LED curable pad printing ink for plastic material

Abstract

LED curable pad printing ink for a plastic material is disclosed and belongs to the technical field of pad printing ink. The disclosed pad printing ink comprises a photoinitiator, a co-initiator, a solvent, hyperbranched polyester acrylate, polyester acrylate, phenolic epoxy acrylate, a defoaming agent, a dispersing agent, pigment, a filler and a thickening agent. Compared with the prior art, thedisclosed pad printing ink has a wide curing range and can be cured by a mercury lamp, a halogen lamp and an LED lamp; pad printed characters utilizing the pad printing ink are fine, with the line width being 0.2 mm, and can tolerate 45 times or above of RCA friction; the residual amount of the ink on the surface of a silica gel head is less than 10% after the silica gel head pad printing of the characters, the ink transfer amount is high, the characters are clear and full, and the phenomenon of paint removing due to poor ink adhesion caused by the erosion of chemicals on the ink coating can be effectively reduced.

Description

technical field [0001] The invention relates to the technical field of pad printing inks, in particular to an LED curing pad printing ink used for plastic materials. Background technique [0002] The pad printing process is a special printing process that is widely used. Firstly, the mold is opened on the steel plate to make the required graphics and text, and then the ink in the mold groove is transferred to the surface of the material through the silicone head. , Printing characters or patterns on products with irregular surfaces has very obvious advantages and makes up for the shortcomings of the screen printing process. Compared with solvent-based pad printing inks, UV pad printing inks have less VOC volatilization and are more environmentally friendly. Advantages, fast curing and high production efficiency. [0003] UV curing methods include mercury lamps, halogen lamps, LED lamps, etc. Among them, mercury lamps and halogen lamps emit ultraviolet wavelengths at 200-400...

AI Technical Summary

Problems solved by technology

[0003] UV curing methods include mercury lamps, halogen lamps, LED lamps, etc. Among them, mercury lamps and halogen lamps emit ultraviolet wavelengths at 200-400nm, with a wide band, and can be used with a variety of photoinitiators, which is easier to achieve the purpose of curing. LED The lamp has a single wavelength band, usually 365nm and 395nm, and there are fewer types of photoinitiators to choose from, making curing more difficult, so the ink curing range in the prior art is narrow

[0004] After retrieval, Chinese patent CN108641470A discloses a solvent-free, UV-LED curable pad printing ink with 5-15 parts of monomers. From the perspective of its monomer ratio, it is difficult to achieve a good ink due to the lack of solvent volatilization gradient. Transferability, the monomer will hardly volatilize. When the monomer is used to achieve the purpose of dilution, the monomer amount exceeding 5% will obviously affect the ink transferability. When the monomer content exceeds 10%, the ink residue on the rubber head will reach 100% %, resulting in defects such as shallow pad printing coating on the material, and bottom penetration

[0005] Chinese patent CN102250508B discloses a UV-curable pad printing ink, whose RCA test can reach 300 times without falling off, but this test does not indicate the specific shape of the tested part, and the test results of the line and the surface are very different. When the pad printing font line is very thin, reaching 0.2mm, the contact area between the roller of the RCA tester and the material is larger than the font line width, and completely covers the font.

[0006] Moreover, the pad printing inks in the prior art are easily eroded by chemicals such as ester solvents and glycerin, resulting in poor adhesion of the ink coating and phenomenon such as paint stripping. Therefore, the pad printing inks in the prior art there are still some shortcomings

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