JPS6281637A - Method for accelerating curing of photographic layer - Google Patents

Abstract

PURPOSE:To quickly and uniformly cure the entire photographic layer of a photographic material wound like a semi-processed product roll by coating a compsn. liquid contg. a protective colloid and curing agent thereof on a flexible belt-like base, drying the coating and taking up the base while subjecting the base to a heating treatment and subjecting the same again to the heating treatment. CONSTITUTION:The photographic material 5 obtd. by coating the compsn. liquid contg. the protective colloid and curing agent thereof on the base 2 by a coater consisting of a coater head 3 and a backing roll 4 and passing the base through a drying device 6 after such coating is subjected to the first heating treatment with a heating roll 7 and is taken up on a take-up roll 8. The photographic material 5 is then subjected to the second heating treatment in the form of the semi-processed product roll. The first heating treatment is so executed that the internal temp. of the semi-processed product roll is maintained at about 30-50 deg.C and the second heating treatment is preferably executed in such a manner that the semi-processed product roll is heated at 30-50 deg.C. The entire photographic layer of the photographic material wound like the semi-processed product is thus quickly and uniformly cured.

Description

DETAILED DESCRIPTION OF THE INVENTION (^) Industrial Application Field The present invention relates to a method of accelerating the curing of a protective colloid layer containing a curing agent, and more particularly to a method of accelerating the curing of a photographic layer of a photographic material.

(B) Prior art and its problems Various photographic layers forming photographic materials, such as silver halide emulsion layer, antihalation layer, backing layer, filter layer, intermediate layer, undercoat layer, protective layer, silver complex salt diffusion transfer In the image-receiving layer used in this method, various hydrophilic colloids such as gelatin, polyvinyl alcohol, and polyacrylamide are usually used as protective colloids.

Photographic materials having these photographic layers on a support are usually subjected to imagewise exposure followed by development-stop constant fixation processing or color development.
After undergoing photographic processing such as development, bleaching, and fixing, a silver image or a dye image is produced.

These photographic treatments are performed by immersing the photographic material in a high pH solution, a low pH solution, a high temperature solution, or the like. It is therefore well known that photographic materials need to have increased physical strength so that the photographic layers are not damaged during processing or various handling.

As a method of increasing the film strength of the photographic layer, it is common practice to incorporate a hardening agent (also referred to as a hardening agent) for the protective colloid forming the photographic layer into the protective colloid. Hardeners include aldehyde hardeners such as formaldehyde and glyoxal, vinyl sulfone hardeners, epoxy hardeners, aziridine hardeners, active halogen hardeners, and isocyanate hardeners. A variety of other methods are known.

These hardeners are usually added to the photographic coating before it is applied onto the support, and at least when the coating layer is applied, dried and wound up, it is added to the coating before it is applied onto the support. The membrane strength has been reached to the extent that it can withstand the pressure and tension applied to the photographic layer.

However, in the photographic layer immediately after coating and drying, the hardening agent usually remains in an unreacted state with the protective colloid, and the film strength is not sufficient to withstand photographic processing. These unreacted hardeners continue to react, albeit gradually, even after the photographic layer is applied and dried, so if the photographic material is left for a long time before being shipped as a product, the film will have the strength to withstand photographic processing. .

However, leaving the product for such a long time not only reduces productivity, but also requires a huge amount of protection space, and it is not possible to control the reaction of the curing agent. Further, there is also the disadvantage that the photographic characteristics deteriorate over time.

As a method to solve these disadvantages, photographic materials that would normally be stored in a cold state are stored at high temperatures for short periods of time, e.g.
There is a method of accelerating the reaction between the unreacted curing agent and the protective colloid in the photographic layer by placing the photographic layer at a suitable temperature of ~50°C and increasing the temperature of the photographic layer. This method has the advantage of solving the above-mentioned problems and increasing the film strength of the photographic layer to a certain practical level in a short period of time.

However, this method has the following drawbacks.

In order to increase the temperature of the photographic layer, when a photographic material is coated and dried and placed in a semi-finished roll state (a so-called mill roll state) under high temperature, the temperature of the surface and sides of the roll and their vicinity increases. However, the temperature rises slowly inside the roll, and it takes a long time for the photo layers of the entire roll to reach a certain temperature level, and during this time, the photo layers whose humidity rose quickly and the photos whose temperature rose later. There is a difference in the degree of reaction of the curing agent between the layers, and a difference also occurs in the film strength.

(C) Object of the Invention An object of the present invention is to provide a curing acceleration method capable of uniformly curing all photographic layers of a photographic material wound into a semi-finished roll in a short period of time.

([) Constitution of the Invention The present invention provides a photographic material obtained by coating a composition liquid containing a protective colloid and a curing agent for the protective colloid on a flexible strip-shaped support using a coating device and drying the composition. This is a method of accelerating the hardening of a photographic layer, which is characterized in that the photographic material is rolled up while being subjected to a first heat treatment, and then subjected to a second heat treatment in the form of a semi-finished roll.

In the present invention, the appropriate temperature range of the temperature inside the photographic material roll in the first heat treatment and the temperature in the second heat treatment is 30°C.
~50°C, and the surface of the photographic material on which the first heat treatment is performed does not matter whether it is the front or the back. .

In the present invention, the first heat treatment method for the photographic material includes (a) bringing the photographic material that has undergone the coating and drying steps into contact with a fully curved roller surface heated by hot water, steam, or electric heater electromagnetic induction; Various methods include: 1)) blowing hot air onto the photographic material, (C) passing the photographic material through a temperature-controlled box or room, and (d) controlling the temperature of the winding chamber.

In the present invention, photographic layers include photosensitive layers such as silver halide emulsion layers, various non-photosensitive layers that do not contain photosensitive silver halide, and image-receiving layers containing physical development nuclei used in the silver complex diffusion transfer method. Refers to all forming layers provided on a support to form a material.

Protective colloids according to the present invention include gelatin, derivative gelatin, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, polyvinyl methyl ether, carboxymethyl cellulose,
All protective colloids conventionally known as binders for photographic layers can be used, such as hydroxyethyl cellulose, acrylic acid-ethyl acrylate copolymer, sodium alginate, casein, albumin, etc., but usually gelatin or gelatin and other protective colloids can be used. A mixed system of colloids is used.

As the curing agent according to the present invention, aldehyde compounds such as formaldehyde, glyoxal, and glitaraldehyde, U.S. Pat.
2.303, British Patent No. 974,723, ibid '167
．． Compounds containing reactive halogens such as those described in 207, ketone compounds such as diacetyl and cyclopentanedione, bis(2-chloroethylurea), 2
-Hydroxy-4,6-dichloro-'1,3,5-triazine, divinylsulfone, 5-acetyl-1,3-diacryloyl, hexahydro-1,3,'5-triazine, U.S. Patent No. 3.635, 718, 3.232.7
63, compounds with reactive olefins described in British Patent No. 994.809, etc., N-didroxymethylphthalimide, and other U.S. Patent No. 2,732,31
6, N-methylol compounds described in U.S. Pat. No. 2,586,168, isocyanates described in U.S. Pat. No. 3,103.437, U.S. Pat.
Aziridine compounds described in U.S. Patent No. 17,280, U.S. Patent No. 2,983,611, etc.;
, acid derivatives described in US Pat. No. 2,725,295, etc., carbodiimide compounds described in US Pat. No. 3,100,704, etc., US Pat. No. 3,091.53.
Epoxy compounds described in U.S. Patent No. 7, etc.
, 321, 313, 3.543.292 etc., halogen carboxaldehydes such as mucochloric acid, dioxane derivatives such as dihydroxydioxane and dichlorodioxane,
Examples include inorganic hardeners such as chromium alum, zirconium sulfate, and chromium trichloride. These curing agents can be used alone or in combination of two or more to cure a small amount of dry protective colloid.
Usually 0.01-100% by weight, preferably 0.1-10%
It is used in the range of %. The curing agent is added by adding a curing agent solution to the protective colloid-containing liquid at any stage up to the application of the photographic coating solution. When added to a silver halide emulsion, it is usually added after ripening and before coating.

(E) Examples The present invention will now be explained in more detail with reference to Examples.
The present invention is not limited to this.

FIG. 1 is a schematic diagram of a process showing one embodiment of the present invention. The arrows in the figure indicate the direction of movement of the support and the photographic material, and a coating device consisting of a coater head (3) and a packing roll (4) coats the support (2) that has left the unwinding roll (1). The liquid is applied, followed by a drying device (6)
The photographic material (5) produced through the heating roll (7)
A first heat treatment is performed at , and the film is wound onto a winding roll (8).

Through the steps shown in Figure 1, one side of the support (2), which is made of paper with a moisture content of about 7% and coated with polyethylene layers on both sides, is treated with corona discharge, and the gelatin-silver halide emulsion layer (hardening of gelatin) is applied. After coating and drying formalin (containing 0.6% by weight of gelatin as an agent), the surface of the emulsion layer was subjected to a first heat treatment with a heating roll (7) and rolled onto a winding core with an outer diameter of 200 m. Winding, width 1105cm, outer diameter 84cm
The roll is 0 mm. Next, the heated and wound photographic material is subjected to a second heat treatment in a room at a temperature of 40° C. (heating R) while remaining in a roll form.

The heating roll (7) has warm water (80°C) flowing inside it, has an outer diameter of 260#, a mirror surface shape, and a surface temperature of 65°C, and the included angle of the heating roll (7) during heating is 180°. °.

FIG. 2 shows the change over time in the temperature distribution inside the roll after it was placed in the heating chamber. The temperature inside the roll was measured by punching a hole in the roll and inserting a mercury rod thermometer. The measurement positions are in the order of depth O#, 80#, '160m, and 240m from the roll surface at the center of the roll, and the temporal changes in temperature distribution at each position are shown by curves a, b, c, and d in the figure. It will be done. Further, FIG. 2 (A> shows the case where the heating roll surface temperature is 65°C, and <8> shows the case when the heating roll surface temperature is 20°C.

From Figure 2, when the heating roll surface temperature is 65°C, 2
It can be seen that the temperature difference depending on the depth is smaller than in the case of 0° C., and the time required for the temperature inside the roll to stabilize is short.

Table 1 shows the melting point of the surface of the emulsion layer and the film strength of the emulsion layer 6 days after the roll was placed in the heating chamber.

Samples were taken from a roll depth of O# (surface) and a position of 240 m (inside).

Table 1 shows that when the heating roll surface temperature is 65°C, the difference in melting point and film strength due to depth is smaller than when the heating roll surface temperature is 20°C.
It can be seen that both the melting point and film strength are high.

From the above, by heating and rolling up the photographic material after coating and drying, the temperature distribution inside the roll can be made uniform and at a high temperature. It can be seen that the photographic layer can be cured uniformly and in a short period of time.

(Margin below) Table 1 (Note 1) Cut out a part of the surface and inside to make a sample, immerse the sample in a developer having the following composition, gradually heat the developer, and when the emulsion film begins to melt. The temperature of the developer was defined as the melting point (°C).

(Developer) Water 750m Metol 1.0g Hydroquinone
4.0g Sodium sulfite 15
．． 0g Sodium carbonate 26.79 Potassium bromide 0.79 Add water to 1010
Set to 0O.

(Note 2) Cut out a part of the surface and inside to make a sample, and after immersing it in a 20"C developer for 2 minutes,
A # ball point needle is placed perpendicular to the sample film surface, and when a load is applied and the sample surface is moved in parallel at a speed of 'Icm/sec, the load (g>) that causes damage to the sample film surface is defined as the film strength. did.

([) Effects of the Invention According to the present invention, all photographic layers of a photographic material wound into a semi-finished roll can be uniformly cured in a short period of time.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a process showing one embodiment of the present invention. Figure 2 is a graph showing the change in temperature distribution inside the roll over time after it is placed in the heating chamber. In the figure, 1... unwinding roll, 2... support 3... coater head, 4... packing roll 5... photographic material, 6... drying device, 7... . . . Heating roll 8 . . . shows a winding roll.

Claims (2)

[Claims] (1) A composition containing a protective colloid and a curing agent for the protective colloid is applied to a flexible strip-shaped support using a coating device, and the photographic material obtained by drying is rolled up while undergoing a first heat treatment. A method for accelerating hardening of a photographic layer, which comprises subjecting the photographic material in the form of a semi-finished roll to a second heat treatment. (2) From the first heating, the internal temperature of the semi-finished product roll of photographic material is 30 to 50°C, and the semi-finished product roll is heated to 30°C.
2. The method of accelerating hardening of a photographic layer according to claim 1, wherein the second heat treatment is performed at a temperature of ~50°C.