KR102473147B1 - Composition for 3D Printing and Filament for 3D Printer - Google Patents

Abstract

The present invention relates to a composition for 3D printing and a filament for a 3D printer using the same, and more particularly, to a composition for 3D printing having excellent surface quality of a printed object and excellent storage stability, and a filament for a 3D printer using the same .
The 3D printing composition includes (a) 80 to 95% by weight of a polylactic acid (PLA) resin; (b) 2 to 16% by weight of an impact resistant agent; (c) 0.5 to 2% by weight of an anti-hydrolysis agent; and (d) 0.5 to 2% by weight of polymethylmethacrylate (PMMA) beads.
The filament for a 3D printer according to the present invention is useful for 3D printing because it has excellent surface quality during printing and excellent storage stability by inhibiting hydrolysis of PLA during storage.

Description

Composition for 3D printing and filament for 3D printer using the same {Composition for 3D Printing and Filament for 3D Printer}

The present invention relates to a composition for 3D printing and a filament for a 3D printer using the same, and more particularly, to a composition for 3D printing having excellent surface quality of a printed object and excellent storage stability, and a filament for a 3D printer using the same .

A 3D (3-Dimension) printer is a device that produces a real three-dimensional shape as it is based on an input three-dimensional drawing, just like printing typefaces or pictures. Recently, 3D printing technology has become quite a hot issue, and is expanding to automobile, medical, art, and education fields, and is widely used for making various models. The principles of 3D printers can be divided into cutting type and stacking type, and most of the 3D printers actually applied are stacked type with no material loss.

There are about 20 methods using the layered principle, but the most used methods are SLA (Stereo Lithography Apparatus), FDM (Fused Deposition Modeling), FFF (Fused Filament Fabrication), and SLS (Selective Laser Sintering) methods. .

In the case of SLA, it is a method of modeling by projecting a laser beam into a water tank containing a photocurable resin in a liquid state, and an epoxy-type photopolymer, which is a photocurable resin, is mainly used. On the other hand, FDM (or FFF), which is a method in which the input filament-like material is ejected in a molten state from the nozzle of a printer moving in Z, Y, and Z axes, and is shaped in three dimensions, uses thermoplastic plastic as the main material. On the other hand, SLS implements 3D printing by selectively sintering a water tank containing powdered materials such as metal, plastic, and ceramic powder.

Among the three methods, the FDM method, in which thermoplastics are manufactured in the form of filaments and used, is the most widely popular because the price of a 3D printer is relatively low and the printing speed is faster than other methods. In the FDM method, polylactic acid (PLA), ABS (Acrylonitrile Butadiene Styrene), HDPE, polycarbonate ( Hard materials such as polycarbonate (PC) and flexible materials such as thermoplastic elastomers are used.

In particular, with the growth of the 3DP market, PLA materials are widely used as materials for extrusion-type 3D printing. Korean Patent Registration No. 1350993 discloses a process of preparing a functional masterbatch by extruding a melamine microcapsule using a melamine resin as a wall material surrounding a core material and a biodegradable resin of a low melting point series; And mixing and extruding the functional masterbatch and PLA to prepare a PLA filament, wherein the low melting point series biodegradable resin has a lower melting point than the PLA, flame retardancy and heat resistance using microcapsules Gaji disclosed a method for manufacturing PLA filaments for 3D printers, and Korean Patent Registration No. 1712506 discloses (a) carbon nanotubes refined using polylactic acid (PLA) resin, ultrasonic waves, and an acid solution. CNT) to prepare a mixture; (b) preparing a molding by extruding the mixture; And (c) including the step of winding the molded article, wherein the extrusion of step (b) is carried out at a temperature of 170 to 180 ° C in the first step, 180 to 190 ° C in the second step, 190 to 200 ° C in the third step, and 190 to 190 ° C. Disclosed is a filament manufacturing method for a 3D printer, which is divided into 4 steps of 200 ° C, 5 steps of 180 to 190 ° C, and 6 steps of 170 to 180 ° C.

However, PLA materials sold on the market generally have poor surface quality when printing sculptures, so processing is required, and there is a problem in that filaments are decomposed due to hydrolysis of PLA in the process of being left unsealed during storage.

Accordingly, the present inventors have made efforts to solve the above problems, and as a result, a hydrolysis agent containing a carbodiimide structure, an impact resistant agent having a glycidyl methacrylate functional group, and PMMA beads together with polylactic acid (PLA) When used, it was confirmed that the surface quality of the printed material can be improved and the hydrolysis of polylactic acid can be inhibited even in a high temperature and high humidity environment, and the present invention was completed.

An object of the present invention is to provide a composition for 3D printing having excellent surface quality during printing and excellent ability to inhibit hydrolysis of PLA during storage, and a filament for a 3D printer prepared by extruding the same.

In order to achieve the above object, the present invention (a) polylactic acid (Polylactic acid, PLA) resin 80 to 95% by weight; (b) 2 to 16% by weight of an impact resistant agent; (c) 0.5 to 2% by weight of an anti-hydrolysis agent; And (d) provides a composition for 3D printing comprising 0.5 to 2% by weight of polymethyl methacrylate (PMMA) beads.

In the present invention, the polylactic acid (PLA) resin is characterized in that the melt flow rate (MFR) value is 2 to 10g / 10min when measured at 190 ° C / 2.16kg according to ASTM D1238 standard.

In the present invention, the impact resistant agent is characterized in that it is a copolymer containing at least one alkylene having 2 to 4 carbon atoms to which a glycidyl methacrylate functional group is grafted.

In the present invention, the impact resistant agent is ethylene/N-butyl acrylate/glycidyl methacrylate copolymer, ethylene/ethyl acrylate/glycidyl methacrylate copolymer, ethylene/glycityl methacrylate/ It is characterized in that it is selected from the group consisting of a methacrylate copolymer, an ethylene/glycidyl methacrylate copolymer, and an ethylene/glycidyl methacrylate/vinyl acetate copolymer.

In the present invention, the hydrolysis-resistant agent is characterized in that it contains a carbodiimide structure.

In the present invention, the anti-hydrolysis agent is N,N'-di-o-tolylcarbodiimide, N,N'-diphenylcarbodiimide, N,N'-dioctyldecylcarbodiimide, N,N'- Di-2,6-dimethylphenylcarbodiimide, N-tolyl-N'cyclohexylcarbodiimide, N,N'-di-2,6-diisopropylphenylcarbodiimide, N,N'-di -2,6-di-tert-butylphenylcarbodiimide, N-tolyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di- p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, N,N'-di-p-tolylcarbodiimide , p-phenylene-bis-di-o-tolylcarbodiimide, p-phenylene-bisdicyclohexylcarbodiimide, hexamethylene-bisdicyclohexylcarbodiimide, ethylene-bisdiphenylcarbodiimide, Benzene-2,4-diisocyanato-1,3,5-tris(1-methylethyl) homopolymer and 2,4-diisocyanato-1,3,5-tris(1-methylethyl) and 2, It is characterized in that it is selected from the group consisting of copolymers of 6-diisopropyl diisocyanate.

In the present invention, the diameter of the polymethyl methacrylate (PMMA) beads is characterized in that 1 to 20㎛.

In the present invention, the aspect ratio of the polymethyl methacrylate (PMMA) beads is characterized in that 0.8 to 1.

The present invention also provides a filament for a 3D printer prepared by extruding the composition for 3D printing.

In the present invention, the filament for the 3D printer is characterized in that the diameter is 0.8 to 4.0 mm.

In the present invention, the composition for the 3D printer is produced as a pellet using a single or twin screw extruder and then injected into a 1/8 inch dumbbell-type specimen of ASTM D638 standard through injection molding, exposed to 80 ℃ 80RH% for 24 hours It is characterized in that the tensile strength retention rate is 80% or more even after.

The filament for a 3D printer according to the present invention is useful for 3D printing because it has excellent surface quality during printing and excellent storage stability by inhibiting hydrolysis of PLA during storage.

1 is a three-dimensional microscope photograph of the surface of a sculpture manufactured according to an embodiment of the present invention.
Figure 2 is a three-dimensional micrograph of the surface of the sculpture manufactured according to a comparative example of the present invention.

In the present invention, when a hydrolysis-resistant agent having a carbodiimide structure, an impact-resistant agent having a glycidyl methacrylate functional group, and PMMA beads are used together with polylactic acid (PLA), the surface quality of the output is improved, and the high-temperature It was attempted to confirm that polylactic acid can be inhibited from being hydrolyzed even in a humid environment.

In the present invention, a composition including polylactic acid (PLA), a hydrolysis agent having a carbodiimide structure, an impact resistance agent having a glycidyl methacrylate functional group, and PMMA beads is extruded and then cut to produce chips ( After manufacturing in the form of a chip, (1) the chip was injection-molded to manufacture a specimen, (2) the chip was extruded to manufacture a 3D printer filament, and then the 3D printer was used to manufacture the filament. The sculpture was printed. As a result, it was confirmed that the hydrolysis resistance of the prepared specimen was excellent and the surface quality of the molded object was excellent.

Accordingly, the present invention provides (a) 80 to 95% by weight of a polylactic acid (PLA) resin; (b) 2 to 16% by weight of an impact resistant agent; (c) 0.5 to 2% by weight of an anti-hydrolysis agent; And (d) it relates to a composition for 3D printing comprising 0.5 to 2% by weight of polymethyl methacrylate (PMMA) beads.

In the present invention, the polylactic acid (PLA) resin is characterized in that the melt flow rate (MFR) value is 2 to 10g / 10min when measured at 190 ° C / 2.16kg according to ASTM D1238 standard.

When the melt flow rate (MFR) value of the polylactic acid (PLA) resin is less than 2 g/10 min, the viscosity is high during extrusion, so extrusion is difficult, or when 3D printing is performed after filament is manufactured, printing is performed under pressure at the printer nozzle. If the melt flow rate (MFR) value exceeds 10g/10min, it is difficult to manufacture the filament due to low viscosity during extrusion, and even if the filament is manufactured, there is a problem that the layer is not stably formed during 3D printing. have.

The polylactic acid (PLA) resin is preferably 80 to 95% by weight of the total composition for 3D printing. If the content of the polylactic acid (PLA) resin is less than 80% by weight, the content of the impact resistant agent is high, so a die swell phenomenon may occur during filament extrusion, and the pressure at the nozzle area increases during printing after filament production, printing Time can be long. In addition, when the content of polylactic acid (PLA) resin exceeds 95% by weight, the impact strength of the filament is reduced due to the relatively low content of the impact resistance, so that the filament can be easily broken, and the role of the hydrolysis agent is In addition, there is a problem in that the hydrolysis resistance property is also deteriorated because the role of the impact resistant agent to hold the end of PLA is lowered.

In the present invention, the impact resistance agent is for inhibiting hydrolysis of polylactic acid (PLA) resin containing an ester functional group, and reacts with the end of polylactic acid (PLA) to cause hydrolysis It is desirable to use one that can control. Since the core-shell structured impact resistant agent is expensive, the present invention is characterized by using a copolymer containing at least one alkylene having 2 to 4 carbon atoms grafted with a glycidyl methacrylate functional group having excellent price competitiveness. . Examples of the alkylene having 2 to 4 carbon atoms include ethylene, propylene and butylene.

The impact resistance agent may be exemplified by maleic anhydride grafted (MAH) polyolefin, polyester-based elastomer, nylon-based elastomer, polyurethane-based elastomer, etc. Specifically, the impact resistance agent is ethylene/N -Butyl acrylate/glycidyl methacrylate copolymer, ethylene/ethyl acrylate/glycidyl methacrylate copolymer, ethylene/glycityl methacrylate/methacrylate copolymer, ethylene/glycidyl methacrylate A acrylate copolymer and an ethylene/glycidyl methacrylate/vinyl acetate copolymer may be exemplified, but are not limited thereto.

The impact resistance agent is preferably 2 to 16% by weight of the total composition for 3D printing. If the content of the impact resistant agent is less than 2% by weight, there is a problem of breakage when manufactured as a filament because the impact strength above a certain level is not implemented, and when it exceeds 16% by weight, the flowability is lowered during filament manufacturing and 3D printing There is a problem in that the printing time is prolonged due to the pressure on the printer nozzle.

In the present invention, the anti-hydrolysis agent is for further suppressing the hydrolysis of polylactic acid (PLA) resin, and the anti-hydrolysis agent preferably includes a carboimide structure. Carboimide-based compounds are N,N'-di-o-tolylcarbodiimide, N,N'-diphenylcarbodiimide, N,N'-dioctyldecylcarbodiimide, N,N'-di-2,6 -Diketylphenylcarbodiimide, N-tolyl-N'cyclohexylcarbodiimide, N,N'-di-2,6-diisopropylphenylcarbodiimide, N,N'-di-2,6- Di-tert-butylphenylcarbodiimide, N-tolyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di-p-aminophenylcarbodiimide Bodyimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, N,N'-di-p-tolylcarbodiimide, p-phenylene -bis-di-o-tolylcarbodiimide, p-phenylene-bisdicyclohexylcarbodiimide, hexamethylene-bisdicyclohexylcarbodiimide, ethylene-bisdiphenylcarbodiimide, benzene-2,4 -diisocyanato-1,3,5-tris(1-methylethyl) homopolymer and 2,4-diisocyanato-1,3,5-tris(1-methylethyl) and 2,6-diisopropyl Groups composed of diisocyanate copolymers may be exemplified, but are not limited thereto.

The hydrolysis-resistant agent is preferably 0.5 to 2% by weight of the total composition for 3D printing. When the content of the hydrolysis agent is less than 0.5% by weight, the hydrolysis inhibitory effect is insignificant, and when the content exceeds 2% by weight, the hydrolysis inhibitory effect is excellent, but there is a problem in that the manufacturing cost of the filament rises rapidly.

In the case of melt extrusion type 3D printing, the filament resin is melted in a high-temperature nozzle and laminated, causing a problem of visible layers on the surface of the output. Therefore, in order to remove the layer formed on the surface, at least one post-processing should be performed after printing. In order to solve this problem, inorganic materials such as Talc and TiO ₂ are usually used. However, since this particle size has a relatively wide distribution, the nozzle of the 3D printer may be clogged, or if the printer is used for a long time, inorganic materials may accumulate in the 3D printer nozzle and clog it.

The polymethyl methacrylate (PMMA) beads of the present invention are for improving the surface quality of the output, and it is preferable to use beads having a diameter of 1 to 20 μm and an aspect ratio of 0.8 to 1. When the diameter or aspect ratio of the polymethyl methacrylate (PMMA) beads is out of the above range, the dispersion in the polylactic acid (PLA) resin is not properly performed, and there is a concern that the surface quality during printing may be poor.

The polymethyl methacrylate (PMMA) is a thermoplastic resin prepared by free radical polymerization using methyl methacrylate (MMA) as a monomer, and means a homopolymer or copolymer of methyl methacrylate (MMA) or a mixture thereof.

Polymethyl methacrylate (PMMA) of the present invention is a homo or copolymer of methyl methacrylate (MMA) is 70% by weight or more, preferably 80% by weight or more, advantageously 90% by weight or more, more advantageously It may contain 95% by weight or more of methyl methacrylate.

The polymethyl methacrylate (PMMA) beads are preferably 0.5 to 2% by weight of the total composition for 3D printing. If the content of the polymethyl methacrylate (PMMA) beads is less than 0.5% by weight, the surface of the output is not smooth, and if it exceeds 2% by weight, the PMMA beads are exposed on the surface, and the surface may become rough. have.

The filament for a 3D printer of the present invention can be prepared by extruding the composition for 3D printing. For example, a composition for 3D printing is extruded with a twin screw extruder, cut to produce a chip, then extruded with a single screw extruder, cooled, Filaments for 3D printers can be manufactured.

In the present invention, the filament for the 3D printer preferably has a diameter of 0.8 to 4.0 mm, more preferably 1.5 to 3 mm.

If the diameter of the filament is less than 0.8 mm, the printer device may not easily supply the filament because it is too thin, or the filament may not be discharged because the filament is pressed, or the printing speed may be slow. In addition, when the filament diameter exceeds 4 mm, the solidification speed is slow, it is difficult to melt the filament, and the precision of the printed object may decrease.

Since the 3D printer filament according to the present invention contains polymethyl methacrylate (PMMA) that improves the surface quality of the output, it has excellent surface quality when printed as a sculpture (40 mm wide, 40 mm long, 3 mm high). It has a characteristic.

In addition, the filament composition for a 3D printer according to the present invention is injection-molded into an ASTM D 638 1/8-inch dumbbell-shaped specimen, and then has a tensile strength retention of 80% or more even after exposure to 80 ° C. and 80 RH% for 24 hours.

[Example]

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention, and it will be apparent to those skilled in the art that the scope of the present invention is not to be construed as being limited by these examples.

Examples 1 to 2 and Comparative Examples 1 to 6: Manufacturing filaments for 3D printers

A composition including the polylactic acid (PLA) resin, impact resistant agent, hydrolysis resistant agent, and polymethyl methacrylate (PMMA) beads of Table 1 was extruded with a twin screw extruder (screw diameter 30 mm). After cooling in a cooling water bath with a length of 0.5 m and cutting, it was manufactured in the form of chips.

Then, the composition in the form of a chip is extruded with a single screw extruder (screw diameter 30 mm, screw length 105 mm), cooled in a cooling water bath with a length of 3 m, and then wound to produce filaments for 3D printers with a diameter of 1.75 mm. did

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 A 85 92 0 100 0 80 85 83 A' 0 0 100 0 85 0 0 0 B 14 6 0 0 14 18 14 13.5 C 0.5 One 0 0 0.5 One 0.5 0.5 D 0.5 One 0 0 0.5 One 0 3 D' 0 0 0 0 0 0 0.5 0

A: PLA: HISUN's REVODE195 MI 2~10g/10min

A': PLA: HISUN's REVODE190 MI 15g/10min

B: Impact resistance: Elvaloy PTW from DUPONT

C: Hydrolysis agent: ZIKO company ZIKA-AH362

D: PMMA beads 2: ASP company particle size 5㎛ / aspect ratio 1

D': PMMA beads 1: ASP company particle size 30㎛ / aspect ratio 1

Experimental example: 3D printing sculpture and specimen manufacturing using filament for 3D printer

Using the 3D printer filaments of Examples 1 to 2 and Comparative Examples 1 to 6, a 3D printer (Opencreator ALMOND) was printed as a sculpture (width 40 mm, length 40 mm, height 3 mm) for surface quality evaluation, and then It was photographed with a 3D microscope and the results are shown in FIGS. 1 and 2 .

1, which is a three-dimensional microscopic photograph of the surface of the sculpture made of the composition of Example 1, no projections are observed, and the surface quality is excellent because there is an even surface on the floor, whereas the surface of the sculpture made of the composition of Comparative Example 5 2, which is a three-dimensional microscopic photograph of Fig. 2, it was found that the surface quality was insufficient because the surface of the protrusion and ridge portion was rough.

The sculpture was printed under conditions of nozzle temperature: 245°C, nozzle diameter: 0.4mm, bed temperature: 80°C, and internal filling: 100%, and was evaluated by varying the printing speed. When the output speed was 50 mm / sec or less, it was judged to be insufficient, and when it was 50 to 100 mm / sec, it was judged to be good, and the results are shown in Table 2.

In addition, in order to check the hydrolysis resistance property (tensile strength), a chip-type composition was prepared as an ASTM D 638 1/8-inch dumbbell-shaped specimen through injection molding, and the tensile strength measurement speed was 5 mm / min After setting to , the tensile strength was measured (A). Next, the specimen was left in a constant temperature and humidity chamber at 80° C. and 80RH% for 24 hours, and then measured by setting the tensile strength measurement speed to 5 mm/min (B). Based on the measured tensile strength value (A), when the tensile strength value (B) was 80% or more, the hydrolysis resistance was judged to be good, and when it was less than 80%, it was judged to be insufficient, and the results are shown in Table 2.

In addition, the filament breakage measurement was judged to be poor if the prepared specimen was broken when held by hand and bent, and good if not broken, and the results are shown in Table 2.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Hydrolysis resistance Good Good Inadequate Inadequate Good Good Good Good print surface quality Good Good Inadequate Inadequate Inadequate Good Inadequate Inadequate Print speed compatibility Good Good Good Good Good Inadequate Good Good broken filament Good Good error error Good Good Good Good

From Table 2, 80 to 95% by weight of polylactic acid (PLA) having a melt flow rate (MFR) value of 2 to 10 g / 10 min, 2 to 16% by weight of an impact resistant agent having a glycidyl methacrylate functional group, Example 1 using a composition for printing comprising 0.5 to 2% by weight of a hydrolysis-resistant agent having a bodyimide structure and 0.5 to 2% by weight of polymethyl methacrylate (PMMA) beads having a diameter of 1 to 20 μm; and It was found that Example 2 was excellent in hydrolysis resistance, printing surface quality, printing speed suitability, and filament breakage.

On the other hand, Comparative Example 1 including only polylactic acid (PLA) having a melt flow rate (MFR) value of 15 g/10 min and polylactic acid (PLA) having a melt flow rate (MFR) value of 2 to 10 g/10 min ) Comparative Example 2, including only, was insufficient or poor in hydrolysis resistance, printing speed suitability, and filament breakage.

Polylactic acid with a melt flow rate (MFR) value of 15 g/10 min with an impact resistant agent having a glycidyl methacrylate functional group, a hydrolysis agent containing a carbodiimide structure, and polymethyl methacrylate (PMMA) beads. Comparative Example 3 using a composition for printing containing acid, PLA) had good hydrolysis resistance, printing speed suitability, and filament breakage, but had poor printing surface quality.

In addition, Comparative Example 4 using an excessive amount of an impact resistant agent having a glycidyl methacrylate functional group had insufficient printing speed suitability, and Comparative Example 5 using polymethyl methacrylate (PMMA) beads having a diameter of 30 μm showed poor printing surface quality. This was insufficient, and Comparative Example 6 using an excessive amount of polymethyl methacrylate (PMMA) beads also had insufficient printing surface quality.

Having described specific parts of the present invention in detail above, it will be clear to those skilled in the art that these specific descriptions are only preferred embodiments, and the scope of the present invention is not limited thereby. will be. Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (11)

(a) 80 to 95% by weight of polylactic acid (PLA) resin;
(b) 2 to 16% by weight of an impact resistant agent;
(c) 0.5 to 2% by weight of an anti-hydrolysis agent; and
(d) 0.5 to 2% by weight of polymethyl methacrylate (PMMA) beads,
The impact resistant agent is a composition for 3D printing that is an ethylene / N-butyl acrylate / glycidyl methacrylate copolymer.
The method of claim 1, wherein the polylactic acid (PLA) resin has a melt flow rate (MFR) value of 2 to 10g/10min when measured at 190°C/2.16kg according to ASTM D1238 standard for 3D printing, characterized in that composition.
delete The method of claim 1, wherein the impact resistance agent is ethylene/ethyl acrylate/glycidyl methacrylate copolymer, ethylene/glycityl methacrylate/methacrylate copolymer, ethylene/glycidyl methacrylate copolymer and ethylene/glycidyl methacrylate/vinyl acetate copolymer.
The composition for 3D printing according to claim 1, wherein the hydrolysis-resistant agent is a hydrolysis-resistant agent containing a carbodiimide structure.
The method of claim 5, wherein the anti-hydrolysis agent is N,N'-di-o-tolylcarbodiimide, N,N'-diphenylcarbodiimide, N,N'-dioctyldecylcarbodiimide, N,N' -Di-2,6-dimethylphenylcarbodiimide, N-tolyl-N'cyclohexylcarbodiimide, N,N'-di-2,6-diisopropylphenylcarbodiimide, N,N'- Di-2,6-di-tert-butylphenylcarbodiimide, N-tolyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di -p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, N,N'-di-p-tolylcarbodiimide Mead, p-phenylene-bis-di-o-tolylcarbodiimide, p-phenylene-bisdicyclohexylcarbodiimide, hexamethylene-bisdicyclohexylcarbodiimide, ethylene-bisdiphenylcarbodiimide , benzene-2,4-diisocyanato-1,3,5-tris(1-methylethyl) homopolymer and 2,4-diisocyanato-1,3,5-tris(1-methylethyl) and 2 A composition for 3D printing, characterized in that it is selected from the group consisting of copolymers of ,6-diisopropyl diisocyanate.
The composition for 3D printing according to claim 1, wherein the polymethyl methacrylate (PMMA) beads have a diameter of 1 to 20 μm.
The composition for 3D printing according to claim 1, wherein the aspect ratio of the polymethyl methacrylate (PMMA) beads is 0.8 to 1.
A filament for a 3D printer prepared by extruding the composition for 3D printing of any one of claims 1, 2, and 4 to 8.
The filament for a 3D printer according to claim 9, wherein the filament for a 3D printer has a diameter of 0.8 to 4.0 mm.
The method of claim 9, wherein the 3D printer filament has a tensile strength retention rate of 80% or more even after exposure to 80 ° C. and 80 RH% for 24 hours when printed as a 1/8-inch dumbbell-shaped specimen in accordance with ASTM D638. 3D, characterized in that Filament for printers.

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