JPH02284144A - Correcting agent for printing plate - Google Patents

Abstract

PURPOSE:To restore the state before a correction even if an correction error arises so that the correction can be rapidly and surely made by incorporating at least a ferric complex salt of org. acid and specific compd. into the above agent. CONSTITUTION:At least the ferric complex salt of org. acid and the compd. expressed by formula I are incorporated into the correcting agent. In the formu la I, A denotes a hydroxyl group, amino group, etc.; R1, R2 form a ring with a C atom to be combined or one thereof is a hydrogen atom and the other denotes a hydrogen atom, alkyl group, aryl group, hydroxyl group; n denotes 0 or 1 to 8 integer; Q denotes -SO3M or -SO2M; M denotes hydrogen atom or cation of an alkaline metal, etc. The rapid and sure correction is possible in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (4) Industrial Field of Application The present invention is directed to an offset printing plate that is utilized for the ink receptivity of a silver image, in which unnecessary portions of the silver image formed on the printing plate are removed. This invention relates to an image modifying agent for offset printing plates that eliminates ink receptivity by converting it to hydrophilicity, and more specifically, it eliminates the need for silver images on offset printing plates formed by photographic or physical methods. It is concerned with completely making the surface hydrophilic and eliminating ink receptivity without causing any problems to printing properties, substrates, etc., by appropriately treating the entire surface of the area with a specific treatment agent at any stage in the printing process. It is something.

Since such processing is usually called "correction" in the printing field, the present inventors will follow it hereafter. Also, the processing agent used in the correction operation will be referred to as "correction agent". .

2) Prior art and its problems In general, areas that require correction that occur in printing master plates manufactured by photolithography include those that already exist in the copy original, those that occur during exposure, and other irregularities. There are some that occur during the development process.

This means, for example, that there are unwanted images, dust and dirt particles, fingerprints or other stains in the reproduced original, or that the original is a combination of various originals. In some cases, shadows may appear during exposure.

In order to obtain good printed matter, all of these points must be corrected during plate making and printing.

Generally speaking, correction operations are essential, and it is desirable to be able to make necessary corrections at any stage of the plate-making and printing processes. Many attempts have been made to modify the necessary images.

For example, JP-A-48-92101, JP-A-51-21901
Compounds having a mercapto or thione group and a hydrophilic group described in ``Sho 54-53002, ``Sho 59-9661, etc.'' can reliably and almost instantaneously make silver images hydrophilic. However, it had a strong odor υ
However, there are drawbacks such as strong acidity that has an adverse effect on the human body and lack of storage stability, and improvements are desired.
Red blood salt or ED described in JP-A-48-41808
Correcting agents containing TA metal salts and thiocyanates have problems with pollution, gradually recover ink receptivity and become smeared after printing after correction, and lack storage stability. It has the following disadvantages.

Furthermore, it is preferable that the corrective agent responds quickly, but if the correction is completed too quickly or if the corrective agent accidentally adheres to an undesired area, the correction should be stopped. I can't. Therefore, it is desirable to use a modifier that causes a rapid reaction after a certain amount of time, for example, several tens of seconds.

(Q Purpose of the Invention The purpose of the present invention is to suppress the progress of an instantaneous correction reaction, to be able to return to the state before correction even if a correction error occurs, and - once the reaction has progressed, to quickly and reliably To provide a correcting agent for offset printing plates that can be corrected and has no adverse effects on the human body or the environment.

■Structure of the Invention The above-mentioned object of the present invention is to provide a correction agent for offset printing plates that utilizes recording material 4a for ink receptivity, which contains at least an organic acid ferric complex salt and a compound represented by the following general formula (I). This was achieved by a modifying agent characterized in that it contains.

General formula (I) (wherein A represents a hydroxyl group or an amino group, R
1s R1 forms a ring with the C atom to which it is bonded, or one is a hydrogen atom and the other is a hydrogen atom, an alkyl group, an aryl group, or a hydroxyl group, and n is O or 1
An integer of ~8, Q represents 18O,M or 18O,M, and M represents a cation such as a hydrogen atom or an alkali metal. )
The present invention will be described in more detail below.0 A preferred example of the organic acid ferric complex salt is an aminopolycarboxylic acid ferric salt, but phosphonic acid ferric salts and the like can also be used.

Organic acid ferric complex salts are usually used in the form of complex salts, but ferric salts such as ferric sulfate, ferric chloride, ferric nitrate, ferric ammonium sulfate, and ferric phosphate can also be used. A ferric ion complex salt may be formed in the bath liquid using diiron or the like and an organic acid.

The aminopolycarboxylic acid second complex salt is a complex of ferric ion and aminopolycarboxylic acid or a salt thereof.

Examples of aminopolycarboxylic acids and salts thereof include ethylenediaminetetraacetic acid (EDTA), EDTA disodium salt, EDTA dianthonium salt, EDTA tetra(trimethylammonium) salt, EDTA tetrapotassium salt, EDTA tetrasodium salt, EDT sodium salt ethylenetriaminepentaacetic acid, diethylenetriaminepentaacetic acid pentasodium salt, ethylenediamine-N-(β-oxyethyl)-N%N'N'
-) diacetic acid, ethylenediamine-N-(β-oxyethyl)-NSN', N'-)triammonium acetate salt,
Propylenediaminetetraacetic acid, propylenediaminetetraacetic acid disodium salt, nitrilotriacetic acid, nitrilotriacetic acid trisodium salt, cyclohexanediaminetetraacetic acid, cyclohexanediaminetetraacetic acid disodium salt, iminodiacetic acid, dihydroxyethylglycine,
Examples include ethyl ether diamine tetraacetic acid and ethylene diamine tetrapropionic acid.

Typical examples of phosphonic acids or salts thereof include diethylenetriaminepentamethylenephosphonic acid, cyclohexanediaminetetramethylenephosphonic acid, triethylenetetraminehexamethylenephosphonic acid, glycol ether diaminetetramethylenephosphonic acid, and 1,2-diaminopropanetetra Methylenephosphonic acid, methyliminodimethylenephosphonic acid, 1,3-diaminopropane-2
-All-tetramethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, and the like.

Any combination of these organic acids and the above-mentioned ferric salts can be used as an organic acid ferric complex salt.

Organic acid ferric complex salts are used to convert recording images used for ink receptivity, and are generally used for silver to which mercapto compounds, etc., which are used to enhance lipophilicity, are strongly adsorbed. For total oxidation, it is better to use a relatively large amount. Generally, the modifier solution 1) is 90.05 to 1
．． The amount is preferably 0.0 mol, preferably 0.1 to 0.5 mol, and two or more types may be combined.

Since the correction is not completed when the silver image is oxidized by the organic acid ferric complex salt, it is necessary to change the silver ion to a hydrophilic metal compound using a compound that reacts with silver ions, or
Needs to be removed. Examples of compounds that react with this silver ion include silver halide solvents such as thiosulfate and thiocyanate, potassium bromide, sodium bromide, ammonium bromide, potassium iodide, sodium iodide, and ammonium iodide. Water-soluble halides are mentioned.

Particularly preferred are the halides as described above, and are about 0.3 mol or more, preferably about 0.3 mol or more per gram of corrector solution.
The amount is up to 5 mol or more and can be dissolved.

28I [The above may be combined.

Representative examples of the metal compound represented by the general formula (I) used in the present invention are shown below.

(I 1 ) HO-CHI-8O1Nm
(I-4) KO-(CH,), -S o3x (Z-5) HO-CH-8OHNa CH.

(I-6) HO-(CHz) a-S OsN H4(I-7) HO-CI (-8o, Nmaro C, I(.

So, Na H (I-18) H, N-CH, -8o, Na
(I-12) H,N-CH,-8o,Nho (I-15) HO-CH鵞-8o,Nho (I-16) HO-(CHl)! -S O@N m It is considered that these compounds represented by the general formula (I) control all the oxidation effects of the organic acid ferric complex salts in a manner convenient for the purpose of the present invention.

The amount of compound of general formula (I) is approximately 0
．． It ranges from 1 to about 1.5 moles, preferably from about 0.2 to about 1 mole.

The correction g of the present invention containing at least the organic ferric complex salt and the compound of general formula (I) is substantially odorless, has excellent stability, and can be used for good correction from immediately after correction to printing a large number of sheets. have the ability.

The correction fluid of the present invention can retain its correction ability for a longer period of time by containing amino alcohol in the two types of basic compounds.

The amino alcohol used in the present invention is a primary, secondary, or tertiary amino alcohol having at least one hydroxyalkyl group.
It is a grade amine compound. Amino alcohol has the general formula (
All compounds represented by A) are included.

General formula (A) (X and X' represent a hydrogen atom, a hydroxyl group, or an amino group), m is O or an integer of 1 or more, and n is 1
An integer f greater than or equal to f is expressed. ) Specifically, ethanolamine, jetanolamine, triethanolamine, diisopropanoamine, N-methylethanolamine, N
-aminoethylethanolamine, N,N-diethylethanolamine, N,N-dimethylethanolamine,
N-methylgetanol 7::7, N-x tilgetanolamine, 3-aminopropanol, 1-amino-propan-2-ol, 4-aminobutanol, 5-amino-penmen-1-ol, 3 , 3/-iminocybrobanol, N-ethyl-2,2'-iminodiethanol, and the like.

Furthermore, 2-amino-2-(hydroxymethyl)propane-1,3-diol, 2-amino-2-methylpropane-1,3-diol, and the like can also be used.

The amino alcohol ranges from about 0.3 to about 3 moles, preferably from about 0.5 to about 2 moles per modified g.

Effect of amino alcohol 4! l! The mechanism is not clear, but it is thought that the silver image area made hydrophilic by the correcting agent, especially the silver image area that has been rubbed off, is prevented from gradually becoming ink receptive and is stably maintained. Modifications containing nru0 amino alcohols are useful for use in so-called modification pen formats, such as felt tip pens. That is, it not only improves the stability of the correction pen over time as described above, but also functions as a drying inhibitor to prevent the correction pen from over-drying.

When the correction fluid of the present invention is used in a correction pen method, by further incorporating low molecular weight gelatin into the composition consisting of the three basic components or the amino alcohol, drying at the pen tip is extremely slow. A correction liquid that dries quickly after correction and allows reliable correction to be obtained.

As is well known, gelatin is used as a photographic material and as food.

Gelatin includes alkali-treated gelatin, acid-treated gelatin, and gelatin derivatives treated and modified by various methods, and usually has an average molecular weight of about 1000 or about 1000.

The typical average molecular weight of low molecular weight gelatin is approximately 3.00.
0 to 30,000, preferably about 5°000 to 20,000. Low molecular weight gelatin is produced by, for example, enzymatically decomposing ordinary photographic gelatin.

Low molecular weight gelatin is about 1 to about 300 parts per part of correction fluid.
! , preferably in the range of about 5 to about 200.

Correction fluids containing low molecular weight gelatin are particularly useful for use in the so-called correction pen system of felt tip pens. That is, it not only improves the stability over time of the corrected edge as described above, but also functions as a drying inhibitor to prevent the corrected pen from overdrying.

Furthermore, it is also preferable that the correction fluid of the present invention contains a non-fluorinated betaine type surfactant.

That is, the non-7-accumulated betaine surfactant can be used after a silver image is subjected to a lipophilic treatment (generally, a mercapto compound as described in Japanese Patent Publication No. 48-29723 is used).
It works so that corrections can be made more easily even after printing has started.

Use of non-fluorinated betaine surfactant i is correction fluid 1
A range of 90.001 to III can be used as a guide.

Specific examples of non-fluorinated betaine type surfactants are shown below.

CI(.

(CHI)s (a Rin CH8 0H.

C,H.

0M.

Modification H of the invention preferably contains sulfites for better stability.

Examples of sulfites include sodium sulfite, potassium sulfite, sodium hydrogen sulfite, and the like.

It is thought that these sulfites control the oxidation effect of the organic acid ferric complex salt in a manner convenient for the purpose of the present invention, but it is not certain.

The amount of sulfite is from about 0.1 to about 1 per layer of modifier solution.
．． 5 moles, preferably in the range of about 0.2 to about 1 mole.

The correction agent of the present invention can be used as a correction fluid using water, various alcohols, or a mixed solvent thereof.

Alternatively, it can also be used in a so-called e-correct pen system.

The pH of the correction fluid is preferably in the range of about 6 to about 9.O In addition, elements to make g viscous, such as carboxymethyl cellulose, polyvinyl alcohol, and glycerin, and dyes, organic or inorganic pigments, etc. It can be included as an element for coloring.

Furthermore, it can also contain fine particle powder as described in the above-mentioned Japanese Patent Application Laid-Open No. 51-21901.

The correction fluid of the present invention is stable. In addition, it can be corrected quickly and completely, and even if it is rubbed strongly after correction, ink will not get on the correction area. Therefore, a larger number of sheets can be printed.

Examples of offset printing plates that utilize the silver image of the present invention for ink receptivity include Time 11848-30562, 脣R Show 53-21602, U.S. Pat. No. 3.721559, U.S. Pat. Other U.S. Patents No. 3 and 4
54,398 and Japanese Patent Application Laid-Open No. 53-9603, offset printing plates with silver halide images that are fully ink receptive are included.

■ Examples Example 1 The same procedure as described in Example 1 of JP-A No. 53-21602 was carried out except that hydroquinone 1.011/d was added to the physical development nucleus layer of the offset printing plate (plate plate 3). A lithographic printing material was prepared.

After image-wise exposure of the lithographic printing material, a transfer of the following formulation ill! Transfer and development was performed by immersing in the solution at 30°C for 30 seconds, and then immersed in the stop solution having the following formulation for 3
Dip for 0 seconds (25℃) and squeeze to remove excess M'e.
and the material was dried under atmospheric conditions.

A corrected WJ was prepared using the compounds and amounts shown in Table 1 below as a correcting agent, and the entire portion of the lithographic printing plate to be corrected was wiped with the correcting liquid impregnated into absorbent cotton.

[Stop liquid]

The ink receptivity (background smudge) of the corrected portions printed on the 5th, 500th, and 5,000th sheets were completely evaluated, and the results are shown in Table 2.

The printing plate thus obtained was printed on an offset printing machine N.B. Dick 350CD (A/B).
(trade name), and printed after wiping the plate surface with a liquid called Prescription ■. The printing room was at 22° C. and 60% humidity.

Table 2 shows the results of examining the ink acceptance method of the corrected areas according to the evaluation criteria below.

○...Ink is not accepted at all.

Δ...Slightly ink receptive 〇 ×...Perfect ink receptivity.

It is understood that E-gB and C in Table 2 do not lose their ink receptivity if they are wiped off in a short period of time.

Example 2 A correction fluid was combined with fA using the compound shown in 2 below and a t-sound, and the mixture was filled into a felt correction pen. The areas to be corrected on the lithographic printing plate were corrected by rubbing with this correction pen.

Gelatin with a water average molecular weight of approximately 1,800,000! 11/Wed 1J) The printing plate thus obtained was processed using an etchant and dampening solution exclusively for the offset printing machine Nie B Dick 350CD (A-B-DIck350CD trade name).
0 sheets were printed.

Ink receptivity in the correction section was not observed from the start of printing until 10,000 sheets were printed. Also, when I modified the Kozu Sansho pen in the same way as above after saving it for three months, I did not get the same result.
It was confirmed that it has excellent storage stability.

Example 3 Exemplary compound 'lli was used as a surfactant in the correction fluid of Example 2.
! 7 (11) A correction pen was made by adding 0.1g of gold to the correction g. Printing was carried out using a printing plate, the ink feed was stopped, the ink was removed from the plate surface, and the desired areas were then corrected by rubbing with the above-mentioned correction pen.

When I started printing again, it was 5゜000 from the start of re-rubbing.
The correction department did not accept any ink up to this point.

[F] Effect of the invention The correction fluid of the present invention can quickly and reliably correct,
It exhibits a correction effect from the beginning of printing to printing multiple sheets, and has excellent storage stability as a 1st standard solution.

Claims (1)

[Scope of Claims] 1. A corrector for offset printing plates that uses a silver image as ink receptivity, containing at least an organic acid ferric complex salt and a compound represented by the following general formula (I). A special correction agent for printing plates. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, A is a hydroxyl group, amino group, ▲There are mathematical formulas, chemical formulas, tables, etc.▼), and R_1 and R_2 are the rings together with the bonded C atoms. or one is a hydrogen atom and the other is a hydrogen atom, an alkyl group, an aryl group, or a hydroxyl group, n is 0 or an integer of 1 to 8, and Q is -SO_3M or -
SO_2M is represented, and M represents a cation such as a hydrogen atom or an alkali metal. )