JPH05201167A - Dampening solution concentrate and dampening solution,and use thereof in offset printing system - Google Patents

Abstract

PURPOSE: To prevent scomming and emulsification of ink by incorporating a specific additive, a low-foaming surfactant and a specific compound. CONSTITUTION: A dampening-solution concentrate contains a buffer substance of 1 to 15% by weight, an additive of 2 to 20% by weight consisting of one kind or several kinds of substances including water-soluble polysaccharides, polyglycols and polyvalent alcohols, and a nonionic low-foaming surfactant of 0.01 to 5% by weight consisting of one kind or several kinds of substances including a tertiary accetylene glycol, an ethylene-oxide-based surfactant, an propylene-oxide-based surfactant, aliphatic alcohol ethoxylates, fatty acid ehoxylates, and siloxane alkoxylates. Further, this dampening-solution concentrate contains a compound expressed by formula I (n denotes an integer of 1 to 10) of 1 to 35% by weight or a mixture of components thereof, and 2- ethyl-1,3-hexanediol of 0.1 to 10% by weight, and water of 25 to 90% by weight.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to dampening liquid concentrates and dampening liquids and their use in offset printing systems.

[0002]

2. Description of the Related Art In offset printing, an aluminum plate having a hydrophilic surface in the non-image area and a hydrophobic coating on the image area is usually fixed on an impression cylinder. Offset printing is also known as "flatbed printing" because these hydrophilic and hydrophobic parts lie in one plane.

During printing, a dampening liquid is required in addition to the printing ink. The purpose is to keep the non-image area hydrophilic. As a result, the printing ink is received only by the hydrophobic part and is transferred to the printing material via the rubber blanket.

Conventionally, various types of substances have been added to dampening solutions in order to stabilize offset printing systems.
These substances are used, for example, for the purpose of optimizing the compatibility with printing inks, pH values or viscosities, or minimizing the problems caused by water of different hardness.

Still other substances in conventional dampening fluid additives serve to protect the plate as well as to prevent microbial attack on the system. In addition, in the constitution of a printing machine having a so-called alcohol dampening device, in addition to the conventional dampening liquid additive,
Isopropyl alcohol is added to the fountain solution.

The action of this alcohol lies in ensuring the required printing quality by ensuring optimum printing plate wetting, but for environmental protection, occupational hygiene and cost savings, isopropyl is used. Efforts have been made to develop a fountain solution composition that allows printing without the use of alcohol.

However, in the preparation of fountain formulations, the choice of alcohol substitute is very problematic with respect to the ink / water balance, ie the effect of such additives on the water absorption of the ink. It has been found. Many alcohol substitutes increase the water uptake of the ink, which can lead to significant problems in the printing process, such as water loss and scumming.

European Patent EPA 0 251 621 describes an aqueous fountain solution, ie a fountain solution concentrate containing an isopropyl alcohol surrogate. According to the examples disclosed therein, the dampening fluid additive and the alcohol substitute are added separately (two component system).

In addition, the dampening solution or concentrate contains a hydrotrope to increase the solubility of the surfactant. Thereby, the precipitation of a high proportion of cross-linking agent is prevented. However, the use of these hydrotrope components will upset the ink / water balance as described above.

Further, when the conventional dampening liquid additive and alcohol substitute are used, the dampening liquid must be prepared separately to make such a two-component system very difficult. This is because, in this case, the automatic weighing device cannot be used to perform the above procedure. Each printing house had to prepare appropriately.

US Pat. No. 4,278,467 also describes a fountain solution containing an isopropyl alcohol surrogate. However, this substitute is provided as a two component system. Another problem with formulating dampening fluids that did not contain isopropyl alcohol was that low water-soluble alcohol substitutes were often incompatible with the rest of the formulation and were not miscible.

Attempts have been made to solve this problem by using hydrotropes or emulsifiers. However, it is generally not possible to use such additives in fountain solution circulation systems, as these additives will introduce the difficulties mentioned above.

Regarding the blending of a one-component system which does not contain isopropyl alcohol, butoxyethanol is used as an alcohol substitute at a high concentration (about 1% relative to the volume of the total dampening solution).
% Or more) has a destructive effect on the printing plate,
There was another problem that resulted in excessive premature wear of the printing plate.

In formulating it must also be taken into account that the dampening fluid should only have a certain range of values for the dynamic surface tension.

[0015]

SUMMARY OF THE INVENTION It is therefore an object of the invention to provide print quality which is particularly free of isopropyl alcohol and which does not have the abovementioned disadvantages and which is comparable to the use of isopropyl alcohol. To provide a dampening liquid for offset printing as a component system.

[0016]

The above objects of the present invention are as follows.
The following components: a) 1 to 15% by weight of buffer substances, b) 2 to 20% by weight of one or several substances consisting of water-soluble polysaccharides, polyglycols and polyhydric alcohols. Additives, c) 2-10 wt% preservatives, d) 0.01-5 wt% tertiary acetylene glycol, ethylene oxide surfactants, propylene oxide surfactants, fatty alcohol ethoxylates, fatty acids A nonionic low-foaming surfactant consisting of one or several substances consisting of ethoxylates and siloxane alkoxylates, e) 1 to 35% by weight of the following formula (1) C ₄ H ₉ − _{O [-CH 2 -CH 2 -O]} n -H (1) ( wherein, n represents an integer of 1 to 10) a compound or a mixture of the components of, f) 0.1 to 10 wt% 2-ethyl-1,3-hexane Ol, and g) characterized by comprising essentially from 25 to 90 wt% of water, it is to provide a dampening liquid concentrate. Also, in a particular embodiment of the present invention, the amount of buffer substance is between 5 and 5.
It may be 15% by weight.

In yet another special embodiment of the present invention, especially as a compound of formula (1) C ₄ H ₉ —O [—CH ₂ —CH ₂ —O] _n —H (1) above. Butoxyethanol in an amount of 1 to 12% by weight can be used, as well as butyltriglycol, butyltetraglycol, butylpentaglycol, or mixtures thereof separately. The additive of component b) above may consist of one or several substances consisting of gum arabic, polyethylene glycol and glycerin. This concentrate is a polyhydric alcohol as a solubilizer,
And additives and dyes may be further included.

Another object of the present invention is a dampening liquid containing one of the above-mentioned dampening liquid concentrates, the dampening liquid having a surface tension of 3%.
D) of the fountain solution concentrate so as to be 0 to 50 mN / m
There is provided a fountain solution, characterized in that the components of f) are blended with each other. This is the case for the fountain solution produced in the usual way using the fountain solution concentrate of the invention. Due to the high printing speed, a dynamic method must be chosen to measure the surface tension. Therefore, static surface tensiometers are not suitable.

Examples of the buffer substance include di- and tricarboxylic acids such as citric acid and malic acid; mineral acids such as phosphoric acid;
Alkali hydroxides such as sodium hydroxide; or phosphates such as sodium dihydrogen phosphate or disodium hydrogen phosphate can be used. Water-soluble polysaccharides, polyglycols or polyhydric alcohols also serve especially to protect the printing plate.

As the preservative, for example, isothiazolinone, benzyl alcohol hemiformalin or n-hydroxymethyl-chloroacetamide can be used. Further, the nonionic low-foaming surfactant is, for example,
It is known under the trade name below. That is, Surfynol 104 (tertiary acetylene glycol), Disponil LS2 (fatty alcohol ethoxylates), Marlosol (fatty acid ethoxylates), and the like.

[0021]

EXAMPLES The particularly advantageous effects of the fountain solution concentrate will be described below in more detail with reference to Examples. The reference examples show that the advantageous effects of the subject matter of the present invention can be achieved only by the intended interaction of the individual components of the fountain solution concentrate of the present invention. Example 1 1.3 parts by weight of citric acid, 0.25 parts by weight of disodium hydrogen phosphate, 0.3 parts by weight of sodium hydroxide, 5 parts by weight of glycerin and 3 parts by weight of preservative Parmentol. ) A compound such as K50 ™ was dissolved in 66.2 parts by weight of water. To this was added 4 parts by weight butoxyethanol, 3 parts by weight 2-ethyl-1,3-hexanediol and 0.05 parts by weight of the surfactant mixture of component d).

Next, 1.2 kg of this mixture was added to 28.8 kg.
This fountain solution is mixed with water and poured into the circulation device of a Heidelberger Speedmaster type two-color sheet printing machine, the temperature is stabilized at about 12 ° C, and printing is performed using the following materials. The test was conducted.

Ink: Universa 6000 ™; Hostmann-Steinbe
rg) Printing plate: Anodized, T7 type plate stand; Eggen (Eg
gen) paper: CRS (MD double-sided coated paper) As a result, no technical printing-related problems such as background stain, piling, ink bleeding or dampening solution foaming occurred. Even after a long period of time, for example 3 weeks, obviously high quality prints could still be produced without any technical printing-related problems. Example 2 Compounds such as 1.5 parts by weight citric acid, 0.4 parts by weight disodium hydrogen phosphate, 6 parts by weight glycerin and 3 parts by weight preservative Permentol K50 ™ are 66.2.
Dissolved in parts by weight of water. 8 parts by weight of 2-ethyl-
1,3-Hexanediol, 2 parts by weight butoxyethanol and 0.01 parts by weight of the above surfactant mixture were added.

Next, 1.3 kg of this mixture was mixed with 28.7 kg of water and this mixture was used as described in Example 1 and printing tests using the same materials as in Example 1. When a water content of 30 to 50% was obtained, a high-quality printed matter obtained by the dampening liquid of the present invention was obtained. Example 3 1.1 parts by weight citric acid, 0.2 parts by weight disodium hydrogen phosphate, 0.1 parts by weight sodium hydroxide, 7 parts by weight glycerin and 4 parts by weight preservative Permentol K.
Compounds such as 50 ™ were dissolved in 63.8 parts by weight of water. To this was added 6 parts by weight butoxyethanol, 4 parts by weight 2-ethyl-1,3-hexanediol and 0.02 parts by weight of the above surfactant mixture.

Next, 1.9 kg of this mixture was mixed with 28.1 kg of water, this mixture was used as described in Example 1 and printing tests using the same materials as in Example 1. When a water content of 30 to 50% was obtained, a high-quality printed matter obtained by the dampening liquid of the present invention was obtained. Example 4 1.8 parts by weight of malic acid, 0.35 parts by weight of disodium hydrogen phosphate, 2 parts by weight of gum arabic and 3 parts by weight of a compound such as the preservative Permentol K50 ™ 66.
Dissolved in parts by weight of water. To this was added 3 parts by weight butoxyethanol, 2 parts by weight 2-ethyl-1,3-hexanediol and 0.03 parts by weight of the above surfactant mixture.

Next, 2 kg of this mixture was mixed with 28 kg of water, and this dampening solution was added to Roland Rekord.
It was poured into a circulation device of a mold type two-color sheet printing machine, the temperature was stabilized at about 13 ° C., and a printing test was conducted using the same material as in Example 1, and it was 30 to 50%. At a water content ratio of 1, the high-quality printed matter obtained by the dampening liquid of the present invention was obtained. Example 5 1.3 parts by weight citric acid, 0.25 parts by weight disodium hydrogen phosphate, 0.3 parts by weight sodium hydroxide, 5 parts by weight glycerin and 3 parts by weight preservative Permentol K50 ( Trademark) and other compounds were dissolved in 66.2 parts by weight of water. 4 parts by weight of butyltriglycol, 3 parts by weight of 2-ethyl-1,3-hexanediol and 0.0
5 parts by weight of the component d) surfactant mixture were added.

Next, 1.2 kg of this mixture was mixed with 28.8 kg of water, and this dampening solution was poured into the circulation device of a Heidelberg Speedmaster type two-color sheet printing machine, and the temperature thereof was set to about 12 ° C. After being stabilized, a printing test was conducted using the following materials.

Ink: ALPHA 4300 Printing plate: Alumite, T7 type plate (made by Eggen) Paper: Art paper with basis weight of 100 g / m ^{2 In} this case, no technical printing-related problems occur and it is long. Even after a period of time, for example 3 weeks, it was possible to still produce clearly high-quality prints without any technical printing-related problems.

Example 6 1.3 parts by weight citric acid, 0.25 parts by weight disodium hydrogen phosphate, 0.3 parts by weight sodium hydroxide, 5 parts by weight glycerin and 3 parts by weight preservative pers. A compound such as menthol K50 ™ was dissolved in 66.2 parts by weight of water. To this was added a mixture of 6 parts by weight 70% butyl triglycol, 20% butyl tetraglycol and 10% butyl pentaglycol, 3 parts by weight 2-ethyl-.
1,3-Hexanediol and 0.05 parts by weight of the surfactant mixture of component d) were added. Next, 1.2 kg of this mixture was mixed with 28.8 kg of water, and the dampening solution was poured into the circulation device of the Heidelberg Speedmaster type two-color sheet printing machine, and the temperature was stabilized at about 12 ° C. A printing test was performed using the following materials.

Ink: REFLECTA FW 8000 Printing plate: Alumite, T7 type printing plate (manufactured by Eggen) Paper: Phoenogrand, basis weight 135 g /
m ^{2 In} this case too, no technical printing-related problems occur, and still after a long period of time, for example 3 weeks, still producing clearly high-quality prints without any technical printing-related problems. I was able to do it. Reference Example 1 1.3 parts by weight of citric acid, 0.25 parts by weight of disodium hydrogen phosphate, 0.3 parts by weight of sodium hydroxide, 5 parts by weight of glycerin and 3 parts by weight of preservative Permentol K50 ( Trademark) and other compounds are dissolved in 38 parts by weight of water, and 4 parts by weight of butoxyethanol are added thereto,
1.2 kg of this mixture was mixed with 28.8 kg of water.

A print test was then carried out using the same procedure as in Example 1, but the prints obtained were not of satisfactory quality. Even at maximum water ratios equivalent to 100% (about 30% based on isopropyl alcohol), technical printing-related problems, i.e. scumming, occurred. Reference Example 2 1.3 parts by weight citric acid, 0.25 parts by weight disodium hydrogen phosphate, 0.3 parts by weight sodium hydroxide, 5 parts by weight glycerin and 3 parts by weight preservative permenthol.
A compound such as K50 (trademark) is dissolved in 38 parts by weight of water,
To this was added 3 parts by weight of 2-ethyl-1,3-hexanediol and 1.2 kg of this mixture was mixed with 28.8 kg of water.

A printing test was then carried out using the same procedure as in Example 1, but the prints obtained were not of satisfactory quality. That is, even at the maximum water ratio, this dampening solution produced only soil. Reference Example 3 1.3 parts by weight of citric acid, 0.25 parts by weight of disodium hydrogen phosphate, 0.3 parts by weight of caustic soda, 5 parts by weight of glycerin and 3 parts by weight of preservative Permentol K50.
Compounds such as (trademark) were dissolved in 38 parts by weight of water.

To this was added 0.25 part by weight of a tertiary acetylene glycol, EO surfactant, PO surfactant, fatty acid ethoxylates and fatty alcohol ethoxylates. Then, 1.2 kg of this mixture was mixed with 28.8 kg of water.

Printing tests were then carried out using the same procedure as in Example 1, but this dampening solution did not give satisfactory printing quality. Even at the maximum water content ratio, not only scumming but also ink loss was recognized.

[0035]

EFFECTS OF THE INVENTION According to the present invention, isopropyl alcohol, which is useful for environmental protection, workplace hygiene and cost reduction, does not contain isopropyl alcohol, does not cause disadvantages such as scumming and ink loss, and still uses isopropyl alcohol. It is possible to obtain a print quality equivalent to that of the case, and to provide a dampening liquid for offset printing which is a one-component system.

 ─────────────────────────────────────────────────── ─── Continued Front Page (71) Applicant 592144973 Hostman-Steinberg Gezershaft Mitt Beschlenktel Hoftong Germany Day-3100 Celle Bremerweg 125 (72) Inventor Fritz Raufs Germany 3101 Aensbeck Pommerweg 9

Claims (8)

[Claims] 1. A) 1 to 15% by weight of buffer substances, b) 2 to 20% by weight of one or several substances consisting of water-soluble polysaccharides, polyglycols and polyhydric alcohols. Additives, c) 2 to 10% by weight of preservatives, d) 0.01 to 5% by weight of tertiary acetylene glycol, ethylene oxide-based surfactants, propylene oxide-based surfactants, fatty alcohol ethoxylates, fatty acids A nonionic low-foaming surfactant consisting of one or several substances consisting of ethoxylates and siloxane alkoxylates, e) 1 to 35% by weight of the following formula (1) C ₄ H ₉ − _{O [-CH 2 -CH 2 -O]} n -H (1) ( wherein, n represents an integer of 1 to 10) compounds or mixtures of those components, f) from 0.1 to 10 wt% 2-ethyl-1,3 Hexanediol, and g) wherein the comprising essentially 25 to 90% by weight of water, fountain solution concentrate. 2. The dampening liquid concentrate according to claim 1, wherein the amount of the buffer substances is 5 to 15% by weight. 3. Butoxyethanol is contained as a component in the formula (1) C ₄ H ₉ —O [—CH ₂ —CH ₂ —O] _n —H (1), The dampening liquid concentrate according to claim 1 or 2. 4. A fountain solution concentrate according to claim 3, characterized in that the concentrate contains 1 to 12% by weight of butoxyethanol. 5. The fountain solution concentrate according to claim 1, wherein the additive comprises one or several substances consisting of gum arabic, polyethylene glycol and glycerin. .. 6. The dampening liquid concentrate according to claim 1, wherein the concentrate further contains a polyhydric alcohol. 7. A fountain solution containing the fountain solution concentrate according to claim 1, wherein the fountain solution concentrates d) to f) are added to the fountain solution concentrate. A dampening liquid, characterized in that the liquids have a surface tension of 30 to 50 mN / m and are mixed together. 8. Use of the dampening liquid concentrate according to claim 1 or the dampening liquid according to claim 7 in offset printing.