Material for fused deposition modeling type three-dimensional modeling, and filament for fused deposition modeling type 3D printing device

Abstract

[Problem] To provide a material for fused-deposition-type three-dimensional modeling whereby a warp-free modeled object is obtained without devising a modeling shape and without installing a special apparatus as a 3D printer device, and whereby a modeled article having flexibility as well as excellent surface polishing properties is obtained. [Solution] A material for fused-deposition-type three-dimensional modeling, obtained by blending 10-900 parts by weight of a styrene-based resin (B1) obtained by copolymerization of an aromatic vinyl-monomer (b1) and a cyanated vinyl-monomer (b2), and/or 5-400 parts by weight of a thermoplastic resin (B2) having a glass transition temperature of 20 C. or lower and/or 5-30 parts by weight of a plasticizer (B3), with respect to 100 parts by weight of a polylactic resin (A).

Claims

1. A material for fused deposition modeling type three-dimensional modeling which comprises a mixture obtained by blending together with 100 parts by weight of a polylactic acid resin (A) and an epoxy group-containing compound (C) one or more of the following components: (i) 10 to 900 parts by weight of a styrene-based resin (B1) obtained by copolymerizing an aromatic vinyl-based monomer (b1) and a vinyl cyanide-based monomer (b2), and/or (ii) 5 to 400 parts by weight of a thermoplastic resin (B2) the glass transition temperature of which is 20 C. or lower, and/or (iii) 5 to 30 parts by weight of a plasticizer (B3), wherein the styrene-based resin (B1) is excluded from the epoxy group-containing compound (C).

2. The material for fused deposition modeling type three-dimensional modeling according to claim 1, wherein the optical purity of the polylactic acid resin (A) is 97% or less.

3. The material for fused deposition modeling type three-dimensional modeling according to claim 1, wherein the thermoplastic resin (B2) comprises a copolymerized polyester resin.

4. The material for fused deposition modeling type three-dimensional modeling according to claim 1, wherein the material comprises the styrene-based resin (B1) and the thermoplastic resin (B2) having a glass transition temperature of 20 C. or lower and the thermoplastic resin (B2) comprises a thermoplastic elastomer.

5. The material for fused deposition modeling type three-dimensional modeling according to claim 1, wherein the plasticizer (B3) comprises an ester-based plasticizer and/or a polyalkylene glycol-based plasticizer.

6. A filament, particle or pellet for a fused deposition modeling type 3D printing device obtained by molding the material for fused deposition modeling type three-dimensional modeling according to claim 1.

7. A modeled article obtained by modeling the filament, particle or pellet for a fused deposition modeling type 3D printing device according to claim 6.

8. A method for producing a filament, particle or pellet for a fused deposition modeling type 3D printing device including a step of obtaining a filament, particle or pellet by molding the material according to claim 1.

9. A method for producing a modeled article including a step of obtaining a modeled article using the filament, particle or pellet according to claim 6 in a fused deposition modeling type 3D printing device.

10. The material for fused deposition modeling type three-dimensional modeling according to claim 1, wherein the mixture includes the styrene-based resin (B1) and the thermoplastic resin (B2).

11. The material for fused deposition modeling type three-dimensional modeling according to claim 1, wherein the mixture includes the thermoplastic resin (B2) and the plasticizer (B3).

Description

EXAMPLES

(1) In order to explain the material for modeling of the present invention more concretely, examples are described below. The present invention is not limited to these examples. In the following examples and comparative examples, items expressed with part and % each denote part by weight and % by weight unless stated otherwise.

(2) [Methods for Measurement of Properties]

(3) (1) Glass Transition Temperature (Tg)

(4) Tg was measured with a differential scanning calorimeter according to JIS K7121. The measurement was performed using 10 mg of a sample in a nitrogen atmosphere at a temperature ramp-up rate of 20 C./minute. The glass transition temperature shall be a mid-point temperature of glass transition.

(5) (2) Weight Average Molecular Weight

(6) The weight average molecular weight of a styrene-based resin (B1) and a fraction soluble in methyl ethyl ketone of a graft copolymer was measured as a polystyrene (PS)-equivalent weight average molecular weight (Mw) under conditions including a flow rate of 1 ml/minute and a column temperature of 40 C. by using a gel permeation chromatograph (GPC) manufactured by Water and using a differential refractometer (Water 2414) as a detector, MIXED-B (two columns) manufactured by Polymer Laboratories as columns, and tetrahydrofuran as an eluate.

(7) The weight average molecular weight of a polylactic acid resin (A) was measured as a polymethyl methacrylate (PMMA)-equivalent weight average molecular weight (Mw) by using the same instruments and conditions as those previously described except using hexafluoroisopropanol as an eluate.

(8) (3) Degree of Grafting of Graft Copolymer

(9) The degree of grafting of a graft copolymer was determined by the following method. Acetone was added to a prescribed amount (m) of a graft copolymer and then was refluxed for 4 hours. This solution was centrifugally separated at a rotation of 8000 rpm (centrifugal force of 10,000 G) for 30 minutes and then insolubles were collected by filtration. The insolubles were dried under reduced pressure at a temperature of 70 C. for 5 hours and then the weight (n) thereof was measured. The degree of grafting was calculated by the following formula. In the following formula, L denotes the rubber content (% by weight) of a graft copolymer.
Degree of grafting (%)=[(n){(m)L/100}]/[(m)L/100]100.
(4) Melt Viscosity

(10) For pellets of the material for modeling obtained in each of Examples and Comparative Examples, a melt flow rate (MFR) was measured at 220 C. and a load of 98 N in accordance with ISO1133 (Method A, 1997).

(11) (5) Deflection Temperature Under Load

(12) Deflection temperature under load was measured from a specimen obtained in each of Examples and Comparative Examples under a load of 0.45 MPa in accordance with ISO 75-1 (2004) flatwise.

(13) (6) Charpy Impact Strength

(14) Charpy impact strength was measured from a specimen obtained in each of Examples and Comparative Examples in accordance with ISO 179-1 (2000) Type A.

(15) (7) Degree of Warpage

(16) The degree of warpage was measured by using a clearance gauge with an obtained modeled article being placed on a plane stand.

(17) (8) Bleeding Out Property

(18) A modeled article was put into a thermohygrostat that was set at a temperature of 40 C. and a humidity of 85% RH and taken cut after one week, and then the presence of bleeding out was examined.

(19) ++: No bleeding out was confirmed on the surface of the modeled article.

(20) +: When the surface of the modeled article was touched by hand, a bleed attached to the hand a little.

(21) : When the surface of the modeled article was touched by hand, a bleed attached to the hand.

(22) (9) Polishability

(23) In order to make the surface of a modeled article flat, the surface was polished with 1200 grade sandpaper.

(24) ++: The surface of the modeled article was able to be polished satisfactorily.

(25) +: When the surface of a modeled article was polished, resin fragments remained on the surface.

(26) : The surface of a modeled article was not able to be polished.

(27) [Feed Materials Used in Examples and Comparative Examples]

(28) The feed materials used for the practice of the present invention are shown below.

(29) (A) Polylactic acid resin

(30) (A-1) D-lactic acid content=1.4%, Mw=215,000 (PMMA-equivalent)

(31) (A-2) D-lactic acid content=4.3%, Mw=245,000 (PMMA-equivalent)

(32) (A-3) D-lactic acid content=1.4%, Mw=116,000 (PMMA-equivalent)

(33) (A-4) D-lactic acid content=12.0%, Mw=220,000 (PMMA-equivalent)

(34) (A-5) D-lactic acid content=5.0%, Mw=220,000 (PMMA-equivalent)

(35) (B1) Styrene-based resin

(36) A reactor was charged with 80 parts by weight of acryl amide, 20 parts by weight of methyl methacrylate, 0.3 parts by weight of potassium persulfate, and 1800 parts by weight of ion-exchanged water, and then the gas phase in the reactor was purged with nitrogen gas and the temperature was kept at 70 C. while stirring well. The reaction was continued until the monomers were converted into a polymer completely, so that a whitish, viscous aqueous solution of an acrylamide-methyl methacrylate copolymer was obtained. To this were added 35 parts by weight of sodium hydroxide and ion-exchanged water, forming 0.6% by weight of acrylamide-methyl methacrylate copolymer, which was then further stirred at 70 C. for 2 hours and cooled to room temperature. Thus, a transparent aqueous solution of an acrylamide-methyl methacrylate copolymer, which would serve as a medium for suspension polymerization, was obtained.

(37) To a polymerization vessel (autoclave made of stainless steel) was added 6 parts by weight of the aforementioned aqueous solution of an acrylamide-methyl methacrylate copolymer, and the inside of the system was purged with nitrogen gas under stirring. Next, the mixed substances given below were added under stirring and then the temperature was raised to 60 C. to start polymerization.

(38) TABLE-US-00001 Styrene 70 parts by weight Acrylonitrile 30 parts by weight t-Dodecylmercaptan 0.36 parts by weight 2,2-Azobisisobutyronitrile 0.31 parts by weight

(39) The reaction temperature was raised to 65 C. over 30 minutes and then raised to 100 C. over 120 minutes. Henceforth, cooling of the reaction system and separation, washing, and drying of a polymer were carried out by ordinary methods and thus a polymer in the form of beads was obtained. The weight average molecular weight of the resulting styrene-based resin (B1-1) was 101,000.

(40) (B2) Thermoplastic resin the glass transition temperature of which is 20 C. or lower

(41) (B2-1) Graft copolymer

(42) Polybutadiene (Nipol LX111A2 produced by Nippon Zeon Co., Ltd., weight average particle diameter=0.35 gel content=75% by weight) 50 parts by weight (solids content equivalent)

(43) TABLE-US-00002 Potassium oleate 0.5 parts by weight Grape sugar 0.5 parts by weight Monosodium pyrophosphate 0.5 parts by weight Ferrous sulfate 0.005 parts by weight Deionized water 120 parts by weight

(44) The substances given above were charged into a polymerization vessel and the temperature thereof was raised to 65 C. under stirring. The time when the internal temperature reached 65 C. was considered as the onset of polymerization, and 35 parts by weight of styrene, 15 parts by weight of acrylonitrile, and 0.3 parts by weight of t-dodecylmercaptan were added dropwise continuously over 5 hours. In parallel, an aqueous solution composed of 0.25 parts by weight of cumene hydroperoxide, 2.5 parts by weight of potassium oleate, and 25 parts by weight of pure water was added dropwise continuously over 7 hours, and thus the reaction was completed. The resulting graft copolymer latex was solidified with sulfuric acid, neutralized with caustic soda, and then washed, filtered, and dried into a powder. The glass transition temperature of polybutadiene was about 70 C., the degree of grafting of the resulting graft copolymer was 50%, and the weight average molecular weight of the fraction soluble in methyl ethyl ketone was 83,000.

(45) (B2-2) Copolymerized polyester (aliphatic aromatic polyester resin)

(46) Polybutylene-adipate terephthalate: ecoflex (registered trademark) C1200 (produced by BASF Japan Ltd.), glass transition temperature=30 C.

(47) (B2-3) Copolymerized polyester (aliphatic polyester resin)

(48) Polybutylene-succinate adipate: Bionolle (registered trademark) 3001MD (produced by Showa Highpolymer Co., Ltd.), glass transition temperature=45 C.

(49) (B2-4) Thermoplastic elastomer

(50) Block copolymer of terephthalic acid, 1,4-butanediol, and tetramethylene glycol: Hytrel (registered trademark) 4047 (produced by Du Pont-Toray Co., Ltd.), glass transition temperature=40 C.

(51) (B2-5) Thermoplastic elastomer

(52) Acrylic elastomer: METABLEN (registered trademark) S-2001 (produced by Mitsubishi Rayon Co., Ltd.), glass transition temperature=40 C.

(53) (B2-6) Blend (mixture) of a styrene-based resin and a graft copolymer

(54) ABS resin: TOYOLAC (registered trademark) produced by Toray Industries, Inc., high flow type ABS resin 250-X01, glass transition temperature of graft copolymer=about 70 C., glass transition temperature of styrene-based resin=105 C.

(55) (B2-7) Blend (mixture) of a styrene-based resin, a graft copolymer, and a thermoplastic resin the glass transition temperature of which is higher than 20 C.

(56) Alloy of an ABS resin and a polycarbonate (PC) resin: TOYOLAC produced by Toray Industries, Inc., high flow type ABS resinPC resin alloy PX10-X11, glass transition temperature of graft copolymer=about 70 C., glass transition temperature of styrene-based resin=105 C., glass transition temperature of PC resin=147 C.
(B2-8) Nylon 6 resin: Amilan (registered trademark) CM1010 (produced by Toray Industries, Inc.), glass transition temperature=58 C.
(B3) Plasticizer
(B3-1) Adipate-based plasticizer: DAIFATTY-101 (produced by Daihachi Chemical Industry Co., Ltd.), weight average molecular weight=340.
(C) Epoxy group-containing compound
(C-1) Epoxy group-containing (meth)acrylic polymer: Joncryl (registered trademark) ADR-4368 (produced by BASF Japan Ltd.), weight average molecular weight=8,000.

Examples 1 to 8, Comparative Examples 1 to 5

Production of Material for Modeling

(57) The polylactic acid resin (A), the styrene-based resin (B1), and the graft copolymer (B2), each described above, were mixed at the mixing ratios given in Table 1, melt-kneaded using a vented 30 mm twin screw extruder (PCM-30 manufactured by Ikegai Ltd.) (barrel temperature set at 230 C.) and extruded to produce a pelletized material for modeling. Using the resulting pelletized material for modeling, the evaluation of (4) described above was carried out.

(58) [Evaluation of Material for Modeling]

(59) A specimen was obtained by injection molding the resulting pelletized material for modeling at a cylinder temperature of 220 C. and a mold temperature of 60 C. Using the specimen obtained, evaluation was performed with respect to the above-mentioned (5) to (6). The results are shown in Table 1 (Examples 1 to 8, Comparative Examples 1 to 5).

(60) [Production and Evaluation of Monofilament]

(61) The resulting material for modeling was dried with hot air at a temperature of 70 C. for 5 hours and then was fed into a single screw melt-extruder the temperature of which was set at 200 C., and it was extruded and drawn with a first roller and simultaneously introduced into a cooling bath set at a temperature of 40 C. and thereby cooled, obtaining an undrawn monofilament 1.8 mm in diameter.

(62) Using the resulting undrawn monofilament, a modeled article with a size of 50 mm10 mm5 mm was obtained using a 3D printing device the nozzle temperature of which was set at 200 C. For the modeled article obtained, evaluation was performed with respect to the above-mentioned (7) to (9).

(63) [Evaluation Result]

(64) As shown in Table 1, a material capable of creating a modeled article that develops little warpage and excels in surface polishability was obtained successfully by bringing the mixing ratios of the polylactic acid resin (A), the styrene-based resin (B1), and/or the thermoplastic resin (B2) the glass transition temperature of which is 20 C. or lower into the ranges of the present invention. The modeled articles in which the materials for modeling of Examples 1 to 8 were used were smaller in the amount (degree) of warpage and superior in warpage resistance as compared with the modeled articles produced using the styrene-based resin (B1; of Comparative Example 1, the ABS resin (B2-6) of Comparative Example 2, and the alloy (B2-7) of ABS resin and PC resin of Comparative Example 3.

(65) As shown in Comparative Example 4, a modeled article using a material for modeling composed of only the polylactic acid resin (A) was remarkably low in polishability and its practical use was difficult.

(66) Similarly, as shown in Comparative Example 5, also when the polylactic acid resin (A) and the styrene-based resin (B1) were mixed at ratios outside the ranges of the present invention, the polishability of the resulting modeled article was remarkably low and its practical use was difficult.

(67) As shown in Table 1, the materials for modeling of the present invention (Examples 1 to 8) were lower in melt viscosity than the materials for modeling formed from the styrene-based resin (A), (Comparative Example 1), the ABS resin (Comparative Example 2), and the alloy of ABS resin and PC resin (Comparative Example 3). Therefore, these materials can be molded at lower temperatures and can reduce electric power consumption during molding with a 3D printing device and can reduce the amount of gas emitted from the resin, and thus, they can contribute to safety and health.

(68) The materials for modeling of Comparative Examples 1 to 3 are all high in melt viscosity and higher temperatures are required for molding them.

Examples 9 to 19, Comparative Examples 6 to 8

(69) Feed materials (a polylactic acid resin (A), a thermoplastic resin (B2) and/or a plasticizer (B3), an epoxy group-containing compound (C)) were mixed at the ratios given in Table 2 and melt-kneaded under conditions including a set temperature of 200 C., a screw rotation speed of 150 rpm, and a discharge rate of 30 kg/h using a vented twin screw extruder having a screw diameter of 30 mm, obtaining a pelletized material for modeling with a pelletizer. The resulting material for modeling was dried with hot air at a temperature of 70 C. for 5 hours and then was fed into a single screw melt-extruder the temperature of which was set at 200 C., and it was extruded and drawn with a first roller and simultaneously introduced into a cooling bath set at a temperature of 40 C. and thereby cooled, obtaining an undrawn monofilament 1.8 mm in diameter. Subsequently, from the resulting undrawn monofilament, a modeled article with a size of 50 mm10 mm5 mm was obtained using a 3D printing device the nozzle temperature of which was set at 200 C. For the modeled article obtained, evaluation was performed with respect to the above-mentioned (7) to (9). Moreover, the pelletized material for modeling was injection molded at a cylinder temperature of 200 C. and a mold temperature of 40 C., obtaining a specimen. Using the specimen obtained, evaluation was performed with respect to the above-mentioned (6). The results are shown in Table 2 (Examples 9 to 19, Comparative Examples 6 to 8).

Comparative Example 9

(70) Feed materials (a polylactic acid resin, nylon 6) were mixed at the ratios given in Table 2 and melt-kneaded under conditions including a set temperature of 240 C., a screw rotation speed of 150 rpm, and a discharge rate of 30 kg/h using a vented twin screw extruder having a screw diameter of 30 mm, obtaining a pelletized material for modeling with a pelletizer. The resulting material for modeling was dried with hot air at a temperature of 70 C. for 5 hours and then was fed into a single screw melt-extruder the temperature of which was set at 240 C., and it was extruded and drawn with a first roller and simultaneously introduced into a cooling bath set at a temperature of 40 C. and thereby cooled, obtaining an undrawn monofilament 1.8 mm in diameter. Subsequently, from the resulting undrawn monofilament, a modeled article with a size of 50 mm10 mm5 mm was obtained using a 3D printing device the nozzle temperature of which was set at 240 C. For the modeled article obtained, evaluation was performed with respect to the above-mentioned (7) to (9). Moreover, the pelletized material for modeling was injection molded at a cylinder temperature of 240 C. and a mold temperature of 40 C., obtaining a specimen. Using the specimen obtained, evaluation was performed with respect to the above-mentioned (6). The results are shown in Table 2 (Comparative Example 9).

(71) TABLE-US-00003 TABLE 1 Example Comparative Example 1 2 3 4 5 6 7 8 1 2 3 4 5 Polylactic acid (A-1) part by 100 resin (A) weight (A-2) part by 100 weight (A-3) part by 100 100 100 100 weight (A-4) part by 100 100 100 100 weight Styrene-based (B1) part by 900 233 233 233 233 100 163 42 100 5 resin (B1) weight Thermoplastic (B2-1) part by 66 29 resin (B2) weight (B2-6) part by 100 weight (B2-7) part by 100 weight Degree of mm 2.1 1.7 1.0 1.7 1.0 1.3 1.8 0.8 3.4 3.3 3.7 0.0 0.1 warpage Polishability + + + + + + + + + + + Bleeding out ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ property MFR (220 C. .Math. 98N) g/10 min 83 81 75 158 82 280 85 79 70 48 7 98 95 Deflection temperature C. 93 92 92 92 92 75 83 58 98 94 117 56 56 under load (0.45 MPa) Charpy impact strength kJ/m.sup.2 1 2 2 1 2 1 15 10 2 10 89 1 1

(72) TABLE-US-00004 TABLE 2 Example Comparative Example 9 1 0 11 12 1 3 14 1.5 1 6 17 13 19 6 7 8 9 Polylactic acid (A-5) part by 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 resin (A) weight Thermoplastic (B2-2) part by 5 150 400 150 125 500 resin (B2) weight (B2-3) part by 150 weight (B2-4) part by 150 weight (B2-5) part by 10 weight (B2-8) part by 150 weight Plasticizer (B3-1) part by 5 25 30 13 100 (B3) weight Epoxy group- (C)-1 part by 0.3 containing weight compound (C) Degree of mm 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 0 5 warpage Polishability + + + + + + + + + + + + Bleeding out ++ ++ ++ ++ ++ ++ ++ + + + ++ ++ ++ ++ property Charpy impact kJ/m.sup.2 2.5 100 NB 100 95 95 95 2.5 NB NB NB 1.5 NB NB 60 strength

(73) As shown in Examples 9 to 15, it is revealed that excellent warpage resistance and impact resistance are attained by bringing the mixing ratios of a polylactic acid resin and a thermoplastic resin into the ranges of the present invention. As shown in Examples 16 to 18, it is revealed that excellent warpage resistance and softness are attained by bringing the mixing ratios of a polylactic acid resin and a plasticizer into the ranges of the present invention. As shown in Example 19, it is revealed that excellent warpage resistance and impact resistance are attained by bringing the mixing ratios of a polylactic acid resin, a thermoplastic resin, and a plasticizer into the ranges of the present invention. In Table 2, the case where a pellet did not break in a prescribed test method is denoted as NB.

(74) On the other hand, as shown in Comparative Examples 6 to 9, it is revealed that polishability or bleeding out property is poor when the mixing ratio of a polylactic acid resin, a thermoplastic resin, or a plasticizer is outside the range of the present invention.