Method for manufacturing three-dimensional shaped object

1. A method for manufacturing a three-dimensional shaped object in which layers formed by ejecting and curing ink including a curing resin are laminated, the method comprising:

forming the layers by using a composition for three-dimensional shaped object including powder for three-dimensional shaped object constituted by particles; and

ejecting an object formation ink to form a region where the three-dimensional shaped object is provided and a sacrificial layer formation ink to form a sacrificial layer in a region at a side of an outermost layer of the three-dimensional shaped object, which is adjacent to a region to become the outermost layer of the three-dimensional shaped object,

during the ejecting, the object formation ink and the sacrificial layer formation ink penetrate into the layers while forming a boundary between a region where the object formation ink penetrates in the layers and a region where the sacrificial layer formation ink penetrates into the layers.

2. The method for manufacturing the three-dimensional shaped object according to claim 1 , wherein

the ejecting includes performing the ejecting of the object formation ink and the ejecting of the sacrificial layer formation ink within the same scanning, or within 100 milliseconds.

3. The method for manufacturing the three-dimensional shaped object according to claim 1 , wherein

an infiltration rate of the object formation ink and the sacrificial layer formation ink to the layers is adjusted.

4. The method for manufacturing the three-dimensional shaped object according to claim 3 , wherein

adjustment of the infiltration rate of the object formation ink and the sacrificial layer formation ink is performed by adjusting an ejecting amount of the object formation ink and the sacrificial layer formation ink.

5. The method for manufacturing the three-dimensional shaped object according to claim 1 , wherein

a curing material of the sacrificial layer formation ink has hydrophilicity.

6. The method for manufacturing the three-dimensional shaped object according to claim 1 , wherein

the sacrificial layer formation ink includes one or more elements selected from a group consisting of tetrahydrofurfuryl(meth)acrylate, ethoxyethoxyethyl (meth)acrylate, polyethylene glycol di(meth)acrylate, (meth)acryloyl morpholine, and (meth)acrylic acid 2-(2-vinyloxyethoxy)ethyl.

7. The method for manufacturing the three-dimensional shaped object according to claim 1 , wherein

the object formation ink includes one or more elements selected from a group consisting of (meth)acrylic acid 2-(2-vinyloxyethoxy)ethyl, polyether-based aliphatic urethane(meth)acrylate oligomer, 2-hydroxy-3-phenoxypropyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate.

8. The method for manufacturing the three-dimensional shaped object according to claim 1 , wherein

as the object formation ink, in addition to a colored ink including a coloring agent, a colorless ink that does not include the coloring agent is used, and

the colorless ink is used to form the region of the outermost layer, and the colored ink is used to form a region positioned inside than the outermost layer.

9. The method for manufacturing the three-dimensional shaped object according to claim 1 , wherein

as the colored ink including the coloring agent, color ink and white ink are used, and

the white ink is used to form a region inside than a region formed by using the colored ink.

10. The method for manufacturing the three-dimensional shaped object according to claim 1 , wherein

when a refractive index of the particles is denoted as n1, and when a refractive index of a curing material of the curing resin included in the object formation ink is denoted as n2, a relationship of |n1−n2|≦0.2 is satisfied.