JPH05273696A - Diazo photosensitive paper - Google Patents

Abstract

(57) [Summary] [Object] To provide a diazo photosensitive paper having improved storability and sensitivity in which recycled pulp made from waste paper is blended in base paper. [Structure] A recycled paper made from recycled paper is contained in the base paper, and the calcium carbonate content in the base paper is 1.7% or less in terms of CaO, preferably pure water according to the dynamic permeability test method for the base paper. Permeation coefficient of 2.5-4.0 ml / m ² · s
Diazo photosensitive paper with ec ^1/2 . [Effect] By defining the alkaline component of the base paper, the stability of the diazonium salt in the diazo photosensitive solution is improved, and the storage stability and the sensitivity are reduced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a diazo photosensitive paper having improved image suitability. More specifically, the present invention relates to a diazo photosensitive paper having improved sensitivity and storability, which is obtained by mixing recycled pulp made from recycled paper into raw paper.

[0002]

2. Description of the Related Art Diazo photosensitive paper utilizes two characteristics of photolysis of diazonium salt and reaction of diazonium salt with a coupling component (coupler) to produce an azo dye (coupling reaction). Depending on the method, a one-component system in which a photosensitive solution containing a diazonium salt and a stabilizer such as an acid is applied on the surface of the base paper, and a two-component system in which a photosensitive layer containing a stabilizer such as a diazonium salt, a coupler and an acid is applied. , And a three-component system in which a diazonium salt, a coupler, and a developer that generates an alkali by heat are applied.

In the two-component and three-component photosensitive papers, the above-mentioned chemicals are usually used together with auxiliary agents such as stabilizers, antioxidants, development accelerators, color tone improvers, dissolution aids and concentration enhancers. The agents are mixed and applied.

In recent years, a large amount of information paper called OA paper has been discarded from office buildings and factories, and the treatment of such rapidly increasing combustible dust has become a serious social problem. For this reason, there is a strong demand for establishment of a method for recycling used pulp from the viewpoints of effective use of resources and international environmental problems.

By the way, the recovery rate of used paper in Japan is about 50%.
It is higher than that of other developed countries, and it is being studied to further increase the recovery rate to 55% in the future. Among them, 90% of recovered newspaper is recovered, and it is widely established as recovered paper pulp.

[0006] On the other hand, when recycled pulp of recycled paper such as OA paper and the like is used as a raw material, there is a possibility that various problems may occur in terms of quality. Therefore, the recycled pulp is hardly reused. For this reason, the reuse of old used paper pulp as well as used paper recycled pulp obtained from information paper is not limited to the problems of each local government, but also occurs due to global forest protection or waste paper incineration. It has become an urgent task as a part of the solution to the international environmental problems such as the global warming phenomenon caused by carbon dioxide.

The base paper for diazo photosensitive paper is no exception, and it is desired that the base paper contains waste paper pulp for the purpose of recycling the waste paper pulp. However, when a base paper containing waste paper pulp is used as the base paper for the diazo photosensitive paper, the stability of the diazonium salt is lost due to the alkaline component contained in the base paper, which lowers the sensitivity of the photosensitive paper and deteriorates the storage stability. The problem occurs (the maximum density decreases and the minimum density increases).

On the other hand, since waste paper pulp uses a large amount of a surfactant in the deinking treatment step, if a raw paper containing waste paper pulp is used as the raw paper for diazo photosensitive paper, the performance of the internally added sizing agent deteriorates. The reduction in size increases the permeation and diffusion of the photosensitive solution into the paper layer, resulting in a problem of promoting the reduction in sensitivity.

[0009]

In view of the above situation, the present inventor has diligently studied a diazo photosensitive paper which does not deteriorate the storage stability and the sensitivity even if the raw paper contains waste paper pulp. The inventors have found that by specifying the range, a remarkable effect that cannot be predicted by a known technique can be obtained, and the present invention has been completed.

[0010]

According to the present invention, recycled paper made from waste paper is contained in the base paper, and the calcium carbonate content in the base paper is in the range of 1.7% or less in terms of CaO. It is a characteristic diazo photosensitive paper.

The raw materials for the waste paper pulp referred to in the present invention include white, ruled white, cream white, card, and white, 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, matte paper and the like. Coated paper or fine paper, fine color, notebook, notepaper, wrapping paper, fancy paper, medium quality paper, newsprint, waste paper,
Waste paper such as super-coated 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.

Further, the used paper pulp is generally (1) disaggregated: used paper is treated with mechanical force and chemicals by a pulper to be disintegrated into fibers, and the printing ink is separated from the fibers. (2) Dust removal: Remove foreign substances (plastic, etc.) and dust contained in used paper with a screen, cleaner, etc. (3) Deinking: The printing ink separated from the fiber with a surfactant is removed to the outside of the system by a flotation method or a cleaning method. (4) Bleaching: Improves the whiteness of the fiber by using the oxidizing action and the reducing action. It is made from a combination of 4 steps.

The base paper containing the above-mentioned waste paper pulp must have a calcium carbonate content in the range of 1.7% or less, preferably 1.2% or less in terms of CaO. Incidentally, when CaO exceeds 1.7%, the sensitivity which is image suitability and the storability are diminished when the diazo photosensitive paper is used, which is not preferable.

As means for controlling calcium carbonate in waste paper pulp, dilution is performed when washing 0.5 to 5.0% of waste paper pulp slurry with a washer installed after the deinking step and after the bleaching step. It can be controlled by changing the magnification. It is also possible to control by treating the used paper pulp with sulfurous acid in the system to precipitate calcium carbonate as calcium sulfate and removing it outside the system.

It has been said that there is a certain degree of correlation between the sensitivity of the diazo photosensitive paper and the sizing property of the base paper. However, the sizing property determined by the conventional Scycht sizing degree or the Cobb sizing degree is used. It is impossible to control the permeation of the photosensitizer in the actual machine. Therefore, the present inventor has conducted extensive studies on a method that meets the above-mentioned purpose, and
It was found that, by using a dynamic permeation measuring method called the Stow method, the permeation coefficient calculated from this measurement result has an extremely large correlation with the desired effect of the present invention, and controls the permeation of the diazo photosensitive solution. It is a thing.

As means for controlling the permeability of the diazo photosensitive solution, there are a method of changing the compounding amount of the internally added sizing agent, a method of introducing a hydrophilic group such as polyethylene glycol or polyoxyethylene polyglyceryl ether into the size press solution. Can be used. In addition, as the internally added sizing agent, a petroleum-based synthetic sizing agent typified by a rosin-based reinforced rosin sizing agent, an emulsion rosin sizing agent, and an alkenyl succinate sizing agent, a petroleum resin sizing agent, etc. Can be used.

Bristow used in the method of the present invention
The test method for measuring the dynamic permeability called the method is JAPA
N TAPPI Paper Pulp Test Method No. No. 51, but here, using 25 mm × 1,000 mm base paper, Kayafect red B (manufactured by Nippon Kayaku)
The permeation coefficient was determined using pure water colored with 0.1%. In this case, the contact time (Tsec.) And the liquid transfer amount (Vml / m ² ) are calculated by the following formulas. T = 0.06 d / S V = 1000 Q / LW where: d: slit width (mm) S: peripheral speed (m / min.) Q: liquid usage amount (μl) L: trajectory length (mm) W: trajectory width (Mm) The permeation coefficient (Ka) is represented as a slope when each measured value is graphed with the square root of the contact time as the horizontal axis and the liquid transfer amount as the vertical axis.

Further, the diazo photosensitive paper base paper used in the present invention has the above-mentioned permeation coefficient of 2.5 to 4.0 ml / m ^2.
-Sec ^1/2 , preferably 2.7-3.5 ml / m ² · s
It is intended to identify the range of ec ^1/2. Incidentally, permeability coefficient is more than ^{4.0ml / m 2 · sec 1/} 2, reduction in tends sensitivity diazo photosensitive solution to penetrate the base paper, and cause a decrease in maximum density. In addition, the permeation coefficient is 2.5 ml / m
^When it is less than ² · sec ^1/2 , the permeation of the diazo photosensitive solution is suppressed and uneven density occurs, and the desired effect of the present invention cannot be obtained.

The diazo photosensitive paper of the present invention can be applied to a one-component diazo photosensitive paper, a two-component multi-component diazo photosensitive paper, and the like, and in the developing method, wet development with an alkaline aqueous solution containing a coupler, ammonia It can be applied to known development methods such as dry development with gas and wet dry development with organic amines.

In addition to waste paper pulp, pulps used in the present invention include NBKP, LBKP, NBSP and LBS.
P, GP, TMP and the like can be mentioned. In use, several of them are mixed and used at a ratio according to the purpose.

If desired, a filler may be added to the paper stock obtained by the method of the present invention. The type of filler can be appropriately selected and used as long as it does not have an alkaline component in the paper among the internal fillers commonly used in the art. Specific examples thereof include mineral fillers such as talc, kaolin, clay, calcined kaolin, deramikaolin, titanium dioxide, aluminosilicate, silica, sericite and bentonite, and organic synthetic fillers.

In addition to the above, various anionic, nonionic, cationic or amphoteric retention improvers and drainage improvers which have been conventionally used within the range of not impairing the desired effects of the present invention. An internal additive for paper making such as a paper strength improver or an internal sizing agent is appropriately selected and used as necessary.
For example, polyvalent metal compounds (sulfuric acid band, aluminum chloride) such as Al, Sn, and Zn other than Fe and various starches, polyacrylamide, polyethyleneimine, polyamine,
Polyamide / polyamine, urea formalin resin, melamine formalin resin, vegetable gum, polyvinyl alcohol, latex, polyethylene oxide, polyamide resin, hydrophilic crosslinked polymer particle dispersion, etc. and derivatives or modified products thereof, colloidal silica, bentonite, etc. One kind or two or more kinds of the compounds are appropriately combined and used.

It is also possible to appropriately add an internal auxiliary agent for papermaking such as a dye, a pH adjusting agent, a defoaming agent, a pitch control agent, a slime control agent or the like according to the purpose.

The papermaking method of the present invention is limited to acidic papermaking having a papermaking pH of about 4.5.
A Fourdrinier paper machine, a twin wire paper machine, a combination paper machine, a round net paper machine, a Yankee paper machine, and the like can be appropriately used.

A conventional size press, a gate roll size press, a metering blade type size press, a billing blade, a short dwell coater or the like is used to apply starch, polyvinyl alcohol, latex or maleic anhydride to the surface of the paper. Apply various surface sizing agents such as size and styrene-acrylic acid type, dimension stabilizers such as ethylene-urea resin, wetting agents such as polyethylene glycol and polyoxyethylene polyglyceryl ether, surfactants, pigments and dyes. Of course, it is possible.

Further, the diazo photosensitive paper of the present invention can be coated with the diazo photosensitive liquid by an air knife coater, a rod coater, a curtain coater and various roll coaters.

[0027]

With regard to the cause of the deterioration of the storage stability and sensitivity of the diazo photosensitive paper using the base paper containing waste paper pulp, it is presumed that the stability of the diazonium salt is lost due to the alkaline component in the base paper. In particular, the pH of the used paper pulp manufacturing process is alkaline, and calcium carbonate in the used paper raw material is present in the used paper pulp as a major alkaline component. On the other hand, it is considered that the stability of the diazonium salt is not impaired by using the base paper in which the content of calcium carbonate used in the present invention is specified.

The present invention will be described in detail below with reference to examples. The present invention is not limited to this. All parts and percentages below are by weight.

Example 1 1. LBKP 40 parts Imitation waste paper pulp 60 parts Talc 2 parts Rosin emulsion sizing agent (made by Dick Hercules; Newho 100) 1.4 parts Sulfate band 3 parts Amphoteric starch (Oji National Co .; Cato 3210) 0.8 parts Above 5% / c of the wet paper obtained by making a 1% slurry of the formulation using a TAPPI standard sheet machine
It was pressed at m ² and then dried at 90 ° C. for 2 minutes to obtain a base paper having a basis weight of 76 g / m ² . The washing dilution ratio of the imitation waste paper pulp in the above formulation was 70 times.
The base paper was size-pressed with the following composition to obtain a base paper for diazo photosensitive paper having an adhesion amount of 0.15 g / m ² . 2. Size-press liquid formulation; ethylene-urea resin (Sumitomo Chemical Co .; Sumirez Resin EU) 0.5 part Polyoxyethylene polyglyceryl ether (Nippon Yushi Co., Uni AV-670) 0.05 part Water 99.45 parts

The above diazo photosensitive paper base paper is 500
After calcining at 900C and 900C for 4 hours, the calcium carbonate content in the base paper was converted to CaO from the difference in ash content. Further, the following diazo photosensitive solution was applied and dried to obtain a two-component diazo photosensitive paper, and then JIS P 4 was prepared using a standard original drawing for a printing test.
Baking according to 505 was performed, and then ammonia development was performed. 1. Diazo Photosensitive Solution; 4-Diethylaminobenzenediazonium chloride / 1/2 zinc chloride 20 g 2,3-dihydroxynaphthalene-6-sulfonic acid soda 30 g Citric acid 25 g Urea 20 g Ethylene glycol 10 g Saponin 0.5 g Zinc chloride 15 g The above blended composition To 1 liter with water.

Further, regarding the diazo photosensitive paper, the one which is completely developed without being exposed is set to the maximum density, and the one which is completely exposed and then developed is set to the minimum density.
The measurement was performed with a reflection densitometer according to K7611.

As for storage stability, 50% of diazo photosensitive paper was used.
When stored for 72 hours under the condition of 50 ° C and 50% RH, it is expressed by the characteristic of how much the recording characteristics after storage are lower than those before storage, and the maximum and minimum densities were evaluated by the density difference before and after storage.

Example 2 A sample was prepared in the same manner as in Example 1 except that the LBKP of the base paper was 10 parts, the simulated waste paper pulp was 90 parts, and the rosin emulsion size was 1.5 parts.

Example 3 A sample was prepared in the same manner as in Example 1 except that LBKP of the base paper was 60 parts, waste paper pulp was 40 parts, and the rosin emulsion size was 1.7 parts.

Example 4 A sample was prepared in the same manner as in Example 1 except that LBKP as the base paper was 75 parts, waste newspaper pulp was 25 parts, and the rosin emulsion size was 1.2 parts.

Example 5 A sample was prepared in the same manner as in Example 1 except that LBKP of the base paper was 40 parts, waste newspaper pulp was 25 parts, imitation waste paper pulp was 40 parts, and rosin emulsion size was 1.4 parts. , Example 5.

Example 6 A sample was prepared in the same manner as Example 6 except that the rosin emulsion size was changed to 1.7 parts in Example 5.

Example 7 A sample was prepared in the same manner as Example 7 except that the washing dilution ratio of waste newspaper pulp was increased to 110 times in Example 2 and the rosin emulsion size was changed to 1.4 parts.

Comparative Example 1 A sample was prepared in the same manner as in Example 1 except that LBKP of the base paper was 20 parts, waste paper pulp was 80 parts, and the rosin emulsion size was 1.4 parts in Example 1.

Comparative Example 2 A sample was prepared in the same manner as in Example 1 except that the LBKP of the base paper was 50 parts, the used waste paper pulp was 50 parts, and the rosin emulsion size was 1.4 parts. ..

Comparative Example 3 A sample was prepared in the same manner as in Example 1 except that 40 parts of LBKP as base paper, 40 parts of newspaper waste paper pulp, 20 parts of imitation waste paper pulp and 1.2 parts of rosin emulsion size were used. And Comparative Example 3.

Comparative Example 4 A sample was prepared in the same manner as Comparative Example 4 except that the rosin emulsion size was changed to 1.5 parts in Comparative Example 3.

Comparative Example 5 A sample was prepared in the same manner as Comparative Example 5 except that the rosin emulsion size was changed to 1.9 parts in Comparative Example 3.

Comparative Example 6 The rosin emulsion size in Example 7 was 1.7 parts,
A sample was prepared in the same manner as Comparative Example 6 except that the washing dilution ratio of waste newspaper pulp was set to 50 times.

The above results are summarized in Table 1. Further, the sensitivity evaluation and the determination of the density unevenness in the table are ◯ ... good, ◯ Δ ... somewhat good, Δ ... product limit, Δx ... somewhat bad,
X: It was judged and entered in the order of bad.

[0046]

[Table 1]

Examples 8 to 14 and Comparative Examples 7 to 12 In the above Examples 1 to 6 and Comparative Examples 1 to 5, the diazo photosensitive solution and the developing solution were changed to the following, respectively, and the same test was conducted. 1. Diazo Photosensitive Solution; 4-diazo-2,5-dibutoxymorpholinobenzene zinc chloride double salt 15 g 2,3-dihydroxynaphthalene-6-sulfonic acid soda 25 g ethylene glycol 15 g citric acid 30 g zinc chloride 30 g urea 25 g To 1 liter with water. 2. Developer; Monoethanolamine 50 cc Diethylene glycol 25 cc Water 25 cc

The above results are summarized in Table 2. In addition, the sensitivity evaluation and the determination of density unevenness in the table are based on Table 1.

[0049]

[Table 2]

[0050]

As is clear from Tables 1 and 2, the present invention can provide sensitivity and sensitivity by specifying the range of calcium carbonate in the base paper even if the base paper contains diazo photosensitive paper. It is possible to produce a diazo photosensitive paper whose storage stability is not deteriorated.

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location D21H 27/00 G03C 1/52 8910-2H 7199-3B D21H 5/14 Z

Claims (2)

[Claims] 1. A diazo photosensitive paper, characterized in that the base paper contains recycled pulp made from waste paper, and the calcium carbonate content in the base paper is in the range of 1.7% or less in terms of CaO. 2. The diazo photosensitive material according to claim 1, wherein the pure water has a permeation coefficient of 2.5 to 4.0 ml / m ² · sec ^1/2 according to the dynamic permeation test method for the base paper. paper.