JP3038836B2 - Long-term storage of photos - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for preventing deterioration and deterioration of a photograph, and more particularly to preventing chemical, biological and physical destruction of a photograph for a long period of time.

[Conventional technology]

The use of photographs to convey images as information is widely and generally used. However, it has been difficult to preserve the developed and fixed image of a photograph for a long period of time because the constituents thereof change over time.

In response to this aging, considerable research has been done to make the photosensitive material more stable and stabilize the image.
For example, it is disclosed in US Pat. No. 3,379,529 and US Pat. No. 3,620,746. Although these methods increase the stability of photographs, they cannot prevent the photographs from gradually discoloring over a long period of time in a normal atmosphere, that is, in the air.

When photographs are stored in a high-humidity atmosphere, mold may form on the gelatin layer used for the material, shrinkage of the base film may occur due to oxidation of the dye or fluctuations in humidity, or the dye may be reduced by reducing substances in the atmosphere. Or deteriorate.

Not by stabilizing the materials that make up the photograph, such as dyes,
There are ways to store photos by controlling the environment.

To date, public periods around the world have protected photographs in this manner, but at temperatures below 20 degrees Celsius (especially below 2 degrees Celsius for color) and temperatures between 10% and 50% relative humidity (particularly preferred). (10% to 30%), the conditions stipulated in ISO-5466 are very expensive to maintain, and it is almost impossible for private institutions such as museums and individuals to do it. Methods for preserving a photosensitive material with an antioxidant (specifically, an inert gas and / or an oxygen scavenger) and / or a desiccant are disclosed in JP-A-61-88256 and JP-A-1-167836. . It is conceivable to use this method as it is for long-term storage of photographs. However, when the problems of this method are listed, when an inert gas is used as an antioxidant, the inside of a closed space for storing a photograph (hereinafter, may be abbreviated as a system).
It is not possible to reduce the oxygen concentration of the material to such an extent that the constituents of the photograph do not oxidize. In addition, this method requires an apparatus for inert gas replacement, and cannot be used simply.

The method of putting the oxygen scavenger in the system and sealing it has the effect of reducing the oxygen concentration to the point where the substances constituting the photograph are not oxidized, but the moisture of the oxygen scavenger transfers to the film in the system. Therefore, physical destruction such as adhesion between the film and the packaging material may occur. In addition, a commonly used iron-based oxygen scavenger absorbs oxygen and generates a small amount of hydrogen, which alters the color of the dye and adversely affects the preservation of photographs.

In the method of sealing the desiccant in the system, since the humidity in the system is reduced, the quality of the photograph is certainly delayed. However, since the desiccant does not have the ability to suppress the oxidation of photographic constituents, from the viewpoint of long-term storage, it has only an effect of suppressing the occurrence of mold and cannot be used for the purpose of retaining images. . Also, if the humidity in the system is too low using a strong desiccant, it may cause physical destruction such as cracking of the photographic constituents, delamination, etc.It is necessary to calculate and use an appropriate amount of the desiccant, This is very difficult.

Although a method in which a desiccant and a desiccant are used in combination has been disclosed, since moisture is essential for the deoxidation reaction, moisture is transferred to the desiccant, and the deoxygenation reaction stops for a short period of time. In some cases, oxygen may remain in the system. Therefore, utilizing such a method for long-term storage is a very dangerous method. Further, there is the problem of hydrogen generation as described above.

As described above, there has been no good way to store photos, and there is a danger that photos that are valuable information and property will gradually be lost, and this is still ongoing.

[Problems to be solved by the invention]

Instead of the incomplete or expensive maintenance method as described above, it is a simple method of simply sealing the container together with a deoxidizer and a humidity control agent and storing the photograph as it is for a long period of time.

[Means for solving the problem]

The present invention is a photograph, the oxygen permeability at 25 degrees Celsius is 10 ml
/ m ² · Atm · Day or less, and the oxygen scavenger water vapor permeability is made of a composition comprising an oxidation promoting catalyst and unsaturated aliphatic compounds in the following packaging material 10g / m ² · Day at 25 ° C The present invention relates to a storage method which is sealed together with a humectant having an equilibrium relative humidity of 10 to 70%. More specifically, the present invention relates to a method of storing a photograph for a long time when the photograph is in a positive or negative state after development and fixing, or when the photograph is fixed on photographic paper.

In the present invention, in the oxygen permeability at 25 ° C is intended to be used as a packaging material is not more than ^{10ml / m 2 · Atm · Day} , and at a water vapor permeability at 25 ° C is 10 g / m ² · Da
y (hereinafter materials with these properties are simply called packaging materials)
PP / PE, polyvinylidene chloride-coated stretched nylon / PE, polyvinylidene chloride-coated polyester / PE, polyvinylidene chloride-coated stretched nylon / evaporated aluminum / PE,
And the like are preferably used.

Particularly, when a positive or negative image after development, a motion picture film, a valuable photograph taken in the past, or the like, which is required to be stored without being opened for a long period of one year or more, oxygen is preferably used. Air permeability and water vapor permeability are substantially zero. Specifically, a metal can with an air-tight structure, basically a thermocompression-bondable resin layer /
Examples include a multilayer film (the number of layers is 3 or more) having a structure of a metal thin film / protective resin layer. In particular, stainless steel for metal cans, low-density polyethylene (PE) and polypropylene (PP) for resin layers that can be thermocompression-bonded for multilayer films, aluminum and its alloys for metal thin films, and stretched nylon and polyester for protective resin layers are preferable. Used.

Examples of the humectant used in the present invention include an aqueous solution of a water-soluble organic compound. As the water-soluble organic compound,
It is freely mixed with water.Specifically, polyethylene glycol, polypropylene glycol, triethanolamine, tripropanolamine as amines, and trimethylolpropane, trimethylolethane, glycerin, neopentyl glycol as polyhydric alcohols, etc. can give.

 The humidifier is usually carried on a carrier.

Specific examples of the carrier include paper, cloth, nonwoven fabric, and the like, and porous adsorbents such as silica gel, activated alumina, zeolite, and activated clay perlite.

Further, the humidity in the system defined by the humidifier is the fusion of gelatin caused by too high humidity, conversely, the cracks caused by too low humidity, physical destruction such as peeling,
RH is 10% or more and 50% or less, and more preferably RH 20% or more and 40% or less, within a range that does not cause biological destruction by mold.

In the present invention, the oxygen scavenger is a main agent for maintaining the oxygen concentration in the system at 0.1% or less for a long period of time to prevent discoloration due to oxidation of photographic materials.

The oxygen scavenger used in the present invention is a composition containing an unsaturated aliphatic compound and an oxidation promoting catalyst.

The unsaturated aliphatic compound used in the present invention includes unsaturated acids such as succinic acid, lindenic acid, tunic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, parinaric acid, dimer acid, ritinoleic acid or ricinoleic acid. Fatty acids, esters thereof, waxes, linseed oil, soybean oil, rapeseed oil, fats and oils such as tall oil, isoprene, butadiene, polymers of diene compounds such as piperylene, squalene, natural rubber and synthetic rubber, etc. , Or a mixture of two or more of these. There is no problem even if a saturated compound or the like is mixed.

Examples of the oxidation promoting catalyst include transition metals such as Fe, Ni, Co, V, and Pt and compounds thereof.

The oxygen scavenger may further contain an adsorbent, a carrier and a heat generation inhibitor, if necessary.

Perlite, activated carbon, zeolite, and the like are used as the adsorbent, and even if water is present, the equilibrium relative humidity of the composition should be 10 to 70% RH. The carrier supports an unsaturated aliphatic compound or a humidity control agent as a main component, and maintains the shape of the composition while increasing the contact area with oxygen. Paper, non-woven fabric, pearlite, Granules such as activated carbon and zeolite. The carrier is impregnated with, mixed with, or coated with an unsaturated aliphatic compound or a humectant, and is carried.

The basic substance absorbs a substance which is decomposed by oxygen absorption of the unsaturated aliphatic compound, and an amine compound, magnesium oxide, magnesium hydroxide, calcium oxide, calcium hydroxide, etc. are preferably used.

The antipyretic agent is used to prevent heat generation when a large amount of the oxygen absorber is exposed to the atmosphere.It is solid at 10 to 50 ° C and becomes liquid at any temperature from 50 to 230 ° C. It is a substance that exhibits fluidity.

These humidifiers and oxygen scavengers may be in any form, but are in the form of solids or sheets because of easy handling.

In the present invention, the humidity control agent and the oxygen scavenger may be packaged together in a breathable packaging material, or the humidity control agent and the oxygen scavenger may be separately packaged in a breathable packaging material and stored. It may be sealed together with the thing.

〔The invention's effect〕

The oxygen scavenger containing the unsaturated aliphatic compound and the oxidation-promoting catalyst used in the present invention does not stop the oxygen scavenging reaction even when the system is maintained at a low humidity with a humidifier, and generates a slight amount of hydrogen. It is very preferably used for the purpose of the present invention to preserve photographs for a long period of time without causing any deterioration of the dye.

Further, the presence of the humidity control agent of the present invention also exerts a function of maintaining a constant humidity required for storing photographs.

If it is left unchecked, it is an enormous cost and incomplete effect, such as a low-temperature and low-humidity storage method that is incomplete, or a combined method of a deoxidizer and a desiccant that stops the deoxidation reaction halfway. Did not. Further, although the image was prevented from being deteriorated by the preservation method using an oxygen scavenger, fusion with a preservation bag or the like was caused by migration of water, and fatal physical destruction was sometimes caused.

The method of the present invention solves the above-mentioned disadvantages of the conventional preservation technology, and enables oxygen-free and easy holding of a photograph under a constant low humidity, thereby reducing the original image quality of the photograph and reducing physical deterioration. Prevention has become simple and inexpensive.

The method of exhibiting the effects of the present invention is very simple, a photograph to be stored in an appropriate packaging material, and a substance having both the function of a deoxidizer and a humidifier or the function of a deoxidizer and a humidifier at the same time. Just put, and seal.

Hereinafter, the effects of the present invention will be specifically described with reference to examples.

Example 1 A photographic color chart (manufactured by Japan Color Research Institute) was photographed under sunlight using a commercially available photographic film.
The camera used a Nikon F-3, and the exposure was determined by a built-in light meter so that the exposure would be appropriate. Thereafter, after developing and fixing according to the developing method specified by the photographic film manufacturer, the photographic density of the gray portion was adjusted to 1.00 for each color.
Those that were between ± 0.03 were selected and stored under the conditions shown in Table 1. Table 2 shows the degree of change of the dye in this film.
3 Print from the above film (35
× 38mm), and among these, those with a photographic density of the gray portion between 1.00 ± 0.03 for each color were selected and stored under the conditions shown in Table 3. The degree of change in the dye of this print is summarized in Table 4. Was. As a dye densitometer, a Macbeth TD903 (transmission type) and RD519 (reflection type) were used.

In the control section, only the print of the film was sealed, and in the nitrogen-substituted section, degassing and nitrogen filling were repeated twice using a gas-filling packaging machine, followed by sealing. 3g of silica gel
And sealed.

The food oxygen absorber was sealed with a commercially available oxygen absorber for low moisture foods (for an air volume of 50 cc).

 Table 1 shows the storage conditions in each section.

From Tables 2 to 4 above, under the light irradiation, the control group (air) and the replacement of the inert gas such as the desiccant and nitrogen, which had been the storage method up to now, have no preservation of the photographic density. It turns out that it is not suitable as a method for storing photographs.
The food oxygen absorber and the humidity control oxygen absorber (the present invention) had a very remarkable effect in preventing a decrease in photographic density under light irradiation. Since the operation for storage is simple, the method using a deoxidizer / humidity-controlled deoxidizer can be said to be an excellent storage method.

Example 2 A storage test of films and prints prepared under the same photographing conditions as in Example 1 was performed.

These films (35 × 38 mm) were stored under the conditions shown in Table 5, and the change in density of each dye in the gray portion was measured. The results are shown in Table 6. Also, physical changes of the film were observed.

In the control section, the silica gel section and the food oxygen absorber section, the method described in Example 1 was used. For the silica gel + food oxygen absorber section, 3 g of the above silica gel and the food oxygen absorber (for an air volume of 50 cc) were used. Table 5
Was stored under the following conditions.

A) In the silica gel section, the curl was strong, and fine cracks were observed under a microscope.

B) In the food oxygen absorber + silica gel section, oxygen in the system was not completely removed, and as a result, a change in the pigment concentration was observed.

C) In the food oxygen absorber, the film was entirely tacky and some parts were fused.

From the results in Table 6, it is found that the storage of the photograph in the dark place is better than the conventional method using a desiccant, an oxygen scavenger, or a combination of a desiccant and an oxygen scavenger. It can be seen that both physical retention and remarkable effect are obtained.

The present invention provides an effective, simple and inexpensive method, especially for long-term storage of photographs, since the conditions under which photographs are actually stored are often dark places.

In addition, the humidity control deoxidizer used in the present invention was adjusted as follows.

90 g of soybean oil was added to 230 g of a 10% aqueous sodium hydroxide solution together with 400 ml of water at 90 ° C., and saponified to obtain an aqueous solution of sodium soybean fatty acid. To this solution was added 270 g of a 10% aqueous solution of ferric chloride, and the aqueous layer was separated to obtain 90 g of soybean oil fatty acid iron.

180 g of quicklime was added thereto, mixed well, solidified, and then pulverized with a cutter mixer to prepare an oxygen scavenger.

The humidifier mixes 8g of water well with 92g of glycerin,
It was impregnated with 300 g of silica gel. The theoretical value of the equilibrium humidity of this humidifier was 30%, but the measured value was 33%.

1 g of the above-described oxygen scavenger and 2 g of the humidity regulator were placed in a small air-permeable bag to obtain a moisture-regulating oxygen absorber.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI G03C 3/00 585 G03C 3/00 585C (56) References JP-A-56-4145 (JP, A) JP-A-1-167836 (JP, A) JP-A-1-316741 (JP, A) JP-A-4-100537 (JP, A) JP-A-4-29741 (JP, A) JP-A-62-67252 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) G03C 11/00 G03C 3/00 585 B01J 20/22

Claims (3)

(57) [Claims] 1. The photograph shows that the oxygen permeability at 25 degrees Celsius is 10
An oxygen scavenger comprising a composition containing an unsaturated aliphatic compound and an oxidation-promoting catalyst in a packaging material having a water vapor permeability of 10 g / m ² Day or less at 25 ° C. or less at ml / m ²・ Atm ・ Day. A storage method that seals with a humidifier having an equilibrium relative humidity of 10 to 70%. 2. The method according to claim 1, wherein the photograph is in a positive or negative state after development and fixing. 3. The storage method according to claim 1, wherein the photograph is fixed on photographic paper.