KR102100722B1 - An ultraviolet curable ink composition for foaming, a printing article produced thereby - Google Patents

Abstract

The present invention discloses a UV curable ink composition for foaming and a printed article produced thereby. According to the present invention, there is provided a UV curable ink composition for foaming comprising a reactive acrylate oligomer, a reactive acrylate monomer, a pigment, a photoinitiator and additives.

Description

An ultraviolet curable ink composition for foaming, a printing article produced thereby}

The present invention relates to a UV curable ink composition for foaming and a printed article produced thereby.

Recently, a foam cup having a foamed surface of a portable container such as coffee or cup noodles has been provided.

The foam cup has an excellent heat insulation effect and is not easily deformed, so it has a long-term advantage. Because of these advantages, the use of foam cups is increasing.

In addition, in order to improve the aesthetics of the foam cup, pictures and letters are printed through ink.

Conventionally, the gravure method is mainly used for printing of the foam cup. Gravure printing is a concave plate printing method using a copper plate. The printing speed is fast and mass printing is possible.

When printing gravure, a foam is coated on the printed material, and then a predetermined pattern is printed through a copper plate. After the printing is completed, a foaming process is performed after molding into a container shape, and as most of the solvent is removed during the foaming process, there is a problem that the print pattern is blurred or blurred.

In addition, since the gravure printing described above uses a solvent, there is a problem of environmental contamination by the solvent, and there is also a problem that wastewater is generated due to corrosion when disposing of the used copper plate.

In order to solve this problem, an ultraviolet curing ink for foaming has been proposed.

UV curable inks typically include photoinitiators, reactive monomers or oligomers, pigments and other additives.

However, as a photopolymerization reaction composition, a conventional ink used by mixing a reactive acrylate monomer and an oligomer has a property that does not increase after being cured once, hindering the foaming phenomenon of the foam coating and cracking of the printing state during foaming (cracks) As this leads to product defects, it needs to be improved.

Patent Publication KR 10-2016-0052753

In order to solve the above-mentioned problems of the prior art, it is intended to propose a UV curable ink composition for foaming and a printed article produced thereby, in which the printing state can be preserved without disturbing the thermal foaming phenomenon.

In order to achieve the above object, according to an embodiment of the present invention, there is provided a UV curable ink composition for foaming comprising a reactive acrylate oligomer, a reactive acrylate monomer, a pigment, a photoinitiator and additives.

The reactive acrylate oligomer may include urethane acrylate oligomer and polyester acrylate oligomer.

The reactive acrylate oligomer may include 50 to 60 weight percent based on the total weight, and the urethane acrylate oligomer may include 50 to 55 weight percent based on the total weight.

The polyester acrylate oligomer may include 10 weight percent or less based on the total weight.

According to another aspect of the present invention, there is provided a printing article manufactured through the above-mentioned foaming UV curable ink composition.

According to the present invention, even if the foaming process is performed after printing through the ultraviolet curing ink, there is an advantage of preventing the foaming phenomenon or preventing the printing state from cracking during foaming.

1 is a view showing a manufacturing process of a printed article (foam cup) using a UV-curable ink composition for foaming according to an embodiment of the present invention.
2 is a view showing an example of a printed article manufactured through the above process.

The present invention can be modified in various ways and can have various embodiments, and thus, specific embodiments will be described in detail.

However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

The present invention relates to a UV curable ink composition for foaming comprising a reactive acrylate and a printed article produced thereby.

According to one preferred embodiment of the present invention, unlike the conventional polyester acrylate-based UV curable ink composition, the reactive urethane acrylate oligomer as a main component does not interfere with the foaming phenomenon of the foam coating after photocuring and cracks after foaming Avoid occurrence.

According to one embodiment of the present invention, the UV curable ink composition for foaming comprises 50 to 60% by weight of reactive acrylate oligomer, 3 to 10% by weight of reactive acrylate monomer, 15 to 20% by weight of pigment, 5 to 5% of photoinitiator (photopolymerization initiator) 10 weight percent and 5 to 10 weight percent of additives.

More preferably, the reactive acrylate oligomer may include urethane acrylate oligomer and polyester acrylate oligomer in a predetermined weight percentage range.

Here, the urethane acrylate oligomer may include 50 to 55 weight percent based on the total weight.

The polyester acrylate oligomer is preferably not more than 10% by weight, because, as described below, cracks may occur after foaming when its content is high.

More preferably, the polyester acrylate oligomer is contained in 5 weight percent or less.

The reactive acrylate monomer according to this embodiment is a monomer having one or more acrylic functional groups, trimethylol propene triacrylate (TMPTA) and dipentaerythritol hexaacrylate (DPHA), tetrahydrofurfuryl acrylate ( THFA) and monofunctional acrylates and 1,6-hexanediol diacrylate (HDDA).

Preferably, the monomer may be trimethylol propene triacrylate (TMPTA) or dipentaerythritol hexaacrylate (DPHA).

The photoinitiator generates active radicals when irradiated with ultraviolet rays in a specific wavelength region, and the generated radicals induce a photopolymerization reaction of a reactive acrylate oligomer or monomer. The photoinitiator is at least one selected from the group consisting of a phosphine oxide photoinitiator, a thioxanthone photoinitiator, and an alkylaryl ketone photoinitiator.

Specific examples of the photoinitiator are diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO), 2-isopropyl thioxanthone (ITX), 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy Hydroxy-2-methyl-1-phenyl-1-propanone, 2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone, and the like, , But is not limited thereto.

It is preferable that the photoinitiator is 5 to 10% by weight relative to the total weight of the ultraviolet curable ink composition. If the content is less than 5% by weight, the curing speed is slow, which may cause problems such as uncuring and scratching. When it exceeds 10% by weight, radical concentration is excessively increased to increase unreacted substances, and odor is generated. , The hardness of the ink is weakened, which is not preferable.

In the present invention, the above-described photoinitiator is used by mixing one or more, preferably two or more. When two or more types of photoinitiators are used, the reactivity of the curing reaction may be improved, and according to the reactivity improvement, an improvement in curing performance of a printing surface such as an improvement in drying speed of a printed material may be achieved.

The pigment may be any of pigments known in the ink field, such as black, white, blue, yellow, and red pigments, without limitation, and is usually used in a range of 15 to 20% by weight relative to the total weight of the ink composition.

The ultraviolet curable ink composition according to the present embodiment may further include a conventional additive well known in the field of ultraviolet curable ink used for securing physical properties, for example, a leveling agent, an antifoaming agent, and the like. These additives maximize the defoaming and leveling properties of the ink composition, thereby improving the appearance of printing and contributing to the improvement of wear resistance.

The leveling agent may include a polyester-modified polydimethylsiloxane-based reactive silicone acrylate. In addition, the ultraviolet curable ink composition of the present invention may further include other additives well known in the ink field.

Additives are fillers that control the viscosity of the ink composition and adjust the viscosity of the ink composition to adjust the viscosity of the ink composition, components for improving and protecting the slip properties of the printing surface, defoaming agents for removing bubbles and improving printability , Stabilizers to improve the shelf life of the product, and components well known in the art.

1 is a view showing a manufacturing process of a printed article (foam cup) using a UV-curable ink composition for foaming according to an embodiment of the present invention.

Referring to FIG. 1, a sheet including a foam coating layer is supplied to a printing machine (step 100).

The foam coating layer may include a binder resin, a filler, and a thermally expandable microsphere.

In the production of the printed article according to the present embodiment, offset printing is performed in which an ink image is transferred from a plate surface to a rubber blanket and printing is performed on a sheet in the rubber blanket (step 102).

In step 102, printing is performed using the ultraviolet curable ink composition according to the present embodiment.

After the above printing process, the sheet is irradiated with ultraviolet rays (step 104).

After UV irradiation, cutting (step 106) and forming 108 into a cup shape are performed, and thermal foaming is performed (step 110).

The UV-curable ink composition according to the present embodiment has an advantage of preventing environmental pollution because it uses offset printing rather than gravure printing.

2 is a view showing an example of a printed article manufactured through the above process.

Example

Urethane acrylate oligomer (product name: SC 2565, manufacturer: Miwon) 55g, polyester acrylate oligomer (product name: PS 4800 manufacturer: Miwon) 5g, reactive monomer (product name: TMPTA, manufacturer: Miwon) 4g, photoinitiator (ITX 1g, 2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone (product name: IRGACURE 907) 5 g), dispersant (product name: D324 manufacturer: DOXA) 2 g, Wax (product name: Deutron 9815 manufacturer: Deutron) 1g, stabilizer (product name: D-526 manufacturer: IGM) 2g, constitution 5g, mixed for at least 30 minutes at room temperature, 3 times or more with 3 rolls, particle size of 3㎛ or less Dispersed with to prepare an ultraviolet curable ink composition.

As a method described in Examples, an ultraviolet curable ink composition having a composition shown in Table 1 below was prepared.

ingredient Example One 2 3 4 5 Oligomer Urethane acrylate (SC 2565) 30 45 50 55 Polyester acrylate (PS-4800) 60 30 15 10 5 Pigment 20 20 20 20 20 Photoinitiator
ITX One One One One One IRGACURE 907 5 5 5 5 5 Monomer IMPTA 4 4 4 4 4 additive WAX (Deutron 9815) One One One One One constitution 5 5 5 5 5 Dispersant (D * 324) 2 2 2 2 2 Stabilizer (D * 526) 2 2 2 2 2 Sum 100 100 100 100 100

Property evaluation and analysis

The ultraviolet curable composition of the composition shown in Table 1 was evaluated by the method described below, and the results are shown in Table 2.

Viscosity and Flow: The viscosity of the ink composition between 10 and 100 seconds was measured using a B-type flat viscometer.

Tackiness: TV was measured at 400 rpm using INK-O-Meter.

Drying: The UV curable composition was applied to 0.1 cc of a 4-part RI-Tester on a printed material coated with foam, and then cured once at 40 m / min on a UV metal ramp.

Foaming and cracking: Cracking was observed after foaming in an oven at 80 ° C. for 5 minutes.

Evaluation items Example One 2 3 4 5 Viscosity
(10 seconds to 100 seconds) 47 ~ 60 47 ~ 60 47 ~ 60 47 ~ 60 47 ~ 60 Tackiness 30 28 28 28 27 dry Good Good Good Good Good firing X X △ ○ ○ Crack has exist has exist has exist has exist none

As shown in Table 2, the UV-curable ink composition according to the present embodiment was foamed without cracking without sacrificing thermal foaming, while having good viscosity, tackiness, and drying suitable for printing.

The above-described embodiments of the present invention have been disclosed for purposes of illustration, and those skilled in the art having various knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. It should be regarded as belonging to the following claims.

Claims (5)

Applied to offset printing, including reactive acrylate oligomer, reactive acrylate monomer, pigment, photoinitiator and additive,
The reactive acrylate oligomer includes urethane acrylate oligomer and polyester acrylate oligomer,
The reactive acrylate oligomer comprises 60% by weight based on the total weight,
The urethane acrylate oligomer comprises 55 weight percent based on the total weight, and the polyester acrylate oligomer comprises 5 weight percent based on the total weight. delete delete delete A printing article produced through the ultraviolet curable ink composition for foaming according to claim 1.

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