Photocurable inkjet printing ink composition, printed matter and molded article

Abstract

A photocurable inkjet printing ink composition includes at least a photopolymerizable compound component and a photopolymerization initiator, wherein in the photopolymerizable compound component, a monofunctional monomer is included in a content of 91.0 to 99.5% by mass and a multifunctional monomer is included in a content of 0.5 to 9.0% by mass; in the monofunctional monomer component, acryloylmorpholine is included in a content of 30.0 to 85.0% by mass; the monofunctional monomer component includes at least one selected from benzyl acrylate, ethyl carbitol acrylate, tetrahydrofurfuryl acrylate and phenoxyethyl acrylate in a content of 5.0 to 40.0% by mass in the monofunctional monomer component; and the stretching rate at 180° C. of the cured coating obtained by photopolymerizing the photocurable inkjet printing ink composition is 120% or more.

Description

TECHNICAL FIELD[0001]The present invention relates to a photocurable inkjet printing ink composition, and a printed matter and a molded article printed with the same ink composition. More specifically, the present invention relates to a photocurable inkjet printing ink composition capable of forming a cured coating having satisfactory stretchability and satisfactory heat resistance, and satisfactory machinability even when a substrate is printed with the ink composition and then the substrate is thermally molded.BACKGROUND ART[0002]A photocurable ink is fast in drying and includes no volatile solvent, is free from the volatilization of a component hazardous to the environment, and has an excellent performance such as the capability of printing on various substrates; thus, photocurable inks are utilized, for example, in wide fields of various coatings and inkjet printing, in addition to the fields of offset printing, gravure printing, screen printing and letterpress printing. In part...

AI Technical Summary

Benefits of technology

The present invention is a photocurable inkjet printing ink composition that includes a specific photopolymerizable monomer and a photopolymerization initiator. The invention has excellent photocurability and can make good heat resistance to the substrate and cracking resistance of the ink coating after curing. Therefore, it can be used in fields where machine processing is performed under harsher conditions, such as high temperatures, without causing tackiness. The invention also has good punching processing performance, which was not previously possible with other ink compositions.

Problems solved by technology

However, for such requirements, cured coatings of photocurable inks using conventional monofunctional monomers and multifunctional monomers frequently provide too high coating hardness.

Accordingly, when stretching or bending processing is performed after the printing, cured coatings cannot follow the stretching or deformation of the substrates, and the adhesiveness of the cured coatings tend to be degraded, to lead to a problem such that the stretching and bending processability of the printed matter is lowered.

Certainly, the active energy line-curable ink described in Patent Literature 1 is regarded to have a satisfactory stretchability, namely, a satisfactory ductility, but is clearly not an ink pursuing excellence in punching processability.

However, there occurs a problem that cutting processing takes very much labor and time, and is not adaptable to objects made of easily deformable materials.

However, even when the foregoing ink satisfactory in stretching and adhesion is used, the ink is not yet of a sufficient level in such a way that in the punching processing of a printed matter, the cracking or the exfoliation of the ink coating occurs in the punched cross section; as affairs now stand, there are no ink compositions capable of satisfying the performances required in the market such as the stretching and bending processability and the punching processability of the substrate.

However, an accumulated irradiation amount of light energy of 300 mj is required to achieve the curing, and the curability is sometimes insufficient.

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