JPH0496060A - Method for long-term preservation of photograph - Google Patents

Abstract

PURPOSE:To easily and inexpensively prevent the degradation in image quality and physical deterioration by hermetically sealing a photograph in a positive or negative state after developing and fixing or fixed onto photographic paper together with a specific deoxidizing agent and humidifying agent into a specific packaging material. CONSTITUTION:Stretched PP/PE, etc., in the case of preservation for about a half year, and metallic cans, thermocompression bondable multilayered films, etc., in the case of preservation for >=1 years without unsealing, which have <=10ml/m<2>.Atm Day oxygen permeability at 25 deg.C and <=10g/m<2>.Day permeability at 25 deg.C are used as the packaging material. The photograph is hermetically sealed into such packaging material together with the deoxidizing agent consisting of the compsn. which contains an unsatd. aliphat. compd., such as oleic acid, and oxidation accelerating catalyst, such as Fe, and is deposited together with an adsorbent, such as pearlite, on a carrier, such as paper or non-woven fabric, by impregnation, etc., and the humidifying agent having 10 to 70% equil. relative humidity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for preventing alteration and deterioration of photographs, and particularly to preventing chemical, biological, and physical destruction of photographs over a long period of time.

[Conventional technology]

2. Description of the Related Art It is widely used to convey images as information using photographs. However, the constituent materials of photographs change over time, making it difficult to preserve developed and fixed images as they are for a long period of time.

A considerable amount of research has been conducted to stabilize images by making photosensitive materials more stable against this change over time. For example, U.S. Pat.
No. 746. Although these methods have increased the stability of photographs, they cannot prevent photographs from gradually discoloring over a long period of time in a normal atmosphere, that is, in air.

If photographs are stored in a high-humidity atmosphere, mold may form on the gelatin layer used in the material, the base film may shrink due to oxidation of dyes or fluctuations in humidity, and the dyes may be affected by reducing substances in the atmosphere. may change in quality.

There is a way to preserve photographs not by stabilizing the substances that make up photographs, such as dyes, but by controlling the physical environment.

To date, public institutions around the world have been protecting photographs using the inlay method, but the temperature is below 20 degrees Celsius (particularly below 2 degrees Celsius for color photos) and the relative humidity is between 10 and 50% (
Particularly preferably 10 to 30%), 15O-546
The conditions stipulated in Section 6 are extremely expensive to maintain and are nearly impossible for private institutions such as museums or individuals to maintain. A method of preserving a photosensitive material using a drying agent) and/or a drying agent is disclosed in JP-A-61-88256 and JP-A-1-1.
No. 67836.

It is conceivable that this method could be used as is for long-term preservation of photographs. However, the problems with this method are as follows: - When using an inert gas as an antioxidant, the inside of the closed space where the photo is stored (hereinafter sometimes abbreviated as "inside the system")
It is impossible to reduce the oxygen concentration in the photograph to a level that does not cause oxidation of the constituent materials of the photograph. Furthermore, this method requires equipment for inert gas replacement and cannot be easily used.

■Inserting an oxygen absorber into the system and sealing it has the effect of reducing the oxygen concentration to a point where it does not oxidize the substances that make up the photograph, but the moisture contained in the oxygen absorber transfers to the film in the system. This may cause physical destruction such as adhesion between the film and packaging material. In addition, commonly used iron-based oxygen scavengers absorb oxygen and generate a small amount of hydrogen, which causes deterioration of pigments and adversely affects the preservation of photographs.

■By putting a desiccant into the system and sealing it up, the humidity in the system decreases, which certainly slows down the deterioration of the photos. However, desiccants do not have the ability to suppress the oxidation of photographic components, so from the perspective of long-term storage, this method is only effective at suppressing the growth of mold, and cannot be used for the purpose of preserving images. .

Furthermore, if a strong desiccant is used to lower the humidity in the system too much, it may cause physical damage such as cracking or layer peeling of the photographic constituent materials, so it is necessary to calculate and use the appropriate amount of desiccant. This is very difficult.

■A method of using a deoxidizing agent and a desiccant together has been disclosed, but since moisture is essential for the deoxidizing reaction, moisture may migrate to the desiccant and the deoxidizing reaction may stop within a short period of time. In some cases, oxygen may remain in the system. Therefore, it is very dangerous to use such a method for long-term storage. Furthermore, there is also the problem of hydrogen generation mentioned above.

As mentioned above, until now there has been no good way to preserve photos, so there is a risk that photos, which are valuable information and assets, are gradually being lost, and this is still happening.

[Problem that the invention sought to solve]

Instead of the aforementioned preservation methods that are incomplete or expensive to maintain, the purpose is to preserve photographs for a long period of time using a simple method of simply sealing them in a container along with an oxygen absorber and a humidifying agent.

[Means to solve the problem]

The present invention provides photographs with an oxygen permeability of I at 25 degrees Celsius.
Q ml/m2・Atm -Day or less, and water vapor permeability at 25 degrees Celsius is 10g/m'・Day
The following packaging materials contain an oxygen scavenger consisting of a composition containing an unsaturated aliphatic compound and an oxidation-promoting catalyst and an equilibrium relative humidity of 10 to 7.
It relates to a storage method in which the product is sealed together with a humidity conditioner that is 0%.

More specifically, the present invention relates to a method for preserving a photograph for a long period of time, when the photograph is in a positive or negative state after being developed and fixed, or when the photograph is fixed on photographic paper.

In the present invention, the packaging material used has an oxygen permeability of 10 ml/m2・At++ at 25 degrees Celsius.
+-Day or less, the water vapor permeability at 25 degrees Celsius is less than 10g7m"day (hereinafter, materials with such characteristics are simply referred to as packaging materials), and the material can be used for about half a year. In the case of storage, packaging materials such as stretched 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.

In particular, oxygen is preferably used in cases where positive or negative images after development, movie films, valuable photographs taken in the past, etc. must be stored without being opened for a long period of one year or more. The air permeability and water vapor permeability are substantially zero. Specifically, metal cans with an airtight structure, and basically multilayer films with a structure of thermocompression-bondable resin layer/thin metal film/protective resin layer (
The number of layers is 3 or more). In particular, it is preferable to use stainless steel for metal cans, low-density polyethylene (PE) or polypropylene (PP) for the thermocompression bondable resin layer for metal cans, aluminum or its alloy for the metal thin film, and stretched nylon or polyester for the protective resin layer. used.

The humidity conditioner used in the present invention includes an aqueous solution of a water-soluble organic compound. Water-soluble organic compounds that mix freely with water include polyethylene glycol, polypropylene glycol, amines such as triethanolamine tripropanolamine, and polyhydric alcohols such as trimethylolpropane, trimethylolethane, and glycerin. , neopentyl glycol, etc.

The above-mentioned humidity conditioner is usually supported on a carrier.

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

In addition, the humidity within the system determined by the humidity conditioner can cause gelatin fusion that occurs if the humidity is too high, physical damage such as cracking and peeling that occurs if the humidity is too low, and biological destruction caused by mold. RHIO% within the range that does not occur
RH 50% or more, more preferably RH 20% or more 4
It is 0% or less.

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 and for preventing discoloration due to oxidation of the constituent materials of the photograph.

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

The unsaturated aliphatic compounds utilized in the present invention include unsaturated aliphatic compounds such as tuccinic acid, lindic acid, tuzunic acid, oleic acid, linoleic acid, lylunic acid, arachidonic acid, parinaric acid, dimer acid, ritylic acid or ricinoleic acid. fatty acid,
These estenope waxes, linseed oil, soybean oil, rapeseed oil,
Examples include fats and oils such as tall oil, polymers of diene compounds such as isoprene, butadiene, and piperylene, squalene, and natural rubber and synthetic rubber, and one or more of these may be used in combination. Further, there is no problem even if saturated compounds etc. are mixed in.

Examples of the oxidation-promoting catalyst include transition metals such as Fe, Ni5Co, V, and Pt, and compounds thereof.

The oxygen scavenger may additionally contain an adsorbent, a carrier, and an anti-pyrogen agent, if necessary.

Perlite, activated carbon, zeolite, etc. are used as adsorbents, and even if they contain water, it is sufficient that the equilibrium relative humidity when made into a composition is R810 to 70%.

The carrier supports the unsaturated aliphatic compound as the main ingredient or the humidity conditioner, maintains the shape of the composition, and increases the contact area with oxygen. These are granular materials such as activated carbon and zeolite. This carrier is impregnated with, mixed with, or coated with an unsaturated aliphatic compound or a humidity conditioner to be supported.

Basic substances absorb substances that decompose when unsaturated aliphatic compounds absorb oxygen, such as amine compounds, magnesium oxide, magnesium hydroxide, calcium oxide,
Calcium hydroxide and the like are preferably used.

The heat generation inhibitor is used to prevent heat generation when a large amount of oxygen scavenger is exposed to the atmosphere, and is solid at 10 to 50°C and becomes liquid at any temperature between 50 and 230 t. It is a substance that exhibits fluidity.

These humidity conditioners and oxygen scavengers can be of any shape, but
It is solid or sheet-like for ease of handling.

In the present invention, the humidity conditioner and the oxygen absorber may be packaged together in a breathable packaging material, or the humidity conditioner and the oxygen absorber may be packaged separately in a breathable packaging material and stored. May be sealed together with other items.

〔Effect of the invention〕

The deoxidizing agent containing an unsaturated aliphatic compound and an oxidation-promoting catalyst used in the present invention does not stop the deoxidizing reaction even when the system is kept at low humidity with a humidity conditioner, and a small amount of hydrogen is generated. It is very preferably used for the purpose of the present invention, which is to preserve photographs for a long period of time without causing any deterioration of the pigments.

Furthermore, due to the presence of the humidity conditioner of the present invention, it also exhibits the function of maintaining constant humidity necessary for preserving photographs.

Until now, only incomplete methods have been available, such as storage methods at low temperatures and low humidity that are extremely expensive and incompletely effective, and methods that use a combination of oxygen scavengers and desiccants that stop the oxygen removal reaction midway through. There wasn't. Furthermore, although it was possible to prevent image deterioration using a preservation method using an oxygen absorber, moisture migration could cause fusion with storage bags, etc., resulting in fatal physical destruction.

The method of the present invention eliminates the drawbacks of the conventional preservation techniques mentioned above, makes it possible to easily preserve photographs in the absence of oxygen and under constant low humidity, and prevents deterioration of the original image quality and physical deterioration of photographs. Prevention can now be done easily and inexpensively.

The method of exhibiting the effects of the present invention is very simple and requires a photograph to be stored in an appropriate packaging material and an oxygen absorber and a humidity conditioner, or a product that has the functions of an oxygen absorber and a moisture conditioner at the same time. , and then seal it.

EXAMPLES The effects of the present invention will be specifically explained below using examples.

Example 1 A photographic color chart (manufactured by Japan Color Research Institute) was photographed under sunlight using a commercially available photographic film. A Nikon F-3 camera was used, and exposure was determined to be appropriate using the built-in exposure meter. After this, after being developed and fixed using the processing method specified by the photographic film manufacturer, the photographic density of the gray part is 1.0 for each color.
Those with a value between 0±003 were selected and stored under the conditions shown in Table 1. The degree of dye change in this film is summarized in Table 2.3. In addition, prints (35 x 38 mm) were made from the above films, and among these prints, the photographic density of the blurred portion was between 1.00±003 for each color, and the prints were stored under the conditions shown in Table 3. Table 4 summarizes the degree of change in the pigment. Macbeth's TD903 (transmission type) and RD519 (reflection type) were used as dye densitometers.

In addition, in the control group, only the film print was sealed, in the nitrogen-substituted environment, it was degassed and filled with nitrogen twice using a gas-filled packaging machine, and then sealed, and in the silica gel group, it was sealed in a breathable bag. 3g of silica gel
sealed with.

In the food oxygen absorber section, the storage conditions in each section were sealed together with a commercially available low moisture food oxygen absorber (for 50 cc of air) as shown in Table 1.

From Tables 2 to 4 above, under light irradiation, both the control group (air) and the conventional preservation methods of desiccant and inert gas replacement such as nitrogen do not preserve the photographic density. It turns out that this is not an appropriate way to save photos. The food-use oxygen absorber and humidity-controlled oxygen absorber (the present invention) were very effective in preventing a decrease in photographic density under light irradiation. The method of using an oxygen absorber/humidity conditioning oxygen absorber can be said to be an excellent preservation method because the operation for preservation is easy.

Example 2 A storage test was conducted on films and prints produced under the same photographic conditions as in Example 1.

These films (35 x 38 mm) were stored under the conditions shown in Table 5, and changes in the density of each dye in the gray area were measured, and the results are summarized in Table 6. Physical changes in the film were also observed.

After sealing using a combination of 3 g of silica gel and a food-grade oxygen absorber (for 50 cc of air), it was stored under the conditions shown in Table 5. Regarding the silica gel 10 food oxygen absorber section, curling was strong in the above silica gel section A), and fine cracks were observed when observed under a microscope.

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

C) In the food oxygen absorber section, the film felt sticky overall, and some parts were fused.

From the results in Table 6, it can be seen that preservation of photographs in the dark is more effective than conventional methods using a desiccant, an oxygen absorber, or a combination of a desiccant and an oxygen absorber. It can be seen that there is a significant effect on both physical retention.

Since the conditions under which photographs are actually stored are often in dark places, the present invention is particularly effective for long-term storage of photographs.
This provides a simple and inexpensive method.

The humidity conditioning oxygen scavenger used in the present invention was prepared as follows.

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

180 g of quicklime was added thereto, stirred well to solidify, and then ground with a cutter mixer to prepare an oxygen scavenger.

Further, as a humidity conditioner, 92 g of glycerin and 8 g of water were thoroughly mixed, and 300 g of silica gel was impregnated with the mixture. The theoretical value of equilibrium humidity of this humidity conditioner is 30%, but the actual value is 33%.
%Met.

1 g of the above oxygen scavenger and 2 g of the humidity conditioning agent were placed in a breathable pouch to prepare a humidity conditioning oxygen scavenger.

Claims (3)

[Claims] (1) The photo shows an oxygen permeability of 10 m at 25 degrees Celsius.
l/m^2・Atm・Day or less, and the packaging material has a water vapor permeability of 10 g/m^2・Day or less at 25 degrees Celsius, and is made of a composition containing an unsaturated aliphatic compound and an oxidation promoting catalyst. A storage method in which the storage method is sealed together with an oxygen agent and a humidity conditioner with an equilibrium relative humidity of 10 to 70%. (2) The preservation method according to claims 1 and 2, wherein the photograph is in the state of a positive image or a negative image after development and fixation. (3) The preservation method according to claims 1 and 2, characterized in that the photograph is fixed on photographic paper.