JPH0627582A - Diazo sensitized paper - Google Patents

Abstract

PURPOSE:To prevent the generation of dust and fibrous uneven development by incorporating the recycled pulp with waste paper as the raw material in the base paper for diazotype and specifying the lignin content in the mixed pulp for the base paper. CONSTITUTION:This diazo sensitized paper is provided with a diazo color developing layer contg. a diazonium salt and a coupling component on the base paper. The base paper contains the regenerated pulp with waste paper as the raw material, and the lignin content in the mixed pulp for the base paper is controlled to <=1.0%. Wood-free-paper, wood-free-paper with ruled lines, cream- colored wood-free-paper, card, newspaper, magazine, etc., are exemplified as the raw material for the waste paper pulp, and the lignin content of the pulp in base paper mixing is controlled to <=1.0% or preferably to <=0.4% in the base paper mixed with waste paper pulp. This diazo sensitized paper is applied to a one-component diazo sensitized paper and a multicomponent diazo sensitized paper including two-component diazo sensitized paper, and wet development by an aq. alkali soln. contg. a coupler, dry development by gaseous ammonia, etc., are used in development.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. 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 blending recycled pulp made from waste paper in the raw paper.

[0002]

2. Description of the Related Art Diazo photosensitive paper utilizes two properties 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 to 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 diazonium salt, a coupler, and a developer that generates an alkali by heat, are classified into a three-component system.

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 these rapidly increasing combustible dusts has become a serious social problem. For this reason, there is a strong demand for establishment of a method for reusing recycled 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 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 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 recycled waste paper pulp obtained from information paper is not limited to the problems of each local government, but 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 a base paper for diazo photosensitive paper, the problem of uneven development of the photosensitive paper occurs due to the lignin contained in the waste paper pulp. Specifically, groundwood pulp (GP), refiner groundwood pulp (RGP), thermomechanical pulp (TM) contained in waste paper pulp.
Mechanical pulp (MP) such as P) contains lignin, but lignin, which has a concentrated distribution as a binding fiber, is not clear as to the cause, but it reduces the photosensitivity speed, so it causes dust and fibrous development unevenness. generate.

[0008]

In view of the above situation, the present inventor has found that even if waste paper pulp is contained in the base paper, dust
As a result of intensive research on a method for producing a diazo photosensitive paper in which fibrous development unevenness does not occur, it was found that by specifying the range of lignin in the base paper, a remarkable effect which cannot be predicted by a known technique can be obtained. Has been completed.

[0009]

The present invention provides a diazo photosensitive paper having a diazo color-forming layer containing a diazonium salt and a coupling component on the base paper, containing recycled pulp made from waste paper in the base paper, and The lignin content in the pulp mixed with base paper is in the range of 1.0% or less, which is a diazo photosensitive paper.

As the raw material for waste paper pulp referred to in the present invention, there are top white, ruled white, cream white, curd,
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.

Further, the used paper pulp is generally (1) disaggregated: the 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.

Further, in the base paper containing the above waste paper pulp, the lignin content of the pulp contained in the base paper is 1.
It should be in the range of 0% or less, preferably 0.4% or less. When the lignin exceeds 1.0%, dust and fibrous development unevenness, which are image suitability when used as a diazo photosensitive paper, occur, which is not preferable.

This development unevenness is mainly due to the binding fibers contained in the waste paper raw material. Among them, GP and TMP, which are the main components of waste newspaper pulp, are left untreated during refining, and they usually have a dark color. Further, in NBKP and LBKP, which are the main constituents of high-quality waste paper pulp, this occurs due to variations in quality such as cooking residue and bleaching residue. The binding fiber is a bundle of cellulose fibers, which is coarser than the normally defibrated cellulose fibers. In addition, since they are not only in the form of a bundle but the wood structure remains as they are, lignin exists between and inside the cellulose fibers. This lignin is knitted due to chemicals (usually alkaline chemicals such as NaOH) and heat used in the pulping process and darkened.

Therefore, these appearances appear as spindle-shaped spots on the paper surface. These spots may remain after recycling as waste paper pulp. If the spots are present on the surface of the diazo photosensitive paper containing the waste paper pulp in the present invention, the dark color causes poor development. Therefore, the solution is to control the amount of lignin in the blended pulp. Most specifically, limiting the high lignin content pulp in the blended pulp may be mentioned.
High lignin content pulp is GP, SGP, CGP, TM
P, CTMP, etc.

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, pulp used in the present invention includes NBKP, LBKP, NBSP and LBSP.
Etc. In use, several of them are mixed and used at a ratio according to the purpose.

If necessary, a filler may be added to the paper stock obtained by the method of the present invention. The kind of the filler can be appropriately selected and used among the internal fillers generally used in the art as long as they do not have an alkaline component in the paper. 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, calcium carbonate is often contained in waste paper, and this remains a little in the ordinary waste paper deinking process, which causes poor photosensitivity. The present inventors have separately filed a patent for the method of controlling the amount of calcium carbonate in the waste paper pulp.

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 the stock do not impair the desired effects of the present invention. In addition, an internal additive for papermaking such as a paper strength improver or an internal sizing agent is appropriately selected and used as necessary.
For example, polyvalent metal compounds other than Fe, such as Al, Sn, and Zn (sulfate band, aluminum chloride) and various starches, polyacrylamide, polyethyleneimine, polyamine,
Polyamide / polyamine, urea formalin resin, melamine formalin resin, plant 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 a paper-making internal additive such as a dye, a pH adjusting agent, a defoaming agent, a pitch control agent and a slime control agent 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 may be 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.

[0023]

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

Example 1 1. Base paper formulation; LBKP 40 parts Imitation waste paper pulp 60 parts Talc 2 parts Rosin emulsion size agent (Dick Hercules; New Ho 100) 1.5 parts Sulfate band 3 parts Amphoteric starch (Oji National; Cato 3210) 0.8 parts Above A 1% slurry of the formulation was made into paper using a TAPPI standard sheet machine, and the wet paper obtained was 5 kg / cm ²
Press, then dry at 90 ° C for 2 minutes,
A base paper having a basis weight of 76 g / m ² was obtained. 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 (NOF Corporation Unigri AV-670) 0.05 part water 99.45 parts

In the pulp used as the base paper for the diazo photosensitive paper, the Clarson lignin method (TAPPI T-2) is used.
22 om-83) to measure the lignin content in the pulp. Also, apply the following diazo sensitizing solution and dry it.
After obtaining the component type diazo photosensitive paper, printing was carried out according to JIS P 4505 using a standard original drawing for printing test, and then ammonia development was carried out. 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.

Example 2 A diazo photosensitive paper was obtained in the same manner as in Example 1 except that 10 parts of LBKP as a base paper and 90 parts of imitation waste paper pulp were used.

Example 3 A diazo photosensitive paper was obtained in the same manner as in Example 1 except that LBKP of the base paper was 40 parts and waste paper pulp was 60 parts.

Example 4 A diazo photosensitive paper was obtained in the same manner as in Example 1 except that LBKP of the base paper was 10 parts and waste paper pulp was 90 parts.

Example 5 A diazo photosensitive paper was obtained in the same manner as in Example 1 except that 20 parts of LBKP as a base paper, 40 parts of imitation used paper pulp and 40 parts of colored used paper pulp were used.

Example 6 A diazo photosensitive paper was obtained in the same manner as in Example 1 except that LBKP of the base paper was 90 parts and waste paper pulp was 10 parts.

Comparative Example 1 A diazo photosensitive paper was obtained in the same manner as in Example 1 except that LBKP of the base paper was 70 parts and pulp of newspaper waste paper was 30 parts.

Comparative Example 2 A diazo photosensitive paper was obtained in the same manner as in Example 1 except that LBKP of the base paper was 40 parts, waste paper pulp for color was 50 parts, and waste paper pulp was 10 parts.

The above results are shown in Table 1.

[0034]

[Table 1]

The determination of dust and fibrous development unevenness in the table is as follows.
○: good, ○ △: somewhat good, Δ: product limit, △ ×: somewhat bad, ×: bad.

Examples 7 to 12 and Comparative Examples 3 to 4 In the above Examples 1 to 6 and Comparative Examples 1 and 2, 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.

[0038]

[Table 2]

The judgment of dust and fibrous development unevenness in the table is as follows.
○: good, ○ △: somewhat good, Δ: product limit, △ ×: somewhat bad, ×: bad.

[0040]

As is clear from Tables 1 and 2, the present invention can be applied to dust / fibrous materials by specifying the range of lignin in the base paper even if the base paper contains diazo photosensitive paper. It is possible to produce a diazo photosensitive paper which does not cause uneven development.

Claims (1)

[Claims] 1. A diazo photosensitive paper having a diazo coloring layer containing a diazonium salt and a coupling component on the base paper, wherein the base paper contains recycled pulp made from waste paper, and the lignin content in the base paper-containing pulp is , 1.0% or less, the diazo photosensitive paper.