Suspension for additive manufacturing and manufacturing process for products made by three-dimensional additive manufacturing

Abstract

An additive manufacturing suspension in one embodiment comprises: inorganic particles; a liquid photopolymerizable resin; and a dispersing agent. The average particle radius R of the inorganic particles satisfies a relationship of 0.1 μm ≤ R ≤ 5.0 μm. The dispersing agent includes a nonionic dispersing agent and an ionic dispersing agent, and a ratio W1:W2, being the ratio of a weight W1 of the nonionic dispersing agent to a weight W2 of the ionic dispersing agent, satisfies a relationship of 95% by weight: 5% by weight ≤ W1:W2 ≤ 10% by weight: 90% by weight. In the additive manufacturing suspension of the embodiment, a viscosity η0.5 at a shear rate stage of 0.5 s-1 and a viscosity η10 at a shear rate stage of 10 s-1 satisfy relationships of η0.5 ≥ 40 [Pa.s], η10 ≤ 340 [Pa.s], and η0.5 / η10 ≥ 2.

Description

Title of the invention: Suspension for additive manufacturing and method of manufacturing a product manufactured by three-dimensional additive manufacturing

[0001] DOMAIN

[0002] Embodiments of the present invention relate to a suspension for additive manufacturing and a method of manufacturing a product manufactured by three-dimensional additive manufacturing.

[0003] CONTEXT

[0004] In manufacturing a product manufactured by three-dimensional additive manufacturing, for example, after an additive manufacturing suspension containing inorganic particles (ceramic particles, or the like) and a liquid photopolymerizable resin is discharged from a syringe and deposited, light is emitted toward a suspension film obtained by smoothing a deposit of the additive manufacturing suspension to thereby polymerize the photopolymerizable resin, so that a polymerized layer is formed. The formation of the aforementioned polymerized layer is repeatedly performed on the basis of three-dimensional design data of the product manufactured by three-dimensional additive manufacturing, so that a stack of the polymerized layer is manufactured.Then, a degreasing treatment, for example, is carried out on the stack of the polymerized layer to thereby remove the photopolymerizable resin having been previously polymerized, and a sintering treatment is carried out to thereby sinter the inorganic particles, so that the product manufactured by three-dimensional additive manufacturing is manufactured.

[0005] When the product manufactured by three-dimensional additive manufacturing is manufactured as described above, it is required that a film thickness of the suspension film is uniform after smoothing the deposition of the additive manufacturing suspension with a scraper. In addition, it is required that a shape of the suspension film is maintained before light emission polymerization. Therefore, the additive manufacturing suspension described above is required to have a thixotropy property where a viscosity is high at a low shear rate and low at a high shear rate.

[0006] However, it is sometimes difficult to achieve sufficient thixotropic property in a suspension for additive manufacturing. In particular, when inorganic particles with small particle radius are used to achieve high-definition shaping, aggregation of inorganic particles tends to occur. in an additive manufacturing suspension, which sometimes makes the thixotropic property of the additive manufacturing suspension insufficient. As a result, it is sometimes difficult to manufacture a product manufactured by three-dimensional additive manufacturing with high precision and stability.

[0007] Therefore, the problems to be solved by the present invention are to provide a suspension for additive manufacturing and a method for manufacturing a product manufactured by three-dimensional additive manufacturing capable of easily realizing the manufacturing of the product manufactured by three-dimensional additive manufacturing with high precision and stability. Brief description of the drawings

[0008] [Fig.l] is a flowchart illustrating an overview of a method for manufacturing a product manufactured by three-dimensional additive manufacturing according to one embodiment.

[0009] [Fig.2A] is a diagram schematically illustrating an overview of a polymerized layer formation step (ST20) in the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment.

[0010] [Fig.2B] is a diagram schematically illustrating the overview of the polymerized layer formation step (ST20) in the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment.

[0011] [Fig.2C] is a diagram schematically illustrating the overview of the polymerized layer formation step (ST20) in the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment.

[0012] [Fig.2D] is a diagram schematically illustrating the overview of the polymerized layer formation step (ST20) in the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment.

[0013] [Fig.3A] is a diagram illustrating a state before a degreasing step (ST30) is implemented in the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment.

[0014] [Fig.3B] is a diagram illustrating a state after the degreasing step (ST30) is implemented in the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment.

[0015] [Fig.3C] is a diagram illustrating a state after a sintering step (ST40) is implemented in the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment.

[0016] [Fig.4] illustrates viscosity results of the additive manufacturing suspensions of respective examples which are measured under a plurality of conditions in which the shear rates are different. DESCRIPTION DETAILLEE

[0017] An additive manufacturing suspension of an embodiment is the additive manufacturing suspension which is used in manufacturing a product manufactured by three-dimensional additive manufacturing, and comprises: inorganic particles; a liquid photopolymerizable resin; and a dispersing agent. An average particle radius R of the inorganic particles satisfies a relationship of 0.1 qm < R < 5.0 qm. The dispersing agent includes a nonionic dispersing agent and an ionic dispersing agent, and a ratio W1:W2 being a ratio of a weight W1 of the nonionic dispersing agent to a weight W2 of the ionic dispersing agent satisfies a relationship of 95 wt%: 5 wt% < W1: W2 < 10 wt%: 90 wt%.In the additive manufacturing suspension of the embodiment, a viscosity q0.5 at a shear rate stage of 0.5 s 1 and a viscosity p 10 at a shear rate stage of 10 s 1 satisfy relationships of q0.5 > 40 [Pa.s], p 10 < 340 [Pa.s], and q0.5 / ql0 > 2. .

[0018] [A] Manufacturing process

[0019] A method of manufacturing a product manufactured by three-dimensional additive manufacturing according to one embodiment will be described below.

[0020] [Fig.l] is a flowchart illustrating an overview of the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment.

[0021] As illustrated in [Fig.l], the manufacturing of the product manufactured by three-dimensional additive manufacturing is carried out by implementing a preparation step (ST 10), a polymerized layer formation step (ST20), a degreasing step (ST30), and a sintering step (ST40) in order. The manufacturing of the product manufactured by three-dimensional additive manufacturing is carried out by using a manufacturing device (e.g., model number SZ-1100 manufactured by SHASHIN KAGAKU CO., LTD). Each step will be described in order.

[0022] [Al] Preparation step (ST 10)

[0023] First, in the preparation step (ST10), a suspension for additive manufacturing used in the manufacture of the product manufactured by three-dimensional additive manufacturing is prepared.

[0024] The additive manufacturing suspension is created by mixing inorganic particles, a liquid photopolymerizable resin, and a dispersing agent.

[0025] [A-1-1] Inorganic particles

[0026] Inorganic particles are ceramic particles made of alumina, zirconia (including yttrium-stabilized zirconia), and the like, for example. The particles inorganic can be metallic particles made of a metallic material.

[0027] Here, inorganic particles of which an average particle radius R satisfies a relationship represented by (formula A) below are used. The average particle radius R is a 50% volume average particle radius (radius D50) and is equivalent to a particle radius of which an integrated value is 50% in a particle size distribution measured on the basis of a laser diffraction scattering method (JIS Z 8825:2013).

[0028] 0.1 qm < R < 5.0 qm ... (formula A)

[0029] When the average particle radius R of the inorganic particles is less than a lower limit of a range indicated by (formula A), aggregation of the inorganic particles is likely to occur in the additive manufacturing slurry, sometimes resulting in a reduction of a coating property of the additive manufacturing slurry. Conversely, when the average particle radius R of the inorganic particles is greater than an upper limit of the range indicated by (formula A), a density may be reduced in the three-dimensional additive manufacturing product manufactured after the sintering step (ST40) is carried out.

[0030] In the additive manufacturing slurry, the inorganic particles are preferably contained in a range from 25% by volume or more to 70% by volume or less. When a content ratio of the inorganic particles is lower than the aforementioned range, a thixotropic property of the additive manufacturing slurry is insufficient and a density of a product manufactured by three-dimensional additive manufacturing manufactured after carrying out the sintering step (ST40) is sometimes reduced. Conversely, when the content ratio of the inorganic particles is higher than the aforementioned range, there may exist many inorganic particles which are not in a dispersed state in the additive manufacturing slurry.

[0031] [Al-2] Photopolymerizable resin

[0032] The liquid photopolymerizable resin contains a polymer component such as a monomer and an oligomer, for example, and a photopolymerization initiator for initiating polymerization of the polymer component when light is emitted. The polymer component is an acrylic monomer, for example.

[0033] [A-1-3] Dispersing agent

[0034] The dispersing agent is added to disperse the inorganic particles in the liquid photopolymerizable resin. A content ratio of the dispersing agent is preferably greater than or equal to 0.3% by weight and less than or equal to 20% by weight relative to 100% by weight inorganic particles. When the content ratio content of the dispersing agent is lower than the above-mentioned range, a reduction in dispersibility may occur due to a lack of adhesion of the dispersing agent required for the amount of inorganic particles, and when the content ratio is higher than the above-mentioned range, an increase in suspension viscosity may occur due to increased viscosities of liquids (photopolymerizable resin, dispersing agent) other than the inorganic particles, aggregation reduction, or the like.

[0035] In the present embodiment, as the dispersing agent, both the nonionic dispersing agent and the ionic dispersing agent are used. As the nonionic dispersing agent, there can be used, for example, polyoxyethylenes and polypropylene glycols being ether type, glycerins, sorbitans and propylene glycols being ester type polyhydric alcohols, polyoxyethylene sorbitans being ester-ether type, diethanolamines being alkanolamide type, and the like. Among the above, ester type polyhydric alcohols are further preferable. Examples of the usable ionic dispersing agent include carboxylic acid salts, sulfonic acid salts, sulfate ester salts, and phosphoric esters being of anion type, amine salts and ammonium salts being of cation type, and those of amphoteric type where those of anion type and those of cation type are included in the same molecule.In particular, a polycarboxylic acid copolymer being anion-type carboxylic acid salts is further preferable.

[0036] In the additive manufacturing suspension of the present embodiment, a ratio W1:W2, i.e., a ratio of a weight W1 of the nonionic dispersing agent to a weight W2 of the ionic dispersing agent satisfies a relationship represented by (formula B) below.

[0037] 95% by weight: 5% by weight < W1: W2 < 10% by weight: 90% by weight ... (formula B)

[0038] When the weight W2 of the ionic dispersing agent is greater than an upper limit (W2 = 90 wt%) indicated in (formula B) above in a total amount (100 wt%) of the weight W1 of the nonionic dispersing agent and the weight W2 of the ionic dispersing agent, it is difficult to maintain a shape of a slurry layer made of the slurry for additive manufacturing at the polymerized layer formation step (ST20). When the weight W2 of the ionic dispersing agent is less than a lower limit (W2 = 5 wt%) indicated in (formula B) above in the total amount (100 wt%) of the weight W1 of the nonionic dispersing agent and the weight W2 of the ionic dispersing agent, it is sometimes impossible to form a uniform coating film at a stage at which The additive manufacturing suspension is applied to build the suspension layer at the polymerized layer building step (ST20).

[0039] The additive manufacturing suspension of the present embodiment contains both a nonionic dispersing agent and an ionic dispersing agent as a dispersing agent. In the case of the nonionic dispersing agent, macromolecule dispersion components adhere to surfaces of the inorganic particles, making it difficult for the inorganic particles to be in contact with each other at a predetermined distance or shorter by steric hindrance repulsion. Therefore, in the additive manufacturing suspension, contact resistance between inorganic particles is suppressed, such that improved fluidity and reduced viscosity are achieved.Meanwhile, since the non-ionic dispersing agent also has an action of firmly interlacing macromolecules with each other, the single addition or addition of a large amount thereof causes aggregation in the suspension for additive manufacturing, so much so that a viscosity is increased. The ionic dispersing agent causes a large repulsive force due to steric hindrance, and the single addition or addition of a large amount thereof causes the suspension for additive manufacturing to lose a thixotropic property and thereby become a Newtonian fluid. Therefore, by adjusting a composition of the two dispersing agents, it is possible to achieve an effect of ensuring both a thixotropic property and a low viscosity in the suspension for additive manufacturing.

[0040] [A-1-4] Viscosity

[0041] In the additive manufacturing slurry of the present embodiment, a viscosity q0.5 at a shear rate stage of 0.5 s-1 and a viscosity q 10 at a shear rate stage of 10 s-1 satisfy relationships represented by (formula C1), (formula C2), and (formula C3) below. The viscosity q0.5 and the viscosity p 10 are values ​​obtained by measurement by using a B-type viscometer under a temperature condition of 23°C (JIS Z 8803).

[0042] q0.5 > 40 [Pa.s] ... (formula Cl)

[0043] qlO < 340 [Pa.s] ... (formula C2)

[0044] q0.5 / ql0 > 2 ... (formula C3)

[0045] When the viscosity q0.5 of the additive manufacturing suspension does not satisfy (formula C1) above, it is difficult to maintain the shape of the suspension layer formed with the additive manufacturing suspension at the polymerized layer formation stage (ST20). When the viscosity p 10 of the additive manufacturing suspension does not satisfy (formula C2) above, it is sometimes impossible to form a uniform coating film at a stage at which the additive manufacturing suspension is applied to form the layer of suspension at the polymerized layer formation stage (ST20). When the viscosity q0.5 and viscosity p 10 of the additive manufacturing suspension do not satisfy (formula C3) above, a thixotropic property of the additive manufacturing suspension may become insufficient.

[0046] [A-2] Step of constituting a polymerized layer (ST20)

[0047] As illustrated in [Fig. 1], after the preparation step (ST10) is carried out, the polymerized layer formation step (ST20) is carried out.

[0048] Figures 2A to 2D are diagrams schematically illustrating an overview of the polymerized layer formation step (ST20) in the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment.

[0049] In the polymerized layer formation step (ST20), as illustrated in [Fig. 2A], a deposit 10 obtained by discharging and depositing the additive manufacturing suspension from a syringe (not illustrated) is smoothed by using a scraper 100. Thereby, as illustrated in [Fig. 2B], a suspension film 20 having a uniform thickness is formed. Then, as illustrated in [Fig. 2C], a light 200 is emitted toward the suspension film 20, to thereby polymerize the photopolymerizable resin constituting the suspension film 20, so that a polymerized layer 30 is formed. As illustrated in [Fig.2D], by implementing the steps illustrated in FIGS. 2A to 2C repeatedly on the basis of three-dimensional design data of the product manufactured by three-dimensional additive manufacturing, a stack of the polymerized layer 30 is formed as a precursor of the product manufactured by three-dimensional additive manufacturing. Note that an unpolymerized portion of the suspension film 20 is removed by a cleaning treatment.

[0050] [A-3] Degreasing step (ST30), sintering step (ST40)

[0051] As illustrated in [Fig. 1], after the implementation of the polymerized layer formation step (ST20), the degreasing step (ST30) and the sintering step (ST40) are implemented.

[0052] [Fig. 3A] is a diagram illustrating a state before implementing the degreasing step (ST30) in the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment. [Fig. 3B] is a diagram illustrating a state after implementing the degreasing step (ST30) in the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment. [Fig. 3C] is a diagram illustrating a state after implementing the sintering step (ST40) in the manufacturing process of the product manufactured by three-dimensional additive manufacturing according to the embodiment. In [Fig.3A] to [Fig.3C], a cross-section of a portion of the polymerized layer that constitutes the stack is schematically illustrated.

[0053] As illustrated in [Fig.3A], the polymerized layer 30 formed in the polymerized layer formation step (ST20) comprises inorganic particles 31 and a matrix 32. The matrix 32 is a base material, and contains a polymerized component resulting from the polymerization of the photopolymerizable resin in the additive manufacturing slurry as well as the dispersing agent of the additive manufacturing slurry.

[0054] As illustrated in [Fig.3B], when a degreasing treatment is carried out in the degreasing step (ST30), the matrix 32 is thermally decomposed and removed from the polymerized layer 30 (see [Fig.3A]).

[0055] Then, as illustrated in [Fig.3C], by performing a sintering treatment in the sintering step (ST40) on the inorganic particles 31 of the stack having been subjected to the degreasing step (ST30), the inorganic particles 30 are sintered. As described above, a sintered body of the inorganic particles 31 is constituted as the product manufactured by three-dimensional additive manufacturing.

[0056] [B] Summary

[0057] The additive manufacturing slurry of the present embodiment comprises the inorganic particles, the liquid photopolymerizable resin, and the dispersing agent. The inorganic particles satisfy the relationship represented by (formula A) as described above. The dispersing agent includes the nonionic dispersing agent and the ionic dispersing agent, and the ratio W1:W2 being the ratio of the weight W1 of the nonionic dispersing agent to the weight W2 of the ionic dispersing agent satisfies the relationship represented by (formula B) as described above. Furthermore, in the additive manufacturing slurry of the present embodiment, the viscosity q0.5 at the shear rate stage of 0.5 s-1 and the viscosity q10 at the shear rate stage of 10 s-1 satisfy the relationships represented by (formula C1), (formula C2), and (formula C3), as described above.Therefore, as will be described in examples hereinafter, when the additive manufacturing slurry is applied to constitute the slurry layer in the polymerized layer constitution step (ST20), the uniform coating film can be constituted and the shape of the slurry layer constituted with the additive manufacturing slurry in the polymerized layer constitution step (ST20) is maintained. Accordingly, according to the present embodiment, it is possible to manufacture the product manufactured by three-dimensional additive manufacturing with high precision and stability. Examples

[0058] Examples of the above-mentioned embodiment will be described with reference to [Fig.4], Table 1 and Table 2. In [Fig.4], Table 1 and Table 2, Example 1 to Example 15 are working examples, and Example C1 to Example C5 are comparative examples.

[0059] [Fig.4] illustrates viscosity results of the additive manufacturing suspensions of respective examples which were measured under a plurality of conditions with different shear rates.

[0060] In Table 1, XI indicates a content ratio (wt%) of inorganic particles in the additive manufacturing slurry, X2 indicates a content ratio (wt%) of a liquid photopolymerizable resin in the additive manufacturing slurry, X31 indicates a content ratio (wt%) of a nonionic dispersing agent in the additive manufacturing slurry, and X32 indicates a content ratio (wt%) of an ionic dispersing agent in the additive manufacturing slurry. Meanwhile, in Table 2, W1 indicates a content ratio (wt%) of the nonionic dispersing agent to the inorganic particles (i.e., W1 = 100*X31 / X1) and W2 indicates a content ratio (wt%) of the ionic dispersing agent to the inorganic particles (i.e., W2 = 100*X32 / X1).

[0061] [Tables 1]

[0062] [Tables2]

[0063] [1] Manufacturing of suspension sample for additive manufacturing

[0064] [1-1] Example 1

[0065] In Example 1, the following materials were prepared as inorganic particles, a photopolymerizable resin, a nonionic dispersing agent, and an ionic dispersing agent.

[0066] (Material)

[0067] - inorganic particles: alumina particles (average particle radius: 2.3 pm, manufactured by Nippon Light Metal Company, Ltd., model number: LS-242C)

[0068] - photopolymerizable resin: acrylic resin (manufactured by Safran SA, model number: SPR-2120)

[0069] - non-ionic dispersing agent: non-ionic surfactant with polyhydric alcohol (manufactured by San Nopco Ltd., model number: SN-dispersant 9228)

[0070] - ionic dispersing agent: copolymer based on polycarboxylic acid (surfactant anionic, manufactured by NOF CORPORATION, model number: MALIALIM SC-0505K)

[0071] Then, a mixture obtained by mixing the respective materials at the content ratios XI, X2, X31, X32 (wt%) indicated in Table 1 is stirred under the following condition, thereby to manufacture a sample of the suspension for additive manufacturing.

[0072] (Agitation condition)

[0073] - agitator: ARE-250 (manufactured by THINKY CORPORATION)

[0074] - number of rotations: 800 rotations per minute

[0075] - number of revolutions: 2000 revolutions per minute

[0076] - stirring time: 5 minutes

[0077] [1-2] Example 2 to Example 6, Example C3, Example C5

[0078] In Example 2 to Example 6, Example C3 and Example C5, as shown in Table 1, a sample of the additive manufacturing suspension was manufactured similarly to Example 1 except that the content ratios XI, X2, X31, X32 (wt%) of materials are different from those in Example 1.

[0079] [1-3] Example 7 to Example 10, Example Cl, Example C4

[0080] In Example 7 to Example 10, Example C1 and Example C4, as is shown in Table 1, the following material was used as inorganic particles, unlike Example 1.

[0081] (Material)

[0082] - inorganic particles: alumina particles (average particle radius: 1.1 pm, manufactured by SUMITOMO CHEMICAL COMPANY, LTD., model number: AES-22s)

[0083] Then, a mixture obtained by mixing the respective materials at the content ratios XI, X2, X31, X32 (% by weight) indicated in Table 1 was stirred, thereby manufacturing a sample of the suspension for additive manufacturing.

[0084] [1-4] Example 11 to Example 13, Example C2

[0085] In Example 11 to Example 13 and Example C2, as shown in Table 1, the following material was used as inorganic particles, unlike Example 1.

[0086] (Material)

[0087] - inorganic particles: alumina particles (average particle radius: 0.1 qm, manufactured by TAIMEI CHEMICALS CO., LTD, model number: TM-DAR)

[0088] Then, a mixture obtained by mixing the respective materials at the content ratios XI, X2, X31, X32 (% by weight) indicated in Table 1 was stirred, thereby manufacturing a sample of the suspension for additive manufacturing.

[0089] [1-5] Example 14

[0090] In Example 14, as shown in Table 1, the following material was used as inorganic particles, unlike Example 1.

[0091] (Material)

[0092] - inorganic particles: zirconia particles (average particle radius: 1.6 qm, manufactured by DAIICHI KIGENSO KAGAKU-KOGYO CO., LTD., model number: KYZ-8)

[0093] Then, a mixture obtained by mixing the respective materials at the content ratios XI, X2, X31, X32 (% by weight) indicated in Table 1 was stirred, thereby manufacturing a sample of the suspension for additive manufacturing.

[0094] [1-6] Example 15

[0095] In Example 15, as shown in Table 1, the following material was used as inorganic particles, unlike Example 1.

[0096] (Material)

[0097] - inorganic particles: zirconia particles (average particle radius: 4.6 qm, manufactured by DAIICHI KIGENSO KAGAKU-KOGYO CO., LTD., model number: UZY-8)

[0098] Then, a mixture obtained by mixing the respective materials at the content ratios XI, X2, X31, X32 (% by weight) indicated in Table 1 was stirred, thereby manufacturing a sample of the suspension for additive manufacturing.

[0099] [2] Suspension viscosity measurement

[0100] As shown in [Fig.4] and Table 2, a viscosity of the sample of the additive manufacturing suspension of each example manufactured as above was measured.

[0101] The viscosity measurement was implemented by using the following viscometer under the following temperature condition.

[0102] - viscometer: type B viscometer HBDV2T (manufactured by EKO INSTRUMENTS CO., LTD.)

[0103] - measurement temperature: 23°C

[0104] Here, viscosity measurement was carried out under a plurality of conditions with different shear rates. [Fig. 4] illustrates results of the viscosities measured under the plurality of conditions with different shear rates. In addition, Table 2 shows a result of a viscosity q0.5 at a shear rate stage of 0.5 s 1 and a result of a viscosity p 10 at a shear rate stage of 10 s1. Furthermore, Table 2 shows a value (t|0.5 / t| 10) obtained by dividing the viscosity q0.5 at the shear rate stage of 0.5 s 1 by the viscosity p 10 at the shear rate stage of 10 s '.

[0105] [3] Exam content

[0106] As shown in Table 2, a shape retention examination and a coating property examination were performed on the sample of the additive manufacturing suspension of each example manufactured as shown above.

[0107] [3-1] Form retention examination

[0108] In the shape retention examination, in a container housing the additive manufacturing suspension of a uniform thickness (5 mm), a spatula is slid in a horizontal direction so that a bottom of the tank is visible, thereby forming a groove in the additive manufacturing suspension housed in the container. Then, 60 seconds after the spatula is slid, a state of the groove is visually observed. A width retention ratio of the groove is judged based on the following ranking criteria, to obtain a shape retention ratio of the suspension.

[0109] - rank 5: width reduction is 0% (shape retention: 100%)

[0110] - rank 4: width reduction is greater than 0% and less than or equal to 25%

[0111] - rank 3: the width reduction is greater than 25% and less than or equal to 60%

[0112] - rank 2: the width reduction is greater than 60% and less than or equal to 95% (on a practical level)

[0113] - rank 1: case where the width reduction is greater than 95% (not at a level practical)

[0114] [3-2] Coating property examination

[0115] In the coating property examination, after the suspension film is formed on a coating surface by using the additive manufacturing suspension of each example, a scraper is moved on the coating surface, thereby smoothing the suspension film to reach a thickness of 30 μm. Here, the smoothing of the suspension film is carried out under conditions of scraper moving speeds of 1 mm / s, 5 mm / s, 10 mm / s, and 25 mm / s. Then, a state of the suspension film after smoothing is visually observed and an observation result of it is judged as the coating property based on the following speed criteria.

[0116] - rank 5: the scraper movement speed is less than or equal to 25 mm / s and the suspension film is uniform

[0117] - rank 4: the scraper movement speed is less than or equal to 10 mm / s and the suspension film is uniform

[0118] - rank 3: the scraper movement speed is less than or equal to 5 mm / s and the suspension film is uniform

[0119] - rank 2: the scraper movement speed is less than or equal to 1 mm / s and the suspension film is uniform (at a practical level)

[0120] - rank 1: the scraper movement speed is less than or equal to 1 mm / s but the suspension film is not uniform (not at a practical level)

[0121] [4] Exam result

[0122] Example 1 to Example 15 satisfy the relationships (see below) represented by (formula A), (formula B), (formula C1), (formula C2), and (formula C3) mentioned above, as shown in Table 1.

[0123] 0.1 qm < R < 5.0 qm ... (formula A)

[0124] 95% by weight: 5% by weight < W1: W2 < 10% by weight: 90% by weight ... (formula B)

[0125] q0.5 > 40 [Pa.s] ... (formula Cl)

[0126] qlO < 340 [Pa.s] ... (formula C2)

[0127] q0.5 / ql0 > 2 ... (formula C3)

[0128] Thus, in Example 1 to Example 15, as illustrated in [Fig.4], sufficient thixotropy property could be obtained. Accordingly, as shown in Table 2, in Example 1 to Example 15, it is possible to obtain the shape retention property and the coating property higher than or equal to the practical level (rank 2 and above).

[0129] Conversely, Example C1 does not satisfy the relationships represented by (formula B) and (formula C2) as shown in Table 1. Therefore, in Example C1, as shown in [Fig.4], the thixotropy property is insufficient and as shown in Table 2, the coating property is reduced below the practical level (rank 2 and above).

[0130] Example C2 does not satisfy the relationship represented by (formula B) as shown in Table 1. Therefore, in Example C2, as shown in [Fig. 4], the viscosity could not be measured when the shear rate is greater than or equal to 10 s-1. Accordingly, in Example C2, as shown in Table 2, the shape retention property could not be judged and the coating property is reduced below the practical level (rank 2 and above).

[0131] Example C3 and Example C4 do not satisfy the relationships represented by (formula B) and (formula C1), as shown in Table 1. Therefore, in Example C3 and Example C4, as shown in [Fig. 4], the thixotropy property is insufficient (liquefaction). Accordingly, in Example C3 and Example C4, as shown in Table 2, the shape retention property is reduced below the practical level (rank 2 and above) and the coating property could not be judged.

[0132] Example C5 does not contain a dispersing agent as shown in Table 1 and does not satisfy the relationship represented by (formula B). Therefore, in Example C5, the sample is in a solid state and the viscosity could not be measured. Accordingly, in Example C5, as shown in Table 2, the shape retention property could not be judged and the coating property is reduced below the practical level (rank 2 and above).

[0133] <divers>

[0134] Although certain embodiments of the present invention have been described, these embodiments are presented by way of example only, and are not intended to limit the scope of the invention. The novel embodiments described herein may be embodied in various other forms; further, various omissions, substitutions, and modifications in the form of the embodiments described herein may be made without departing from the spirit of the invention. The appended claims and their equivalents are intended to encompass such changes in accordance with the scope and spirit of the invention.

[0135] LIST OF REFERENCE NUMBERS

[0136] 10: deposit, 20: suspension film, 30: polymerized layer, 31: particles inorganic, 32: matrix, 100: scraper, 200: light< / divers>

Claims

Claims

1. An additive manufacturing suspension which is used in manufacturing a product manufactured by three-dimensional additive manufacturing, the additive manufacturing suspension comprising: inorganic particles; a liquid photopolymerizable resin; and a dispersing agent, wherein an average particle radius R of the inorganic particles satisfies a relationship of 0.1 qm < R < 5.0 qm, the dispersing agent includes: a nonionic dispersing agent and an ionic dispersing agent, and a ratio W1:W2 being a ratio of a weight W1 of the nonionic dispersing agent to a weight W2 of the ionic dispersing agent satisfies a relationship of 95 wt%: 5 wt% < W1:W2 < 10 wt%: 90 wt%, a viscosity q0.5 at a shear rate stage of 0.5 s-1 and a viscosity p 10 at a shear rate stage of 10 s-1 satisfy relationships of q0.5 > 40 [Pa.s], q10 < 340 [Pa.s],s], and q0.5 / p 10 > 2, and the non-ionic dispersing agent is at least selected from ether-type polyoxyethylenes and polypropylene glycols, glycerins, sorbitans and propylene glycols being ester-type polyhydric alcohols, ester-ether-type polyoxyethylene sorbitans, alkanolamide-type diethanolamines, the ionic dispersing agent is at least selected from anion-type carboxylic acid salts, sulfonic acid salts, sulfate ester salts, and phosphoric esters, cation-type amino salts and ammonium salts, and amphoteric-type ones where anion-type ones and cation-type ones are included in the same molecule.

2. The additive manufacturing suspension according to claim 1, wherein the inorganic particles are contained at 25% by volume or more and 70% by volume or less.

3. A method of manufacturing a product manufactured by three-dimensional additive manufacturing for manufacturing the product manufactured by three-dimensional additive manufacturing by using the suspension for

4. additive manufacturing according to claim 1 or 2, the manufacturing method comprising: preparing the suspension for additive manufacturing; and constituting a polymerized layer by light emission towards a suspension film obtained by smoothing a deposit of the suspension for additive manufacturing to thereby polymerize the photopolymerizable resin, wherein a stack of the polymerized layer is formed by repetitively implementing the constitution of the polymerized layer on the basis of three-dimensional design data of the product manufactured by three-dimensional additive manufacturing. A method of manufacturing the product manufactured by three-dimensional additive manufacturing according to claim 3, further comprising: degreasing by performing a degreasing treatment on the stack obtained by stacking the polymerized layer to thereby remove the polymerized photopolymerizable resin; and sintering the inorganic particles by performing a sintering treatment on the stack on which the degreasing has been carried out.

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