JPS62156653A - Manufacture of photothermal photographic material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to photothermography (photothermography).
ic) relating to recording materials and their manufacturing methods.

Photothermographic materials are light-sensitive materials that can be imagewise exposed to light and then processed by the application of heat to form a visible image.

Conventional silver halide recording materials, which have great advantages, have severe limitations that in most cases they must be processed in wet conditions using several processing liquids. This is a drawback that has shocked research into silver halide threads that provide access to images in a dry process while retaining the fundamental advantageous properties inherent in the use of silver halide.

Dry imaging based on the use of silver halide as a photosensitive material is described, for example, in British Patent No. 1110046 and consists of two main constituents: (a) a relatively small amount of halogenation; (b) Imaging with large amounts of non-light-sensitive imageable materials, especially silver soaps such as silver behenate and reducing agents, is operated with layering.

Components (,) and (b) are photolyzed from silver halide while heating the recording layer to about 100°C for a few seconds.
Catalytic proximity means that one must be able to catalyze the image-forming redox reaction between the silver soap and the reducing agent and thus develop the silver image.
proximity).

Good photosensitivity is achieved by the fact that the required silver halide is produced in situ at the surface of the non-photosensitive complex salt by reaction with a compound that generates halide ions, as described for example in US Pat. Obtained when formed.

The materials obtained by that method are sensitive in the short wavelength range of the visible spectrum due to the inherent sensitivity of the silver halide formed, and can be spectrally sensitized to longer wavelength light by the addition of a spectral sensitizing dye. can.

According to one embodiment described in U.S. Pat. No. 3,457,075, in situ formation of silver halide is performed using hydrogen bromide as a source of halide ions in equal volumes of alcohol and water such that the silver soap is dispersed. is being carried out. The dispersion is thoroughly mixed by stirring, whereby the silver halide is formed in situ, ie, in reactive combination with the other components necessary for photothermographic imaging.

According to another embodiment described in the above-mentioned U.S. Pat. No. 3,457,075, the first coating is a silver soap, e.g., silver stearate, in a binder such as polyvinyl butyral from a mixture of a polar solvent such as acetone and a non-polar solvent such as toluene. A second coating containing polyvinylpyrrolidone, ammonium bromide, hydroquinone, and a spectral sensitizer is applied thereon from acetone. The amount of ammonium bromide is about 4 mole percent of silver stearate.

According to one embodiment described in U.S. Pat. No. 3,770,448, the silver halide is coated in the recording layer with a non-photosensitive silver salt at their surface by a vapor of hydrohalic acid, e.g. hydrogen chloride in the vapor phase. It is generated on the spot by processing.

As is generally known, chemical reactions involving ionic substances proceed faster and occur in a medium containing polar solvents than in a medium with non-polar properties, since polar solvents are This is because it causes dissociation in the form of reactive ions.

Journal of Dispersion Science and Technology - Volume 4, No. 1, Pages 29-45 (1
(983) provides a study of the precipitation of silver chloride in microemulsion media. According to a particular embodiment described therein, an ionic surfactant, aerosol (AERO8OL), in dry hebutane to make a microemulsion of an aqueous silver nitrate solution and an aqueous sodium chloride emulsion.
OT [(American Cyanamid Corporation trade name for sodium 2-ethyl-hexylsulfosuccinate) was used. For precipitation of silver chloride, an aliquot of silver nitrate microemulsion was added to an equal volume of 1 volume of sodium chloride microemulsion and the mixture was shaken rapidly. A rapid exchange of reagents occurs between the water pool (i.e. the aqueous salt phase) surrounded by a surfactant structure and the non-polar hebutane, and the silver chloride is
irrverted micelles (irrverted micells), also called reverse micelles
).

The formation of inverted micelles in non-aqueous solvents is described, for example, in Topics in Current Chemistry, Vol. 87, pp. 86-145 (1979) by H.F.・Polar Trubenz Aggregation and Miscellation” and Advanced Colloid Interface・
Science Vol. 12, pp. 109-140 (1980
(2010) by Nie Kitahora as ``Solbilization and Catalysis, in Reverse Micelle'', published by Blenheim Press, New York, K.
It was published as "Solution Chemistry of Surfactan" by El Khalid in El Mittal, Volume 1, Page 429 (1979). More recent work on reversed micelles can be found in the book Reverse Micelles J (1988), edited by P.L. Luigi and B.E. Straub, published by Plenum Press, New York.
4 years).

Micelles of organic surfactants in non-polar solvents have an inverted structure of surfactant micelles in aqueous solutions. In aqueous surfactant solutions, micelles have a hydrocarbon core, whereas in nonpolar organic solvents, inverted micelles have a dense polar core containing water in the center of the micelle.

It is an object of the present invention to provide the manufacturability of photothermographic materials using the formation of small quantities of photosensitive silver halide in small aqueous phase centers surrounded by surfactants in a non-polar liquid medium.

Another object of the present invention is to provide photothermographic materials incorporating light-sensitive silver halide in small aqueous phase centers that are studded with surfactants in a solid non-polar binder medium.

Other objects and advantages of the invention will become apparent from the description below.

According to the present invention, a method for producing a photothermographic material is provided, which method comprises: (1) activating an interface in a non-polar liquid medium in the presence of water used in a small amount relative to the non-polar liquid; (2) reacting halogen ions with silver ions in water;
(3) by mixing the micelles in the non-polar liquid medium with a film-forming polymeric organic binder that is soluble in the liquid medium; forming a film-forming photosensitive coating composition, wherein the liquid medium contains a dissolved or dispersed developing agent for the exposed silver halide; (4) coating the composition onto a support; evaporation to leave a solid photosensitive layer on the support.

As used herein, "a small amount of water relative to the non-polar liquid" means less than 10% by volume of water relative to the volume of the non-polar liquid.

According to one embodiment, a hydrophilic colloid, such as gelatin, is introduced into the core of the micelles.

According to another embodiment, the photosensitive layer is applied in combination with an undercoat and/or a topcoat containing a developing agent that can diffuse into the photosensitive layer when heated.

Surfactants are amphiphilic substances characterized by a relatively large non-polar hydrophobic molecular moiety that chemically binds and carries a polar hydrophilic molecular moiety, which allows the substance to lower the surface tension of water. It has the property of causing

Surfactants suitable for use in making inverted micelles are cationic, anionic, and nonionic surfactants.

In cationic surfactants, the ion containing the organic portion of the molecule is the cation. Examples of cationic surfactants include alkylammonium salts and salts of high molecular weight amines. In anionic surfactants, the ion containing the organic portion of the molecule is an anion. Examples of anionic surfactants include higher carboxylic acid metal soaps, sulfosuccinates, higher alkyl sulfonates, and alkylaryl sulfonates.

Examples of nonionic surfactants include alkyl or alkylaryl substituted polyoxyalkylene compounds such as isooctyl phenyl polyoxyethylene ether.

Preferred surfactants for the formation of inverted micelles with a relatively large capacity to contain aqueous liquid in the core are amphiphiles having one branched hydrocarbon chain or two separate hydrocarbon chains attached to the ionic structure. substance
θ8). Examples of such surfactants include di-(2-
06-C1 of ethylhexyl]-sulfosuccinic acid, mono(2-hexyl-decyl) phosphoric acid ester and phosphoric acid
There is a sodium salt of 8 alkyl diester. Particularly suitable for containing large amounts of aqueous liquid is R-N H-(
CH2) n-COOH (R is C12-C18 alkyl and n is 1-4) are other amphiphiles with ionic moieties of the betaine type, such as in the form of aminocarboxylic acids.

According to a first embodiment for producing silver halide in the core of inverted micelles, a cationic surfactant with a halogen counterion is mixed in a non-polar solvent, e.g. aliphatic, cycloaliphatic, in the presence of a small amount of water. Formula group or aromatic hydrocarbon liquids or mixtures thereof are dispersed to form inverted micelles, and a small amount of water containing a dissolved silver salt such as silver nitrate is mixed therewith, at least partially into the core of said micelles. introduction to obtain the formation of silver halide within the core.

According to a second embodiment of the production of silver halide in the core of inverted micelles, an anionic surfactant with silver counterions is mixed in a non-polar solvent, e.g. an aliphatic solvent, in the presence of a small amount of water.
A small amount of water containing a dissolved halogen salt, e.g. It is also partially introduced into the core of the micelles to obtain the formation of silver halide within the core.

According to a third embodiment, silver halide is prepared within the core of inverted micelles by dispersing a surfactant in a non-polar solvent in the presence of a small amount of water containing a water-soluble silver salt, e.g. silver nitrate. forming inverted micelles and mixing therewith a small amount of water containing a dissolved halide, such as ammonium bromide, such that at least a portion of the aqueous solution of the halide salt is introduced into the core; formation within the core.

Fourth Embodiment for Producing Silver Halide in the Core of Inverted Micelles 1 According to a surfactant in a non-polar solvent in the presence of a small amount of water containing a water-soluble halogen salt, e.g. sodium chloride. to form inverted micelles and mix with it a small amount of water containing a dissolved silver salt, e.g. silver nitrate, thereby at least partially introducing an aqueous solution of the silver salt into said core. None, silver halide formation occurs within the core.

According to a fifth embodiment of the preparation of silver halide in the core of inverted micelles, a surfactant is dispersed in a non-polar solvent in the presence of a small amount of water containing a water-soluble silver salt such as silver nitrate. Form a first group of inverted micelles by dispersing a surfactant in the above non-polar solvent in the presence of a small amount of water containing a water-soluble halide salt such as ammonium bromide. forming and mixing both groups of micelles, thus causing the aqueous content of the core to intermix and causing the formation of silver halide within the core.

According to a sixth embodiment of producing silver halide in the core of inverted micelles, an anionic surfactant having a silver ion as a countercation and a cationic surfactant having a halogen, e.g. a chloride ion, as a countercation are combined in small amounts. Form inverted micelles by simultaneous mixing in a non-polar liquid medium in the presence of water.

Amounts of photosensitive silver halide of 1 to 30% relative to non-photosensitive silver salt are sufficient to form catalytically active silver in thermal reduction processes.

The organic silver salts used in the photothermographic materials of the present invention as substantially non-photosensitive, image-silver-forming substances are silver salt surfactants that form inverted micelles with photosensitive silver halide in the core. Preferably, but higher alkyl (01
Silver salts of aliphatic carboxylic acids, known as silver sulfonates and fatty acids, preferably containing at least 12 carbon atoms, such as silver behenate and silver stearate, with groups □~C2□) may be used in addition to n-hebutane, but they must be used in dispersed form, since these salts are inherently insoluble in non-polar liquids such as n-hebutane.

The use of silver dodecyl sulfonate in photothermographic recording materials is described, for example, in US Pat. No. 4,504,575.

For example, U.S. Pat. No. 3,770,448 and U.S. Pat.
As described in No. 435,499, silver behenate and silver stearate can be used in the presence of free fatty acids such as behenic acid, since the recording composition of the photothermographic material is alkaline in order to become developable. That means it's not necessary. Other non-photosensitive silver compounds for use in thermographic recording materials are described in GB 1111492.

The non-photosensitive silver salt used according to the invention has a relatively low melting point, preferably 10 Preferably, it has a melting point of less than 0.degree.

When the photothermographic recording material of the present invention is heated, reverse me 1
z /L/ is for disaggregation (desaggregate)
, catalytic contact of the exposed silver halide with a non-photosensitive silver compound forming the main portion of the image silver.

According to a preferred embodiment, the anionic surfactant containing silver counterions not only serves to generate sufficient silver ions to form a small amount of photosensitive silver halide within the core of the inverted micelles. , in an amount that also provides the amount of silver ion necessary for imagewise thermal development of the photothermographic material following imagewise exposure.

Particularly suitable anionic surfactants for this purpose are n
- Di-(2 -ethylhexyl)-sulfosuccinic acid silver salt. Other sulfonate salts which form inverted micelles in nonpolar solvents such as n-hebutane form smaller micelles in hatripentylmethylbenzene sulfonate and dinonylnaphthalene sulfonate.

The silver salt of di-(2-ethylhexyl)-sulfosuccinic acid was produced, for example, as follows = 1 3, 3 9 (
30 mmol) of sodium di-(2-ethylhexyl)-sulfosuccinate were dissolved in 900 at of distilled water by vigorous stirring. While maintaining the above stirring, the resulting solution was added with 1 ml of water in 20 ml of water.
A solution of 0.29 (60 mmol) silver nitrate was added. The solution became slightly turbulent. Stirring was continued for 4 hours at 20°C. The aqueous liquid was then diluted with diethyl ether, once at 200 °C.
Extracted using 100++/ml, three times. After separation, residual water was removed, and the ether in the extract was evaporated under reduced pressure. The white solid residue was introduced into methanol in the presence of decolorizing charcoal and 2
Stirred at 0°C for 4 hours. After filtration and evaporation of methanol, a white waxy material was obtained. This at 20℃ for 12
Dry for an hour. Yield = 12g. The silver content determined by titration was 15.53%, which corresponds to a conversion of the sodium salt to silver salt of 77%.

The preparation of silver di-(2-ethylhexyl)-sulfosuccinate can be similarly carried out in a manner analogous to the preparation of silver salts of fatty acids as described in U.S. Pat. No. 3,700,458.

Reducing agents which act as developing agents for the exposed silver halide in the photothermographic recording material according to the invention include, for example, hydroquinone and their derivatives, which are used in acidic media to resist their oxidation by oxygen in the air. It is preferable to use it in Preferred developing agents that resist air oxidation include 0-alkyl substituted phenols, aminophenols and methoxynaphthols and their derivatives. 0- suitable as reducing agent for photothermographic recording materials
Examples of alkyl-substituted biphenols are published German Patent Application (DE-OS) No. 2,321,328 and US Pat.
No. 589901. Additional reducing agents for use in photothermographic recording materials are described in Research Disclosure, June 1978, Item 17029.

Other components that are useful in image formation during heat treatment include, for example, substances that liberate alkali when heated, so-called alkali precursors. Representative examples of these are listed in the Research Disclosures mentioned last above. Particularly useful for liberating alkali by thermal decarboxylation is guanidinium trichloroacetate.

Other such precursors include, for example, British Patent No. 1141
It is described in No. 591. Urea and silylamines that produce ammonia when heated to 80°C or higher and/or
Alternatively, there are co-crystalline adducts of amines and bisphenols, such as those described in US Pat. No. 3,076,707, which liberate the amine when heated.

Still other useful ingredients include image tone modifiers (toning agents) and chemical and spectral sensitizers.

The thermographic recording layer may contain pigments that are n-type photoconductors to improve photographic speed. Such pigments include, for example, photoconductive zinc oxide (French process) made by reduction of titanium dioxide and zinc vapor. The use of zinc oxide in thermographic recording materials is described, for example, in US Pat. No. 3,457,075.

Any suitable chemical and/or spectral sensitizer known in silver halide photography can be used to improve the overall and/or spectral sensitivity of the photothermographic materials made according to the invention; such sensitizers The silver halide is mixed into the aqueous medium in the core of the inverted micelles to bring them into contact.

Toning agents which are preferably used in thermographic recording materials according to the invention include, for example, 7-talazinone derivatives as described in British Patent No. 1,420,815.

For the production of the photothermographic recording material according to the invention, the inverted micelles described above are incorporated into a suitable film-forming binder which is soluble in such non-polar solvents as to give rise to the formation of micelles. Suitable film-forming binders that are soluble in aliphatic or cycloaliphatic raw hydrocarbon liquids include, for example, inbutyl methacrylate, stearyl methacrylate, copolymers of methacrylic acid (75/24.810.2), styrene and dodecyl. Copolymers of methacrylate, isobutyl methacrylate, lauryl methacrylate, methacrylic acid, and vinyltoluene, isobutyl methacrylate, stearyl methacrylate (60/20/2
(0% by weight) copolymers and low molecular weight polybutenes.

The support used in the photothermographic recording material according to the invention is described in Research Disclosure, June 1978, No. 1702.
It can be a resin film support as described in Section 9 or paper.

Film and paper supports having a glass transition temperature of 190°C or higher are preferred, but other materials capable of withstanding processing temperatures, e.g. temperatures in the range 80-150°C, such as glass and metal supports, are also preferred Can be used for

The photothermographic recording layer can be coated with an overcoat layer to reduce its susceptibility to fingerprints and to reduce its susceptibility to scratches that may occur during heat processing. Suitable overcoat layers are also described in the aforementioned Research Disclosure, which also describes many of the components of color developing photothermographic recording materials. Components suitable for the production of color images include, for example, color couplers which react with oxidized reducing agents or developing agents, or leuco dyes which become image-wise oxidized on heat treatment.

The following examples illustrate the invention but do not limit it. All ratios and percentages are by weight unless otherwise specified.

Example 1 The following composition A for the production of a thermographic recording material according to the invention
, B, C and D were made.

Composition A 0.618 g (0,006
1?1O1) of sodium bromide.

Composition B 5 g of isobutyl methacrylate, stearyl methacrylate, methacrylic acid (75/24.870.2%) dissolved in 50 ml of n-hebutane by sonication
) copolymer.

Composition C 0, 55 g (0,01 of OOS) of hydroquinone
ome in distilled water.

Silver di-(2-ethylhexyl)sulfosuccinate of composition D a6q was dissolved in 50 Wtl of composition B by sonication.

To make a photothermographic film, 2.5 d of composition was added to a sufficient amount of composition B to obtain a total volume of 1 k 5 ml. After the mixing step, 13 μl of composition A was added and sonication continued until a white cloudy dispersion was obtained. The mixture thus obtained was coated on a polyethylene terephthalate support to a wet coating thickness of 200 μm and dried in air to remove the n-heptane.

The dried photothermographic layer had a total silver compound equivalent to 0.889 silver for 1-, more specifically 0.2809 A3Br for 1-.

It contained 3 grams of water and 8.39 grams of Composition C copolymer.

UV rays used in dry film chromatography
It was exposed for 5 minutes through a halftone pattern using 360 nm light from a lamp, treated with ammonia vapor for 1 minute, and heated at 100° C. for 5 minutes.

The density (D) obtained in the exposed area was 0.8.

Example 2 Hydroquinone was converted into bis-(4-hydroxyphenyl)-
Example 1 was repeated with the only change being the substitution of 2,2'-furopane (bisphenol A).

In a 5-ply flask, add 138 μl of distilled water and 2.5 μl of distilled water.
ml of the composition of Example 1 was added to 1 l 101 n of bisphenol A and mixed by sonication.

Add 150μl of acetone to obtain a clear liquid, then add composition B of Example 1 and 42μl while continuing sonication.
1 of Composition A was added to obtain a cloudy dispersion.

Film materials were prepared and exposed as described in Example 1.

The density (D) obtained in the exposed area was 0.510.

Example 3 5.7 g of hydroquinone monosulfonic acid monopotassium salt was added to 154 μl of distilled water, followed by 25 ml of the composition of Example 1. Sonicate the mixture until clear and continue to sonicate composition B and 26μ
l of sodium bromide aqueous solution C1.59 to 5ml of distilled water
(prepared by dissolving NaBr) was added. A white cloudy mixture was obtained.

The mixture thus obtained was coated on a polyethylene terephthalate support to a wet coating thickness of 200 μm and dried in air to remove the n-hebutane.

The dried photothermographic layer is 0.2801i for Ifrl.
1 AgEr, 3 g water and 8.3 g composition C
It contained a copolymer of

The dried film was exposed as described in Example 1 and
Treated in ammonia vapor for minutes and heated at 100° C. for 5 minutes.

The density (D) obtained in the exposed area was 25.

Example 4 154 μl of distilled water was added to 6.1 g of potassium salt of hydroquinone monosulfonic acid and 9.6 to 9.6 g of guanidinium trichloroacetate to obtain a solution. 2 for this
5 parts of the composition of Example 1 were added and the mixture was sonicated until clear. The resulting mixture has a final volume of 5
A sufficient amount of Composition B from Example 1 was added to obtain the vtl.

Then 26 μl of 3m01 sodium bromide aqueous solution was added and sonication was continued which resulted in a cloudy dispersion.

The dispersion thus obtained was coated on a polyethylene terephthalate support to a wet coating thickness of 200 μm and dried in air to remove the n-hebutane.

Transfer the dried film to Dupuri Photo H8130 (DUP
LIPHOT H3l 3 Q: Ultraviolet rays are emitted through a halftone pattern using a contact exposure device manufactured by Agfa Gev (product name of Lut N.V.) in Belgium.
Exposure was performed for 20 seconds using eight 25W mercury vapor lamps. The density (D) produced in the exposed area was 0.98.

procedural correction band Showa Otsu 1/February 77th

Claims (1)

[Claims] 1. (1) Inverted micelles having a polar core are produced by mixing a surfactant in a non-polar liquid medium in the presence of water used in a small amount relative to the non-polar liquid; (2) reacting halogen ions with silver ions in water to introduce a small amount of silver halide into the polar core of the micelles; (4) a film-forming polymer mixed with an organic binder to form a film-forming photosensitive coating composition and containing a dissolved or dispersed developing agent for silver halide exposed to the liquid medium; A method for producing a photothermographic material comprising the steps of coating the composition on a support and evaporating the non-polar liquid leaving a solid photosensitive layer on said support. 2. The method according to claim 1, wherein a hydrophilic colloid is introduced into the core of the micelles. 3. The method according to claim 1 or 2, wherein the photosensitive layer is applied in combination with an undercoat and/or a top layer coating containing a developing agent that can diffuse into the photosensitive layer when heated. . 4. To produce silver halide in the core of inverted micelles, a cationic surfactant with a halogen counterion was dispersed in a non-polar solvent in the presence of a small amount of water to form inverted micelles and dissolved therein. 2. A method as claimed in claim 1, in which a small amount of water containing silver salts is admixed and introduced at least partially into the core of the micelles to obtain the formation of silver halide within the core. 5. To produce silver halide in the core of inverted micelles, an anionic surfactant with silver counterions is dispersed in a nonpolar solvent in the presence of a small amount of water to form inverted micelles, and the dissolved halogen salt A method as claimed in claim 1, in which a small amount of water containing is mixed therewith and introduced at least partially into the core of the micelles to obtain the formation of silver halide within the core. 6. To produce silver halide in the core of inverted micelles, a surfactant is dispersed in a nonpolar solvent in the presence of a small amount of water containing a water-soluble silver salt to form inverted micelles, and A patent for mixing with a small amount of water containing a dissolved halide, thereby introducing at least a portion of the aqueous solution of the halide salt into the core, causing the formation of silver halide within the core. Claims 1 to 3
The method described in any one of the sections. 7. In order to produce silver halide in the core of inverted micelles, a surfactant containing a water-soluble halogen salt is dispersed in a non-polar solvent in the presence of a small amount of water to form inverted micelles. mixed with a small amount of water containing dissolved silver salts,
Claims 1 to 3, whereby an aqueous solution of silver salt is at least partially introduced into the core, causing the formation of silver halide within the core. The method described in. 8. To produce silver halide in the core of the inverted micelles, the first step of the inverted micelles was prepared by dispersing a surfactant containing a water-soluble silver salt in a non-polar solvent in the presence of a small amount of water. A second group of inverted micelles is formed by dispersing a surfactant containing a water-soluble halogen salt in the non-polar solvent in the presence of a small amount of water, and mixing both groups of micelles. 4. A method as claimed in any one of claims 1 to 3, wherein the aqueous contents of the core are mixed and the formation of silver halide occurs within said core. 9. In order to produce silver halide in the core of inverted micelles, a cationic surfactant having a halogen ion as a counter-anion and an anionic surfactant having a silver ion as a counter-ion were mixed into a non-polar surfactant in the presence of a small amount of water. 4. A method according to any one of claims 1 to 3, wherein inverted micelles are formed by simultaneous mixing in a liquid medium. 10. In the production of inverted micelles, an anionic surfactant containing silver counterions is used to generate sufficient silver ions to form a small amount of photosensitive silver halide within the core of the inverted micelles. Any one of claims 1 to 9 used in such an amount as to provide not only the amount of silver ions required for image-forming thermal development following image-wise exposure of the photothermographic material. The method described in one of the following. 11. The method according to claim 10, wherein a silver salt of di-(2-ethylhexyl)-sulfosuccinic acid is used as the anionic surfactant. 12. Hydroquinone or its derivatives, or o-alkyl substituted phenols, aminophenols,
12. The method according to any one of claims 1 to 11, wherein methoxynaphthol or a derivative thereof is incorporated. 13. Claims 1 to 1 in which a substance that generates an alkali when heated is mixed into the thermographic recording material.
The method described in any one of Section 2. 14. Titanium dioxide and/or
Or, claim 1 contains photoconductive zinc oxide.
The method according to any one of Items 1 to 13.