U.S. patent application number 17/106812 was filed with the patent office on 2021-03-18 for method of manufacturing three-dimensional object, liquid set for manufacturing three-dimensional object, device for manufacturing three-dimensional object, and gel object.
The applicant listed for this patent is Hiroshi IWATA, Takashi MATSUMURA, Hiroyuki NAITO, Tatsuya NIIMI, Yoshihiro NORIKANE. Invention is credited to Hiroshi IWATA, Takashi MATSUMURA, Hiroyuki NAITO, Tatsuya NIIMI, Yoshihiro NORIKANE.
Application Number | 20210078243 17/106812 |
Document ID | / |
Family ID | 1000005248307 |
Filed Date | 2021-03-18 |
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United States Patent
Application |
20210078243 |
Kind Code |
A1 |
IWATA; Hiroshi ; et
al. |
March 18, 2021 |
METHOD OF MANUFACTURING THREE-DIMENSIONAL OBJECT, LIQUID SET FOR
MANUFACTURING THREE-DIMENSIONAL OBJECT, DEVICE FOR MANUFACTURING
THREE-DIMENSIONAL OBJECT, AND GEL OBJECT
Abstract
A method of manufacturing a three-dimensional object includes
imparting a first liquid having a first composition including a
solvent and a curable material and a second liquid having a second
composition to form a liquid film, curing the liquid film, and
repeating the imparting and the curing to obtain the
three-dimensional object, wherein the imparting position and the
imparting amount of each of the first liquid and the second liquid
are controlled in such a manner that the liquid film includes
multiple areas where at least one of post-curing compression stress
and post-curing modulus of elasticity is different.
Inventors: |
IWATA; Hiroshi; (Kanagawa,
JP) ; NORIKANE; Yoshihiro; (Kanagawa, JP) ;
MATSUMURA; Takashi; (Kanagawa, JP) ; NIIMI;
Tatsuya; (Kanagawa, JP) ; NAITO; Hiroyuki;
(Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IWATA; Hiroshi
NORIKANE; Yoshihiro
MATSUMURA; Takashi
NIIMI; Tatsuya
NAITO; Hiroyuki |
Kanagawa
Kanagawa
Kanagawa
Kanagawa
Tokyo |
|
JP
JP
JP
JP
JP |
|
|
Family ID: |
1000005248307 |
Appl. No.: |
17/106812 |
Filed: |
November 30, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15194934 |
Jun 28, 2016 |
10882245 |
|
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17106812 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29K 2105/0005 20130101;
B29K 2105/0002 20130101; B33Y 70/00 20141201; B29C 64/129 20170801;
B29C 64/112 20170801; B33Y 30/00 20141201; B33Y 80/00 20141201;
B29K 2105/0073 20130101; B33Y 10/00 20141201; B29C 64/40 20170801;
B33Y 50/02 20141201 |
International
Class: |
B29C 64/112 20060101
B29C064/112; B29C 64/129 20060101 B29C064/129; B29C 64/40 20060101
B29C064/40; B33Y 70/00 20060101 B33Y070/00; B33Y 10/00 20060101
B33Y010/00; B33Y 50/02 20060101 B33Y050/02; B33Y 30/00 20060101
B33Y030/00; B33Y 80/00 20060101 B33Y080/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 6, 2015 |
JP |
2015-135174 |
Jul 22, 2015 |
JP |
2015-145139 |
Jul 22, 2015 |
JP |
2015-145151 |
Nov 26, 2015 |
JP |
2015-231140 |
Mar 28, 2016 |
JP |
2016-063311 |
Claims
1. A method of manufacturing a three-dimensional object comprising:
imparting a first liquid having a first composition including a
solvent and a curable material and a second liquid having a second
composition to form a liquid film; curing the liquid film; and
repeating the imparting and the curing to obtain the
three-dimensional object, wherein an imparting position and an
imparting amount of each of the first liquid and the second liquid
are controlled in such a manner that the liquid film includes
multiple areas where at least one of post-curing compression stress
and post-curing modulus of elasticity is different.
2. The method according to claim 1, wherein the imparting position
of the first liquid matches the imparting position of the second
liquid.
3. The method according to claim 1, wherein the imparting is
conducted utilizing a liquid discharging method.
4. The method according to claim 1, wherein the imparting amount of
the first liquid and the imparting amount of the second liquid are
controlled based on a volume of a droplet or a number of droplets
to be imparted.
5. The method according to claim 1, wherein the second liquid
includes no curable material.
6. The method according to claim 1, wherein the imparting position
and the imparting amount of each of the first liquid and the second
liquid are controlled to further form a support structure to
support the three-dimensional object.
7. A liquid set for manufacturing a three-dimensional object
comprising: a first liquid having a first composition including a
solvent and a curable material; and a second liquid having a second
composition.
8. The liquid set according to claim 7, wherein the solvent
includes water, the curable material includes a polymerizable
monomer, and the first liquid further includes a mineral.
9. The liquid set according to claim 7, wherein the second liquid
includes at least one of a cross-linking agent and a mineral.
10. The liquid set according to claim 7, wherein at least one of
the first liquid and the second liquid includes a polymerization
initiator.
11. The liquid set according to claim 7, wherein the second liquid
includes a different polymerizable monomer from the polymerizable
monomer included in the first liquid.
12. The liquid set according to claim 7, wherein the second liquid
includes a same polymerizable monomer as the polymerizable monomer
included in the first liquid.
13. The liquid set according to claim 7, wherein the second liquid
includes no curable material.
14. The liquid set according to claim 7, further comprising a third
liquid having a third composition.
15. A method of manufacturing a three-dimensional object
comprising: imparting the first liquid and the second liquid of the
liquid set of claim 7 to form a liquid film; and curing the liquid
film.
16. A device for manufacturing a three-dimensional object
comprising: an imparting device to impart the first liquid and the
second liquid of the liquid set of claim 7 to form a liquid film;
and a curing device to cure the liquid film.
17. The device according to claim 16, wherein the curing device
includes an ultraviolet light-emitting diode.
18. The device according to claim 16, further comprising a
smoothing device to smooth the liquid film cured.
19. A gel object comprising: a solvent; and a polymer, wherein at
least one of 80 percent compressive stress-strain and modulus of
elasticity has a continuous gradient.
20. The gel object according to claim 19, wherein 80 percent
compressive stress-strain is 10-10,000 kPa.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of and claims the
benefit of priority to U.S. application Ser. No. 15/194,934, filed
Jun. 28, 2016, which is based on and claims priority pursuant to 35
U.S.C. .sctn. 119 to Japanese Patent Application Nos. 2015-135174,
2015-145139, 2015-145151, 2015-231140, and 2016-063311, filed on
Jul. 6, 2015, Jul. 22, 2015, Jul. 22, 2015, Nov. 26, 2015, and Mar.
28, 2016, respectively, in the Japan Patent Office, the entire
disclosures of which are hereby incorporated by reference
herein.
BACKGROUND
Technical Field
[0002] The present invention relates to a method of manufacturing a
three-dimensional object, a liquid set for manufacturing a
three-dimensional object, a device for manufacturing a
three-dimensional object, and a gel object.
Description of the Related Art
[0003] 3D printing or Additive Manufacturing (AM) is known as a
technology to form a three-dimensional object.
[0004] This technology calculates cross-sections sliced vertical to
lamination direction and forms and laminates respective layers
according to the form of cross-sections to form a three-dimensional
object.
[0005] As the method of manufacturing a three-dimensional object,
for example, a fused deposition molding (FDM) method, an inkjetting
method, a binder jetting method, a material jetting method, a
stereo lithography apparatus (SLA) method, and a selective laser
sintering method are known. Of these, images of photocurable liquid
resins are formed at positions for a three-dimensional object by
the material jetting method and multi-layered to form the
three-dimensional object.
[0006] A device for manufacturing the three-dimensional object is
developed, which laminates forming materials according to the
filling ratio or the mixing ratio indicating the degree of density
of the forming materials and changes the mass by using different
materials depending on areas or parts to form a three-dimensional
object.
SUMMARY
[0007] According to the present invention, provided is an improved
method of manufacturing a three-dimensional object which includes
imparting a first liquid having a first composition including a
solvent and a curable material and a second liquid having a second
composition to form a liquid film, curing the liquid film, and
repeating the imparting and the curing to obtain the
three-dimensional object, wherein the imparting position and the
imparting amount of each of the first liquid and the second liquid
are controlled in such a manner that the liquid film includes
multiple areas where at least one of post-curing compression stress
and post-curing modulus of elasticity is different.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0008] Various other objects, features and attendant advantages of
the present invention will be more fully appreciated as the same
becomes better understood from the detailed description when
considered in connection with the accompanying drawings in which
like reference characters designate like corresponding parts
throughout and wherein:
[0009] FIG. 1 is a schematic diagram illustrating an example of
strength distribution in a three-dimensional object (hydrogel
object) of Example 1 described later containing water as the main
ingredient when changing the mass ratio of the first liquid and the
second liquid in the hydrogel object per layer;
[0010] FIG. 2 is a diagram illustrating a view of the hydrogel
object illustrated in FIG. 1 when the hydrogel object stands on its
side;
[0011] FIG. 3 is a schematic diagram illustrating an example of the
mass ratio distribution of the first liquid and the second liquid
in the hydrogel object (three-dimensional object) of Example 2
described later containing water as the main ingredient;
[0012] FIG. 4 is a schematic diagram illustrating the modulus of
elasticity distribution under 20 percent compression in FIG. 3;
[0013] FIG. 5 is a schematic diagram illustrating an example of the
mass ratio distribution of the first liquid and the second liquid
in the hydrogel object (three-dimensional object) of Example 3
described later containing water as the main ingredient;
[0014] FIG. 6 is a schematic diagram illustrating the modulus of
elasticity distribution under 20 percent compression in FIG. 5;
[0015] FIG. 7 is a schematic diagram illustrating an example of the
mass ratio distribution of the first liquid and the second liquid
in the hydrogel object (three-dimensional object) of Example 4
described later containing water as the main ingredient;
[0016] FIG. 8 is a schematic diagram illustrating the modulus of
elasticity distribution under 20 percent compression in FIG. 7;
[0017] FIG. 9 is a graph illustrating an example of the change of
modulus of elasticity and compression stress when the mass ratio of
the first liquid and the second liquid in the hydrogel object
(three-dimensional object) of Example 5 described later containing
water as the main ingredient is changed;
[0018] FIG. 10 is a graph illustrating an example of the change of
modulus of elasticity and compression stress when the mass ratio of
the first liquid and the second liquid in the hydrogel object
(three-dimensional object) of Example 6 described later containing
water as the main ingredient is changed;
[0019] FIG. 11 is a graph illustrating an example of the change of
modulus of elasticity and compression stress when the mass ratio of
the first liquid and the second liquid in the hydrogel object
(three-dimensional object) of Example 7 described later containing
water as the main ingredient is changed;
[0020] FIG. 12 is a schematic diagram illustrating an example of
the mass ratio distribution of the first liquid and the second
liquid in the hydrogel object (three-dimensional object) of Example
8 described later containing water as the main ingredient;
[0021] FIG. 13 is a schematic diagram illustrating the modulus of
elasticity distribution under 20 percent compression in FIG.
12;
[0022] FIG. 14 is a schematic diagram illustrating an example of
the mass ratio distribution of the first liquid and the second
liquid in the oil object (three-dimensional object) of Example
9;
[0023] FIG. 15 is a schematic diagram illustrating the modulus of
elasticity distribution at 20 percent compression in FIG. 14;
[0024] FIG. 16 is a schematic diagram illustrating an example of
the mass ratio distribution of the first liquid and the second
liquid in the oil gel object (three-dimensional object) of Example
10;
[0025] FIG. 17 is a schematic diagram illustrating the modulus of
elasticity distribution at 20 percent compression in FIG. 16;
[0026] FIG. 18 is a schematic diagram illustrating an example of
the mass ratio distribution of the first liquid and the second
liquid in the hydrogel object (three-dimensional object) of
Comparative Example 1 described later including water as the main
ingredient;
[0027] FIG. 19 is a schematic diagram illustrating the modulus of
elasticity distribution under 20 percent compression in FIG.
18;
[0028] FIG. 20 is a schematic diagram illustrating an example of
the device for manufacturing a three-dimensional object for use in
the method of manufacturing a three-dimensional object according to
an embodiment of the present invention;
[0029] FIG. 21 is a schematic diagram illustrating an example in
which the first liquid and the second liquid according to the
liquid discharging method according to an embodiment of the present
disclosure;
[0030] FIG. 22 is a schematic diagram illustrating an example where
the mass ratio distribution of the first liquid and the second
liquid are changed in the three-dimensional object according to an
embodiment of the present invention;
[0031] FIG. 23 is a schematic diagram illustrating an example of
the device for manufacturing a three-dimensional object for use in
the method of manufacturing a three-dimensional object according to
an embodiment of the present invention;
[0032] FIG. 24 is a schematic diagram illustrating an example of
the device for manufacturing a three-dimensional object for use in
the method of manufacturing a three-dimensional object according to
an embodiment of the present invention;
[0033] FIG. 25 is a schematic diagram illustrating an example of
the device for manufacturing a three-dimensional object for use in
the method of manufacturing a three-dimensional object according to
an embodiment of the present invention;
[0034] FIG. 26 is a diagram illustrating a method of obtaining a
dimension accuracy of a three-dimensional object;
[0035] FIG. 27 is a diagram illustrating a state in which the
three-dimensional object is supported by a support structure;
and
[0036] FIG. 28 is a diagram illustrating a state in which the
three-dimensional object is separated from the support
structure.
[0037] The accompanying drawings are intended to depict example
embodiments of the present invention and should not be interpreted
to limit the scope thereof. The accompanying drawings are not to be
considered as drawn to scale unless explicitly noted.
DESCRIPTION OF THE EMBODIMENTS
[0038] Method of Manufacturing Three-dimensional Object and Device
for Manufacturing Three-dimensional Object
[0039] The method of manufacturing a three-dimensional object of
the present disclosure includes discharging liquid including a
first liquid including a solvent and a curable material and a
second liquid having a different composition (second composition)
from the first composition of the first liquid to form a liquid
film, curing the liquid film to form a cured layer, and repeating
the discharging and the curing to manufacture the three-dimensional
object, wherein the imparting position and the imparting amount of
each of the first liquid and the second liquid are controlled in
such a manner that the liquid film includes multiple areas where at
least one of post-curing compression stress and post-curing modulus
of elasticity is different.
[0040] The method of manufacturing a three-dimensional object of
the present disclosure is based on what the present inventors have
found, which is that forming a liquid film having multiple areas
where at least one of post-curing compression stress and
post-curing modulus of elasticity or a device which simply forms
such a liquid film has not been developed yet.
[0041] The present inventors have found the following:
[0042] Gels have mixed characteristics of liquid and a solid and
include a solvent stably taken inside the three-dimensional network
of organic polymer compounds, etc. These are widely used in the
fields of medicine, medical care, food, agriculture, and industry.
Of these gels, gels having water as the main ingredient of the
solvent (also hereinafter referred to as hydrogel) have biological
compatibility due to high containing ratio of water so that
application thereof to medical care is expected.
[0043] In addition, needs for three-dimensional objects formed of a
gel or a hydrogel having a soft form which can control hardness in
the three-dimensional object are increasing on application to
alternatives (for example, cartilage and hyaline body of eye balls,
etc.) of a biological body.
[0044] However, no method of manufacturing a three-dimensional
object reproducing a complex and fine structure from
three-dimensional data or freely controlling hardness inside the
three-dimensional object is not provided yet in reality.
[0045] To manufacture a three-dimensional object, it is preferable
to use typical inkjet three-dimensional object manufacturing
methods. However, the present inventors have found that it is
extremely difficult to control hardness of the inside of an
obtained three-dimensional object.
[0046] The method of manufacturing a three-dimensional object of
the present disclosure includes a first process of imparting a
first liquid having a first composition including a solvent and a
curable material and a second liquid having a second composition to
form a liquid film and a second process of curing the liquid film,
and repeating the first process and the second process multiple
times to obtain the three-dimensional object, wherein the imparting
position and the imparting amount of each of the first liquid and
the second liquid are controlled in such a manner that the liquid
film includes multiple areas where at least one of post-curing
compression stress and post-curing modulus of elasticity are
different. There is no specific limitation to how many times the
imparting (first process) and the curing (second process) are
repeated. It can be suitably selected to suit to the size and form
of a three-dimensional object to be manufactured.
[0047] With regard to the size of the three-dimensional object, the
average thickness per layer is preferably 10-50 .mu.m. When the
average thickness is 10-50 .mu.m, it is possible to accurately
manufacture a three-dimensional object free of peel-off so that the
layers are piled up as high as the three-dimensional object.
[0048] In the method of manufacturing a three-dimensional object,
the position and the amount of the first liquid and the second
liquid to be imparted are controlled so that a liquid film is
formed which has multiple areas where at least one of post-curing
compression stress and post-curing modulus of elasticity is
continuously different. Therefore, it is possible to efficiently
manufacture a three-dimensional object including areas each having
different compression stress and modulus of elasticity.
[0049] The multiple areas where at least one of post-curing
compression stress and post-curing modulus of elasticity is
continuously different are present in the same liquid film or
across films obtained in the first process. Of these, it is
preferable that the post-curing compression stress and/or
post-curing modulus of elasticity be continuously different in the
same film obtained in the first process.
[0050] With regard to the position and the amount of the first
liquid and the second liquid, there is no specific limitation
thereto and they can be suitably selected to suit to a particular
application if they are different in a single film or across
films.
[0051] In addition, it is also preferable that the method of
manufacturing a three-dimensional object include an embodiment
including a liquid imparting process to impart the first liquid and
the second liquid in the liquid set for manufacturing a
three-dimensional object described later and a film curing process
to cure the imparted film.
[0052] Each process in the method of manufacturing a
three-dimensional object is described in detail.
[0053] First Process and First Device
[0054] The first process (liquid imparting process) includes
imparting the first liquid containing a solvent and a curable
material and the second liquid having different composition from
that of the first liquid to a single area.
[0055] The first process is suitably conducted by a liquid
imparting device to impart the first liquid and the second
liquid.
[0056] There is no specific limitation to the method of imparting
the first liquid and the second liquid as long as liquid droplets
are applied to a target area with an appropriate precision. The
method can be suitably selected to suit to a particular
application. For example, a liquid discharging method is suitable.
For example, the liquid discharging method includes a dispenser
method, a spray method, or an inkjet method. Known devices are used
to conduct these methods.
[0057] Of these, the dispenser method is excellent liquid
quantitative property but the application area is small. The spray
method is capable of simply forming a fine discharging material,
has a wide application area, and demonstrates excellent
applicability but the quantitative property thereof is poor so that
powder scatters due to the spray stream. The inkjet method has a
good quantitative property in comparison with the spray method and
a wider application area in comparison with the dispenser method.
Accordingly, the inkjet method is capable of accurately and
efficiently forming a complex object. For this reason, in the
present disclosure, using the inkjet method is preferable.
[0058] When the liquid discharging method is used, it is preferable
to have a nozzle capable of discharging the first liquid and the
second liquid. As for the nozzle, nozzles in a known inkjet printer
can be suitably used. In addition, it is possible to use, for
example, MH5420/5440 (manufactured by Ricoh Industry Company,
Ltd.). It is preferable to use the inkjet printer because the head
portion can drip a large amount of the liquid at once and the
application area is large, which leads to high application
performance.
[0059] First Liquid
[0060] The first liquid includes a solvent, a curable material, and
other optional ingredients.
[0061] The first liquid has a different composition from the second
liquid.
[0062] Solvent
[0063] Specific examples of the solvent include, but are not
limited to, water, alcohol, ketone, ether, ester, and hydrocarbons.
These can be used alone or in combination.
[0064] Specific examples of alcohol include, but are not limited
to, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol,
2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol,
1-hexanol, 1-octanol, 2-ethyl-1-hexanol, allyl alcohol, benzyl
alcohol, cyclohexanol, 1,2-ethane diol, 1,2-propane diol, 2-methoxy
ethanol, 2-ethoxy ethanol, 2-propoxy ethanol,
2-(methoxyethoxy)ethanol, 1-methoxy-2-propanol, dipropylene glycol
monomethylether, diacetone alcohol, ethyl carbitol, and butyl
carbitol. These can be used alone or in combination.
[0065] Specific examples of the ketone include, but are not limited
to, acetone, methyl ethyl ketone, 2-pentanone, 3-pentanonoe,
2-hexanone, methyl isobutyl ketone, 2-heptanone, 4-heptanone,
diisobutylketone, and cyclohexanone. These can be used alone or in
combination.
[0066] Specific examples of the ether include, but are not limited
to, diethylether, dipropylether, diisopropylether, dibutylether,
1,4-dioxane, tetrahydrofuran, and 1,2-diethoxyethane. These can be
used alone or in combination.
[0067] Specific examples of the ester include, but are not limited
to, methyl acetate, ethyl formate, propyl formate, ethyl formate,
propyl acetate, butyl acetate, ethylene glycol monoethylether
acetate, ethylene glycol monobutylether acetate,
hydroxyethylmethacrylate, hydroxyethyl acrylate,
.gamma.-butylolactone, methyl methacrylate, isobutyl acrylate,
cyclohexyl acrylate, 2-ethoxyethyl acrylate, trifluoroethyl
acrylate, and glycidyl methacrylate. These can be used alone or in
combination.
[0068] Specific examples of the hydrocarbon include, but are not
limited to, n-hexane, cyclohexane, benzene, toluene, xylene,
solvent naphtha, styrene, and halogen hydrocarbon such as
dichloromethane and trichloroethylene. These can be used alone or
in combination.
[0069] Of these, water and toluene are preferable.
[0070] Curable Materials
[0071] There is no specific limitation to the curable material and
a suitable curable material is selected to suit to a particular
application. For example, compounds having a photopolymerizable
functional group is preferable and polymerizable monomers are more
preferable.
[0072] There is no specific limitation to the polymerizable
monomer. It can be selected to suit to a particular application.
Compounds including an ethylenic unsaturated group curable by a
photopolymerization initiator producing a radical such as a
(meth)acryloyl group, a vinyl group, and an allyl group and
compounds having a cyclic ether group curable by a photoacid
generator producing an acid such as an epoxy group are preferable.
In terms of curing property, compounds including an ethylenic
unsaturated group are more preferable.
[0073] Examples of the compound including an ethylenic unsaturated
group are compounds having (meth)acrylamide group, (meth)acrylate
compounds, compounds having a (meth)acryloyl group, compounds
having a vinyl group, and compounds having an allyl group.
[0074] As the polymerizable monomer, for example, monovalent
polymerizable monomers and polyfuncitonal polymerizable monomers
are suitable. These can be used alone or in combination.
[0075] Monovalent Polymerizable Monomer
[0076] Specific examples of the monovalent polymerizable monomer
include, but are not limited to, acrylamide, N-substituted
acrylamide derivatives, N,N-di-substituted acrylamide derivatives,
N-substituted methacrylamide derivatives, N--N-di-substituted
methacrylamide derivatives, 2-ethylhexyl(meth)acrylate (EHA),
2-hydroxyethyl(meth)acrylate (HEA), 2-hydroxypropyl(meth)acrylate
(HPA), caprolactone-modified tetrahydrofurfuryl(meta)acrylate,
isobonyl(meth)acrylate, 3-methoxybutyl(meth)acrylate, tetrahydro
furfuryl(meth)acrylate, lauryl(meth)acrylate, 2-phenoxyethyl
(meth)acrylate, isodecyl(meth)acrylate, isooctyl(meth)acrylate,
tridecyl(meth)acrylate, caprolactone(meth)acrylate, and ethoxyfied
nonylphenol(meth)acrylate.
[0077] These can be used alone or in combination. Of these,
acrylamide, N,N-dimethylacrylamide, N-isopropylacrylamide, and
acryloyl morpholine are preferable.
[0078] Organic polymers can be obtained by polymerizing the
mono-valent polymerizable monomer.
[0079] The proportion of the mono-valent polymerizable monomer is
0.5-20 percent by mass to the total amount of the first liquid.
[0080] Polyfunctional Polymerizable Monomer
[0081] Furthermore, the polyfuncitonal polymerizable monomer
includes a bi-functional polymerizable monomer and a tri- or higher
functional polymerizable monomer. These can be used alone or in
combination.
[0082] Specific examples of the bi-functional monomer include, but
are not limited to, tripropylene glycol di(meth)acrylate, tri
ethylene glycol di(meth)acrylate, tetraethyl ene glycol
di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl
glycol hydroxy pivalic acid ester di(meth)acrylate (MANDA),
hydroxypivalic acid neopentyl glycol ester di(meth)acrylate
(HPNDA), 1,3-butanediol di(meth)acrylate (BGDA), 1,4-butanediol
di(meth)acrylate (BUDA), 1,6-hexanediol di(meth)acrylate (HDDA),
1,9-nonane diol(meth)acrylate, diethylene glycol di(meth)acrylate
(DEGDA), neopentyl glycol di(meth)acrylate (NPGDA), tripropylene
glycol di(meth)acrylate (TPGDA), caprolactone-modified hydroxy
pivalic acid neopentyl glycol ester di(meth)acrylate, propoxinated
neopentyl glycol di(meth)acrylate, ethoxy-modified bisphenol A
di(meth)acrylate, polyethylene glycol 200 di(meth)acrylate,
polyethylene glycol 400 di(meth)acrylate, and methylenebis
acrylamide. These can be used alone or in combination.
[0083] Specific examples of the tri- or higher functional
polymerizable monomers include, but are not limited to, trimethylol
propane tri(meth)acrylate (TMPTA), pentaerythritol
tri(meth)acrylate (PETA), dipentaerythritol hexa(meth)acrylate
(DPHA), tirallyl isocyanate, .epsilon.-caprolactone modified
dipentaerythritol (meth)acrylate, tris(2-hydroxyethyl)isocyanulate,
ethoxified trimethylol propane tri(meth)acrylate, propoxified
trimethylol propane tri(meth)acrylate, propoxified glyceryl
tri(meth)acrylate, pentaerythritol tetra(meth)acrylate,
dipentaerythritol tetra(meth)acrylate, pentaerythritol
tetra(meth)acrylate, dipentaerythritol hydroxypenta(meth)acrylate,
ditrimethylol propane tetra(meth)acrylate,
ethoxified(pentaerythritol) tetra(meth)acrylate, and
penta(meth)acrylate ester.
[0084] These can be used alone or in combination.
[0085] The proportion of the polyfunctional polymerizable monomer
is 0.01-10 mol percent to the total amount of the mono-functional
monomer in the first liquid. When the proportion is 0.01-10 mol
percent, gel compression stress is easily adjusted.
[0086] When the three-dimensional object is an internal organ
model, the three-dimensional object is preferably a soft
three-dimensional object of a hydrogel object containing water as
the main ingredient.
[0087] As the soft three-dimensional object, an organic-inorganic
hydrogel is preferable which contains water and an ingredient
dissoluble in the water in a three-dimensional network structure
formed by complexing a water-soluble organic polymer and a
dispersion of a laminate clay mineral.
[0088] In this case, the first liquid preferably includes water and
hygrogel precursor. The first liquid containing water and the
hygrogel precursor is also referred to as "material for soft shape
forming object".
[0089] Water
[0090] As the water, deionized water, ultrafiltered water, reverse
osmosis water, pure water such as distilled water, and ultra pure
water are suitable.
[0091] It is suitable to dissolve or disperse other ingredients
such as organic solvents in the water to impart moisturizing
property, antibiotic property, and conductivity and adjust
compression stress and modulus of elasticity.
[0092] Property of Hydrogel Precursor
[0093] The hygrogel precursor contains a mineral, a polymerizable
monomer, and optional other ingredients.
[0094] Mineral
[0095] The mineral has no specific limitation and is suitably
selected to suit to a particular application. For example, minerals
dispersible in water are suitable.
[0096] An example of the mineral dispersible in water is a
dispersion of a laminated clay mineral.
[0097] The dispersion of the laminated clay mineral is uniformly
dispersible in water at the level of primary crystal.
[0098] Specific examples thereof include, but are not limited to,
water swellable smectite and water swellable mica. More specific
examples include, but are not limited to, water swellable hectorite
containing sodium as ion between layers, water swellable
montmorillonite, water swellable saponite, and water swellable
synthesized mica. These can be used alone or in combination. Also,
these can be appropriately synthesized or available on the
market.
[0099] Specific examples of the product available on the market
include, but are not limited to, synthesized hectorite (laponite
XLG, manufactured by RockWood), SWN (manufactured by Coop Chemical
Ltd.), and fluorinated hectorite SWF (manufactured Coop Chemical
Ltd.).
[0100] There is no specific limitation to the proportion of the
mineral and it can be suitably selected to suit to a particular
application. It is preferably 1-40 part by mass to the total
content of the first liquid.
[0101] Polymerizable Monomer
[0102] As the polymerizable monomer in the hydrogel precursor, it
is possible to use the same polymerizable monomer as the curable
material in the first liquid.
[0103] The polymerizable monomer is polymerized to become an
organic polymer.
[0104] As the organic polymer, water soluble organic polymers are
preferable in terms of usage of hydrogel precursor.
[0105] As the water-soluble organic polymer, water-soluble organic
polymers having, for example, an amide group, an amino group, a
hydroxyl group, a tetramethyl ammonium group, a silanol group, an
epoxy group, etc. are suitable.
[0106] The water soluble organic polymers having an amide group, an
amino group, a hydroxyl group, a tetramethyl ammonium group, a
silanol group, an epoxy group, etc. are advantageous to maintain
the strength of a hydrogel.
[0107] The volume of the droplet of the first liquid has no
particular limitation and can be suitably selected to suit to a
particular application. For example, the volume is preferably 2-60
pL and more preferably 15-30 pL. When the volume of the droplet of
the first liquid is 2 pL or greater, the discharging stability is
improved. When the volume is 60 pL or less, filling a discharging
nozzle for forming (shape-forming) with liquid is easy.
[0108] There is no specific limitation to the amount (percent by
mass) of the first liquid in the liquid film formed in the first
process. It can be selected to suit to a particular application.
The amount is controlled based on the imparting amount of the first
liquid.
[0109] The imparting amount of the first liquid is calculated by
multiplying the volume of the liquid droplet of the first liquid by
the number of droplets in the first liquid.
[0110] Other Ingredients
[0111] The other optional ingredients in the first liquid have no
particular limit. For example, stabilizers, surface treatment
chemicals, polymerization initiators, coloring materials, viscosity
modifiers, drying retarders, adhesion imparting agents,
antioxidants, anti-aging agents, cross-linking promoters,
ultraviolet absorbents, plasticizers, preservatives, dispersants,
and polymerization promoters.
[0112] Stabilizer
[0113] Stabilizers are used to disperse and stabilize the mineral
to keep a sol state.
[0114] In addition, stabilizers are also optionally used to
stabilize properties of the liquid in the liquid discharging
method.
[0115] As the stabilizer, for example, highly concentrated
phosphates, glycols, and non-union surfactants are suitable.
[0116] The non-union surfactants can be synthesized or products
available on the market are also usable. A specific example of the
product is LS106 (Kao Corporation).
[0117] Surface Treatment Chemical
[0118] Specific examples of the surface treatment chemical include,
but are not limited to, polyester resins, polyvinyl acetate resins,
silicone resins, coumarone resins, esters of aliphatic acids,
glyceride, and wax.
[0119] Polymerization Initiator
[0120] Examples of the polymerization initiator are thermal
polymerization initiators and photopolymerization initiators. Of
these, in terms of storage stability, photopolymerization
initiators are preferable because it produces a radical or a cation
at irradiation of an active energy ray.
[0121] As the photopolymerization initiator, any material can be
used which produces a radical at irradiation of light (ultraviolet
having in a wavelength range of 220-400 nm).
[0122] Specific examples of the photopolymerization initiator
include, but are not limited to, acetophenone, 2,2-di
ethoxyacetophenone, p-dimethylaminoacetone, benzophenone,
2-chlorobenzophenone, p,p'-dichlorobenzophenone, p,p-bi
sdiethylamonobenzophenoen, Michler's Ketone, benzyl, benzoin,
benzoin methylether, benzoin ethylether, benzoin isopropylether,
benzoin-n-propylether, benzoin isobutylether, benzoin-n-butylether,
benzyl methyl ketal, thioxanthone, 2-chlorothioxanthone,
2-hydroxy-2-methyl-1-phenyl-1-one,
1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one,
methylbenzoyl formate, 1-hydroxy cyclohexyl phenylketone,
azobisisobutylo nitrile, benzoylperoxide, and
di-tert-butylperoxide. These can be used alone or in
combination.
[0123] The photopolymerization initiator is available on the
market. A specific example thereof is Irgacure 184 (manufactured by
BASF).
[0124] The thermal polymerization initiator has no particular
limitation and can be suitably selected to suit to a particular
application. Examples thereof are azo-based initiators, peroxides
initiators, persulfate initiators, and oxidation-reduction
initiators. These can be used alone or in combination.
[0125] Specific example of the azo-based initiator include, but are
not limited to, VA-044, VA-46B, VA-50, VA-057, VA-061, VA-067,
VA-086, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile)(VAZO 33),
2,2'-azobis(2-amidinopropane)dihydrochloride (VAZO 50),
2,2'-azobis(2,4-dimetaylvaleronitrile) (VAZO 52),
2,2'-azobis(isobutylonitrile) (VAZO 64),
2,2'-azobis-2-methylbutylonitrile) (VAZO 67), and
1,1-azobis(1-cyclohexane carbonitrile) (VAZO 88) (all available
from Dupont Chemical), 2,2'-azobis(2-cyclopropylpropionitrile), and
2,2'-azo-bis(methylisobutylate) (V-601) (all available from Wako
Pure Chemical Industries, Ltd.). These can be used alone or in
combination.
[0126] Specific examples of the peroxide initiator include, but are
not limited to, benzoyl peroxide, acetyl peroxide, lauroyl
peroxide, decanoyl peroxide, dicetyl peroxy dicarbonate,
di(4-t-butylcyclohexyl)peroxy dicarbonate (Perkadox 16S) (available
from Akzo Nobel), di(2-ethylhexyl)peroxy dicarbonate, t-butyl
peroxypivalate (Lupersol 11) (all available from Elf Atochem),
t-butylperoxy-2-ethyl hexanoate (Trigonox 21-050) (available from
Akzo Nobel), and dicumyl peroxide. These can be used alone or in
combination.
[0127] Specific examples of the persulfate initiator include, but
are not limited to, potassium persulfate, sodium persulfate,
ammonium persulfate, and sodium peroxodisulfate. These can be used
alone or in combination.
[0128] Specific examples of oxidation-reduction initiator include,
but are not limited to, a combination of the persulfate initiator
and a reducing agent such as methacid sodium sulfite and acid
sodium sulfite, a system based on the organic peroxide and tertiary
amine (such as a system based on benzoyl peroxide and
dimethylaniline), and a system based on organic hydroperoxide and
transition metal (such as a system based on cumenhydroperoxide and
cobalt naftate). These can be used alone or in combination.
[0129] The photopolymerization initiator is preferably
independently included in the second liquid having a composition
different from that of the first liquid. When the
photopolymerization initiator is not included in the first liquid
but in the second liquid only, storage stability of the first
liquid is improved. Also, in terms of storage storage stability,
additives can be added more than the case in which the
polymerization initiator is used in the first liquid. Therefore,
the polymerization ratio of a three-dimensional object increases,
thereby improving efficiency of manufacturing.
[0130] Like the case of the photopolymerization initiator, the
thermal polymerization initiator is preferably included in the
second liquid in terms of storage stability of the first liquid. It
is preferable to contain a polymerization promoter.
[0131] In addition, the proportion of the photopolymerization
initiator is preferably not greater than 1 percent by mass to the
total content of the liquid set for a three-dimensional object.
When the proportion is not greater than 1 percent by mass,
inhibition of curing reaction can be prevented after the first
liquid and the second liquid are mixed.
[0132] Coloring Agent
[0133] The coloring agent may be included in the first liquid
and/or the second liquid. However, it is preferable that the second
liquid contain the coloring agent.
[0134] The coloring agent are dissolved or stably dispersed in the
second liquid. As the coloring agent, dyes and pigments having
excellent thermal stability are suitable. Of these, solvent dyes
are preferable. Two or more kinds of coloring agents can be mixed
to adjust colors.
[0135] For example, black dyes, magenta dyes, cyan dyes, and yellow
dyes are suitable as the dye.
[0136] Specific examples of the black dyes include, but are not
limited to, MS BLACK VPC (manufactured by Mitsui Chemicals,
Incorporated), AIZEN SOT BLACK-1 and AIZEN SOT BLACK-5 (Both
manufactured by HODOGAYA CHEMICAL CO., LTD.), RESORIN BLACK GSN
200% and RESOLIN BLACK BS (both manufactured by Bayer Holding
Ltd.), KAYASET BLACK A-N (manufactured by Nippon Kayaku Co., Ltd.,
DAIWA BLACK MSC (manufactured by Daiwa Fine Chemicals Co., Ltd.),
HSB-202 (manufactured by Mitsubishi Chemical Corporation), NEPTUNE
BLACK X60 and NEOPEN BLACK X58 (Manufactured by BASF), Oleosol Fast
BLACK RL (manufactured by Taoka Chemical Co., Ltd., Chuo BLACK80
and Chuo BLACK80-15 (manufactured by Chuo synthetic Chemical Co.,
Ltd.).
[0137] Specific examples of the magenta dye include, but are not
limited to, MS Magenta VP, MS Magenta HM-1450, and MS Magenta
Hso-147 (All manufactured by Mitsui Chemicals, Incorporated), AIZEN
SOT Red-1, AIZEN SOT Red-2, AIZEN SOT Red-3, AIZEN SOT Pink-1,
SPIRON Red GEHSPECIAL (all manufactured by HODOGAYA CHEMICAL CO.,
LTD.), RESOLIN Red FB 200%, MACROLEX Red Violet R, MACROLEX ROT 5B
(all manufactured by Bayer Holding Ltd.), KAYASET ReD B, KAYASET
Red 130, and KAYASET ReD 802 (Manufactured by Nippon Kayaku Co.,
Ltd.), PHLOXIN, ROSE BENGAL, and ACID Red (all manufactured by
Daiwa Fine Chemicals Co., Ltd.), HSR-31 AND DIARESIN RedK (both
manufactured by Mitsubishi Chemical Corporation), Oil Red
(manufactured by BASF), and Oil Pink330 (manufactured by Chuo
synthetic Chemical Co., Ltd.).
Specific examples of the cyan dye include, but are not limited to,
MS Cyan HM-1238, MS Cyan HSo-16, Cyan Hso-144, and MS Cyan VPG (all
manufactured by Mitsui Chemicals, Incorporated), AIZEN SOT Blue-4
(manufactured by HODOGAYA CHEMICAL CO., LTD.), RESOLIN BR.BLUE BGLN
200%, MACROLEX Blue RR, CERES Blue GN, SIRUS SUPRATURQ.Blue Z-BGL,
and SIRUS SUPRA TURQ.Blue FB-LL330% (all manufactured by Bayer
Holding Ltd.), KAYASET Blue Fr, KAYASET Blue N. KAYASET Blue 814,
Turq.Blue GL-5 200, and LightBlue BGL-5 200 (all manufactured by
Nippon Kayaku Co., Ltd.), DAIWA Blue 7000 and Oleosol Fast Blue GL
(both manufactured by Daiwa Fine Chemicals Co., Ltd.), DIARESINBLUE
P (manufactured by Mitsubishi Chemical Corporation), SUDAN Blue
670, NEOPEN Blue808, and ZAPON Blue 806 (all manufactured by
BASF).
[0138] Specific examples of the yellow dye include, but are not
limited to, MS Yellow HSm-41, Yellow KX-7, and Yellow EX-27
(manufactured by Mitsui Chemicals, Incorporated), AIZEN SOT
Yellow-1, AIZEN SOT Yellow-3, and AIZEN SOT Yellow-6 (all
manufactured by HODOGAYA CHEMICAL CO., LTD.), MACROLEX Yellow 6G,
MACROLEX FLUOR, and Yellow 10GN (all manufactured by Bayer Holding
Ltd.), KAYASET Yellow SF-G, KAYASET Yellow 2G, KAYASET Yellow A-G,
and KAYASET Yellow E-G (all manufactured by Nippon Kayaku Co.,
Ltd.), DAIWA Yellow 330HB (Daiwa Fine Chemicals Co., Ltd.), HSY-68
(Mitsubishi Chemical Corporation), SUDAN Yellow 146 and NEOPEN
Yellow 075 (all manufactured by BASF), and Oil Yellow 129
(manufactured by Chuo synthetic Chemical Co., Ltd.)
[0139] Examples of the pigments include organic pigments and
inorganic pigments. For example, azo pigments (azo lake, insoluble
azo pigments, condensed azo pigments, chelate azo pigments, etc.),
polycyclic pigments (phthalocyanine pigments, perylene pigments,
anthraquinone pigments, quinacridone pigments, di oxazine pigments,
thioindigo pigments, isoindolinone pigments, and quinofuranone
pigments).
[0140] Specific examples of the pigment include, but are not
limited to, the organic pigments and inorganic pigments referenced
by the following number in Color Index.
[0141] Red or Magenta Pigments:
[0142] Pigment Red 3, 5, 19, 22, 31, 38, 43, 48:1, 48:2, 48:3,
48:4, 48:5, 49:1, 53:1, 57:1, 57:2, 58:4, 63:1, 81, 81:1, 81:2,
81:3, 81:4, 88, 104, 108, 112, 122, 123, 144, 146, 149, 166, 168,
169, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257, Pigment
Violet 3, 19, 23, 30, 37, 50, 88, and Pigment Orange 13, 16, 20,
and 36.
[0143] Blue or cyan pigments:
[0144] Pigment Blue 1, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17-1,
22, 27, 28, 29, 36, and 60
[0145] Green pigments:
[0146] Pigment Green 7, 26, 36, and 50.
[0147] Yellow pigments:
[0148] Pigment Yellow 1, 3, 12, 13, 14, 17, 34, 35, 37, 55, 74, 81,
83, 93, 94, 95, 97, 108, 109, 110, 137, 138, 139, 153, 154, 155,
157, 166, 167, 168, 180, 185, and 193.
[0149] Black pigments:
[0150] For example, Pigment Black 7, 26, and 28 are suitable.
[0151] The pigments are available on the market. Specific examples
thereof include, but are not limited to, CHROMOFINE YELLOW 2080,
5900, 5930, AF-1300, 2700L, CHROMOFINE ORANGE 3700L, 6730,
CHROMOFINE SCARLET 6750, CHROMOFINE MAGENTA 6880, 6886, 6891N,
6790, and 6887, CHROMOFINE VIOLET RE, CHROMOFINE RED 6820, 6830,
CHROMOFINE BLUE HS-3, 5187, 5108, 5197, 5085N, SR-5020, 5026, 5050,
4920, 4827, 4837, 4824, 4933GN-EP, 4940, 4973, 5205, 5208, 5214,
5221, 5000P, CHROMOFINE GREEN 2GN, 2G0, 2G-500D, 5310, 5370, 6830,
CHROMOFINE BLACK A-1103, SEIKAFAST Yellow, 10GH, A-3, 2035, 2054,
2200, 2270, 2300, 2400(B), 2500, 2600, ZAY-260, 2700(B), and 2770,
SEIKAFAST RED 8040, C405(F), CA120, LR-116, 1531B, 8060R, 1547,
ZAW-262, 1537B, GY, 4R-4016, 3820, 3891, ZA-215, SEIKAFAST CARMINE
6B1476T-7, 1483LT, 6840, and 3870, SEIKAFAST BORDEAUX 10B-430,
SEIKALIGHT ROSE R40, SEIKALIGHT VIOLET B800, 7805, SEIKAFAST MAROON
460N, SEIKAFAST ORANGE 900, 2900, SEIKALIGHT BLUE C718, A612,
cyanine blue 4933M, 4933GN-EP, 4940, 4973 (all manufactured by
Dainichiseika Color & Chemicals Mfg. Co., Ltd.), KET Yellow
401, 402, 403, 404, 405, 406, 416, 424, KET Orange 501, KET Red
301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 336, 337, 338,
346, KET Blue 101, 102, 103, 104, 105, 106, 111, 118, 124, KET
Green 201 (all manufactured by DIC Corporation), Colortex Yellow
301, 314, 315, 316, P-624, 314, U10GN, U3GN, UNN, UA-414, U263,
Finecol Yellow T-13, T-05, Pigment Yellow1705, Colortex Orange 202,
Colortex Red101, 103, 115, 116, D3B, P-625, 102, H-1024, 105C, UFN,
UCN, UBN, U3BN, URN, UGN, UG276, U456, U457, 105C, USN, Colortex
Maroon601, Colortex BrownB610N, Colortex Violet600, Pigment Red
122, Colortex Blue516, 517, 518, 519, A818, P-908, 510, Colortex
Green402, 403, Colortex Black 702, U905 (all manufactured by Sanyo
Color Works, LTD.), Lionol Yellow 1405G, Lionol Blue FG7330,
FG7350, FG7400G, FG7405G, ES, ESP-S (all manufactured by TOYO INK
CO., LTD.), Toner Magenta E02, Permanent RubinF6B, Toner Yellow HG,
Permanent Yellow GG-02, Hostapeam BlueB2G (all manufactured by
Hoechst AG, carbon black #2600, #2400, #2350, #2200, #1000, #990,
#980, #970, #960, #950, #850, MCF88, #750, #650, MA600, MA7, MA8,
MA11, MA100, MA100R, MA77, #52, #50, #47, #45, #45L, #40, #33, #32,
#30, #25, #20, #10, #5, #44, CF9 (all manufactured by Mitsubishi
Chemical Corporation).
[0152] Viscosity Modifier
[0153] The viscosity modifier is not particularly limited and can
be selected to a suitable application. A specific example thereof
is propylene glycol.
[0154] Drying Retardant
[0155] There is no specific limitation to the drying retardant. It
can be suitably selected to suit to a particular application. A
specific example thereof is glycerin.
[0156] Dispersant
[0157] There is no specific limitation to the dispersant and it can
be suitably selected to suit to a particular application. A
specific example thereof is etidronic acid.
[0158] Polymerization Promoter
[0159] There is no specific limitation to the polymerization
promoter and it can be suitably selected to suit to a particular
application. A specific example thereof is
N,N,N',N'-tetramethylethylene diamine.
[0160] There is no specific limitation to the surface tension of
the first liquid and it can be selected to suit to a particular
application. For example, the surface tension is preferably 20-45
mN/m and more preferably 25-34 mN/m.
[0161] When the surface tension is 20 mN/m or greater, discharging
stability is improved. When the surface tension is 45 mN/m or less,
filling a discharging nozzle for forming (shape-forming) with
liquid is easy.
[0162] The surface tension can be measured by a surface tensiometer
(automatic contact angle DM-701, manufactured by Kyowa Interface
Science Co., LTD.), etc.
[0163] Viscosity of the first liquid has no particular limitation
and can be suitably selected to suit to a particular application.
The temperature can be adjusted. For example, viscosity is 3-20
mPas and more preferably 6-12 mPas at 25 degrees C.
[0164] When the viscosity is 3-20 mPas, discharging stability can
be improved.
[0165] The viscosity can be measured by, for example, a rotation
viscometer (VISCOMATE VM-150 III, manufactured by TOKI SANGYO CO.,
LTD.) in a 25 degrees C. environment.
[0166] Second Liquid
[0167] The second liquid has a composition different from the
composition of the first liquid and has a feature to control the
density of the ingredient contained in the first liquid when
forming a three-dimensional object. That is, in the present
disclosure, the first liquid and the second liquid are imparted to
the same area and mixed to form a liquid film. The density of the
curable material in the liquid film is adjusted by controlling the
imparting position and the amount of the first liquid and the
second liquid.
[0168] The second liquid preferably includes a solvent and other
optional ingredients such as a photopolymerization initiator, a
thermal polymerization initiator, a mineral, and a cross-linking
agent.
[0169] As the solvent, the same as those for the first liquid can
be used.
[0170] The second liquid may further optionally include the same or
different polymerizable monomer as in the first liquid.
[0171] However, when an additive such as a polymerization initiator
is added to the first liquid, it reacts with the curable material
(e.g., polymerizable monomer) in the first liquid, which may cause
deterioration of storage stability. In such a case, if the additive
is added to the second liquid and thereafter the first liquid and
the second liquid are mixed, the effect of the additive such as
polymerization initiator is imparted to the curable material.
Therefore, the second liquid preferably includes no curable
material such as a polymerization monomer.
[0172] Photopolymerization Initiator and Thermal Polymerization
Initiator
[0173] As for the thermal polymerization initiator and the
photopolymerization initiator, the same material as those for the
first liquid can be used.
[0174] Although it is possible to include the thermal
polymerization initiator and the photopolymerization initiator in
the first liquid, it is preferable that the second liquid include
them in terms of storage stability.
[0175] If a thermal polymerization initiator is contained in
addition to a photopolymerization initiator, the thermal
polymerization initiator can promote and complete polymerization
reaction which is not completed by solely the photopolymerization
initiator. In addition, it is preferable to contain a
polymerization promoter.
[0176] When the first liquid includes the thermal polymerization
initiator, the thermal polymerization initiator reacts with the
polymerizable monomer, which degrades storage stability of the
liquid. Therefore, it is preferable that the second liquid
including no polymerizable monomer include a thermal polymerization
initiator.
[0177] Mineral
[0178] As the mineral, the same as those for the first liquid can
be used.
[0179] Cross-linking Agent Specific examples of the cross-linking
agent include, but are not limited to, N,N'methylene bisacrylamide
and polyethylene glycol diacrylate.
[0180] Other Ingredients
[0181] The other optional ingredient has no particular limit and
can be selected to suit to a particular application.
[0182] For example, the same ingredients in the first liquid can be
used.
[0183] There is no specific limitation to the surface tension of
the second liquid and it can be selected to suit to a particular
application. For example, the surface tension is preferably 20-45
mN/m and more preferably 25-34 mN/m.
[0184] When the surface tension is 20 mN/m or greater, discharging
stability is improved. When the surface tension is 45 mN/m or less,
filling a discharging nozzle for forming (shape-forming) with
liquid is easy.
[0185] The surface tension can be measured by a surface tensiometer
(automatic contact angle DM-701, manufactured by Kyowa Interface
Science Co., LTD.), etc.
[0186] Viscosity of the second liquid has no particular limitation
and can be suitably selected to suit to a particular application.
The temperature can be adjusted. For example, the viscosity is 3-20
mPas and more preferably 6-12 mPas at 25 degrees C.
[0187] When the viscosity is 3-20 mPas, discharging stability can
be improved.
[0188] The viscosity can be measured by, for example, a rotation
viscometer (VISCOMATE VM-150 III, manufactured by TOKI SANGYO CO.,
LTD.) in a 25 degrees C. environment.
[0189] The volume of the droplet of the second liquid has no
particular limitation and can be suitably selected to suit to a
particular application. For example, the volume is preferably 2-60
pL and more preferably 15-30 pL. When the volume of the droplet of
the second liquid is 2 pL or greater, the discharging stability is
improved. When the volume is 60 pL or less, filling a discharging
nozzle for forming (shape-forming) with liquid is easy.
[0190] There is no specific limitation to the amount (percent by
mass) of the second liquid in the liquid film formed in the first
process. It can be selected to suit to a particular application.
The amount is controlled based on the imparting amount of the
second liquid.
[0191] The imparting amount of the second liquid is calculated by
multiplying the volume of the liquid droplet of the second liquid
by the number of droplets of the second liquid.
[0192] Viscosity Change Rate
[0193] The viscosity change rate in the first liquid and the second
liquid between the viscosity before storage (initial viscosity) and
the viscosity after the liquid is left undone for two weeks at 50
degrees C. is preferably not greater than 20 percent and more
preferably not greater than 10 percent.
[0194] When the viscosity change rate is not greater than 20
percent, storage stability of the first liquid and the second
liquid is appropriate. For example, discharging stability is good
when the second liquid is imparted by an inkjet method.
[0195] The viscosity change rate between the viscosity before
storage (initial viscosity) and the viscosity (post storage
viscosity) after the liquid is left undone for two weeks at 50
degrees C. can be measured in the following manner.
[0196] Each of the liquid of the first liquid and the second liquid
is placed in a polypropylene bottle (50 mL) and left undone for two
weeks in a constant temperature tank at 50 degrees C. The liquid is
taken out from the tank and left undone until the temperature
thereof lowers to room temperature (25 degrees C.). Thereafter,
viscosity thereof is measured. Each of viscosity of the first
liquid and the second liquid before it is placed in the tank is
determined as pre-storage viscosity and viscosity of each liquid
taken out from the constant temperature tank is determined as
post-storage viscosity. The viscosity change rate is calculated
according to the following relation. The pre-storage viscosity and
the post-storage viscosity can be measured by, for example, an R
type viscometer (manufactured by TOKI SANGYO CO., LTD.) at 25
degree C.
Viscosity change rate (percent)={(post-storage
viscosity)-(pre-storage viscosity)]/(pre-storage
viscosity)}.times.100
[0197] Pre-storage viscosity of the first liquid and the second
liquid is preferably a viscosity of 25 mPas or less at 25 degrees
C., more preferably 3-20 mPas, and particularly preferably 3-10
mPas. When the viscosity is not greater than 25 mPas, discharging
the liquid from an inkjet nozzle is stabilized.
[0198] Post-storage viscosity of the first liquid and the second
liquid is preferably 3-10 mPas at 25 degrees.
[0199] There is no specific limitation to the method of controlling
the imparting position and the imparting amount of the first liquid
and the second liquid. It can be suitably selected to suit to a
particular application. For example, a control method including
changing the volume of a droplet or a control method including
changing the number of droplets is suitable.
[0200] The method of manufacturing a three-dimensional object of
the present disclosure includes mixing the first liquid and the
second liquid to conduct reaction to cure the liquids. Therefore,
since the first liquid include a curable material (for example,
polymerizable monomer), it is preferable that the second liquid
include an additive which reacts with the curable material and
degrades storage stability.
[0201] When a material that lowers storage stability (normally
viscosity substantially increases, causing gelation) due to
reaction with the curable material in the first liquid is added to
the second liquid, the film is gelated immediately after the film
is formed during shape-forming, which contributes to improvement on
the shape-forming accuracy.
[0202] Second Process and Second Device
[0203] In the second process, the liquid film formed in the first
process is cured and the cured film (layer) is laminated, so that a
three-dimensional object having different compression stress and
modulus of elasticity depending on area is manufactured. In the
post-curing film, a structure formed of the curable material is
formed with other ingredients. The second process (liquid film
curing process) is suitably conducted by the following second
device (film curing device).
[0204] As the second device to cure the film, an ultraviolet (UV)
irradiating lamps, electron beam irradiators, etc. are used. The
liquid curing device preferably has a mechanism to remove
ozone.
[0205] The ultraviolet irradiating lamp includes, for example, a
high pressure mercury lamp and an ultra high pressure mercury lamp,
and a metal halide lamp.
[0206] The ultra-high pressure mercury lamp is a point light source
but if the DeepUV type combined with an optical system to have a
high light use efficiency is used, the lamp is capable of emitting
light in a short-wavelength range.
[0207] Since the metal halide has a wide range of wavelength, it is
suitable for colored materials. Halogenated materials of metal such
as Pb, Sn, and Fe are used therefor and can be selected to suit to
absorption spectrum of a photopolymerization initiator. The lamp
for use in curing has no particular limit and can be suitably
selected to suit to a particular application. Lamps available on
the market such as H lamp, D lamp, or V lamp, (manufactured by
Fusion System) can be used.
[0208] In the present disclosure, an ultra violet-light emitting
diode (UV-LED) is preferably used.
[0209] There is no specific limitation to the emitting wavelength
of the LED. In general, wavelengths of 365 nm, 375 nm, 385 nm, 395,
nm and 405 nm are used. Taking into account the impact on the color
of an object, short wavelength irradiation is advantageous to
increase absorption of an initiator.
[0210] Since thermal energy imparted by a UV-LED during curing is
less than that of ultraviolet irradiation lamp (high pressure
mercury lamp, ultra pressure mercury lamp, metal halide lamp) for
general purpose and electron beams, the heat damage to a sample is
reduced.
[0211] In particular, the hydrogels formed in the present
disclosure are present containing water. Therefore, the feature
thereof is demonstrated and the effect is significant.
[0212] Third Process and Third Device
[0213] The third process includes imparting a third liquid having a
third composition forming a hard object to support a
three-dimensional object formed of the curable material cured in
the second process to a site where no first liquid or second liquid
is imparted to form a film. The third process is conducted by the
third device.
[0214] The same device as the first device for use in the device of
manufacturing a three-dimensional object can be the third device to
impart the third liquid.
[0215] Third Liquid
[0216] The third liquid (also referred to as material for hard
object) forms a hard object to support a three-dimensional object.
The third liquid includes a curable material, preferably a
polymerization initiator, and other optional ingredients but no
water or laminate viscous mineral.
[0217] The third liquid preferably has ingredients different from
those of the first liquid and the second liquid.
[0218] The curable material is preferably a compound cured in
polymerization reaction caused by irradiation of active energy ray
(ultraviolet ray, electron beam, etc.), heating, etc. For example,
active energy ray curable compounds and thermally-curable compounds
are suitable.
[0219] The curable material is preferably liquid at 25 degrees
C.
[0220] "To impart to a site where no first liquid or second liquid
is imparted" is that the site of the third liquid does not overlap
the site of the first liquid and the second liquid. However, the
third liquid site may be adjacent to the first liquid site or the
second site.
[0221] The method of imparting the third liquid is not particularly
limited and can be suitably selected to suit to a particular
application. Preferably, droplets formed of the third liquid are
applied to target positions with appropriate precision. For
example, a liquid discharging method is suitable. Examples of the
liquid discharging method are a dispenser method and an inkjet
method.
[0222] The third process and device can be replaced with the
following.
[0223] Using the first liquid and the second liquid for use in the
first process, a structure to support a three-dimensional object is
manufactured in the same manner. This support structure has
significantly different compression stress and modulus of
elasticity from the three-dimensional object to be formed. The
support structure is cured in the second process as in the case
described above. The support structure is removed after the
three-dimensional object is formed.
[0224] Since the support structure supports a three-dimensional
object when forming the three-dimensional object and is removed
thereafter, minimal strength to support the object is enough.
Alternatively, since increasing removability of the support
structure leads to increasing productivity of a three-dimensional
object, it is suitable to form a support structure having low
modulus of elasticity which easily collapses by an external
force.
[0225] In either case, it is suitable to form a support structure
having a different physical properties from a target
three-dimensional object using the first liquid and the second
liquid forming the target three-dimensional object. Simply
speaking, the ratio of the second liquid to the first liquid in the
support structure is significantly changed from the ratio in the
target three-dimensional object in a range where it is possible to
form the support structure.
[0226] Other Optional Process
[0227] There is no specific limitation to the other optional
processes and a suitable process is selected to suit to a
particular application. Specific examples thereof include, but are
not limited to, a peeling-off process, a process of polishing a
three dimensional object, and a process of cleaning the
three-dimensional object.
[0228] In particular, it is desirable to introduce a process of
smoothing the film cured in the third process.
[0229] The formed and cured film in the second process and the
third process do not always have desired thickness in all the
sites.
[0230] In the case of inkjet methods, non-discharging may occur. In
both inkjet/dispenser methods, unevenness between dots may occur.
As a result, a laminate structure obtained may lack precision.
[0231] To compensate this, for example, a film can be smoothed or
mechanically scraped immediately after the film is formed.
Alternatively, the smoothness is detected and the amount of forming
the next film is adjusted to the dot level.
[0232] The hygrogel for use in the present disclosure is relatively
soft because the target object is an internal organ. Therefore,
with regard to smoothing, it is suitable to utilize mechanical
smoothing immediately after a film is formed.
[0233] For example, the method of mechanically smoothing a film can
be conducted by, for example, a member having a blade form or a
roller form.
[0234] FIG. 24 illustrates smoothing members 20 and 21 having a
roller form and FIG. 215 illustrates smoothing members 20 and 21
having a blade form.
[0235] As described above, in the method of manufacturing a
three-dimensional object of the present disclosure, liquid is
discharged and imparted through a fine hole in a liquid discharging
method to form an image film by film. The first liquid and the
second liquid prior to curing are imparted to determined sites in
predetermined amounts to form a liquid film having areas having
locally different post-curing compression stress and/or post-curing
modulus of elasticity. When the ratio of the first liquid and the
second liquid is changed, the mass ratio is easily changed so that
the amount of a cross-linking agent and a polymerizable polymer per
a constant volume can be controlled. For this reason, it is
possible to obtain a three-dimensional object having multiple areas
having different compression stress and modulus of elasticity.
[0236] In a typical method of manufacturing a three-dimensional
object, a single or multiple curable materials are imparted to
different sites to form a three-dimensional object having portions
different compression stress and modulus of elasticity. However, in
such a typical manufacturing method, obtained three-dimensional
objects have only compression stresses and moduli of elasticity
derived from multiple curable materials. As a result, it is not
possible to form a three-dimensional object having continuously
different compression stresses and moduli of elasticity. To the
contrary, in the method of manufacturing a three-dimensional object
of the present disclosure, the first liquid and the second liquid
are imparted to form a liquid film having multiple areas having
different post-curing compression stresses and/or post-curing
moduli of elasticity depending on the ratio of the first liquid and
the second liquid to control the compression stress and the modulus
of elasticity.
[0237] By the method of manufacturing a three-dimensional object of
the present disclosure, complex and fine soft three-dimensional
objects can be simply and efficiently manufactured, which is
suitable for manufacturing internal organ models.
[0238] The method of manufacturing a three-dimensional object and
the device for manufacturing a three-dimensional object are
described below with reference to specific embodiments. The method
of manufacturing a hydrogel three-dimensional object containing
water as the main ingredient is described as a typical example.
[0239] The first liquid (also referred to as liquid "A") is used as
the liquid material composition for a hydrogel object and the
second liquid (also referred to as liquid "B") is used as ink to
dilute the liquid "A" including a polymerization initiator to
manufacture a hydrogel object containing water as the main
ingredient having different compression stresses and moduli of
elasticity depending on areas.
[0240] First, surface data or solid data of three-dimensional form
designed by three dimensional computer-aided design (CAD) or taken
in by a three-dimensional scanner or a digitizer are converted into
Standard Template Library (STL) format, which is thereafter input
into a lamination forming device.
[0241] Next, compression stress distribution of the three
dimensional form is measured. There is no specific limitation to
methods of measuring the compression stress. For example,
three-dimensional compression stress distribution data are obtained
by using MR Elastography (MRE), which are thereafter input into the
lamination forming device. Based on the compression stress data,
the amounts of the liquid "A" and the liquid "B" to be imparted to
sites corresponding to the three-dimensional data are
determined.
[0242] Based on the these input data, the direction of the
three-dimensional form to be formed is determined.
[0243] The direction is not particularly limited. Normally, the
direction is chosen in which the Z direction (height direction) is
the lowest.
[0244] After the direction of the three-dimensional form is
determined, the projected areas in X-Y plane, X-Z plane, and Y-Z
plane of the three-dimensional form are obtained to obtain a block
form thereof. The thus-obtained block form is sliced in the Z
direction with a thickness of a single layer. The thickness of a
single layer changes depending on the material and is preferably,
for example, 20 to 60 .mu.m. When only one three-dimensional object
is manufactured, this block form is arranged to be placed in the
center of the Z stage (i.e., table on which the object lifted down
layer by layer for each layer forming is placed).
[0245] In addition, when a plural of three-dimensional objects are
manufactured at the same time, the block forms are arranged on the
Z stage. Also, the block forms can be piled up. It is possible to
automatically create these block forms, the slice data (contour
line data), and the placement on the Z stage if materials to be
used are determined.
[0246] The next forming process is conducted. Different heads
.alpha. and .beta. (illustrated in FIG. 20) are moved
bi-directionally (direction A and direction B indicated by
respective arrows) and discharge the liquid "A" and the liquid "B"
to a determined area in a determined imparting ratio to form a dot.
The liquid "A" and the liquid "B" are mixed in the dot as
illustrated in FIG. 21 to obtain the pre-determined mass ratio
(liquid "A":liquid "B").
[0247] Moreover, such dots are continuously formed to form a liquid
mixture liquid film of the liquid "A" and the liquid "B" having the
pre-determined mass ratio (liquid "A":liquid "B") in the
pre-determined area. Thereafter, the liquid mixture liquid film is
irradiated with ultraviolet (UV) ray and cured to form a hygrogel
film having the pre-determined ratio (liquid "A":liquid "B") in the
pre-determined area as illustrated in FIG. 20.
[0248] After a single layer of the hygrogel film is formed, the
stage (FIG. 20) is lowered in an amount corresponding to the
thickness of the single layer. Again, the dots are continuously
formed on the hydrogel film to form a liquid mixture liquid film of
the liquid "A" and the liquid "B" having a pre-determined mass
ratio (liquid "A":liquid "B") in a pre-determined area. Thereafter,
the liquid mixture liquid film of the liquid "A" and the liquid "B"
is irradiated with ultraviolet (UV) ray and cured to form a
hygrogel film. These processes are repeated to form a
three-dimensional object as illustrated in FIG. 22.
[0249] The thus-obtained three-dimensional object (hydrogel object)
containing water as the main ingredient has different mass ratios
(liquid "A":liquid "B") depending on the portion in the hydrogel
object as illustrated in FIG. 22. Compression stress and modulus of
elasticity therein can be continuously changed.
[0250] Furthermore, the UV ray irradiator is arranged next to an
inkjet head jetting a hygrogel precursor to save time to be taken
for smoothing treatment, thereby speeding up the manufacturing. If
a UV-LED is used as the UV ray irradiator, it is possible to reduce
thermal energy used to irradiate an object when forming the
object.
[0251] As illustrated in FIGS. 24 and 25, if smoothing members 20,
21, 22, and 23 are provided adjacent to the inkjet head and the UV
ray irradiator 14 and 15, smoothing and controlling the thickness
layer by layer are possible, which is very useful to the
manufacturing in the present disclosure.
[0252] Liquid Set for Manufacturing Three-Dimensional Object
[0253] The liquid set for manufacturing a three-dimensional object
of the present disclosure includes the first liquid, the second
liquid, and other optional ingredients.
[0254] The first liquid preferably includes water as the solvent
and a polymerizable monomer as the curable material, more
preferably a mineral, and furthermore preferably a polymerization
initiator.
[0255] As the polymerizable monomer, the same polymerizable monomer
as in the first liquid in the method of manufacturing a
three-dimensional object can be used.
[0256] The second liquid preferably includes at least one of a
cross-linking agent and a mineral and more preferably a
polymerization initiator.
[0257] As the cross-linking agent, the same cross-linking agent as
in the second liquid in the method of manufacturing a
three-dimensional object can be used.
[0258] As the mineral, the same mineral as in the second liquid in
the method of manufacturing a three-dimensional object can be
used.
[0259] As the polymerization initiator in the first liquid and the
second liquid, the same polymerization initiator as in the second
liquid in the method of manufacturing a three-dimensional object
can be used.
[0260] The liquid set for manufacturing a three-dimensional object
is suitably used to manufacture various three-dimensional objects.
In particular, the liquid set is suitable to manufacture complex
and fine three-dimensional objects such as internal organ
models.
[0261] Hydrogel Object
[0262] The hydrogel object is manufactured by the method of
manufacturing a three-dimensional object of the present disclosure
and at least one of 80 percent compressive stress-strain and
modulus of elasticity has a continuous gradient.
[0263] As 80 percent compressive stress-strain of the hydrogel
object, 10-10,000 kPa is preferable. When the 80 percent
compressive stress-strain is 10 kPa or greater, shape-losing during
forming is prevented. When the 80 percent compressive stress-strain
is 100,000 kPa or less, cracking after forming is prevented. The 80
percent compressive stress-strain can be measured by, for example,
a universal tester (AG-I, manufactured by Shimadzu
Corporation).
[0264] The hydrogel object is preferably biocompatible in terms of
application to the medical field, more preferably contains water as
the main ingredient, and particularly preferably has different
compression stresses and moduli of elasticity depending on the area
therein.
[0265] "At least one of 80 percent compressive stress-strain and
modulus of elasticity has continuous gradients" is that the 80
percent compressive stress-strain and the modulus of elasticity are
controlled for each area in the hydrogel object and at least one of
the 80 percent compressive stress-strain and the modulus of
elasticity constantly increases or decreases in multiple areas.
[0266] Having generally described preferred embodiments of this
invention, further understanding can be obtained by reference to
certain specific examples which are provided herein for the purpose
of illustration only and are not intended to be limiting. In the
descriptions in the following examples, the numbers represent
weight ratios in parts, unless otherwise specified.
EXAMPLES
[0267] Next, the present disclosure is described in detail with
reference to Examples but is not limited thereto.
Manufacturing Example 1 of First Liquid and Second Liquid
[0268] Preparation of Liquid A
[0269] Pure water was prepared by evacuating deionized water for 30
minutes.
[0270] While stirring 60 percent by mass of pure water, 6 percent
by mass of synthesized hectorite (laponite XLG, manufactured by
RockWood) having a composition of
[Mg.sub.5.34Li.sub.0.66Si.sub.8O.sub.20(OH).sub.4]Na.sup.-.sub.-0.66
as laminate clay mineral was slowly added to the pure water
followed by stirring to prepare a first liquid dispersion. Next,
0.3 percent by mass of etidronic acid (manufactured by Tokyo
Chemical Industry Co. Ltd.) as the dispersant for the synthesized
hectorite was added to the first liquid dispersion to obtain a
second liquid dispersion.
[0271] Next, to the second liquid dispersion, 22 percent by mass of
acryloyl morpholine (ACMO, manufactured by KJ Chemicals
Corporation) from which a polymerization inhibitor was removed by
passing through active alumina column was added as the curable
material.
[0272] Furthermore, 0.2 percent by mass of N,N'-methylene
bisacrylamide (MBAA, manufactured by Tokyo Chemical Industry Co.
Ltd.) was added as a cross-linking agent. 10.2 percent by mass of
glycerin (manufactured by Sakamoto Yakuhin kogyo Co., Ltd.) as a
drying retardant and 0.3 percent by mass of LS106 (manufactured by
Kao Corporation) as a surfactant were admixed.
[0273] Next, after 0.4 percent by mass of a photopolymerization
promotor {N,N,N',N'-tetramethylethylene dimaine (TEMED,
manufactured by Tokyo Chemical Industry Co. Ltd.)} was added and
0.6 percent by mass of photopolymerization initiator {4 percent by
mass of Irgacure 184 (manufactured by BASF) and 96 percent by mass
of methanol} were admixed and stirred. Subsequent to the stirring
and mixing, the resultant was evacuated for ten minutes.
Subsequently, impurities were removed by filtration to obtain a
uniform liquid A.
[0274] Surface tension and viscosity of the thus-obtained liquid A
were measured in the following manner. The surface tension was 30.0
mN/m and the viscosity was 6.5 mPAs at 25 degrees C.
[0275] Measuring of Surface Tension
[0276] The surface tension of the thus-obtained liquid A was
measured by a surface tensiometer (automatic contact angle meter
DM701, manufactured by Kyowa Interface Science Co., LTD.) according
to hanging drop method.
[0277] Measuring of Viscosity
[0278] The viscosity of the liquid A was measured by a rotation
viscometer (VISCOMATE VM-150 III, manufactured by TOKI SANGYO CO.,
LTD.) in a 25 degrees C. environment.
Manufacturing Examples 2 to 9 of First Liquid and Second Liquid
[0279] Preparation of Liquid B to Liquid I
[0280] Liquid B to Liquid I were obtained in the same manner as in
Manufacturing Example 1 of the first liquid and the second liquid
except that the compositions and the amounts were changed as shown
in Table 1.
[0281] Surface tension and viscosity of the thus-obtained liquid B
to liquid I were measured in the same manner as in Manufacturing
Example 1 of the first liquid and the second liquid.
[0282] The compositions and the properties of Liquid A to Liquid I
were shown in Table 1.
TABLE-US-00001 TABLE 1 First liquid and second liquid A B C D E F G
H I Solvent Pure water 60 87.2 60.2 60 60 66.3 -- -- -- Toluene --
-- -- -- -- -- 60 85 82.6 Viscosity Propylene -- -- -- -- -- -- 8.8
15 15 modifier alcohol Drying retardant Glycerin 10.2 10.2 10.2
10.2 10.2 10.2 -- -- -- Surfactant LS106 0.3 0.3 0.3 0.3 0.3 0.3 --
-- -- Dispersant etidronic acid 0.3 0.3 0.3 0.3 0.3 0.3 -- -- --
Polymeri- Photopolymerization 0.6 -- 0.6 0.6 0.6 0.6 0.6 -- --
zation initiator initiator liquid Thermal -- 2 -- -- -- -- -- -- --
polymerization initiator liquid 1 Thermal -- -- -- -- -- -- -- -- 2
polymerization initiator liquid 2 Polymeri- N,N,N',N'- 0.4 -- 0.4
0.4 0.4 0.4 0.4 -- 0.4 zation tetramethyl promoter ethylnene
diamine Mineral Laponite 6 -- 6 6 6 -- -- -- -- Curable Acryloyl 22
-- 22 22 -- 22 30 -- -- material morpholine N,N-dimethyl -- -- --
-- 22 -- -- -- -- acrylamide Organic N,N'-methylene 0.2 -- -- 0.2
0.2 0.2 0.2 -- -- cross- bisacrylamide linking agent Total (percent
by mass) 100 100 100 100 100 100 100 100 100 Viscosity (mPa s) 6.5
4.8 6.5 6.8 6.5 4.6 7.8 6.2 6.3 Surface tension (mN/m) 30.0 29.8
29.9 30.1 30.0 30.0 29.8 29.3 29.3
[0283] In Table 1, the product name and the manufacturing company
of the ingredients are as follows: [0284] Toluene: solvent
(manufactured by Wako Pure Chemical Industries, Ltd.) [0285]
Propyleneglycol: viscosity modifier (manufactured by Wako Pure
Chemical Industries, Ltd.) [0286] Glycerin: drying retardant
(manufactured by Sakamoto Yakuhin kogyo Co., Ltd.) [0287] LS106:
surfactant (manufactured by Kao Corporation) [0288] Etidronic acid:
dispersant (manufactured by Tokyo Chemical Industry Co. Ltd.)
[0289] Photopolymerization initiator: 4 percent by mass Irgacure
184 (manufactured by BASF) and 96 percent by mass methanol [0290]
Thermal polymerization initiator 1: 2 percent by mass peroxo sodium
pyrosulfate and 98 percent by mass pure water [0291] Thermal
polymerization initiator 2: 2,2'-azobis(2,4-dimethylvaloronitrile)
[0292] Laponite XLG: (laminate clay mineral, manufactured by
Rockwood) [0293] Acryloylmorpholine (ACMO): manufactured by KJ
Chemicals Corporation [0294] N, N-dimethylacrylamide (DMAA),
manufactured by KJ Chemicals Corporation [0295] N, N'-methylene
bisacrylamide (MBAA): manufactured by Tokyo Chemical Industry Co.
Ltd. [0296] N, N, N',N'-tetramethylethylene dimaine
(TEMED)--polymerization promoter (manufactured by Tokyo Chemical
Industry Co. Ltd.)
Example 1
[0297] Liquid A was used as the first liquid and Liquid B was used
as the second liquid.
[0298] A three-dimensional object as hydrogel object containing
water as the main ingredient as illustrated in FIG. 1 was obtained
by conducting the following process 1 to process 4 using the liquid
A and the liquid B.
[0299] 1. The liquid A and the liquid B were mixed with a mass
ratio of 2:1 (liquid A:liquid B) and poured in a mold having a
dimension of 30 mm (depth).times.30 mm (width).times.8 mm (height)
until the height of the mixture reached 2 mm, that is, 7.2 cube
centi-meter. The mixture was left undone for 6 hours at 27 degrees
C. to manufacture the first layer of a hydrogel.
[0300] 2. Next, the liquid A and the liquid B were mixed with a
mass ratio of 1:1 (liquid A:liquid B) and 7.2 cube centi-meter
thereof was poured on the first layer in the mold having a
dimension of 30 mm (depth).times.30 mm (width).times.8 mm (height).
The mixture was left undone for 6 hours at 27 degrees C. to
manufacture a second layer.
[0301] 3. Next, the liquid A and the liquid B were mixed with a
mass ratio of 1:2 (liquid A:liquid B) and 7.2 cube centi-meter
thereof was poured on the second layer in the mold having a
dimension of 30 mm (depth).times.30 mm (width).times.8 mm (height).
The mixture was left undone for 6 hours at 27 degrees C. to
manufacture a third layer.
[0302] 4. Finally, the liquid A and the liquid B were mixed with a
mass ratio of 1:3 (liquid A:liquid B) and 7.2 cube centi-meter
thereof was poured on the second layer in the mold having a
dimension of 30 mm (depth).times.30 mm (width).times.8 mm (height).
The mixture was left undone for 12 hours at 27 degrees C. to
manufacture a fourth layer to obtain a three-dimensional object
(hydrogel object) containing water as the main ingredient.
[0303] The structure of the thus-obtained hygrogel is schematically
shown in Table 1.
[0304] To measure modulus of elasticity of each layer of the
three-dimensional object (hydrogel object) containing water of the
thus-obtained four-layer structure as the main ingredient, the
three-dimensional object containing water as the main ingredient
was placed on the side as illustrated in FIG. 2 and cylindrical
metal having a diameter of 1 mm was pressed into the hydrogel
object containing water as the main ingredient from above using a
compression tester. The stress was measured at three points N1, N2,
and N3 for each layer by the compression tester. Thus, the modulus
of elasticity under 20 percent compression was measured for each
layer. The results are shown in Table 2.
TABLE-US-00002 TABLE 2 Mass ratio 20 percent modulus of elasticity
(MPa) Layer number (A:B) N1 N2 N3 1 2:1 0.26 0.24 0.26 2 1:1 0.10
0.09 0.09 3 1:2 0.03 0.03 0.03 4 1:3 0.01 0.01 0.01
[0305] As seen in the results of Table 2, when the mass ratio of
the liquid A and the liquid B is changed for each layer, each layer
is found to have a different modulus of elasticity.
[0306] The degree of modulus of elasticity is shown by shading. As
the modulus of elasticity increases, the density (shade)
increases.
[0307] When a hydrogel layer was overlaid while changing the mass
ratio (liquid A:liquid B) of the liquid A and the liquid B in the
mold as illustrated in FIG. 1, a three-dimensional object (hygrogel
object) containing water as the main ingredient free of layer
peeling off was obtained. Furthermore, when the modulus of
elasticity was measured as illustrated in FIG. 2, it was found that
a hydrogel object containing water as the main ingredient which had
multiple areas having different values of modulus of elasticity as
shown in Table 2 was obtained.
Example 2
[0308] The liquid A (forming liquid) was used as the first liquid
and the liquid B (diluting liquid) was used as the second
liquid.
[0309] The inkjet heads (MH5420, manufactured by Ricoh Industry
Company, Ltd.) were filled with the liquid A and the liquid B and
discharged them in 300 dpi.times.300 dpi. The volume of droplets
discharged was controlled to change the mass ratio (liquid A:liquid
B) as illustrated in FIG. 3 to obtain a three-dimensional object
(hydrogel object) containing water as the main ingredient. FIG. 3
is a diagram illustrating the mixing ratio distribution in which
the volume of the droplets of the liquid A and the liquid B in a
single area in the three-dimensional object (hydrogel object)
containing water as the main ingredient.
[0310] To be specific, four heads were used for the first liquid
and another four was used for the second liquid to discharge the
liquid A and the liquid B. The total amount of the liquid imparted
on the single area was controlled to be 144 pL.
[0311] For example, the liquid volume was changed in such a manner
that the ratio of the volume of a droplet of the liquid A and the
volume of a droplet of the liquid B was 24 pL:120 pL, 48 pL:96 pL,
and 72 pL:72 pL to form a film including a hydrogel. Thereafter,
the film was cured by light emitted by an ultraviolet ray irradiaor
(SPOT CURE SP5-250DB, manufactured by USHIO INC.) in a light amount
of 350 mJ/cm.sup.2. A hundred layers were formed in the same manner
and cured to manufacture a three-dimensional object (hydrogel
object) containing water as the main ingredient. Thus, a hydrogel
object containing water as the main ingredient with a dimension of
20 mm (depth).times.20 mm (width).times.2 mm (height) free of layer
peel-off was obtained.
[0312] The modulus of elasticity under 20 percent compression of
the hydrogel object containing water as the main ingredient was
measured. The modulus of elasticity was measured by using a
universal tester (AG-I, manufactured by Shimadzu Corporation), a
load cell 1 kN, and compression jig for 1 kN while pressing
cylindrical metal having a diameter of 1 mm into the hydrogel
object containing water as the main ingredient. The stress against
the compression applied to the load cell was recorded in a computer
and the stress against displacement was plotted to measure the
modulus of elasticity. In addition, the pressed-in area was an area
(x,y) of the hydrogel object containing water as the main
ingredient and the modulus of elasticity was measured for each area
of 2 mm.times.2 mm while changing both x and y from 0 to 20 in FIG.
3.
[0313] The measuring results of modulus of elasticity are shown in
Table 3 and FIG. 4. FIG. 4 is a diagram illustrating the values of
modulus of elasticity for each area of 2 mm.times.2 mm in the
hydrogel object containing water as the main ingredient illustrated
in FIG. 3. The area of film of each mass ratio (liquid A:liquid B)
of FIG. 3 corresponds to the area of the value of the modulus of
elasticity under 20 percent compression in FIG. 4. The modulus of
elasticity under 20 percent compression is a gradient of the
compression stress under 20 percent compression.
[0314] As seen in the results of Table 3 and FIG. 4, when the
volumes of droplets of the liquid A and the liquid B were changed
to control the mass ratio (liquid A:liquid B), a three-dimensional
object (hydrogel object) containing water as the main ingredient
was manufactured having multiple areas with continuously different
modulus of elasticity in a layer.
Example 3
[0315] The liquid A (forming liquid) was used as the first liquid
and the liquid B (diluting liquid) was used as the second
liquid.
[0316] The inkjet heads (MH5420, manufactured by Ricoh Industry
Company, Ltd.) were filled with the liquid A and the liquid B and
discharged them in 300 dpi.times.300 dpi. The number of droplets to
be discharged was changed to change the mass ratio (liquid A:liquid
B) in each area as illustrated in FIG. 5 to manufacture a
three-dimensional object (hydrogel object) containing water as the
main component. FIG. 5 is a diagram illustrating the mixing ratio
distribution in which the number of the droplets of the liquid A
and the liquid B in a single area in the three-dimensional object
(hydrogel object) containing water as the main component.
[0317] To be specific, four heads were used for the first liquid
and another four was used for the second liquid to discharge the
liquid A and the liquid B. The total amount of the liquid imparted
on the single area was controlled to be 144 pL.
[0318] The volume of a single droplet was determined to be 36 pL
and four droplets were discharged for the single area. For example,
the number of droplets was controlled in such a manner that the
ratio of the number of droplets of the liquid A and the number of
droplets of the liquid B in a single area was 1:3, 2:2, 3:1, and
4:0 to form a film including a three-dimensional object (hydrogel
object) containing water as the main ingredient. Thereafter, the
film was cured by light emitted by an ultraviolet ray irradiaor
(SPOT CURE SP5-250DB, manufactured by USHIO INC.) in a light amount
of 350 mJ/cm.sup.2. A hundred layers were formed and cured in the
same manner to manufacture a three-dimensional object (hydrogel
object) containing water as the main ingredient. Thus, a hydrogel
object containing water as the main ingredient with a dimension of
20 mm (depth).times.20 mm (width).times.2 mm (height) free of layer
peel-off was obtained.
[0319] The modulus of elasticity under 20 percent compression of
the thus-obtained hydrogel object containing water as the main
component was measured.
[0320] The modulus of elasticity under 20 percent compression was
measured in the same manner as described in Example 2. The
measuring results are shown in Table 3 and FIG. 6.
[0321] FIG. 6 is a diagram illustrating the values of modulus of
elasticity for each area of 2 mm.times.2 mm in the hydrogel object
containing water as the main ingredient illustrated in FIG. 5.
[0322] The area of film of each mass ratio (liquid A:liquid B) of
FIG. 5 corresponds to the area of the values of the modulus of
elasticity under 20 percent compression in FIG. 6.
[0323] As seen in the results of Table 3 and FIG. 6, when the mass
ratio (liquid A:liquid B) of the liquid A and the liquid B, namely,
the number of droplets of the liquid A and the liquid B, was
changed as illustrated in FIG. 5, the modulus of elasticity under
20 percent compression was easily changed as illustrated in FIG.
6.
[0324] Unlike Example 1, a three-dimensional object (hydrogel
object) containing water as the main ingredient was manufactured
having multiple areas with continuously different modulus of
elasticity in a layer.
Example 4
[0325] The liquid F (forming liquid) was used as the first liquid
and the liquid B (diluting liquid) was used as the second
liquid.
[0326] The inkjet heads (MH5420, manufactured by Ricoh Industry
Company, Ltd.) were filled with the liquid F and the liquid B and
discharged them in 300 dpi.times.300 dpi. The volume of a droplet
of discharged was controlled to change the mass ratio (liquid
F:liquid B) as illustrated in FIG. 7 to obtain a three-dimensional
object (hydrogel object) containing water as the main ingredient.
FIG. 7 is a diagram illustrating the mixing ratio distribution in
which the volume of the droplet of the liquid F and the liquid B in
a single area in the three-dimensional object (hydrogel object)
containing water as the main ingredient.
[0327] To be specific, four heads were used for the first liquid
and another four was used for the second liquid to discharge the
liquid F and the liquid B. The total amount of the liquid imparted
on the single area was controlled to be 144 pL.
[0328] For example, the liquid droplet volume was changed in such a
manner that the ratio of the volume of a droplet of the liquid F
and the volume of a droplet of the liquid B was 24 pL:120 pL, 48
pL:96 pL, and 72 pL:72 pL to form a liquid film including a
hydrogel containing water as the main ingredient. Thereafter, the
liquid film was cured by light emitted by an ultraviolet ray
irradiaor (SPOT CURE SP5-250DB, manufactured by USHIO INC.) in a
light amount of 350 mJ/cm.sup.2. A hundred layers were formed and
cured in the same manner to manufacture a three-dimensional object
(hydrogel object) containing water as the main ingredient. Thus, a
hydrogel object containing water as the main ingredient with a
dimension of 20 mm (depth).times.20 mm (width).times.2 mm (height)
free of layer peel-off was obtained.
[0329] The modulus of elasticity under 20 percent compression of
the thus-obtained hydrogel object containing water as the main
ingredient was measured in the same manner as in Example 2. The
measuring results of the modulus of elasticity are shown in Table 3
and FIG. 8. FIG. 8 is a diagram illustrating the values of modulus
of elasticity for each area of 2 mm (depth).times.2 mm (width) in
the hydrogel object containing water as the main ingredient
illustrated in FIG. 7. The area of film of each mass ratio (liquid
F:liquid B) of FIG. 7 corresponds to the area of the value of the
modulus of elasticity under 20 percent compression in FIG. 8.
[0330] As seen in the results of Table 3 and FIG. 8, when the mass
ratio (liquid F:liquid B) of the liquid F and the liquid B was
changed, the modulus of elasticity was changed.
[0331] Unlike Example 1, a three-dimensional object (hydrogel
object) containing water as the main ingredient was manufactured
having multiple areas with continuously different modulus of
elasticity in a layer. However, it was found that, without laponite
XLG, the obtained three-dimensional object contained a hygrogel
having extremely low modulus of elasticity as the main
ingredient.
Example 5
[0332] The liquid A (forming liquid) was used as the first liquid
and the liquid B (diluting liquid) was used as the second
liquid.
[0333] The liquid A and the liquid B were mixed changing the mass
ratio (liquid A:liquid B) of the liquid A and the liquid B and the
liquid mixture was poured in a mold having a dimension of 30 mm
(depth).times.30 mm (width).times.8 mm (height). The mixture was
left undone for 12 hours at 27 degrees C. to manufacture a
three-dimensional object (hydrogel object) containing water as the
main ingredient.
[0334] According to the same measuring manner as modulus of
elasticity under 20 percent compression described in Example 1,
compression stress under 70 percent compression (70 percent
compressive stress-strain), compression stress under 80 percent
compression (80 percent compressive stress-strain), and modulus of
elasticity under 20 percent compression were measured.
[0335] Toughness of a three-dimensional object (hydrogel
compression) containing water as the main ingredient can be
evaluated by the compression stress under 70 percent compression
and 80 percent compression. The results are shown in Table 9.
[0336] As described in FIG. 9, as the ratio of the liquid A
increased, the compression stress of a three-dimensional object
(hydrogel object) containing water as the main ingredient was found
to increase. Namely, it was found that, when the mass ratio of the
liquid A and the liquid B was changed, the compression stress of a
three-dimensional object (hydrogel object) containing water as the
main ingredient was easily changed.
[0337] It was also found that, when the imparting amount of each
liquid of the liquid set for manufacturing a three-dimensional
object was controlled, it was possible to form a three-dimensional
object (hydrogel object) containing water as the main ingredient
and having multiple areas having different values of post-curing
modulus of elasticity.
Example 6
[0338] The liquid C (forming liquid) was used as the first liquid
and the liquid D (diluting liquid) was used as the second
liquid.
[0339] The liquid C and the liquid D were mixed changing the mass
ratio (liquid C:liquid D) of the liquid C and the liquid D as shown
in Table 3 in the same manner as described in Example 1 and the
liquid mixture was poured in a mold having a dimension of 30 mm
(depth).times.30 mm (width).times.8 mm (height). The mixture was
left undone for 12 hours at 27 degrees C. to manufacture a
three-dimensional object (hydrogel object) containing water as the
main ingredient. The compression stress under 70 percent
compression, the compression stress under 80 percent compression,
and the modulus of elasticity 20 percent compression of the
thus-obtained hydrogel object containing water as the main
ingredient were measured in the same manner as in Example 1. The
measuring results are shown in Table 3 and FIG. 10.
[0340] As described in FIG. 10, as the ratio of the liquid D
increased, the compression stress of a three-dimensional object
(hydrogel object) containing water as the main ingredient also
increased. Namely, it was found that, when the mass ratio of the
liquid C and the liquid D was changed, the compression stress and
modulus of elasticity of a three-dimensional object (hydrogel
object) containing water as the main ingredient were easily
changed.
[0341] It was also found that, when the imparting amount of each
liquid of the liquid set for manufacturing a three-dimensional
object was controlled, it was possible to form a three-dimensional
object (hydrogel object) containing water as the main ingredient
having multiple areas having different values of post-curing
modulus of elasticity.
Example 7
[0342] The liquid A (forming liquid) was used as the first liquid
and the liquid E (diluting liquid) was used as the second
liquid.
[0343] The liquid A and the liquid E were mixed changing the mass
ratio (liquid A:liquid E) of the liquid A and the liquid E and the
liquid mixture was poured in a mold having a dimension of 30 mm
(depth).times.30 mm (width).times.8 mm (height). The mixture was
left undone for 12 hours at 27 degrees C. to manufacture a
three-dimensional object (hydrogel object) containing water as the
main ingredient. The compression stress under 70 percent
compression, the compression stress 80 percent compression, and the
modulus of elasticity under 20 percent compression of the
thus-obtained hydrogel object containing water as the main
ingredient were measured in the same manner as in Example 5. The
measuring results are shown in Table 3 and FIG. 11.
[0344] As described in FIG. 11, as the ratio of the liquid E
increased, the compression stress of a three-dimensional object
(hydrogel object) containing water as the main ingredient
decreased. Namely, it was found that, when the mass ratio of the
liquid A and the liquid E was changed, the compression stress of a
three-dimensional object (hydrogel object) containing water as the
main ingredient was easily changed.
[0345] It was also found that, when the imparting amount of each
liquid of the liquid set for manufacturing a three-dimensional
object was controlled, it was possible to form a three-dimensional
object (hydrogel object) containing water as the main ingredient
having multiple areas having different values of post-curing
modulus of elasticity.
Example 8
[0346] A non-contact dispenser (Cyber Jet 2, manufactured by
MUSASHI ENGINEERING INC.) was used with twin heads. When Cyber Jet
2 was used with twin heads, the mixing ratio of two kinds of
liquids can be precisely managed by the number of jetting.
[0347] The liquid A (forming liquid) was used as the first liquid
and the liquid B (diluting liquid) was used as the second
liquid.
[0348] The dispenser 1 discharged the liquid A and the dispenser 2
discharged the liquid B at a rate of 0.03 mg per droplet The number
of droplets to be discharged was changed to change the mass ratio
(liquid A:liquid B) as illustrated in FIG. 12 to manufacture a
three-dimensional object (hydrogel object) containing water as the
main ingredient. FIG. 12 is a diagram illustrating the mixing ratio
distribution in which the volume of the droplets of the liquid A
and the liquid B in a single area in the three-dimensional object
(hydrogel object) containing water as the main ingredient.
[0349] To be specific, the mass of the liquid discharged to the
single area of 5 mm (depth).times.5 mm (width).times.5 mm (height)
was 0.09 mg, namely, equivalent to the amount of three droplets.
For example, the discharging volume of the liquid droplet was
changed in such a manner that the ratio of the number of liquid
droplets of the liquid A to the number of liquid droplets of the
liquid B was 3:0, 2:1, and 1:2. The liquid mixture was irradiated
and cured with light emitted by an ultraviolet ray irradiaor (SPOT
CURE SP5-250DB, manufactured by USHIO INC.) in a light amount of
350 mJ/cm.sup.2 to form a three-dimensional object (hydrogel
object). Thus, the three-dimensional object (hydrogel object)
containing water as the main ingredient with a dimension of 15 mm
(depth).times.15 mm (width).times.5 mm (height) free of layer
peel-off was obtained. The modulus of elasticity under 20 percent
compression of the hydrogel object containing water as the main
ingredient was measured in the same manner as in Example 2. In
addition, the pressed-in area of a cylindrical metal having a
diameter of 1 mm was each area (x, y) of 2.5 mm.times.2.5 mm of the
hydrogel object containing water as the main ingredient while
changing both x and y from 0 to 15. The measuring results are shown
in Table 3 and FIG. 13.
[0350] The area of the film of each mass ratio (liquid A:liquid B)
of FIG. 12 corresponds to the area of the value of the modulus of
elasticity under 20 percent compression in FIG. 13.
[0351] As seen in the results of FIG. 13, when the mass ratio
(liquid A:liquid B) of the liquid A and the liquid B, namely, the
number of droplets, was changed as illustrated in FIG. 12, the
modulus of elasticity was easily changed as illustrated in FIG.
13.
[0352] Unlike Example 1, a three-dimensional object (hydrogel
object) containing water as the main ingredient was manufactured
having multiple areas with continuously different compression
stress in a layer.
Example 9
[0353] The liquid G (forming liquid) was used as the first liquid
and the liquid H (diluting liquid) was used as the second
liquid.
[0354] The inkjet head (MH5420, manufactured by Ricoh Industry
Company Ltd.) was filled with the liquid G and the liquid H and
discharged them. The volume of droplets discharged was changed to
change the mass ratio (liquid G:liquid H) as illustrated in FIG. 14
to obtain an oil gel. FIG. 14 is a diagram illustrating the mixing
ratio distribution in which the volume of the droplets of the
liquid G and the liquid H in a single area in the oil gel.
[0355] To be specific, four inkjet heads (MH5420, manufactured by
Ricoh Industry Company Ltd.) were filled with the liquid G and
another four were filled with the liquid H to discharge them. The
total amount of the liquid imparted on the single area was
controlled to be 144 pL.
[0356] For example, the liquid volume was changed in such a manner
that the ratio of the volume of a droplet of the liquid G and the
volume of a droplet of the liquid H was 24 pL:120 pL, 48 pL:96 pL,
and 72 pL:72 pL to form a liquid film of an oil gel. Thereafter,
the liquid film was cured by light emitted by an ultraviolet ray
irradiaor (SPOT CURE SP5-250DB, manufactured by USHIO INC.) in a
light amount of 350 mJ/cm.sup.2. A hundred layers were formed and
cured in the same manner to manufacture a three-dimensional oil gel
object. Thus, the three-dimensional oil gel with a dimension of 20
mm (depth).times.20 mm (width).times.2 mm (height) free of layer
peel-off was obtained.
[0357] The modulus of elasticity under 20 percent compression of
the oil gel was measured in the same manner as described in Example
2. The measuring results are shown in Table 3 and FIG. 15. FIG. 15
is a diagram illustrating the values (MPa) of the modulus of
elasticity for each area of 2 mm (depth).times.2 mm (width) in the
oil gel illustrated in FIG. 14. The area of film of each mass ratio
(liquid G:liquid H) of FIG. 14 corresponds to the area of the value
of the modulus of elasticity under 20 percent compression in FIG.
15.
[0358] It is found that different modulus of elasticity can be
obtained by changing the mixing ratio of the liquid G and the
liquid H.
Example 10
[0359] The liquid G (forming liquid) was used as the first liquid
and the liquid I (diluting liquid) was used as the second liquid.
The inkjet head (MH5420, manufactured by Ricoh Industry Company,
Ltd.) was filled with the liquids and discharged them in the same
manner as in Example 2.
[0360] The volume of droplets discharged was changed to change the
mass ratio (liquid G:liquid I) as illustrated in FIG. 16 to obtain
an oil gel. FIG. 16 is a diagram illustrating the mixing ratio
distribution in which the volume of the droplets of the liquid G
and the liquid I in a single area in the oil gel.
[0361] To be specific, four inkjet heads (MH5420, manufactured by
Ricoh Industry Co., Ltd.) were filled with the liquid A and another
four inkjet heads were filled with the liquid B to discharge them.
The total amount of the liquid imparted on the single area was
controlled to be 144 pL. For example, the liquid volume was changed
in such a manner that the ratio of the volume of a droplet of the
liquid G and the volume of a droplet of the liquid I was 24 pL:120
pL, 48 pL:96 pL, and 72 pL:72 pL to form a liquid film of an oil
gel. Thereafter, the liquid film was cured by light emitted by an
ultraviolet ray irradiaor (SPOT CURE SP5-250DB, manufactured by
USHIO INC.) in a light amount of 350 mJ/cm.sup.2. A hundred layers
were formed and cured in the same manner to manufacture a
three-dimensional oil gel object. Thus, the three-dimensional oil
gel with a dimension of 20 mm (depth).times.20 mm (width).times.2
mm (height) free of layer peel-off was obtained.
[0362] The modulus of elasticity under 20 percent compression of
the oil gel was measured in the same manner as described in Example
2. The measuring results are shown in Table 3 and FIG. 17. FIG. 17
is a diagram illustrating the values (MPa) of the modulus of
elasticity for each area of 2 mm (depth).times.2 mm (width) in the
oil gel illustrated in FIG. 16. The area of film of each mass ratio
(liquid G:liquid I) of FIG. 16 corresponds to the area of the value
of the modulus of elasticity under 20 percent compression in FIG.
17.
[0363] It is found that different modulus of elasticity can be
obtained by changing the mixing ratio of the liquid G and the
liquid I.
[0364] The degree of polymerization of the oil gel obtained in the
area of the liquid G:the liquid I=1:0 and the area of the liquid
G:the liquid I=1:1 was measured by a thermal mass analyzer
(Thermoplus TG8120, manufactured by Rigaku Corporation). To be
specific, after a cube of 2 mm (depth).times.2 mm (width).times.2
mm (height) was cut out from the oil gel in the areas, the polymer
containing ratio was measured by thermal mass analysis to obtain
the degree of polymerization. While the degree of polymerization
was 92 percent in the area of the liquid G:the liquid I=1:0, the
degree of polymerization was increased to 97 percent in the area of
the liquid G:the liquid I=1:1. Therefore, the effect of the thermal
polymerization initiator was confirmed.
Comparative Example 1
[0365] The liquid A (forming liquid) was used as the first liquid
and the liquid B (diluting liquid) was used as the second
liquid.
[0366] The inkjet head (MH5420, manufactured by Ricoh Industry
Company, Ltd.) was filled with the liquid A and the liquid B and
discharged them in 300 dpi.times.300 dpi in the same manner as in
Example 2. The volume of droplets discharged, that is, the mass
ratio (liquid A:liquid B) was set to be 1:1 to manufacture a
three-dimensional object (hydrogel object) containing water as the
main ingredient. FIG. 18 indicates that the volume ratio of the
droplets of the liquid A and the liquid B in a single area in the
three-dimensional object (hydrogel object) containing water as the
main ingredient is 1:1.
[0367] To be specific, four inkjet heads (MH5420, manufactured by
Ricoh Industry Co., Ltd.) were filled with the liquid A and another
four was filled with the liquid B to discharge both liquids. The
total amount of the liquid imparted on the single area was
controlled to be 144 pL. The liquid volume was maintained constant
in such a manner that the ratio of the volume of a droplet of the
liquid A and the volume of a droplet of the liquid B was 72 pL:72
pL to form a liquid film of a three-dimensional object (hydrogel
object) containing water as the main ingredient. Thereafter, the
liquid film was cured by light emitted by an ultraviolet ray
irradiaor (SPOT CURE SP5-250DB, manufactured by USHIO INC.) in a
light amount of 350 mJ/cm.sup.2. Such a liquid film was formed
hundred times and cured in the same manner to manufacture a
three-dimensional object (hydrogel object) containing water as the
main ingredient. Thus, a hydrogel object containing water as the
main ingredient with a dimension of 20 mm (depth).times.20 mm
(width).times.2 mm (height) free of layer peel-off was
obtained.
[0368] The modulus of elasticity under 20 percent compression of
the thus-obtained hydrogel object containing water as the main
ingredient was measured in the same manner as in Example 2. The
measuring results are shown in Table 3 and FIG. 19.
[0369] The area of film of each mixing ratio of FIG. 18 corresponds
to the area of the value of the modulus of elasticity in FIG.
19.
[0370] When the mass ratio (liquid A:liquid B) of the liquid A and
the liquid B was kept constant, a uniform three-dimensional object
(hydrogel object) containing water as the main ingredient was
formed having a uniform 20 percent modulus of elasticity.
[0371] Unlike Examples 2 and 3, a three-dimensional object
(hydrogel object) containing water as the main ingredient with
multiple areas having different values of modulus of elasticity was
not formed.
TABLE-US-00003 TABLE 3 20 percent 70 percent 80 percent Mass ratio
modulus of compression compression First Second (first
liquid:second elasticity stress stress liquid liquid liquid) (MPa)
(MPa) (MPa) Example 1 liquid liquid 1:3 0.01 -- -- A B 1:2 0.03 --
-- 1:1 0.09-0.10 -- -- 2:1 0.24-0.26 -- -- 2 liquid liquid 1:3 0.01
-- -- A B 1:2 0.02-0.03 -- -- 1:1 0.03-0.10 -- -- 2:1 0.13-0.28 --
-- 3 liquid liquid 1:3 0.01 -- -- A B 1:1 0.03-0.12 -- -- 3:1
0.34-0.42 -- -- 4:0 0.46-0.57 -- -- 4 liquid F liquid 1:3
0.003-0.004 -- -- B 1:2 0.007-0.009 -- -- 1:1 0.01 -- -- 2:1
0.02-0.04 -- -- 5 liquid liquid 1:2 0.13 0.051 0.15 A B 1:1 0.27
0.18 0.49 2:1 0.13 0.45 1 6 liquid liquid 1:2 0.23 0.52 1.5 C D 1:1
0.18 0.44 1.2 2:1 0.12 0.27 0.8 7 liquid liquid E 1:2 0.12 0.26 0.9
A 1:1 0.16 0.38 1.2 2:1 0.2 0.49 1.5 8 liquid liquid 1:2 0.03-0.08
-- -- A B 1:1 0.20-0.27 -- -- 2:1 0.31-0.37 -- -- 9 liquid liquid
1:0 0.75-0.84 -- -- G H 2:1 0.45-0.55 -- -- 1:1 0.16-0.23 -- -- 1:2
0.60-0.10 -- -- 10 liquid liquid I 1:0 0.75-0.83 -- -- G 2:1
0.48-0.58 -- -- 1:1 0.21-0.27 -- -- 1:2 0.09-0.13 -- -- Comparative
1 liquid liquid 1:1 0.02-0.04 -- -- Example A B -- --
Example 11
[0372] Liquid A was used as the first liquid and Liquid B was used
as the second liquid.
[0373] Like Example 2, the liquid A and the liquid B were laminated
in such a manner while forming an area having a mixing ratio
(liquid A:liquid B) of 2:1 and an area having a mixing ratio
(liquid A:liquid B) of 1:2 to form a three-dimensional object of 20
mm (depth).times.20 mm (width).times.20 mm (height) using the
device illustrated in FIG. 20. The manufacturing conditions are
according to Example 2.
Example 12
[0374] A three-dimensional object of 20 mm (depth).times.20 mm
(width).times.20 mm (height) was manufactured in the same manner as
in Example 11 using the device illustrated in FIG. 23.
[0375] The light source for use in the device illustrated in FIG.
23 was a UV-LED (SubZero-LED 365 nm, manufactured by Integration)
and the light amount was adjusted to 350 mJ/cm.sup.2.
Example 13
[0376] A three-dimensional object of 20 mm (depth).times.20 mm
(width).times.20 mm (height) was manufactured in the same manner as
in Example 11 using the device illustrated in FIG. 24. In FIG. 24,
reference numerals 10, 11, 12, 16, 17, and 18 represent a
manufacturing device, an ink jetting head unit for liquid for
forming a three-dimensional object, an ink jetting head unit for
liquid for dilution, a support substrate to support a
three-dimensional object, a stage, and a three-dimensional object,
respectively.
[0377] The light source for use in the device illustrated in FIG.
24 was a UV-LED (SubZero-LED 365 nm, manufactured by Integration)
and the light amount was adjusted to 350 mJ/cm.sup.2.
[0378] The smoothing member was reversely rotated.
[0379] The three-dimensional objects of Examples 11 to 13 were
evaluated as follows. Forming Property of Three-dimensional
Object
[0380] The form of the entire three-dimensional object and whether
there was deficiency in areas having different ingredients were
visually checked.
[0381] Evaluation Criteria
A: Good
B: Fair
C: Bad
[0382] Error in Horizontal Direction and Error in Perpendicular
Direction
[0383] As illustrated in FIG. 26, the dimensions of the
three-dimensional object formed in Examples 11 to 13 were measured
at 10 positions in the horizontal direction and the perpendicular
direction. The degree of deviation of the 10 positions was obtained
and evaluated.
[0384] Evaluation Criteria
A: Good
B: Fair
C: Bad
TABLE-US-00004 [0385] TABLE 4 Forming property of Error in
three-dimensional Error in horizontal perpendicular object
direction direction Example 11 A B to A B Example 12 A A B Example
13 A A A
Example 14
[0386] Liquid A was used as the first liquid and Liquid B was used
as the second liquid.
[0387] The three-dimensional object and the support structure
illustrated in FIG. 27 were formed using the device illustrated in
FIG. 23.
[0388] The area of the three-dimensional object was formed with the
mixing ratio of the liquid A and the liquid B of 2:1 and the area
of the support structure was formed with the mixing ratio of the
liquid A and the liquid B of 1:5.
[0389] When forming the support structure, the area thereof kept at
least minimal strength to support the three-dimensional object.
[0390] After the forming, as illustrated in FIG. 28, the
three-dimensional object 30 was taken out while breaking the
support structures 31 and 32 to separate it from the
three-dimensional object.
[0391] Embodiments of the present disclosure are, for example, as
follows.
[0392] 1. A method of manufacturing a three-dimensional object
includes imparting a first liquid having a first composition
including a solvent and a curable material and a second liquid
having a second composition to form a liquid film, curing the
liquid film and repeating the imparting and the curing to obtain
the three-dimensional object, wherein the imparting position and
the imparting amount of each of the first liquid and the second
liquid are controlled in such a manner that the liquid film
includes multiple areas where post-curing compression stress and/or
post-curing modulus of elasticity are different.
[0393] 2. The method according to 1 mentioned above, wherein the
imparting position of the first liquid matches the imparting
position of the second liquid.
[0394] 3. The method according to 1 or 2 mentioned above, wherein
the first liquid and the second liquid are imparted in a liquid
discharging method.
[0395] 4. The method according to any one of 1 to 3 mentioned
above, wherein the imparting amount of the first liquid and the
imparting amount of the second liquid are controlled based on the
volume of a droplet or the number of droplets to be imparted.
[0396] 5. The method according to any one of 1 to 4 mentioned
above, wherein the second liquid includes no curable material.
[0397] 6. The method according to any one of 1 to 5 mentioned
above, wherein the imparting position and the imparting amount of
each of the first liquid and the second liquid are controlled to
further form a support structure to support the three-dimensional
object.
[0398] 7. A liquid set for manufacturing a three-dimensional object
includes a first liquid having a first composition including a
solvent and a curable material and a second liquid having a second
composition.
[0399] 8. The liquid set according to 7 mentioned above, wherein
the solvent includes water, the curable material includes a
polymerizable monomer, and the first liquid further includes a
mineral.
[0400] 9. The liquid set according to 7 or 8 mentioned above,
wherein the second liquid includes at least one of a cross-linking
agent and a mineral.
[0401] 10. The liquid set according to any one of 7 to 9 mentioned
above, wherein at least one of the first liquid and the second
liquid includes a polymerization initiator.
[0402] 11. The liquid set according to any one of 7 to 10 mentioned
above, wherein the second liquid includes a different polymerizable
monomer from the polymerizable monomer included in the first
liquid.
[0403] 12. The liquid set in any one of 7 to 10 mentioned above,
wherein the second liquid includes the same polymerizable monomer
as the polymerizable monomer included in the first liquid.
[0404] 13. The liquid set according to any one of 7 to 10 mentioned
above, wherein the second liquid includes no curable material.
[0405] 14. The liquid set according to any one of 7 to 13 mentioned
above, further comprising a third liquid having a third
composition.
[0406] 15. A method of manufacturing a three-dimensional object
includes imparting the first liquid and the second liquid of the
liquid set of any one of 7 to 13 mentioned above to form a liquid
film and curing the liquid film.
[0407] 16. A device for manufacturing a three-dimensional object
includes an imparting device to impart the first liquid and the
second liquid of the liquid set of any one of 7 to 13 mentioned
above to form a liquid film and a curing device to cure the liquid
film.
[0408] 17. The device according to 16 mentioned above, wherein the
curing device includes an ultraviolet light-emitting diode.
[0409] 18. The device according to 16 or 17 mentioned above,
further including a smoothing device to smooth the liquid film
cured.
[0410] 19. A gel object includes a solvent and a polymer, wherein
at least one of 80 percent compressive stress-strain and modulus of
elasticity has a continuous gradient.
[0411] 20. The gel object according to 19 mentioned above, wherein
80 percent compressive stress-strain is 10-10,000 kPa.
[0412] According to the present invention, the method of
manufacturing a three-dimensional object capable of simply and
efficiently manufacturing a three-dimensional object having
multiple areas where compression stress and modulus of elasticity
are different.
[0413] Having now fully described embodiments of the present
invention, it will be apparent to one of ordinary skill in the art
that many changes and modifications can be made thereto without
departing from the spirit and scope of embodiments of the invention
as set forth herein.
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