KR102125596B1 - An Ink Composition for 3D Printing Support - Google Patents

Abstract

Disclosed is an ink composition for a 3D printing support that can be used in an inkjet 3D printer, is easy to control the spreadability of ink, and is easily dissolved in water after curing, so that the support can be easily removed. The 3D printing support ink composition includes a phase change material; A photopolymerizable monomer having at least one of a monomer containing an amine group and a monomer containing a hydroxy group; And a curing agent.

Description

An ink composition for 3D printing support

The present invention relates to an ink composition for a 3D printing support, and more specifically, it can be used in an inkjet 3D printer, it is easy to control the spreadability of ink, and it is easily dissolved in water after curing, so it is easy to remove the support. It relates to an ink composition for a 3D printing support.

A 3D printer (three dimentional printer) is a type of printer that photographs a specific object in three dimensions, and is a device that can create a real object in a three-dimensional space as if a three-dimensional design is printed on paper. Just like the principle of printing a 2D image by jetting ink onto a paper surface when a digitized file is transferred from an inkjet printer, the 2D printer moves only forward and backward (x-axis) and left and right (y-axis), but the 3D printer moves up and down ( z-axis) is added to create a three-dimensional object based on the input 3D drawing.

In order to form a sculpture with an inkjet 3D printer, a structure ink for forming the sculpture and a support ink for forming a support in the form of a bridge or floating in the air to support the sculpture. Is needed. These support inks must be sprayed on the substrate at the same time as the structure inks or sprayed sequentially, and then cured together. At this time, the two types of inks should not be mixed with each other, and each should be able to form a desired pattern shape. In addition, it should be possible to control the spreadability of the ink. On the other hand, since the support formed by the support ink is a part temporarily formed to support it well when forming a structure (structure), it must be removed well after the structure is completed.

Republic of Korea Patent Publication 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 target pattern shape, it is necessary to control the spreadability of the ink. However, during the inkjet process, the viscosity of the ink should be kept low (20 cP or less), and in this case, there is a problem that the ink spreads easily when the ink is dropped on the substrate. In order to solve such a problem and control the spreadability of the ink, there is a need for a study of an ink that maintains a low viscosity during an inkjet process and increases in viscosity after jetting, and thus does not spread well.

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

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

According to the ink composition for a 3D printing support according to the present invention, it can be used in an inkjet 3D printer, has an advantage in that it is easy to control the spreadability of the ink and is easily soluble in water after curing, so that the support can be easily removed.

Hereinafter, the present invention will be described in detail.

The ink composition for a 3D printing support according to the present invention includes a photopolymerizable monomer and a curing agent which are 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 phase change material), the ink (composition) for the 3D printing support according to the present invention exists in a solid or gel state at room temperature, but in a liquid state capable of jetting during heating It is an ingredient that changes. In other words, by including such a phase change material in the ink, it is converted into a liquid state that can be jetted only upon heating, wherein the liquid ink has a viscosity of 20 cP or less, preferably 15 cP or less. . Therefore, when the phase change material is included in the ink, jetting is possible at a high temperature, and when the ink falls on the substrate after the jetting process, the ink cools (the temperature of the ink is lowered) and changes into a solid (or gel) state. Therefore, the spreadability of the ink can be minimized.

The phase change material is a linear or branched hydrocarbon compound having 6 to 30 carbon atoms containing one oxygen (O) atom, and preferably a (higher grade) alcohol having 14 to 22 carbon atoms containing one oxygen atom. A compound or a linear or branched hydrocarbon compound having 6 to 30 carbon atoms containing 2 oxygen atoms, preferably a (higher) fatty acid compound having 14 to 22 carbon atoms containing 2 oxygen atoms, these compounds Can be used alone or in combination of two or more.

Specific examples of the case where the phase change material is a (higher) alcohol compound having 14 to 22 carbon atoms (or a hydrocarbon compound) containing one oxygen atom, Myristyl alcohol (C ₁₄ H ₃₀ O), Cetyl alcohol (Cetyl alcohol, C ₁₆ H ₃₄ O), 9-heptadecanol (C ₁₇ H ₃₆ O), Stearyl alcohol (C ₁₈ H ₃₈ O) and Behenyl alcohol (C) ₂₂ H ₄₆ O), and specific examples of the case where the phase change material is a (high-grade) fatty acid compound having 14 to 22 carbon atoms (or a hydrocarbon compound) containing 2 oxygen atoms, myristic acid (Myristic acid) , C ₁₄ H ₂₈ O ₂ ), palmitic acid (C ₁₆ H ₃₂ O ₂ ), behenic acid or docosanoic acid (C ₂₂ H ₄₄ O ₂ ), and the like.

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 relative to the total weight of the ink composition according to the present invention, the content of the phase change material If it is less than 3% by weight relative to the total weight of the ink composition, it does not function as a phase change material, and there is a fear that the ink may spread excessively when the ink is dropped on the substrate, and the content of the phase change material is relative to the total weight of the ink composition. When it exceeds 75% by weight, a problem that the support cured film is not easily dissolved in water may not be removed.

In addition, 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, and if the melting point of the phase change material is less than 35°C, When the ink falls on the substrate, there is a fear that the ink does not solidify and cannot function as a phase change ink, and when the melting point of the phase change material exceeds 120° C., the ink must be excessively heated for jetting. Therefore, there is a concern that a material stability problem may occur. For example, the melting point of the stearyl alcohol is 71 to 71.5°C, and the melting point of the cetyl alcohol is about 49.3°C. In addition, the melting point of the ink composition according to the present invention is also 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 included in the ink composition.

Next, a photopolymerizable monomer which is at least one of a monomer containing an amine group and a monomer containing a hydroxyl group, which is included in the ink composition for a 3D printing support according to the present invention, will be described. The photopolymerizable monomer having at least one of the monomer containing the amine group and the monomer containing the hydroxy group is included in the ink composition to improve the solubility in water when the support is removed, especially to maintain good solubility in water even when the ink film is cured. It can be used alone or in combination of two or more. On the other hand, as such a photopolymerizable monomer may contain one or more double bonds. When the double bond is included in the monomer, photopolymerization is possible to harden the ink, thereby securing a desired support capacity. It is possible.

The monomer containing the amine group (hereinafter, mixed with'amine-containing monomer') is not particularly limited as long as it is used in the art, preferably a monomer having 1 to 30 carbon atoms containing at least one amine group, more preferably May be a monomer having 2 to 10 carbon atoms containing at least one amine group, for example, N,N-dimethyl acrylamide (N,N-dimethyl acrylamide, DMA), diacetone acrylamide (DAA), N-[3-(dimethylamino)propyl]methacrylamide (DMAPMA), N-methyl-N-vinylacetamide (NMNVA) , 2-(dimethylamino)ethylacrylate (DMAEA), N-vinyl pyrrolidone (VP), 4-acryloylmorpholine (ACMO) , N-methacryloylmorpholine, isopropyl acrylamide (IPAM), 2-methyl-2-oxazoline, 2-ethyl-2- It may be oxazoline (2-ethyl-2-oxazoline), N-isopropyl-2-oxazoline, Ethylene imine, or aziridine, and mixtures thereof. have.

The monomer containing the hydroxy group (hereinafter, mixed with the'hydroxy group-containing monomer') is also not particularly limited as long as it is used in the art, preferably a monomer having 1 to 30 carbon atoms containing at least one hydroxy group, more preferably May be a monomer having 2 to 10 carbon atoms containing at least one hydroxy group, for example, 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (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, the content of the photopolymerizable monomer If it is less than 10% by weight based on the total weight of the ink composition, there is a fear that the dissolving property in water may not be sufficient when the support is removed, and when the content of the photopolymerizable monomer exceeds 90% by weight based on the total weight of the ink composition , There is a possibility that the properties as a phase change ink are deteriorated.

On the other hand, when both the monomer containing an amine group and a monomer containing a hydroxy group are included in the photopolymerizable monomer, the composition ratio is not particularly limited, and the ratio can be variously adjusted according to 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 to be used in a curing process through various curing methods, and various curing agents may be used depending on the curing method, and the conventional curing agent is limited. 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 according to the light source to be used. ), Irgacure 369 (α-aminoketone system), Irgacure 184 (α-hydroxyketone system), Irgacure 907 (α-aminoketone system), Irgacure 2022 (Bis acryl phosphine/α-hydroxyketone system), Irgacure 2100 (Phosphine oxide system), Commercial products such as Darocur ITX (isopropyl thioxanthone) or a similar structure 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, and 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, there is a fear that curing does not occur, and if it exceeds 20% by weight, the curing sensitivity may rise excessively and the head may be clogged.

Meanwhile, the ink composition for a 3D printing support according to the present invention may further include a water-soluble polymer if necessary. The water-soluble polymer is to adjust the viscosity of the ink, and to make the cured product (support) more readily soluble in water, a conventional water-soluble polymer can be used without limitation, for example, polyacrylic acid (Polyacrylic acid, PAA), poly(2-hydroxyethyl acrylate) and poly(2-hydroxyethyl methacrylate). Meanwhile, the water-soluble polymer may be in the form of a co-polymer in which two or more types of monomers are polymerized, in addition to the homo-polymer form 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, and if the content of the water-soluble polymer is less than 0.01% by weight relative to the total weight of the ink composition, The effect of increasing the solubility due to the addition may be negligible, and when it exceeds 30% by weight, the viscosity of the ink may increase excessively, making jetting difficult.

In addition, the ink composition for a 3D printing support according to the present invention may further include any one or more additives such as surfactants, plasticizers, (thermal) polymerization inhibitors, stabilizers, antifoaming agents, diluents, and viscosity modifiers, if necessary. The additives may include a minimum amount in which the above action can occur in an economical aspect, and preferably may be included in an amount of 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 more precise molding by controlling the spreadability of the ink, and it is possible to prevent mixing of the ink constituting the support of the molding. In addition, since the ink for a 3D printing support according to the present invention is easily soluble in water, there is an advantage that the support can be easily removed after formation of the molding.

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

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely illustrative of the present invention, and it is apparent to those skilled in the art that various changes and modifications are possible within the scope and technical thought scope of the present invention. It is natural that such changes and modifications fall within the scope of the appended claims.

Example

Preparation of ink

As shown in Table 1 below, an ink as in Examples 1 to 4 was prepared by mixing a phase change material, a monomer containing an amine group, and a photopolymerizable monomer and a curing agent having at least one of a monomer containing a hydroxy group, etc. Inks of Comparative Examples 1 to 3 were prepared with the composition 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 wt%) 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 patterns of the prepared supports in water were evaluated, and the results are shown in Table 2 below. The viscosity and melting point (mp) of each ink was also indicated.

Experimental Example 1. Evaluation of solubility in water

Each ink prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was dropped onto a film substrate with an eyedropper, and then exposed to 1,000 mJ/cm ² with a high-pressure mercury lamp. Subsequently, a plurality of layers are repeatedly formed to prepare a specimen of a support ink cured product, which is removed from the substrate and immersed in water, and then a bottle in which the ink cured product is immersed is placed in a sonicator and subjected to sonication for 60 minutes, thereby curing the support film. Solubility was evaluated by confirming whether it was dissolved in water, and the results are shown in Table 2 below. At this time, it is indicated by an o mark when dissolved in water, a △ mark when only some components are dissolved, and a x mark when not dissolved. On the other hand, dissolving here means that the cured support component is dissolved in water to remove all of the cured mass, and at this time, a trace amount of residue (ie, a powder-like component) may remain. Accordingly, the'when only a part of the component is melted' denoted by Δ means that only a small amount of the cured support mass is melted and removed, not a trace amount of residue.

Experimental Example 2. Pattern formation evaluation

Each of the inks prepared in Examples 1 to 4 and Comparative Examples 1 to 3, under a jetting voltage of 85 V and a jetting frequency of 1,000 Hz, the temperatures of Examples 1 to 3 and Comparative Example 3 were 70° C., Example 4 The temperature of 85 ℃, the temperature of Comparative Examples 1 and 2 was injected through an ink jet head (80pL Nova head) set to 25 ℃, then formed by curing with a SPOT UV curing machine (InnoCure 5000, LICHTZEN) 1,270 Each was evaluated under the resolution conditions of dpi, and the results are shown in Table 2 below.

Viscosity (cP) Melting point (℃) Solubility in water Pattern evaluation (1270 dpi) Example 1 6.06 (at 70 ℃) 50~55 ○ Width: 5.5 mm, Thickness: 145 μm Example 2 5.20 (at 70 ℃) 50~55 ○ Width: 5.8 mm, Thickness: 125 μm Example 3 5.25 (at 70 ℃) 50~55 ○ Width: 5.8 mm, Thickness: 129 μm Example 4 3.40 (at 70 ℃) 75-80 ○ Width: 5.6 mm, Thickness: 138 μm Comparative Example 1 11.6 (at 25 ℃) - ○ Width: 7.8 mm, Thickness: 45 μm Comparative Example 2 1.8 (at 25 ℃) - ○ Ink spreads too many mm,
No pattern formation Comparative Example 3 6.44 (at 70 ℃) 50~55 × Insoluble in water,
Not rated

As shown in Table 2 above, it can be confirmed that all of the inks prepared from the compositions of Examples 1 to 4 were excellent in solubility and patternability in water (of the cured film formed of ink). Comparative Examples 1 and 2 without adding a phase change material also had good solubility in water, but it was found that Comparative Example 3 with an excess (80 wt%) of phase change material added had poor solubility. In the case of patterning, since each ink prepared from the compositions of Examples 1 to 4 has less spreadability, it is possible to implement a high-resolution pattern having a thin width and a high thickness, as shown in Table 2, so that precise formation of moldings is possible. It was possible (ie, because the height of one layer is higher, 3D sculptures can be produced faster). 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 hardly spread on the substrate after being ejected (the rest) Similarly for Examples 2 to 4).

On the other hand, in Comparative Example 1, it was confirmed that the ink spreads well and the line width (7.8 mm) is large and the thickness is also low (ie, a low aspect ratio), making it difficult to form a pattern with a thin width, and it is not easy to precisely form a molding. Could. That is, since the ink viscosity of Comparative Example 1 is very similar to that of an ink used in a conventional inkjet process, it is relatively difficult to control spreadability.

Claims (16)

Phase change material;
Photopolymerizable monomers; And
Curing agent; and
The photopolymerizable monomer contains a monomer containing an amine group,
The monomer containing the amine group is N,N-dimethylacrylamide, diacetoneacrylamide, N-[3-(dimethylamino)propyl]methacrylamide, N-methyl-N-vinyl acetamide, 2-(dimethylamino )Ethyl acrylate, N-vinylpyrrolidone, 4-acryloylmorpholine, N-methacryloylmorpholine, isopropylacrylamide, 2-methyl-2-oxazoline, 2-ethyl-2-oxa At least one selected from the group consisting of sleepy, N-isopropyl-2-oxazoline and ethyleneimine,
The content of the photopolymerizable monomer is 10 to 90% by weight relative to the total weight of the ink composition, 3D printing support ink composition. The method according to claim 1, wherein the phase change material is a linear or branched hydrocarbon compound having 6 to 30 carbon atoms containing one or two oxygen atoms, 3D printing ink composition for a support. The method according to claim 2, wherein the hydrocarbon compound Myristyl alcohol (Cetyl alcohol), 9-heptadecanol (9-heptadecanol), stearyl alcohol (Stearyl alcohol) and behenyl alcohol (Behenyl alcohol) Characterized in that it is an alcohol compound selected from the group consisting of, 3D printing support ink composition. The method according to claim 2, The hydrocarbon compound is myristic acid (Myristic acid), palmitic acid (Palmitic acid) and behenic acid (behenic acid), 3D printing support ink, characterized in that the fatty acid compound selected from the group consisting of Composition. The method according to claim 1, The melting point of the phase change material is characterized in that 35 to 120 ℃, 3D printing support ink composition. The method according to claim 1, The content of the phase change material, characterized in that 3 to 75% by weight relative to the total weight of the ink composition, 3D printing support ink composition. The ink composition for a 3D printing support according to claim 1, wherein the photopolymerizable monomer further contains a monomer containing a hydroxy group. The ink composition for a 3D printing support according to claim 7, wherein the monomer containing the hydroxy group is a monomer having 1 to 30 carbon atoms containing at least one hydroxyl group. delete The method according to claim 7, The monomer containing the hydroxy group, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth) acrylic Characterized in that it is selected from the group consisting of rates and mixtures thereof, 3D printing support ink composition. delete The method according to claim 1, The curing agent is characterized in that the photoinitiator, 3D printing support ink composition. The method according to claim 1, The content of the curing agent, characterized in that 0.01 to 20% by weight relative to the total weight of the ink composition for the 3D printing support, 3D printing support ink composition. The method according to claim 1, The ink composition is characterized in that it further comprises a water-soluble polymer selected from the group consisting of polyacrylic acid, poly (2-hydroxyethyl acrylate) and poly (2-hydroxyethyl methacrylate) The ink composition for 3D printing support. The method according to claim 1, The ink composition is characterized in that it further comprises any one or more additives selected from the group consisting of surfactants, plasticizers, (thermal) polymerization inhibitors, stabilizers, antifoaming agents, diluents and viscosity modifiers, 3D printing Ink composition for support. The method according to claim 1, The melting point of the ink composition is characterized in that 35 to 120 ℃, 3D printing ink composition for a support.