Patent Description:
A 3D printer is a printer that imprints a specific stuff three-dimensionally, and it is a device that can create a real object in a three-dimensional space as printing a three-dimensional design on a paper. Like the principle of printing a 2D image on a paper by jetting an ink onto the surface of the paper after a digitalized file is transferred to an inkjet printer, a 2D printer only moves front to back (x-axis) and left to right (y-axis), but the 3D printer adds an up-and-down (z-axis) motion to this to make a three-dimensional article based on the imputted 3D design.

When making a sculpture by this 3D printer, the sculpture of a bridge shape or a shape of floating in the air needs a support material. The support material should have a good supporting function when forming the sculpture and also should be well removed later.

Thus, a support ink which can be used in an inkjet type 3D printer is required, but the existing support ink had a problem that it needs a complicated removal process such as removing the support part manually or removing the support part one by one through a water jet method. For example, <CIT> discloses a support material for supporting shape when manufacturing an inkjet photo-shaped article, but in this case, there are problems that it takes much time and effort to remove the support part, it is difficult to remove completely, and contraction of the support is happened.

Thus, in order to solve these problems, studies for an ink which can be photo-cured and also removed by a simple method such as shaking in water after being cured or sonication are needed.

<CIT> discloses ink jet inks for support structures for printing of <NUM>-dimensional objects, comprising acryloylmorpholine, a water-soluble polymer of N-isopropylacrylamide, and hydroxy butyl vinylether.

The present invention has been made keeping in mind the above problems in the related art, and an object of the present invention is to provide an ink composition for a 3D printing support, which has an excellent jetting property, is well dissolved in water after being photo-cured to be easily removed, and has less curing contraction and excellent storage stability.

The present invention provides an ink composition for a 3D printing support comprising an amine-containing monomer and a photo-initiator, which ink composition further comprises a water soluble polymer, wherein the water soluble polymer is the compound of the following Formula 8a:
<CHM>.

According to the ink composition for a support,
there are advantages that it is well dissolved in water after being photo-cured to be easily removed, and has an excellent dimensional stability due to improved curing contraction characteristic.

The ink composition for a 3D printing support comprises an amine-containing monomer and a photo-initiator, which ink composition further comprises a water soluble polymer, wherein the water soluble polymer is the compound of the following Formula 8a:
<CHM>.

The ink composition for a 3D printing support according to the present invention, having the above composition, can provide an ink composition for a 3D printing support, which has an excellent jetting property, is well dissolved in water after being photo-cured to be easily removed, and has less curing contraction and excellent storage stability.

First, the ink composition for a 3D printing support according to the present invention comprises an amine-containing monomer. The ink composition for a 3D printing support of the present invention may have an excellent curing property and be dissolved in water after being cured by comprising the amine-containing monomer.

First, as the amine-containing monomer of the present invention, the compound of the following Formula <NUM> may be used.

In the Formula <NUM>, R<NUM> is hydrogen or methyl, and R<NUM> and R<NUM> are each independently hydrogen, C<NUM> to C<NUM> alkyl, vinyl, alkoxyl, cyclohexyl, phenyl, benzyl, alkylamine, alkyl ester, alkyl ether,.

Furher, preferably, in the Formula <NUM>, R<NUM> and R<NUM> may be each independently hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl,
<CHM>
R'<NUM> is CH<NUM>, CH<NUM>CH<NUM>, CH<NUM>CH<NUM>CH<NUM>, CH(CH<NUM>)CH<NUM>, CH<NUM>CH<NUM>CH<NUM>CH<NUM>, CH<NUM>C(CH<NUM>)<NUM> or C(CH<NUM>)<NUM>CH<NUM>CH<NUM>, R'<NUM> and R'<NUM> are each independently hydrogen, CH<NUM>, CH<NUM>CH<NUM>, CH<NUM>CH<NUM>CH<NUM>, CH<NUM>CH(CH<NUM>)<NUM>, CH<NUM>C(CH<NUM>)<NUM>, CH(CH<NUM>)<NUM>, CH<NUM>CH<NUM>CH<NUM>CH<NUM>, or C(CH<NUM>)<NUM>CH<NUM>CH<NUM> , R"<NUM> is CH<NUM>, CH<NUM>CH<NUM>, CH<NUM>CH<NUM>CH<NUM>, CH(CH<NUM>)CH<NUM>, CH<NUM>CH<NUM>CH<NUM>CH<NUM>, CH<NUM>C(CH<NUM>)<NUM> or C(CH<NUM>)<NUM>CH<NUM>CH<NUM>, and R"<NUM> is hydrogen, CH<NUM>, CH<NUM>CH<NUM>, CH<NUM>CH<NUM>CH<NUM>, CH<NUM>CH(CH<NUM>)<NUM>, CH<NUM>C(CH<NUM>)<NUM>, CH(CH<NUM>)<NUM>, CH<NUM>CH<NUM>CH<NUM>CH<NUM>, or C(CH<NUM>)<NUM>CH<NUM>CH<NUM>.

Further, preferably, the Formula <NUM> may be the following Formula 1a.

In the Formula 1a, R'<NUM> is hydrogen or methyl, and R'<NUM> and R'<NUM> are each independently hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, or tert-butyl.

Further, as the amine-containing monomer of the present invention, the compound of the following Formula <NUM> may be used. <CHM>
<CHM>.

In the Formula <NUM>, R'<NUM> and R'<NUM> are each independently hydrogen, C<NUM> to C<NUM> alkyl, vinyl, alkoxyl, cyclohexyl, phenyl, benzyl, alkylamine, alkyl ester or alkyl ether, and R'<NUM> is hydrogen or methyl.

Further, preferably, in the Formula <NUM>, R'<NUM> and R'<NUM> may be each independently hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl,
<CHM>
or
<CHM>.

Further, as the amine-containing monomer of the present invention, the compound of the following Formula <NUM> may be used.

In the Formula <NUM>, R<NUM> is hydrogen or methyl, R<NUM> is CH<NUM>, CH<NUM>CH<NUM>, CH<NUM>CH<NUM>CH<NUM>, CH(CH<NUM>)CH<NUM>, CH<NUM>CH<NUM>CH<NUM>CH<NUM>, CH<NUM>C(CH<NUM>)<NUM> or C(CH<NUM>)<NUM>CH<NUM>CH<NUM>, and R<NUM> and R<NUM> are each independently hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, -CH=CH<NUM> or -CH<NUM>-CH=CH<NUM>.

In the Formula <NUM>, n is an integer of <NUM> to <NUM>, A is C, O, N or S, R<NUM>, R<NUM> and R<NUM> are each independently hydrogen or C<NUM> to C<NUM> alkyl, and R<NUM> is -CH=CH<NUM>,
<CHM>
<CHM>
<CHM>.

Further, preferably, the Formula <NUM> may be ,
<CHM>
<CHM>
or
<CHM>.

Further, as the amine-containing monomer of the present invention, the compound of the following Formula <NUM>, Formula <NUM> or Formula <NUM> may be used. <CHM>
<CHM>
<CHM>
<CHM>.

The amine-containing monomer may be contained in an amount of <NUM> to <NUM> wt% based on the total weight of the ink composition of the present invention. If the amount of the amine-containing monomer is less than <NUM> wt%, water solubility may be insufficient when removing a support, and if the amount thereof is more than <NUM> wt%, a curing characteristic may be worsen.

The ink composition for a 3D printing support according to the present invention comprises a curing agent. The ink composition for a 3D printing support of the present invention may be used in a curing process through various curing methods by comprising the curing agent.

In the present invention, as the curing agent, various curing agents used in the art may be used depending on curing methods, without particular limitation. As a specific example of the curing agent, a photo-initiator may be used. The photo-initiator may be anything used in the art in accordance with a light source in use, without particular limitation. Preferably, it may be a commercial item, for example, Irgacure <NUM> (bis acryl phosphine-based), Darocur TPO (mono acryl phosphine-based), Irgacure <NUM> (α-aminoketone-based), Irgacure <NUM> (α-hydroxyketone-based), Irgacure <NUM> (α-aminoketone-based), Irgacure <NUM> (Bis acryl phosphine/α-hydroxyketone-based), Irgacure <NUM> (Phosphine oxide-based), Darocur ITX (isopropyl thioxanthone) or a photo-initiator having similar structure thereto.

In the present invention, the curing agent may be contained in an amount of <NUM> to <NUM> wt% based on the total weight of the ink composition of the present invention, and preferably, it may be contained in an amount of <NUM> to <NUM> wt%. If the amount of the curing agent is less than <NUM> wt%, curing may not be happened, and if the amount thereof is more than <NUM> wt%, a head may be blocked because curing sensitivity is too much increased.

The ink composition for a 3D printing support according to the present invention further comprises a monomer containing at least one of a vinyl group and an acrylate group. The ink composition for a 3D printing support of the present invention may have characteristics that it can control curing sensitivity and membrane properties such as strength of a cured product (softness or hardness), by comprising the monomer containing at least one of a vinyl group and an acrylate group.

In the present invention, the monomer containing at least one of a vinyl group and an acrylate group may be anything used in the art, without particular limitation. Preferably, it may be at least one selected from the group consisting of vinyl acetate, <NUM>-hydroxyethyl(meth)acrylate, <NUM>-hydroxymethyl(meth)acrylate, <NUM>-hydroxypropyl(meth)acrylate, <NUM>-hydroxybutyl(meth)acrylate, ethyl-<NUM>-hydroxyacrylate, <NUM>-(acryloyloxy)ethyl hydrogen succinate and methacylic acid.

In the present invention, the monomer containing at least one of a vinyl group and an acrylate group may be contained in an amount of <NUM> to <NUM> wt% based on the total weight of the ink composition of the present invention. If the amount of the monomer containing at least one of a vinyl group and an acrylate group is less than <NUM> wt%, it may be difficult to obtain sufficient effect according to addition of the monomer, and if the amount thereof is more than <NUM> wt%, a cured product may not be dissolved in water.

The ink composition for a 3D printing support according to the present invention further comprise a water soluble polymer. The ink composition for a 3D printing support of the present invention may have characteristics that it can control viscosity of the ink, and it allows the cured product to be easily dissolved in water, by comprising the water soluble polymer.

In the present invention, the water soluble polymer is the compound of the following Formula 8a
<CHM>
(In Formula 8a , n is <NUM> to <NUM>,<NUM>.

In the present invention, the water soluble polymer may be contained in an amount of <NUM> to <NUM> wt% based on the total weight of the ink composition of the present invention. If the amount of the water soluble polymer is less than <NUM> wt%, effect on solubility increase according to addition of the polymer may be minor, and if the amount thereof is more than 30wt%, jetting may be impossible due to increased viscosity of the ink.

The ink composition for a 3D printing support according to the present invention further comprises a vinyl ether compound. The ink composition for a 3D printing support of the present invention may prevent contraction of the cured product of the composition, by comprising the vinyl ether compound.

In the present invention, the vinyl ether compound is selected from <NUM>-hydroxybutyl vinyl ether(HBVE), ethyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether, <NUM>-ethylhexyl vinyl ether, dodecyl vinyl ether, diethylene glycol divinyl ether, <NUM>,<NUM>-cyclohexane dimethanol divinyl ether, triethylene glycol divinyl ether, and <NUM>,<NUM>-butanediol divinyl ether.

In the present invention, the vinyl ether compound may be contained in an amount of <NUM> to <NUM> wt% based on the total weight of the ink composition of the present invention. If the amount of the vinyl ether compound is less than <NUM> wt%, improvement of contraction while curing may be little, and if the amount there of is more than 50wt%, hardness and strength of the membrane while curing may become weak, and curing sensitivity may be reduced.

The ink composition for a 3D printing support according to the present invention may further comprise additives in addition to the above composition. The additives contained in the composition may be a surfactant, a plasticizer, a polymerization inhibitor, an antifoaming agent, a diluent, a thermal stabilizer, or a viscosity controlling agent.

The additives may be contained in the least amount that it can induce the above effects in terms of economics, and preferably contained in an amount of <NUM> to <NUM> wt% based on the whole ink composition.

Further, provided is a support manufactured with the ink composition for a 3D printing support mentioned above.

The support may be anything used in a 3D printing process without particular limitation.

Further, provided is a manufacturing method for 3D printing characterized by using the ink composition for a 3D printing support mentioned above.

The manufacturing method may be any manufacturing method related to a 3D printing process, without particular limitation.

The present invention will be explained in detail with reference to the following examples, including test examples. However, these examples are provided for illustrative purposes only and are not intended to limit the scope of the invention.

As shown in the following Table <NUM>, a monomer containing at least one of an amine-containing monomer, a vinyl group and an acrylate group (VIA monomer), a curing agent, a water soluble polymer, and a vinyl ether compound were mixed to prepare ink compositions of Examples <NUM> to <NUM>.

Further, ink compositions of Comparative Examples <NUM> to <NUM> were prepared as follows.

Supports were prepared using the ink compositions prepared in Examples <NUM> to <NUM> and Comparative Examples <NUM> to <NUM>. Specifically, <NUM> to <NUM> drops of the ink composition was dropped on a substrate and then exposed to a high pressure mercury lamp at <NUM> mJ/cm<NUM> to prepare a support. Then, hardness, solubility in water and improvement of curing contraction were evaluated as follows.

The ink composition was spin coated on a glass and exposed to a LED lamp of wavelength of <NUM>. Whether the composition was cured or not was observed with eyes while controlling exposure amount to <NUM> to <NUM> mJ/cm<NUM> and then curing sensitivity was decided. If the composition was cured successfully, it was decided as ∘, and if the composition was cured unsuccessfully, it was decided as ×. The results are shown in Table <NUM>.

The ink composition was dropped on a film substrate using a spuit, and then exposed to a high pressure mercury lamp at <NUM> mJ/cm<NUM>. Multiple layers were repeatedly formed to make a support ink cured product sample, and the sample was peeled off from the substrate and immersed in water. A bottle where the ink cured product was immersed was put in a sonicator and sonicated for <NUM> mins. Then, whether the cured product sample was dissolved or not was confirmed to evaluate solubility.

If the sample was dissolved well in water, it was decided as o, if the sample was dissolved little, it was decided as △, and if the sample was not dissolved in water, it was decided as ×. The results are shown in Table <NUM>.

The ink composition was dropped on a film substrate using a spuit, and then exposed to light for curing. Then whether the film was bent or not was observed. If the film was bent sharply, it was decided that curing contraction was happened, and if original shape of the film was kept, it was decide that there was no curing contraction.

If there was no curing contraction, it was decided as o, if there was small curing contraction, it was decided as △, if there was large curing contraction, it was decided as ×, and if the was sample was not dissolved in water, it was decided as - because improvement of curing contraction was not measured. The results are shown in Table <NUM>.

As shown in Table <NUM> of Test Example, the ink compositions of Example <NUM> to Example <NUM> had excellent hardness and solubility in water. In particular it can be found that the compositions of Example <NUM>, Example <NUM>, and Example <NUM> to Example <NUM> are excellent in terms of curing contraction. Herein, the term "soluble" means all states that, when the cured product is immersed in water and then shaken or sonicated, lumps of the cured product are dissolved in water, the cured product is dispersed in water, or the cured product is floated in water in the shape of fine powder. Thus, the ink compositions of Example <NUM> to Example <NUM> were evaluated that it is very sufficient for the ink composition for a support used in a 3D printing process.

Claim 1:
An ink composition for a 3D printing support comprising an amine-containing monomer and a photo-initiator, which ink composition further comprises a water soluble polymer, wherein the water soluble polymer is the compound of the following Formula 8a:
<CHM>
wherein n is <NUM> to <NUM>,<NUM> and
which ink composition further comprises a monomer containing at least one of a vinyl group and an acrylate group, and a vinyl ether compound,
wherein the vinyl ether compound is selected from <NUM>-hydroxybutyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether, <NUM>-ethylhexyl vinyl ether, dodecyl vinyl ether, diethylene glycol divinyl ether, <NUM>,<NUM>-cyclohexane dimethanol divinyl ether, triethylene glycol divinyl ether and <NUM>,<NUM>-butanediol divinyl ether,
wherein the amine-containing monomer is the compound of the following Formula <NUM>:
<CHM>
<CHM>
wherein R<NUM> is hydrogen or methyl, and R<NUM> and R<NUM> are each independently hydrogen, C<NUM> to C<NUM> alkyl, vinyl, alkoxyl, cyclohexyl, phenyl, benzyl, alkylamine, alkyl ester, alkyl ether,
<CHM>
the amine-containing monomer is the compound of the following Formula <NUM>:
<CHM>
wherein R'<NUM> and R'<NUM> are each independently hydrogen, C<NUM> to C<NUM> alkyl, vinyl, alkoxyl, cyclohexyl, phenyl, benzyl, alkylamine, alkyl ester or alkyl ether, and R'<NUM> is hydrogen or methyl,
the amine-containing monomer is the compound of the following Formula <NUM>:
<CHM>
wherein, R<NUM> is hydrogen or methyl, R<NUM> is CH<NUM>, CH<NUM>CH<NUM>, CH<NUM>CH<NUM>CH<NUM>, CH(CH<NUM>)CH<NUM>, CH<NUM>CH<NUM>CH<NUM>CH<NUM>, CH<NUM>C(CH<NUM>)<NUM> or C(CH<NUM>)<NUM>CH<NUM>CH<NUM>, and R<NUM> and R<NUM> are each independently hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, -CH=CH<NUM> or -CH<NUM>-CH=CH<NUM>,
the amine-containing monomer is the compound of the following Formula <NUM>:
<CHM>
wherein n is an integer of <NUM> to <NUM>, A is C, O, N or S, R<NUM>, R<NUM> and R<NUM> are each independently hydrogen or C<NUM> to C<NUM> alkyl, and R<NUM> is -CH=CH<NUM>,
<CHM>
<CHM>
<CHM>
or the amino-containing monomer is a compound selected from:
<CHM>
or
the amine-containing monomer is the compound of the following Formula <NUM>, Formula <NUM> or Formula <NUM>:
<CHM>
<CHM>
<CHM>
<CHM>