JP2020029091A - Fused deposition modeling-based filament for three-dimensional molding, and molded body obtained by molding the same - Google Patents

Abstract

To provide a fused deposition modeling-based filament for three-dimensional molding that can be suitably used as a molding material in obtaining a three-dimensional molding with a 3D printer.SOLUTION: The present invention provides a fused deposition modeling-based filament for three-dimensional molding with a core/sheath type composite profile, wherein a core component contains a crystalline thermoplastic resin with a melting point of 140°C or less and a glass transition temperature of 20°C or less, or an amorphous thermoplastic resin with a glass transition temperature of 20°C or less, and a sheath component contains a crystalline thermoplastic resin with a melting point of more than 140°C.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a filament for 3D printing by a hot-melt lamination method and a molded body obtained by molding the filament.

  In recent years, 3D printers for producing three-dimensional objects (three-dimensional objects) based on data of three-dimensional CAD and three-dimensional computer graphics have rapidly become popular mainly in industrial applications. As a molding method of the 3D printer, there are methods such as optical molding, inkjet, powder plaster molding, powder sintering molding, and hot melt lamination molding.

  2. Description of the Related Art In recent years, many low-cost 3D printers for individuals and the like have adopted a hot melt lamination method (FDM method). In addition, the hot-melt lamination method is used to manufacture extremely fine equipment and equipment parts for industrial use.

  In the hot melt lamination 3D printer, a filament is used as a molding material, and various materials are used as a resin constituting the molding material, including polylactic acid and ABS resin, as well as engineering plastics. However, polylactic acid has a problem that it is hard and brittle and lacks bending resistance, flexibility, and impact resistance, and an ABS resin has a problem that it has large warpage and poor dimensional stability.

  Use of a flexible material such as a thermoplastic elastomer has been studied to impart bending resistance, flexibility, and the like to the filament. For example, Patent Literature 1 discloses a filament formed by blending a styrene resin or a thermoplastic elastomer with polylactic acid as a hot-melt lamination three-dimensional molding material, and Patent Literature 2 discloses polylactic acid and various functional groups. A forming filament of a resin composition containing a conjugated diene (co) polymer having one functional group selected from the group is disclosed. Patent Document 3 discloses a polyamide-based thermoplastic elastomer having predetermined physical properties. A filament for forming a three-dimensional printer is disclosed, and Patent Document 4 discloses a filament for forming a three-dimensional printer made of a polyester-based thermoplastic elastomer having predetermined physical properties.

  However, if a flexible material such as a thermoplastic elastomer is used for the filament, the flexible material usually has a low glass transition temperature and a high tackiness, so that blocking between pellets occurs and foreign matter such as dust and dirt is mixed. There is a problem that it is easily adhered. Further, when a flexible material is made into a monofilament, there is a problem that the fiber becomes flat and the fiber diameter becomes uneven, and the unwinding of the bobbin of the filament is remarkably deteriorated due to adhesion. Furthermore, stable hot-melt additive manufacturing such as extremely high frictional resistance during running of the filament, which makes it difficult to supply it to the 3D printer stably, or where the filament is too soft and bends in front of the nozzle, making it impossible to supply. There was also a problem that can not be.

Japanese Patent No. 5751388 JP-A-2006-035751 Japanese Patent No. 6265314 JP-A-2006-55637

  An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a filament for a three-dimensional molding method that can be suitably used as a molding material when a three-dimensional molded object is obtained by a 3D printer. Things.

The present inventors have studied to solve the above-mentioned problems, and as a result, by forming a filament of a core / sheath type composite cross section in which a thermoplastic resin having a specific temperature characteristic is disposed in each of a core component and a sheath component, The inventors have found that the object is achieved, and arrived at the present invention.
That is, the gist of the present invention is as follows.
(1) A crystalline thermoplastic resin having a melting point of 140 ° C. or less and a glass transition temperature of 20 ° C. or less, or an amorphous thermoplastic resin having a glass transition temperature of 20 ° C. or less is disposed on the core component. A core / sheath type composite cross-section three-dimensional molding filament having a core / sheath composite cross section, in which a crystalline thermoplastic resin having a melting point exceeding 140 ° C. is disposed as a component.
(2) The filament for three-dimensional modeling according to (1), wherein the thermoplastic resin to be disposed in the sheath component is an amide resin.
(3) The filament for three-dimensional molding according to (1), wherein the thermoplastic resin disposed in the sheath component is an ester resin.
(4) The filament for three-dimensional molding according to (1), wherein the thermoplastic resin to be disposed in the sheath component is an olefin-based resin.
(5) The three-dimensional shaping method according to any one of (1) to (4), wherein the mass ratio of the core component and the sheath component (core component / sheath component) is 95/5 to 20/80. filament.
(6) A shaped body obtained by shaping the filament for hot melt lamination three-dimensional shaping according to any one of (1) to (5).

  Advantageous Effects of Invention According to the present invention, it is possible to provide a filament for a three-dimensional molding method that can be suitably used as a molding material when a three-dimensional molded object is obtained by a 3D printer. The filament of the present invention is excellent in bending resistance and has no tackiness on the surface, so that it can be stably supplied to a 3D printer. In addition, the shaped article obtained by shaping the filament of the present invention has excellent flexibility, mechanical properties, impact resistance, and dimensional stability because the core component layer and the sheath component layer are laminated in a micrometer order in multiple layers. ing.

It is the figure which showed the example of the core / sheath type composite cross section. It is a figure of "Luke" produced for evaluating 3D printer modeling. It is a figure of the "anchor" produced in order to evaluate warpage.

  In the filament of the present invention, a crystalline thermoplastic resin having a melting point of 140 ° C. or lower and a glass transition temperature of 20 ° C. or lower, or an amorphous thermoplastic resin having a glass transition temperature of 20 ° C. or lower is provided in the core component. In addition, the filament is a sheath component in which a crystalline thermoplastic resin having a melting point of more than 140 ° C. is arranged.

  In the filament of the present invention, as the core component, a crystalline thermoplastic resin having a melting point of 140 ° C. or less and a glass transition temperature of 20 ° C. or less, or an amorphous thermoplastic resin having a glass transition temperature of 20 ° C. or less is used. Must be used. By using a thermoplastic resin having a glass transition temperature of 20 ° C. or less for the core component, flexibility and rubber elasticity can be imparted, and the dimensional stability of the molded article can be improved. The lower limit of the glass transition temperature of the thermoplastic resin is not particularly limited, but if the temperature is too low, it may be difficult to use the obtained molded article. In the present invention, “crystalline” means that the value of the heat of fusion measured by a differential scanning calorimeter (DSC) at a heating rate of 20 ° C./min in a nitrogen atmosphere is greater than 4 J / g. "Amorphous" means that the value of the heat of fusion is 4 J / g or less.

  Examples of the crystalline thermoplastic resin having a melting point of 140 ° C. or lower and a glass transition temperature of 20 ° C. or lower, or an amorphous thermoplastic resin having a glass transition temperature of 20 ° C. or lower include an ester resin and a thermosetting resin. And a plastic elastomer.

  The ester resin is a resin having an ester bond, and examples thereof include an aliphatic polyester, an alicyclic polyester, and a copolymerized polyester of an aromatic polyester and an aliphatic polyester. As the aliphatic polyester, for example, polyethylene succinate, polybutylene succinate, polyethylene adipate, polybutylene adipate, polyethylene succinate adipate, polybutylene succinate adipate, polyhydroxybutyrate hexanoate, polyhydroxybutyrate hexanoate Is mentioned. Examples of the copolyester of an aromatic polyester and an aliphatic polyester include, for example, polybutylene terephthalate succinate, polybutylene terephthalate adipate, polybutylene terephthalate sebacate, polyethylene terephthalate succinate, polyethylene terephthalate adipate, polyethylene terephthalate sebacate And polyethylene terephthalate sulfoisophthalate. Examples of commercially available ester-based resins include “Ecoflex C1200” (polybutylene terephthalate adipate) manufactured by BASF Japan, and “Bionole 3001MD” (polybutylene succinate adipate) manufactured by Showa Kogyo KK.

  Examples of the thermoplastic elastomer include an amide-based elastomer, a styrene-based elastomer, an olefin-based elastomer, a urethane-based elastomer, an ester-based elastomer, and other elastomers. The thermoplastic elastomer may be one in which a double bond site is hydrogenated, and may be any of a random copolymer, a block copolymer, and a graft copolymer. Further, the thermoplastic elastomer may be a mixture of the above elastomers or a copolymer.

  Examples of the amide-based elastomer include those having a polyamide component as a hard segment and a poly (alkylene oxide) glycol component and / or an aliphatic polyester component as a soft segment. Examples of the poly (alkylene oxide) glycol component constituting the soft segment include polyethylene glycol, poly (1,2- and 1,3-propylene oxide) glycol, poly (tetramethylene oxide) glycol, and a copolymer of ethylene oxide and propylene oxide. Examples of the polymer include a copolymer of ethylene oxide and hydrofuran, and examples of the aliphatic polyester component include polyethylene adipate, polybutylene adipate, poly-ε-caprolactone, polyethylene sebacate, and polybutylene sebacate. Commercially available polyamide elastomers include, for example, “Daiamide” series and “Vestamide” series manufactured by Daicel Evonik, “Pebax” series manufactured by ARKEMA, “Grill Flex” series manufactured by Ms. Chemie Japan, and “UBESTA XPA” manufactured by Ube Industries. Series, "TPAE-12" manufactured by T & K TOKA.

  As the styrene-based elastomer, for example, styrene-butadiene copolymer, styrene-butadiene-styrene copolymer, styrene-isoprene copolymer, styrene-isoprene-styrene copolymer, styrene-vinylisoprene-styrene copolymer, Styrene-ethylene-butylene-styrene copolymer and styrene-ethylene-propylene-styrene copolymer are exemplified. Commercially available styrene elastomers include, for example, the "HIBLER" series manufactured by Kuraray Co., Ltd., the "AR-815C" manufactured by Aron Kasei, and the "ToughTech" series manufactured by Asahi Kasei Corporation.

  Examples of the olefin-based elastomer include an ethylene-propylene copolymer, an ethylene-propylene-nonconjugated diene copolymer, an ethylene-butene copolymer, an ethylene-acrylic acid copolymer and an alkali metal salt thereof (so-called “ionomer”). ), Ethylene-glycidyl (meth) acrylate copolymer, ethylene- (meth) acrylic acid alkyl ester copolymer, ethylene-vinyl acetate copolymer, and acid-modified ethylene-propylene copolymer. Commercially available olefin elastomers include, for example, the "Engage" series manufactured by Dow Chemical Company.

  Examples of the urethane-based elastomer include those having a polyurethane component as a hard segment and a poly (alkylene oxide) glycol component and / or an aliphatic polyester component as a soft segment. Examples of the poly (alkylene oxide) glycol component and / or the aliphatic polyester component are the same as the poly (alkylene oxide) glycol component and / or the aliphatic polyester component constituting the soft segment of the amide-based elastomer. Commercially available urethane elastomers include, for example, the "Elastron" series manufactured by BASF.

  Examples of the ester-based elastomer include those having an aromatic polyester component as a hard segment and a poly (alkylene oxide) glycol component and / or an aliphatic polyester component as a soft segment. The aromatic polyester component constituting the hard segment refers to a polymer obtained by polycondensation of a diol component and a dicarboxylic acid component whose terephthalic acid component usually accounts for 60 mol% or more. Examples of the aromatic polyester component constituting the hard segment include polyethylene terephthalate, polybutylene terephthalate, polytetramethylene terephthalate, polyethylene terephthalate isophthalate, and polybutylene terephthalate isophthalate. Examples of the poly (alkylene oxide) glycol component and / or the aliphatic polyester component constituting the soft segment are the same as the poly (alkylene oxide) glycol component and / or the aliphatic polyester component constituting the soft segment of the amide-based elastomer. . Examples of commercially available ester-based elastomers include “Hytrel” series manufactured by Toray Industries, Inc.

  Examples of other elastomers include acrylic elastomers, PVC elastomers, and chlorinated polyethylene elastomers.

  In the filament of the present invention, it is necessary to use a crystalline thermoplastic resin having a melting point exceeding 140 ° C. as the sheath component. In general, the surface of filaments and shaped objects is not tacky, has smoothness, has a soft touch and is preferred to be smooth, and filaments and shaped objects need general heat resistance. Because it is done. The upper limit of the melting point of the thermoplastic resin used for the sheath component is preferably 260 ° C. or lower, and more preferably 230 ° C. or lower, since the upper limit of the nozzle temperature of the general-purpose hot-melt lamination type 3D printer is about 260 ° C. Is preferred. However, when an industrial hot-melt lamination type 3D printer is used, since the upper limit of the nozzle temperature is about 400 ° C., the upper limit of the melting point of the thermoplastic resin used for the sheath component can be further increased. In the present invention, the term “crystalline” means that the value of the heat of fusion measured by a differential scanning calorimeter (DSC) under a nitrogen atmosphere at a heating rate of 20 ° C./min is greater than 4 J / g. .

  Examples of the crystalline thermoplastic resin having a melting point exceeding 140 ° C. used for the sheath component include, for example, an olefin resin, an amide resin, an ester resin, a styrene resin, a polyethylene vinyl alcohol, an ABS resin, and these resins. Examples thereof include a mixture with a thermoplastic elastomer or a rubber-like elastic material.

  The olefin-based resin is a resin having an olefin bond, and examples thereof include polyethylene such as LDPE, LLDPE, and HDPE, and polypropylene such as homopolypropylene and ethylene copolymerized polypropylene. Among them, polypropylene is preferable because it is lightweight and has excellent mechanical properties. Examples of commercially available olefin-based elastomers include “J700GP” (homopolypropylene) and “J2041GA” (copolymerized polypropylene) manufactured by Prime Polymer.

  The amide-based resin is a resin having an amide bond, for example, polyamide 46, polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 69, polyamide 610, polyamide 612, polyamide 9T, polyamide 10T, and the like. A polyamide copolymer is exemplified.

  Examples of the polyamide copolymer include a polyamide 6/66 copolymer, a polyamide 6/12 copolymer, a polyamide 6/66/12 copolymer, a polyamide 6 / 10T, and a polyamide 6/12 copolymer. Among these, polyamide 6/66 copolymer, polyamide 6/12 copolymer, and polyamide 6/66/12 copolymer are preferable because of their relatively low melting point and flexibility.

  Commercially available polyamides include, for example, "A1030BRL" (polyamide 6) manufactured by Unitika, "BMNO" (polyamide 11), and "AMNO" (polyamide 12) manufactured by Arkema. Commercially available polyamide copolymers include, for example, "5023" (polyamide 6/66 copolymer), "7034B" (polyamide 6/12 copolymer), or "6434B" (polyamide 6 / 66/12 copolymer) and "CX1004" (polyamide copolymer) manufactured by Unitika Ltd.

  The ester resin is a resin having an ester bond, and examples thereof include an aromatic polyester, an aliphatic polyester, and a copolymerized polyester of an aromatic polyester and an aliphatic polyester.

  Examples of the aromatic polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate isophthalate, and polybutylene terephthalate isophthalate. Commercially available aromatic polyesters include, for example, "IP20" (polyethylene terephthalate isophthalate) manufactured by Unitika.

  Examples of the aliphatic polyester include polylactic acid, polyethylene succinate, polybutylene succinate, polyethylene adipate, polybutylene adipate, polyethylene succinate adipate, polybutylene succinate adipate, and polyhydroxybutyrate hexanoate. Among them, polylactic acid is preferable because it has a relatively low melting point and is easy to use.

  Examples of the polylactic acid include poly (L-lactic acid), poly (D-lactic acid), a mixture thereof, and a copolymer thereof. Among them, polylactic acid mainly composed of poly (L-lactic acid) is preferable because of high moldability. The polylactic acid mainly composed of poly (L-lactic acid) preferably has a D-lactic acid content of 3 mol% or less, more preferably 2 mol% or less, and preferably 1.5 mol% or less. Is more preferred. Since polylactic acid has high moldability, it is preferable that the melt flow rate (MFR) at a temperature of 190 ° C. and a load of 2.16 kg is 0.3 to 15 g / 10 minutes. Examples of commercially available polylactic acid include “4032D” (D-lactic acid content = 1.4 mol%) and “3001D” (D-lactic acid content = 1.4 mol%) manufactured by NatureWorks.

  Examples of the copolymerized polyester of an aromatic polyester and an aliphatic polyester include, for example, polybutylene terephthalate succinate, polyethylene terephthalate succinate, polybutylene terephthalate adipate, polyethylene terephthalate adipate, polyethylene terephthalate sulfoisophthalate, polyethylene terephthalate sebacate And polybutylene terephthalate sebacate.

  Polyethylene vinyl alcohol is obtained by block copolymerizing vinyl alcohol with polyethylene. Polyethylene vinyl alcohol may be modified with a silyl group, acetoacetyl group, or the like. Commercial products of polyethylene vinyl alcohol include the "Soarnol" series manufactured by Nippon Gohsei Kagaku and the "Eval" series manufactured by Kuraray.

  The core component and / or the sheath component of the present invention may be used as one component by mixing two or more of the various resin components described above. As a method of mixing, a single screw extruder, a twin-screw extruder, a roll kneader, a method using a general kneader such as Brabender, and the like, among which, for improving the kneading state, a twin-screw extruder is used. The method used is preferred.

  In the present invention, it is preferable that the thermoplastic resin of the core component and the thermoplastic resin of the sheath component have high affinity and compatibility. Examples of the combination of the core component / sheath component having high affinity and compatibility include, for example, olefin elastomer / olefin resin, ester elastomer / ester resin, styrene elastomer / amide resin, amide elastomer / amide resin. Is mentioned.

  As a method for indicating affinity or compatibility, a solubility parameter (SP value) proposed by Van Krevelen and HoftyZer is known. The closer the SP value of the core component and the sheath component is, the higher the affinity and compatibility of the core component and the sheath component are, and the operability such as the spinning property is improved.

  In the present invention, if the thermoplastic resin of the core component and the thermoplastic resin of the sheath component have low affinity or compatibility, a compatibilizer may be added to the core component and / or the sheath component. Examples of the compatibilizer include the "Alphon" series manufactured by Toagosei Co., Ltd., the "Modepar-A" series manufactured by NOF CORPORATION, the "SAG" series manufactured by TrendSign, and the "JONCRYL ADR" series manufactured by BASF. In addition, in the compatibilizer containing a reactive functional group such as an epoxy group or an allyl group, these functional groups may react with the core component and the sheath component, and may be easily gelled. When gelled, it becomes difficult to obtain a filament with good spinnability, and a gelled portion appears on the surface of the obtained shaped article, which may degrade the quality.

  The mass ratio of the core component and the sheath component (core component / sheath component) is preferably 95/5 to 20/80, more preferably 90/10 to 20/80, and 75/25 to 20/80. 80 is more preferred. When the mass ratio of the core component to the total of the core component and the sheath component exceeds 95% by mass, the ratio of the sheath component covering the core component is reduced, and the core component is exposed on the fiber surface, and the tackiness of the fiber surface is reduced. Due to the increase, blocking, adhesion of dust and dirt may easily occur, the unwinding property of the yarn may decrease, and the running resistance of the yarn may increase. Further, the structural accuracy in the spinning nozzle pack becomes extremely high, which may increase the cost. On the other hand, when the mass ratio of the core component is less than 20% by mass, flex resistance and impact resistance may be reduced.

  The fiber cross section of the filament of the present invention may be a round cross section or an irregular cross section as long as the core component is a core / sheath type composite cross section in which a sheath component is coated. Examples of the round cross section include a core / sheath type composite cross section of a thin skin (FIG. 1A), a three-component type core / sheath / core type cross section (FIG. 1B), a multi-core type or a sea-island type. (FIG. 1c). Examples of the deformed cross section include a core-sheath composite deformed cross section having a protruding sheath component (FIG. 1D), a 6-leaf core-sheath deformed cross section (FIG. 1E), and a radial cross-sectional shape of the core. (See FIG. 1F).

  The filament of the present invention preferably has a fiber diameter of 1.5 to 3.2 mm, more preferably 1.6 to 3.1 mm. The fiber diameter of the filament is the average of the maximum major axis and the minimum minor axis in a cross section cut perpendicularly to the longitudinal direction of the filament. If the fiber diameter of the filament is less than 1.5 mm, it may be too thin to be used in a general-purpose 3D printer of the hot melt lamination method. In addition, the upper limit of the fiber diameter of the filament suitable for a general-purpose hot-melt lamination 3D printer is about 3.2 mm.

  The core component and the sheath component of the filament of the present invention can improve the durability of the obtained molded article, and therefore, include a hindered phenol compound, a phosphite compound, a phosphate compound, a benzophenone compound, and a benzotriazole compound. It is preferable to add an antioxidant such as a compound, a salicylate compound, a thioether compound, an aromatic benzoate compound, and a hindered amine compound, an ultraviolet absorber, and a light stabilizer.

  The core component and the sheath component of the filament of the present invention may contain a filler in order to improve the dimensional stability of the obtained molded article. Examples of the filler include glass beads, glass fiber powder, wollastonite, mica, synthetic mica, sericite, talc, clay, zeolite, bentonite, kaolinite, dronite, silica, potassium titanate, finely divided silica, silas Balloon, calcium carbonate, magnesium carbonate, barium sulfate, aluminum oxide, magnesium oxide, calcium oxide, titanium oxide, aluminum silicate, zirconium silicate, gypsum, graphite, montmorillonite, carbon black, calcium sulfide, zinc oxide, boron nitride, cellulose Fiber is mentioned, and talc is more preferable.

  The average particle diameter of the filler is preferably 100 μm or less, more preferably 50 μm or less, in order to obtain a filament with good spinnability. When the average particle diameter of the filler exceeds 100 μm, the filter of the spinning machine may be clogged during the production of the filament, and the filtration pressure may increase. Further, the roughness of the obtained filament surface may become strong, and the quality may deteriorate. The average particle size of the filler is a value defined by a particle size value at a mass accumulation of 50% when a particle size distribution is measured using a particle size distribution measuring device such as a laser diffraction / scattering particle size distribution meter. . The measurement is usually carried out after adding a filler to water or alcohol so as to have a permissible measurement concentration, adjusting the suspension, and dispersing the suspension with an ultrasonic disperser.

  The content of the filler is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the resin. If the content of the filler is more than 20 parts by mass, the bending resistance may be impaired, the spinning property may be reduced, the fiber diameter of the filament may be non-uniform, and the surface may have a rough surface.

  When the resin composition of the present invention contains the above-mentioned filler, dirt may easily adhere to the nozzle at the time of producing a filament and at the time of shaping with a 3D printer. Therefore, when the resin composition of the present invention contains a filler, it is preferable to contain a stain inhibitor. Examples of the antifouling agent include a metal soap, a fluorine-based lubricant, and a lubricant containing fatty acid amide as a main component. Metal soap refers to a fatty acid salt of a metal other than the alkali metal, and examples of the main metal include magnesium, calcium, zinc, copper, lead, aluminum, iron, cobalt, chromium, and manganese. Examples of the fluorine-based lubricant include, for example, perfluoroalkane, perfluorocarboxylic acid ester, perfluoro organic compound, and fluorinated polymer, and examples of the aliphatic amide include oleic acid amide and ethylenebisstearic acid amide. No. Among them, a vinylidene fluoride-hexafluoropropylene copolymer is preferable because the effect of preventing the adhesion of dirt is high. Examples of commercially available products include the PPA series manufactured by Daikin Industries, Ltd.

  The core component and the sheath component of the filament of the present invention further include plasticizers such as phthalate esters and phosphate esters; colorants such as dyes and pigments; bromide compounds, as long as the object of the present invention is not impaired. Flame retardants such as antimony trioxide and antimony pentoxide; anti-colorants; antistatic agents; terminal blocking agents; anti-glazing agents; anti-fog agents; A release agent; a moisture-proofing agent; an oxygen barrier agent; and a nucleating agent may be added. One of the above additives may be used alone or in combination.

  The filament of the present invention may be a monofilament or a multifilament, but is preferably a monofilament because discharge of a 3D printer can be easily controlled.

  The filament of the present invention can be obtained by a spinning method using a known core / sheath type composite cross-section nozzle. For example, using a composite spinning device having two or more extruders and a gear pump corresponding to the extruders, individually melt-weighed core components and sheath components are introduced into an arbitrary nozzle pack, and after passing through individual filter media and filtration filters, After repeating the distribution and joining of the components and finally integrating them, extruding them into an arbitrary cross-sectional shape from the nozzle hole, and cooling and solidifying this in a liquid bath at 20 to 80 ° C., and a spinning speed of 1 to 50 m / min. And winding it around a bobbin. When the filament is formed, it may be stretched at a magnification of more than 1.0 times and 5.0 times or less. The stretching ratio is more preferably more than 1.0 times and 3.5 times or less. By stretching, the bending resistance of the obtained filament can be improved. The stretching of the monofilament may be performed after winding the filament after the spinning once, or may be performed continuously after the spinning without being wound after the spinning. When a suitable heating stretching and heat treatment are performed during stretching, a more stable filament is formed, and the filament strength is increased.

  The filament of the present invention has a core / sheath composite cross-sectional structure in which a low melting point thermoplastic resin or an amorphous thermoplastic resin is arranged in a core component, and a high melting point thermoplastic resin is arranged in a sheath component. Since it is a filament, it has excellent bending resistance.

In addition, the molded article molded using the filament of the present invention, a low-melting thermoplastic resin or amorphous thermoplastic resin of the core component, and a high-melting thermoplastic resin are laminated on a micrometer order. Therefore, it has excellent flexibility, mechanical properties, impact resistance and dimensional stability. Therefore, the flexural modulus, which is an index indicating the flexibility of the molded article, can be 600 MPa or less, and preferably 500 MPa or less. Tensile strength, which is an index of mechanical properties, can be 2.0 MPa or more, and preferably 5.0 MPa or more. Further, the Charpy impact strength, which is an index of impact resistance, can be ²⁰ kJ / m ² or more. More preferably, the Charpy impact strength does not break during measurement.

  The filament of the present invention can be suitably used as a shaping material for a 3D printer by the hot-melt lamination method.

  Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these.

1. Measurement of physical properties The physical properties of the used resin, the obtained filament and the molded article were measured by the following methods.

(1) Glass transition temperature The resin used in each Example and Comparative Example was kept at -100 ° C for 5 minutes in a nitrogen atmosphere using a differential scanning calorimeter (DSC-7, manufactured by PerkinElmer). The temperature was raised at a temperature rising rate of 20 ° C./min, and the intermediate value between the two bending temperatures derived from the glass transition in the temperature rising curve was determined.

(2) Melting point The resin used in each of Examples and Comparative Examples was kept at -100 ° C for 5 minutes in a nitrogen atmosphere using a differential scanning calorimeter (DSC-7, manufactured by PerkinElmer), and then heated. After the temperature was raised to 260 ° C. at a rate of 20 ° C./min, the temperature was maintained at 260 ° C. for 5 minutes, then the temperature was lowered to 25 ° C. at a rate of 20 ° C./min. The temperature was raised at 20 ° C./min, and the top of the endothermic peak at the time of the second temperature increase was determined.

(3) Relative Viscosity The amide resin was dissolved in 96% sulfuric acid so that the resin concentration became 1.0 g / dl, and measured using an Ubbelohde viscometer at a temperature of 25 ° C.
The ester resin is dissolved in phenol / tetrachloroethane = 60/40 (mass ratio) so that the resin concentration becomes 0.5 g / dl, and measured at a temperature of 20 ° C. using an Ubbelohde viscometer. did.

(4) D-lactic acid content of polylactic acid About 0.3 g of polylactic acid was added to 6 ml of a 1N potassium hydroxide / methanol solution, sufficiently stirred at 65 ° C. to decompose polylactic acid, and then 450 μl of sulfuric acid was added. And stirred at 65 ° C. to obtain lactate methyl ester. 5 ml of the obtained lactate methyl ester sample, 3 ml of pure water, and 13 ml of methylene chloride were mixed and shaken. After standing separation, about 1.5 ml of the lower organic layer was collected, filtered through a HPLC disk filter (pore size: 0.45 μm), and measured by gas chromatography.
Gas chromatography (Hewlett Packard, HP-6890) uses helium (He) as a carrier gas at a flow rate of 1.8 ml / min, the oven program is maintained at 90 ° C for 3 minutes, and at 50 ° C / min at 220 ° C. And kept for 1 minute. The column was measured by an internal standard method using J & W DB-17 (30 m × 0.25 mm × 0.25 μm) and the detector using FID (temperature: 300 ° C.). The ratio (%) of the peak area of D-lactate methyl ester to the total peak area of lactate methyl ester was calculated.

(5) MFR
Regarding the resin used in each of the examples and comparative examples, any one of 250 ° C., 230 ° C., 210 ° C., and 190 ° C. within a range that can be measured based on (the melting point of the used resin + 20 ° C.) according to JIS K7210. At a load of 2.16 kgf.

(6) Yarn-making properties The following criteria were evaluated based on the number of yarn breaks when a monofilament was collected at a spinning speed of 10 m / min for 24 hours.
：: 0 times of thread breaks １: 1 time of thread breaks ×: 2 or more times of thread breaks In the present invention, “○” or more was regarded as acceptable.

(7) Fiber diameter of monofilament The monofilament obtained in each of Examples and Comparative Examples was cut every 20 cm perpendicularly to the longitudinal direction of the monofilament to obtain 30 measurement samples. The maximum major axis and the minimum minor axis in the cross section of each sample were measured using a micrometer, the average was calculated, and this was defined as the average diameter. The average diameter of all 30 samples was averaged to obtain the monofilament fiber diameter.

(8) Uniformity of monofilament fiber diameter The uniformity of monofilament fiber diameter was calculated using the maximum value (M1) and the minimum value (M2) of the average diameter of all the samples calculated in (7) above.
Fiber diameter uniformity = (M1-M2) / 2

(9) Adhesiveness of monofilament Five samples having a length of 12 cm were collected from the monofilaments obtained in each of the examples and comparative examples, placed in parallel, and fixed for 10 mm at both ends with cellotape (registered trademark). At 23 ° C. × 65% humidity control, a standard test plate of polypropylene (100 mm × 25 mm × 2 mm, weight of about 4.6 g) manufactured by Nippon Test Panel was placed on the sample, and a load of 10 kg was applied from above to the sample for 60 seconds. , Gradually. The sample mount was turned upside down, and the time required for the standard test plate to fall was measured and evaluated according to the following criteria.
A: Dropped immediately.
〇: Not dropped immediately, but dropped in less than 2 seconds.
□: Dropped for 2 seconds or more and less than 5 seconds.
X: It did not fall or it took 5 seconds or more to fall.
In the present invention, “□” or more was regarded as acceptable.

(10) Bending resistance of monofilament After leaving the monofilament in a standard state (room temperature 22 ± 2 ° C., humidity 50 ± 2%) for 48 hours or more, mize according to the MIT bending resistance test described in JIS P 8115. Using a MIT folding tester manufactured by Testing Machine Co., Ltd., the load was 5 N, the tip R of the clamp was 0.38 mm, the grip interval was 2.0 mm, the test speed was 175 rpm, and the bending angle was 135 degrees. .
The following criteria were used to evaluate the number of times of folding.
◎: 100 times or more ○: 30 to 99 times Δ: 5 to 29 times ×: Less than 5 times In the present invention, if the number of fold resistance is 5 or more, it is judged as acceptable, and it is preferably 30 or more, More preferably, it is 100 times or more.

(11) 3D printer moldability Using the monofilament obtained in each of the examples and comparative examples, using a 3D printer (manufactured by FLASHFORGE, CREATOR PRO) under the conditions of a nozzle temperature of 190 to 240 ° C and a table temperature of 50 ° C. The "Luke" of FIG. 2 was formed. When the resin was not discharged uniformly or the resin was peeled off from the molding table due to excessively large warpage and could not be molded, the evaluation was "x". When molding was possible, the appearance of 1 (overhang portion) in FIG. 2 was evaluated according to the following criteria.
：: The overhang portion did not sag.
：: Overhang portion was dripped.
In the present invention, "O" or more was judged as acceptable.

(12) Flexural Modulus of Modeled Product The monofilament obtained in each of the examples and comparative examples was dried under the conditions of 60 ° C. × 24 hours to reduce the moisture content to 0.02%. Using a dried monofilament, a 3D printer (NJB-200HT) manufactured by Ninjabot Co., Ltd., a nozzle diameter of 0.4 mmφ, a molding speed of 50 mm / sec, a molding temperature of 200 to 260 ° C., a lamination thickness of 0.1 mm, and a resin diameter of 0 extruded. Under the conditions of .22 mm, a filling rate of 100%, and a table temperature of 60 ° C., a temperature condition for obtaining the best molded product was selected based on (the highest melting point of the resin of the monofilament sheath component used + 30 ° C.). A test piece (dumbbell piece) for measuring general physical properties according to ISO was prepared.
The prepared dumbbell pieces were measured at 23 ° C. × 65% humidity control at a bending span of 64 mm and a test speed of 2 mm / sec according to JIS K7171.

(13) Tensile strength of the shaped article The dumbbell piece prepared in (12) was measured at 23 ° C x 65% humidity control at a gripping interval of 115 mm and a tensile speed of 5 mm / min according to JIS K 7161-2.

(14) Charpy Impact Strength of Modeled Product An ISO-compliant test piece (80 mm × 10 mm × 4.0 mm, with a notch) was prepared from the dumbbell piece prepared in (12).
The above notched test piece was measured at a distance between supports of 62 mm according to JIS K 72111-1.

(14) Warpage of molded article Using the obtained monofilament, using a 3D printer (NJB-200HT, manufactured by Ninjabot Co., Ltd.) under the conditions of a nozzle temperature of 200 to 260 ° C and a table temperature of 60 ° C, “ Anchor ". When the molded article was peeled off from the modeling table and could not be molded because the warpage was too large, it was evaluated as “×”. If the model can be formed, place the modeled anchor on a smooth bench (such as marble), fix the weight at the position 5 in FIG. 3 and fix it. The height from the table was measured with a gap gauge or a vernier caliper, and an average value was obtained.
A: The average value was more than 0 mm and less than 1 mm.
：: The average value was 1 mm or more.
In the present invention, "O" or more was judged as acceptable.

2. Raw Materials Raw materials used in Examples and Comparative Examples are as follows.

A. Low melting point thermoplastic resin or amorphous thermoplastic resin (ester resin)
(A-1a)
・ Polybutylene terephthalate adipate, “Ecoflex C1200” manufactured by BASF Japan, melting point = 100-120 ° C., glass transition temperature = −30 ° C., MFR at 190 ° C. = 3 g / 10 min (A-1b)
-Polybutylene succinate adipate, "Vionole 3001MD" manufactured by Showa Polymer Co., Ltd., melting point = 95 ° C, glass transition temperature = -45 ° C, MFR at 190 ° C = 10 g / 10 min.

(Amide elastomer)
(A-2a)
-Block copolymer of aliphatic polyamide and polyetherester, "TPAE-12" manufactured by T & K TOKA, melting point = none, glass transition temperature = -60 ° C, MFR at 200 ° C = 200 g / 10 minutes

(Styrene elastomer)
(A-3a)
Styrene-vinyl isoprene-styrene copolymer, "HIBLER 7311" manufactured by Kuraray, melting point = none, glass transition temperature = -32 ° C, MFR at 190 ° C = 0.5 g / 10 min (A-3b)
"AR-815C" manufactured by Aron Kasei Co., Ltd., melting point = 101 ° C., glass transition temperature = −30 ° C., MFR at 230 ° C. = 0.1 g / 10 minutes (A-3c)
・ Hydrogenated styrene-butadiene copolymer, “ToughTech MP-10” manufactured by Asahi Kasei Corporation, melting point = none, glass transition temperature = −40 ° C., MFR at 230 ° C. = 4 g / 10 min.

[Olefin-based elastomer]
(A-4a)
“Engage 8401” manufactured by Dow Chemical Company, melting point = 80 ° C., glass transition temperature = −47 ° C., MFR at 190 ° C. = 30 g / 10 min.

[Urethane-based elastomer]
(A-5a)
-"Elastollan 1180A" manufactured by BASF Japan, melting point = none, glass transition temperature = -42 ° C, MFR at 230 ° C = 83.5 g / 10 min.

(Ester-based elastomer)
(A-6a)
A block copolymer of polybutylene terephthalate and polyether, "Hytrel 4047" manufactured by Toray Industries, Ltd., melting point = 182 ° C., glass transition temperature = −40 ° C., MFR at 230 ° C. = 8 g / 10 min.

B. High melting point thermoplastic resin [olefin resin]
(B-1a)
Homopolypropylene, “J700GP” manufactured by Prime Polymer Co., Ltd., melting point = 165 ° C., glass transition temperature = 44 ° C., MFR at 230 ° C. = 8 g / 10 min (B-1b)
Copolymerized polypropylene, “J2041GA” manufactured by Prime Polymer Co., Ltd., melting point = 145 ° C., glass transition temperature = −5 ° C., MFR at 230 ° C. = 22 g / 10 min.

(Amide resin)
(B-2a)
-Polyamide 6/66/12 copolymer, "6434B" manufactured by Ube Industries, melting point = 188 ° C, glass transition temperature = 44 ° C, MFR at 210 ° C = 1.4 g / 10 min (B-2b)
-Polyamide 6/12 copolymer, "7034B" manufactured by Ube Industries, melting point = 201 ° C, glass transition temperature = 60 ° C, MFR at 210 ° C = 1.6 g / 10 minutes (B-2c)
Polyamide copolymer, “CX1004” manufactured by Unitika, melting point = 210 ° C., glass transition temperature = 47 ° C., MFR at 230 ° C. = 8.6 g / 10 min, relative viscosity = 2.5
(B-2d)
Polyamide 6, "A1030BRL" manufactured by Unitika Ltd., melting point = 225 ° C., glass transition temperature = 47 ° C., MFR at 230 ° C. = 26 g / 10 minutes, relative viscosity = 2.55
(B-2e)
-Polyamide 11, "BMNO" manufactured by Arkema, melting point = 185 ° C, glass transition temperature = 50 ° C, MFR at 210 ° C = 37 g / 10 minutes (B-2f)
Polyamide 12, “AMNO” manufactured by Arkema, melting point = 175 ° C., glass transition temperature = 37 ° C., MFR at 210 ° C. = 50 g / 10 min.

(Ester resin)
(B-3a)
・ Polyethylene terephthalate isophthalate, “IP20” manufactured by Unitika, melting point = 210 ° C., glass transition temperature = 71 ° C., MFR at 230 ° C. = 1.6 g / 10 min, relative viscosity = 1.38
(B-3b)
・ Polylactic acid, “3001D” manufactured by NatureWorks, D-lactic acid content: 1.4 mol%, melting point = 168 ° C., glass transition temperature = 58 ° C., MFR at 190 ° C. = 10 g / 10 min (B-3c)
-Copolyester, "Elitel UE-9200" manufactured by Unitika, melting point = none, glass transition temperature = 65 ° C, intrinsic viscosity = 0.53

[Polyethylene vinyl alcohol]
(B-4a)
・ Polyethylene vinyl alcohol, “Soarnol ET3803” manufactured by Nippon Synthetic Chemical Co., Ltd., melting point = 170 ° C., glass transition temperature = 63 ° C., MFR at 190 ° C. = 1.8 g / 10 min.

[Amide resin / styrene elastomer blend]
(B-5a), (B-5b), (B-5c)
Using a twin screw extruder (manufactured by Ikegai Co., Ltd., PCM-30, screw diameter 29 mm, L / D30, die diameter 3 mm, number of holes 3), A1030BRL (B-2d) and Hibler 7311 (A-3a) were respectively used. , 25/75, 50/50 and 25/75 in mass ratio and fed to an extruder. Kneading and extrusion were performed at a temperature of 230 ° C., a screw rotation speed of 120 rpm, and a discharge rate of 7 kg / hour. Subsequently, the strand discharged from the tip of the extruder was cooled in a cooling bath, then taken up by a pelletizer, and cut to obtain a pellet.
The obtained pellets were dried under the conditions of 65 ° C. × 48 hours to make the moisture content 0.01%, and were respectively (B-5a), (B-5b) and (B-5c).

Example 1
A spinning machine composed of two single screw extruders (manufactured by Nippon Steel Works Co., Ltd., screw diameter 40 mm, L / D22) is used, and the nozzle is a core-sheath type composite spinning type having a nozzle diameter of 4 mmφ and two holes. Nozzle pack was used. Hybler 7311 was melted at 230 ° C as the core component, A1030BRL was melted at 230 ° C as the sheath component, and the spin block temperature was 230 ° C. The core component / sheath component was extruded from a spinneret with a mass ratio of 75/25 and a total discharge rate of 4.4 kg / hour. Subsequently, the two extruded monofilaments are immersed in 50 ° C. of cooling hot water 20 cm below the spinneret, taken up while adjusting the discharge at a cooling time of 1 minute and a take-up speed of 10 m / min, and a core having a fiber diameter of 1.75 mm. A monofilament having a composite / sheath type cross section was obtained.

Examples 2 to 27, Comparative Examples 10 and 11
The same operation as in Example 1 was performed except that the resin composition and the manufacturing conditions were changed as shown in Tables 1 to 3, to obtain a monofilament having a core / sheath composite cross section having a fiber diameter of 1.75 mm.

Comparative Example 1
A single-screw extruder (manufactured by Nippon Steel Works Co., Ltd., screw diameter: 40 mm, L / D22) is used, and the nozzle is a single type nozzle pack for spinning having a nozzle diameter of 4 mmφ and one hole. Was. Hybler 7311 alone was melted at 230 ° C., and the spin block temperature was set to 230 ° C. It was extruded from a spinneret at a discharge rate of 2.2 kg / hour. Subsequently, one extruded monofilament is immersed in 50 ° C. of cooling hot water 20 cm below the spinneret, taken off while adjusting discharge at a cooling time of 1 minute, and a take-up speed of 10 m / min. One component monofilament was obtained.

Comparative Examples 2 to 9
A single component monofilament having a fiber diameter of 1.75 mm was obtained in the same manner as in Comparative Example 1, except that the resin composition and the production conditions were changed as shown in Tables 1 to 3.

  Tables 1 to 3 show the resin compositions, production conditions, and evaluation results of the monofilaments of Examples 1 to 27 and Comparative Examples 1 to 11.

All of the filaments of Examples 1 to 27 were able to be satisfactorily produced, had a uniform fiber diameter, and were excellent in bending resistance. In addition, since the surface had no tackiness, it could be supplied to a 3D printer without resistance, and the moldability was good. Further, the obtained molded article had a low flexural modulus and excellent flexibility, a high tensile strength and a Charpy impact strength, excellent mechanical properties and impact resistance, small warpage and excellent dimensional stability.
By comparing the filaments of Examples 1 to 5, it can be seen that increasing the mass ratio of the sheath component to the total of the core component and the sheath component improves the 3D print formability.
By comparing the filaments of Examples 10 to 12, it can be seen that the higher the mass ratio of the polyamide resin as the sheath component, the better the 3D print formability.

As for the filaments of Comparative Examples 1, 3 to 6, and 10, any of the filaments could be produced, but the filaments wound on the bobbin adhered to each other, the unwinding resistance of the yarn became strong, and it was difficult to pull out the 3D. Could not supply to printer.
In Comparative Examples 2 and 9, the bending elastic modulus of the obtained shaped article was too high.
The filaments of Comparative Examples 7 and 8 were both capable of spinning, but were too flexible to be supplied to a 3D printer.
Since the filament of Comparative Example 11 had a core component containing a component having a glass transition temperature of more than 20 ° C., it was possible to form a yarn, but the bending resistance was low, and the obtained shaped article had Charpy impact strength and flexural modulus. Was low.

1 Overhang part 2 Tip part 3 Tip part 4 Tip part 5 Place to put weight

Claims (6)

In the core component, a crystalline thermoplastic resin having a melting point of 140 ° C. or less and a glass transition temperature of 20 ° C. or less, or an amorphous thermoplastic resin having a glass transition temperature of 20 ° C. or less is disposed. A core / sheath composite cross-section, heat-melt lamination three-dimensional shaping filament comprising a crystalline thermoplastic resin having a melting point exceeding 140 ° C. 2. The filament for three-dimensional molding according to claim 1, wherein the thermoplastic resin disposed in the sheath component is an amide resin. 3. The filament for hot-melt lamination three-dimensional shaping according to claim 1, wherein the thermoplastic resin disposed in the sheath component is an ester resin. 2. The filament for three-dimensional molding according to claim 1, wherein the thermoplastic resin disposed in the sheath component is an olefin resin. The filament for hot-melt lamination three-dimensional shaping according to any one of claims 1 to 4, wherein a mass ratio of the core component and the sheath component (core component / sheath component) is 95/5 to 20/80. A shaped body obtained by shaping the filament for three-dimensional shaping according to any one of claims 1 to 5.

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