JP2002214750A - Exposure method of heat developing photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure method of a heat developing photosensitive material by which the adaptability for ultrafast process, process stability, dot quality and linearity are improved. SOLUTION: The exposure method of a heat developing photosensitive material is carried out by exposing a heat developing photosensitive material containing organic silver particles, silver halide particles, a reducing agent and a contrasting agent on a support to two or more emission beams. It is preferable that the exposure wavelength of the two or more emission beams is >=700 nm, the average particle size of the silver halide particles included in the heat developing photosensitive material ranges from 0.02 to 0.06 μm, and that the angle made by the incident light and the reflected light on a spinner ranges from 88.0 to 92.0 deg. during the exposure to two or more emission beams.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for exposing a photothermographic material, and more particularly, to a method for exposing a photothermographic material capable of obtaining high density and high linearity.

[0002]

2. Description of the Related Art Conventionally, in the field of printing plate making and medical treatment, waste liquids caused by wet processing of image forming materials have become a problem in terms of workability. Weight loss is strongly desired. Therefore, there is a need for a technique relating to photothermographic materials for photographic applications, which enables efficient exposure with a laser imagesetter or laser imager and can form a high-resolution and clear black image. This technique includes, for example, U.S. Pat. Nos. 3,152,904 and 3,487,075 and D.C. "Dry Silver Photograph" by Morgan
ic Materials) ”(Handbook o
f Imaging Materials, Marce
l Dekker, Inc. 48, 1991), a photothermographic material containing an organic silver salt, photosensitive silver halide particles, a reducing agent and a binder on a support is known.

[0003] These photothermographic materials form a photographic image by a heat development process, and include a reducible silver source (organic silver salt), a photosensitive silver halide, a reducing agent and, if necessary, a silver salt. A color toning agent for suppressing color tone is usually contained in a dispersed state in an (organic) binder matrix. The photothermographic material is stable at room temperature, but after exposure to high temperatures (80 to 14).
(0 ° C.). Heating generates silver through an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. This redox reaction is
It is accelerated by the catalytic action of the latent image generated on the silver halide upon exposure. The silver formed by the reaction of the organic silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image. This reaction process proceeds without supplying a processing liquid such as water from the outside.

Although such photothermographic materials are partially used in the printing plate making market in view of improving the working environment, rapid processing is also desired from the viewpoint of working efficiency. However, when a photothermographic material is used for printing plate making, its linearity and exposure latitude are inferior to those of a conventional photosensitive material, and improvement thereof has been desired.

[0005] US Patent Nos. 5,464,738 and 5,4
Nos. 96,695 and 5,545,515 describe the use of hydrazine compounds and acrylonitrile compounds for high contrast. However, since these compounds are powerful reducing agents, they degrade the processing stability during development and the raw storage stability. For example, a desired halftone image may be uneven due to temperature fluctuation during processing, or fog may occur due to high temperature storage in a warehouse in summer.

[0006] Further, ultra-rapid processing is required from the viewpoint of work efficiency. However, with hydrazine compounds and acrylonitrile compounds alone, ultra-rapid processing can be performed but processing stability is sacrificed. But it was.

[0007] From the environmental point of view, the coating is preferably not a solvent system but an aqueous system. In the case of an aqueous system, a solid dispersion must be added since the material is insoluble in water. However, when dispersed in a solid state, it is necessary to diffuse an additive in the light-sensitive material before the chemical reaction of heat development, which has a disadvantage that it is not suitable for ultra-rapid processing.

On the other hand, multi-beam exposure is known in conventional exposure of a photosensitive material to increase the exposure speed. With conventional photosensitive materials, no effect on photographic performance was found for single beam or multi-beam, and only the effect of increasing the exposure speed was found. Further, the conventional photothermographic material is exposed only to a single beam instead of a multi-beam, and the conventional photothermographic material has no photographic effect.

The photothermographic material has low sensitivity and the output of the light source is increased to increase the density, or a large amount of dye is added to cause interference fringes. (DQ) is inferior to conventional photosensitive materials.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for exposing a photothermographic material which is improved in ultra-rapid processing suitability, processing stability, dot quality and linearity.

[0011]

In view of the above circumstances, the present inventor has attempted to solve these problems from the exposure method. However, the use of multi-beam exposure increased the density, and caused interference fringes and linearity. And DQ also improved. Regarding the density increase, it is an estimation to the last, but when performing exposure while overlapping the beams with a single beam, the overlap part is drawn twice,
At this time, the latent image nuclei formed or likely to be formed may be destroyed, or the electrons and the holes that are trying to form the latent image nuclei may be recombined, so that the increase in density may be hindered.

It has also been found that the use of the high contrast agent of the present invention and the use of silver halide grains having an average particle size of 0.02 to 0.06 μm make the above effect more remarkable. Reached.

That is, the object of the present invention is to provide a photothermographic material containing organic silver particles, silver halide particles, a reducing agent and a high contrast agent on a support by exposing the photothermographic material with two or more light-emitting beams. This was achieved by the method of exposing the developed photosensitive material.

The exposure wavelength of the two or more emission beams is 700 nm or more, and the average particle diameter of the silver halide grains contained in the photothermographic material is 0.02 to 0.06.
μm, the angle between the incident light on the spinner and the reflected light when exposing with two or more emission beams is 88.0-9.
The range of 2.0 degrees is a preferred embodiment.

Hereinafter, the present invention will be described more specifically. In the present invention, the photothermographic material is exposed with two or more beams, and this exposure is called "multi-beam exposure".
This means that when performing exposure using a laser diode (LD) or LED, simultaneous exposure is performed using two or more light beams, which is different from a multi-mode laser that performs exposure using a plurality of wavelengths. This exposure system includes, for example, JP-A-10-133.
No. 132 and No. 5-5846.

In the multi-beam exposure, an exposure system can be designed relatively easily with an external cylinder type or flat bed type image setter, but a spinner (mirror) can be designed with an internal cylinder type.
Special control is required because the beams intersect during one revolution. The spinner refers to a mirror rotating body as shown in FIG. 1 at 30 described in JP-A-10-133132.

Usually, the beams are exposed in an overlapped manner, and the overlap coefficient, which is the ratio of the half width (FWHM) of the beam intensity of the light beam diameter to the width of the sub-scanning pitch, is 0.1 to 0.1.
1.5 is preferred.

In the present invention, the exposure wavelength of the multi-beam needs to be 700 nm or more.
0 nm, preferably between 700 and 90 nm.
0 nm is desirable.

Next, the organic silver particles, silver halide particles, reducing agent and high contrast agent contained in the photothermographic material used in the present invention will be described.

The photosensitive silver halide functions as an optical sensor. The average particle size is preferably small, 0.1 μm or less, more preferably 0.01 to 0.1.
μm, particularly preferably 0.02 to 0.08 μm. The term "grain size" as used herein refers to the length of a ridge of a silver halide grain when the silver halide grain is a cubic or octahedral so-called normal crystal. In the case of non-normal crystals, for example, in the case of spherical, rod-shaped, or tabular grains, it refers to the diameter of a sphere equivalent to the volume of silver halide grains.
Further, the silver halide is preferably monodispersed. Here, the monodispersion means that the degree of monodispersion obtained by the following equation is 40.
Say the following. The particle size is more preferably 30 or less, and particularly preferably 0.1 to 20.

Monodispersity = (standard deviation of particle size) / (average value of particle size) × 100 The shape of silver halide grains is not particularly limited, but the proportion occupied by the Miller index [100] plane is high. It is preferable that this ratio is 50% or more, further 70% or more,
In particular, it is preferably at least 80%. Another preferred form of silver halide is tabular grains. The term “tabular grain” as used herein refers to the square root of the projected area as the particle size r μm.
Where the aspect ratio = r / h when the vertical thickness is h μm is 3 or more. Among them, the aspect ratio is preferably 3 to 50. The particle size is 0.1
μm or less, more preferably 0.01 to 0.0
8 μm is preferred.

The halogen composition is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide. For photographic emulsions, acid method, neutral method,
It may be prepared using any method such as an ammonia method,
Further, as the formation of reacting the soluble silver salt with the soluble halogen salt, any one of a one-side mixing method, a simultaneous mixing method, a combination thereof and the like may be used. The silver halide may be added to the image-forming layer in any manner, with the silver halide being positioned close to the reducible silver source. Further, the silver halide may be prepared by converting a part or all of the silver in the organic acid silver by the reaction of the organic acid silver and the halogen ion into silver halide, or may be prepared by preparing silver halide in advance. In advance, this may be added to a solution for preparing an organic silver salt, or a combination of these methods is possible, but the latter is preferred. Generally, the silver halide is preferably contained in an amount of 0.75 to 30% by mass based on the organic silver salt.

The silver halide used in the present invention preferably contains metal ions belonging to groups 6 to 11 of the periodic table. The above metals include W, Fe, Co, N
i, Cu, Ru, Rh, Pd, Re, Os, Ir, P
t and Au are preferred.

The photosensitive silver halide grains can be desalted by washing with water using a method known in the art such as a noodle method or a flocculation method. The photosensitive silver halide grains are preferably chemically sensitized. Preferred chemical sensitization methods include sulfur sensitization, selenium sensitization, tellurium sensitization, noble metal sensitization such as gold compounds, platinum, palladium, and iridium compounds, and reduction sensitization, as is well known in the art. Sensitization can be used.

Organic silver is a reducible silver source, and silver salts of organic acids and heteroorganic acids containing a reducible silver ion source, especially long chains (10-30, preferably 15-25 carbon atoms). The aliphatic carboxylic acid and the nitrogen-containing heterocyclic ring are preferred. Organic or inorganic silver salt complexes wherein the ligand has a total stability constant for silver ions of 4.0 to 10.0 are also useful. An example of a suitable silver salt is Research Discl
osure (RD) 17029 and 29996. Preferred silver sources are silver behenate, silver arachidate and silver stearate.

The organic silver compound can be obtained by mixing a water-soluble silver compound and a compound which forms a complex with silver. The organic silver compound can be obtained by a forward mixing method, a reverse mixing method, a simultaneous mixing method, or a method disclosed in JP-A-9-127743.
The controlled double jet method as described in No. 1 is preferably used.

The average particle size of the organic silver particles is 0.2 to 1.2 μm.
m, more preferably 0.35 to 1
μm. The organic silver particles are preferably monodispersed, and have a monodispersity of 1 to 30.

In order to prevent devitrification of the light-sensitive material, the total amount of silver halide and organic silver is preferably 0.5 to 2.2 g per m ² in terms of silver.

Next, the reducing agent for silver ions will be described.
Examples of suitable reducing agents are described in US Pat. No. 3,770,448,
Nos. 3,773,512 and 3,593,863 and RD17029 and 29963. Among them, particularly preferred reducing agents are hindered phenols, and include the following compounds.

1,1-bis (2-hydroxy-3,5-
Dimethylphenyl) -3,5,5-trimethylhexane bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane 2,2-bis (4-hydroxy-3-methylphenyl)
Propane As the high contrast agent used in the present invention, JP-A-2000-
Preferred are a substituted alkene derivative of the general formula (1), a substituted isoxazole derivative of the general formula (2), an acetal compound of the general formula (3), and a hydrazine derivative of the general formula (H) described in JP-A-112066. Can be Specific examples of the compound include C-1 for general formulas (1) to (3).
To C-64, and 1 to 137 for the general formula (H). As the hydrazine derivative, JP-A-200
Compounds represented by the general formula (H) described in JP-A-147708 (H-1 to H-63 are exemplified);
No. 779, the compound represented by the general formula [H] (H-1)
To H-30), but as the vinyl compound,
General formulas (1) to (1) described in JP-A-11-119372.
There is a compound represented by 4) (1 to 66 are exemplified).

The layer to which the high contrast agent is added is a photosensitive layer containing silver halide and / or a layer adjacent to the photosensitive layer. The addition amount depends on the particle size of the silver halide grains, the halogen composition,
Although the optimum amount is not uniform depending on the degree of chemical sensitization, the kind of the inhibitor, etc., it is preferably 1 × 10 ^-6 to 1 mol per mol of silver, more preferably 1 × 10 ^{-5 to} 5 × 10 ^-1 mol. Preferably 2 ×
Most preferably, it is 10 ^{-5 to} 2 × 10 ^-1 mol.

It is also preferable to use a high contrast accelerator in addition to these high contrast agents. For this purpose, for example, the amine compounds described in US Pat. No. 5,545,505 (Example A)
M-1 to AM-5), hydroxamic acids (specific examples HA-1 to HA-11) and acrylonitriles (specific examples CN-1 to CN-13) described in JP-A-5-545507. No. 558,983, hydrazine compounds (specific examples CA-1 to CA-6), and quaternary onium salts described in JP-A-10-207022 (specific examples P-1 to P-55, T)
-1 to T-18) can be used.

A method for synthesizing and adding the above-mentioned high contrast promoting agent,
The cited patent can be referred to for the addition amount and the like.

Preferred embodiments of the photothermographic material include:
An undercoat layer, a photosensitive layer, and a photosensitive layer surface protective layer may be provided in this order on a support and provided on the photosensitive surface side. The undercoat layer is preferably composed of two or more layers, and the total thickness is about 0.2 to 5 μm, preferably 0.5 to 3 μm. The thickness of the photosensitive layer is preferably 5 to 13 μm, more preferably 7 to 13 μm.
１１11 μm. The thickness of the photosensitive layer surface protective layer is 2 to 10
μm is preferred, and more preferably 4 to 8 μm. The surface protective layer of the photosensitive layer preferably contains a matting agent, and the matting agent has an average particle size of about 1 to 10 μm, preferably 3 to 7 μm.
μm.

On the back surface side, it is preferable to provide an undercoat layer, a back layer, and a back layer surface protective layer on the support in this order. The undercoat layer is preferably composed of two or more layers, and the undercoat layer closest to the support is preferably an antistatic layer containing a conductive metal oxide and / or a conductive polymer. As the conductive metal oxide, SnO ₂ surface-treated with Sb is preferable, and as the conductive polymer, polyaniline is preferable. The sum of the thickness of the undercoat layer is 0.2 to 4 μm
Degree, preferably 0.5 to 2 μm. The thickness of the back coat layer is preferably 2 to 10 μm, more preferably 4 to 8 μm.
It is. The back coat layer preferably contains an antihalation dye. The thickness of the back coat surface protective layer is preferably 2 to 10 μm, more preferably 4 to 8 μm. It is preferable that a matting agent is contained in this surface protective layer. The average particle size of the matting agent is about 1 to 10 μm, preferably 3 to
7 μm.

[0036]

EXAMPLES The present invention will be described below with reference to examples, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, “%” in the examples represents “% by mass”.

Example 1 <Preparation of Photothermographic Material Sample S-1> (Preparation of PET support) PET (polyethylene terephthalate) pellets were dried at 130 ° C. for 4 hours, and then dried.
After being melted at 0 ° C. and extruded from a T-die, it was rapidly cooled to produce an unstretched film. This was longitudinally stretched 3.0 times using rolls having different peripheral speeds, and then horizontally stretched 4.5 times using a tenter. The temperature at this time is 110 ° C., respectively.
130 ° C. After that, it was heat-set at 240 ° C. for 20 seconds, and relaxed 4% in the horizontal direction at the same temperature. After this,
After slitting the chuck portion of the tenter, knurling was performed on both ends, and the film was wound at 3.92 × 10 ⁵ Pa. Thus, a width of 2.4 m, a length of 800 m, and a thickness of 125
A roll of μm PET film was obtained.

Each of the biaxially stretched and heat-fixed PET film supports prepared as described above was provided with 8 W /
m ² · min of corona discharge treatment, on one side, the following undercoating coating solution a-1 is applied so as to have a dry film thickness of 0.8 μm and dried to form an undercoating layer A-1, On the opposite surface, the following antistatic coating solution b-1 was applied with a dry film thickness of 0.8.
It was applied and dried so as to have a thickness of μm to obtain an antistatic processed subbing layer B-1. Undercoat coating liquid a-1 Copolymer latex liquid of butyl acrylate / t-butyl acrylate / styrene / 2-hydroxyethyl acrylate (30/20/25/25% ratio) (solid content 30%) 270 g Compound (C -1) 0.6 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g Polystyrene fine particles (average particle size 3 μm) 0.05 g Colloidal silica (average particle size 90 μm) 0.1 g Finish to 1 L with water Coating solution b-1 SnO ₂ / Sb (9/1 mass ratio, average particle size 0.18 μm) Amount to become 200 mg / m ² Butyl acrylate / styrene / glycidyl acrylate (30/20/40% ratio) copolymer latex Liquid (solid content 30%) 270 g Compound (C-1) 0.6 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g Finish to 1L with water Then, on the upper surface of the undercoat layer A-1 and the undercoat layer B-1,
A corona discharge of 8 W / m ² · min.
On top of the lower coating layer A-2, a lower coating layer A-2 is formed as the lower coating layer A-2 so that the dry coating thickness a-2 is 0.1 μm.
-1 is coated with the following undercoating layer coating solution b-2 having a dry film thickness of 0.
Coating was performed so as to have a thickness of 8 μm as an undercoating upper layer B-2 having an antistatic function. Undercoating upper layer coating solution a-2 Gelatin 0.4 g / m ² amount Compound (C-1) 0.2 g Compound (C-2) 0.2 g Compound (C-3) 0.1 g Silica particles (average particle size) 0.1 g Finished to 1 L with water Undercoating upper layer coating solution b-2 Compound (C-4) 60 g Latex liquid containing compound (C-5) as a component (solid content 20%) 80 g Ammonium sulfate 0.5 g Compound (C-6) 12 g Polyethylene glycol (weight average molecular weight 600) 6 g Finish to 1 L with water

[0039]

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[0040]

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(Heat Treatment of Support) In the above-mentioned undercoat drying step of the undercoated support, the support was heated at 140 ° C.
Then, it cooled gradually. This support was 2.94 × 10
^It was wound up with a tension of ⁵ Pa. <Preparation of photosensitive emulsion> (Preparation of silver halide emulsion) In 900 ml of water, 7.5 g of inert gelatin and 10 mg of potassium bromide were dissolved.
After adjusting to 35 ° C. and pH 3.0, 370 ml of an aqueous solution containing 74 g of silver nitrate, an aqueous solution containing sodium chloride, potassium bromide and potassium iodide in a molar ratio of (60/38/2), and [Ir (NO ) Cl ₅ ] salt 1 × 10
^-6 molar and rhodium chloride salt 1 × 10 ^-6 mol aqueous solution containing 3
70 ml was added by the controlled double jet method while keeping the pAg at 7.7. Thereafter, 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, and the resulting mixture was adjusted to pH 8 and pAg 6.5 with sodium hydroxide to perform reduction sensitization. 08
μm, coefficient of variation of projected diameter area of monodispersity 10% 8%,
[100] An emulsion composed of cubic silver iodobromide grains having an area ratio of 87% was obtained. This emulsion was subjected to coagulation sedimentation using a gelatin coagulant and desalting treatment, and then 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and the pAg to 7.5 to obtain a silver halide emulsion. (Preparation of Na behenate solution) In 945 ml of pure water, 32.4 g of behenic acid, 9.9 g of arachidic acid and 5.6 g of stearic acid were dissolved at 90 ° C. Next, 98 ml of a 1.5 mol / L aqueous sodium hydroxide solution was stirred at a high speed.
Was added. Next, after adding 0.93 ml of concentrated nitric acid,
C. and stirred for 30 minutes to obtain a sodium behenate solution. (Preparation of preform emulsion) 1.51 g of the above silver halide emulsion was added to the above-mentioned sodium behenate solution, the pH was adjusted to 8.1 with sodium hydroxide solution, and 147 ml of a 1 mol / L silver nitrate solution was added over 7 minutes. In addition, the mixture was further stirred for 20 minutes, and water-soluble salts were removed by ultrafiltration. The produced silver behenate has an average grain size of 0.8 μm and a monodispersity of 8%.
Particles. After the floc of the dispersion was formed, the water was removed, and the resultant was washed with water six times, and then dried with a flash jet drier.

Using 1/2 of the preform emulsion,
Polyvinyl butyral (average molecular weight 3000)
544 g of butyl ethyl ketone solution (17%) and toluene 1
After adding and mixing 07g gradually, 0.5mm size
Media disperser using zirconium oxide bead mill
For 30 minutes at 4000 psi. <Coating of sample> The following layers were formed on the support described above.
Coat both sides simultaneously to obtain photothermographic material sample S-1
Was. The drying was performed at 60 ° C. for 15 minutes. (Back side coating) On the B-2 layer of the support, the following composition
(1m)^TwoPer coated amount). Backing layer coating solution Cellulose acetate butyrate (10% MEK solution) 2.5 ml Cellulose acetate propylate (10% MEK solution) 5 ml Dye (F-1) 650 nm Optical density of 0.9 A matting agent (monodisperse) Degree 15%, average particle size 8μm monodisperse silica) 90mg C₈F₁₇(CH_TwoCH_TwoO)₁₂C₈F₁₇ 50 mg sodium p-perfluorononylbenzenesulfonate 10 mg C₉F₁₇SO_TwoN (C_ThreeH₇) CH_TwoCOONa 5mg Backing protective layer coating solution Cellulose acetate butyrate (10% MEK solution) 5ml C₈F₁₇SO_ThreeLi 50mg C₉F₁₇(CH_TwoCH_TwoO)_{twenty two}C₉F₁₇ 50 mg Compound (C-7) 50 mg (coating on photosensitive layer side) A photosensitive layer coating solution having the following composition was coated on layer A-2 of the support at a silver amount of 1.5 g / m 2. ^Two It was applied so that it became. Coating solution for photosensitive layer 240 g of the photosensitive emulsion 240 g of sensitizing dye (SD-1) (0.1% methanol solution) 1.7 ml pyridinium bromide perbromide (6% methanol solution) 3 ml calcium bromide (0.1% methanol solution) 1.7 ml Oxidizing agent (O-1) (10% methanol solution) 1.2 ml 2-carboxy-4'-chlorobenzophenone (12% methanol solution) 9.2 ml 2-mercaptobenzimidazole (1% methanol solution) 11 ml Tribromomethylsulfoquinoline (5% methanol solution) 17 ml Hardener-1 0.1 g Hardener-2 1.0 g Phthalazine 0.6 g 4-Methylphthalic acid 0.25 g Tetrachlorophthalic acid 0.2 g Average particle size 3 μm 0.1 g of 1,1-bis (2-hydroxy-3,5-dimethylphenol) Enyl) -2-methylpropane (20% methanol solution) 20.5 ml Dye (F-1) Amount at which the optical density of 650 nm on the emulsion side (including the protective layer) becomes 0.2 Compound (C-8) 0 0.5 g Compound (C-9) 1.0 g Compound (C-10) 0.5 g Compound (C-11) 0.3 g Compound (C-12) 0.4 g Compound (C-13) 0.3 g Compound (C -14) 0.2 g Compound (C-15) 0.3 g MEK: methyl ethyl ketone O-1: [CH_ThreeCON (CH_Three)_Two]_TwoHBr ・ Br_Two

[0043]

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[0044]

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A coating solution for a surface protective layer having the following composition was simultaneously coated on the photosensitive layer (indicated by the coating amount per m ² ). Coating solution for surface protection layer Acetone 5 ml Methyl ethyl ketone 21 ml Cellulose acetate butyrate 2.3 g Methanol 7 ml Phthalazine 250 mg Matting agent (monodispersion degree 10%, average particle size 4 μm monodisperse silica) 5 mg C ₈ F ₁₇ SO ₃ Li 50 mg C ₉ F ₁₇ (CH ₂ CH ₂ O) ₂₂ C ₉ F ₁₇ 50 mg Using the sample S after forming the coating film, removing the binder, and observing by an electron microscope with a replica method, the organic silver particles were found to have a long axis diameter. Tabular grains having a thickness of 0.5 ± 0.05 μm, a minor axis diameter of 0.4 ± 0.05 μm, and a thickness of 0.01 μm were grains having a monodispersity of 5%, which accounted for 90% of all organic silver grains. <Preparation of Photothermographic Material Sample Y-1> (Preparation of silver halide emulsion A) 11 g of phthalated gelatin, 30 mg of potassium bromide, and 10 mg of sodium benzenethiosulfonate were dissolved in 700 ml of water, and the pH was adjusted at 40 ° C. After adjusting to 5.0, 159 ml of an aqueous solution containing 18.6 g of silver nitrate and 1 mol / L of potassium bromide, (NH
4) 5 × 10 ⁻⁶ mol / L of 2RhCl ₅ .H ₂ O and K
_An aqueous solution containing ₃ × 10 ⁻⁵ mol / L of ₃ IrCl ₆ was pAg
While maintaining at 7.7, it was added over 6 minutes and 30 seconds by the controlled double jet method. Then, 55.5 silver nitrate.
476 ml of an aqueous solution containing 1 g / g and 1 mol / L of potassium bromide
A halogen salt aqueous solution containing 2 × 10 ⁻⁵ mol / L of K ₃ IrCl ₆ and K ₃ IrCl ₆ was added by a controlled double jet method over 28 minutes and 30 seconds while maintaining the pAg at 7.7. Thereafter, the pH was lowered to cause coagulation sedimentation and desalting treatment, and 0.17 g of compound (C-16) and 23.7 g of deionized gelatin (calculated as 20 ppm or less) were added.
H5.9 and pAg8.0 were adjusted. The resulting silver halide grains in the middle of the emulsion were cubic grains having an average grain size of 0.08 μm, a projected area variation coefficient of 9%, and a [100] plane ratio of 90%.

The silver halide emulsion thus obtained was heated to 60 ° C., and 7.6 × 10 ^-5 mol of sodium benzenethiosulfonate per mol of silver was added. ^10-4 mol was added and the mixture was aged for 100 minutes, and 4-hydroxy-6-methyl-1,3,3a, 7 was added.
After addition of 5 × 10 ⁻⁴ mol of ^{tetrazaindene} ,
The temperature was lowered.

Thereafter, the temperature was maintained at 40 ° C., and 12.8 × 10 ^-4 mol of sensitizing dye (S
D-1), 6.4 × 10 ⁻³ mol of the compound (C-17) was added with stirring, and after 20 minutes, the mixture was rapidly cooled to 30 ° C. to complete the preparation of silver halide emulsion A.

[0048]

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(Preparation of organic acid silver salt dispersion) 6.1 g of arachidic acid, 37.6 g of behenic acid, 700 ml of distilled water, t
-70 ml of butanol and 123 ml of a 1 mol / L aqueous sodium hydroxide solution were mixed, reacted by stirring at 75 ° C for 1 hour, and cooled to 65 ° C. Next, 112.5 ml of an aqueous solution of 22 g of silver nitrate was added over 45 seconds, left as it was for 5 minutes, and the temperature was lowered to 30 ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate became 30 μS / cm. The solid content thus obtained was handled as a wet cake without drying, and the dry solid content was 1%.
To a wet cake equivalent to 00 g, 7.5 g of polyvinyl alcohol (trade name: PVA-217) and water were added to make the total amount 500 g, and the mixture was preliminarily dispersed with a homomixer.

The stock solution having been pre-dispersed is dispersed in a dispersing machine (Microfluidizer M-110S-EH, G, manufactured by Microfluidics International Corporation).
10Z interaction chamber).
The mixture was adjusted to 72 × 10 ⁷ P and treated three times to obtain an organic acid silver dispersion A. The organic acid silver particles contained in this organic acid silver dispersion have an average minor axis diameter of 0.04 μm, an average major axis diameter of 0.8 μm,
Needle-like particles having a coefficient of variation of 30%. Particle size measurements are available from Malvern Instruments Ltd.
Manufactured by Master SizerX. The cooling operation was performed by installing a coiled heat exchanger before and after the interaction chamber and adjusting the temperature of the refrigerant to a desired dispersion temperature. Thus, an organic acid silver salt A having a silver behenate content of 85 mol% was prepared. (Preparation of solid fine particle dispersion of reducing agent) 1,1-bis (2
-Hydroxy-3,5-dimethylphenyl) -3,5
3.0 g of MP polymer (manufactured by Kuraray Co., Ltd .: MP-203) and 77 ml of water were added to 20 g of 5-trimethylhexane, stirred well, and left as a slurry for 3 hours. Thereafter, 360 g of 0.5 mm zirconia beads were prepared, put into a vessel together with the slurry, and dispersed for 3 hours with a dispersing machine (manufactured by Imex Co., Ltd .: 1/4 G sand grinder mill) to prepare a solid dispersion of reducing agent solid particles. did. As for the particle diameter, 80% of the particles were 0.3 to 1.0 μm. (Preparation of solid fine particle dispersion of antifoggant) 0.5 g of hydroxypropylmethylcellulose and 0.5 g of compound (C-18) were added to 30 g of tribromomethylphenylsulfone.
g and 88.5 g of water were added, stirred well, and left as a slurry for 3 hours. Thereafter, a solid fine particle dispersion of the antifoggant was prepared in the same manner as the preparation of the reducing agent solid fine particle dispersion. 80% of the particles have a diameter of 0.3 to 1.0 μm.
m. (Preparation of Coating Solution for Emulsion Layer) Silver 1 of the organic acid silver salt dispersion described above
The following binder, material and silver halide emulsion A were added to the moles, and water was added to prepare an emulsion layer coating solution. Emulsion layer coating solution Binder (Luckstar 3307B: manufactured by Dainippon Ink and Chemicals, SBR Latex, glass transition temperature 17 ° C) 406 g (solid content) 119 g of the reducing agent (solid content) 21.6 g of the antifoggant (solid) Min) sodium benzenethiosulfonate 0.44 g benzotriazole 1.25 g polyvinyl alcohol (MP-203: supra) 20 g i-propylphthalazine 0.10 mol sodium dihydrogen orthophosphate 0.13 g development inhibitor (DI-1) 9.38 g Hardening agent-3 0.03 mol Dye (F-1) Amount at which the optical density at 650 nm becomes 0.3 Silver halide emulsion A 0.05 mol as Ag amount

[0051]

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(Preparation of coating solution for non-photosensitive layer) Polymer latex (Luckstar 3307B: SBR latex manufactured by Dainippon Ink and Chemicals, Tg = 17 ° C., solid content concentration 4)
4%) to 102 g of compound (C-19) as a film-forming aid
5 g, 0.2 g of compound (C-20), 4 g of dye (F-1) and polyvinyl alcohol (PVA-235: manufactured by Kuraray Co., Ltd.) so that the optical density at 650 nm becomes 0.5.
Was added, and water was further added to prepare a non-photosensitive layer coating solution. The pH of the coating solution was 5.6.

[0053]

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(Preparation of Coating Solution for Emulsion Surface Protective Layer) Polymer latex of methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid (59/9/26/5/1% ratio) (glass transition) (Temperature: 54 ° C., solid content: 44%, C-19: 15% as a film-forming aid)
75 g of carnauba wax (Cerosol 524:
1.89 g of a 30% solution of Chukyo Yushi Co., Ltd., compound (C-2)
0) 0.188 g, 2.55 g of 4-methylphthalic acid, matting agent (polystyrene particles having an average particle diameter of 7 μm) 0.56
g and polyvinyl alcohol (PVA-235: supra)
0.4 g was added, and water was further added to prepare an emulsion surface protective layer coating solution. The pH of the coating solution was 2.8. <Preparation of PET Support with Back Layer / Undercoat Layer> (1) Support Using terephthalic acid and ethylene glycol, IV (intrinsic viscosity) = 0.66 (“phenol / tetrachloroethane = 6/4”) according to a conventional method. (Measured at 25 ° C. in the “ratio”). After pelletizing this, it was dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die and quenched to prepare an unstretched film having a film thickness after heat setting of 120 μm. Using rolls with different peripheral speeds,
The film was longitudinally stretched 3.3 times and then transversely stretched 4.5 times with a tenter. The temperatures at this time were 110 ° C. and 13 ° C., respectively.
It was 0 ° C. Then, after heat setting at 240 ° C for 20 seconds,
At the same temperature, it relaxed 4% in the horizontal direction. Then, after slitting the chuck portion of the tenter, knurling was performed on both ends, and the film was wound up with a tension of 4.7 × 10 ⁵ P. Thus, the width 2.4 m, the length 3500 m, the thickness 120 μm
m rolls were obtained. (2) Undercoat layer a '(shown in the coating amount per 1 m ² ) Polymer latex V-5 (core-shell type latex having a core portion of 90% and a shell portion of 10% “core portion: vinylidene chloride / methyl acrylate / methyl methacrylate” Rate / acrylonitrile / acrylic acid (93/3/3 / 0.9 / 0.1% ratio), shell part: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid (88/3/3/3 / 3% ratio) ", weight average molecular weight 38000) 3.0 g (solid content) 2,4-dichloro-6-hydroxy-s-triazine 23 mg matting agent (polystyrene, average particle size 2.4 μm) 1.5 mg (3) a subbing layer b '(indicated by the coating amount per 1 m ²⁾ deionized gelatin (Ca ²⁺ content 0.6 ppm, jelly strength 230 g) 50 g (4) (indicated by the coating amount per 1 m ²⁾ conductive layer Jurymer ET-410 (Nippon Junyaku, Ltd.) 96 mg alkali-treated gelatin (molecular weight about 10000, Ca ²⁺ content 30 ppm) 42 mg deionized gelatin (Ca ^{2 +} content 0.6 ppm) 8 mg compound (C-16) 0.2mg polyoxyethylene phenyl ether 10mg Sumitex resin M-3 (manufactured by Sumitomo chemical Co., Ltd., water-soluble melamine compound) 18 mg dye (F-1) 650nm optical Amount at which the concentration becomes 1.2 SnO ₂ / Sb (9/1 mass ratio, needle-like fine particles, major axis / minor axis = 20 to 30: manufactured by Ishihara Sangyo Co., Ltd.) 160 mg Matting agent (polymethyl methacrylate, average particle diameter 5 μm) ) 7 mg (5) shows the coating amount per protective layer (1 m ²⁾ the polymer latex [methyl methacrylate / styrene / -Ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid (59/9/26/5/1% ratio) latex] 1000 mg Polystyrene sulfonate (molecular weight 1000-5000) 2.6 mg Cellolsol 524 (Chukyo) 25 mg Sumitex Resin M-3 (described above) 218 mg An undercoat layer a 'and an undercoat layer b' are sequentially applied to one side of a support,
Each was dried at 180 ° C. for 4 minutes. Then, a conductive layer and a protective layer were sequentially applied to the opposite surfaces to which the undercoat layer a 'and the undercoat layer b' were applied, and each was dried at 180 ° C for 30 seconds to provide a back layer / undercoat layer. A PET support was made.

The PET support having a back layer / undercoat layer was
It was placed in a heat treatment zone with a total length of 30 m set at 50 ° C. and transported under its own weight at a tension of 1.37 × 10 ⁵ P and a transport speed of 20 m / min. After that, it was passed through a 40 ° C. zone for 15 seconds, and 9.8 ×
The film was wound with a winding tension of 10 ⁵ P. <Application of Sample> The coating solution for the non-photosensitive layer was applied and dried on the undercoat layer of the PET support on which the undercoat layer a 'and the undercoat layer b' were applied. Thereafter, the emulsion layer coating solution was coated so as to have a coating silver amount of 1.5 g / m ² , and the emulsion surface protective layer coating solution was further coated thereon with a coating amount of the solid content of the polymer latex of 3.0 g / m ^2. It was simultaneously coated with the emulsion coating solution so as to m ^2.

Samples S-1 and Y-1 produced in this manner
Was rolled into a roll of 458 mm × 61 m, and packed in a bright room. Exposure and thermal development were performed using these, and the following photographic performance was evaluated.

The exposure apparatus is shown in FIG. 1 of JP-A-5-5846.
A self-made exposure system was used as shown in Table 2, and the development was carried out by a self-made heat developing machine. FIG. 1 is a schematic sectional view of a heat developing machine. The following describes this.

The preheating section 1 has six pairs of aluminum cylindrical rollers having a surface of silicon rubber with a thickness of 4 mm mounted on the surface thereof. The upper side is a transport roller 5, and the lower side is internally provided with a halogen lamp heater. There is a built-in roller 4. The surface temperature of the lower roller is 75 from the insertion port side,
The temperature was set at 90, 105, 120, and 125 ° C., and the temperature was controlled. The upper roller of the main developing section 2 uses the same roller as the upper roller of the pre-heating section, and the lower side uses a 2 mm-long non-woven fabric of aromatic polyamide adhered to an aluminum panel heater 6 and is set at 120 ° C. . The upper roller of the slow cooling unit 3 was the same as the upper roller of the preheating unit, and the lower roller used was a ceramic heater instead of the halogen lamp used in the preheating unit.

The processing is performed on the photosensitive surface, and the width is an effective processing width of 69.
0 mm. The line speed was 40 mm / sec. Both the preheat roller temperature and the main developing unit temperature are 12
The treatment was performed at 0 ° C. for 10 seconds in the preheating section and 12 seconds in the main development section.

<< Density >> The density is output when the linearity has not been corrected and the laser output when the output portion of the theoretical value of 50% has become the measured value of 50% and the solid output of 100% has been output.
The concentration was measured with a Konica Densitometer PDA65.

<< Interference fringes >> The density after development processing is 0.7 to
Solid exposure was performed at an exposure amount of about 1.4, and the generated interference fringes were visually evaluated in 10 steps. “5” is a practical lower limit level.

10: No interference fringes are generated at all. 9: It looks like interference fringes are slightly generated when viewed closely. 8: It is understood that interference fringes are generated when viewed closely. Occurrence of interference fringes can be seen at a glance. 6: Occurrence of interference fringes can be clearly seen. 5: Occurrence of interference fringes can be clearly confirmed, but there is no practical problem. 4: Level that causes practical problems. A level that some people recognize as being quite bad 2: A person who is not engaged in plate making / printing recognizes that it is too bad 1: A very bad level << Linearity >> Output without linearity correction, This is the measured value of the output portion with a theoretical value of 95% in the laser output when the output portion with the theoretical value of 50% becomes the measured value of 50%. 95%
The closer to, the better.

<< DQ >> At 175 lines, 50% halftone dots were observed with a 100-power loupe at the same output as the above density, and evaluated on a 10-point scale. The side of the halftone dot is 45
Output so that the degree. “5” is a practical lower limit level.

10: Hard tone and smoothness comparable to a squirrel film 9: Slight roughness but good hardness and smoothness 8: Slight graininess but high contrast when closely observed 7: Glossiness is clearly visible at large points 6: Gasatsuki is clearly seen at large points and also at midpoints. 5: Slightly soft and gassatsu and pepper fog are visible around halftone dots. Clearly understandable 2: Roughness is very bad 1: Roughness is so bad that it is not possible to distinguish between small dots and roughness The results are summarized in Table 1.

[0065]

[Table 1]

As is clear from the results shown in the table, the present invention subjected to two or more beam exposures (wavelength: 650 nm) is superior to the comparison in all evaluations of density, interference fringe, linearity, and DQ. In addition, experiment No. 1-9, 1-10, we
The results of SV (photosensitive material for imagesetter printing) manufactured by Konica Corporation, which is a t-sensitive material, are described, but the effect of the multi-beam is not observed here.

Example 2 <Preparation of Sample S-2> A sample was prepared in the same manner as in Sample S-1 of Example 1, except for the following changes.

The dye (F-1) in the backing layer was designated as the following dye (F-2), and an amount of the dye having an optical density at 780 nm of 0.9 was added.

The sensitizing dye (SD-1) was replaced with the following sensitizing dye (S
Changed to D-2). <Preparation of Sample Y-2> The dye (F-1) in the backing layer was designated as the following dye (F-3), and the optical density at 780 nm was 0.1.
Add 9 amounts.

The sensitizing dye (SD-1) was replaced with the following sensitizing dye (S
Changed to D-3). High contrast agent-3 was changed to equimolar amount of the following high contrast agent-4.

[0071]

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Using Samples S-2, Y-2, S-1 and Y-1, exposure and thermal development were carried out in the same manner as in Example 1, and the density, interference fringes, linearity and DQ were evaluated. The measurement was performed at a beam exposure wavelength of 780 nm. Table 2 shows the results.

[0073]

[Table 2]

Samples S-2 and Y-2 have a wavelength of 780 nm.
It can be seen that the linearity and DQ are further improved by the exposure.

Example 3 <Preparation of Sample S-3> A sample was prepared in the same manner as Sample S-1 of Example 1, except for the following changes.

In the preparation of the silver halide emulsion, the addition time when adding by the double jet method is shortened, and the average grain size is reduced to 0.1.
04 μm particles were prepared and used. <Preparation of Sample S-4> Similar to Sample S-3, the addition time was controlled to prepare particles having an average particle size of 0.06 μm.
The particles were used. <Preparation of Sample S-5> As in the case of Sample S-3, the addition time was controlled and the pAg was lowered to reduce the average particle size to 0.02 μm.
m particles were prepared and used. <Preparation of Sample S-6> As in Sample S-3, the addition time was controlled, and the pAg was lowered to reduce the average particle size to 0.01 μm.
m particles were prepared and used. <Preparation of Sample S-7> Silver halide grains prepared in the same manner as in Sample S-2 of Example 2 and having an average particle size of 0.06 μm used in Sample S-4 were used. <Preparation of Sample Y-3> A sample was prepared in the same manner as Sample Y-1 of Example 1, except for the following changes.

In the preparation of the silver halide emulsion, the addition time when adding by the double jet method is shortened, and the average grain size is reduced to 0.1.
04 μm particles were prepared and used. <Preparation of Sample Y-4> Similarly to Sample Y-3, the addition time was controlled to prepare particles having an average particle size of 0.06 μm.
The particles were used. <Preparation of Sample Y-5> As in Sample Y-3, the addition time was controlled and the pAg was lowered to reduce the average particle size to 0.02 μm.
m particles were prepared and used. <Preparation of Sample Y-6> Similar to Y-3, the addition time was controlled and the pAg was lowered to prepare particles having an average particle diameter of 0.01 μm, and these particles were used. <Preparation of Sample Y-7> A silver halide particle having a mean particle size of 0.06 μm used in Sample Y-4 was prepared in the same manner as in Sample Y-2 of Example 2.

Samples S-3 to S-7, Y-3 to Y-7, S
Exposure and thermal development were carried out in the same manner as in Example 2 using -1 and Y-1, and the density, interference fringes, linearity, and DQ were evaluated. The wavelength of the beam exposure is 633 nm and 780 nm.
It was carried out in. Table 3 shows the results.

[0079]

[Table 3]

The average grain size of the silver halide grains is 0.02 to 0.02.
It is understood that the linearity and the DQ are improved by setting the thickness to 0.06 μm.

Example 4 <Preparation of Sample S-8> In Sample S-3 of Example 3,
The same preparation was carried out except that an equimolar amount of the contrasting agent-5 was used instead of the contrasting agent-1 and the contrasting agent-2. <Preparation of Sample Y-8> In Sample Y-3 of Example 3,
The same preparation was carried out except that an equimolar amount of the high contrast agent-6 was used instead of the high contrast agent-3.

[0082]

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Using Samples S-8 and Y-8, exposure and heat development were performed in the same manner as in Example 3, and the density, interference fringes, linearity, and DQ were evaluated. The angle between the incident angle and the reflection angle of the beam exposure was changed between 87.0 and 93.0 degrees.
Table 4 shows the results.

[0084]

[Table 4]

The angle formed by the incident angle and the reflection angle is 88.0-9.
By setting it in the range of 2.0 degrees, the linearity and DQ were improved.

[0086]

According to the exposure method of the present invention, when a photothermographic material for printing plate making is thermally developed, ultra-rapid processing suitability, processing stability, dot quality and linearity can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a heat developing machine.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 preheating section 2 main development section 3 cooling section 4 roller with built-in halogen lamp heater 5 transport roller 6 aluminum panel heater 7 temperature sensor

Claims (4)

[Claims] A photothermographic material containing organic silver particles, silver halide particles, a reducing agent and a high contrast agent on a support,
A method for exposing a photothermographic material, comprising exposing with two or more light beams. 2. The exposure wavelength of two or more emission beams is 70
2. The method for exposing a photothermographic material according to claim 1, wherein the thickness is 0 nm or more. 3. The method for exposing a photothermographic material according to claim 1, wherein the average particle diameter of the silver halide grains contained in the photothermographic material is 0.02 to 0.06 μm. . 4. An angle between incident light to a spinner and reflected light when exposing with two or more light-emitting beams is 88.0-9.
4. The exposure method for a photothermographic material according to claim 1, wherein the temperature is in a range of 2.0 degrees.