JP2016112824A - Model material ink, ink set and method for manufacturing 3d molded object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink for 3D molding having a low viscosity, from which a 3D molded object having high levels of a yield stress, elongation and impact resistance can be manufactured, and a method for manufacturing a 3D molded object by using the above ink.SOLUTION: A model material ink for 3D molding by an inkjet process is provided, which comprises a photopolymerizable monomer, a polymer and a photopolymerization initiator. In the ink, the polymer has a molecular weight of 5000 or more and 30000 or less; a difference in a solubility parameter between the photopolymerizable monomer and the polymer is 0.5 to 2.0 (cal/cm); and a mass ratio of the polymer to the photopolymerizable monomer is 85/15 or more and 60/40 or less.SELECTED DRAWING: None

Description

  The present invention relates to a model material ink, an ink set, and a method for manufacturing a 3D structure.

  In recent years, as a method for producing a 3D model using a photocurable 3D modeling ink, a method of curing and laminating a cured layer formed by irradiating a liquid surface of a liquid 3D modeling ink with an actinic ray (hereinafter referred to as a “3D model”) , Or simply “SLA method”) or a method in which a 3D modeling ink is landed on a substrate from a nozzle of an inkjet head, and a cured layer formed by irradiating the landed 3D modeling ink with actinic rays is laminated ( Hereinafter, simply referred to as “inkjet method”) is widely known. Since the 3D model is relatively easy to manufacture, it can be used as a prototype before the final product is manufactured.

  Particularly in recent years, in order to verify whether or not the final product functions as desired at the prototype stage, it is required to manufacture a 3D shaped object having the same physical properties as the final product. However, a 3D structure manufactured by a conventional manufacturing method often has low yield stress, elongation, or impact resistance, and may not satisfy the performance required as the prototype. Therefore, there is a demand for a material for manufacturing a 3D model and a method for manufacturing the 3D model that can improve both of these characteristics.

  In Patent Document 1 and Patent Document 2, in the production of a 3D structure by the SLA method, an elastic modulus, elongation and impact resistance are obtained by using a 3D modeling ink containing a cationic polymerizable monomer and organic solid particles made of a block copolymer. It is described that it is possible to produce a 3D model having high properties, and in particular, to improve the impact resistance of the 3D model by setting the monomer and organic solid particles in phase separation.

JP 2014-111774 A International Publication No. 2004/113056

  However, according to the study by the present inventors, in the SLA method, it is difficult to uniformly irradiate the entire 3D modeling ink with actinic rays because the actinic rays irradiated to the liquid surface diffuse. Therefore, in the method for producing a 3D structure described in Patent Document 1 and Patent Document 2, the organic solid particles are taken in while the monomers are non-uniformly polymerized. In such a method, since the particle size and distribution of the organic solid particles are likely to be non-uniform, the impact resistance and elongation at break of the manufactured 3D structure cannot be sufficiently increased.

  In contrast, since the ink jet method irradiates only the landed 3D ink with light, the influence of light diffusion is small, and a phase separation structure can be formed in units of droplets. Thereby, since it is easy to make the particle size and distribution of the organic solid particles of the 3D modeled object uniform, it is considered that the ink jet method can produce a 3D modeled object with sufficiently improved impact resistance and elongation at break.

  Here, the 3D modeling ink used in the SLA method is prepared so as to have a high viscosity in order to suppress fluctuation of the liquid surface during irradiation with actinic rays. For this reason, inks used in the methods described in Patent Literature 1 and Patent Literature 2 have low fluidity, and when these inks are ejected from an inkjet head, there is a possibility that nozzle clogging may occur. Further, according to the study by the present inventors, when the viscosity of the ink for 3D modeling is high, the organic solid particles are less likely to aggregate with each other, so that the particle size of the polymer is not sufficiently large, and the impact resistance and elongation at break are high. Hard to become.

  The viscosity of the ink can be lowered by reducing the weight average molecular weight of the organic solid particles, but sufficient impact resistance cannot be obtained even if the 3D modeling ink having organic solid particles having a low molecular weight is cured. There is a fear. On the other hand, it is conceivable to increase the impact resistance of the 3D model by increasing the ratio of the polyfunctional monomer contained in the 3D modeling ink to increase the chemical cross-linking. If this is done, there is a problem that the flexibility of the 3D object is lost and the elongation is reduced.

  In view of the above problems, the present invention provides a 3D modeling ink having a low viscosity and capable of producing a 3D modeled object having high yield stress, elongation, and impact resistance, and such an ink. It is an object of the present invention to provide a method for producing the 3D model used.

The first of the present invention relates to the following ink composition.
[1] A photocurable model material ink for 3D modeling by an ink jet method containing a photopolymerizable monomer, a polymer, and a photopolymerization initiator,
The molecular weight of the polymer is 5000 or more and 30000 or less,
The difference in solubility parameter between the photopolymerizable monomer and the polymer is 0.5 (cal / cm ³ ) ^1/2 or more and 2.0 (cal / cm ³ ) ^1/2 or less,
The model material ink according to claim 1, wherein a mass ratio of the polymer to the photopolymerizable monomer in the model material ink is 85/15 or more and 60/40 or less.
[2] The model material ink according to [1], wherein a difference in glass transition temperature between the photopolymerizable monomer and the polymer is 80 ° C. or more.
[3] The model material ink according to [1] or [2], wherein the polymer has a glass transition temperature of 0 ° C. or lower.
[4] The model material ink according to any one of [1] to [3], wherein the polymer has a photopolymerizable functional group of 1 mole equivalent or more per mole of polymer.
[5] The polymer according to any one of [1] to [4], wherein the polymer includes a constituent part composed of a straight chain hydrocarbon having a double bond and having 4 to 7 carbon atoms. Model material ink.
[6] Any one of [1] to [5], wherein the polymer includes a constituent portion having one or more functional groups selected from the group consisting of a carbonate group, an ester group, and an ether group. Model material ink described in 1.
[7] The model material ink according to any one of [1] to [6], wherein the polymer is polyurethane.

The second of the present invention relates to the following ink set.
[8] An ink set for 3D modeling by an inkjet method, including the model material ink according to any one of [1] to [7] and a curable support agent ink.

The third of the present invention relates to a method for manufacturing the following 3D structure.
[9] A method for producing a 3D structure formed by laminating a model material layer obtained by curing a photocurable model material ink,
Ejecting the model material ink from the nozzles of an inkjet head to form an ink layer including a portion of the model material ink; and irradiating the model material ink portion included in the formed ink layer with an actinic ray Including a step of producing a material layer,
The model material ink is the model material ink according to any one of [1] to [7], and a method for producing a 3D structure.
[10] discharging the curable support material ink from the nozzles of the inkjet head to form the ink layer including the portion of the support material ink;
A step of removing a support material layer formed by curing the support material ink after the irradiation with the actinic ray;
A method for producing the 3D structure according to [9].

  According to the present invention, ink that can produce a 3D modeling object that has a low viscosity and has a high yield stress, elongation, and impact resistance, and a 3D modeling that uses such an ink. A method of manufacturing an article is provided.

FIG. 1 is a schematic diagram showing an aspect of a 3D modeling system using an inkjet method. FIG. 2 is a flowchart showing an example of the manufacturing flow of the 3D modeling method by the ink jet method. FIG. 3 is a schematic side view of the 3D modeling system in step S103 of the manufacturing flow. FIG. 4A is a schematic side view of the 3D modeling system in step S110 of the manufacturing flow, and FIG. 4B is a top view thereof. FIG. 5A is a schematic side view of the 3D modeling system in step S114 of the manufacturing flow, and FIG. 5B is a top view thereof. FIG. 6A is a schematic side view of the 3D modeling system in step S110 in which the manufacturing flow is repeated, and FIG. 6B is a top view thereof. FIG. 7A is a schematic side view of the 3D modeling system in step S110, which is further repeated in the manufacturing flow, and FIG. 7B is a top view thereof. FIG. 8 is a perspective view of the 3D structure precursor obtained in the manufacturing flow. FIG. 9A is a side view illustrating a state in which the first layer of the 3D structure precursor is manufactured in the example, and FIG. 9B is a side view illustrating a state in which the second layer of the 3D structure precursor is manufactured in the example. FIG. 9C is a side view illustrating a state in which the third layer of the 3D structure precursor is manufactured in the example, and FIG. 9D is a side view illustrating a state in which the 3D structure precursor is manufactured in the example. FIG. 10A is a plan view illustrating a second 3D structure manufactured in the example, and FIG. 10B is a perspective view illustrating a second 3D structure manufactured in the example.

  Hereinafter, the present invention will be described with reference to exemplary embodiments.

  The model material ink of the present invention (hereinafter also simply referred to as “model material ink”) contains a photopolymerizable monomer, a polymer, and a photopolymerization initiator, and is a photocurable model material ink for 3D modeling by an inkjet method. It is.

1. Photopolymerizable monomer The photopolymerizable monomer is a monomer having a photopolymerizable group that is polymerized by irradiation with light. The photopolymerizable monomer is polymerized and cross-linked by being irradiated with actinic rays to form a linear polymer, and constitutes a 3D shaped object together with the polymer described later. The photopolymerizable monomer may be one type of monomer or a combination of a plurality of types of monomers.

  The photopolymerizable group includes a radical polymerizable functional group having an ethylenic double bond and a cationic polymerizable functional group. Examples of radical polymerizable functional groups include ethylene, propenyl, butenyl, vinylphenyl, (meth) acryloyl, allyl ether, vinyl ether, maleyl, maleimide, (meth) acrylamide, acetyl Vinyl groups and vinylamide groups are included. Examples of the cationic polymerizable functional group include an epoxy group, an oxetane group, a furyl group, and a vinyl ether group. “(Meth) acryloyl” means both and / or “acryloyl” and “methacryloyl”, “(meth) acryl” means both and / or “acryl” and “methacryl”, and “( “Meth) acrylate” means “acrylate” and / or “methacrylate”.

  From the viewpoint of further increasing the reactivity to irradiated light, the radical polymerizable photopolymerizable group is preferably a (meth) acryloyl group, an allyl ether group, a vinyl ether group or a maleimide group, and a (meth) acryloyl group or A vinyl ether group is more preferable, and a (meth) acryloyl group is more preferable. Similarly, from the viewpoint of further increasing the reactivity, the cationically polymerizable photopolymerizable group is preferably a vinyl ether group, an epoxy group or an oxetane group, and more preferably a vinyl ether group or an oxetane group. Of these, from the viewpoint of further increasing the reactivity, the photopolymerizable group is most preferably a (meth) acryloyl group.

  Examples of the monomer having a (meth) acryloyl group include monofunctional acrylates, bifunctional acrylates, and trifunctional or higher acrylates.

  Examples of monofunctional acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) ) Acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, isomyristyl (meth) Acrylate, isostearyl (meth) acrylate, n-stearyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate Phenoxyethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, methoxyethyl (Meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) Acryloyloxyethylphthalic acid, 2- (meth) acryloyloxyethyl-2-hydroxyethyl-phthalic acid, t-butylcyclohexyl (meth) acrylate, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, -Ethylhexyl-diglycol (meth) acrylate, 4-hydroxybutyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, 2- (2-ethoxyethoxy) Ethyl (meth) acrylate and 2-ethylhexyl carbitol (meth) acrylate are included.

  Examples of bifunctional acrylates include triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) Acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dimethylol-tri Cyclodecane di (meth) acrylate, PO adduct di (meth) acrylate of bisphenol A, neopentyl glycol di (meth) acrylate hydroxypivalate and polytetramethylene glycol di (meth) acrylate It includes door.

  Examples of tri- or higher functional acrylates include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane tetra (meth) ) Acrylate, glycerin propoxytri (meth) acrylate and pentaerythritol ethoxytetra (meth) acrylate.

  The monomer having the (meth) acryloyl group may be a modified product. Examples of modified products include ethylene oxide modified trimethylolpropane tri (meth) acrylate and ethylene oxide modified (meth) acrylate including ethylene oxide modified pentaerythritol tetraacrylate, caprolactone modified including caprolactone modified trimethylolpropane tri (meth) acrylate Caprolactam-modified (meth) acrylates including (meth) acrylates as well as caprolactam-modified dipentaerythritol hexa (meth) acrylates are included.

  Examples of the monomer having an allyl ether group include a monofunctional allyl ether compound, a bifunctional allyl ether compound, and a trifunctional or higher functional allyl ether compound.

  Examples of monofunctional allyl ether compounds include phenyl allyl ether, o-, m-, p-cresol monoallyl ether, biphenyl-2-ol monoallyl ether, biphenyl-4-ol monoallyl ether, butyl allyl ether, Cyclohexyl allyl ether and cyclohexane methanol monoallyl ether are included.

  Examples of the bifunctional allyl ether compound include trimethylolpropane diallyl ether, glycerol α, α'-diallyl ether, diallyl phthalate and diallyl isophthalate.

  Examples of the trifunctional or higher functional allyl ether compound include pentaerythritol triallyl ether, diallyl phthalate polymer and diallyl isophthalate polymer.

  Examples of the monomer having a vinyl ether group include a monofunctional vinyl ether compound, a bifunctional vinyl ether compound, and a trifunctional or higher functional vinyl ether compound.

  Examples of monofunctional vinyl ether compounds include butyl vinyl ether, butyl propenyl ether, butyl butenyl ether, hexyl vinyl ether, ethyl hexyl vinyl ether, phenyl vinyl ether, benzyl vinyl ether, ethyl ethoxy vinyl ether, acetyl ethoxy ethoxy vinyl ether, cyclohexyl vinyl ether and adamantyl vinyl ether It is.

  Examples of bifunctional vinyl ether compounds include ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol vinyl ether, butylene divinyl ether, dibutylene glycol divinyl ether, neopentyl glycol divinyl ether Cyclohexanediol divinyl ether, cyclohexane dimethanol divinyl ether, norbornyl dimethanol divinyl ether, isovinyl divinyl ether, divinyl resorcin and divinyl hydroquinone.

  Examples of trifunctional or higher functional vinyl ether compounds include glycerin trivinyl ether, glycerin ethylene oxide adduct trivinyl ether (addition moles of ethylene oxide 6), trimethylolpropane trivinyl ether, trivinyl ether ethylene oxide adduct trivinyl ether (addition moles 3 of ethylene oxide). ), Pentaerythritol trivinyl ether and ditrimethylolpropane hexavinyl ether and their oxyethylene adducts.

  Examples of the monomer having a maleimide group include phenylmaleimide, cyclohexylmaleimide and n-hexylmaleimide.

  Examples of the monomer having an epoxy group include a monofunctional epoxy compound, a bifunctional epoxy compound, and a trifunctional or higher functional epoxy compound.

  Examples of monofunctional epoxy compounds include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenol (polyethyleneoxy) 5-glycidyl ether, butylphenyl glycidyl ether, hexahydrophthalic acid glycidyl ester, lauryl glycidyl ether, 1,2- Epoxycyclohexane, 1,4-epoxycyclohexane, 1,2-epoxy-4-vinylcyclohexane and norbornene oxide are included.

  Examples of the bifunctional epoxy compound include neopentyl glycol diglycidyl ether and 1,6 hexanediol diglycidyl ether.

  Examples of the trifunctional or higher functional epoxy compound include polyglycerol triglycidyl ether, sorbitol polyglycidyl ether, and pentaerythritol polyglycidyl ether.

  Examples of the monomer having an oxetane group include 2- (3-oxetanyl) -1-butanol, 3- (2- (2-ethylhexyloxyethyl))-3-ethyloxetane and 3- (2-phenoxyethyl). -3-Ethyloxetane is included.

1-2. Polymer The polymer can increase the yield stress, elongation and impact resistance of the 3D structure formed. When the weight average molecular weight of the polymer is 5000 or more, the photopolymerizable monomer and the polymer are sufficiently phase-separated, so that the impact resistance of the 3D structure is further increased. On the other hand, when the weight average molecular weight of the polymer is 30000 or less, the viscosity of the model material ink does not increase too much, so that the ink can be sufficiently emitted from the nozzles of the inkjet head. Only one type of polymer may be used, or two or more types may be used in combination. From the viewpoint of achieving both the high impact resistance of the 3D model and the low viscosity of the ink, the weight average molecular weight of the polymer is preferably 5000 or more and 20000 or less, and more preferably 7000 or more and 15000 or less. The polymer may be a homopolymer consisting of repetitions of the same constituent part, or a copolymer containing two or more different constituent parts.

  From the viewpoint of enhancing the impact resistance due to the polymer and enhancing the stretchability, the Tg of the polymer is preferably 0 ° C. or lower. Examples of polymers having a Tg of 0 ° C. or less include urethane polymers, butadiene rubber and isoprene rubber, and hydrogenated butadiene rubber and isoprene rubber.

The difference between the solubility parameter of the polymer (hereinafter also simply referred to as “SP value”) and the SP value of the photopolymerizable monomer is 0.3 (cal / cm ³ ) ^1/2 or more and 2.0 (cal / Cm ³ ) ^1/2 or less. When the model material ink contains a combination of two or more polymers, the SP value of the polymer is the SP value of the whole polymer, and the model material ink contains a combination of two or more photopolymerizable monomers. In this case, the SP value of the photopolymerizable monomer is the SP value of the entire photopolymerizable monomer. According to the knowledge newly obtained by the present inventors, when the difference in SP value is 0.3 (cal / cm ³ ) ^1/2 or more, the polymer and the photopolymerizable monomer are not compatible with each other. A separation structure is formed, and the impact resistance of the 3D object is increased. Further, when the difference in SP value is 2.0 (cal / cm ³ ) ^1/2 or less, the polymer and the photopolymerizable monomer are not separated too much, and fine particles of the polymer are contained in the photopolymerizable monomer. Since the dotted sea-island structure is formed, the impact resistance of the 3D structure is increased. From the above viewpoint, the difference in SP value is preferably 0.5 (cal / cm ³ ) ^1/2 or more and 1.5 (cal / cm ³ ) ^1/2 or less, and 0.6 (cal / cm ³ ) More preferably, it is ^½ or more and 1.0 (cal / cm ³ ) ^½ or less.

As the SP value of the photopolymerizable monomer and polymer, a value estimated by the Bicerano method is adopted by substituting the structure of each compound into Scigress Version 2.6 installed in a commercially available personal computer and Fujitsu. When the polymer is a combination of two or more types, the SP value of the whole polymer is obtained by substituting the volume fraction φ _k and SP value δ _k of each polymer into Equation 1, and the copolymer weight obtained by copolymerizing the polymers The combined SP value is adopted. When the photopolymerizable monomer is a combination of two or more, the SP value of the entire photopolymerizable monomer can be obtained by substituting the volume fraction φ _k and SP value δ _k of each photopolymerizable monomer into Equation 1. The SP value of a copolymer obtained by copolymerizing a photopolymerizable monomer is employed.

  The polymer content in the model material ink may be within a range where the phase separation occurs. For example, the content ratio in the ink between the photopolymerizable monomer and the polymer in the model material ink is 85. / 15 or more and 60/40 or less. The content ratio represents a numerical value of (photopolymerizable monomer) / (polymer).

  The elastic value of the 3D object was measured using ARES-G2, manufactured by T.A. Instruments Co., Ltd., and two sharp peaks (inflections) were displayed on the graph of tan Δ representing the ratio of storage elastic modulus to loss elastic modulus. When the point) is seen, it can be determined that phase separation between the photopolymerizable monomer and the polymer occurs in the manufactured 3D structure.

  When the difference in glass transition temperature (hereinafter also simply referred to as “Tg”) between the photopolymerizable monomer and the polymer is 80 ° C. or more, the impact resistance of the 3D object can be further improved. This is considered to be due to the following reasons. That is, if the Tg difference between the photopolymerizable monomer and the polymer is large, components having a low Tg (especially polymer) can easily absorb the impact, but components having a high Tg (especially the photopolymerizable monomer) have an impact. Because it is difficult to absorb, the behavior with respect to impact is greatly different between the two. For this reason, particularly in the vicinity of the interface between the polymer and the photopolymerizable monomer, a large amount of craze is likely to occur on the photopolymerizable monomer side due to the different behavior between the two, and this craze absorbs the impact. Improves impact.

  When the model material ink contains a combination of two or more polymers, the Tg of the polymer is the Tg of a polymer obtained by polymerizing the whole polymer, and the model material ink contains two or more photopolymerizable monomers. When contained in combination, the Tg of the photopolymerizable monomer is the Tg of a polymer obtained by polymerizing the entire photopolymerizable monomer. The Tg of the polymer obtained by polymerizing the whole polymer and the Tg of the polymer obtained by polymerizing the whole photopolymerizable monomer are represented by the elastic values of these polymers, ARES-G2, manufactured by TA Instruments, and Diamond. It is calculated | required as a temperature of the peak (inflection point) in the graph of tan (DELTA) obtained by measuring using DSC and the measuring instrument containing the product made by PerkinElmer.

1-2-1. Polymer having a photopolymerizable group When the polymer has a photopolymerizable group of 1 molar equivalent or more per 1 mol of the polymer, the impact resistance of the 3D model can be further improved. This is considered to be due to the following reason. That is, when a model material ink containing such a polymer is irradiated with an active configuration, a covalent bond is also formed between the polymer and the photopolymerizable monomer. Therefore, a fine phase separation structure is easily formed due to the polymer particles entering between the linear polymers, and the interfacial strength of the polymer particles is increased by the covalent bond, so that the polymer particles are not easily decomposed. . In this way, since a fine phase separation structure is formed, the impact resistance of the 3D structure is further increased. Examples of the photopolymerizable group that the polymer may have include the photopolymerizable groups exemplified above. From the viewpoint of preventing the polymer from being compatible with the photopolymerizable monomer by acting as a crosslinking agent, the polymer may have 1 to 10 molar equivalents of a photopolymerizable group per mole of polymer. Preferably, it has a photopolymerizable group of 1 to 4 molar equivalents. Only one type of polymer having a photopolymerizable group may be used, or two or more types may be used in combination.

  From the viewpoint of facilitating the formation of the covalent bond, the photopolymerizable group is preferably attached to the end of the polymer. For example, when a polymer is prepared by polymerization of monomers, a photopolymerizable group can be imparted to the end of the polymer by using a compound having a site that reacts with the polymer and a photopolymerizable group as a reaction terminator.

  The molar equivalent of the photopolymerizable group possessed by the polymer can be determined by dividing the amount of the photopolymerizable group possessed by the polymer in the 3D structure by the weight average molecular weight of the polymer. The amount of the photopolymerizable group can be estimated by using ordinary analysis methods including, for example, nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), and mass spectrometry (MS). it can. The weight average molecular weight of the polymer can be measured by performing gel permeation chromatography (GPC) using a column with o-dichlorobenzene as the solvent and substituting the obtained value into a calibration curve of polystyrene.

  In addition, the amount of the photopolymerizable group and the weight average molecular weight of the polymer in the polymer in the already produced 3D structure are obtained by analyzing a sample of the 3D structure by a usual analysis method including NMR, FT-IR, and MS. Can be specified.

1-2-2. Polymer having a compatible part and an incompatible part with the photopolymerizable monomer When the polymer has a compatible part and an incompatible part with the photopolymerizable monomer in the molecule, a 3D shaped object The impact resistance of the model material ink can be further improved, and the viscosity of the model material ink can be lowered to a range more suitable for inkjet discharge. This is considered to be due to the following reason. That is, when a model material ink containing such a polymer is irradiated with actinic rays, a phase separation structure is formed by a portion incompatible with the photopolymerizable monomer, while the polymer is formed by a portion compatible with the photopolymerizable monomer. Since it becomes easy to be taken in between linear polymers, the phase separation structure tends to become finer. When the phase separation structure becomes finer, the stress is also finely divided and diffused, so that it is difficult for stress to concentrate only on a specific portion of the 3D structure, and local destruction of the 3D structure due to stress concentration is less likely to occur. Further, since the polymer has a portion compatible with the photopolymerizable monomer in the molecule, the polymer and the photopolymerizable monomer are appropriately compatible, and the viscosity of the model material ink can be further reduced. The said polymer may be only 1 type and may be used in combination of 2 or more type.

  Examples of the portion compatible with the photopolymerizable monomer include a urethane bond, a carbonate group, an ester group, and an ether group. Of these, carbonate groups, ester groups, and ether groups are preferred from the viewpoint of causing these parts to self-aggregate to aggregate the polymers to facilitate phase separation of the photopolymerizable monomer and the polymer.

  Examples of the portion incompatible with the photopolymerizable monomer include a hydrocarbon group having 4 to 7 carbon atoms. The hydrocarbon group may be linear or branched and may contain a double structure. From the viewpoint of further improving the impact resistance by lowering the Tg of the polymer to increase the difference from the Tg of the photopolymerizable monomer and facilitating the occurrence of crazing, the polymer has a carbon number of 4-7. It preferably has a hydrocarbon group consisting of a straight chain hydrocarbon which may contain a heavy bond. Further, from the viewpoint of further improving impact resistance by facilitating the formation of a fine phase separation structure, the polymer is preferably a polyurethane having a plurality of urethane bonds, and is incompatible with the photopolymerizable monomer. More preferred is a polyurethane having a hydrocarbon group consisting of a straight chain hydrocarbon having a double bond and having a constituent part, particularly a carbon number of 4 to 7.

1-3. Photopolymerization initiator The photopolymerization initiator is a photoradical initiator when the photopolymerizable monomer is a compound having a radically polymerizable functional group, and the photopolymerizable monomer has a cationically polymerizable functional group. When it is a compound having a photoacid generator. Only one type of photopolymerization initiator may be used, or two or more types may be combined, or a combination of both a photo radical initiator and a photo acid generator may be used.

  The photo radical initiator includes a cleavage type radical initiator and a hydrogen abstraction type radical initiator. Of these, the model material ink preferably includes at least a cleavage type photopolymerization initiator. That is, the model material ink may contain both a cleavage type and a hydrogen abstraction type photopolymerization initiator, or may contain only a cleavage type photopolymerization initiator.

  When the model material ink contains both the cleavage type and the hydrogen drawing type, the mass of the cleavage type is preferably larger than the mass of the hydrogen drawing type. The ratio of the hydrogen abstraction type initiator contained in the photopolymerization initiator is preferably 30% by mass or less, and more preferably 20% by mass or more and 30% by mass or less.

  If the model material ink contains both a cleavage type and a hydrogen abstraction type photoradical initiator as a photopolymerization initiator, the curing speed of the model material ink increases. The reason for this is not clear, but if the photopolymerization initiator of the cleavage type radical initiator and the hydrogen abstraction type radical initiator coexist, the polymerization initiator of the hydrogen abstraction type radical initiator functions as a sensitizer. It is considered that the polymerization rate is improved.

  On the other hand, when the model material ink does not substantially contain a hydrogen abstraction type photoradical initiator, the elongation or yield stress of the 3D structure tends to increase. The reason for this is not clear, but can be considered as follows. When graft polymerization occurs between linear polymers obtained by polymerization of photopolymerizable monomers with a hydrogen abstraction type photoradical initiator, irregular crosslinking may occur. If there is an irregular cross-link in the 3D model, the stress concentrates on a specific part in the composition when the cured product is stretched, so that the 3D model does not stretch sufficiently and yields. However, if the model material ink does not substantially contain a hydrogen abstraction type photoradical initiator, the above-mentioned graft polymerization hardly occurs, so that the elongation or yield stress tends to be high.

  Therefore, when it is required to increase the production speed of the 3D structure, it is preferable that the model material ink contains both the cleavage type radical initiator and the hydrogen abstraction type radical initiator. On the other hand, when importance is attached to the durability of the 3D structure, it is preferable not to contain a hydrogen abstraction type radical initiator substantially.

  Examples of cleavage type radical initiators include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2- Methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) An acetophenone-based radical initiator including propan-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, a benzoin-based radical initiator including benzoin, benzoin methyl ether and benzoin isopropyl ether; 2,4,6-trimethylbe Acylphosphine oxide-based radical initiator containing a zone in diphenyl phosphine oxide, benzyl and methyl phenylglyoxylate ester.

  Examples of hydrogen abstraction type radical initiators include benzophenones including benzophenone and N, N-diethylbenzophenone, thioxanthones including 2,4-diethylthioxanthone, isopropylthioxanthone, chlorothioxanthone and isopropoxychlorothioxanthone, ethyl anthraquinone, benz Anthraquinones including anthraquinone, aminoanthraquinone and chloroanthraquinone, and acridines including 9-phenylacridine and 1,7-bis (9,9'-acridinyl) heptane are included.

  Examples of the photoacid generator include known sulfonium salts, ammonium salts, diaryliodonium salts, triarylsulfonium salts and the like. Specifically, triarylsulfonium hexafluorophosphate salt, iodonium (4-methylphenyl) (4- (2-methylpropyl) phenyl) hexafluorophosphate, triarylsulfonium hexafluoroantimonate, 3-methyl-2-butyl Tenenyltetramethylenesulfonium hexafluoroantimonate and the like are included. Examples of commercially available photoacid generators include Bayer UVI-6990, Daicel Ornex Uvacure 1591 ("Uvacure 1591" is a registered trademark of Ornex), Ciba Specialty Chemicals CGI-552 and Ir250, Asahi Denka Kogyo's SP-150, SP-152, SP-170, SP-172 and CP-77, and San Apro's CPI-100P, CPI-101A, CPI-200K and CPI-210S can be used.

  The content of the photopolymerization initiator is preferably 0.01% by mass or more and 10% by mass or less with respect to the total mass of the model material ink, although it depends on the type of actinic ray or actinic ray curable compound.

1-4. Other Components The model material ink may further include other components including a sensitizer, a photopolymerization initiator auxiliary agent, a polymerization inhibitor, and a release accelerator as long as the effects of the present invention are obtained. These components may be used alone or in combination of two or more.

  Examples of the sensitizer include those that exhibit a sensitizing function by light having a wavelength of 400 nm or more. Specifically, 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, 9,10 -Anthracene derivatives including dipropoxyanthracene and 9,10-bis (2-ethylhexyloxy) anthracene are included. Examples of commercially available sensitizers include DBA and DEA from Kawasaki Chemical Industries.

  The photopolymerization initiator auxiliary agent may be a tertiary amine compound, and is preferably an aromatic tertiary amine compound. Examples of aromatic tertiary amine compounds include N, N-dimethylaniline, N, N-diethylaniline, N, N-dimethyl-p-toluidine, N, N-dimethylamino-p-benzoic acid ethyl ester, N, N-dimethylamino-p-benzoic acid isoamyl ethyl ester, N, N-dihydroxyethylaniline, triethylamine and N, N-dimethylhexylamine are included.

  Examples of polymerization inhibitors include (alkyl) phenol, hydroquinone, catechol, resorcin, p-methoxyphenol, t-butylcatechol, t-butylhydroquinone, pyrogallol, 1,1-picrylhydrazyl, phenothiazine, p-benzoquinone , Nitrosobenzene, 2,5-di-t-butyl-p-benzoquinone, dithiobenzoyl disulfide, picric acid, cuperone, aluminum N-nitrosophenylhydroxylamine, tri-p-nitrophenylmethyl, N- (3-oxyanilino- 1,3-dimethylbutylidene) aniline oxide, dibutylcresol, cyclohexanone oxime cresol, guaiacol, o-isopropylphenol, butyraloxime, methyl ethyl ketoxime and cyclohexanone oxime.

  When a 3D model is manufactured while supporting a model material layer being manufactured from below by a support material layer formed by curing a support material ink described later, the peeling accelerator is formed between the model material layer and the support material layer. Make peeling easier. Examples of release promoters include higher fatty acid esters including silicon surfactants, fluorosurfactants and stearyl sebacate. From the viewpoint of facilitating peeling, the peeling accelerator is preferably a silicon surfactant. The content of the peeling accelerator is preferably 0.01% by mass or more and 3.0% by mass or less with respect to the total mass of the ink. By making content of a peeling accelerator into 0.01 mass% or more, the peelability of a base material and 3D modeling thing can be improved more. By setting the content of the peeling accelerator to 3.0% by mass or less, it is possible to make it difficult to generate a distortion of the shape of the 3D modeled object due to coalescence of the droplets of the model material ink before curing.

2. Ink Set The model material ink may be combined with a support material ink for 3D modeling by an inkjet method (hereinafter also simply referred to as “support material ink”) to form an ink set. The ink set only needs to be in a form that can be used to package and sell the model material ink and the support material ink at the same time and form one 3D structure. For example, the model material ink and the support material ink may be individually stored in a plurality of ink cartridges, or the plurality of ink storage portions may be integrally configured so that each of the ink storage portions includes the model material ink and the ink. An ink cartridge containing support material ink may be used.

  From the viewpoint of facilitating removal, the support material ink may be cured depending on temperature so that the cured product is heat-meltable, or photocured and the cured product is water-soluble or water-swellable. preferable.

  Examples of support materials that are cured depending on temperature and whose cured product is heat-meltable include paraffin wax, microcrystalline wax, carnauba wax, ester wax, amide wax, and waxes including PEG 20000. Examples of a support material that is photocurable and whose cured product is water-soluble or water-swellable includes a water-soluble compound having a photopolymerizable functional group, a cleavage type radical initiator, and a photocurable resin composition mainly composed of water. Things are included. The support material may further contain a water-soluble polymer.

  Examples of water-soluble monomers that can be included in the support material ink include water-soluble monomers including polyoxyethylene di (meth) acrylate, polyoxypropylene di (meth) acrylate, (meth) acryloylmorpholine and hydroxyalkyl (meth) acrylate Included are (meth) acrylates and water-soluble (meth) acrylamides including (meth) acrylamide, N, N-dimethyl (meth) acrylamide and N-hydroxyethyl (meth) acrylamide. Examples of the cleavage type radical initiator contained in the support material include the compounds exemplified above. Examples of water-soluble polymers that can be included in the support material include polyethylene glycol, polypropylene glycol, and polyvinyl alcohol.

3. 3D Model Manufacturing Method The 3D model manufacturing method according to the present invention includes a model material ink portion by discharging the model material ink from a nozzle of an inkjet head, except that the model material ink described above is used. A 3D object comprising a model material obtained by curing a model material ink, including a step of creating an ink layer and a step of irradiating a portion of the model material ink included in the formed ink layer with an actinic ray. It can be carried out in the same manner as a known production method. The ink layer is a layer formed by ejected model material ink and optionally ejected support material ink described later. By irradiating the portion of the model material ink with actinic rays in the ink layer, a model material layer that is each layer obtained by finely dividing the 3D model to be manufactured into a thin piece is produced. By stacking the model material layer, a 3D model is produced.

3-1. A process of ejecting model material ink to form an ink layer including a portion of model material ink Model material ink is ejected to a predetermined position on the basis of position data occupied by the model material in each layer of the 3D model to be manufactured. As a result, a portion of the model material ink included in the ink layer is formed. The model material ink is ejected onto a base material, a model material layer that has already been irradiated with light, or a support material layer that is optionally formed. The portion of the model material ink contained in each ink layer is cured by being irradiated with actinic rays in a subsequent process, thereby forming a model material layer.

  From the viewpoint of further improving the ejection properties from the nozzles, the amount of droplets per droplet of model material ink is preferably 1 pl or more and 70 pl or less. From the viewpoint of obtaining a higher-resolution 3D object, the amount of droplets per droplet of model material ink is more preferably 2 pl or more and 50 pl or less.

3-2. Step of creating a model material layer by irradiating a portion of the model material ink included in the formed ink layer with an actinic ray The discharged model material ink can be cured by irradiating with an actinic ray from a light source. Examples of actinic rays that can be used for curing the model material ink include ultraviolet rays and electron beams.

Examples of the light source for irradiating ultraviolet rays include fluorescent tubes including a low-pressure mercury lamp and a germicidal lamp, cold cathode tubes, ultraviolet lasers, mercury lamps having an operating pressure within a range of 100 Pa to 1 MPa, metal halide lamps, and light emission A diode (LED) or the like is included. From the viewpoint of curing the 3D model faster, the light source is preferably a high-pressure mercury lamp, a metal halide lamp, an LED, or the like that can irradiate ultraviolet rays having an illuminance of 100 mW / cm ² or more. LED is preferable from the viewpoint of. Specific examples of the LED include a 395 nm water-cooled LED, manufactured by Phaseon Technology.

  Examples of a method for generating an electron beam include a scanning method, a curtain beam method, and a broad beam method. From these viewpoints, the curtain beam method is preferable from the viewpoint of generating an electron beam more efficiently. Examples of the light source that can irradiate the electron beam include Curetron EBC-200-20-30, manufactured by Nisshin High Voltage Co., Ltd., and Min-EB manufactured by AIT.

  When the actinic ray is an electron beam, the acceleration voltage for electron beam irradiation is preferably 30 kV or more and 250 kV or less, and more preferably 30 kV or more and 100 kV or less from the viewpoint of sufficient curing. When the acceleration voltage is in the range of 100 kV to 250 kV, from the viewpoint of sufficient curing, the electron beam irradiation dose is preferably 30 kGy to 100 kGy, more preferably 30 kGy to 60 kGy. From the viewpoint of improving the adhesiveness between the upper and lower layers, the irradiated model material ink is not completely cured but is in a semi-cured state. The strength may be set such that the cured model material ink is completely cured.

  From the viewpoint of making the adjacent model material ink droplets more difficult to unite, it is preferable that the actinic ray is irradiated within 10 seconds after the model material ink droplets adhere to the recording medium. From the above viewpoint, the actinic ray is preferably irradiated for 0.001 second to 5 seconds after the ink droplet of the model material has landed, and is irradiated for 0.01 second to 2 seconds. Is more preferable.

  From the viewpoint of facilitating the formation of the next layer, the surface of the model material ink cured by irradiation with light may be flattened with a film thickness adjusting roller or the like.

3-3. The step of forming the ink layer including the support material ink by discharging the support material ink The manufacturing method of the present invention discharges the curable support material ink and includes the ink layer including the support material ink. The step of forming may optionally be included. The support material ink is ejected to a predetermined position on the basis of data on positions where it is desirable to arrange the support material in order to support the model material to be subsequently formed in each layer of the 3D model to be manufactured. Thus, a portion of the support material ink arbitrarily included in the ink layer is formed. The support material ink is then cured to form a support material layer. The support material formed by laminating the support material layer fills the space portion of the 3D model being manufactured, and supports the model material layer being manufactured from below in the direction of gravity. Thereby, the support material can prevent the 3D model being manufactured from collapsing due to gravity from a portion where the model material layer does not yet have sufficient strength.

  The support material layer may be manufactured independently of the model material layer. However, from the viewpoint of shortening the working time, it is preferable to simultaneously form the model material layer and the support material layer in the same ink layer. Specifically, the same ink layer is formed by discharging the model material ink and the support material ink simultaneously or successively. Thereafter, the model material ink and the support material layer are formed by irradiating the model material ink portion with actinic rays. The next ink layer is formed by discharging the model material ink or the support material ink on the formed model material layer or the support material layer.

  At this time, the nozzle for the support material ink and the nozzle for the model material ink may be provided in the ink jet head so that the ink is ejected from the same ink jet head, or the model material ink and the support material ink may be separated. You may discharge from an inkjet head. From the viewpoint of shortening the work time, the flow path is communicated from the storage section for storing each ink to another inkjet head, and the model material ink and the support material ink are ejected independently from the nozzles of the other inkjet head. It is preferable to do.

3-4. Step of removing support material layer When the manufacturing method of the present invention includes a step of discharging the support material ink, the support material is removed after all the model material layers and the support material layers are formed. In the present invention, a 3D structure in which all model material layers and support material layers are formed is also referred to as a 3D structure precursor.

  When the support material is cured depending on the temperature and the cured product is heat-meltable, for example, the 3D shaped object precursor is held for 1 minute or more and 5 minutes or less in an environment of 60 ° C. or more and 130 ° C. or less. By doing so, the support material can be removed. When a support material that is photocurable and whose cured product is water-soluble or water-swellable is used, for example, 10 minutes in water of -30 ° C. or higher and + 30 ° C. or lower than the Tg of the 3D modeled precursor. Immerse the 3D model precursor for 60 minutes or less or leave the 3D model precursor for 10 minutes or more and 60 minutes or less in an environment with a relative humidity of 50% to 90% and a temperature of 40 ° C to 70 ° C. Thus, the support material can be removed.

4.3 Specific Manufacturing Example Using 3D Modeling System 4-1.3 Example of 3D Modeling System FIG. 1 shows an outline of an example of a 3D modeling system based on an inkjet method. The 3D modeling system shown in FIG. 1 includes an inkjet unit 1, a calculation control unit 2, a storage device 3, an input device 4, an output device 5, and a display device 6.

  The ink jet unit 1 is a model material arranged on a rail (not shown) movably left and right (drawing XY direction) and a stage 11 provided with a drive unit (not shown) that drives up and down (drawing Z direction). An inkjet device 12 that ejects ink or support material ink.

  The inkjet device 12 includes an inkjet head 13 for model material ink, an inkjet head 14 for support material ink, a film thickness adjusting roller 15, and a light source 16. Each of the model material ink inkjet head 13 and the support material ink inkjet head 14 has an ejection nozzle. The ink jet head 13 for model material ink communicates with a pump 13b and a model material ink tank 13c via a pipe 13a. Model material ink can be placed in the model material ink tank 13c. The support material ink inkjet head 14 communicates with a pump 14b and a support material ink tank 14c via a pipe 14a. Support material ink can be placed in the support material ink tank 14c. A plurality of model material ink tanks 13c and support material ink tanks 14c may be provided, and each may be assigned an ink set number.

  The calculation control unit 2 includes a calculation unit 21, an ink selection unit 22, a stage control unit 23, an inkjet control unit 24, a roller control unit 25, and a light source control unit 26.

  The computing unit 21 uses the CAD data recorded in the storage device 3, the STL data for manufacturing the 3D structure, and the model material and support in each layer obtained by finely dividing the virtual 3D structure formed from the STL data into thin pieces Calculate material placement. The ink selection unit 22 selects an appropriate model material ink and support material ink in accordance with the 3D model to be manufactured. Further, the ink selection unit 22 communicates the model material ink tank 13c in which the selected model material ink is placed with the pipe 13a, and the support material ink tank 14c in which the selected support material ink is put in the pipe 14a. Information for communicating with the inkjet unit 1 is sent. The stage control unit 23 sends information for driving the stage 11 to the inkjet unit 1. The inkjet control unit 24 drives the model material ink inkjet head 13 and the support material ink inkjet head 14 so that the model material ink and the support material ink land on the positions of the model material and the support material in each layer, respectively. Information is sent to the inkjet unit 1. The roller control unit 25 sends information for driving the film thickness adjusting roller 15 to the inkjet unit 1. The light source control unit 26 sends information for driving the light source 16 to the inkjet unit 1. The calculation control unit 2 can be configured by a calculation device used in a normal computer system such as a CPU.

  The storage device 3 stores information necessary for manufacturing the 3D object, such as the lot number of the model material ink tank 13c and the support material ink tank 14c, the CAD data number, the STL data number, and the ink set number. Recorded in association. Examples of the storage device 3 include a storage device including a ROM, a RAM, and a magnetic disk.

  The input device 4 is a device for inputting an instruction for correcting STL data. Examples of the input device 4 include a pointing device including a keyboard and a mouse.

  The output device 5 is a device for outputting information displayed on the display device 6. An example of the output device 5 includes a printer.

  The display device 6 is a device for displaying the STL data and the lower layer 3D structure formed from the STL data. Examples of the display device 6 include an image display device including a liquid crystal display and a monitor.

4-2.3 Example of Manufacturing Flow of 3D Modeled Object A method for manufacturing a 3D modeled object using the 3D modeling system shown in FIG. 1 will be described in more detail with reference to the flowchart of FIG.

  (A) In step S <b> 101, the arithmetic control unit 2 inputs CAD data selected from the recording device 3 to the arithmetic unit 21. In step S102, the calculation unit 21 converts the CAD data into STL data that is 3D modeling data. Note that a virtual 3D structure formed from the STL data is displayed on the output device 5 to check whether a desired shape is formed. If the desired shape is not formed, the STL data is input from the input device 4. Modifications may be made to the data.

  (B) In step S103, as shown in FIGS. 3A and 3B, the calculation unit 21 finely divides the virtual 3D structure into a plurality of flaky layers D1 to DX in the Z direction in FIG. Material arrangement data and support material arrangement data for supporting the model material constituting the so-called overhang portion, for example, the second image portion of the letter “K”, from below are created. The calculation unit 21 combines the arrangement data of the model material and the arrangement data of the support material for each same layer, and “first plane data D1, second plane data D2,... Xth plane data DX” in the present invention. Get.

  (C) In step S105, the ink selection unit 22 selects the optimal model material ink and support material ink based on the data of the virtual 3D model and the plurality of plane data, and these inks are connected to the pipes 13a and 14a. The information for communicating with each is sent to the inkjet unit 1.

  (D) In step S108, the stage control unit 23 uses the inkjet unit 1 to drive the stage 11 so that the first model material layer and the support material layer can be formed based on the first plane data D1. Send to. The ink jet unit 1 moves the stage 11 in the Z direction according to the received information, and aligns the relative positions of the stage 11 and the respective ink jet heads.

  (E) In step S110, the inkjet control unit 24 sends information for controlling the position of each inkjet head to the inkjet unit 1 based on the arrangement of the model material and the support material in the first. As shown in FIGS. 4A and 4B, the inkjet unit 1 controls the position of each inkjet head according to the received information, and at least the model material ink (Ma) and the support material ink (S) are placed on the stage. Either one is discharged from the nozzle of each inkjet head.

  (F) In step S <b> 112, the light source control unit 26 sends information for driving the light source 16 to the inkjet unit 1. The ink jet unit 1 drives the light source 16 in accordance with the received information, and irradiates the model material ink ejected from the nozzle and landed with actinic rays to cure the model material ink, thereby obtaining a model material layer. From the viewpoint of making the thickness of the model material layer uniform, the roller control unit 25 sends information for driving the film thickness adjusting roller 15 to the ink jet apparatus 1 after irradiation with actinic rays, and receives the information. 1 may drive the film thickness adjusting roller 15 to polish a thick portion, thereby making the thickness of the first hardened layer uniform. The thickness of each cured layer after curing and optional polishing is preferably 1 μm or more and 25 μm or less.

  (G) In step S114, the arithmetic control unit 2 determines whether there is a further model material layer to be formed. When there are more model material layers to be formed, the process returns to step S108, and the position of the stage 11 is moved downward (Z direction) by the thickness of one model material layer as shown in FIGS. 5A and 5B. In step S110 and S112, the nth hardened layer is formed on the n-1st hardened layer. Thereafter, as shown in FIGS. 6A, 6B, 7A, and 7B, the steps S108, S110, S112, and S114 are repeated until the final model material layer (Xth model material layer) is laminated. A plurality of layers are stacked. If there are no more layers to be formed in step S114, the process proceeds to step S116.

  (H) In step S116, the 3D modeled precursor as shown in FIG. 8 is taken out from the inkjet apparatus 1, and the support material is removed.

  By the above, 3D modeling thing can be produced.

  In the following, the invention will be described in more detail with reference to examples. These examples do not limit the scope of the present invention.

1. Preparation of model material ink 1-1. Monomer composition The photocurable monomer described in Table 1 was mixed in an amount corresponding to the composition described in Table 2 to prepare monomer compositions 1 to 9.

  In Table 1, the numbers described in “SP value” represent the SP value of each monomer.

In Table 2, the numbers described in the “monomer” column represent the amounts (mass%) of the monomers described in Table 1 contained in the respective monomer compositions. The number described in the “SP value” column represents the SP value of each monomer composition. The SP value of each monomer composition was determined by substituting the structure of each compound into Scigress Version 2.6 installed in a commercially available personal computer, Fujitsu, and the SP value δ _k estimated by the Bicerano method, and the molecular weight of the monomer Further, the volume fraction φ _k of each monomer obtained from the mass% is a value obtained by substituting into the above formula 1. The number described in the “Tg” column represents the Tg of each monomer composition. Tg is a peak (inflection point) in a graph of tan Δ obtained by measuring the elasticity value of the polymer obtained by polymerizing each monomer composition using ARES-G2, manufactured by TA Instruments Inc. ) Is the value obtained as the temperature.

1-2. Polymer 1-2-1. Preparation of Urethane Polymer 1 ETERNACOLL UH-200, which is a polypropylene glycol having a weight average molecular weight of about 2000, Ube Industries, Ltd. ("ETERARNACOLL" is a registered trademark of the company) and norbornene methane isocyanate are in a molar ratio of 1: 1. The mixture was further mixed with toluene and tin catalyst and heated to 70 ° C. After 4 hours, as a reaction terminator, a hydroxyethyl acrylate having a molar ratio with respect to polycarbonate diol of 4: 1 was added and allowed to stand for 2 hours. The urethane polymer 1-1 having a weight average molecular weight of 8500 and a functional group equivalent of 2 was used. Got.
A urethane polymer 1-2 having a weight average molecular weight of 8500 and a functional group equivalent of 0 was obtained in the same manner as the urethane polymer 1-1 except that the reaction stopper was ethanol.
Urethane polymer 1-1 and urethane polymer 1-2 were mixed in an amount such that the molar ratio was 1: 1 to obtain urethane polymer 1 having a weight average molecular weight of 8500 and a functional group equivalent of 1.

1-2-2. Preparation of urethane polymers 2-5 Urethane polymer except that the reaction time when preparing urethane polymer 1-1 and urethane polymer 11 was adjusted so that the weight average molecular weight of the resulting polymer would be the numerical values shown in Table 3. In the same manner as in Example 1, urethane polymers 2 to 5 were obtained.

1-2-3. Preparation of urethane polymer 6 Polyethylene glycol used in preparing urethane polymer 1-1 and urethane polymer 11 is made of ETERNACOLL UH-300 having a weight average molecular weight of about 3000, manufactured by Ube Industries, Ltd., and the molecular weight of the resulting polymer is 16000. A urethane polymer 6 having a weight average molecular weight of 16000 and a functional group equivalent of 1 was obtained in the same manner as the urethane polymer 1 except that the reaction time was adjusted to

1-2-4. Preparation of urethane polymer 7 Plaxel CD210 having a weight average molecular weight of about 1000 is the polypropylene glycol used in preparing urethane polymer 1-1 and urethane polymer 11, manufactured by Daicel Chemical Industries, Ltd. (“Placcel” is a registered trademark of the company) The urethane polymer 7 having a weight average molecular weight of 8000 and a functional group equivalent of 1 was obtained in the same manner as the urethane polymer 1 except that the reaction time was adjusted so that the molecular weight of the resulting polymer was 8,000.

1-2-5. Preparation of Urethane Polymer 8 The weight average molecular weight is 19000 and the functional group equivalent is 2 except that polypropylene glycol is made of OD-X-102 having a weight average molecular weight of about 2000, and manufactured by DIC. A urethane polymer 8 containing a constituent part having an ester group was obtained.

1-2-6. Preparation of Urethane Polymer 9 The weight average molecular weight is 11000 and the functional group equivalent is 1 in the same manner as the urethane polymer 11, except that polypropylene glycol is made of OD-X-102 having a weight average molecular weight of about 2000 and DIC. A urethane polymer 9 containing a constituent part having an ether group was obtained.

1-2-7. Preparation of Urethane Polymer 11 Urethane polymer 11 was obtained in the same manner as urethane polymer 1-2, except that the reaction time was adjusted so that the weight average molecular weight of the resulting polymer was 10,000.

1-2-8. Other polymers The following products were used as other polymers.
Urethane polymer 10: UN-7600, manufactured by Negami Kogyo Co., Ltd. Butadiene rubber: BAC-45, manufactured by Osaka Organic Chemical Co., Ltd. (butadiene rubber diacrylate)
Isoprene rubber: UC-102, manufactured by Kuraray (Isoprene rubber methacrylate)
Methyl methacrylate rubber: AA-6, manufactured by Toa Gosei Co., Ltd. (polymethyl methacrylate)

  Table 3 shows each polymer. In Table 3, the numerical value described in the “molecular weight” column is the weight average molecular weight of each polymer, the numerical value described in the “functional group equivalent” column is the equivalent functional group equivalent of each polymer, and “SP value” The value described in the column “” is the SP value of each polymer, and the description in the column “C4 to C7” consists of a linear hydrocarbon structure having a double bond having 4 to 7 carbon atoms in each polymer. It is the presence or absence of a moiety, and the functional group described in the column of “functional group constituent portion” is a functional group when each polymer has an ether group, an ester group or a carbonate group, and is described in the column of “Tg”. Is the Tg of each polymer. The SP value is a value estimated by the Bicerano method by substituting the structure of each compound into Scigress Version 2.6 installed in a commercially available personal computer.

1-3. Model Material Ink The monomer composition described in Table 2, the polymer described in Table 3, and DAROCUR TPO (BASF, “DAROCUR” is a registered trademark of the company, hereinafter also referred to simply as “TPO”). 3D inks were prepared in amounts corresponding to the compositions described in Tables 4 to 8 and dissolved while stirring at 80 ° C. while stirring.

  In Tables 4 to 8, the numerical values described in the “SP value difference” column are values obtained by subtracting the SP value of the polymer from the SP value of the monomer composition, and are described in the “Tg difference” column. The numerical value is a value obtained by subtracting the Tg of the monomer composition from the Tg of the polymer.

2. Support Material Ink A support material ink was prepared by mixing and dissolving the following components in the following amounts.
Octadecanol 60 parts by mass Hexadecanol 40 parts by mass

3. 3. Production of 3D object by IJ-UV method 3-1. Production of First 3D Model 1-57 Model material ink 1 was filled into the first head (piezo head 512L, manufactured by Konica Minolta IJ) and support material ink into a second head of the same type. While scanning the stage in the horizontal direction, the model material ink 1 is emitted from the first head, and the support material ink 200 is emitted from the second head, landed, and cured by irradiation with UV light, as shown in FIG. 9A. The first layer including the model material layer 100 and the support material layer 200 was formed. Next, the head and the light source were raised in the vertical direction, the model material ink 1 and the support material ink were landed on the formed layer and cured in the same manner, and the second layer was laminated as shown in FIG. 9B. After the formation of the second layer is repeated to reach a predetermined thickness, the model material ink 1 and the support material ink are landed on different positions from the first layer and the second layer on the formed layer and cured in the same manner. The third layer was laminated as shown in FIG. 9C. A 3D modeling precursor having the model material 110 and the support material 210 as shown in FIG. 9D is repeated by repeating the step of laminating the third layer while changing the positions where the model material ink 1 and the support material ink are emitted as necessary. 1 was produced.

The head temperature at the time of ink ejection is set to “75 ° C.” when the ink viscosity exceeds 10 mPa · s even at 75 ° C., or “the temperature at which the ink viscosity is 10 mPa · s”. . The amount of one droplet when ejecting ink was 42 pl, and the frequency was 8 kHz. As the UV light source, an LED of 395 nm was used, and each layer was set to a condition where light was irradiated for 1 second at an illuminance of 100 mW / cm ² .

  The 3D modeled object precursor 1 was put in an oven at 60 ° C. for 5 minutes to remove the support material 210, thereby obtaining a first 3D modeled object 1.

  Except having changed the model material ink 1 into the model material inks 2-57, the 1st 3D modeling objects 2-57 were obtained similarly.

3-2. Manufacture of 2nd 3D modeling objects 1-57 2nd 3D modeling objects 1-57 which have the shape shown in Drawing 10 like 1st 3D modeling objects 1-57 were manufactured.

4). Evaluation 4-1. Phase Separability For each of the first 3D shaped objects 1 to 57, it was visually confirmed whether or not coarse phase separation of 500 μm or more was observed. For the first 3D model without coarse phase separation, the elastic value was measured using ARES-G2, manufactured by TA Instruments Inc., and a peak (inflection point) was seen in the tan Δ graph. I checked if it was possible. When two peaks were observed, it was judged that the polymer, the monomer, and the photopolymerization initiator were phase-separated, and the 3D structure had two Tg.
○: Two sharp peaks are observed Δ: Two non-sharp peaks are observed ×: Only one peak is observed.
XX: Coarse phase separation of 500 μm or more is observed

4-2. Outgoing property For each of the model material inks 1 to 57, the ink was heated from −20 ° C. to 100 ° C. at a temperature rising rate of 3 ° C./min, and ink viscosity at 70 ° C. was measured using a rheometer MCR102 manufactured by Anton Paar. Was measured. When the ink viscosity was 20 mPa · s or less, it was judged that the emission from the ejection head was good and that a 3D shaped article could be manufactured.
○: Ink viscosity is less than 20 mPa · s Δ: Ink viscosity is 20 mPa · s or more and less than 25 mPa · s ×: Ink viscosity is 25 mPa · s or more

4-3. Yield stress Using the Tensilon universal testing machine RTF-2430, manufactured by A & D Co., Ltd., the tensile test was performed at a tensile speed of 20 mm / min and a distance between chucks of 5 cm. The stress at break was measured.
◎: Stress at break is 40 MPa or more ○: Stress at break is 30 MPa or more and less than 40 MPa Δ: Stress at break is 20 MPa or more and less than 10 MPa ×: Stress at break is less than 10 MPa

4-4. Elongation at break Using the Tensilon universal testing machine RTF-2430, manufactured by A & D Corporation, a tensile test was performed at a tensile speed of 20 mm / min and a distance between chucks: 5 cm. The elongation at break was measured.
◎: Elongation at break is 15% or more ○: Elongation at break is 10% or more and less than 15% △: Elongation at break is 5% or more and less than 10% ×: Elongation is less than 5% Brittle fracture

4-5. Impact resistance For the second 3D objects 1 to 57, energy required for destruction in accordance with JIS K7110 (kJ / m) in Izod impact tester, Yasuda Seiki Seisakusho, Hammer 5.5J, Izod test mode. ) Was measured.
◎: destroyed at 10 kJ / m2 or more ○: destroyed at 5 kJ / m2 or more and less than 10 kJ / m2 Δ: destroyed at 2 kJ / m2 or more and less than 5 kJ / m2 ×: destroyed at 2 kJ / m2 or less

4-6. Results The results are shown in Tables 9-13.

  According to the composition of the model material ink of the present invention, the monomer composition and the polymer were phase-separated, and it was possible to produce a 3D modeled object having high yield stress, breaking elongation, and impact resistance (model material ink). 2-7, 10, 11, 14, 15, 18, 19, 23-33, 35, 36, 41-43, 44-57).

  On the other hand, when the content of the polymer with respect to the monomer composition is less than 15% by mass, the elongation and impact resistance of the produced 3D structure are low (comparison between the model material inks 1 and 2 to 7 and the model). According to the comparison between the material ink 8 and 9 to 11.), when the polymer content with respect to the monomer composition is more than 40% by mass, the viscosity of the model material ink becomes high, and it becomes difficult to eject from the discharge head, and Since no phase separation occurred in the manufactured 3D structure, the yield stress was low (by comparison between the model material inks 8 and 2 to 7 and comparison between the model material inks 12 and 9 to 11).

  When the molecular weight of the polymer is less than 5,000, phase separation does not occur in the manufactured 3D model, and elongation and impact resistance are low (comparison between the model material inks 13 and 14 to 15 and the model material ink 17). And comparison with 18-19). When the molecular weight of the polymer is larger than 30000, the viscosity of the model material ink becomes high and it becomes difficult to eject from the ejection head, and the phase separation does not occur in the manufactured 3D model, so the yield stress and impact resistance are low. (Based on the comparison between the model material inks 16 and 14 to 15 and the comparison between the model material inks 20 and 18 to 19).

When the difference between the solubility parameter of the monomer composition and the solubility parameter of the polymer is less than 0.5 (cal / cm ³ ) ^1/2 , phase separation did not occur in the manufactured 3D structure, so yield stress, fracture Both the elongation and impact resistance were low (by comparison between the model material inks 26 and 34 and comparison between the model material inks 37 to 40 and 41 to 43). When the difference between the solubility parameter of the monomer composition and the solubility parameter of the polymer is larger than 2.0 (cal / cm ³ ) ^1/2 , phase separation did not occur in the manufactured 3D shaped object, and therefore The impact properties were all low (by comparison with model material inks 21, 22 and 29, 30).

  When the difference in Tg between the monomer composition and the polymer was 80 ° C. or higher, the impact resistance of the produced 3D model was higher (by comparison with the model material inks 44 to 56 and 57). This is probably because a large Tg difference between the monomer composition and the polymer causes a large amount of crazes to be generated when an impact is applied to the 3D model, and these crazes absorb the impact.

  When the Tg of the polymer is 0 ° C. or less, the elongation until the produced 3D model is broken is longer and the impact resistance is higher (by comparison with the model material inks 44 to 56 and 57). .)

  When the polymer had a photopolymerizable functional group, the impact resistance of the produced 3D model was higher (by comparison with the model material inks 44 to 54 and 55 to 57). This is thought to be because the photopolymerizable functional group of the polymer reacts with the monomer contained in the monomer composition, so that the polymer is easily incorporated into the monomer composition and the particle size of the polymer is reduced. It is done.

  When the polymer has a constituent part composed of a straight chain hydrocarbon having a carbon number of 4 or more and 7 or less and containing a double bond, the impact resistance of the produced 3D structure is higher (model material inks 44 and 45). And comparison with 48-57).

  When the polymer has a component having a carbonate group, an ester group or an ether group, the yield stress of the manufactured 3D object was higher (model material inks 44 to 48, 50, 51, 53 to 55 and 49, Comparison with 52.)

  When the polymer was polyurethane, the impact resistance of the manufactured 3D model was higher (by comparison with the model material inks 44 to 56 and 57). This is presumably because polyurethane has a compatible component part and an incompatible component part with the monomer composition, so that a finer phase separation structure was formed and the particle size of the polymer was reduced.

5. Manufacture and evaluation of 3D objects by SLA method Perfection 3 manufactured by Environment Tech Co., Ltd. was prepared by adding model material ink 3 prepared by adding propylene glycol 4000, manufactured by Wako Pure Chemical Industries, Ltd. to a viscosity of 300 CP at room temperature. And a screwed part having the same shape as that of the second 3D structure was created. Change the torque to 0.58N, 0.88N, and 1.2N in this threaded part through-hole, and insert a seated flat-tapping screw B tight M3 × 8mm with an electric torque screwdriver. evaluated. The results are shown in Table 14.
○ Screwed parts are not damaged and screws do not rotate freely × Screwed parts are damaged or screws are idled

  In the second 3D structure 1, the parts were not damaged until the torque was 1.20N. This is presumably because the fine sea-island structure formed in units of droplets is uniformly irradiated with light in the inkjet discharge, and thus a fine and uniform phase separation occurs in the manufactured 3D structure.

  On the other hand, the screwed parts were weak in strength, and the parts were damaged at 0.88N. In the SLA method, it is necessary to increase the viscosity of the ink to some extent in order to suppress fluctuations in the liquid surface. When light is cured with this viscosity, the aggregation of the polymer does not progress, and the islands are not formed well. It becomes small and it is thought that impact property and elongation at break are low. In addition, in the SLA method, the difference in light intensity between the central portion and the interface due to the influence of light diffusion has caused the formation of islands to be non-uniform.

  According to the method of manufacturing a 3D structure according to the present invention, a 3D structure having high toughness can be manufactured, and thus it is preferable for manufacturing a prototype of a product that is loaded during operation, such as a threaded part or a snap part. Can be used.

DESCRIPTION OF SYMBOLS 1 Inkjet part 2 Arithmetic control part 3 Memory | storage device 4 Input device 5 Output device 6 Display apparatus 11 Stage 12 Inkjet apparatus 13 Inkjet head for model material ink 13a Piping 13b Pump 13c Model material ink tank 14 Inkjet head for support material ink 14a Piping 14b Pump 14c Support material ink tank 15 Film thickness adjusting roller 16 Light source 21 Calculation unit 22 Ink selection unit 23 Stage control unit 24 Inkjet control unit 25 Roller control unit 26 Light source control unit Ma Model material ink S Support material ink 100 Model material layer 110 Model material 200 Support material layer 210 Support material

Claims (10)

A photocurable model material ink for 3D modeling by an ink jet method containing a photopolymerizable monomer, a polymer and a photopolymerization initiator,
The molecular weight of the polymer is 5000 or more and 30000 or less,
The difference in solubility parameter between the photopolymerizable monomer and the polymer is 0.5 (cal / cm ³ ) ^1/2 or more and 2.0 (cal / cm ³ ) ^1/2 or less,
The model material ink according to claim 1, wherein a mass ratio of the polymer to the photopolymerizable monomer in the model material ink is 85/15 or more and 60/40 or less.   The model material ink according to claim 1, wherein a difference in glass transition temperature between the photopolymerizable monomer and the polymer is 80 ° C. or more.   The model material ink according to claim 1, wherein the polymer has a glass transition temperature of 0 ° C. or lower.   The model material ink according to any one of claims 1 to 3, wherein the polymer has a photopolymerizable functional group of 1 mole equivalent or more per mole of the polymer.   5. The model material ink according to claim 1, wherein the polymer includes a constituent part composed of a straight chain hydrocarbon having a double bond and having a carbon number of 4 or more and 7 or less. .   The said polymer contains the structural part which has a 1 or several functional group selected from the group which consists of a carbonate group, ester group, and ether group, The any one of Claims 1-5 characterized by the above-mentioned. Model material ink.   The model material ink according to claim 1, wherein the polymer is polyurethane.   An ink set for 3D modeling by an ink jet method, comprising the model material ink according to any one of claims 1 to 7 and a curable support agent ink. A method for producing a 3D modeled object in which a model material layer formed by curing a photocurable model material ink is laminated,
Ejecting the model material ink from the nozzles of an inkjet head to form an ink layer including a portion of the model material ink; and irradiating the model material ink portion included in the formed ink layer with an actinic ray Including a step of producing a material layer,
The method for producing a 3D structure, wherein the model material ink is the model material ink according to claim 1. Discharging the curable support material ink from the nozzles of the inkjet head to form the ink layer including the support material ink portion; and
A step of removing a support material layer formed by curing the support material ink after the irradiation with the actinic ray;
A method for manufacturing the 3D structure according to claim 9.

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