JP2016196137A - Radiation-curable binder and production method of three-dimensional molded object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation-curable binder which can give a three-dimensional molded object excellent in tensile strength and moisture absorption resistance, and to provide a production method of a three-dimensional molded object.SOLUTION: The radiation-curable binder is used for a production method of a three-dimensional molded object, including: a deposition step of depositing a radiation-curable binder on a base material comprising particles and 10 mass% or more of a water-soluble resin; and a binding step of binding the particles and the water-soluble resin by the radiation-curable binder to form a three-dimensional molded object. The radiation-curable binder comprises a hydrophilic polymerizable compound having an SP value of 11 or more, in which the content of the hydrophilic polymerizable compound is 10 to 40 mass% with respect to the total amount of the radiation-curable binder.SELECTED DRAWING: None

Description

  The present invention relates to a radiation curable binder and a method for producing a three-dimensional structure.

  The ink jet recording method is capable of recording high-definition images with a relatively simple device, and has been rapidly developed in various fields. Among them, various studies have been made on a method for producing a three-dimensional three-dimensional structure using an inkjet method. For example, Patent Document 1 discloses a layer having a predetermined thickness of a powder material on a support for the purpose of providing a method for producing a three-dimensional structure having good ejection properties and excellent curability. In a method for manufacturing a three-dimensional structure, including a step of sequentially forming a step of forming the object to be formed and a step of bonding the powder material layer with a binder so as to have a cross-sectional shape obtained by cutting the object to be parallelized at 25 ° C. A method for producing a three-dimensional structure in which the binder has a viscosity of 5 to 100 mPa · s is disclosed.

JP 2005-67138 A

  Such a three-dimensional structure requires physical properties peculiar to the three-dimensional structure such as tensile strength as compared with a two-dimensional recorded object. However, the three-dimensional structure obtained by the method described in Patent Document 1 has a problem of low tensile strength.

  The present invention has been made to solve at least a part of the above-described problems, and is a radiation-curable binder capable of providing a three-dimensional structure excellent in tensile strength and moisture absorption resistance, and manufacturing a three-dimensional structure. It aims to provide a method.

  The present inventors diligently studied to solve the above problems. As a result, it was found that the above problems can be solved by using a radiation curable binder having a predetermined composition, and the present invention has been completed.

That is, the present invention is as follows.
[1]
An attachment step of attaching a radiation curable binder to a base material including particles and 10% by mass or more of a water-soluble resin; and binding the particles and the water-soluble resin with the radiation curable binder. And a binding step for forming a three-dimensional structure, the radiation-curable binder used in the method for manufacturing a three-dimensional structure,
The radiation curable binder contains a hydrophilic polymerizable compound having an SP value of 11 or more,
The content of the hydrophilic polymerizable compound is 10 to 40% by mass with respect to the total amount of the radiation curable binder.
Radiation curable binder.
[2]
The radiation curable binder according to item [1], wherein the hydrophilic polymerizable compound includes at least one selected from the group consisting of a hydroxyl group-containing compound, a compound having a heterocyclic ring containing a nitrogen atom, and N-vinylamide. .
[3]
The radiation curable binder according to [1] or [2] above, wherein the water-soluble resin contains poly (meth) acrylic acid.
[4]
The radiation curable binder according to any one of [1] to [3], wherein the molecular weight of the hydrophilic polymerizable compound is less than 500.
[5]
The radiation curable binder according to any one of [1] to [4], wherein the base material contains a solvent.
[6]
The radiation curable binder according to any one of [1] to [5], wherein the particles include inorganic particles.
[7]
The radiation curable binder according to any one of [1] to [6] above, wherein in the attaching step, the radiation curable binder is ejected by an ink jet method and adhered to the base material.
[8]
The radiation curable binder according to any one of [1] to [7], wherein the manufacturing method of the three-dimensional structure is performed by a lamination method.
[9]
The radiation curable binder according to any one of [1] to [8] above;
A base material containing particles and a water-soluble resin of 10% by mass or more,
Modeling material set.
[10]
Adhesion to which the radiation curable binder according to any one of [1] to [8] above is ejected by an ink jet method and adhered to a base material including particles and 10% by mass or more of a water-soluble resin. Process,
Binding the particles and the water-soluble resin with the radiation curable binder to form a three-dimensional model, and
Manufacturing method of a three-dimensional molded item.

It is a 1st schematic diagram which shows each process of the manufacturing method of the three-dimensional molded item of this embodiment. It is a 2nd schematic diagram which shows each process of the manufacturing method of the three-dimensional molded item of this embodiment.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary. However, the present invention is not limited to this, and the gist thereof is described below. Various modifications are possible without departing from the scope. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, positional relationships such as up, down, left and right are based on the positional relationships shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios. In the present specification, “(meth) acrylate” means both acrylate and the corresponding methacrylate.

[Radiation curable binder]
The radiation curable binder of the present embodiment includes an attachment step of attaching a radiation curable binder to a base material containing particles and a water-soluble resin of 10% by mass or more, and the radiation curable binder. And binding the particles and the water-soluble resin to form a three-dimensional model, and the radiation-curable binder used in the method for manufacturing a three-dimensional model, The radiation curable binder contains a hydrophilic polymerizable compound having an SP value of 11 or more, and the content of the hydrophilic polymerizable compound is 10 to 40 relative to the total amount of the radiation curable binder. It is mass%, and 15-35 mass% is preferable.

  As one of the methods for forming a three-dimensional structure, a radiation curable binder is attached to a base material containing particles and a water-soluble resin, and the attached radiation curable binder is cured and not cured. There is a method for manufacturing a three-dimensional structure having an arbitrary shape by removing a portion. In this method, the composition of the base material and the radiation curable binder affects the physical properties of the resulting three-dimensional model. For example, from the viewpoint of increasing the hardness of the resulting three-dimensional structure, it is conceivable to use a polyfunctional polymerizable compound in the radiation curable binder. However, since the three-dimensional model obtained in this case is inferior in tensile strength, the practicality may be limited when the three-dimensional model is to be used for some purpose.

  On the other hand, the radiation curable binder of the present embodiment can be obtained by using a predetermined amount of the water-soluble polymerizable compound to improve the binding force and obtain a three-dimensional structure excellent in tensile strength. The moisture absorption resistance of the three-dimensional structure can be improved. Hereinafter, each component position of the radiation curable binder will be described.

  The radiation curable binder of the present embodiment is used in a method for producing a three-dimensional structure, and can be particularly suitably used for a laminating method. “Lamination method” means an adhesion step in which a radiation curable binder is adhered to a base material containing particles and a water-soluble resin, and the particles and the water-soluble resin are bound by the radiation curable binder. And a binding step of forming one layer in an arbitrary direction of the three-dimensional object, and a three-dimensional object manufacturing method for forming a three-dimensional object by laminating the layers. In the attaching step, it is preferable that the radiation curable binder is ejected by an ink jet method and attached to the base material. By using the ink jet method, the precision of a model tends to be further improved by arbitrarily arranging minute droplets.

(Polymerizable compound)
The radiation curable binder of this embodiment includes a hydrophilic polymerizable compound having an SP value of 11 or more and a polymerizable compound having an SP value of less than 11 (hereinafter also referred to as “other polymerizable compound”). , Can be used together. In the present embodiment, “hydrophilic” means that the SP value is 11 or more.

The SP value of the hydrophilic polymerizable compound is 11 or more, preferably 11 to 15, and more preferably 11 to 12.5. When the SP value of the hydrophilic polymerizable compound is 11 or more, the tensile strength of the three-dimensional structure to be obtained is further improved. Moreover, it exists in the tendency which the moisture absorption resistance of the three-dimensional molded item obtained improves more because SP value of a hydrophilic polymeric compound is 12.5 or less. The SP value is also referred to as a solubilization parameter and means a value calculated using the Small formula shown below.
σ = ρ · (ΣFi) / M
(In the above formula, σ represents the SP value, ρ represents the density, Fi represents the molar attractive force constant, and
M represents the molecular weight of the repeating unit (monomer) of the polymer. )

  The hydrophilic polymerizable compound is not particularly limited, and examples thereof include a hydroxyl group-containing compound, a compound having a heterocyclic ring containing a nitrogen atom, and N vinylamide. Although it does not specifically limit as a hydroxyl-containing compound, For example, 4-hydroxybutyl acrylate (SP value 11.3), tetrahydrofurfuryl alcohol (SP value 11.58), 2-hydroxy-3-phenoxypropyl acrylate (SP value) 11.8), DA-141 (trade name, SP value 11.83) manufactured by Nagase Chemtex Corporation, and hydroxyethyl acrylamide (SP value 15.63). Moreover, it does not specifically limit as a compound which has a heterocyclic ring containing a nitrogen atom, For example, an acroyl morpholine (SP value 11.6) is mentioned. Further, the N vinylamide is not particularly limited, and examples thereof include N vinylacetamide (10.9) and N vinylformamide (SP value 11). Among these, at least one selected from the group consisting of 4hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, and acroylmorpholine is preferable. By using such a hydrophilic polymerizable compound, there is a tendency that the tensile strength and moisture absorption resistance of the resulting three-dimensional structure are further improved.

  The molecular weight of the hydrophilic polymerizable compound is preferably less than 500, more preferably 100 to 300, and still more preferably 125 to 250. When the molecular weight of the hydrophilic polymerizable compound is within the above range, the safety such as skin irritation tends to be further improved while keeping the viscosity of the ink low.

  The content of the hydrophilic polymerizable compound is 10 to 40% by mass, preferably 10 to 35% by mass, and more preferably 15 to 30% by mass with respect to the total amount of the radiation curable binder. . When the content of the hydrophilic polymerizable compound is 10% by mass or more, the tensile strength of the three-dimensional structure to be obtained is further improved. Moreover, when the content of the hydrophilic polymerizable compound is 40% by mass or less, the moisture absorption resistance of the resulting three-dimensional structure is further improved.

[Other polymerizable compounds]
The SP value of the other polymerizable compound is preferably 8.0 to 10.9, more preferably 8.5 to 10.5, and still more preferably 9.0 to 10.25. When the SP value of the other polymerizable compound is 8.0 or more, the compatibility in the ink tends to be further improved. Moreover, it exists in the tendency which the water resistance of a molded article improves more because SP value of another polymeric compound is 10.9 or less.

  Other polymerizable compounds are not particularly limited. For example, isobornyl acrylate (SP value 7.24), isostearyl acrylate (SP value 8.23), isodecyl acrylate (SP value 8.36), lauryl Acrylate (SP value 8.36), isooctyl acrylate (SP value 8.42), MEDOL-10 (trade name, manufactured by Osaka Organic Chemical Co., Ltd., (2-methyl-2-ethyl-1,3-dioxolan-4-yl) ) Methyl acrylate, SP value 8.59), diethylene glycol divinyl ether (SP value 9.07), 1,9-nonanediol diacrylate (SP value 9.08), dipentaerythritol hexaacrylate (SP value 9.31) 1,6-hexanediol diacrylate (SP value 9.31), ethyl carbitol acrylate (SP value 9.37), acrylic acid-2- (2-vinyloxyethoxy) ethyl (SP value 9.4), dipropylene glycol diacrylate (SP value 9.5), phenoxyethyl acrylate (SP value) 10). Of these, 2- (2-vinyloxyethoxy) ethyl acrylate (SP value 9.4), dipropylene glycol diacrylate (SP value 9.5), and phenoxyethyl acrylate (SP value 10) are preferable. By using such other polymerizable compounds, the tensile strength tends to be further improved.

  The content of the other polymerizable compound is preferably 55 to 80% by mass, more preferably 55 to 75% by mass, and further preferably 60 to 75% by mass with respect to the total amount of the radiation curable binder. %. When the content of the other polymerizable compound is 55% by mass or more, since the hydrophilic compound is not included more than necessary, water resistance tends to be further improved without moisture absorption. Moreover, since content of another polymeric compound is 80 mass% or less, since it does not drop hydrophilicity more than necessary, it exists in the tendency for the tensile strength of a molded article to improve more.

(Polymerization inhibitor)
The radiation curable binder of this embodiment may further contain a polymerization inhibitor. Although it does not specifically limit as a polymerization inhibitor, For example, hydroquinones represented by hydroquinone, hydroquinone monomethyl ether (MEHQ), 1-o-2,3,5-trimethylhydroquinone, 2-tert-butylhydroquinone; Catechols typified by 4-methylcatechol and 4-tert-butylcatechol; phenol, butylhydroxytoluene, butylhydroxyanisole, p-methoxyphenol, cresol, pyrogallol, 3,5-di-t-butyl-4-hydroxy Toluene, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-butylphenol), and 4,4′-thiobis (3-methyl-6- Phenol represented by t-butylphenol) A compound having a 2,2,6,6-tetramethylpiperidine-N-oxyl skeleton represented by 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxyl, 2,2 , 6,6-Tetramethylpiperidine skeleton compound, 2,2,6,6-tetramethylpiperidine-N-alkyl skeleton compound, and 2,2,6,6-tetramethylpiperidine-N-acyl skeleton Hindered amines represented by the compound having Among these, p-methoxyphenol is more preferable. In addition, a polymerization inhibitor may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the polymerization inhibitor is preferably 0.10 to 0.30% by mass, more preferably 0.15 to 0.25% by mass, based on the total amount of the radiation curable binder. Preferably it is 0.175-0.20 mass%. When the content of the polymerization inhibitor is within the above range, the storage stability of the radiation curable binder and the binding properties of the particles and the water-soluble resin tend to be further improved.

[Surfactant]
The radiation curable binder of this embodiment may further contain a surfactant. The surfactant is not particularly limited, and examples thereof include acetylene glycol surfactants, fluorine surfactants, and silicone surfactants. Of these, silicone surfactants are preferred from the viewpoint of wettability to particles.

  Although it does not specifically limit as a commercial item of surfactant, For example, BYK UV3500, UV3570, BYK350 (BIC Chemie Japan company brand name) is mentioned.

  The content of the surfactant is preferably 0.050 to 1.5% by mass, more preferably 0.10 to 1.0% by mass, based on the total amount of the radiation curable binder. Preferably it is 0.25-0.75 mass%. When the content of the surfactant is within the above range, the wettability of the radiation curable binder to the particles and the water-soluble resin is further improved, and as a result, the binding properties of the particles and the water-soluble resin are further improved. Tend to.

(Polymerization initiator)
The radiation curable binder of this embodiment may further contain a polymerization initiator. The polymerization initiator is not particularly limited. For example, aromatic ketones, acylphosphine compounds, aromatic onium salt compounds, organic peroxides, thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, Examples thereof include azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds. Of these, acylphosphine compounds are preferred. By using such a polymerization initiator, since the internal curability is excellent, the binding property of the particles tends to be further improved, and curing with an inexpensive LED light source becomes possible.

  Although it does not specifically limit as a commercial item of a polymerization initiator, For example, IRGACURE 651 (2,2-dimethoxy-1,2-diphenylethane-1-one), IRGACURE 184 (1-hydroxy-cyclohexyl-phenyl-ketone) DAROCUR 1173 (2-hydroxy-2-methyl-1-phenyl-propan-1-one), IRGACURE 2959 (1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1 -Propan-1-one), IRGACURE 127 (2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl] -2-methyl-propan-1-one} IRGACURE 907 (2-methyl-1- (4-methylthiophenyl)- -Morpholinopropan-1-one), IRGACURE 369 (2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1), IRGACURE 379 (2- (dimethylamino) -2- [ (4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone), DAROCUR TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), IRGACURE 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide), IRGACURE 784 (bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole) -1-yl) -phenyl) titanium), IRGACURE OXE 01 (1.2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)]), IRGACURE OXE 02 (ethanone, 1- [9-ethyl-6- (2-methyl) Benzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime)), IRGACURE 754 (oxyphenylacetic acid, 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester and oxyphenylacetic acid, 2- (2-hydroxyethoxy) ethyl ester mixture (above, manufactured by Ciba Japan KK), KAYACURE DETX-S (2,4-diethylthioxanthone) (Nippon Chemical Co., Ltd. (Nippon) Kayaku Co. , Ltd., Ltd. ), Lucirin TPO, LR 8893, LR 8970 (above, manufactured by BASF), Speedcure TPO (above, made by Lambson) and Ubekrill P36 (made by UCB). A polymerization initiator may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the polymerization initiator is preferably 2.5 to 15% by mass, more preferably 5.0 to 12.5% by mass, and still more preferably based on the total amount of the radiation curable binder. 7.5 to 10% by mass. When the content of the polymerization initiator is within the above range, the binding properties of the particles and the water-soluble resin tend to be further improved.

[Modeling material set]
The modeling material set of this embodiment includes a base material including particles, 10% by mass or more of a water-soluble resin, and the radiation curable binder.

[Method for producing three-dimensional model]
The manufacturing method of the three-dimensional structure according to the present embodiment includes an attachment step in which the radiation curable binder is ejected by an inkjet method and adhered to a base material containing particles and 10% by mass or more of a water-soluble resin. A binding step of binding the particles and the water-soluble resin with the radiation curable binder to form a three-dimensional model.

  Hereinafter, each step will be described. FIG.1 and FIG.2 is a schematic diagram which shows each process of the manufacturing method of the three-dimensional molded item of this embodiment.

[Layer formation process]
The manufacturing method of the three-dimensional molded item of this embodiment may have a layer formation process which forms the layer 1 containing a base material before an adhesion process (1a, 1d). The layer forming method is not particularly limited, and examples thereof include a squeegee method, a screen printing method, a doctor blade method, and a spin coating method. Moreover, formation of the layer 1 may be performed on the support body 9, or may be performed on the three-dimensional molded item already formed partially.

  The thickness of the layer 1 to be formed is preferably 10 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less. Thereby, while making the productivity of the three-dimensional structure 100 sufficiently excellent, the occurrence of unintentional unevenness in the three-dimensional structure 100 to be manufactured is more effectively prevented, and the dimensional accuracy of the three-dimensional structure 100 is improved. It can be made particularly excellent.

[Drying process]
The manufacturing method of the three-dimensional molded item of this embodiment may have a drying process which heat-drys the layer 1 obtained by the layer formation process (1a, 1d). In the case where the base material contains a binder resin, the inorganic particles can be bonded (temporarily fixed) by the drying step, and the unintentional scattering of the inorganic particles can be effectively prevented. When the base material contains a solvent, at least a part of the solvent contained in the base material can be removed by a drying process. By removing the solvent, the tensile strength and the tensile elongation tend to be further improved as compared with the case where the adhesion step and the binding step are performed without removing the solvent.

  The heating temperature in the drying step is preferably not less than the glass transition temperature of the binder resin, more preferably not less than 30 ° C and not more than 140 ° C, and further preferably not less than 40 ° C and not more than 120 ° C.

[Adhesion process]
The attaching step is a step in which the radiation curable binder 2 is ejected by an ink jet method and attached to a base material (layer 1) containing particles and 10% by mass or more of a water-soluble resin (1b, 1e). . As the inkjet method, a piezo method, a method in which a radiation curable binder is ejected by bubbles generated by heating ink, or the like can be used. By using an inkjet system, a three-dimensional model with higher accuracy can be obtained. The base material to which the radiation curable binder is attached later becomes a three-dimensional model.

[Base material]
The base material contains particles and 10% by mass or more of a water-soluble resin, and may contain other components such as a solvent as necessary. In the present embodiment, the base material may be a paste or a powder. In particular, since it is a paste-type base material, the inorganic particles are less likely to be scattered and the lamination property tends to be improved.

(particle)
Although it does not specifically limit as particle | grains, For example, organic particles, such as inorganic particles, such as a silica; polymethyl methacrylate, are mentioned. Among these, inorganic particles such as silica are preferable from the viewpoints of ensuring strength, being inexpensive and having many variations.

  Content of particle | grains is 55-85 mass% with respect to the total amount of a base material, Preferably it is 60-80 mass%, More preferably, it is 65-75 mass%.

(Water-soluble resin)
The water-soluble resin is not particularly limited. For example, poly (meth) acrylic acid, polyvinyl alcohol, naphthalene sulfonate polymarine condensate, styrene / maleic anhydride copolymer, olefin / maleic anhydride copolymer, Examples thereof include carboxymethyl cellulose, polystyrene sulfonate, acrylamide / acrylic acid copolymer, alginic acid, polyalkylene polyamine, polyacrylamide, polyethyleneimine, aminoalkyl (meth) acrylate copolymer, polymer starch, and satkinsan. Among these, poly (meth) acrylic acid is preferable from the viewpoint of compatibility. When the compatibility between the binder and the water-soluble resin is further improved, both are compatible in the adhesion step, and a three-dimensional structure with a further improved tensile hardness can be obtained in the binding step. The term “water-soluble” means that it can be dissolved in water at room temperature (25 ° C.) to form an aqueous solution.

  Content of water-soluble resin is 10 mass% or more with respect to the total amount of a base material, Preferably it is 11 mass% or more, More preferably, it is 15 mass% or more. Although the upper limit of content of water-soluble resin is not specifically limited, For example, 50 mass% or less is preferable, 30 mass% or less is more preferable, and 20 mass% or less is further more preferable.

(solvent)
Although it does not specifically limit as a solvent, For example, water and ethanol are mentioned. Even if water is used as the solvent, the physical properties of the resulting three-dimensional structure can be improved with the radiation curable binder of the present embodiment. In the case of containing a solvent, the base material can be pasty. By using a paste, there is a tendency that applicability and suppression of powder scattering are further improved. This increases the accuracy of the model and the reliability of the device.

[Binding process]
The binding step is a step of forming the three-dimensional structure 3 by binding the particles and the water-soluble resin with a radiation curable binder (1c, 1f). The radiation curable binder exists so as to fill the gap between the particles and the water-soluble resin, and the particles and the water-soluble resin can be bound by polymerizing the polymerizable compound in the radiation curable binder. . The radiation curable binder also contributes to bonding between adjacent layers. Specifically, by polymerizing a polymerizable compound in a radiation curable binder that exists so as to fill a gap between a part of a layer (three-dimensional modeled object) that has already been formed and particles before binding. , Particles can be bound.

  Although it does not specifically limit as a binding method, For example, the method of irradiating light with respect to the particle | grains and water-soluble resin to which the radiation-curing-type binder adhered, or the method of heating is mentioned. For example, the radiation curable type can be obtained by irradiating light to the particles and water-soluble resin to which the radiation curable binder is attached, or by heating the particles and water-soluble resin to which the radiation curable binder is attached. The polymerization reaction of the water-soluble polymerizable compound contained in the binder starts, and the particles and the water-soluble resin are bound. Examples of the light source (radiation source) include a mercury lamp, a gas / solid laser, an ultraviolet light emitting diode (UV-LED), and an ultraviolet laser diode (UV-LD).

(Laminated)
After the binding process, a layer is formed again on the obtained three-dimensional modeled object, and the three-dimensional modeled object 3 having an arbitrary shape is formed by repeating the layer forming process, the drying process, the attaching process, and the binding process. (1 g). As a result, among the layers 1, the particles and the water-soluble resin at the site to which the radiation curable binder 2 has been applied are combined, and a three-dimensional structure as a laminate in which a plurality of layers 1 in such a state are stacked. A model 100 is obtained (1h).

[Removal process]
The manufacturing method of the three-dimensional molded item of this embodiment may have the removal process which removes the particle | grains and water-soluble resin which are not bound by the radiation curable binder (1h). The method for removing the particles and the water-soluble resin is not particularly limited. For example, a method for removing unbound particles by a brush, a method for removing unbound particles by suction, a method for blowing a gas such as air, a water And a method of applying a liquid such as a method of immersing the laminate obtained as described above in a liquid, a method of spraying a liquid, a method of applying vibration such as ultrasonic vibration, and the like.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited in any way by the following examples.

[Material of radiation curable binder]
The main materials of the radiation curable binder used in the following examples and comparative examples are as follows.
[Water-soluble polymerizable compound]
4HBA (4-hydroxybutyl acrylate)
DA141 (2-hydroxy-3-phenoxypropyl acrylate)
ACMO (Acroylmorpholine)
N vinylformamide [other polymerizable compounds]
PEA (phenoxyethyl acrylate)
VEEA (2- (2-vinyloxyethoxy) ethyl acrylate)
DPGDA (dipropylene glycol diacrylate)
(Polymerization inhibitor)
MEHQ
[Surfactant]
BYK UV3500 (silicone surfactant, manufactured by Big Chemie Japan)
(Polymerization initiator)
Irgacure 819 (manufactured by Ciba Japan)
Speedcure TPO (Lambson)

[Preparation of radiation curable binder]
Each material was mixed with the composition shown in Table 1 below, and stirred sufficiently to obtain each radiation curable binder. In Table 1 below, the numerical unit is mass%, and the total is 100.0 mass%.

[Material of base material]
The main materials of the base material used in the examples and comparative examples are as follows.
〔particle〕
Silica particles (FB5D, manufactured by Denki Kagaku Kogyo)
Polymethyl methacrylate particles (MB20X-5, manufactured by Sekisui Plastics Co., Ltd.)
(Water-soluble resin)
Polyacrylic acid ammonium salt 1 (AS1100 (30% aq) manufactured by Toa Gosei Co., Ltd.)
Polyacrylic acid ammonium salt 2 (AS1800 (45% aq), manufactured by Toa Gosei Co., Ltd.)
〔solvent〕
water

[Base material adjustment]
Each material was mixed with the composition shown in Table 1 below, and stirred sufficiently to obtain each base material. In Table 1 below, the numerical unit is mass%, and the total is 100.0 mass%.

[Evaluation]
[Tensile strength and tensile elongation]
A paste material was applied on the modeling stage by a squeegee method and dried with a dryer to form a base material with a film thickness of 50 μm (step 1). The film thickness can be controlled by the height of the stage base and the squeegee. Next, the radiation curable binder obtained as described above is filled into a laminating apparatus (in-house manufactured by Seiko Epson), and discharged by an ink jet method to a portion to be bound, and a base material of each composition (Step 2). The base material to which the radiation curable binder was attached was irradiated with LED light of 395 nm, and the particles and the water-soluble resin were bound by the radiation curable binder (Step 3). Next, the stage was lowered by 50 μm, and the operations of Steps 1 to 3 were repeated, thereby stacking a three-dimensional object every 50 μm. This operation was repeated 200 times to form a three-dimensional structure having a 4 mm-thick dumbbell structure in accordance with JIS K 7161. Thereafter, the obtained three-dimensional model was annealed at 80 ° C. for 1 hour.

The tensile strength and tensile elongation of the three-dimensional structure obtained in this way were measured under the conditions of tensile yield stress: 50 mm / min in accordance with JIS K 7161: 1994 (ISO 527: 1993). The evaluation criteria are shown below.
(Evaluation criteria for tensile strength)
A: Tensile strength is 14 MPa or more.
B: The tensile strength is 8 MPa or more and less than 14 MPa.
C: Tensile strength is less than 8 MPa.
(Evaluation criteria for tensile elongation)
A: Tensile elongation is 2.5% or more.
B: Tensile elongation is less than 2.5%.

[Hygroscopic resistance]
50 cc of the radiation curable binder obtained as described above was placed in a 100 cc sample bottle and left for 1 week in an environment of 40 ° C. and 80% RH without a lid. The weight change rate of the binder before and after being left was calculated, and the hygroscopicity was evaluated according to the following evaluation criteria based on the obtained value.
(Evaluation criteria)
A: Less than 5% moisture absorption B: More than 5% moisture absorption

[Storage stability]
The viscosity at 20 ° C. of the radiation curable binder obtained as described above was measured using MCR-100 (manufactured by Physa). Thereafter, the binder was enclosed in a polyethylene pack (manufactured by Seiko Epson) and stored in a constant temperature bath at 60 ° C. for 10 days. The viscosity of the binder after storage was measured, the viscosity change rate before and after storage was calculated, and storage stability was evaluated according to the following evaluation criteria based on the obtained value.
(Evaluation criteria)
A: Viscosity change rate of less than 10% B: Viscosity change rate of 10% or more

[Laminate]
The base material was laminated by a squeegee method, and the lamination property was evaluated according to the following evaluation criteria.
A: Can be stacked at a squeegee speed of 50 mm / sec. B: Cannot be stacked at a squeegee speed of 50 mm / sec. Can be stacked at 10 mm / sec. C: Cannot be stacked at a squeegee speed of 10 mm / sec.

  It was found that Comparative Example 1 in which the content of the hydrophilic polymerizable compound was too large was inferior in tensile strength, hygroscopicity, and storage stability as compared with Examples. Moreover, it turns out that the comparative example 2 with which there is too little content of a hydrophilic polymeric compound, and the comparative example 3 which does not contain a hydrophilic polymeric compound are inferior to tensile strength and tensile elongation compared with each Example. It was. Furthermore, Comparative Examples 4 and 5 using a base material that does not contain a water-soluble resin or has a low content of water-soluble resin are inferior in tensile strength and tensile elongation compared to each of the examples, and have good lamination properties. It turned out to be inferior.

  DESCRIPTION OF SYMBOLS 1 ... Base material, 1 ... Layer, 2 ... Radiation hardening type binder, 3 ... Three-dimensional molded item, 100 ... Three-dimensional molded item, 9 ... Support body (stage)

Claims (10)

An attachment step of attaching a radiation curable binder to a base material including particles and 10% by mass or more of a water-soluble resin; and binding the particles and the water-soluble resin with the radiation curable binder. And a binding step for forming a three-dimensional structure, the radiation-curable binder used in the method for manufacturing a three-dimensional structure,
The radiation curable binder contains a hydrophilic polymerizable compound having an SP value of 11 or more,
The content of the hydrophilic polymerizable compound is 10 to 40% by mass with respect to the total amount of the radiation curable binder.
Radiation curable binder.   The radiation curable binder according to claim 1, wherein the hydrophilic polymerizable compound includes at least one selected from the group consisting of a hydroxyl group-containing compound, a compound having a heterocyclic ring containing a nitrogen atom, and N-vinylamide.   The radiation-curable binder according to claim 1 or 2, wherein the water-soluble resin contains poly (meth) acrylic acid.   The radiation curable binder according to any one of claims 1 to 3, wherein the hydrophilic polymerizable compound has a molecular weight of less than 500.   The radiation curable binder according to claim 1, wherein the base material contains a solvent.   The radiation curable binder according to claim 1, wherein the particles include inorganic particles.   The radiation curable binder according to any one of claims 1 to 6, wherein, in the attaching step, the radiation curable binder is ejected by an ink jet method to adhere to the base material.   The radiation curable binder according to claim 1, wherein the manufacturing method of the three-dimensional structure is performed by a lamination method. The radiation curable binder according to any one of claims 1 to 8,
A base material containing particles and a water-soluble resin of 10% by mass or more,
Modeling material set. An adhesion step in which the radiation curable binder according to any one of claims 1 to 8 is ejected by an ink jet method and adhered to a base material containing particles and a water-soluble resin of 10% by mass or more,
Binding the particles and the water-soluble resin with the radiation curable binder to form a three-dimensional model, and
A manufacturing method of a three-dimensional model

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