KR20220000876A - Carbon fiber-reinforced thermoplastic resin composition suitable for 3D printing filament and molded article comprising the same - Google Patents

Abstract

The present invention relates to a carbon fiber-reinforced thermoplastic resin composition and a molded article comprising the same, and more specifically, to a carbon fiber-reinforced thermoplastic resin composition which can be printed with a 3D printer at a low temperature, has excellent printability and anti-shrinking properties, and has excellent properties such as prevention of spider web formation and mechanical properties so as to be suitable for a 3D printing filament by containing carbon fibers surface-treated with a thermoplastic resin in a specific content, a molded article comprising the same, and in particular, a filament for 3D printing.

Description

Carbon fiber-reinforced thermoplastic resin composition suitable for 3D printing filament and molded article comprising the same

The present invention relates to a carbon fiber-reinforced thermoplastic resin composition and a molded article comprising the same, and more particularly, by including a carbon fiber surface-treated with a thermoplastic resin in a specific content, it is possible to output with a 3D printer at a low temperature, Carbon fiber-reinforced thermoplastic resin composition suitable for 3D printing filaments and molded articles containing the same, especially for 3D printing, as it has excellent printability and anti-shrinking properties at the same time, and also has excellent properties such as prevention of cobweb formation and mechanical properties It's about filament.

3D-printing output method varies according to its use, but considering equipment price, supply and demand of materials, and difficulty in printing, the most popular output method in industry and home is the material extrusion method. The material extrusion method is a method in which materials provided in the form of filaments are melted and laminated in a nozzle. Resins for 3D-printing filaments used in this method include polylactic acid (PLA), acrylonitrile-butadiene-styrene (ABS), and poly carbonate (PC) and polyimide (PI);

Among them, the most commonly used 3D-printing filament resin is polylactic acid resin. Polylactic acid resin does not emit an odor when printing, and since printing is possible even at a relatively low temperature, expensive printing equipment is not required. However, since polylactic acid resin has poor mechanical properties, there is a need for a resin for 3D-printing filaments that can exhibit excellent mechanical properties and printability at the same time.

Methods of improving the properties of materials by adding inorganic substances to existing resins are widely used, and even in the case of materials for 3D printing, there is a method of improving the rigidity of materials by using carbon fibers (eg, Korean Patent No. 10- 1774941). However, the simple use of carbon fiber as disclosed in this patent does not simultaneously improve output and anti-shrinkage properties, and the effect of carbon fiber properties on changes in the physical properties of the filament for 3D printing is also unknown.

Therefore, there is a need for development of a thermoplastic resin composition for 3D printing that contains carbon fibers while simultaneously improving printability and anti-shrinkage properties, and further has excellent properties such as prevention of cobweb formation and mechanical properties.

An object of the present invention is carbon fiber suitable for 3D printing filament because it is possible to print with a 3D printer at a low temperature, and has excellent printability and anti-shrinkage properties, and also has excellent properties such as prevention of spider web formation and mechanical properties. - To provide a reinforced thermoplastic resin composition and a molded article including the same, in particular, a filament for 3D printing.

In order to solve the above technical problem, the present invention includes a thermoplastic resin and a surface-treated carbon fiber, and the content of the surface-treated carbon fiber based on 100 parts by weight of the total composition is 1 part by weight to 49 parts by weight, carbon fiber -Provides a reinforced thermoplastic resin composition.

According to another aspect of the present invention, a molded article including the carbon fiber-reinforced thermoplastic resin composition of the present invention, preferably a filament for 3D printing is provided.

The carbon fiber-reinforced thermoplastic resin composition according to the present invention has a low output temperature and excellent printability suitable for use as a filament for 3D printing, and at the same time has a low degree of shrinkage of the printout, enabling delicate printing. At the same time, it can be usefully used as a filament for 3D printing because it has excellent properties for preventing cobweb formation and mechanical properties.

1 is a view illustrating the evaluation criteria of output performance of a filament for 3D printing, and the higher the surface of the 3D printing output, the higher the score (up to 5 points).
Figure 2 is a view illustrating the evaluation criteria for the shrinkage resistance of the filament for 3D printing, the higher the score (up to 5 points) as the corner portion is not bent when outputting a square box with 3D printing.
3 is a view illustrating the evaluation criteria for preventing spider web generation of filaments for 3D printing, and corresponds to a higher score (up to 5 points) as no spider web is generated during 3D printing.

Hereinafter, the present invention will be described in more detail.

The carbon fiber-reinforced thermoplastic resin composition of the present invention includes a thermoplastic resin.

In one embodiment, the thermoplastic resin may be selected from polyamide (PA) resin, polycarbonate (PC) resin, polyether ether ketone (PEEK) resin, and combinations thereof.

In one embodiment, the viscosity average molecular weight of the thermoplastic resin may be 15,000 to 50,000, more specifically, 16,000 to 30,000.

In one embodiment, the carbon fiber-reinforced thermoplastic resin composition of the present invention may contain the thermoplastic resin in an amount of 51 to 99 parts by weight based on 100 parts by weight of the total composition. If the content of the thermoplastic resin in the total 100 parts by weight of the composition is lower than the above level, there may be a problem in the outputability of 3D printing.

More specifically, the content of the thermoplastic resin in the resin composition based on a total of 100 parts by weight of the carbon fiber-reinforced thermoplastic resin composition of the present invention may be 52 parts by weight or more, 55 parts by weight or more, 58 parts by weight or more, or 60 parts by weight or more. , may also be 98 parts by weight or less, 95 parts by weight or less, 93 parts by weight or less, or 90 parts by weight or less.

The carbon fiber-reinforced thermoplastic resin composition of the present invention also includes surface-treated carbon fibers.

In one embodiment, the surface-treated carbon fiber may be surface-treated with a surface treatment agent including a silane-based polymer, or a titanate-based polymer, a polyamide-based polymer, a polyurethane-based polymer, or a combination thereof. When a plurality of surface treatment agents are used, at least one of them is preferably a surface treatment agent having good affinity with the thermoplastic resin used in the carbon fiber-reinforced thermoplastic resin composition.

In one embodiment, the surface-treated carbon fiber may include 0.1 to 10 parts by weight of a surface treatment agent based on 100 parts by weight of the carbon fiber, and more specifically, 0.5 to 8 parts by weight, or 1 to 5 parts by weight A surface treatment agent may be included.

The surface treatment of the carbon fiber may be performed by continuously impregnating the carbon fiber with the surface treatment agent by various known methods such as, for example, a melt impregnation method and a powder charging method.

In one embodiment, the surface-treated carbon fiber may have a length of 1 to 10 mm, more specifically 2 to 8 mm or 3 to 6 mm, and may be used in various lengths depending on the purpose of use. have.

In the carbon fiber-reinforced thermoplastic resin composition of the present invention, the surface-treated carbon fiber is included in an amount of 1 to 49 parts by weight based on 100 parts by weight of the total composition. If the content of the surface-treated carbon fiber in the total 100 parts by weight of the composition is lower than 1 part by weight, the anti-shrinkage property, anti-cobweb properties, mechanical strength and heat resistance are inferior, and when it is higher than 49 parts by weight, the output performance of 3D printing is poor.

More specifically, the content of the surface-treated carbon fibers in the resin composition based on a total of 100 parts by weight of the carbon fiber-reinforced thermoplastic resin composition of the present invention is 2 parts by weight or more, 5 parts by weight or more, 7 parts by weight or more, or 10 parts by weight. or more, and may be 48 parts by weight or less, 45 parts by weight or less, 42 parts by weight or less, or 40 parts by weight or less.

In addition to the above components, one or more other additives may be added to the carbon fiber-reinforced thermoplastic resin composition of the present invention as needed within a range capable of achieving the object of the present invention.

The type of the other additives is not particularly limited, and additives commonly used in the thermoplastic resin composition may be used without limitation, for example, a compatibilizer, a fluidizing agent, an antioxidant, a lubricant, or a mixture of two or more thereof. One or more additives may be used.

In one embodiment, as the compatibilizing agent, maleic anhydride-grafted modified polypropylene may be used.

In one embodiment, as the fluidizing agent, aromatic phosphate, aliphatic phosphate, or a mixture thereof may be used, and any monophosphate compound or phosphate oligomer compound commonly known in the art may be used. For example, commercially available PX-200, PX-201, PX-202, CR-733S, CR-741, CR747 (above DAIHACHICHEMICAL INDUSTRY Co., Ltd.), FP-600, FP-700, FP-800 (above ADEKA) Co.) and the like may be used.

In one embodiment, the antioxidant is tris(nonylphenyl)phosphite, (2,4,6-tri-tert-butylphenyl)(2-butyl-2-ethyl-1,3-propanediol)phosphite , tris(2,4-dibutylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite , an organophosphorus antioxidant such as bis(2,4-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite or distearyl pentaerythritol diphosphite; Pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate or octadecyl-3-(3,5-di-tert-butyl-4-hydroxyl) A phenol-based antioxidant such as phenyl) propionate, a thioester-based antioxidant such as pentaerythritol tetrakis(3-dodecylthiopropionate), or the like, or a mixture of two or more thereof may be used.

In one embodiment, as the lubricant, a long chain ester of pentaerythritol or stearyl stearate may be used.

The content of the other additives is not particularly limited, and may be used up to 3 parts by weight, for example, within the range of about 0.5 to 2 parts by weight, based on 100 parts by weight of the resin composition of the present invention, depending on the purpose and use.

In one embodiment, when the thermoplastic resin is a polyamide resin, the carbon fiber-reinforced thermoplastic resin composition of the present invention may have a 3D printing output temperature of 260° C. or less (eg, 250° C. to 260° C.).

In another embodiment, when the thermoplastic resin is a polycarbonate resin, the carbon fiber-reinforced thermoplastic resin composition of the present invention may have a 3D printing output temperature of 290°C or less (eg, 280°C to 290°C).

In another embodiment, when the thermoplastic resin is a polyether ether ketone resin, the carbon fiber-reinforced thermoplastic resin composition of the present invention may have a 3D printing output temperature of 390° C. or less (eg, 380° C. to 390° C.). .

Accordingly, according to another aspect of the present invention, a molded article including the carbon fiber-reinforced thermoplastic resin composition of the present invention, preferably, a filament for 3D printing is provided.

The filament for 3D printing may be manufactured by extrusion molding the resin composition of the present invention.

Hereinafter, the present invention will be described in more detail through Examples and Comparative Examples. However, the scope of the present invention is not limited thereto.

[Examples and Comparative Examples]

Each component used in the following Examples and Comparative Examples is as follows:

PA: polyamide resin

PC: Polycarbonate resin (3022PJ, Samyang Corporation)

PEEK: polyetheretherketone resin

CF-1: carbon fiber treated with polyurethane-based surface treatment agent (average length: 6mm)

CF-2: carbon fiber without surface treatment (average length: 6mm)

GF: Glass fiber treated with polyurethane-based surface treatment agent (average length: 6mm)

Examples 1-1 to 1-4 and Comparative Examples 1-1 to 1-4

A polyamide resin was used as the thermoplastic resin. In the composition shown in Table 1, each component was put into a super mixer, the components were mixed for about 2 minutes, and then the pellets were prepared by putting it into the extruder hopper. For the extruder, a 12-barrel 30mm extruder from Japan Steel Works was used. After drying the produced pellets with hot air at a temperature of 80° C. for 4 hours or more, injection molding was performed at a temperature of 250 to 280° C. to prepare a specimen. The physical properties of the prepared specimens were measured and evaluated, and the results are shown in Table 1 below.

Examples 2-1 to 2-4, Comparative Examples 2-1 to 2-4

A polycarbonate resin was used as the thermoplastic resin. Pellets and specimens were prepared in the same manner as in Example 1 set using each component with the composition shown in Table 2, and the physical properties of the prepared specimen were measured and evaluated in the same manner as in Example 1 set, and the results are shown below. Table 2 shows.

Examples 3-1 to 3-4, Comparative Examples 3-1 to 3-4

A polyether ether ketone resin was used as the thermoplastic resin. Pellets and specimens were prepared in the same manner as in Example 1 set using each component with the composition shown in Table 3, and the physical properties of the prepared specimen were measured and evaluated in the same manner as in Example 1 set, and the results are shown below. Table 3 shows.

[Method of measuring and evaluating physical properties]

(1) Output temperature

When the filament specimen was output with a nozzle having a diameter of 0.4 mm in a 3D printer of a general material extrusion method, the nozzle temperature at which the product was formed by stably stacking was measured as the output temperature.

(2) Printability

During 3D printing, a score was given by visually checking the evenness of the surface of the printout. 5 points were given as the surface was more even, and 0 points were given when the surface was rough or uneven (see FIG. 1).

(3) anti-shrinkage

After outputting a rectangular box with a 3D printer, the degree of bending of the corner was visually observed when 1 hour had elapsed, and 0 to 5 points were given according to the degree of bending (see FIG. 2 ). The criteria are as follows.

5 points: Shrink less than 2% of the total area

4 points: Shrinkage of more than 2% to less than 4% of the total area

3 points: Shrinkage of 4% or more to less than 6% of the total area

2 points: Shrinkage of more than 6% to less than 8% of the total area

1 point: Shrink by more than 8% to less than 10% of the total area

0 points: Shrink more than 10% of the total area

(4) cobweb

A square specimen of 50 mm * 50 mm was output at the corresponding output temperature. In addition to the printout, the phenomenon that comes out as thin as a thread is expressed as a spider web. Since spider webs damage the appearance of the printed product, scores were given according to the degree of occurrence. According to the degree of cobwebs, 5 to 0 points were given as follows.

5 points: less than 2 cobwebs

4 points: 2 or more but less than 5 cobwebs

3 points: 5 or more but less than 10 cobwebs

2 points: 10 or more but less than 15 cobwebs

1 point: more than 15 to less than 20 cobwebs

0 points: 20 or more spider webs

(5) Tensile Strength

According to the ASTM D638 method, the crosshead speed was pulled to 200 mm/min (1T) using a test device, UTM (manufacturer; Instron, model name; 4466), and the point at which the specimen was cut was measured. . Tensile strength was calculated as follows.

Tensile strength (kgf/cm2) = load value (kgf) / thickness (cm) x width (cm)

(6) Heat Deflection Temperature (HDT)

Measured according to ASTM D648.

[Table 1]

[Table 2]

[Table 3]

From the results of Tables 1 to 3, the carbon fiber-reinforced thermoplastic resin compositions of Examples according to the present invention all had a low output temperature and excellent printability, and at the same time had a low degree of shrinkage of the printout, and at the same time, a spider web prevention property and It can be seen that all mechanical properties were also excellent. On the other hand, the compositions of Comparative Examples were inferior in at least one of printability, anti-shrinkage property, and anti-cobweb formation property.

Claims (1)

A carbon fiber-reinforced thermoplastic resin composition for manufacturing filaments for 3D printing, comprising:
Including a thermoplastic resin and surface-treated carbon fiber,
The content of the surface-treated carbon fiber is 10 parts by weight to 40 parts by weight based on 100 parts by weight of the total composition,
The thermoplastic resin is one selected from a polyamide resin, a polycarbonate resin, and a polyether ether ketone resin,
When the thermoplastic resin is a polyamide resin, it has a 3D printing output temperature of 250 to 260 ° C.
When the thermoplastic resin is a polycarbonate resin, it has a 3D printing output temperature of 280 to 290°C,
When the thermoplastic resin is a polyether ether ketone resin, having a 3D printing output temperature of 380 to 390 ° C.
A carbon fiber-reinforced thermoplastic resin composition.

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