DE2248606B2 - Wetting liquid for offset printing - Google Patents

Description

© who applies their salts, for example with sodium acetate, a thickness of 100 microns and the film

Borax or sodium citrate in a by adding together the following

A written liquid I to ΠΙ that is outside of this pH value range is produced

pH reduces the achievable print run as well as the palladium sulfide sol is immersed:

Noticeable stability of the liquid. The wetting 5

liquid must for the perfect fulfillment of your liquid I:

Task always in the form of an aqueous dispersion ⁵ 8 ^pdC1 ' ⁴ ^ ¹ ^ ^HC1 > ^10C0 " ³ ^ water;

are present. Liquid II:

The proportion of the dispersed 8.6 g Na ₂ S, 30 ml polyethylene glycol, 10 ml

Oxides 0.5 weight percent on a solids basis. The io alkyl ethers (10 percent), 1000 ml of water;

Alkali metal sulfates are preferably in the 4- to RiiiwiaViMt m

6 times the proportion of the dispersed oxides. The inn "i lJrtti ,,
Polyol compound is preferably in the range
from 5 to 10 percent by weight of the composition

before, but their proportion depends essentially on the offset printing plate obtained in this way

Adjustment of the viscosity and the consistency of the is from a negative template using the

Dispersion from. The weak organic acid or silver salt diffusion transfer process creates an image

Their salt is transferred to a pH adjustment facility. Then the offset printing plate

required amount added. It is preferably wetted with the aforementioned wetting liquid

their proportion in the range from 0.1 to 10 percent by weight made ao or water-bearing. After that the plate

the wetting composition. for printing in a standard offset printing

The machine used in the manner described above. The conditions of the pressure fluid is introduced to the about 10 to 2Ofache are room temperature (25 ⁰ C) and 70% relative diluted. The degree of dilution depends on the type of moisture,
the plates, the type of printing ink and the given 25 _v,. . ,. . . units in printing (type of printing machine, external Vergieicnsoeispiei 1
Weather conditions) and cannot be set within a conventional wetting liquid that is 10 g of a defined range. An NH ₄ H ₂ PO ₁ , 15 g of Ni (NO ₃ V 6H ₂ O, 4 g of carboxy dilution of less than 10 times the methylcellulose, 100 g of glycerin and 1000 ml of water in the case of the wetting agent according to the invention contains 30 water, is mixed with water but easily diluted to ten times its composition to form an emulsification.

appearance, while a degree of dilution of more _v,. . . ■ _.i ·,

than the 2Ofold difficulties in the wetting coating process ζ

Process can occur. A wetting liquid analogous to that in

For the sake of discernment and 35 Example 1 used, but in which the sodium

the appearance of the wetting liquid co-sulfate and the colloidal silicon dioxide are omitted

In addition, dyes such as cobalt chloride or tertiary sodium phosphate can be replaced.

Manganese chloride, phthalocyanine pigments, malachite. .

green or ultramarine, in a small amount compared to Comparative Example 3

be set. 40 Furthermore, a wetting agent according to Example 1

Furthermore, if necessary, hydrophilic ones from DT-AS 11 05 439 can also be produced.
Substances such as carboxymethyl cellulose, rubber The wetting liquids according to the comparative arabic, sodium alginate, vinyl pyrrolidone, vinyl examples 1 to 3 are tested in terms of their bearing imidazole, methyl vinyl ether or maleic anhydride, resistance, their service life when used in offset which substances have been tried and tested in terms of their printing behavior Representing components, looking for water-miscible ones and comparing them with organic solvents such as methanol, dimethyl wetting liquid obtained for example. The data are in the formamide or dioxane, as well as those in the Japanese table below.
Patent publication 10 910/61 and U.S. Patent 34 90 906 described ion-containing Ver 5 °
bond can be added.

The invention will now be explained with the aid of the following examples.

For example

It becomes a liquid of 820 parts by weight
Water, 6 parts by weight of succinic acid, 8.4 parts by weight of borax, 25 parts by weight of anhydrous sodium sulfate, 2.5 parts by weight of cobalt chloride hexahydrate,
100 parts by weight of ethylene glycol and 28 parts by weight 60
share colloidal silicon dioxide (20 percent liquid) made. The pH of the liquid is
4.8. The liquid becomes ten times as much
The above evaluations were made with bare

liquid composition (wetting liquid) he 65 eye. It means:
holds. Persistence: Degree of clarity of the liquid

A printing plate is also made by, after standing for 7 days at a constant temperature a base layer with moisture on a polyester base film.

example 1 Ver
equal
example 1 Ver
equal
example 2 Ver
equal
example 3 resistance +
+ X ° X
X Staining
the basic color + X - X +: very good,
0: good,
X: relatively bad
-: bad.

22 48 608 U-

5 6

Emulsification state: degree of clarity of the liquid obtained layer is further a

Sigkdt and condition of the wetting roller after about light-sensitive liquid from the following

1 hour from the start of printing. Components in a proportion of 15 g / m ²

Staining of the base color: Degree of staining:

^^^^ fZ ^ AgCl emulsion (superconcentration

500th and 1000th print copies. %. ^ Motarozentt 600e

vSiSZSSS !? * ^{W <len VCtStChenden} Aqueous siponin solution (percent) 40 g

Always try the same. Aqueous formaldehyde solution The wetting effect that can be achieved according to the invention is a percentage ο

is due to differences in the type of io water 830 e.

Printing ink and process conditions are not

strongly influenced; in the case of appropriate attempts, the

essentially those shown in the table above by mixing the liquids below Results achieved. I and II obtained, cloudy photosensitive material

is stratification liquid in a proportion of about

B e i s ρ i e 1 2 7 g / m * applied. The clouding of the liquid

was above 40 ^° C. for about 40 minutes

Essentially the same effects as done chemically, game 1 can be achieved if, in this example, the composition of liquid I:

AhiminiumoMdsol instead of colloidal silicon ao _Ag Cl emulsion (silver concentration dioxide and a mixture of 60 g polyethylene glycol, ₀ x * "i« _m ™ nrt izn ",

d 20 Äll ll Ä ^ 21

g yygy and 20 g ethylene glycol instead of ethylene glycol ^used

Wasse ^ 2001

Example 3 Aqueous formaldehyde solution

* ⁵ (2 percent) 5 g

r λ «ι. it. «. u · jm t- »u *. ι i_ * l ι * Composition of the liquid II:

5 g of 4-phylcatechol and 50 g of dibutyl phthalate u ^ q nw \ 3 5 _K

in 300 g of a 10 percent gelatin solution, aqueous saponin solution (15 percent), 10 g

T3% ■ Z * "lt"".Di" P ""? N ^. in turn, aqueous formaldehyde solution

with the help of a colloid mill in a dispersion 30 (2orozenüe ^ ■> °

medium from 25 ml 8 percent saponin solution and water 955 g

180 ml of water dispersed. You get a

Developer dispersion. The obtained in the manner described above It is then an aqueous dispersion with the offset printing plate is backed by a line original

Prepared with the following composition: 35 by exposed. The exposed plate is about

20 seconds with a 4 percent aqueous Na-

The aforementioned developer dispersion .. 120 g of trium carbonate solution and then 1 minute with Aqueous gelatin solution (10 percent) 400 g of 2 percent acetic acid as an interruption solution. Aqueous saponin solution (15 percent) is 50 g. Finally the plate is pushed through an lpro- Aqueous formaldehyde solution (forma- ₄₀ percent aqueous phosphoric acid solution. Man

lin) (2 percent) 5 g is given a printing plate.

Water 425 g Mk of this plate is used in the example 1 be

in the manner described using the same

The aqueous dispersion is carried out on a paper support, wetting liquid and offset printing; since the polyethylene is laminated, applied (on top of that, essentially the same proportion is achieved: about 7 g / m *). After fixation, as in Example 1.

Claims (5)

wetting liquid on the wetting roller of a patent claim: offset printing machine strong opacities. In continuous operation, this already leads to the most one 1. Usage liquid for offset printing with up to three hundredth prints to an unmistakable one the basis of highly dispersed silicon dioxide and 5 underground fouling. The image quality of the or prints made from aluminum oxide with the grain size of a printing plate or drum of at most 0.1 µm, alkali metal salt, lower - is therefore not constant, but already increases molecular polyhydric alcohols and / or relatively small quantities clearly recognizable k-jfend or polyglycols and water as well as at least. With the underground staining goes into the ^ .gel a weak organic acid or an io an increasingly more uneven and not their salts to adjust a pH of 4.0 to sufficient coverage in the image areas 5.6, characterized by the opposing side. In addition to the number of wetting processes wait at least one alkali metal sulfate. environmental parameters of the pressure 2. wetting liquid according to claim 1, da- machine a, in particular temperature and relative characterized in that the alkali metal sulfate 15 moisture. Sodium and / or potassium sulfate is. Another problem that the well-known wetting 3. You cannot master the wetting liquid sufficiently after one of the dissolutions is the coupling Proverbs 1 and 2, characterized in that between the wetting effect of the wetting Percentage of dispersed oxides 0.1 to 1 liquids and their tendency to affect the oil components weight percent, the proportion of alkali metal sulfate to emulsify the ao of the printing ink. The more pronounced the 3 to 8 times the oxides and the proportion of more wettability of the wetting liquid, the more Alcohol and / or polyglycol 5 to stronger, the tendency to emulsify is also pronounced. Conversely, the wetting effect of wetting carriers, wherein the polyglycol is a polyalkylene oxide liquids that have no tendency to emulsify have a molecular weight of at most 1000 25, extremely poor. The degree of this is. Linking of properties or the extent to which this 4. Wetting liquid can be canceled after one of the properties linkage, Speaking 1 to 3, characterized by an access directly as a parameter in the image quality as radio phrases Content of the liquid staining tion of the number of copies. Also the structure and Substance. 30 the condition of the printing plates themselves, the emulsifying 5. Influence the wetting liquid according to the tendency to tarnish. Proverbs 3 or 4, characterized in that the invention is therefore based on the object Polyalkylene oxide is polyethylene glycol. a wetting liquid of the type mentioned at the beginning To create a type that can be stored for a long time, with continuous printing operation, a long service life. knows, d. i.e., up to one opposite the booth the technology significantly higher number of editions. Producing clear and unstained prints The invention relates to a wetting liquid. for offset printing on the basis of highly dispersed 4 ° To solve this problem, a wetting silicon dioxide and / or aluminum oxide with liquid of the type mentioned is proposed, a grain size of at most 0.1 μΐη, alkali metal, which is characterized according to the invention by the salt , low molecular weight polyhydric alcohols and the presence of at least one alkali metal sulfate,
or or polyglycols and water as well as at least. According to a preferred embodiment of the invention, a weak organic acid or one of its 45 is added to the wetting liquids, in particular Na salts to adjust a pH of 4.0 to 5.6. Ins- and / or potassium sulfate added. The particular relates to the invention a wetting proportion of the dispersed oxides is preferably liquid for presensitized printing plates in silver 0.1 to 1 percent by weight, the proportion of alkali metal salt diffusion transfer systems (US-PS3728114) sulfates three to eight times the oxides and the or for a silver salt · offset printing plate, for example 50 percent of polyhydric alcohol and / or poly-wise for photolithographic plates, the 5 to 10 percent by weight of the developer set together with the glycol in US Pat. No. 3,146,104. The polyglycol is preferably a polyamide. alkylene oxide with a molecular weight of maximum A dampening solution of the type mentioned is from the least 1000. In particular, the polyalkylene oxide is a DT-AS 11 05 439 known. Compared to the remaining 55 polyethylene glycol. Prior art can use this wetting The dispersed oxides have a grain size of liquid, although thoroughly improved copies get a maximum of 0.1 μm, preferably a grain size im be, however, the resistance is in the range from 0.001 to 0.05 μίτι. The reason for this DT-AS 11 05 439 known wetting liquid grain size restrictions is that the water not satisfactory. Already after seven days of 60-rige dispersion it must be transparent. aside from that open storage at a constant temperature and the wetting effect must not be impaired constant relative humidity occurs considerably and the oxide dispersion with the other components must and opacities that affect the pressure are compatible. The stability of the dispers by agglomeration of the dispersed particles. sior. becomes evident by ionic and Due to the same phenomena, the 65 coordinative bond to the alkali metal sulfate has stable known wetting liquid is also only slightly lized. Standing time on the wetting roller. Already after adjusting the pH to the range one hour of continuous operation shows the well-known loading between 4.0 and 5.6 takes place with weak acids