KR20210037347A - 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 that minimizes deformation of an output due to shrinkage during printing, and a filament for a 3D printer using the same.
The composition for 3D printing is characterized in that it comprises acrylonitrile-butadiene-styrene (ABS) and polymethyl methacrylate (PMMA).
The filament for a 3D printer according to the present invention is useful for 3D printing because it can minimize deformation of an output due to shrinkage during printing.

Description

Composition for 3D printing and filament for 3D printer using 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 that minimizes deformation of an output due to shrinkage during printing, and a filament for a 3D printer using the same.

A 3D (3-Dimension) printer is an equipment that produces a real three-dimensional shape based on the input 3D drawing as it is to print a type or picture. Recently, 3D printing technology has become a very hot issue, and it is expanding to the fields of automobiles, medical care, arts, and education, and is widely used for making various models. The principle of 3D printers can be divided into cutting type and stacking type, and most of the 3D printers that are actually applied are stacked type without material loss.

There are about 20 methods that use the stacking 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, a laser beam is projected into a water tank containing a liquid photocurable resin to form a shape, and an epoxy-type photopolymer, which is a photocurable resin, is mainly used. On the other hand, FDM (or FFF), a method in which the injected filament-like material is ejected in a molten state from the printer's nozzle moving in the 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 laser in a tank containing powdery materials such as metal, plastic, and ceramic powder.

Among the three methods, the FDM method, which uses a thermoplastic plastic in the form of a filament, is the most widely popularized because the price of a 3D printer is relatively inexpensive and printing speed is faster than other methods. The FDM method generally has excellent bed adhesion and interlayer adhesion when forming 3D sculptures, and because of its good shape stability, polylactic acid (PLA), ABS (Acrylonitrile Butadiene Styrene), HDPE, and polycarbonate ( Hard materials such as polycarbonate, PC) and flexible materials such as thermoplastic elastomers are used.

In particular, acrylonitrile-butadiene-styrene (hereinafter: ABS) is widely used as a general injection and extrusion molding material, and at the same time, it is in the spotlight as an extrusion-type 3D printer material. However, in the case of general ABS, it is easy to manufacture filaments for 3D printers, but when printing a 3D sculpture using this, the sculpture falls out of the 3D printer bed due to dimensional deformation, or the lower part of the sculpture is deformed, causing the lower part of each corner to roll up. Occurs.

In order to solve this problem, a method of controlling the content of the styrene-based or rubber phase in the ABS molecular structure has been studied.

Korean Patent No. 1860388 describes 70 to 95 parts by weight of an ABS (Acrylonitrile butadienestyrene) resin based on 100 parts by weight of the total composition; And 5 to 30 parts by weight of a thermoplastic elastomer, wherein the thermoplastic elastomer is a thermoplastic urethane-based copolymer (TPU) and a thermoplastic styrene-based copolymer (TPE-S) from 90 to 93: 7 to 10 The ABS composition for a 3D printer filament, characterized in that it is a mixture of TPU and TPE-S mixed in a weight% or 7 to 10: 90 to 93% by weight, is disclosed. It consists of 10 to 25 parts by weight of the thermoplastic crystalline resin mixture, and the thermoplastic amorphous resin mixture includes 100 parts by weight of a general-purpose polystyrene resin, 60 to 90 parts by weight of a high-impact polystyrene resin, and an acrylonitrile butadiene styrene copolymer 25 to 50 Disclosed is a filament composition for a 3D printer, characterized in that it consists of parts by weight.

However, they did not get a satisfactory effect in minimizing the shrinkage rate during printing.

Accordingly, the present inventors have made efforts to solve the above problem, and as a result, it has been confirmed that dimensional deformation due to shrinkage can be minimized when polymethyl methacrylate (PMMA) is used together with acrylonitrile-butadiene-styrene (ABS). , Has completed the present invention.

An object of the present invention is to provide a 3D printing composition capable of minimizing dimensional deformation due to shrinkage during printing, and a filament for a 3D printer manufactured by extruding the same.

In order to achieve the above object, the present invention provides a composition for 3D printing comprising acrylonitrile-butadiene-styrene (ABS) and polymethyl methacrylate (PMMA).

In the present invention, the polymethyl methacrylate (PMMA) is characterized in that it contains 10 to 30 parts by weight based on 100 parts by weight of acrylonitrile-butadiene-styrene (ABS).

In the present invention, the acrylonitrile-butadiene-styrene (ABS) is (a) a styrene-acrylonitrile copolymer and an acrylonitrile-butadiene rubber (NBR). Rubber, BR) or (b) styrene-butadiene rubber (SBR) It is characterized in that it is a graft type or graft-blend type obtained by graft copolymerization of styrene and acrylonitrile in the presence of latex.

In the present invention, the acrylonitrile-butadiene-styrene (ABS) is a graft-blend type, and the rubber content is 10 to 50% by weight.

In the present invention, the acrylonitrile-butadiene-styrene (ABS) has a melt flow index (MFR) of 37g/10min to 50g/10min according to ASTM D 1238 standard.

In the present invention, the polymethyl methacrylate (PMMA) is characterized in that it is a thermoplastic resin produced by free radical polymerization using methyl methacrylate as a monomer.

The present invention also provides a filament for a 3D printer manufactured 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 ~ 4.0mm.

In the present invention, the filament for the 3D printer is characterized in that the average of the shrinkage ratio of each corner is 5% or less when output as a sculpture (60 mm width, 60 mm length, 20 mm height).

The filament for a 3D printer according to the present invention is useful for 3D printing because it can minimize deformation of an output due to shrinkage during printing.

1 is a view showing the output direction of ASTM D638 for a tensile strength test of a 3D printed specimen manufactured according to an embodiment of the present invention.
2 is a three-dimensional scanning photograph of a sculpture manufactured according to Comparative Example 1 of the present invention.
3 is a three-dimensional scanning photograph of a sculpture manufactured according to an embodiment of the present invention.

In the present invention, when polymethyl methacrylate (PMMA) is used together with acrylonitrile-butadiene-styrene (ABS), it has been attempted to confirm that dimensional deformation due to shrinkage can be minimized during 3D printing.

In the present invention, a composition containing acrylonitrile-butadiene-styrene (ABS) and polymethyl methacrylate (PMMA) was extruded to prepare a filament for a 3D printer, and then it was again output as a sculpture and a specimen in a 3D printer. . As a result, it was confirmed that the tensile strength of the manufactured specimen and the shrinkage rate of the corners of the sculpture were excellent, so that dimensional deformation due to shrinkage during 3D printing was small.

Therefore, in one aspect, the present invention relates to a composition for 3D printing comprising acrylonitrile-butadiene-styrene (ABS) and polymethyl methacrylate (PMMA).

In the present invention, the acrylonitrile-butadiene-styrene (ABS) is a blend of (a) a styrene-acrylonitrile copolymer and an acrylonitrile-butadiene rubber (NBR). Rubber, BR) or (b) graft type or graft-blend type obtained by graft copolymerization of styrene and acrylonitrile in the coexistence of styrene-butadiene rubber (SBR) latex can be used, but the rubber content is 10 It is preferable to use a graft-blend type of ~50% by weight.

When the rubber content of the acrylonitrile-butadiene-styrene (ABS) is less than 10% by weight, the impact strength is low and there is a problem that the filament is easily broken, and when it exceeds 50% by weight, it is extruded due to a decrease in the flow index. It can be disadvantageous for 3D printing.

Therefore, it is preferable that the acrylonitrile-butadiene-styrene (ABS) has a melt flow index (MFR) of 37g/10min to 50g/10min according to ASTM D 1238 standard.

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

Polymethyl methacrylate (PMMA) of the present invention is a single 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.

In the composition for 3D printing of the present invention, the polymethyl methacrylate (PMMA) is preferably contained in an amount of 10 to 30 parts by weight based on 100 parts by weight of acrylonitrile-butadiene-styrene (ABS).

If the polymethyl methacrylate (PMMA) is less than 10 parts by weight, the bottom of the 3D sculpture is deformed after printing due to the shrinkage of ABS, and if it exceeds 30 parts by weight, the interlayer adhesion of the 3D sculpture decreases in the Z direction. There may be a problem that the strength of the sculpture is weakened.

When the composition for 3D printing of the present invention is extruded in a single-screw extruder and then cooled, a filament for a 3D printer can be prepared, and the filament for a 3D printer is preferably 0.8 to 4.0 mm in diameter, and 1.5 to 3 mm. More preferable.

If the diameter of the filament is less than 0.8 mm, the printer device may not be able to easily supply the filament because the filament is too thin, the filament may be pressed to prevent ejection, 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 sculpture may be degraded.

The filament for a 3D printer according to the present invention contains polymethyl methacrylate (PMMA) that improves the shrinkage rate of acrylonitrile-butadiene-styrene (ABS), so the sculpture (width 60 mm, length 60 mm, height 20 mm) When output as, the average of each corner shrinkage can be less than 5%.

In addition, the filament for a 3D printer according to the present invention is 37.5 based on the tensile strength (40 MPa) of the specimen produced through injection molding when outputting a dumbbell-shaped specimen of ASTM D 638 V type by the method (c) of Fig. 1 It corresponds to %~50% (15~20MPa) and has good tensile strength.

[Example]

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

Examples 1 to 3 and Comparative Examples 1 to 4: Preparation of filaments for 3D printers

The length after extruding the composition containing acrylonitrile-butadiene-styrene (ABS) and polymethyl methacrylate (PMMA) in Table 1 with a single screw extruder (screw diameter 30 mm, screw length 105 mm) It was cooled in a 3m cooling water bath and wound up to prepare a filament for a 3D printer having a diameter of 1.75 mm.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 A 100 100 100 100 100 0 0 A' 0 0 0 0 0 100 100 B 10 30 25 0 40 25 0

A: ABS LG Chem HF 380 (Melt Flow Index: 45g/10min (at.220℃/10kg))

A': ABS Styrolution's GP35 (Melt Flow Index: 35g/10min (at.220℃/10kg))

B: PMMA: IF870S from LG MMA

Experimental Example: 3D Printing Sculpture and Specimen Preparation Using Filament for 3D Printer

Using the filaments for 3D printers of Examples 1 to 3 and Comparative Examples 1 to 4, a 3D printer (ALMOND of Opencreator) was used to print out a sculpture (60 mm wide, 60 mm long, 20 mm high) for deformation evaluation. The shrinkage was checked and the results are shown in Table 2. The sculpture was printed by setting the conditions of printing speed: 70mm/sec ~ 50mm/sec, nozzle temperature: 245℃, nozzle diameter: 0.4mm, bed temperature: 80℃, and filling: 100%.

The corner shrinkage rate was determined as good when the shrinkage rate was less than 5% and insufficient when the shrinkage rate was 5% or less by measuring the actual height as a percentage by measuring each corner with a vernier caliper after leaving the printed object for 24 hours.

In addition, in order to check the tensile strength, a dumbbell-shaped specimen of ASTM D 638 V type was output by the method (c) of Fig. 1, and a specimen of the same standard was manufactured through injection molding. If the tensile strength in the Z direction exceeds 37.5% (15 MPa) of the tensile strength (40 MPa) of the tensile specimen produced through injection molding, it is evaluated as good, and if it is less than 37.5% (15 MPa), it is evaluated as insufficient, and the results are shown in Table 2. I got it.

In addition, according to the melt flow index (MFR) of acrylonitrile-butadiene-styrene (ABS), when the printing speed is 70 mm/sec and the specimen or sculpture is excellently output, the printing speed is good, and when the printing speed is 50 mm/sec, the specimen or If the sculpture was excellently output, it was judged that the printing speed was insufficient, and the results are shown in Table 2.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Z direction
The tensile strength 18 MPa
Good 16MPa
Good 17MPa
Good 19 MPa
Good 13 MPa
Inadequate 16MPa
Good 17MPa
Good Printout
edge
Shrinkage rate 4.8%
Good 4.0%
Good 4.3%
Good 6%
Inadequate 3%
Good 4.3%
Good 7%
Inadequate Printing speed Good Good Good Good Good Inadequate Inadequate

From Table 2, the Z-direction tensile strength of the specimens of Examples 1 to 3 output as a filament containing 10 to 30 parts by weight of PMMA per 100 parts by weight of ABS(A) having a melt flow index of 45 g/10 min or more, and printing All of the speeds were found to be good.

On the other hand, Comparative Example 1 without PMMA had good Z-direction tensile strength and printing speed, but the printout edge shrinkage was insufficient, and Comparative Example 2 containing an excessive amount of PMMA had good printout edge shrinkage and printing speed, but Z-direction tensile It was confirmed that the strength was insufficient.

In addition, Comparative Example 3, which was printed with a filament containing 25 parts by weight of PMMA, using ABS (A') having a melt flow index of 35 g/10 min or less, was confirmed to have good Z-direction tensile strength and edge shrinkage of the printed product, but the printing speed was insufficient. Became.

Finally, it was confirmed that in Comparative Example 4, only ABS (A') having a melt flow index of 35 g/10min or less and without PMMA was good, the tensile strength in the Z direction was good, but the shrinkage rate and printing speed of the printed material were insufficient.

As described above, specific parts of the present invention have been described in detail, and it will be apparent to those of ordinary skill in the art that these specific techniques are only preferred embodiments, and the scope of the present invention is not limited thereby. will be. Accordingly, it will be said that the substantial scope of the present invention is defined by the appended claims and their equivalents.

Claims (9)

3D printing composition comprising acrylonitrile-butadiene-styrene (ABS) and polymethyl methacrylate (PMMA).
The composition for 3D printing according to claim 1, wherein the polymethyl methacrylate (PMMA) is contained in an amount of 10 to 30 parts by weight based on 100 parts by weight of acrylonitrile-butadiene-styrene (ABS).
The method of claim 1, wherein the acrylonitrile-butadiene-styrene (ABS) is a blended type of (a) a styrene-acrylonitrile copolymer and a polymer blend of acrylonitrile-butadiene rubber (NBR) ( A composition for 3D printing, characterized in that it is a graft type or a graft-blend type obtained by graft copolymerization of styrene and acrylonitrile in the presence of butadiene rubber, BR) or (b) styrene-butadiene rubber (SBR) latex. .
The composition for 3D printing according to claim 3, wherein the acrylonitrile-butadiene-styrene (ABS) is a graft-blend type and has a rubber content of 10 to 50% by weight.
The composition for 3D printing according to claim 3, wherein the acrylonitrile-butadiene-styrene (ABS) has a melt flow index (MFR) of 37g/10min to 50g/10min according to ASTM D 1238 standard.
The composition for 3D printing according to claim 1, wherein the polymethyl methacrylate (PMMA) is a thermoplastic resin prepared by free radical polymerization using methyl methacrylate as a monomer.
A filament for a 3D printer manufactured by extruding the composition for 3D printing of any one of claims 1 to 6.
The 3D printer filament according to claim 7, wherein the 3D printer filament has a diameter of 0.8 to 4.0 mm.
[8] The filament for a 3D printer according to claim 7, wherein the filament for a 3D printer has an average of 5% or less of shrinkage at each corner when the filament is output as a sculpture (60 mm wide, 60 mm long, and 20 mm high).

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