KR102041235B1 - Photo-curable composition for three dimensional printer - Google Patents

Abstract

The present invention relates to a photocurable composition for a three-dimensional printer, the photocurable composition for a three-dimensional printer is 0.01 to 20% by weight of carbon nanotube dispersion; 25-50% by weight of polyfunctional aliphatic (meth) acrylates; 25-50 wt% aliphatic urethane (meth) acrylate oligomers; 0.1 to 0.5 wt% light stabilizer; And photoinitiator 0.1 to 5% by weight; may include, thereby providing a technique for a composition for a three-dimensional printer with improved strength.
According to the present invention, since the photocurable composition includes a carbon nanotube dispersion in which carbon nanotubes are uniformly dispersed, the composition has high strength, high shrinkage and low dimensional stability when photocuring the composition, and has high durability and high durability for prototypes. It can be manufactured for practical use as well as mockups and models.

Description

Photocuring composition for three-dimensional printers {PHOTO-CURABLE COMPOSITION FOR THREE DIMENSIONAL PRINTER}

The present invention relates to a photocuring composition for a three-dimensional printer.

In recent years, three-dimensional printing techniques have been used to produce a large number of objects in a short period of time, and there are many ways to make three-dimensional articles using photocurable materials. One of the most effective techniques in 3D printing is the digital light process (DLP) method or stereolithography (SLA).

In 3D printing using the DLP or SLA method, the photocurable material in liquid form is laminated or applied to a vat, and a predetermined portion or surface of the photocurable material is controlled by a digital micro-mirror device or a rotating polyhedron. Are exposed to ultraviolet / visible (UV / Vis) light.

In the DLP method, additional layers are repeatedly or continuously stacked and each layer cures until the desired 3D article is formed, but the SLA method differs from the DLP method in that the liquid material solidifies by a line of radiation beams. This exists.

Thus, most photocurable resins for 3D printing are made in liquid form to have a low viscosity and cure rate suitable for 3D printers, and photopolymerizable resin compositions applied to such SLA 3D prints are hard to cure at the wavelength of the laser to be projected. It should be made, have sufficient formability and hardness, and have dimensional stability through low shrinkage. In this regard, Korean Patent Publication No. 2016-0082280 discloses a technique for an ink composition for three-dimensional printing.

However, the existing compositions have low modulus values due to the composition ratio between the photopolymerization oligomer and the reaction diluent present in the composition, due to insufficient curing of the composition to the ultraviolet rays emitted from the light sources of the SLA and DLP 3D printers, and low amount of ultraviolet light. There was a technical limitation that does not show high hardness at.

In order to solve this problem, various researches are still underway, and it is difficult to secure an excellent level of mechanical properties by using the existing composition. Therefore, an attempt to improve the mechanical strength of the composition by adding a filler such as carbon nanotubes is performed. However, carbon nanotubes have a strong tendency to agglomerate into bundles due to strong van der Waals forces, so that the solubility in water or other solvents is very low, and thus, processing is difficult.

The present invention has been made to solve the above problems, and an object thereof is to provide a technology relating to a composition for three-dimensional printer with improved strength.

The problem to be solved by the present invention is not limited to the above-described problem, other technical problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve this object, in one aspect of the present invention, the photocurable composition for a three-dimensional printer is a carbon nanotube dispersion of 0.01 to 20% by weight; 25-50% by weight of polyfunctional aliphatic (meth) acrylates; 25-50 wt% aliphatic urethane (meth) acrylate oligomers; 0.1 to 0.5 wt% light stabilizer; And photoinitiator 0.1 to 5% by weight; may include.

And, carbon nanotube dispersion is 0.1 to 5% by weight of carbon nanotubes; 40-50% by weight of monofunctional acrylate; 40-50% by weight of bifunctional di (meth) acrylate; And 0.1 to 5% by weight dispersant; may include.

In addition, the photocuring composition for a three-dimensional printer is 0.05 to 3% by weight colored pigment; 0.1 to 3 wt% leveling agent; And 0.1 to 5% by weight antioxidant; may further include.

Means for solving the above problems are merely exemplary and should not be construed as limiting the present invention. In addition to the exemplary embodiments described above, there may be additional embodiments described in the drawings and detailed description of the invention.

As described above, according to the present invention, the photocurable composition includes a carbon nanotube dispersion in which carbon nanotubes are uniformly dispersed, and thus has high strength, high shrinkage and low dimensional stability at photocuring of the composition, and high durability. Its high height makes it possible to manufacture not only mockups or models for prototypes, but also for practical use.

Therefore, when manufacturing the 3D printed SLA or DLP printing method using the present invention, it shows a smooth workability, the resulting printed material also has excellent physical properties, so the photocurable composition according to an embodiment of the present invention is used for home and commercial It can be usefully used as a material for 3D printer used as.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

Preferred embodiments of the present invention will be described in more detail below, but the technical parts that are well known will be omitted or compressed for brevity of description.

The photocuring composition for a three-dimensional printer according to an embodiment of the present invention may include a carbon nanotube dispersion, a polyfunctional aliphatic (meth) acrylate, an aliphatic urethane (meth) acrylate oligomer, a light stabilizer, and a photoinitiator.

In one embodiment, the carbon nanotube dispersion may be prepared in a liquid phase by dispersing carbon nanotubes in a solvent, and may improve mechanical properties of the photocurable composition for a 3D printer due to uniformly dispersed carbon nanotubes.

The carbon nanotube dispersion may be included in an amount of 0.01 to 20% by weight within the total weight of the photocuring composition for a three-dimensional printer. If the carbon nanotube dispersion is less than 0.01% by weight, the strength increase effect by the carbon nanotubes is insignificant, and when it exceeds 20% by weight, the polyfunctional aliphatic (meth) acrylate and the aliphatic urethane (meth) As the amount of the acrylate oligomer decreases, cracks due to overcuring may occur during photocuring.

In addition, the carbon nanotube dispersion may include carbon nanotubes, monofunctional acrylates, bifunctional di (meth) acrylates, and dispersants. Specifically, carbon nanotubes (carbon nanotubes) may be included in 0.1 to 5% by weight within the total weight of the carbon nanotube dispersion.

In one embodiment, the carbon nanotubes may be selected from at least one selected from the group consisting of single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanofibers, and mixtures thereof, but is not limited thereto. It can also be applied as a material.

If the carbon nanotubes are less than 0.1% by weight in the carbon nanotube dispersion, the hardness and tensile strength of the photocurable composition may be lowered. It is preferable to be applied within the above-mentioned range because it is agglomerated into bundles by the Derbals force, the dispersibility thereof is poor, the degree of mixing with other additives is poor, and the dimensional stability of the photocurable composition may be degraded. .

In one embodiment, the monofunctional acrylate facilitates the dispersion of the carbon nanotubes by adjusting the viscosity in the carbon nanotube dispersion, and helps the carbon nanotubes to mix well with other additives. Monofunctional acrylate may be included in 40 to 50% by weight in the carbon nanotube dispersion.

If the monofunctional acrylate is less than 40% by weight, it is difficult to control the viscosity of the carbon nanotube dispersion, so that the agglomeration of the carbon nanotubes occurs, which may cause a decrease in mechanical properties of the photocurable composition. If exceeded, the amount of carbon nanotubes and the dispersant is relatively reduced, and thus the mechanical properties of the photocurable composition are limited to maintain a certain level or more.

Monofunctional acrylate according to one embodiment may be applied as monofunctional hydroxy acrylate, more specifically hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacryl One or more may be selected from the group consisting of latex, hydroxybutyl acrylate, hydroxypentyl acrylate, hydroxyhexyl acrylate and caprolactone modified hydroxy acrylate, among which 2-phenoxyethyl acrylate It is preferable to apply (2-phenoxyethyl acrylate, 2-PHEA) or biphenyl acrylate in terms of viscosity control.

In one embodiment, the bifunctional di (meth) acrylate together with the monofunctional acrylate controls the viscosity of the carbon nanotube dispersion to be low, so that the carbon nanotubes are easily dispersed, and the carbon nanotubes are other additives. Help them mix well with the fields.

The bifunctional di (meth) acrylate may be included in the carbon nanotube dispersion in 40 to 50% by weight. If the bifunctional di (meth) acrylate is less than 40% by weight, it is difficult to control the viscosity of the carbon nanotube dispersion, so that the agglomeration of the carbon nanotube occurs, which may cause a decrease in mechanical properties of the photocurable composition. When the amount exceeds 50% by weight, the amount of carbon nanotubes and the dispersant is relatively reduced, so that the mechanical properties of the photocurable composition are limited to a certain level or more.

The bifunctional di (meth) acrylate according to one embodiment is ethyleneglycol diacrylate, ethyleneglycol dimethacrylate, ethyleneglycol dimethacrylate, diethylene glycol diacrylate (diethyleneglycol) diacrylate), ethylene glycol dimethacrylate, triethyleneglycol diacrylate, triethyleneglycol dimethacrylate, neopentylglycol diacrylate (neopentylglycol diacrylate), neopentylglycol dimethacrylate (neopentylglycol dimethacrylate), polyethylene glycol 200 diacrylate, polyethylene glycol 200 dimethacrylate (polyehtyleneglycol 200 dimethacrylate), polyethylene glycol Richol 400 Diacryle (Polyehtyleneglycol 400 diacrylate), polyethylene glycol 400 dimethacrylate (polyehtyleneglycol 400 dimethacrylate), polyethylene glycol 600 diacrylate, polyethylene glycol 600 dimethacrylate (polyehtyleneglycol 600 dimethacrylate) , Polyethyleneglycol 1000 diacrylate, polyethyleneglycol 1000 dimethacrylate, polypropyleneglycol 400 diacrylate, polypropyleneglycol Polypropyleneglycol 400 dimethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol diacrylate Acrylate (1,4-butanediol dimethacrylate), 1,6-hexanediol diacrylate (1,6-hexanediol diacrylate), 1,6-hexanediol dimethacrylate (1,6-hexanediol dimethacrylate), 1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol diacrylate ( 1,10-decanediol diacrylate, 1,10-decandiol dimethacrylate, polytetramethyleneglycol diacrylate, polytetramethylene glycol dimethacrylate Acrylate (polytetramethyleneglycol dimethacrylate), glycerin diacrylate, glycerin dimethacrylate, trimethylopropane benzoate acrylate, trimethyllopropane ben Trimethylopropane benzoate methacrylate, dimethylol tricyclo decane diacrylate, dimethylol tricyclo decane dimethacrylate, 2,2-bis 4- (acryloxyethoxy) phenyl) propane (2,2-bis (4-acryloxyethoxy) phenyl) propane), 2,2-bis (4- (methacryloxyethoxy) phenyl) propane (2,2- bis (4-methacryloxyethoxy) phenyl) propane), 2,2-bis (4- (acryloxydiethoxy) phenyl) propane (2,2-bis (4-acryloxydiethoxy) phenyl) propane), 2,2-bis (4- (methacryloxydiethoxy) phenyl) propane (2,2-bis (4-methacryloxydiethoxy) phenyl) propane), 2,2-bis (4- (acryloxypolyethoxy) phenyl) propane (2 , 2-bis (4-acryloxypolyethoxy) phenyl) propane), 2,2-bis (4- (methacryloxypolyethoxy) phenyl) propane (2,2-bis (4-methacryloxypolyethoxy) phenyl) propane), ethoxy Siliti Ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, ethoxylated (2) ethoxylated (2) bisphenol A diacrylate , Ethoxylated (2) bisphenol A dimethacrylate, ethoxylated (3) ethoxylated (3) bisphenol A diacrylate, ethoxylated (3) Ethoxylated (3) bisphenol A dimethacrylate, ethoxylated (4) Ethoxylated (4) bisphenol A diacrylate, ethoxylated (4) Bisphenol A dimethacrylate Ethoxylated (4) bisphenol A dimethacrylate, ethoxylated (8) bisphenol A diacrylate (ethoxylated (8) bisphenol A diacrylate), ethoxylated (8) bisphenol A dimethacrylate, ethoxylated (10) ethoxylated (10) bisphenol A diacrylate, ethoxyl (10) bisphenol A dimethacrylate, ethoxylated (30) bisphenol A diacrylate and ethoxylated (30) At least one or more may be selected from the group consisting of bisphenol A dimethacrylate (ethoxylated (30) bisphenol A dimethacrylate), but is not limited thereto.

In one embodiment, the dispersant uniformly disperses the carbon nanotubes in the carbon nanotube dispersion to prevent agglomeration of the carbon nanotubes. Dispersant may be included in 0.1 to 5% by weight in the carbon nanotube dispersion.

If the dispersant is less than 0.1% by weight, the dispersion of carbon nanotubes may not be performed smoothly, so that the mixing with other additives may be poor, and the strength of the photocurable composition may be reduced. Since the degree of improvement of the dispersing effect is insignificant compared to the input amount to be applied, it is preferable to be applied within the aforementioned range.

Dispersant according to one embodiment is applied to at least one selected from the group consisting of polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate and polyoxyethylene sorbitan monooleate Can be.

Meanwhile, in one embodiment, the polyfunctional aliphatic (meth) acrylate oligomer may cause a photocuring reaction with a photoinitiator or a light stabilizer upon light irradiation, and may be included in an amount of 25 to 50% by weight in the entire photocurable composition.

If the polyfunctional aliphatic (meth) acrylate is less than 25% by weight, mechanical properties such as hardness and tensile strength of the photocurable composition may be deteriorated. If the polyfunctional aliphatic (meth) acrylate is more than 50% by weight, the viscosity increases to increase workability. Since the crosslinking density of a cured coating film becomes high too much, a coating film becomes brittle, and a crack may arise by heat or an impact, it is preferable to carry out within the above-mentioned range.

According to one embodiment, the multifunctional aliphatic (meth) acrylate is ethoxylated pentaerythritol tetraacrylate, ethoxylated dipentaerythritol pentaacrylate, and ethoxylated. It may be applied to at least one selected from the group consisting of tide dipentaerythritol hexaacrylate (ethoxylated dipentaerythritol hexaacrylate), but is not limited to the above-mentioned kind.

In one embodiment, the aliphatic urethane (meth) acrylate oligomer causes a photocuring reaction (eg, a crosslinking reaction) by light irradiation, and may be included in an amount of 25 to 50% by weight in the entire photocurable composition.

If the aliphatic urethane (meth) acrylate oligomer is less than 25% by weight, there is a problem in that the curing shrinkage of the photocurable composition is increased to lower the mechanical properties of the three-dimensional article manufactured by the photocurable composition. When it exceeds, since the viscosity of all the photocurable compositions becomes high and workability falls, there exists a possibility that a crack may arise at the time of photocuring, It is preferable to apply within the said range.

The aliphatic urethane (meth) acrylate oligomer according to one embodiment may be applied to at least one of bifunctional to 15 functional aliphatic urethane (meth) acrylates, but is not limited thereto, and other types of aliphatic urethane (meth) acrylates are also known. Can be used

In one embodiment, the light stabilizer is added to improve the thermal and oxidative stability and storage stability of the photocurable composition, it may be included in 0.1 to 0.5% by weight in the total photocurable composition. If the light stabilizer is less than 0.1% by weight, the light stabilizer effect is insignificant, and if the light stabilizer is more than 0.5% by weight, it is preferable that the light stabilizer is applied within the aforementioned range.

The light stabilizer according to one embodiment may be applied to at least one selected from the group consisting of diethylethanolamine, trihexylamine, hindered amine, organic phosphate, and hindered phenol, Tablets can also be used.

In one embodiment, the photoinitiator absorbs energy from the light source to start the photopolymerization reaction of the photocurable composition, and may be included in an amount of 0.1 to 5% by weight in the total photocurable composition. If the photoinitiator is less than 0.1% by weight, the curing speed of the photocurable composition is slowed down and mechanical properties are lowered due to uncuring. If the photoinitiator exceeds 5% by weight, cracking may occur due to overcuring. It is desirable to be.

Photoinitiator according to one embodiment phenylphosphine oxide (Phenylphosphineoxide), monoacrylphosphine (MonoAcylphosphine), alpha-hydroxyketone (-Hydroxyketone), alpha-aminoketone (-Aminoketone), (o-ethoxycarboxyl) O-ethoxycarboxyoxime, acetophenone, phenyl glyoxylic, benzyldimethyl-ketal, Michler's Ketone, imidazole, methylididi Methylidynetrisdimethylaniline, idonium, sulfonium timonate, sulfonium phosphonate, metallocene, oligomeric alpha-hydroketone group consisting of -hydroxyketone, thioxanthone, benzoyl-sulphide, benzophenone, aminobenzoate and hydroxycyclohexylphenylketone But it can be applied in at least one selected, and the like.

On the other hand, the photocuring composition for a three-dimensional printer according to an embodiment of the present invention may further include a color pigment, leveling agent and antioxidant.

Specifically, in one embodiment, the colored pigment may be included in 0.05 to 3% by weight in the total photocurable composition. If the colored pigment is out of the range of 0.05 to 3% by weight, it is not easy to adjust the pigment of the composition is preferably carried out within the above-mentioned range.

As the colored pigment according to an embodiment, at least one selected from the group consisting of carbon black pigments, metal oxide pigments, and graphite pigments may be used, and known pigments other than the above-described types may be used.

In one embodiment, the leveling agent is added to improve the surface uniformity during curing of the photocurable composition, it may be included in 0.1 to 3% by weight in the total photocurable composition. If the leveling agent is less than 0.1% by weight, the smoothness of the surface of the coating film is lowered, and when the leveling agent exceeds 5% by weight, there is a problem that the manufacturing cost increases, so it is preferable to be applied within the aforementioned range. In addition, the leveling agent according to an embodiment may be used Tego RAD2100, RAD2200N, RAD2300 products, etc., but is not limited thereto.

In one embodiment, the antioxidant may be included in 0.1 to 5% by weight in the total photocurable composition. If the antioxidant is less than 0.1% by weight, the antioxidant effect is insignificant and the workability is inferior. When the antioxidant is more than 5% by weight, it may cause yellowing or affect the crosslinking rate of the coating film. Do.

Antioxidant according to one embodiment 3,5-di-tertiary-4-butylhydroxy toluene (3,5-di-tertiary-4-butylhydroxy toluene), tetrakis [methylene (3,5-di-tert Butyl-4-hydroxyphenyl) propionate methane (Tetrakis [3,5-di-tert-butyl-4-hydroxyphenyl) propionate methane), 1,2-bis (3,5-di-tert- Butyl-4-hydroxyhydrokinamoly) hydrazine (1,2-Bis (3,5-di-tert-butyl-4-hydroxyhydrocinnamoly) hydrazine), triodiethylene bis [3- (3,5-di-tartle -Butyl-4-hydroxyphenyl) propionate] (Thiodiethylene bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]), octadecyl-3- (3,5-di- Tert-butyl-4-hydroxyphenyl) propionate (Octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), isotryldecyl-3- (3,5-di-tert -Butyl-4-hydroxyphenyl) propionate (Isotridecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), N, N'-hexamethylene bis (3,5-di- part 4-hydroxyhydrocinamide) (N, N'-Hexamethylene bis (3,5-di-t-butyl-4-hydroxyhydrocinnamamide)), Benzenepropanoic acid, 3,5-bis (1,1-dimethylethyl) -4-hydroxy-C7-9-branched alkyl ester (3,5-bis (1,1-dimethylethyl) -4-hydroxy-C7-9-branched alkylesters), 2 , 2'-ethyridenebis (4,6-di-tert-butylphenol) (2,2'-Ethylidenebis (4,6-di-tert-butylphenol)), 1,3,5-triethyl-2, 4,6-tri (3,5-di-butyl-4-hydroxy benzyl) benzene (1,3,5-Triethyl-2,4,6-tris (3,5-di-tbutyl-4-hydroxy benzyl ) benzene, 1,3,5-tri (2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate (1,3,5-Tris (2,6-dimethyl- 3-hydroxy-4-tert-butylbenzyl) isocyanurate), triethylene glycol-bis-3- (3-tert-butyl-4hydroxy-5-methylphenyl) propionate (Triethylene glycol-bis-3- (3- tert-butyl-4-hydroxy-5-methylphenyl) propionate), tri- (3,5-di-tertbutylhydroxybenzyl) isocy Tris- (3,5-di-tertbutylhydroxybenzyl) isocyanurate and 4,4'-butyridenebis (6-tert-butyl-3-methylphenol) (4,4'-Butylidenebis (6-tert-butyl -3-methylphenol)) may be applied to at least one selected from the group consisting of, but is not limited to.

Hereinafter, the present invention will be described in more detail with reference to specific examples. The following examples are only examples to help the understanding of the present invention, and thus the scope of the present invention is not limited or limited thereto.

1. Preparation of Carbon Nanotube Dispersion

Carbon nanotube dispersions of Examples 1 and 2 and Comparative Examples 1 and 2 were prepared in the following manner, and the content of each component included in the dispersion was as shown in Table 1 below.

First, the carbon nanotubes (CNT, MWCNT MR99, Carbon Nano-material Technology Co., Ltd.) are washed for 60 minutes to remove impurities from the surface of the carbon nanotubes, and then put into a dryer at a temperature of 60 ° C. for 12 hours. Dried. Subsequently, the completely dried carbon nanotubes were monofunctional acrylate solution (Miramer M1192, Miwon Specialty Chemical Co., Ltd), difunctional diacrylate solution (Miramer M200, Miwon Specialty Chemical Co., Ltd), dispersant (Tween 20 from KAO). The mixture was introduced into a homogenizer (IKA homogenizer) and the dispersion was strongly dispersed for 1 hour by setting the rotation speed of the homogenizer to 4000 rpm. Thereafter, the carbon nanotubes were physically dispersed by ultrasonically treating the mixture for 2 hours using an ultrasonic device (desktop type ultrasonic cleaner 4020, Co., Ltd.) having an ultrasonic frequency set to 40 kHz to prepare a carbon nanotube dispersion.

Unit: g Example 1 Example 2 Comparative Example 1 Comparative Example 2 Carbon nanotubes 5 2 0.05 10 Dispersant 5 2 0.05 10 Monofunctional acrylate 45 48 51.5 40 Difunctional diacrylate 45 48 48.4 40

2. Preparation of Photocuring Composition

The photocurable compositions of Preparation Examples 1 to 4 were prepared by the following method, and the content of each component in the photocurable composition was as described in Table 2 below.

First, polyfunctional aliphatic acrylates and aliphatic urethane acrylate oligomers were mixed according to the contents of Table 2 below, and mechanically stirred for 1 hour. Thereafter, each of the carbon nanotube dispersions of Examples 1, 2, Comparative Example 1, and Comparative Example 2 was added to the stirred solution in the amount shown in Table 2, and mixed using a homogenizer (rotational speed: 4000 rpm) for 2 hours. After that, it was uniformly dispersed by dispersion treatment for 2 hours with an ultrasonic device (40 kHz). Thereafter, the mixture was degassed for 30 minutes with low speed stirring in a vacuum deaerator to remove bubbles generated during mixing.

The photoinitiator and the light stabilizer were added to the defoamed preliminary photocurable composition in the amount shown in Table 2, and the mixture was added with stirring using a homogenizer to complete the photocurable composition.

Unit: g Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 ¹ Carbon Nanotube Dispersion 19 19 19 19 ² polyfunctional aliphatic acrylates 50 50 50 50 ³ aliphatic urethane acrylate oligomer 30 30 30 30 ⁴ Light Stabilizer 0.5 0.5 0.5 0.5 ⁵ Photoinitiators 0.5 0.5 0.5 0.5 week)
1: Carbon nanotube dispersion-Preparation Example 1 is Example 1, Preparation Example 2 is Example 2, Preparation Example 3 is Comparative Example 1, Preparation Example 4 uses the carbon nanotube dispersion of Comparative Example 2
2: Multifunctional Aliphatic Acrylate-Miramer M4004, Miwon Specialty Chemical Co., Ltd
3: Aliphatic urethane acrylate oligomer-Miramer PU622, Miwon Specialty Chemical Co., Ltd
4: Light Stabilizer-benetex OB +, Mayzo
5: Photoinitiators-Irgacure 819, ciba

3. Experimental Evaluation of Mechanical Properties of Photocurable Composition

After preparing the 3D printed matter using the photocuring compositions prepared in Preparation Examples 1 to 4, the strength of the manufactured product was measured. In the production of 3D printed materials, 3D printers using self-made DLP type printers and SLA type printers were used. Methods and results of measuring mechanical properties of the fabrics are as shown in Table 3 below.

Properties Test specification Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 Rockwell hardness ASTM D785 48.2 43.7 36.5 34.3 Tensile Strength (MPa) ASTM D638 41.6 38.2 32.4 31.8

As a result of the evaluation of mechanical properties, the photocurable compositions of Preparation Examples 1 and 2, in which the contents of carbon nanotubes, dispersant, monofunctional acrylate, and difunctional diacrylate were set within the above-mentioned content ranges, showed Rockwell hardness and tensile strength. It can be seen that the strength is superior to Preparation Examples 3 and 4.

In addition, when the content of each component included in the carbon nanotube dispersion is greater than or less than the input range of each component through the evaluation results of the physical properties of Preparation Example 3 and Preparation Example 4, aggregation of carbon nanotubes occurs and viscosity control is not easy. As a result, the workability is lowered, and the photocuring reaction is poor, indicating that the mechanical properties of the 3D fabricated product made from the photocurable composition are poor.

As a result, the present invention includes a carbon nanotube dispersion in which carbon nanotubes are uniformly dispersed, and thus has high strength, high shrinkage and low dimensional stability when photocuring the composition, and high durability. It can also be manufactured for practical use.

That is, by using carbon nanotubes that have the potential to be 8 times higher in tensile strength than steel and 5 times higher in thermal conductivity than copper, and have the potential to exhibit excellent electrical, mechanical and thermal properties compared to other additives. By preparing a carbon nanotube dispersion and introducing it into a photocurable resin, it is possible to prepare a photocurable resin composition for a three-dimensional printer excellent in high mechanical strength, dimensional stability, and durability.

In particular, carbon nanotubes have a strong tendency to agglomerate into bundles due to strong van der Waals forces, so their solubility in water or other solvents is very low, and when carbon nanotubes are agglomerated, the mechanical properties that are inherent to carbon nanotubes are sufficiently Although limited to exhibit, the carbon nanotube dispersion according to an embodiment of the present invention is adjusted to a low level so that the carbon nanotubes present in the dispersion do not aggregate with each other, so that the dispersion without impairing the mechanical properties of the carbon nanotubes. It can dissolve the carbon nanotubes in high concentration.

In summary, the present invention can disperse carbon nanotubes well in a solution without impairing the mechanical properties of the carbon nanotubes themselves. That is, the monofunctional acrylate and the difunctional di (meth) acrylate in the carbon nanotube dispersion control the viscosity of the dispersion so that the carbon nanotubes are uniformly dispersed without impairing the properties of the carbon nanotubes themselves. The strength of the nanotubes can be maintained at an excellent level.

In addition, since the present invention does not modify specific functional groups on the surface of the carbon nanotubes through a chemical process, the surface of the carbon nanotubes is damaged during the surface modification process, thereby preventing the mechanical properties from deteriorating.

In addition, when manufacturing the 3D printed SLA or DLP printing method using the present invention, it shows a smooth workability, and the resulting printed material also has excellent physical properties, so that the photocurable composition according to an embodiment of the present invention is used for home and commercial It can be usefully used as a material for 3D printer used as. That is, the composition according to the embodiments of the present invention can be used as a photocurable material of the three-dimensional printer using at least one of the SLA and DLP scheme.

As described above, the detailed description of the present invention has been made by the embodiments with reference to the attached table. However, since the above-described embodiments have only been described by way of example, the present invention is limited to the above embodiments. It should not be understood that the scope of the present invention is to be understood by the claims and equivalent concepts described below.

Claims (3)

0.01-20% by weight of carbon nanotube dispersion;
25-50% by weight of polyfunctional aliphatic (meth) acrylates;
25-50 wt% aliphatic urethane (meth) acrylate oligomers;
0.1 to 0.5 wt% light stabilizer; And
0.1 to 5% by weight of photoinitiator;
The carbon nanotube dispersion is
0.1-5% by weight of carbon nanotubes;
40-50% by weight of monofunctional acrylate;
40-50% by weight of bifunctional di (meth) acrylate; And
0.1 to 5% by weight of dispersant; characterized in that it comprises
Photocuring composition for a three-dimensional printer. delete The method of claim 1,
The 3D printer photocurable composition
0.05-3% by weight of colored pigments;
0.1 to 3 wt% leveling agent; And
0.1 to 5% by weight of antioxidant; characterized in that it further comprises
Photocuring composition for a three-dimensional printer.