KR20190062906A - 3d printing polylactic acid filament composition for improving surface property - Google Patents

Abstract

The present invention relates to a polylactic acid resin composition for a three-dimensional printer filament to realize a wood texture in a final printed material. Specifically, disclosed are: the polylactic acid resin composition for the three-dimensional printer filament having excellent output performance and mechanical properties while improving surface properties to exhibit the wood texture; and the three-dimensional printer filament manufactured by using the same. The present invention provides the polylactic acid resin composition for the three-dimensional printer filament and the three-dimensional printer filament manufactured by using the same, wherein the polylactic acid resin composition comprises: (A) 81 to 98 wt% of a polylactic acid resin; (B) 1 to 9 wt% of a wood flour; and (C) 1 to 10 wt% of a biodegradable resin.

Description

TECHNICAL FIELD [0001] The present invention relates to a poly (lactic acid) resin composition for a three-dimensional printer filament having improved surface properties,

The present invention relates to a polylactic acid resin composition for a three-dimensional printer filament, and more particularly to a polylactic acid resin composition for a three-dimensional printer filament for improving surface properties.

A three-dimensional (3-dimensional) printer is a device that produces three-dimensional objects by layering layers of fine thickness by sequentially injecting ink of a specific material. 3D printing is spreading in various fields. In addition to the automotive sector, which is composed of many parts, it is used by many manufacturers for making various models such as medical human body models, household products such as toothbrushes and razors.

Currently, the most widely used material for 3D printing is photopolymer, which is a photocurable macromolecule that solidifies upon receiving light. This accounts for 56% of the total market. The next most popular material is solid, thermoplastic, which is free to melt and solidify. It occupies 40% of the market and metal powder is expected to grow gradually in the future. The shape of the double thermoplastics material may be in the form of filaments, particles or powder powders. The three-dimensional printing of the filament type is faster than the other type in speed, so the productivity is high and the spreading speed is fast.

On the other hand, efforts to reduce greenhouse gases due to global warming have been extensively carried out. As one of the efforts, development of biodegradable polymer materials that are decomposed in nature has been attracting attention. Most of the existing polymers use petroleum resources as basic raw materials, but this may be exhausted in the future. Carbon dioxide generated by mass consumption of petroleum resources is recognized as a main cause of global warming. Therefore, attention has been focused on the development and industrial application of biodegradable polymers using plant resources grown by using carbon dioxide as a raw material. In particular, biodegradable polymer materials such as polylactic acid (PLA) have been actively applied as three-dimensional printer filaments.

However, poly (lactic acid) has a slow crystallization rate and has a limitation of slow 3D printing speed. The commercially available poly (lactic acid) filament weighs about 35 g and is about 70 × 61 × 64 mm in size.

Korean Prior Patent Publication No. 2012-0108798 discloses an L-type and D-type polylactic acid stereocomposite which is heated at a temperature of 100 to 110 ° C after cooling to cool the surface of a mold cavity. However, the application is limited to automobile materials and is not mentioned in the application of filaments for three-dimensional printers. The use of D-type polylactic acid causes a problem of cost burden.

Korean Patent Laid-Open Publication No. 2012-0129500 discloses a poly (lactic acid) resin composition having improved mechanical properties and crystallization speed by applying phyllite powder and carbon nanotubes subjected to an organic surface treatment to poly (lactic acid) , But it is not suitable as a material for a three-dimensional printer requiring various colors by using carbon nanotubes.

Korean Patent Laid-Open Publication No. 2012-0022420 relates to a process for producing a heat-resistant poly (lactic acid) fiber blended with an L-type poly (lactic acid), a D-type poly (lactic acid) and a polyester, However, the application is confined to stretched fibers and is not mentioned in the application of filaments for three-dimensional printers. The use of D-type polylactic acid causes a problem of cost burden.

In recent years, attempts have been made to realize a wood texture in a final print as a filament for a three-dimensional printer. In the case of currently sold wood PLA filaments, a material containing wood with a high content of wood with a wood content of 20% Are used, which can be compounded with dedicated equipment.

However, in the case of containing a large amount of wood, the strand is broken without a separate device such as a kneader, the extrusion is not properly performed, the moisture content is large and storage and use is not easy, and troubles such as nozzle clogging there is a problem.

In addition, in the case of wood PLA filaments, the luster of the wood is relatively small due to the characteristics of the surface, and there is a problem that it is difficult to show the texture due to the luster when mixed with poly (lactic acid). In addition, due to the nature of the brittle wood, it is more fragile during PLA and compounding, which makes it difficult to form filaments. In the case of FDM (Fused Deposition Modeling) 3D printers, breakage often occurs.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a poly (lactic acid) resin composition for a three-dimensional printer filament for achieving a wood texture in a final print, The present invention provides a poly (lactic acid) resin composition for a three-dimensional printer filament and a filament for a three-dimensional printer manufactured using the same.

In order to solve the above problems, the present invention provides a polylactic acid composition comprising (A) 81 to 98% by weight of a polylactic acid resin; (B) 1 to 9% by weight of wood flour; And (C) 1 to 10% by weight of a biodegradable resin, based on the total weight of the three-dimensional printer filament.

The present invention also provides a poly (lactic acid) resin composition for a three-dimensional printer filament, wherein the wood powder (B) has a size of 50 to 120 mesh.

The present invention also provides a poly (lactic acid) resin composition for a three-dimensional printer filament, wherein the biodegradable resin (c) is an aliphatic polyester resin.

The biodegradable aliphatic polyester resin (C) is at least one selected from the group consisting of polybutylene succinate, polyethylene succinate, polybutylene adipate and polybutylene succinate adipate. Dimensional polyolefin resin composition for a printer filament.

Also, the present invention provides a poly (lactic acid) resin composition for a three-dimensional printer filament, wherein the filaments made of the poly (lactic acid) resin composition are used and the nozzles are clogged or the filaments are not monocapped at the time of output under the following conditions.

[Output condition]

Using the filament, 35 g of output is output to a three-dimensional printer set at a nozzle temperature of 200 ° C., an output speed of 110 mm / s, and a layer output time of 10 seconds.

The present invention also provides a poly (lactic acid) resin composition for a three-dimensional printer filament, wherein the resin composition has a glossiness of 3 to 7% according to the following measurement method.

[Polishing degree measurement method]

The intensity of the reflected light received at an angle of incidence (60 degrees) of incident light through a specular reflection glossmeter according to ASTM D523 and D2457 was measured to determine the gloss of the glass surface with a refractive index of 1.567 to be 100 Calculate the relative ratio.

In order to solve the above-mentioned problems, the present invention provides a filament for a three-dimensional printer made of the poly (lactic acid) resin composition.

According to the present invention, wood powder and biodegradable resin are mixed with polylactic acid resin in a specific amount to improve surface characteristics so that wood texture can be obtained, and excellent output performance and mechanical properties such as nozzle clogging and filament monofilament A poly (lactic acid) resin composition for a three-dimensional printer filament, and a filament produced using the composition.

The present invention provides a poly (lactic acid) resin composition for a three-dimensional printer filament having elasticity similar to that of a wood surface without using a quencher, and a filament manufactured using the poly (lactic acid) resin composition, Can have a large ripple effect.

1 is a photograph of a filament prepared according to Example 1 and Comparative Example 3 in Test Example 1 of the present invention using a stereomicroscope,
Fig. 2 is a photograph showing the output performance evaluation standard using a three-dimensional printer, in which filaments prepared according to Examples and Comparative Examples in Test Example 2 of the present invention were used,
Fig. 3 is a photograph showing the results of outputting filaments produced according to Example 1 and Comparative Example 2 in Test Example 3 of the present invention using a three-dimensional printer. Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, when an element is referred to as "including " an element, it means that it can include other elements, not excluding other elements, unless specifically stated otherwise.

DISCLOSURE OF THE INVENTION [0006] The present inventors have found that, in conventional poly (lactic acid) resin composition for printer filament for wood texture realization, the present inventors have found that the glossiness due to the poly (lactic acid) component causes deterioration of the woodiness and the extrusion problem, As a result of repeated research to solve the problems of frequent process troubles, it has been found that mixing of wood flour and biodegradable resin in polylactic acid resin improves the surface characteristics so that the wood texture becomes remarkable, The present inventors have found that there is a specific content ratio to have excellent output performance and mechanical properties that do not cause development, and have reached the present invention.

Accordingly, the present invention provides a polylactic acid composition comprising (A) 81 to 98% by weight of a polylactic acid resin; (B) 1 to 9% by weight of wood flour; And (C) 1 to 10% by weight of a biodegradable resin; and (C) a polylactic acid resin composition for a three-dimensional printer filament.

The poly (lactic acid) resin in the present invention is a polyester resin produced by an ester reaction using a lactic acid obtained by decomposing corn starch as a monomer.

The polylactic acid resin is classified into poly-L-lactic acid composed of repeating units derived from L-isomeric lactic acid, poly D-lactic acid composed of repeating units derived from D-isomeric lactic acid, - lactic acid may be used singly or in combination, and is not particularly limited in the present invention.

In the case of L-poly lactic acid (PLLA) having a repeating unit derived from L-lactic acid, the repeating unit derived from L-lactic acid is preferably 95% by weight or more, more preferably 97% by weight or more in terms of balance of heat resistance and formability And most preferably at least 99% by weight. It is more preferable that 95 to 100% by weight of the repeating units derived from L-lactic acid and 0 to 5% by weight of the repeating units derived from D-lactic acid are taken into consideration in consideration of the hydrolysis resistance. There is no particular limitation on the molecular weight and the molecular weight distribution within the range in which the molding can be carried out, but it is preferable to use a resin having a weight average molecular weight of 80,000 or more from the viewpoint of balance of the mechanical strength and heat resistance of the molded article, more preferably 90,000 to 500,000 Can be used.

In the case of D-polylactic acid (PDLA) having a repeating unit derived from D-lactic acid, the repeating unit derived from D-lactic acid is preferably 95% by weight or more, more preferably 97% by weight or more in terms of balance of heat resistance and formability And most preferably at least 99% by weight. It is more preferable that 95 to 100% by weight of the repeating unit derived from D-lactic acid and 0 to 5% by weight of the repeating unit derived from L-lactic acid are taken into account in consideration of the hydrolysis resistance. In addition, there is no particular limitation on the molecular weight and the molecular weight distribution within the range in which the molding process is possible, but it is generally preferable that the weight average molecular weight is 10,000 or more from the viewpoint of balance of the mechanical strength and heat resistance of the molded article, Of 20,000 to 100,000 can be used.

The content of the polylactic acid resin is 81 to 98% by weight based on 100% by weight of the total of the components (A) and (C), and preferably 85% To 94% by weight, and more preferably from 86 to 90% by weight.

The wood flour (B) is a component for realizing the wood texture in the final print. The wood flour (B) is not particularly limited as long as it can realize the texture of the wood according to the type of wood in the present invention. From the viewpoint of achieving the desired particle size range, one can be employed.

That is, in the present invention, it is preferable to use the wood powder formed by pulverizing the wood powder to a size of 50 to 120 mesh. When the size of the wood powder is less than 50 mesh, the mechanical properties may deteriorate. When the wood powder is larger than 120 mesh, the wood is too fine to cause a phenomenon such as lump of wood during the compounding process, This can lead to poor output.

The content of the wood powder may be 1 to 9% by weight, preferably 3 to 8% by weight, more preferably 6 to 8% by weight, based on 100% by weight of the total of the components (A) have. If the wood powder content is less than 1% by weight, it is difficult to realize the wood texture due to the increase in gloss. If the wood powder content exceeds 9% by weight, defective molding may occur due to excessive shrinkage due to wood component during molding with the resin composition , Nozzle clogging or filament monofilament phenomenon may occur at the time of output using the filament.

The biodegradable resin (C) is mixed with the polylactic acid resin (A) and the wood flour component (B) in the present invention to minimize the degradation of output performance and mechanical properties while realizing a whitish wood texture.

As such a biodegradable resin, a biodegradable aliphatic polyester resin can be preferably used, and examples thereof include polybutylene succinate, polyethylene succinate, polybutylene adipate, and polybutylene succinate adipate. Polybutylene succinate may be used. In addition, a copolymer such as glycolic acid,? -Caprolactone, trimethylene carbonate, or polyethylene glycol may be used in combination. In addition, other biodegradable polymers such as cellulose acetate, polycaprolactone, copolymers of polyhydroxybutyrate and barrylate, chitin, chitosan, or starch may be used in combination without impairing the physical properties of the biodegradable polyester resin It is possible.

The content of the biodegradable resin may be 1 to 10% by weight, preferably 3 to 8% by weight, more preferably 4 to 7% by weight, based on 100% by weight of the total of the components (A) Lt; / RTI > When the content of the biodegradable resin is less than 1% by weight, clogging of the nozzle or monofilament phenomenon occurs at the output using the filament. When the content of the biodegradable resin is more than 10% by weight, it is preferable to further improve the output performance I do not.

As described above, the poly (lactic acid) resin composition for filament in which the wood powder and the biodegradable resin are mixed in the poly (lactic acid) resin at a specific content ratio is improved in surface texture so that the wood texture is remarkably exhibited and the nozzle clogging or filament monofilament phenomenon Good output performance and mechanical properties.

That is, the poly (lactic acid) resin composition for a three-dimensional printer filament according to the present invention is characterized in that the nozzle is clogged at the time of output under the following conditions, the filaments are not single-edged and the gloss according to the following measurement method is 3-7% It is possible to provide a filament for a three-dimensional printer which is expressed in a smooth manner.

[Output condition]

Using the filament, 35 g of output is output to a three-dimensional printer set at a nozzle temperature of 200 ° C., an output speed of 110 mm / s, and a layer output time of 10 seconds.

[Polishing degree measurement method]

The intensity of the reflected light received at an angle of incidence (60 degrees) of incident light through a specular reflection glossmeter according to ASTM D523 and D2457 was measured to determine the gloss of the glass surface with a refractive index of 1.567 to be 100 Calculate the relative ratio.

The polylactic acid resin composition for use in the production of the filament for a three-dimensional printer according to the present invention may further contain other additives in addition to the above-mentioned main components within the scope of the intended use or effect. For example, the additive may be added for various applications by further adding a nucleating agent, heat stabilizer, light stabilizer, flame retardant, carbon black, antioxidant, impact modifier, etc., 10 parts by weight.

The poly (lactic acid) resin composition used for producing the filament for a three-dimensional printer according to the present invention can be produced by a known melt extrusion method for producing a general resin composition. That is, polylactic acid resin, wood powder, biodegradable resin, other additives and the like may be mixed at the same time and then melt-extruded in an extruder to produce a desired product.

For example, the components are first mixed in an appropriate amount. At this time, mixing may be performed by arbitrarily selecting mixing means which are well known in the art such as a tumbler mixer, a blending machine, a hopper, and the like. Thereafter, the homogeneously mixed composition is melt-extruded at 170 to 200 DEG C by using a twin-screw extruder and molded into a pellet state. Thereafter, the resin composition molded into pellets is extruded by a single-screw extruder at 170 to 200 ° C, cooled, and wound up to be re-formed into filaments having a constant diameter, and can be used for a three-dimensional printer filament. The filament may be extruded by a uniaxial extruder having a screw diameter of 20 to 40 mm and a screw length of 100 to 110 mm, cooling the filament using a cooling water bath, and winding the filament into a filament having a diameter of 1.5 to 3 mm.

Hereinafter, a specific embodiment of the present invention will be described.

First, the specifications of the components used in Examples and Comparative Examples of the present invention are as follows.

(A) a polylactic acid resin

Ingeo 4032D (MI 7 g / 10 min (210 ° C, 2.16 kg)), a PLA product manufactured by NatureWorks LLC, USA, was used.

(B) Wood flour

And 80 mesh sized wood flour manufactured from Oriental sawdust were used.

(C) Biodegradable resin

(PBS G4560M, MI 3.2 g / 10 min (190 캜, 2.16 kg)) manufactured by Lotte Chemical Co., Ltd. was used.

Example 1

88 parts by weight of polylactic acid resin, 7 parts by weight of wood powder, 5 parts by weight of polybutylene succinate, and 5 parts by weight of talc as a nucleating agent were mixed for 5 minutes using a tumbler mixer, and then kneaded in a twin screw extruder having L / The extrudates were extruded in the temperature range of ~ 200 < 0 > C and then pelletized. The extruded pellets were dried at 80 DEG C for 12 hours and then subjected to injection molding at an injection temperature of 180 to 200 DEG C for 80 seconds using an injection machine (Dongshin Hydraulic Co., Ltd., Korea) with a mold clamping force of 150 tons After cooling, the molded product was extracted to obtain a physical specimen. Further, the dried pellets were extruded by a single-screw extruder at 170 to 200 ° C, cooled and taken up to produce filaments having a constant diameter of 1.75 mm.

Example 2

The pellets were prepared in the same manner as in Example 1 except that 90 parts by weight of polylactic acid resin and 5 parts by weight of wood powder were used in Example 1, and then physical properties specimens and filaments were prepared.

Comparative Example 1

Pellets were prepared in the same manner as in Example 1, except that 94.9 parts by weight of polylactic acid resin, 5 parts by weight of wood powder and 0.1 part by weight of polybutylene succinate were used in Example 1, .

Comparative Example 2

The pellets were prepared in the same manner as in Example 1, except that 92.9 parts by weight of the polylactic acid resin and 0.1 part by weight of polybutylene succinate were used in Example 1, and then physical specimens and filaments were prepared.

Comparative Example 3

The pellets were prepared in the same manner as in Example 1 except that 85 parts by weight of the polylactic acid resin and 10 parts by weight of the wood powder were used in Example 1, and then physical properties test pieces and filaments were prepared.

Comparative Example 4

A pellet was prepared in the same manner as in Example 1 except that the wood powder having a size of 150 mesh was used in Example 1 to prepare a physical specimen and a filament.

Comparative Example 5

A commercially available Wood PLA from Colorfabb (PLA and regenerated wood powder at a weight ratio of 70:30) was prepared.

The composition (unit: parts by weight) of the resin composition prepared according to the above Examples and Comparative Examples is shown in Table 1 below.

Test Example 1

In order to confirm the molding conditions of the filament for a three-dimensional printer according to the present invention, the cross-sections of the filaments produced according to Example 1 and Comparative Example 3 were confirmed by using a stereoscopic microscope (OLYMPUS, Japan) Respectively.

Referring to FIG. 1, it can be seen that filaments made of a polylactic acid resin composition for a three-dimensional printer filament having a specific composition according to the present invention (FIG. 1 (a)) have smooth filament cross sections, 1 (b)), it can be confirmed that the cross-section is distorted due to the shrinkage.

Test Example 2

In order to evaluate the three-dimensional output performance of the filament for a three-dimensional printer according to the present invention, the output performance of the filament manufactured according to the above-described Examples and Comparative Examples was evaluated using a three-dimensional printer. As a three-dimensional printer, MARV manufactured by Canon Korea was used. The conditions of a three-dimensional printer were 10 seconds for a layer output, 110 mm / s for an output speed, 200 ° C for an output temperature and Wood Mode. 2 (b), when the output is formed without being different from the printer drawing as shown in FIG. 2 (b), 'output success', FIG. 2 (c), and If the output state is poor as shown in FIG. 2 (d), it is evaluated as "output failure". 2 (c) and Fig. 2 (d) is that the nozzle is clogged at the time of outputting, which causes a break in the middle. The filament produced according to each of the Examples and Comparative Examples was subjected to ten times of output under the above conditions and the output success rate results are shown in Table 2 below.

Referring to Table 2, it can be seen that the use of the filament made of the poly (lactic acid) resin composition for a three-dimensional printer filament according to the present invention has no problem in the output performance despite the high output condition.

On the other hand, when the content of the biodegradable resin is less than a certain range (Comparative Examples 1 and 2), the wood grain content is excessive (Comparative Examples 3 and 6), and the wood grain size is too small (Comparative Example 4) It can be confirmed that an output failure occurs due to the occurrence of nozzle clogging.

Test Example 3

For the evaluation of the gloss of the filament for a three-dimensional printer according to the present invention, the glossiness of the specimens prepared according to the examples and the comparative examples were measured according to the following methods, and the results are shown in Table 3 below. Also, the filament produced according to Example 1 and Comparative Example 2 was output using a three-dimensional printer under the same conditions as in Test Example 2, and the output was performed with different printer drawings. The results are shown in FIG.

[Polishing degree measurement method]

The intensity of the reflected light received at an angle of incidence (60 degrees) of incident light through a specular reflection glossmeter according to ASTM D523 and D2457 was measured to determine the gloss of the glass surface with a refractive index of 1.567 to be 100 Calculate the relative ratio.

Referring to Table 3, it can be seen that the gloss of the polylactic acid resin composition for a three-dimensional printer filament of a specific composition according to the present invention is appropriately lowered without the use of a light-quencher, but if the content of the biodegradable resin is less than a certain range (Comparative Examples 1 and 2), it can be confirmed that the glossiness is relatively large.

On the other hand, referring to FIG. 3, in the case of Comparative Example 2 in which the output was made using the filament produced according to Example 1 (FIG. 3 (a)) and the gloss was reduced in the lamination plane and the biodegradable resin content was small (b)), the wood texture is relatively smoothly realized, which is a result of the reduction of the gloss as described above.

As described above, when the poly lactic acid resin composition for a three-dimensional printer filament according to the present invention is used, excellent output performance can be obtained without wood flour at a level of 20% by weight or more like conventional wood filament, have.

The preferred embodiments of the present invention have been described in detail above. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning, range, and equivalence of the claims are included in the scope of the present invention Should be interpreted.

Claims (7)

(A) 81 to 98% by weight of a polylactic acid resin;
(B) 1 to 9% by weight of wood flour; And
(C) 1 to 10% by weight of a biodegradable resin;
Wherein the poly (lactic acid) resin composition for a three-dimensional printer filament is a poly (lactic acid) resin composition for a three-dimensional printer filament. The method according to claim 1,
Wherein the wood flour (B) has a size of 50 to 120 mesh. The method according to claim 1,
Wherein the biodegradable resin (c) is an aliphatic polyester resin. The method of claim 3,
The biodegradable aliphatic polyester resin (C) is at least one selected from the group consisting of polybutylene succinate, polyethylene succinate, polybutylene adipate, and polybutylene succinate adipate. Polylactic acid resin composition for filament. The method according to claim 1,
Characterized in that the filaments made of the poly (lactic acid) resin composition are used and the nozzles are clogged or the filaments are not single-wounded at the time of output under the following conditions:
[Output condition]
Using the filament, 35 g of output is output to a three-dimensional printer set at a nozzle temperature of 200 ° C., an output speed of 110 mm / s, and a layer output time of 10 seconds. The method according to claim 1,
Wherein the resin composition has a glossiness of 3 to 7% according to the following measurement method:
[Polishing degree measurement method]
The intensity of the reflected light received at an angle of incidence (60 degrees) of incident light through a specular reflection glossmeter according to ASTM D523 and D2457 was measured to determine the gloss of the glass surface with a refractive index of 1.567 to be 100 Calculate the relative ratio. A filament for a three-dimensional printer produced from the polylactic acid resin composition according to any one of claims 1 to 6.

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