JP2001022022A - Heat developable photographic sensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat developable photographic sensitive material less liable to cause conveyance trouble in a heat developing machine and having improved dimensional stability and wrinkles after heat development by specifying the surface elastic modulus of a photosensitive layer at the heat development temperature. SOLUTION: The heat developable photographic sensitive material has a photosensitive layer having 0.05-0.8 GPa, preferably 0.1-0.6 GPa, further preferably 0.1-0.4 GPa surface elastic modulus at the heat development temperature. Preferably the indent depth of the photosensitive layer at the heat development temperature is 1-10 μm and the plastic deformation energy of the photosensitive layer at the heat development temperature is 1-10 nJ. Jamming due to sticking to a driving roll or belt in a heat developing machine and non-punctual conveyance due to the slip of the driving roll or belt on the photosensitive layer are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material having excellent transportability in a photothermographic machine.

[0002]

2. Description of the Related Art A heat-developable photosensitive material is exposed to form a latent image,
Usually, development is carried out by heating at 80 to 150 ° C., but it is necessary to improve dimensional stability or wrinkles after thermal development processing.
No. 95/30934 pamphlet and JP-A-8-2115
No. 47 is described. However, many of these heat-developable light-sensitive materials use polyethylene terephthalate (PET) as a support, and the heat-development temperature is higher than the glass transition temperature (Tg = 70 ° C.) of PET. For this reason, the elasticity of the heat-developable photosensitive material is reduced and the stiffness is weakened, so that many troubles occur during transportation of the heat-developing machine, and improvement has been desired. For example, during the conveyance, the conveyance force of the drive roll or the drive belt cannot be sufficiently received, and the conveyance time in the heat developing machine is delayed, or the slack occurs during the conveyance. Therefore, troubles such as wrinkles occurring in the heat-developable light-sensitive material due to the occurrence of the transfer force being not uniformly applied to the right and left, and the improvement have been desired. Such a transport trouble occurred particularly remarkably in the non-contact type thermal developing machine.
In particular, this was particularly noticeable in a large-sized photosensitive material (for example, 45 cm square or more).

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-developable photographic light-sensitive material which is less likely to cause a transport trouble in a heat developing machine, and has improved dimensional stability and wrinkles after heat development. is there.

[0004]

These objects have been achieved by a heat-developable photosensitive material having the following characteristics. That is, in the present invention, the surface elastic modulus of the photosensitive layer at the heat development temperature is 0.0
An object of the present invention is to provide a heat-developable photographic light-sensitive material characterized by being at least 5 GPa and at most 0.8 GPa.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the surface elastic modulus at the heat development temperature of a photosensitive layer is defined as a value obtained by inserting a Vickers indenter at a constant load into the surface of the photosensitive layer heated to the heat development temperature and removing the load. Refers to the repulsive force that the indenter receives from the surface of the photosensitive material.
This surface elastic modulus is 0.05 GPa or more and 0.8 GPa or less, preferably 0.1 GPa or more and 0.6 GPa or less, and more preferably 0.1 GPa or more and 0.4 GPa or less. If the surface elastic modulus is less than 0.05 GPa, it tends to stick to the roll in the heat developing machine, and the passage time is easily delayed. If it exceeds 0.8 GPa, the roll easily slips with the roll in the heat developing machine, and the passage time is easily delayed. The heat development temperature differs depending on the composition of the photosensitive layer, but is preferably 8
0 ° C or more and 150 ° C or less, more preferably 90 ° C or more and 14
0 ° C or lower, more preferably 100 ° C or higher and 130 ° C or lower. The present invention is particularly preferable when the heat development temperature is higher than the glass transition temperature of the support of the heat-developable photosensitive material. Furthermore, the indentation depth at the heat development temperature of the photosensitive layer is 1 μm.
It is preferable that it is not less than 10 μm. In this method, a Vickers indenter was pressed at 2 mN into the photosensitive material heated to the heat development temperature, and then the insertion depth of the indenter was measured. More preferably 2 μm or more and 9 μm or less, further preferably 4 μm
m or more and 8 μm or less. Further, the plastic deformation energy of the photosensitive layer at the heat development temperature is preferably 1 nJ or more and 10 nJ or less. It is more preferably from 1 nJ to 8 nJ, further preferably from 1.5 nJ to 6 nJ.
The plastic deformation energy is defined as the plastic deformation (depression) after pushing in a Vickers indenter at 2 mN and removing it.
Refers to the energy consumed. By setting the surface elastic modulus, indentation depth, and plastic deformation energy, jamming occurs due to sticking to the drive roll or drive belt in the heat developing machine, or the drive roll or drive belt slips on the photosensitive layer. Further, it is possible to further prevent the occurrence of troubles such as a failure to convey in an accurate time, and to perform stable conveyance.

[0006] Such a photosensitive layer is achieved by the following a), b) or c). B) A photosensitive layer is formed using a latex polymer.
The photosensitive layer is formed of a polymer layer, but is preferably formed using a latex-based polymer dispersed in water, rather than being dissolved in an organic solvent and applied. This is because, in a heat-developable light-sensitive material such as the present invention, a silver carboxylate having substantially the same amount as a binder polymer is used as an image forming agent, but in an organic solvent-based coating, these are uniformly dispersed and act as a plasticizer.
This is because the photosensitive layer is likely to be soft. On the other hand, in the polymer latex system, these are dispersed individually,
The silver carboxylate hardly exerts the plasticizing effect. Preferred examples of latex include acrylic resin, vinyl acetate resin, polyester resin, polyurethane resin, rubber-based resin, vinyl chloride resin, vinylidene chloride resin, and polyolefin resin, and more specifically, methyl methacrylate / ethyl methacrylate / methacrylic acid copolymer. , Methyl methacrylate / 2-ethylhexyl acrylate / hydroxyethyl methacrylate / styrene /
Acrylic acid copolymer, styrene / butadiene / acrylic acid copolymer, styrene / butadiene / divinylbenzene / methacrylic acid copolymer, methyl methacrylate / vinyl chloride / acrylic acid copolymer, vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymer, more preferably. Is styrene /
Butadiene polymer latex (LACSTAR3307B, Ni
pol Lx430, 435). These weight average molecular weights are 5,000 to 1,000,000, preferably 10,000.
About 100000 is preferred. The coating amount of the latex binder is 0.2 to 30 g / m ² , more preferably 1.0 to 30 g / m ² .
Range to 15 g / ^{m 2} is preferred.

(B) The temperature during drying after the application of the photosensitive layer is made non-uniform by making the lower part of the photosensitive layer (the support side) higher than the upper part (the air side) of the photosensitive layer. By raising the temperature below the photosensitive layer,
An uneven structure can be formed in the thickness direction of the photosensitive layer. That is, by forming a layer with more polymer latex on the lower side and a layer with more silver carboxylate on the upper side,
A photosensitive layer having the surface hardness of the present invention and the more preferable indentation depth or plastic deformation energy described above can be formed. Furthermore, this drying method prevents the formation of skin on the polymer latex surface. As a result, the thin skin can achieve the surface hardness of the present invention without remaining volatile components such as moisture inside. Specifically, drying is performed at 35 to 90 ° C., more preferably 40 to 85 ° C., and still more preferably 45 to 80 ° C., but the temperature of the lower part (back layer side) is increased to the upper part (photosensitive layer side).
The temperature is raised to 1 to 20 ° C, more preferably 2 to 15 ° C, still more preferably 3 to 10 ° C, and dried. This can be easily achieved by blowing air having individually adjusted temperatures from air outlets provided so as to sandwich the photosensitive material from above and below.

(C) The amount of dry air on the lower side of the photosensitive layer is made larger than that on the upper side of the photosensitive layer. The amount of dry air on the lower side of the photosensitive layer is from 1% to 30%, more preferably 2%, from the upper part of the photosensitive layer.
By increasing the thickness by at least 25% or less, and more preferably by at least 3% or more by 20% or less, it is easy to achieve a non-uniform structure in the thickness direction of the processed layer as in the above item b). This can be easily achieved by adjusting the damper of the outlet provided so as to sandwich the photosensitive material from above and below. The difference in the air volume referred to here is defined as follows. Difference in air volume (%) = 200 × (Sl × Vl−Su × Vu) / (Sl × Vl
+ Su × Vu) where Su = total area of outlets installed above Vu = average wind velocity of outlets installed above Sl = total area of outlets installed below Vl = average of outlets installed below wind speed

Further, in order to reduce the transport trouble in the heat developing machine, the change in the thermal dimension of MD (longitudinal direction) and TD (width direction) due to the treatment at 120 ° C. for 30 seconds is −0.05 over the entire area in the width direction. % To 0.05%, more preferably −0.04% to 0.04%, and still more preferably −0.03% to 0.03%. This makes it possible to suppress the meandering of the photosensitive material due to the non-uniformity of the thermal contraction in the front, rear, left, and right directions when the photosensitive material is transported in the thermal developing machine. For this, a support having a difference in orientation angle between the left and right ends of 0 to 30 degrees, more preferably 0 to 20 degrees, and still more preferably 0 to 10 degrees,
140-200 ° C, more preferably 150-190 ° C,
More preferably, 0.3 to 5 kg / m at 150 to 180 ° C,
More preferably 0.5 to 4 kg / m, even more preferably 1 to 4 kg / m
At 4 kg / m, 20 to 400 seconds, more preferably 30 to 30 seconds
This can be achieved by performing a heat treatment for 0 second, more preferably 40 to 250 seconds. A support having such an orientation angle can be stretched in a length of 2.5 to 3.5 times and stretched in a width of 3 to 4.5 times in stretching film formation, and heat-set at 220 to 250 ° C. for 3 to 60 seconds to obtain a film having a thickness of 22 to 22 times.
1 to 10% at 0 to 250 ° C, more preferably 1 to 8%,
It is more preferably achieved by stretching in the transverse direction by 2 to 6%. Furthermore, it is more preferable that at least one of the large ends of the orientation angle is dropped by a slit. The preferred width of slit removal (per one end) is 3 to 30% of the entire width, more preferably 5 to 25%, and still more preferably 7 to 20%.
It is.

Further, the water absorption rate of the support after heat development is 0%.
% / Hour or more and 0.16% / hour or less, more preferably 0%
% / Hour or more and 0.14% / hour or less, more preferably 0% / hour or more and 0.13% / hour or less can also improve the transportability in the heat developing machine. This is to prevent the support from being degraded due to rapid dehumidification at the entrance and exit of the heat generator, and shrinkage of the support due to moisture absorption and deformation of the photosensitive material due to elongation. Such a waterproof layer may be any of an inorganic substance and an organic substance. In the case of an inorganic substance, a silica vapor-deposited layer as described in JP-A-8-224595 or a metal oxide such as alumina, tin oxide, or indium oxide is vapor-deposited. Is also good.
Further, inorganic fine particles such as mica may be dispersed in a polymer binder and applied.

In the case of an organic substance, it is preferable to apply a layer of polyvinylidene chloride resin (PVdC), polyvinyl alcohol (PVA), high-density polyethylene, polyfluoroethylene, or the like. Among these, PVdC and PVA are preferred, and polyvinylidene chloride resin is more preferred. It is preferable to use a copolymer for the polyvinylidene chloride resin, and the amount of the vinylidene chloride residue to be contained is 70 to 99.
The content is preferably 9% by weight, more preferably 85 to 99% by weight, and still more preferably 90 to 99% by weight. As copolymerization components other than vinylidene chloride, methacrylic acid, acrylic acid, methyl methacrylic acid, itaconic acid, citraconic acid and esters thereof, acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, methyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl Examples include methacrylate, vinyl acetate, acrylamide, and styrene. The weight average molecular weight of these copolymers is preferably from 5,000 to 100,000, more preferably from 8,000 to 80,000, even more preferably from 10,000 to 45,000.

The polyvinylidene chloride resin can be coated on the support by dissolving it in an organic solvent or by applying a water-dispersed latex, but the latter is more preferred. In the case of an aqueous dispersion of an aqueous dispersion latex, a so-called core having a different composition between the core portion and the shell portion even if the latex is a polymer particle having a uniform structure.
Latex of polymer particles having a shell structure may be used.

Specific examples of the vinylidene chloride copolymer include the following. However, the numbers in parentheses indicate weight ratios. Mw represents a weight average molecular weight. (A) Vinylidene chloride: methyl acrylate: acrylic acid (9
0: 9: 1) latex (Mw = 42000) (B) vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: methacrylic acid (87: 4: 4: 4:
1) Latex (Mw = 40000) (C) Vinylidene chloride: methyl methacrylate: glycidyl methacrylate: methacrylic acid (90: 6: 2: 2) latex (Mw = 38000) (D) Vinylidene chloride: ethyl methacrylate: 2- Hydroxyethyl methacrylate: acrylic acid (90: 8: 1.5: 0.
5) Latex (Mw = 44000) (E) Core-shell type latex (core 90% by weight, shell 10% by weight) Core vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: acrylic acid (93: 3:
3: 0.9: 0.1) Shell part Vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: acrylic acid (88:
(3: 3: 3: 3) (Mw = 38000) (F) Core-shell type latex (core 70% by weight, shell 30% by weight) Core vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: methacrylic acid (92 .
5: 3: 3: 1: 0.5) Shell part Vinylidene chloride: methyl acrylate: methyl methacrylate: acrylonitrile: methacrylic acid (9
0: 3: 3: 1: 3) (Mw = 20000) The thickness of these waterproof layers is 0. 0 on at least one side of the support.
The thickness is preferably 5 μm or more and 10 μm or less, more preferably 0.8 μm or more and 5 μm or less on each side of the support, and still more preferably 1.0 μm or more and 3 μm or less on each side. Further, in the present invention, by combining the following means (1) and / or (2), the effect of the present invention can be further enhanced.

(1) The surface elastic modulus of the back layer at the heat development temperature is 1 GPa or more and 5 GPa or less. The surface elastic modulus at the thermal development temperature of the back layer is measured by measuring the stress applied to the indenter by removing the load after pushing a Vickers indenter into the back surface of the photosensitive material heated to the thermal development temperature with a load of 2 mN. It was done. This surface elastic modulus is preferably 1 GPa or more and 5 GPa or less, more preferably 2 GPa or more and 5 GPa.
Or less, more preferably 2 GPa or more and 4.5 GPa or less. Further, the indentation depth of the back layer at the heat development temperature is preferably 0.4 μm or more and 2 μm or less.
More preferably, it is 0.5 μm or more and 1.7 μm or less, and further preferably 0.5 μm or more and 1.4 μm or less. further,
It is preferable that the plastic deformation energy at the thermal development temperature of the back layer be 0.01 nJ or more and 1 nJ or less. It is more preferably 0.02 nJ or more and 0.6 nJ or less, and still more preferably 0.03 nJ or more and 0.5 nJ or less. By forming a back layer having such a surface elastic modulus, indentation depth, and plastic deformation energy, jamming occurs due to sticking to a driving roll or a driving belt in contact with the back layer in the thermal developing machine, It is possible to prevent the occurrence of troubles such as the drive belt and the back layer slipping and not being transported in an accurate time, and to perform stable transport.

The following two points are required to achieve such a back layer. B) The back layer has at least one layer containing inorganic fine particles. Although inorganic fine particles are not particularly limited, silica,
Alumina, mica, talc, tin oxide, indium oxide, titanium oxide, acid value zinc and the like can be mentioned. The preferred particle size is 0.01 to 0.7 μm, more preferably 0.02 to 0.7 μm.
０．５0.5 μm. The preferred addition amount is 50 mg / m ²
500 mg / m ² or less, more preferably 100 mg / m ² or less.
/ M ² or more and 400 mg / m ² or less, more preferably 1
It is 50 mg / m ² or more and 350 mg / m ² or less. Although the shape of these fine particles is not particularly limited, an aspect ratio of 3
The above-mentioned needle-like or flat plate-like ones are more preferable. These inorganic fine particles are preferably dispersed in a polymer binder and applied. Preferred polymers are acrylic resin, vinyl acetate resin, polyester resin, polyurethane resin, cellulose acetate resin, polyester resin,
Rubber-based resins, vinyl chloride resins, vinylidene chloride resins, and polyolefin resins are preferred. More specifically, methyl methacrylate / ethyl methacrylate / methacrylic acid copolymer, methyl methacrylate / 2-ethylhexyl acrylate / hydroxyethyl methacrylate / styrene / acrylic acid copolymer, Styrene / butadiene /
Acrylic acid copolymers, styrene / butadiene / divinylbenzene / methacrylic acid copolymers, methyl methacrylate / vinyl chloride / acrylic acid copolymers, vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymers may be mentioned. Their weight average molecular weight is 5000 to 1,000,000, preferably 1000
About 0-100,000 is preferable. The coating amount of the polymer binder is preferably 5 to 100 mg / m ² , more preferably 10 to 80 mg / m ² , and still more preferably 20 to 80 mg / m ² .
５０50 mg / m ² .

B) Back surface calendering processing. The contact pressure on the back surface is calendered according to equation 1, more preferably according to equation 2. Preferred temperatures are 80
180 ° C. to 180 ° C., more preferably 110 ° C. to 17
0 ° C. or lower, more preferably 120 ° C. or higher and 170 ° C. or lower, for 5 seconds to 240 seconds, more preferably 10 seconds to 2 seconds
It is carried out at a contact pressure satisfying the formula 1, more preferably at a contact pressure satisfying the formula 2, for 00 seconds or less, more preferably for 20 seconds to 180 seconds. 10,000 / (heat treatment temperature (° C.)-79) ≧ contact pressure (g / cm ² ) ≧ 50 / (heat treatment temperature (° C.)-79) Formula 1 5000 / (heat treatment temperature (° C.)-79) ≧ contact pressure (g) / Cm ² ) ≧ 100 / (heat treatment temperature (° C.)-79) Equation 2

Such adjustment of the contact pressure can be achieved by the transfer tension and the roll having the edge. Transfer tension is 5g / mm
^It is preferably from ^{2 to} 100 g / mm ² , more preferably from 8 g / mm ^{2 to} 80 g / mm ² , still more preferably from 1 to 80 g / mm ^2.
0 g / mm ² or more and 60 g / mm ² or less. At this time, it is more preferable to lower the contact pressure by floating and transporting the base using a roll (edge-held roll) in which the end of the transport roll is further raised. The height of the raised edge portion is preferably 0.05 mm or more and 10 mm or less, more preferably 0.1 mm or more and 5 mm or less, and even more preferably 0.15 mm or more and 3 mm or less. The preferred width of the edge is 5mm or more 2
00 mm or less, more preferably 8 mm or more and 100 mm or less, and still more preferably 10 mm or more and 80 mm or less. The edge portion is provided so as to be located at the end of the base to be conveyed, and is more preferably provided at both ends. Such an edge portion may be processed so that a predetermined portion becomes higher when the roll is made, and it is also preferable that a heat-resistant tape or the like be wound around an existing roll to increase the height. Further, it is more preferable to subject the support at the portion corresponding to the edge portion to knurling. The knurling may be extruded from one side or from both sides. The preferred width is 3 to 50 mm, more preferably 5 to 30 mm. The height of the thickening process (when thickening is performed from both sides, the average of both surfaces) is preferably 5 μm or more and 150 μm or less, more preferably 1 μm or less.
It is more preferably from 0 μm to 80 μm.

(2) XPS measurement of 284.6 eV signal and 288.
_4eV signal intensity ratio (I _284.6 / I
_288.4 (50% RH)) is 5 or more and 18 or less. After the humidity control of the back layer at 25 ° C. and 50% RH, the back layer was subjected to photoelectron spectroscopy (XPS) by the following method, and the intensity ratio of a signal of 284.6 eV to a signal of 288.4 eV (I _284.6).
/ I _288.4 (50% RH)). These are signals due to C1s electrons, the former indicating the amount of long chain hydrocarbons derived from C-C carbon and acting as a slip agent. X
Since PS measures only the extreme surface (5 nm), a strong signal can increase the surface slipperiness. On the other hand, the latter 288.4 eV signal is derived from the C ＝ O bond,
It is easy to reduce the slipperiness of the surface. Therefore, their ratio (I
_284.6 / I _288.4 (50% RH)), the slipperiness tends to decrease. Preferred (I _284.6 / I
_288.4 (50% RH)) is 5 or more and 18 or less, more preferably 6 or more and 16 or less, still more preferably 7 or more and 15 or less.
It is as follows.

Further, the back layer after humidity control at 25 ° C. and 75% RH was subjected to XPS measurement to obtain a signal of 284.6 eV and a signal of 284.6 eV.
8.4 eV signal intensity ratio (I _284.6 / I
_288.4 (75% RH)) with (I _284.6 / I _288.4
(50% RH)) is 0.6 or more and 1 or less, more preferably 0.65 or more and 0.95 or less, and still more preferably 0.1 to 0.95.
More preferably, it is set to 7 or more and 0.90 or less. This is to prevent the slipping agent composed of a long-chain hydrocarbon from being sunk into the back layer under high humidity due to its hydrophobicity to reduce the slipperiness. This XPS intensity ratio is measured in the same manner as above except that the humidity control is changed to 75% RH. 25% 50% R
The ratio (Fs / Cs) of the surface fluorine amount (Fs) to the surface carbon amount (Cs) of the back layer after H humidity control is 0.25 or more and 0.5 or less;
It is more preferably 0.3 or more and 0.45 or less, more preferably 0.3 or more and 0.4 or less. This is because a fluorine-based surfactant is added to stably apply the long-chain carbon-based slip agent, but these tend to emerge on the surface competitively,
It is preferable to be within this range.

Further, the dynamic friction coefficient of the back layer is 0.05
It is preferably 0.5 or more and 0.5 or less, more preferably 0.05 or more and 0.4 or less, and further more preferably 0.05 or more and 0.3 or less. The kinetic friction coefficient is a value measured using a stainless steel ball having a diameter of 0.5 mm at 25 ° C. and 60% rh. With such characteristics, friction between the heat-developable photosensitive material and the heat developing machine can be reduced, and jamming due to frictional resistance can be reduced. Further, highly reliable transportability can be ensured under a wide range of environmental conditions. Such characteristics are particularly effective in a non-contact type thermal developing machine, and in particular, a system in which the back layer is transported while being in contact with a nonwoven fabric (for example, Japanese Patent Application Nos. 10-177610 and 10-177610).
-249940).

There are the following three points in achieving the back layer having such characteristics. B) Mixing a fluorine-based surfactant and a long-chain hydrocarbon-based slip agent in the outermost layer of the back. In order to obtain slipperiness, a long-chain hydrocarbon slip agent having 10 to 50 carbon atoms, more preferably 10 to 40 carbon atoms, and still more preferably 10 to 30 carbon atoms is used.
Specific examples include compounds having the following structures, and more preferred are long-chain alkylsulfonic acid, long-chain alkylbenzenesulfonic acid, carnauba wax (Cerosol 524), and modified polyethylene latex (Chempearl).

Preferred long-chain hydrocarbon-based slip agent n-C ₁₆ H ₃₃ -O-SO ₃ Nan-C ₁₂ H ₂₅ -O-SO ₃ Lin-C ₂₀ H ₄₁ -O-SO ₃ Nan-C _{12 H 25 -C 6 H 4 -OSO} 3 Na n-C 16 H 33 COOK n-C 20 H 41 COONa carnauba wax (e.g., Chukyo Yushi Cellosol 524) modified polyethylene latex (e.g., Mitsui Toatsu Ltd. CHEMIPEARL) stearyl amide _{n-C 15 H 31 COOC 30} H 61 -n n-C 15 H 31 COOC 40 H 81 -n n-C 27 H 55 COOC 28 H 57 -n n-C 21 H 43 COO- (CH 2) 7 _{CH- (CH 3) -C 9 H} 19 -n n-C 15 H 31 COOC 24 H 49 -iso n-C 29 H 59 OCO (CH 2) 2 COOC 24 H 49 -n n-C 40 H ₈₁ OCO ( _{H 2) 2 COO-C 50} H 101 -n n-C 17 H 35 COO (CH 2) 6 OCO-C 17 H 35 -n iso-C 23 H 47 COO (CH 2) 2 OCO-C 23 H 47 -n n-C ₄₀ H ₈₁ O (CH ₂ CH ₂ O) ₁₅ H n-C ₅₀ H ₁₀₁ O (CH ₂ CH ₂ O) ₃₀ H n-C ₄₀ H ₈₁ OCOCH ₂ CH ₂ COO- (CH ₂ CH _{2 O) 16 H n-C} 50 H 101 OCOCH 2 CH 2 COO- (CH 2 CH 2 (OH) CH 2 O) 3 (CH 2 CH 2 O) 15 H

Further, a fluorine-based surfactant is added for imparting coating stability of the slip agent (measures against cissing). Thereby, uniform slipperiness can be imparted to the entire surface. Preferred fluorinated surfactants include a fluoroalkyl group, a fluoroalkenyl group, or a fluoroaryl group having 4 or more (usually 15 or less) carbon atoms, and an anionic group (sulfonic acid (salt), sulfuric acid ( Salt), carboxylic acid (salt), phosphoric acid (salt)), cationic group (amine salt, ammonium salt, aromatic amine salt, sulfonium salt, phosphonium salt), betaine group (carboxyamine salt, carboxyammonium salt, sulfoamine salt) , A sulfonium salt, a phosphoammonium salt) or a surfactant having a nonionic group (substituted or unsubstituted polyoxyalkylene group, polyglyceryl group or sorbitan residue). These fluorine-containing surfactants are disclosed in JP-A-49-107.
No. 22, UK Patent No. 1,330,356, U.S. Patent No. 4,335,201
No. 4,347,308, British Patent No. 1,417,915, JP-A-55
-149938, 58-196544 and British Patent No. 1,439,402. These fluorinated surfactants,
You may mix two or more types.

[0024]

Embedded image

The ratio of the amount of the fluorine-based surfactant (F-based surfactant) to the amount of the long-chain hydrocarbon-based slip agent added is from 1:10 to 1:10.
1: 1, more preferably 1: 8 to 1: 1;
More preferably, it is 1: 4 to 1: 1. The preferred coating amount of the long-chain hydrocarbon-based slip agent is 5 to 100 mg / m ² , more preferably 8 to 80 mg / m ² , and still more preferably 10 to 60 mg / m ² . The preferred application amount of the F-based surfactant is 0.5 to 100 mg / m ² , more preferably 1 to 80 mg / m ² , and still more preferably 2.
It is a 5~60mg / ^{m 2.}

B) Heat treatment using a roll lined with a fluororesin 100 to 200 ° C., more preferably 120 to 190 ° C.
The back surface having the above characteristics can be achieved by contacting the surface with a roll coated with a fluororesin, more preferably at 140 to 180 ° C. That is, the amount of deposition on the back surface is controlled by the member to be brought into contact. Preferred fluororesins include Teflon (polytetrafluoroethylene: PTFE), polyvinylidene fluoride (PVd)
F), polyvinyl fluoride (PVF), polychlorotrifluoroethylene (PCTFE), polyfluoroalkyl vinyl ether (PFAVE) and the like, and more preferably Teflon. Their lining thickness is 1
0 to 10000 μm is preferred. The roll used for the lining can be made of aluminum, iron, stainless steel, or the like. A preferred roll diameter is 10 to 1000 mm. The back characteristic can be controlled by the time for which the fluororesin is brought into contact with the lined roll, preferably 1 to 30
0 second, more preferably 2 to 200 seconds, still more preferably 3 to 60 seconds.

C) Low humidity take-up after coating and drying After the back layer is applied or after the low tension heat treatment, the base has a water absorption of 0 to 0.2% by weight, more preferably 0 to 0.1% by weight.
More preferably, it is wound at 0 to 0.05% by weight. This is particularly effective for suppressing humidity dependency. This means that the winding is performed at a humidity of 0 to 60% rh, preferably 10 to 50% rh, more preferably 10 to 30% rh, and the temperature of the support during the winding is 35 to 70% rh.
C., more preferably at 40 to 60.degree.

The following describes how to prepare a heat-developable photosensitive material using the present invention.
The law is described. (1) Preparation of Support The support used for the light-sensitive material of the present invention is not particularly limited.
The elastic modulus (E120) at 20 ° C is 100 kg / mm²More than 60
0kg / mm²Is preferably, more preferably
Is 120kg / mm²More than 500kg / mm²It is as follows. Ingredient
Physically, polyethylene naphthalate (E120 = 410kg /
mm²), Polyethylene terephthalate (E120 = 150
kg / mm²), Polybutylene phthalate (E120 = 160k
g / mm²), Polycarbonate (E120 = 170kg / mm
²), Syndiotactic polystyrene (E120 = 220)
kg / mm²), Polyetherimide (E120 = 190 kg / m
m ²), Polyarylate (E120 = 170kg / mm)²),
Polysulfone (E120 = 180kg / mm²), Polyate
Rusulfone (E120 = 170kg / mm²) Etc.
You. These may be used alone, or they may be laminated or mixed.
May be used. Preferred is polyethylene naphthalene
G, polyethylene terephthalate, syndiotactic
It is polystyrene. Particularly preferred is polyethylene
It is phthalate. In these supports, handlin
1μm to 0.01μm to 10μm fine particles
It is also preferred to add ~ 1000 ppm. The thickness of the support
Although not particularly limited, preferably 80 to 250 μm,
Preferably 90 to 200 μm, more preferably 95 to 200 μm
150 μm.

Further, in order to prepare the light-sensitive material of the present invention, it is preferable to provide the following undercoat layer and back layer on a support. Undercoat Layer An undercoat layer is provided on at least one surface of the support. Prior to this, a surface treatment may be performed to firmly fix these layers and the support. For example, a glow discharge process (Japanese Unexamined Patent Application Publication No.
194286), corona treatment (for example, JP-B-48-48)
Nos. 5043 and 47-51905, JP-A-47-28
Nos. 067, 49-83767 and 51-41770
No. 51-131576), ultraviolet treatment (for example, JP-B-43-2603, JP-B-43-2604, and JP-B-45-3828) and flame treatment.

As the undercoat layer, a layer (hereinafter, abbreviated as first undercoat layer) that adheres well to the support is provided as a first layer.
A so-called multi-layer method, in which a second layer is applied as a second layer to adhere the first undercoat layer and the photographic layer well (hereinafter abbreviated as the second undercoat layer), and only one layer adheres the support and the photographic layer well. There is a single layer method of coating. In the single-layer method, a method is often used in which a support is swelled and good adhesion is obtained by interfacial mixing with a base coat polymer. Examples of the undercoat polymer include gelatin, gelatin derivatives, casein, agar, sodium alginate, starch, polyvinyl alcohol, polyacrylic acid copolymers, water-soluble polymers such as maleic anhydride copolymers, and celluloses such as carboxymethyl cellulose and hydroxyethyl cellulose. Ester, vinyl chloride-containing copolymer, vinylidene chloride-containing copolymer, acrylate-containing copolymer,
Latex polymers such as vinyl acetate-containing copolymers and vinyl acetate-containing copolymers are used. Preferred among these is gelatin. As the gelatin, any of those generally used in the art such as so-called lime-processed gelatin, acid-processed gelatin, enzyme-processed gelatin, gelatin derivatives, and modified gelatin can be used.
Among these gelatins, lime-treated gelatin and acid-treated gelatin are most preferably used.

The first undercoat layer in the multilayer method is selected from, for example, vinyl chloride, vinylidene chloride, butadiene, vinyl acetate, styrene, acrylonitrile, methacrylic acid ester, methacrylic acid, acrylic acid, itaconic acid, and maleic anhydride. Copolymer starting from the obtained monomer, epoxy resin, gelatin, nitrocellulose,
Polyvinyl acetate or the like is used. Also, if necessary,
Triazine-based, epoxy-based, melamine-based, isocyanate-based including blocked isocyanate-based, aziridine-based, oxazaline-based crosslinking agents, colloidal silica and other inorganic particles, surfactants, thickeners, dyes, preservatives, etc. Is also good. When a polyvinylidene chloride-based resin is used, it can be used also as the waterproof layer. In the second layer of the undercoat, gelatin is mainly used.

Back Layer A back layer (backing layer) is preferably provided on the side opposite to the image forming layer (photosensitive layer). Prior to coating the back layer, a glow discharge treatment, a corona treatment, an ultraviolet treatment or a flame treatment may be performed to improve the adhesion to the support. The back layer of the present invention has a maximum absorption in a desired wavelength range of 0.3 or more 2
Or less, more preferably 0.5 or more 2
It is preferably a layer having an optical density of 0.001 or more and less than 0.5, and more preferably 0.001 or more and less than 0.3, in the visible region after treatment. It is also preferable to apply an antihalation dye used for the back layer.

By adding conductive crystalline gold oxide or its composite oxide fine particles as a charge controlling agent, the surface resistivity is adjusted to 10
It is also preferable to set it to ¹² or less. The volume resistivity of the fine particles of the conductive crystalline oxide or its composite oxide is 10
It is desirably ⁷ Ωcm or less, more preferably 10 ⁵ Ωcm or less. The particle size is 0.01 to 0.7 μm,
In particular, the thickness is preferably 0.02 to 0.5 μm. The method for producing these conductive crystalline metal oxide or composite oxide fine particles is described in detail in the specification of JP-A-56-143430. That is, first, a method of producing by baking with metal oxide fine particles and performing heat treatment in the presence of a heteroatom for improving conductivity, and second, a method of improving conductivity when producing metal oxide fine particles by baking. Thirdly, when producing fine metal particles by firing, lowering the oxygen concentration in the atmosphere,
A method for introducing oxygen vacancies is easy. Examples including metal atoms include Al and In for ZnO, Nb and Ta for TiO ₂ , and Sb and N for SnO ₂ .
b, a halogen element and the like. The addition amount of the hetero atom is preferably in the range of 0.01 to 30 mol%, but 0.1 to 1 mol%.
0 mol% is particularly preferred. Of these, SnO ₂ composite metal oxide fine particles to which Sb is added are most preferred.

It is also preferred to add fine particles for matting the back surface. Examples of the fine particles include inorganic fine particles (such as silica, alumina, calcium carbonate, titania, and zirconia) and organic fine particles (such as PMMA, PSt, and a crosslinked product thereof). In the present invention, the porous matting agent described in JP-A-3-109542, page 2, lower left column, line 8 to page 3, upper right column, line 4, JP-A-4-127142, page 3, upper right column, line 7 Page 5, lower right column, line 4, matting agent surface-modified with alkali, paragraph No. "000" of JP-A-6-118542.
It is more preferable to use the organic polymer matting agent described in 5) to “0026”. The preferred particle size is 0.3
It is from μm to 10 μm, more preferably from 1 μm to 8 μm, further preferably from 3 μm to 7 μm. The preferred addition amount is 1 to 50 mg / m ² , more preferably 2 to 3 mg / m ² .
0 mg / ^{m 2,} more preferably from 3 to 15 mg / ^{m 2.} The preferred Beck smoothness achieved by this (JI
SP 8119) is 2,000 seconds or less, more preferably 10 seconds to 2,000 seconds.

In these back layers, a hydrophilic colloid may be used as a binder, and a hydrophobic polymer may be used as a binder. The most preferred hydrophilic polymer is gelatin. When a hydrophilic polymer is used, it is also preferable to apply the same undercoat as the photosensitive layer and then apply a back layer in order to provide stronger adhesion. Polymethyl methacrylate as a binder for the hydrophobic polymer layer,
A (meth) acrylate polymer such as ethyl acrylate, an olefin polymer such as polyethylene, a styrene polymer, a urethane polymer, and a rubber polymer such as butadiene are used. This layer can be one layer or two
It may be more than layers. Further, a hardener may be used for the back layer. Examples of hardeners include U.S. Pat.No. 4,281,060, polyisocyanates described in JP-A-6-208193, epoxy compounds described in U.S. Pat. For example, vinyl sulfone compounds described in US Pat.

A protective layer may be provided as the outermost layer of the back layer. The total binder amount for the protective layer is 0.2-5.0 g / m
² , more preferably in the range of 0.5 to 3.0 g / m ² . As a binder for the back layer, an acrylic, olefin, or vinylidene chloride-based polymer latex is used.Specifically, acrylic resin-based Julimer ET-410, Sebian A-4635, polysol F410, and other olefin resin-based Chemipearl S120, vinylidene chloride L5
02, Alon D7020 and the like are preferred. Such a back layer may be a single layer or a multilayer, and each layer has a thickness of 0.02 to 1
The thickness is preferably 0 μm, more preferably 0.1 to 7 μm, and the total thickness of these layers is preferably 0 to 5 μm. The back layer and the undercoat layer can be applied by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, or the like. These may be applied one by one or two or more layers at the same time.

(2) Preparation of photosensitive layer The heat-developable photosensitive material of the present invention has an image forming layer (photosensitive layer) containing an organic silver salt, a reducing agent and a photosensitive silver halide on a support. At least one protective layer is provided thereon. The photosensitive layer is obtained by dispersing silver halide, a chemical sensitizer, an organic silver salt, a reducing agent, a super-high contrast agent, a sensitizing dye, an antifoggant, a plasticizer, and the like in a binder.

The binder used is preferably an acrylic resin, a vinyl acetate resin, a polyester resin, a polyurethane resin, a rubber resin, a vinyl chloride resin, a vinylidene chloride resin, or a polyolefin resin, and more specifically, methyl methacrylate / ethyl methacrylate. / Methacrylic acid copolymer, methyl methacrylate / 2-ethylhexyl acrylate / hydroxyethyl methacrylate / styrene / acrylic acid copolymer, styrene / butadiene / acrylic acid copolymer, styrene / butadiene / divinylbenzene / methacrylic acid copolymer, methyl methacrylate / vinyl chloride / acrylic acid Copolymers, vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymers, more preferably styrene / Tajien based polymer latex (LACSTAR3307B, Nipol Lx430,435) is preferably used. These weight average molecular weights range from 5,000 to 10,000.
00, preferably about 10,000 to 100,000. In addition, 20wt% of the total binder in the binder
A hydrophilic polymer such as polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, or hydroxypropylmethylcellulose may be added in the following range. The coating amount of the binder is 0.2 to 30 g / m ² , more preferably 1.0 to 1 g / m ² .
A range of 5 g / m ² is preferred.

Further, the present invention provides a method for forming a super-high contrast image.
A high contrast accelerator can be used in combination with the ultrahigh contrast agent. For example, amine compounds described in U.S. Pat.No. 5,545,505, hydroxamic acids described in 5,545,507, acrylonitriles described in 5,545,507, 5,55
Hydrazine compound described in JP-A-8983
Onium salts described in No. 297368 can be used.

As the sensitizing dye in the present invention, cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, styryl dyes, hemicyanine dyes, oxonol dyes, hemioxonol dyes and the like can be used. Examples of spectral sensitization to red light, He-Ne laser, for a red light source such as red semiconductor laser or LED, JP-A-54-18726, JP-A-6-75322, JP-A-7-287338
No., JP-B-55-39818, JP-A-62-284343, JP-A-7-2
The compounds described in 87338 can be used. 750-14
The semiconductor laser light source in the wavelength region of 00 nm can be advantageously sensitized with various known dyes including cyanine, merocyanine, styryl, hemicyanine, oxonol, hemioxonol and xanthene dyes. US Pat. No. 5,51 as a dye forming a J-band
No. 0,236, No. 3,871,887, JP-A-2-96131, JP-A-5
No. 9-48753 can be preferably used. The amount of the sensitizing dye used in the present invention is preferably from 10 ^-6 to 1 mol, more preferably from 10 ^-4 to 10 mol, per mol of silver halide in the photosensitive layer.
^-1 mol is more preferred.

Antifoggants, stabilizers and stabilizer precursors include thiazonium salts described in US Pat. Nos. 2,131,038 and 2,694,716, azaindenes described in US Pat. Nos. 2,886,437 and 2,444,605, and US Pat. 2,72
8,663 mercury salt, U.S. Pat.No. 3,287,135 urazole, U.S. Pat.No. 3,235,652 sulfocatechol, British Patent 623,448 Oxime,
Nitrone, nitroindazole, U.S. Patent No. 2,839,405
No. 3,220,839, thiuronium salts, and U.S. Pat.Nos. 2,566,263 and 2,597,915, palladium, platinum and gold salts, U.S. Pat.Nos. 4,108,665 and 4,442,202 No. 4,128,557
Nos. 4,137,079 and 4,138,365 and 4,
No. 4,59,350 and U.S. Pat.
And the phosphorus compounds described in No. 1,985. Further, benzoic acids may be contained for the purpose of preventing fog and increasing sensitivity. Examples of preferred benzoic acid structures include U.S. Pat.Nos. 4,784,939, 4,152,160, JP-A-9-329865,
Compounds described in JP-A Nos. 9-329864 and 9-281637 are mentioned, and it is preferable to add them to the organic silver salt-containing layer. The addition amount is preferably 1 μmol or more and 2 mol or less, more preferably 1 mmol or more and 0.5 mol or less per 1 mol of silver.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained in order to suppress or accelerate development to control development, to improve spectral sensitization efficiency, to improve storage stability before and after development, and the like. be able to. The mercapto compound is preferably a mercapto-substituted heteroaromatic compound, and specific examples thereof include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, and 2-mercapto-5.
-Methylbenzimidazole, 6-ethoxy-2-mercaptobenzothiazole, 2,2'-dithiobis-benzothiazole, 3-mercapto-1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2- Mercaptoimidazole, 1-ethyl-2-mercaptobenzimidazole, 2-mercaptoquinoline, 8-mercaptopurine, 2-mercapto
-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol, 2,3,5,6-tetrachloro-4-pyridinethiol, 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate , 2-amino-5-mercapto-1,3,4-thiadiazole, 3-amino-5-mercapto-1,2,4-triazole,
4-hydroxy-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-diamino-2-mercaptopyrimidine, 2
-Mercapto-4-methylpyrimidine hydrochloride, 3-mercapto-5-phenyl-1,2,4-triazole, 2-mercapto-4-phenyloxazole and the like. The addition amount of these mercapto compounds is preferably 0.0001 to 1.0 mol, more preferably 0.001 to 1.0 mol per mol of silver in the emulsion layer.
〜0.3 mol.

In the image forming layer, polyhydric alcohols (for example, glycerin and diols of the type described in US Pat. No. 2,960,404) as plasticizers and lubricants, and those described in US Pat. Nos. 2,588,765 and 3,121,060. Fatty acids or esters, such as the silicone resins described in British Patent No. 955,061, can be used. Various dyes and pigments can be used from the viewpoint of color tone improvement and irradiation prevention in the photosensitive layer which is the image forming layer, and preferred dyes are anthraquinone dyes (JP-A-5-341441, JP-A-5-165147). Described compounds), azomethine dyes (compounds described in JP-A-5-341441), indoaniline dyes (JP-A-5-289227, JP-A-5-341441, compounds described in JP-A-5-165147) and Azo dyes (eg, compounds described in JP-A-5-341441). These compounds are preferably used in an amount of 1 μg or more and 1 g or less per 1 m ^{2 of the} light-sensitive material.

An antihalation layer can be provided on the side farther from the light source than the photosensitive layer. The antihalation layer preferably has a maximum absorption in a desired wavelength range of 0.3 or more and 2 or less, more preferably an absorption of an exposure wavelength of 0.5 or more and 2 or less, and an absorption in a visible region after processing of 0.001 or more. It is preferably less than 0.5, and more preferably a layer having an optical density of 0.001 or more and less than 0.3. As a single dye, JP-A-59-564
No. 58, JP-A-2-216140, No. 7-13295, No. 7-11432,
U.S. Patent No. 5,380,635, JP-A-2-68539, 3-24539
No. etc. can be used. JP-A 52-139136, 53-132334, 56-501480
Nos. 57-16060, 57-68831, 57-101835, 5
No. 9-182436, JP-A-7-36145, 7-199409, Japanese Patent Publication No. 4
No. 8-33692, No. 50-16648, Japanese Patent Publication No. 2-41734, U.S. Pat.No. 4,088,497, No. 4,283,487, No. 4,548,896,
No. 5,187,049 can be preferably used.

It is also preferable to provide a protective layer on the outermost layer of the photosensitive layer. As a binder for the protective layer, an acrylic, styrene, acryl / styrene, vinyl chloride, or vinylidene chloride polymer latex is preferably used. Specifically, acrylic resin-based VONCORT R3370, 428
0, Nipol Lx857, methyl methacrylate / 2-ethylhexyl acrylate / hydroxyethyl methacrylate / styrene / acrylic acid copolymer, vinyl chloride resin
Nipol G576 and Alon D5071 of vinylidene chloride resin are preferably used. It is more preferable to add a crosslinking agent such as isocyanate to these layers. The preferred coating amount of the protective layer is 0.5 to 10 g / m ² , more preferably 1 to 7 g / m ² .
m ² , more preferably 1.5 to 5 g / m ² . More preferably, a matting agent is added to the protective layer. Examples of inorganic matting agents include silicon dioxide, oxides of titanium and aluminum, carbonates of zinc and calcium, sulfates of barium and calcium, silicates of calcium and aluminum, and examples of organic matting agents include cellulose. Mention may be made of organic polymeric matting agents such as esters, polymethyl methacrylate, polystyrene or polydivinylbenzene and copolymers thereof. Two or more of these matting agents may be used in combination.
The preferred average particle size of the matting agent is 1 to 10 μm, and the preferred addition amount is 5 to 400 mg / m ² , particularly 10 to 200 mg.
/ M ² .

The heat-developable photosensitive material thus prepared is cut when used, but may be used in the form of a roll or in the form of a sheet. In each case, the preferred width (the direction perpendicular to the processing direction when passing through a heat developing machine) is 40 cm or more and 150 cm or less, more preferably 45 cm or more and 1 cm or more.
00 cm or less, more preferably 50 cm or more and 80 cm or less. These light-sensitive materials are packaged and shipped at 20% RH or more and 80% RH or less, more preferably 30% RH or more and 70% RH or less.

The heat-developable image recording material of the present invention may be exposed by any method, but a laser beam is preferred as an exposure light source. As the laser beam according to the present invention, a gas laser, a YAG laser, a dye laser, a semiconductor laser and the like are preferable. Further, a semiconductor laser and a second harmonic generation element can be used. The heat-developable image recording material of the present invention has a low haze at the time of exposure and tends to cause interference fringes. As this technology for preventing the occurrence of interference fringes, Japanese Patent Application Laid-Open
No. 5,113,548, a technique for obliquely entering a laser beam into an image recording material, such as disclosed in WO95 / 31754, and a method using a multi-mode laser disclosed in WO95 / 31754 are known. It is preferable to use these techniques. To expose the heat-developable image recording material of the present invention, SPIE v
ol.169 Laser Printing 116-128 (1979), JP-A-4-510
No. 43, WO95 / 31754, etc., it is preferable to expose the laser beams so that they overlap each other so that the scanning lines are not visible.

In the heat development step of the image forming method of the present invention, development may be performed by any method. Usually, development is performed by raising the temperature of a photosensitive material exposed imagewise. As a preferred embodiment of the thermal developing machine to be used, as a type in which the photothermographic material is brought into contact with a heat source such as a heat roller or a heat drum, Japanese Patent Publication No. 5-56499, Patent Publication No. 684453, Japanese Patent Application Laid-Open No. 9-292695, Kaihei 9-297385 and International Patent WO
No. 95/30934, as a non-contact type, JP-A-7-13294, International Patent WO 97/28489, and 97/2848
Nos. 8 and 97/28487. A particularly preferred embodiment is a non-contact type thermal developing machine. The preferred development temperature is from 80 to 150 ° C, more preferably from 90 to 140 ° C, even more preferably from 100 to 130 ° C.
The present invention is particularly preferable when the heat development temperature is higher than the glass transition temperature of the support of the heat-developable photosensitive material. The development time is preferably from 10 seconds to 5 minutes, more preferably from 15 seconds to 3 minutes.
Minutes, more preferably 20 seconds to 1 minute. In addition, 80
A multi-stage thermal development method in which the above-mentioned thermal development is carried out after preheating for 5 seconds or more so that an image is not formed at a temperature of not less than 115 ° C and not less than 115 ° C is particularly preferable.

Hereinafter, the measuring method used in the present invention will be described. (1) Surface elastic modulus, indentation depth, and plastic deformation energy of the photosensitive layer and the back layer After a sample is stuck on a slide glass plate with an instant adhesive, the sample is placed on a heating stage and heated to a predetermined temperature. This is a micro hardness tester (Fisherscope H-100: F
(manufactured by Ischer) in the following manner.

A) Surface Elastic Modulus A Vickers indenter is pressed into the photosensitive material heated to the heat development temperature at 2 mN and held for 5 seconds, then the load is removed and the stress applied to the indenter is measured. B) Depth of Depth The depth at which the indenter reaches when the Vickers indenter is pressed at 2 mN into the photosensitive material heated to the heat development temperature is measured. C) Plastic deformation energy The stress (Fi) and the insertion depth (Di) of the Vickers indenter when the Vickers indenter is pressed at 2 mN at the heat development temperature are measured. Fi is plotted on the vertical axis and Di is plotted on the horizontal axis, and the area formed therebetween is defined as insertion energy (Ei). After inserting under the above conditions and holding for 5 seconds, when the force applied to the Vickers indenter is removed, the Vickers indenter is pushed back by the elastic force of the sample. At this time, the stress (Fo) and the depth (Do) received by the Vickers indenter were measured, and Fo was plotted on the ordinate and Do was plotted on the abscissa.
(Eo). Let Ei-E0 be the plastic deformation energy.

(2) 25 ° C, 50% RH, 25 ° C, 75%
XPS measurement of the back layer after% RH humidity control was 284.6 e.
V signal and 288.4 eV signal intensity ratio (I
_{284 . 6} / I _288.4 (50% RH)), (I _284.6 /
I _288.4 (75% RH)) Back layer at 25 ° C 50% RH or 25 ° C 75% RH
After conditioning with H for 12 hours, XPS measurement is performed in a range of 295 eV to 280 eV (binding energy). The peak that appears on the lowest binding energy side in the obtained spectrum is 284.6 eV, and charge correction (parallel movement) is performed. The lowest point in 293-291 eV and 284-2
The lowest point in 82 eV is connected as a baseline.
From this, the intensity (peak height) of the signal of 284.6 eV and the signal of 288.4 eV is measured, and the ratio is determined.

(3) The ratio (Fs / C) of the surface fluorine content (Fs) to the surface carbon content (Cs) of the back layer after humidity control at 25 ° C. and 50% RH.
s) After the humidity of the back layer was adjusted at 25 ° C. and 50% RH for 12 hours, 70
XPS measurement is performed in a range of 0 eV to 680 eV (binding energy). The lowest point among 698 eV to 696 eV, and 684
The lowest point among eV to 682 eV is defined as a connecting baseline. After integrating the area above the baseline, the value divided by the ionization cross section (4.3) is defined as Fs. Continuously, 295 eV to 280 eV (binding energy)
Is measured by XPS. The lowest point in 293 eV to 291 eV and the lowest point in 282 eV to 284 eV are defined as a baseline. After integrating the area above the baseline, the value divided by the ionization cross section (1) is Cs
And Fs is divided by Cs to obtain an Fs / Cs value.

(4) Coefficient of dynamic friction of the back layer Measured at 25 ° C. and 60% rh using stainless steel balls having a diameter of 0.5 mm. (5) Thermal dimension change of MD and TD at 120 ° C. for 30 seconds From the heat-developable photosensitive material after coating the photosensitive layer and before cutting, an MD sample (MD 25 cm × TD5) was obtained at three points in the width direction (both ends and center).
cm) and a TD sample (MD 5 cm × TD 25 cm). After conditioning for 24 hours at 25 ° C. and 60% rh, a pair of holes are made at intervals of 20 cm, and the distance between the holes is measured using a pin gauge.
(L1). The sample is brought into contact with the hot plate heated to 120 ° C. for 30 seconds. After humidity control at 25 ° C. and 60% rh for 24 hours, the length is measured using a pin gauge (L2). 100 × (L1−L2) / L1 is defined as a thermal dimensional change rate (%) associated with the treatment at 120 ° C. for 30 seconds.

(6) Water Absorption Rate of Support after Thermal Development The support coated up to the undercoat and the back layer was subjected to 25 ° C. and 40% RH.
Condition for 12 hours. This is thermally developed at 120 ° C. for 30 seconds,
Place under 25 ° C. and 75% RH. The difference between the amount of water measured after 3 minutes and the amount of water measured after 1 hour is defined as the water absorption rate after thermal development (% / hour). The measurement of the water content was carried out by the following method. The sample is cut into 1 cm × 3 cm at 25 ° C. and 75% RH, and the weight (F) is sealed in a glass tube. While heating the sample to 150 ° C. using a Karl Fischer moisture meter equipped with a heating device (Mitsubishi Kasei Kogyo Co., Ltd. Trace Moisture Analyzer CA-03 + Moisture Vaporizer VA-05), the weight of water (W) Ask for. 100 × W
(g) / F (g) was defined as a water content (%).

[0055]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. Example 1 (1) Preparation of Support (Base) IV (intrinsic viscosity) = 0.66 (phenol / tetrachloroethane = 6/4 (weight ratio)) using terephthalic acid and ethylene glycol according to a conventional method. (Measured at 25 ° C.). This was pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, and quenched on a 50 ° C. cooling drum to form an unstretched film.

This was longitudinally stretched 3.3 times at 105 ° C. using rolls having different peripheral speeds. Next, the film was transversely stretched 4.3 times at 125 ° C. with a tenter. Thereafter, the sheet was heat-treated at the temperature shown in Table 1 for the time shown in Table 1 without changing the tenter width, and then heat-set at 240 ° C. for 20 seconds, and then stretched laterally at the same temperature at the ratio shown in Table 1. After slitting the chuck part of the tenter for each 15 cm, knurling was performed on both ends,
After cooling to ℃, it was wound up at 4.8 kg / m. In this way,
A stretched PET support having a thickness of 100 μm and a width of 2.5 m was obtained. This was slit at both ends by the ratio shown in Table 1.
Thereafter, knurling of 1 cm in width was performed on both ends with a thickness of 25 μm. Thereafter, the molecular orientation angles at both ends were measured according to the above method, and the results are shown in Table 2.

(2) Waterproof / Undercoat Layer on Photosensitive Layer As shown in Table 2, a waterproof layer having the following composition was provided on one surface of the support (base). The PVdC-based waterproofing layer and the SBR-based waterproofing layer were applied to a dry thickness shown in Table 2, and then dried at 180 ° C. for 4 minutes. PV
The A-type waterproof layer was formed by coextrusion using a malt manifold die at the time of melt extrusion of the support so as to have a thickness shown in Table 2 after biaxial stretching. The following undercoat layer was applied on these waterproof layers and dried at 180 ° C. for 4 minutes.

(2-1) Waterproofing layer PVdC-based waterproofing layer PVdC polymer latex A core-shell type latex having a core of 90% by weight and a shell of 10% by weight Core: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 93/3/3 / 0.9 / 0.1 (% by weight) Shell part: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 88/3/3/3/3 (% by weight) weight average Molecular weight 38000 3000 parts by weight 2,4-dichloro-6-hydroxy-s-triazine 23 parts by weight Matting agent (polystyrene, average particle size 2.4 μm) 1.5 parts by weight SBR-based waterproof layer SBR polymer latex styrene / butadiene / hydroxy Ethyl methacrylate / divinylbenzene = 67/30 / 2.5 0.5 (% by weight) 160 parts by weight 2,4-dichloro-6-hydroxy-s-triazine 4 parts by weight Matting agent (polystyrene, average particle size 2.4 μm) 3 parts by weight PVA-based waterproofing layer polyvinyl alcohol polymer Latex EVAL EP-F101 (manufactured by Kuraray Co., Ltd.) 3000 parts by weight Matting agent (spherical silica, average particle size 2.4 μm) 1.5 parts by weight

(2-2) Undercoat layer Alkali-treated gelatin (Ca ++ content 30 ppm, jelly strength 230 g) 50 mg / m ²

(3) Back layer The following coating was performed on the opposite side of the undercoat layer. (3-1) Inorganic fine particle layer One of the following is selected (described in Table 1), and
After drying at ℃ for 4 minutes, curry at the temperature and contact pressure shown in Table 1.
Rendering was performed. Calendering is 45g tension
/ Mm²Contact the knurled part of the support while transporting
Using an edge roll with the raised part (both ends) raised by 75 μm
That was implemented. Tin oxide layer Julimer ET-410 (manufactured by Nippon Pure Chemical Co., Ltd.): Tg = 52 ° C. 38 mg / m²  SnO₂/ Sb (9/1 weight ratio, average particle size 0.25 μm, acicular shape with aspect ratio 5) Table 1 Matting agent (polymethyl methacrylate, average particle size 5 μm) 7 mg / m²  Denacol EX-614B (manufactured by Nagase Kasei Kogyo Co., Ltd.) 13 mg / m²  Silica layer Julimer ET-410 (manufactured by Nippon Pure Chemical Co., Ltd.): Tg = 52 ° C. 38 mg / m²  Spherical silica particles (average particle size 0.15 μm) described in Table 1 Matting agent (polymethyl methacrylate, average particle size 5 μm) 7 mg / m²  Denacol EX-614B (manufactured by Nagase Kasei Kogyo Co., Ltd.) 13 mg / m²  Mica layer Julimar ET-410 (manufactured by Nippon Pure Chemical Co., Ltd.): Tg = 52 ° C. 38 mg / m²  Mica (average particle size 0.35 μm: flat) Matting agent (polymethyl methacrylate, average particle size 5 μm) described in Table 1 7 mg / m²  Denacol EX-614B (manufactured by Nagase Kasei Kogyo Co., Ltd.) 13 mg / m²

(3-2) Intermediate Layer The following coating solution was applied on the inorganic fine particle layer,
Dried for minutes. Julimer ET-410 (manufactured by Nippon Pure Chemical Co., Ltd.): Tg = 52 ° C. 38 mg / m ²

(3-3) Back-side waterproof layer The PVdC-based waterproof layer and the SBR-based waterproof layer were applied on the inorganic fine particle layer and the intermediate layer so that the dry thickness shown in Table 2 was obtained.
It was dried at 180 ° C. for 4 minutes. The PVA-based waterproof layer was formed by coextrusion using a malt manifold die at the time of melt extrusion of the support so as to have a thickness shown in Table 1 after melt-extrusion of the support before coating the inorganic fine particle layer and the intermediate layer. PVdC-based waterproofing layer A core-shell type latex having a core portion of 90% by weight and a shell portion of 10% by weight. Core portion: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 93/3/3 / 0.9 / 0. 1 (% by weight) Shell part: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 88/3/3/3/3 (% by weight) Weight average molecular weight 38,000 3000 parts by weight 2,4-dichloro-6 Hydroxy-s-triazine 23 parts by weight Matting agent (polystyrene, average particle size 2.4 μm) 1.5 parts by weight SBR-based waterproofing layer Styrene / butadiene / hydroxyethyl methacrylate / divinylbenzene = 67/30 / 2.5 / 0. 5 (% by weight) 160 parts by weight 2,4-dichloro-6-hydroxy s-Triazine 4 parts by weight Matting agent (polystyrene, average particle size 2.4 μm) 3 parts by weight PVA-based waterproofing layer polyvinyl alcohol polymer latex EVAL EP-F101 (manufactured by Kuraray Co., Ltd.) 3000 parts by weight Matting agent (spherical silica) , Average particle size 2.4 μm) 1.5 parts by weight

(3-4) Back Outer Layer A back of the following composition is placed on the inorganic fine particle layer, the intermediate layer, and the waterproof layer.
The outermost layer was applied and dried at 180 ° C. for 3 minutes. Julimer ET-410 (manufactured by Nippon Pure Chemical Co., Ltd.): Tg = 52 ° C. 1000 mg / m²  Matting agent (polystyrene, average particle size 5μm) 10mg / m²  Sodium linear alkyl (C20) sulfonate 30mg / m²  Hydrocarbon slip agent (select one from A, B, C and D below: described in Table 1) A. Carnauba wax The coating amount is described in Table 1. B. Chemipearl (modified polyethylene latex) 〃 C. Stearylamide 〃 D.C₁₆H₃₃-O-SO₃Na Ｆ F-based surfactant (select one from the following a, b, c and d: listed in Table 1) b.₈F₁₇-C₆H₄-OSO₃The amount of Na applied is described in Table 1.₈F₁₇-SO₃Na 〃 C₈F₁₇-N (C₃H₇)-(CH₂CH₂O)₈-C₄H₈-SO₃Na ニ Ni. C₈F₁₇-N (C₃H₇) -CH₂COOK 〃

(4) Heat treatment After the support having the back layer / undercoat layer was once wound up, heat treatment was carried out while transporting the inside of the heating zone under the conditions shown in Table 2. Thereafter, the roll is lined with a fluorine-based resin of the material shown in Table 1 and conveyed at the temperature and time shown in Table 1 for heat treatment. The winding part is adjusted to the humidity shown in Table 1 and the temperature of the support is 50 ° C. To achieve the base water absorption shown in Table 1 and to perform low-moisture winding. The water absorption rate of the support thus completed up to the low tension heat treatment was measured according to the above method, and is shown in Table 2.

(5) Image-forming layer (photosensitive layer) The following image-forming layer and protective layer were formed on the undercoat layer (opposite the back layer) of the support coated with an undercoat and a back layer by the above-mentioned method and completed with heat treatment. The layers were sequentially applied and dried under the conditions described in Table 2. At this time, drying is performed so as to provide a temperature difference between the upper surface and the lower surface of the photosensitive material as shown in Table 2, but a set temperature of a hot air blowing device provided above and below a drying zone which is transported horizontally is adjusted. Carried out. Further, the amount of dry air on the upper surface and the lower surface of the photosensitive material is also different as shown in Table 2, and this was achieved by adjusting dampers attached to upper and lower outlets.

(5-1) Preparation of silver halide grains In 700 ml of water, 11 g of phthalated gelatin, 30 mg of potassium bromide and 10 mg of sodium thiosulfonate were dissolved, and the pH was adjusted to 5.0 at a temperature of 35 ° C. Silver nitrate 1
159 ml of an aqueous solution containing 8.6 g and an aqueous solution containing potassium bromide at 1 mol / l were added by a controlled double jet method over 6.5 minutes while keeping the pAg at 7.7. Then, 476 ml of an aqueous solution containing 55.4 g of silver nitrate and a halogen salt aqueous solution containing 1 mol / l of potassium bromide at a pAg of 7.7 were added by a control double jet method over 30 minutes.
Methyl-1,3,3a, 7-tetrazaindene (1 g) was added, and the pH was further lowered to cause coagulation and sedimentation for desalination. Thereafter, 0.1 g of phenoxyethanol was added and p
After adjusting to H5.9 and pAg8.2, preparation of silver bromide grains (cubic grains having an average size of 0.12 μm, a variation coefficient of projected area diameter of 8%, and a (100) face ratio of 88%) was completed. The silver halide grains thus obtained were heated to 60 ° C., and 8.5 × 10 ⁻⁴ mol of sodium thiosulfonate per mol of silver was added. After ripening for 120 minutes, the mixture was rapidly cooled to 40 ° C., and then 1 ×
^10-5 mol of dye S-1, 5 × 10 ^-5 mol of 2-mercapto-5-methylbenzimidazole and 5 × 1
0 ^-5 mol of N- methyl -N '- rapidly cooled was added to {3- (mercaptomethyl tetrazolyl) phenyl} urea 30 ° C. to obtain a silver halide emulsion.

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(5-2) Preparation of Dispersion of Organic Acid Silver 4.4 g of stearic acid, 39.4 g of behenic acid, 77 of distilled water
While stirring 0 ml at 90 ° C, 103 ml of 1N-NaOH aqueous solution was added, reacted for 240 minutes, and cooled to 75 ° C. Then
112.5 ml of an aqueous solution of 19.2 g of silver nitrate was added over 45 seconds, left as it was for 20 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. 100 g of a 10 wt% aqueous solution of hydroxypropylmethylcellulose was added to the solid content thus obtained, and water was further added to a total weight of 270 g, followed by elementary dispersion in an automatic mortar to obtain a coarse dispersion of silver organic acid. Using a Nanomizer (manufactured by Nanomizer), the crude organic acid silver dispersion was subjected to a collision pressure of 1000 kg / kg.
cm ³ to obtain a dispersion of silver organic acid. The organic acid silver particles contained in the organic acid silver dispersion thus obtained had an average minor axis of 0.0.
Needle-like particles having a particle size of 4 μm, an average major axis of 0.8 μm, and a variation coefficient of 30% were obtained.

(5-3) Preparation of dispersion of reducing agent 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-
850 g of water was added to 100 g of trimethylhexane and 50 g of hydroxypropyl cellulose and mixed well to form a slurry. 840 g of zirconia beads with an average diameter of 0.5 mm
Was placed in a vessel together with the slurry, and dispersed in a disperser (（G sand grinder mill: manufactured by Imex Co., Ltd.) for 5 hours to obtain a reducing agent dispersion.

(5-4) Preparation of Organic Polyhalide Dispersion To 50 g of tribromomethylphenylsulfone and 10 g of hydroxypropylmethylcellulose, 940 g of water was added and mixed well to form a slurry. Prepare 840 g of zirconia beads having an average diameter of 0.5 nm, put them in a vessel together with the slurry, and use a dispersing machine (１ ／ G sand grinder mill:
The mixture was dispersed for 5 hours with IMEX Co., Ltd. to obtain an organic polyhalide dispersion.

(5-5) Preparation of Coating Solution for Image Forming Layer A coating solution for the image forming layer having the following composition was prepared. The above-mentioned organic acid silver dispersion 100 g The above-mentioned reducing agent dispersion 20 g The above-mentioned organic polyhalide dispersion 15 g Polymer latex material (select one from the following) LACSTAR3307B (SBR latex manufactured by Dainippon Ink and Chemicals, Ltd .; Tg13) C) 49 wt% 40 g Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / methacrylic acid = 59/9/26/5/1 copolymer; Tg 47 ° C.) 40 g Julimer ET-410 (Nihon Jun) Tg = 52 ° C. 40 g Styrene / butadiene / hydroxyethyl methacrylate = 67/30 / 2.5 / 0.5 (% by weight) 40 g MP-203 (manufactured by Kuraray Co., Ltd .; polyvinyl alcohol) 10 wt % Aqueous solution 20 g Halogenated emulsion 20 g Hydrazine derivative (Compound Example 3) 7a) 1 wt% methanol solution 8 ml water 100 g This coating solution was applied so that the coating amount of silver was 1.5 g / m ² and the coating amount of the solid content of the polymer latex was 5.7 g / m ² .

(6) Protective Layer (6-1) Preparation of Coating Solution for Protective Layer The following coating solution was applied on the photosensitive layer so that the solid content of the polymer latex was 2 g / m ² . 40wt% polymer latex (methyl methacrylate / styrene /
2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / methacrylic acid = 59/9/26 /
Copolymers of 5/1; the Tg47 ℃) _{500g, H} 2 O
262 g, and as a film-forming auxiliary, 14 g of benzyl alcohol, the following compound -22.5 g, and cellosol 524
(Manufactured by Chukyo Yushi Co., Ltd.) 3.6 g, the following compound-312
g, the following compound-41 g, the following compound-52 g, the following compound-6 7.5 g, and a matting agent having an average particle size of 3
3.4 g of polymethyl methacrylate fine particles of μm were sequentially added, and H ₂ O was further added to 1000 g to prepare a coating solution having a viscosity of 5 cp (25 ° C.) and a pH of 3.4 (25 ° C.).

[0073]

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[0074]

[Table 1]

[0075]

[Table 2]

(7) Evaluation of photosensitive material The mechanical strength of the photosensitive layer (surface elastic modulus, indentation depth, plastic deformation energy) and the mechanical strength of the back layer surface (surface elastic modulus, indentation depth) of the photosensitive material prepared by the above method were evaluated. The plastic deformation energy), the XPS measurement of the backing layer, and the kinetic friction coefficient of the backing layer were measured in accordance with the above-described methods. The results are shown in Table 3.
Further, the center of the photosensitive material in the width direction, 5 cm from both ends, is M
Sampling was performed in the D and TD directions, and the dimensional change rate was measured according to the method described above.

(8) Evaluation of heat-development of light-sensitive material The obtained heat-developable light-sensitive material was subjected to a longitudinal direction (MD) and a width direction (T
A 60 cm square was cut out along D). this,
Processing was performed using the following three types of heat developing machines, and evaluation was performed.

(8-1) Thermal development After the above-mentioned heat-developable photosensitive material (60 cm × 60 cm) was exposed in a flat screen,
After exposing "register marks (cross-shaped marks)" to the four corners at 50 cm intervals, heat development was performed using the following three types of heat developing machines. Table 4 shows the preheating and heat development conditions (temperature and time). Non-contact heat developing machine

Processing is performed using the heat developing machine shown in FIG.
The feature of this method is that the photosensitive material is transported on the nonwoven fabric in a constant temperature bath maintained at a constant temperature without directly contacting the heat source. As a result, the photosensitive layer side is transported without contact with the heat source. Details will be described with reference to the side view of the heat developing machine of FIG. The thermal developing machine shown in FIG. 1 is a pair of carry-in rollers 11 (a lower roller is a heat roller) for carrying the thermal development photosensitive material 10 into a heating unit while correcting and preheating the thermal development photosensitive material 10 in a plane, and a photothermographic material after thermal development after thermal development. It has an unloading roller pair 12 that unloads the material 10 from the heating unit while correcting it into a flat shape. The photothermographic material 10 is thermally developed while being transported from the carry-in roller pair 11 to the carry-out roller pair 12. The transport means for transporting the photothermographic material 10 during the thermal development includes a plurality of rollers 13 on the side where the surface having the image forming layer contacts.
A smooth surface 14 on which a non-woven fabric (for example, made of polyphenylene sulfide or Teflon) or the like is attached is provided on the opposite side to which the back surface contacts. The back surface of the photothermographic material 10 is conveyed by sliding on the smooth surface 14 by driving a plurality of rollers 13 that come into contact with the surface having the image forming layer. Heating means roller 1
A heater 15 is provided at the upper part of the photothermographic material 3 and at the lower part of the smooth surface 14 so as to heat the photothermographic material 10 from both sides. As a heating means in this case, a plate heater or the like can be used. The clearance between the roller 13 and the smooth surface 14 varies depending on the member of the smooth surface, but is appropriately adjusted to a clearance that allows the photothermographic material 10 to be transported. Preferably 0
１1 mm.

The surface material of the roller 13 and the smooth surface 14
May be any material as long as it has high-temperature durability and does not hinder conveyance of the photothermographic material 10, but the material of the roller surface is silicon rubber, and the material of the smooth surface is a nonwoven fabric made of aromatic polyamide or Teflon (PTFE). Is preferred. It is preferable to use a plurality of heaters as the heating means and to set the heating temperature freely. The preliminary heating section upstream of the thermal development processing section is lower than the thermal development temperature (for example, 1
It is desirable to set the temperature and time to be sufficient to evaporate the amount of water in the photothermographic material, and to be lower than the glass transition temperature (Tg) of the support of the photothermographic material 10. It is preferable to set at a high temperature so that development unevenness does not occur. Further, a guide plate 16 is provided downstream of the thermal development processing section, and a slow cooling section is further provided. The guide plate is preferably made of a material having low thermal conductivity, and is preferably cooled gradually.

Roll contact type heat developing machine A heat developing machine of the system described in Example 1 of WO 95/30934 was used. Hot plate contact type heat developing machine The heat developing machine of the system described in Example 1 of Japanese Patent Application Laid-Open No. 7-505488 was used.

(8-2) Evaluation of transportability of thermal developing machine and photosensitive material after thermal development Passage time The time required for carrying out the photosensitive material was measured (T1 second), and set time (T0 second) (100 × (T1-T0) /
T0) is shown in Table 4. Acceptable is 6% or less.
Note that Δ indicates that the paper was not discharged from the heat developing machine (jamming occurred (the photosensitive material wrapped around the roll and became entangled). Development unevenness The image of the flat screen after heat development was visually evaluated. Table 4 shows that the stripe-shaped development unevenness (density unevenness) appeared at a pitch of 3 to 15 cm in the horizontal direction (perpendicular to the transport direction) due to the poor transport, and evaluated as ○ when it did not occur. ○ is acceptable,
X is out of tolerance. Table 4 shows that those which were wrapped around the transport roll during the heat development and did not come out were evaluated as x, and those transported without any problem were evaluated as ○.
○ is acceptable and X is out of tolerance. Registration mark shift The same photographic material was thermally developed in two successive plates, and these were superimposed, and the registration mark shift on the four sides was observed with a magnifier of 50 times. Table 4 shows the case where the displacement occurred, and the case where the displacement did not occur was shown in Table 4. ○ is acceptable and X is out of tolerance.

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[Table 3]

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[Table 4]

As is clear from the results in Tables 3 and 4, the surface elastic modulus of the photosensitive layer at the heat development temperature was 0.05 to 0.5.
The sample of the present invention in the range of 8 GPa shows excellent heat transfer property of the developing device, while Comparative Example 1 having 0.03 GPa shows no heat transfer property of the heat developing device.

[0086]

The photothermographic material of the present invention has excellent transportability in a photothermographic machine.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a configuration of a non-contact type heat developing machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Thermal developing material 11 Carry-in roller pair 12 Carry-out roller pair 13 Roller 14 Smooth surface 15 Heater 16 Guide plate A Preheating part B Thermal development part C Slow cooling part

Claims (6)

[Claims] 1. A photothermographic material comprising a photosensitive layer having a surface elastic modulus at a thermal development temperature of 0.05 GPa or more and 0.8 GPa or less. 2. The photothermographic material according to claim 1, wherein the indentation depth of the photosensitive layer at the temperature of thermal development is 1 μm or more and 10 μm or less. 3. The photothermographic material according to claim 1, wherein the plastic deformation energy of the photosensitive layer at a thermal development temperature is 1 nJ or more and 10 nJ or less. 4. The thermal dimensional change in MD (longitudinal direction) and TD (width direction) due to treatment at 120 ° C. for 30 seconds is −0.05% or more and 0.05% or less over the entire region in the width direction. The photothermographic material according to any one of claims 1 to 3. 5. The photothermographic photograph according to claim 1, wherein a support having a water absorption rate after thermal development of 0% / hour to 0.16% / hour is used. Photosensitive material. 6. Thermal development at a temperature of 80 ° C. to 150 ° C.
The method is carried out for at least 2 seconds and at most 5 minutes.
5. The photothermographic material according to any one of the above items 5.