KR100461687B1 - Optical forming apparatus for forming three-dimensional objects - Google Patents

Abstract

The present invention relates to an optical molding apparatus that can suppress the sedimentation of a filler even when the filler is likely to settle in the photocurable resin composition, and can form a homogeneous three-dimensional object exhibiting desired properties over all parts. The photoforming apparatus of the present invention is capable of producing a three-dimensional object composed of laminated layers of uncured resin produced by repeating the formation of the uncured resin layer by selective irradiation of the liquid photocurable resin composition disposed in the vessel 20. The optical shaping device may be provided with means 60 for circulating a liquid photocurable resin composition.

Description

Optical shaping device for shaping three-dimensional object {OPTICAL FORMING APPARATUS FOR FORMING THREE-DIMENSIONAL OBJECTS}

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an optical shaping device and method for shaping three-dimensional objects.

Conventionally, the molding method is known as a method of molding a three-dimensional model from a resin. However, this mold forming method requires a long time and a considerable cost to manufacture the mold. In addition, since a number of steps are required to complete the three-dimensional model, there is a problem that it becomes complicated. In order to overcome such problems and the like, an optical molding method that does not require mold molding has been proposed (for example, Japanese Patent Laid-Open Nos. 35966/1987, 113925/1990, 6640/1994 and 125079/1995). number). This optical shaping method is provided by selectively irradiating an uncured layer (n) of a liquid radiation-curable or photo-curable resin in accordance with slice shape data (n) of a three-dimensional model. Forming a cured resin layer (n); Supplying a liquid radiation-curable or photo-curable resin on the cured resin layer (n) to form a new uncured resin layer (n + 1); Selectively irradiating an uncured layer (n + 1) of the liquid photo-curable resin according to the slice shape data (n + 1); And repeating these steps to obtain a three-dimensional model composed of laminated layers of cured resin.

Fig. 2 is a schematic diagram showing the basic configuration of an optical shaping device used in the method. The apparatus comprises a fixed base 1; A container 2 containing the photo-curable resin 3; A light source device 4 for irradiating the liquid surface of the photo-curable resin 3; And a stage 5 for supporting the laminated feature 6 of the cured resin layer. The stage 5 is movable up and down. For example, when the stage 5 moves down from the position shown in FIG. 2, the photo-curable resin 3 is supplied onto the surface 6A of the laminated layer 6 to lower the stage 5. Form an uncured layer having a thickness corresponding to the distance.

One problem with the optical shaping method is that it takes quite a long time to model a number of three-dimensional models having the same shape. Another problem is that there is a limit to the type of shape that can be applied to the method. This limitation leads to the creation of a stereoscopic model that does not possess the intended properties.

As a means to solve these problems, a modeling method of a three-dimensional model has been proposed, which is a mold of a heat-resistant resin (hereinafter referred to as a "resin-made mold" by a photoforming method using a radiation-curable resin. May be referred to as ")"; Using the resin-based mold, forming a target three-dimensional model from a raw raw material resin exhibiting intended properties. It is possible to model a number of three-dimensional models that retain the characteristics intended by the method without compromising the advantages of the simplicity of the photoforming method.

Addition of a filler to the photo-curable resin composition is an effective method for improving the physical properties (reinforcement effect) and heat resistance of the cured resin by a photoforming method. Japanese Patent Application No. JP-A-05286040, German Patent No. Known from DE-A-4305201, and EP-A-393676. Inorganic fillers such as powdered inorganic fillers or fibrous inorganic fillers are given as examples of suitable fillers.

Since the filler mixed with the photo-curable resin composition typically has a density higher than that of the photo-curable resin, the filler easily precipitates when the photo-curable resin composition is filled into the container. From the photo-curable resin composition in which the photo-curable resin composition in which the filler is contained is dispersed only insufficiently, a photo-shaped article (stereoscopic article) having desired physical properties and heat resistance cannot be obtained. When the dispersion state of the filler in the photo-curable resin composition in the container changes over time, especially when the concentration of the filler decreases near the liquid surface, the resulting photo-form is produced at the initial stage of molding and At the end molded at the end, they have different concentrations of filler. Thus, the properties of the resulting light shaping feature vary depending on the area (or area).

Further, German Patent Application DE-A-4414775, German Patent Application DE-A-4417083, and Japanese Patent Application JP-A-04118221 disclose the overflow of the resin composition in a container in which a model is generated. An optical shaping device for a three-dimensional model is provided, which is provided with a device for moving vice versa.

1 shows an embodiment of the light shaping device of the present invention.

2 shows a basic configuration of an optical shaping device used for an optical shaping operation.

3 is a perspective view showing a state in which a composition is filled into a container.

Explanation of reference numerals

1, 10: fixed base

2, 20: container

3: photocurable resin

4, 30: light source device

5: supporting stage

6: laminated cured resin layer

11: vertical supporting column

20A, 20B: opening

30: light source device

40: stage

41: stage surface

50: whipping mechanism

60: circulator

61: circulation pump

62: pipe on the liquid suction side

63: pipe on the liquid discharge side

70 control means

80: imaginary cube

90: imaginary horizontal surface

Summary of the Invention

Accordingly, a first object of the present invention is to provide a light shaping method for molding a three-dimensional object that can effectively eliminate sedimentation of a filler even when a filler that is susceptible to settling is mixed with a radiation-curable resin composition disposed in a container. It is to produce a homogeneous three-dimensional object that can exhibit the desired properties over all regions (or regions).

It is a second object of the present invention to provide a method for producing a three-dimensional object having improved heat resistance.

An object of these invention is an optical molding apparatus for molding a three-dimensional object composed of a laminated layer of cured resin produced by repeatedly forming a cured resin layer by selective irradiation of a liquid radiation-curable resin disposed in a container. Achieved by a circulating device for circulating a liquid radiation-curable resin composition; It is also characterized in that it is used in a method for producing a shape having improved heat resistance.

The optical shaping device for molding the three-dimensional object of the present invention exhibits particularly excellent effects when the filler is mixed and dispersed in the radiation-curable resin composition.

It is preferable that the optical shaping | molding apparatus for shaping the three-dimensional object of this invention is provided with the control means which can control the operation of a circulation apparatus.

The molding method of the three-dimensional object of the present invention,

(a) introducing an uncured layer of liquid, radiation-curable resin composition in a photoforming apparatus;

(b) selectively irradiating the uncured layer of the radiation-curable resin composition according to the slice shape data to cure selected areas of the resin;

(c) repeating steps (a) and (b) to obtain a three-dimensional object composed of laminated layers of cured resin,

The photosensitive resin composition includes a filler having a density different from that of the resin, wherein the resin composition is circulated by the circulation device for a predetermined time or more during the execution of the method.

Detailed Description of the Preferred Embodiments

The circulation device, which is an essential component of the light shaping device of the present invention, is a means for moving the photo-curable resin composition present in the lower part (near the bottom part) of the container to the upper part (near the liquid surface) of the container. This disperses the filler into a homogeneous, photo-curable resin composition throughout the entire photo-curable resin composition present in the container by moving the composition present in the bottom of the container where the concentration of filler tends to increase over time. To ensure that the state is maintained. At the same time, the dispersed state of the filler is stabilized at a position near the liquid surface. Thus, the conformation produced from the cured resin layer formed near the liquid surface has excellent homogeneity and exhibits intended properties over all regions (or portions).

Hereinafter, with reference to drawings, the optical shaping | molding apparatus for shape | molding the three-dimensional object of this invention is explained in full detail. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view for explaining a specific example of an optical shaping device of the present invention, which includes a fixed base 10, a support column 11 extending vertically from the fixed base, and a photo-curable resin composition R Is a container 20 containing "composition R", a light source device 30 for selectively irradiating the liquid surface of composition R, and a stage 40 for supporting a laminated layer H of cured resin layer. , The stage surface 41, the whipping device 50, the circulating device 60 for circulating the composition R, and the control means 70.

The container is made of a material that is not transparent (eg metal such as stainless steel). The light source device 30 includes a laser beam oscillator or an ultraviolet lamp (not shown in the figure), and a light source such as a light scanning device or a masking device to selectively irradiate a portion of the composition R.

The stage 40 is installed to be movable up and down along the vertical support column 11. When the stage 40 moves down as shown in FIG. 1, the composition R is applied to the surface of the layer H laminated to form an uncured layer at a thickness corresponding to the volume created by the downward movement of the stage 40. Supplied. The whipping mechanism 50 is a mechanism for making a flat and smooth surface of the uncured liquid photo-curable resin layer. This is achieved by first lowering the platform 1-10 mm so that the entire surface of the cured layer is moderately wet, secondly raising the platform to the desired height, and thirdly whipping excess resin to obtain a flat surface, Can be achieved. It is also possible to spray (slightly) resin over the surface of the cured layer and then whirl out excess resin using a calandring or a doctor blade.

The circulation device 60 includes a circulation pump 61, a pipe 62 on the liquid intake side, and a pipe 63 on the liquid outlet side. In the present specification, examples of the circulation pump 61 are a bellows type pump, an eccentric screw pump, a rotary pump, a type of rotary pump having an outer surface, a gear pump, a diaphragm type pump, and the like. Of these circulation pumps, bellows type pumps, diaphragm type pumps or columnar pistons are preferred because of their ability to move highly viscous slurry, retain very small amounts of friction and minimize heat generation during operation.

A pipe 62 on the liquid suction side connects the circulation pump with the opening 20A formed at the bottom of the side wall of the vessel 20. A pipe 63 on the liquid discharge side connects the circulation pump 61 with the opening 20B formed at the top of the vessel 20 side wall. The plurality of openings 20A and 20B are diagonally installed in the horizontal direction (up and down and left and right directions of the ground) to increase the circulation effect (homogeneity of the composition) in the container 20.

In the region (or region) where the liquid composition is in contact, each internal constituent of the circulation pump 61, the pipe 62 on the liquid intake side and the pipe 63 on the liquid outlet side is a type of photo-curable resin, dispersion Appropriately selected according to the type and amount of fillers to be formed and the molding conditions (e.g., the temperature of the composition), thereby preventing deterioration of the composition due to exothermic and high share, the flow of fillers and chemical attack of the photo-curable composition Wear can be prevented.

In addition to the circulation device 60, a spare circulation device having a configuration similar to the circulation device 60 shown in FIG. 1 is provided so that when a mechanical failure can occur in the circulation device 60, continuous light without interruption is provided. Molding operation can be guaranteed. Moreover, multiple circulation devices can be used at the same time to increase the circulation effect.

The control means 70 is turned on, off, scanning and stopping of the light source device 30, raising and lowering and stopping of the stage 40, operating and stopping the whipping mechanism 50, and operating the circulator 60 and Computer for controlling stop, and the like.

Examples of photo-curable resins used as resin components of Composition R include modified polyurethane (meth) acrylates, oligo-ester (meth) acrylates, urethane (meth) acrylates, epoxy (meth) acrylates, photosensitive poly Monomers and oligomers such as amides, aminoalkyds, epoxy compounds, vinyl ethers, oxetane, spiro-ortho-ester compounds, vinyl ether-maleic acid and thiol-enes. The monomers and oligomers may be used alone or in combination of two or more thereof.

Other components that may be added to the composition R include photoinitiators that generate radicals or cations when irradiated with light, preservatives, and other additives that may improve the properties of the composition R.

Powdery inorganic fillers or fibrous inorganic fillers are presented as fillers which constitute Composition R. Specific examples include glass powder, silica powder, alumina, alumina hydrate, magnesium oxide, magnesium hydroxide, barium sulfate, calcium sulfate, calcium carbonate, magnesium carbonate, silicate minerals, diatomaceous earth, silicate sand, silica powder, titanium oxide, aluminum powder, bronze , Zinc powder, copper powder, lead powder, gold powder, silver powder, glass fiber, potassium titanate whisker, carbon whisker, sapphire whisker, beryllia whisker, boron carbide whisker, silicon carbide whisker and silicon nitride whisker. The average fiber length or average particle size of the inorganic filler is typically in the range of 1-50 μm. The amount of the inorganic filler incorporated into the composition R is 50-200 parts by volume, preferably 100-175 parts by volume, more preferably 140-160 parts by volume, based on 100 parts by volume of the mixture of the photo-curable resin.

A typical example of composition R is 50 parts by weight of SA-1002 (tm) (manufactured by Mitsubishi Chemical Co., Ltd.) as a photo-curable resin, FA-513A (tm) as a photo-curable resin (Hitachi Chemical Co., Ltd.) 25 parts by weight, 25 parts by weight of N-vinyl pyrrolidone as a photopolymerization initiator, 0.25 parts by weight of Irgacure (tm) 184 (produced by Ciba Geigy) as a photopolymerization initiator, and p-methoxy as a stabilizer 100 parts by volume of the resin mixture consisting of 0.1 parts by weight of phenol; And 136 parts by volume glass bead GB045ZC (manufactured by Toshiba Balotini) as an inorganic filler.

Using the optical shaping device of the present invention having the above-described configuration, a three-dimensional object can be molded according to the following method:

[1] The group of slice shape data calculated from the CAD data of the three-dimensional object to be molded is input to the control means 70. Each slice has a constant distance in the height direction of the three-dimensional shape.

[2] Upon receiving a control signal from the control means 70, the support stage 40 moves downward by a distance such that the stage surface 41 descends from the liquid surface of the composition R to a level equivalent to one layer. . Thereafter, the composition R is supplied onto the stage surface 41 to form an uncured layer (first layer) of the composition R.

[3] The whipping mechanism 50 is actuated by a control signal derived from the control means 70 and ensures a uniform thickness of the uncured layer (first layer) and a smooth liquid surface of the composition R.

[4] The uncured layer (first layer) is selectively irradiated with light originating from the light source device 30 in accordance with the slice shape data (data for the first layer) by the control means 70. The part irradiated with the light of the composition R is cured by photopolymerization to form a cured resin layer (first layer).

[5] The stage 40 descends by the distance of another floor in accordance with the control signal derived from the control means 70. Thereafter, the next uncured layer (second layer) of composition R is fed over the cured resin layer (first layer).

[6] The whipping mechanism 50 operates in accordance with the control signal originating from the control means 70 to ensure the uniform thickness of the uncured layer (second layer) and the smooth liquid surface of the composition R.

[7] The non-hardened layer (second layer) is selectively irradiated with light originating from the light source device 30 in accordance with the slice shape data (data for the second layer) by the control means 70. The part irradiated with the light of the composition R is cured by photopolymerization to form a cured resin layer (second layer).

[8] The operations of the above [5] to [7], that is, the formation of the non-hardened layer, the smoothing of the surface of the liquid resin, and the formation of the cured resin layer are repeated to produce a three-dimensional article composed of the laminated cured resin layer.

In the light shaping device of the present invention, the composition R is circulated. That is, the composition existing near the bottom portion is moved to the liquid surface by the circulation device 60 while the photoforming operation of the three-dimensional shape is being performed or when the pretreatment step before the photoforming operation is started. In particular, of the compositions R filled in the vessel 20, the composition present near the bottom portion where the dispersion ratio of the filler increases over time is moved from the opening 20A to the outside of the vessel 20, and the pipe on the liquid suction side 62, the circulation pump 62 and the pipe 62 on the liquid discharge side, and return to the vessel from the opening 20B. This ensures mixing of the composition containing the high density filler and present near the bottom of the container with the composition present near the liquid surface. Thus, a uniform density of filler in composition R can be maintained throughout the container, thereby stabilizing the density of the filler near the liquid surface and suppressing the change (decrease) in density over time. Therefore, in the three-dimensional object composed of laminated cured resin layers formed near the liquid resin surface, the concentration of the filler is uniform in the upper resin layer formed at the end of the molding operation and the lower resin layer formed at the beginning of the molding operation. . Thus, the steric formation obtained exhibits excellent homogeneity in physical properties throughout.

Since the openings 20A and 20B formed in the container are arranged opposite in the horizontal direction, the circulation effect (homogeneity of the composition) in the container 20, in particular, the uniformity of the physical properties of the same cured resin layer is significantly improved.

The circulation device 60, which is an essential component of the optical shaping device of the present invention, does not need to be constantly operated during every molding operation, but can be intermittently operated to maintain a desirable circulation effect. For example, the circulation device 60 may be stopped to prevent the liquid surface from becoming uneven while the whipping mechanism 50 is operated, and to smooth the liquid surface while the composition is cured by light irradiation. have. Intermittent operation of the circulation device 60 is controlled by the control means 70.

The quantity of the composition (transport capacity of the circulation pump 61) transported by the circulation device 61 per unit time can be calculated as follows.

3 is a perspective view showing a state in which the composition R is filled into the container 20. In FIG. 3, 80 represents an imaginary cube containing the microvolume of composition R, and 90 is the imaginary horizontal plane in composition R. In FIG. A part of the side wall constituting the container 20, an opening formed on the side wall, and the circulation device are omitted in the drawing.

In this specification, the density of filler particles present in composition R (homogeneous dispersed state) is represented by “ρ” (g / cm 3), and the density of filler particles near the liquid surface of composition R is “ρ ₁ ” (g / Cm 3), and the density of the filler particles at the bottom of the composition R is expressed as “ρ ₂ ” (g / cm 3).

The sedimentation of the filler particles in the total composition R contained in the vessel 20 is considered the result of the overall migration of the individual filler particles. In the case of the virtual cube 80, the inflow of filler particles into the top surface of the virtual cube 80 and the outflow of filler particles from the bottom of the virtual cube 80 occur simultaneously while the filler particles are settling. If there is no significant change in the physical properties of the composition R near the virtual cube 80, the amount (weight) of filler particles flowing into the virtual cube 80 is equal to the amount (weight) of filler particles flowing out of the virtual cube 80. Thus, there is no change in the amount (weight) of the filler particles present in the virtual cube 80. On the other hand, if the top surface of the virtual cube 80 is in contact with the liquid surface of the composition R, there will be no filler particles flowing into the virtual cube 80 through the top surface, resulting in filler particles present in the virtual cube 80. The amount (weight) of will decrease. Conversely, if the bottom surface of the virtual cube 80 is in contact with the vessel 20, the filler particles will not flow out through the bottom portion, and the amount (weight) of filler particles present in the virtual cube 80 will increase. While the density of the filler particles in the middle of the vessel 20 is nearly constant, the density ρ ₂ of the filler particles near the liquid surface decreases over time, and ultimately there will be no filler particles present on the liquid surface. In addition, the density ρ ₁ of the filler particles in the vicinity of the bottom portion increases over time, and eventually, the settling of the filler particles occurs.

Based on this model, the amount (weight), W (g / min) of precipitated filler particles per unit time is determined by the following equation.

W = ws

w is the weight (g / cm 2? min) of filler particles passing through the unit area of the virtual horizontal plane 90 per unit time, and s is the area of the virtual horizontal plane 90 (cm 2).

The filler particles of the composition are moved by the circulation device 60 in an amount of volume V (cm 3 / min) (circulation capacity) per unit time, and the amount of filler particles supplied per unit time to the top of the container (near the liquid surface) is ρ _2. ? V (g / min). The amount of ρ ₁ -V is equal to the amount of filler particles that were present near the liquid surface before the composition was transported. Therefore, the actual amount of filler particles transported per unit time, Wp (g / min), is determined by the following equation.

Wp = (ρ ₁ -ρ ₂ ) V

When reaching a steady state after the operation of the circulation device 60, the weight W reduced during the unit time is equal to the weight Wp actually transported for the unit time. Therefore, the relationship of the following equation (3) is established.

W = Wp = (ρ ₁ -ρ ₂ ) V = ws

On the other hand, from the model described above, the decrease in the density ρ ₁ of the filler particles near the liquid surface is the same as the density ρ ₂ of the filler particles near the bottom part. The densities ρ ₁ and ρ ₂ are then represented by Equations 4 and 5, respectively, using the deviation of the filler density from ρ ₀ .

ρ _{1 =} ρ ₀ -Δρ

ρ _{2 =} ρ ₀ -Δρ

None of ρ ₁ and ρ ₂ is less than 0 and no greater than the maximum depending on the type of filler or the like.

The amount of change Δρ, which represents the difference between ρ ₁ and ρ ₂ , is greater than the limit tolerance ρ _t, which is determined by the properties required for the conformation to be shaped (eg, high heat distortion temperature or high Young's modulus). It must be small. One skilled in the art can determine the allowable particle density differences to achieve proper physical properties with some simple tests. In this respect, it is particularly important to determine the required density of filler particles near the surface of the resin because the surface layer creates a cured layer.

In the case of defined p _t , Equation 6 is established. Then, Equation 7 is derived by substituting Equation 6 into Equation 3 described above.

ρ _t > Δρ = (ρ ₂ -ρ ₀ ) / 2

V ＞ ws / 2 ρ _t

As shown in Equation 7, the amount V (circulating capacity) of the composition transported by the circulation device 60 per unit time is the weight w of the filler particles passing through the unit area of the virtual horizontal plane 90 per unit time (of the filler Sedimentation degree), the area s of the imaginary horizontal plane 90 (the area of the bottom part of the container 20) and the allowable limit ρ _t of the amount of change in the filler particle density.

The transport volume V calculated in this way is the minimum required. This amount is preferably set to 2-5 times ws / 2ρ _t . In particular, a composition comprising a mixture of 100 parts by volume consisting of 30-50 parts by volume of photo-curable resin and a photopolymerization initiator and an inorganic filler of 50-70 parts by volume of the container 20 (the area of the bottom of the container is 300-20,000 cm 2 ], The transport amount V (cm 3 / min) by the circulation device 60 is 0.2 to 100,000, preferably 2 to 10,000, more preferably 20 to 2,000.

The optical shaping device of the present invention is detailed by a typical embodiment. However, the present invention is not limited to these specific examples. Various variations are possible. For example, (1) the circulation device of the photo-curable resin composition can be disposed inside the container to make the device smaller in size, or (2) other means (eg, stirring means, convection means, etc.) in addition to the circulation device. ) May be used together to homogenize the photo-curable resin composition in the container. The photo-fabrication apparatus of this invention can manufacture a three-dimensional object using the photo-curable resin composition which does not contain a filler.

<Production of Photo-Curable Resin Composition>

50 parts by weight of SA-1002 (trade name) (manufactured by Mitsubishi Chemical Co., Ltd., polyfunctional monomer having a cyclic structure), 25 parts by weight of FA-513 (trade name) manufactured by Hitachi Chemical Co., Ltd. One, mono-functional monomer having a cyclic structure, 25 parts by weight of N-vinyl pyrrolidone (single-functional monomer), 0.25 parts by weight of Irgacure 651 (trade name) manufactured by Ciba Geigy) and 0.1 The resin composition was prepared by mixing a weight part of p-methoxy phenol (stabilizer). 136 volume parts of glass beads GB045ZC (trade name) manufactured by Toshiba Balotini and 100 volume parts of the resin mixture having a particle size distribution of about 5-65 μm were mixed to obtain a photo-curable resin composition.

<Example>

A rectangular column (100 mm ×) consisting of a cured resin layer (thickness of one layer: 200 μm) laminated using the optical shaping device of the present invention shown in FIG. 1 while operating the circulation device 60 for at least 12 hours. 10 mm x height 60 mm) in the form of a three-dimensional object. The size of the container 20 for accommodating the photo-curable resin composition was 20 cm x 15 cm x 10 cm. An argon laser emitter was used as the light source for the light source device 30, and a bellows type pump was used as the pump 61 for the circulation device 60. In this example, the weight w of filler particles passing through the unit area per unit time was 0.98 mg / min, and the area of the bottom of the vessel 20 was 300 cm 2. The threshold value p _t of the amount of change in the filler density was 3.6 mg / cm 3. The threshold value ρ _t of the amount of change was converted into about 0.1 wt% of the weight percentage of the filler. Substituting the above data into Equation 7, (ws / 2ρ _t ) was about 41 cm 3 / min. The actual measured amount transported by the circulation device 60 in this example was about 140 cm 3 / min, about 3.4 times (ws / 2ρ _t ).

Test specimen from the lower portion formed at the initial stage of the photoforming operation (5 mm distance from the edge of the three-dimensional object) and the upper portion formed at the end of the photoforming operation (5 mm from the edge of the three-dimensional object). Was prepared. The weight percent of filler determined from density, elastic modulus as an indicator of physical properties, and heat distortion temperature (HDT) as an indicator of heat resistance were measured. The results are shown in Table 1.

<Reference Example>

The photoforming was performed in the same manner as in the above embodiment, except that the circulation device 60 was not operated. The weight percent, elastic modulus and heat deflection temperature (HDT) of the filler relative to the top and bottom of the resulting conformation were measured. The results are shown in Table 1 together with the results of the above examples. In this reference example, 6 hours after the start of the photoforming, no filler was present in the composition near the liquid surface of the container 20 in which the cured resin layer was formed (located 2 mm from the liquid surface).

Amount of filler (% by weight) Young's modulus (㎏ / ㎠) HDT (℃) Example Top 78.678.5 815805 212208 Reference lower part 78.50.9 810190 200110

As is apparent from the results in Table 1, there was no difference in the amount of fillers at the top and bottom of the three-dimensional body produced in the examples. The three-dimensional object prepared in the example showed excellent homogeneity showing excellent physical properties and heat resistance throughout. In contrast, the three-dimensional feature prepared in the reference example contained less amount of filler on the top and exhibited poor physical properties and heat resistance, which resulted in poor homogeneity of the three-dimensional feature prepared in the reference example and the physical properties and It indicates that the heat resistance is not uniform.

Even when the filler is susceptible to sedimentation in the photo-curable resin composition, a homogeneous three-dimensional object exhibiting desired physical properties can be molded over the entire portion using the optical shaping device of the present invention while effectively suppressing the sedimentation of the filler.

Claims (11)

(a) introducing a non-cured layer of a liquid radiation-curable resin composition into a photoforming apparatus; (b) selectively irradiating the radiation-curable resin according to slice shape data of the three-dimensional object to cure selected areas of the radiation-curable resin; (c) repeating steps (a) and (b) to obtain a three-dimensional object composed of laminated layers of the cured resin composition, wherein the three-dimensional object molding method comprises: The radiation-curable resin composition includes a filler having a density different from that of the radiation-curable resin, The radiation-curable resin composition is at least a predetermined time during the execution of the method, w? S / 2ρ _t [w is the weight of filler particles passing through the unit area of the virtual horizontal plane 90, and s is the area of the virtual horizontal plane 90 , ρ _t is circulated by the circulation device (60) at a rate of 2-5 times the limit of the allowable difference in the density of filler particles dispersed in the composition. Method according to claim 1, characterized in that the circulation device (60) comprises a circulation pump (61). 3. The method of claim 2, wherein the circulation device (60) comprises a bellows-type pump, a diaphragm-type pump or a circumferential piston. 4. Method according to any one of the preceding claims, characterized in that the optical shaping device comprises control means (70) for actuating or stopping the circulation device (60).        5. The control device (70) according to claim 4, wherein the control means (70) is turned on, off, scanning and stopping of the light source device (30), raising, lowering and stopping of the stage (40), and whipping mechanism (50). Computer for controlling the operation and stopping of the circuit and the operation and stopping of the circulation device (60). The method according to any one of claims 1 to 3, wherein the circulation device (60) is capable of moving a liquid radiation-curable resin at a rate of 0.2 to 100,000 cm 3 / min. The method of claim 1, wherein the radiation-curable resin comprises at least one radiation-curable monomer or oligomer and further comprises at least one photoinitiator. Way. The method of any one of claims 1 to 3, wherein the radiation-curable resin composition comprises at least one powdery or fibrous inorganic filler. The method of claim 1, wherein the filler has an average fiber length or average particle size of 1-50 μm. The method according to any one of claims 1 to 3, wherein the amount of the filler is in the range of 50 to 200 parts by volume based on 100 parts by volume of the mixture of the radiation-curable resin. An apparatus for shaping a three-dimensional object from continuous build-up and curing of layers of liquid radiation-curable composition, A storage container for containing a liquid radiation-curable composition; Vertical movement through the liquid radiation-curable composition and the storage container, wherein the vertical radiation causes the liquid radiation-curable composition to become layers of the non-curable composition, each layer being part of the conformation upon radiation-curing of the selected area. A mobility stage to form a; A whipping device for forming a surface of a laminated uncured layer of substantially flat and smooth radiation-curable composition; A radiation source for carrying out curing of the laminated layer of liquid radiation-curable composition; And Circulator for increasing homogeneity between different parts of the liquid radiation-curable composition in the storage device, the circulator being more than a certain time w? S / 2ρ _t (w is the virtual horizontal plane 90) Is the weight of the filler particles passing through the unit area of s, s is the area of the imaginary horizontal plane 90, and ρ _t is the limit of the allowable difference in density of filler particles dispersed in the composition). Capable of circulating a liquid radiation-curable composition at a rate].