U.S. patent application number 15/123720 was filed with the patent office on 2017-01-19 for method of producing three-dimensional shaped article.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Yukio Hanyu, Naotake Sato, Akira Sugiyama, Tatsuya Tada, Satoru Yamanaka.
Application Number | 20170015063 15/123720 |
Document ID | / |
Family ID | 52997490 |
Filed Date | 2017-01-19 |
United States Patent
Application |
20170015063 |
Kind Code |
A1 |
Hanyu; Yukio ; et
al. |
January 19, 2017 |
METHOD OF PRODUCING THREE-DIMENSIONAL SHAPED ARTICLE
Abstract
A method of producing a three-dimensional shaped article
includes a step of forming particle layers by arranging particles
containing a material for forming a shaped article and particles
containing a material having higher solubility in fluid than the
material for forming the shaped article, a step of forming a stack
by melting and stacking the particle layers, and a step of removing
the material having higher solubility in the fluid than the
material for forming the shaped article from the stack by
dissolving the material having higher solubility in the fluid than
the material for forming the shaped article in the fluid.
Inventors: |
Hanyu; Yukio; (Isehara-shi,
JP) ; Sugiyama; Akira; (Yokohama-shi, JP) ;
Sato; Naotake; (Sagamihara-shi, JP) ; Tada;
Tatsuya; (Yokohama-shi, JP) ; Yamanaka; Satoru;
(Kawasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
52997490 |
Appl. No.: |
15/123720 |
Filed: |
March 3, 2015 |
PCT Filed: |
March 3, 2015 |
PCT NO: |
PCT/JP2015/056764 |
371 Date: |
September 6, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 64/40 20170801;
B29C 67/0081 20130101; B29K 2995/0062 20130101; B29C 64/223
20170801; B33Y 10/00 20141201; G03G 15/22 20130101; B29C 64/165
20170801; B29C 64/147 20170801; B33Y 40/00 20141201; B29K 2105/251
20130101; G03G 15/224 20130101; B29C 64/141 20170801 |
International
Class: |
B29C 67/00 20060101
B29C067/00; G03G 15/22 20060101 G03G015/22; B33Y 10/00 20060101
B33Y010/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 7, 2014 |
JP |
2014-045622 |
Mar 7, 2014 |
JP |
2014-045623 |
Claims
1. A method of producing a three-dimensional shaped article,
comprising: a step of forming particle layers by arranging
particles containing a material for forming a shaped article and
particles containing a material having higher solubility in water
than the material for forming the shaped article; a step of forming
a stack by melting and stacking the particle layers; and a step of
removing the material having higher solubility in the water than
the material for forming the shaped article from the stack by
dissolving the material having higher solubility in the water than
the material for forming the shaped article in the water, wherein
the material having higher solubility in the water and the material
for forming the shaped article contains a water-soluble
carbohydrate.
2.-4. (canceled)
5. The method according to claim 1, wherein the water-soluble
carbohydrate is a water-soluble dietary fiber.
6. (canceled)
7. The method according to claim 1, wherein the material having
higher solubility in the water than the material or forming the
shaped article contains at least one selected from the group
consisting of a water-soluble dietary fiber, polydextrose,
lactitol, and maltotetraose.
8.-9. (canceled)
10. The method according to claim 1, wherein the material for
forming the shaped article is at least one selected from the group
consisting of polypropylene, an acrylonitrile-butadiene-styrene
copolymer, polymethyl methacrylate, and polyvinyl acetate.
11. The method according to claim 1, wherein the step of removing
the material having higher solubility in the water than the
material for forming the shaped article is performed by immersing
the stack in the water.
12. The method according to claim 1, wherein the step of forming
the particle layers by arranging the particles containing the
material for forming the shaped article and the particles
containing the material having higher solubility in the water than
the material for forming the shaped article is performed by
transfer.
13. The method according to claim 12, wherein the transfer is
performed by electrostatic transfer.
14. The method according to claim 1, wherein the step of forming
the stack by melting and stacking the particle layers is performed
by stacking the particle layers after the particle layers are
melted.
15. The method according to claim 1, wherein the step of forming
the stack by melting and stacking the particle layers is performed
by melting the particle layers after the particle layers are
stacked.
The method according to claim 1, wherein the stacking of the
particle layers is performed by transfer.
17. The method according to claims 1, wherein the melting of the
particle layers is performed by heating.
18. The method according to claim 1, wherein the solubility
parameter of the particles containing the material having higher
solubility than the material for forming the shaped article is 2
(MPa).sup.1/2 or more closer to the solubility parameter of the
water than the solubility parameter of the particles containing the
material for forming the shaped article.
19. The method according to claim 18, wherein the solubility
parameter of the particles containing the material having higher
solubility than the material for forming the shaped article is 15
(MPa).sup.1/2 or more closer to the solubility parameter of the
fluid water than the solubility parameter of the material for
forming the shaped article.
20. The method according to claim 1, wherein the water-soluble
carbohydrate is sugar.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method of producing a
three-dimensional shaped article.
BACKGROUND ART
[0002] Patent Literature 1 discloses a three-dimensional shaping
method in which slice images made of resin particles are formed by
electrophotography and are stacked. In Patent Literature 1, resin
particles with a melting point lower than that of a material for
forming a shaped article are used to form a support portion of a
stack under construction and the support portion is removed in such
a manner that the support portion is selectively melted by taking
advantage of the difference in melting point between the support
portion and the shaped article.
[0003] Patent Literature 2 discloses that
poly(2-ethyl-2-oxazoline), which is a water-soluble material, is
used to form a support portion.
CITATION LIST
Patent Literature
[0004] PTL 1 Japanese Patent Laid-Open No. 2003-53849
[0005] PTL 2 Japanese Patent No. 4301733
SUMMARY OF INVENTION
Technical Problem
[0006] However, in Patent Literature 1, the difference in melting
point between the material for forming the shaped article and a
material for forming the support portion needs to be large and
therefore the degree of freedom in selecting a material that can be
used to form an article is low. Furthermore, since the support
portion is made of a low-melting point material, there is a problem
in that the support portion is softened by heating during stacking
and therefore the supporting function thereof is reduced.
[0007] In Patent Literature 2, a material for forming the support
portion is rapidly melted in an extruder and is extruded into
fibers, which are stacked such that an article is formed.
Therefore, in the case of using a material with high moisture
content, this material foams and cannot be stably extruded. Thus,
the material for forming the support portion needs to be a
water-soluble material with low moisture content.
Solution to Problem
[0008] The present invention provides a method of producing a
three-dimensional shaped article. The method includes a step of
forming particle layers by arranging particles containing a
material for forming a shaped article and particles containing a
material having higher solubility in fluid than the material for
forming the shaped article, a step of forming a stack by melting
and stacking the particle layers, and a step of removing the
material having higher solubilty in the fluid than the material for
forming the shaped article from the stack by dissolving the
material having higher solubility in the fluid than the material
for forming the shaped article in the fluid.
[0009] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is an apparatus of producing a three-dimensional
shaped article according to an embodiment of the present
invention.
[0011] FIG. 2A is a scanning electron microscope (SEM) photograph
of polydextrose particles prepared in Example 1.
[0012] FIG. 2B is a SEM photograph of maltotetraose particles
prepared in Example 2.
[0013] FIG. 2C is a SEM photograph of PEG 6000 particles prepared
in Example 4.
[0014] FIG. 3A is a SEM photograph of polypropylene particles
prepared in Example 2.
[0015] FIG. 3B is a SEM photograph of ABS particles prepared in
Example 3.
[0016] FIG. 4 is a graph showing the dynamic viscoelasticity of the
polydextrose particles prepared in Example 1, the dynamic
viscoelasticity of the maltotetraose particles prepared in Example
2, and the dynamic viscoelasticity of the PEG 6000 particles
prepared in Example 4.
[0017] FIG. 5A is an illustration of particle layers formed during
shaping.
[0018] FIG. 5B is an illustration of a stack obtained by stacking
the particle layers shown in FIG. 5A.
[0019] FIG. 5C is an illustration of an apparatus (support
portion-removing apparatus) used to remove a support portion from
the stack shown in FIG. 5B.
[0020] FIG. 5D is an illustration of a three-dimensional shaped
article obtained by removing the support portion from the stack
shown in FIG. 5B.
[0021] FIG. 6 is a graph showing the dynamic viscoelasticity of the
polydextrose particles prepared in Example 1, the dynamic
viscoelasticity of the maltotetraose particles prepared in Example
2, and the dynamic viscoelasticity of particles of a mixture of
polydextrose and maltotetraose, the particles being prepared in
Example 3.
[0022] FIG. 7 is a graph showing the time taken to remove a support
portion from a stack obtained in each of Examples 1, 2, and 4
depending on a material for forming support material particles.
DESCRIPTION OF EMBODIMENTS
[0023] Preferred embodiments of the present invention will now be
described in detail with reference to the attached drawings.
[0024] A method of producing a three-dimensional shaped article
according to an embodiment of the present invention includes the
following steps: [0025] (1) a step of forming particle layers by
arranging particles containing a material for forming a shaped
article and particles containing a material having higher
solubility in fluid than the material for forming the shaped
article, [0026] (2) a step of forming a stack by melting and
stacking the particle layers, and [0027] (3) a step of removing the
material having higher solubility in the fluid than the material
for forming the shaped article from the stack by dissolving the
material having higher solubility in the fluid than the material
for forming the shaped article in the fluid.
[0028] These steps are described below with reference to FIG.
1.
[0029] Each step described be is an example of a step of the method
of producing the three-dimensional shaped article. The present
invention is not limited to the step.
((1) Step of Forming Particle Layers By Arranging Particles
Containing Material for Forming Shaped Article and Particles
Containing Material Having Higher Solubility in Fluid than Material
for Forming Shaped Article)
[0030] A laser beam 3a is scanned across the curved surface of an
electrophotographic photosensitive drum 2a and a laser beam 3b is
scanned across the curved surface of an electrophotographic
photosensitive drum 2b, whereby each of latent images is formed on
a corresponding one of the electrophotographic photosensitive drums
2a and 2b.
[0031] The particles containing the material for forming the shaped
article are supplied from a supply section la to the
electrophotographic photosensitive drum 2a and are arranged
depending on the latent image formed on the electrophotographic
photosensitive drum 2a. The particles containing the material
having higher solubility in the fluid than the material for forming
the shaped article are supplied from a supply section 1b to the
electrophotographic photosensitive drum 2b and are arranged
depending on the latent image formed on the electrophotographic
photosensitive drum 2b. The terms "material for forming the shaped
article" and "solubility in the fluid" are hereinafter simply
referred to as "article material" and "solubility",
respectively.
[0032] The particles, arranged on the electrophotographic
photosensitive drum 2a, containing the article material and the
particles, arranged on the electrophotographic photosensitive drum
2b, containing the material having higher solubility than the
article material are electrostatically transferred to a transfer
belt 4, whereby particle layers 8 are formed so as to contain the
particles containing the article material and the particles
containing the material having higher solubility than the article
material.
[0033] Examples of the article material include polyethylene (PE),
polypropylene (PP), acrylonitrile-butadiene-styrene (ABS)
copolymers, nylon 12, nylon 6, nylon 66, polyoxymethylene (POM),
polycarbonate (PC), acrylic resins such as polymethyl methacrylate
(PMMA), cyclic olefin copolymers (COCs), polyethylene terephthalate
(PET), polybutylene terephthalate (PET), and polyvinyl acetate
(PVAc). Naturally, the article material is not limited to these
exemplified materials and may be appropriately selected depending
on purposes.
[0034] The particles containing the article material may be made of
the article material only and may further contain a material such
as a dispersant in addition to the article material. The article
material may be a main component of the particles containing the
article material. The term "main component of particles" as used
herein refers to a component that accounts for 90% by weight or
more of each particle.
[0035] The article material may be made of a single ingredient or
may be made by mixing two or more ingredients. When the article
material is a mixture of two or more ingredients, characteristics
of the particles containing the article material, particularly, for
example, the dynamic viscoelasticity thereof can be adjusted.
[0036] A method of preparing the particles containing the article
material may be any known process.
[0037] Examples of the method of preparing the particles containing
the article material include a mechanical crushing method, a melt
dispersion cooling method in which particles are obtained in such a
manner that the molten article material is dispersed in a medium
and is then cooled, a chemical polymerization method such as a
suspension polymerization method in which polymer particles are
prepared in a medium, and a spray drying method in which particles
are obtained in such a manner that a solution prepared by
dissolving the article material in a solvent is sprayed and is
rapidly dried. In particular, the melt dispersion cooling method,
the chemical polymerization method, and the spray drying method are
preferred because the shape and size distribution of particles can
be relatively freely controlled.
[0038] When the size of particles used for shaping is large, the
shaping time can be reduced. When the particle size is small, the
shaping accuracy can be increased. The average size of particles
preferred in the present invention preferably ranges from 5 .mu.m
to 100 .mu.m, more preferably 10 .mu.m to 70 .mu.m, and further
more preferably 20 .mu.m to 50 .mu.m depending on the accuracy
required of the shaped article or the shaping time of the shaped
article. The term "average size of particles" as used herein refers
to the volume-average size of particles that is determined by a
laser diffraction/scattering method.
[0039] The material having higher solubility than the article
material is provided in a portion for forming a cavity of the
shaped article or under an overhanging portion thereof in Steps (1)
and (2), is dissolved in the fluid, and is thereby removed in Step
(3). That is, the material having higher solubility than the
article material forms the stack, which is obtained through Steps
(1) and (2), and, however, does not form the shaped article, which
is obtained through Step (3). A role required of the material
having higher solubility than the article material is to support
the article material provided on the portion for forming the cavity
of the shaped article or provided in an overhanging pattern in
Steps (1) and (2) and is to be quickly removed in Step (3).
[0040] A portion that is dissolved in the fluid and is thereby
removed in Step (3) and the particles containing the material
having higher solubility than the article material are hereinafter
referred to as the support portion and the support material
particles, respectively, in some cases. Incidentally, particles
described herein are not limited to a spherical shape and may have
a spherical shape, a prismatic shape, a cylindrical shape, an oval
shape, or an amorphous shape which is a mixture of some of these
shapes that are deformed in general, particles prepared by crushing
are likely to have an amorphous shape and particles prepared by a
melt dispersion cooling method, a chemical polymerization method, a
spray drying method, or the like using a medium are readily
controlled to have a spherical shape or a certain shape due to a
crystal shape.
[0041] The solubility parameter of the particles containing the
material having higher solubility than the article material is
preferably 2 (MPa).sup.1/2 or more and more preferably 15
(MPa).sup.1/2 or more closer to the solubility parameter of the
fluid than the solubility parameter of the particles containing the
article material. This allows the support portion, which is made of
the particles containing the material having higher solubility than
the article material, that is, the support material particles, to
be selectively dissolved in Step (3).
[0042] The solubility parameter described herein is one calculated
by Fedors' method, which is one of methods of determining the
solubility parameter from the molecular structure. When the fluid
is, for example, water, the solubility parameter of the fluid is
47.9 (MPa).sup.1/2. When the fluid is, for example, hexane, the
solubility parameter of the fluid is 14.1 (MPa).sup.1/2.
[0043] The support material particles may be made of a single
material or a mixture of two or more materials.
[0044] In particular, the support material particles may be made of
the single material having higher solubility than the article
material or two or more materials having higher solubility than the
article material. Alternatively, the support material particles may
be made of the material having higher solubility than the article
material and a material having lower solubility than the article
material.
[0045] When the support material particles are made of a mixture of
two or more materials, the dynamic viscoelasticity of the support
material particles can be adjusted close to the dynamic
viscoelasticity of the particles containing the article material.
In the case where the-dynamic viscoelasticity of the support
material particles and the dynamic viscoelasticity of the particles
containing the article material can be adjusted close to each
other, the molten article material deposited on a portion made of
the support material particles can be supported in a less deformed
state.
[0046] In the present invention, the solubility parameter of the
support material particles can be determined by a method below. In
the case where the support material particles are made of the
material having higher solubility than the article material and the
case where the support material particles are made of the material
having higher solubility than the article material and the material
having lower solubility than the article material, the solubility
parameter of the material having higher solubility than the article
material is regarded as the solubility parameter of the support
material particles. In the case where the support material
particles are made of the two or more materials having higher
solubility than the article material, a value obtained by
weight-averaging the solubility parameters of these materials on
the basis of the contents of these materials is regarded as the
solubility parameter of the support material particles.
[0047] In the case of using a liquid mainly containing water in
Step (3), the support material particles preferably contain a
material having higher water solubility than the article material.
The term "liquid mainly containing water" as used herein refers to
a liquid containing 95% or more water on a weight basis.
[0048] A water-soluble material that can be used as a material
having higher solubility than the article material is preferably a
compound containing a hydroxy group. Examples of the water-soluble
material include water-soluble carbohydrates such as water-soluble
dietary fibers, sugar, and water-soluble polymers. Examples of the
dietary fibers include polydextrose and insulin. Examples of the
sugar include sucrose, lactose, maltose, trehalulose, melezitose,
stachyose, xylose, glucose, fructose, isomaltooligosaccharide,
fructooligosaccharide, xylooligosaccharide, soy oligosaccharide,
xylitol, sorbitol, mannitol, maltotetraose, maititol, lactitol, and
oligosaccharide alcohols. Examples of the water-soluble polymers
include polyvinylpyrrolidone, polyalkylene oxides, and polyvinyl
alcohol.
[0049] However, the material having higher solubility than the
article material is not limited to the above materials.
((2) Step of Forming Stack By Melting and Stacking Particle
Layers)
[0050] The particle layers 8 formed by transferring the particles
containing the article material and the support material particles
to the transfer belt 4 are moved to a stacking stage 5.
[0051] Thereafter, the particle layers 8 are melted with a heater
6. The particle layers 8 are transferred to and stacked on the
elevated stacking stage 5 or a stack 7 placed on the stacking stage
5. The stack 7 is obtained by stacking the particle layers 8
several times and includes an article portion 7a formed by melting
the particles containing the article material and a support portion
7b made of the particles containing the material having higher
solubility than the article material.
[0052] A procedure in which the particle layers 8 are stacked after
being melted is described herein. The particle layers 8 may be
melted after being stacked or during stacking.
[0053] The particle layers 8 may be melted by heating or by the
contact with a solution.
[0054] Referring to FIG. 1, a region of each particle layer 8 that
contains the particles containing the article material is stacked
on the article portion 7a after the particles containing the
article material are melted, a region of the particle layer 8 that
contains the support material particles is stacked on the support
portion 7b.
[0055] However, the region of the particle layer 8 that contains
the support material particles and the region of the particle layer
8 that contains the particles containing the article material may
be stacked on the support portion 7b and the article portion 7a,
respectively, depending on the shape of the shaped article.
[0056] The particle layers 8, which contain the particles
containing the article material and the support material particles,
are stacked by transfer. Step (2) is a step or stacking the
particle layers 8 after melting. The particle layers 8 may be
transferred by taking advantage of the stickiness of the molten
particle layers 8 or may be electrostatically transferred.
[0057] Incidentally, stacking by transfer is exemplified herein.
The particle layers 8 may be directly stacked on the article
portion 7a and the support portion 7b without using transfer.
((3) Step of Removing Material Having Higher Solubility in Fluid
than Article Material By Dissolving Material Having Higher
Solubility in Fluid than Article Material in Fluid)
[0058] In Step (3), the material having higher solubility than the
article material is removed from the stack 7, which is obtained in
Step (2), by dissolving the material having higher solubility than
the article material in the fluid. As a result, the support portion
7b can be removed from the stack 7. The fluid may be liquid or gas
and is preferably liquid.
[0059] Any method capable of removing the material having higher
solubility than the article material using the fluid may be used.
As such a method, for example, a method of immersing the stack 7,
which is obtained in Step (2), in the fluid filled in a vessel is
cited.
[0060] In the case of removing the support portion 7b by placing
the stack 7 in the fluid, a flow is preferably formed in the fluid
by stirring. The fluid may be heated or ultrasonically vibrated
such that the material having higher solubility than the article
material is quickly removed.
EXAMPLES
[0061] (Confirmation of Foamability of Particles Containing
Material Having Higher Water Solubility than Article Material)
[0062] A material having higher water solubility than the article
material may possibly be foamed during heating as disclosed in
Patent Literature 2. Therefore, the foamability of the material was
confirmed by actually melting the material by heating.
Incidentally, a water-insoluble material is not foamed even if the
water-insoluble material is melted by heating.
[0063] Particles obtained by mechanically crushing polydextrose
with a moisture content of 4% were classified with a sieve
classifier, whereby polydextrose particles with an average size of
25 .mu.m, polydextrose particles with an average size of 50 .mu.m,
and polydextrose particles with an average size of 100 .mu.m were
prepared. The polydextrose particles with an average size of 25
.mu.m, the polydextrose particles with an average size of 50 .mu.m,
and the polydextrose particles with an average size of 100 m were
densely attached to polyimide sheets by electrostatic transfer. The
polyimide sheets were heated to the softening point of
polydextrose, that is, 140.degree. C. using a hotplate and were
observed for condition.
[0064] Foaming could not be visually confirmed from the
polydextrose particles with an average size of 25 .mu.m, 50, .mu.m,
or 100 .mu.m. This is probably because these polydextrose particles
were small particles with an average size of 100 .mu.m or less and
therefore moisture contained in polydextrose was smoothly removed
from these polydextrose particles.
[0065] Next, the polydextrose particles with an average size of 50
.mu.m were molded at 50.degree. C. with a load of 20 kg using a
tableting machine, whereby a pellet having a diameter of 1 cm and a
thickness of 1 mm was prepared. The obtained pellet was heated to
the softening point of polydextrose, that is, 140.degree. C. using
a hotplate and was observed for condition. As a result, vigorous
foaming was observed together with softening. This confirmed that
when the size of the heated material having higher water solubility
than the article material is 100 .mu.m or less, foaming caused by
the evaporation of moisture contained in the material having higher
water solubility than the article material can be reduced to a
non-problematic level.
Example 1
[0066] In this example, a three-dimensional shaped article was
prepared using particles of a cyclic olefin copolymer (COC) as
particles containing an article material, a liquid mainly
containing water as fluid for removing a support portion, and
particles of polydextrose as support material particles.
[0067] The three-dimensional shaped article, which was prepared in
this example, had a shape shown in FIG. 5D. In particular, the
three-dimensional shaped article had a shape formed by stacking a
cylinder having a diameter of 3 cm and a height of 1 cm, a cylinder
having a diameter of 1 cm and a height of 1 cm, and a cylinder
having a diameter of 3 cm and a height of 1 cm.
[0068] The COC and polydextrose were mechanically crushed. Obtained
particles of the COC and obtained particles of polydextrose were
adjusted with a sieve classifier so as to have an average size of
50 .mu.m.
[0069] The COC particles and the polydextrose particles were
measured for average size by a laser diffraction/scattering method,
resulting in that the COC particles and the polydextrose particles
had an average size of 50 .mu.m. FIG. 2A snows a SEM photograph of
the polydextrose particles.
[0070] Next, the temperature dependence of dynamic viscoelasticity
of the polydextrose particles was measured within a temperature
range of 100.degree. C. to 180.degree. C. using a rheometer, MCR
302, available from Anton Paar. The measurement results are shown
in FIG. 4.
[0071] Particle layers were formed from the COC particles and the
polydextrose particles using a shaping apparatus shown in FIG. 1.
One of the particle layer was melted, was solidified, and was then
measured for thickness, resulting in that this particle layer had a
thickness of 30 .mu.m.
[0072] At a stack temperature of 120.degree. C., 1,000 of the
particle layers were stacked in total. The term "stack temperature"
as used herein refers to the temperature of a stack surface of a
transfer belt, the stack surface being located directly under a
heater.
[0073] In order to form a cylindrical section having a diameter of
3 cm and a height of 1 cm in an early part of a step and a
cylindrical section having a diameter of 3 cm and a height of 1 cm
in a later part of the step, particle layers each including only a
region 9a in which the COC particles were arranged were formed as
shown in FIG. 5A. The number of the particle layers stacked to form
each cylindrical section was 333. In order to form a cylindrical
section having a diameter of 1 cm and a height of 1 cm, the
cylindrical section being interposed between the cylindrical
sections having a diameter of 3 cm and a height of 1 cm, particle
layers each including the region 9a in which the COC particles were
arranged and a region 9b in which the polydextrose particles were
arranged were formed. The number of the particle layers stacked to
form this cylindrical section was 334.
[0074] A stack 7 obtained by stacking these particle layers was
immersed in the liquid mainly containing water, followed by
removing polydextrose from the stack 7 using a support
portion-removing apparatus shown in FIG. 5C. The support
portion-removing apparatus included a magnetic stirring unit 10 and
a stirrer 11 for magnetic stirring. A sample platen was net-shaped
such that the stack 7 was uniformly contacted with the liquid
mainly containing water, the liquid being stirred with the stirrer
11.
[0075] The liquid mainly containing water may be one prepared by
mixing water with a pH adjuster or the like. In this case, the
amount of the pH adjuster or the like is preferably 5% or less of
water on a weight basis.
[0076] The relationship between the time (removal time) taken to
remove polydextrose making up the support portion and the rate of
removal of polydextrose is shown by solid rhombuses in FIG. 7.
Polydextrose could be removed within 40 minutes without leaving any
residue. The obtained three-dimensional shaped article included an
upper cylindrical section having a diameter of 3 cm and a height of
1 cm. An overhanging portion. (a portion with no structural layer
thereunder) of the upper cylindrical section was not deformed
downward. No cavities or irregularities due to the foaming of
material were observed in the surface of the three-dimensional
shaped article. It was confirmed that the three-dimensional shaped
article could be accurately prepared.
Example 2
[0077] In this example, a three-dimensional shaped article was
prepared by a method similar to that described in Example 1 using
particles of polypropylene as particles containing an article
material, a liquid mainly containing water as fluid for removing a
support portion, and particles of maltotetraose as support material
particles.
[0078] The polypropylene particles were prepared by a melt
dispersion cooling method. In particular, polypropylene, Noblen
W-531, available from Sumitomo Chemical Co., Ltd. and a medium,
that is, polyethylene glycol, PEG #20000, available from Sanyo
Chemical Industries, Ltd. were mixed at a ratio of 1:6, were melted
at a temperature of 200.degree. C., and were kneaded, followed by
cooling, washing with water, and drying, whereby the polypropylene
particles were obtained. The polypropylene particles had an average
size of 50 .mu.m.
[0079] After being mechanically crushed, the maltotetraose
particles were adjusted with a sieve classifier so as to have an
average size of 50 .mu.m.
[0080] FIG. 2B shows a SEM photograph of the maltotetraose
particles. FIG. 3A shows a SEM photograph of the polypropylene
particles.
[0081] The maltotetraose particles were measured for dynamic
viscoelasticity at different temperatures. The measurement results
are shown in FIG. 4.
[0082] Particle layers were prepared from the polypropylene
particles and the maltotetraose particles using a shaping apparatus
shown in FIG. 1. A stack was prepared by stacking 1,000 of the
particle layers at a stack temperature of 130.degree. C. The stack
was immersed in the liquid mainly containing water as described in
Example 1, whereby a support portion was removed from the stack.
The relationship between the time taken to remove maltotetraose and
the rate of removal of maltotetraose is shown by gray circles in
FIG. 7 Maltotetraose could be removed within 30 minutes without
leaving any residue. An overhanging portion of the
three-dimensional shaped article was not deformed downward as
described in Example 1. No cavities or irregularities due to the
foaming of material were observed in the surface of the
three-dimensional shaped article. It was confirmed that the
three-dimensional shaped article could be accurately prepared.
Example 3
[0083] In this example, a three-dimensional shaped article was
prepared by a method similar to that described in Example 1 using
particles of acrylonitrile-butadiene-styrene (ABS) as particles
containing an article material and particles of a mixture of
maltotetraose and polydextrose as particles containing a material
having higher solubility than the article material.
[0084] ABS, Techno ABS 130, available from Techno Polymer Co., Ltd.
and a medium, that is, polyethylene glycol, PEG #20000, available
from Sanyo Chemical Industries, Ltd. were mixed at a ratio of 1:4,
were melted at a temperature of 250.degree. C., and were kneaded,
followed by cooling, washing with water, and drying, whereby the
ABS particles were obtained. The ABS particles had an average size
of 50 .mu.m.
[0085] FIG. 3B shows a SEM photograph of the ABS particles.
[0086] The particles of the maltotetraose-polydextrose mixture were
prepared by a spray drying method. In particular, the polydextrose
particles prepared in Example 1 and the maltotetraose particles
prepared in Example 2 were dissolved in water, whereby a solution
was prepared. The solution was dried in such a manner that the
solution was sprayed in a high-temperature atmosphere, whereby the
particles of the maltotetraose-polydextrose mixture were
obtained.
[0087] The particles of the maltotetraose-polydextrose mixture were
measured for dynamic viscoelasticity at different temperatures. The
measurement results are shown in FIG. 6 together with the dynamic
viscoelasticity of the polydextrose particles prepared in Example 1
and the dynamic viscoelasticity of the maltotetraose particles
prepared in Example 2. As is clear from FIG. 6, the relationship
between the temperature and dynamic viscoelasticity of particles of
a mixture of equal parts of maitotetraose and polydextrose is
different from that of the polydextrose particles and that of the
maltotetraose particles. That is, desired dynamic viscoelasticity
can be adjusted at a desired temperature by mixing polydextrose and
maltotetraose.
[0088] Particle layers were formed from the ABS particles and the
particles of the maltotetraose-polydextrose mixture in a manner
shown in FIG. 5A. At a stack temperature of 140.degree. C. 1,000 of
the particle layers were stacked, whereby a structure was obtained.
The structure was immersed in water and maltotetraose and
polydextrose were removed from the structure using a support
portion-removing apparatus shown in FIG. 5C as described in Example
1. A support portion made of maltotetraose and polydextrose could
be removed within 30 minutes without leaving any residue. An
overhanging portion of the three-dimensional shaped article was not
deformed downward as described in Example 1. No cavities or
irregularities due to the foaming of material were observed in the
surface of the three-dimensional shaped article. It was confirmed
that the three-dimensional shaped article could be accurately
prepared.
Example 4
[0089] In this example, a three-dimensional shaped article was
prepared using particles of Lubriwax 103 available from Freund
Corporation as particles containing an article material, a liquid
mainly containing water as fluid for removing a support portion,
and particles of polyethylene glycol as particles having higher
water solubility than the particles containing the article
material. A method similar to that described in Example 1 was used
to prepare the three-dimensional shaped article.
[0090] The Lubriwax 103 particles had an average size of 69
.mu.m.
[0091] The polyethylene glycol particles were obtained in such a
manner that polyethylene glycol, PEG 6000, having an average
molecular weight of 6,000 was mechanically crushed and obtained
particles of the polyethylene glycol were adjusted with a sieve
classifier so as to have an average size of 70 .mu.m. FIG. 2C shows
a SEM photograph of the polyethylene glycol particles.
[0092] Furthermore, the polyethylene glycol particles were measured
for dynamic viscoelasticity at different temperatures. The
measurement results are shown in FIG. 4.
[0093] Particle layers were formed from the Lubriwax 103 particles
and the polyethylene glycol particles in a manner shown in FIG. 5A
using a shaping apparatus shown in FIG. 1. One of the particle
layers was melted, was solidified, and was then measured for
thickness, resulting in that this particle layer had a thickness of
42 .mu.m. At a stack temperature of 69.degree. C., 1,000 of the
particle layers were stacked in total, whereby a stack was
prepared. The stack was immersed in the liquid mainly containing
water and polyethylene glycol was removed from the stack using a
support portion-removing apparatus shown in FIG. 5C. The
relationship between the time taken to remove polyethylene glycol
and the rate of removal of polyethylene glycol is shown by open
squares in FIG. 7. A support portion made of polyethylene glycol
could be removed within 30 minutes without leaving any residue. An
overhanging portion was not deformed downward as described in
Example 1. It was confirmed that the particle layers could be
accurately stacked.
Example 5
[0094] In this example, a three-dimensional shaped article shown in
FIG. 3D was prepared in substantially the same manner as that
described in Example 3 except that the average size of particles
containing an article material and the average size of support
material particles were adjusted to 25 .mu.m.
[0095] Particle layers were formed from the particles containing
the article material and the support material particles in a manner
shown in FIG. 5A using a shaping apparatus shown in FIG. 1. One of
the particle layers was melted, was solidified, and was then
measured for thickness, resulting in that this particle layer had a
thickness of 15 .mu.m. At a stack temperature of 140.degree. C.,
714 of the particle layers were stacked in total, whereby a stack
was prepared. The stack was immersed in water as described in
Example 3, whereby a support portion made of maltotetraose and
polydextrose was removed from the stack. The support portion made
of maltotetraose and polydextrose could be removed within 30
minutes without leaving any residue. An overhanging portion of the
three-dimensional shaped article was not deformed downward as
described in Example 1. No cavities or irregularities due to the
foaming of material were observed in the surface of the
three-dimensional shaped article. It was confirmed that the
three-dimensional shaped article could be accurately prepared.
Example 6
[0096] In this example, a three-dimensional shaped article was
prepared using particles of PEG as particles containing an article
material, hexane as fluid for removing a support portion, and
particles of Lubriwax 103 available from Freund Corporation, as
support material particles.
[0097] After being mechanically crushed, the PEG particles were
adjusted with a sieve classifier so as to have an average size of
70 .mu.m. The Lubriwax 103 particles had an average size of 69
.mu.m.
[0098] Particle layers were formed from the PEG particles and the
Lubriwax 103 particles in a manner shown in FIG. 5A using a shaping
apparatus shown in FIG. 1. One of the particle layers was melted,
was solidified, and was then measured for thickness, resulting in
that this particle layer had a thickness of 42 .mu.m. At a stack
temperature of 69.degree. C., 714 of the particle layers were
stacked in total, whereby a stack was prepared. The stack was
immersed in hexane and a support portion made of Lubriwax 103 was
removed from the stack using a support portion-removing apparatus
shown in FIG. 5C. The support portion made of Lubriwax 103 could be
removed within 30 minutes without leaving any residue. An
overhanging portion of the three-dimensional shaped article was not
deformed downward as described in Example 3. No cavities or
irregularities due to the foaming of material were observed in the
surface of the three-dimensional shaped article. It was confirmed
that the three-dimensional shaped article could be accurately
prepared.
[0099] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
[0100] This application claims the benefit of Japanese Patent
Application No. 2014-045623, filed Mar. 7, 2014, and Japanese
Patent Application No. 2014-045622, filed Mar. 7, 2014, which are
hereby incorporated by reference herein in their entirety.
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