JPH0689281B2 - Ink cleaner for printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is intended for washing and cleaning ink adhered to rollers and blanket cylinders of a printing machine, particularly an rosin-modified alkyd resin and an offset printing machine using an ink containing a maleic acid resin as a main component. Ink cleaning agent.

In printing with an offset printing machine, the non-image area of the printing master that has an ink-receptive image on its surface is converted to hydrophilic by using an etching solution, and then the ink is attached to the image area of the printing master. Printing is accomplished by transferring to a blanket cylinder and then from the blanket cylinder to the paper to be printed.

When the necessary printing is finished and another printing is performed again, the blanket portion of the printing machine must be washed with a cleaning agent to remove the ink and the etching liquid residue. It is also common practice to terminate the ink roller after the completion of the work for one day.

The ink cleaning agent used here is of course required to have a dissolving power, but offset printing is often performed in a place where ventilation is relatively poor, such as an indoor corner or a small room. The person in charge is often performed by a very limited number of people, so it is desirable that the person with minimal toxicity be used.

Conventionally, as an ink cleaning agent for a printing machine, a kerosene fraction of petroleum, which is a hydrocarbon solvent, has been used as a main component, and chlorinated hydrocarbons such as tetrachloroethylene and 1,1,1-trichloroethane,
Alternatively, those containing chlorinated fluorinated hydrocarbons such as 1,1,2,2-tetrachloro-1,2-difluoroethane are widely used. In particular, a chlorine-based solvent such as tetrachloroethylene or 1,1,1-trichloroethane has a strong ink-dissolving power and is an excellent component for an ink cleaning liquid, but has a strong odor and toxicity, which leaves a problem.

As another means, a kerosene fraction is used as the main agent of the detergent, and the amount of aromatic hydrocarbons in the kerosene fraction, which is the main agent, can be increased to improve the ink dissolution performance. However, increasing the aromatic hydrocarbon content is not preferable from the viewpoint of odor and toxicity.

In recent years, as the automation of offset printing machines has advanced, operability has improved, and the number of printed sheets from one plate has decreased,
Now that you can print from many plates per day,
In particular, the amount of ink cleaning agent used has increased, and at the same time, the problems of odor and toxicity have been highlighted, and improvements in these are strongly desired.

The present invention has been made to solve the above-mentioned drawbacks, and in particular has an extremely low odor and toxicity, excellent ink solubility, and an object of the invention to provide a good drying ink cleaner for a printing press. There is.

That is, the present invention is called an odorless solvent in the kerosene fraction of petroleum, and contains almost no aromatic hydrocarbons, but a solvent composed of paraffinic and naphthenic hydrocarbons is added to dipropylene glycol monomethyl ether, 3-methoxy. The present invention relates to an ink cleaning agent for a printing machine, which is obtained by mixing 5 to 60 volume partstone with one or more of butanol and 3-methyl-3-methoxybutanol.

The kerosene-based odorless solvent is obtained by subjecting petroleum kerosene fraction to hydrogenation or the like to remove unsaturated hydrocarbons, and is widely available as a commercial product. For example, as a kerosene solvent that does not contain aromatic hydrocarbons at all, or contains very little (0.4 vol% or less), IP Solvent 10
16, IP Solvent 1620, IP Solvent 2028 (all manufactured by Idemitsu Oil Co., Ltd.), Isopar E, Isopar H, Isopar G
(Made by Exxon Co., Ltd.), Cielsol 340, Ciesol 1
40, a large number of products such as Mineral Subit EC (all manufactured by Ciel Oil Co., Ltd.) are commercially available. In the present invention, what is called a kerosene fraction or an odorless solvent, which seems to be clear, means a kerosene solvent having a low aromatic hydrocarbon content as described above.

The cleaning agent of the present invention comprises these odorless solvents as one component, and one or two kinds of dipropylene glycol monomethyl ether, 3-methoxybutanol or 3-methyl-3-methoxybutanol for improving the ink cleaning power. The above is mixed, and the mixing amount of these polyhydric alcohol derivatives is 5 to 60% by volume. If it is less than 5% by volume, the detergency is insufficient and the printed matter is contaminated when the next printing is performed after cleaning, and if it exceeds 60% by volume, the detergency is decreased at the same time. This is because the drying property of the cleaning liquid is poor and the ink is not sufficiently deposited on the blanket cylinder during the next printing process, resulting in a low image density of the printed matter at the initial stage of printing. And, as can be seen from the examples described below, the most desirable mixing amount range is 15% by volume.
To 50% by volume.

Among the polyhydric alcohol derivatives, the reason why these three, namely dipropylene glycol monomethyl ether, 3-methoxybutanol and 3-methyl-3-methoxybutanol equivalent were carefully selected and specified, must meet the following conditions. by. That is, a, it can be mixed with an odorless solvent, b, it can improve the dissolving power of ink, c, it has a minimum of odor, d, it has low toxicity and does not touch laws such as organic law, e, it has low flammability. F, moderately dry, evaporation of odorless solvent, no difference in dryness, g, no adverse effects on rubber or resins of printing machine rollers and blanket cylinders, A low and stable supply, a slight fragrance odor, as found in Li, 3-methoxybutanol and 3-methyl-3-methoxybutanol, etc. The characteristics of the three compounds do not change even if they are used together.

The ink cleaning agent for a printing machine of the present invention, which uses a polyhydric alcohol derivative meeting these conditions, has excellent ink cleaning power and drying property, and has almost no odor and is not toxic.

Example 1 Idemitsu Petroleum IP Solvent 16 was used as an odorless solvent for kerosene fraction.
20 and Isoxon G manufactured by Exxon were selected. These solvents have a low aromatic hydrocarbon content of 0.2 vol% or less,
Therefore, since these alone have a low performance as an ink cleaning agent for a printing machine, dipropylene glycol monomethyl ether was mixed with this as shown in Table 1 and used.
When the blanket cylinders and rollers of the offset printing machine [AP-2600 manufactured by Ricoh Co., Ltd.] were cleaned using the cleaning liquids No. 1 to 30 thus prepared, the results shown in Table 2 were obtained. It was

The judgment was made according to the following criteria.

A: Sufficient detergency was visually observed.

◯: Detergency having no practical problem was visually observed.

Δ: Cleaning is time-consuming and not practical. Or the cleaning power was insufficient and ink stains were confirmed on the next printed matter.

Example 2 In place of the dipropylene glycol monomethyl ether of Example 1, 3-methoxybutanol and 3-methyl-3-methoxybutanol were added, respectively, and roller cleaning, blanket cleaning and printing test were carried out. The results were obtained.

Example 3 Idemitsu Petroleum IP Solvent 1620 was selected as the odorless solvent,
Dipropylene glycol, 3-methoxybutanol and 3-methyl-3-methoxybutanol were mixed with this as shown in Table 3 and subjected to the operation.

Using the samples No. 31 to 44 thus prepared, the blanket cylinder cleaning and the roller cleaning were performed in the same manner as in Example 1, and good results were obtained as shown in Table 4. The criteria for determination are the same as in the example.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Minor Kanazawa 6-14-6 Ginza, Chuo-ku, Tokyo Sanaiishi Oil Co., Ltd. (72) Tadashi Yoshihara 6-14-6 Ginza, Chuo-ku, Tokyo Sanai Within Ishi Oil Co., Ltd. (56) Reference JP-A-59-176398 (JP, A)

Claims (1)

[Claims] 1. A printing comprising (a) a kerosene fraction and (b) 5-60% by volume of dipropylene glycol monomethyl ether, 3-methoxybutanol and 3-methyl-3-methoxybutanol. Machine ink cleaner.