Composition for 3 dimensional printing

Abstract

The present application relates to a composition for 3D printing, a 3D printing method using the same, and a three-dimensional shape comprising the same, and provides an ink composition capable of realizing precise formation of a three-dimensional shape and uniform curing physical properties of the three-dimensional shape.

Claims

1. A composition for 3D printing comprising: magnetic particles having two or more magnetic domains; and gas-containing particles, wherein the magnetic domains are configured to be irregularly arranged when an external magnetic field is absent and are configured to be magnetized by an external alternate-current magnetic field, and wherein the magnetic particles and the gas-containing particles have surfaces that are physically or chemically bonded to each other.

2. The composition for 3D printing according to claim 1, wherein the magnetic particles and the gas-containing particles are included in a magnetic composite, and wherein, in the magnetic composite, the magnetic particles surround the gas-containing particles, or the gas-containing particles surround the magnetic particles.

3. The composition for 3D printing according to claim 2, wherein the magnetic composite has a density of 0.1 g/cm.sup.3 to 10 g/cm.sup.3.

4. The composition for 3D printing according to claim 1, wherein the magnetic particles comprise pure iron, iron oxide, ferrite, iron alloy, cobalt alloy, nickel alloy or manganese alloy.

5. The composition for 3D printing according to claim 1, wherein the magnetic particles have a coercive force in a range of 1 to 200 kOe.

6. The composition for 3D printing according to claim 1, wherein the magnetic particles have a saturation magnetization value at 25° C. in a range of 20 to 150 emu/g.

7. The composition for 3D printing according to claim 1, wherein the magnetic particles have an average particle diameter in a range of 20 to 300 nm.

8. The composition for 3D printing according to claim 1, wherein the magnetic domains have an average size in a range of 10 to 50 nm.

9. The composition for 3D printing according to claim 1, wherein the gas-containing particles are hollow particles.

10. The composition for 3D printing according to claim 1, wherein the gas-containing particles comprise an inorganic material, an organic material or an organic-inorganic composite.

11. The composition for 3D printing according to claim 1, wherein the gas-containing particles have an average size in a range of 10 nm to 100 μm.

12. The composition for 3D printing according to claim 1, wherein the gas-containing particles have a density of 0.01 g/cm.sup.3 to 1.02 g/cm.sup.3.

13. The composition for 3D printing according to claim 1, wherein the composition comprises the gas-containing particles in an amount of 80 to 200 parts by weight relative to 100 parts by weight of the magnetic particles.

14. The composition according to claim 1, further comprising a dispersant.

15. The composition for 3D printing according to claim 1, further comprising a thermosetting resin.

16. The composition for 3D printing according to claim 1, wherein the magnetic particles are configured to form magnetic clusters.

17. The composition for 3D printing according to claim 1, wherein the magnetic particles are configured to be vibrated by magnetization reversal.

18. A 3D printing method comprising forming a three-dimensional object with the composition for 3D printing of claim 1.

19. A three-dimensional object comprising a cured product of the composition for 3D printing of claim 1.

20. The composition for 3D printing according to claim 1, wherein the gas-containing particles are glass particles.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is photographs showing the compositions for 3D printing prepared in Examples and Comparative Examples of the present invention.

BEST MODE

(2) Hereinafter, the present invention will be described in more detail with reference to Example complying with the present invention and Comparative Examples not complying with the present invention, but the scope of the present invention is not limited by the following examples.

Example 1

(3) 0.2 g of magnetic particles (Fe.sub.2O.sub.3 particles, multi-magnetic domains, average particle diameter: about 100 nm: measured by Field Emission Scanning Electron Microscope (using DLS)) are treated through diluted hydrochloric acid, and reactive groups on the surface of the magnetic particles are activated to form positive charges on the surface. The acid-treated magnetic particles are dispersed in a polyacrylic acid aqueous solution and treated with about 120 W ultrasonic waves for 15 minutes. Magnetic particle-glass bubble particle composites are produced by reacting 0.3 g of glass bubble particles whose surface is substituted with amine groups (average particle diameter about 18 μm) and the magnetic particles in the aqueous solution such that the magnetic particles surround the surface of the glass bubble particles.

(4) Separately from the above, KSR-177 from Kukdo Chemical as an epoxy resin and an imidazole-based curing agent of Shikoku Kasei C11ZA as a curing agent were mixed at a weight ratio of 90:5 (KSR-177:C11ZA). A composition for 3D printing was prepared by dispersing the magnetic composites prepared in advance in the mixture so as to have a solid content of 5 wt %.

(5) Immediately after laminating the prepared composition on a support through a nozzle in a feeding device, a magnetic field was applied thereto with a current value of 100 A for 180 seconds in an external alternate-current magnetic field generator. The magnetic field was applied by introducing the composition into a sample vial in a solenoid coil (3 turns, OD 50 mm, ID 35 mm) and adjusting the current value and time of the magnetic field generator (Easyheat from Ambrell). The resin composition was cured with vibrational heat generated through application of the magnetic field to form a pattern or a three dimensional shape.

Example 2

(6) A composition for 3D printing was prepared and a three-dimensional shape was formed, in the same manner as in Example 1, except that MnOFe.sub.2O.sub.3 particles (multi-magnetic domains, average particle diameter about 100 nm: measured by Field Emission Scanning Electron Microscope (using DLS)) were used as the magnetic particles.

Comparative Example 1

(7) Ferromagnetic (hard type) Fe.sub.2O.sub.3 particles (single-magnetic domain, average particle diameter about 100 nm) as magnetic particles, a bisphenol-based epoxy resin and a curing agent were each mixed at a weight ratio of 5:95:5 to prepare a resin composition.

(8) Immediately after laminating the prepared composition on a support through a nozzle in a feeding device, a magnetic field was applied thereto with a current value of 100 A for 180 seconds in an external alternate-current magnetic field generator. The magnetic field was applied by introducing the composition into a sample vial in a solenoid coil (3 turns, OD 50 mm, ID 35 mm) and adjusting the current value and time of the magnetic field generator (Easyheat from Ambrell). The resin composition was thermally cured with vibrational heat generated through application of the magnetic field to form a pattern or a three-dimensional shape.

Experimental Example 1—Measurement of Coercive Force and Saturation Magnetization Value (Ms) of Magnetic Particles

(9) Coercive force and saturation magnetization Ms were measured by placing the magnetic particles dried at room temperature in a vibrating sample magnetometer (SQUID, measured by Korea Basic Science Institute) and using an HS curve (VSM curve) at ±1 Tesla as an external magnetic field.

Experimental Example 2—Measurement of Temperature of Composition after Curing

(10) For each three-dimensional shape produced in Examples and Comparative Example, immediately after the magnetic field application, a temperature inside the three-dimensional shape is confirmed by sticking a thermocouple therein.

Experimental Example 3—Measurement of Cure Degree (Visual Touch Sense)

(11) After curing each composition in Examples and Comparative Example, it was confirmed whether or not the cured product flowed when it was turned over after cooling, and then the curing was confirmed by checking the pressing degree of the cured product with a metal spatula. Here, it can be confirmed that when the cured product has been flowable and pressed, it has been not cured.

Experimental Example 4—Confirmation of Dispersibility Before Curing

(12) When the magnetic composites prepared in Example 1 and the magnetic particles in Comparative Example 1 were dispersed in PDMS (polydimethylsiloxane), respectively, they were observed immediately, 30 minutes and 2 hours after the dispersion, and the results were shown in order from the left side in FIG. 1 (as made, after 30 minutes, and after 2 hours). In FIG. 1, the left bottle is the result according to Comparative Example 1, and the right bottle is the result according to Example 1. As in FIG. 1, it could be confirmed that the magnetic particles according to Comparative Example 1 exhibited noticeable phase separation.

(13) TABLE-US-00001 TABLE 1 Coercive Temperature Measurement of Ms Force after Curing Cure Degree (emu/g) (kOe) (° C.) Visual Touch Sense Example 1 72 70 71 cured Example 2 80 94 76 cured Comparative 218 2000 35 non-cured Example 1