave heating.

In accordance with the present invention, (i) exposing the photothermographic recording material described above imagewise with actinic radiation to which the photothermographic recording material is sensitive, and (ii) exposing the imagewise exposed photothermographic recording material to actinic radiation. There is also provided a photothermographic recording method comprising thermally developing a thermographic recording material.

Applications The photothermographic recording materials of the present invention can be used for the production of both transmission and reflection type prints. This means that the support is transparent or opaque, for example, having a white reflective surface. For example, there are paper-based substrates that may contain white reflective pigments, which may optionally have been applied to an intermediate layer between the recording material and the paper-based recording. If a transparent base is used, the base may be colorless or colored, for example having a blue color.

In the field of hard copy, photothermographic recording materials on a white opaque base are used, whereas in the field of medical diagnostics, black image transparent positives are widely used in diagnostic techniques operated with light boxes.

Although the invention is described below in terms of preferred embodiments, it is to be understood that the invention is not limited to those embodiments. On the contrary, the intention is to cover all alterations, modifications and equivalents, which are included in the spirit and scope of the invention as defined by the appended claims.

[0111] In addition to the above components, the following were used in the photothermographic recording materials of the examples and comparative examples of the present invention.

A) Photoaddressable thermally developable element components for coating elements from aqueous media: BINDER 01: from 45% by weight methyl methacrylate, 45% by weight butadiene and 10% by weight itaconic acid SENSI C01:

[0113]

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[0114]

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[0115]

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The following Examples and Comparative Examples illustrate the present invention. The percentages and ratios used in the examples are by weight unless otherwise indicated.

[0117]

EXAMPLES Example 1 of the Invention Synthesis of SENSI 01 The synthesis of SENSI 01 involves the coupling of two intermediates A and B, which themselves are synthesized in a continuous synthesis step from a series of intermediates. .

Synthesis of Intermediate A: The first step in the synthesis of Intermediate A was the synthesis of D. D was prepared according to the following reaction scheme:

[0119]

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10 L of butyl acetate, 2425 g of F and 3038 g of E were added to the flask and the mixture was heated to reflux and then at reflux for a further 8 hours. Upon cooling to room temperature, the product precipitated. It is then filtered off and washed with butyl acetate, 74
A% yield of intermediate D was prepared.

Intermediate A was then synthesized according to the following scheme:

[0122]

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294 g of intermediate D, 343 g of intermediate C
And 600 mL of sulfolane were added to the flask and heated to 125 ° C. with stirring on an oil bath for 24 hours. The reaction mixture is then cooled to 60 ° C and 1200
mL of acetone was added. The resulting suspension was then stirred at room temperature for 1 hour, after which it was filtered and washed well with acetone to produce 51% yield of intermediate A.

Synthesis of Intermediate B The first step in the synthesis of Intermediate B was the preparation of Intermediate H according to the following synthetic scheme:

[0125]

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2 L of ethanol, 5.5 g of sodium ethoxide and 759 mL of diethyl malonate were added to the flask and the mixture was cooled to -30 ° C and the atmosphere above the mixture was changed to nitrogen. The temperature of the reaction mixture is
758 mL of acrolein dissolved in 750 mL of ethanol was then added over a period of 60 hours, keeping at 5 ° C. Upon completion of the acrolein addition, the temperature was spontaneously raised to room temperature and 8 g of sodium ethoxide dissolved in 180 mL of ethanol were added. After standing overnight, 19 mL of acetic acid was added and the reaction mixture was evaporated under reduced pressure. The liquid residue is then distilled under reduced pressure to 26
A% yield of intermediate H was prepared.

Intermediate H was then used to prepare intermediate G according to the following synthetic formula:

[0128]

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162 g of Intermediate H, 162 mL of ethanol and 0.16 g of p-toluenesulfonic acid monohydrate were added to the flask and mixed well at room temperature.
206 mL of Intermediate I are then added with stirring and the stirred reaction mixture is then added to the reaction until complete.
Heated to ４０40 ° C. 0.33 mL of a 33% solution of sodium methoxide is then added and the mixture is treated with 30-40.
Stirred at C for an additional 15 minutes. Finally, the reaction mixture was distilled under vacuum to produce 99% yield of Intermediate G.

Intermediate G was then used to prepare intermediate B according to the following reaction scheme:

[0131]

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In a flask, 73 mL of dimethylformamide was cooled to 0 ° C. 59 mL of phosphoryl chloride was then added with stirring and the mixture was stirred at room temperature for an additional hour. 98 g of intermediate G were then added with stirring and the mixture was stirred at room temperature for a further 90 minutes. 720 mL of ethanol and 3
3 mL of deionized water was then added and the mixture was stirred at room temperature for another 30 minutes. 273 mL of aniline were then added with stirring and the mixture was stirred at room temperature for a further 30 minutes. Finally 3000
mL of 6N hydrochloric acid solution was added and the mixture was stirred at room temperature for another 15 minutes. The resulting precipitate was filtered off and washed with a warm mixture of methanol and ethyl acetate to produce 86% yield of intermediate B.

Synthesis of SENSI 01: SENSI 01
Was prepared according to the following reaction scheme:

[0134]

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28 g of intermediate B, 180 mL of N, N-
Dimethylacetamide, 11 mL acetic anhydride and 37
mL of 1-8 diazabicyclo [5,4,0] undec-7ene was added to the flask and mixed at room temperature to produce an orange solution. 39 g of intermediate A were then added to the reaction mixture and then stirred at room temperature for 2.5 hours. An additional 9 mL of 1-8 diazabicyclo [5,4,0] undec-7ene was then added and the mixture was stirred at room temperature for another hour. Finally, 360 mL of acetone was added to precipitate the product and filtered, washed and dried to produce 62% yield of SENSI 01.

Examples 2 to 35 of the present invention and Comparative Examples 1 to
6 Silver behenate dispersion liquid 34 g (0.1 mol) of behenic acid was added to 340 mL of 65 ° C.
Of 2-propanol in 400 mL of 0.2 mL.
The conversion of behenic acid to sodium behenate by adding 5 M aqueous sodium hydroxide to the stirred behenic acid solution and finally adding 250 mL of 0.4 M aqueous silver nitrate to precipitate the silver behenate, Silver was produced. This is filtered off and then 10% by volume of 2
-Washing with a mixture of propanol and 90% by volume of deionized water to remove residual sodium nitrate.

After drying at 45 ° C. for 12 hours, the silver behenate is added to the anionic dispersant Ultra.
Dispersed in deionized water containing von ^™ W and Mersolat ^™ H to obtain a paste after rapid mixing using a high-speed collision mill (rotor-starter mixer) and homogenization using a microfluidizer.
0% by weight of silver behenate, 2.1% by weight of Ultravo
n ^™ W and 0.203% by weight of Mersolat ^™
A finely divided stable dispersion containing H was obtained. The resulting dispersion paste was adjusted to about 6.5.

The following components: 8 mol% with respect to silver behenate
2 g of 3- (triphenyl-phosphonium) propionic bromide (PC02) corresponding to the concentration of PC02
Was added to 3.0 g of the silver behenate dispersion with stirring at a pH such that a portion of the silver behenate was converted in situ to silver bromide. After stirring for a further 10 minutes, the supersensitizer was added with stirring in a solution in water and / or methanol as indicated in Table 1 and immediately afterwards the infrared-spectral sensitizer was indicated in Table 1. In water and / or methanol as previously described. After stirring for a further 15 minutes, 2 g of 30
% BINDER 01 at pH 4 and then 2% by weight
g of a 4.5% by weight aqueous solution of 3- (3 ', 4'-dihydroxyphenyl) propionic acid was added with stirring.

[0139]

[Table 1]

[0140]

[Table 2]

* Coating and drying of photothermographic materials, calculated using the amount of silver behenate present before partial conversion to silver halide. 90% silver / silver bromide dispersion
Doctor blade coating was performed with a blade setting of μm. After drying on the coating bed at 40 ° C. for 5 or 6 minutes, the emulsion layer was dried in a hot air oven at 40 ° C. for 1 hour.

Image-wise exposure and heat treatment The photothermographic materials of Examples 2-35 of the present invention and Comparative Examples 1-6 are focused at 12.8 mW to give a point diameter (1 / e ² ) of 115 μm. Exposure to a light beam of 836 nm diode laser type HL8318G manufactured by Hitachi, having a nominal power of 0, with a pitch of 63 μm and a 30% overlap at a speed of 5 m / s.
Scanned through wedge filters with optical densities varying between 3.3. The maximum exposure (filter optical density = 0) was about 50 J / m ² .

A heat treatment was carried out for 15 seconds using a metal block heated to a temperature of 105 ° C. on the side of the support not provided with the silver behenate / silver halide emulsion layer. The optical density of the image was measured by transmittance through a visible filter using a MacBeth ^™ TR924 densitometer,
A sensitometer curve for a photographic recording material was produced and then D _min
The exposure required to obtain an optical density of +0.5 was measured.

Examples 2 to 35 of the present invention and Comparative Examples 1 to
Exposure values for the optical density of D _min +0.5 obtained by image-wise exposure and heat treatment of the photothermographic recording material of No. 6 were compared with infrared sensitizer, supersensitizer, supersensitizer versus infrared The molar ratios of the sensitizers and the heat treatment conditions used are summarized in Table 2.

[0145]

[Table 3]

[0146]

[Table 4]

Table 2 shows that the spectral sensitization of the photothermographic recording material with the infrared sensitizing dye used according to the present invention produces sufficient spectral sensitization in the infrared region of the spectrum.
It is clear from the results. In the case of the infrared sensitizing dye used according to the invention, the infrared sensitizing dye SENSI C01,
2,2'-Disulfo-4,4'-bis [2, a supersensitizer exhibiting sufficient supersensitization of the photothermographic recording materials of Comparative Examples 2, 4 and 6 using SENSI C02 and SENSI C03 -{4,6-bis (2-oxy-
The presence of the dilithium salt of naphtho)}-triazino] -aminostilbene indicates that 2,2′-disulfo-4,
4'-bis [2- {4,6-bis (2-oxy-naphtho)}-
Only the omission of the dilithium salt of [triazino] -aminostilbene resulted in optical densities of D _min +0.5 between 100% and 712% of the required exposure with different photothermographic materials. This demonstrates the unexpected infrared sensitizing properties of the dyes used according to the present invention in photothermographic recording materials coated from aqueous media comprising photoaddressable thermally developable elements. I have.

While the preferred embodiment of the invention has been described in detail, it will be apparent to those skilled in the art that many modifications may be made without departing from the scope of the invention as defined in the claims. Will.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Paul Currant Belgium 2640 Maltcell Septes Trat 27 Agfa-Gevert na Mrose Fennoutjajap (72) Inventor Hermann Witzterhoven Belgium Bee 2640 Malt Cell Septes Trat 27, Agfa-Gevert Naar, in Mrose-Fennoutjap

Claims (2)

[Claims] 1. A support, and a substantially light-insensitive organic silver salt, a reducing agent therefor in thermal relation therewith,
Photosensitive silver halide spectrally sensitized to a wavelength of> 700 nm with a dye and catalytically associated with the substantially light-insensitive organic silver salt, and a water-soluble binder, a water-dispersible binder Alternatively, a photothermographic recording material comprising a photoaddressable thermally developable element containing a mixture of a water-soluble binder and a water-dispersible binder, wherein the photothermographic recording material is 80 J / m2. A photothermographic recording material characterized by having an infrared sensitivity of less than ² and the dye satisfying the following test: prepared as described in the specification and comprising the dye and the formula 1) The exposure required by a photothermographic recording material A consisting of a 100 μm thick polyester support provided with a photoaddressable thermally developable element containing a compound corresponding to > 90% of the exposure required by photothermographic recording material B produced as described for photothermographic recording material A, wherein the exposure of materials A and B is exposed to infrared radiation to which it is sensitive And obtaining an optical density in the exposed portion which is 0.5 times higher than the unexposed portion when the polyester support is heated to 105 ° C. for 15 seconds with the heat source in contact with the heat source. It is necessary. 2. (i) the substantially light-insensitive organic silver salt, a photosensitive silver halide spectrally sensitized to infrared by the dye, the reducing agent and the water-soluble binder, water Producing one or more aqueous dispersions containing a mixture of a dispersible binder or a water-soluble binder and a water-dispersible binder,
2. The method for producing a photothermographic recording material according to claim 1, comprising a step of (ii) coating the one or more aqueous dispersions on a support.