JPS591426B2 - Resin composition for printing ink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition for printing ink that can be easily polymerized and cured by irradiation with active energy rays, particularly electron beams or ultraviolet rays.

BACKGROUND ART In recent years, solvent-free active energy ray-curable printing inks have been attracting attention as printing inks that can speed up printing processes and make them pollution-free.

The present inventors have also investigated printing inks using (meth)acrylic acid-modified polyepoxy compounds, oligoester (meth)acrylates, etc. as base resins used as binders for activated energy radiation curable printing inks. However, active energy ray-curable printing inks that use these base resins as main components suffer from the so-called "fountain escape" phenomenon, in which the printing ink is not properly drawn out of the ink fountain during high-speed printing processes, and the printing ink It has been found that there is a problem in that the material itself easily emulsifies, leading to the phenomenon of "plate smearing" and making it impossible to form a clear printed surface. Therefore, the inventors of the present invention have investigated these "pot escape" phenomena or "plate stains" that occur during the printing process.
The present invention was completed as a result of extensive research in order to obtain a resin composition for printing ink that can prevent this phenomenon and that can be easily polymerized and cured in the air by irradiation with active energy rays to form an excellent printing surface. The gist of the present invention is an acrylic modified urethane resin (2) obtained by reacting bisphenol A dioxyalkyl ether with a diisocyanate compound and a hydroxyl group-containing acrylic monomer.
30 to 80 parts by weight, and 70 to 20 parts by weight of polyol poly(meth)acrylate (B).

When carrying out the present invention, acrylic modified urethane resin (own)
As the bisphenol A dioxyalkyl ether used to obtain , compounds represented by the general formula are used, and among these compounds, bisphenol A dioxyethyl ether and bisphenol A dioxypropyl ether are particularly preferred.

Examples of diisocyanate compounds that undergo an addition reaction with these bisphenol A dioxyalkyl ethers include tetramethylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, and diphenylene diisocyanate. These include isocyanate, m-phenylene diisocyanate, biphenylene diisocyanate, dimer monoate diisocyanate, cyclohexane diisocyanate, lysine diisocyanate, etc. Among the diisocyanate compounds, tolylene diisocyanate, xylylene diisocyanate, and diphenylenemethane diisocyanate are particularly suitable when considering the activity with respect to the active energy line of the acrylic modified urethane resin. be. In addition, as the hydroxyl group-containing acrylic monomer, for example, the general formula (however,
R1, R3, R4 are hydrogen atoms or methyl groups, R2 is 1,000('H-)- or 1,000CH2-dH-
In this case, n is an integer of 1 to 10), specific examples include compounds in which the hydroxylalkyl group is 2-hydroxyethyl, 2-hydroxypropyl, 4-hydroxybutyl, 6-hydroxyhexyl,
Examples include hydroxyalkyl (meth)acrylates which are polyethylene glycol and polypropylene glycol residues, and monoepoxy compounds such as butyl glycidyl ether, allyl glycidyl ether, glycidyl (meth)acrylate, and phenyl. An addition reaction product of glycidyl ether and (meth)acrylic acid can also be used.

Such bisphenol A dioxyalkyl ether, diisocyanate compound, and hydroxyl group-containing acrylic monomer are reacted to form an acrylic modified urethane resin (
To obtain the bisphenol A dioxyalkyl ether, the hydroxyl group of the bisphenol A dioxyalkyl ether is first converted into an isocyanate group by an addition reaction with a diisocyanate compound, and then the isocyanate group and the hydroxyl group are converted into an isocyanate group. A method of conducting an addition reaction with a group-containing acrylic monomer is suitable. Here, the molecular weight of the acrylic modified urethane resin A is preferably 2,000 or less when considering printing workability and activity with respect to the active energy line. As a specific example of the polyol poly(meth)acrylate (B) used in carrying out the present invention, ethylene glycol di(
meth) acrylate, diethylene glycol di(meth)
Acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra (Meta)acrylate,
This includes dipentaerythritol hexa(meth)acrylate, etc., but in particular, pentaerythritol tri(), which does not swell the rubber rollers and blankets of printing machines, etc.
Preferably, meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate are used. When carrying out the present invention, the acrylic modified urethane resin (A) 30 to
It is preferable to mix polyol poly(meth)acrylate (8) in an amount of 70 to 20 parts by weight with respect to 80 parts by weight. This is undesirable because it causes the phenomenon of "run-off" or "plate smearing", and
If it exceeds 1 part by weight, the viscosity of the resin composition becomes extremely high and the workability of the printing ink becomes poor, which is not preferable.

In order to produce a printing ink using the resin composition of the present invention, it is sufficient to add and knead the resin composition, a coloring pigment, an extender pigment, and other additives such as wax and a polymerization inhibitor as necessary, and then knead the resin composition. In order to dry and harden printed matter using ink by electron beam irradiation, an electron beam with a dose rate of 0.1 to 60 Mrad/sec is taken out from an electron beam accelerator with an acceleration voltage of 0.1 to 20 Me, and the absorbed dose is 0.1 It is sufficient to irradiate the UV light to 10 Mrad, and when ultraviolet rays are used, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin butyl ether, benzophenone, Michler's ketone, diethoxyacetophenone is added to the composition as a sensitizer. , anthraquinone etc. 0
．． Added in the range of 1 to 10% by weight, wavelength 2000 to 80
Near ultraviolet rays of 00N, preferably 2500 to 4500N may be irradiated.

The printing ink obtained using the resin composition of the present invention does not cause the "pot runout" phenomenon or "plate stain" phenomenon during the printing process, and has extremely excellent printability despite being solvent-free. In particular, it has been discovered that it exhibits suitability for offset printing, and that it can quickly dry and harden even in air when irradiated with active energy rays, forming an excellent printing surface, and its industrial value is extremely high. It is.

Parts in the following examples mean parts by weight.

Example 1 344 parts of bisphenol A dioxypropyl ether (an adduct of 1 mole of bisphenol A and 2 moles of propylene oxide) was placed in a Mitsuro flask and heated to 6°C, and then 370 parts of tolylene diisocyanate was added under a nitrogen stream. 3
dripped over time.

After completion of dropping 2-hydroxypropyl acrylate 286
10 parts of dimethylaminoethyl methacrylate and 5 parts of hydroquinone monomethyl ether were added, and the reaction was carried out at 70°C for 5 hours. 100 parts of a resin composition consisting of 70 parts of the acrylic modified urethane resin obtained by this method and 30 parts of pentaerythritol tetraacrylate, and 25 parts of phthalocyanine blue were kneaded using three rolls to obtain a printing ink. When this printing ink was printed on calton paper at a speed of 5,000 sheets/hour using an offset printing machine, no ink "pot run-off" or "plate smearing" phenomena were observed, and even after printing 10,000 sheets of calton paper, the initial condition remained. There was no difference at all from the printed version. In addition, the printed matter was processed using a 300 KV accelerator with a current intensity of 60 mA and an absorbed dose of 1.2 Mrad.
When irradiated with an electron beam under the following conditions, the printed surface was completely dried and cured, and an excellent printed matter was obtained. Example 2 1 mole of bisphenol A dioxyethyl ether (adduct of bisphenol A/mol and 2 moles of ethylene oxide) and various diisocyanate compounds shown in Table 1 2
．． 25 parts of phthalocyanine blue and 5 parts of benzoin ethyl ether were added to 100 parts of a resin composition consisting of 60 parts of an acrylic modified urethane resin synthesized from 2 moles of 2 moles of hydroxyl 2 ethyl ether and 40 parts of pentaerythritol triacrylate. A printing ink was obtained by kneading.

When the printing ink was printed on a tin plate using an R-work tester, no ink "pot run-off" phenomenon or "plate smearing" phenomenon was observed. Then, it was dried by irradiating ultraviolet rays with a high-pressure mercury lamp having an output of 80 W/Cm. From the results shown in Table 1, printing inks using any acrylic modified urethane resin exhibit good drying properties, but especially when tolylene diisocyanate, xylylene diisocyanate, or diphenylene methane diisocyanate is used as the diisocyanate. It was observed that the drying time was short.

Claims (1)

[Scope of Claims] 1 30 to 80 parts by weight of an acrylic modified urethane resin (A) obtained by reacting bisphenol A dioxyalkyl ether with a diisocyanate compound and a hydroxyl group-containing acrylic monomer, polyol poly(meth)acrylate (B) ) 70 to 20 parts by weight. 2. The resin composition for printing ink according to claim 1, characterized in that bisphenol A dioxyethyl ether and/or bisphenol A dioxypropyl ether is used as the bisphenol A dioxyalkyl ether. 3. The resin composition for printing ink according to claim 1, wherein one or a mixture of two or more of tolylene diisocyanate, xylylene diisocyanate, and diphenylmethane diisocyanate is used as the diisocyanate compound. 4. A patent claim characterized in that one type or a mixture of two or more of pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate is used as the polyol poly(meth)acrylate. The resin composition for printing ink according to item 1.