JP6874531B2 - Manufacturing method of three-dimensional model, powder material used for it, and fluid for bonding - Google Patents

Description

The present invention relates to a method for producing a three-dimensional model, a resin composition used therein, and a binding fluid.

In recent years, various methods have been developed that can relatively easily produce three-dimensional objects having complicated shapes, and rapid prototyping and rapid manufacturing using such methods are attracting attention. As a method for producing a three-dimensional model, a fused deposition modeling method and a powder bed fusion bonding method are known.

In the Fused Deposition Modeling method, for example, the resin composition is melt-extruded into filaments to form a thin layer on the stage in which the three-dimensional model is finely divided in the thickness direction. Then, by repeating melt extrusion and formation of a thin layer, a three-dimensional model having a desired shape is obtained.

On the other hand, in the laser sintering powder lamination method, particles made of a resin material or a metal material are spread flat to form a thin layer. Then, a laser beam is irradiated to a desired position of the thin layer to selectively sinter or melt-bond adjacent particles. That is, also in this method, a modeled object layer is formed by subdividing the three-dimensional modeled object in the thickness direction. A powder material is further spread on the modeled object layer formed in this manner, and laser light irradiation is repeated to produce a three-dimensional modeled object having a desired shape.

In recent years, new modeling methods have been actively studied. For example, a thin layer of a powder material made of a resin material, a metal material, or the like is formed, and a binding fluid (adhesive or the like) for binding the powder material is applied to a desired position of the thin layer, and the binding fluid is applied. A peeling fluid for suppressing the diffusion of the binding fluid is applied to the non-applied area. Then, only the powder material in the region coated with the binding fluid is cured to obtain a modeled object layer. Further, a method of producing a three-dimensional model having a desired shape by repeating these steps and laminating the model layers has been proposed (for example, Patent Document 1).

On the other hand, there is also a method of forming a thin layer containing nanocellulose, applying a binder liquid to a desired region of the thin layer, and solidifying the thin layer only in the region to which the binder liquid is applied to form a three-dimensional model. It has been proposed (Patent Document 2).

Japanese Unexamined Patent Publication No. 2004-262243 Japanese Unexamined Patent Publication No. 2015-21260

In the method of Patent Document 1, the accuracy of the modeled object largely depends on the miscibility of the coupling fluid and the peeling fluid. It is difficult to sufficiently suppress the miscibility and diffusion of the binding fluid and the exfoliating fluid simply by adding a solvent that is difficult to mix, and the interface between the model layer and the other regions becomes ambiguous. It was easy. Therefore, the dimensional accuracy of the obtained three-dimensional model tends to decrease.

Further, in recent years, after applying an infrared light absorber or the like to the binding fluid and applying the binding fluid and the peeling fluid, only the powder material in the region to which the binding fluid is applied is heated and melted by irradiating infrared light. A method for making the fluid is also proposed (HP JET FUSION 3D (registered trademark) method). In this method, the powder material (thermoplastic resin, etc.) in the region to which the binding fluid is applied can be partially heated and melted by batch irradiation with infrared light or the like, and the molding is much faster than the conventional method. It is possible. However, even with this method, it is difficult to sufficiently suppress the miscibility with the coupling fluid and the peeling fluid. Then, when the infrared absorber or the like contained in the binding fluid enters the region where the modeled object layer is not formed together with the solvent or the like, the interface between the region where the modeled object layer is formed and the other regions tends to be ambiguous. The dimensional accuracy of the three-dimensional model to be created was likely to decrease.

On the other hand, the method of Patent Document 2 also has a problem that the binder liquid easily diffuses and the dimensional accuracy of the three-dimensional modeled object tends to decrease.

The present invention has been made in view of the above problems. That is, an object of the present invention is to provide a method for producing a three-dimensional model having high dimensional accuracy, a powder material used for the method, and a fluid for bonding.

The first aspect of the present invention is the following method for manufacturing a three-dimensional model.
[1] The thin layer forming step of forming a thin layer containing a powder material containing a thermoplastic resin, a binding fluid containing an energy absorber, and a peeling fluid for suppressing diffusion of the binding fluid are described above. The fluid coating step of applying the thin layer to the regions adjacent to each other and the thermoplastic resin in the region to which the binding fluid is applied are melted by irradiating the thin layer with energy after the fluid coating step to melt the model layer. A method for producing a three-dimensional model, which comprises an energy irradiation step of forming the above, wherein the powder material and / or the binding fluid contains nanofibers of a polysaccharide, and the binding fluid has a specific dielectric constant. A method for producing a three-dimensional model, which comprises a fluid of 20 to 50.

[2] The method for producing a three-dimensional model according to [1], wherein the peeling fluid contains a solvent having a relative permittivity of 1 to 5.
[3] The method according to [1] or [2], wherein the thin layer forming step, the fluid coating step, and the energy irradiation step are repeated a plurality of times to stack the shaped object layers to form a three-dimensional shaped object. Manufacturing method of three-dimensional model.
[4] The method for producing a three-dimensional model according to any one of [1] to [3], wherein in the fluid coating step, the bonding fluid and the peeling fluid are coated by an inkjet method.
[5] The method for producing a three-dimensional model according to any one of [1] to [4], wherein the energy absorber is an infrared light absorber and is irradiated with infrared light in the energy irradiation step.

The second aspect of the present invention lies in the following powder materials and bonding fluids.
[6] A powder material used in the method for producing a three-dimensional model according to any one of the above [1] to [5], which comprises a thermoplastic resin and nanofibers of a polysaccharide.
[7] The powder material according to [6], wherein the polysaccharide nanofibers have an average fiber diameter of 3 to 30 nm and an average fiber length of 200 to 10000 nm.
[8] The powder material according to [6] or [7], wherein the polysaccharide nanofibers contain cellulose nanofibers.

[9] A binding fluid used in the method for producing a three-dimensional model according to any one of the above [1] to [5], which comprises an energy absorber, a polysaccharide nanofiber, and a relative permittivity of 20. A binding fluid, comprising a solvent of ~ 50.
[10] The binding fluid according to [9], wherein the polysaccharide nanofibers have an average fiber diameter of 3 to 30 nm and an average fiber length of 200 to 10000 nm.
[11] The binding fluid according to [9] or [10], wherein the polysaccharide nanofibers contain cellulose nanofibers.

According to the present invention, it is possible to provide a method for producing a three-dimensional model, a powder material used for the method, and a fluid for bonding, which have high dimensional accuracy of the obtained three-dimensional model.

FIG. 1 is a side view schematically showing a configuration of a three-dimensional modeling apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a main part of a control system of a three-dimensional modeling apparatus according to an embodiment of the present invention.

As described above, conventionally, a bonding fluid for binding the powder material and a peeling fluid for suppressing the diffusion of the bonding fluid are applied to the thin layer made of the powder material so as to be adjacent to each other. , A method has been proposed in which only the powder material in the region coated with the binding fluid is bonded to obtain a three-dimensional model. In this method, two immiscible fluids are applied separately on a thin layer of powder material.

However, conventionally, the miscibility of the binding fluid and the peeling fluid is adjusted by the type of the solvent contained therein, and such a method cannot sufficiently suppress the miscibility of the binding fluid and the peeling fluid. was difficult. Therefore, in the conventional method, there is a problem that the boundary between the region coated with the coupling fluid and the region coated with the peeling fluid tends to be ambiguous, and the dimensional accuracy of the obtained three-dimensional model tends to be low. ..

On the other hand, as a result of diligent studies by the present inventors, it was found that the powder material and / or the binding fluid contained polysaccharide nanofibers, and that the binding fluid contained a solvent having a relatively high relative dielectric constant (a solvent). It has been found that the dimensional accuracy of the obtained three-dimensional model is remarkably improved by including (hereinafter, also referred to as “polar solvent”). Nanofibers of polysaccharides have a relatively large number of polar groups such as hydroxyl groups, and have high affinity with polar solvents (solvents having a high relative permittivity). Therefore, when the powder material contains the polysaccharide nanofibers, the binding fluid (particularly the polar solvent) applied to the powder material is attracted to the polysaccharide nanofibers. As a result, it becomes difficult for the components in the binding fluid to diffuse to the side to which the peeling fluid is applied, and it becomes easy to melt only the powder material in the region to which the bonding fluid is applied.

On the other hand, when the binding fluid contains nanofibers of a polysaccharide, when the binding fluid is applied to the powder material, the nanofibers are solid and fibrous, so that they tend to stay in place without diffusing. On the other hand, the polar solvent and the like in the binding fluid have a property of being relatively easy to move, but are attracted to the nanofiber side due to the affinity between the nanofiber and the polar solvent. Therefore, also in this case, the components in the binding fluid are less likely to diffuse to the side to which the stripping fluid is applied, and only the powder material in the region to which the binding fluid is applied is likely to be melted.

Therefore, according to the manufacturing method of the present invention, it is possible to form a three-dimensional model with high dimensional accuracy. Hereinafter, the method for producing the three-dimensional model will be described separately in a mode in which the polysaccharide nanofibers are included in the powder material (first embodiment) and a mode in which the polysaccharide nanofibers are included in the binding fluid (second embodiment).

1-1. About the first embodiment The method for producing a three-dimensional model of the present embodiment includes a thin layer forming step of forming a thin layer containing a powder material containing at least a thermoplastic resin and nanofibers of a polysaccharide, a fluid for binding, and peeling. The fluid coating step of applying the fluid for bonding to the regions adjacent to each other of the thin layer and the thin layer after the fluid coating step are irradiated with energy to melt the thermoplastic resin in the coating region of the coupling fluid to form a model layer. Including an energy irradiation step of forming. The manufacturing method of the present embodiment may have other steps, if necessary.

(1) Thin layer forming step In the thin layer forming step of the present embodiment, a thin layer mainly containing a powder material containing at least a thermoplastic resin and nanofibers of a polysaccharide is formed. The method for forming the thin layer is not particularly limited as long as a layer having a desired thickness can be formed. For example, this step can be a step of laying the powder material supplied from the powder supply unit of the three-dimensional modeling apparatus flat on the modeling stage by a recorder. The thin layer may be formed directly on the modeling stage or may be formed so as to be in contact with the already spread powder material or the already formed modeling layer.

The thickness of the thin layer is the same as the thickness of the desired model layer. The thickness of the thin layer can be arbitrarily set according to the accuracy of the three-dimensional model to be manufactured, but is usually 0.01 mm or more and 0.30 mm or less. By setting the thickness of the thin layer to 0.01 mm or more, the already produced modeled object layer is melted by energy irradiation for forming a new modeled object layer (energy irradiation in the energy irradiation step described later). Can be prevented. Further, when the thickness of the thin layer is 0.01 mm or more, it becomes easy to spread the powder material uniformly. Further, by setting the thickness of the thin layer to 0.30 mm or less, energy (for example, infrared light) can be conducted to the lower part of the thin layer in the energy irradiation step described later. This makes it possible to melt the thermoplastic resin in a desired region (region to which the binding fluid is applied) over the entire thickness direction. From the above viewpoint, the thickness of the thin layer is more preferably 0.01 mm or more and 0.20 mm or less.

After forming the thin layer, preheating may be performed if necessary. By performing preheating, it is possible to reduce the amount of energy to be irradiated in the energy irradiation step described later. Furthermore, it becomes possible to efficiently form the modeled object layer in a short time. The preheating temperature is lower than the temperature at which the thermoplastic resin contained in the thin layer melts, and is lower than the boiling point of the solvent contained in the bonding fluid or the peeling fluid to be applied in the fluid coating step described later. preferable. Specifically, at the melting point of the thermoplastic resin or the boiling point of the solvent contained in the bonding fluid or the peeling fluid, the temperature on the lower side of the melting point or boiling point is -50 ° C or higher to -5 ° C or lower. It is preferably -30 ° C or higher and more preferably -5 ° C or lower. At this time, the heating time is preferably 1 to 60 seconds, more preferably 3 to 20 seconds. By setting the heating temperature and the heating time within the above ranges, the amount of energy irradiation in the energy irradiation step can be reduced.

The powder material used in this step may contain at least a thermoplastic resin and nanofibers of a polysaccharide, and may contain various additives, a flow agent, a filler, and the like, if necessary. Here, the powder material may separately contain particles made of a thermoplastic resin and nanofibers of a polysaccharide, or may contain particles containing a thermoplastic resin and nanofibers of a polysaccharide. Moreover, the powder material may contain both of these.

When the thermoplastic resin and the polysaccharide nanofibers are contained in the same particles, it is preferable that at least a part of the polysaccharide nanofibers is exposed on the surface of the particles. Since a part of the polysaccharide nanofibers is exposed, the binding fluid applied in the fluid coating step described later is attracted to the nanofibers and is difficult to diffuse.

More preferably, the average particle size of the particles made of the thermoplastic resin or the particles containing the thermoplastic resin and the nanofibers of the polysaccharide is 10 μm or more and 100 μm or less. When the average particle size of these particles is within the range, it is possible to produce a three-dimensional model having a complicated shape. The average particle size of the particles is the volume average particle size measured by the dynamic light scattering method. The volume average particle size can be measured by a laser diffraction type particle size distribution measuring device (MT3300EXII manufactured by Microtrac Bell) equipped with a wet disperser.

Here, the thermoplastic resin contained in the powder material is not particularly limited as long as it is a resin that can be melted in the energy irradiation step described later, and is appropriately selected according to a desired type of three-dimensional model and a method for forming the three-dimensional model. Will be done. The powder material may contain only one type of thermoplastic resin, or may contain two or more types of thermoplastic resin.

As the thermoplastic resin, a resin or the like contained in particles for general three-dimensional modeling can be used, but if the melting temperature of the thermoplastic resin is too high, the amount of energy irradiation required in the energy irradiation step described later will be increased. The number increases, and it may take time to form the model layer, or the polysaccharide nanofibers may deteriorate. Therefore, the melting temperature of the thermoplastic resin is preferably 300 ° C. or lower, more preferably 230 ° C. or lower. On the other hand, from the viewpoint of heat resistance of the obtained three-dimensional model, the melting temperature of the thermoplastic resin is preferably 100 ° C. or higher, more preferably 120 ° C. or higher. The melting temperature can be adjusted depending on the type of thermoplastic resin and the like.

Examples of the thermoplastic resin include polyamide resins such as polyamide 6, polyamide 11, polyamide 12, polypropylene resin, polyethylene resin, polyphenylene sulfide resin, polyacetal resin, polybutylene terephthalate resin, polyamide elastomer resin, thermoplastic polyurethane and the like. ..

The powder material preferably contains 40 to 99.5% by mass of the thermoplastic resin, more preferably 50 to 99% by mass, and even more preferably 70 to 99% by mass. When the powder material contains 40% by mass or more of the thermoplastic resin, the strength of the obtained three-dimensional model is sufficiently high. On the other hand, when the amount of the thermoplastic resin is 99.5% by mass or less, the amount of nanofibers and the like is relatively sufficient, and the dimensional accuracy of the obtained three-dimensional model tends to be improved.

On the other hand, the polysaccharide nanofibers may be integrated with the thermoplastic resin as described above, or may be contained separately from the thermoplastic resin. The nanofibers of such polysaccharides are not particularly limited as long as they are fibers derived from polysaccharides having an average diameter of 10,000 nm or less. The polysaccharide nanofiber can be an aggregate having an average fiber diameter of 10,000 nm or less, which contains nanofibrils in which a polysaccharide in which a monosaccharide is glycosidic bonded or a derivative thereof is aggregated. The powder material may contain only one type of polysaccharide nanofibers, or may contain two or more types of nanofibers.

The polysaccharide nanofibers may be chemically modified to enhance their affinity with the thermoplastic resins described above and the binding fluids described below. For example, it may be treated by various methods such as acetylation treatment, carboxymethylation treatment, and silane coupling agent treatment. Further, the polysaccharide nanofiber may be an untreated polysaccharide nanofiber that has not been subjected to the above treatment.

Further, the polysaccharide nanofiber may contain a component other than the polysaccharide or its derivative as long as the object of the present invention is not impaired, but the polysaccharide or its derivative is based on the total mass of the nanofiber. It is preferably 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, and 99% by mass or more. Is particularly preferable.

Here, the structure of the polysaccharide nanofiber is not particularly limited, and it may be composed of a single chain or may have a branched structure. Having a branched structure means that there is a branched chain protruding laterally from the main chain containing nanofibrils as a main component.

The average fiber diameter of the polysaccharide nanofibers is preferably 3 nm or more and 30 nm or less. When the average fiber diameter is 3 nm or more, it is easy to disperse uniformly. On the other hand, when the average fiber diameter is 30 nm or less, the strength of the obtained three-dimensional model tends to increase. The average fiber diameter of the polysaccharide nanofibers is more preferably 3 nm or more and 20 nm or less, and further preferably 5 nm or more and 20 nm or less.

On the other hand, the average fiber length of the polysaccharide nanofibers is preferably 200 nm or more and 10000 nm or less, and more preferably 250 nm or more and 10000 nm or less. When the average fiber length is 10,000 nm or less, the polysaccharide nanofibers are less likely to protrude from the three-dimensional model, and a three-dimensional model having a good appearance can be easily obtained. On the other hand, when the average fiber length is 200 nm or more, the binding fluid is less likely to diffuse in the fluid coating step described later, and the dimensional accuracy of the obtained three-dimensional model is more likely to be improved. The average fiber length of the polysaccharide nanofibers is more preferably 300 nm or more and 10000 nm or less, and particularly preferably 500 nm or more and 10000 nm or less. When the polysaccharide nanofiber has a branched structure, the length when the nanofiber is the longest is defined as the fiber length.

The aspect ratio of the polysaccharide nanofibers (value obtained by dividing the average fiber length by the average fiber diameter) is preferably 5 or more and 3500 or less, and more preferably 10 or more and 3500 or less. When the aspect ratio is in this range, it becomes difficult for the coupling fluid to diffuse in the fluid coating step described later.

The average fiber diameter and the average fiber length of the polysaccharide nanofibers can be specified as follows. First, the above-mentioned resin is removed from the powder material with a solvent or the like, and only the nanofibers are taken out. Then, from the image obtained by imaging this with a scanning electron microscope (SEM), the fiber diameter and the fiber length of 100 arbitrarily selected nanofibers can be added and averaged.

The magnification of the SEM may be adjusted so that 100 or more nanofibers can be imaged.

Here, examples of polysaccharides constituting nanofibers include cellulose, hemicellulose, lignocellulose, chitin and chitosan. Among these, nanofibers of cellulose or its derivatives (hereinafter, also referred to as “nanocellulose”) are preferably used from the viewpoint of high strength, low coefficient of thermal expansion, and light weight.

Nanocellulose is derived from plant-derived fibrils or mechanical defibration of plant cell walls, biosynthesis by acetic acid bacteria, and N-oxyl compounds such as 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO). Cellulose nanofibers containing fibrous nanofibrils as a main component, which are obtained by oxidation or electrolytic spinning, may be used. In addition, nanocellulose is mainly composed of nanofibrils crystallized in a whisker shape (needle shape), which is obtained by mechanically defibrating plant-derived fibrous material or plant cell walls and then treating with acid. It may be a cellulose nanocrystal. Further, the nanocellulose may have other shapes.

In addition, nanocellulose may contain lignin, hemicellulose, and the like together with cellulose. Nanocellulose containing hydrophobic lignin without delignin treatment is preferable because it has a high affinity with a thermoplastic resin.

The shape of the polysaccharide nanofibers (presence or absence of a branched structure, average fiber diameter, average fiber length, aspect ratio, etc.) can be adjusted by a method for producing polysaccharide nanofibers or the like. For example, when the polysaccharide nanofiber is nanocellulose, the average fiber diameter, average fiber length, etc. can be adjusted by adjusting the method of defibration or synthesis (strength of defibration, etc.) and the number of defibration. Can be adjusted.

The powder material preferably contains 0.5 to 60.0% by mass of nanofibers of the polysaccharide, and more preferably 1 to 30% by mass. If the polysaccharide nanofibers are contained in an amount of 0.5% by mass or more, the binding fluid becomes difficult to diffuse in the fluid coating step described later. On the other hand, when the content of the polysaccharide nanofibers is 60.0% by mass or less, the amount of the thermoplastic resin is relatively sufficient, and the strength of the obtained three-dimensional model is increased.

Moreover, the powder material may contain various additives. Examples of various additives include antioxidants, acidic compounds and their derivatives, lubricants, UV absorbers, light stabilizers, nucleating agents, flame retardants, impact modifiers, foaming agents, colorants, organic peroxides, and exhibitions. Includes adhesives, adhesives, etc. The powder material may contain only one kind of these, or may contain two or more kinds of these.

Further, the powder material may include a filler. Examples of fillers are talc, calcium carbonate, zinc carbonate, wallastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, glass cut. Fiber, glass milled fiber, glass flakes, glass powder, silicon carbide, silicon nitride, gypsum, gypsum whisker, calcined silicic acid, carbon black, zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, metal powder , Ceramic whisker, potassium titanate, boron nitride, graphite, carbon fiber and other inorganic fillers; organic fillers other than the above-mentioned polysaccharide nanofibers; various polymers and the like are included. The powder material may contain only one kind of these, or may contain two or more kinds of these.

The powder material may also contain a flow agent. The flow agent may be a material having a small coefficient of friction and self-lubricating property. Examples of such flow agents include silicon dioxide and boron nitride. These flow agents may be used alone or in combination of two. The amount of the flow agent can be appropriately set within a range in which the fluidity of the powder material is improved and the melt bond of the powder material is sufficiently generated, for example, more than 0% by mass with respect to the total mass of the powder material. It can be less than 2% by mass.

Here, the powder material preferably has a melting temperature of 100 to 300 ° C, more preferably 120 to 230 ° C. When the melting temperature is within this range, it is possible to form a modeled object layer without excessive energy irradiation in the energy irradiation step described later. The melting temperature of the powder material can be adjusted by the type of the thermoplastic resin or the like.

The melting temperature of the powder material can be specified as follows. First, the hot plate is kept at, for example, 180 ° C., 185 ° C., 190 ° C., 195 ° C., and 200 ° C., respectively. Then, 1 g of the powder material is spread on an aluminum foil dish having a diameter of 5 cm, and placed on a hot plate set at each temperature. Then, the fusion state of the powder material is confirmed, and the temperature at which the start of fusion is recognized is specified as the melting temperature of the powder material. In the above description, the case where the melting temperature of the powder material is 180 ° C. or higher and lower than 200 ° C. is described as an example, but when the melting temperature of the powder material is outside the range, the temperature of the hot plate is appropriately adjusted. change.

The maximum value of the elastic modulus of the powder material in the range of the melting temperature of ± 20 ° C. is preferably 30 to 500 times, preferably 50 to 200 times the minimum value of the elastic modulus of loss in the range of the melting temperature of ± 20 ° C. Is more preferable. When the ratio of the maximum value and the minimum value of the loss elastic modulus in the range of the melting temperature ± 20 ° C. is in the range, the deformation of the melted powder material becomes appropriate. Therefore, the dimensional accuracy of the obtained three-dimensional model is further improved. The loss elastic modulus can be specified by the method shown in Examples described later.

The method for preparing the powder material is not particularly limited, and for example, a method in which a thermoplastic resin, nanofibers of a polysaccharide, and if necessary, other components are mixed at a desired ratio can be used. Alternatively, for example, a method may be used in which a thermoplastic resin, nanofibers of a polysaccharide, and other components, if necessary, are stirred and mixed while being heated and cooled. In this case, in order to make the average particle diameters of the particles constituting the powder material uniform, mechanical pulverization, classification, or the like may be performed as necessary.

(2) Fluid coating step In the fluid coating step of the present embodiment, the binding fluid and the peeling fluid are coated on the regions adjacent to each other of the thin layers formed in the thin layer forming step, respectively. Specifically, the binding fluid is selectively applied to the position where the modeled object layer should be formed, and the peeling fluid is applied to the region where the modeled object layer is not formed. By applying the peeling fluid adjacent to the periphery of the region to which the bonding fluid is applied, it is possible to suppress the diffusion of the bonding fluid in the thin layer to some extent. In the present embodiment, either the coupling fluid or the peeling fluid may be applied first, but from the viewpoint of the dimensional accuracy of the obtained three-dimensional model, the coupling fluid is preferably applied first.

The method of applying the binding fluid and the peeling fluid is not particularly limited, and for example, coating by a dispenser, coating by an inkjet method, spray coating, or the like can be performed, but the bonding fluid and the peeling fluid can be applied to a desired region at high speed. From the viewpoint that the above can be applied, it is preferable to apply at least one by the inkjet method, and it is more preferable to apply both by the inkjet method.

The coating amounts of the binding fluid and the peeling fluid are preferably 0.1 to 50 μL, and more preferably 0.2 to 40 μL ^{, respectively, per 1 mm 3 of the thin layer.} When the application amount of the binding fluid and the peeling fluid is within the above range, the powder material in the region where the modeled object layer is formed and the region where the modeled object layer is not formed is sufficiently impregnated with the bonding fluid and the peeling fluid, respectively. It is possible to form a three-dimensional model with good dimensional accuracy.

The binding fluid applied in this step contains at least an energy absorber and a solvent having a relative permittivity in a specific range. The binding fluid may contain a known dispersant or the like, if necessary.

The energy absorber is not particularly limited as long as it can absorb the energy irradiated in the energy irradiation step described later and efficiently raise the temperature of the region to which the binding fluid is applied. Specific examples of energy absorbers include carbon black, infrared absorbers such as ITO (indium tin oxide) and ATO (antimony tin oxide), cyanine pigments, phthalocyanine pigments mainly composed of aluminum and zinc, various naphthalocyanine compounds, and flat surfaces. Infrared absorbing dyes such as nickel dithiolene complex having a tetracoordinate structure, squalium dye, quinone compound, diimmonium compound, and azo compound are included. Among these, an infrared absorber is preferable, and carbon black is more preferable, from the viewpoint of versatility and the ability to efficiently raise the temperature of the region to which the binding fluid is applied.

The shape of the energy absorber is not particularly limited, but it is preferably in the form of particles. The average particle size is preferably 0.1 to 1.0 μm, more preferably 0.1 to 0.5 μm. If the average particle size of the energy absorber is excessively large, it becomes difficult for the energy absorber to enter the gaps of the thermoplastic resin, nanofibers, etc. when the binding fluid is applied onto the thin film. On the other hand, when the average particle size is 1.0 μm or less, the energy absorber easily penetrates into the thin film. On the other hand, when the average particle size of the energy absorber is 0.1 μm or more, heat can be efficiently transferred to the thermoplastic resin in the energy irradiation step described later, and the surrounding thermoplastic resin can be melted. Become.

The binding fluid preferably contains 0.1 to 10.0% by mass, more preferably 1.0 to 5.0% by mass of the energy absorber. When the amount of the energy absorber is 0.1% by mass or more, it is possible to sufficiently raise the temperature of the region to which the binding fluid is applied in the energy irradiation step described later. On the other hand, when the amount of the energy absorber is 10.0% by mass or less, the energy absorber is less likely to aggregate in the binding fluid, and the coating stability of the binding fluid is likely to be improved.

On the other hand, the solvent has a relative permittivity of 20.0 to 50.0, is capable of dispersing an energy absorber, and is particularly difficult to dissolve components (for example, thermoplastic resin) in the powder material. Not limited. The relative permittivity is more preferably 20.0 to 45.0, and even more preferably 20.0 to 40.0, from the viewpoint of the affinity of the polysaccharide with the nanofibers. The value of the relative permittivity can be referred to from publicly known documents such as the Chemical Handbook Basic Edition II Revised 5th Edition, and the value at the measurement temperature of 20 ° C. is used. If the relative permittivity of the solvent is excessively large (more than 50), the affinity between the solvent and the nanofibers of the polysaccharide becomes excessively high, a capillary phenomenon or the like occurs, and the molding accuracy tends to decrease. Further, if the relative permittivity of the solvent is excessively small (less than 20), the affinity between the solvent and the polysaccharide nanofiber is low, and it is difficult to obtain the above-mentioned effect of improving the molding accuracy.

The boiling point of the solvent is preferably 100 to 300 ° C, more preferably 125 to 300 ° C. If the boiling point of the solvent is too high, the solvent tends to remain in the obtained three-dimensional model, and the strength of the three-dimensional model tends to decrease. On the other hand, if the boiling point of the solvent is too low, the solvent may volatilize when the binding fluid is applied, and the coating stability of the binding fluid may decrease.

Specific examples of the solvent include triethylene glycol, ethylene glycol, dimethyl sulfoxide, dimethylformamide, and the like. Among these, triethylene glycol and ethylene glycol are preferable from the viewpoints of high relative permittivity and high coating stability of the bonding fluid.

The binding fluid preferably contains the above solvent in an amount of 90.0 to 99.9% by mass, more preferably 95.0 to 99.0% by mass. When the amount of the solvent in the binding fluid is 90.0% by mass or more, the fluidity of the binding fluid becomes high, and it becomes easy to apply by, for example, an inkjet method.

The viscosity of the binding fluid is preferably 0.5 to 50.0 mPa · s, more preferably 1.0 to 20.0 mPa · s. When the viscosity of the binding fluid is 0.5 mPa · s or more, diffusion when the binding fluid is applied to the thin layer is more likely to be suppressed. On the other hand, when the viscosity of the binding fluid is 50.0 mPa · s or less, the coating stability of the binding fluid tends to increase.

On the other hand, the peeling fluid applied in this step is not particularly limited as long as it contains a solvent that is difficult to mix with the binding fluid and is difficult to dissolve the components in the powder material. The relative permittivity of the solvent contained in the stripping fluid is preferably 1.0 to 5.0, and more preferably 1.0 to 3.0. The difference between the relative permittivity of the solvent in the bonding fluid and the relative permittivity of the solvent in the stripping fluid is preferably 25.0 or more, and more preferably 30.0 or more. The larger these differences are, the more difficult it is for the coupling fluid and the peeling fluid to be mixed, and it becomes easier to obtain a three-dimensional model with higher dimensional accuracy.

The boiling point of the solvent is preferably 100 to 300 ° C, more preferably 125 to 300 ° C. If the boiling point of the solvent contained in the peeling fluid is too low, the solvent may volatilize when the peeling fluid is applied, and the coating stability of the peeling fluid may decrease.

Examples of such solvents include non-polar hydrocarbons such as n-decane, n-dodecane and cyclooctane, aromatic hydrocarbons such as xylene and the like.

The stripping fluid preferably contains 90% by mass or more of the above solvent, and more preferably 95% by mass or more. When the amount of the solvent in the peeling fluid is 90% by mass or more, the fluidity of the peeling fluid becomes high, and it becomes easy to apply by, for example, an inkjet method.

The viscosity of the stripping fluid is preferably 0.5 to 50.0 mPa · s, more preferably 0.5 to 30.0 mPa · s. When the viscosity of the peeling fluid is 0.5 mPa · s or more, it becomes difficult for the peeling fluid to diffuse to the bonding fluid side. On the other hand, when the viscosity of the peeling fluid is 30.0 mPa · s or less, the coating stability of the peeling fluid tends to increase.

(3) Energy Irradiation Step In the energy irradiation step of the present embodiment, energy is collectively irradiated to the thin layer after the fluid coating step, that is, the thin layer coated with the binding fluid and the peeling fluid. At this time, in the region where the binding fluid is applied, the energy absorber absorbs the energy, and the temperature of the region partially rises. Then, only the thermoplastic resin in the region is melted to form a modeled object layer.

The type of energy to be irradiated in this step is appropriately selected according to the type of energy absorber contained in the binding fluid. Specific examples of the energy include infrared light, white light and the like. Among these, from the viewpoint that the thermoplastic resin can be efficiently melted in the region coated with the bonding fluid, while the temperature of the thin layer is unlikely to rise in the region coated with the stripping fluid. Infrared light is preferable, light having a wavelength of 780 to 3000 nm is more preferable, and light having a wavelength of 800 to 2500 nm is more preferable.

The time for irradiating energy in this step is appropriately selected according to the type of the thermoplastic resin contained in the powder material, but is usually preferably 5 to 60 seconds, preferably 10 to 30 seconds. More preferred. By setting the energy irradiation time to 5 seconds or more, it becomes possible to sufficiently melt the thermoplastic resin and combine them. On the other hand, if the time is 60 seconds or less, it becomes possible to efficiently manufacture a three-dimensional model.

1-2. Second Embodiment In the method for producing a three-dimensional model of the present embodiment, a thin layer forming step of forming a thin layer containing a powder material containing at least a thermoplastic resin, and a thin layer of a binding fluid and a peeling fluid are used. A fluid coating step of applying to adjacent regions, and an energy irradiation step of irradiating a thin layer after the fluid coating step with energy to melt the thermoplastic resin in the coating region of the binding fluid to form a model layer. including. In this embodiment, the binding fluid comprises an energy absorber, polysaccharide nanofibers, and a solvent having a specific permittivity range. The manufacturing method of the present embodiment may have other steps, if necessary.

Here, the method for producing the three-dimensional model of the present embodiment is the same as that of the first embodiment except for the composition of the powder material and the composition of the binding fluid. Therefore, only the composition of the powder material and the composition of the binding fluid will be described below, and the other description will be omitted.

The powder material used in the thin layer forming step of the present embodiment may contain at least a thermoplastic resin, and may be composed of, for example, only a thermoplastic resin. Further, the powder material may contain various additives, a flow agent, a filler and the like, if necessary.

The type, average particle size, melting temperature, and the like of the thermoplastic resin contained in the powder material used in the present embodiment can be the same as those of the thermoplastic resin contained in the powder material of the first embodiment. Here, in the present embodiment, the powder material preferably contains 40% by mass or more of the thermoplastic resin, and more preferably 50% by mass or more. When the powder material contains 40% by mass or more of the thermoplastic resin, the strength of the obtained three-dimensional model is sufficiently increased.

On the other hand, the types and contents of various additives, flow agents, fillers and the like contained in the powder material can be the same as those of various additives, flow agents, fillers and the like contained in the powder material of the first embodiment. .. The powder material of the present embodiment may also contain nanofibers of a polysaccharide, if necessary.

On the other hand, the binding fluid used in the fluid coating step contains at least an energy absorber, a polysaccharide nanofiber, and a solvent having a relative permittivity of 20 to 50. The binding fluid may contain a known dispersant or the like, if necessary. The energy absorber and solvent contained in the binding fluid of the present embodiment can be the same as the energy absorbing agent and solvent contained in the binding fluid to be applied in the fluid coating step of the first embodiment, respectively. On the other hand, the polysaccharide nanofiber contained in the binding fluid of the present embodiment can be the same as the polysaccharide nanofiber contained in the powder material of the first embodiment.

The binding fluid of the present embodiment preferably contains an energy absorber in an amount of 0.1 to 10.0% by mass, more preferably 1.0 to 5.0% by mass. When the amount of the energy absorber is 0.1% by mass or more, it is possible to sufficiently raise the temperature of the region to which the binding fluid is applied in the energy irradiation step. On the other hand, when the amount of the energy absorber is 10.0% by mass or less, the energy absorber is less likely to aggregate in the binding fluid, and the coating stability of the binding fluid is likely to be improved.

The binding fluid preferably contains the polysaccharide nanofibers in an amount of 0.1 to 10.0% by mass, more preferably 0.1 to 5.0% by mass. When the amount of the polysaccharide nanofibers is in the above range, when the binding fluid is applied onto the thin layer, the solvent is difficult to move due to the affinity between the polysaccharide nanofibers and the solvent in the binding fluid. Become. This makes it difficult for the energy absorber to move, and makes it easier to obtain a three-dimensional model with high dimensional accuracy.

On the other hand, the binding fluid preferably contains the above solvent in an amount of 80.0 to 99.8% by mass, more preferably 90.0 to 99.8% by mass. When the amount of the solvent in the binding fluid is 80.0% by mass or more, the fluidity of the binding fluid becomes high, and it becomes easy to apply by, for example, an inkjet method.

The viscosity of the binding fluid of the present embodiment is preferably 0.5 to 50.0 mPa · s, more preferably 1.0 to 20.0 mPa · s. When the viscosity of the binding fluid is 0.5 mPa · s or more, the diffusion of the binding fluid is more likely to be suppressed. On the other hand, when the viscosity of the binding fluid is 50.0 mPa · s or less, the coating stability of the binding fluid tends to increase.

2. Three-dimensional modeling device A three-dimensional modeling device that can be used in the method for manufacturing a three-dimensional model will be described. The three-dimensional modeling apparatus that can be used in the present embodiment can have the same configuration as the known three-dimensional modeling apparatus. Specifically, the three-dimensional modeling apparatus 200 according to the present embodiment has a modeling stage 210 located in the opening and a thin film forming portion 220 for forming a thin film made of a powder material, as shown in the schematic side view of FIG. , Preheating part 230 for preheating the thin film, fluid coating part 300 for applying the binding fluid and the peeling fluid to the thin film, infrared irradiation part 240 for irradiating the thin film with infrared light, in the vertical direction. A stage support portion 250 that supports the modeling stage 210 in a variable position, and a base 290 that supports each of the above portions are provided.

On the other hand, the main part of the control system of the three-dimensional modeling apparatus 200 is shown in FIG. As shown in FIG. 2, the three-dimensional modeling apparatus 200 controls a thin film forming unit 220, a preheating unit 230, a fluid coating unit 300, an infrared irradiation unit 240, and a stage support unit 250 to form and stack a modeled object. A storage unit for storing various information including a control unit 260 to be performed, a display unit 270 for displaying various information, an operation unit 275 including a pointing device for receiving an instruction from a user, and a control program executed by the control unit 260. The unit 280 and a data input unit 285 including an interface for transmitting and receiving various information such as three-dimensional modeling data to and from an external device may be provided. Further, the three-dimensional modeling apparatus 200 may include a temperature measuring device 235 for measuring the surface temperature of the thin layer formed on the modeling stage 210. Further, a computer device 310 for generating data for three-dimensional modeling may be connected to the three-dimensional modeling device 200.

The modeling stage 210 is controlled so as to be able to move up and down, and on the modeling stage 210, a thin layer is formed by the thin film forming portion 220, the thin layer is preheated by the preheating portion 230, and the connecting fluid and the peeling are performed by the fluid coating portion 300. The fluid is applied and the infrared light irradiation unit 240 irradiates the infrared light. Then, the shaped objects formed by these are laminated to form a three-dimensional shaped object.

The thin film forming unit 220 is provided from the powder supply unit 221 and the powder supply unit 221 having a powder material storage unit 221a for storing the powder material, a supply piston 221b provided at the bottom of the powder material storage unit 221a and moving up and down in the opening. The supplied powder material can be spread flat on the molding stage 210 to include a recorder 222a that forms a thin layer of the powder material. In the present embodiment, the upper surface of the opening of the powder material storage portion 221a is arranged on substantially the same plane as the upper surface of the opening for raising and lowering the modeling stage 210 (for forming a three-dimensional model).

The powder supply unit 221 discharges a powder material storage unit (not shown) provided vertically above the modeling stage 210 and a powder material stored in the powder material storage unit in desired amounts. A nozzle (not shown) for the purpose may be provided. In this case, a thin layer can be formed by uniformly discharging the powder material from the nozzle onto the modeling stage 210.

The preheating unit 230 may be any one that can heat the region of the surface of the thin layer on which the modeled object layer should be formed and maintain the temperature. In the present embodiment, the preheating unit 230 heats the first heater 231 capable of heating the surface of the thin layer formed on the modeling stage 210 and the powder material before being supplied onto the modeling stage 210. The heater 232 and the like, but these may be only one of them. Further, the preheating unit 230 may be configured to selectively heat the region where the modeled object layer should be formed. Further, the entire inside of the apparatus may be preheated so that the surface of the thin film is adjusted to a predetermined temperature.

The temperature measuring device 235 may be any one capable of measuring the surface temperature of the thin layer, particularly the surface temperature of the region where the modeled object layer should be formed, in a non-contact manner, and may be, for example, an infrared sensor or an optical thermometer.

The fluid coating unit 300 includes a coupling fluid coating unit 301 and a peeling fluid coating unit 302. The coupling fluid coating unit 301 and the peeling fluid coating unit 302 each include a storage unit (not shown) for storing the coupling fluid or the peeling fluid, and an inkjet nozzle (not shown) connected thereto. Can be.

The infrared light irradiation unit 240 can be configured to include an infrared lamp. The infrared lamp may be a light source capable of irradiating infrared light at a desired timing.

The stage support portion 250 may variably support the vertical position of the modeling stage 210. That is, the modeling stage 210 is configured to be precisely movable in the vertical direction by the stage support portion 250. Various configurations can be adopted for the stage support portion 250. For example, the stage support portion 250 is engaged with a holding member for holding the modeling stage 210, a guide member for guiding the holding member in the vertical direction, and a screw hole provided in the guide member. It can be composed of a matching ball screw or the like.

The control unit 260 includes a hardware processor such as a central processing unit, and controls the operation of the entire three-dimensional modeling device 200 during the modeling operation of the three-dimensional modeled object.

Further, the control unit 260 may be configured to convert, for example, the three-dimensional modeling data acquired from the computer device 310 by the data input unit 285 into a plurality of slice data sliced in the stacking direction of the modeling object layer. The slice data is the modeling data of each modeled object layer for modeling the three-dimensional modeled object. The thickness of the slice data, that is, the thickness of the modeled object layer, coincides with the distance (stacking pitch) corresponding to the thickness of one layer of the modeled object layer.

The display unit 270 can be, for example, a liquid crystal display or a monitor.

The operation unit 275 may include a pointing device such as a keyboard or a mouse, and may include various operation keys such as a numeric keypad, an execution key, and a start key.

The storage unit 280 may include various storage media such as ROM, RAM, magnetic disk, HDD, and SSD.

The three-dimensional modeling apparatus 200 receives the control of the control unit 260 to depressurize the inside of the apparatus, and under the control of a decompression unit (not shown) such as a decompression pump or the control unit 260, the inert gas is introduced into the apparatus. It may be provided with an inert gas supply unit (not shown) for supplying.

Here, a three-dimensional modeling method using the three-dimensional modeling apparatus 200 of the present embodiment will be specifically described. The control unit 260 converts the three-dimensional modeling data acquired by the data input unit 285 from the computer device 310 into a plurality of slice data sliced thinly in the stacking direction of the modeling object layers. After that, the control unit 260 controls the following operations in the three-dimensional modeling apparatus 200.

The powder supply unit 221 drives a motor and a drive mechanism (both not shown) according to the supply information output from the control unit 260, moves the supply piston upward in the vertical direction (in the direction of the arrow in FIG. 1), and forms the above-mentioned modeling. Extrude the powder material on the same plane in the horizontal direction as the stage.

After that, the recorder drive unit 222 moves the recorder 222a in the horizontal direction (in the direction of the arrow in the figure) according to the thin film formation information output from the control unit 260, transports the powder material to the modeling stage 210, and forms a thin layer. The powder material is pressed so that the thickness is the thickness of one layer of the modeled object layer.

The preheating unit 230 heats the surface of the thin layer formed according to the temperature information output from the control unit 260 or the entire inside of the apparatus. The preheating unit 230 may start heating after the thin layer is formed, or heats a portion corresponding to the surface of the thin layer to be formed before the thin layer is formed or the inside of the apparatus. You may.

After that, the fluid coating unit 240 applies the coupling fluid from the coupling fluid coating unit 301 onto the thin film of the region constituting the three-dimensional model in each slice data according to the fluid coating information output from the control unit 260. On the other hand, the peeling fluid is applied from the peeling fluid coating unit 302 to the thin film in the region that does not form the three-dimensional model.

After that, the infrared light irradiation unit 240 irradiates the entire thin film with infrared light according to the infrared light irradiation information output from the control unit 260. The temperature of the region where the binding fluid is applied rises partially due to the irradiation of infrared light, and the thermoplastic resin contained in the powder material melts. As a result, a model layer is formed.

After that, the stage support unit 250 drives the motor and the drive mechanism (both not shown) according to the position control information output from the control unit 260, and pushes the modeling stage 210 vertically downward by the stacking pitch (in the direction of the arrow in the figure). ).

The display unit 270 is controlled by the control unit 260 as necessary, and displays various information and messages to be recognized by the user. The operation unit 275 receives various input operations by the user and outputs an operation signal corresponding to the input operation to the control unit 260. For example, the virtual three-dimensional model to be formed is displayed on the display unit 270 to check whether or not the desired shape is formed, and if the desired shape is not formed, the operation unit 275 may make corrections. Good.

The control unit 260 stores data in the storage unit 280 or retrieves data from the storage unit 280, if necessary.

By repeating these operations, the modeled object layers are laminated to produce a three-dimensional modeled object.

Hereinafter, specific examples of the present invention will be described. It should be noted that these examples do not limit the scope of the present invention.

<Making nanocellulose>
Carboxymethyl cellulose manufactured by Sugino Machine Limited was repeatedly defibrated with NanoVeda manufactured by Yoshida Kikai Kogyo Co., Ltd. until the size of the nanocellulose reached the average fiber diameter and average fiber length shown in Table 1 and dried.

<Preparation of powder material>
・ Example 1
In a small kneader manufactured by Xplore Instruments, defibrated nanocellulose and polyamide 12 resin (hereinafter, also referred to as "PA12"), Daicel Evonik Co., Ltd., Daiamide L1600) are mixed with the ratio of nanocellulose to the total amount of powder material. The mixture was mixed so as to be 1% by mass, charged, and heated and mixed at 180 ° C. and 100 rpm. After cooling the mixture, it was pulverized using a lab jet manufactured by Nippon Pneumatic Industries Co., Ltd. to obtain a powder material having an average particle size of 50 μm. The average particle size was measured by a laser diffraction measurement method using MT-3000II manufactured by Microtrac Bell.

-Example 2
The powder material was obtained in the same manner as in Example 1 except that the nanocellulose was mixed so as to have a ratio of nanocellulose to 30% by mass with respect to the total amount of the powder material and put into a kneader.

・ Example 3
The powder material was obtained in the same manner as in Example 1 except that the nanocellulose was mixed so as to be 70% by mass with respect to the total amount of the powder material and put into a kneader.

・ Example 4
The powder material was obtained in the same manner as in Example 1 except that the nanocellulose was mixed so as to have a ratio of nanocellulose to 75% by mass with respect to the total amount of the powder material and put into a kneader.

-Examples 5 to 8
A powder material was obtained in the same manner as in Example 2 except that the nanocellulose was defibrated so that the average fiber diameter and the average fiber length were the values shown in Table 1.

・ Comparative example 1
A powder material was obtained in the same manner as in Example 1 except that nanocellulose was not mixed.

<Making a three-dimensional model>
The powder materials prepared in Examples 1 to 8 and Comparative Example 1 were spread on a modeling stage installed on a hot plate to form a thin layer having a thickness of 0.1 mm, and preheated to 160 ° C. .. A binding fluid was applied to this thin layer by an inkjet method in the shape of a test piece of ISO5272-1BA (maximum length: 75 mm, maximum width: 10 mm). As the binding fluid, a fluid containing 95 parts by mass of triethylene glycol (relative permittivity: 23.7) and 5 parts by mass of an infrared light absorber (carbon black (Mogul-L manufactured by Cabot Corporation)) was used. The coating amount of the coupling fluid, 1 mm ³ per set to 30 [mu] L. Next, the peeling fluid was applied by an inkjet method to a region other than the area to which the binding fluid was applied. The peeling fluid was n-decane (relative permittivity: 2.0). The coating amount of the stripping fluid, 1 mm ³ per set to 30 [mu] L. Then, the thin layer was irradiated with infrared light from an infrared lamp and heated until the surface temperature of the region coated with the coupling fluid reached 220 ° C. As a result, the powder material in the region coated with the binding fluid was melt-bonded to form a model layer. Then, the process was repeated 10 times to produce a three-dimensional model in which 10 layers of the model were laminated.

<Evaluation of accuracy in 3D objects>
The dimensions of each three-dimensional object were measured in the length direction with a digital caliper (manufactured by Mitutoyo Co., Ltd., Super Caliper CD67-S PS / PM, "Super Caliper" is a registered trademark of the same company). The difference between the dimensions to be manufactured (maximum length 75 mm) and the dimensions of the manufactured three-dimensional model was averaged to obtain a deviation in modeling accuracy. At this time, the evaluation was performed according to the following criteria.
⊚: Error less than ± 0.05 mm with respect to the reference length 75 mm 〇: Error ± 0.05 mm or more to less than ± 0.15 mm with respect to the reference length 75 mm Δ: Error ± 0.15 mm or more with respect to the reference length 75 mm ~ ± Less than 0.3 mm ×: Error ± 0.3 mm or more with respect to the standard length of 75 mm

<Specification of elastic modulus of powder material>
-Specification of melting temperature of powder material The hot plate was maintained at 180 ° C., 185 ° C., 190 ° C., 195 ° C., and 200 ° C., respectively. The prepared powder material was spread on an aluminum foil dish having a diameter of 5 cm in an amount of 1 g, and placed on a hot plate set at each temperature. Then, the fusion state of the powder material was confirmed, and the temperature at which the start of fusion was recognized was specified as the melting temperature of the powder material.

・ Measurement of loss modulus (preparation of sample)
Using a pressure molding machine (NT-100H, manufactured by NPA System Co., Ltd.), pressurize the powder material at room temperature at 30 kN for 1 minute to make the resin composition into a columnar sample with a diameter of about 8 mm and a height of about 2 mm. Molded.

(Measurement procedure)
The temperature of the parallel plate of the above apparatus was adjusted to 150 ° C., and the columnar sample prepared as described above was heated and melted. Then, a load was applied in the vertical direction so that the axial force did not exceed 10 g weight), and the sample was fixed to the parallel plate. In this state, the parallel plate and the columnar sample were heated to a measurement start temperature of 250 ° C., and the viscoelastic data was measured while slowly cooling. The measured data is transferred to a computer equipped with Microsoft Windows 7, and the computer is controlled, data collected and analyzed through software (TRIOS), and the loss in the melting temperature range of ± 20 ° C. of the powder material is performed. The value of elastic modulus (Pa) was read.
Then, the value of the maximum value (maximum value / minimum value) of the loss elastic modulus at the melting temperature of the powder material ± 20 ° C. was calculated with respect to the minimum value of the loss elastic modulus at the melting temperature of the powder material ± 20 ° C.

(Measurement condition)
Measurement frequency: 6.28 Radian / sec Measurement strain setting: Initial value set to 0.1%, sample elongation correction measured in automatic measurement mode: Measurement temperature adjusted in automatic measurement mode: 250 Measurement interval of slow cooling from ° C to 100 ° C at a rate of 5 ° C per minute: Viscoelastic data was measured at 1 ° C.

As shown in Table 1 above, when a three-dimensional model was produced by applying a binding fluid and a peeling fluid to a thin layer made of a powder material containing nanocellulose (Examples 1 to 8), the obtained three-dimensional object was obtained. The dimensional accuracy of the modeled object was good. However, when the relative permittivity of the solvent contained in the bonding fluid is more than 50, the molding accuracy is lowered (Comparative Example 2). If the relative permittivity of the solvent contained in the binding fluid is too high, the affinity between the solvent and nanocellulose is excessively increased, and it is presumed that the molding accuracy is rather lowered due to the induction of capillarity and the like. Further, the molding accuracy was low even when the relative permittivity of the solvent contained in the bonding fluid was less than 20 (Comparative Example 3). It is presumed that the affinity between the solvent contained in the binding fluid and nanocellulose was low, and the diffusion of the components in the binding fluid could not be sufficiently prevented.

<Preparation of binding fluid>
-Example 9
94.5 parts by mass of ethylene glycol (relative permittivity: 38.7), 0.5 parts by mass of nanocellulose, and 5.0 parts by mass of an infrared light absorber were mixed using an ultrasonic disperser.

-Examples 10 to 12 and Comparative Example 4
The solvent is shown in Table 2, the amount of nanocellulose is changed to the values shown in Table 2 with respect to the total amount of the binding fluid, and the average fiber diameter and average fiber length are the nanocellulose shown in Table 2. A coupling fluid was prepared in the same manner as in Example 7, except that the fluid was not present. The amount of the infrared light absorber was kept constant, and the amount of nanocellulose was adjusted according to the amount of the solvent. Moreover, in Comparative Example 4, nanocellulose was not mixed.

<Making a three-dimensional model>
As shown in Table 2, a powder material made of PA12 or polypropylene having an average particle diameter of 50 μm was spread on a molding stage installed on a hot plate to form a thin layer having a thickness of 0.1 mm, and preheated to 160 ° C. Was done. The binding fluid prepared in each example was applied to this thin layer in the shape of a test piece of ISO5272-1BA (maximum length: 75 mm, maximum width: 10 mm) by an inkjet method. The coating amount of the binding fluid was 30 μL per ^{1 mm 2.} Next, the peeling fluid was applied by an inkjet method to a region other than the area to which the binding fluid was applied. The exfoliating fluid was n-decane (relative permittivity: 2.0) or n-dodecane (relative permittivity: 2.0). The amount of the release agent fluid applied was 30 μL per ^{1 mm 2.} Then, the thin layer was irradiated with infrared light from an infrared lamp and heated until the surface temperature of the region coated with the coupling fluid reached 220 ° C. The above process was repeated 10 times to produce a three-dimensional model in which 10 layers of the model were laminated.

<Evaluation of accuracy in 3D objects and identification of loss elastic modulus of powder materials>
The accuracy of each three-dimensional model produced was evaluated in the same manner as in Example 1 and the like. Furthermore, the maximum value (maximum value / minimum value) of the loss elastic modulus at the melting temperature of the powder material ± 20 ° C. with respect to the minimum value of the loss elastic modulus at the melting temperature ± 20 ° C. of the powder material used for producing the three-dimensional model. Was calculated. The results are shown in Table 2.

As shown in Table 2 above, even when the binding fluid contains nanocellulose, the modeling accuracy is improved as compared with the case where the modeling fluid does not contain nanocellulose (Comparative Example 4) (Examples 9 to 12). ).

According to the present invention, it is possible to manufacture a three-dimensional model having high dimensional accuracy. Therefore, the present invention is considered to contribute to the further spread of the three-dimensional modeling method.

200 Three-dimensional modeling device 210 Modeling stage 220 Thin film forming unit 221 Powder supply unit 222 Recoater drive unit 222a Recoater 230 Preheating unit 231 First heater 232 Second heater 235 Temperature measuring instrument 240 Infrared light irradiation unit 250 Stage support unit 260 Control unit 270 Display unit 275 Operation unit 280 Storage unit 290 Base 285 Data input unit 300 Fluid coating unit 301 Coupling fluid coating unit 302 Peeling fluid coating unit 310 Computer device

Claims (11)

A thin layer forming step of forming a thin layer containing a powder material containing a thermoplastic resin,
A fluid coating step of applying a binding fluid containing an energy absorber and a peeling fluid for suppressing diffusion of the binding fluid to regions adjacent to each other in the thin layer.
An energy irradiation step of irradiating the thin layer after the fluid coating step with energy and melting the thermoplastic resin in the region to which the binding fluid is applied to form a modeled object layer.
It is a manufacturing method of a three-dimensional model including
The powder material and / or the binding fluid comprises nanofibers of a polysaccharide and
The bonding fluid contains a solvent having a relative permittivity of 20 to 50.
A method for manufacturing a three-dimensional model. The peeling fluid contains a solvent having a relative permittivity of 1 to 5.
The method for manufacturing a three-dimensional model according to claim 1. By repeating the thin layer forming step, the fluid coating step, and the energy irradiation step a plurality of times, the shaped object layers are laminated to form a three-dimensional shaped object.
The method for manufacturing a three-dimensional model according to claim 1 or 2. In the fluid coating step, the bonding fluid and the peeling fluid are coated by an inkjet method.
The method for manufacturing a three-dimensional model according to any one of claims 1 to 3. The energy absorber is an infrared light absorber,
In the energy irradiation step, infrared light is irradiated.
The method for manufacturing a three-dimensional model according to any one of claims 1 to 4. A powder material used in the method for producing a three-dimensional model according to any one of claims 1 to 5.
With thermoplastic resin
Polysaccharide nanofibers and
Including powder material. The average fiber diameter of the polysaccharide nanofibers is 3 to 30 nm, and the average fiber length is 200 to 10000 nm.
The powder material according to claim 6. The polysaccharide nanofibers include cellulose nanofibers.
The powder material according to claim 6 or 7. A coupling fluid used in the method for producing a three-dimensional model according to any one of claims 1 to 5.
Energy absorber and
Polysaccharide nanofibers and
With a solvent having a relative permittivity of 20 to 50,
For bonding fluids, including. The average fiber diameter of the polysaccharide nanofibers is 3 to 30 nm, and the average fiber length is 200 to 10000 nm.
The coupling fluid according to claim 9. The polysaccharide nanofibers include cellulose nanofibers.
The coupling fluid according to claim 9 or 10.

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