JP2021053941A5 - - Google Patents

Description

The present invention relates to a granule for a hot-melting three-dimensional printer and a method for manufacturing a model using the same.

In Patent Document 1, a filament, which is a modeling material, is supplied to an extrusion head, the filament is melted by a liquefier mounted on the extrusion head, and the molten filament is extruded onto a base through a nozzle to create a model. The method of forming is disclosed.

In such a method, a method of sending the filament directly to the tip of the nozzle by biting by a gear or the like is generally adopted, but when the filament is made of a highly flexible thermoplastic elastomer, the gear is used. May not bite into the filament and the filament may not be supplied to the nozzle tip.

Patent Document 2 solves the above problem by using a filament having a linear reinforcing portion on a part of the outer peripheral surface of the core material portion containing a thermoplastic elastomer.

Special Table 2009-500194 JP-A-2017-177497

However, in the method of Patent Document 2, since the linear reinforcing portion is also formed together, in order to obtain a shaped object composed of only an elastomer, the linear reinforcing portion is linearly reinforced with water or an organic solvent after modeling with a three-dimensional printer. A process to dissolve the part is required. In addition to being troublesome, such processing may deteriorate the quality of the modeled object.

In addition, in the case of thermoplastic elastomers, in order to make the modeled object particularly flexible, the distance between the line portions constituting the modeled object may be widened, but the shape of the modeled object may vary depending on the material used. It easily collapses and it is very difficult to make high-precision modeling.

The present invention has been made in view of such circumstances, and provides a granule for a hot-melt type three-dimensional printer capable of producing a flexible model with high accuracy.

According to the present invention, it is a granular body for a thermomolten type three-dimensional printer composed of a thermoplastic elastomer, and the thermoplastic elastomer is a rotary type with a parallel plate of 20 mmφ, a measurement gap of 1.3 mm, and a frequency of 1 Hz. Provided are granules having a loss tangent tan δ of 0.40 or more and a loss elasticity G ″ of 11000 Pa or less at at least one point of measurement temperature of 120 to 270 ° C. when measured with a leometer. Will be done.

The first feature of the present invention is that it is not a filament but a granular material. Since the granular material of the present invention can be melted by using a screw type extruder and extruded from the nozzle, it is not necessary to use the linear reinforcing portion as in Patent Document 2, and the linear reinforcing portion is melted from the modeled object. There is no need for the process of putting it out.

The second feature of the present invention is that the thermoplastic elastomer has specific viscoelastic properties. If a thermoplastic elastomer having a viscoelastic property within the range specified in the present invention is used, a flexible model can be produced with high accuracy by adjusting the modeling temperature.

Hereinafter, various embodiments of the present invention will be illustrated. The embodiments shown below can be combined with each other.

Preferably, the thermoplastic elastomer has a loss tangent tan δ of 0.40 or more and a loss elastic modulus G ″ of 8000 Pa or less at at least one point at a measurement temperature of 120 to 230 ° C. It is a granular material.
Preferably, it is a granular material having a loss elastic modulus G'' of 600 to 4500 Pa.
Preferably, the thermoplastic elastomer is a granular material having a Shore A hardness of 0 to 10.
Preferably, it is a method for manufacturing a modeled object, comprising a scanning step of melting the granules in a screw extruder and scanning the strands formed by extruding the granules from a nozzle.
Preferably, the strand has a loss tangent tan δ of 0.40 or more and a loss modulus when measured at a molding temperature with a rotary rheometer at a parallel plate of 20 mmφ, a measurement gap of 1.3 mm, and a frequency of 1 Hz. The method is such that the ratio G ″ is 11000 Pa or less, and the molding temperature is the temperature of the strand immediately after being extruded from the nozzle.
Preferably, it is a method in which the loss elastic modulus G ″ of the strand at the molding temperature is 600 to 4500 Pa.
Preferably, the laminated structure is formed by laminating the single-layer structures formed by performing the scanning step, and the single-layer structures are each provided with a plurality of parallel line portions spaced apart from each other. The method is such that the two single-layer structures adjacent to each other in the vertical direction in the laminated structure are provided so that the plurality of parallel line portions intersect with each other.
Preferably, the pitch ratio defined by the pitch of the parallel line portion to the line width of the parallel line portion is 1.5 to 6.

1A shows an example of the shape of the granules according to the embodiment of the present invention, and FIG. 1B is a sectional view taken along the line AA in FIG. 1A. It is explanatory drawing which shows the state which puts the granular material 1 into the extruder 2 of the Fused Deposition Modeling three-dimensional printer which can be used in this invention, and forms a strand 4. A mesh-like laminated structure 5 is shown, FIG. 3A is a perspective view, and FIG. 3B is a plan view. A single-layer structure 6 is shown, FIG. 4A is a perspective view, and FIG. 4B is a plan view. A single-layer structure 7 is shown, FIG. 5A is a perspective view, and FIG. 5B is a plan view. A single-layer structure 8 is shown, FIG. 6A is a perspective view, and FIG. 6B is a plan view.

Hereinafter, embodiments of the present invention will be described. The various features shown in the embodiments shown below can be combined with each other. In addition, the invention is independently established for each feature.

1. 1. Granules for a heat-melting three-dimensional printer The granules 1 for a heat-melting three-dimensional printer according to the embodiment of the present invention shown in FIG. 1 are made of a thermoplastic elastomer. This thermoplastic elastomer has a loss tangent tan δ of 0 at at least one point of the measurement temperature of 120 to 270 ° C. when measured with a rotary rheometer at a parallel plate of 20 mmφ, a measurement gap of 1.3 mm, and a frequency of 1 Hz. It is .40 or more and the loss elasticity G'' is 11000 Pa or less. Hereinafter, it will be described in detail.

The granular body 1 of the present embodiment is not a thread-like form like a filament, but a granular form that can be easily put into a screw type extruder. As shown in FIG. 1, where L is the length of the longest portion of the grains constituting the granular body and D is the diameter of the maximum circumscribed circle 1a on the plane perpendicular to the longest portion, the L / D is For example, it is 1 to 10, preferably 1 to 5. L is, for example, 0.5 to 10 mm, preferably 1 to 6 mm, and more preferably 2 to 4 mm. Specifically, the L / D is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10, and is within the range between any two of the numerical values exemplified here. May be good. Specifically, L is, for example, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 mm, and is within the range between any two of the numerical values exemplified here. There may be.

Examples of the thermoplastic elastomer constituting the granular material 1 include styrene-based elastomers, olefin-based elastomers, and acrylic-based elastomers. The thermoplastic elastomer preferably contains a styrene-based elastomer. Since the styrene-based elastomer has high flexibility, the flexibility of the thermoplastic elastomer becomes high when the thermoplastic elastomer contains the styrene-based elastomer. The proportion of the styrene-based elastomer in the thermoplastic elastomer is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, and specifically, for example, 50, 60, 70, 80, 90, 100% by mass. , It may be within the range between any two of the numerical values exemplified here.

The styrene-based elastomer is a thermoplastic elastomer having a styrene unit, and is a styrene-based copolymer (for example, a styrene-ethylene-styrene block copolymer (SES), a styrene-butadiene-styrene block copolymer (SBS), etc.). Styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene rubber (SBR), etc.), hydrogenated styrene-based polymer (eg, styrene-ethylene / propylene-styrene block copolymer (SEPS), styrene- One or more selected from ethylene / butylene-styrene block copolymer (SEBS), styrene-butylene / butadiene-styrene block copolymer (SBBS), hydrogenated styrene-butadiene rubber (HSBR), etc.) Blended ones can be mentioned.

The Shore A hardness of the thermoplastic elastomer is preferably 0 to 10, specifically, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. It may be within the range between any two of the exemplified values. When the shore A hardness is within this range, a model having more flexibility can be obtained. Shore A hardness is measured based on JIS K6253.

The viscoelasticity of the thermoplastic elastomer is measured according to JIS K 7244-10. Specifically, the viscoelastic property was measured with a rotary leometer while raising the temperature from a parallel plate of 20 mmφ, a measurement gap of 1.3 mm, and a temperature of 1 Hz at a heating rate of 2 ° C./min to 40 to 280 ° C. In the case of the case, the loss elastic modulus G ″ (Pa) at the measured temperature of 120 to 230 ° C., and the loss positive tangent tan δ (= G) calculated from the loss elastic modulus G ″ (Pa) and the storage elastic modulus G ′ (Pa). '' / G').

As will be described later, when the loss tangent tan δ at the modeling temperature is 0.40 or more and the loss elastic modulus G'' is 11000 Pa or less, between the line portions constituting the modeled object. Even when the intervals are relatively wide, it is possible to manufacture a modeled object with high accuracy by using a hot-melting three-dimensional printer. The molding temperature of the Fused Deposition Modeling 3D printer is usually 120 to 270 ° C. Therefore, when the loss tangent tan δ and the loss elastic modulus G ″ of the thermoplastic elastomer satisfy the above conditions, it is possible to manufacture a highly accurate model by appropriately adjusting the modeling temperature. In one embodiment, the storage modulus G'may be considered.

Further, since the modeling is easy when the modeling temperature is relatively low, it is preferable that the modeling can be performed at 120 to 230 ° C. Therefore, when the loss elastic modulus G'' at a molding temperature of 120 to 230 ° C. is 8000 Pa or less, 600 to 4500 Pa, particularly 700 to 2000 Pa, the molded product can be manufactured with particularly high accuracy at a relatively low temperature. Therefore, the loss elastic modulus G'' of the thermoplastic elastomer is preferably 8000 Pa or less, more preferably 600 to 4500 Pa, and 700 to 2000 Pa at at least one point of the measured temperature of 120 to 230 ° C. Is particularly preferred.

Specifically, the measured temperatures are, for example, 120, 125, 130, 135, 140, 145, 150, 155, 158, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210. , 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270 ° C., and may be within the range between any two of the numerical values exemplified here. In one embodiment, the loss tangent tan δ is, for example, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0. .90, 0.95, 1.00, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0 , 6.5, 7.0, and may be within the range between any two of the numerical values exemplified here. Specifically, the loss elastic modulus G'' is, for example, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000. , 7500, 8000, 8500, 9000, 9500, 10000, 10500, 11000 Pa, and may be within the range between any two of the numerical values exemplified here.

The temperature range in which the loss tangent tan δ and the loss elastic modulus G'' are within the above ranges is preferably 10 ° C. or higher, more preferably 20 ° C. or higher. In this case, it becomes easy to set the molding temperature. This temperature range is, for example, 10 to 50 ° C., specifically, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50 ° C., and any two of the numerical values exemplified here. It may be within the range between.

2. 2. Method for Manufacturing a Modeled Product As shown in FIG. 2, in the method for manufacturing a modeled product according to an embodiment of the present invention, the granular material 1 described above is melted in a screw extruder 2 and extruded from a nozzle 2c to form a product. The scanning step of scanning the strand 4 is provided. The strand 4 is extruded in a molten state and scanned as it is.

The extruder 2 includes a hopper 2a, a cylinder 2b, and a nozzle 2c. The granular material 1 is charged into the cylinder 2b from the hopper 2a and heated in the cylinder 2b to be melted and become a molten material. This molten material is conveyed toward the tip of the cylinder 2b by the rotation of the screw arranged in the cylinder 2b, and is extruded from the nozzle 2c provided at the tip of the cylinder 2b to become the strand 4. In such a method, the strand 4 can be easily formed even with a highly flexible material such as a thermoplastic elastomer.

The strand 4 is linear and has a diameter of, for example, 0.5 to 6.0 mm, preferably 1.0 to 4.0 mm. Specifically, this diameter is, for example, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, It is 5.5 and 6.0 mm, and may be within the range between any two of the numerical values exemplified here.

A model can be manufactured by scanning the strands 4 so that the desired model is formed and cooling and solidifying the scanned strand 4. The cooling may be natural cooling or forced cooling.

The temperature of the strand 4 immediately after being extruded from the nozzle 2c is defined as the molding temperature. The molding temperature is preferably 120 to 270 ° C. In this case, the strand 4 is easily solidified sufficiently during cooling, and deterioration due to heating of the modeling material is unlikely to occur. It is preferable that the loss tangent tan δ of the strand 4 at the molding temperature is 0.40 or more and the loss elastic modulus G'' is 11000 Pa or less. When the molding temperature is a relatively low temperature of 120 to 230 ° C., the loss elastic modulus G'' of the strand 4 is more preferably 8000 or less, further preferably 600 to 4500 Pa, and 700 to 2000 Pa. Is particularly preferred. This is because, as shown in Examples described later, the molding accuracy is particularly high when the loss tangent tan δ and the loss elastic modulus G'' at the molding temperature are within this range.

Specifically, the molding temperature is, for example, 120, 125, 130, 135, 140, 145, 150, 155, 158, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210. , 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270 ° C., and may be within the range between any two of the numerical values exemplified here. In one embodiment, the loss tangent tan δ is, for example, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0. .90, 0.95, 1.00, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0 , 6.5, 7.0, and may be within the range between any two of the numerical values exemplified here. The loss elastic modulus G'' is specifically, for example, for example, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500. , 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, 10000, 10500, 11000 Pa, and may be within the range between any two of the numerical values exemplified here.

FIG. 3 shows a modeled object composed of a mesh-like laminated structure 5. The laminated structure 5 is formed by laminating the single-layer structures 6, 7, and 8 formed by the scanning step.

The single-layer structure 6 shown in FIG. 4 includes an outer peripheral line portion 6a and an inner line portion 6b. The outer peripheral line portion 6a and the inner line portion 6b are each formed by cooling the strand 4, and the line width thereof is substantially equal to the diameter of the strand 4. The inner line portion 6b is provided in the region surrounded by the outer peripheral line portion 6a. The outer peripheral line portion 6a and the inner wire portion 6b are welded to each other. It is preferable that the outer peripheral line portion 6a and the inner line portion 6b are each formed by a single stroke without stopping the extrusion of the strand 4, and it is more preferable that the entire single-layer structure 6 is formed by a single stroke. .. In this case, the number of times the strand 4 is stopped in the scanning process is reduced, and the molding accuracy and productivity are improved.

The inner line portion 6b includes a plurality of parallel line portions 6b1 provided at intervals from each other, and a connecting line portion 6b2 connecting adjacent parallel line portions 6b1. As shown in FIG. 4B, the pitch ratio defined by the pitch P of the parallel line portion 6b1 with respect to the line width W of the parallel line portion 6b1 is preferably 1.5 to 6, and more preferably 2.0 to 5.0. If the pitch ratio is too small, the flexibility of the modeled object may be insufficient, and if the pitch ratio is too large, modeling may be difficult. Specifically, the pitch ratio is, for example, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0. Yes, it may be within the range between any two of the numerical values exemplified here.

The single-layer structure 7 shown in FIG. 5 has an outer peripheral line portion 7a and an inner line portion 7b. The inner wire portion 7b includes a plurality of parallel wire portions 7b1 and a connecting wire portion 7b2. The single-layer structure 7 has the same configuration as the single-layer structure 6 except that the direction in which the parallel line portion 7b1 extends is different from that of the parallel line portion 6b1. The parallel line portion 7b1 is formed so as to intersect with a plurality of parallel line portions 6b1, and the larger the pitch ratio, the larger the distance (bridge distance) that the parallel line portion 7b1 straddles the two parallel line portions 6b1 and is parallel. The wire portion 7b1 bends and the modeling accuracy tends to decrease. In the present embodiment, the loss tangent tan δ and the loss elastic modulus G'' at the molding temperature are set in the above ranges to suppress the deterioration of the molding accuracy due to the deflection of the parallel line portion.

The single-layer structure 8 shown in FIG. 6 has an outer peripheral line portion 8a and an inner line portion 8b. The inner wire portion 8b includes a plurality of parallel wire portions 8b1 and a connecting wire portion 8b2. The single-layer structure 8 has the same configuration as the single-layer structure 6 except that the direction in which the parallel line portion 8b1 extends is different from that of the parallel line portion 6b1.

The laminated structure 5 is composed of single-layer structures 6, 7, and 8 repeatedly laminated in this order. The parallel line portions 6b1, 7b1, and 8b1 are non-parallel to each other, and the parallel line portions of the two single-layer structures adjacent to each other in the vertical direction intersect each other. Further, in the present embodiment, the parallel line portions 6b1, 7b1, and 8b1 are offset by 60 degrees and their pitches are the same. Therefore, the laminated structure 5 is parallel to the laminated structure 5 as shown in the plan view shown in FIG. 3B. The linear portions 6b1, 7b1, and 8b1 form an equilateral triangular void S. The larger the pitch ratio, the larger the void S and the more flexible the modeled object.

Table 1 shows the shore A hardness of the granules made of a thermoplastic elastomer, and the maximum and minimum values of each measured value regarding viscoelasticity measured at 120 to 270 ° C. Table 2 shows the shore A hardness (same as in Table 1) for the granules made of thermoplastic elastomer, and the maximum and minimum values of the measured values for viscoelasticity measured at 120 to 230 ° C.

Viscoelasticity was measured according to JIS K 7244-10. Specifically, first, a sheet of about 100 mm x 100 mm x 1 mm (length x width x thickness) was created by compression molding (equipment: hydraulic molding machine 26 tons, manufactured by Our Press Mfg. Co., Ltd.), and then 20 mm x 20 mm. It was cut out into (vertical x horizontal) and used as a test piece. The gauge pressure in compression molding is 5 MPa, and the press temperatures are 130 ° C, 230 ° C, 230 ° C, and 150 for AR-SC-0, AR-815C, G1645MO, AR-SC-5, JS20N, and CJ103, respectively. The temperature was 170 ° C, 170 ° C, and 230 ° C.

The measurement conditions are as follows.
Geometry: Parallel plate 20mmφ
Temperature: 40-280 ° C
Temperature rise rate: 2 ° C / min
Frequency: 1Hz (6.28rad / s)
Gap: 1.3-1.4 mm
Setting distortion: 0.01
Number of measurements: n = 1
Measuring device: MARSIII

Table 3 shows the evaluation of viscoelasticity and formability at each temperature. For the evaluation of formability, using these granules as a material, a three-dimensional printer equipped with a screw extruder was used to prepare a model composed of the laminated structure 5 shown in FIG. 3 at the temperature shown in Table 3. evaluated. The temperature in Table 3 is the temperature of the strand 4 immediately after coming out of the nozzle 2c, and was measured using thermography (infrared thermography camera Thermo GEAR, model: G120EX, manufactured by Nippon Avionics Co., Ltd.). The diameter of the strand 4 was 2 mm, the moving speed of the nozzle 2c was 50 mm / s, and the pitch of the parallel lines was 6.5 mm. The line width of the parallel line portion was 2.0 mm. Therefore, the pitch ratio was 3.25.

The obtained modeled object was visually observed, and the formability was evaluated according to the following criteria.
⊚: No collapse of modeling was observed.
◯: A slight collapse of the model (for example, turning of the corner of the model) was observed.
Δ: The shape collapse was observed, but no significant collapse was observed.
X: The strands were torn, the strands were not fixed to the modeling bed, or the modeling was significantly distorted.

As shown in Table 3, when the loss tangent tan δ at the molding temperature is 0.40 or more and the loss elastic modulus G'' is 11000 Pa or less, the molding property is good. Above all, at a relatively low molding temperature of 120 to 230 ° C., the formability is good when the loss elastic modulus G ″ is 8000 Pa or less, and the formability is better when the loss elastic modulus is 600 to 4500 Pa. When the loss elastic modulus G'' was 700 to 2000 Pa, the formability was particularly good.

Details of the thermoplastic elastomer in the table are as follows.
CJ103: Kuraray Co., Ltd., Arneston JS20N: Kuraray Co., Ltd., Arneston AR-SC-0: Aronkasei Co., Ltd. AR-SC-5: Aronkasei Co., Ltd. AR-815C: Aronkasei Co., Ltd. G1645MO : Made by Clayton Polymer Japan Co., Ltd.

1: Granules for thermal melting type 3D printer 1a: Circumscribed circle 2: Screw type extruder 2a: Hopper 2b: Cylinder 2c: Nozzle 4: Strand 5: Laminated structure 6: Single layer structure 6a: Outer line portion 6b : Inner line part 6b1: Parallel line part 6b2: Connecting line part 7: Single layer structure 7a: Outer line part 7b: Inner line part 7b1: Parallel line part 7b2: Connecting line part 8: Single layer structure 8a: Outer line Part 8b: Inner line part 8b1: Parallel line part 8b2: Connecting line part P: Pitch S: Void W: Line width

Claims (9)

Fused Deposition Modeling Granules for 3D Printers Consists of Thermoplastic Elastomers
The thermoplastic elastomer has a loss tangent tan δ of 0.40 or more at at least one of the measured temperatures of 120 to 270 ° C. when measured with a rotary rheometer at a set strain of 0.01 and a frequency of 1 Hz. Granules having a loss elastic modulus G'' of 11000 Pa or less. The thermoplastic elastomer has a loss tangent tan δ of 0.40 or more and a loss elastic modulus G ″ of 8000 Pa or less at at least one point of a measurement temperature of 120 to 230 ° C. 1 . Granules described in . The granular material according to claim 2.
A granular material having a loss elastic modulus G'' of 600 to 4500 Pa at at least one point of a measurement temperature of 120 to 230 ° C. The granular material according to any one of claims 1 to 3.
The thermoplastic elastomer is a granular material having a shore A hardness of 0 to 10. A method for manufacturing a modeled product, comprising a scanning step of melting the granules according to any one of claims 1 to 4 in a screw extruder and scanning the strands formed by extruding the granules from a nozzle. The method according to claim 5.
The strand has a loss tangent tan δ of 0.40 or more and a loss elastic modulus G'' of 11000 Pa or less when measured at a molding temperature with a rotary rheometer at a set strain of 0.01 and a frequency of 1 Hz. And
The method, wherein the molding temperature is the temperature of the strand immediately after being extruded from the nozzle. The method according to claim 6.
A method in which the loss elastic modulus G'' of the strand at the molding temperature is 600 to 4500 Pa. The method according to any one of claims 5 to 7.
A laminated structure is formed by laminating the single-layer structure formed by performing the scanning step.
Each of the single-layer structures includes a plurality of parallel line portions provided at intervals from each other.
A method in which the two single-layer structures adjacent to each other in the vertical direction in the laminated structure are provided so that the plurality of parallel line portions intersect with each other. The method according to claim 8.
The method, wherein the pitch ratio defined by the pitch of the parallel line portion to the line width of the parallel line portion is 1.5 to 6.