JPS62143984A - Printing ink - Google Patents

Abstract

PURPOSE:A printing ink, containing a specific amount of spherical particles of a specified resin or wax having a specific particle diameter, having good paper releasing property from a blanket and stacking property of printing paper and capable of giving strong printed and coated surfaces for sheet offset printing. CONSTITUTION:A printing ink obtained by incorporating 0.1-20wt% spherical particles of a resin or wax housing 0.1-30mum average particle diameter without dissolving or swelling in an ink in a sheet offset ink.

Description

Detailed Description of the Invention Object of the Invention (Industrial Field of Application) The present invention provides a sheet-fed offset ink that has a strong printing film surface with good paper release properties from a printing paper blanket and stacking properties. Regarding printing ink that gives

(Prior Art) Printed matter printed by a sheet-fed offset printing machine is sometimes output as is, either stacked or framed.

In some cases, printed matter is irradiated with infrared rays to prevent it from sticking, or after a small amount of starch is sprinkled on the printed matter, the printed matter is delivered in stacks or frames. Misregistration problems that occur with sheet-fed offset printing on sheet-like paper are caused by the expansion and contraction of the paper.

This is especially likely to occur during process printing. In addition, since the printed ink is discharged in stacks in an undried state, there are many problems with backing. Poor registration and backing both significantly reduce product value.

As a means to prevent registration errors, 1. Change to paper with a different papermaking direction. ■Season the paper. ■Re-make the plate based on the first color. ■Lower the ink tack.

Improves paper planke/gutter separation. There are other methods. However, dealing with the paper aspect of ■ and ■ causes a delay in delivery, and redoing plate making based on the first color of ■ is less accurate because the expansion and contraction ratio differs depending on the paper. In addition, tack-down of ink (■) causes stains and printing troubles, both of which are undesirable.

On the other hand, the means to prevent backing problems are: 1) Sprinkling fine powder such as starch on the printed surface to make it difficult to adhere to it, and 2) Expediting the drying of the printed coating surface by irradiating it with infrared rays. ■ Framing is done to reduce the total load on the printed coating surface. ■Fine particles with various shapes. There is a method of adding so-called amorphous wax particles, starch particles, etc. to the ink. However, the spraying of starch etc. in (■) tends to cause problems during printing and polishing on the back side, and the infrared irradiation (ii) increases running costs. Furthermore, the framing shown in (■) increases the amount of work for the printing press operator and is also problematic in terms of safety. With the method (2), gloss tends to be a problem, and paper fading resistance is not necessarily improved.

(Problem to be solved by the invention) Therefore, the printing ink produced in two-sheet offset printing has good paper texture from the blanket, excellent stability in register accuracy, good stackability, and easy drying. There was a desire for an ink that would provide a strong printed coating surface.

"Structure of the Invention" (Means for Solving the Problems) The present invention provides sheet-fed offset ink with a resin or wax that does not melt or swell in the ink, with an average particle size of 0.
This is a printing ink containing 0.1 to 20% by weight of spherical particles of 1 to 30 μm.

The resin and/or wax particles used in the present invention are preferably spherical, ellipsoidal, or nearly spherical. In addition, the single spherical particles of resin and/or wax include known resins such as nylon, vinyl, silicone, epoxy, olefin, and styrene resins, natural waxes, paraffin waxes, polyolefins, and their oxides and derivatives. Examples include one type or a mixture of two or more types of well-known Wa Nox, etc., which are spherical and have an average particle size of 0.1 to 30 μm.

In addition, these resins or waxes are the solvent in the ink,
A material that does not melt or swell with oil or the like is used; if it melts or swells, it is unfavorable in terms of gloss and paper texture.

In terms of average particle size, if it is smaller than 0.1 μm, paper fading from the blanket cannot be improved, and if it is larger than 30 μm, it causes plate residue or blanket residue during printing.

Further, if the amount added is less than 0.1% by weight, the paper texture from the blanket cannot be improved, and if it is more than 20% by weight, the fluidity of the printing ink will be impaired, which is not preferable.

The sheet-fed offset ink according to the present invention is made of rosin-modified phenol resin 1 petroleum resin and alkyd 7 resin.

Or 20 to 50% by weight of these drying oil-modified resins, O to 60% by weight of drying oil such as linseed oil, tung oil, soybean oil, etc.
%, normal paraffin, isoparaffin, naphthene,
Solvents such as α-olefins or mixtures thereof 10~
60% by weight, and 0 to 60% by weight of additives such as organic pigments, inorganic pigments, extender pigments, dryers, and drying inhibitors.

The printing ink of the present invention can be used not only as a sheet-fed offset ink but also as a single-fed letterpress ink, a metal plate ink, and a non-heat off-wheel ink.

This will be explained below using examples. "Parts" in the text indicate parts by weight.

Example I Finevar 3000F for 100 parts of TK New Bright (Toyo Ink Manufacturing ■: sheet-fed offset ink)
(Sumiman Kagaku Kogyo ■: Polystyrene, true spherical particles with an average particle size of 6 μm) were mixed in a high-speed mixer to prepare Ink-1.

Example 2 Orgasy/shi2 for 100 copies of TK New Bright
Example 3 Ink-2 was prepared by mixing 3 parts of EXDNAT (Japan Rilsan LnJ: 12 nylon, spherical particles with an average particle size of 10 μm) using a high-speed mixer.
(Toshiba Silicone @: Silicone resin, average particle size 2 μm
(spherical particles) were mixed using a high-speed mixer to prepare Ink-3.

Example 4 1 part of Miperon XM220 (Mitsui Petrochemical Industries ■: polyolefin, spherical particles with an average particle size of 20 μm) was mixed with 100 parts of TKu Aquares (Toyo Ink Manufacturing ■: sheet-fed TAP plate ink) using a high-speed mixer. Then, Ink-4 was prepared.

Comparative Example I 100 parts of TK New Bride was mixed with Sasol Waxox H-1 (Sasol Corporation; FT Wax, average particle size 10μ).
Ink-5 was prepared by kneading and mixing 3 parts of particles having various shapes with 90% of the particles being 90% of the particles (partially dissolved in the ink) using 3 rolls.

Comparative Example 2 3 parts of AC polyethylene 6 (allied fiber plastics: polyethylene, pellets with an average particle size exceeding 30 μm) were added to 100 parts of TK New Bright.
Using this roll, the dough was mixed and Ink-6 was created.

Comparative Example 3 AC polyethylene 6 for 100 parts of TKu Acwares
Three parts were kneaded and mixed using three rolls to prepare Ink-7.

Printing test examples 1 to 4. Printing tests were conducted on the inks of Comparative Examples 1 to 3 using a Mitsubishi Heavy Industries DAIYA-I four-color offset printing machine.

The evaluation results are shown in Table 1. In addition, as a printing evaluation, paper release property: The pressure of the gripping claw of the printing machine was adjusted to three levels: strong, medium, and weak, and printing was performed, and the paper release property was determined based on the presence or absence of the nail coming out. ○... - No nails missing, ×: Nails missing, stacking properties: 10,000 sheets of printed matter were stacked in a stack, and the quality was determined based on the number of sheets in which backing occurred.

Abrasion resistance: The printed matter was tested using a Surtherland rub tester under the conditions of 2 bonds 20 times, and a good one was rated O1, a poor one was rated ×, and an intermediate one was rated Δ.

Table 1 (Evaluation results) As the evaluation results show, the printing ink obtained by the present invention.

It was possible to simultaneously satisfy paper release properties, stacking properties, and coating film strength.

Claims (1)

[Claims] 1. In sheet-fed offset ink, the average particle size of the resin or wax that does not melt or swell in the ink is 0.1 to
A printing ink characterized by containing 0.1 to 20% by weight of 30 μm spherical particles.