JPS59125731A - Support for photographic printing paper - Google Patents

Abstract

PURPOSE:To increase sufficiently the strength of base paper without deteriorating the sizing effect and to reduce extremely the edge coloring after development by impregnating the base paper with vegetable galactomannan and a dicyanodiamide-formaldehyde condensation product. CONSTITUTION:When both sides of base paper are coated with polyolefin resin to manufacture a support for photographic printing paper, the base paper is impregnated with natural gum obtd. by refining albumens in the seeds of gar and locust beans, vegetable galactomannan which is a chemically modified deriv. of the natural gum, and a dicyanodiamide-formaldehyde condensation produce which is commonly used as a cationic flocculating or fixing agent. The preferred weight ratio of the galactomannan to the condensation product is 20/1-1/5. In case of >=20/1, the galactomannan exerts unfavorable influence on the sizing effect, so the extent of edge permeation is increased. In case of 1/>=5, the compounds do not produce a sufficient effect of reducing the edge coloring of photographic printing paper.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support for photographic paper in which both sides of a base paper are coated with a polyolefin resin. More specifically, the present invention relates to a support for photographic paper in which coloring of the cut end surface after development is improved by containing a formalin condensate of vegetable-derived ctomannan heptadicimandiamide in an M bottle.

Conventionally, paper that has the highest quality in terms of appearance, stiffness, strength, price, etc. has been used as a support for photographic paper, but the biggest drawback of paper is that it is highly absorbent to developing processing solutions.

From the viewpoint of rapid development processing, it is not preferable that the processing liquid be completely absorbed into the support. Therefore, it is widely practiced to coat the front and back sides of base paper with a water-resistant resin such as polyolefin in order to reduce the absorbency of the processing liquid. Although this completely prevents the processing liquid from penetrating from the front and back sides of the support, it cannot prevent the processing liquid from penetrating from the cut surfaces of the ends. The processing liquid that has seeped into the edges cannot be removed by a short water wash, and will turn brown due to heat or over time, staining the white areas of the photograph and significantly reducing its value as a photograph.

In order to prevent the treatment liquid from penetrating through the edges, a neutral sizing agent is often added to the base paper.

Although it is possible to impart static processing liquid resistance to the base paper by adding a neutral sizing agent, it is possible to prevent the processing liquid from penetrating under the strain filter, such as when developing with an automatic processor. It is insufficient to do so. It is known that it is necessary to add a paper strength enhancer to base paper in order to increase resistance to processing liquids under stress. The kite force enhancer to be added internally to the base paper of the photographic paper support coated on both sides with polyolefin resin must satisfy the following conditions. In other words, (1) it has the effect of increasing paper strength to counter the stress generated by automatic processors, (2) it does not adsorb the processing solution and causes coloring, and (3) it is added internally to the base paper. (4) Do not inhibit the size effect of the neutral sizing agent used.
This means that it does not adversely affect the photographic properties of Capri, etc.

Paper strength enhancers can be roughly divided into anionic paper strength enhancers such as vegetable galactomannan, carboxyl-modified polyvinyl alcohol, and anionic polyacrylamide, and cationic paper strength enhancers such as cationic starch, cationic polyacrylamide, and polyamide polyamine epichlorohydrin. There are enhancers. By internally adding the former anionic paper strength enhancer to the base paper, a sufficient paper strength enhancement effect can be obtained.
It cannot be used because it adversely affects size. The latter cationic paper strength enhancer is neutral and widely used when making abrasive paper, but it not only does not provide sufficient paper strength enhancement effect, but also tends to adsorb development processing solution and cause discoloration. Therefore, there is a problem in adding it alone to the base paper of the photographic paper support.

It is also known to use an anionic paper strength agent and a cationic paper strength agent or fixing agent together. By using these paper strength enhancers together, a sufficient paper strength enhancing effect can be obtained without impairing the sizing properties, but anionic paper strength enhancers, cationic paper strength enhancers or Many of the fixer combinations were insufficient in improving edge coloration after processing. The present invention improves these drawbacks.

SUMMARY OF THE INVENTION An object of the present invention is to provide a support for photographic paper that has improved coloring of the cut end surface after processing using an automatic processor or the like.

As a result of intensive studies to solve the various problems mentioned above, the inventors of the present invention have found that by incorporating vegetable galactomannan and dicyandiamide-formalin condensate into the base paper, sufficient paper strength can be obtained without impairing the size properties. The present invention was completed based on the discovery that a reinforcing effect can be obtained and that there is very little coloring at the edges after development.

That is, the present invention provides a support for photographic paper in which both sides of a base paper are coated with a polyolefin resin, which is characterized in that the base paper contains a vegetable galactomannan and a dicyandiamide-formalin condensate. The present invention provides a support for photographic paper with improved coloring.

In the present invention, vegetable galactomannans are natural gums obtained by purifying the endosperm of guar, locust, and bean seeds, and chemically modified derivatives thereof.

The dicyandiamide-formalin condensate used in the present invention is commonly used as a cationic flocculant or fixing agent.
This is as described in No.-23231. Of course, in this dicyandiamide-formalin condensate,
For example, a modifier such as a diamine may be included as a third component.

The gft ratio of vegetable galactomannan and dicyandiamide-formalin condensate used in the present invention is (vegetable galactomannan/dicyandiamide-formalin condensate) -
The range of 20/1 to 115 is preferable. That is, 20/
If it is more than 1, the vegetable galactomannan will have a negative effect on the size properties/increase the penetration width at the edges, and if it is less than 115, the effect of improving the edge coloring of photographic paper will be small.

As the neutral sizing agent used in the present invention, for example, a modified ketene dicarboxylic compound, a substituted present dicarboxylic acid anhydride, an epoxidized higher fatty acid amide, etc. can be used alone or in combination of several kinds.

The base paper obtained according to the present invention contains additives normally used in paper making, such as anti-capri agents, fillers, dyes, fixing agents, and retention aids, as required. Surface treatments such as starch, polyvinyl alcohol, gelatin, etc., and antistatic treatments using Glauber's salt, sodium chloride, aluminum chloride, etc., can also be carried out on the base paper, if necessary.

Polyolefin resins include homopolymers of goo-olefins such as ethylene and bu-pyrene, copolymers of two or more of olefins such as ethylene and propylene, or copolymers consisting of goo-olefins as a main component and other monomers copolymerizable with them. Preference is given to copolymers and mixtures thereof. Further, a white pigment such as titanium oxide or alumina, a colored pigment, a stabilizer, an anti-oxidizing agent, a dispersant, a lubricant, etc. which are usually mixed with the resin may be added to the resin.

The polyolefin resin-coated paper used in the practice of the present invention is manufactured by a so-called extrusion coating method in which a heated and molten resin is cast onto a running base paper, and both sides of the paper are coated with the resin.

By incorporating a vegetable galactomannan hydicyandiamide formalin condensate into the base paper as in the present invention, the permeation width and coloring of the end cut surface after processing with an automatic processor etc. can be reduced compared to conventional polyolefin resins. A photographic paper support is obtained which is significantly improved compared to coated photographic paper supports.

The polyolefin-coated support for photographic paper of the present invention is used for color photographic paper, black and white photographic paper, typesetting photographic paper, copying photographic paper, and the like.

The present invention will be described in detail below with reference to Examples. In addition,
The invention is not limited to the examples. All parts and weights stated in Examples are by weight.

Example 1 1 s Og/n? containing the following components at the following contents: The paper was hand-sheeted and dried on a cylindrical dryer at 105°C.

A mixture of hardwood bleached kraft pulp and softwood bleached sulfide pulp beaten to 350 mt by Peter at Canadian standard freeness in a weight ratio of 1:1: 10 parts vegetable galactomannan (Maproid 7700 manufactured by Me1' Hall): 2.0 parts dicyandiamide phosphorus complex (NIKAFLOC D-1000 manufactured by Nippon Carbide Co., Ltd.) 0.8 parts Epoxidized higher fatty acid amide (MS-71 manufactured by Kindai Kagaku Co., Ltd.)
5): 0° 3-part alkyl ketene dimer (Vercon W manufactured by Dick Vercules):
0.5 parts of the obtained hand-made paper was treated with polyvinyl alcohol to a tab size of 1.5 g/I, and supercara L/7 with powdered ash of 90 KP/crn.
f −%'f31. After corona treatment, the surface was coated with low-density flash polyethylene containing titanium oxide, and the back was coated with low-density polyethylene to a thickness of 30 mm by extruding the whole base at a resin temperature of 330 t to form a support for photographic paper. I got it. This sample is designated as 1-1.

Comparative Example 1 In Example 1, instead of the vegetable galactomannan and dicyandiamide-formalin condensate, the following four types of paper strength enhancers or a combination thereof were added in the same amount as in Example 1. Four types of supports for photographic paper were manufactured in exactly the same manner except that 2 and 8 parts of each support were added. The internally added paper strength enhancers are: ■Anionic polyacrylamide (Star Gum A-15, manufactured by Seiko Kagaku Co., Ltd.), ■Cationic starch (Kate 2, manufactured by Tamago National Co., Ltd.), ■Carboxy-modified polyvinyl alcohol (Gosenal, manufactured by Nippon Gosei Kagaku Co., Ltd.) T-330H) 0゜3-part cationic starch (Kate 2 manufactured by Tamago National Co., Ltd.)
2.5 parts Vegetable galactomannan (Maeproid 7700 manufactured by Mayhall Co.) 2.0 parts Cationic polyacrylamide (Star Gum AD-S manufactured by Seiko Kagaku Co., Ltd.) O,S
There are four types of parts, and each of these samples,! -2.
1-3.1-4 and l-5.

The results are summarized in Table 1.

Table 1 From Table 1, it can be seen that an anionic or cationic paper strength enhancer alone, or a combination of anionic or cationic paper strength enhancers other than A5 or a combination of vegetable galactomannan and dicia/diamide-formalin condensate It is clear that no sufficient coloring improvement effect was observed.

Example 2 Three types of photographic paper supports were produced in exactly the same manner as in Example 1, except that the contents of each of the following components were different.

The same pulp as in Example 1:

The total additive amount of Tsuku D-1000) was 3.0 parts, and the M amount ratio of vegetable gasictomanna (f/dicyandiamide-formalin condensate) was 3 Q/1 e20/1.
It was changed to 5 levels: 3/1.1/S and 1/10.

Alkyl Ctenguimer (Acorbel, manufactured by Dick Vercules): o, s parts polyaminopolyamide shrimp chlorohydrin (Evinox, manufactured by Dick Vercules); 0.5 parts 2-1.2-22-3.2-4 and 2-1.2-22-3.2-4 and 2-1.2-22-3.2-4 and 2-1.
5.

The results are shown in Table 2.

Note) (Ar! Physical properties galactomannan (B) dicyandiamide-polmarin condensate From Table 2, the prize ratio of (vegetable galactomannan/dicyandiamide-formalin condensate) is in the range of 20/1 to 115. It is preferable from the viewpoint of peeling strength and size, has a sufficient effect of improving external coloration, and has no adverse effect on the ears.

1) The peel strength of each piece was measured by measuring the 90° peel strength of both sides of the opposite side with polyethylene. This peel strength ζ'i represents the strength of the base paper layer, and a strength of 80 g or more is required as a support for photographic paper.

32) Measurement of penetration depth (constructed using the following test method).

Color photographic paper obtained by coating a color photographic emulsion on a photographic paper support whose both sides of the original sample have been destroyed with polyethylene and T1 fat is developed using a continuous automatic developing machine (Color Roll Processor manufactured by Fc Seisakusho). did. The depth of penetration of the processing solution from the edge of the photographic paper after processing was read using a magnifying glass.

Note 3) The edge coloring was evaluated using a densitometer (Union Optical) for a sample of photographic paper that had undergone the same treatment as in Note 2) and was aged for 5 days at 50°C and 6595 RI. This was carried out by measuring with a microphotometer (manufactured by Seiko Co., Ltd.).

In order not to damage the value as a photograph, the density index must be 0.8 or less.

Claims (2)

[Claims] (1) A photographic paper support comprising a base paper coated on both sides with a polyolefin resin, wherein the base paper contains a vegetable galactomannan and a dicyandiamide-formalin condensate. (2) Vegetable galactomannan and dicyandiamide-formalin metal condensate in the base paper (vegetable galactomannan/dicyandiamide-formalin metal condensate) = 20/
The support for photographic paper according to claim 1, wherein the support is contained in a weight ratio of 1 to 115.