JP2022146902A - Manufacturing method of molding - Google Patents

Abstract

To provide a sinter inhibition liquid capable of sufficiently reducing relative sinter density in a sinter inhibition region, when a sinter inhibition region is formed by imparting a sinter inhibition liquid to a layer of powder containing sinterable particles, and having high storage stability.SOLUTION: A manufacturing method of a molding comprising: a powder layer forming step of forming a powder layer 101 containing sinterable particles; a molding liquid application step of applying a molding liquid to the powder layer to form a molding region 104; a sintering inhibiting liquid application step of applying a sintering inhibiting liquid to the layer of powder to form a sintering inhibiting region 103 where sintering of the particles is inhibited; and a lamination step for forming a laminate by repeating these steps sequentially, the molding region and the sinter inhibition region are adjacent, the sinter inhibition liquid contains a first resin, the sinter inhibition region contains a first resin or a second resin derived from the first resin, an estimated residue amount calculated by a predetermined method is 800 ppm or more.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a modeled object.

2. Description of the Related Art In recent years, there has been an increasing need to produce complex and finely shaped objects made of metal or the like. As a technique for meeting this need, particularly from the viewpoint of high productivity, there is a method of sintering and densifying a sintered precursor shaped by a binder jetting method by a powder metallurgy method.

However, deformation such as warpage or distortion may occur in the sintered body obtained through the sintering process. As a method of suppressing this deformation, a method of using a support material that has a shape along the sintered precursor and supports the sintered precursor is being studied. If the sintered body is sintered in this state, the sintered body and the support material may bind together, making it difficult to remove the support material.

In Patent Document 1, by sintering an interface containing a powder of a material that inhibits sintering such as ceramics between a sintering precursor and a support material, the separation between the sintered body and the support material is improved. Techniques for improving are disclosed.

However, when forming a sintering inhibition region by applying a sintering inhibition liquid that inhibits sintering of particles to a powder layer containing sinterable particles, the sintered product of the sintering inhibition region It is difficult to provide a method for producing a shaped article using a sintering inhibitor liquid that can sufficiently lower the relative sintering density in the sintering process and has high storage stability.

A method for manufacturing a modeled object according to the present invention comprises a powder layer forming step of forming a powder layer containing sinterable particles, and applying a modeling liquid to the powder layer to form a modeling region. and a sintering inhibiting liquid applying step of applying a sintering inhibiting liquid to the powder layer to form a sintering inhibiting region where sintering of the particles is inhibited. A method for manufacturing a modeled object, comprising a stacking step of forming a laminate by sequentially repeating a powder layer forming step, the modeling liquid applying step, and the sintering inhibiting liquid applying step, wherein the modeling region and the The sintering-inhibiting regions are adjacent, the sintering-inhibiting liquid contains a first resin, and the sintering-inhibiting region contains the first resin or a second resin derived from the first resin. Then, the mass ratio of the first resin or the second resin to the powder in the sintering inhibition portion formed by stacking the sintering inhibition regions, and the mass ratio of the first resin or the second resin The present invention relates to a method for manufacturing a shaped article, wherein a predicted residue amount calculated by multiplying a thermal decomposition residue rate of resin at 550° C. is 800 ppm or more.

According to the present invention, it is possible to provide a method for manufacturing a shaped article using a sintering inhibition liquid that can sufficiently reduce the relative sintering density of the sintered product in the sintering inhibition region and has high storage stability. can.

FIG. 1 is a schematic diagram showing an example of a layer of powder having a build region, a sintering inhibition region, and a support region. FIG. 2 is a schematic diagram showing an example of a structure having a shaped portion, a sintering inhibition portion, and a support portion. FIG. 3 is a schematic diagram showing an example of a layer of powder having a modeling region and a sintering inhibition region surrounding the modeling region. FIG. 4 is a schematic diagram showing an example of an integrated product in which a plurality of shaped parts and a plurality of connecting parts are integrated. FIG. 5 is a schematic diagram showing an example of a laminate having a molded part and a sintering inhibiting part covering the entire periphery of the molded part. FIG. 6A is a schematic diagram showing an example of the operation of the three-dimensional object manufacturing apparatus. FIG. 6B is a schematic diagram showing another example of the operation of the three-dimensional object manufacturing apparatus. FIG. 6C is a schematic diagram showing another example of the operation of the three-dimensional object manufacturing apparatus. FIG. 6D is a schematic diagram showing another example of the operation of the three-dimensional object manufacturing apparatus. FIG. 6E is a schematic diagram showing another example of the operation of the three-dimensional object manufacturing apparatus. FIG. 7 is a microscope image of the sintered product of the shaping part. FIG. 8 is a microscope image of the sintered product of the sintering inhibition portion.

An embodiment of the present invention will be described below.

<<Manufacturing method>>
The method of manufacturing a model includes a powder layer forming step of forming a powder layer containing sinterable particles, and a modeling liquid application step of applying a modeling liquid to the powder layer to form a modeling region. and a sintering inhibiting liquid application step of applying a sintering inhibiting liquid to the powder layer to form a sintering inhibiting region where sintering of the particles is inhibited, and a powder layer forming step; It includes a stacking step of forming a laminate by sequentially repeating a modeling liquid applying step and a sintering inhibiting liquid applying step.
At this time, the shaping area and the sintering inhibition area are adjacent to each other.
Further, the laminate has a shaping portion formed by stacking shaping regions and a sintering inhibition portion formed by stacking sintering inhibition regions.
A "modeling liquid" in the present disclosure is a liquid composition that is applied to a layer of powder containing sinterable particles to form a build region.
Also, a "sintering inhibiting liquid" is a liquid composition that is applied to a powder layer containing sinterable particles to form a sintering inhibiting region where sintering of the particles is inhibited.
A "feature" in the present disclosure is a precursor structure of a feature.
The "sintering inhibition part" is defined as a shape part (sintered precursor) and a support material for supporting the sintered precursor during sintering, which is pre-sintered so that the shaped part (sintered precursor) can be easily separated after sintering. It means what is formed between the bonding precursor and the support material. The sintering-inhibiting portion means that sintering does not progress in the sintering process, or that the relative sintering density is sufficiently low compared to the sintering precursor and the support material. It should be noted that the "sintering inhibition part" is not a precursor structure of the model, but a structure that is detached from the model after sintering, and is a sintered product formed by sintering the sintering inhibition part. It has a characteristic that the relative sintered density is lower than the relative sintered density of the sintered product formed by sintering the modeled product.

Further, the forming liquid application step may be a step of applying the modeling liquid to the powder layer to form the modeling region and the support region. At this time, the shaping region and the sintering inhibition region are adjacent, and the shaping region and the support region are adjacent via the sintering inhibition region.
Further, in this case, the laminate includes a modeling portion formed by laminating the modeling regions, a sintering inhibition portion formed by laminating the sintering inhibition regions, and a support portion formed by laminating the support regions. and have
In the present disclosure, the "supporting part" is not a precursor structure of the shaped object, but a structure that supports the shaped part via the sintering inhibition part and is detached from the shaped object after sintering.
Further, when the modeling liquid application step is a step of forming the modeling region and the support region as described above, the modeling liquid is applied to the powder layer containing the sinterable particles, and the modeling region and the support region are applied. It is a liquid composition that forms a region.

In addition to the above-described layering process, the manufacturing method of the model includes, for example, a heating process of heating the laminate at a temperature corresponding to the softening point of the resin contained in the laminate, a modeling liquid, a sintering inhibiting liquid, and the like. A surplus powder removing process for removing surplus powder that is powder to which liquid has not been applied, a drying process for removing liquid components remaining in the shaped part and the sintering inhibition part, etc. is heated to remove at least part of the resin contained in each part to obtain a degreased product, and a sintering step for obtaining a sintered product by heating the degreased products such as the shaped part and the sintering inhibition part. , and a post-processing step of post-processing the sintered product such as the shaping part and the sintering inhibition part (for example, a process of detaching the sintered product such as the sintering inhibition part from the sintered product of the shaping part) is preferably included. In the present disclosure, the shaped part after the heating process may be referred to as a "green body (unsintered body)", and the shaped part after the degreasing process may be referred to as a "degreased body". may be referred to as a "sintered body".
In the present disclosure, the term “modeled object” refers to a generic term for a three-dimensional object that maintains a certain three-dimensional shape. For example, it is a green body or a structure derived from a green body. It is a concept representing a body, a degreased body, a sintered body, and the like.
Each step will be described in detail below.

<Powder layer forming process>
The method for manufacturing a shaped article has a powder layer forming step of forming a layer of powder containing sinterable particles. A layer of powder is formed on the support (on the build stage).
The method of disposing the powder on the support to form a thin layer of the powder is not particularly limited and can be appropriately selected depending on the purpose. A method using a known counter rotating mechanism (counter roller) used in the laser sintering method, a method in which the powder is spread using a member such as a brush, a roller, or a blade, and a method in which the surface of the powder is pressed by a pressing member to spread. method, and a method using a known laminate-molding apparatus.

When forming a powder layer using a powder layer forming means such as a counter rotating mechanism (counter roller), a brush, a blade, and a pressing member, the following method can be used, for example.
That is, a counter rotating mechanism ( A counter roller), brush, roller, blade, or pressing member is used to place the powder. At this time, when using a support that can move up and down in the outer frame, the support is placed at a position slightly lower than the upper end opening of the outer frame (in other words, the thickness of the powder layer is one layer). down) and lay the powder on the support. As described above, a thin layer of the powder can be placed on the support.

The thickness of the powder layer is not particularly limited and can be appropriately selected according to the purpose.
When the average thickness is 30 μm or more, the strength of the green body formed by applying the modeling liquid to the powder is improved, and deformation that may occur in the subsequent steps such as the sintering step can be suppressed. can. In addition, when the average thickness is 500 μm or less, the dimensional accuracy of the shaped object derived from the green body formed by applying the shaping liquid to the powder is improved.
The average thickness is not particularly limited and can be measured according to a known method.

The powder supplied by the powder layer forming means may be stored in the powder storage section. The powder storage unit is a member such as a container that stores powder, and examples thereof include a storage tank, a bag, a cartridge, and a tank.

-Sinterable Particles-
The “sinterable particles (sometimes referred to as “particles” in the following description)” of the present disclosure are particles that are used to manufacture shaped objects and contain sinterable materials such as metals as constituent materials. be. The constituent material of the particles is not particularly limited as long as it contains a sinterable material, and may contain a material other than a sinterable material, but the main material is a sinterable material. preferable. The fact that the main material is a sinterable material means that the mass of the sinterable material contained in the particles is 50.0% by mass or more with respect to the mass of the particles, and 60.0% by mass or more. is preferably 70.0% by mass or more, more preferably 80.0% by mass or more, and particularly preferably 90.0% by mass or more.

The sinterable material that is the constituent material of the particles is preferably a metal, such as magnesium (Mg), aluminum (Al), titanium (Ti), vanadium (V), chromium (Cr), manganese ( Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), lead ( Pd), silver (Ag), indium (In), tin (Sn), tantalum (Ta), tungsten (W), neodymium (Nd), and alloys of these metals. Among these, stainless steel (SUS), iron (Fe), copper (Cu), silver (Ag), titanium (Ti), aluminum (Al), and alloys of these metals are preferably used. Examples of aluminum alloys include _AlSi10Mg , _AlSi12 , _{AlSi7Mg0.6 , AlSi3Mg} , _AlSi9Cu3 , _Scalmalloy , and _ADC12 . These may be used individually by 1 type, and may use 2 or more types together.

Particles can be produced using conventionally known methods.
Methods for producing particles include, for example, a pulverization method in which a solid is subdivided by applying compression, impact, friction, etc., an atomization method in which molten metal is sprayed to obtain quenched powder, and a precipitation method in which a component dissolved in a liquid is precipitated. , a gas-phase reaction method of vaporizing and crystallizing, and the like. Among these methods, the atomization method is preferable because a spherical shape can be obtained and there is little variation in particle size. Examples of the atomizing method include water atomizing method, gas atomizing method, centrifugal atomizing method, plasma atomizing method, and the like, all of which are preferably used.

Commercially available particles may be used.
Examples of commercial products of particles whose constituent material is metal include pure Al (manufactured by Toyo Aluminum Co., Ltd., A1070-30BB), pure Ti (manufactured by Osaka Titanium Technologies), SUS316L (manufactured by Sanyo Special Steel Co., Ltd., trade name : PSS316L), AlSi ₁₀ Mg (manufactured by Toyo Aluminum Co., Ltd., Si ₁₀ MgBB), SiO ₂ (manufactured by Tokuyama Co., Ltd., product name: EXCELICA SE-15K), AlO ₂ (manufactured by Taimei Chemical Industry Co., Ltd., product name: Thailand Micron TM-5D), ZrO ₂ (manufactured by Tosoh Corporation, trade name: TZ-B53), and the like.

The volume average particle diameter of the particles is not particularly limited and can be appropriately selected according to the purpose. When the volume average particle diameter of the particles is 2 μm or more, aggregation of the particles is suppressed, and a decrease in production efficiency of shaped objects and a decrease in handling properties of the particles can be suppressed. Further, when the average particle diameter of the particles is 100 μm or less, it is possible to suppress the decrease in contact points between particles and the increase in voids, thereby suppressing the reduction in the strength of the shaped article.
The particle size distribution of the particles is not particularly limited and can be appropriately selected according to the purpose, but a sharper particle size distribution is preferred.
The volume average particle diameter and particle size distribution of the particles can be measured using a known particle size measuring device, for example, a particle size distribution measuring device Microtrac MT3000II series (manufactured by Microtrac Bell).

-Powder containing sinterable particles-
The above particles are used as a powder that is an aggregate containing a plurality of particles, and a sintering inhibiting liquid and a modeling liquid are applied to the powder layer.
The powder can contain other ingredients in addition to the sinterable particles, if desired. Other components include, for example, fillers, leveling agents, sintering aids, polymer resin particles, and the like.
A filler is a material that is effective in adhering to the surface of particles and filling voids between particles. By using a filler, for example, the fluidity of the powder can be improved, and contact points between particles can be increased to reduce voids, so that the strength and dimensional accuracy of the model can be increased.
A leveling agent is a material that is effective in controlling the wettability on the surface of the powder layer. By using the leveling agent, for example, the penetration of the modeling liquid into the powder layer is increased, and the strength of the modeled article can be increased.
A sintering aid is a material that is effective in increasing the sintering efficiency when sintering a shaped article. By using a sintering aid, for example, the strength of the shaped article can be improved, the sintering temperature can be lowered, and the sintering time can be shortened.
Polymer resin particles are materials effective for adhering to the surface of particles, and are also called organic external additives. Although the average particle size of the polymer resin particles is not particularly limited, it is preferably 0.1 μm or more and 10 μm or less, more preferably 0.1 μm or more and 1 μm.

The angle of repose of the powder is preferably 60° or less, more preferably 50° or less, and even more preferably 40° or less. When the angle is 60° or less, the powder can be efficiently and stably arranged at a desired position on the support. The angle of repose can be measured using, for example, a powder property measuring device (Powder Tester PT-N type, manufactured by Hosokawa Micron Corporation).

<Modeling liquid application process>
The method for manufacturing a modeled object has a modeling liquid application step of applying a modeling liquid to a powder layer to form a modeling region.
Further, the modeling liquid applying step is preferably a step of applying the modeling liquid to the powder layer to form the modeling region and the support region.
Further, when the support region is formed in the modeling liquid application step, the modeling liquid forming the support region, as shown in FIG. provided adjacent to the build area 104 . As a result, during the degreasing process and the sintering process, as shown in FIG. 2, the support portion 201 formed by stacking the support regions is arranged to support the shaping portion 203 via the sintering inhibition portion 202. (in other words, the support portion 201 is provided along the undulations of the shaped portion 203 via the sintering inhibition portion 202), and damage or deformation of the shaped portion is suppressed. In particular, a protruding part provided on the upper part called an overhang, and a shaped part having a shape that does not have a structure to support the protruding part in the lower part, during the degreasing process or the sintering process In the above, damage or deformation due to its own weight is likely to occur, so damage or deformation can be suppressed by providing a support portion at the bottom of the overhang. In addition, when forming the support region in the modeling liquid applying process, the timing of forming the modeling region and the support region does not have to be consecutive. For example, the formation of the sintering inhibition regions may occur after formation of the build regions and before formation of the support regions.

As a method of applying the modeling liquid to the powder layer, a method of discharging the modeling liquid is preferable. The method of ejecting the modeling liquid is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include a dispenser method, a spray method, an inkjet method, and the like. Among these, the dispenser method is excellent in the quantification of droplets, but the application area is narrow. In addition, the spray method can easily form fine ejected matter, has a large application area, and is excellent in application properties, but has poor quantification of droplets, and the modeling liquid scatters due to the spray flow. For this reason, the inkjet method is preferable. The ink jet method has the advantage that the droplets can be quantified better than the spray method, and the application area can be widened compared to the dispenser method.

When the inkjet method is used, the modeling liquid application means for applying the modeling liquid by ejecting it is an inkjet head having nozzles for ejecting the modeling liquid.
As the inkjet head, an inkjet head for a known inkjet printer can be suitably used. In addition, as an inkjet head in an inkjet printer, for example, an industrial inkjet RICOH MH/GH SERIES manufactured by Ricoh Co., Ltd. may be used. Moreover, as an inkjet printer, for example, SG7100 manufactured by Ricoh Co., Ltd. may be used.

In addition to the step of applying the modeling liquid to the powder layer to form the modeling region, the modeling liquid applying step also applies the sintering inhibiting region formed by the sintering inhibiting liquid applying step described later. It may include applying the modeling liquid to the substrate later. As a result, the strength of the sintering inhibition portion before the degreasing step can be improved, and the handleability of the green body (unsintered body) can be improved. In addition, since two types of resin (second resin and molding resin, which will be described later) are included in the sintering inhibition area, the resin is degreased in two steps during the degreasing process. Excessive cracking of the part is suppressed.

The modeling liquid supplied to the modeling liquid applying means may be stored in the modeling liquid storage section. The modeling liquid storage part is a member such as a container in which the modeling liquid is stored, and examples thereof include a storage tank, a bag, a cartridge, a tank, and the like.

-molding liquid-
The modeling liquid contains additives such as resins, organic solvents, and surfactants. Various components contained in the modeling liquid will be described in detail below.
In addition, the resin contained in the modeling liquid, the resin contained in the sintering inhibition liquid described later (first resin), the resin derived from the resin contained in the sintering inhibition liquid (second resin), and the resin generation liquid In order to distinguish the resin (third resin) generated by the contact of X and the resin generation liquid Y, the resin contained in the modeling liquid may be referred to as "modeling resin".

--Resin (modeling resin)--
The resin contained in the modeling liquid is placed in the powder layer by applying the modeling liquid to the powder layer containing sinterable particles, and an appropriate heating process is performed according to the softening point of the resin. By going through, it functions as a binder that binds the sinterable particles together in the build area.

The resin used in the modeling liquid is not particularly limited, but examples thereof include resins having a structural unit represented by the following structural formula (1). In addition, in the present disclosure, "structural unit" represents a partial structure in a resin derived from one or more polymerizable compounds.

Since the resin having the structural unit represented by the structural formula (1) has excellent thermal decomposability, it is appropriately removed in the degreasing process, and the relative sintered density in the sintered body produced through the subsequent sintering process improves.
Specifically, the resin having the structural unit represented by Structural Formula (1) is preferably thermally decomposed at 95% by mass or more when the temperature is raised from 30° C. to 550° C., and is thermally decomposed at 97% by mass or more. more preferably.
The thermal decomposability is measured using a TG-DTA (differential thermal/thermogravimetric simultaneous measurement apparatus).
Specifically, when the temperature is raised from 30° C. to 550° C. at a rate of 10° C./min in the air or nitrogen atmosphere, and the temperature is maintained for 2 hours after reaching 550° C., the weight loss rate before and after the temperature rise is determined.

Specific examples of resins having structural units represented by structural formula (1) include polyvinyl acetate resins, partially saponified polyvinyl acetate resins, and polyvinyl butyral resins. Moreover, although these resins may be used independently, you may use 2 or more types together. Moreover, both commercial products and synthetic products can be used.
The partially saponified polyvinyl acetate resin is a resin obtained by partially saponifying a polyvinyl acetate resin. In addition, the partially saponified polyvinyl acetate resin in the present disclosure has a degree of saponification of 40 or less, preferably 35 or less, more preferably 30 or less, even more preferably 25 or less, and 20 or less. It is even more preferable to have

The content of the resin having the structural unit represented by Structural Formula (1) is preferably 5.0% by mass or more, more preferably 7.0% by mass or more, and 10.0% by mass with respect to the mass of the modeling liquid. The above is more preferable, and 11.0% by mass or more is particularly preferable. The content of the resin having the structural unit represented by structural formula (1) is preferably 30.0% by mass or less, more preferably 25.0% by mass or less, and even more preferably 20.0% by mass or less.

--Organic solvent--
The modeling liquid contains an organic solvent. The organic solvent is a liquid component used to keep the modeling liquid in a liquid state at room temperature.
Moreover, it is preferable that the modeling liquid is a non-aqueous modeling liquid by containing an organic solvent.
In the present disclosure, the term "non-aqueous modeling liquid" means that the liquid component of the modeling liquid contains an organic solvent, and the component having the largest mass in the liquid component is the organic solvent. The content of the organic solvent with respect to the content of the components is preferably 90.0% by mass or more, more preferably 95.0% by mass or more.
This is because, when the modeling liquid is non-aqueous, the solubility of the resin having the structural unit represented by the structural formula (1) is improved, and the viscosity of the modeling liquid is lowered.
Also, the non-aqueous modeling liquid may be rephrased as a modeling liquid that does not substantially contain water, for example. This makes it possible to apply the modeling liquid even if the material that constitutes the sinterable particles is a highly active metal, in other words, a water-repellent material (eg, aluminum, zinc, magnesium, etc.). As an example, aluminum generates hydrogen when it comes into contact with water, which poses the problem of being difficult to handle.

Examples of organic solvents include n-octane, m-xylene, solvent naphtha, diisobutyl ketone, 3-heptanone, 2-octanone, acetylacetone, butyl acetate, amyl acetate, n-hexyl acetate, n-octyl acetate, ethyl butyrate, ethyl valerate, ethyl caprylate, ethyl octanoate, ethyl acetoacetate, ethyl 3-ethoxypropionate, diethyl oxalate, diethyl malonate, diethyl succinate, diethyl adipate, bis-2-ethylhexyl maleate, triacetin, tributyrin, Propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, dibutyl ether, 1,2-dimethoxybenzene, 1,4-dimethoxybenzene, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, 2-methoxy-1-methylethyl acetate , γ-butyrolactone, propylene carbonate, cyclohexanone, and butyl cellosolve. These may be used individually by 1 type, and may use 2 or more types together.

60.0 to 95.0 mass % is preferable with respect to the mass of a modeling liquid, and, as for content of an organic solvent, 70.0 to 95.0 mass % is more preferable.

--Additive--
Depending on the purpose, the modeling liquid may contain surfactants, anti-drying agents, viscosity modifiers, penetrants, antifoaming agents, pH adjusters, preservatives, antifungal agents, coloring agents, preservatives, stabilizers, etc. It may be contained as appropriate. Conventionally known materials can be used for these.

--Other ingredients--
The modeling liquid does not substantially contain water. In the present disclosure, "substantially free of water" means that the water content is 10.0% by mass or less relative to the mass of the modeling liquid, and preferably 5.0% by mass or less. , more preferably 3.0% by mass or less, even more preferably 1.0% by mass or less, and particularly preferably the modeling liquid does not contain water. In addition, in the present disclosure, "the modeling liquid does not contain water" means that water is not actively used as a material at the time of manufacturing the modeling liquid, or that the water content in the modeling liquid is a known and common technical method. It is below the detection limit when used.
In addition, since the modeling liquid does not substantially contain water, the modeling liquid can be applied even if the material constituting the particles is a highly active metal, in other words, a water-retaining material (e.g., aluminum, zinc, magnesium, etc.). be able to. As an example, aluminum generates hydrogen when it comes into contact with water, which poses the problem of being difficult to handle.

--Production method--
The method for producing the modeling liquid is not particularly limited, and can be appropriately selected according to the purpose. Examples thereof include a method of mixing and stirring the above materials.

--Physical properties--
The viscosity of the modeling liquid is preferably low as described above. ·s or more and 30 mPa·s or less is more preferable. When the viscosity of the modeling liquid is within the above range, the ejection from the modeling liquid applying means such as an inkjet head is stabilized, and the dimensional accuracy is improved.
The viscosity can be measured according to JIS K7117, for example.

The surface tension of the modeling liquid is preferably 40 mN/m or less, more preferably 10 mN/m or more and 30 mN/m or less at 25°C. When the surface tension is 40 mN/m or less, ejection from a modeling liquid applying means such as an inkjet head is stabilized, and dimensional accuracy is improved.
The surface tension can be measured by, for example, DY-300 manufactured by Kyowa Interface Science Co., Ltd.

<Sintering inhibiting liquid application step>
The method for manufacturing a modeled article has a sintering inhibiting liquid applying step of applying a sintering inhibiting liquid to a powder layer to form a sintering inhibiting region where sintering of particles is inhibited.
In addition, in the sintering inhibiting liquid applying step, the sintering inhibiting liquid is applied so that the sintering inhibiting area to be formed is adjacent to the modeling area.

As a method of applying the sintering inhibiting liquid to the powder layer, a method of discharging the sintering inhibiting liquid is preferable. A method for discharging the sintering inhibitor liquid is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include a dispenser method, a spray method, and an inkjet method. Among these, the dispenser method is excellent in the quantification of droplets, but the application area is narrow. In addition, the spray method can easily form fine droplets, has a wide application area, and is excellent in application properties, but the droplets are poor in quantitativeness, and the sintering inhibitor liquid scatters due to the spray flow. For this reason, the inkjet method is preferable. Compared to the spray method, the inkjet method has better droplet quantification, and has the advantage of being able to apply a wider coating area than the dispenser method. .

When the inkjet method is used, the sintering inhibitor applying means for applying the sintering inhibitor by ejecting the sintering inhibitor is an inkjet head having a nozzle for ejecting the sintering inhibitor. As the inkjet head, an inkjet head for a known inkjet printer can be suitably used. In addition, as an inkjet head in an inkjet printer, for example, an industrial inkjet RICOH MH/GH SERIES manufactured by Ricoh Co., Ltd. may be used. Moreover, as an inkjet printer, for example, SG7100 manufactured by Ricoh Co., Ltd. may be used.

The application amount per unit area of the sintering inhibitor liquid applied to form the sintering inhibition region in the sintering inhibition liquid application step is the amount of the modeling liquid applied to form the modeling region in the modeling liquid application step. It is preferable that the amount is larger than the amount applied per unit area. As a result, the strength of the sintering-inhibited portion before the degreasing process is improved, thereby improving the handleability. This is because the process of detaching the sintered product of the sintering inhibition portion from the object becomes easier.

As shown in FIG. 3, the sintering inhibiting region formed by the sintering inhibiting liquid applying step is arranged such that the sintering inhibiting region 302 surrounds the molding region 303 in the powder layer 301. preferable. This suppresses the collapse of the sintering inhibition portion during the sintering process, thereby improving the dimensional accuracy of the modeled object.

At the boundary between the modeling region and the sintering inhibition region, the sintering inhibition liquid is preferably applied by the sintering inhibition liquid application step within 100 msec after the modeling liquid is applied by the modeling liquid application step. Specifically, for example, when the modeling liquid and the sintering inhibition liquid are each applied to the powder layer in the form of droplets, at the boundary between the modeling region and the sintering inhibition region, on the powder layer, The location where the droplets of the modeling liquid are applied and the location where the droplets of the sintering inhibitor liquid are applied are adjacent to each other. It means that droplets of the sintering inhibitor liquid are applied within 100 msec after the droplets of are applied. As a result, the molding liquid applied to the powder is suppressed from seeping into the sintering inhibition region, and the dimensional accuracy of the molded object is improved.

The sintering inhibiting liquid supplied to the sintering inhibiting liquid supplying means may be contained in the sintering inhibiting liquid container. The sintering-inhibiting liquid storage part is a member such as a container in which the sintering-inhibiting liquid is stored, and includes, for example, a storage tank, a bag, a cartridge, a tank, and the like.

- Sintering inhibitor liquid -
The sintering-inhibiting liquid contains the first resin, an organic solvent, additives such as surfactants, and the like. The characteristics of the sintering-inhibiting liquid and various components contained in the sintering-inhibiting liquid will be described in detail below.
In addition, since the sintering inhibitor liquid contains the first resin as described above, the sintering inhibitor formed by applying the sintering inhibitor liquid to the powder layer containing the sinterable particles The inhibition region contains the first resin or a second resin derived from the first resin.
The second resin is not limited as long as it is derived from the first resin, and may be a resin that is chemically identical to the first resin, or a resin that is chemically different from the first resin. There may be. When the second resin becomes a resin chemically different from the first resin, for example, due to the heating process performed after the sintering inhibiting liquid is applied to the powder layer, Examples include the case where the first resin chemically changes (for example, the case where a cross-linking reaction proceeds in the first resin to generate the second resin).
A sintering inhibiting region formed by applying a sintering inhibiting liquid to a powder layer containing sinterable particles may contain a first resin. For example, there is a case where the first resin does not change chemically in a heating process performed after the sintering inhibiting liquid is applied to the powder layer.

--Predicted residue amount--
The sintering inhibitor liquid has predetermined properties related to the first resin or the second resin. Specifically, the sintering inhibitor liquid is the mass ratio of the first resin or the second resin to the powder in the sintering inhibition region, and the mass ratio of the first resin or the second resin at 550 ° C. It has a characteristic that the predicted residue amount calculated by multiplying by the thermal decomposition residue rate is 800 ppm or more, preferably 1000 ppm or more, and more preferably 1200 ppm or more. When the predicted residue amount is 800 ppm or more, the relative sintering density of the sintered product in the sintering inhibition region can be sufficiently reduced (a "sintering inhibition part" formed by laminating the sintering inhibition region The relative sintered density in the sintered body can also be sufficiently reduced in the same manner), and the releasability is improved when the sintered product of the sintering inhibition portion is detached from the sintered product of the shaped portion. Next, a method for calculating the predicted residue amount will be described in detail.

First, in the present disclosure, the “mass ratio of the first resin or the second resin to the powder in the sintering inhibition portion formed by stacking the sintering inhibition regions” is expressed by the following formula “the first resin in the sintering inhibition portion It is expressed by "the mass of the first resin or the second resin/the mass of the powder in the sintering inhibition portion".
Calculations based on this formula are based on the method of manufacturing a model (for example, the type of sinterable particles to which the sintering inhibitor is applied, the amount of sintering inhibitor applied, and the amount of sintering inhibitor after applying the sintering inhibitor. including information on how to use the sintering inhibitor liquid such as the treatment method).
As a method of using the sintering inhibiting liquid, for example, if there is a specific apparatus using the sintering inhibiting liquid, there are procedures for using the sintering inhibiting liquid stored in the specific apparatus.
As a specific procedure for using the sintering inhibitor liquid, for example, a powder layer (average thickness: 84 μm) made of particles of an aluminum alloy (material: AlSi ₁₀ Mg, volume average particle diameter: 35 μm) is formed. A procedure such as applying 45 pL of sintering inhibitor liquid per region of 300 dpi × 300 dpi to the powder layer and then placing it in an environment of 200 ° C. for 4 hours. Calculations based on the above equations are performed in the inhibition section.
The above-mentioned "mass of the first resin or the second resin in the sintering inhibition part" is, for example, the ratio (w / v%) of the first resin contained in the sintering inhibition liquid, and the sintering per layer It can be calculated by multiplying the volume of the sintering inhibitor liquid applied to the inhibition portion and the number of layers.
The above-mentioned "mass of powder in the sintering inhibition part" can be calculated, for example, by multiplying the volume of the powder in the sintering inhibition part per layer, the density of the powder, and the number of layers. .

The above-mentioned "mass ratio of the first resin or the second resin to the powder in the sintering inhibition part" is preferably 3000 ppm or more, more preferably 4000 ppm or more, and further preferably 5000 ppm or more. preferable. When the mass ratio is 3000 ppm or more, it becomes easy to make the predicted residue amount 800 ppm or more.
Also, the "mass ratio of the first resin or the second resin to the powder in the sintering inhibition portion" is preferably 60000 ppm or less, more preferably 16000 ppm or less. When the mass ratio is 60000 ppm or less, the amount of the sintering inhibitor applied is not excessive, and productivity is improved.

Next, in the present disclosure, "the thermal decomposition residue rate of the first resin or the second resin at 550 ° C." mass/mass of the first resin or the second resin before pyrolysis".
The calculation based on this formula is similar to the calculation in the above "Mass ratio of the first resin or the second resin to the powder in the sintering inhibition part", the sintering inhibition part formed according to the manufacturing method of the modeled product is used.
That is, the second resin in the present formula is a resin derived from the first resin in the sintering inhibition portion formed according to the manufacturing method of the shaped article.
The "residue mass when the first resin or the second resin is thermally decomposed at 550° C." is measured by using, for example, a TG-DTA (differential thermal/thermogravimetric simultaneous measurement apparatus). Specifically, the sintering inhibition portion formed according to the manufacturing method of the shaped article is heated from 30° C. to 550° C. at a rate of 10° C./min in the air or nitrogen atmosphere, and after reaching 550° C., the temperature is increased for 2 hours. The weight (residual mass) after the temperature rise is determined when the temperature is maintained.

The above "thermal decomposition residue rate of the first resin or the second resin at 550 ° C." is preferably 0.100 or more, more preferably 0.130 or more, and 0.150 or more is more preferable, and 0.200 or more is particularly preferable. When the thermal decomposition residue ratio is 0.100 or more, it becomes easy to make the predicted residue amount 800 ppm or more.

--Relative Sintered Density--
The sintering inhibition portion formed by stacking the sintering inhibition regions formed using the sintering inhibition liquid is, as described above, relative sintering of the sintered product formed by sintering the sintering inhibition portion. It has the property of low density. Specifically, the relative sintered density is preferably 85% or less, more preferably 80% or less, and even more preferably 75% or less. It is more preferably 70% or less, even more preferably 65% or less, even more preferably 60% or less, and particularly preferably 55% or less. As a result, it is possible to obtain the effect of improving the releasability when the sintered material of the sintering inhibition portion is detached from the sintered material of the shaping portion.
The relative sintered density represents the ratio of the density of the sintered body to the true density of the material forming the sintered body. Moreover, each density can be measured by a known method.

--first resin--
The sintering inhibition liquid contains the first resin as a material that lowers the relative sintering density of the sintered product formed by sintering the sintering inhibition portion. Conventionally, ceramics have been used as materials for lowering the relative sintering density as described above, but such conventional materials are inferior in terms of dispersibility in the sintering inhibitor liquid. It was difficult to discharge the sintering inhibiting liquid at Moreover, such conventional materials are inferior in sedimentation or redispersibility in a sintering inhibiting liquid, making it difficult to provide a sintering inhibiting liquid with high storage stability. On the other hand, in the present disclosure, dispersibility and storage stability of the sintering-inhibiting liquid are improved by adopting resin instead of ceramics as the material that lowers the relative sintering density as described above.

The first resin is preferably a resin capable of increasing the thermal decomposition residue ratio at 550° C. of the second resin derived from the first resin. Specific examples of the first resin include polyvinyl chloride, polyvinylidene chloride, cellulose acetate, polyacrylonitrile, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, and vinyl chloride-vinyl acetate copolymer. coalescence, polyethylene terephthalate, phenolic resin, melamine resin, urea resin, unsaturated polyester, epoxy resin, silicone resin, polyvinylpolypyrrolidone, benzoguanamine resin and the like. These may be of one type, or two or more types may be used in combination.

In addition, the first resin chemically changes due to the heating process or the like performed after the sintering inhibition liquid is applied to the powder layer, and the first resin and the second resin chemically change. When different resins are used for the second resin, it is preferable to use the second resin whose thermal decomposition residue rate at 550°C is higher than the thermal decomposition residue rate at 550°C of the first resin. Polyvinylpyrrolidone or the like can be used as such a first resin. This is because when polyvinylpyrrolidone is heated at 170° C. or higher, a cross-linking reaction proceeds and polyvinylpolypyrrolidone, which is the second resin, is produced.
In addition, when the sintering inhibition region contains the second resin, the thermal decomposition residue rate of the first resin at 550 ° C. is measured as follows using the first resin alone. .
<Method for measuring the thermal decomposition residue rate of the first resin alone>
Using TG-DTA (simultaneous differential thermal/thermogravimetry), the temperature is raised from 30°C to 550°C at a rate of 10°C/min in the air or nitrogen atmosphere, and the temperature is maintained for 2 hours after reaching 550°C. , determine the weight (residual mass) after the temperature is raised.

From the viewpoint of improving the dispersibility and storage stability of the sintering-inhibiting liquid, the first resin is more preferably dissolved in the sintering-inhibiting liquid, but may be dispersed. When the first resin is dispersed in the sintering inhibitor liquid, the volume average particle diameter of the first resin is 1 μm or less from the viewpoint of improving the dispersibility and storage stability of the sintering inhibitor liquid. is preferred, 500 nm or less is more preferred, and 300 nm or less is even more preferred.

The content of the first resin is preferably 5.0% by mass or more and 25.0% by mass or less, and is 10.0% by mass or more and 20.0% by mass or less with respect to the mass of the sintering inhibitor liquid. is more preferable. By being 5.0% by mass or more and 25.0% by mass or less, the relative sintering density of the sintered product formed by sintering the sintering inhibition portion is reduced, and the dispersibility and storage of the sintering inhibition liquid It is possible to achieve both improvement in stability and

--Organic solvent--
The organic solvent is a liquid component used to make the sintering inhibitor liquid in a liquid state at room temperature. When dissolving the first resin in the sintering inhibiting liquid, an organic solvent that dissolves the first resin is selected. When dispersing the first resin in the sintering inhibiting liquid, an organic solvent that does not dissolve the first resin is selected.
Moreover, the sintering inhibiting liquid is preferably a non-aqueous sintering inhibiting liquid by containing an organic solvent. In the present disclosure, the term “non-aqueous sintering-inhibiting liquid” refers to a sintering-inhibiting liquid that contains an organic solvent as a liquid component and that the component having the largest mass in the liquid component is an organic solvent. The content of the organic solvent is preferably 90.0% by mass or more, more preferably 95.0% by mass or more, relative to the content of the liquid component in the binding inhibitor. Moreover, the non-aqueous sintering inhibiting liquid may be rephrased as, for example, a sintering inhibiting liquid that does not substantially contain water. This makes it possible to apply the sintering-inhibiting liquid even if the material that constitutes the sinterable particles is a highly active metal, in other words, a water-reactive material (eg, aluminum, zinc, magnesium, etc.). As an example, aluminum generates hydrogen when it comes into contact with water, so it is difficult to handle, but this problem can be suppressed by using a sintering inhibiting liquid that does not contain water.

The organic solvent is not particularly limited and may be appropriately selected depending on the type of the first resin to be used in combination. Acetylacetone, butyl acetate, amyl acetate, n-hexyl acetate, n-octyl acetate, ethyl butyrate, ethyl valerate, ethyl caprylate, ethyl octanoate, ethyl acetoacetate, ethyl 3-ethoxypropionate, diethyl oxalate, malonic acid diethyl, diethyl succinate, diethyl adipate, bis-2-ethylhexyl maleate, triacetin, tributyrin, propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, dibutyl ether, 1,2-dimethoxybenzene, 1,4-dimethoxybenzene, Diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, 2-methoxy-1-methylethyl acetate, γ-butyrolactone, propylene carbonate, cyclohexanone, and butyl cellosolve. These may be used individually by 1 type, and may use 2 or more types together.

The content of the organic solvent is preferably 50.0% by mass or more and 95.0% by mass or less, and preferably 70.0% by mass or more and 90.0% by mass or less, relative to the mass of the sintering inhibitor liquid. more preferred. When the content is 50.0% by mass or more and 95.0% by mass or less, the dispersibility and storage stability of the sintering-inhibiting liquid can be improved.

--Additive--
The sintering inhibitor liquid may contain surfactants, anti-drying agents, viscosity modifiers, penetrants, antifoaming agents, pH adjusters, preservatives, antifungal agents, coloring agents, preservatives, and stabilizers, depending on the purpose. etc. may be contained as appropriate. Conventionally known materials can be used for these.

--Other ingredients--
The sintering inhibition liquid does not substantially contain water. In the present disclosure, “substantially free of water” means that the water content is 10.0% by mass or less with respect to the mass of the sintering inhibitor liquid, and is 5.0% by mass or less. is preferably 3.0% by mass or less, more preferably 1.0% by mass or less, and particularly preferably the sintering-inhibiting liquid does not contain water. In addition, in the present disclosure, "the sintering inhibitor liquid does not contain water" means that water is not actively used as a material during the production of the sintering inhibitor liquid, or that the water content in the sintering inhibitor liquid is known. And it means that it is below the detection limit when using the method of technical common sense.
Since the sintering-inhibiting liquid does not substantially contain water, sintering can be performed even if the material that constitutes the sinterable particles is a highly active metal, in other words, a water-reactive material (such as aluminum, zinc, and magnesium). An anticoagulant solution can be applied. As an example, aluminum generates hydrogen when it comes into contact with water, which makes it difficult to handle.

The sintering inhibition liquid does not contain ceramics. In the present disclosure, "does not contain ceramics" means that ceramics are not actively used as a material in the production of the sintering inhibitor solution, or that the content of ceramics in the sintering inhibitor solution is known and uses a common general technical method. It means that it is below the detection limit.
Since the sintering-inhibiting liquid does not contain ceramics, the dispersibility and storage stability of the sintering-inhibiting liquid can be improved.

--Production method--
The method for producing the sintering-inhibiting liquid is not particularly limited and can be appropriately selected according to the purpose.

--Physical properties--
The viscosity of the sintering inhibitor liquid is preferably low as described above. Specifically, at 25° C., it is preferably 5 mPa·s or more and 50 mPa·s or less, more preferably 5 mPa·s or more and 40 mPa·s or less. , more preferably 5 mPa·s or more and 30 mPa·s or less. When the viscosity of the sintering-inhibiting liquid is within the above range, ejection from a sintering-inhibiting liquid applying means such as an inkjet head is stabilized.
The viscosity can be measured according to JIS K7117, for example.

The surface tension of the sintering-inhibiting liquid is preferably 40 mN/m or less, more preferably 10 mN/m or more and 30 mN/m or less at 25°C. When the surface tension is 40 mN/m or less, ejection from a sintering inhibitor applying means such as an inkjet head is stabilized.
The surface tension can be measured by, for example, DY-300 manufactured by Kyowa Interface Science Co., Ltd.

--Usage--
As described above, the sintering inhibition liquid is applied to the powder layer to form the sintering inhibition region, and the sintering inhibition region is laminated to form the sintering inhibition portion, and the sintering inhibition The relative sintered density of the sintered product formed by sintering the part is lower than the relative sintered density of the sintered product formed by sintering the shaped article. As a result, it is possible to obtain the effect of improving the releasability when the sintered material of the sintering inhibition portion is detached from the sintered material of the shaping portion. The use of the sintering inhibitor liquid based on this effect is not particularly limited, but for example, use for improving the peelability of the support part from the molded part, use as a connection part for connecting a plurality of molded parts, and surplus powder Applications such as omitting the removal step are included.

A case of using a sintering inhibiting liquid for improving the releasability of the support portion from the molded portion will be described. Specifically, for example, when providing a support portion that supports the shaping portion via the sintering inhibition portion, relative sintering is performed between the sintered product (sintered body) of the shaping portion and the sintered product of the support portion. An interface consisting of a sintering inhibition portion with a low density is formed to suppress binding between the sintered product of the shaping portion and the sintered product of the support portion, thereby preventing the sintered product of the shaping portion from the sintering of the support portion. It is possible to improve the releasability when detaching the conjunctiva.

A case of using a sintering inhibiting liquid as an application of a connecting portion that connects a plurality of shaped portions will be described. A connection part is a member that connects multiple modeling parts to form an integrated object that integrates multiple modeling parts. For example, a rod-shaped member whose end is connected to the modeling part can be mentioned. By making multiple shaped parts into the form of the above-mentioned integrated body, it is possible to reduce the man-hours in the sintering process, etc., by rearranging the multiple shaped parts and placing them in a sintering furnace, etc., improving workability when manufacturing shaped objects. do. In addition, by forming at least a region of the connecting portion that contacts with the shaping portion to be a sintering inhibiting portion, the sintered product of the connecting portion is detached from the sintered product of the shaping portion, and the peelability is improved. effect is obtained.
FIG. 4 is a schematic diagram showing an example of an integrated product in which a plurality of shaped parts and a plurality of connecting parts are integrated. The integrated body shown in FIG. 4 has a shaped portion 401 and a connection portion 402, and the connection portion 402 is formed by a sintering inhibition portion.

A case of using a sintering inhibiting liquid for omitting the excessive powder removing step will be described. Usually, in manufacturing a modeled object, a surplus powder removing step is performed to remove surplus powder, which is powder to which liquid such as a modeling liquid or a sintering inhibiting liquid has not been applied. However, when the entire periphery of the modeled portion is covered with the sintering inhibition portion, surplus powder cannot adhere to the modeled portion, so the surplus powder removing step can be omitted. However, the fact that the surplus powder removing step can be omitted means that the use of surplus powder removing means such as an air blowing device or a removing liquid can be omitted, and the surplus powder is removed manually to the extent that it is shaken off. shall not be included in the scope of omission. In addition, the sintering inhibition portion covering the entire periphery of the shaped portion is continuous to the outer surface of the laminate, and the laminate has two or more outer surfaces bounded by the sintering inhibition portion exposed on the outer surface. When the region is divided into regions, the sintering inhibiting portion and the sintered product of surplus powder can be easily removed from the sintered product of the shaped portion after the sintering process, which is preferable.
FIG. 5 is a schematic diagram showing an example of a laminate having a molded part and a sintering inhibiting part covering the entire periphery of the molded part. The laminate shown in FIG. 5 includes a shaped portion 501, a sintering inhibition portion 502A having the shaped portion 501 inside and covering the entire circumference of the shaped portion, a sintering inhibition portion 502A, and an outer surface of the laminate. It has a plate-like sintering inhibition portion 502B and surplus powder 503. Also, the outer surface of the laminate is divided into two regions 504 and 505 with the sintering inhibition portion 502B as a boundary.

<Step of applying sintering inhibitor liquid set>
The method for manufacturing a model may have a "sintering inhibitor liquid set application step" instead of the "sintering inhibitor liquid application step" described above. The sintering inhibition liquid set application step is to independently apply the resin generation liquid X and the resin generation liquid Y to the powder layer, and the resin generation liquid X and the resin generation liquid are applied to the powder layer after application. This is a step of forming a sintering inhibition region where the sintering of the particles is inhibited by the contact of Y. In other words, the sintering inhibition liquid set application step includes a resin generation liquid X application step of applying the resin generation liquid X to the powder layer, and a resin generation liquid X application step of applying the resin generation liquid Y to the powder layer. A step of applying a liquid Y and a contacting step of forming a sintering inhibition region where sintering of particles is inhibited by the contact of the generated resin liquid X and the generated resin liquid Y applied in the powder layer. That is, the sintering inhibition liquid set including the resin generation liquid X and the resin generation liquid Y has the same function as the sintering inhibition liquid by being used instead of the above sintering inhibition liquid, and is used for the same purpose. be able to.

As a method for applying the resin-generating liquid X and the resin-generating liquid Y to the powder layer, the same method as described in the above-described "sintering-inhibiting liquid applying step" can be used.
The resin generation liquid X application step is preferably carried out by the resin generation liquid X application means.
The resin generation liquid Y applying step is preferably carried out by the resin generation liquid Y applying means.
As the resin generation liquid X supply means and the resin generation liquid Y supply means, the same as the sintering inhibitor liquid supply means described above can be used.

Incidentally, the resin-generated liquid X to be supplied to the resin-generated liquid X supply means may be contained in the resin-generated liquid X containing section. The resin generation liquid X storage part is a member such as a container in which the resin generation liquid X is stored, and examples thereof include a storage tank, a bag, a cartridge, a tank, and the like.
Further, the resin production liquid Y supplied to the resin production liquid Y applying means may be stored in the resin production liquid Y storage section. The resin generation liquid Y storage unit is a member such as a container that stores the resin generation liquid Y, and includes, for example, a storage tank, a bag, a cartridge, a tank, and the like.

- Sintering inhibitor set -
The resin generation liquid X contains a resin precursor X, an organic solvent, additives such as surfactants, and the like. The resin generation liquid Y contains a resin precursor Y, an organic solvent, additives such as surfactants, and the like. The characteristics of the sintering inhibition liquid set and various components contained in the resin generation liquid X and the resin generation liquid Y will be described in detail below. However, with respect to additives such as organic solvents and surfactants contained in resin generation liquid X and resin generation liquid Y, the same additives as organic solvents and surfactants contained in the sintering inhibiting liquid are used. Therefore, the description is omitted.
In addition, the sintering inhibition region contains a third resin that is generated when the resin generation liquid X and the resin generation liquid Y come into contact with each other. More specifically, the resin precursor X contained in the resin generation liquid X and the resin precursor Y is generated by the reaction of

--Predicted residue amount--
The sintering inhibitor liquid set has predetermined properties regarding the third resin.
Specifically, the sintering inhibition liquid set is calculated by multiplying the mass ratio of the third resin to the powder in the sintering inhibition region by the thermal decomposition residue rate of the third resin at 550 ° C. It has a characteristic that the predicted residue amount is 800 ppm or more, preferably 1000 ppm or more, and more preferably 1200 ppm or more. When the predicted residue amount is 800 ppm or more, the relative sintering density of the sintered product in the sintering inhibition region can be sufficiently reduced (a "sintering inhibition part" formed by laminating the sintering inhibition region The relative sintered density in the sintered body can also be sufficiently reduced in the same manner), and the releasability is improved when the sintered product of the sintering inhibition portion is detached from the sintered product of the shaped portion. Next, a method for calculating the predicted residue amount will be described in detail.

First, in the present disclosure, “the mass ratio of the third resin to the powder in the sintering inhibition portion formed by stacking the sintering inhibition regions” is expressed by the following formula “the mass ratio of the third resin in the sintering inhibition portion mass/mass of powder in the sintering inhibition region”.
Calculations based on this formula are based on the method of manufacturing a shaped object (for example, the type of sinterable particles to which the resin generation liquid X and the resin generation liquid Y are applied, the amount of the resin generation liquid X and the resin generation liquid Y applied, and including information on how to use the sintering inhibiting liquid set, such as the treatment method after applying the resin forming liquid X and the resin forming liquid Y).
As a method of using the sintering inhibitor liquid set, for example, if there is a specific device using the sintering inhibitor liquid set, the procedure for using the sintering inhibitor liquid set stored in this specific device, etc. mentioned.
As a specific procedure for using the sintering inhibition liquid set, for example, a powder layer (average thickness: 84 μm) made of particles of an aluminum alloy (material: AlSi ₁₀ Mg, volume average particle diameter: 35 μm) is applied. Form, apply 22.5 pL of resin generation liquid X and 22.5 pL of resin generation liquid Y per area of 300 dpi × 300 dpi to the powder layer, and then place in an environment at 200 ° C. for 4 hours. Calculation based on the above formula is performed in the sintering inhibition region produced by such a procedure.

Next, in the present disclosure, "thermal decomposition residue rate of the third resin at 550 ° C." The mass of
The calculation based on this formula is performed using the sintering inhibition portion formed according to the manufacturing method of the modeled object, like the calculation in the above "mass ratio of the third resin to the powder in the sintering inhibition portion". That is, the resin derived from the resin precursor X and the resin precursor Y contained in the sintering inhibition portion formed according to the manufacturing method of the shaped article is defined as the third resin in this formula.

--Relative Sintered Density--
The sintering inhibition portion formed by stacking the sintering inhibition regions formed using the sintering inhibition liquid set is, as described above, the relative sintering of the sintered product formed by sintering the sintering inhibition portion. It has low cohesion density. Specifically, the relative sintered density is preferably 85% or less, more preferably 80% or less, and even more preferably 75% or less. It is more preferably 70% or less, even more preferably 65% or less, even more preferably 60% or less, and particularly preferably 55% or less. As a result, it is possible to obtain the effect of improving the releasability when the sintered material of the sintering inhibition portion is detached from the sintered material of the shaping portion.

--Resin precursor X and resin precursor Y--
Since the resin precursor X and the resin precursor Y are components that hardly settle in the resin generation liquid X and the resin generation liquid Y, respectively, the dispersibility and storage stability of the resin generation liquid X and the resin generation liquid Y are improved. Excellent.
Moreover, the resin precursor X and the resin precursor Y that can be used are not limited as long as the resin precursor X and the resin precursor Y can be reacted to produce the third resin. Further, the reaction between the resin precursor X and the resin precursor Y is not limited to the reaction that proceeds only when the resin generation liquid X and the resin generation liquid Y come into contact with each other. It may be a reaction that proceeds with the treatment (heating, etc.).
Specifically, one of the resin precursor X and the resin precursor Y can be selected from diglycidyl ether, polyisocyanate, and the like, and the other can be selected from diamine and the like.
Examples of the third resin produced from the resin precursor X and the resin precursor Y include epoxy resin and urea resin.

The content of the resin precursor X is preferably 20.0 mass % or more with respect to the mass of the resin production liquid X. Moreover, the content of the resin precursor Y is preferably 20.0 mass % or more with respect to the mass of the resin production liquid Y. The relative sintered density of the sintered product formed by sintering the sintering inhibition portion is further reduced by setting the contents of the resin precursor X and the resin precursor Y to 20.0% by mass or more, respectively. can be done.

<Lamination process>
The method for manufacturing a modeled object has a stacking step of forming a laminate by sequentially repeating a powder layer forming step, a modeling liquid applying step, and a sintering inhibiting liquid applying step. Although the modeling liquid applying process and the sintering inhibiting liquid applying process are performed after the powder layer forming process, the order of the modeling liquid applying process and the sintering inhibiting liquid applying process is not particularly limited. A “laminate” is a structure in which multiple layers of powder having a modeling region and a sintering inhibition region are laminated, and multiple layers of powder having a modeling region, a sintering inhibition region, and a support region are laminated. It can also be a structure with

<Heating process>
It is preferable that the method for manufacturing the model includes a heating step of heating the laminate at a temperature corresponding to the softening point of the resin contained in the laminate. The sinterable particles are bound together by the softened resin, and a modeled part (green body, unsintered body) in which a fixed three-dimensional shape is maintained is modeled.
Further, when the first resin contained in the sintering inhibitor liquid changes to a chemically different second resin by heating performed after the sintering inhibitor liquid is applied to the powder layer, the heating step may be the temperature that promotes this change.
Although the heating means is not particularly limited, for example, a dryer, a constant temperature/humidity bath, or the like can be used.

<Excess powder removal step>
It is preferable that the method for manufacturing a model includes a surplus powder removing step of removing surplus powder that is powder to which no modeling liquid or sintering inhibiting liquid has been applied. The surplus powder removing step preferably includes at least one step selected from a step of removing surplus powder by air blowing and a step of removing surplus powder by immersion in a removal liquid. It is more preferable to have a step.

When excess powder is removed by an air blow, it is preferable that the modeling part or the like has strength capable of withstanding the pressure of the air blow. For example, the three-point bending stress is preferably 3 MPa or more, and preferably 5 MPa or more. more preferred.

When the excess powder is removed by immersion in a removal liquid, the removal liquid used contains an organic solvent and the like, and optionally other components.

Examples of organic solvents include ketones, halogens, alcohols, esters, ethers, hydrocarbons, glycols, glycol ethers, glycol esters, pyrrolidones, amides, amines, and carbonates.

<Drying process>
It is preferable that the method for manufacturing a shaped article includes a drying step for removing liquid components remaining in the shaped portion and the sintering inhibition portion. As a drying means, for example, a known dryer, a constant temperature and humidity bath, or the like can be used.

<Degreasing process>
It is preferable that the manufacturing method of the shaped article includes a degreasing step of heating the shaped part, the sintering inhibition part, and the like to remove at least part of the resin and the like contained in each part, thereby obtaining a degreased product.
In the degreasing step, a degreasing means is used, and the melting point or solidus temperature of the material constituting the sinterable particles is higher than the thermal decomposition temperature of the organic component such as resin (for example, when using AlSi ₁₀ Mg particles If it is about 570° C.), the organic components are decomposed and removed by heating for a certain period of time (eg, 1 to 10 hours). Examples of degreasing means include a known sintering furnace and an electric furnace.

<Sintering process>
It is preferable that the manufacturing method of the shaped article includes a sintering step of heating the degreased material such as the shaped portion and the sintering inhibition portion to obtain a sintered product.
The sintering step uses a sintering means to heat the degreased material for a certain period of time (for example, 1 to 10 minutes) at a heating temperature that is higher than the solidus temperature of the material that constitutes the sinterable particles and lower than the liquidus temperature. time) Heating integrates the materials that make up the sinterable particles. The heating temperature is preferably 550° C. or higher and 600° C. or lower when, for example, aluminum-containing particles are used as the sinterable particles. More specifically, when AlSi ₁₀ Mg particles are used as sinterable particles, the temperature is preferably 570° C. or higher and 600° C. or lower. The sintering means includes, for example, a known sintering furnace, and may be the same means as the degreasing means described above. Also, the degreasing step and the sintering step may be performed continuously.

<Post-treatment process>
It is preferable that the method for manufacturing a shaped article includes a post-treatment step of post-treating the sintered article such as the shaped portion and the sintering inhibition portion. The post-treatment process is not particularly limited and can be appropriately selected according to the purpose. and a step of coating.

<Flow of modeling>
The flow of modeling in the method for manufacturing a modeled article of the present disclosure will be described with reference to FIGS. 6A to 6E. 6A to 6E are schematic diagrams showing an example of the operation of the model manufacturing apparatus.

First, the state in which the first powder layer 30 is formed on the modeling stage of the modeling tank will be described. When forming the next powder layer on the first powder layer 30, as shown in FIG. 6A, the supply stage 23 of the supply tank is raised and the modeling stage 24 of the modeling tank is lowered. At this time, the lowering distance of the modeling stage 24 is set so that the interval (stacking pitch) between the upper surface of the powder layer in the modeling tank 22 and the lower portion (lower tangential portion) of the flattening roller 12 becomes Δt1. Although the interval Δt1 is not particularly limited, it is preferably about several tens to 100 μm.

In the present disclosure, the flattening roller 12 is arranged to form a gap with respect to the upper end surfaces of the supply tank 21 and the modeling tank 22 . Therefore, when the powder 20 is transferred and supplied to the modeling tank 22 to be flattened, the upper surface of the powder layer is positioned higher than the upper end surfaces of the supply tank 21 and the modeling tank 22 . As a result, it is possible to reliably prevent the flattening roller 12 from coming into contact with the upper end surfaces of the supply tank 21 and the modeling tank 22 , thereby reducing damage to the flattening roller 12 . If the surface of the flattening roller 12 is damaged, streaks are generated on the surface of the powder layer 31 (see FIG. 6D) supplied to the modeling tank 22, and the flatness tends to deteriorate.

Next, as shown in FIG. 6B, the powder 20 arranged at a position higher than the upper end surface of the supply tank 21 is moved toward the modeling tank 22 while rotating the flattening roller 12 in the direction of the arrow. 20 is transported and supplied to the modeling tank 22 (powder supply). Further, as shown in FIG. 6C, the flattening roller 12 is moved parallel to the stage surface of the modeling stage 24 of the modeling tank 22, and the powder layer having a predetermined thickness Δt1 on the modeling tank 22 of the modeling stage 24 is formed. 31 is formed (planarization). At this time, the surplus powder 20 that has not been used to form the powder layer 31 drops into the surplus powder receiving tank 29 . After forming the powder layer 31, the flattening roller 12 is moved to the supply tank 21 side and returned (returned) to the initial position (origin position), as shown in FIG. 6D.

Here, the flattening roller 12 can move while maintaining a constant distance from the upper end surfaces of the modeling tank 22 and the supply tank 21 . The constant movement allows the flattening roller 12 to convey the powder 20 onto the modeling vessel 22 while providing a uniform thickness on the modeling vessel 22 or the already formed modeling region and sintering inhibition region 30 . A powder layer 31 having a thickness h (corresponding to the lamination pitch Δt1) can be formed. Hereinafter, the thickness h of the powder layer 31 and the lamination pitch Δt1 may be described without distinguishing between them, but unless otherwise specified, they have the same thickness and have the same meaning. Alternatively, the thickness h of the powder layer 31 may be obtained by actually measuring it. In this case, it is preferable to use the average value of a plurality of locations.

After that, as shown in FIG. 6E, droplets 10 of the modeling liquid and the sintering inhibitor liquid are respectively discharged from the head 52 of the liquid discharge unit, and the next powder layer 31 has a desired shape of a modeling region and sintering. An inhibition region 30 is laminated. Next, the powder layer forming process, the modeling liquid applying process, and the sintering inhibiting liquid applying process are repeated to form a new modeling region and a sintering inhibiting region 30 and stack them. At this time, the new shaping region and sintering inhibition region 30 and the underlying shaping region and sintering inhibition region 30 are integrated. Thereafter, the powder layer forming process, the modeling liquid applying process, and the sintering inhibiting liquid applying process are further repeated to complete the laminate.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

<Preparation of sintering inhibition liquid and sintering inhibition liquid set>
(Adjustment example 1)
Polyvinylpyrrolidone (trade name: PVP-K15, weight average molecular weight (Mw): 10,000, manufactured by Tokyo Chemical Industry Co., Ltd.) and γ-butyrolactone were mixed and dissolved by stirring for 6 hours using a magnetic stirrer. After stirring, the solution was passed through a 1 μm filter to obtain a sintering inhibitor solution of Preparation Example 1. The content of polyvinylpyrrolidone, which is the first resin, in the sintering inhibitor liquid of Preparation Example 1 was 20.0% (w/v).

(Adjustment example 2)
Polyvinylpyrrolidone (trade name: PVP K-25, weight average molecular weight (Mw): 25,000, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and γ-butyrolactone are mixed and stirred for 6 hours using a magnetic stirrer. Dissolved. After stirring, the mixture was passed through a 1 μm filter to obtain a sintering inhibitor liquid of Preparation Example 2. The content of polyvinylpyrrolidone, which is the first resin, in the sintering inhibitor liquid of Preparation Example 2 was 16.7% (w/v).

(Adjustment example 3)
A vinyl chloride-vinyl acetate copolymer (trade name: Solbin TAO, weight average molecular weight (Mw): 26,000, manufactured by Nissin Chemical Co., Ltd.) and octyl acetate are mixed and stirred for 6 hours using a magnetic stirrer. It was dissolved by After stirring, the solution was passed through a 1 μm filter to obtain a sintering inhibitor solution of Preparation Example 3. The content of the vinyl chloride-vinyl acetate copolymer as the first resin in the sintering inhibitor liquid of Preparation Example 3 was 9.0% (w/v).

(Adjustment example 4)
Cellulose acetate (manufactured by Daicel Corporation) and triethyl phosphate were mixed and dissolved by stirring for 6 hours using a magnetic stirrer. After stirring, the mixture was passed through a 1 μm filter to obtain a sintering inhibitor liquid of Preparation Example 4. The content of cellulose acetate, which is the first resin, in the sintering inhibitor liquid of Preparation Example 4 was 6.0% (w/v).

(Adjustment example 5)
Melamine fine particles (trade name: Eposter SS, volume average particle diameter: 100 nm, manufactured by Nippon Shokubai Co., Ltd.) and triethylene glycol dimethyl ether were mixed and dispersed using a homogenizer to obtain a sintering inhibitor solution of Preparation Example 5. The content of the melamine fine particles, which is the first resin, in the sintering inhibitor liquid of Preparation Example 5 was 8.0% (w/v).

(Adjustment example 6)
Benzoguanamine fine particles (trade name: Eposter MS, volume average particle size: 2 μm, manufactured by Nippon Shokubai Co., Ltd.) and triethylene glycol dimethyl ether were mixed and dispersed using a homogenizer to obtain a sintering inhibitor solution of Preparation Example 6. The content of the benzoguanamine fine particles, which is the first resin, in the sintering inhibitor liquid of Preparation Example 6 was 8.0% (w/v).

(Adjustment example 7)
A sintering inhibition liquid set of Preparation Example 7 was obtained by combining the following resin generation liquid X and resin generation liquid Y.

-Adjustment of Resin Generation Liquid X-
Bisphenol A-diglycidyl ether and neopentyl glycol diglycidyl ether were mixed and stirred for 6 hours using a magnetic stirrer. After stirring, the solution was passed through a 1 μm filter to obtain a resin production solution X. The content of bisphenol A-diglycidyl ether and neopentyl glycol diglycidyl ether, which are resin precursors X, in the resin generation liquid X was 100.0% (w/v).

-Adjustment of resin generation liquid Y-
Polyamine (trade name: Fujicure FXH-8095, manufactured by T&K TOKA) and 1,3-bisaminomethylcyclohexane were mixed and stirred for 6 hours using a magnetic stirrer. After stirring, the solution was passed through a 1 μm filter to obtain a resin production liquid Y. The content of polyamine and 1,3-bisaminomethylcyclohexane, which are resin precursors Y, in the resin generation liquid Y was 100.0% (w/v).

(Adjustment example 8)
A sintering inhibition liquid set of Preparation Example 8 was obtained by combining the following resin generation liquid X and resin generation liquid Y.

-Adjustment of Resin Generation Liquid X-
A cyanatomethylcyclohexane-trimethylolpropane adduct (trade name: Takenate D120N, manufactured by Mitsui Chemicals, Inc.) and propylene glycol monomethyl ether acetate were mixed and stirred for 6 hours using a magnetic stirrer. After stirring, the solution was passed through a 1 μm filter to obtain a resin production solution X. The content of the cyanatomethylcyclohexane-trimethylolpropane adduct, which is the resin precursor X, in the resin generation liquid X was 30.0% (w/v).

-Adjustment of resin generation liquid Y-
1,3-Bisaminomethylcyclohexane was passed through a 1 μm filter to obtain a resin production liquid Y. The content of 1,3-bisaminomethylcyclohexane, which is the resin precursor Y, in the resin generation liquid Y was 100.0% (w/v).

(Comparative adjustment example 1)
Ceramic fine particles (zirconia powder, trade name: TZ-3Y-E, manufactured by Tosoh Corporation) and triethylene glycol dimethyl ether were mixed and dispersed using a homogenizer to obtain a sintering inhibitor liquid of Comparative Preparation Example 1. The content of the ceramic fine particles in the sintering inhibiting liquid of Comparative Adjustment Example 1 was 8.0% (w/v). For convenience of description in Table 1, the ceramic fine particles are described in the item of "first resin", and the content thereof is described in the item of "first resin content [% (w/v)]". .

(Comparative adjustment example 2)
Polyvinylpyrrolidone (trade name: PVP-K15, weight average molecular weight (Mw): 10,000, manufactured by Tokyo Chemical Industry Co., Ltd.) and γ-butyrolactone were mixed and dissolved by stirring for 6 hours using a magnetic stirrer. After stirring, the mixture was passed through a 1 μm filter to obtain a sintering inhibitor liquid of Comparative Preparation Example 2. The content of polyvinylpyrrolidone in the sintering inhibitor liquid of Comparative Adjustment Example 2 was 9.0% (w/v).

(Comparative adjustment example 3)
A sintering inhibition liquid set of Comparative Preparation Example 3 was obtained by combining the following resin generation liquid X and resin generation liquid Y.

-Adjustment of Resin Generation Liquid X-
A cyanatomethylcyclohexane-trimethylolpropane adduct (trade name: Takenate D120N, manufactured by Mitsui Chemicals, Inc.) and propylene glycol monomethyl ether acetate were mixed and stirred for 6 hours using a magnetic stirrer. After stirring, the solution was passed through a 1 μm filter to obtain a resin production solution X. The content of the cyanatomethylcyclohexane-trimethylolpropane adduct in the resin generation liquid X was 30.0% (w/v).

-Adjustment of resin generation liquid Y-
1,3-propanediol and propylene glycol monomethyl ether acetate were mixed and stirred for 6 hours using a magnetic stirrer. After stirring, the solution was passed through a 1 μm filter to obtain a resin production liquid Y. The content of 1,3-propanediol in the resin production liquid Y was 30.0% (w/v).

Each composition of the sintering inhibitor liquid is shown in Table 1 below, and each composition of the sintering inhibitor liquid set is shown in Table 2 below.

[Dispersibility (discharge stability)]
The adjusted sintering inhibition liquid and each resin generation liquid constituting the sintering inhibition liquid set were filled in an inkjet head GH5420 (manufactured by Ricoh Co., Ltd.) and allowed to stand for a certain period of time. observed at. An extended coating device EV2500 (manufactured by Ricoh Co., Ltd.) was used as a discharge device. The observation results were evaluated based on the following evaluation criteria, and the evaluation results are shown in Tables 3 and 4 below.
(Evaluation criteria)
A: Can be discharged without crooked discharge or missing nozzles when the standing time is set to 10 minutes. B: Can be discharged without crooked discharges or missing nozzles when the standing time is set to 3 minutes. C: When the standing time is set to 3 minutes, the discharge crookedness or nozzle clogging occurs and pressurization discharge etc. occurs. The normal ejection state does not recover even after the maintenance operation of

[Storage stability]
The prepared sintering inhibition liquid and each resin generation liquid constituting the sintering inhibition liquid set were each hermetically stored in a 100 mL vial bottle, and after standing for a certain period of time, the state of each liquid was evaluated based on the following evaluation criteria. . The evaluation results are shown in Tables 3 and 4 below.
(Evaluation criteria)
A: No sediment occurs and no concentration unevenness occurs between the upper and lower portions of the liquid when left standing for one day. B: Concentration unevenness occurs between the upper and lower portions of the liquid when left standing for one day Recover to a uniform state by shaking 2-3 times C: A precipitate occurs when left standing for a day, does not recover to a uniform state unless sufficiently shaken, and even if shaken, the upper and lower parts of the liquid Density unevenness occurs between

[viscosity]
The viscosities at 25° C. of the prepared sintering-inhibiting liquid and each of the resin-forming liquids constituting the sintering-inhibiting liquid set were each measured to be 30 mPa·s or less.

<Preparation of sample body>
(Examples 1 to 8, Comparative Examples 1 to 3)
Using the adjusted sintering inhibition liquid or sintering inhibition liquid set and powder (AlSi ₁₀ Mg powder (manufactured by Toyo Aluminum Co., Ltd., Si10Mg-30BB, volume average particle diameter: 35 μm)), the sintering inhibition part and A sample body that can be considered was prepared as follows.

1) First, using a known modeled article manufacturing apparatus as shown in FIGS. A thin layer (one layer) was formed from the powder with a thickness of 84 μm.

2) Next, on the surface of the formed thin layer of powder, a sintering-inhibiting liquid or each resin generation liquid constituting a sintering-inhibiting liquid set was ejected from a nozzle of a known inkjet ejection head and applied. When the sintering inhibitor liquid was applied, it was discharged so that the applied amount was 45 pL per area of 300 dpi×300 dpi. Further, when applying each resin generation liquid constituting the sintering inhibition liquid set, the resin generation liquid X is discharged so that the amount of application of the resin generation liquid X is 22.5 pL per area of 300 dpi × 300 dpi, and the resin is applied to the same area. The generated liquid Y was discharged in an amount of 22.5 pL.

3) Next, a sample body containing "first resin or second resin" or "third resin" was prepared by placing in a vacuum environment at 200 ° C. for 4 hours using a vacuum dryer. .

4) Next, the sample body was degreased by heating to obtain a degreased product. Furthermore, the degreased material was heated and sintered to produce a sintered material.

Next, the thermal decomposition residue rate at 550 ° C. of the "first resin or second resin" or "third resin" contained in the sample body prepared in 3) above is calculated, and the evaluation results are shown in the table below. 3-4.
The thermal decomposition residue rate is calculated based on the following formula "residue mass when the first resin or the second resin is thermally decomposed at 550 ° C. / mass of the first resin or the second resin before thermal decomposition". did. Further, the residue mass when the first resin or the second resin was thermally decomposed at 550° C. was measured using a TG-DTA (differential thermal/thermogravimetric simultaneous measurement apparatus). Specifically, when the temperature was raised from 30 ° C. to 550 ° C. at 10 ° C./min in the air or nitrogen atmosphere, and the temperature was maintained for 2 hours after reaching 550 ° C., the weight after the temperature rise (residual mass) was asked.
Incidentally, each polyvinylpyrrolidone as the first resin contained in the sintering-inhibiting liquids of Examples 1 and 2 and Comparative Example 2 undergoes a cross-linking reaction in the heating step of 3) above, resulting in a polyvinyl polyvinylpyrrolidone as the second resin. produced pyrrolidone.

Next, the mass ratio of the first resin or the second resin to the powder in the sintering inhibition region (sintering inhibition portion), the thermal decomposition residue rate of the first resin or the second resin at 550 ° C., The predicted residue amount was calculated by multiplying by , and the evaluation results are shown in Tables 3 and 4 below.

[Relative sintering density]
First, the density of the sintered material produced in 4) above was measured. Next, the ratio of the density of the sintered product to the true density of the material constituting the sintered product was calculated, and the calculation results are shown in Tables 3 and 4 below.

According to Examples 1 and 2, a sintering inhibitor liquid excellent in dispersibility and storage stability could be obtained. Moreover, a sintering inhibitor liquid capable of providing a sintered product with a low relative sintering density was obtained. Furthermore, it was possible to obtain a sintering-inhibiting liquid capable of improving the handleability of the sintering-inhibiting portion due to the binder function of binding particles in the powder layer.

According to Examples 3 and 4, a sintering inhibitor liquid excellent in dispersibility and storage stability could be obtained. In addition, a sintering inhibiting liquid capable of providing a sintered product with a low relative sintering density was obtained, although it was slightly inferior to those of Examples 1 and 2 due to the difference in the type of resin. Furthermore, although slightly inferior to Examples 1 and 2 due to the different types of resin, a sintering inhibition liquid that can improve the handling of the sintering inhibition part by the binder function that binds between particles in the powder layer. I was able to get However, it was superior to Examples 1 and 2 in that it was not necessary to chemically change the first resin by the heating process.

According to Example 5, a sintering inhibiting liquid excellent in dispersibility and storage stability could be obtained, although it was slightly inferior to Examples 1 and 2 because the resin was in a dispersed form. Moreover, a sintering inhibitor liquid capable of providing a sintered product with a low relative sintering density was obtained. In addition, since the sintering inhibitory effect can be exhibited by adding a small amount, it is excellent in that it can be used in combination with a resin having a binder function.

According to Example 6, a sintering inhibiting liquid excellent in dispersibility could be obtained, although it was slightly inferior to Examples 1 and 2 because the resin was in a dispersed form. Moreover, a sintering inhibitor liquid capable of providing a sintered product with a low relative sintering density was obtained. In addition, since the sintering inhibitory effect can be exhibited by adding a small amount, it is excellent in that it can be used in combination with a resin having a binder function. However, the dispersibility was poor due to the large volume average particle size of the resin.

According to Comparative Example 1, although a sintered product with a low relative sintering density could be provided, the dispersibility and storage stability were inferior due to the large specific gravity of the ceramic fine particles.

According to Comparative Example 2, although the same material as in Example 1 was used, it was difficult to provide a sintered product with a low relative sintered density due to the low resin content.

According to Example 7, a sintering inhibitor liquid excellent in dispersibility and storage stability could be obtained. In addition, a sintering inhibiting liquid capable of providing a sintered product with a low relative sintering density was obtained, though slightly inferior to those of Examples 1 and 2.

According to Example 8, a sintering inhibitor liquid excellent in dispersibility and storage stability could be obtained. Moreover, a sintering inhibitor liquid capable of providing a sintered product with a low relative sintering density was obtained.

According to Comparative Example 3, since the materials used in Example 8 were changed, it was difficult to provide a sintered product with a low relative sintered density.

<Preparation of modeling liquid>
Polyvinyl butyral (S-Lec BL-10 manufactured by Sekisui Chemical Co., Ltd.) and triethylene glycol dimethyl ether (Triglyme manufactured by Sankyo Chemical Industry) were mixed and dissolved by stirring for 30 minutes using a homomixer. After stirring, the liquid was passed through a 1 μm filter to obtain a modeling liquid. The content of polyvinyl butyral in the modeling liquid was 7.0% by mass with respect to the mass of the modeling liquid.

<Production of modeled objects>
(Example 9)
Using the sintering inhibitor liquid of Preparation Example 1, the modeling liquid, and the powder (AlSi ₁₀ Mg powder (manufactured by Toyo Aluminum Co., Ltd., Si10Mg-30BB, volume average particle diameter: 35 μm)), a modeled object was produced as follows. manufactured in this way.

1) First, using a known modeled article manufacturing apparatus as shown in FIGS. A thin layer of powder with a thickness of 84 μm was formed.

2) Next, a modeling liquid was ejected from a nozzle of a known inkjet ejection head to form a modeling region and a support region on the surface of the formed thin layer of powder. When the modeling liquid was applied, it was discharged in an amount of 45 pL per area of 300 dpi×300 dpi. Further, a sintering inhibiting liquid was ejected from a nozzle of a known inkjet ejection head to form a sintering inhibiting region on the surface of the formed thin layer of powder. When the sintering inhibitor liquid was applied, it was discharged so that the applied amount was 45 pL per area of 300 dpi×300 dpi. The modeling liquid and the sintering inhibiting liquid were discharged so that the modeling area and the support area were adjacent to each other with the sintering inhibiting area interposed therebetween.

3) Next, the operations 1) and 2) above are repeated until a predetermined layer average thickness (the total thickness of the modeled object, 15 mm) is reached, and the modeled portion formed by laminating the modeled regions and sintered A sintering inhibition portion formed by laminating inhibition regions and a support portion formed by laminating support regions are provided, and the support portion is arranged to support the molding portion via the sintering inhibition portion. A laminated laminate was formed.

4) Next, it was placed in a vacuum environment at 200° C. for 4 hours using a vacuum dryer.

5) Next, excess powder was removed by air blow.

6) Next, the structure composed of the shaping portion, the sintering inhibition portion, and the support portion was heated to be degreased to obtain a degreased product. Furthermore, the degreased material was heated to be sintered to obtain a sintered material.

7) Next, the sintered product of the sintering inhibition portion and the support portion was removed to obtain a modeled object.

In the sintered product obtained in 6) above, the relative sintering density of the shaped part and the support part is 93%, and sintering progresses, and the particle shape of the sinterable material in the shaped part and the support part changes. Densification was complete. On the other hand, the relative sintering density of the sintering-inhibited portion was 56%, sintering hardly progressed, and the particle shape of the sinterable material was maintained in the sintering-inhibited portion. FIG. 7 shows a microscope image of the sintered product of the shaping portion, and FIG. 8 shows a microscope image of the sintered product of the sintering inhibition portion. Microscopic images were taken using Keyence's VHX-7000.
In addition, during the degreasing and sintering of 6) above, deformation of the shaped part was suppressed by being supported by the support part, and a shaped article with high dimensional accuracy was obtained.
In the above 7), since the sintered body of the sintering inhibition part has minute cracks, it is impossible to obtain the sintered body of the modeling part by detaching the sintered body of the sintering inhibition part and the support part. It was easy.

(Comparative Example 4)
A model was produced in the same manner as in Example 9, except that the modeling liquid was used instead of the sintering inhibiting liquid of Preparation Example 1.
As a result, sintering progressed, and densification of the particle shape of the sinterable material was completed in all of the shaped portion, the sintering inhibition portion, and the support portion. For this reason, in 7) above, it was difficult to obtain the sintered body of the shaped portion by detaching the sintered product of the sintering inhibition portion and the support portion.

(Example 10)
A shaped article was manufactured in the same manner as in 2) of Example 9 above, except that the amount of the sintering inhibitor applied was increased from 45 pL to 200 pL.
As a result, the strength of the sintering-inhibited portion before degreasing in 6) was improved, and thus the handleability was improved. In addition, in the sintered product obtained in 6) above, the relative sintering density of the sintering inhibition portion is further reduced, and in 7) above, the sintered product of the sintering inhibition portion and the support portion is detached. It became easier to obtain a sintered body of the shaped part.

(Example 11)
After the above 2) of Example 9 is completed, a modeled object is produced in the same manner except that the formed sintering inhibition region is further discharged and applied with a modeling liquid from a nozzle of a known inkjet discharge head. did When the modeling liquid was later applied to the sintering inhibition region, the liquid was discharged in an amount of 45 pL per region of 300 dpi×300 dpi.
As a result, the strength of the sintering-inhibited portion before degreasing in 6) was improved, and thus the handleability was improved. In addition, since the resin is degreased in two stages, excessive cracking of the sintering inhibition portion was suppressed during the degreasing of 6) above.

(Example 12)
In the above 2) of Example 9, as shown in FIG. 3, in the powder layer, the modeling liquid and the sintering inhibition liquid were discharged so that the sintering inhibition area was arranged surrounding the modeling area. produced a modeled object in the same manner.
As a result, during the sintering of 6) above, collapse of the sintering inhibition portion was suppressed, and the dimensional accuracy of the model was improved.

(Example 13)
In the above 2) of Example 9, droplets of the modeling liquid ejected to the position forming the boundary between the modeling region and the sintering inhibition region and droplets of the sintering inhibition liquid ejected adjacent thereto are applied. A modeled article was produced in the same manner, except that the timing was adjusted so that the droplets of the sintering-inhibiting liquid were applied within 100 msec after the droplets of the modeling liquid were applied.
As a result, the molding liquid applied to the powder was suppressed from seeping into the sintering inhibition region, and the dimensional accuracy of the molded object was improved.

(Example 14)
In the above 3) of the ninth embodiment, as shown in FIG. 4, an integrated product having a plurality of shaped parts and a connecting part composed of a sintering inhibiting part connecting between the shaped parts, and integrating them A modeled article was produced in the same manner, except that a laminate containing
As a result, before the sintering in 6) above, the number of man-hours for rearranging the plurality of molded parts and placing them in the sintering furnace was reduced, and the workability at the time of manufacturing the molded article was improved.

(Example 15)
In the above 3) of Example 9, the outer surface of the laminate is divided into two areas continuously with the outer surface of the laminate, the structure covering the entire circumference of the molded part, and the laminate as shown in FIG. and a sintering inhibition portion having a plate-like structure, and furthermore, the modeled product is produced in the same manner except that the step of removing the surplus powder by air blowing in 5) above is omitted. gone.
As a result, since surplus powder cannot adhere to the modeled part, the step of removing surplus powder can be omitted, and the productivity in manufacturing the modeled object is improved.

Embodiments of the present invention are, for example, as follows.
<1> A powder layer forming step of forming a powder layer containing sinterable particles;
a modeling liquid application step of applying a modeling liquid to the powder layer to form a modeling region;
a sintering inhibition liquid application step of applying a sintering inhibition liquid to the powder layer to form a sintering inhibition region where sintering of the particles is inhibited,
A method for manufacturing a modeled article including a stacking step of forming a laminate by sequentially repeating the powder layer forming step, the modeling liquid applying step, and the sintering inhibiting liquid applying step,
The modeling region and the sintering inhibition region are adjacent to each other,
The sintering inhibitor liquid contains a first resin,
The sintering inhibition region contains the first resin or a second resin derived from the first resin,
The mass ratio of the first resin or the second resin to the powder in the sintering inhibition portion formed by stacking the sintering inhibition regions, and the mass ratio of the first resin or the second resin A predicted residue amount calculated by multiplying the thermal decomposition residue rate at 550° C. and the product is 800 ppm or more.
<2> The method for manufacturing a modeled article according to <1>, wherein the predicted residue amount is 1000 ppm or more.
<3> The method for manufacturing a shaped article according to <1> or <2>, wherein the first resin is dissolved in the sintering inhibition liquid.
<4> The method according to <1> or <2>, wherein the first resin is dispersed in the sintering inhibition liquid.
<5> The method for manufacturing a shaped article according to <4>, wherein the first resin has a volume average particle diameter of 1 μm or less.
<6> The method for manufacturing a shaped article according to any one of <1> to <5>, wherein the thermal decomposition residue rate at 550° C. of the first resin or the second resin is 0.100 or more. be.
<7> The method for manufacturing a shaped article according to any one of <1> to <6>, wherein the sintering inhibitor liquid has a viscosity of 30 mPa·s or less at 25°C.
<8> The sintering inhibition region contains the second resin,
The thermal decomposition residue rate of the second resin of the sintering inhibition portion at 550 ° C. is higher than the thermal decomposition residue rate of the first resin at 550 ° C. Any one of <1> to <7>. It is a manufacturing method of a modeled article.
<9> The sintering inhibition region contains the second resin,
In the method of manufacturing a shaped article according to any one of <1> to <8>, the second resin of the sintering inhibition portion is generated by a cross-linking reaction of the first resin.
<10> The method for manufacturing a shaped article according to any one of <1> to <9>, wherein the first resin is polyvinylpyrrolidone.
<11> The first resin is polyvinyl chloride, polyvinylidene chloride, cellulose acetate, polyacrylonitrile, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, vinyl chloride-vinyl acetate copolymer, Polyethylene terephthalate, phenolic resin, melamine resin, urea resin, unsaturated polyester, epoxy resin, silicone resin, polyvinylpolypyrrolidone, and benzoguanamine resin <1> to <7>, which is at least one selected from the group consisting of A method for manufacturing a modeled article according to any one of the above.
<12> The method for manufacturing a shaped article according to any one of <1> to <11>, wherein the particles contain aluminum.
<13> The relative sintered density of the sintered product formed by sintering the sintering inhibition portion formed by stacking the sintering inhibition regions is 60% or less. 3. A method for manufacturing a modeled article according to any one of
<14> The modeling liquid application step is a step of applying the modeling liquid to the powder layer to form the modeling region and the support region,
The method for manufacturing a model according to any one of <1> to <13>, wherein the modeling region and the support region are adjacent to each other via the sintering inhibition region.
<15> The application amount of the sintering inhibitor liquid applied per unit area in the sintering inhibition region is greater than the application amount of the modeling liquid applied per unit area in the modeling region From <1><14> The method for manufacturing a modeled article according to any one of <14>.
<16> The modeled object according to any one of <1> to <14>, wherein the modeling liquid post-applying step further applies the modeling liquid to the formed sintering inhibition region afterward. is a manufacturing method.
<17> The method for manufacturing a shaped article according to any one of <1> to <14>, wherein the shaping region is surrounded by the sintering inhibition region.
<18> Any one of <1> to <14>, wherein the sintering inhibitor liquid is applied within 100 msec after the modeling liquid is applied at the boundary between the modeling area and the sintering inhibition area. A method for manufacturing the described shaped article.
<19> The laminate has a plurality of shaping portions formed by stacking the shaping regions, and a connection portion connecting the shaping portions,
<14>, wherein at least a region of the connection portion that contacts the shaped portion is formed of a sintering inhibition portion formed by stacking the sintering inhibition regions. is a method for manufacturing a shaped article.
<20> The laminate has a shaping portion formed by stacking the shaping regions and a sintering inhibition portion formed by stacking the sintering inhibition regions,
The method for manufacturing a shaped article according to any one of <1> to <14>, wherein the shaped portion is entirely covered with the sintering inhibition portion.
<21> A powder layer forming step of forming a powder layer containing sinterable particles;
a modeling liquid application step of applying a modeling liquid to the powder layer to form a modeling region;
The resin generation liquid X and the resin generation liquid Y are independently applied to the powder layer, and the resin generation liquid X and the resin generation liquid Y come into contact with the powder layer after application. a sintering inhibition liquid set providing step of forming a sintering inhibition region where sintering of the particles is inhibited;
A method for manufacturing a modeled article including a stacking step of forming a laminate by sequentially repeating the powder layer forming step, the modeling liquid applying step, and the sintering inhibiting liquid set applying step,
The modeling region and the sintering inhibition region are adjacent to each other,
The sintering inhibition region contains a third resin generated by the contact of the resin generation liquid X and the resin generation liquid Y,
By multiplying the mass ratio of the third resin to the powder in the sintering inhibition portion formed by stacking the sintering inhibition regions by the thermal decomposition residue rate of the third resin at 550 ° C. The calculated predicted residue amount is 800 ppm or more.

According to the method for manufacturing a modeled article described in any one of <1> to <21>, various problems in the related art can be solved and the object of the present invention can be achieved.

US Publication 2019/0375014

Claims (21)

a powder layer forming step of forming a layer of powder containing sinterable particles;
a modeling liquid application step of applying a modeling liquid to the powder layer to form a modeling region;
a sintering inhibition liquid application step of applying a sintering inhibition liquid to the powder layer to form a sintering inhibition region where sintering of the particles is inhibited,
A method for manufacturing a modeled article including a stacking step of forming a laminate by sequentially repeating the powder layer forming step, the modeling liquid applying step, and the sintering inhibiting liquid applying step,
The modeling region and the sintering inhibition region are adjacent to each other,
The sintering inhibitor liquid contains a first resin,
The sintering inhibition region contains the first resin or a second resin derived from the first resin,
The mass ratio of the first resin or the second resin to the powder in the sintering inhibition portion formed by stacking the sintering inhibition regions, and the mass ratio of the first resin or the second resin A method for manufacturing a shaped article, wherein a predicted residue amount calculated by multiplying a rate of thermal decomposition residue at 550° C. and the calculated residue amount is 800 ppm or more. 2. The method of manufacturing a modeled article according to claim 1, wherein the predicted residue amount is 1000 ppm or more. 3. The method of manufacturing a shaped article according to claim 1, wherein the first resin is dissolved in the sintering inhibiting liquid. 3. The method of manufacturing a shaped article according to claim 1, wherein the first resin is dispersed in the sintering inhibiting liquid. 5. The method of manufacturing a modeled object according to claim 4, wherein the volume average particle diameter of the first resin is 1 [mu]m or less. 6. The manufacturing of the shaped article according to any one of claims 1 to 5, wherein the thermal decomposition residue rate of the first resin or the second resin in the sintering inhibition portion at 550°C is 0.100 or more. Method. The method for manufacturing a shaped article according to any one of claims 1 to 6, wherein the viscosity of the sintering inhibitor liquid at 25°C is 30 mPa·s or less. The sintering inhibition region contains the second resin,
The modeling according to any one of claims 1 to 7, wherein the thermal decomposition residue rate of the second resin in the sintering inhibition portion at 550°C is higher than the thermal decomposition residue rate of the first resin at 550°C. A method of making things. The sintering inhibition region contains the second resin,
The method for manufacturing a modeled object according to any one of claims 1 to 8, wherein the second resin of the sintering inhibition portion is generated by a cross-linking reaction of the first resin. The method for manufacturing a modeled article according to any one of claims 1 to 9, wherein the first resin is polyvinylpyrrolidone. The first resin includes polyvinyl chloride, polyvinylidene chloride, cellulose acetate, polyacrylonitrile, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, vinyl chloride-vinyl acetate copolymer, polyethylene terephthalate, 8. The resin according to any one of claims 1 to 7, which is at least one selected from the group consisting of phenolic resin, melamine resin, urea resin, unsaturated polyester, epoxy resin, silicone resin, polyvinylpolypyrrolidone, and benzoguanamine resin. The manufacturing method of the molding. The method for manufacturing a shaped article according to any one of claims 1 to 11, wherein the particles contain aluminum. 13. The sintered product formed by sintering the sintering inhibition portion formed by stacking the sintering inhibition regions has a relative sintering density of 60% or less, according to any one of claims 1 to 12 A method for manufacturing the described shaped article. The modeling liquid application step is a step of applying the modeling liquid to the powder layer to form the modeling region and the support region,
14. The method of manufacturing a shaped article according to any one of claims 1 to 13, wherein the shaping region and the support region are adjacent to each other via the sintering inhibition region. 15. Any one of claims 1 to 14, wherein the amount of the sintering inhibitor applied per unit area in the sintering inhibition area is greater than the amount of the modeling liquid applied per unit area in the modeling area. 1. The method for manufacturing the modeled article according to item 1. 15. The method of manufacturing a shaped object according to any one of claims 1 to 14, wherein the forming liquid post-applying step further applies the forming liquid to the formed sintering inhibition region afterward. 15. The method of manufacturing a model according to any one of claims 1 to 14, wherein the modeling region is surrounded by the sintering inhibition region. 15. The manufacturing of a model according to any one of claims 1 to 14, wherein the sintering inhibitor liquid is applied within 100 msec after the modeling liquid is applied to the boundary between the modeling area and the sintering inhibition area. Method. The laminate has a plurality of shaping parts formed by stacking the shaping regions, and a connection part connecting the shaping parts,
15. The shaped article according to any one of claims 1 to 14, wherein at least a region of said connecting portion that contacts said shaped portion is formed of a sintering inhibition portion formed by stacking said sintering inhibition regions. manufacturing method. The laminate has a shaping portion formed by stacking the shaping regions and a sintering inhibition portion formed by stacking the sintering inhibition regions,
The method of manufacturing a shaped article according to any one of claims 1 to 14, wherein the shaped portion is entirely covered with the sintering inhibiting portion. a powder layer forming step of forming a layer of powder containing sinterable particles;
a modeling liquid application step of applying a modeling liquid to the powder layer to form a modeling region;
The resin generation liquid X and the resin generation liquid Y are independently applied to the powder layer, and the resin generation liquid X and the resin generation liquid Y come into contact with the powder layer after application. a sintering inhibition liquid set providing step of forming a sintering inhibition region where sintering of the particles is inhibited;
A method for manufacturing a modeled article including a stacking step of forming a laminate by sequentially repeating the powder layer forming step, the modeling liquid applying step, and the sintering inhibiting liquid set applying step,
The modeling region and the sintering inhibition region are adjacent to each other,
The sintering inhibition region contains a third resin generated by the contact of the resin generation liquid X and the resin generation liquid Y,
By multiplying the mass ratio of the third resin to the powder in the sintering inhibition portion formed by stacking the sintering inhibition regions by the thermal decomposition residue rate of the third resin at 550 ° C. A method for manufacturing a model, wherein the calculated predicted residue amount is 800 ppm or more.

Images