JP2003029380A - Diazo copying material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide diazo photosensitive paper which prevents formation of a low contrast image, lowering of image uniformity (texture) and precoupling in storage (deterioration of preservability) as defects in an acid-free paper containing calcium carbonate, kaolin, talc, titanium dioxide or the like even when the acid-free paper is used as a support for the diazo photosensitive paper, has high color developing property and gives a clear developed color image. SOLUTION: The diazo copying material obtained by disposing a photosensitive layer consisting essentially of a diazo compound and a coupling component on a support comprising acid-free paper whose surface has >=pH 6 by way of an undercoat layer is characterized in that one or more hydrophobic emulsion resins are contained in the undercoat layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diazo copying material, and more particularly to a diazo copying material having a diazo photosensitive layer via an undercoat layer on a base paper having a neutral paper as a support. If necessary, a precoat layer may be provided between the undercoat layer and the diazo photosensitive layer,
It relates to a diazo copying material having a back layer provided on the side opposite to the photosensitive layer.

[0002]

2. Description of the Related Art A diazo photosensitive paper generally comprises a photosensitive layer containing a diazo compound, a coupling component and various auxiliaries on a support of an acidic paper having a surface pH of 2 to 5 which is sized with a rosin size agent or the like. , A back layer coated on the opposite side.

However, in recent years, the mainstream in the field of high-quality paper and copy printing paper used as a support for diazo photosensitive paper is a paper surface pH 6 sized with a neutral sizing agent such as alkyl ketene dimer and alkenyl succinic anhydride.
Most of the neutral papers are -9, and the conventional acidic papers are made into special papers, which makes the cost high and difficult to obtain.

As a result, in the future, it will be unavoidable to use the neutral paper for the diazo photosensitive paper. However, when these neutral papers are used as the support for the diazo photosensitive paper, the image density is increased. It is said that it is not possible to put it into practical use because the image quality is low, the texture of the background is bad, a low-contrast image is obtained, and pre-coupling gradually progresses during storage, which causes undesirable coloring. The reason is that these neutral papers generally contain calcium carbonate, kaolin, talc, titanium oxide, etc. in the paper as a filler, and due to their alkaline nature, precoupling gradually progresses during storage. .

In Japanese Unexamined Patent Publication No. 8-269893, the carboxyl group contained in the dye of the ink for ink jet recording reacts with calcium carbonate contained in the neutral paper to change the color developability and impair the quality of the printed matter. Therefore, instead of calcium carbonate, use a base paper containing a silicate-based filler,
A recording paper has been proposed which has a recording layer containing amorphous silica and a water-based binder as its main components on one side, but when a paper containing a silicate-based filler is used as the support for the diazo photosensitive paper. Not only the pH of the paper surface may shift to acidic,
Now, the trend of the neutral paper market with calcium carbonate as a filler cannot be ignored.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and includes calcium carbonate, kaolin,
Even when a neutral paper containing talc, titanium oxide, etc. is used as a support for a diazo photosensitive paper, its disadvantages are a low-contrast image, a reduction in image uniformity (hereinafter referred to as "texture"), and a pre-during storage. It is an object of the present invention to provide a diazo photosensitive paper which is prevented from coupling (deterioration of storage stability) and has a high color forming property and a clear color image.

[0007]

In order to solve the above-mentioned problems, the present invention has conducted intensive studies by paying attention to the material used for the diazo copying layer, and as a result, it has been found that an undercoat layer using a specific material is interposed. As a result, they have found a diazo copying material capable of preventing pre-coupling during storage, providing excellent image quality with excellent contrast and uniformity (texture), and have completed the present invention based on this finding.

[0008] That is, the above-mentioned problem is (1) of the present invention.
"A diazo copying material comprising a support made of neutral paper having a pH of 6 or more on the surface of a paper and a photosensitive layer containing a diazo compound and a coupling component as main components through an undercoat layer, the undercoat layer A diazo copying material characterized by containing at least one kind of hydrophobic emulsion type resin in the above ", (2)" Neutral paper in which the support contains 50% or more of recycled pulp made from waste paper. (3) The glass transition temperature of the hydrophobic emulsion type resin of the undercoat layer is in the range of -20 to 20 ° C. (4) "The hydrophobic emulsion type resin is polyvinyl acetate, polyacrylic acid ester, styrene-acrylic acid". The diazo compound according to any one of items (1) to (3), which is an acid ester copolymer, a styrene-methacrylic acid ester copolymer, or a vinyl chloride-acrylic acid copolymer. Achieved by "copy material".

The present invention will be described in detail below. As described above, the present invention is a diazo copying material using a neutral paper having a paper surface pH of 6 or more as a support, and further, an undercoat comprising a specific hydrophobic emulsion type resin or the like on the support. It is a diazo copying material having layers. By using a specific hydrophobic emulsion type resin as the undercoat layer on the neutral paper that is the support, it acts as a water-resistant and alkali-resistant barrier layer, and reduces the diffusion and penetration of the photosensitive layer into the support. In addition, since the adverse effect of alkaline substances such as calcium carbonate, kaolin, talc and titanium oxide in the neutral paper as the support is reduced, it is believed that the drawbacks of using the neutral paper base paper will be solved.

The neutral paper used in the present invention is LBKP, N
Papermaking is carried out by a conventional method, mainly consisting of chemical pulp typified by BKP, sizing agents, and fillers, and other papermaking auxiliaries as needed. The pulp material used may be mechanical pulp or waste paper pulp in combination, or may be mainly composed of these. The pH of the surface of the neutral paper thus obtained is 6 or more (the pH of the neutral paper when extracted with cold water or the like is 7 to 9).

As the raw material of the waste paper pulp referred to in the present invention, the top white, the ruled white, the cream white, the card, which are shown in the waste paper standard quality standard table of the waste paper recycling promotion center,
Special white, medium white, imitation, fair white, Kent, white art, special cut,
Examples include separate papers, newspapers and magazines. Further specific examples include non-coated computer paper which is information related paper, printer paper such as thermal paper and pressure sensitive paper, and OA waste paper such as PPC paper, art paper, coated paper, lightly coated paper and matte paper. Coated paper or fine paper, fine color, notebook, notepaper, wrapping paper, fancy paper, medium quality paper, newsprint, waste paper,
Waste paper such as super-wrapping paper, imitation paper, pure white roll paper, uncoated paper such as milk carton and paperboard, chemical pulp paper,
High-yield pulp-containing paper is used, but printing, copying,
It is not particularly limited whether it is printed or not.

In the present invention, the hydrophobic emulsion type resin used as the undercoat layer formed on the neutral paper is polyvinyl acetate, polyacrylic acid ester, styrene-acrylic acid ester copolymer, styrene-methacrylic acid. Examples thereof include ester copolymers and vinyl chloride-acrylic acid copolymers. The glass transition temperature (T
g) is preferably −20 to 20 ° C., particularly preferably −5 ° C. to 5 ° C. Further, those having an average molecular weight of about tens of thousands to hundreds of thousands are suitable. Outside of this range, the barrier property with respect to the support is lowered, the contrast, loss, and uniformity (texture) of the image are lowered, and it becomes difficult to maintain the storability. Further, if a resin other than the above is used, sufficient storability cannot be obtained and the properties required for diazo photosensitive paper cannot be obtained.

The concentration of the undercoat liquid of the present invention is 0.5 to
It is used in the range of 15%, preferably in the range of 1-10%. The amount of resin attached to the undercoat liquid is 0.05 to 5
It is applied in the range of g / m ² , preferably 0.1 to 1 g /
m ² .

The diazo copying material of the present invention comprises a fine particle powder and a binder for the purpose of directly coating a photosensitive solution on the obtained undercoated paper or improving the image density and photosensitivity to improve the writability. You may provide the precoat layer comprised from.

The fine particle powder used in the precoat layer is
Inorganic fine particle powder and organic fine particle powder can be used, and specific examples of the inorganic fine particle powder include silica, alumina, kaolin, talc, titanium, aluminum hydroxide, magnesium hydroxide, and the like, and the organic fine particle powder is styrene resin. Examples thereof include particles, urea-formalin condensate resin particles, benzoguanamine resin particles, and the like.

As the binder, polyvinyl alcohol,
Water-soluble resins such as polyacrylamide, casein, gelatin, starch and its derivatives, polyvinylpyrrolidone, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, polyvinyl acetate, polyacrylic acid ester, vinyl chloride-acrylic acid ester copolymer, ethylene -Various emulsion resins such as vinyl acetate copolymers may be mentioned.

The diazo compound used in the present invention is a diazonium salt represented by the general formula ArN ²⁺ X ⁻ (wherein Ar represents a substituted or unsubstituted aromatic moiety,
ArN ²⁺ represents a diazonium cation, and X ⁻ represents an acid anion. )

Specific examples of the diazo compound include, for example,
4-diazo-N, N-dimethylaniline, 4-diazo-
N, N-diethylaniline, 4-diazo-N, N-methylhydroxyethylaniline, 4-diazophenylmorpholine, 4-diazo-N, N-dibutylaniline, 4-
Diazo-2,5-dimethoxyphenylmorpholine, 4-
Diazo-2,5-diethoxyphenylmorpholine, 4-
Diazo-2,5-dipropoxyphenylmorpholine, 4
-Diazo-2,5-dibutoxyphenylmorpholine, 4
-Diazo-2,5-dibutoxy-N-benzyl-N-ethylaniline, 4-diazo-2,5-dibutoxy-N,
N-dibutylaniline, 4-diazo-2,5-dibutoxy-N-benzyl-N-oxyethylaniline, 4-diazo-2,5-dibutoxyphenylpiperazine, 4-diazo-2,5-diethoxyphenylpyrrolidine , 4-diazo-2,5-dipropoxyphenylpiperidine, 4-
Diazo-2,5-diethoxy-N, N-dimethylaniline, 4-diazo-1-benzoylamino-2,5-dibutoxybenzene, 4-diazo-1- (4′-methoxybenzoylamino) -2,5 -Dimethoxybenzene, 4-
Diazo-1- (4'-methoxybenzoylamino)-
2,5-diethoxybenzene, 4-diazo-1- (4 '
-Methylbenzoylamino) -2,5-dipropoxybenzene, 4-diazo-1- (3'-chlorobenzoylamino) -2,5-diethoxybenzene, 4-diazo-1
-(3'-Methoxybenzoylamino) -2,5-dibutoxybenzene, 4-diazo-1- (3'-methylbenzoylamino) -2,5-dimethoxybenzene, 4-diazo-1-phenylmercapto-2 , 5-dipropoxybenzene, 4-diazo-1- (4'-toluylmercapto) -2,5-diethoxybenzene, 4-diazo-1-
(4'-Methoxyphenylmercapto) -2,5-dibutoxybenzene, 4-diazo-1- (4'-chlorophenylmercapto) -2,5-dimethoxybenzene, 4-
Diazo-1- (3'-toluylmercapto) -2,5-
Diethoxybenzene, 4-diazo-1- (3'-methoxyphenylmercapto) -2,5-dipropoxybenzene, 4-diazo-1- (2'-toluylmercapto)-
2,5-dibutoxybenzene, 4-diazo-1-phenoxy-2,5-dibutoxybenzene, 4-diazo-1-
(4'-Methoxyphenoxy) -2,5-diethoxybenzene and other chloride chlorides such as zinc chloride, cadmium chloride, tin chloride and other double salts, and the diazo sulfuric acid, hexafluorophosphoric acid, tetrafluoroboric acid, etc. Examples thereof include salts of inorganic acids.

The coupler used in the present invention forms a dye by coupling with a diazo compound.
There are so-called active methylene compounds having a methylene group next to a carbonyl group, phenol derivatives, naphthol derivatives and the like. For example, resorcin, phloroglucin,
Sodium 2,3-dihydroxynaphthalene-6-sulfonate, 2-hydroxy-3-naphthoic acid morpholinopropylamide, 2-hydroxy-3-naphthoic acid ethanolamide, 2-hydroxy-3-naphthoic acid-N, N
-Dimethylaminomorpholinopropylamide, 2-hydroxy-3-naphthoic acid octylamide, 1-hydroxy-2-naphthoic acid morpholinopropylamide, 1,5
-Dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,3-dihydroxy-6-sulfanylnaphthalene, sodium 2,7-dihydroxynaphthalene-3,6-disulfonate, 2,3-dihydroxynaphthalene-6-sulfonic acid, 1 -Hydroxynaphthalene-4-
Sodium sulfonate, 2-hydroxy-3-naphthoic acid anilide, benzoylacetanilide, 3-hydroxycyanoacetanilide, parasulfoacetanilide,
1-phenyl-3-methyl-5-pyrazolone, 1-
(2,4,6-Trichlorophenyl) -3-anilino-
5-pyrazolone, 2,4-bis- (benzoylacetamino) toluene, 1,3-bis- (pivaloylacetaminomethyl) benzene and the like can be mentioned, of course, but not limited to these. These couplers can be used alone or in combination of two or more, and any hue can be obtained if necessary.

In the diazo photosensitive paper of the present invention, in addition to the above-mentioned color-forming components, various additives which are applied to ordinary diazo photosensitive paper, for example, naphthalene-sodium monosulfonate and naphthalene-disulfonic acid are used as preservability improvers. Aromatic sulfonates such as sodium, sodium naphthalene-trisulfonate and sulfosalicylic acid, and metal salts such as cadmium sulfate, magnesium sulfate, aluminum sulfate, cadmium chloride, zinc chloride, calcium chloride and magnesium chloride can be used.

Further, caffeine, tioferin and the like as solubilizers, citric acid, tartaric acid and sulfuric acid as acid stabilizers,
Oxalic acid, boric acid, phosphoric acid, pyrophosphoric acid and the like can be used, and in addition, a small amount of alcohols such as saponin and ethyl alcohol can be added as a coating stabilizer.

[0022]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Further, all parts and% in the following are by weight. The neutral paper used in the examples and comparative examples is a base paper made by a known method.

Example 1 Neutral paper (pulp is LBKP1
00% usage, pH on paper surface: 7.2), an undercoat liquid consisting of the following composition was applied, and after drying, an adhesion amount of 0.2 g / m
² undercoat paper was obtained. <Undercoat layer liquid composition> Styrene-acrylic acid ester copolymer emulsion 3 parts (Mitsui Toatsu Chemicals, 45%) Water 97 parts

A precoat layer liquid having the following composition was coated on the above undercoated paper and dried, and then the amount of adhesion was 1.2 g /
A m ² precoat layer was formed. <Precoat layer liquid composition> Amorphous silica powder (Shionogi Pharmaceutical Co., FPS) 3 parts Polyvinyl alcohol 5 parts (Kuraray PVA-205, 20% aqueous solution) Vinyl chloride-acrylic acid ester copolymer emulsion 5 parts (DENKA Made, 40%) 87 parts of water

On this precoat layer, a diazo photosensitive layer liquid having the following composition was applied, and after drying, the amount of adhesion was 1.2 g /
A photosensitive layer of m ² was formed. <Photosensitive layer liquid composition> 4-dimethylaminobenzenediazonium chloride / 1/2 zinc chloride 0.5 part 2,3-dihydroxynaphthalene-6-sulfonic acid sodium salt 1.5 parts citric acid 1 part thiourea 3 parts triethylene glycol 2 parts Zinc chloride 2 parts Saponin 0.1 parts Water 90 parts

Example 2 Used base paper (pulp is LB
KP 30%, imitation waste paper pulp 70% used, paper surface pH:
A diazo copying material of the present invention was prepared by the same liquid and manufacturing method as in Example 1, except that 6.4) was neutral paper containing recycled pulp.

Example 3 Using the base paper of Example 1, an undercoat liquid having the following composition was applied and dried to obtain an undercoat paper having an adhesion amount of 0.2 g / m ² . <Undercoat layer liquid composition> Vinyl chloride-acrylic acid ester copolymer emulsion 4 parts (manufactured by DENKA, 45%) Water 96 parts Onto the undercoat layer thus obtained, the precoat liquid and the photosensitive liquid of Example 1 were applied. Apply and dry with the same manufacturing method,
A diazo copying material of the present invention was prepared.

Comparative Example 1 A diazo copying material was prepared by coating the base paper of Example 1 with the precoat liquid and the photosensitive liquid of Example 1 by the same manufacturing method without undercoating and drying.

Comparative Example 2 A diazo copying material was prepared by the same manufacturing method as in Example 2 except that the liquid composition of the undercoat layer in Example 2 was changed to the following. <Undercoat layer liquid composition> Polyvinyl alcohol 10 parts (Kuraray PVA-205, 20% aqueous solution) Water 90 parts The samples of Comparative Examples all penetrate the coating liquid when the diazo photosensitive liquid layer is applied, as compared to the Examples. Therefore, the amount of liquid adhered increased and the sensitivity was lowered, so that it was necessary to dilute the photosensitive liquid.

An original image was overlaid on the thus prepared diazo copying material and exposed and developed in a dry diazo copying machine to obtain a blue image. (Ricoh's SM-1500 was used.) The obtained image density was evaluated by a reflection densitometer (Macbeth densitometer, RD914 type).

Further, the uniformity, smoothness and denseness of the image area of the sample developed with the obtained diazo copying material were visually evaluated for comparison (hereinafter referred to as texture. 5 is the best, and the lower the texture, the lower the formation.)

Further, in order to test the raw storability, each sample was left standing at 50 ° C. for 5 days, forcibly deteriorated, taken out, and exposed on the whole surface by the above copying machine, and the density of the background portion was measured by a reflection densitometer. did. The results are shown in Table 1.

[0033]

[Table 1]

From Table 1, the diazo copying materials of the examples provided with the undercoat layer of the present invention have high density and good texture,
It has excellent raw storability. On the other hand, it can be seen that the diazo copying materials of Comparative Examples are low in concentration and poor in formation, and only diazo copying materials having extremely poor raw storability (large fog) can be obtained.

[0035]

As is clear from the detailed and specific description above, the neutral paper of the present invention having a paper surface pH of 6 or more is provided with an undercoat layer containing a specific hydrophobic emulsion type resin. The diazo copying material provides an image having excellent raw storability, high color development, high image density, and image uniformity and smoothness (texture), even though a neutral paper support is used.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazunori Umehara             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Yasuyuki Hosoki             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh F-term (reference) 2H123 AC00 AC02 AC11 BA00 BA33                       BA45

Claims (4)

[Claims] 1. A diazo copying material comprising a support made of neutral paper having a paper surface pH of 6 or more and a photosensitive layer containing a diazo compound and a coupling component as main components through an undercoat layer. A diazo copying material, wherein the undercoat layer contains at least one hydrophobic emulsion type resin. 2. The diazo copying material according to claim 1, wherein the support is a neutral paper containing 50% or more of recycled pulp made from waste paper. 3. The diazo copying material according to claim 1, wherein the hydrophobic emulsion type resin of the undercoat layer has a glass transition temperature in the range of −20 to 20 ° C. 4. The hydrophobic emulsion type resin is polyvinyl acetate, polyacrylic acid ester, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, vinyl chloride-acrylic acid copolymer. The diazo copying material according to any one of claims 1 to 3, characterized in that: