JPH0299693A - Paper for photography and production thereof - Google Patents

Abstract

PURPOSE:To obtain a paper for photography giving a high-quality photograph and effectively exhibiting defoaming property by using a nonionic defoaming agent containing propylene oxide as a component and using a paper material adjusted to give a cold water extract having a pH falling within a specific range. CONSTITUTION:The objective paper for photography such as packaging material for photosensitive material or substrate for photography is produced by using a nonionic defoaming agent containing propylene oxide as a component and using a paper material adjusted to give a cold water extract (JIS P-8133) having a pH of 6.0-9.0.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a packaging material for photographic light-sensitive materials, a photographic paper such as a photographic support, and the like.

[Conventional technology]

- S, unbleached kraft paper for packaging (unbleached talpack paper,
(including special papers such as unbleached Duostress paper), regardless of the pH, e.g. cold water extraction pH (JIS P-8133
Even when the neutral paper had a value of 6.5 to 9.0, the photographic properties were poor. Therefore, unbleached kraft paper cannot be used in contact with photographic materials, and as shown in JP-A-62-53829, it has been constructed into a double bag and used as the outer paper of the bag.

In addition, in order to improve the photographic properties of unbleached kraft paper, large amounts of well water were used for washing in the valve washing process and papermaking process, and special additives were added (Special Publications No. 58-43
No. 730), there was a technique for removing or stabilizing substances that adversely affect photographic properties.

[Problem to be solved by the invention]

However, the manufacturing cost of double-bagged packaging bags is high;
There was a problem that it was difficult to work in a darkroom and that one's hands could get stuck between the outer paper and the inner paper.

In addition, even unbleached kraft paper produced using techniques for improving photographic properties, such as the addition of the above-mentioned special additives, has not been able to completely improve photographic properties.

On the other hand, bleached kraft paper has good photographic properties and can be used as single-layer bags, but is expensive and does not have sufficient physical strength such as surface strength.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide an inexpensive photographic paper that has good photographic properties and high physical strength.

[Means to solve the problem]

The present invention has been made to achieve the above objects,
This was first achieved through research by the present inventor into the effects of additives on photographic properties.

The present inventor investigated the effects of various additives added in the manufacturing process of unbleached kraft paper on photographic properties, and as a result, it was found that certain antifoaming agents have an extremely large effect on photographic properties. .

That is, in the manufacturing process of unbleached kraft paper, a special nonionic mineral oil-based antifoaming agent containing silicone is generally used in the washer process, and a nonionic activator containing propylene oxide is used in the screen and mixer processes. Antifoaming agents were used. It was also discovered that propylene oxide, a component of this antifoaming agent, remained and had an adverse effect on photographic properties.

Therefore, for photographic properties, it is preferable to use an antifoaming agent that does not contain propylene oxide as a component, but if an antifoaming agent that does not contain propylene oxide as a component is used, the antifoaming effect will be reduced. there were.

Therefore, the present inventor further conducted extensive research and found that cold water extraction PH
If it is in the range of 6.0 to 9.0, unless a special nonionic mineral oil-based defoaming agent containing silicone is used, the use of an antifoaming agent containing propylene oxide as a component will not have much of an effect on photographic properties. The present invention was completed based on the discovery that there is no such thing.

That is, the photographic paper of the present invention contains a nonionic antifoaming agent containing propylene oxide as a component, and has a cold water extraction pH (JIS
P-8133) is 6.0 to 9.0.

Further, the method for producing photographic paper of the present invention uses a nonionic antifoaming agent containing propylene oxide as a component, and cold water extraction PH
(JIS P-8133) is characterized by using paper stock adjusted to be 6.0 to 9.0.

Nonionic antifoaming agents containing propylene oxide as one of their ingredients have a large oxidation effect, have excellent foam breaking and antifoaming effects, and have a cold water extraction PH (JIS P
-8133) is 6.0 to 9.0, there is no adverse effect on the photographic material.

A typical preferred form of use is a solution in which additives such as propylene oxide and ethylene oxide are emulsified in a nonionic surfactant.

Preferred processes used are the screening process of pulp manufacturing processes and the papermaking process of photographic paper, where residual oils such as mineral oil are disliked.

A representative example of a nonionic surfactant, which is one of the essential components used together with propylene oxide, is
Nonionic surfactants described in Publication No. 6697 and “Practical Handbook of Additives for Augmented Plastics and Rubber” (February 1988)
Nonionic surfactants listed on page 367 of KK Kagaku Kogyo Co., Ltd. and "9887 Chemical Products" (Showa 6).
930-937 (Published by Kagaku Kogyo Nippo on January 30, 2013)
There are nonionic surfactants, etc. described on the page.

Propylene oxide, also called propylene oxide or 1,2-epoxy propylene, is highly reactive and easily changes into other substances by heat or metal objects. For example, when heated together with alumina, it becomes propionaldehyde, which has an adverse effect on photographic materials.

The amount of the nonionic antifoaming agent added is 20 to 500% as a stock solution.
g/pulpton is preferred. Addition amount is 20
If it is less than 50 g/barton, the antifoaming effect will not be exhibited.
If it exceeds 0 g/pulpton, photographic properties will deteriorate.

In addition, the cold water extraction pH is 6.0 to 9.0, and the pH is 6.0 to 9.0.
．． If it is less than 0, the sensitization is too large and it cannot be put to practical use.
．． Even if it exceeds 0, the sensitization is similarly large and cannot be put to practical use.

Adjustment within this range of 6.0 to 9°0 is achieved by adjusting the amount of additives such as sulfuric acid. If necessary, various acids or alkalis may be added to adjust the pH.

In the present invention, the photographic paper is a packaging material for photographic light-sensitive materials,
Light-shielding paper, photographic support, protective light-shielding paper, cardboard boxes, winding cores,
It includes mount paper, leader paper, constituent materials for instant films, etc., and is preferably used in the outermost layer of a single-layer laminated film that comes into contact with the emulsion surface of the light-sensitive material.

[Function] In the photographic paper and its manufacturing method of the present invention, the influence of propylene oxide on photographic properties is reduced by a predetermined pH, and the propylene oxide exhibits an antifoaming effect.

(Example] The photographic paper of the present invention will be explained based on examples.

Invention Product I Special nonionic activator antifoaming agent characterized by propylene oxide and ethylene oxide (Pronal-121 manufactured by Toho Chemical Industry)
Using unbleached kraft pulp to which 200 g/pulpton was added, the pulp slurry was beaten to a Canadian standard freeness of 450 ml, and cold water extraction pH (JI
A handmade unbleached kraft paper with a basis material of 10 g/rr was prepared using a paper stock adjusted to have a paper stock of 7 (S P-8133) with a TAPPI type hand papermaking machine.

Comparative product I P H4.5 except that it was adjusted with sulfuric acid band.
This is the same kraft paper as the invention product (■).

The photographic properties of the above handmade unbleached kraft paper were tested.

The test results are shown in Table 1.

Table 1 Test method *A Photographic properties (contact) Contact the emulsion side of the handmade paper with the emulsion side of the color photographic paper for 50 minutes.
After 3 days at .degree. C., the photographic paper was developed in the usual manner and measured with a Fuji densitometer.

*B Photographic properties (gas) Handmade paper is not brought into contact with the emulsion side of the color photographic paper, but changes in photographic properties are caused by the influence of gas through a perforated sheet, and then developed in the usual manner. Measured with a densitometer.

The numerical values in Table 1 are values when chemical-free paper is taken as the standard (0).

Note that the present invention is not limited to the above embodiments.

〔Effect of the invention〕

Since the present invention is configured as described above, it has good photographic properties,
Moreover, the defoaming effect can be effectively exhibited.

Claims (2)

[Claims] (1) Contains a nonionic antifoaming agent consisting of propylene oxide, and has a cold water extraction pH (JISP-8133) of 6.0 to 9.
．． Photo paper characterized by 0 (2) A nonionic antifoaming agent containing propylene oxide as a component is used, and cold water extraction pH (JISP-8133) is 6.0.
A method for manufacturing photographic paper characterized by using paper stock adjusted to have a paper stock of ~9.0.