JPH02196696A - Damping water composition and printing method - Google Patents

Abstract

PURPOSE:To reduce the use amount of a chemical agent and to perform printing generating no environmental pollution by using a specific surfactant as the component of damping water. CONSTITUTION:Damping water to be used is based on water and a nonionic surfactant having HLB of 11-13. The nonionic surfactant is composed of an ethylene oxide additive of octylphenolor aliphatic alcohol or sorbitol ester, and one having HLB of 11-13 independently and one whose HLB enters a range of 11-13 by mixing can be used. When the HLB of the surfactant in damping water is below 11, the wettability with a non-image part becomes insufficient and the water emulsifying amount of ink increases while a printing density is lowered and, when HLB exceeds 13, the wettability with the non-image part becomes bad and ink becomes easy to emulsify with water and spot like stain is generated on the non-image part.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a dampening solution and a printing method using the same, and more particularly to a dampening solution composition and a printing method that do not cause stains on printed matter or various other troubles. .

(Prior Art and Problems Thereof) Various printing methods have been widely used in the past, and the most widely used method among them is the lithographic printing (offset) method.

This lithographic printing method uses a printing plate on the surface of a photosensitive aluminum plate, etc., on which a lipophilic image area to which printing ink adheres and a hydrophilic non-image area to which printing ink does not adhere are formed by photolithography. . This printing plate is wound around a plate cylinder, contacts an ink supply roll, and printing ink is supplied from the ink roll, but at this time, the ink adheres only to the image area and does not adhere to the non-image area. In addition, water called dampening water is supplied to the printing plate in advance. This water forms a uniform thin film on the non-image areas, and this water film prevents ink from adhering to the non-image areas.

Such dampening water is required to have an appropriate surface tension, and conventionally, an aqueous solution of isopropyl alcohol has been used.

However, this aqueous solution of isopropyl alcohol has a concentration of about 5% by weight, and in a large printing factory, it is several hundred kg (as isopropyl alcohol) per day.
This is also a big problem in terms of printing costs. Furthermore, since almost all of this dampening water eventually evaporates into the air, it poses a considerable environmental hygiene problem not only for the working environment but also for the outside world.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a dampening solution composition that is low in cost and does not contaminate the working environment or the external environment, and a printing method using the same.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention provides a dampening solution composition comprising water and a surfactant, wherein the surfactant is a nonionic surfactant with an HLB of 11 to 13; In a printing method using a printing plate having a non-printing area, applying oil-based ink to the printing area and applying dampening water to the non-printing area, the dampening water contains water and a surfactant. This is a printing method characterized in that the surfactant is a nonionic surfactant with an HLB of 11 to 13.

(Function) By using a specific surfactant as a component of dampening water, cost issues, environmental hygiene, and environmental pollution issues can be solved, and printing can be performed without causing various problems such as scumming. becomes.

(Preferred Embodiments) Next, the present invention will be explained in more detail using preferred embodiments.

The dampening solution used in the present invention is characterized by containing water and nonionic surfactants HLBll to No. 13 as main components.

The nonionic surfactants used in the present invention include ethylene oxide adducts of octylphenol, ethylene oxide adducts of aliphatic alcohols, sorbitol esters, etc., and stiff nonionic surfactants are all known.

In the present invention, among these nonionic surfactants, those having an HLB in the range of 11 to 13 are selected and used.

As these suitable nonionic surfactants, those having HLB11 to 13 can be used alone, and although they do not fall within the HLB range of 11 to 13 alone, when mixed, the HLB of 11 to 13 can be used. Anything within this range can be used as well.

For example, Nonion NS-208, 5 (HLB manufactured by NOF Corporation) has an HLB of 11 to 13.
B-12,6), nonionic 5H-206 (HLB-1
1,2), Lion Corporation's Reocol 5C-70 (formerly, B-12,0), Revox N C-70 (1
1LB-11,9), Dopanox DL-0415 (H
LB-13,0), and the mixed system is Nonionic NS-204,5 (HLB-9,5)/Nonionic NS212 (HLB-14,1) (HLB-12
, 0), Reocol SC-120 (HLB-14,
5) /Leocol 5C-30 (HLB-7,9)
(HLB-12,8), nonionic N5-204,
5 (HLB-9,5) /Liponox NC-140
()ILB-14,7) /Liponox QC-20(
HLB-6,0) (HLB-11,2) and the like.

If the HLB of the surfactant in dampening water is less than 11, wetting with non-image areas will be insufficient, and there will be problems such as an increase in the amount of water emulsified ink and a decrease in printing density. On the other hand, if the HLB exceeds 13, wetting with non-image areas becomes poor and the ink tends to emulsify in water.
This is not preferable because problems such as dotted stains occur in non-image areas.

All of the above nonionic surfactants are known and can be obtained from the market and used in the present invention. Further, the present invention is not limited to the above-mentioned nonionic surfactants as long as the HLB is in the range of 11 to 13 either alone or as a mixture.The water used in the present invention is ordinary water, for example, Industrial water, drinking water, underground water, distilled water, etc. can all be used, and there is no particular limitation. It is economical for the concentration of these water-soluble surfactants to be about 0.5 to 20% by weight during production, and to a concentration of about 0.001 to 0.5% by weight during use. It is preferable to use it diluted.

The dampening solution composition of the present invention has the above-mentioned components as essential components,
It can also contain other hydrophilic substances such as gum arabic, boric acid, sodium phosphate, tartaric acid, inorganic salts, anionic activators, cationic activators, amphoteric activators, and other additives, and the pH at the time of use is The pH varies depending on the printing method; for example, in the case of a Morton water supply method or continuous water supply method in a sheet-fed printing press, the pH is often controlled to a weak acidity in the range of 4.5 to 6; In many cases, the pH is adjusted to be slightly alkaline, such as within the range of 7 to 10. Many organic acids,
Inorganic acids, alkalis, and buffers are used.

The printing method of the present invention is characterized by using the dampening water as described above, and can be used in conventional lithographic printing, lithography, zinc plates, negative plates of aluminum plates, positive plates, paper plates, etc.
Any system that has a lipophilic image area and a hydrophilic non-image area as a printing plate and uses dampening water in the hydrophilic non-image area can be used in the present invention.

(Effects) According to the present invention as described above, by using a specific surfactant as a component of the dampening solution, only a small amount of the chemical can be used, and the components that evaporate into the air are avoided for people other than people. Because there is no
The problems of cost, environmental hygiene, and environmental pollution can be solved, and printing can be performed without causing various troubles such as scumming.

(Example) Next, the present invention will be explained in more detail by giving examples and comparative examples.

The dampening water compositions shown in Table 1 below were prepared, and the following tests were conducted on these dampening waters to obtain the results shown in Table 2 below.

Kuinmachi Roland PRAKTIKA Kikushi cutting machine, dot fraction 100% (solid printing), 90%, 80%, 70%, 60
%, 50%, 40%, 30%, 20%, or 10% and non-printing (0% halftone) bands were arranged alternately in the circumferential direction. Commercially available black ink was placed in an ink bottle, and dampening water shown in Table 1 below was placed in a water cannon.

Print speed 6.00 on art paper 93.5kg/ream
Printing was carried out at 0 sheets/hour so that the printing density of the solid printing portion was 2.0 (the obtained printed matter is designated as A). Based on these conditions, the amount of dampening water supplied was reduced to a minimum, and 300 sheets were printed under conditions where stains were generated (the printed matter obtained in this process is referred to as B).

The amount of dampening water supplied was returned to the original level, 500 sheets were printed, and then the printing was interrupted (the resulting printed material is designated as C). After 30 minutes, printing was restarted under the same conditions and 300 sheets were printed (the obtained printed matter is referred to as D).

The halftone dot fractions of the above prints A, B, C and D were measured, and the halftone dot reproducibility was examined based on the thickness of the halftone dots and the magnitude of its fluctuation. The stains in the non-image areas were checked for the presence or absence of ink adhesion, and after the print quality was obtained, the presence or absence of ink adhesion to the dampening water supply system roll was examined to evaluate the printing suitability of the dampening water composition.

(Margins below) Niga L”-” Kai Niki Example 1 No Nisai: /NS-208,512,60,0
5 Example 2 1ft>hsc-70 12,0 0,02 Example 3 Liponox NG-70 11,9 0,05 6,415 6,420 6,2223 Liponox QC-20 6,0 0, Ol Two Fang L ≦ Ri” Mr. 2 ([1 total 9 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 None None None None None None None None None None None None None Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Liponox Tartrate NG-140 )Nion NS-204,5 71'jt&imA Fl&l, Bo, ooa 14.7 0,05 9.5 0.02 Example 1O Example 11 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 None No Yes Yes Yes No No No No No Yes No No

Claims (4)

[Claims] (1) Consists of water and a surfactant, and the surfactant is HL
A dampening solution composition characterized by being a nonionic surfactant B11 to B13. (2) The dampening water composition according to claim 1, which has a pH in the range of 4 to 10. (3) The dampening solution composition according to claim 1, wherein the concentration of the surfactant is in the range of 0.001 to 20% by weight. (4) A printing method using a printing plate having a lipophilic image area and a hydrophilic non-image area, applying oil-based ink to the image area and dampening water to the non-image area, A printing method characterized in that the dampening solution comprises water and a surfactant, and the surfactant is a nonionic surfactant with an HLB of 11 to 13.