KR20170115720A - An Ink Composition for 3D Printing Support - Google Patents

Abstract

Disclosed is an ink composition for a 3D printing support which can be used in an inkjet type 3D printer, easily controls the spreadability of ink, and is easily dissolved in water after curing to facilitate removal of the support. The ink composition for a 3D printing support comprises: a phase change material; A photopolymerizable monomer having at least one of a monomer including an amine group and a monomer including a hydroxy group; And a curing agent.

Description

An ink composition for a 3D printing support {An Ink Composition for 3D Printing Support}

The present invention relates to an ink composition for a 3D printing support, and more particularly, to an ink composition for a 3D printing support, which can be used in an inkjet 3D printer, easily control the spreadability of ink, easily dissolve in water after curing, To an ink composition for a 3D printing support.

3D printers (three dimentional printers) are a type of printer that prints a specific object in three dimensions. It is a device that can create real objects in three-dimensional space like a three-dimensional printed design on paper. When a digitized file is transferred from an inkjet printer, 2D printers move only in front and back (x-axis) and left and right (y-axis), as in the principle of ejecting ink onto a paper surface to print 2D images. z axis) movements to create 3D objects based on the 3D drawings.

In order to form a molding with the ink jet type 3D printer, a structure ink for forming a molding and a support ink for forming a support in the shape of a bridge or air in order to support the molding are formed. . These support inks must be sprayed onto the substrate simultaneously with the structured ink, or they must be sequentially sprayed and cured together. At this time, the two kinds of ink should not be mixed with each other and each should form a desired pattern shape. , It is necessary to control the spreadability of the ink. On the other hand, since the support formed by the support ink is a temporarily formed portion for supporting the formation of the molding (structure) well, it should be removed well after the molding is completed.

Korean Patent Publication No. 10-2013-0141561

As described above, in order to prevent the two types of ink (structure ink and support ink) from being mixed with each other and to form a desired pattern shape, it is necessary to control the spreadability of the ink. However, during the ink-jet process, the viscosity of the ink should be kept low (20 cP or less). In this case, the ink easily spreads when the ink is dropped on the substrate. In order to solve such a problem and to control the spreadability of the ink, there is a need for research on an ink which maintains a low viscosity during the inkjet process and has a high viscosity after jetting and does not spread well.

Accordingly, an object of the present invention is to provide an ink composition for a 3D printing support which can be used in an inkjet 3D printer, easily control the spreadability of ink, and is easily dissolved in water after curing to facilitate removal of the support .

In order to achieve the above object, the present invention provides a phase change material comprising: a phase change material; A photopolymerizable monomer having at least one of a monomer including an amine group and a monomer including a hydroxy group; And a curing agent. The present invention also provides an ink composition for a 3D printing support.

The ink composition for a 3D printing support according to the present invention is advantageous in that it can be used in an inkjet 3D printer, easily control the spreadability of the ink, and dissolves in water after curing to facilitate removal of the support.

Hereinafter, the present invention will be described in detail.

The ink composition for a 3D printing support according to the present invention comprises a photopolymerizable monomer and a curing agent, which is at least one of a phase change material, a monomer containing an amine group and a monomer containing a hydroxy group.

The phase change material (or the phase change material) may be in the form of a solid or a gel state at room temperature, but may be a liquid state capable of jetting when heating, . That is to say, such a phase change material is contained in the ink and is converted into a liquid state capable of jetting only upon heating, wherein the liquid state ink has a viscosity of 20 cP or less, preferably 15 cP or less . Therefore, when the phase change material is contained in the ink, the ink can be jetted at a high temperature, and when the ink drops onto the substrate after the jetting process, the ink is cooled (the temperature of the ink is lowered) Therefore, the spreadability of the ink can be minimized.

The phase change material may be a linear or branched hydrocarbon compound having 6 to 30 carbon atoms containing one oxygen (O) atom, preferably a (higher, higher) alcohol having 14 to 22 carbon atoms containing one oxygen atom, Or a linear or branched hydrocarbon compound having 6 to 30 carbon atoms and containing 2 oxygen atoms, preferably a (higher) fatty acid compound having 14 to 22 carbon atoms and containing 2 oxygen atoms, May be used singly or in combination of two or more.

Specific examples of the case where the phase change material in (advanced) alcohol compound with a carbon number of 14 to 22 (or, a hydrocarbon compound) containing one oxygen atom, myristyl alcohol (Myristyl alcohol, C ₁₄ H ₃₀ O), cetyl alcohol _{(Cetyl alcohol, C 16 H 34} O), 9- cyclohepta decanol _{(9-heptadecanol, C 17 H} 36 O), stearyl alcohol _{(stearyl alcohol, C 18 H 38} O) and behenyl alcohol (behenyl alcohol, C ₂₂ H ₄₆ O), and the above-mentioned phase change material is a (higher) fatty acid compound (or a hydrocarbon compound) having 14 to 22 carbon atoms and containing two oxygen atoms, there may be mentioned Myristic acid , C ₁₄ H ₂₈ O ₂ ), palmitic acid (C ₁₆ H ₃₂ O ₂ ), and behenic acid (docosanoic acid, C ₂₂ H ₄₄ O ₂ ).

The content of the phase change material is 3 to 75% by weight, preferably 10 to 60% by weight, more preferably 15 to 55% by weight based on the total weight of the ink composition according to the present invention, If the content of the phase-change material is less than 3% by weight based on the total weight of the ink composition, the ink may not function as a phase-change material and the ink may excessively spread when the ink is dropped on the substrate. If it exceeds 75% by weight, the support cured film may not be dissolved in water and may not be removed.

The melting point (mp) of the phase-change material is 35 to 120 ° C, preferably 40 to 100 ° C, more preferably 50 to 80 ° C. When the melting point of the phase-change material is less than 35 ° C, When the ink falls on the substrate, the ink is not solidified and may not function as a phase change ink. When the melting point of the phase change material exceeds 120 캜, excessive heating of the ink for jetting must be performed For example, the stearyl alcohol has a melting point of 71 to 71.5 ° C, and the cetyl alcohol has a melting point of about 49.3 ° C. In addition, the melting point of the ink composition according to the present invention is also in the range of 35 to 120 ° C, preferably 40 to 100 ° C, more preferably 50 to 80 ° C, similar to the melting point of the phase change material contained in the ink composition.

Next, the photopolymerizable monomer contained in the ink composition for a 3D printing support according to the present invention, which is at least one of a monomer containing an amine group and a monomer containing a hydroxyl group will be described. The photopolymerizable monomer having at least one of the monomer containing an amine group and the monomer containing a hydroxy group is included in the ink composition to improve the dissolving power for water when the support is removed. In particular, when the ink film is hardened, And may be used alone or in combination of two or more. On the other hand, such a photopolymerizable monomer may contain at least one double bond, and if the double bond is included in the monomer, the photopolymerization can be performed to firmly cure the ink, thereby securing a desired supporting ability It is possible.

The monomer containing an amine group (hereinafter, mixed with an amine-containing monomer) is not particularly limited as long as it is used in the art, but is preferably a monomer having 1 to 30 carbon atoms and at least one amine group, For example, N, N-dimethyl acrylamide (DMA), diacetone acrylamide (DAA), and the like, may be used. N-methyl-N-vinylacetamide (NMNVA), N- [3- (dimethylamino) propyl] methacrylamide, N-vinyl pyrrolidone (VP), 4-acryloylmorpholine (ACMO), 2- (dimethylamino) ethylacrylate, , N-methacryloylmorpholine, isopropyl a (meth) acrylamide 2-oxazoline, 2-ethyl-2-oxazoline, N-isopropyl-2-oxazoline, (N-isopropyl-2-oxazoline), ethylene imine (or aziridine), and mixtures thereof.

The monomer containing a hydroxy group (hereinafter, mixed with a hydroxy group-containing monomer) is not particularly limited as long as it is used in the art, but it is preferably a monomer having 1 to 30 carbon atoms and at least one hydroxyl group, May be a monomer having 2 to 10 carbon atoms and containing at least one hydroxyl group, for example, 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate ), 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and mixtures thereof.

The content of the photopolymerizable monomer is 10 to 90% by weight, preferably 30 to 85% by weight, more preferably 40 to 80% by weight based on the total weight of the ink composition according to the present invention, If the content of the photopolymerizable monomer is less than 10% by weight based on the total weight of the ink composition, there is a fear that the dissolution characteristics with respect to water may not be sufficient when the support is removed. When the content of the photopolymerizable monomer exceeds 90% , There is a possibility that the properties as the phase change ink are lowered.

When the photopolymerizable monomer contains both a monomer having an amine group and a monomer having a hydroxy group, there is no particular limitation on the composition ratio thereof, and the ratio can be variously controlled depending on the use environment and the like.

Finally, the curing agent is included in the ink composition for a 3D printing support according to the present invention, and can be used in a curing process through various curing methods. Various curing agents can be used depending on the curing method. Can be used without. More specifically, a photoinitiator may be used as the curing agent, and there is no particular limitation as long as it is used in the art in accordance with the light source to be used. Preferably, Irgacure 819 (Bis acryl phosphine type), Darocur TPO ), Irgacure 369 (α-aminoketone type), Irgacure 184 (α-hydroxyketone type), Irgacure 907 (α-aminoketone type), Irgacure 2022 (Bis acryl phosphine / Darocur ITX (isopropyl thioxanthone) or a similar photoinitiator may be used.

The curing agent may be included in an amount of 0.01 to 20% by weight, preferably 1 to 10% by weight, more preferably 1 to 5% by weight based on the total weight of the ink composition for a 3D printing support according to the present invention. If the content of the curing agent is less than 0.01% by weight, curing may not occur. If the content is more than 20% by weight, the curing sensitivity may excessively increase and the head may be clogged.

On the other hand, the ink composition for a 3D printing support according to the present invention may further comprise a water-soluble polymer, if necessary. The water-soluble polymer is used to control the viscosity of the ink and to allow the cured product (support) to dissolve more easily in water. Conventional water-soluble polymers can be used without limitation, for example, polyacrylic acid, PAA), poly (2-hydroxyethyl acrylate), and poly (2-hydroxyethyl methacrylate). On the other hand, the water-soluble polymer may be in the form of a co-polymer obtained by polymerizing two or more kinds of monomers besides a homo-polymer in which only one monomer is polymerized. When the water-soluble polymer is used, the content thereof is 0.01 to 30% by weight based on the total weight of the ink composition for a 3D printing support according to the present invention. If the content of the water-soluble polymer is less than 0.01% by weight based on the total weight of the ink composition, The effect of increasing the solubility may be insignificant depending on the addition, and if it exceeds 30% by weight, the viscosity of the ink may excessively increase and jetting may become difficult.

The ink composition for a 3D printing support according to the present invention may further contain at least one additive such as a surfactant, a plasticizer, a (thermal) polymerization inhibitor, a stabilizer, a defoaming agent, a diluent, The additives may include the minimum amount in which the action can take place economically, and preferably 0.01 to 5% by weight based on the total weight of the ink composition.

According to the ink composition for a 3D printing support according to the present invention described so far, it is possible to form a molding more precisely by controlling the spreading property of the ink, and to prevent mixing with the ink constituting the support of the molding. In addition, since the ink for a 3D printing support according to the present invention has a property of being easily dissolved in water, the support can be easily removed after the molding is formed.

In addition, the present invention provides a method for manufacturing 3D printing using the above-described ink composition for a 3D printing support, and there is no particular limitation as long as it is a manufacturing method related to a 3D printing process.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as set forth in the appended claims. Such changes and modifications are intended to be within the scope of the appended claims.

Example

Manufacture of ink

As shown in the following Table 1, inks like those of Examples 1 to 4 were prepared by mixing a photopolymerizable monomer and a curing agent, which are at least one of a monomer containing a amine group and a monomer containing a hydroxyl group, and a curing agent, The inks of Comparative Examples 1 to 3 were prepared with the compositions shown in Table 1 below.

Phase change material Photopolymerizable monomer Hardener Example 1 Cetyl alcohol
(50% by weight) IPAM
(47% by weight) I 819
(3% by weight) Example 2 Cetyl alcohol
(50% by weight) IPAM + HEMA
(37% by weight + 10% by weight) I 819
(3% by weight) Example 3 Cetyl alcohol
(50% by weight) IPAM + ACMO
(37% by weight + 10% by weight) I 819
(3% by weight) Example 4 Stearic alcohol
(20% by weight) IPAM + HEMA
(38.5% by weight + 38.5% by weight) I 819
(3% by weight) Comparative Example 1 - IPAM + HEMA
(37% by weight + 60% by weight) I 819
(3% by weight) Comparative Example 2 - DMA + VP
(48.25% by weight + 48.25% by weight) I 819
(3.5% by weight) Comparative Example 3 Cetyl alcohol
(80% by weight) IPAM
(17% by weight) I 819
(3% by weight)

PAM: Isopropyl acrylamide

HEMA: 2-hydroxyethyl methacrylate

ACMO: 4-acryloylmorpholine

DMA: N, N-dimethyl acrylamide

VP: N-vinylpyrrolidone

Experimental Example

Supports were prepared using the inks of Examples 1 to 4 and Comparative Examples 1 to 3, and the solubility and pattern of the prepared support in water were evaluated. The results are shown in Table 2 below. The viscosity and melting point (mp) of each ink were also shown.

Experimental Example  1. Evaluation of solubility in water

Each of the inks prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was dropped onto a film substrate with a sphere and exposed to 1,000 mJ / cm ² using a high-pressure mercury lamp. Subsequently, several layers were repeatedly formed to prepare a support ink cured specimen. The specimen was taken out from the substrate and immersed in water. Sonicated bottle was immersed in the ink cured product and sonicated for 60 minutes to obtain a cured support film The solubility was evaluated by confirming the dissolution in water. The results are shown in Table 2 below. In this case, when it was dissolved in water, it was indicated by?, When only a part of the components were dissolved,?, And when it was not dissolved, it was indicated by x. On the other hand, it means that the cured support component dissolves in water to remove all of the cured masses, and a trace amount of residue component (i.e., a component similar to the powder) may remain. Therefore, "when only a part of components is melted" indicated by? Means that not only a small amount of residue components remain but only a part of the cured mass of the support is melted and removed.

Experimental Example  2. Pattern formation evaluation

Each of the inks prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was subjected to a heat treatment under the conditions of a jetting voltage of 85 V and a jetting frequency of 1,000 Hz at 70 ° C in Examples 1 to 3 and Comparative Example 3, (InnoCure 5000, manufactured by LICHTZEN), which was set at a temperature of 85 占 폚, and the temperature of Comparative Examples 1 and 2 was set at 25 占 폚 through an 80 pL Nova head, dpi, respectively, and the results are shown in Table 2 below.

Viscosity (cP) Melting point (캜) Solubility in water Pattern evaluation (1270 dpi) Example 1 6.06 (at 70 < 0 > C) 50 to 55 ○ Width: 5.5 mm, thickness: 145 占 퐉 Example 2 5.20 (at 70 < 0 > C) 50 to 55 ○ Width: 5.8 mm, thickness: 125 탆 Example 3 5.25 (at 70 < 0 > C) 50 to 55 ○ Width: 5.8 mm, thickness: 129 占 퐉 Example 4 3.40 (at 70 < 0 > C) 75 to 80 ○ Width: 5.6 mm, thickness: 138 占 퐉 Comparative Example 1 11.6 (at 25 < 0 > C) - ○ Width: 7.8 mm, thickness: 45 탆 Comparative Example 2 1.8 (at 25 C) - ○ The ink spreads too much by a few millimeters,
No pattern formation Comparative Example 3 6.44 (at 70 < 0 > C) 50 to 55 × Not soluble in water,
Not rated

As shown in Table 2 above, it can be confirmed that the inks prepared from the compositions of Examples 1 to 4, respectively, are superior in solubility and patternability in water (of the support cured film formed of ink). Comparative Examples 1 and 2 without addition of a phase change material also showed good solubility in water, but Comparative Example 3 in which an excessive amount of phase change material (80 wt%) was added showed poor solubility. In the case of patterning, since each ink prepared from the compositions of Examples 1 to 4 has low spreadability, it is possible to realize a high-resolution pattern having a thin width and a high thickness as shown in Table 2, (I.e., the higher the height of one layer, the faster the 3D sculpture can be made). That is, in the case of Example 1, a pattern with a line width of 5.5 mm similar to the line width (5.12 mm) originally discharged at 1,270 dpi was obtained, which means that the ink was not spread from the substrate after the ink was discharged The same was true for Examples 2 to 4).

On the other hand, in the case of Comparative Example 1, it is confirmed that it is difficult to form a pattern with a thin width, and it is not easy to precisely form a molding, because the ink spreads well and has a large line width (7.8 mm) I could. That is, since the ink viscosity of Comparative Example 1 is very similar to the viscosity of an ink used in a conventional inkjet process, control of spreadability is relatively difficult.

Claims (16)

Phase change material;
A photopolymerizable monomer having at least one of a monomer including an amine group and a monomer including a hydroxy group; And
An ink composition for a 3D printing support comprising a curing agent. The ink composition according to claim 1, wherein the phase change material is a linear or branched hydrocarbon compound having from 6 to 30 carbon atoms containing one or two oxygen atoms. The method according to claim 2, wherein the hydrocarbon compound is selected from the group consisting of myristyl alcohol, cetyl alcohol, 9-heptadecanol, stearyl alcohol, and behenyl alcohol. ≪ / RTI > is an alcohol compound selected from the group consisting of: < RTI ID = 0.0 > The 3D printing support according to claim 2, wherein the hydrocarbon compound is a fatty acid compound selected from the group consisting of Myristic acid, Palmitic acid, and behenic acid. Composition. The ink composition of claim 1, wherein the phase change material has a melting point of from 35 to 120 占 폚. The ink composition according to claim 1, wherein the content of the phase change material is 3 to 75% by weight based on the total weight of the ink composition. The ink composition for a 3D printing support according to claim 1, wherein the monomer containing an amine group is a monomer having 1 to 30 carbon atoms and at least one amine group. The ink composition for a 3D printing support according to claim 1, wherein the monomer containing a hydroxy group is a monomer having 1 to 30 carbon atoms and at least one hydroxyl group. [4] The method according to claim 1, wherein the monomer containing an amine group is at least one selected from the group consisting of N, N-dimethylacrylamide, diacetone acrylamide, N- [3- (dimethylamino) propyl] methacrylamide, Methyl acrylate, 2-methyl-2-oxazoline, 2-methyl-2-oxazoline, 2- -Ethyl-2-oxazoline, N-isopropyl-2-oxazoline, ethyleneimine, and mixtures thereof. [2] The method of claim 1, wherein the monomer containing a hydroxy group is selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl And mixtures thereof. ≪ RTI ID = 0.0 > 11. < / RTI > The ink composition for a 3D printing support according to claim 1, wherein the content of the photopolymerizable monomer is 10 to 90% by weight based on the total weight of the ink composition. The ink composition according to claim 1, wherein the curing agent is a photoinitiator. The ink composition for a 3D printing support according to claim 1, wherein the content of the curing agent is 0.01 to 20% by weight based on the total weight of the ink composition for the 3D printing support. The ink composition according to claim 1, wherein the ink composition further comprises a water-soluble polymer selected from the group consisting of polyacrylic acid, poly (2-hydroxyethyl acrylate) and poly (2-hydroxyethyl methacrylate) Wherein the ink composition is a three-dimensional printing support. The ink composition according to claim 1, wherein the ink composition further comprises at least one additive selected from the group consisting of a surfactant, a plasticizer, a (thermal) polymerization inhibitor, a stabilizer, a defoamer, a diluent, Ink composition for support. The ink composition for a 3D printing support according to claim 1, wherein the melting point of the ink composition is 35 to 120 占 폚.