JPH01108280A - Drying agent for lithographic ink - Google Patents

Abstract

PURPOSE:To obtain the title drying agent which provides an excellent efficiency in drying an ink under high humidity conditions due to water for moistening, by using a water-insoluble metal peroxide as its principal constituent. CONSTITUTION:The title drying agent is obtained by using a water-insoluble metal peroxide such as CaO2, BaO2 or MgO2 as its principal constituent. 100pts. wt. lithographic ink is mixed with 1-10pts.wt., preferably 2-6pts.wt., this drying agent and, if required, other drying agents.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a desiccant for lithographic printing ink, and more specifically, by mixing it into lithographic printing ink, the drying agent can be used to dry the ink under high humidity caused by dampening water. It relates to a desiccant used for drying.

[Conventional technology]

Fatty acid salts of lead, manganese, and cobalt or borates have conventionally been used as desiccants for lithographic oil-based inks that are dried by oxidative polymerization of drying vegetable oils. Among these, cobalt is mainly responsible for drying the surface of the ink film, lead is responsible for drying the bottom layer, and manganese is generally responsible for drying the intermediate layer, and it is true that the combination of these works as a catalyst for drying a well-balanced ink film. It is. However, since lithographic printing uses dampening water, moisture remains on the surface or inner layer of the printing material, and even if various drying agents have been used in the past,
The current situation is that this moisture significantly reduces the drying speed of ink, frequently causing problems such as deterioration in the quality of printed matter and delays in delivery.

[Problem that the invention seeks to solve]

In order to completely eliminate the quality deterioration that occurs due to delayed drying of ink, such as chalking, poor gloss, poor friction resistance, etc., as well as delivery delays, we have developed As a result of continuing research to develop a desiccant that can sufficiently dry even in humid conditions, the present invention was completed.

[Means for solving problems]

This problem is solved by using water-insoluble metal peroxides as drying agents for lithographic printing inks.

The present inventor has discovered that by mixing a compound that releases oxygen and an oxidizing agent upon contact with water, that is, an insoluble metal peroxide, into an oil-based ink for lithographic printing, the ink drying rate is significantly increased due to the action of the released oxygen and oxidizing agent. A particularly significant feature of this study is that the presence of water further accelerates drying.

[Structure and operation of the invention]

The metal peroxide used in the present invention can be widely used as long as it is water-insoluble, and typical examples include barium peroxide, magnesium peroxide, calcium peroxide, etc. It is not limited to metal.

The formation mechanism of oxygen and oxidizing agents that occur in the presence of water, that is, when these metal peroxides contain dampening water in lithographic printing, is expressed by the following reaction formula. itself acts as an oxidizing agent, but since it is a fairly stable compound, it tends not to act as an oxidizing agent unless heated. Hydrogen peroxide is generated with water and this product acts as an oxidizing agent. It is more effective to do so.

In this way, the present invention uses drying vegetable oil, which is the main component of oil-based ink for lithographic printing, through oxidative polymerization using the synergistic effect of H, Ot as oxidizing agents generated by the action of water from the metal peroxide, and free 02 gas. It is extremely effective in drying.

The drying agent of the present invention is usually blended in an amount of about 1 to 10 parts by weight, preferably about 2 to 6 parts by weight, per 100 parts by weight of the lithographic printing ink.

The method of using the desiccant of the present invention is the same as that of conventional desiccants of this kind, and it may be blended in advance when preparing the ink, or may be blended into the ink during printing.

Furthermore, the desiccant of the present invention can not only be used alone, but also in combination with conventional desiccants.

<Example> Example 1-3 100 parts by weight of lithographic printing ink rNo. 2 Super light-fast red for synthetic paper (manufactured by Toka Shiki Kagaku Kogyo Hata) was mixed with the desiccant shown in Table 1 in a predetermined ratio and uniformly mixed. It was kneaded.

Comparative Example 1 A predetermined amount of the corrected drying agent shown in Table 1 was added to the same ink as in Example 1 and thoroughly kneaded.

However, "rUG dryer" in Table 1 is a conventionally used drying agent manufactured by Godo Ink (■). Also C
a0z 'N025J, Bang and Mg0z'
NO2O'' are all manufactured by Tomita Pharmaceutical ■.

Test-1> Each of the above inks was applied to high-quality paper and synthetic paper "Yubo" with an ink film thickness of 2μ using a color spreader called R1 Tester (manufactured by Mei Seisakusho).
(manufactured by Tamago Yuka Co., Ltd.). Each developed color sample was immediately cut in half, one half was dried in an oven in an anhydrous state, the other half was fully hydrated, and each was inserted into a plastic bag and sealed, and the drying time was measured. . The ambient temperature in all cases was room temperature (22°C). These results are shown in Table 2.

Table 1 Table 2 As is clear from Table 2 above, in Comparative Example 1 using only the conventional dryer, the drying time was significantly delayed in the water-containing state, whereas in Examples 1 to 3 of the present invention, the drying speed was remarkable in the water-containing state. is promoted. Example 2, especially using barium peroxide
The drying speed of the ink is extremely fast.

Test-2> All the drying data shown in Test-1 is complete drying data in which the tackiness (aftertack) of the ink film has completely disappeared. The problem of set-off that occurs when printing substrates are piled up immediately after printing is dominated by finger contact drying (setting) of the printing ink. For each ink immediately after color spreading in the same way as in Test-1, use the R1 tester to apply the results to the surface of high-quality paper with white high-quality paper overlaid on the colored side, and the white synthetic paper overlaid on the colored side of synthetic paper waste using the R1 tester. A rubber roll with a hardness of 70 degrees and a diameter of 65 m was rolled intermittently in 10 minute increments, and while water was occasionally added to moisten the paper, the state of set-off onto the white paper was observed. The applied pressure is a linear pressure of 12 thresholds. The end point of dryness to the touch was defined as the point at which no set-off occurred, and the results are shown in Table 3.

Table 3 <Effects of the Invention> The peroxide used in the present invention further improves the efficiency of ink drying compared to conventional dryers. It is extremely effective in eliminating all problems (aptitude).

(Above) Patent applicant King Printing Co., Ltd. Procedural amendment (voluntary) 1.! Indication of IC case 1988 Patent Application No. 267462 2 Name of the invention Desiccant for lithographic printing ink 3 Relationship with the person making the amendment Patent applicant address
2-7-16 Tamade Nishi, Nishinari-ku, Osaka Name: King Printing Co., Ltd. President Taku Tsumura 4, Agent: 25 Yachiyo Building South Building, 1-1 Minamimorimachi, Kita-ku, Osaka 530! 06 (314) Item 6 of the Detailed Description of the Invention in Specification No. 0248, Contents of the Amendment The amendment is made as shown in the attached sheet.

Contents of amendment (1) "Correction" in line 5 on page 5 of the specification is amended to read "prescribed."

that's all

Claims (1)

[Claims] Desiccant for lithographic printing ink containing water-insoluble metal peroxide as main component