3D printer modeling material and modeled object

Abstract

Provided is a 3D printer modeling material to be used in fused-deposition-layering 3D printer modeling, the 3D printer modeling material containing a matrix polymer and hollow particles, the apparent density at 20°C being 0.9 g / cm3 or lower, and the Shore A hardness at a timing 15 seconds after needle pressing is started being 61-98 when the Shore A hardness is measured in conformance with JIS K 6253-3:2012.

Description

3D printer modeling materials and models

[0001] The present invention relates to a material for 3D printer modeling and a modeled object.

[0002] In recent years, 3D printer modeling technology (three-dimensional modeling technology) has been attracting attention as a method for manufacturing resin molded bodies. 3D printer modeling technology offers a high degree of design freedom, can produce a variety of objects with complex three-dimensional shapes, and can also reduce design time and costs, so it is being applied to an extremely wide range of applications.

[0003] Constituent components of flying objects such as drones often have complex three-dimensional shapes and are sometimes manufactured using 3D printer modeling technology. Lightweight components are required for flying object components to improve the flying object's operating time, while excellent flexibility is also required to absorb shock and resist breakage during drops or collisions. Therefore, there is a demand for 3D printer modeling materials that can achieve the above properties.

[0004] For example, Patent Document 1 describes a filament used as a raw material for printed objects printed by a three-dimensional printing device using fused deposition modeling (FDM), which is characterized by containing polylactic acid resin and a thermoplastic elastomer.

[0005] JP 2017-136739 A

[0006] When using 3D printer modeling technology to manufacture components for flying objects such as drones, it is necessary to be able to manufacture lightweight, flexible, and highly sculptible objects. However, the inventors' investigations have revealed that the filament described in Patent Document 1 results in a high apparent density of the resulting shaped object, and that it is difficult to manufacture a flexible, shaped object with high sculptibility.

[0007] Therefore, an object of the present invention is to provide a material for 3D printer modeling that can produce lightweight and highly flexible models with high modeling properties.

[0008] The inventors conducted research to achieve the above-mentioned object and discovered that the above-mentioned object can be achieved by incorporating hollow particles into a 3D printer modeling material and further controlling the apparent density and Shore A hardness of the 3D printer modeling material within specific ranges, thereby completing the present invention.

[0009] That is, according to the present invention, the following 3D printer modeling material and modeled object are provided: [1] A 3D printer modeling material used in fused deposition modeling 3D printer modeling, comprising a matrix polymer and hollow particles, and having an apparent density of 0.9 g / cm at 20°C. ３ [2] A 3D printer modeling material according to [1], which is in a filament shape. [3] The 3D printer modeling material according to [1] or [2], which contains a thermoplastic elastomer as the matrix polymer. [4] The 3D printer modeling material according to any one of [1] to [3], which contains a thermoplastic plastomer and a thermoplastic elastomer as the matrix polymer. [5] The 3D printer modeling material according to any one of [1] to [4], which contains crosslinked hollow particles as the hollow particles. [6] The matrix polymer has a density of 0.91 to 1.3 g / cm at 20°C. ３ [7] The 3D printer modeling material according to any one of [1] to [5], wherein the apparent density of the hollow particles at 20°C is 0.2 to 0.8 g / cm ３[8] The 3D printer modeling material according to any one of [1] to [7], wherein the content of the hollow particles is 1 to 50 parts by mass relative to 100 parts by mass of the total content of the matrix polymer and the hollow particles. [9] A shaped object formed from the 3D printer modeling material according to any one of [1] to [8], wherein the Shore A hardness measured 15 seconds after the start of indentation in accordance with JIS K 6253-3:2012 is 61 to 98.

[10] The shaped object according to [9], which is a flying object component.

[0010] According to the present invention, it is possible to provide a 3D printer modeling material that can produce lightweight and highly flexible models with high modeling properties.

[0011] <3D printer modeling material> The 3D printer modeling material of the present invention is a 3D printer modeling material used in fused deposition modeling 3D printer modeling, and contains a matrix polymer and hollow particles, and has an apparent density of 0.9 g / cm at 20°C. ３ The Shore A hardness is measured in accordance with JIS K 6253-3:2012 and is 61 to 98 Shore A hardness 15 seconds after the start of the indentation.

[0012] The 3D printer modeling material of the present invention is capable of producing a lightweight, flexible object, specifically, a object having a low apparent density and a large maximum point bending strain. Furthermore, the 3D printer modeling material of the present invention is capable of producing such an object with high modeling performance. Specifically, by using the 3D printer modeling material of the present invention, the generation of eye gunk (aggregates near the outlet) during 3D printer modeling using the fused deposition modeling method is suppressed, nozzle clogging is suppressed, and a beautiful object with reduced surface roughness (roughness on the surface of the object) can be produced.

[0013] [Matrix Polymer] The 3D printer modeling material of the present invention contains a matrix polymer.

[0014] The matrix polymer is not particularly limited as long as it can be used for 3D printer modeling and can provide the material for 3D printer modeling of the present invention with a specific apparent density and Shore A hardness. Examples of the matrix polymer include thermoplastic plastomers and thermoplastic elastomers.

[0015] A plastomer generally refers to a material that exhibits little or no elastic deformation and easily undergoes plastic deformation, whereas an elastomer is the polar opposite of a plastomer, which refers to a material that deforms instantly in response to an external force and quickly recovers its original shape when the external force is removed.

[0016] In this disclosure, the term "thermoplastic plastomer" refers to a polymer that has the property of easily flowing and deforming when heated and solidifying into the deformed shape when cooled. In this disclosure, a thermoplastic plastomer can typically be stretched to 200% at room temperature (20°C) with a small external force, assuming the original dimension to be 100%, in a tensile test, and does not return to a dimension of less than 130% even after the external force is removed. A small external force specifically refers to an external force with a tensile strength of 1 to 100 MPa. More specifically, the thermoplastic plastomer can be a polymer that can be stretched without breaking in a tensile test at 20°C based on the tensile permanent set test of JIS K 6262-1997 to twice the gauge length of a dumbbell-shaped No. 4 test piece specified in JIS K 6251-1993 before tensioning, and that, after being held for 60 minutes at a position where it has been stretched to twice the gauge length before tensioning, has a tensile permanent set of 30% or more 5 minutes after the external tensile force is removed.

[0017] Elastomers generally refer to materials that have the property of instantly deforming in response to an external force when applied and quickly recovering their original shape when the external force is removed. Thermoplastic elastomers generally exhibit rubber elasticity at room temperature (25°C) and are plasticized and moldable at high temperatures.

[0018] In the present disclosure, the thermoplastic elastomer can typically be a material that can be deformed by a small external force at room temperature (20°C) to 200% of its original size, assuming that its original size is 100%, and that returns to less than 130% when the external force is removed. Specifically, a small external force refers to an external force resulting in a tensile strength of 1 to 100 MPa. More specifically, the thermoplastic elastomer can be a polymer that can be stretched to twice the gauge length of a dumbbell-shaped No. 4 test piece specified in JIS K 6251-1993 in a tensile test at 20°C without breaking, based on the tensile permanent set test of JIS K 6262-1997, and that, after being held at twice the gauge length for 60 minutes at the point where it was stretched, has a tensile permanent set of less than 30% 5 minutes after the external tensile force is removed.

[0019] Specific examples of thermoplastic plastomers include acrylonitrile-butadiene-styrene resins (ABS resins), acrylonitrile-styrene resins (AS resins), polylactic acid resins (PLA resins), polyolefin resins such as polypropylene and polyethylene, polyamide resins such as PA6, PA66, and PA12, polyimide resins such as polyimide, polyamideimide, and polyetherimide, polycarbonate resins, polystyrene resins, fluorine-based resins such as polyvinylidene fluoride and polytetrafluoroethylene, polyester resins, acrylic resins, polyvinyl chloride resins, polyether ketone ketone, poly(meth)acrylate, polyphenylene ether, polyphenylene sulfide, and silicone resins. These thermoplastic plastomers can be used alone or in combination of two or more. Among these, polylactic acid resin (PLA resin) is preferred from the viewpoints that the apparent density and Shore A hardness of the material for 3D printer modeling can be easily controlled within the preferred ranges described below, that thermal shrinkage during modeling can be reduced, that modeling properties can be further improved, and that the mechanical strength of the resulting modeled object can be increased.

[0020] Polylactic acid resin (PLA resin) is a synthetic resin produced by polymerizing lactic acid through ester bonds, and typically has a melting point of approximately 170°C and a Shore A hardness of 100. Polylactic acid resin (PLA resin) is preferably a resin with a purity of 95% or higher, which may contain 5% or less of additives. Furthermore, the polylactic acid resin (PLA resin) preferably has a D-isomer content of 1.0 mol% or less or 99.0 mol% or more, and more preferably has a D-isomer content of 0.1 to 0.6 mol% or 99.4 to 99.9 mol%. Having a D-isomer content within this range results in excellent crystallization performance, which leads to even better moldability (shortening the molding cycle) and improved heat resistance of the resulting molded object.

[0021] Specific examples of polymers constituting the thermoplastic elastomer include olefin-based elastomers and styrene-based elastomers.

[0022] The olefin-based elastomer is not particularly limited, but a propylene-based elastomer in which polyethylene-polypropylene rubber (EPDM, EPM) is finely dispersed in polypropylene is preferred.

[0023] As the styrene-based elastomer, a block copolymer having a polystyrene block as a hard segment and a conjugated diene polymer block as a soft segment is preferred. Such a block copolymer typically exhibits crosslinked rubber-like physical properties at low temperatures and melts under heat to exhibit fluidity. The conjugated diene polymer block may be at least partially hydrogenated or unhydrogenated. Examples of block copolymers having a polystyrene block and a conjugated diene polymer block include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene-ethylene / propylene-styrene block copolymer (SEPS), partially hydrogenated styrene-ethylene / butylene-styrene block copolymer (partially hydrogenated SEBS), and styrene-(ethylene-ethylene / propylene)-styrene block copolymer (SEEPS). Among these, styrene-ethylene / butylene-styrene block copolymer (SEBS) and styrene-(ethylene-ethylene / propylene)-styrene block copolymer (SEEPS) are preferred.

[0024] As the thermoplastic elastomer, a styrene-based elastomer is preferred, and a block copolymer having a polystyrene block and a conjugated diene polymer block is more preferred, from the viewpoints that the apparent density and Shore A hardness of the 3D printer modeling material can be easily controlled within the preferred ranges described below, and that a modeled object with higher modeling properties and greater flexibility can be produced.

[0025] The weight average molecular weight of the polymer constituting the thermoplastic elastomer is not particularly limited, but is preferably 100,000 or more and 200,000 or less from the viewpoint of the mechanical strength of the resulting shaped body.

[0026] In the present invention, when a thermoplastic elastomer is used as the matrix polymer, the 3D printer modeling material of the present invention preferably contains a thermoplastic elastomer containing a plasticizer. Specific examples of plasticizers that can be used include mineral oil-based plasticizers such as paraffinic oil, naphthenic oil, and higher fatty acids. For example, when a styrene-based elastomer is used as the polymer constituting the thermoplastic elastomer, a refined petroleum paraffinic hydrocarbon oil containing paraffin as the main component is preferably used as the plasticizer, in view of its good compatibility with the styrene-based elastomer. When the 3D printer modeling material of the present invention contains a thermoplastic elastomer containing a plasticizer, the mass ratio of the polymer constituting the thermoplastic elastomer to the plasticizer content, in terms of the ratio of "polymer constituting the thermoplastic elastomer / plasticizer," is preferably 25 / 75 to 30 / 70.

[0027] The melting point of the thermoplastic elastomer is preferably within the range of 100 to 170°C.

[0028] The 3D printer modeling material of the present invention preferably contains a thermoplastic elastomer as the matrix polymer, and more preferably contains both a thermoplastic plastomer and a thermoplastic elastomer.

[0029] When both a thermoplastic plastomer and a thermoplastic elastomer are contained, the ratio of the thermoplastic elastomer content (including the amount of plasticizer if the thermoplastic elastomer contains a plasticizer) to the total content of the thermoplastic plastomer and the thermoplastic elastomer in the 3D printer modeling material is not particularly limited, but is preferably 9.1 to 90.1% by mass, more preferably 20 to 85% by mass, and even more preferably 30 to 80% by mass. Having the thermoplastic elastomer content within the above range further improves modeling properties and the balance between mechanical strength and flexibility of the resulting modeled object.

[0030] Furthermore, when even greater flexibility is required, the ratio of the content of the thermoplastic elastomer to the total content of the thermoplastic plastomer and the thermoplastic elastomer is particularly preferably 50 to 80 mass %, and most preferably 65 to 80 mass %.

[0031] The density (true density) at 20°C of the matrix polymer used in the present invention is not particularly limited as long as it can provide the 3D printer modeling material of the present invention having a specific apparent density, and is preferably 0.91 to 1.3 g / cm ３ is preferably 0.92 to 1.2 g / cm ３ More preferably, it is 0.93 to 1.1 g / cm ３ It is more preferable that:

[0032] The melting point of the matrix polymer used in the present invention is preferably within the range of 100 to 170°C.

[0033] The matrix polymer used in the present invention preferably has a Shore A hardness of less than 61, more preferably 30 to 60, 15 seconds after the start of needle indentation, as measured in accordance with JIS K 6253-3:2012.

[0034] When the Shore A hardness of the matrix polymer used in the present invention is measured in accordance with JIS K 6253-3:2012, the return rate of the Shore A hardness, which is calculated by dividing the difference between the Shore A hardness immediately after the start of needle indentation and the Shore A hardness 15 seconds after the start of needle indentation, by 15 seconds, is preferably 0.01 to 0.4, and more preferably 0.1 to 0.3.

[0035] [Hollow Particles] The 3D printer modeling material of the present invention contains hollow particles in addition to the matrix polymer described above.

[0036] The hollow particles used in the present invention are particles having a shell (outer shell) and a hollow portion surrounded by the shell. Here, the hollow portion is a hollow space that is clearly distinguishable from the shell of the hollow particle. The hollow portion may be filled with a gas such as air, or may contain a solvent. The hollow particles used in the present invention may have one or more hollow portions, but preferably have only one hollow portion in order to maintain a good balance between high porosity and mechanical strength.

[0037] The hollow particles used in the present invention usually have a shell that is free of interconnected pores and shell defects, and the hollow portion is isolated from the outside of the particle by the shell. However, the shell may have one or more interconnected pores, and the hollow portion may be connected to the outside of the particle via the interconnected pores. Furthermore, the shell of the hollow particles, and when the hollow particles have two or more hollow portions, the partition walls separating adjacent hollow portions may be porous. In such cases, the hollow portions have a size that allows them to be clearly distinguished from the numerous minute spaces uniformly dispersed within the porous structure. Furthermore, the hollow particles used in the present invention may be subjected to known surface treatments such as boron treatment, surface coupling treatment, fluorine coating, and diamond coating.

[0038] The external shape of the hollow particles is not particularly limited, but a spherical shape is preferred from the viewpoint of further improving the formability and further improving the balance between the mechanical strength and flexibility of the resulting shaped body. The external shape of the hollow particles can be confirmed, for example, by observing the particles with a SEM or a TEM. The internal shape of the hollow particles can be confirmed, for example, by observing the cross section of the particles with a SEM or a TEM.

[0039] The hollow particles may be inorganic hollow particles, organic hollow particles, organic-inorganic composite hollow particles, etc. Among them, organic hollow particles are preferably used from the viewpoint that when using a fused deposition modeling 3D printer using a 3D printer material, the adhesiveness between a strand discharged first and a strand discharged on top of it can be improved, further improving the modeling properties, and further improving the balance between the mechanical strength and flexibility of the resulting modeled object.

[0040] Examples of inorganic hollow particles include ceramic hollow particles containing Si-based oxide components (e.g., silica) or Al-based oxide components (e.g., alumina), such as glass balloons, glass bubbles, fly ash balloons, shirasu balloons, silica balloons, and aluminosilicate balloons. Glass balloons and glass bubbles can be produced by blowing air onto a molten material while allowing it to flow down. Fly ash balloons and shirasu balloons can be produced using gas generated when minerals are heated and melted. Ceramic hollow particles can be produced by forming ceramic on the outside of a mold, such as oil droplets of an O / W emulsion or polystyrene beads, using a sol-gel method, and then removing the mold.

[0041] Examples of organic hollow particles include thermoplastic plastomer particles and thermosetting resin particles. Thermoplastic plastomers that can be used as hollow particles include organic hollow particles having a shell made of a homopolymer of a monomer such as a monomer having a styrene skeleton (styrene, parachlorostyrene, α-methylstyrene, etc.), a monomer having a (meth)acryloyl group (acrylic acid, methacrylic acid, (meth)acrylic acid esters (methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, acrylic acid nitrile, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), vinyl acetate, vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), or an olefin (e.g., ethylene, propylene, butadiene, etc.), or a copolymer of two or more of these monomers.

[0042] Further, examples of organic hollow particles include organic hollow particles having a shell made of a non-vinyl resin (epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, modified rosin, etc.), a mixture of these with the vinyl resins, or a graft polymer obtained by polymerizing a vinyl monomer in the presence of these.

[0043] Other examples of organic hollow particles include crosslinked hollow particles made from resins containing crosslinkable monomer units. The hollow shape derived from the hollow particles is well maintained during the production of 3D printer modeling materials or during 3D printer modeling using the 3D printer modeling materials, the effects of adding hollow particles can be more effectively obtained, and a modeled object with excellent mechanical strength can be obtained. Therefore, crosslinked hollow particles are preferably used as the hollow particles. Suitable crosslinked hollow particles are described below.

[0044] The outer shell of the crosslinked hollow particles is composed of a resin consisting of a shell polymer containing a crosslinkable monomer unit. The shell polymer is a polymer used to form the shell of the hollow particles and contains a crosslinkable monomer unit. The crosslinkable monomer that forms the crosslinkable monomer unit is a monomer that has two or more polymerizable functional groups and forms a crosslinked bond in the resin by polymerization reaction. As the crosslinkable monomer, a compound having at least one ethylenically unsaturated bond as the polymerizable functional group is generally used.

[0045] The crosslinkable monomers that form the crosslinkable monomer units include crosslinkable hydrocarbon monomers and heteroatom-containing crosslinkable monomers.

[0046] The crosslinkable hydrocarbon monomer is not particularly limited, but examples thereof include bifunctional crosslinkable hydrocarbon monomers such as divinylbenzene, divinyldiphenyl, divinylnaphthalene, dicyclopentadiene, and ethylidenetetracyclododecene, with divinylbenzene being preferred. In addition, crosslinkable hydrocarbon monomers composed of polymers can also be used. Examples include polybutadiene, polyisoprene, styrene-butadiene block copolymers (SBS), and styrene-isoprene block copolymers (SIS).

[0047] The heteroatom-containing crosslinkable monomer is not particularly limited, and examples thereof include bifunctional heteroatom-containing crosslinkable monomers such as diallyl phthalate, allyl (meth)acrylate (meaning allyl acrylate and / or allyl methacrylate; the same applies hereinafter), ethylene glycol di(meth)acrylate, and pentaerythritol di(meth)acrylate; and trifunctional or higher functional heteroatom-containing crosslinkable monomers such as trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and dipentaerythritol poly(meth)acrylate.

[0048] Other examples of the heteroatom-containing crosslinkable monomer that can be used include polyisocyanate compounds such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate (IPDI), hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, m-phenylene diisocyanate, biphenylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, and dimers or trimers thereof. Furthermore, polyfunctional urethane (meth)acrylate compounds obtained by reacting a polyisocyanate compound with a hydroxyl group-containing (meth)acrylate having a hydroxyl group and a (meth)acryloyl group can also be used. Specific examples of hydroxyl group-containing (meth)acrylates include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane di(meth)acrylate, and dipentaerythritol penta(meth)acrylate; isocyanuric acid di(meth)acrylic acid esters, and ethylene oxide and caprolactone modified versions of these.

[0049] Of these, the heteroatom-containing crosslinkable monomer is preferably ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, or pentaerythritol tri(meth)acrylate, more preferably ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, or pentaerythritol tetra(meth)acrylate, and even more preferably ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, or pentaerythritol tetramethacrylate.

[0050] As the crosslinkable monomer, a crosslinkable hydrocarbon monomer, ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, and pentaerythritol tri(meth)acrylate are preferred, divinylbenzene, ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate are more preferred, and divinylbenzene, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and pentaerythritol tetramethacrylate are even more preferred.

[0051] The crosslinkable monomers can be used alone or in combination of two or more. In the crosslinked hollow particles, the shell polymer preferably contains a bifunctional crosslinkable monomer unit and a trifunctional or higher functional crosslinkable monomer, more preferably a bifunctional crosslinkable monomer unit and a trifunctional or higher functional heteroatom-containing crosslinkable monomer unit, and even more preferably a bifunctional heteroatom-containing crosslinkable monomer unit and a trifunctional or higher functional heteroatom-containing crosslinkable monomer unit. The trifunctional or higher functional crosslinkable monomer is not particularly limited, but is preferably a trifunctional to hexafunctional crosslinkable monomer, more preferably a trifunctional to pentafunctional crosslinkable monomer, and even more preferably a trifunctional to tetrafunctional crosslinkable monomer. Furthermore, in the crosslinked hollow particles, the shell polymer can also contain a crosslinkable hydrocarbon monomer unit and a heteroatom-containing crosslinkable monomer unit.

[0052] The shell polymer may consist essentially of crosslinkable monomer units alone, or may contain monofunctional monomer units in addition to crosslinkable monomer units.

[0053] The monofunctional monomer forming the monofunctional monomer unit is a monomer having only one polymerizable functional group, and a compound having an ethylenically unsaturated bond as the polymerizable functional group is generally used. Examples of the monofunctional monomer forming the monofunctional monomer unit include monofunctional hydrocarbon monomers and heteroatom-containing monofunctional monomers.

[0054] The monofunctional hydrocarbon monomer is not particularly limited, but examples thereof include aromatic vinyl monomers such as styrene, ethylvinylbenzene, vinyltoluene, α-methylstyrene, p-methylstyrene, and halogenated styrene; monoolefin monomers such as ethylene, propylene, butylene, and 4-methyl-1-pentene; and diene monomers such as butadiene and isoprene. Of these, styrene and ethylvinylbenzene are preferred.

[0055] The heteroatom-containing monofunctional monomer is not particularly limited, but examples thereof include hydrophilic monofunctional monomers; acrylic monovinyl monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and glycidyl (meth)acrylate; carboxylic acid vinyl ester monomers such as vinyl acetate; halogenated vinyl monomers such as vinyl chloride; halogenated vinylidene monomers such as vinylidene chloride; vinylpyridine monomers; urethane (meth)acrylate, and allyl glycidyl ether.

[0056] The hydrophilic monofunctional monomer preferably has a solubility in water of 1% by mass or more. The hydrophilic monofunctional monomer is not particularly limited, but examples thereof include monofunctional monomers having a hydrophilic group, such as acid group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, and polyoxyethylene group-containing monomers.

[0057] The term "acid group-containing monomer" refers to a monomer containing an acid group. The acid group referred to here includes both a proton-donating group (Brønsted acid group) and an electron pair-accepting group (Lewis acid group). The acid group-containing monomer is not particularly limited as long as it has an acid group, and examples thereof include carboxyl group-containing monomers and sulfonic acid group-containing monomers. Examples of carboxyl group-containing monomers include ethylenically unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid, fumaric acid, maleic acid, and butenetricarboxylic acid; and monoalkyl esters of unsaturated dicarboxylic acids such as monoethyl itaconate, monobutyl fumarate, and monobutyl maleate. Examples of sulfonic acid group-containing monomers include styrenesulfonic acid.

[0058] Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

[0059] Examples of the amide group-containing monomer include acrylamide and dimethylacrylamide.

[0060] Examples of polyoxyethylene group-containing monomers include methoxypolyethylene glycol (meth)acrylate.

[0061] The monofunctional monomer units may be used either alone or in combination of two or more.

[0062] The content of the crosslinkable monomer units in the shell polymer is not particularly limited, but is preferably 20 to 100% by mass, more preferably 40 to 100% by mass, even more preferably 60 to 100% by mass, and particularly preferably 80 to 100% by mass. By having the crosslinkable monomer content within the above range, a dense covalent bond network is formed throughout the shell, suppressing the formation of interconnected pores and shell defects. As a result, the effects of adding hollow particles to the 3D printer modeling material of the present invention can be more effectively obtained, and the mechanical strength of the resulting model can also be increased.

[0063] The content of the monofunctional monomer unit in the shell polymer is not particularly limited, but from the viewpoint of more effectively obtaining the effect of adding the hollow particles, it is preferably 0 to 80% by mass, more preferably 0 to 60% by mass, even more preferably 0 to 40% by mass, and particularly preferably 0 to 20% by mass.

[0064] The shell polymer may contain a heteroatom-containing monomer unit. Examples of the heteroatom-containing monomer that forms the heteroatom-containing monomer unit include the heteroatom-containing crosslinkable monomer and the heteroatom-containing monofunctional monomer described above. The content of the heteroatom-containing monomer unit in the shell polymer is not particularly limited, but is preferably 1 to 99% by mass, more preferably 10 to 95% by mass, and even more preferably 30 to 90% by mass.

[0065] The shell polymer is not limited to the above-mentioned ones, as long as it has a three-dimensional crosslinked structure and can form the shell of the crosslinked hollow particles. The shell polymer may be, for example, a phenolic resin, a melamine resin, a urea resin, an unsaturated polyester resin, an epoxy resin, a polyurethane resin, a silicon resin, an alkyd resin, a thermosetting modified polyphenylene ether resin, a thermosetting polyimide resin, a benzoxazine resin, a urea resin, an allyl resin, an aniline resin, a maleimide resin, a bismaleimide triazine resin, a liquid crystalline polyester resin, a vinyl ester resin, an unsaturated polyester resin, a cyanate ester resin, or a polyetherimide resin.

[0066] The crosslinked hollow particles can be preferably produced by a production method including the following steps: (A) a mixed solution preparation step, (B) a suspension step, (C) a polymerization step, and (D) a solvent removal step.

[0067] That is, the crosslinked hollow particles can be preferably produced by a production method including: (A) a mixed solution preparation step of preparing a mixed solution containing polymerizable monomers including a crosslinkable monomer, a hydrophobic organic solvent, a polymerization initiator, and an aqueous medium; (B) a suspending step of suspending the mixed solution obtained in the mixed solution preparation step to prepare a suspension in which droplets of a polymerizable monomer composition containing the polymerizable monomer, the hydrophobic organic solvent, and the polymerization initiator are dispersed in the aqueous medium; (C) a polymerization step of subjecting the suspension obtained in the suspending step to a polymerization reaction to prepare a precursor composition containing precursor particles having hollow portions and encapsulating the hydrophobic organic solvent in the hollow portions; and (D) a solvent removal step of removing the hydrophobic organic solvent encapsulated in the precursor particles obtained in the polymerization step.

[0068] (A) Mixed Liquid Preparation Step The mixed liquid preparation step is a step of preparing a mixed liquid containing polymerizable monomers including a crosslinkable monomer, a hydrophobic organic solvent, a polymerization initiator, and an aqueous medium. The crosslinked hollow particles are preferably produced by a production method including such a step.

[0069] (Polymerizable Monomer) As the polymerizable monomer, the above-mentioned crosslinkable monomer and, if necessary, the above-mentioned monofunctional monomer are used. The monomer composition of the polymerizable monomer may be any monomer composition that can obtain the monomer composition of the target shell polymer. The content of the polymerizable monomer (total amount of crosslinkable monomer and monofunctional monomer) in the mixed liquid prepared in the mixed liquid preparation step is not particularly limited, but from the viewpoint of the balance between particle size and mechanical strength, it is preferably 15 to 55% by mass, more preferably 25 to 50% by mass, relative to 100% by mass of the total mass of the components in the mixed liquid excluding the aqueous medium.

[0070] (Hydrophobic Organic Solvent) The hydrophobic organic solvent is a non-polymerizable, poorly water-soluble organic solvent. The hydrophobic organic solvent acts as a spacer material that forms hollow spaces inside the particles. The hydrophobic organic solvent is not particularly limited, but hydrocarbon solvents can be suitably used. Specific examples include saturated hydrocarbon solvents such as butane, pentane, normal hexane, cyclohexane, heptane, and octane; aromatic hydrocarbon solvents such as benzene, toluene, and xylene; and relatively volatile solvents such as carbon disulfide and carbon tetrachloride. The content of the hydrophobic organic solvent in the mixed solution is preferably 50 to 500 parts by mass, more preferably 60 to 400 parts by mass, even more preferably 80 to 350 parts by mass, and particularly preferably 100 to 320 parts by mass, per 100 parts by mass of the total mass of the polymerizable monomers.

[0071] (Polymerization Initiator) It is preferable to use an oil-soluble polymerization initiator as the polymerization initiator. By using an oil-soluble polymerization initiator as the polymerization initiator, the polymerization initiator can be suitably incorporated into the droplets of the polymerizable monomer composition in the suspension obtained in the suspension step described below. The oil-soluble polymerization initiator is not particularly limited as long as it is lipophilic and has a solubility in water of 0.2% by mass or less. Examples of oil-soluble polymerization initiators include benzoyl peroxide, lauroyl peroxide, t-butyl peroxide-2-ethylhexanoate, t-butyl peroxydiethyl acetate, t-butyl peroxypivalate, 2,2'-azobis(2,4-dimethylvaleronitrile), and azobisisobutyronitrile. The content of the polymerization initiator is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 12 parts by mass, and even more preferably 1 to 10 parts by mass, per 100 parts by mass of the total mass of the polymerizable monomers in the mixed solution. By setting the content of the polymerization initiator within the above range, the polymerization reaction can be sufficiently progressed, and there is little risk of the polymerization initiator remaining after completion of the polymerization reaction, and there is also little risk of an unexpected side reaction proceeding.

[0072] (Aqueous Medium) Examples of aqueous media include media selected from the group consisting of water, hydrophilic solvents, and mixtures of water and hydrophilic solvents. The hydrophilic solvent is not particularly limited as long as it is sufficiently miscible with water and does not cause phase separation. Examples include alcohols such as methanol and ethanol; tetrahydrofuran (THF); dimethyl sulfoxide (DMSO); and the like. Among aqueous media, water is preferred due to its high polarity. When using a mixture of water and a hydrophilic solvent, it is preferable that the polarity of the entire mixture is not too low in order to properly form droplets of a polymerizable monomer composition containing a polymerizable monomer, a hydrophobic organic solvent, and a polymerization initiator. When using a mixture of water and a hydrophilic solvent, it is preferable that the mixing ratio (mass ratio) of water to hydrophilic solvent is 99:1 to 50:50.

[0073] In addition, in the mixed solution preparation step, it is preferable to use a dispersion stabilizer in addition to the polymerizable monomer, the hydrophobic organic solvent, the polymerization initiator, and the aqueous medium. That is, the mixed solution preparation step is preferably a step of preparing a mixed solution containing the polymerizable monomer, the hydrophobic organic solvent, the polymerization initiator, the aqueous medium, and the dispersion stabilizer.

[0074] The dispersion stabilizer is a compound that disperses droplets of the polymerizable monomer composition in an aqueous medium in the suspension step described below, and may be either an inorganic dispersion stabilizer or an organic dispersion stabilizer.

[0075] Examples of inorganic dispersion stabilizers include colloidal silica, magnesium hydroxide, calcium phosphate, calcium carbonate, barium sulfate, calcium oxalate, calcium carbonate, magnesium carbonate, barium carbonate, tricalcium phosphate, aluminum hydroxide, magnesium hydroxide, ferric hydroxide, hydroxyapatite, diatomaceous earth, clay, and bentonite.

[0076] Examples of organic dispersion stabilizers include methyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, and starch.

[0077] Among these, inorganic dispersion stabilizers are preferred from the viewpoint of having a high dispersion stabilizing effect and making it easier to control the particle size of droplets of a polymerizable monomer composition containing a polymerizable monomer, a hydrophobic organic solvent, and a polymerization initiator. Among inorganic dispersion stabilizers, metal-containing dispersion stabilizers are preferred, and poorly water-soluble inorganic metal salts are more preferred. Furthermore, poorly water-soluble inorganic metal salts are preferably inorganic metal salts having a solubility of 0.5 g or less in 100 g of water, such as magnesium hydroxide, calcium hydroxide, barium hydroxide, calcium phosphate, etc., and among these, magnesium hydroxide is more preferred. Each dispersion stabilizer can be used alone or in combination of two or more.

[0078] In addition, from the viewpoint of further enhancing the dispersion stabilizing effect, it is preferable to use the dispersion stabilizer in the form of a dispersion or solution by dispersing or dissolving it in an aqueous medium. That is, in the mixed liquid preparation step, it is preferable to obtain the mixed liquid by mixing the dispersion stabilizer in the form of a dispersion or solution with the polymerizable monomer, the hydrophobic organic solvent, and the polymerization initiator. Note that the above-mentioned aqueous medium can be used.

[0079] In the dispersion or solution of the dispersion stabilizer, the mixing ratio of the dispersion stabilizer to the aqueous medium, in terms of the mass ratio of "dispersion stabilizer:aqueous medium", is preferably 0.7:100 to 7:100, more preferably 1.0:100 to 4.0:100, and even more preferably 1.4:100 to 3:100. By setting the mixing ratio of the dispersion stabilizer to the aqueous medium within the above range, the dispersion stabilization effect can be more appropriately enhanced.

[0080] In the mixed solution preparation step, the above-mentioned components are mixed by stirring or the like to obtain a mixed solution. In this case, in addition to the above-mentioned components, other materials may be mixed as needed. In the mixed solution preparation step, a mixed solution is prepared in which an oil phase containing a polymerizable monomer, a hydrophobic organic solvent, and a lipophilic material such as a polymerization initiator is dispersed in an aqueous medium and an aqueous phase containing a dispersion stabilizer used as needed, with particles having a particle size of about several mm. The dispersion state of these components in the mixed solution can be observed with the naked eye, depending on the type of each component.

[0081] In addition, in the mixed solution preparation step, from the viewpoint that the composition of the shell portion is likely to be uniform, it is preferable to prepare the mixed solution in advance by preparing an oil phase containing a polymerizable monomer, a hydrophobic organic solvent, and a polymerization initiator, and mixing this with a dispersion or solution obtained by dispersing or dissolving a dispersion stabilizer in an aqueous medium.

[0082] (B) Suspension Step The suspension step is a step of preparing a suspension in which droplets of a polymerizable monomer composition containing a polymerizable monomer, a hydrophobic organic solvent, and a polymerization initiator are dispersed in an aqueous medium by suspending the mixed liquid obtained in the mixed liquid preparation step described above.

[0083] The method of suspending the polymerizable monomer composition to form droplets is not particularly limited, but a method of stirring the mixture obtained in the mixture preparation step described above using a stirring device capable of strong stirring is preferred.

[0084] In the suspending step, a suspension can be obtained in which droplets of the polymerizable monomer composition containing the lipophilic material are uniformly dispersed in an aqueous medium. Such droplets of the polymerizable monomer composition are difficult to observe with the naked eye and can be observed using known observation equipment such as an optical microscope. Furthermore, in the suspending step, phase separation occurs in the droplets of the polymerizable monomer composition, which makes it easy for the low-polarity hydrophobic organic solvent to collect inside the droplets. As a result, the resulting droplets contain the hydrophobic organic solvent in their interiors and materials other than the hydrophobic organic solvent distributed around their peripheries.

[0085] (C) Polymerization Step The polymerization step is a step of subjecting the suspension prepared in the suspension step described above to a polymerization reaction to prepare a precursor composition having hollow portions and encapsulating a hydrophobic organic solvent in the hollow portions.

[0086] In the polymerization process, the polymerizable monomer in the droplets of the polymerizable monomer composition is polymerized while the droplets still contain the hydrophobic organic solvent, thereby forming precursor particles having a shell containing a resin, which is a polymer of the polymerizable monomer, and a hollow portion filled with the hydrophobic organic solvent.

[0087] In the polymerization step, droplets of the polymerizable monomer composition are subjected to the polymerization reaction while encapsulating the hydrophobic organic solvent, which facilitates the polymerization reaction while maintaining the shape, and facilitates the adjustment of the size and porosity of the precursor particles. Furthermore, since the polymerizable monomer and the hydrophobic organic solvent are used in combination, the polarity of the hydrophobic organic solvent is low relative to the shell of the precursor particles, and the hydrophobic organic solvent is not easily compatible with the shell, which leads to sufficient phase separation and the formation of only one hollow portion.

[0088] The polymerization method is not particularly limited, and for example, a batch method, a semi-continuous method, a continuous method, etc. can be used. The polymerization temperature is preferably 40 to 90°C, more preferably 50 to 80°C. The polymerization reaction time is preferably 1 to 48 hours, more preferably 3 to 24 hours.

[0089] The polymerization step yields a precursor composition in which precursor particles encapsulating a hydrophobic solvent are dispersed in an aqueous phase containing an aqueous medium as the main component.

[0090] (D) Solvent Removal Step The solvent removal step is a step of removing the hydrophobic organic solvent contained in the precursor particles obtained by the polymerization step.

[0091] Before the solvent is removed in the solvent removal step, it is preferable to perform solid-liquid separation on the precursor composition obtained in the polymerization step in advance, and obtain a solid content containing precursor particles encapsulating the hydrophobic organic solvent by the solid-liquid separation. After obtaining a solid content containing the precursor particles by the solid-liquid separation, the hydrophobic organic solvent encapsulated in the precursor particles is removed in air, whereby the hydrophobic organic solvent inside the precursor particles is replaced with air, and crosslinked hollow particles filled with gas can be obtained.

[0092] The method for performing solid-liquid separation of the precursor composition is not particularly limited, and known methods can be used. Examples of solid-liquid separation methods include centrifugation, filtration, and static separation. Among these, centrifugation or filtration can be used, and centrifugation may be used from the viewpoint of ease of operation. After solid-liquid separation, an optional step such as a pre-drying step may be further employed. Examples of the pre-drying step include a step of pre-drying the solid content obtained after the solid-liquid separation step using a drying device such as a dryer or a drying appliance such as a hand dryer.

[0093] Furthermore, in the solvent removal step, "in the air" strictly refers to an environment in which no liquid is present outside the precursor particles, or an environment in which only a trace amount of liquid is present outside the precursor particles, so as not to affect the removal of the hydrophobic organic solvent. "In the air" can also be referred to as a state in which the precursor particles are not present in a slurry, or a state in which the precursor particles are present in a dry powder. That is, in the solvent removal step, it is desirable to remove the hydrophobic organic solvent in an environment in which the precursor particles are in direct contact with the external gas.

[0094] The method for removing the hydrophobic organic solvent from the precursor particles in air is not particularly limited, and known methods can be used, such as vacuum drying, heat drying, and flash drying, which may be used in combination. In particular, when heat drying is used, the heating temperature must be equal to or higher than the boiling point of the hydrophobic organic solvent and equal to or lower than the maximum temperature at which the shell structure of the precursor particles does not collapse. Therefore, depending on the shell composition and the type of hydrophobic organic solvent in the precursor particles, the heating temperature is preferably 50 to 200°C, more preferably 70 to 200°C, and even more preferably 100 to 200°C. The drying operation in air replaces the hydrophobic organic solvent inside the precursor particles with the external gas, resulting in crosslinked hollow particles whose hollow portions are filled with gas.

[0095] The drying atmosphere is not particularly limited and can be appropriately selected depending on the application of the crosslinked hollow particles. Examples of the drying atmosphere include air, oxygen, nitrogen, argon, etc. Alternatively, crosslinked hollow particles with a temporary vacuum inside can be obtained by filling the inside of the crosslinked hollow particles with a gas and then drying under reduced pressure.

[0096] Alternatively, the hydrophobic organic solvent may be removed by replacing the hydrophobic organic solvent contained in the precursor particles with the aqueous medium of the slurry containing the precursor particles in the slurry without subjecting the slurry-like precursor composition obtained in the polymerization step to solid-liquid separation.

[0097] Other methods for removing the hydrophobic organic solvent contained in the precursor particles may include, for example, a method of removing the hydrophobic organic solvent in the precursor particles in a liquid by bubbling; a method of evaporating and distilling off the hydrophobic organic solvent contained in the precursor particles from the precursor composition in air under a predetermined pressure (high pressure, normal pressure, or reduced pressure); or a method of introducing an inert gas such as nitrogen, argon, or helium, or water vapor, into the precursor composition under a predetermined pressure (high pressure, normal pressure, or reduced pressure), and evaporating and distilling off the hydrophobic organic solvent.

[0098] (E) Other Steps The above manufacturing method may also include other steps, such as (E-1) a cleaning step and (E-2) a hollow portion re-replacement step.

[0099] (E-1) Washing Step The above-described production method preferably includes a washing step before or after the recovery step. For example, when a dispersion stabilizer is used, it is preferable to include a washing step of adding an acid or alkali to wash the crosslinked hollow particle slurry containing the crosslinked hollow particles and the aqueous medium before the recovery step in order to remove any dispersion stabilizer remaining in the crosslinked hollow particle slurry. When the dispersion stabilizer used is an acid-soluble dispersion stabilizer, it is preferable to add an acid to the precursor composition containing the precursor particles to perform washing. On the other hand, when the dispersion stabilizer used is an alkali-soluble dispersion stabilizer, it is preferable to add an alkali to the precursor composition containing the precursor particles to perform washing.

[0100] Furthermore, when an acid-soluble dispersion stabilizer is used as the dispersion stabilizer, it is preferable to add an acid to the precursor composition containing the precursor particles to adjust the pH to preferably 6.5 or less, more preferably 6 or less. The acid to be added may be an inorganic acid such as sulfuric acid, hydrochloric acid, or nitric acid, or an organic acid such as formic acid or acetic acid, but sulfuric acid is particularly preferable because it has a high efficiency in removing the dispersion stabilizer and places a small burden on the production equipment.

[0101] (E-2) Hollow Portion Re-Substitution Process The hollow portion re-substitution process is a process of substituting the gas or liquid inside the crosslinked hollow particles with another gas or liquid. Such substitution can change the environment inside the crosslinked hollow particles, selectively confine molecules inside the crosslinked hollow particles, or modify the chemical structure inside the crosslinked hollow particles depending on the application.

[0102] As organic-inorganic composite hollow particle, can be enumerated the hollow particle that has shell that combines above-mentioned inorganic material and organic material.The manufacturing method of organic-inorganic composite hollow particle is not particularly limited, but can be enumerated as follows: emulsion polymerization, dropwise emulsion polymerization, soap-free polymerization, microemulsion polymerization, miniemulsion polymerization, microsuspension polymerization, using polymerizable silane coupling agent that has vinyl group, acrylic group, methacrylic group, styryl group etc. in its structure and non-polymerizable organic solvent; interfacial polymerization that uses silane coupling agent that has epoxy group, isocyanate group, ureido group, amino group, mercapto group, halogen group in its structure; the method that uses silane coupling agent to cover silica on the surface of organic hollow particle that is prepared in advance, and other suitable polymerization methods.

[0103] The volume average particle size (Dv) of the hollow particles is not particularly limited, but is preferably 1 to 50 μm, more preferably 5 to 45 μm, and even more preferably 2 to 40 μm.

[0104] The particle size distribution (Dv / Dn) (volume average particle size (Dv) / number average particle size (Dn)) of the hollow particles is not particularly limited, but is preferably 1.02 to 2.00, more preferably 1.04 to 1.60.

[0105] The true density of the hollow particles is not particularly limited, but is preferably 0.95 to 1.4 g / cm ３ is preferably 1.0 to 1.3 g / cm ３ It is more preferable that the true density of the hollow particles means the density of only the shell portion of the hollow particles.

[0106] The apparent density of the hollow particles at 20°C is not particularly limited, but is preferably 0.15 to 0.9 g / cm ３ is preferably 0.2 to 0.8 g / cm ３ More preferably, it is 0.25 to 0.7 g / cm ３ More preferably, it is 0.25 to 0.6 g / cm ３ It is particularly preferable that the density is 0.25 to 0.5 g / cm ３When the apparent density of the hollow particles is within the above range, the effect of adding the hollow particles to the 3D printer modeling material of the present invention can be more effectively obtained.

[0107] The apparent density of the hollow particles means the density of the entire hollow particles, including the shell and hollow portions of the hollow particles. For example, when the hollow particles are crosslinked hollow particles, the apparent density can be adjusted by adjusting the monomer composition of the shell polymer, the types and amounts of the dispersion stabilizer and hydrophobic organic solvent used in producing the hollow particles by suspension polymerization, the suspension conditions, etc.

[0108] Apparent density D of hollow particles １ The measurement method is as follows: First, a volume of 100 cm ３ About 30 cm ３ The volumetric flask is filled with hollow particles, and the mass of the filled hollow particles is accurately weighed. Next, the volumetric flask filled with the hollow particles is accurately filled with isopropanol up to the marked line, taking care not to introduce air bubbles. The mass of isopropanol added to the volumetric flask is accurately weighed, and the apparent density D of the hollow particles is calculated based on the following formula (II): １ (g / cm ３ ) is calculated. １ (g / cm ３ ) = [Mass of hollow particles] ÷ (100 - [Mass of isopropanol] ÷ [Density of isopropanol at measurement temperature]) (II)

[0109] The content of the hollow particles is not particularly limited, but is preferably 1 to 50 parts by mass, more preferably 2 to 40 parts by mass, even more preferably 3 to 30 parts by mass, and particularly preferably 5 to 25 parts by mass, relative to 100 parts by mass of the total content of the matrix polymer and the hollow particles. Furthermore, from the viewpoint of obtaining a lighter shaped body, the content of the hollow particles may be 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more, relative to 100 parts by mass of the total content of the matrix polymer and the hollow particles. On the other hand, from the viewpoint of producing a shaped body having superior flexibility and mechanical strength with higher formability, the content of the hollow particles may be 20 parts by mass or less, 15 parts by mass or less, or 12 parts by mass or less, relative to 100 parts by mass of the total content of the matrix polymer and the hollow particles.

[0110] [Other Compounding Materials] The 3D printer modeling material of the present invention may contain other compounding materials in addition to the matrix polymer and hollow particles, as long as the object of the present invention is not impaired.

[0111] Other compounding materials may include fillers including organic fillers and inorganic fillers, colorants including dyes and pigments, antistatic agents, end-capping agents, ultraviolet absorbers, ultraviolet inhibitors, heat stabilizers, light stabilizers, anti-fogging agents, anti-misting agents, plasticizers, flame retardants, color inhibitors, anti-staining agents, antioxidants, release agents (erucic acid amide, stearic acid amide, oleic acid amide, ethylene bisstearic acid amide, ethylene bisoleic acid amide, ethylene bislauric acid amide), moisture-proof agents, oxygen barrier agents, crystal nucleating agents, compatibilizers, crosslinking agents, crosslinking aids, etc. The above compounding materials may be used alone or in combination of two or more.

[0112] Examples of organic fillers include fibrous organic fillers such as aramid fiber, polyimide fiber, polybenzthiazole fiber, and polyethylene fiber; and plant fibers such as nanocellulose, hemp, and bamboo.

[0113] Examples of inorganic fillers include boron fiber, glass beads, glass fiber, flat cross-section glass fiber, milled glass fiber, ceramic beads, wollastonite, mica, synthetic mica, sericite, talc, clay, zeolite, bentonite, kaolinite, dolomite, silica, zeolite, feldspar powder, potassium titanate, finely powdered silicic acid, calcium carbonate, magnesium carbonate, barium sulfate, aluminum oxide, magnesium oxide, calcium oxide, titanium oxide, silicon oxide, aluminum silicate, zirconium silicate, gypsum, novaculite, dawsonite, montmorillonite, calcium sulfide, zinc oxide, boron nitride, glass flakes, metal flakes, metal fiber, basalt fiber, rock wool, ceramic fiber, slag potassium titanate, boron whiskers, aluminum borate, xonotlite, palygorskite (attapulgite), and sepiolite. Examples of inorganic fillers include carbon fibers such as carbon fiber, carbon milled fiber, and carbon nanotubes; carbon black; graphite; and carbon flakes. Furthermore, inorganic fillers whose surfaces have been treated with a coupling agent to improve the adhesive strength with the matrix polymer can be used. Examples of coupling agents include silane coupling agents, aluminum-based coupling agents, and titanium-based coupling agents.

[0114] The organic filler and inorganic filler are preferably not in the form of hollow particles, and specifically, are preferably in the form of fibers, particles or plates.

[0115] The content of other compounding materials in the 3D printer modeling material is not particularly limited as long as it does not impair the object of the present invention, but is preferably 0 to 5 parts by mass, and more preferably 0 to 1 part by mass, relative to 100 parts by mass of the total content of the matrix polymer and hollow particles. The 3D printer modeling material of the present invention may consist essentially of only the matrix polymer and hollow particles.

[0116] [Characteristics of 3D printer modeling material] The 3D printer modeling material of the present invention contains the above-mentioned matrix polymer and hollow particles, and has an apparent density of 0.9 g / cm at 20°C. ３ The Shore A hardness is measured in accordance with JIS K 6253-3:2012 and is 61 to 98 Shore A hardness 15 seconds after the start of needle insertion.

[0117] The apparent density of the 3D printer modeling material of the present invention at 20 ° C. is 0.9 g / cm ３ The 3D printer modeling material of the present invention has such a low apparent density that it is possible to produce a lightweight modeled object.

[0118] The apparent density of the 3D printer modeling material of the present invention at 20 ° C. is 0.9 g / cm ３ There are no particular restrictions on the amount as long as it is below 0.6 to 0.9 g / cm. From the viewpoint of being able to produce a lighter shaped object with high formability that is excellent in mechanical strength as well as flexibility, the amount is preferably 0.6 to 0.9 g / cm. ３ is preferably 0.65 to 0.86 g / cm ３ More preferably, it is 0.7 to 0.83 g / cm ３ The apparent density of the 3D printer modeling material at 20°C can be measured by the underwater displacement method in accordance with JIS K 7112.

[0119] The apparent density of the 3D printer modeling material of the present invention at 20°C is preferably 0.5 to 0.99 times, more preferably 0.6 to 0.95 times, and even more preferably 0.7 to 0.9 times the density of the matrix polymer constituting the 3D printer modeling material of the present invention at 20°C.

[0120] The 3D printer modeling material of the present invention has a Shore A hardness of 61 to 98 15 seconds after the start of indentation, when measured in accordance with JIS K 6253-3:2012. Hereinafter, this Shore A hardness may be referred to as the "Shore A hardness of the 3D printer modeling material."

[0121] The Shore A hardness of the 3D printer modeling material of the present invention is not particularly limited as long as it is 61 to 98, but is preferably 64 to 95, and more preferably 67 to 90. When the Shore A hardness of the 3D printer modeling material is within the above range, the modeling properties can be further improved, and the balance between the mechanical strength and flexibility of the obtained modeled object can be further improved.

[0122] In addition, when the shape, etc. of the 3D printer modeling material is not suitable for measuring the Shore A hardness, the Shore A hardness of a test piece (modeled object) formed from the 3D printer modeling material can be measured, and the measured value can be identified as the Shore A hardness of the 3D printer modeling material. Specifically, the Shore A hardness of the 3D printer modeling material can be identified by the method described in the Examples.

[0123] Furthermore, the 3D printer modeling material of the present invention preferably has a Shore A hardness recovery rate, as specified by the following conditions, of 0.01 to 0.4 / second. That is, when the Shore A hardness of a shaped object formed from the 3D printer modeling material obtained by fused deposition modeling 3D printer modeling at a modeling temperature of 240°C is measured in accordance with JIS K 6253-3:2012, the Shore A hardness recovery rate is preferably 0.01 to 0.4 / second, calculated by dividing the difference between the Shore A hardness immediately after the indentation starts and the Shore A hardness 15 seconds after the indentation starts by 15 seconds. Hereinafter, this Shore A hardness recovery rate may be referred to as the "Shore A hardness recovery rate of the 3D printer modeling material."

[0124] The Shore A hardness recovery rate of the 3D printer modeling material is preferably 0.01 to 0.4 / sec, more preferably 0.05 to 0.38 / sec, and even more preferably 0.1 to 0.36 / sec. By having the Shore A hardness recovery rate of the 3D printer modeling material within the above range, modeling properties can be further improved, and the balance between the mechanical strength and flexibility of the resulting modeled object can be further improved.

[0125] A method for setting the Shore A hardness and Shore A hardness return rate of a material for 3D printer modeling within a suitable range includes, for example, using the preferred matrix polymer and hollow particles described above, and setting the content of these to the preferred amounts described above.

[0126] The 3D printer modeling material of the present invention is preferably molded into a shape that can be used in a 3D printer. Examples of shapes that can be used in a 3D printer include pellets and filaments. In particular, the 3D printer modeling material of the present invention is preferably in the form of a filament, from the viewpoint of being applicable to a general-purpose fused deposition modeling 3D printer.

[0127] [Method for manufacturing a material for 3D printer modeling] The material for 3D printer modeling is obtained by mixing the above-mentioned matrix polymer and hollow particles with compounding agents used as needed. Specifically, a method is exemplified in which hollow particles and compounding agents used as needed are added to a molten matrix polymer and then melt-kneaded to mix them. In this case, all components may be supplied independently to a melt-kneader, or some components may be pre-mixed, and then the pre-mixed components and the remaining components may be supplied independently to a melt-kneader.

[0128] The matrix polymer, hollow particles, and optional compounding agents can be kneaded using, for example, a kneader, roll mill, Brabender, single-screw extruder, twin-screw extruder, or multi-screw extruder. Extrusion molding is preferred from the viewpoint of enabling high production efficiency of filament- and pellet-shaped 3D printer modeling materials that are applicable to general-purpose 3D printers. Melt-kneading is preferably performed using a twin-screw extruder, as this results in a 3D printer modeling material with excellent uniformity. When melt-kneading is performed using an extruder, the cylinder temperature is preferably 150 to 220°C, more preferably 170 to 210°C, and the die temperature is preferably 160 to 220°C, more preferably 180 to 210°C.

[0129] As described above, when the 3D printer modeling material is produced using an extruder such as a twin-screw extruder, the kneaded material can be extruded from the extruder and subsequently molded into pellets, filaments, or the like, thereby producing the 3D printer modeling material in pellet or filament form with high production efficiency. In this case, the preferred cylinder and die temperatures are as described above.

[0130] Pelletized 3D printer modeling material can be obtained, for example, by extruding the kneaded material and directly cutting it into pellets, while pelletized 3D printer modeling material can also be obtained by extruding the kneaded material into strands, cooling them, and then cutting them.

[0131] The filament-shaped 3D printer modeling material may be a monofilament or a multifilament, but is preferably a monofilament. The filament-shaped 3D printer modeling material may also be unstretched or stretched. The diameter of the filament-shaped 3D printer modeling material can be freely adjusted to suit the 3D printer being used, but is generally preferably 1.5 to 3.2 mm, and more preferably 1.6 to 3.1 mm.

[0132] Filament-shaped 3D printer modeling materials can be produced, for example, by extruding a kneaded material and then cooling and solidifying it. Cooling and solidifying is usually performed in a liquid bath at 0 to 100°C, preferably 20 to 80°C.

[0133] The kneaded material may be extruded into a filament, and then stretched before or after cooling and solidifying to produce a filament-shaped material for 3D printer modeling. Examples of stretching methods include, but are not limited to, heat treatment at 170 to 250°C while stretching at a stretch ratio of 2 to 5, and repeated stretching as necessary. After stretching, it is preferable to perform a relaxation heat treatment (stretch ratio of 0.9 to 0.99) while performing heat treatment at 130 to 200°C.

[0134] The filament-shaped 3D printer modeling material obtained in the manner described above is usually wound onto a bobbin or the like and then housed in a cartridge or the like.

[0135] <Modeled object> The 3D printer modeling material of the present invention is used for 3D printer modeling using a fused deposition modeling method, and a modeled object can be formed by performing 3D printer modeling using the fused deposition modeling method using the 3D printer modeling material of the present invention. The present invention also relates to a modeled object formed from the 3D printer modeling material of the present invention.

[0136] The shaped object of the present invention is obtained using the 3D printer modeling material of the present invention, and is therefore lightweight and highly flexible, and has a beautiful appearance with reduced surface roughness (roughness on the shaped object surface).Furthermore, the shaped object of the present invention has sufficient mechanical strength and elasticity.

[0137] The apparent density of the shaped body of the present invention at 20 ° C. is usually 0.9 g / cm ３ or less, 0.6 to 0.9 g / cm ３ is preferably 0.65 to 0.86 g / cm ３ More preferably, it is 0.7 to 0.83 g / cm ３ The apparent density of the shaped body at 20°C can be measured by the underwater displacement method in accordance with JIS K 7112.

[0138] The apparent density of the shaped body of the present invention at 20°C is preferably 0.5 to 0.99 times, more preferably 0.6 to 0.95 times, and even more preferably 0.7 to 0.9 times the density of the matrix polymer constituting the shaped body of the present invention at 20°C.

[0139] When the Shore A hardness of the shaped object of the present invention is measured in accordance with JIS K 6253-3:2012, the Shore A hardness (Shore A hardness measured in accordance with JIS K 6253-3:2012) 15 seconds after the start of indentation is typically 61 to 98, preferably 64 to 95, and more preferably 67 to 90.

[0140] Furthermore, when the Shore A hardness of the shaped object of the present invention is measured in accordance with JIS K 6253-3:2012, the recovery rate of the Shore A hardness, which is calculated by dividing the difference between the Shore A hardness immediately after the start of the indentation and the Shore A hardness 15 seconds after the start of the indentation, by 15 seconds, is preferably 0.01 to 0.4 / second, more preferably 0.05 to 0.38 / second, and even more preferably 0.1 to 0.36 / second.

[0141] [Method for Forming a Modeled Object] The modeled object of the present invention can be formed by 3D printer modeling using the material for 3D printer modeling of the present invention. The 3D printer modeling method using the fused deposition modeling method will be described below.

[0142] First, the 3D printer modeling material is supplied to the 3D printer. When using a filament (filament-like 3D printer modeling material), the filament is generally engaged with a driving roll such as a nip roll or gear roll and supplied to the extrusion head while being pulled.

[0143] The 3D printer modeling material supplied to the 3D printer is heated and melted in the extrusion head and extruded from the tip nozzle. The temperature of the extrusion head is preferably 150 to 250°C, more preferably 200 to 240°C. The temperature of the 3D printer modeling material discharged from the extrusion head is preferably 150 to 250°C, more preferably 200 to 240°C. The base temperature is preferably 80°C or lower. By keeping the temperature of the 3D printer modeling material discharged from the extrusion head within the above range, lightweight models can be manufactured with excellent productivity and even better modeling properties. Furthermore, by keeping the temperature within the above range, problems such as thermal decomposition of the resin, burning, yellowing, smoke, odor, stickiness, and poor appearance can be easily prevented.

[0144] The 3D printer modeling material is preferably discharged from the extrusion head in the form of strands with a diameter of 0.01 to 1.0 mm, more preferably 0.02 to 0.5 mm. Discharging the 3D printer modeling material in such a shape is preferred because it tends to further improve the reproducibility of the modeled model. Furthermore, to improve the solvent resistance and heat resistance of the resulting modeled object, the modeled object can also be crosslinked by irradiating it with radiation or an electron beam.

[0145] The 3D printer modeling material and the modeled object of the present invention are applicable to fused deposition modeling 3D printer modeling, which has a high degree of design freedom, and are therefore applicable to an extremely wide range of applications. In particular, the 3D printer modeling material of the present invention is capable of producing lightweight and flexible models with high modeling properties, and is therefore suitable for applications requiring lightweight or flexibility.

[0146] Applications of the 3D printer modeling material of the present invention are not particularly limited, but include, for example, parts for moving objects such as aircraft, automobiles, trains, motorcycles, boats, bicycles, drones, satellites, and shuttles (e.g., space shuttles); parts for everyday items such as stationery, brushes, rings, jewelry, watches, cooking utensils, kitchen utensils, cleaning tools, home appliances, and toys; parts for wearable items such as shoes, clothing, zippers, buttons, snaps, gloves, shin guards, hats, knee pads, elbow pads, helmets, and headgear; and parts for wearable devices such as braces, assist suits, and wearable devices. parts for sports equipment such as rackets and grips; various materials such as agricultural supplies, gardening supplies, fishing supplies, civil engineering and construction materials; electrical and electronic parts such as electronic circuit boards and casings; industrial parts such as gears, motors, tools, propellers, impellers, wheels, machinery housings, gaskets, O-rings, piping, connectors and reflectors; medical parts such as medical equipment, stents, catheters, orthodontic appliances and artificial organs; containers such as food containers, mobile device covers and bottles; scale models of cars, houses and buildings; heat insulation materials; soundproofing materials; vibration damping materials; cushioning materials; etc.

[0147] In particular, components of flying objects such as drones often have complex three-dimensional shapes and are therefore often shaped using 3D printers. While lightweight components are required for flying object components in order to improve the flying object's operating time, excellent flexibility is also required in order to absorb shock and resist breakage during drops and collisions. Therefore, the 3D printer modeling material and shaped object of the present invention can be suitably used for flying object components. More specifically, the 3D printer modeling material of the present invention can be suitably used for components such as the body, propeller, arm, and legs of a flying object, as well as for components such as covers, guard parts, reinforcing parts, supports, and vibration-isolating members for protecting or supporting parts such as motors, batteries, cameras, propellers, and antennas provided on the flying object.

[0148] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Parts and percentages are by mass unless otherwise specified. Various measurements were carried out according to the following methods.

[0149] <Apparent density of hollow particles> Volume 100 cm ３ About 30 cm ３ The volumetric flask was filled with isopropanol up to the marked line, taking care not to introduce air bubbles. The mass of the isopropanol added to the volumetric flask was accurately weighed, and the apparent density D of the sample was calculated based on the following formula (II): １ (g / cm ３ The apparent density of the sample, D １ (g / cm ３ ) = [mass of sample] ÷ (100 - [mass of isopropanol] ÷ [density of isopropanol at measurement temperature]) (II)

[0150] <Apparent Density of Filaments and Shaped Objects> The apparent density of the filaments and shaped objects was measured by the underwater displacement method in accordance with JIS K 7112.

[0151] <Shore A Hardness and Shore A Hardness Return Rate of Filament> Test specimens were produced by fused deposition modeling 3D printer modeling under the following test specimen production conditions using the filaments obtained in each Example and Comparative Example. The Shore A hardness of the obtained test specimens was measured in accordance with JIS K 6253-3:2012, and the Shore A hardness 15 seconds after the start of indentation was determined. The Shore A hardness return rate was also determined by dividing the difference between the Shore A hardness immediately after the start of indentation and the Shore A hardness 15 seconds after the start of indentation by 15 seconds.

[0152] (Test piece production conditions) 3D printer: fused deposition modeling 3D printer (product name "FLASHFORGE Creator Pro2", manufactured by APPLE TREE) Modeling temperature (nozzle temperature): 240°C Processing speed (head speed): 10 mm / s Layer height (printing pitch) setting value: 0 mm Modeling model: bending test sample model (80 mm x 10 mm x height 4 mm)

[0153] <Modeling Performance> In each Example and Comparative Example, the modeling performance (nozzle clogging and appearance of the modeled object) when 3D printer modeling was performed using the filament was evaluated according to the following criteria. [Nozzle Clogging] If no eye boogers (aggregates near the discharge port) occurred and no nozzle clogging was observed during the modeling of one model, the nozzle was evaluated as "absent." On the other hand, if eye boogers occurred and nozzle clogging was observed, the nozzle was evaluated as "present." [Appearance of Modeled Object] The appearance of the obtained modeled object was visually observed, and if the surface of the model was smooth and no roughness was observed, the evaluation was "good," and if the surface of the model was uneven and roughness was observed, the evaluation was "poor."

[0154] <Maximum bending strain (flexibility)> A bending test was performed on the shaped object at a test speed of 2 mm / min and a support distance of 64 mm according to JIS K 7171, and the maximum bending strain (bending strain corresponding to the maximum bending stress) was determined. The greater the maximum bending strain, the more flexible the shaped object can be judged to be.

[0155] <Maximum Point Stress (Elasticity)> A bending test was performed on the shaped body at a test speed of 2 mm / min and a support distance of 64 mm in accordance with JIS K 7171 to determine the maximum point stress (maximum bending stress). The greater the maximum point stress, the more elastic the shaped body can be determined.

[0156] [Production Example (Production Example of Crosslinked Hollow Particles)] (1) Mixture Preparation Step First, the following materials were mixed to prepare an oil phase: Ethylene glycol dimethacrylate (bifunctional heteroatom-containing crosslinkable monomer) 3.97 parts Pentaerythritol tetraacrylate (tetrafunctional heteroatom-containing crosslinkable monomer) 9.5 parts Divinylbenzene (bifunctional crosslinkable hydrocarbon monomer) 4.37 parts Ethylvinylbenzene (monofunctional hydrocarbon monomer) 0.182 parts 2,2'-Azobis(2,4-dimethylvaleronitrile) (oil-soluble polymerization initiator) 1.24 parts Hexane 54.5 parts

[0157] Next, in a stirring tank, an aqueous solution of 16.5 parts of sodium hydroxide (alkali metal hydroxide) in 55 parts of ion-exchanged water was gradually added under stirring to an aqueous solution of 23.5 parts of magnesium chloride (a water-soluble polyvalent metal salt) in 225 parts of ion-exchanged water to prepare a magnesium hydroxide colloid (poorly water-soluble metal hydroxide colloid) dispersion, and an aqueous phase was obtained. The obtained aqueous phase and oil phase were mixed to prepare a mixed liquid.

[0158] (2) Suspension Step Next, the mixture obtained in the mixture preparation step was stirred and suspended for 1 minute using a disperser (manufactured by Primix Corporation, product name: Homomixer) at a rotation speed of 4,000 rpm to prepare a suspension in which monomer droplets encapsulating a hydrophobic organic solvent were dispersed in water.

[0159] (3) Polymerization step: The suspension obtained in the suspension step was heated to 65° C. in a nitrogen atmosphere and stirred for 24 hours at a temperature of 65° C. to carry out a polymerization reaction. This polymerization reaction yielded a precursor composition that was a slurry liquid in which precursor particles encapsulating a hydrophobic organic solvent were dispersed in water.

[0160] (4) Washing Step and Solid-Liquid Separation Step The precursor composition obtained in the polymerization step was washed with dilute sulfuric acid (25°C, 10 minutes) to adjust the pH to 5.5 or less. Next, water was separated by filtration, and 200 parts of ion-exchanged water was added to re-slurry the mixture. The water washing treatment (washing, filtration, dehydration) was repeated several times at room temperature (25°C), and a solid was separated by filtration.

[0161] (5) Drying Step The precursor particles obtained in the solid-liquid separation step were heat-treated in a vacuum dryer at 200°C for 24 hours to remove moisture and encapsulated solvent, thereby obtaining crosslinked hollow particles 1. The monomer composition of the shell polymer in the obtained crosslinked hollow particles 1 was roughly consistent with the composition of the polymerizable monomers used in the polymerization. The apparent density of the obtained crosslinked hollow particles 1 was 0.33 g / cm ３ It was.

[0162] [Matrix Polymer] The matrix polymers used in each Example and Comparative Example are as follows: Polymer A: a polymer containing 33% by mass of polylactic acid resin (melting point 170°C) and 67% by mass of thermoplastic elastomer (an elastomer containing a block copolymer having a weight-average molecular weight of 100,000 or more and 200,000 or less, a polystyrene block and a conjugated diene polymer block, and a mineral oil-based plasticizer in a mass ratio of block copolymer / mineral oil-based plasticizer = 25 / 75 to 30 / 70, melting point 100°C to 170°C), density 0.95 g / cm ３ , melting point 100 to 170 ° C. PLA: polylactic acid resin, density 1.25 g / cm ３

[0163] Example 1-1 Polymer A was used as the matrix polymer, and crosslinked hollow particles 1 obtained in Production Example 1 were used as the hollow particles. The matrix polymer and hollow particles were fed into a twin-screw kneading extruder at a ratio of 90 parts matrix polymer to 10 parts hollow particles. Then, twin-screw kneading extrusion was performed at a twin-screw kneading temperature of 200°C and an extrusion molding temperature of 200°C to obtain a filament (a material for 3D printer modeling). The apparent density, Shore A hardness, and Shore A hardness return rate of the obtained filament were evaluated. The results are shown in Table 1.

[0164] Using the obtained filament, 3D printing was performed under the following printing conditions to obtain a molded object. Then, according to the methods described above, the moldability, apparent density, Shore A hardness, Shore A hardness return rate, maximum point bending strain, and maximum point stress were measured and evaluated. The results are shown in Table 1.

[0165] (Modeling conditions) 3D printer: fused deposition modeling 3D printer (product name "FLASHFORGE Creator Pro2", manufactured by APPLE TREE) Modeling temperature (nozzle temperature): 220°C Processing speed (head speed): 10 mm / s Layer height (printing pitch) setting value: 0 mm Modeling model: bending test sample model (80 mm x 10 mm x height 4 mm)

[0166] [Examples 1-2 and 1-3] A shaped body was obtained in the same manner as in Example 1-1, except that the filament obtained in Example 1-1 was used and the shaping temperature was set as shown in Table 1. The obtained shaped body was evaluated in the same manner as in Example 1-1. The results are shown in Table 1.

[0167] [Example 2] A filament (3D printer modeling material) was obtained in the same manner as in Example 1-1, except that the compounding ratio of the matrix polymer and hollow particles was set as shown in Table 1. Then, using the obtained filament, a shaped body was obtained in the same manner as in Example 1-1, except that the modeling temperature was set as shown in Table 1, and evaluation was performed in the same manner as in Example 1-1. The results are shown in Table 1.

[0168] Example 3 A composition consisting of 50% by mass of polymer A and 50% by mass of PLA was used as the matrix polymer, and the crosslinked hollow particles 1 obtained in Production Example 1 were used as the hollow particles. The matrix polymer and hollow particles were fed into a twin-screw kneading extruder at a ratio of 80 parts matrix polymer (40 parts polymer A and 40 parts PLA) to 20 parts hollow particles. A filament (3D printer modeling material) was obtained by twin-screw kneading and extrusion under conditions of a twin-screw kneading temperature of 200°C and an extrusion molding temperature of 200°C. A shaped body was obtained using the obtained filament in the same manner as in Example 1-1, except that the modeling temperature was as shown in Table 1. Evaluations were then performed in the same manner as in Example 1-1. The results are shown in Table 1.

[0169] Example 4 A composition consisting of 70% by mass of polymer A and 30% by mass of PLA was used as the matrix polymer, and the crosslinked hollow particles 1 obtained in Production Example 1 were used as the hollow particles. The matrix polymer and hollow particles were fed into a twin-screw kneading extruder at a ratio of 80 parts matrix polymer (56 parts of polymer A and 24 parts of PLA) to 20 parts hollow particles. A filament (3D printer modeling material) was obtained by twin-screw kneading and extrusion under conditions of a twin-screw kneading temperature of 200°C and an extrusion molding temperature of 200°C. A shaped body was obtained using the obtained filament in the same manner as in Example 1-1, except that the modeling temperature was as shown in Table 1. Evaluations were then performed in the same manner as in Example 1-1. The results are shown in Table 1.

[0170] Comparative Example 1 Polymer A was supplied as a matrix polymer to a twin-screw kneading extruder. A filament (3D printer modeling material) was obtained by twin-screw kneading and extrusion under conditions of a twin-screw kneading temperature of 200°C and an extrusion molding temperature of 200°C. A shaped body was obtained in the same manner as in Example 1-1, except that the obtained filament was used, and evaluation was performed in the same manner as in Example 1-1. The results are shown in Table 1.

[0171] Comparative Example 2 PLA was supplied as a matrix polymer to a twin-screw kneading extruder. A filament (3D printer modeling material) was obtained by twin-screw kneading and extrusion under conditions of a twin-screw kneading temperature of 200°C and an extrusion molding temperature of 200°C. A shaped body was obtained in the same manner as in Example 1-1, except that the obtained filament was used and the modeling temperature was set as shown in Table 1, and evaluation was performed in the same manner as in Example 1-1. The results are shown in Table 1. When the Shore A hardness of the shaped body of Comparative Example 2 was measured, the Shore A hardness remained at 100 (the upper limit of Shore A hardness) for 15 seconds or more from the start of the indenter, and therefore the return speed of the Shore A hardness could not be determined.

[0172] Comparative Example 3 A filament (3D printer modeling material) was obtained in the same manner as in Example 1-1, except that PLA was used as the matrix polymer. A shaped object was obtained in the same manner as in Example 1-1, except that the obtained filament was used and the modeling temperature was set as shown in Table 1, and evaluation was performed in the same manner as in Example 1-1. The results are shown in Table 1. When the Shore A hardness of the shaped object of Comparative Example 3 was measured, the Shore A hardness remained at 100 (the upper limit of Shore A hardness) for 15 seconds or more from the start of the indenter, and therefore the return speed of the Shore A hardness could not be determined.

[0173]

[0174] As is clear from Table 1, the composition contains a matrix polymer and hollow particles and has an apparent density of 0.9 g / cm at 20°C. ３ The 3D printer modeling materials having a Shore A hardness of 61 to 98 measured under specified conditions were capable of producing lightweight and flexible models with high modeling properties (Examples 1-1, 1-2, 1-3, 2, 3, and 4).

[0175] On the other hand, a 3D printer modeling material that did not contain hollow particles, had a too high apparent density, and had a too low Shore A hardness measured under specified conditions resulted in poor modeling properties and the resulting modeled object had a too high apparent density (Comparative Example 1). A 3D printer modeling material that did not contain hollow particles, had a too high apparent density, and had a too high Shore A hardness measured under specified conditions resulted in the resulting modeled object having a too high apparent density and poor flexibility (Comparative Example 2). A 3D printer modeling material that did not contain hollow particles, had a too high apparent density, and had a too high Shore A hardness measured under specified conditions resulted in the resulting modeled object having a too high apparent density and poor flexibility (Comparative Example 3).

Claims

1. A 3D printing material used in fused deposition modeling (FDM) 3D printing, It contains a matrix polymer and hollow particles, The apparent density at 20°C is 0.9 g / cm³. ３ The following: A 3D printing material whose Shore A hardness is 61 to 98 at 15 seconds after the start of indentation, as measured in accordance with JIS K 6253-3:2012.

2. A 3D printer material according to claim 1, which is in the form of a filament.

3. The 3D printing material according to claim 1 or 2, comprising a thermoplastic elastomer as the matrix polymer.

4. The 3D printing material according to claim 1 or 2, comprising a thermoplastic plastomer and a thermoplastic elastomer as the matrix polymer.

5. The 3D printing material according to claim 1 or 2, which contains cross-linked hollow particles as the hollow particles.

6. The density of the matrix polymer at 20°C is 0.91 to 1.3 g / cm³. ３ A 3D printer material according to claim 1 or 2.

7. The apparent density of the hollow particles at 20°C is 0.2 to 0.8 g / cm³. ３ A 3D printer material according to claim 1 or 2.

8. The 3D printing material according to claim 1 or 2, wherein the content of the hollow particles is 1 to 50 parts by mass with respect to 100 parts by mass of the total content of the matrix polymer and the hollow particles.

9. A molded body formed from a 3D printing material according to claim 1 or 2, wherein the Shore A hardness measured in accordance with JIS K 6253-3:2012 is 61 to 98 at 15 seconds after the start of indentation.

10. The molded body according to claim 9, which is a component of a flying object.