TW201635022A - Photocuring three dimensional printing material and stereolithography printing method using the same - Google Patents

Abstract

A photocuring three dimensional printing material including a photocuring resin and a photoinitiator is provided. The photocuring resin is a UV resin, a visible light resin, or a mixture thereof. The photocuring resin includes at least one or more functional groups, including a carbonyl group, a nitro group, a phenyl group, a hydroxyl group or an amino group and is suitable for absorbing an infrared light of a wavelength ranging from 2.5 microns to 15 microns. The content of the photoinitiator ranges from 0.003 wt.% to 1 wt.%, relative to the total weight of the three dimensional printing material. A stereolithography three dimensional printing method using the same material is also provided.

Description

Light curing three-dimensional printing material and photocuring three-dimensional printing method using the same

The present invention relates to a printing material and a printing method, and more particularly to a photocuring three-dimensional printing material and a three-dimensional printing method.

3D printing technology, also known as Additive Manufacturing (AM) technology, is a kind of Rapid Prototyping (RP) technology. It uses the digital model file as the basis and uses material to accumulate layer by layer. The way to ultimately generate the required 3D objects. The physical construction generated by this technique can be very delicate and complicated, and a three-dimensional object of almost any shape can be manufactured without the aid of a mold during the molding process.

Existing three-dimensional printing has a variety of different molding mechanisms depending on the type of machine and material. Among them, Stereolithography (SLA) is based on the polymerization of a photocurable liquid resin, and is cured by ultraviolet light irradiation on a photocurable liquid resin, while the unilluminated photocurable resin will remain in a liquid state. . After completing a layer of construction, the surface of the cured resin is covered with a new layer of photocurable liquid resin, which is continuously repeated in accordance with such a pattern to form a multilayer structure to stack three-dimensional objects.

The use of photocuring technology is characterized by high precision and good surface quality, so that objects with more complicated shapes and fine shapes can be produced. However, the work environment in which a photocurable liquid resin is used is difficult to maintain and the long-term stability of the material is a common problem in the present technology. How to improve the reaction rate of photocurable resin polymerization, make the article solidify and form faster, and improve product yield, is also a subject to be studied at present.

The invention provides a photocuring three-dimensional printing material and a three-dimensional printing method using the same, which increases the reaction rate and makes the three-dimensional printing material solidify and form faster.

The present invention provides a photocured three-dimensional printing material comprising a photocurable resin and a photoinitiator. The photocurable resin is an ultraviolet curable resin, a visible light curable resin or a mixture thereof. The photocurable resin has at least one or more functional groups including a carbonyl group, a nitro group, a phenyl group, a hydroxyl group and an amino group, and the photocurable resin has a functional group having an absorption wavelength between 2.5 μm and 15 μm. infrared. The proportion of the photoinitiator is from 0.003 wt.% to 1 wt.% of the total weight of the three-dimensional printing material.

The photocuring three-dimensional printing method provided by the present invention comprises the following steps. First, a three-dimensional printing material is provided. The three-dimensional printing material comprises a photocurable resin and a photoinitiator, wherein the photocurable resin is an ultraviolet curable resin, a visible light curable resin or a mixture thereof. The photocurable resin has at least one or more functional groups, said functional groups The group includes a carbonyl group, a nitro group, a phenyl group, a hydroxyl group and an amino group. The proportion of the photoinitiator is from 0.003 wt.% to 1 wt.% of the total weight of the three-dimensional printing material. Infrared to three-dimensional printing material is then provided for heating, wherein the functional group of the photocurable resin in the three-dimensional printing material absorbs infrared rays, and the infrared wavelength is between 2.5 micrometers and 15 micrometers. Thereafter, ultraviolet or visible light is supplied to the three-dimensional printing material to trigger the conversion of the photoinitiator into a radical to cause the photocurable resin to undergo polymerization curing.

In an embodiment of the invention, the three-dimensional printing material and the three-dimensional printing method, wherein the photocurable resin comprises urethane acrylate, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, Polypropylene glycol diacrylate, propoxyglycerol triacrylate, ethoxylated bisphenol A diacrylate, pentaerythritol triacrylate, bisphenol A epoxy acrylate, amino modified polyether acrylate or mixtures thereof.

In an embodiment of the invention, the three-dimensional printing material and the three-dimensional printing method, wherein the photoinitiator comprises 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylbenzene Ketone, benzoin dimethyl ether, benzophenone, -hydroxyketone, benzoylformate, acylphosphine oxide or mixtures thereof.

In an embodiment of the invention, the three-dimensional printing material and the three-dimensional printing method, wherein the proportion of the photoinitiator is from 0.01 wt.% to 0.08 wt.% of the total weight of the three-dimensional printing material.

In an embodiment of the present invention, the three-dimensional printing material and the three-dimensional printing method, wherein the three-dimensional printing material further comprises ceramic powder, and the proportion of the ceramic powder is 5 vol.% to 85 vol of the total volume of the three-dimensional printing material. .%.

In an embodiment of the invention, the three-dimensional printing material and the three-dimensional column a printing method, wherein the three-dimensional printing material further comprises a ceramic powder, and the ceramic powder comprises zirconia, alumina, cerium oxide, cerium carbide, cerium nitride or a mixture thereof, and the proportion of the ceramic powder is the total of the three-dimensional printing material 20 vol.% to 80 vol.% by volume.

In an embodiment of the invention, the three-dimensional printing method described above, wherein the infrared to three-dimensional printing material is provided by means of non-contact heating.

Based on the above, the invention can heat the three-dimensional printing material by infrared rays, increase the reaction rate of resin polymerization, and make the three-dimensional printing material solidify and form faster, which not only can improve the product yield, but also can quickly produce a complicated shape by rapid prototyping technology. product.

The above described features and advantages of the invention will be apparent from the following description.

110‧‧‧Reaction tank

120‧‧‧3D printing materials

130‧‧‧lifting platform

132‧‧‧Action surface

140‧‧‧ objects

150‧‧‧Infrared heater

160‧‧‧UV source

1A is a schematic view showing the application of a three-dimensional printing method according to an embodiment of the present invention.

FIG. 1B is a schematic diagram of an application of a three-dimensional printing method according to an embodiment of the present invention.

In one embodiment of the present invention, a photocured three-dimensional printing material is proposed, the composition of which comprises at least a photocurable resin and a photoinitiator. The choice of photocurable resin depends on the specific functional group type and is used with infrared rays of a specific wavelength range to increase the absorption efficiency of the three-dimensional printing material for infrared rays. Further, when the photocurable resin When a specific functional group is present, such as a carbonyl group, a nitro group, a phenyl group, a hydroxyl group or an amino group, the ratio of absorption of infrared rays can be as high as 80% or more. In the present embodiment, the resin monomer or oligomer used in the photocurable resin is mainly an acrylate such as urethane acrylate, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, Polypropylene glycol diacrylate, propoxyglycerol triacrylate, ethoxylated bisphenol A diacrylate, pentaerythritol triacrylate, bisphenol A epoxy acrylate, amino modified polyether acrylate or mixtures thereof.

The above photoinitiator may, for example, be selected from the group consisting of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, benzoin dimethyl ether, benzophenone, -hydroxy ketone, benzene. Formylformate, acylphosphine oxide or a mixture thereof. In the present embodiment, the proportion of the photoinitiator is 0.003 weight percent (wt.%) to 1 weight percent (wt.%), preferably 0.01 wt.%, to the total weight of the three-dimensional printing material. 0.08 wt.%. When the photoinitiator absorbs ultraviolet light or visible light, it is converted into a radical and undergoes a chain polymerization reaction with the photocurable resin.

In addition, the present invention provides a photocuring three-dimensional printing method, which uses infrared light as a heating method to catalyze a photocurable resin reaction, thereby improving the curing speed of the three-dimensional printing material. The following is a detailed description of the embodiment.

First, a photocured three-dimensional printing material is provided, the components of which include a photocurable resin and a photoinitiator. Next, infrared rays are supplied to the three-dimensional printing material for heating. The infrared wavelength range referred to herein is, for example, between 2.5 μm and 15 μm, and is heated by infrared rays, for example, by non-contact heating, but the method of using infrared rays is not limited thereto. After that, in the case of providing infrared heating, simultaneous supply Ultraviolet or visible light to three-dimensional printing materials, using ultraviolet light or visible light to trigger the photoinitiator to cure the photocurable resin.

It should be noted that the principle adopted in the present embodiment is because in the organic reaction, the temperature rise can provide molecular kinetic energy to make it easier to overcome the reaction energy barrier and catalyze or accelerate the polymerization curing reaction when the ultraviolet light or visible light is subsequently supplied. . Therefore, in the step as described above, when the heating is performed by infrared rays, the reaction does not start, and after the actual irradiation of the ultraviolet light or the visible light, the photoinitiator in the three-dimensional printing material is triggered to be converted into ultraviolet light or visible light. Free radicals begin to undergo polymerization.

In other embodiments, the three-dimensional printing material may further comprise a ceramic powder. Since the absorption efficiency of the ceramic powder for the infrared light source is excellent (greater than 85%), in addition to the photocurable resin, the three-dimensional printing material can absorb infrared rays to achieve a heating effect, and the ceramic powder absorbs infrared rays and heats the surrounding resin by heat conduction. The subsequent curing efficiency is further improved, thereby improving the problem that the local printing material becomes slow after the general printing material is added to the ceramic powder. The ceramic powder may be selected, for example, from zirconia, alumina, cerium oxide, cerium carbide, cerium nitride or a mixture thereof. The proportion of the ceramic powder is from 5 volume percent (vol. %) to 85 volume percent (vol. %) of the total volume of the three-dimensional printing material, preferably from 20 vol.% to 80 vol.%.

Since the provided three-dimensional printing material is matched with infrared rays to help provide thermal energy, the content of the photoinitiator used in the three-dimensional printing material can be reduced compared to the conventional photocurable resin material, thereby improving the three-dimensional printing material. Stability, which can extend material storage time.

The following examples provide for the preparation of photocured three-dimensional printing materials and the application of a photocurable three-dimensional printing method.

First, the printing raw material of the present invention is prepared. A properly proportioned photocurable resin is mixed with a photoinitiator to form a three-dimensional printing material; or a suitably proportioned photocurable resin is uniformly mixed with a photoinitiator and a ceramic powder to form a three-dimensional printing material. The mixing method includes mixing and stirring using a physical means such as a homogenizer, a ball mill, a blender, a stirrer, a mortar, and a mortar.

Next, the prepared printing material is supplied to a three-dimensional printing machine, and then the printing material is cured by ultraviolet or visible light source laser on the forming table. Then, by repeating the foregoing steps using a three-dimensional printer, the three-dimensional molded object to be formed can be stacked layer by layer. Thereafter, the three-dimensional shaped article may be further dried or sintered as needed.

Example 1

First, a photocurable resin (for example, provided in the form of a monomer/oligomer mixture used: urethane acrylate (PUA)) and a solvent are first mixed with an ultrasonic homogenizer, and operating conditions are: oscillating power: 1200 W, frequency 19.6. KHz and operation time: 10 minutes, and then added with a photoinitiator to form a three-dimensional printing material. The photoinitiator comprises from 0.01 wt.% to 0.08 wt.% of the total weight of the three-dimensional printing material. The resulting three-dimensional printing material is a slurry having a viscosity of 0.5 cP to 1500 cP. The solvent may be selected from organic solvents such as alcohols, ethers and ketones, such as dibasic ether, ethanol, acetone or isopropyl ether. In addition, in the step of preparing the three-dimensional printing material, an auxiliary agent such as a rheological agent (thixotropical) may be added according to requirements. An agent), a slipping agent, a wetting agent, or a leveling agent.

Next, the prepared three-dimensional printing material is irradiated with infrared rays to achieve a temperature rising effect. Since the urethane acrylate has a functional group including a hydroxyl group and a carbonyl group, the infrared energy absorption rate of the wavelength range of 2.8 μm to 3.2 μm or between 6 μm and 7 μm can be increased to 80% or more. After being irradiated by infrared rays, the infrared energy is converted into kinetic energy to raise the temperature of the molecules to be polymerized, thereby increasing the reaction rate. Further, the polymerization rate can be increased by 1.2 times to 2 times for every 10 degrees Celsius increase in resin temperature.

Example 2

First, a photocurable resin (for example, provided in the form of a acrylate monomer/oligomer mixture used), a dispersant, a ceramic powder, and a solvent are first mixed by an ultrasonic homogenizer, and operating conditions are as follows: an oscillating power of 1200 W, The frequency was 19.6 KHz and the operation time was 10 minutes, and the photoinitiator was further added to be dispersed by ball milling. The ball mill uses a grinding ball size of 30 to 50 microns, a rotational speed of 3000 to 5000 rpm, and an operation time of 2 to 4 hours to be mixed into a three-dimensional printing material. The resulting three-dimensional printing material is a slurry having a viscosity of 0.5 cP to 1500 cP. The resin is an ultraviolet or visible light curing resin, and an organic molecule can be selected. The photoinitiator comprises from 0.01 wt.% to 0.08 wt.% of the total weight of the three-dimensional printing material. The ceramic powder may be selected, for example, from zirconia, alumina, cerium oxide, cerium carbide, cerium nitride or a mixture thereof in a mixing ratio of from 20 vol.% to 80 vol.% of the total volume of the three-dimensional printing material. The solvent may be selected from organic solvents such as alcohols, ethers and ketones, such as dibasic ether, ethanol, acetone or isopropyl ether. (isopropyl ether). The solvent accounts for less than 20 vol.% of the total volume of the three-dimensional printing material, and the recommended ratio is 10 vol.% or less.

Next, the prepared three-dimensional printing material is irradiated with infrared rays to achieve a temperature rising effect. Since the ceramic powder has a relatively good absorption rate of infrared energy for wavelengths greater than 10 μm, and heating adjacent resins by heat conduction, the temperature of the molecules to be polymerized is increased, and the reaction rate is increased.

Example 3

1A and 1B are schematic diagrams showing the application of a three-dimensional printing method according to an embodiment of the present invention.

The three-dimensional printing method is, for example, a photocuring molding technique, and its application mode is first referred to FIG. 1A. The reaction tank 110 is used to hold the three-dimensional printing material 120. In the present embodiment, the three-dimensional printing material 120 is a liquid substance and maintains a constant water level in the reaction tank 110. The three-dimensional printing material 120 includes at least a mixture of a photocurable resin and a photoinitiator. The three-dimensional printing material 120 may further comprise ceramic powder, and the operation mode may be adjusted according to the viscosity of the slurry material. A lifting table 130 is disposed inside the reaction tank 110, and an active surface 132 is provided as an action surface for the subsequent solidification molding reaction. A non-contact infrared heater 150 is disposed around the exterior of the reaction vessel, which will continue to act to heat the three-dimensional printing material 120 inside the reaction vessel 110. In other words, after the three-dimensional printing material 120 is heated to the target temperature by the infrared heater 150, the infrared heater 150 continues to act to maintain the constant temperature. The infrared wavelength ranges from 2.5 microns to 15 microns. Since the photocurable resin or the ceramic powder in the three-dimensional printing material 120 absorbs infrared rays well, the infrared energy can be converted. For thermal energy, the temperature of the three-dimensional printing material 120 is increased to facilitate the subsequent polymerization. When the program begins, under the control of a computer (not shown), the ultraviolet light source 160 moves in accordance with the programmed position and illuminates the active surface 132 to form a layered configuration of a particular shape. When the three-dimensional printing material 120 is irradiated by the ultraviolet light source 160, the photoinitiator therein absorbs the energy of the ultraviolet light source 160 to be decomposed into radicals, and the photocurable resin is subjected to polymerization reaction curing molding. In other words, only the area illuminated by the ultraviolet light source 160 will solidify, and the area illuminated by the ultraviolet light source 160 will be determined according to the cross-sectional layered design of the shape of the object to be formed, and is not a comprehensive illumination. The wavelength of ultraviolet light ranges from 200 nm to 450 nm.

It is worth noting that the UV curing resin does not have a specific irradiation time, which is determined by the curing characteristics of the selected resin and the energy of the ultraviolet light source. In addition, the polymerization rate can be increased by 1.2 times to 2 times for every 10 degrees Celsius increase in the resin temperature, so the time for heating the resin by infrared rays and the time for curing the resin with ultraviolet light need to be matched.

Next, please refer to FIG. 1B. When the three-dimensional printing material 120 that originally appeared in the liquid state is cured, the lifting table 130 will move downward from the initial active surface 132. At this time, the active surface 132 will flow into the new liquid three-dimensional printing material 120, and contact with the cured first layer three-dimensional printing material 120, and then irradiate the ultraviolet liquid source 160 to cure the new liquid three-dimensional printing material 120. Connected to the previous layer of three-dimensional printing material 120. The cycle is performed in this manner, accurately and layer by layer until the article 140 is formed. In other words, the initial solid matter is formed under the active surface 132, and when the lifting platform 130 moves downward, the position of the original acting surface 132 will be vacated. The new liquid three-dimensional printing material 120 can be caused to flow into the active surface 132 and be subjected to a curing reaction by irradiation with the ultraviolet light source 160. After repeated several times, the resulting layered structure will be continuously stacked into objects 140.

In summary, the photocured three-dimensional printing material and the three-dimensional printing method provided by the present invention provide thermal energy by providing a three-dimensional printing material capable of absorbing infrared rays, and heating the three-dimensional printing material with infrared rays, thereby improving the photocuring resin. The reaction rate of the polymerization enables the three-dimensional printing material to be cured more quickly, which not only improves the product yield, but also enables the rapid prototyping technology to produce products with more complicated shapes. In addition, since the provided three-dimensional printing material is matched with infrared rays to help provide thermal energy, the content of the photoinitiator used in the three-dimensional printing material can be reduced, thereby improving the stability of the three-dimensional printing material, and the material can be extended. Storage time.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

110‧‧‧Reaction tank

120‧‧‧3D printing materials

130‧‧‧lifting platform

132‧‧‧Action surface

140‧‧‧ objects

150‧‧‧Infrared heater

160‧‧‧UV source

Claims (14)

A three-dimensional printing material comprising: a photocurable resin, wherein the photocurable resin is an ultraviolet curable resin, a visible light curable resin or a mixture thereof; and a photoinitiator, the proportion of the photoinitiator is the three-dimensional column 0.003 wt.% to 1 wt.% of the total weight of the printing material, wherein the photocurable resin has at least one or more functional groups including a carbonyl group, a nitro group, a phenyl group, a hydroxyl group and an amino group, and the photocuring The resin has a functional group that absorbs an infrared ray having a wavelength between 2.5 microns and 15 microns. The three-dimensional printing material according to claim 1, wherein the photocurable resin comprises urethane acrylate, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, polypropylene glycol diacrylate. , propoxyglycerol triacrylate, ethoxylated bisphenol A diacrylate, pentaerythritol triacrylate, bisphenol A epoxy acrylate, amino modified polyether acrylate or a mixture thereof. The three-dimensional printing material according to claim 1, wherein the photoinitiator comprises 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, benzoin Dimethyl ether, benzophenone, -hydroxy ketone, benzoylformate, acylphosphine oxide or mixtures thereof. The three-dimensional printing material according to claim 1, wherein the photoinitiator accounts for 0.01 wt.% to 0.08 wt.% of the total weight of the three-dimensional printing material. The three-dimensional printing material as described in claim 1 of the patent application includes a pottery Porcelain powder, wherein the ceramic powder accounts for 5 vol.% to 85 vol.% of the total volume of the three-dimensional printing material. The three-dimensional printing material according to claim 5, wherein the ceramic powder comprises zirconia, alumina, cerium oxide, cerium carbide, cerium nitride or a mixture thereof, and the proportion of the ceramic powder is the three-dimensional column The total volume of the printed material ranges from 20 vol.% to 80 vol.%. A three-dimensional printing method, comprising: providing a three-dimensional printing material, the three-dimensional printing material comprising a photocurable resin and a photoinitiator, wherein the photocuring resin is an ultraviolet curing resin, a visible light curing resin or a mixture thereof. The photocurable resin has at least one or more functional groups including a carbonyl group, a nitro group, a phenyl group, a hydroxyl group and an amino group, and the photoinitiator is 0.003 wt% of the total weight of the three-dimensional printing material. % to 1 wt.%; providing an infrared ray to the three-dimensional printing material for heating, wherein the functional group of the photocurable resin in the three-dimensional printing material absorbs the infrared ray, and the infrared wavelength is between 2.5 micrometers Between 15 microns; and providing an ultraviolet light or a visible light to the three-dimensional printing material to trigger the conversion of the photoinitiator into a radical to cure the photocurable resin. The three-dimensional printing method according to claim 7, wherein the infrared ray is supplied to the three-dimensional printing material by means of non-contact heating. The three-dimensional printing method according to claim 7, wherein the photocurable resin comprises urethane acrylate, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, polypropylene glycol diacrylate. , propoxyglycerol triacrylate, Ethoxylated bisphenol A diacrylate, pentaerythritol triacrylate, bisphenol A epoxy acrylate, amino modified polyether acrylate or mixtures thereof. The three-dimensional printing method according to claim 7, wherein the photoinitiator comprises 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, benzoin Dimethyl ether, benzophenone, -hydroxy ketone, benzoylformate, acylphosphine oxide or mixtures thereof. The three-dimensional printing method according to claim 7, wherein the photoinitiator accounts for 0.01 wt.% to 0.08 wt.% of the total weight of the three-dimensional printing material. The three-dimensional printing method of claim 7, wherein the three-dimensional printing material further comprises a ceramic powder, the ceramic powder occupies a ratio of 5 vol.% to 85 vol.% of the total volume of the three-dimensional printing material. The three-dimensional printing method according to claim 12, wherein the ceramic powder comprises zirconia, alumina, cerium oxide, cerium carbide, cerium nitride or a mixture thereof. The three-dimensional printing method according to claim 12, wherein the ceramic powder accounts for 20 vol.% to 80 vol.% of the total volume of the three-dimensional printing material.