JPH04179960A - Processing method and processing device for photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To allow the stable and common processing of positive type photosensitive planographic printing plates and negative type photosensitive planographic printing plates by using a substantially unused developer by measuring the reflection density on the surface of the photosensitive planographic printing plates to be processed to discriminate plate kinds and automatically changing development conditions. CONSTITUTION:This device has a developing section 1, a washing section 2, a rinse gum section 3, a transporting path PS for the printing plates, a developer supply nozzle 8, such as developer tank 14, a replenishing device 15, an area measuring reflection sensor 30, a plate width detecting circuit 31, and a plate area integrating circuit 32. Further this device is provided with a discrimination reflecting sensor 35, a negative/positive discriminating circuit 36, a flow rate control circuit 37, a pump driving circuit 38, a transporting speed control circuit 41, a roller driving circuit 42, and a roller driving motor 43. The reflection density on the surfaces of the printing plates to be processed is measured, by which the kinds of the positive type and negative type photosensitive planographic printing plates are discriminated prior to a developing stage. The developing conditions are automatically changed according to the discriminated kinds of the plates. The positive and negative type photosensitive planographic printing plates are commonly and stably developed by using the substantially unused developer with one unit of an automatic developing machine.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a processing method and a processing apparatus for photosensitive lithographic printing plates, and more specifically, to a positive-working photosensitive lithographic printing plate and a negative-working photosensitive lithographic printing plate. The present invention relates to a processing method and a processing apparatus suitable for commonly processing.

[Conventional technology]

Conventionally, a positive-working photosensitive lithographic printing plate and a negative-working photosensitive lithographic printing plate are developed using a developer that can commonly develop a positive-working photosensitive lithographic printing plate and a negative-working photosensitive lithographic printing plate with one automatic developing machine. As a technology for processing printing plates, there is a processing method in which substantially unused developer is supplied to the surface to be processed and discarded (new solution processing method), and a processing method in which the developer is repeatedly used by replenishing the replenisher. A processing method (circulation method) is known.

[Problem to be solved by the invention]

However, the circulation method has the problem that it is difficult to manage replenishment because the degree of fatigue of the developer is different between positive-working photosensitive lithographic printing plates and negative-working photosensitive lithographic printing plates, and it is difficult to perform stable processing in practice. It was hot. In addition, the new liquid processing method has the problem of consuming a large amount of developer compared to the circulation method, and when using a developer that can develop both positive and negative photosensitive planographic printing plates, the photosensitive Depending on the type of lithographic printing plate, there is a problem in that it is difficult to process it under the same conditions.

An object of the present invention is to use one automatic processor, at least one substantially unused developer, to produce a positive-working photosensitive lithographic printing plate and a negative-working photosensitive lithographic printing plate regardless of plate polarity. An object of the present invention is to provide a processing method and a processing apparatus for photosensitive planographic printing plates that can be stably and commonly processed.

It is also an object of the present invention to commonly produce positive-working photosensitive lithographic printing plates and negative-working photosensitive lithographic printing plates in one automatic processor using at least one substantially unused developer. An object of the present invention is to provide a technology that can reduce processing costs in a processing method and apparatus.

[Means to solve the problem]

The purpose of the present invention is to provide the following treatment method (1) and the following (
2) is achieved by the processing device.

(,1) Using an automatic processor, at least one exposed positive photosensitive lithographic printing plate and one negative photosensitive lithographic printing plate are processed.
In a common processing method using two substantially unused developing solutions, the reflection density of the surface of the photosensitive lithographic printing plate to be processed is measured prior to the development step, and A method for processing a photosensitive lithographic printing plate, characterized in that the plate pole of the photosensitive lithographic printing plate is determined, and development conditions are automatically changed according to the determined plate pole.

(2) means for developing using at least one substantially unused developer, means for measuring the reflection density of the surface of the photosensitive lithographic printing plate, and determining whether the positive-working photosensitive lithographic printing plate is different from the negative-working one from the measurement results; 1. A processing device for a photosensitive lithographic printing plate, comprising a means for discriminating between the two and a photosensitive lithographic printing plate, and a means for automatically changing development conditions based on the result of this discrimination.

Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 1 is a configuration diagram showing an embodiment of a processing device according to the present invention. The processing apparatus shown in the figure is roughly divided into a developing section 1, a water washing section 2, and a rinsing/gum section 3 for processing with a rinsing liquid or a desensitizing liquid.

PS is a conveyance path for the photosensitive planographic printing plate.

In the figure, 4 is a pair of conveying rollers for conveying the photosensitive planographic printing plate, 5, 6, 7 is a squeezing roller that squeezes the processing liquid from the surface of the photosensitive planographic printing plate, and 8 is a pair of substantially unused rollers. A developer supply nozzle for supplying the developer onto the photosensitive lithographic printing plate; 9 is a scan belt for reciprocating the developer supply nozzle 8 in the width direction (horizontal direction perpendicular to the transport direction); 10 is a pulse motor; 11 is a developer diffusion plate for spreading the developer on the photosensitive planographic printing plate to a uniform thickness;
Reference numeral 2 designates a swing brush that scrubs the plate surface of the photosensitive planographic printing plate to accelerate development, 13 a lower guide plate, and 14 c a developer tank. 15 is a replenishing device, which includes a metering pump for feeding the developer in the developer tank 14 to the developer supply nozzle 8;
It also has a mechanism that operates a buzzer based on the detection result of a sensor (shown in the diagram below) that detects the amount of developer in the developer tank 14. 16 is a waste liquid tank for storing developer waste, 18 is a washing water tank, 19 is a shower pipe, 2o
2I is a pump that sends the rinsing water in the rinsing water tank 18 to the shower pipe 19, 2I is a rinsing/gum liquid tank that holds rinsing liquid or desensitizing liquid, and 23 is a rinsing/gum liquid tank 21.
This is a pump that sends the rinsing liquid or desensitizing liquid inside to the shower pipe 22.

Next, the development condition control mechanism shown in the figure will be explained.

Reference numeral 30 denotes area measuring reflection sensors, which are installed in large number at intervals in the width direction in the insertion section of the photosensitive planographic printing plate of the processing device, and read the reflected signals of the photosensitive planographic printing plate to be inserted, and transmit the signals. The plate width detection circuit 31 detects the width of the photosensitive lithographic printing plate, and the plate area integration circuit 32 integrates the time of the width size information to calculate the plate area. 33 is a scan book control circuit which determines the scan width of the developer supply nozzle 8 in the width direction in response to the output signal from the plate width detection circuit 31;
In the next motor drive control circuit 34, a signal for operating the scanning pulse motor is issued, and the developer supply nozzle 8 is scanned in the width direction with a necessary radius.

Reference numeral 35 denotes a discrimination reflection sensor, which is configured to detect the difference in spectral reflectance on the surface of the photosensitive layer between a positive photosensitive lithographic printing plate and a negative photosensitive lithographic printing plate to discriminate between the two plates. There is. Preferably, the reflection density of the photosensitive layer in the exposed area (non-image area) of a positive-working photosensitive lithographic printing plate and the unexposed area (non-image area) of a negative-working photosensitive lithographic printing plate is measured to determine whether it is a positive type or a negative type. The system is configured to determine the board area of the board. The wavelength range of light used for determining plate size is preferably 350 to 450 ng+
and at least one region of 550-650 nm, more preferably 360-430 nm and 550-62
At least one region within 0 nm.

Reference numeral 36 denotes a negative/positive plate discrimination circuit, which measures the reflection density of light in a specific wavelength range as described above using a discrimination reflection sensor 35, compares it with a predetermined reference value, and discriminates between a positive type and a negative type. is configured to do so.

The above-mentioned positive type/negative type discrimination signal and plate area signal are input to the flow rate control circuit 37, and a replenishment amount is calculated based on a predetermined functional relationship. is configured to be controlled. Known techniques can be applied to the above functional relationship. 5. Separately, negative/positive plate discrimination circuit 3
Based on the negative-type and positive-type discrimination signals output from 4, the conveyance speed control circuit 41 generates signals representing the respective conveyance speeds of the positive-type photosensitive lithographic printing plate and the negative-type photosensitive lithographic printing plate. The roller drive circuit 42 is controlled by the signal to switch the conveyance speed for each negative type and positive type plate stack, and drive the row drive motor 43.

Next, the operation will be explained using FIG.

First, when a photosensitive lithographic printing plate is inserted into the processing apparatus from the left end in the figure, it is transported by a pair of transport rollers 4 and pairs of squeezing rollers 5 to 7, and a developer supply nozzle 10 is applied to the surface of the photosensitive layer.
The developer is supplied from

At this time, the developer supply nozzle reciprocates with the plate width detected by the plate width detection circuit 31 based on the signal detected by the area measurement reflection sensor 30, and the plate area is calculated by the plate area integration circuit 32. Separately, based on the signal detected by the discrimination reflection sensor 33, a negative/positive plate discrimination circuit 36 determines whether the plate is positive or negative, and these signals are input to the flow rate control circuit 37. The flow rate control circuit 37 calculates the amount of developing solution based on a predetermined functional relationship that uses the plate area and whether it is a negative type or a positive type as variables, and the pump 15 is operated by the pump drive circuit 38 based on this amount of liquid. , the developer in the developer tank 14 is supplied onto the photosensitive planographic printing plate from the developer supply vibrator 8.

In the developing section 1, the developer supplied at the above-mentioned amount is spread onto the photosensitive planographic printing plate by the developer diffusion plate 12, the plate surface is rubbed by the swing brush 12, and the front and back surfaces are rubbed by the squeeze roller pair 5. The adhering developer and the eluate of the photosensitive layer of the photosensitive lithographic printing plate are removed, and development is completed.

Next, the photosensitive planographic printing plate is conveyed to the washing section 2, and the washing water in the washing water tank 18 is supplied from the shower vibrator 19 to the plate surface of the photosensitive planographic printing plate by the pump 20, and is washed with water. The deposits on the back side are removed.

Next, the photosensitive planographic printing plate is conveyed to the rinse/gum section 3 , and the rinsing liquid or desensitizing liquid contained in the rinse/gum tank 21 is supplied from the shirt-vibrator 22 to the plate surface by the pump 23 , and the rinsing roller 7 is removed leaving only the required amount, and the process ends.

FIG. 2 is a block diagram of a processing device showing another embodiment according to the present invention. The processing equipment shown in the figure includes a developing section lax and a washing section 2.
, rinsing gum part 3 treated with a rinsing liquid or a desensitizing liquid
It consists of PS is a conveyance path for the photosensitive planographic printing plate.

The processing apparatus shown in FIG. 1 is the same as the processing apparatus shown in FIG. 1 except for the developer supply mechanism of the developing section. The developer supply mechanism in this figure has two systems so that two types of developer can be supplied independently under arbitrary conditions depending on the plate area and the like. That is, in FIG. 2, in addition to the flow rate control circuit 37, a pump switching circuit 40 is provided, and the pump switching circuit 40 is switched based on the positive type and negative type discrimination signal from the negative/positive plate discrimination circuit 36. Accordingly, one of the two pumps 17 can be selected and operated to supply the necessary developer.

Next, the operation of the processing device shown in FIG. 2 will be explained.

When the photosensitive lithographic printing plate is inserted into the processing device from the left end in the figure, the plate width detection circuit 3 is activated based on the signal detected by the area measurement reflection sensor 30, as in the device shown in FIG.
The developer supply nozzle reciprocates with the plate width detected for the first plate. On the other hand, the print area is calculated by the print area integration circuit 32. Separately, a negative/positive plate discrimination circuit 36 determines whether the plate is positive or negative based on the signal detected by the discrimination reflection sensor 35, and these signals are sent to the flow rate control circuit 3.
7 is input. The flow rate control circuit 37 calculates the amount of developing solution based on a predetermined functional relationship using the plate area and whether it is a negative type or a positive type as variables. Further, the flow rate control circuit 37 selects one of the pump drive circuits 38 using the pump switching circuit 40 based on the signals from the negative/positive plate discrimination circuit 36 and the plate area integration circuit 32, and selects one of the pump drive circuits 38 to select the signal? Then, either of the two pumps 15 is activated, and the developer from either of the two developer tanks 14 is supplied from the developer supply pipe 8 onto the photosensitive planographic printing plate.

FIG. 3 is a block diagram of a processing device showing another embodiment of the present invention. The processing equipment shown in the figure includes a developing section lb, a washing section 2, and a water washing section 2.
, rinsing gum part 3 treated with rinsing liquid or desensitizing liquid
It's also happening. PS is a conveyance path for the photosensitive planographic printing plate.

The processing apparatus shown in the figure is configured so that the developing time is changed by changing the conveyance speed depending on the plate size of positive and negative types. That is, the signal from the discrimination reflection sensor 35 is input to a negative/positive plate discrimination circuit 36 to determine whether it is a negative type or a positive type, and based on the discrimination signal, the conveying speed control circuit 41 selects a positive type photosensitive lithographic printing plate. A signal representing the transport speed of the negative photosensitive lithographic printing plate and the negative photosensitive lithographic printing plate is generated, and this signal controls the roller drive circuit 42 to switch the transport speed for each negative and positive plate stack, and the roller drive motor 43 It is designed to drive.

In the developing section 1b, 4 is a pair of transport rollers, 5 is a pair of squeezing rollers, 45 is a shower pipe, and 46 is a slit formed from two flexible plates to apply a developer to a uniform thickness on the plate surface. A developer supply member configured to
This configuration is described in Japanese Unexamined Patent Publication No. 62-238564. 47 is a concentrated developer tank, 48 is a dilution water tank, 49 is a developer tank, 50, 511 and 52 are metering pumps, and metering pumps 50 and 51 keep the liquid level of the developer tank 47 constant by a liquid level control mechanism (not shown). The operation is controlled to keep it within this range. 53 is a pump for circulating the developer to a heater 54 with a thermostat; 55 is a developer recovery; 56 is a brush roller that rubs the surface of the photosensitive planographic printing plate to accelerate development; 57 is a shower pipe; and 58 is a receiver. 59 is a roller, 59 is a waste liquid tank, 60 is a pump that sends the liquid in the waste liquid tank 59 to the shower pipe 57, and 61 is an overflow tank (not shown) to an overflow tank.
This is the piping that sends 0-. The water washing section 2 and the rinsing gum section 3 are the same as in FIG.

In the present invention, the reflection density on the surface of the photosensitive layer for determining the plate area may be measured anywhere on the photosensitive planographic printing plate, but preferably at the edge within 5 cm from the edge of the photosensitive planographic printing plate. More preferably, it is an end within 5c layers from the leading end or trailing end in the transport direction of the photosensitive planographic printing plate. This means that the above part is usually the exposed part in positive photosensitive planographic printing plates,
Since this is the unexposed area in a negative-working photosensitive lithographic printing plate, this is the preferred method for determining plate area in the present invention. This is because it is convenient for measuring the reflection density on the surface of the photosensitive layer.

The development conditions that are automatically changed according to the results of automatically distinguishing between positive-working photosensitive planographic printing plates and negative-working photosensitive planographic printing plates according to the present invention are optional, and known techniques can be applied; It can be determined by means such as experiments.

Preferred development conditions that vary depending on the plate size of positive and negative types include the amount of developer per unit area of the photosensitive lithographic printing plate, the activity of the developer that varies depending on the dilution rate, the composition of the developer, the type of developer, Development temperature, development time, brush conditions,
(number, type, rotation speed, etc.), and particularly preferred ones include developer amount, developer type or composition, and development time.

In the present invention, it is preferable to supply the substantially unused developer in an amount proportional to the plate area, and it is preferable to collect and reuse the unused developer from the supplied developer.

Photosensitive lithographic printing plates to which the present invention is applied include those in which a layer of a photosensitive composition as described below is provided on the surface of a support having a hydrophilic surface.

l) Photosensitive composition containing a diazo compound The diazo compound in this photosensitive composition is, for example, a diazo resin typified by a condensate of an aromatic diazonium salt and formaldehyde or acetaldehyde. For example, p
- a diazo resin inorganic which is a salt of a condensate of diazodiphenylaminte with formaldehyde or acetaldehyde, such as a reaction product of said condensate with a hexafluoroborophosphate, a tetrafluoroborate, a perchlorate or a periodate; Salts and diazo resin organic salts which are reaction products of the above condensates and sulfonic acids as described in US Pat. No. 3,300,309 can be mentioned. Furthermore, the diazo resin is preferably used together with a binder.

Various polymer compounds can be used as such a binder, but monomers having aromatic hydroxyl groups such as those described in JP-A No. 54-98613, such as N-( 4-hydroxyphenyl)acrylamide, N-(4-hydroxyphenyl)methacrylamide, o-, m-, or p-hydroxystyrene, 0
-9II-+ or copolymer of p-hydroxyphenyl methacrylate, etc. and other monomers, US Pat. No. 4.123
．． Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as main repeating units as described in US Pat. No. 276, natural resins such as shellac and rosin, polyvinyl alcohol, US Pat. Polyamide resin as described in U.S. Pat. No. 3,660,09
Linear polyurethane resins as described in No. 7, heptalated resins of polyvinyl alcohol, epoxy resins condensed from bisphenol A and epichlorohydrin, cellulose derivatives such as cellulose acetate and cellulose acetate phthalate are included. .

2) A photosensitive composition containing an o-quinonediazide compound. −
In a photosensitive composition containing a quinonediazide compound,
It is preferable to use an 0-quinonediazide compound and an alkali-soluble resin together.

Examples of the 0-quinonediazide compound include: Examples include ester compounds of -su7toquinone diacytosulfonic acid and polycondensation resins of phenols and aldehydes or ketones.

Examples of the phenols include phenol, 0-
Cresol, m-cresol, p-cresol, 3.5
Examples include m-phenols such as xylenol, carvacrol, and thymol, dihydric phenols such as catechol, resorcinol, and hydroquinone, and trihydric phenols such as pyrogallol and 70 loglucin. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Preferred among these are formaldehyde and benzaldehyde. Further, examples of the ketone include acetone and methyl ethyl ketone.

Specific examples of the polycondensation resin include phenol/formaldehyde resin, I-cresol/formaldehyde resin, 1l-1p/mixed cresol/formaldehyde resin, resorcinol/benzaldehyde resin, pyrogallol/acetone resin, and the like.

The condensation rate of 0-naphthoquinonediazide sulfonic acid with respect to the OH group of the phenol in the 0-su7toquinonediazide compound (reaction rate with respect to one OH group) is 15 to 80%.
is preferable, and more preferably 20 to 45%.

As a 0-quinonediazide compound, JP-A-58-434
The following compounds described in Publication No. 51 can also be used.

Also, Special Publication No. 37-1953, No. 37-3627, No. 37-13109, No. 40-26126, No. 40-
No. 3801, No. 45-5604, No. 45-27345
1,2-quinonediazide compounds described in JP-A No. 51-13013, JP-A No. 48-96575, JP-A No. 48-63802, and JP-A No. 48-63802 can also be mentioned.

The support used in the photosensitive lithographic printing plate is as follows:
Paper, plastics (e.g. polyethylene, polypropylene, polystyrene, etc.) laminated paper, sheets of metals such as aluminum (including aluminum alloys), zinc, copper, etc., cellulose diacetate, cellulose triacetate, cellulose propionate, polyethylene terephthalate, polyethylene Plastic films, such as polypropylene, polycarbonate, polyvinyl acetal, etc.
Examples include paper laminated or vapor-deposited with the metals mentioned above, and chrome-plated steel plates. Among these, aluminum and aluminum-coated composite supports are particularly preferred.

Further, the surface of the aluminum material is preferably roughened for the purpose of increasing water retention and adhesion to the photosensitive layer.

Examples of the surface roughening method include generally known methods such as brush polishing, pole polishing, electrolytic etching, chemical etching, liquid honing, and sandblasting, and combinations thereof, and preferably brush polishing, electrolytic etching, and chemical etching. Target etching and liquid honing may be mentioned, among which roughening methods involving the use of electrolytic etching are particularly preferred. The electrolytic bath used in electrolytic etching is an aqueous solution containing an acid, an alkali, or a salt thereof, or an aqueous solution containing an organic solvent. Liquid is preferred. Further, the roughened aluminum plate is desmutted with an acid or alkali aqueous solution, if necessary.

It is desirable that the aluminum plate thus obtained be anodized, particularly preferably a method of treatment in a bath containing ia or phosphoric acid.

Furthermore, if necessary, a sealing treatment and other surface treatments such as immersion in a potassium fluorozirconate aqueous solution can be performed.

The at least one substantially virgin developer used in the method of the invention has water as the predominant solvent (specifically 50%
The developer must be an alkaline developer (consisting of at least % by weight of water), and a developer capable of developing both negative-working photosensitive lithographic printing plates and positive-working photosensitive lithographic printing plates (a developer for both negative and positive use). preferable. Each of the developing solutions contains an alkali silicate and has a pH of 10 or higher, more preferably 9.
An alkaline aqueous developer having an H of 12 to 13°5 is preferred.

Examples of the alkali silicate include potassium silicate, sodium silicate, sodium metasilicate, potassium metasilicate, and ammonium silicate. The content of alkali silicate in the developer is preferably in the range of 0.3 to 10% by weight. In addition, alkali silicate has a SiO2 concentration of 0.
A range of 1 to 7.0% by weight is preferred.

Alkali agents other than alkali silicates can be used in combination with the developer and developer replenisher, such as potassium hydroxide,
Sodium hydroxide, lithium hydroxide, sodium triphosphate, sodium diphosphate, potassium triphosphate, potassium diphosphate, ammonium diphosphate, ammonium diphosphate, sodium metasilicate, sodium bicarbonate, carbonic acid Inorganic alkaline agents such as sodium, potassium carbonate, ammonium carbonate, etc., organic alkaline agents such as mono-, di- or triethanolamine and tetraalkyl hydroxide can be used in combination.

As an organic solvent, the solubility in water at 20°C is 1.
Preferably 0% by weight or less, such as carboxylic acid esters such as ethyl acetate, propyl acetate, butyl acetate, pendyl acetate, ethylene glycol monobutyl ethertyl, butyl levulinate; ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone. Ketones such as: ethylene glycol monobutyl ether, ethylene glycol benzyl ether, ethylene glycol monophenyl ether, benzyl asacol, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol; alkyls such as xylene Substituted aromatic hydrocarbons include halogenated hydrocarbons such as methylene dichloride, ethylene dichloride, and monochlorobenzene. These organic solvents can be used alone or in combination of two or more.

As the surfactant, at least one of nonionic, anionic, cationic and amphoteric surfactants can be used. Preferably it is a nonionic surfactant.

Nonionic surfactants can be broadly classified into polyethylene glycol type and polyhydric alcohol type, both of which can be used, but polyethylene glycol type nonionic surfactants are preferred from the viewpoint of developing performance, and among them, ethylene glycol type nonionic surfactants are preferred. 3 or more, and HLB value (HLB is Hydrophi 1e-Lipophile Ba1
ance) is 5 or more (more preferably 8 to 20).

Among nonionic surfactants, those having both an ethyleneoxy group and a propyleneoxy group are particularly preferred, and among these, those having an HLB value of 8 or more are more preferred.

Preferred examples of nonionic surfactants include the following general formula (1
) to [8].

(1) R-0-(CH2CH20)nH(3)
RO(CH3COO)III (CHzCHzO)
nH(6) HO(C,H,O)a (CJsO)
b (C,H40)cH(7) H(QC!H,)
y-(OC3HI)X included/(CsH@0)X-(C2H
40)yHH(OC2Ha)Y (OC3H@)X/
\(C3HsO)x (canto)yu(8)
)10- (CHzC)IiO)nH (1) In formulas [8], R represents a hydrogen atom or a monovalent radical. The organic group is, for example, a linear or branched group having 1 to 3 carbon atoms.
0, an alkyl group which may have a substituent (for example, an aryl group (phenyl, etc.)), an alkyl carbonyl group whose alkyl moiety is the above-mentioned alkyl group, a substituent (for example, a hydroxyl group, the above-mentioned alkyl group) phenyl group, etc., which may have a group). all), c, mS
n, x and y each represent an integer of 1-40.

Specific examples of nonionic surfactants are shown below.

Polyethylene glycol, polyoxyethylene lauryl ether, polyoxyethylene nonyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene behenyl ether, polyoxyethylene polyoxypropylene cetyl ether, polyoxy Ethylene polyoxypropylene behenyl ether lyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene stearylamine, polyoxyethylene oleylamine,
Polyoxyethylene stearamide, polyoxyethylene oleic acid amide, polyoxyethylene castor oil, polyoxyethylene abiethyl ether, polyoxyethylene lanolin ether, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene Glyceryl monooleate, polyoxyethylene glycer monostearate, polyoxyethylene propylene glycol monostearate, oxyethylene oxypropylene block polymer, distyrenated phenol polyethylene oxide adduct, tribenzylphenol polyethylene oxide adduct, octylphenol polyoxyethylene polyoxy propylene adduct,
Glycerol monostearate, sorbitan monolaurate, polyoxyethylene sorbitan monolaurate, etc.

The weight average molecular weight of the nonionic surfactant is 300 to 100
A range of 00 is preferred, and a range of 500 to 5000 is particularly preferred.

Examples of anionic surfactants include higher alcohols (C.I.
~Czz) Sulfuric ester salts [e.g., sodium salt of lauryl alcohol sulfate, sodium salt of op5-l alcohol sulfate, ammonium salt of lauryl alcohol sulfate, rTeepol-81
J (trade name, manufactured by Shell Chemical Co., Ltd.), sodium chloride alkyl sulfate, etc.], aliphatic alcohol phosphate ester salts (e.g., sodium salt of cetyl alcohol phosphate, etc.), alkylaryl sulfonates (e.g., dotesylbenzene), Sodium salt of sulfonic acid, sodium salt of isopropylnaphthalene sulfonic acid,
sodium salt of sinaphthalene disulfonic acid, sodium salt of metanitrobenzenesulfonic acid, etc.), sulfonate salts of alkylamides (e.g., C, H33CON (C
(H, ) CH, SO, Na, etc.), sulfonic acid salts of dibasic fatty acid esters (for example, sodium sulfosuccinate dioctyl ester, sodium sulfosuccinate dihexyl ester, etc.).

Among these, sulfonate salts are particularly preferably used.

Cationic surfactants are broadly classified into amine type and quaternary ammonium salt type, and any of these can be used.

Examples of amine types include polyoxine ethylene alkyl amines, N-alkyl propylene amines alkyl polyethylene polyamines, N-alkyl polyethylene polyamine dimethyl sulfates, alkyl biguanides, long chain amine oxides, alkylimidacillins, l-hydroxyethyl-
Examples include 2-alkylimidacillin, l-acetylaminoethyl-2-alkylimidacillin, 2-alkyl-4-methyl-4-hydroxymethyloxazoline, and the like.

Examples of quaternary ammonium salts include long-chain primary amine salts, alkyltrimethylammonium salts, dialkyldimethylethylammonium salts, alkyldimethylammonium salts, alkyldimethylbenzylammonium salts, alkylpyridinium salts, and alkylquinolinium salts. , alkylisoquinolinium salt, alkylpyridinium sulfate, stearamidemethylpyridinium salt, acylaminoethyldiethylamine salt, acylaminoethylmethyldiethylammonium salt, alkylamidopropyldimethylbenzylammonium salt, fatty acid polyethylene polyamide, acylaminoethylpyridinium pyridinium Salt, stearoxymethylpyridinium salt, fatty acid triethanolamine, fatty acid triethanolamine formate, trioxyethylene fatty acid triethanolamine, fatty acid dibutylaminoethanol, cetyloxymethylpyridinium salt, p-octylphenoxyethoxyethyldimethylbenzylammonium There is salt etc. ("Alkyl" in the above compound examples refers to a straight chain or partially substituted alkyl having 6 to 20 carbon atoms, and specifically, straight chain alkyl such as hexyl, octyl, cetyl, stearyl, etc.) (Preferably used.) Among these, water-soluble quaternary ammonium salt type cationic surfactants are particularly effective, and among these, alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts, ethylene oxide addition ammonium salts, etc. are preferable. It is. Further, a polymer having a cationic component as a repeating unit is also a cationic surfactant in a broad sense, and the cationic surfactant of the present invention has a golden color. In particular, a polymer containing a quaternary ammonium salt obtained by copolymerizing with a lipophilic monomer can be suitably used.

The weight average molecular weight of the polymer is in the range of 300 to 50,000, particularly preferably in the range of 500 to 5,000.

As the amphoteric surfactant, for example, a compound such as sodium N-methyl-N-pentadecylaminoacetate can be used.

These surfactants can be contained in a range of 0.5 to 10% by weight.

Examples of inorganic reducing agents include sulfites such as sodium sulfite, potassium sulfite, ammonium sulfite, sodium hydrogen sulfite, and potassium hydrogen sulfite, sodium phosphite, potassium phosphite, sodium hydrogen phosphite, and potassium hydrogen phosphite. , phosphates such as sodium dihydrogen phosphite and potassium hydrogen sulfite, hydrazine, sodium thiosulfate, sodium dithionite, etc. Among the reducing agents that are particularly effective are sulfites. These reducing agents are contained in an amount of 0.1 to 10% by weight, more preferably 0.5 to 5% by weight.

The developer and its replenisher may contain other known additives, such as water-soluble or alkali-soluble organic reducing agents, organic carboxylic acids, and salts thereof.

Examples of organic reducing agents include phenolic compounds such as hydroquinone, metol, and methoxyquinone, and amine compounds such as phenylenediamine and phenylhydrazine.

Organic carboxylic acids include aliphatic carboxylic acids having 6 to 20 carbon atoms and aromatic carboxylic acids in which a benzene ring or a 7-talene ring is substituted with a carboxyl group.

The aliphatic carboxylic acid is preferably an alkanoic acid having 6 to 20 carbon atoms, and specific examples include caproic acid, enantylic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, mystylic acid, palmitic acid, and stearic acid. etc., and particularly preferred are alkanoic acids having 6 to 12 carbon atoms. Also, fatty acids with double bonds in their carbon chains,
It may also have a branched carbon chain. The above aliphatic carboxylic acids may be used as sodium or potassium salts or ammonium salts.

Specific compounds of aromatic carboxylic acids include benzoic acid, 0-chlorobenzoic acid, p-chlorobenzoic acid, 0-hydroxybenzoic acid, p-hydroquinebenzoic acid, p-ter
t-butylbenzoic acid, 0-aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 2゜5-dihydroxybenzoic acid, 2.3-dihydroxybenzoic acid,
2.3-dihydroxybenzoic acid, 3.5-dihydroxybenzoic acid, gallic acid, l-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 2-hydroxy-
These include 1-naphthoic acid, 1-naphthoic acid, 2-naphthoic acid, and the like.

The above aromatic carboxylic acid may be used as a sodium or potassium salt or an ammonium salt.

The content of aliphatic carboxylic acid and aromatic carboxylic acid is preferably 0.1 to IO% by weight.

Furthermore, the following additives can be added to the developer and replenisher in the present invention in order to improve development performance. For example, NaC4 described in JP-A-58-75152
, KCQ, KBr and other neutral salts, JP-A-59-1909
Chelating agents such as EDTA and NTA described in Publication No. 52,
CCoCNHs described in JP-A-59-121336
)]*Complexes such as CQs, amphoteric polymer electrolytes such as copolymers of vinylbenzyltrimethylammonium chloride and sodium acrylate described in JP-A-56-142528, lithium chloride as described in JP-A-58-59444 Inorganic lithium compounds such as, Japanese Patent Publication No. 50-34442
Examples include organolithium compounds such as lithium benzoate described in JP-A-59-75255, organometallic surfactants containing Si, Ti, etc. described in JP-A-59-75255, and organoboron compounds described in JP-A-59-84241. It will be done.

Furthermore, the negative/positive common developer used in the method of the present invention includes Japanese Patent Application Laid-open Nos. 62-24263, 62-24264, 62-25761, 62-35351, and 6
No. 2-75535, No. 62-89060, No. 62-1
No. 25357, No. 62-133460, No. 62-15
No. 9148, No. 62-168160, No. 62-175
No. 758, No. 63-200154, No. 63-2056
No. 58, and developers described in each publication are included.

〔Example〕

The method of the present invention will be explained below with reference to Examples.

Example 1 Creation of a positive photosensitive lithographic printing plate A JIS-1050 aluminum plate with a thickness of 0-24t+++ was immersed in a 2% aqueous sodium hydroxide solution, degreased, and then subjected to electrochemical treatment in a dilute hydrochloric acid solution. After roughening the aluminum plate and washing it thoroughly, the aluminum plate was anodized in a dilute sulfuric acid solution to form an oxide film of 2.0 g/m” on the surface of the aluminum plate. After washing with water and drying, dry weight 2.2g of photosensitive liquid with the following composition.
/m" and dried to obtain a positive photosensitive planographic printing plate. The size of the photosensitive planographic printing plate was 10010.
O380011g+.

(Photosensitive liquid) Resorcinol-benzaldehyde resin naphthoquinone-1
, 2-diazide (2)-5-sulfonic acid ester (described in Example 1 of JP-A-56-1044) ... 1 part by weight Cresol-phenol-formaldehyde resin
...3 parts by weight of tert-butylphenol-benzaldehyde resin naphthoquine-1,2-diazide (2
)-5-sulfonic acid ester (JP-A-60-31188
(described in Example 1 of the publication)
, 0.11 parts crystal violet (B, A, S,
Manufactured by Company F, dye)...0.03 parts by weight Victoria Pure Blue BOH (Product name, manufactured by Odogaya Chemical Co., Ltd., dye)...0.0
2 parts by weight Ethylene glycol monomethyl ether...20 parts by weight Preparation of negative-working photosensitive lithographic printing plate A photosensitive solution having the following composition was placed on the same aluminum support as the above-mentioned positive-working photosensitive lithographic printing plate, dry weight 1.8 g/ II! A negative photosensitive planographic printing plate was obtained by coating and drying.

(Photosensitive liquid) Hexafluorophosphate of a condensate of p-diazizodiphenylamine and paraformaldehyde...1 part by weight N-(4-hydroxyphenyl) methacrylamide copolymer (Japanese Patent Publication No. 57-43890 ) 10 parts by weight Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd., dye) 0.2 parts by weight Ethylene glycol monomethyl ether 100 Part by Weight A large number of the above positive photosensitive lithographic printing plates and negative photosensitive lithographic printing plates were prepared, and the positive photosensitive lithographic printing plates were heated with a transparent positive film in close contact with each other for 50 seconds using a 2 kW metal halide lamp from a distance of 70 cI11. The negative photosensitive lithographic printing plate was exposed to light for 30 seconds from a distance of 70 cm using a 2 kW metal halide lamp, with a transparent negative film in close contact with the plate.

These exposed photosensitive lithographic printing plates were used in the following Examples and Comparative Examples.

Example 1 The exposed photosensitive lithographic printing plate described above was developed using the processing apparatus shown in FIG. 1 using a developer having the following composition.

Developer composition Sodium silicate (Japanese Industrial Standard Sodium Silicate No. 3)...19 parts by weight Sodium hydroxide...5411 Amount mEthylene glycol monomethyl ether...6 parts by weight 3-methyl 3-methoxybutanol... 11 parts by weight Sodium sulfite...11 parts by weight Pionin A-44B (trade name, manufactured by Monomoto Yushi Co., Ltd., anionic surfactant)...11 parts by weight Emulgen A-500 (minami product name, manufactured by Kao Corporation, non-containing) ionic surfactant) ...0.05 parts by weight pure water
...500 weight part discrimination reflection sensor 35
Detection is performed by measuring the reflection density of light with a wavelength of 410 nm, and measuring the reflection density of the exposed area for positive-working photosensitive lithographic printing plates and the unexposed area for negative-working photosensitive lithographic printing plates.
When it was less than 7, it was determined to be a positive-working photosensitive lithographic printing plate, and when it was 0.7 or more, it was determined to be a negative-working photosensitive lithographic printing plate. The development conditions for the processed plate area for each plate stack are: development for 20 seconds at 27°C for positive photosensitive lithographic printing plates, and 27°C for negative photosensitive lithographic printing plates.
It was developed for 30 seconds.

As a result of randomly processing 50 sheets each of positive-working photosensitive planographic printing plates and negative-working photosensitive planographic printing plates under the above conditions, 1
Good printed matter was obtained even on the 00th plate.

Example 2 The exposed photosensitive lithographic printing plate described above was processed using the processing apparatus shown in FIG. Detection by the discrimination reflection sensor 35 uses light with a wavelength of 420 nm, and measures the reflection density of the exposed area for a positive photosensitive lithographic printing plate and the unexposed area for a negative photosensitive lithographic printing plate. When it was less than .68, it was determined to be a positive-working photosensitive lithographic printing plate, and when it was 0.68 or more, it was determined to be a negative-working photosensitive lithographic printing plate.

For development, a developer exclusively for positive alignment having the following composition was supplied for the positive-working photosensitive lithographic printing plate, and a developer exclusively for negative-working having the following composition was supplied for the negative-working photosensitive lithographic printing plate. The developer supply amount is 250+nI2/m2 for positive type and 300mI2 for negative type.
/IIlχ, and the developing temperature is 27° for both positive and negative types.
The C1 development time was 20 seconds.

Positive type developer composition Sodium silicate (Japanese Industrial Standard Sodium Silicate No. 3)...100 parts by weight Potassium hydroxide, 7.6 parts by weight Sodium n-propylnaphthalenesulfonate...3 parts by weight Water
...402 parts by weight Negative type developer composition Ethylene glycol monophenyl ether ...20 parts by weight Sodium carbonate hydrate ...3 parts by weight Sodium sulfite ...3 parts by weight 3-methyl-
3-methoxybutanol...74 parts by weight Water...500 parts by weight As a result of randomly processing 50 positive-working photosensitive planographic printing plates and 50 negative-working photosensitive planographic printing plates each under the above conditions, the 100th Good prints were obtained with the plate.

Example 3 Processing was carried out using the processing apparatus shown in FIG. 3 and using the same developer as in Example 1. Detection by the discrimination reflection sensor 35 uses light with a wavelength of 415 nm, and measures the reflection density of the exposed area for a positive photosensitive lithographic printing plate and the unexposed area for a negative photosensitive lithographic printing plate. When it was less than .70, it was judged as a positive-working photosensitive lithographic printing plate, and when it was 0.70 or more, it was judged as a negative-working photosensitive lithographic printing plate. Regarding the development conditions for the treated plate area for each plate stack, the positive-working photosensitive lithographic printing plate was developed at 27°C for 20 seconds, and the negative-working photosensitive lithographic printing plate was developed at 27°C for 30 seconds.

As a result of randomly processing 50 sheets each of positive-working photosensitive planographic printing plates and negative-working photosensitive planographic printing plates under the above conditions, 1
Good printed matter was obtained even on the 00th plate.

The comparative example discrimination reflective sensor 35 was stopped and the developing conditions were set to 27°C.
The same experiment as in Example 1 was conducted except that development was performed for 20 seconds. As a result, some of the negative photosensitive lithographic printing plates had poor development, and stains occurred when they were run on a printing press. In addition, when we changed only the development time to 30 seconds under the above conditions, no stains occurred on both positive and negative plates, but
When 100 sheets of 1σ plate were passed through a photosensitive planographic die, the efficiency of the development process decreased by about 20%.

〔Effect of the invention〕

According to the present invention, it is possible to stably develop both a positive-working photosensitive lithographic printing plate and a positive-working photosensitive lithographic printing plate using a substantially unused developer in one automatic developing machine. is possible,
Furthermore, it is possible to reduce the cost of one process by automating the adjustment of the development conditions corresponding to the different types of photosensitive planographic printing plates.

[Brief explanation of drawings]

Figure 1, 21! FIG. 3 is a block diagram showing an embodiment of the processing apparatus of the present invention. 1, la, lb...Developing section 2...Water washing section 3...Rinse/gum section 8
．． 8a...Developer supply nozzle 14.47...Developer tank 30...area measurement reflection sensor 31...plate width detection circuit 32...plate area integration circuit 35...discrimination reflection sensor 36. ...Negative/positive plate discrimination circuit 37...Flow rate control circuit 38...Pump drive circuit 40...Pump switching circuit 41...Conveyance speed control circuit 42...Roller drive circuit 43...Roller drive motor

Claims (2)

[Claims] (1) A method in which an exposed positive-working photosensitive lithographic printing plate and a negative-working photosensitive lithographic printing plate are commonly processed using at least one substantially unused developer using an automatic processor, Prior to the development process, the reflection density on the surface of the photosensitive planographic printing plate to be processed is measured, the plate type of the positive photosensitive planographic printing plate and the negative photosensitive planographic printing plate is determined, and the A method for processing a photosensitive lithographic printing plate, characterized by automatically changing development conditions. (2) means for developing using at least one substantially unused developer, means for measuring the reflection density of the surface of the photosensitive lithographic printing plate, and determining whether the positive-working photosensitive lithographic printing plate is different from the negative-working one from the measurement results; 1. A processing device for a photosensitive lithographic printing plate, comprising a means for discriminating between the two and a photosensitive lithographic printing plate, and a means for automatically changing development conditions based on the result of this discrimination.