JPS61275750A - Diazo copying photosensitive paper eliminated in curling tendency - Google Patents

Abstract

PURPOSE:To enhance color development velocity and to prevent curling during storage of a diazo copying photosensitive paper by incorporating diethylene glycol in the photosensitive layer formed on the paper base of the copying paper and also coating the reverse side of the base with diethylene glycol. CONSTITUTION:A barrier layer 2 is formed on the paper base 1 by using a neutral sizing agent, and it is coated with the photosensitive layer 3 contg. diethylene glycol in an amt. of 0.2-2g/m<2> together with diazonium salt and a coupler, such as pyrocatechol, and the reverse side of the paper base is also coated with diethylene glycol in an amt. of 0.05-2g/m<2> to form a coat 4. Diethylene glycol has small tendency to diffuse into the inside of the base, thus permitting the obtained photosensitive copying paper to be prevented from curling by the presence of the same kind of polyol in both sides of the base 1, and yet, to have superior color development velocity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a photosensitive paper for diazo copying, and more particularly, the present invention relates to a photosensitive paper for diazo copying. Related to photosensitive paper for diazo copying that has been resolved.

(Prior Art) The diazo copying method, in which a two-component diazo photosensitive layer containing a photosensitive diazonium salt and a coupler is exposed and then developed with ammonia steam or an alkaline solution, is widely practiced as a low-cost copying method. There is.

An important quality characteristic of photosensitive paper for diazo copying is that the color development speed is high, and in order to improve this color development speed, polyhydric alcohols such as potassium, glycerin, ethylene glycol, and diethylene glycol are contained in the diazo photosensitive layer. is widely practiced.

However, these polyhydric alcohols contained in the photosensitive layer naturally have water-absorbing properties, and when photosensitive paper, that is, copy paper, is stored after exposure and development, it has the disadvantage of curling due to its water-absorbing property. arise.

(Gist and Object of the Invention) The present inventor selected diethylene glycol among various polyhydric alcohols, and by incorporating this diethylene glycol into the photosensitive layer and coating it on the back side of the paper substrate, the color development rate of the photosensitive layer was improved. It has been found that the curling tendency of photosensitive paper can be significantly suppressed while maintaining the paper at an excellent level.

That is, an object of the present invention is to provide a photosensitive paper for diazo copying which has a combination of excellent color development speed and stress resistance.

(Structure of the Invention) According to the present invention, in a photosensitive paper for diazo copying in which a photosensitive layer containing a photosensitive diazonium salt and a coupler is provided on a paper substrate, diethylene glycol is contained in the photosensitive layer and the paper substrate is There is provided a photosensitive paper for diazo copying which is prevented from curling and is characterized in that the back side of the paper is also coated with diethylene glycol.

(Preferred Embodiment of the Invention) In FIG. 1, which is an attached drawing showing the cross-sectional structure of the photosensitive paper for diazo copying of the present invention, a barrier layer 2 is provided on the upper surface of a paper substrate 1, if desired. contains a photosensitive (photodegradable) diazonium salt and a coupler.

A two-component diazo photosensitive layer 3 is provided.

According to the present invention, diethylene glycol is contained in the diazo photosensitive layer 3 and a coating layer 4 of diethylene glycol is provided on the back surface of the paper substrate 1.

The water absorption tendency of the polyhydric alcohol contained in the photosensitive layer is closely related to the coloring speed and image clarity during development. Figure 2 of the attached drawings shows the relationship between the standing time and water absorption amount under the conditions of 20°C and 75% RI for various polyhydric alcohols.
It is understood that the order of magnitude is sorbitol, glycerin, diethylene glycol, and ethylene boule.

In the present invention, diethylene glycol is selected and used among various polyhydric alcohols for the following reason. Ethylene glycol has the greatest tendency to absorb water, but it also has a greater tendency to penetrate paper substrates, just like normal monohydric alcohols. Thus, when ethylene glycol is used, even if the color development rate is high, it tends to form a smeared image due to penetration into the paper substrate, and the image density tends to decrease on the contrary. On the other hand, polyhydric alcohols with a large number of hydroxyl groups, such as sorbitol, have low permeability into paper substrates, but also have a tendency to have a significantly lower coloring speed (development speed) during development due to their low tendency to absorb water. . Such a tendency is similarly observed for triethylene glycol and polyethylene glycol having a higher degree of polymerization. When diethylene glycol is selected as the polyhydric alcohol, despite its relatively large water absorption tendency, it has a relatively small tendency to penetrate into the paper substrate, and while maintaining the color development rate at a very high level during development, it can be used at high concentration and without bleeding. It is possible to form a clear copy image without any blemishes. Moreover, even if diethylene glycol is contained in the photosensitive layer and a coating layer 4 of diethylene glycol is provided on the back side of the paper substrate, this diethylene glycol has little tendency to penetrate into the inside of the paper substrate, is effectively retained on the back side, and is coated on both sides of the paper. As a result of the retention of homogeneous polyhydric alcohols, the tendency to curl is effectively prevented. In this regard, the curling tendency of paper is closely related to the hygroscopicity of the polyhydric alcohol located on its surface; for example, if a diethylene glycol layer is located on the front side and glycerin is located on the back side, it will cause forward curling and reverse curling. If the film has a glycerin layer on the front side and a diethylene glycol layer on the back side, reverse curling occurs.

In the present invention, the coating amount of diethylene glycol in the photosensitive layer is 0.2 to 2, ji'/m''
, especially in an amount of 0.5 to 1.5 g/m2;
5 to 297 m2, especially 0.1 to 1. ! i'/m"
It is best to provide the amount such that . That is, when the amount contained in the photosensitive layer is less than the above range, a sufficient development speed cannot be obtained, and when the amount provided on the back surface is less than the above range, the curl prevention effect is not sufficient. The upper limit of the coating amount is set within the above range from the viewpoint of paper texture and economical efficiency.

In the present invention, the type of paper substrate, the composition of the barrier layer and the composition of the diazo sensitizer may be known per se.

For example, diazo photosensitive paper base paper is used as the paper base, and the weight Ji (weight per area of 880 days of paper x 1100 m fl (kll/)) of the paper base can be varied over a wide range; Materials as thin as 68klI to relatively thick as 68klI can be used for the purposes of the present invention. Of course, this paper is made of Merck, diatomaceous earth, fine powdered silica,
It may contain fillers such as magnesium oxide, calcium carbonate, barium sulfate, magnesium carbonate, various clays, gypsum, titanium dioxide, etc., acidic sizing agents such as aluminum sulfate, or neutral sizing agents such as alkyl ketene dimer. .

A neutral sizing agent mixed with a filler, etc., if necessary, is used as a barrier layer to be formed on the paper substrate as desired.As the neutral sizing agent, in addition to the alkyl ketene dimer mentioned above, water-soluble polyamide-epichlorohydry resin.

Polyacrylamide sizing agent.

, d IJ ethylene oxide sizing agent.

Petroleum resin wax emulsion.

Styrene-butadiene is Muratex.

Styrene-maleic acid resin emulsion.

Polyvinyl alcohol-based sizing agent.

Polyvinyl acetate emulsion.

Starch flour etc. are used. Although this barrier layer varies depending on factors such as the thickness of the paper substrate, it is generally 0.05 to 3. It is preferable to apply the coating at a coating amount of OI/m 2 , particularly 1.0 to 2-01/m 2 .

The composition for forming a barrier layer can be coated by means known per se, such as a coating roller, an air knife coater, a per coater, a blade coater, a reverse coater, a hard coater, etc.
Apply by means known per se such as spraying or dipping,
After drying if necessary, a two-component diazo-sensitive layer, which is known per se, is provided.

As the photosensitive diazonium salt to be contained in this diazo photosensitive layer, any diazonium salt can be used as long as it is photodegradable and can be campolized with the cazoler used in the diazo copying method under normal development conditions. be able to.

Suitable examples of diazo compounds constituting such diazonium salts are as follows, although they are of course not limited thereto.

Ethylaniline 4-diazo-N-methyl-N-β-hydroxyethylanilinemino)-ethylaniline 4-diazo-2-chloro-N,N-diethylaniline 4-diazo-2-methyl-N,N-diethyl Aniline 4-diazo-2-iodo-N,N-diethylaniline 4-diazo-Nethyl-N-benzylanilinediethylaniline-N-benzoylaniline 4-diazo-2,5-dibenzyloxy-N-benzoylaniline 4 -diazo-2-chloro-5-methoxy-N-benzoylaniline-diazodiphenylamine 4-diazo-2,5,4'-)ethoxydiphenylamine 4-diazo-2,5,4-triethoxydiphenylsulphur Itolumorpholine 4-siagu 2.5-dibutoxy-N-phenylmorpholine 4-diazo-2-methoxy-N-thiomorpholine 4-diazo-N-2enylbiveridine 4-diazo-N-phenylpyrrolidine 4-diazo- 2,5-n-Butoxy-N-phenylpiperidic acid The diazo compounds exemplified above can be used as relatively stable diazonium salts such as sulfate or hydrochloride, or can be further complexed with zinc chloride, magnesium chloride, tin chloride, etc. Used as salt. Further, stabilization methods such as allylsulfonate and diazosulfonate can also be used.

As the acid stabilizer to be contained in the diazo photosensitive layer, any organic or inorganic acid such as sulfosalicylic acid, p
-Toluenesulfonic acid, citric acid, tartaric acid, oxalic acid,
Sulfamic acid, maleic acid, phosphoric acid, etc. are used.

The photosensitizer composition contains a coupler in addition to the above-mentioned essential components. Such couplers are also well known per se, and any compound capable of coupling with the aforementioned diazonium salts can be used. Suitable examples include, but are not limited to:

Pyrocatechol resorcinol chloroglycine pyrogallol resorcinol monoglycol ether resorcin glycol ether meta-aminophenol non-9-aminophenol 2-methyl-5-impropyl-4-morpholinomethylphenol 3,3',5-) IJ hydroxy diphenyl 3
-3', 5, 5'-tetrahydroxydiphenyl 2,2', 4,4'-tetrahydroxydiphenyl enyl 2,2', 4,4'-tetrahydroxydiphenyl sulfite 2,3-dioxynaphthalene β- Naphthol α-Naphthol 1.6-Dioxynaphthalene 2.7-Dioxynaphthalenediethylaminophenol ortho(hydroxyethoxy)phenol 2.5.6-
Dolimethylphenol 2-hydroxymethylphenol 2-(ω-phenylaminomethyl)-phenol 1,3-dimethyl ether of pyrogallol Hydroxydiphenyllupisuguanidi 2-
+7 toll-3 + 6-thisulfonic acid 1,8-aminonaphthol-5-sulfonic acid 7 toll l-hydroxynaphthyl-7-phenylguanidine 2-hydroxy-naphthyl-8-piguanidine bis-[5-oxy-7- Sulfonaphthyl (2)] Amine 1-phenyl-3-methylpyrazolone (5) Acetoacetic acid anilide l-phenyl-3-cal? Xypyrazolone Acetoacetic Acid Penzylamide Cyanoacetanilide Cyanoacetomorpholine 8-Hydroxy-1,2-naphthiimidazole 2-Methyl-4-hydroxypenzimidazole 7-Methyl-4-hydroxybenzothiazole Rick Acid 1.3 .4-Cyclo(ntatrione) These couplers may be used alone or in combination of two or more.

Of course, in addition to the above-mentioned essential components, the diazo photosensitive composition used in the present invention may contain compounding agents known per se, such as wetting agents, stabilizing agents, extenders, dispersants, pigments, etc. Each of these components is dissolved or dispersed in a solvent such as water to prepare a coating composition. A typical example of this prescription is as follows.

Two-component diazo photosensitizer composition diazonium salt 0.1 to 4.01 Kagura
0.1-5.0% acid stabilizer
2 to 10.0 thidiethylene glycol 2
~1o, 0% extender 〇~10.0
% Dispersant 0 to 1.0% Pigment
0 to 0.003% solvent
Residual Amount As the above-mentioned stabilizing aids, zinc chloride, thiourea, etc. can be used, and as extenders, dextrin, gum arabic, colloidal silica, polyvinyl acetate resin emulsion, starch, etc. can be used. Further, as the dye, a blue dye such as methylene blue or /'P Tenpur 4, or a fluorescent whitening agent is suitably used in order to clarify the photosensitive surface or further increase the whiteness of the pack ground.

The coating amount of the above-mentioned photosensitive composition varies depending on the type of substrate and the development method, but generally speaking, the coating amount of the diazonium salt is 0.605 to 0.21/m2,
In particular, it may be within the range of 0.075 to 0.15117 m2.

The photosensitive paper for diazo copying of the present invention can be developed by using ammonia-steam, or by using amines such as monoethanolamine, jetanolamine, and triethanolamine and alcohol-based materials such as ethylene glycol and diethylene glycol heptanoethyl ether. This is done by applying a thin layer of an aqueous composition containing a solvent to the photosensitive layer.

The invention is illustrated by the following example.

Example 1 As a composition for forming a barrier layer Add water to bring total '1it to 11.

After uniformly dispersing or dissolving a solution of this composition using an ultra-high-speed stirrer, it is applied to photosensitive paper base paper (SK base paper manufactured by Kokusaku Dezumi and Haha Runo Co., Ltd.) using an air knife coater, and dried to form a uniform barrier. After forming one layer, diethylene glycol was added as a coating layer forming composition.
...30.9 Water was added to bring the total volume to 11. This coating solution was coated uniformly on the back side of the barrier layer using an air knife coater and dried to form a coating layer.The composition of the photosensitive solution was then pxy as a thing ・・・・・・・・・・・・
・・・・・・・・・151 Zinc chloride ・
・・・・・・・・・・・・・・・Dan・55g diethylene glycol ・・・・・・・・・・・・・・・・・・・・・
50I Thiourea... Decoy old... Old...
・40.9 no 4 tent full ・・・・・・
・・・・・・・・・・・・・・・0.1.9 Add water to make the total volume 11. Apply the photosensitive liquid evenly on the barrier layer with an air knife coater and dry it to make a uniform coating. A diazo photosensitive sheet was prepared by photosensitive #all formation.

This photosensitive sheet is layered with a manuscript sheet on top of the photosensitive layer, and exposed using a Dyna A-1 dry copying machine manufactured by Sanda Kogyo Co., Ltd., and developed by contacting with a mixed gas of ammonia and water vapor. A copy with an image was obtained, and it was good without curling even after storage - Example 2 - Zinc chloride as a single layer forming composition
...Add 10g of water to bring the total amount to 11.

After dispersing or dissolving this composition in the same manner as in Example 1 and forming a barrier layer on diazo photosensitive paper base paper in the same manner as in Example 1, diethylene glycol was added as a coating layer forming composition.
...Add 30g of water to bring the total amount to 11, and use citric acid as a photosensitive liquid composition.
・・・・・・ 7 & Zinc chloride ・・
・・Old・river・・・ⅡRice starch・・・・
・・・・・・・・・・・・5g Thiourea
・・・・・・・・・・・・・・・ 2g diethylene glycol ・・・・・・・・・・・・ Group・
3g methylene blue B conc...Old...
... 0.12 Ii water was added to bring the total i to 11, and a coating layer was formed on the back side of the barrier layer, and a photosensitive layer was formed on the barrier layer to prepare a diazo photosensitive sheet.

Layer the original sheet on this photosensitive sheet and
The exposed photosensitive sheet was exposed using a D-800 diazo copying machine, and the exposed photosensitive sheet was developed using a developer having the following formulation. i! A clear and high-contrast blue ridge image was obtained when it was washed (developer adhesion amount was about 0.04.9/A4), and it was well preserved without curling.

Developer formulation monoethanolamine ・・・・・・・・・・・・
...18011 diethylene glycol...
・・・・・・・・・・・・・・・2009 Ethylene Glycol ・・・・・・・・・・・・・・・Zoo,
! i' Sodium acetate ・・・・・・・・・
・・・・・・・・・ 50g ethylene glycol monomethyl ether ・・・・・・・・・100g Add water to make total
is 11.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the diazo photosensitive paper of the present invention, and FIG. 2 is a diagram showing the relationship between discharge time and water absorption of various polyhydric alcohols under conditions of 20° C. and 75 SRH. 1... Paper substrate 2... Barrier layer 3... Photosensitive layer 4... Coating layer Figure 1 Figure 2 Between e and r (hr)

Claims (1)

[Claims] (1) A photosensitive paper for diazo copying in which a photosensitive layer containing a photosensitive diazonium salt and a coupler is provided on a paper substrate, in which diethylene glycol is contained in the photosensitive layer and diethylene glycol is also added to the back side of the paper substrate. A photosensitive paper for diazo copying which is prevented from curling and is characterized by being coated.