JPS62215277A - Processing liquid for lithographic printing - Google Patents

Abstract

PURPOSE:To obtain a processing liquid for lithographic printing which has a good inking property, permits quick ink pick up, maintains the initial hydrophilic power for a long period of time and obviates the generation of the ground stain of printed matter by incorporating specific components therein. CONSTITUTION:This processing liquid for lithographic printing is formed by contg. the component expressed by the formula, where n denotes 0-500, D denotes a simple bond or substd. or unsubstd. alkylene, etc., and E denotes -SO3M or -O-SO3M. The example of the compd. includes a butanesulfonic acid, hexanesulfonic acid, etc. The amt. of the compd. to be used is 0.001-5wt%, more preferably 0.01-0.5wt%. All the known compds. including yellow prussiate of potash and phosphate, phytitate, hexamminecobalt salt, etc., are usable for the chief hydrophiling material, and in addition, a pH controlling agent and pH buffer agent are usable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a processing liquid, that is, an etching liquid and a dampening solution, used for printing an electrophotographic offset master, 28th plate.

(Prior art) In an electrophotographic offset master, a photoconductive fine powder such as zinc oxide is first coated on a support together with an electrically insulating resin to form a lipophilic image on a photosensitive layer using a photographic method. .

There are also methods of forming a printing plate by directly forming an image on the master using a lipophilic writing instrument or type, and methods of using an electrophotographic transfer method.

These are used as printing plates by converting the non-image areas from lipophilic to hydrophilic through etching treatment. In order to maintain hydrophilicity during printing, the processing liquid is usually diluted several times and used as dampening water.

Many treatment solutions have been proposed so far. If they are classified according to their main components, they can be divided into yellow blood salt type and non-yellow blood salt type.

Yellow blood salts have been used for a long time. It is unstable to heat and light, and has drawbacks such as a decrease in etching power and the formation of precipitates even with natural aging. Therefore, many proposals have been attempted to improve these drawbacks. Efforts are being made mainly to improve the etching power of non-yellow blood salts. However, they are still not enough. Furthermore, in recent years, the scope of application of printing using electrophotographic offset masters has expanded, and more advanced performance than ever has been required.

That is, no printing stains occur in the non-image area, and sufficient ink is applied to the image area (=good ink receptivity).

In order to prevent stains such as fingerprints, hydrophilic treatment is performed using a lithographic printing processing liquid immediately after plate making, and even if printed several hours later, the ink will not smear and the highlighted areas of fine lines and halftone dots will be blurred. = good ink receptivity after being left to dry), normal prints can be obtained immediately after printing begins (= ink transfer is quick), scumming does not occur even when printing multiple sheets, and non-image areas Even if ink accidentally adheres to the surface and causes stains, the stain can be easily removed by rotating the printing machine at medium speed (excellent ability to remove ink adhesion stains), and the hydrophilicity remains unchanged even after long-term use. It must have characteristics such as not generating crystals or scum.

(Problems to be Solved by the Invention) However, when the etching process is performed using a conventional processing liquid and then dried, there is a drawback that ink adhesion to one image area deteriorates. This drawback becomes even more noticeable when the plate is left for a long time (plate placement) after etching and drying.

To prevent this, there is a method of weakening the etching power (dilution, reducing the base material content, etc.), but in this case, deterioration of the first ink layer can be prevented, but it also causes stains in non-image areas during printing, causing background stains on the printed matter. I end up.

The present invention solves the above-mentioned drawbacks and provides a processing liquid for lithographic printing that does not cause background stains on printed matter.

The first object of the present invention is to provide a processing liquid that has good ink receptivity under any conditions and is less likely to cause printing stains.

A second object of the present invention is to provide a processing liquid that is quick to ink and has an excellent ability to remove ink-attached dirt.

A third object of the present invention is to provide a treatment liquid whose hydrophilicity does not change over a long period of time and which is maintenance-free.

(Means for Solving the Problems) The objects of the present invention are achieved by a lithographic printing processing liquid containing a component represented by the following general formula (I).

General formula (I) RA　(-B　+nD　-E Here, R is substituted or unsubstituted σ-alkyl.

represents an alkenyl, aryl, or aralkyl group,
Preferably, substituted or unsubstituted C1-C22 alkyl or C2-C22 alkenyl, C6-C14
represents an aryl group or a C7 to C26 aralkyl group. Are humans just a combination, -0-1-S-?

vinegar. Here, R1 is ■ or an alkyl of 022 or less.

represents an alkenyl, aryl, or aralkyl group,
Preferably H, C1~C1° alkyl or C2~
C1o alkenyl, C6-C1o aryl.

Or it represents an aralkyl group of 07 to C1°.

B represents +C9P-, where each of the 2m R2's is independently selected from H, an alkyl group or an aryl group. m is selected from an integer of 1 or 4, preferably an integer of 2 or 3, and when n≧2, n Bs may be the same or different from each other. n is 0 to 1000. Preferably 0-5
Represents an integer of 00. D is a simple bond or substituted or unsubstituted alkylene (preferably C1 to C10)
- Alkenylene (preferably C2-C4°) or arylene group (preferably C6-C1o). E
represents 1803M or 10-803M. Here, M is an Hl-valent metal (preferably Na, etc.) or a base (an inorganic base capable of forming onium such as NH5, PH3, etc., a chain containing a petro atom (preferably N, S, O, etc.) , a cyclic organic compound (an organic base capable of forming onium). It may also be a condensate oligomer of general formula (I).

The substituent for the group R is preferably a halogen such as chloro or bromo, an amine group such as nitro, cyan, or dimethylamine, an acylamido group such as acetamide or acetoxy, an acyloxy group, or an alkoxy group such as methoxy. group, further hydroxyl group, -COOM, -805M
Alternatively, a 10-803M group may be mentioned.

Preferred specific examples of B include -(-Chorse-j謬-(n
etc., or a combination thereof.

Each monomer of the condensate oligomer formed from the monomer compound represented by general formula (I) may be the same or different. In this case, the monomers.

Alternatively - a crosslinking agent (e.g. formaldehyde).

Acetaldehyde, divalent calzenic acid, etc.), etc.), but preferably a dimer to an octamer.

Examples of compounds are shown below, but the present invention is not limited thereto.

Butanesulfonic acid, hexanesulfonic acid, sodium octanesulfonate, ammonium dodecanesulfonate,
Trimethylammonium tetradecanesulfonate, triethanolammonium octadecanesulfonate, p-
t-1 Sodium thylbenzenesulfonate, Sodium octylbenzenesulfonate) IJium, Sodium dodecylbenzenesulfonate, Ammonium -octylnaphthalenesulfonate, Sodium tetradecylnaphthalenesulfonate, Sodium tetradecylnaphthalenesulfonate, (Dodecylenedi) Sodium oxy)dibenzene polysulfonate (2 in sulfonic acid group), sodium naphthalene sulfonate formaldehyde condensate, butane sultone adduct of polyoxyethylene nonylphenyl ether, butane sultone adduct of polyoxyethylene naphthyl ether (sodium salt), propane Saltone adduct (sodium salt), butane sultone adduct (sodium salt) of stearic acid polyoxyethylene ester.

Sodium 2-ethylhexyl sulfate, decyl sulfate.

Triethanolammonium dotecyl sulfate, ammonium hexadecyl sulfate, polyoxyethylene hexadenyl ether sulfate (sodium salt).

Polyoxyethylene dodecyl ether sulfate (triethanolamine salt), polyoxyethylene phenyl ether sulfate compound (
lauric acid polyoxyethylene ester sulfate (potassium salt), stearic acid polyoxyethylene ester sulfate (ammonium salt), polyoxyethylene p-butylphenyl ether sulfate (ammonium salt), polyoxy Ethylene-p-nonylphenyl ether sulfate (sodium salt).

The amount used is o,oot~5% by weight, more preferably 0.01~0.5% by weight.

As the main hydrophilizing agent, all conventionally known compounds such as yellow blood salt, phosphate, phytate, hexaammine cobalt salt, etc. can be used.

Furthermore, in addition to these, a regulating agent and a buffering agent can be used in combination. They use well-known inorganic acids, organic acids and their salts alone or in combination. For example, formic acid, acetic acid, butyric acid, and valeric acid.

Lactic acid, tartaric acid, propionic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, phthalic acid, citraconic acid, itaconic acid, fumaric acid, tricarballylic acid, glycolic acid, propionic acid, thioglycolic acid, malic acid , citric acid, gluconic acid, pyruvic acid, gelcholic acid,
salicylic acid, adipic acid, hydroacrylic acid, glyceric acid, p-toluenesulfonic acid and metal salts thereof,
These include organic amine salts.

In addition, addition of a chelating agent such as EDTA-2Na and a reducing agent such as sulfite is also preferred, especially when the main hydrophilizing agent is yellow blood salt, in order to maintain the hydrophilizing power and prevent precipitation.

In addition, when the main agent is phytate, JP-A-60-23
It is also desirable to add a water-soluble cationic polymer shown in No. 099 and a low molecular weight electrolyte compound to prevent staining.

Also ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin as humectants and wetting agents.

Gum arabic, cardoxymethylcellulose, acrylic polymers, methanol, ethanol, iso and normal propyl alcohol, triethanolamine, etc. can be added.

Furthermore, preservatives such as salicylic acid, phenol, zotylphenolzobenzoate, sodium dehydroacetate, and 4-inchazolon-3-one compounds can be added.

In addition, rust preventives such as sodium nitrite and dicyclohexylammonium nitrite can also be added.

When applying the lithographic printing processing liquid of the present invention to printing plates, any etching processor conventionally used in this field may be used.

Furthermore, its characteristics can be fully utilized for hand etching and pre-etching for the purpose of preventing stains such as fingerprints.

Furthermore, this lithographic printing processing liquid can also be used as a dampening water for offset masters and 28 plates by diluting it with water.

Examples of the present invention are shown below. However, the present invention is not limited by this.

Example 1 Sodium ferrocyanide 20.1' Monoammonium phosphate 60.01 Diammonium citrate 30. (1 Sodium sulfite
6.0yEDTA-disodium 0.4
Ammonium tadodecyl sulfate 2.5) (Product name: Emar AD-25 manufactured by Kao Atlas Co., Ltd.) Water (total) 1000.0v Use this formulation as an etching solution and further dilute it 7 times with water to use it as a dampening solution.
A master made using the Fujifilm ELP-* Mark 11 system was printed using ELP ink (black, quick-drying) using Hamada Star 800. I was able to print 10,000 sheets clearly without any smudging from the start of printing. Further, the processing of 3000 plates was tested for one month while supplementing this etching solution. As a result, the first 1st edition and the last 300
There was almost no difference in the quality of the 0th printing, and no deterioration in hydrophilicity, ink receptivity, etc. was observed. Almost no crystals, dregs, or precipitates were observed in the etching apparatus. Furthermore, when a master that had been left indoors for two days after etching was dried was similarly printed (drying test), the inking of the highlighted areas of fine lines and halftone dots was extremely good.

Comparative Example The same test was conducted as in Example 1 except that ammonium dodecyl sulfate was omitted. In the drying test, there was a tendency for ink to be difficult to get on some parts of the image.

Example 2 Potassium ferrocyanide 15, Oy monoammonium phosphate go, oy diammonium citrate 15. Of! sodium sulfite
8.0y EDTA-disodium 1.
0y Sodium dodecylbenzenesulfonate 1. (1 (Product name: Newlex Paste H, manufactured by NOF Corporation) Glycerin 50.0y water (total)
1000. (1) When the same test as in Example 1 was conducted, the same good results were obtained.

Example 3 The test was carried out in the same manner as in Example 1, except that equimolar amount of sodium polyoxyethylene nonyl phenyl ether sulfate (trade name: Emar NC, manufactured by Kao Atlas Co., Ltd.) was used instead of ammonium dodecyl sulfate. I did it. The results were as satisfactory as in Example 1.

Example 4 Test was carried out in the same manner as in Example 1 except that 1 equimolar sodium polyoxyethylene hexatecyl ether sulfate (trade name: Repenol WX, manufactured by Kao Atlas Co., Ltd.) was used instead of ammonium dodecyl sulfate. was carried out. The results were as satisfactory as in Example 1.

Example 5 In Example 1, 1 equimole of sodium tetradecylnaphthalene sulfonate (trade name: Perex NBL) was used instead of ammonium dodecyl sulfate.

Kao Atkus Co., Ltd. The test was conducted in the same manner as in Example 1, except that the sample was used. The results were as satisfactory as in Example 1.

(Effects of the Invention) The compound of general formula (I) contained in the lithographic printing processing liquid of the present invention includes commercially available products and is relatively easily available.
An excellent treatment solution of the present invention can be prepared easily and economically.

Claims (2)

[Claims] (1) A lithographic printing processing liquid containing a component represented by the following general formula (I). General formula (I) R-A-(B)-_nD-E Here, R represents a substituted or unsubstituted alkyl, alkenyl, aryl, or aralkyl group. Is A just a bond, -O-, -S-, -COO-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ represents,
Here, R_1 represents H or an alkyl, alkenyl, aryl, or aralkyl group of C_2_2 or less. B represents ▲a mathematical formula, a chemical formula, a table, etc.▼, where 2m R_2 are each independently selected from H, an alkyl group, or an aryl group. m is selected from an integer from 1 to 4, and when n≧2, n Bs may be the same or different from each other. n represents an integer from 0 to 1000. D
is a simple bond, substituted or unsubstituted alkylene,
Indicates alkenylene or arylene group. E is -SO
Represents _3M or -O-SO_3M. Here, M
represents H, a monovalent metal or a base. Also, the general formula (
It may also be a condensate oligomer of I). (2) The lithographic printing processing liquid according to claim 1, which contains a yellow blood salt and/or a red blood salt as a main ingredient.