KR20160058595A

KR20160058595A - The 3D Full Color Ink Composition and 3D soft sculpture formed by using the same

Info

Publication number: KR20160058595A
Application number: KR1020140160286A
Authority: KR
Inventors: 전선미; 김영진; 한규홍
Original assignee: 대한잉크 주식회사
Priority date: 2014-11-17
Filing date: 2014-11-17
Publication date: 2016-05-25

Abstract

A 3D color ink composition for forming a three-dimensional flexible molding and a three-dimensional flexible molding formed using the same are disclosed. The 3D color ink composition is a color ink composition for applying to an ultraviolet curable inkjet apparatus using a piezo head to form a three-dimensional flexible molding. Wherein said ink composition comprises from 13 to 30% by weight of an acrylate oligomer, from 60 to 80% by weight of an acrylate monofunctional and polyfunctional monomer, from 0.1 to 2.0% by weight of a pigment, from 4 to 12% by weight of a photoinitiator, 1.0 to 5.0% by weight of an additive.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition for forming a three-dimensional flexible molding and a three-dimensional flexible molding formed using the same,

TECHNICAL FIELD The present invention relates to a 3D color ink composition and a three-dimensional flexible molding formed using the same, and more particularly, to an ink composition for forming a three-dimensional flexible molding applied to an ultraviolet curable inkjet apparatus using a piezo head, Dimensional ductile sculpture.

Conventional inkjet ink is composed of a colorant, a resin, a solvent and an additive as disclosed in Korean Patent No. 10-1039523. The four components can be variously changed depending on the application range of the ink and the head type of the printing apparatus to which the ink is applied.

Particularly, they are classified into aqueous, solvent and ultraviolet curable inks depending on the solvent. Among these, water and solvent inks adversely affect the human body and the environment due to waste water and odor generated during the printing and curing process.

In the case of aqueous and solvent inks, the solids content in the inks required for three-dimensional printing is significantly lower than 10%, making it impossible to use for the purpose of three-dimensional printing such as ultraviolet curable inks having a solid content close to 100%.

However, in Korea, FDM (Fused Deposition Modeling) printing method, in which solid-based filaments are melted and laminated, is dominant in the domestic market.

In the case of FDM printing method, the quality of the model surface roughness is not high, the production speed is very slow, and it is produced only in a single color. Therefore, the present technology is limited to the personal and household use.

SLS (Stereolithography Apparatus), DLP (Digital Light Processing), and SLP (Selective Laser Sintering) printing method, which is known as a method of stereolithographically forming a large amount of fine plastic powder, ceramic metal, It has similar advantages, but it does not require supporter, but it has the disadvantage that the equipment itself is the highest price and the powder inside can not be taken out separately during the modeling process.

DLP (Digital Light Processing) printing method using an SLA (Stereolithography Apparatus) printing method for forming a photocurable resin by a laser or an image hardening method using a beam project has an advantage of excellent output detail and fast output speed It has the disadvantage that color and raw materials are limited and raw materials are expensive.

On the other hand, in the case of the photocurable inkjet method, it is possible to improve the quality of the model surface roughness, to realize a full color at the same time as printing, and to provide product realism in response to a wide range of material change demands. However, a 3D color ink composition that is currently applied to an ultraviolet curable inkjet head using a piezo head has not been developed. Therefore, there is a demand for a 3D color ink composition meeting these characteristics.

Disclosure of the Invention Problems to be Solved by the Invention It is an object of the present invention to provide an ink composition for forming a three-dimensional flexible molding, which is applicable to an ultraviolet curable inkjet head using a piezo head and which can exhibit a mixed color using four primary color pigments and a white pigment .

Another object of the present invention is to form a three-dimensional flexible molding using the ink composition for forming a three-dimensional flexible molding.

An ink composition for forming a three-dimensional flexible molding for achieving an object of the present invention is a color ink composition for forming a three-dimensional flexible molding by being applied to an ultraviolet curing inkjet apparatus using a piezo head. Wherein said ink composition comprises from 13 to 30% by weight of an acrylate oligomer, from 60 to 80% by weight of an acrylate monofunctional and polyfunctional monomer, from 0.1 to 2.0% by weight of a pigment, from 4 to 12% by weight of a photoinitiator, 1.0 to 5.0% by weight of an additive.

In one embodiment, the acrylate oligomer may be used by mixing the urethane compound acrylate and the epoxy compound acrylate in a weight ratio of 1: 1 to 1.5.

In one embodiment, examples of the urethane compound acrylate include acrylate containing a hydroxy group such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate Acrylate, 2-hydroxypropyl methacrylate and pentaerythritol triacrylate. These may be used singly or in a mixture of two or more.

In one embodiment, examples of the epoxy compound acrylate include an oligomer obtained by reacting an epoxy resin with a carboxylic acid having an arc-forming group, and examples thereof include a bisphenol-A-series and novolac-series resin. These may be used singly or in a mixture of two or more.

In one embodiment, the pigment includes a light-resistant pigment that imparts a hue to the printed matter for identification. Examples of the light-resistant pigment include phthalocyanine, Pigment Blue 60, 15, 15: 2, 15: 3, 15: 4, carbon black, Pigment Black 2, 5, 7, benzimidazole, quinacridone, anthraquinone, Pyrrole-pyrrole, the present arylamide, Pigment Red 112, 149, 170, 178, 179, 185, 187, 188, 207, 208, 214, 220, 224, 242, 251, 254, 255, 260 , 264, azo nickel compounds, isoindolinone, benzimidazolone, azo fused product, tetrachloroisoindolinone, arylamide, azomethine copper compound, Pigment Yellow 17,201,138,131,151,155, 168, 175, 179, 180, 181, 185 (by color). They may be used alone or in combination of two or more for color combination.

When the content of the light-resistant pigment to be applied to the 3D color ink composition is less than 0.05 part by weight, the color of the 3D color ink molding is transparent and it is difficult to reproduce the color of the desired molding. When the content is more than 5% by weight, Respectively. Accordingly, the ink-jet ultraviolet curing ink contains about 0.05 to 5 parts by weight, preferably about 0.1 to 2 parts by weight of a light-resistant pigment.

In order to achieve the other object of the present invention, a three-dimensional flexible molding is characterized by comprising 13 to 30% by weight of an acrylate oligomer, 60 to 80% by weight of an acrylate monofunctional and polyfunctional monomer, 0.1 to 2.0% by weight of a pigment, A three-dimensional flexible molding comprising weight% and 1.0 to 5.0% by weight of an additive comprising a leveling agent and a stabilizer is formed from an ink composition for forming.

For example, the three-dimensional flexible molding may be formed by an ultraviolet curing inkjet method using a piezo head.

The ink composition for forming a three-dimensional flexible molding according to the present invention can be expressed in a mixed color by using a CMYK four primary color pigment and a white pigment used in a UV photocurable inkjet printing technique. It is possible to easily form a three-dimensional flexible molding having excellent curability by using a UV photo-curable inkjet printing apparatus to which a piezo type head is applied.

Hereinafter, an ink composition for forming a three-dimensional flexible molding according to an embodiment of the present invention and a three-dimensional flexible molding formed using the same will be described in detail. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are further described in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

On the other hand, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

3D color ink composition

The ink composition for forming a three-dimensional flexible molding according to an embodiment of the present invention is a 3D color ink composition used for forming a three-dimensional flexible molding by being applied to an ultraviolet curing inkjet apparatus using a piezo head.

The ink composition for forming a three-dimensional flexible molding includes an additive including an acrylate-based oligomer, an acrylate-based monofunctional and polyfunctional monomer, a pigment, a photoinitiator, and a leveling agent and a stabilizer.

If the amount of the acrylate-based oligomer used is less than 13% by weight in the ink composition for forming a three-dimensional flexible molding of the present invention, the 3D color ink molding easily breaks during printing or breaks easily after molding. If the amount exceeds 30% by weight, There is a problem that it is difficult to apply to an inkjet. Therefore, in the 3D color ink composition, the acrylate-based oligomer preferably comprises 13 to 30% by weight, more preferably 15 to 25% by weight.

In particular, the acrylate oligomer used in the ink composition for forming a three-dimensional flexible molding may be prepared by mixing a urethane compound acrylate and an epoxy compound acrylate in a weight ratio of 1: 1 to 2: 1, .

When the use ratio of the epoxy compound acrylate to the amount of the urethane compound acrylate is less than 1 time, UV ultraviolet curing is delayed, and the elongation of the three-dimensional molding is greatly increased and the shape can not be maintained. On the contrary, when the use ratio of the epoxy compound acrylate is more than 2 times, the problem arises that the 3D molding is easily broken even at a small external pressure.

In one embodiment, the urethane compound acrylate preferably has a urethane (-NHCOO-) bond and an acrylate group (-OCOHC = CH ₂ ) in one molecule and has a molecular weight of about 2,500 to 3,500.

Examples of the urethane compound acrylate include an aliphatic urethane acrylate containing an aliphatic compound and an acrylate containing a hydroxy group such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate and pentaerythritol triacrylate. These may be used singly or in a mixture of two or more.

In one embodiment, the epoxy compound acrylate is obtained by reacting an epoxy resin with a carboxylic acid having an acrylate group, and has a molecular weight of 500 to 1,000.

As examples of the epoxy compound acrylate, a bisphenol-A-type or novolac-type acrylate can be used.

If the acrylate-based monofunctional and polyfunctional monomer content of the ink composition for forming a three-dimensional flexible molding of the present invention is less than 60% by weight, There is a problem that the three-dimensional flexible molding is easily broken during printing or is easily broken after molding. Therefore, in the ink composition for forming a three-dimensional flexible molding, the acrylate-based monofunctional and polyfunctional monomer preferably comprises 60 to 80% by weight, more preferably 64 to 76% by weight.

Examples of the acrylate monofunctional monomer to be used in the ink composition for forming a three-dimensional flexible molding include monofunctional monomer such as butyl acrylate, 2-ethylhexyl acrylate, octyldecyl acrylate, hydroxyalkyl acrylate , Nonylphenol ethoxy acrylate, betacarboxyl acrylate, monoacrylate, isobornyl acrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, cyclohexyl acrylate, dicyclopentyl acrylate, di Propyleneglycol monoacrylate, 2-ethoxyethyl acrylate, ethoxylate monoacrylate, and borneol acrylate, which may be used singly or in combination of two or more. .

Examples of the acrylate-based polyfunctional monomer to be applied to the ink composition for forming a three-dimensional flexible molding include butanediol diacrylate, ethoxyethyl acrylate, 1,3-butylene glycol dimethacrylate, 1,6- Hexanediol dimethacrylate, neopentyl glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, Acrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, dianold diacrylate, and dianole methacrylate. These may be used alone or in admixture of two or more.

Particularly, it is preferable to mix acrylate monofunctional monomers and acrylate monofunctional monomers in a weight ratio of 4: 1 to 3: 1.

For example, when the amount of the pigment to be applied to the ink composition for forming a three-dimensional flexible molding is less than 0.1% by weight, it is difficult to maintain the clear color of the ink, thereby losing the function of imparting color. There is a problem with the actual color of the back-computer-designed model. On the other hand, if the content exceeds 2 wt%, the ink drying is delayed. If the content exceeds 5 wt% . Therefore, in the ink composition for forming a three-dimensional flexible molding, the pigment preferably contains 0.1 to 2.0% by weight, more preferably 0.5 to 1.5% by weight.

Examples of the pigments include blue pigments, white pigments, yellow pigments, black pigments, yellow pigments and the like, and they may be used singly or in combination of two or more.

For example, when the content of the photoinitiator is less than 4% by weight, the photo-curing can not proceed effectively and the curing time is slowed down. On the other hand, when the content of the photoinitiator exceeds 12% by weight The storage stability is deteriorated and a residual amount of photoinitiator may remain as a contaminant after curing. Therefore, in the ink composition for forming a three-dimensional flexible molding, the photoinitiator preferably includes 4 to 12% by weight, more preferably 6 to 10% by weight. Since the photoinitiator may be a conventional photoinitiator distributed in the market, a detailed description thereof will be omitted.

The leveling agent and the stabilizer may be used as the additive to be applied to the ink composition for forming a three-dimensional flexible molding, and it is preferably used in the range of 1.0 to 5.0% by weight.

The ink composition for forming a three-dimensional flexible molding, which is produced by the above-described method, can be expressed in a mixed color using CMYK four primary color pigments and a white pigment used in a UV photocurable inkjet printing technique, and a UV light- It is possible to easily form a three-dimensional flexible molding having excellent hardenability using an inkjet printing apparatus.

A three-dimensional flexible molding formed using an ink composition for forming a three-dimensional flexible molding

The three-dimensional flexible molding of the present invention comprises 13 to 30% by weight of an acrylate oligomer, 60 to 80% by weight of an acrylate monofunctional and polyfunctional monomer, 0.1 to 2.0% by weight of a pigment, 4 to 12% by weight of a photoinitiator, And an additive including a stabilizer in an amount of 1.0 to 5.0% by weight based on the total weight of the ink composition for forming a three-dimensional flexible molding, using an ultraviolet curable inkjet method using a piezo head.

The detailed description of the ink composition for forming a three-dimensional flexible molding is omitted in order to avoid duplication because it has been described in detail above. The three-dimensional soft prototypes can be used as materials for medical products, flexible displays, and wearable products.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments and comparative examples of the present invention. However, the following examples are merely examples for helping understanding of the present invention, and thus the scope of the present invention should not be limited or limited.

Example 1

A blue 3D color ink composition was prepared according to the compounding ratio shown in Table 1 below.

Combination weight (%) Phthalocyanine 0.3 Epoxy acrylate 17.4 Allypetic urethane acrylate 10.2 Borneol acrylate 45.4 Ethoxyethyl acrylate 13.7 Phosphine oxide photopolymerization initiator 4.0 Alpha hydroxyquinone type photopolymerization initiator 7.5 Logic Active Silicone Glycol Copolymer 1.0 UV stabilizer 0.5

Example 2

A red 3D color ink composition was prepared according to the compounding ratio shown in Table 2 below.

Combination weight (%) Quinacridone 0.4 Epoxy acrylate 17.4 Allypetic urethane acrylate 10.2 Borneol acrylate 45 Ethoxyethyl acrylate 13.9 Phosphine oxide photopolymerization initiator 4.0 Alpha hydroxyquinone type photopolymerization initiator 7.5 Logic Active Silicone Glycol Copolymer 1.0 UV stabilizer 0.6

Example 3

A yellow 3D color ink composition was prepared according to the blend ratio shown in Table 3 below.

Combination weight (%) Azo-nickel compound 0.3 Epoxy acrylate 17.4 Allypetic urethane acrylate 10.2 Borneol acrylate 44.8 Ethoxyethyl acrylate 14.1 Phosphine oxide photopolymerization initiator 4.0 Alpha hydroxyquinone type photopolymerization initiator 7.5 Logic Active Silicone Glycol Copolymer 1.0 UV stabilizer 0.7

Example 4

A black 3D color ink composition was prepared according to the blend ratio shown in Table 4 below.

Combination weight (%) Carbon black 0.2 Epoxy acrylate 17.4 Allypetic urethane acrylate 10.2 Borneol acrylate 45.4 Ethoxyethyl acrylate 13.7 Phosphine oxide photopolymerization initiator 4.1 Alpha hydroxyquinone type photopolymerization initiator 7.7 Logic Active Silicone Glycol Copolymer 1.0 UV stabilizer 0.3

Example 5

A white 3D color ink composition was prepared according to the blend ratio shown in Table 5 below.

Combination weight (%) Titanium dioxide 0.1 Epoxy acrylate 17.4 Borneol acrylate 45.5 Allypetic urethane acrylate 10.2 Ethoxyethyl acrylate 13.7 Phosphine oxide photopolymerization initiator 4.1 Alpha hydroxyquinone type photopolymerization initiator 7.7 Logic Active Silicone Glycol Copolymer 1.0 UV stabilizer 0.3

Comparative Example 1

A blue 3D color ink composition was prepared according to the blend ratio shown in Table 6 below.

Combination weight (%) Pigment Blue 15: 4 1.8 Glycol acrylate 3.6 Reactive polymeric dispersant 2.6 Cyclopentenyloxyethyl acrylate 57.5 N-vinylcaprolactam 14.5 Caprolactone-modified dipentaerythritol acrylate 2.0 Ethylene glycol vinyl ether 3.0 Polymerization inhibitor 0.3 Ethyl benzoyl phenylphosphine oxide 9.0 Benzophenone 3.2 Hydroxycyclohexyl phenyl ketone 2.44 Silicone surfactant 0.06

Comparative Example 2

A red 3D color ink composition was prepared according to the blend ratio shown in Table 7 below.

Combination weight (%) Pigment Red 122 3.9 Glycol acrylate 7.8 Reactive polymeric dispersant 4.3 Cyclopentenyloxyethyl acrylate 55.4 N-vinylcaprolactam 10.0 Caprolactone-modified dipentaerythritol acrylate 1.4 Ethylene glycol vinyl ether 3.0 Polymerization inhibitor 0.3 Ethyl benzoyl phenylphosphine oxide 9.0 Benzophenone 3.2 Isopropylthioxanthone 3.0 Silicone surfactant 0.06

Comparative Example 3

A yellow 3D color ink composition was prepared according to the blend ratio shown in Table 8 below.

Combination weight (%) Pigment Yellow 151 3.9 Glycol acrylate 7.8 Reactive polymeric dispersant 3.3 Cyclopentenyloxyethyl acrylate 58.4 N-vinylcaprolactam 10.0 Caprolactone-modified dipentaerythritol acrylate 1.4 Ethylene glycol vinyl ether 3.0 Polymerization inhibitor 0.3 Ethyl benzoyl phenylphosphine oxide 9.0 Benzophenone 3.2 Silicone surfactant 0.06

Comparative Example 4

A black 3D color ink composition was prepared according to the blend ratio shown in Table 9 below.

Combination weight (%) Pigment Black 1 1.8 Glycol acrylate 3.6 Reactive polymeric dispersant 2.6 Cyclopentenyloxyethyl acrylate 57.5 N-vinylcaprolactam 14.5 Caprolactone-modified dipentaerythritol acrylate 2.0 Ethylene glycol vinyl ether 3.0 Polymerization inhibitor 0.3 Ethyl benzoyl phenylphosphine oxide 9.0 Benzophenone 3.2 Hydroxycyclohexyl phenyl ketone 2.44 Silicone surfactant 0.06

Comparative Example 5

A white 3D color ink composition was prepared according to the compounding ratio shown in Table 10 below.

Combination weight (%) Pigment White 1 0.8 Glycol acrylate 30.0 Borneol acrylate 25.0 Cyclopentenyloxyethyl acrylate 15.0 Epoxy acrylic resin 19.3 Acrylic acid ester 0.5 Ethylene glycol vinyl ether 0.3 Ethyl benzoyl phenylphosphine oxide 3.0 Benzophenone 5.0 Polymerization inhibitor 0.3 Silicone surfactant 0.8

Evaluation of inking stability

An experiment on the inking stability of the ultraviolet curing type full-color three-dimensional ink jet ink composition of Example 1 and Comparative Examples 1 to 5 was carried out. The ink stability test was carried out using a homogenizing stirrer at 50 ° C for 2 hours, followed by stirring. After 24 hours, the state of the ink was visually observed at 25 ° C.

The results are shown in Table 11 below.

Inking stability Example 1 ○ (Good) Comparative Example 1 ○ (Good) Comparative Example 5 △ (partially dissolved)

Evaluation of ink storage stability

An experiment on the storage stability of the ultraviolet curing type full-color three-dimensional inkjet ink composition of Example 1 and Comparative Examples 1 to 5 was carried out. The storage stability test was performed using LUMiSizer 610/611/612 from L.U.M GmbH for 1 hour at 25 ° C to observe how the phase separation of the ink progressed for 2 months. The results are shown in Table 12 below.

Storage stability Example 1 ○ (No phase separation) Comparative Example 1 ○ (No phase separation) Comparative Example 5 ○ (No phase separation)

Ink viscosity measurement evaluation

Experiments on viscosity measurement of the ultraviolet curing type full-color three-dimensional inkjet ink compositions of Example 1 and Comparative Examples 1 to 5 were carried out. Viscosity measurements were made using a BROOKFIELD viscometer to measure the viscosity of the inventive and comparative inks, and the results are shown in Table 13.

Viscosity (at 25 ℃) Example 1 24 ± 3 cps Comparative Example 1 15 ± 3 cps Comparative Example 5 260 ± 10 cps

Ink surface tension measurement evaluation

Experiments on the measurement of the surface tension of the ultraviolet curing type full-color three-dimensional ink jet ink composition of Example 1 and Comparative Examples 1 to 5 were carried out. The surface tension of the invention and the comparative ink was measured using a SITA dynamic surface tension meter, and the results are shown in Table 14. [

Surface tension (at 25 ℃) Example 1 47.2-34.2 mN / m Comparative Example 1 35.4-28.5 mN / m Comparative Example 5 Not measurable

Evaluation of Ink Discharge Temperature Measurement

Experiments on measurement of discharge temperature of the ultraviolet curing type full-color three-dimensional inkjet ink composition of Example 1 and Comparative Examples 1 to 5 were carried out. In the ink discharge temperature measurement experiment, the viscosity at which the temperature of the invention and the comparative ink reached 14 cps or less was measured using an AR Rhometer, and the results are shown in Table 15.

Temperature (14 cps or less) Example 1 35 ± 5 ° C Comparative Example 1 27 ± 5 ° C Comparative Example 5 70 ± 5 ° C

Evaluation of tensile strength of material

Experiments on measurement of tensile strength of three-dimensional materials produced from the ultraviolet curing type full-color three-dimensional inkjet ink composition of Example 1 and Comparative Examples 1 to 5 were carried out. The tensile strength test was carried out using a CT-UTM101 universal testing machine and the results are shown in Table 16. [

The tensile strength Example 1 8-10 MPa Comparative Example 1 0.1-0.5 MPa Comparative Example 5 50-65 MPa

Test conditions: Pre-Load: 0.5 kgf, Tensile speed: 50 mm / min

Evaluation of elongation of material

Experiments on measurement of elongation of a three-dimensional material produced from the ultraviolet curing type full-color three-dimensional inkjet ink composition of Example 1 and Comparative Examples 1 to 5 were carried out. The elongation test was carried out using a CT-UTM101 universal material tester and the results are shown in Table 17.

Elongation Example 1 80-100% Comparative Example 1 77-90% Comparative Example 5 10-25%

Test conditions: Pre-Load: 0.5 kgf, Tensile speed: 50 mm / min

Evaluation of pencil hardness of material

An experiment on the measurement of pencil hardness of a three-dimensional material produced from the ultraviolet curing type full-color three-dimensional inkjet ink composition of Example 1 and Comparative Examples 1 and 5 was carried out. The pencil hardness test was carried out using MITSU-BISHI PENCIL (pencil for pencil hardness test by Mitsubishi Laboratory) as follows. First, the pencil lead was exposed at about 3 cm, and the end of the core was flattened and sharpened so that the angle became sharp. Then, the pencil lead was applied to the coated surface at an angle of about 45 ㅀ, . The test specimens were repeated five times each while changing the position of the pencil lead, and the hardness of the pencil peeled off the coating one or more times was recorded. The results are shown in Table 18.

Pencil hardness Example 1 6H Comparative Example 1 6H Comparative Example 5 6H

Evaluation of light resistance of material

The light resistance test was performed by observing the color change on a daily basis while performing the test for 8 hours a day for one month using a FOCUS SCIENTIFIC FADE-O-Meter after leaving the printed substrate at room temperature for 24 hours.

The light resistance test of the FADE-O-Meter used in the present invention for 1 hour is the same as that of the light resistance test for 1.5 days at room temperature. Therefore, it can be said that the light resistance test is similar to the result of the experiment conducted at room temperature for 360 days. The light resistance test results are shown in Table 19 below.

Light resistance Example 1 ○ (no change) Comparative Example 1 ○ (no change) Comparative Example 5 ○ (no change)

Claims

1. A color ink composition for forming a three-dimensional flexible molding by applying an ultraviolet curing inkjet system using a piezo head,
From 13 to 30% by weight of an acrylate-based oligomer;
From 60 to 80% by weight of an acrylate-based monofunctional and polyfunctional monomer;
0.1 to 2.0% by weight of pigment;
4 to 12% by weight of a photoinitiator; And
1 to 5% by weight of an additive comprising a leveling agent and a stabilizer.

The ink composition according to claim 1, wherein the acrylate oligomer is a mixture of a urethane compound acrylate and an epoxy compound acrylate in a ratio of 1: 1 to 1.5: 1.

[Claim 3] The urethane compound acrylate according to claim 2, wherein the urethane compound acrylate is at least one selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2- Acrylate, 2-hydroxypropylmethacrylate, and pentaerythritol triacrylate. The ink composition for forming a three-dimensional flexible molding according to claim 1,

The epoxy compound acrylate according to claim 2, wherein the epoxy compound acrylate is an oligomer obtained by reacting an epoxy resin with a carboxylic acid having an arc-forming group, and may be a bisphenol-A or novolac resin.
And at least one selected from the group consisting of polyvinyl alcohol, polyvinyl alcohol, and polyvinyl alcohol.

The method of claim 1, wherein the acrylate monofunctional monomer is selected from the group consisting of butyl acrylate, 2-ethylhexyl acrylate, octyldecyl acrylate, hydroxyalkyl acrylate, nonylphenol ethoxy acrylate, Acrylate, isobornyl acrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, cyclohexyl acrylate, dicyclopentyl acrylate, dicyclopentyloxyethyl acrylate, propylene glycol monoacrylate, 2- Ethoxyethyl acrylate, ethoxylate monoacrylate and borneol acrylate, wherein the acrylate-based polyfunctional monomer is at least one selected from the group consisting of butanediol diacrylate, ethoxyethyl acrylate, 1 , 3-butylene glycol dimethacrylate 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, triethylene glycol diacrylate, A method for forming a three-dimensional flexible molding, characterized in that it comprises at least one of diacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, dianold diacrylate, / RTI >

A three-dimensional flexible molding formed of an ink composition for forming a three-dimensional flexible molding having the composition of claim 1.

The method according to claim 6, wherein an ultraviolet curing inkjet method using a piezo head
Wherein the three-dimensional flexible molding is formed by using the three-dimensional flexible molding.