U.S. patent application number 16/211419 was filed with the patent office on 2019-06-13 for curable resin composition.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Chiaki Nishiura, Ryo Ogawa, Kyohei Wada.
Application Number | 20190177469 16/211419 |
Document ID | / |
Family ID | 66735150 |
Filed Date | 2019-06-13 |
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United States Patent
Application |
20190177469 |
Kind Code |
A1 |
Wada; Kyohei ; et
al. |
June 13, 2019 |
CURABLE RESIN COMPOSITION
Abstract
A curable resin composition includes (A) a specific curable
resin and (C) a curing agent, and further includes (BI) 0.1 parts
by mass or more and 20 parts by mass or less of a polyhydric
alcohol having 2 to 5 hydroxyl groups, based on based on 100 parts
by mass of the curable resin (A); (BII) a cyclic compound having 3
to 6 reactive groups and a reactive group equivalent of 100 g/eq or
more and 300 g/eq or less; or (BIII) a specific oxetane compound in
a mass ratio of the curable resin (A) to the oxetane compound
(BIII) being 5:5 to 9:1.
Inventors: |
Wada; Kyohei; (Kawasaki-shi,
JP) ; Nishiura; Chiaki; (Tokyo, JP) ; Ogawa;
Ryo; (Kawasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
66735150 |
Appl. No.: |
16/211419 |
Filed: |
December 6, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B33Y 10/00 20141201;
B33Y 70/00 20141201; C08G 65/18 20130101; B29K 2063/00 20130101;
B29C 64/106 20170801; C08G 59/3245 20130101; C08G 59/38 20130101;
C08G 59/4064 20130101; B29C 64/30 20170801; B33Y 40/00 20141201;
C08G 59/36 20130101; C08G 65/22 20130101 |
International
Class: |
C08G 59/38 20060101
C08G059/38; C08G 59/36 20060101 C08G059/36; C08G 59/40 20060101
C08G059/40; B29C 64/106 20060101 B29C064/106; B29C 64/30 20060101
B29C064/30; B33Y 70/00 20060101 B33Y070/00; B33Y 40/00 20060101
B33Y040/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 13, 2017 |
JP |
2017-238733 |
Dec 13, 2017 |
JP |
2017-238734 |
Dec 13, 2017 |
JP |
2017-238735 |
Nov 29, 2018 |
JP |
2018-223323 |
Nov 29, 2018 |
JP |
2018-223324 |
Claims
1. A curable resin composition comprising: (A) a curable resin
represented by the following General Formula (1):
Y.sub.1-L.sub.3-X.sub.1 L.sub.1-X.sub.3-L.sub.2-X.sub.2
.sub.nL.sub.4-Y.sub.2 General Formula (1) where X.sub.1 and X.sub.2
are independently of each other a divalent linking group containing
an aromatic ring, X.sub.3 is an alkylene group having 4 to 18
carbon atoms, in which a carbon atom forming the alkylene group may
be substituted by an oxygen atom, a sulfur atom, a nitrogen atom,
or a silicon atom, L.sub.1, L.sub.2, L.sub.3, and L.sub.4 are
independently of one another a divalent linking group containing
one or more bonds selected from the group consisting of --O--,
--C--O--, --S--, --C--S--, an ester bond, a urethane bond, an ether
bond, a thiourethane bond, and a thioether bond, Y.sub.1 and
Y.sub.2 are independently of each other an epoxy group, a
cycloalkene oxide group, or an oxetanyl group, and n is an average
value of repeating structural units, and a real number of 0.1 or
more and 10 or less; and (C) a curing agent, wherein the curable
resin composition further comprises: (BI) 0.1 parts by mass or more
and 20 parts by mass or less of a polyhydric alcohol having 2 to 5
hydroxyl groups, based on 100 parts by mass of the curable resin
(A); (BII) a cyclic compound having 3 to 6 reactive groups and a
reactive group equivalent of 100 g/eq or more and 300 g/eq or less;
or (BIII) an oxetane compound represented by the following General
Formula (2): ##STR00028## where X.sub.4 is a divalent linking group
which is linked by a carbon atom forming an aromatic ring, X.sub.5
and X.sub.6 are independently of each other a hydrogen atom or an
alkyl group having 1 to 6 carbon atoms, L.sub.5 and L.sub.6 are
independently of each other a divalent linking group containing a
bond selected from the group consisting of --O--, --C--O--, an
ester bond, and an ether bond, and s is an average value of
repeating structural units, and a real number of 0.1 or more and 10
or less, a mass ratio of the curable resin (A) to the oxetane
compound (BIII) being 5:5 to 9:1.
2. The curable resin composition according to claim 1, wherein
X.sub.1 and X.sub.2 are a phenylene group, a biphenylene group, a
naphthalenediyl group, an anthracenediyl group, a phenanthrenediyl
group, a fluorenediyl group, a diphenylmethanediyl group, a
diphenylethanediyl group, a diphenylpropanediyl group, a
diphenyletherdiyl group, or a diphenylsulfonediyl group, which is
optionally substituted.
3. The curable resin composition according to claim 1, wherein
X.sub.3 is an optionally substituted acyclic alkylene group having
a straight chain or a branched chain structure.
4. The curable resin composition according to claim 1, wherein
L.sub.1, L.sub.2, L.sub.3, and L.sub.4 contain a bond selected from
the group consisting of --O--, --C--O--, --S--, --C--S--, an ether
bond, and a thioether bond.
5. The curable resin composition according to claim 1, wherein
Y.sub.1 and Y.sub.2 are an epoxy group.
6. The curable resin composition according to claim 1, wherein the
curing agent (C) is a photoacid generator.
7. The curable resin composition according to claim 1, wherein the
curable resin composition comprises the polyhydric alcohol (BI),
and the polyhydric alcohol (BI) has a molecular weight of 1,000 or
less.
8. The curable resin composition according to claim 7, wherein the
curable resin composition further comprises an oxetane compound
(D), and comprises 0.1 parts by mass or more and 20 parts by mass
or less of the polyhydric alcohol (BI), based on total 100 parts by
mass of the curable resin (A) and the oxetane compound (D).
9. The curable resin composition according to claim 8, wherein the
oxetane compound (D) is represented by the following General
Formula (4): ##STR00029## where X.sub.8 is a dihydric alcohol
residue, or a divalent linking group containing one or more bonds
selected from the group consisting of --O--, --C--O--, an ether
bond, a carbonate bond, a urethane bond, and a urea bond, and may
contain an aromatic ring.
10. The curable resin composition according to claim 8, wherein the
curable resin composition comprises 5 parts by mass or more and 90
parts by mass or less of the oxetane compound (D), based on total
100 parts by mass of the curable resin (A) and the oxetane compound
(D).
11. A cured product formed by curing a curable resin composition,
the curable resin composition comprising: (A) a curable resin
represented by the following General Formula (1):
Y.sub.1-L.sub.3-X.sub.1 L.sub.1-X.sub.3-L.sub.2-X.sub.2
.sub.nL.sub.4-Y.sub.2 General Formula (1) where X.sub.1 and X.sub.2
are independently of each other a divalent linking group containing
an aromatic ring, X.sub.3 is an alkylene group having 4 to 18
carbon atoms, in which a carbon atom forming the alkylene group may
be substituted by an oxygen atom, a sulfur atom, a nitrogen atom,
or a silicon atom, L.sub.1, L.sub.2, L.sub.3, and L.sub.4 are
independently of one another a divalent linking group containing
one or more bonds selected from the group consisting of --O--,
--C--O--, --S--, --C--S--, an ester bond, a urethane bond, an ether
bond, a thiourethane bond, and a thioether bond, Y.sub.1 and
Y.sub.2 are independently of each other an epoxy group, a
cycloalkene oxide group, or an oxetanyl group, and n is an average
value of repeating structural units, and a real number of 0.1 or
more and 10 or less; (C) a curing agent; and (BI) 0.1 parts by mass
or more and 20 parts by mass or less of a polyhydric alcohol having
2 to 5 hydroxyl groups, based on 100 parts by mass of the curable
resin (A), the polyhydric alcohol having a molecular weight of
1,000 or less, wherein the curable resin composition includes: (A)
a curable resin represented by the following General Formula (1):
Y.sub.1-L.sub.3-X.sub.1 L.sub.1-X.sub.3-L.sub.2-X.sub.2
.sub.nL.sub.4-Y.sub.2 General Formula (1) where X.sub.1 and X.sub.2
are independently of each other a divalent linking group containing
an aromatic ring, X.sub.3 is an alkylene group having 4 to 18
carbon atoms, in which a carbon atom forming the alkylene group may
be substituted by an oxygen atom, a sulfur atom, a nitrogen atom,
or a silicon atom, L.sub.1, L.sub.2, L.sub.3, and L.sub.4 are
independently of one another a divalent linking group containing
one or more bonds selected from the group consisting of --O--,
--C--O--, --S--, --C--S--, an ester bond, a urethane bond, an ether
bond, a thiourethane bond, and a thioether bond, Y.sub.1 and
Y.sub.2 are independently of each other an epoxy group, a
cycloalkene oxide group, or an oxetanyl group, and n is an average
value of repeating structural units, and a real number of 0.1 or
more and 10 or less; and (C) a curing agent, and further includes:
(BI) 0.1 parts by mass or more and 20 parts by mass or less of a
polyhydric alcohol having 2 to 5 hydroxyl groups, based on 100
parts by mass of the curable resin (A), the polyhydric alcohol (BI)
having a molecular weight of 1,000 or less.
12. A method of manufacturing a three-dimensional shaped article,
comprising: photocuring a curable resin composition by layer based
on a slice data to shape a shaped article, wherein the curable
resin composition includes: (A) a curable resin represented by the
following General Formula (1): Y.sub.1-L.sub.3-X.sub.1
L.sub.1-X.sub.3-L.sub.2-X.sub.2 .sub.nL.sub.4-Y.sub.2 General
Formula (1) where X.sub.1 and X.sub.2 are independently of each
other a divalent linking group containing an aromatic ring, X.sub.3
is an alkylene group having 4 to 18 carbon atoms, in which a carbon
atom forming the alkylene group may be substituted by an oxygen
atom, a sulfur atom, a nitrogen atom, or a silicon atom, L.sub.1,
L.sub.2, L.sub.3, and L.sub.4 are independently of one another a
divalent linking group containing one or more bonds selected from
the group consisting of --O--, --C--O--, --S--, --C--S--, an ester
bond, a urethane bond, an ether bond, a thiourethane bond, and a
thioether bond, Y.sub.1 and Y.sub.2 are independently of each other
an epoxy group, a cycloalkene oxide group, or an oxetanyl group,
and n is an average value of repeating structural units, and a real
number of 0.1 or more and 10 or less; and (C) a curing agent, and
further includes: (BI) 0.1 parts by mass or more and 20 parts by
mass or less of a polyhydric alcohol having 2 to 5 hydroxyl groups,
based on 100 parts by mass of the curable resin (A), where the
polyhydric alcohol (BI) having a molecular weight of 1,000 or
less.
13. The method of manufacturing a three-dimensional shaped article
according to claim 12, further comprising subjecting the shaped
article to heat treatment to obtain the three-dimensional shaped
article.
14. The curable resin composition according to claim 1, wherein the
curable resin composition comprises the cyclic compound (BII), and
the cyclic compound (BII) is a compound having 1 to 6 cyclic
structures selected from the group consisting of isocyanurate rings
and aromatic rings.
15. The curable resin composition according to claim 14, wherein a
reactive group of the cyclic compound (BII) is an epoxy group.
16. The curable resin composition according to claim 14, wherein
the curable resin composition comprises 50 parts by mass or more
and 97 parts by mass or less of the curable resin (A) and 3 parts
by mass or more and 50 parts by mass or less of the cyclic compound
(BII), based on total 100 parts by mass of the curable resin (A)
and the cyclic compound (BII).
17. The curable resin composition according to claim 14, wherein
the curable resin composition comprises an oxetane compound
(D).
18. The curable resin composition according to claim 14, wherein
the curable resin composition comprises 0 parts by mass or more and
90 parts by mass or less of the oxetane compound (D), based on
total 100 parts by mass of the curable resin (A), the cyclic
compound (BII), and the oxetane compound (D).
19. A method of manufacturing a three-dimensional shaped article,
comprising: photocuring a curable resin composition by layer based
on a slice data to shape a shaped article, wherein the curable
resin composition includes: (A) a curable resin represented by the
following General Formula (1): Y.sub.1-L.sub.3-X.sub.1
L.sub.1-X.sub.3-L.sub.2-X.sub.2 .sub.nL.sub.4-Y.sub.2 General
Formula (1) where X.sub.1 and X.sub.2 are independently of each
other a divalent linking group containing an aromatic ring, X.sub.3
is an alkylene group having 4 to 18 carbon atoms, in which a carbon
atom forming the alkylene group may be substituted by an oxygen
atom, a sulfur atom, a nitrogen atom, or a silicon atom, L.sub.1,
L.sub.2, L.sub.3, and L.sub.4 are independently of one another a
divalent linking group containing one or more bonds selected from
the group consisting of --O--, --C--O--, --S--, --C--S--, an ester
bond, a urethane bond, an ether bond, a thiourethane bond, and a
thioether bond, Y.sub.1 and Y.sub.2 are independently of each other
an epoxy group, a cycloalkene oxide group, or an oxetanyl group,
and n is an average value of repeating structural units, and a real
number of 0.1 or more and 10 or less; and (C) a curing agent, and
further includes: (BII) a cyclic compound having 3 to 6 reactive
groups and a reactive group equivalent of 100 g/eq or more and 300
g/eq or less, the cyclic compound (BII) being a compound having 1
to 6 cyclic structures selected from the group consisting of
isocyanurate rings and aromatic rings.
20. The curable resin composition according to claim 1, wherein the
curable resin composition comprises the oxetane compound (BIII),
and the oxetane compound (BIII) is a compound having two oxetanyl
groups.
21. The curable resin composition according to claim 20, wherein a
mass ratio of the curable resin (A) to the oxetane compound (BIII)
is 7:3 to 9:1.
22. The curable resin composition according to claim 20, wherein
X.sub.4 is a phenylene group, a biphenylene group, a
naphthalenediyl group, an anthracenediyl group, a phenanthrenediyl
group, a fluorenediyl group, a diphenylmethanediyl group, a
diphenylethanediyl group, a diphenylpropanediyl group, a
diphenyletherdiyl group, a diphenylsulfonediyl group, a
triphenylethanediyl group, or a tetraphenylmethanediyl group, which
is optionally substituted.
23. A method of manufacturing a three-dimensional shaped article,
comprising: photocuring a curable resin composition by layer based
on a slice data to shape a shaped article, wherein the curable
resin composition includes: (A) a curable resin represented by the
following General Formula (1): Y.sub.1-L.sub.3-X.sub.1
L.sub.1-X.sub.3-L.sub.2-X.sub.2 .sub.nL.sub.4-Y.sub.2 General
Formula (1) where X.sub.1 and X.sub.2 are independently of each
other a divalent linking group containing an aromatic ring, X.sub.3
is an alkylene group having 4 to 18 carbon atoms, in which a carbon
atom forming the alkylene group may be substituted by an oxygen
atom, a sulfur atom, a nitrogen atom, or a silicon atom, L.sub.1,
L.sub.2, L.sub.3, and L.sub.4 are independently of one another a
divalent linking group containing one or more bonds selected from
the group consisting of --O--, --C--O--, --S--, --C--S--, an ester
bond, a urethane bond, an ether bond, a thiourethane bond, and a
thioether bond, Y.sub.1 and Y.sub.2 are independently of each other
an epoxy group, a cycloalkene oxide group, or an oxetanyl group,
and n is an average value of repeating structural units, and a real
number of 0.1 or more and 10 or less; and (C) a curing agent, and
further includes: (BIII) an oxetane compound represented by the
following General Formula (2): ##STR00030## where X.sub.4 is a
divalent linking group which is linked by a carbon atom forming an
aromatic ring, X.sub.5 and X.sub.6 are independently of each other
a hydrogen atom or an alkyl group having 1 to 6 carbon atoms,
L.sub.5 and L.sub.6 are independently of each other a divalent
linking group containing a bond selected from the group consisting
of --O--, --C--O--, an ester bond, and an ether bond, and s is an
average value of repeating structural units, and a real number of
0.1 or more and 10 or less, a mass ratio of the curable resin (A)
to the oxetane compound (BIII) being 5:5 to 9:1, the oxetane
compound (BIII) being a compound having two oxetanyl groups.
24. The method of manufacturing a three-dimensional shaped article
according to claim 23, further comprising subjecting the shaped
article to thermal irradiation to obtain the three-dimensional
shaped article.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a curable resin
composition, and a method of manufacturing a three-dimensional
shaped article using the same.
Description of the Related Art
[0002] A method of optically forming a three-dimensional shaped
article by curing a liquid curable resin by layer by energy-active
light such as an ultraviolet ray, and laminating the layers to
obtain a three-dimensional shaped article, has been intensively
studied. The optical three-dimensional shaped article is developed
into a prototype for confirming a shape (rapid prototyping), and
also creation of a type (rapid tooling) and service parts (real
products) (rapid manufacturing). Accordingly, a demand for material
properties for a three-dimensional shaped article (toughness,
thermal resistance, etc.) is becoming higher, and recently,
physical properties equivalent to those of engineering plastics
have been demanded.
[0003] The three-dimensional shaped article by a curable resin is
required to have certain degrees of hardness (modulus of
elasticity) and toughness, and in particular high fracture
toughness. Japanese Patent Application Laid-Open No. 2000-302964
has reviewed a system of adding a polyhydric alcohol to a resin
composition for improving toughness of three-dimensional
shaping.
[0004] However, since the modulus of elasticity and toughness are
in a reciprocal relationship, when the toughness of the composition
of Japanese Patent Application Laid-Open No. 2000-302964 is
increased, the modulus of elasticity thereof is lowered, and thus,
the composition of Japanese Patent Application Laid-Open No.
2000-302964 is insufficient for being used in rapid prototyping or
rapid manufacturing.
SUMMARY OF THE INVENTION
[0005] Based on the above circumstances, an object of the present
invention is to provide a resin composition which is appropriate
for rapid prototyping or rapid manufacturing and can impart a cured
product having excellent toughness.
[0006] A curable resin composition according to an aspect of the
present invention includes:
[0007] (A) a curable resin represented by the following General
Formula (1):
Y.sub.1-L.sub.3-X.sub.1 L.sub.1-X.sub.3-L.sub.2-X.sub.2
.sub.nL.sub.4-Y.sub.2 General Formula (1)
[0008] where
[0009] X.sub.1 and X.sub.2 are independently a divalent linking
group containing an aromatic ring,
[0010] X.sub.3 is an alkylene group having 4 to 18 carbon atoms, in
which a carbon atom forming the alkylene group may be substituted
by an oxygen atom, a sulfur atom, a nitrogen atom, or a silicon
atom,
[0011] L.sub.1, L.sub.2, L.sub.3, and L.sub.4 are independently of
one another a divalent linking group containing one or more bonds
selected from the group consisting of --O--, --C--O--, --S--,
--C--S--, an ester bond, a urethane bond, an ether bond, a
thiourethane bond, and a thioether bond,
[0012] Y.sub.1 and Y.sub.2 are independently of each other an epoxy
group, a cycloalkene oxide group, or an oxetanyl group, and
[0013] n is an average value of repeating structural units, and a
real number of 0.1 or more and 10 or less; and
[0014] (C) a curing agent,
[0015] wherein the curable resin composition further includes:
[0016] (BI) 0.1 parts by mass or more and 20 parts by mass or less
of a polyhydric alcohol having 2 to 5 hydroxyl groups, based on 100
parts by mass of the curable resin (A);
[0017] (BII) a cyclic compound having 3 to 6 reactive groups and a
reactive group equivalent of 100 g/eq or more and 300 g/eq or less;
or
[0018] (BIII) an oxetane compound represented by the following
General Formula (2):
##STR00001##
[0019] where
[0020] X.sub.4 is a divalent linking group which is linked by a
carbon atom forming an aromatic ring,
[0021] X.sub.5 and X.sub.6 are independently of each other a
hydrogen atom or an alkyl group having 1 to 6 carbon atoms,
[0022] L.sub.5 and L.sub.6 are independently of each other a
divalent linking group containing a bond selected from the group
consisting of --O--, --C--O--, an ester bond, and an ether bond,
and
[0023] s is an average value of repeating structural units, and a
real number of 0.1 or more and 10 or less,
[0024] a mass ratio of the curable resin (A) to the oxetane
compound (BIII) being 5:5 to 9:1.
[0025] According to the present invention, there is provided a
curable resin composition which allows a cured product having
excellent toughness to be formed, and is preferred for
three-dimensional shaping.
[0026] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a graph representing a relationship between
crosslinking density (calculated value) and Charpy impact
strength.
[0028] FIG. 2 is a graph representing a relationship between
crosslinking density (calculated value) and a deflection
temperature under load.
DESCRIPTION OF THE EMBODIMENTS
[0029] Preferred embodiments of the present invention will now be
described in detail in accordance with the accompanying drawings.
An embodiment described below is merely one of the embodiments of
the present invention, and the present invention is not limited
thereto.
First Embodiment
[0030] A curable resin composition according to the present
embodiment includes:
[0031] (A) a curable resin represented by the following General
Formula (1):
Y.sub.1-L.sub.3-X.sub.1 L.sub.1-X.sub.3-L.sub.2-X.sub.2
.sub.nL.sub.4-Y.sub.2 General Formula (1)
[0032] where
[0033] X.sub.1 and X.sub.2 are independently of each other a
divalent linking group containing an aromatic ring,
[0034] X.sub.3 is an alkylene group having 4 to 18 carbon atoms, in
which a carbon atom forming the alkylene group may be substituted
by an oxygen atom, a sulfur atom, a nitrogen atom, or a silicon
atom,
[0035] L.sub.1, L.sub.2, L.sub.3, and L.sub.4 are independently of
one another a divalent linking group having one or more bonds
selected from the group consisting of --O--, --C--O--, --S--,
--C--S--, an ester bond, a urethane bond, an ether bond, a
thiourethane bond, and a thioether bond,
[0036] Y.sub.1 and Y.sub.2 are independently of each other an epoxy
group, a cycloalkene oxide group, or an oxetanyl group, and
[0037] n is an average value of repeating structural units, and a
real number of 0.1 or more and 10 or less;
[0038] (BI) a polyhydric alcohol having 2 to 5 hydroxyl groups;
and
[0039] (C) a curing agent,
[0040] wherein the polyhydric alcohol (BI) is included at 0.1 parts
by mass or more and 20 parts by mass or less, based on 100 parts by
mass of the curable resin (A).
[0041] <Curable Resin (A) (Component (A))>
[0042] The curable resin (A) used in the present invention is
represented by the following General Formula (1):
Y.sub.1-L.sub.3-X.sub.1 L.sub.1-X.sub.3-L.sub.2-X.sub.2
.sub.nL.sub.4-Y.sub.2 General Formula (1)
where X.sub.1 and X.sub.2 are independently of each other a
divalent linking group containing an aromatic ring. It is preferred
that X.sub.1 and X.sub.2 have two or less aromatic rings, from the
viewpoint of ease of availability and solubility in solvents. When
there are two or less aromatic rings, it is difficult for problems
in a synthesis reaction such as increased crystallinity and poor
solubility in solvents to occur. X.sub.1 and X.sub.2 may be linking
groups linked to an adjacent group (L.sub.1, L.sub.2, L.sub.3, and
L.sub.4) by a carbon atom forming an aromatic ring, or a linking
group linked to an adjacent group by an atom other than a carbon
atom forming an aromatic ring, however, it is preferred that
X.sub.1 and X.sub.2 are a linking group linked to an adjacent group
by a carbon atom forming an aromatic ring.
[0043] An example of X.sub.1 and X.sub.2 may include a hydrocarbon
group having a structure having only one aromatic ring, a
hydrocarbon group having a structure in which an aromatic ring is
bonded via a single bond, a hydrocarbon group having a structure in
which an aromatic ring is bonded via an aliphatic carbon atom, a
hydrocarbon group having a structure in which an aromatic ring is
bonded via an aliphatic cyclic hydrocarbon group, a hydrocarbon
group having a structure in which a plurality of benzene rings are
condensed and polycyclized, a hydrocarbon group having a structure
in which an aromatic ring is bonded via an aralkyl group, a
hydrocarbon group having a structure in which an aromatic ring is
bonded via an oxygen atom, a sulfur atom, a nitrogen atom, or
silicon atom, or the like. Specific example thereof may include a
phenylene group, a biphenylene group, a naphthalenediyl group, an
anthracenediyl group, a phenanthrenediyl group, a fluorenediyl
group, a diphenylmethanediyl group, a diphenylethanediyl group, a
diphenylpropanediyl group, a diphenyletherdiyl group, a
diphenylsulfonediyl group, or the like. These groups may be
unsubstituted or substituted. An example of the substituent may
include a straight chain or branched chain alkyl group having 1 to
6 carbon atoms, and the like.
[0044] In particular, from the viewpoint of excellent balance of
flexibility and toughness of a cured product obtained from the
curable resin composition of the present invention, and light
transmittance, a diphenylmethanediyl group (General Formula (1-I)),
a diphenylpropanediyl group (General Formula (1-II)), a biphenylene
group (General Formula (1-III)), and a diphenyletherdiyl group
(General Formula (1-IV)) are preferred, and these groups may be
unsubstituted or substituted. An example of the substituent may
include a straight chain or branched chain alkyl group having 1 to
6 carbon atoms.
##STR00002##
where * denotes a bond to L.sub.1, L.sub.2, L.sub.3, or
L.sub.4.
[0045] X.sub.3 is an alkylene group having 4 to 18 carbon atoms,
preferably 4 to 12 carbon atoms, and more preferably 4 to 10 carbon
atoms. When there are 3 or less carbon atoms, flexibility is
damaged, so that sufficient toughness cannot be exhibited. In
addition, when there are 19 or more carbon atoms, hardness of a
cured product is lowered, resulting in a damaged modulus of
elasticity. A specific example of X.sub.3 may include an acyclic
alkylene group having a straight chain or branched chain structure
such as a butylene group, a pentylene group, a hexylene group, a
heptylene group, an octylene group, a nonylene group, a decanylene
group, a dodecanylene group, a tridecanylene group, a
tetradecanylene group, a pentadecanylene group, a hexadecanylene
group, a heptadecanylene group, and an octadecanylene group; or an
alkylene group having a cyclic structure such as a bicyclic
structure, a tricyclic structure, or a polycyclic structure, such
as a cyclobutylene group, a cyclopentylene group, a cyclohexylene
group, a cycloheptylene group, and a cyclooctylene group, and the
like, and may be unsubstituted or substituted. An example of the
substituent may include a straight chain or branched chain alkyl
group having 1 to 6 carbon atoms, or the like. Among them, from the
viewpoint of ease of availability, an acyclic alkylene group having
4 to 12 carbon atoms, having a straight chain or branched chain
structure is preferred, and a straight chain acyclic alkylene group
having 4 to 10 carbon atoms is more preferred.
[0046] In X.sub.3, the carbon atom forming the alkylene group may
be substituted by an oxygen atom, a sulfur atom, a nitrogen atom,
or a silicon atom, or X.sub.3 may have a repeating structure such
as oxymethylene, oxyethylene, or oxypropylene. In this case, it is
preferred that there are 4 to 10 unsubstituted carbons.
[0047] The alkylene group represented by the following General
Formula (1-VII) as X.sub.3 is preferred from the viewpoint of
compatibility between hydrophobicity or toughness and a modulus of
elasticity, and the alkylene group represented by General Formula
(1-VIII) is more preferred from the viewpoint of toughness
improvement.
##STR00003##
where 1 is an integer of 4 or more and 18 or less, and preferably
an integer of 4 or more and 10 or less, R.sub.1 and R.sub.2 are
hydrogen or a methyl group, m is an integer selected so that the
alkylene group has 4 to 18, preferably 4 to 10 carbon atoms. *
denotes a bond to L.sub.1 or L.sub.2.
[0048] L.sub.1, L.sub.2, L.sub.3, and L.sub.4 are independently of
one another a divalent linking group containing one or more bonds
selected from the group consisting of --O--, --C--O--, --S--,
--C--S--, an ester bond, a urethane bond, an ether bond, a
thiourethane bond, and a thioether bond. Hereinafter, "a bond
selected from the group consisting of --O--, --C--O--, --S--,
--C--S--, an ester bond, a urethane bond, an ether bond, a
thiourethane bond, and a thioether bond" is sometimes referred to
as "a specific bond". L.sub.1 to L.sub.4 may be a linking group
which is directly linked to an adjacent group (Y.sub.1, Y.sub.2,
X.sub.1, X.sub.2, or X.sub.3) by a specific bond, or a linking
group which is linked by one or more carbon atoms between the
specific bond and an adjacent group. When the specific bond is one
of --O--, --C--O--, --S--, and --C--S--, it is preferred that an
oxygen atom or a sulfur atom of the specific bond may be bonded to
a carbon atom interposed between the specific bond and the adjacent
group, or a carbon atom of the adjacent group to form an ether bond
or a thioether bond.
[0049] When L.sub.1 to L.sub.4 contains one or two bonds selected
from the group consisting of --O--, --C--O--, --S--, --C--S--, an
ether bond, and a thioether bond, rotational movement of a
molecular chain of the curable resin (A) becomes easy, and an
effect of toughness improvement becomes greater, which is thus
preferred. When there are two or less bonds selected from the group
consisting of --O--, --C--O--, --S--, --C--S--, an ether bond, and
thioether bond, the modulus of elasticity of the cured product can
be maintained, without an excessive increase of motility.
[0050] In addition, when L.sub.1 to L.sub.4 have a hydroxyl group,
an effect of promoting a polymerization reaction of the curable
resin (A) occurs, which is thus preferred. It is preferred that the
number of hydroxyl groups is 6 or less in one molecule of the
curable resin (A). When the number of hydroxyl groups is 6 or less
in one molecule, water absorption by the curable resin composition
and the cured product therefrom is not lowered, thereby having
stability over time.
[0051] Specific examples of L.sub.1, L.sub.2, L.sub.3, and L.sub.4
are preferably groups represented by the following General Formulae
(1-a), (1-b), (1-c), (1-d), (1-e), (1-f), and (1-g). In particular,
the groups represented by General Formulae (1-a), (1-d), (1-e),
(1-f), and (1-g) are more preferred from the viewpoint of
availability of materials and synthesis efficiency. In addition,
the groups represented by General Formula (1-d), (1-e), (1-f), and
(1-g) are more preferred from the viewpoint of an effect of
toughness improvement. In addition, the group represented by
General Formula (1-g) is preferred from the viewpoint of promoting
polymerization reaction of the curable resin (A).
##STR00004##
where a, b, c, d, e, f, g, h, i, j, k, o, p, and q are
independently of one another an integer of 0 or more and 5 or less,
and from the viewpoint of flexibility of the cured product of the
composition and viscosity of the composition, preferably an integer
of 0 or more and 2 or less, and from the viewpoint of further
maintaining a modulus of elasticity, more preferably an integer of
0 or more and 1 or less, and * denotes a bond to Y.sub.1, Y.sub.2,
X.sub.1, X.sub.2, or X.sub.3.
[0052] Y.sub.1 and Y.sub.2 are polymerizable groups, and
independently of each other an epoxy group, a cycloalkene oxide
group, or an oxetanyl group. The cycloalkene oxide group may be a
cyclopropeneoxide group, a cyclobuteneoxide group, a
cyclopenteneoxide group, a cyclohexeneoxide group, a
cyclohepteneoxide group, or the like. It is preferred that Y.sub.1
and Y.sub.2 are specifically represented by the following General
Formula (1-h), (1-i), or (1-j), in terms of synthesis or ease of
availability:
##STR00005##
where R.sub.3 and R.sub.4 are independently of each other hydrogen
or an alkyl group having 1 to 4 carbon atoms, and from the
viewpoint of polymerizability and ease of availability, preferably
hydrogen or an alkyl group having 1 to 2 carbon atoms, and more
preferably hydrogen, and * denotes a bond to L.sub.3 or
L.sub.4.
[0053] n denotes an average value of repeating structural units,
and a real number of 0.1 or more and 10 or less. For suppressing a
viscosity increase of the composition, n is preferably in a range
of 0.2 or more and 5 or less, and from the viewpoint of balance of
the toughness and the modulus of elasticity of the cured product,
more preferably in a range of 0.5 or more and 3 or less.
[0054] As the curable resin (A), commercially available products
such as for example, EPICLON EXA-4816 (manufactured by DIC
Corporation), EPICLON EXA-4850-150 (manufactured by DIC
Corporation), and EPICLON EXA-4850-1000 (manufactured by DIC
Corporation) may be preferably used.
[0055] A specific example of the curable resin (A) is preferably
the curable resin represented by the following structures, from the
viewpoint of compatibility between toughness and a modulus of
elasticity, and more preferably, n is 1. In addition, when there is
a hydroxyl group, an effect of promoting curing of the curable
resin (A) occurs, which is thus more preferred.
##STR00006## ##STR00007##
[0056] (Preparation Method of Curable Resin (A))
[0057] A preparation method of the curable resin (A) is not
particularly limited, however, for example, a diglycidyl ether
compound (A-1) and an aromatic dihydroxy compound (A-2) are reacted
to obtain a dihydroxy compound (A-3). Then, a halogen group of a
cation-polymerizable compound having a halogen group is reacted
with a hydroxyl group of the dihydroxy compound (A-3) to obtain the
curable resin (A).
[0058] An example of the diglycidyl ether compound (A-1) may
include a compound represented by the following General Formula
(3). X.sub.3 corresponds to X.sub.3 of General Formula (1), and the
details are as defined for General Formula (1). The diglycidyl
ether compound (A-1) may be used alone or in combination of two or
more.
##STR00008##
[0059] An example of the compound represented by General Formula
(3) may include 1,4-butanediol diglycidyl ether, diethyleneglycol
diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol
diglycidyl ether, 1,7-heptanediol diglycidyl ether, 1,8-octanediol
diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether,
tripropylene glycol diglycidyl ether, 1,9-nonaediol diglycidyl
ether, 1,10-decanedioil diglycidyl ether, 1,11-undecanediol
diglycidyl ether, 1,12-dodecanediol diglycidyl ether,
1,18-stearyldiol diglycidyl ether, or the like.
[0060] An example of the aromatic dihydroxy compound (A-2) may
include a compound represented by the following General Formula
(5). X.sub.7 corresponds to X.sub.1 and X.sub.2 of General Formula
(1), and the details are as defined for General Formula (1).
HO--X.sub.7--OH General Formula (5)
[0061] An example of the compound represented by General Formula
(5) may include 1,4-dihydroxybenzene, catechol,
4,4'-dihydroxydiphenylmethane,
4,4'-methylenebis(2,6-dimethylphenol),
2,2-bis(4-hydroxyphenyl)propane, 2,2'-methylenebis(4-methylphenol),
4,4'-ethylidenebisphenol, 4,4'-dihydroxybenzophenone,
4,4'-(1,3-dimethylbutylidene)diphenol,
4,4'-(.alpha.-methylbenzylidene)bisphenol,
4,4'-(.alpha.-methylbenzylidene)bisphenol,
4,4'-dihydroxytetraphenylmethane, 2,7-naphthalenediol,
2,3-naphthalenediol, 2,6-anthracenediol, or the like.
[0062] The cation-polymerizable compound having a halogen group
refers to a compound having an epoxy group, a cycloalkene oxide
group, or an oxetanyl group, simultaneously with having a halogen
group such as --I, --Br, and --Cl. A specific example thereof may
include 2-(chloromethyl)-1,2-epoxypropane,
2-(chloromethyl)-1,2-epoxybutane, or the like.
[0063] In addition, as other preparation methods, a difunctional
phenol compound as an aromatic dihydroxy compound and divinyl ether
are reacted. Then, the obtained difunctional phenol resin is
reacted with the cation-polymerizable compound having a halogen
group to obtain the curable resin (A).
[0064] <Polyhydric Alcohol (BI) (Component (BI))>
[0065] The polyhydric alcohol (BI) is useful for expressing
toughness improvement of a cured product. The polyhydric alcohol
used as the component (BI) has, in one molecule, 2 to 5 hydroxyl
groups, preferably 2 to 4 hydroxyl groups, and more preferably 2
hydroxyl groups. When an alcohol having one hydroxyl group in one
molecule is used, poor curing occurs. Meanwhile, when a polyhydric
alcohol having 6 or more hydroxyl groups in one molecule is
included, the toughness of the obtained cured product tends to be
lowered.
[0066] As a dihydric alcohol, for example, salicyl alcohol,
catechol, resorcinol, hydroquinone, 1,4-benzenedimethanol,
bisphenol A, bisphenol F, neopentyl glycol ethylene glycol,
propanediol, butanediol, pentanediol, hexanediol, or the like may
be used. As a trihydric alcohol, for example, glycerin,
phloroglucinol, trimethylolpropane, or the like may be used. As a
tetrahydric alcohol, for example, erythritol, threitol,
pentaerythritol, or the like may be used. As a pentahydric alcohol,
for example, xylitol, arabitol, fucitol, glycose, galactose,
fructose, or the like may be used. The polyhydric alcohol (BI) is
not limited thereto. In addition, the polyhydric alcohol (BI) may
be used alone or in combination or two or more.
[0067] The polyhydric alcohol (BI) has a molecular weight of
preferably 1,000 or less, and more preferably 800 or less. When the
molecular weight is more than 1,000, there is a possibility to
locally lower crosslinking density to reduce a modulus of
elasticity.
[0068] The content of the polyhydric alcohol (BI) is 0.1 parts by
mass or more and 20 parts by mass or less, preferably 0.2 parts by
mass or more and 15 parts by mass or less, and more preferably 0.5
parts by mass or more and 10 parts by mass or less, based on 100
parts by mass of the component (A) (when the component (D) is
included, based on total 100 parts by mass of component (A) and
component (D)). When the content of the polyhydric alcohol (BI) is
less than 0.1 parts by mass, the effect of the polyhydric alcohol
(BI) does not occur, so that a cured product having a sufficient
modulus of elasticity is not obtained. When the content of the
polyhydric alcohol (BI) is more than 20 parts by mass, the
polyhydric alcohol (BI) interferes with polymerization of the
component (A), and when the component (D) is included, the
polyhydric alcohol (BI) interferes with polymerization of the
component (A) and the component (D), whereby sufficient toughness
is not obtained.
[0069] (Function of Polyhydric Alcohol (BI))
[0070] A mechanism representing toughness improvement of the
curable composition of the present embodiment will be described
using a case including an epoxy resin as the component (A), a
cationic polymerization initiator as the component (C), and the
component (D) as an example. When the cationic polymerization
initiator absorbs an active energy ray or thermal energy, cations
occur, and these cations initiate cationic polymerization of an
epoxy group of the component (A) or an oxetanyl group of the
component (D). The epoxy group and the oxetanyl group are
cationically polymerized with each other or respectively to
increase the molecular weight, and since the activated epoxy group
and oxetanyl group are labile, polymerization is easily stopped.
Thus, a low-molecular weight polymer chain having an unreacted
epoxy group or oxetanyl group at the end of the polymer is
produced. The component (BI) of the present embodiment has a higher
molecular weight by reacting these low molecular weight polymer
chains with a hydroxyl group, thereby improving toughness, for
example, as represented in the following formula. In addition, it
is considered that a polyhydric alcohol incorporated to the polymer
chain forms a hydrogen bond, thereby more efficiently improving
toughness.
##STR00009##
[0071] <Curing Agent (C) (Component (C))>
[0072] As the curing agent (C), a cation-polymerizable initiator
such as a photoacid generator, a photobase generator, and a thermal
acid generator can be used. To the extent that the effect of the
present invention is not impaired, the curing agent may be used
alone or in combination of two or more. When a three-dimensional
shaped article is formed by photocuring, it is preferred to use the
photoacid generator or the photobase generator, and it is
particularly preferred to use the photoacid generator, due to the
stability over time of the curable resin composition of the present
invention or the restriction of the three-dimensional shaping
method. In addition, as the curing agent (C), a radical
polymerization initiator, for example, other curing agents such as
a thermal latent curing agent may be included.
[0073] [Cationic Polymerization Initiator]
[0074] (Photoacid Generator)
[0075] An example of a photoacid generator is a
photocation-polymerizable initiator which generates an acid capable
of initiating cationic polymerization by irradiation of an energy
ray such as an ultraviolet ray. When the photoacid generator is
used as a curable resin for three-dimensional shaping, it is
preferred to use the photocation-polymerizable initiator.
[0076] As the photocation-polymerizable initiator, for example, an
onium salt having a cation portion which is an aromatic sulfonium,
an aromatic iodonium, an aromatic diazonium, an aromatic ammonium,
a thianthrenium, a thioxanthonium, or a
(2,4-cyclopentadien-1-yl)[(1-methylethylbenzene]-Fe cation, and an
anion portion which contains BF.sub.4.sup.-, PF.sub.6.sup.-,
SbF.sub.6.sup.-, or [BX.sub.4].sup.- (with a proviso that X is a
phenyl group substituted by two or more fluorine or trifluoromethyl
groups) may be used alone or in combination of two or more.
[0077] As the aromatic sulfonium salt, for example,
bis[4-(diphenylsulfonio)phenyl]sulfidebishexafluorophosphate,
bis[4-(diphenylsulfonio)phenyl]sulfidebishexafluoroantimonate,
bis[4-(diphenylsulfonio)phenyl]sulfidebistetrafluoroborate,
bis[4-(diphenylsulfonio)phenyl]sulfidetetrakis(pentafluorophenyl)borate,
diphenyl-4-(phenylthio)phenylsulfoniumhexafluorophosphate,
diphenyl-4-(phenylthio)phenylsulfoniumhexafluoroantimonate,
diphenyl-4-(phenylthio)phenylsulfoniumtetrafluoroborate,
diphenyl-4-(phenylthio)phenylsulfoniumtetrakis(pentafluorophenyl)borate,
triphenylsulfoniumhexafluorophosphate,
triphenylsulfoniumhexafluoroantimonate,
triphenylsulfoniumtetrafluorob orate,
triphenylsulfoniumtetrakis(pentafluorophenyl)borate,
bis[4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl]sulfidebishexafluorop-
hosphate,
bis[4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl]sulfidebishe-
xafluoroantimonate,
bis[4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl]sulfidebistetrafluoro-
borate,
bis[4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl]sulfidetetraki-
s(pentafluorophenyl)borate, or the like may be used.
[0078] In addition, as the aromatic iodonium salt, for example,
diphenyliodoniumhexafluorophosphate,
diphenyliodoniumhexafluoroantimonate,
diphenyliodoniumtetrafluoroborate,
diphenyliodoniumtetrakis(pentafluorophenyl)borate,
bis(dodecylphenyl)iodoniumhexafluorophosphate,
bis(dodecylphenyl)iodoniumhexafluoroantimonate,
bis(dodecylphenyl)iodoniumtetrafluoroborate,
bis(dodecylphenyl)iodoniumtetrakis(pentafluorophenyl)borate,
4-methylphenyl-4-(1-methylethyl)phenyliodoniumhexafluorophosphate,
4-methylphenyl-4-(1-methylethyl)phenyliodoniumhexafluoroantimonate,
4-methylphenyl-4-(1-methylethyl)phenyliodoniumtetrafluoroborate,
4-methylphenyl-4-(1-methylethyl)phenyliodoniumtetrakis(pentafluorophenyl)-
borate, or the like may be used.
[0079] In addition, as the aromatic diazonium salt, for example,
phenyldiazoniumhexafluorophosphate,
phenyldiazoniumhexafluoroantimonate,
phenyldiazoniumtetrafluoroborate,
phenyldiazoniumtetrakis(pentafluorophenyl)borate, or the like may
be used.
[0080] In addition, as the aromatic ammonium salt,
1-benzyl-2-cyanopyridiniumhexafluorophosphate,
1-benzyl-2-cyanopyridiniumhexafluoroantimonate,
1-benzyl-2-cyanopyridiniumtetrafluoroborate,
1-benzyl-2-cyanopyridiniumtetrakis(pentafluorophenyl)borate,
1-(naphthylmethyl)-2-cyanopyridiniumhexafluorophosphate,
1-(naphthylmethyl)-2-cyanopyridiniumhexafluoroantimonate,
1-(naphthylmethyl)-2-cyanopyridiniumtetrafluoroborate,
1-(naphthylmethyl)-2-cyanopyridiniumtetrakis(pentafluorophenyl)borate,
or the like may be used.
[0081] In addition, as the thianthrenium salt,
5-methylthianthreniumhexafluorophosphate,
5-methyl-10-oxothianthreniumtetrafluoroborate,
5-methyl-10,10-dioxothianthreniumhexafluorophosphate, or the like
may be used.
[0082] In addition, as the thioxanthonium salt, S-biphenyl
2-isopropylthioxanthoniumhexafluorophosphate, or the like may be
used.
[0083] In addition, as the
(2,4-cyclopentadien-1-yl)[(1-methylethyl)benzene]-Fe salt,
(2,4-cyclopentadien-1-yl)[(1-methylethylbenzene]-Fe(II)hexafluorophosphat-
e,
(2,4-cyclopentadien-1-yl)[(1-methylethylbenzene]-Fe(II)hexafluoroantimo-
nate,
(2,4-cyclopentadien-1-yl)[(1-methylethylbenzene]-Fe(II)tetrafluorobo-
rate,
(2,4-cyclopentadien-1-yl)[(1-methylethylbenzene]-Fe(II)tetrakis(pent-
afluorophenyl)borate, or the like may be used.
[0084] As the photocation-polymerizable initiator, for example,
CPI.RTM.-100P, CPI.RTM.-110P, CPI.RTM.-101A, CPI.RTM.-200K, and
CPI.RTM.-210S (all manufactured by San-Apro Ltd.), CYRACURE.RTM.
photocuring initiator UVI-6990, CYRACURE.RTM. photocuring initiator
UVI-6992, and CYRACURE.RTM. photocuring initiator UVI-6976 (all
manufactured by Dow Chemical Japan Limited), ADEKA OPTOMER SP-150,
ADEKA OPTOMER SP-152, ADEKA OPTOMER SP-170, ADEKA OPTOMER SP-172,
and ADEKA OPTOMER SP-300 (all manufactured by ADEKA Corporation),
CI-5102 and CI-2855 (both manufactured by Nippon Soda Co., Ltd.),
SAN-AID.RTM. SI-60L, SAN-AID.RTM. SI-80L, SAN-AID.RTM. SI-100L,
SAN-AID.RTM. SI-110L, SAN-AID.RTM. SI-180L, SAN-AID.RTM. SI-110,
and SAN-AID.RTM. SI-180 (all manufactured by SANSHIN CHEMICAL
INDUSTRY CO., LTD.), ESACURE.RTM. 1064 and ESACURE.RTM. 1187 (both
manufactured by Lamberti Group), Omnicat 550 (manufactured by IGM
Resins, Co., Ltd.), Irgacure.RTM. 250 (manufactured by BASF
Corporation), RHODORSILPHOTOINITIATOR 2074 (manufactured by Rhodia
Japan, Ltd.), or the like is commercially available.
[0085] In the present invention, two or more photocationic
polymerization initiators may be used in combination; however, the
photocationic polymerization initiator may be used alone. In
addition, in order to proceed with a polymerization reaction in
heat treatment after shaping, other curing agents such as a thermal
cationic polymerization initiator may be included at the same
time.
[0086] (Photobase Generator)
[0087] A photobase generator refers to a compound which generates a
base by irradiation of an energy ray such as an ultraviolet ray or
visible ray. In particular, since the photobase generator has good
sensitivity to light, a salt containing a borate anion is
preferred. A specific product thereof may include U-CAT.RTM. 5002
or the like manufactured by San-Apro Ltd., or P3B, BP3B, N3B, MN3B,
or the like manufactured by Showa Denko K.K., but is not limited
thereto.
[0088] (Thermal Acid Generator)
[0089] A thermal acid generator is also called a thermal cationic
polymerization initiator. The thermal acid generator exerts a
substantial function as a curing agent, whereby a compound
containing a cationic species is excited by heating, and undergoes
a thermal decomposition reaction to proceed with thermosetting.
Unlike acid anhydrides, amines, phenol resins, or the like which
are commonly used as a curing agent, the thermal cationic
polymerization initiator does not cause a viscosity increase over
time or gelation of a resin composition at room temperature, even
in the case that it is included in the resin composition. Thus, it
is possible to provide a one-part resin composition having an
excellent handling property.
[0090] An example of the thermal cationic polymerization initiator
may include diphenyliodoniumhexafluoroarsenate,
diphenyliodoniumhexafluorophosphate,
diphenyliodoniumtrifluoromethanesulfonate,
triphenylsulfoniumtetrafluoroborate,
tri-p-tolylsulfoniumhexafluorophosphate,
tri-p-tolylsulfoniumtrifluoromethanesulfonate,
bis(cyclohexylsulfonyl)diazomethane,
bis(tert-butylsulfonyl)diazomethane,
bis(p-toluenesulfonyl)diazomethane,
triphenylsulfoniumtrifluoromethanesulfonate,
diphenyl-4-methylphenylsulfoniumtrifluoromethanesulfonate,
diphenyl-2,4,6-trimethylphenylsulfonium-p-toluenesulfonate,
diphenyl-p-phenylthiophenylsulfoniumhexafluorophosphate, or the
like.
[0091] In the present invention, as the thermal cationic
polymerization initiator, for example, commercial products such as
AMERICURE series (manufactured by American Can Co. which is a
diazonium salt-based compound, ULTRASET series (manufactured by
ADEKA Corporation), WPAG series (manufactured by Wako Pure Chemical
Corporation), UVE series (manufactured by General Electric Company)
which is an iodonium salt-based compound, FC series (manufactured
by 3M Company), UV9310C (manufactured by Ge Toshiba Silicones Co.,
Ltd.), WPI series (manufactured by Wako Pure Chemical Corporation),
CYRACURE series which is a sulfonium salt-based compound
(manufactured by Union Carbide Corporation), UVI series
(manufactured by General Electric Company), FC series (manufactured
by 3M Company), CD series (manufactured by Sartomer Company),
Optomer SP series and Optomer CP series (manufactured by ADEKA
Corporation), SAN-AID SI series (manufactured by SANSHIN CHEMICAL
INDUSTRY CO., LTD.), CI series (manufactured by Nippon Soda Co.,
Ltd.), WPAG series (manufactured by Wako Pure Chemical
Corporation), CPI series (manufactured by San-Apro Ltd.), or the
like may be used.
[0092] In the present invention, the thermal cationic
polymerization initiator may be used in combination of two or more,
or may be used alone. In addition, in order to proceed with a
polymerization reaction by heat treatment after shaping, the
thermal cationic polymerization initiator which performs
decomposition at high temperature may be used.
[0093] (Added Amount of Cationic Polymerization Initiator)
[0094] The added amount of a cationic polymerization initiator is
preferably 0.05 parts by mass or more and 20 parts by mass or less,
and more preferably 0.1 parts by mass or more and 5 parts by mass
or less, based on 100 parts by mass of the component (A) (when the
component (D) is included, based on total 100 parts by mass of the
component (A) and the component (D)). When the added amount of the
cationic polymerization initiator is less than 0.05 parts by mass,
a polymerization activation species to be produced is insufficient,
a polymerization conversion rate of the resin composition is
lowered, and as a result, there is a possibility that strength of
the cured product is insufficient. When the added amount of the
cationic polymerization initiator is more than 20 parts by mass,
the starting point of polymerization is increased, whereby
polymerization is not sufficiently repeated, and thus, there is a
possibility that the cured product has insufficient strength.
[0095] [Radical Polymerization Initiator]
[0096] When the resin composition according to the present
embodiment includes in particular a radical polymerizable compound
(F), a radical polymerization initiator may be included.
[0097] The radical polymerization initiator is mainly classified
into an intramolecular cleavage type and a hydrogen drawing type.
In the intramolecular cleavage type radical polymerization
initiator, a bond at a specific site is broken by absorbing light
at a specific wavelength, a radical occurs at the broken site, and
the radical becomes a polymerization initiator, whereby
polymerization of the radical polymerizable compound (F) begins.
Meanwhile, in the case of the hydrogen drawing type, light at a
specific wavelength is absorbed to reach an excitation state, and
the excited species causes a hydrogen abstraction reaction from a
hydrogen donor to generate a radical, which becomes a
polymerization initiator, thereby initiating polymerization of the
radical polymerizable compound (F).
[0098] As the intramolecular cleavage type photoradical
polymerization initiator, an alkylphenone-based photoradical
polymerization initiator, an acylphosphineoxide-based photoradical
polymerization initiator, and an oxime ester-based photoradical
polymerization initiator are known in the art. These photoradical
polymerization initiators are the types in which a bond adjacent to
a carbonyl group is .alpha.-cleaved to produce a radical species.
The alkylphenone-based photoradical polymerization initiator may
include a benzylmethylketal-based photoradical polymerization
initiator, an .alpha.-hydroxyalkylphenone-based photoradical
polymerization initiator, an aminoalkylphenone-based photoradical
polymerization initiator, or the like. As a specific compound, for
example, 2,2'-dimethoxy-1,2-diphenylethane-1-one (Irgacure.RTM.
651, manufactured by BASF Corporation) or the like as the
benzylmethylketal-based photoradical polymerization initiator;
2-hydroxy-2-methyl-1-phenylpropane-1-one (Darocur.RTM. 1173,
manufactured by BASF Corporation), 1-hydroxycyclohexylphenylketone
(Irgacure.RTM. 184, manufactured by BASF Corporation),
1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one
(Irgacure.RTM. 2959, manufactured by BASF Corporation),
2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpro-
pane-1-one (Irgacure.RTM. 127, manufactured by BASF Corporation),
or the like as the .alpha.-hydroxyalkylphenone-based photoradical
polymerization initiator;
2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one
(Irgacure.RTM. 907, manufactured by BASF Corporation),
2-benzylmethyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone
(Irgacure.RTM. 369, manufactured by BASF Corporation), or the like
as the aminoalkylphenon-based photoradical polymerization initiator
may be included, but is not limited thereto. The
acylphosphineoxide-based photoradical polymerization initiator may
include 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin.RTM.
TPO, manufactured by BASF Corporation),
bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure.RTM.
819, manufactured by BASF Corporation), or the like, but is not
limited thereto. The oxime ester-based photoradical polymerization
initiator may include
(2E)-2-(benzoyloxyimino)-1-[4-(phenylthio)phenyl]octane-1-one
(Irgacure.RTM. OXE-01, manufactured by BASF Corporation) or the
like, but is not limited thereto.
[0099] The hydrogen drawing type radical polymerization initiator
may include anthraquinone derivatives such as
2-ethyl-9,10-anthraquinone and 2-t-butyl-9,10-anthraquinone, and
thioxantone derivatives such as isopropyl thioxantone and
2,4-diethyl thioxantone, but is not limited thereto.
[0100] In the present invention, the photoradical polymerization
initiator may be used in combination of two or more, but also used
alone. In addition, in order to proceed with a polymerization
reaction in the heat treatment after shaping, a thermal radical
polymerization initiator may be included.
[0101] The added amount of the photoradical polymerization
initiator is preferably 0.1 parts by mass or more and 15 parts by
mass or less, and more preferably 0.1 parts by mass or more and 10
parts by mass or less, based on 100 parts by mass of the radical
polymerizable compound (F). When the amount of the photoradical
polymerization initiator is small, polymerization tends to be
insufficient. When the amount of the initiator is large, a light
transmittance is lowered, and polymerization may become
heterogeneous.
[0102] In addition, the thermal radical polymerization initiator is
not particularly limited, as long as it generates a radical by
heating, and conventional existing compounds may be used, and an
azo-based compound, peroxides and persulfates may be illustrated as
a preferred example. The azo-based compound may include
2,2'-azobisisobutyronitrile, 2,2'-azobis(methylisobutylate),
2,2'-azobis-2,4-dimethylvaleronitrile,
1,1'-azobis(1-acetoxy-1-phenylethane), or the like. The peroxides
may include benzoyl peroxide, di-t-butylbenzoyl peroxide,
t-butylperoxy pivalate, di(4-t-butylcyclohexyl)peroxy decarbonate,
or the like. The persulfates may include persulfate salts such as
ammonium persulfate, sodium persulfate and potassium persulfate, or
the like.
[0103] The added amount of the thermal radical polymerization
initiator is preferably 0.1 parts by mass or more and 15 parts by
mass or less, and more preferably 0.1 parts by mass or more and 10
parts by mass or less, based on 100 parts by mass of the radical
polymerizable compound (F). When the polymerization initiator is
added in excess, the molecular weight is not increased, and
physical properties may be lowered.
[0104] [Other Curing Agents]
[0105] As the curing agent (C), the following thermal latent curing
agent may be used. The thermal latent curing agent refers to a
curing agent which proceeds with thermal curing by overheating.
[0106] As an acid anhydride (an acid anhydride-based curing agent),
a known or commonly used acid anhydride-based curing agent may be
used, and though not particularly limited thereto, for example,
methyltetrahydrophthalic anhydride (4-methyltetrahydrophthalic
anhydride, 3-methyltetrahydrophthalic anhydride, or the like),
methylhexahydrophthalic anhydride (4-methylhexahydrophthalic
anhydride, 3-methylhexahydrophthalic anhydride, or the like),
dodecenyl succinic anhydride, methylendomethylene
tetrahydrophthalic anhydride, phthalic anhydride, maleic anhydride,
tetrahydrophthalic anhydride, hexahydrophthalic anhydride,
methylcyclohexenedicarboxylic anhydride, pyromellitic anhydride,
trimellitic anhydride, benzophenone tetracarboxylic anhydride,
nadic anhydride, methyl nadic anhydride, hydrogenated methyl nadic
anhydride, 4-(4-methyl-3-pentenyl)tetrahydrophthalic anhydride,
succinic anhydride, adipic anhydride, sebacic anhydride,
dodecandiacid anhydride, methylcyclohexene tetracarboxylic
anhydride, vinylether-maleic anhydride copolymer,
alkylstyrene-maleic anhydride copolymer, or the like may be used.
Among them, from the viewpoint of a handling property, an acid
anhydride which is liquid at 25.degree. C. [e.g.,
methyltetrahydrophthalic anhydride, methylhexahydrophthalic
anhydride, dodecenyl succinic anhydride,
methylendomethylenetetrahydrophthalic anhydride, or the like] is
preferred. Meanwhile, an acid anhydride which is solid at
25.degree. C. is dissolved in for example, an acid anhydride which
is liquid at 25.degree. C. to produce a liquid mixture, thereby
improving the handling property as the curing agent (C) in the
curable epoxy resin composition of the present invention. As the
acid anhydride-based curing agent, an anhydride of saturated
monocyclic hydrocarbon dicarboxylic acid (including those having a
substituent such as an alkyl group bonded to a ring) is preferred,
from the viewpoint of thermal resistance and transparency of the
cured product.
[0107] As the amines (an amine-based curing agent), a known or
commonly used amine-based curing agent may be used, and though not
particularly limited thereto, an example thereof may include an
aliphatic polyamine such as ethylenediamine, diethylenetriamine,
triethylenetetramine, tetraethylenepentamine, dipropylenediamine,
diethylaminopropylamine, and polypropylenetriamine; a
cycloaliphatic polyamine such as menthendiamine, isophoronediamine,
bis(4-amino-3-methyldicyclohexyl)methane,
diaminodicyclohexylmethane, bis(aminomethyl)cyclohexane,
N-aminoethylpiperazine, and
3,9-bis(3-aminopropyl)-3,4,8,10-tetraoxaspiro[5,5]undecane; a
mononuclear polyamine such as m-phenylenediamine,
p-phenylenediamine, tolylene-2,4-diamine, tolylene-2,6-diamine,
mesitylene-2,4-diamine, 3,5-diethyltolylene-2,4-diamine, and
3,5-diethyltolylene-2,6-diamine; an aromatic polyamine such as
biphenylenediamine, 4,4-diaminodiphenylmethane,
2,5-naphthylenediamine, and 2,6-naphthylenediamine, or the
like.
[0108] As the phenols (a phenol-based curing agent), a known or
commonly used phenol-based curing agent may be used, and though not
particularly limited thereto, an example thereof may include an
aralkyl resin such as a novolac type phenol resin, a novolac type
cresol resin, a paraxylylene modified phenol resin, and a
paraxylylene-metaxylylene modified phenol resin, a terpene modified
phenol resin, a dicyclopentadiene modified phenol resin,
triphenolpropane, or the like.
[0109] An example of the polyamide resin may include a polyamide
resin having any one or both of a primary amino group and secondary
amino group in the molecule.
[0110] As the imidazoles (an imidazole-based curing agent), a known
or commonly used imidazole-based curing agent may be used, and
though not particularly limited thereto, an example thereof may
include 2-methylimidazole, 2-ethyl-4-methylimidazole,
2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole,
1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole,
1-cyanoethyl-2-ethyl-4-methylimidazole,
1-cyanoethyl-2-undecylimidazole,
1-cyanoethyl-2-undecylimidazoliumtrimellitate,
1-cyanoethyl-2-phenylimidazoliumtrimellitate,
2-methylimidazoliumisocyanurate, 2-phenylimidazoliumisocyanurate,
2,4-diamino-6-[2-methylimidazolyl-(1)]-ethyl-s-triazine,
2,4-diamino-6-[2-ethyl-4-methylimidazolyl-(1)]-ethyl-s-triazine, or
the like.
[0111] An example of the polymercaptans (a polymercaptan-based
curing agent) may include liquid polymercaptan, a polysulfide
resin, or the like.
[0112] An example of the polycarboxylic acids may include adipic
acid, sebacic acid, terephthalic acid, trimellitic acid, carboxyl
group-containing polyester, or the like.
[0113] The added amount of other curing agents is preferably 0.1
parts by mass or more and 75 parts by mass or less, and more
preferably 5 parts by mass or more and 30 parts by mass or less,
based on 100 parts by mass of the component (A) (when the component
(D) is included, based on total 100 parts by mass of the component
(A) and the component (D)). When the amount of the thermal latent
polymerization initiator is small, polymerization tends to be
insufficient, and when the amount is too large, a crosslinking
reaction tends to proceed, causing deterioration of toughness.
[0114] <Oxetane Compound (D) (Component (D))>
[0115] The curable resin composition of the present invention can
include an oxetane compound (D) other than the component (A).
[0116] The oxetane compound (D) may be composed only one kind of
oxetane compound, or plural kinds of oxetane compounds. The oxetane
compound is not particularly limited, as long as it is a compound
having an oxetanyl group. The number of the oxetanyl group of the
oxetane compound (D) is not particularly limited. For example, a
monofunctional oxetane compound having one oxetanyl group in the
molecule,
[0117] a difunctional oxetane compound having two oxetanyl groups
in the molecule, a trifunctional oxetane compound having three
oxetanyl groups in the molecule, a tetra- or higher functional
oxetane compound having four or more oxetanyl groups in the
molecule, or the like may be listed, but is not limited thereto. In
addition, as the oxetane compound (D), an oxetane compound having
an aromatic ring or an ether bond in the molecule may be used.
[0118] A specific example of the oxetane compound (D) may include a
monooxetane compound such as
3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane,
3-ethyl-3-hydroxymethyloxetane,
3-ethyl-3-(4-hydroxybutyl)oxymethyloxetane,
3-ethyl-3-hexyloxymethyloxetane, 3-ethyl-3-allyloxymethyloxetane,
3-ethyl-3-benzyloxymethyloxetane,
3-ethyl-3-methacryloxymethyloxetane, 3-ethyl-3-carboxyoxetane, and
3-ethyl-3-phenoxymethyloxetane; a dioxetane compound such as
bis[1-ethyl(3-oxetanyl)]methyl ether,
4,4'-bis[3-ethyl-(3-oxetanyl)methoxymethyl]biphenyl,
1,4-bis(3-ethyl-3-oxetanylmethoxy)methylbenzene,
xylylenebisoxetane, bis[(ethyl(3-oxetanyl)]methyl carbonate,
bis[ethyl(3-oxetanyl)]ethyl adipate, bis[ethyl(3-oxetanyl)]methyl
terephthalate, bis[ethyl(3-oxetanyl)]methyl
1,4-cyclohexanecarboxylate, bis
{4-[ethyl(3-oxetanyl)methoxycarbonylamino]phenyl}methane, and
.alpha.,.omega.-bis-{3-[1-ethyl(3-oxetanyl)methoxy]propyl(polydimethylsil-
oxane); and a polyoxetane compound such as
oligo(glycidyloxetane-co-phenylglycidylether), or the like, but is
not limited thereto.
[0119] Among them, 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane,
3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(4-hydroxybutyl)oxymethyl
oxetane, bis[1-ethyl(3-oxetanyl)]methylether,
4,4'-bis[3-ethyl-(3-oxetanyl)methoxymethyl]biphenyl,
1,4-bis(3-ethyl-3-oxetanylmethoxy)methylbenzene, and
xylylenebisoxetane are preferred, and
3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane,
3-ethyl-3-hydroxymethyloxetane,
3-ethyl-3-(4-hydroxybutyl)oxymethyloxetane,
bis[1-ethyl(3-oxetanyl)]methylether, and
4,4'-bis[3-ethyl-(3-oxetanyl)methoxymethyl]biphenyl are more
preferred, since they have low viscosity and are easily handled,
and also represent high reactivity.
[0120] As the oxetane compound (D), a commercially available
product having a cation-polymerizable monomer as a main component
can be used, for example, ARON OXETANE.RTM. OXT-121, OXT-221, EXOH,
POX, OXA, OXT-101, OXT-211, and OXT-212 (manufactured by TOAGOSEI
CO., LTD.), ETERNACOLL.RTM. OXBP, OXTP (manufactured by Ube
Industries, Ltd.), or the like may be used.
[0121] In addition, the oxetane compound (D) is preferably a
compound represented by the following General Formula (4):
##STR00010##
[0122] In General Formula (4), X.sub.8 is a dihydric alcohol
residue, or a divalent linking group containing one or more bonds
selected from the group consisting of --O--, --C--O--, an ether
bond, a carbonate bond, a urethane bond, and a urea bond, and may
include an aromatic ring. The divalent compound represented by
General Formula (4) is preferred for increasing the modulus of
elasticity of the curable resin (A).
[0123] The compound represented by General Formula (4) may include
a compound exemplified as the dioxetane compound. The commercially
available product thereof may include ARON OXETANE.RTM. OXT-121,
OXT-221 (manufactured by TOAGOSEI CO., LTD.), ETERNACOLL.RTM. OXBP
(manufactured by Ube Industries, Ltd.), or the like. Among them, in
particular, bis[1-ethyl(3-oxetanyl)]methylether is preferred for
obtaining the effect of the present invention, in that the compound
has an ether bond and flexibility, thereby guaranteeing toughness,
and at the same time has a small molecular weight of X.sub.8, and
can improve crosslinking density. In addition,
4,4'-bis[3-ethyl-(3-oxetanyl)methoxymethyl]biphenyl is preferred in
that it has an aromatic ring, has a strong interaction with the
aromatic ring of the component (A) of the present invention and the
cyclic structure of the component (BI), and improves thermal
resistance.
[0124] In addition, the oxetane compound (D) is preferably a
compound represented by the following General Formula (2):
##STR00011##
[0125] The number of the oxetanyl groups of the compound
represented by General Formula (2) is not particularly limited. For
example, a difunctional oxetane compound having two oxetanyl groups
in the molecule, a trifunctional oxetane compound having three
oxetanyl groups in the molecule, a tetra- or higher functional
oxetane compound having four or more oxetanyl groups in the
molecule, or the like may be included, but is not limited thereto.
Among them, the difunctional oxetane compound having two oxetanyl
groups in the molecule is preferred.
[0126] In General Formula (2), X.sub.4 is a divalent linking group
which is linked by a carbon atom forming an aromatic ring. An
example of X.sub.4 may include a hydrocarbon group formed of a
structure having only one aromatic ring, a hydrocarbon group formed
of a structure in which an aromatic ring is bonded by a single
bond, a hydrocarbon group formed of a structure in which an
aromatic ring is bonded by an aliphatic carbon atom, a hydrocarbon
group formed of a structure in which an aromatic ring is bonded by
an aliphatic cyclic hydrocarbon group, a hydrocarbon group formed
of a structure in which a plurality of benzene rings are
polycyclized by condensation, a hydrocarbon group formed of a
structure in which an aromatic ring is bonded by an aralkyl group,
a hydrocarbon group formed of a structure in which an aromatic ring
is bonded by an oxygen atom or a sulfur atom, or the like. A
specific example thereof may include a phenylene group, a
biphenylene group, a naphthalenediyl group, an anthracenediyl
group,
[0127] a phenanthrenediyl group, a fluorenediyl group, a
diphenylmethanediyl group, a diphenylethanediyl group, a
diphenylpropanediyl group, a diphenyletherdiyl group, a
diphenylsulfonediyl group, a triphenylethanediyl group, a
tetraphenylmethanediyl group, or the like, which may be
unsubstituted or substituted. An example of the substituent may
include a straight chain or branched chain alkyl group having 1 to
6 carbon atoms. Among them, a phenylene group, a biphenylene group,
or a diphenylmethanediyl group, which may be substituted, is
preferred. X.sub.4 may have a group including an oxetanyl
group.
[0128] X.sub.5 and X.sub.6 are independently of each other a
hydrogen atom or an alkyl group having 1 to 6 carbon atoms. A
specific example of the alkyl group having 1 to 6 carbon atoms
represented by X.sub.5 and X.sub.6 may include an acyclic alkyl
group such as a methyl group, an ethyl group, an n-propyl group, an
isopropyl group, an n-butyl group, an isobutyl group, an s-butyl
group, a t-butyl group, a pentyl group, and a hexyl group; a cyclic
alkyl group such as a cyclopropyl group, a cyclobutyl group, a
cyclopentyl group, and a cyclohexyl group, or the like. Among them,
a methyl group and an ethyl group are preferred.
[0129] L.sub.5 and L.sub.6 are independently of each other a
divalent linking group containing a bond selected from the group
consisting of --O--, --C--O--, an ester bond, and an ether bond.
Hereinafter, "the bond selected from the group consisting of --O--,
--C--O--, an ester bond, and an ether bond" may sometimes be
referred to as "a second specific bond". L.sub.5 and L.sub.6 may be
a linking group which is directly linked to an adjacent group (a
methylene group, X.sub.4) by the second specific bond, or a linking
group which is linked by one or more carbon atoms between the
second specific bond and the adjacent group. When the second
specific bond is any one of --O-- and --C--O--, it is preferred
that an oxygen atom of the second specific bond is bonded to a
carbon atom interposed between the second specific bond and the
adjacent group, or a carbon atom of the adjacent group to form an
ether bond. A specific example of L.sub.5 and L.sub.6 may include
the above General Formula (1-a)(1-d), or the like. L.sub.5 and
L.sub.6 may include a group containing an oxetanyl group.
[0130] An average value of repeating structural units represented
by s is a real number of 0.1 or more and 10 or less, preferably 0.2
or more and 5 or less from the viewpoint of toughness of a cured
product, and more preferably 0.5 or more and 3 or less from the
viewpoint of the viscosity of the oxetane compound.
[0131] As the compound represented by General Formula (2),
commercially available products such as ETERNACOLL.RTM. OXBP
(manufactured by Ube Industries, Ltd.), ETERNACOLL.RTM. OXIPA
(manufactured by Ube Industries, Ltd.), ARON OXETANE OXT-121
(manufactured by TOAGOSEI CO., LTD.), or the like may be preferably
used.
[0132] As a specific example of the compound represented by General
Formula (2), a compound represented by the following structure is
preferred from the viewpoint of compatibility between toughness and
a modulus of elasticity.
##STR00012## ##STR00013##
[0133] When the resin composition includes the oxetane compound
(D), the content is preferably 5 parts by mass or more and 90 parts
by mass or less, more preferably 10 parts by mass or more and 80
parts by mass or less, and still more preferably 15 parts by mass
or more and 70 parts by mass or less, based on total 100 parts by
mass of the component (A) and the component (D). When the content
of the oxetane compound (D) is 5 parts by mass or more, a cured
product having a sufficient modulus of elasticity is obtained. When
the content of the oxetane compound (D) is more than 90 parts by
mass, there is a possibility that crosslinking density is
increased, and sufficient toughness is not obtained.
[0134] <Cation-Polymerizable Compound (E) (Component
(E))>
[0135] The curable resin composition of the present invention may
include, for example, an epoxy resin, or the like as a
cation-polymerizable compound other than the component (A) and the
component (D).
[0136] The epoxy resin other than the component (A) used in the
present invention may include a bisphenol A type epoxy resin, a
bisphenol F type epoxy resin, a biphenyl type epoxy resin, a
tetramethylbiphenyl type epoxy resin, a naphthalene type epoxy
resin, a phenol novolac type epoxy resin, a cresol novolac type
epoxy resin, a triphenylmethane type epoxy resin, a
tetraphenylethane type epoxy resin, a dicyclopentadien-phenol
addition reaction type epoxy resin, a phenolaralkyl type epoxy
resin, a naphthol novolac type epoxy resin, a naphtholaralkyl type
epoxy resin, a naphthol-phenol co-condensation novolac type epoxy
resin, a naphthol-cresol co-condensation novolac type epoxy resin,
an aromatic hydrocarbon formaldehyde resin modified phenol resin
type epoxy resin, a biphenyl modified novolac type epoxy resin, a
naphthylene ether type epoxy resin, or the like.
[0137] These epoxy resins may be an oligomerised one as a multimer,
and though a photocuring resin which can be preferably used in the
present invention has a low crystallinity so that it is hard to be
solidified, the cured product thereof tends to become hard, and
thus, the bisphenol type epoxy resin is preferred. Among the
bisphenol type epoxy resins, monomers such as bisphenol A
diglycidyl ether or bisphenol F diglycidyl ether are preferred in
that the photocuring resin composition has low viscosity.
[0138] It is preferred that the epoxy resin of the present
invention has an aromatic ring, for improving the hardness of the
cured product.
[0139] In order to express the effect of the present invention, the
content of the cation-polymerizable compound (E) is preferably 0
parts by mass or more and 75 parts by mass or less, based on 100
parts by mass of the component (A) (when the component (D) is
included, based on total 100 parts by mass of the component (A) and
the component (D)). When the amount of the cation-polymerizable
compound (E) is in excess, the effect of the present invention may
be impaired.
[0140] <Radical Polymerizable Compound (F) (Component
(F))>
[0141] The curable resin composition of the present invention may
include, for example, a (meth)acrylate compound, or the like, as
the radical polymerizable compound (F).
[0142] The (meth)acrylate compound may be a monofunctional
(meth)acrylate compound having one (meth)acryloyl group in the
molecule, a polyfunctional (meth)acrylate compound having two or
more (meth)acryloyl groups in the molecule, or the like. In the
present invention, any polymerizable (meth)acryl compound which can
be polymerized by a common method can be used. The monofunctional
(meth)acrylate compound and the polyfunctional (meth)acrylate
compound may be used by optionally mixing one or more.
[0143] The monofunctional (meth)acrylate compound may include
methyl(meth)acrylate, ethyl(meth)acrylate, n-butyl(meth)acrylate,
isobutyl(meth)acrylate, t-butyl(meth)acrylate,
2-ethylhexyl(meth)acrylate, n-octyl(meth)acrylate,
i-octyl(meth)acrylate, lauryl(meth)acrylate, stearyl(meth)acrylate,
cyclohexyl(meth)acrylate, isobornyl(meth)acrylate,
adamantyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate,
2-hydroxypropyl(meth)acrylate 2-hydroxybutyl(meth)acrylate,
4-hydroxybutyl(meth)acrylate, glycidyl(meth)acrylate,
tetrahydroperfuryl(meth)acrylate, phenylglycidyl(meth)acrylate,
dimethylaminomethyl(meth)acrylate, phenylcellosolve(meth)acrylate,
dicyclopentenyl(meth)acrylate,
dicyclopentenyloxyethyl(meth)acrylate, biphenyl(meth)acrylate,
2-hydroxyethyl(meth)acryloylphosphate, phenyl(meth)acrylate,
phenoxyethyl(meth)acrylate, phenoxypropyl(meth)acrylate,
benzyl(meth)acrylate, or the like.
[0144] The polyfunctional (meth)acrylate compound may include
ethyleneglycoldi(meth)acrylate, diethyleneglycoldi(meth)acrylate,
triethyleneglycoldi(meth)acrylate,
tetraethyleneglycoldi(meth)acrylate,
nonaethyleneglycoldi(meth)acrylate,
1,3-butyleneglycoldi(meth)acrylate, 1,4 butanedioldi(meth)acrylate,
dimethyloltricyclodecanedi(meth)acrylate, trimethylol
propanetri(meth)acrylate, neopentylglycoldi(meth)acrylate,
1,6-hexamethylenedi(meth)acrylate, hydroxypyvalicester
neopentylglycol di(meth)acrylate, pentaerythritoltri(meth)acrylate,
pentaerythritoltetra(meth)acrylate,
ditrimethylolpropanetetraacrylate,
dipentaerythritoltetra(meth)acrylate,
dipentaerythritolpenta(meth)acrylate,
dipentaerythritolhexa(meth)acrylate, tris(meth)acryl
oxyethylisocyanurate, or the like.
[0145] For expressing the effect of the present invention, the
content of the radical polymerizable compound (F) is preferably 0
parts by mass or more and 75 parts by mass or less, based on 100
parts by mass of the component (A) (when the component (D) is
included, based on total 100 parts by mass of the component (A) and
the component (D)). When the amount of the radical polymerizable
compound (F) is in excess, the effect of the present invention may
be impaired.
[0146] <Curable Resin Composition>
[0147] In the curable resin composition of the present invention,
to the extent that the object and the effect of the present
invention are not impaired, various additive materials may be
included, as other optional components. Such additive material may
include polymers or oligomers such as an epoxy resin, polyamide,
polyamideimide, polyurethane, polybutadiene, polychloroprene,
polyether, polyester, a styrene-butadiene block copolymer, a
petroleum resin, a xylene resin, a ketone resin, cellulose resin,
fluorine-based oligomer, silicone-based oligomer, and
polysulfide-based oligomer; polymerization inhibitors such as
phenothiazine and 2,6-di-t-butyl-4-methylphenol; polymerization
initiation aids; leveling agents; wettability improving agents;
surfactants; plasticizers; UV absorbers; silane coupling agents;
inorganic fillers; pigments; dyes, or the like.
[0148] The composition of the present invention can be prepared by
placing the essential components (A), (BI) and (C), and if
necessary, the component (D) and other optional components in
appropriate amounts, in a stirring container, and stirring the
components usually at 30.degree. C. or more and 120.degree. C. or
less, and preferably at 50.degree. C. or more and 100.degree. C. or
less. Here, a stirring time is usually 1 minute or more and 6 hours
or less, and preferably 10 minutes or more and 2 hours or less.
When the total content of the component (A) and the component (BI)
(when the component (D) is included, based on total 100 parts by
weight of the component (A), the component (BI), and the component
(D)) is preferably 1 part by mass or more and 100 parts by mass or
less, more preferably 25 parts by mass or more and 100 parts by
mass or less, and still more preferably 75 parts by mass or more
and 100 parts by mass or less, based on 100 parts by mass of the
curable resin composition except the component (C), whereby the
effect of the present invention can be sufficiently obtained.
[0149] The viscosity of the composition of the present invention at
25.degree. C. is preferably 50 mPas or more and 10,000 mPas or
less, and more preferably 70 mPas or more and 5,000 mPas or
less.
[0150] The composition of the present invention obtained as
described above is preferably used as a photocurable resin
composition in the method of optically forming a three-dimensional
shaped article. That is, by the method of optically forming a
three-dimensional shaped article in which the photocurable resin
composition of the present invention is selectively irradiated with
active energy rays such as an ultraviolet ray, an electron beam, an
X-ray and a radiation to supply energy required for curing, a
three-dimensional shaped article having a desired shape can be
manufactured.
[0151] <Cured Product>
[0152] The essential components of the composition of the present
invention are the curable resin (A), the polyhydric alcohol (BI),
and the curing agent (C), which are cured to obtain a cured
product. Curing can be performed by any known method such as active
energy ray curing or thermal curing, depending on the curing agent
included. A curing method may be a combination of plural types.
[0153] In the obtained cured product of the present invention, the
curable resin (A) has an aromatic ring to have strong interaction
between molecules, and when the oxetane compound (D) is included,
the oxetane compound (D) has an effect of promoting curing of the
curable resin (A). In addition, X.sub.3 of the curable resin (A) is
a flexible backbone, whereby the backbone can be cured in a bent
state, and rigid X.sub.1 or X.sub.2 can be relatively freely
arranged in the cured product. Thus, after curing, the rigid
structures of the curable resin (A) are very effectively interacted
with each other. In addition, in the case that the component (A) is
an epoxy resin, for example, since a protonated epoxy group is
labile in the cationic polymerization system, there is a problem in
that a polymerization chain is hard to grow. In the present
invention, it is considered that an appropriate amount of the
polyhydric alcohol (BI) is added to the resin composition to allow
the unreacted epoxy group to be reacted, whereby polymer chains are
extended. In addition, interaction by a hydrogen bond of the
curable resin (A) or the oxetane compound (D) with an oxygen atom
is effectively generated, thereby improving toughness. In addition,
it is considered that due to the effect of the physical
crosslinking by the extension of polymer chains and the hydrogen
bond, the polymer chains cannot move freely with each other to
improve a modulus of elasticity. Thus, it is considered therefrom
that though the modulus of elasticity and the toughness are usually
conflicting physical properties, characteristic curing to allow the
two conflicting physical properties to be compatible with each
other can be exerted.
[0154] <Method of Manufacturing a Three-Dimensional Shaped
Article>
[0155] The curable resin composition according to the present
embodiment can be preferably used in the method of manufacturing a
three-dimensional shaped article by a method of optically forming a
three-dimensional shaped article (optical shaping method).
Hereinafter, the method of manufacturing a three-dimensional shaped
article using the curable resin composition according to the
present embodiment will be described.
[0156] As the optical shaping method, a known method can be used.
That is, the method of manufacturing a three-dimensional shaped
article of the present embodiment includes a step of selectively
irradiating the liquid curable resin composition of the present
embodiment with an activate energy ray such as light to cure, for
example, photocuring the curable resin composition by layer, and
repeating this step to manufacture the three-dimensional shaped
article.
[0157] In the step of curing the curable resin composition layer by
layer, the curable resin composition is selectively irradiated with
active energy ray, based on a slice data of the three-dimensional
shaped article to be created. The active energy ray with which the
curable resin composition is irradiated is not particularly
limited, as long as it is an active energy ray capable of curing
the curable resin composition according to the present embodiment.
A specific example of the active energy ray may include
electromagnetic waves such as an ultraviolet ray, a visible ray, an
infrared ray, an X-ray,
[0158] a gamma ray, and a laser beam, and particle beams such as an
alpha ray, a beta ray, and an electron beam. Among them, from the
viewpoint of the absorption wavelength of the curing agent (C) to
be used and the cost of equipment installation, the ultraviolet ray
is most preferred. As the light source at this time, an ultraviolet
ray laser (e.g., Ar laser, He--Cd laser, etc.), a mercury lamp, a
xenon lamp, a halogen lamp, a fluorescent lamp, or the like may be
used. Among them, the laser light source is preferably adopted in
that it raises an energy level to shorten a shaping time, and
furthermore, has an excellent light collecting property to obtain
high shaping precision. A light exposure amount is not particularly
limited, however, preferably 0.001 J/cm.sup.2 or more and 10
J/cm.sup.2 or less. When the amount is less than 0.001 J/cm.sup.2,
the curable resin composition may not be sufficiently cured, and
when the amount is more than 10 J/cm.sup.2, the irradiation time is
extended to decrease productivity.
[0159] A method of irradiating the curable resin composition with
the active energy ray is not particularly limited, and for example,
when light is emitted as the active energy ray, the following
methods may be adopted. A first method is to use spot-like
collected light such as laser light to two-dimensionally scan the
curable resin composition. Here, the two-dimensional scanning may
be in a point drawing manner, or a line drawing manner. A second
method is a face exposure method to use a projector to irradiate a
shape of a section data with light. In this case, through a planar
drawing mask formed by arranging a plurality of micro-optical
shutters such as a liquid crystal shutter or a digital micromirror
shutter, the active energy ray may be planarly emitted.
[0160] A representative example of the optical shaping method is
described as follows. First, a supporting stage which is provided
to freely move up and down in a storage container is lowered (sunk)
in a small amount, thereby supplying a resin composition on the
supporting state, and forming a thin layer 1. Then, on this thin
layer 1, light is selectively irradiated to form a solid phase
cured resin layer 1. Then, on this cured resin layer 1, the curable
resin composition is supplied to form a thin layer 2, and the thin
layer 2 is selectively irradiated with light, thereby forming a new
cured resin layer 2 which is integrally laminated continuously on
the cured resin layer 1. Further, this step is repeated a
predetermined number of times with a pattern to be light-emitted
being changed or not, whereby the three-dimensional shaped article
which is formed by integrally laminating a plurality of cured resin
layers (1, 2, . . . n) is shaped.
[0161] The thus-obtained three-dimensional shaped article is taken
out of the storage container, the unreacted curable resin
composition remaining on the surface of the container is removed,
and if necessary, the article is cleaned. Here, as the cleaning
agent, alcohol-based organic solvents represented by alcohols such
as isopropylalcohol and ethylalcohol; ketone-based organic solvents
represented by acetone, ethyl acetic acid, methylethylketone, or
the like; and aliphatic organic solvents represented by terpenes
may be used. In addition, after cleaning the article with a
cleaning agent, if necessary, post-curing may be performed by light
irradiation or thermal irradiation. Post-curing can cure the
unreacted curable resin composition which may remain on the surface
or in the three-dimensional shaped article, thereby suppressing
stickiness of the shaped surface, and also improving initial
strength of the shaped article.
EXAMPLES
[0162] Hereinafter, Examples are provided to illustrate the present
invention in detail, however, the present invention is not limited
to the Examples.
Example 1
[0163] According to the following prescription, each component was
added to a light-shielded bin, and stirred using a stirring
defoamer until the components are uniform, thereby preparing a
curable composition.
[0164] Component (A): 70 parts by mass of curable resin A-i (n=1)
(manufactured by DIC Corporation `EXA4816` (purity of 99%))
[0165] Component (BI): 6 parts by mass of 1,4-benzenedimethanol
[0166] Component (C): 2 parts by mass of a photoacid generator
`CPI-210S` (manufactured by San-Apro Ltd.)
[0167] Component (D): 30 parts by mass of an oxetane compound
represented by the following formula (manufactured by TOAGOSEI CO.,
LTD. `OXT-221`):
##STR00014##
[0168] [Creation of Cured Product and Evaluation of Mechanical
Properties]
[0169] Creation of Film Type Specimen (for Evaluating Modulus of
Elasticity)
[0170] A cured product was manufactured by the following method,
using the prepared curable composition. First, a spacer of 300
.mu.m was interposed between two sheets of quartz glass, and the
curable composition was flowed into the gap having a width of 300
.mu.m. The flowed curable composition was irradiated with an
ultraviolet ray at 5 mW/cm.sup.2 for 300 seconds (total energy of
1500 mJ/cm.sup.2) with an ultraviolet ray irradiator (manufactured
by HOYA CANDEO OPTRONICS, product name: `LIGHT SOURCE EXECURE
3000`) to obtain a photocured product. The thus-obtained cured
product was heat-treated in a heating oven at 50.degree. C. for 1
hour, and in a heating oven at 100.degree. C. for 2 hours, thereby
obtaining a cured product.
[0171] Creation of Columnar Specimen (for Evaluating Toughness)
[0172] A cured product was manufactured by the following method,
using the prepared curable composition. First, a mold having a
length of 80 mm, a width of 10 mm, and a thickness of 4 mm was
interposed between two sheets of quartz glass, and the curable
resin was flowed thereinto. The flowed curable composition was
irradiated with an ultraviolet ray at 5 mW/cm.sup.2 from both
surfaces of the mold for 120 seconds with the ultraviolet ray
irradiator which was used in the creation of the film type
specimen, thereby performing temporary curing. Thereafter, an
ultraviolet ray was emitted again from the both surfaces for 600
seconds each time to perform main curing, thereby obtaining a
photocured product (total energy of 7200 mJ/cm.sup.2). The
thus-obtained cured product was heat-treated in a heating oven at
50.degree. C. for 1 hour, and in a heating oven at 100.degree. C.
for 2 hours, thereby obtaining a cured product.
[0173] Measurement and Evaluation of Modulus of Elasticity (Test
Method of Tensile Property)
[0174] The thus-obtained photo-thermal cured product having a
thickness about 300 .mu.m was punched into a No. 8 type dumbbell
shape to manufacture a specimen. For this specimen, according to
JIS K 7127, a tensile testing machine (product name: STROGRAPH EII,
manufactured by Toyo Seiki Seisaku-sho, Ltd.) was used to measure a
tensile modulus as an indicator of rigidity, at a test temperature
of 23.degree. C., at a tensile speed of 10 mm/min. The results are
shown in Table 1.
[0175] Measurement and Evaluation of Toughness (Method of Obtaining
Charpy Impact Property)
[0176] For the thus-obtained specimen having a length of 80 mm, a
width of 10 mm, and a thickness of 4 mm, according to JIS K 7111, a
cutout (notch) having a depth of 2 mm at 45.degree. was placed in
the center of the specimen, with a notch forming machine
(manufactured by Toyo Seiki Seisaku-sho, Ltd., product name:
NOTCHING TOOL A-4). Thereafter, an impact testing machine
(manufactured by Toyo Seiki Seisaku-sho, Ltd., product name:
`IMPACT TESTER IT`) was used to destroy the specimen from the rear
of the cutout of the specimen with energy of 2 J. The energy
required for destruction was calculated from the angle at which the
hammer which was swung up to 1500 was swung down after destruction
of the specimen, and was used as an indicator of toughness. The
results are shown in Table 1.
Examples 2 to 5, and Comparative Examples 1 and 2
[0177] A curable composition was prepared in the same manner as in
Example 1, except that the content of each component and the number
of hydroxyl groups of the component (BI) were changed as shown in
Table 1, and evaluation was performed in the same manner as in
Example 1. The results are shown in Table 1. In addition, the
components (BI) used in each of the Example and Comparative
Examples are as follows:
Example 2: 1, 6-hexanediol
Example 3: trimethylolpropane
Example 4: erythritol
Example 5: erythritol
Comparative Example 2: mannitol
TABLE-US-00001 [0178] TABLE 1 Comparative Examples Examples 1 2 3 4
5 1 2 Compo- Content ratio 70 70 70 70 96 70 70 nent (A) [part by
mass] Compo- Number of 2 2 3 4 4 -- 6 nent (B) hydroxy l group
Content ratio 6 5 4 3 3 0 3 [part by mass] Compo- Content ratio 2 2
2 2 2 2 2 nent (C) [part by mass] Compo- Content ratio 30 30 30 30
30 30 30 nent (D) [part by mass] Toughness [kJ/m.sup.2] 4.8 5.5 4.9
4.6 6.9 2.5 1.1 Modulus of elasticity 1.86 1.82 1.73 1.59 1.44 1.35
1.48 [GPa]
[0179] It was confirmed that as compared with Comparative Example 1
to which a polyhydric alcohol was not added, a toughness value and
a modulus of elasticity were improved in Examples 1 to 5. In
addition, in the case that a polyhydric alcohol having two hydroxyl
groups was used (Examples 1 and 2), a system to which an oxetane
compound (D) was added had the highest toughness value and modulus
of elasticity. In addition, even in Example 5 to which the oxetane
compound (D) was not added, a cured product having sufficient
toughness and modulus of elasticity was able to be manufactured.
When the number of hydroxyl groups of the polyhydric alcohol was 6
(Comparative Example 2), the toughness value was decreased to
approximately half, as compared with the case that the polyhydric
alcohol was not added (Comparative Example 1).
Second Embodiment
[0180] The curable resin composition according to a second
embodiment includes:
[0181] (A) a curable resin represented by the following General
Formula (1):
Y.sub.1-L.sub.3-X.sub.1 L.sub.1-X.sub.3-L.sub.2-X.sub.2
.sub.nL.sub.4-Y.sub.2 General Formula (1)
where
[0182] X.sub.1 and X.sub.2 are independently of each other a
divalent linking group containing an aromatic ring,
[0183] X.sub.3 is an alkylene group having 4 to 18 carbon atoms, in
which the carbon atom forming the alkylene group may be substituted
by an oxygen atom, a sulfur atom, a nitrogen atom, or a silicon
atom,
[0184] L.sub.1, L.sub.2, L.sub.3, and L.sub.4 are independently of
one another divalent linking group containing one or more bonds
selected from the group consisting of --O--, --C--O--, --S--,
--C--S--, ester bond, urethane bond, ether bond, thiourethane bond,
and thioether bond,
[0185] Y.sub.1 and Y.sub.2 are independently of each other an epoxy
group, a cycloalkene oxide group, or an oxetanyl group, and
[0186] n is an average value of repeating structural units, and a
real number of 0.1 or more and 10 or less;
[0187] (BII) a cyclic compound having 3 to 6 reactive groups and a
reactive group equivalent of 100 g/eq or more and 300 g/eq or less;
and
[0188] (C) a curing agent.
[0189] <Curable Resin (A) (Component (A))>
[0190] As a curable resin (A) used in the present embodiment, the
curable resin (A) described in the first embodiment can be used.
The preparation method of the curable resin (A) also follows the
preparation method of the curable resin (A) of the first
embodiment.
[0191] The content of the curable resin (A) is preferably 50 parts
by mass or more and 97 parts by mass or less, based on total 100
parts by mass of the component (A) and the component (BII) (when
the component (D) is included, based on total 100 parts by mass of
the component (A), the component (BII), and the component (D)),
since the effect of improving toughness of a cured product is
large. In addition, for having a good balance between thermal
resistance and toughness, and preferred hardness of the cured
product, the content of 65 parts by mass or more and 97 parts by
mass or less is more preferred.
[0192] <Cyclic Compound (BII) (Component (BII))>
[0193] A cyclic compound (BII) has 3 to 6 reactive groups, and a
reactive group equivalent of 100 g/eq or more and 300 g/eq or less.
The cyclic compound (BII) is a compound having one or a plurality
of cyclic structures in the molecule.
[0194] An example of the reactive group may include an epoxy group,
a cycloalkene oxide group, an oxetanyl group, or the like, and may
be used in combination of two or more reactive groups. As the
reactive group, an epoxy group is preferred, in terms of ease of
availability. The number of the reactive groups is 3 or more and 6
or less, preferably 3 or more and 4 or less, and more preferably 3.
When the number of the reactive groups is 2 or less, the effect of
increasing crosslinking density is low, and also the effect of
improving thermal resistance is low. When the number of the
reactive groups is 7 or more, the crosslinking density is
excessively increased, thereby causing significant deterioration of
toughness.
[0195] The reactive group equivalent of the cyclic compound (BII)
is 100 g/eq or more and 300 g/eq or less, preferably 125 g/eq or
more and 220 g/eq or less, and more preferably 125 g/eq or more and
210 g/eq or less. Within the range of the reactive group
equivalent, the cured product of the resin composition of the
present invention has a suppressed increase of crosslinking
density, and due to an increased molecular weight between
crosslinking points, a molecular chain between crosslinking points
has a room to move upon impact, thereby having improved impact
resistance and good toughness. As a result, improvement of thermal
resistance and toughness by a crosslinked structure can be
compatible. Here, the reactive group equivalent refers to a value
representing a molecular weight per one reactive group. For
example, when an epoxy group is the reactive group, it is called an
epoxy equivalent. The reactive group equivalent can be calculated
using a known method such as a method of calculating the epoxy
equivalent of an epoxy resin (JISK7236).
[0196] In addition, by having the reactive group equivalent of 100
g/eq or more and 300 g/eq or less and 3 to 6 reactive groups, the
cured product of the composition has a large increase of the
molecular weight of the resin after cured, and at the same time,
has a large effect of entanglement of molecular chains, thereby
having a large effect of improvement in thermal resistance.
[0197] An example of the cyclic structure of the cyclic compound
(BII) may include a monocyclic or polycyclic aromatic ring, a
cyclic aliphatic hydrocarbon, a heterocyclic structure such as an
isocyanurate ring, or the like, and a rigid cyclic structure such
as an aromatic ring and an isocyanurate ring is preferred. This
cyclic structure has low motility at high temperature, and a large
effect of improving thermal resistance of a cured product. In
addition, this cyclic structure has strong interaction between
molecules, and may suppress a decrease of thermal resistance, even
in the case that crosslinking density is substantially reduced. It
is considered that by this effect, the cured product can express
high thermal resistance and toughness. In particular, when the
compound has 1 to 6 cyclic structures, the effect of thermal
resistance is large, and at the same time, the effect of lowering
toughness is lowered, which is thus preferred.
[0198] The cyclic compound (BII) may include specifically a
compound having an aromatic ring as a cyclic structure. For
example, compounds having a reactive group introduced to the
hydroxyl group of 4,4',4''-trihydroxytriphenylmethane,
1,1,1-tris(4-hydroxyphenyl)ethane, or
1,1,2,2-tetrakis(p-hydroxyphenyl)ethane, and the like may be
included. As a commercially available product, TECHMORE VG3101
(manufactured by Printec Corporation) (a reactive group equivalent
of 210 g/eq) which is obtained by reacting
1,1,1-tris(4-hydroxyphenyl)ethane with epichlorohydrin, or the like
may be preferably used.
[0199] In addition, the cyclic compound (BII) may include
specifically a compound having an isocyanurate ring as a cyclic
structure. For example, tris(2,3-epoxypropyl) isocyanurate,
tris(3,4-epoxybutyl) isocyanurate, tris(4,5-epoxypentyl)
isocyanurate, tris(5,6-epoxyhexyl) isocyanurate, or the like may be
included. As a commercially available product, TEPIC.RTM.-VL (a
reactive group equivalent of about 135 g/eq), TEPIC.RTM.-UL (a
reactive group equivalent of about 195 g/eq, or TEPIC.RTM.-FL (a
reactive group equivalent of about 175 g/eq) (manufactured by
Nissan Chemical Corporation) can be preferably used.
[0200] In addition, as the cyclic compound (BII), an example of a
compound having an oxetanyl group may include the following
compounds:
##STR00015## ##STR00016##
[0201] The content of the cyclic compound (BII) is preferably 3
parts by mass or more and 50 parts by mass or less, based on total
100 parts by mass of the component (A) and the component (BII)
(when the component (D) is included, based on total 100 parts by
mass of the component (A), the component (BII), and the component
(D)), since the thermal resistance and hardness of a cured product
are improved. In addition, since the toughness of the cured product
is not impaired, the content of 5 parts by mass or more and 40
parts by mass or less is more preferred. In addition, when the
cyclic compound (BII) is included at 10 parts by mass or more and
35 parts by mass or less, the crosslinking density of the cured
product can be preferably adjusted, and high thermal resistance and
toughness can be expressed. When the cyclic compound (BII) is
included at 10 parts by mass or more and 30 parts by mass or less,
higher toughness can be expressed and therefore, it is more
preferable.
[0202] <Curing Agent (C) (Component (C))>
[0203] As a curing agent (C), a cation-polymerizable initiator such
as a photoacid generator, a photobase generator, or a thermal acid
generator can be used. To the extent that the effect of the present
invention is not impaired, the curing agent may be used alone or in
combination of two or more. When the three-dimensional shaped
article is formed by photocuring, due to the stability over time of
the curable resin composition of the present invention, or a
restriction of a three-dimensional shaping method, it is preferred
to use a photoacid generator or a photobase generator, and it is
particularly preferred to use a photoacid generator. In addition,
other curing agents such as a radical polymerization initiator, for
example, a thermal latent curing agent may be included as the
curing agent (C).
[0204] [Cationic Polymerization Initiator]
[0205] (Photoacid Generator)
[0206] An example of a photoacid generator is a
photocation-polymerizable initiator which generates an acid capable
of initiating cationic polymerization by, for example, irradiation
with an energy ray such as an ultraviolet ray. When the photoacid
generator is used as a curable resin for three-dimensional shaping,
it is preferred to use the photocation-polymerizable initiator.
[0207] The photocation-polymerizable initiator can be used by
appropriately selecting one among the photocation-polymerizable
initiators described as the photoacid generator in the first
embodiment.
[0208] The added amount of the photoacid generator is preferably
0.1 parts by mass or more and 15 parts by mass or less, and more
preferably 0.1 parts by mass or more and 10 parts by mass or less,
based on total 100 parts by mass of the component (A) and the
component (BII) (when the component (D) is included, based on total
100 parts by mass of the component (A), the component (BII), and
the component (D)). When the amount of the photoacid generator is
small, polymerization tends to be insufficient. When the amount of
the initiator is large, a light transmittance is lowered, and
polymerization may become heterogeneous.
[0209] (Photobase Generator)
[0210] A photobase generator can be used by selecting one among the
photocation-polymerizable initiators described in the first
embodiment as the photobase generator.
[0211] The added amount of the photobase generator is preferably
0.1 parts by mass or more and 15 parts by mass or less, and more
preferably 0.1 parts by mass or more and 10 parts by mass or less,
based on total 100 parts by mass of the component (A) and the
component (BII) (when the component (D) is included, based on total
100 parts by mass of the component (A), the component (BII), and
the component (D)). When the amount of the photobase generator is
small, polymerization tends to be insufficient.
[0212] (Thermal Acid Generator)
[0213] A thermal acid generator can be also used by selecting one
among the photocation-polymerizable initiators described as the
thermal acid generator in the first embodiment.
[0214] The added amount of the thermal acid generator is preferably
0.1 parts by mass or more and 15 parts by mass or less, and more
preferably 0.1 parts by mass or more and 10 parts by mass or less,
based on total 100 parts by mass of the component (A) and the
component (BII) (when the component (D) is included, based on total
100 parts by mass of the component (A), component (BII), and
component (D)). When the amount of the thermal acid generator is
small, polymerization tends to be insufficient.
[0215] [Radical Polymerization Initiator]
[0216] In the case that the resin composition according to the
present embodiment includes in particular the radical polymerizable
compound (F) as described below, a radical polymerization initiator
may be included. Even in the present embodiment, the radical
polymerization initiator which is the same as the first embodiment
may be used.
[0217] The added amount of the photoradical polymerization
initiator is preferably 0.1 parts by mass or more and 15 parts by
mass or less, and more preferably 0.1 parts by mass or more and 10
parts by mass or less, based on 100 parts by mass of the radical
polymerizable compound (F). When the amount of the photoradical
polymerization initiator is small, polymerization tends to be
insufficient. When the amount of the initiator is large, a light
transmittance is lowered, and polymerization may become
heterogeneous.
[0218] In addition, the added amount of the thermal radical
polymerization initiator is preferably 0.1 parts by mass or more
and 15 parts by mass or less, and more preferably 0.1 parts by mass
or more and 10 parts by mass or less, based on 100 parts by mass of
the radical polymerizable compound (F). When the polymerization
initiator is added in excess, the molecular weight is not
increased, and the physical properties may be lowered.
[0219] [Other Curing Agents]
[0220] As the curing agent (C), a thermal latent curing agent
described in the first embodiment can be used.
[0221] The added amount of other curing agents is preferably 0.1
parts by mass or more and 75 parts by mass or less, and more
preferably 5 parts by mass or more and 30 parts by mass or less,
based on total 100 parts by mass of the component (A) and the
component (BII) (when the component (D) is included, based on total
100 parts by weight of the component (A), component (BII), and
component (D)). When the amount of the thermal latent
polymerization initiator is small, polymerization tends to be
insufficient, and when the amount is too large, a crosslinking
reaction proceeds, causing deterioration of toughness.
[0222] <Oxetane Compound (D) (Component (D))>
[0223] It is preferred that the curable resin composition of the
present invention includes an oxetane compound other than the
component (A) and component (BII).
[0224] The oxetane compound (D) may be composed of only one kind of
oxetane compound, or plural kinds of oxetane compounds. The oxetane
compound is not particularly limited as long as the compound has an
oxetanyl group. The number of the oxetanyl groups in the oxetane
compound (D) is not particularly limited. For example, a
monofunctional oxetane compound having one oxetanyl group in the
molecule, a difunctional oxetane compound having two oxetanyl
groups in the molecule, a trifunctional oxetane compound having
three oxetanyl groups in the molecule, a tetra- or higher
functional oxetane compound having four or more oxetanyl groups in
the molecule, or the like, may be included, but is not limited
thereto. In addition, as the oxetane compound (D), an oxetane
compound having an aromatic ring or an ether bond in the molecule
may be used. Among them, in particular, the difunctional oxetane
compound or the monofunctional oxetane compound having no aromatic
ring is preferred.
[0225] As a specific example of the oxetane compound (D), the
oxetane compound (D) described in the first embodiment can be
identically used.
[0226] Among them, since the oxetane compound (D) improves thermal
resistance, like the first embodiment, the compound represented by
General Formula (2) or General Formula (4) described above is
preferred.
[0227] However, in the present embodiment, since the compound
wherein in the above General Formula (2), L.sub.5 or L.sub.6 has a
group including an oxetanyl group corresponds to the component (B),
the compound is excluded from the component (D). Therefore, the
compounds described in (B-xiii) to (B-xvii) are excluded from the
preferred oxetane compound (D) in the present embodiment.
[0228] The content of the oxetane compound (D) is preferably 0
parts by mass or more and 90 parts by mass or less, based on total
100 parts by mass of the component (A), the component (BII), and
the component (D), from the viewpoint of an effect of reaction
promotion of the curable resin (A). By adding the oxetane compound,
effects of decreasing the viscosity of the resin composition of the
present invention, and increasing a handling property occur. In
addition, by containing 5 parts by mass or more and 30 parts by
mass or less, the cured product has a growing molecular weight and
appropriate crosslinking density, thereby expressing excellent
toughness and thermal resistance.
[0229] <Cation-Polymerizable Compound (E) (Component
(E))>
[0230] The curable resin composition of the present embodiment may
include, for example, an epoxy resin, or the like, as a
cation-polymerizable compound other than the component (A), the
component (BII), and the component (D).
[0231] The epoxy resin which may be used in addition to the
component (A) and the component (BII), used in the present
embodiment, and the preferred epoxy resin are identical to those of
the first embodiment.
[0232] For expressing the effect of the present invention, the
content of the cation-polymerizable compound (E) is preferably 0
parts by mass or more and 75 parts by mass or less, based on total
100 parts by mass of the component (A) and the component (BII)
(when the component (D) is included, based on total 100 parts by
mass of the component (A), the component (BII), and the component
(D)). When the amount of the cation-polymerizable compound (E) is
in excess, the effect of the present invention may be impaired.
[0233] <Radical Polymerizable Compound (F) (Component
(F))>
[0234] The curable resin composition of the present embodiment may
include a compound described as the component (F) in the first
embodiment, as a radical polymerizable compound (F).
[0235] For expressing the effect of the present invention, the
content of the radical polymerizable compound (F) is preferably 0
parts by mass or more and 75 parts by mass or less, based on total
100 parts by mass of the component (A) and the component (BII)
(when the component (D) is included, based on total 100 parts by
mass of the component (A), the component (BII), and the component
(D)). When the amount of the radical polymerizable compound (F) is
in excess, the effect of the present invention may be impaired.
[0236] <Other Components>
[0237] The curable resin composition of the present embodiment may
include various additives as other optional components, to the
extent that the object and the effect of the present invention are
not impaired. The additives may include resins such as an epoxy
resin, polyurethane, polybutadiene, polychloroprene, polyester, a
styrene-butadiene block copolymer, polysiloxane, a petroleum resin,
a xylene resin, a ketone resin, and a cellulose resin; or
engineering plastics such as polycarbonate, modified polyphenylene
ether, polyamide, polyacetal, polyethylene terephthalate,
polybutylene terephthalate, ultra high molecular polyethylene,
polyphenylsulfone, polysulfone, polyarylate, polyetherimide,
polyetheretherketone, polyphenylene sulfide, polyethersulfone,
polyamideimide, a liquid crystal polymer, polytetrafluoroethylene,
polychlorotrifluoroethylene, and polyfluorovinylidene; reactive
monomers such as a fluorine-based oligomer, a silicone-based
oligomer, a polysulfide-based oligomer, a fluorine-containing
monomer, and a siloxane structure-containing monomer; soft metals
such as gold, silver, and lead; layered crystal structure materials
such as graphite, molybdenum disulfide, tungsten disulfide, boron
nitride, graphite fluoride, calcium fluoride, barium fluoride,
lithium fluoride, silicon nitride, and molybdenum selenide;
polymerization inhibitors such as phenothiazine and
2,6-di-t-butyl-4-methylphenol; photosensitizers such as a benzoin
compound, an acetophenone compound, an anthraquinone compound, a
thioxantone compound, a ketal compound, a benzophenone compound, a
tertiary amine compound, and a xantone compound; a polymerization
initiation aids, a leveling agent, a wettability improver, a
surfactant, a plasticizer, an ultraviolet absorbent, a silane
coupling agent, an inorganic filler, a pigment, a dye, an
antioxidant, a flame retardant, a thickener, a defoamer, and the
like.
[0238] <Curable Resin Composition>
[0239] The composition of the present invention can be prepared by
placing the components (A), (BII), and (C), and if necessary, the
component (D) and other optional components in appropriate amounts
in a stirring container, and stirring the components usually at
30.degree. C. or more and 120.degree. C. or less, and preferably
50.degree. C. or more and 100.degree. C. or less. The stirring time
herein is usually 1 minute or more and 6 hours or less, and
preferably 10 minutes or more and 2 hours or less. The content of
the sum of the component (A) and the component (BII) (when the
component (D) is included, the sum of the component (A), the
component (BII), and the component (D)) is preferably 1 part by
mass or more and 100 parts by mass or less, more preferably 25
parts by mass or more and 100 parts by mass or less, and still more
preferably 75 parts by mass or more and 100 parts by mass or less,
based on 100 parts by mass of the curable resin composition except
the component (C), thereby sufficiently obtaining the effect of the
present invention.
[0240] The viscosity of the composition of the present invention at
25.degree. C. is preferably 50 Pas or more and 10,000 mPas or less,
and more preferably 70 mPas or more and 5,000 mPas or less.
[0241] The composition of the present invention obtained as
described above is preferably used as a photocurable resin
composition in a method of optically forming a three-dimensional
shaped article. That is, by the method of optically forming a
three-dimensional shaped article in which the photocurable resin
composition of the present invention is selectively irradiated with
an active energy ray such as an ultraviolet ray, an electron beam,
an X-ray, and a radiation to supply energy required for curing, a
three-dimensional shaped article having a desired shape can be
manufactured.
[0242] <Cured Product>
[0243] The composition of the present invention has the curable
resin (A), the cyclic compound (BII), and the curing agent (C) as
an essential component, and the components are cured to obtain a
cured product. As a curing method, any known method such as active
energy ray curing and thermal curing may be used, depending on a
curing agent contained in the composition. The curing method may be
a combination of plural types.
[0244] In the thus-obtained cured product of the present invention,
the curable resin (A) has an aromatic ring, whereby intermolecular
interaction is strong, and the cyclic compound (BII) exerts strong
intermolecular interaction by a cyclic structure. In addition,
X.sub.3 of the curable resin (A) is a flexible backbone, whereby
the backbone may be cured in a bent state, and rigid X.sub.1 or
X.sub.2 can be relatively freely arranged in the cured product.
Thus, after curing, interaction of a rigid structure of the curable
resin (A) and a cyclic structure of the cyclic compound (BII)
occurs very effectively. It is considered that by having a
structure which allows the intermolecular interaction to
effectively occur, the cured product obtained by curing the curable
resin composition of the present invention including the curable
resin (A) and the cyclic compound (BII) exerts a characteristic
effect that thermal resistance and toughness which are usually
conflicting physical properties are compatible. In addition, when
the curable resin (A) has a bond selected from the group consisting
of --O--, --C--O--, --S--, --C--S--, an ether bond, and a thioether
bond as in General Formulae (1-d) to (1-g), rigid X.sub.1 or
X.sub.2 takes more free arrangement more easily in the cured
product. Thus, the effect of thermal resistance and toughness being
compatible can be improved.
[0245] In addition, by combining the difunctional curable resin (A)
and the polyfunctional cyclic compound (BII), the crosslinking
density of the cured product is preferably controlled, while taking
a network structure, thereby reinforcing the interaction of the
component (A) and the component (BII) to contribute compatibility
between thermal resistance and toughness.
[0246] When the oxetane compound (D) is included, copolymerization
of the oxetane compound (D) with the curable resin (A) and the
cyclic compound (BII) occurs to increase the molecular weight of
the cured product, and adhesion strength at a microdomain interface
occurring during polymerization increases, thereby suppressing
degradation of mechanical physical properties caused by the
microdomain. This effect becomes significant particularly when the
compound is the difunctional oxetane compound represented by
General Formula (2).
[0247] The curable resin composition of the present invention
includes a photoacid generator or a photobase generator as the
curing agent (C), thereby being preferably used in an optical
shaping method.
EXAMPLES
[0248] Hereinafter, the present invention will be described in
detail by the following Examples, however, the present invention is
not limited to the Examples.
[0249] [Materials]
[0250] Hereinafter, materials used in the Examples and Comparative
Examples will be listed.
[0251] <Curable Resin (A)>
[0252] A1: EPICLON EXA-4816 (manufactured by DIC Corporation,
containing 99% of a compound represented by the above Formula (A-i)
where n=1)
[0253] <Cyclic Compound (BII)>
[0254] BII-1: TECHMORE VG3101 (manufactured by Printec Corporation,
a reactive group equivalent of 210 g/eq, containing 95% or more of
a compound represented by the following General Formula (6))
##STR00017##
[0255] BII-2: TEPIC.RTM.-VL (manufactured by Nissan Chemical
Corporation, containing 98% of a compound represented by the
following General Formula (7), a reactive group equivalent of about
135 g/eq)
##STR00018##
[0256] BII-3: TEPIC.RTM.-UL (manufactured by Nissan Chemical
Corporation, a reactive group equivalent of about 195 g/eq,
represented by the following General Formula (8))
##STR00019##
[0257] <Curing Agent (C)>
[0258] C1: CPI.RTM.-210S (manufactured by San-Apro Ltd.)
[0259] <Oxetane Compound (D)>
[0260] D1: ETERNACOLL.RTM. OXBP (manufactured by Ube Industries,
Ltd., represented by the following General Formula (9))
##STR00020##
[0261] D2: OXT-221 (manufactured by TOAGOSEI CO., LTD., represented
by the following General Formula (10))
##STR00021##
[0262] D3: OXT-101 (manufactured by TOAGOSEI CO., LTD., represented
by the following General Formula (11))
##STR00022##
[0263] <Cation-Polymerizable Compound (E)>
[0264] E1: 2,2-bis(4-glycidyloxyphenyl)propane which is an epoxy
resin (manufactured by Tokyo Chemical Industry Co., Ltd.,
represented by the following General Formula (12))
##STR00023##
[0265] E2: jER.RTM. 806 which is an epoxy resin (manufactured by
Mitsubishi Chemical Corporation, represented by the following
General Formula (13))
##STR00024##
[0266] [Preparation of Curable Resin Composition]
[0267] Each component was combined in combination ratios shown in
Tables 2 and 3, heated to 75.degree. C., and stirred with a
stirring apparatus for 2 hours to obtain a curable resin
composition. The combination ratios in Tables 1 and 2 are expressed
in a parts by mass.
[0268] [Preparation of Specimen]
[0269] From the prepared curable resin composition, a cured product
was created by the following method. First, a mold having a length
of 80 mm, a width of 10 mm, and a thickness of 4 mm was interposed
between two sheets of quartz glass, and the curable resin
composition was flowed thereinto. The flowed curable resin
composition was irradiated with an ultraviolet ray at 5 mW/cm.sup.2
from both surfaces of the mold for 120 seconds, with an ultraviolet
ray irradiator (manufactured by HOYA CANDEO OPTRONICS, product
name: `LIGHT SOURCE EXECURE3000`), thereby performing pre-curing.
Thereafter, the ultraviolet ray was emitted again for 600 seconds
for each time from the both surfaces to perform main curing,
thereby obtaining a cured product (total energy of 7200
mJ/cm.sup.2). The thus-obtained cured product was heat-treated in a
heating oven at 50.degree. C. for 1 hour, and a heating oven at
100.degree. C. for 2 hours, thereby obtaining a specimen having a
length of 80 mm, a width of 10 mm, and a thickness of 4 mm.
[0270] [Evaluation]
[0271] (Charpy Impact Strength)
[0272] For the specimen, like the first embodiment, Charpy impact
strength was calculated according to JIS K 7111, and used as an
indicator of toughness. The obtained results are shown in Tables 2
and 3.
[0273] (Deflection Temperature Under Load)
[0274] For the specimen, according to JIS K 7191-2, the specimen
was heated, using a deflection temperature under load tester
(manufactured by Toyo Seiki Seisaku-sho, Ltd., product name: `No.
533 HDT test equipment 3M-2`) at a bending stress of 1.80 MPa, from
room temperature with a rate of 2.degree. C./min. A temperature at
which a deflection quantity of the specimen reached 0.34 mm is
defined as a deflection temperature under load, and used as an
indicator of thermal resistance. The obtained results are shown in
Tables 2 and 3.
[0275] (Crosslinking Density)
[0276] Crosslinking density was obtained by calculation based on
the combination ratio with the density of each component of 1
g/cm.sup.3, from the molecular weight and the number of the
reactive group of each component. A calculating method of the
crosslinking density is as follows: when an epoxy group, an
oxetanyl group and a cycloalkene oxide group are polymerized, two
molecular chains are branched from the reactive group by the
polymerization. Thus, since the two molecular chains have this one
molecule as a crosslink, and one molecular chain is shared with the
other one molecule (crosslinking point), the crosslinking density
is calculated by conversion into a half of (the reactive
group.times.2). The number of the branched chains produced from one
molecule is the number of the reactive groups.times.2. Therefore,
when calculating crosslinking density, the crosslinking density was
calculated from an equation of (the number of reactive
groups.times.2)/2/(molecular weight). Values obtained by
multiplying the crosslinking density calculated by the method for
each material which was combined by a combination ratio were
integrated for all materials, and the crosslinking density of the
final cured product was defined as the crosslinking density. In
addition, since a molecule having only one reactive group does not
occur branching, calculation was performed with the reactive group
equal to 0.
TABLE-US-00002 TABLE 2 Examples 6 7 8 9 10 11 12 13 14 15 16 17
Composition A1 70 70 70 70 70 70 70 70 70 50 80 90 BII-1 10 20 10
20 30 -- -- -- -- 34 14 7 BII-2 -- -- -- -- -- 10 20 -- -- -- -- --
BII-3 -- -- -- -- -- -- -- 20 20 -- -- -- C1 2 2 2 2 2 2 2 2 2 2 2
2 D1 -- -- 20 10 -- -- -- -- 10 -- -- -- D2 20 10 -- -- -- 20 10 10
-- 16 6 3 D3 -- -- -- -- -- -- -- -- -- -- -- -- E1 -- -- -- -- --
-- -- -- -- -- -- -- E2 -- -- -- -- -- -- -- -- -- -- -- --
Evaluation Charpy impact 4 4.3 5.2 4.1 4 4 4.7 2.9 3 0.7 4.3 5.2
strength [kj/m.sup.2] deflection 93 100 89 100 97 93 100 84 82 119
100 79 temperature under load [.degree. C.] crosslinking 4127 3699
3231 3251 3270 4409 4262 3852 3404 4496 3300 2902 density
[mol/cm.sup.3]
TABLE-US-00003 TABLE 3 Comparative Examples 3 4 5 6 7 8 9 10 11 12
Composition A1 70 90 50 50 70 70 70 100 -- -- B1 -- -- -- -- -- --
-- -- -- -- B2 -- -- -- -- -- -- -- -- -- -- B3 -- -- -- -- -- --
-- -- -- -- C1 2 2 2 2 2 2 2 2 2 2 D1 -- -- -- -- -- -- -- -- -- --
D2 -- -- -- 50 30 20 25 -- -- -- D3 30 10 50 -- -- 10 5 -- -- -- E1
-- -- -- -- -- -- -- -- 100 -- E2 -- -- -- -- -- -- -- -- -- 100
Evaluation Charpy impact 11.1 7.3 5.2 1.6 2.6 8.2 10.1 7.5 0.8 1.1
strength [kj/m.sup.2] deflection 47 55 38 82 75 52 48 64 71 66
temperature under load [.degree. C.] crosslinking 1752 2253 1252
5924 4556 3621 4089 2503 5882 6410 density [mol/cm.sup.3]
[0277] The cured products obtained from the resin compositions of
the present invention represented in Examples 6 to 17 had an
excellent balance of toughness and thermal resistance, as compared
with the cured products obtained from the compositions which did
not include the component (BII), represented in Comparative
Examples 3 to 10, and thus, are preferred for obtaining the effect
of the present invention. In addition, the cured product obtained
from the resin composition of the present invention, represented in
Example 5, had much better toughness and thermal resistance, as
compared with the cured products of the epoxy resin (E),
represented in Comparative Examples 11 and 12.
[0278] The results of the crosslinking density and the Charpy
impact strength are shown in FIG. 1, in which the Examples are
plotted as .cndot., and the Comparative Examples are plotted as
.tangle-solidup.. As shown in FIG. 1, a correlation between the
crosslinking density and the Charpy impact strength was shown, and
it was found that when the crosslinking density was determined, the
Charpy impact strength was almost as expected. Meanwhile, the
results of the crosslinking density and the deflection temperature
under load are shown in FIG. 2, in which the Examples are plotted
as .cndot., and the Comparative Examples are plotted as
.tangle-solidup.. Usually, in the cured product of the epoxy resin,
when the deflection temperature under load is expected to be within
the range of the results of the Comparative Examples
(.tangle-solidup.) from the calculated value of the crosslinking
density. However, the cured product obtained from the curable resin
composition of the present invention had a deflection temperature
under load of the Example (.cndot.), which was beyond the
expectable range, and thus, it was found that a cured product
having an excellent deflection temperature under load was obtained.
As a result, it is clear that the curable resin composition of the
present invention unexpectedly has an effect of compatibility
between excellent thermal resistance and excellent toughness.
[0279] From the above results, it is clear that the curable resin
composition of the present invention has an excellent effect of
compatibility between toughness and thermal resistance, thereby
being preferably used in optical three-dimensional shaping.
Third Embodiment
[0280] The curable resin composition according to a third
embodiment includes:
[0281] (A) a curable resin represented by the following General
Formula (1):
Y.sub.1-L.sub.3-X.sub.1 L.sub.1-X.sub.3-L.sub.2-X.sub.2
.sub.nL.sub.4-Y.sub.2 General Formula (1)
[0282] where
[0283] X.sub.1 and X.sub.2 are independently of each other a
divalent linking group containing an aromatic ring,
[0284] X.sub.3 is an alkylene group having 4 to 18 carbon atoms, in
which a carbon atom forming the alkylene group may be substituted
by an oxygen atom, a sulfur atom, a nitrogen atom, or a silicon
atom,
[0285] L.sub.1, L.sub.2, L.sub.3, and L.sub.4 are independently of
one another a divalent linking group containing one or more bonds
selected from the group consisting of --O--, --C--O--, --S--,
--C--S--, an ester bond, a urethane bond, an ether bond, a
thiourethane bond, and a thioether bond,
[0286] Y.sub.1 and Y.sub.2 are independently of each other an epoxy
group, a cycloalkene oxide group, or an oxetanyl group, and
[0287] n is an average value of repeating structural units, and a
real number of 0.1 or more and 10 or less;
[0288] (BIII) an oxetane compound represented by the following
General Formula (2):
##STR00025##
[0289] where
[0290] X.sub.4 is a divalent linking group which is linked by a
carbon atom forming an aromatic ring,
[0291] X.sub.5 and X.sub.6 are independently of each other a
hydrogen atom or an alkyl group having 1 to 6 carbon atoms,
[0292] L.sub.5 and L.sub.6 are independently of each other a
divalent linking group containing a bond selected from the group
consisting of --O--, --C--O--, an ester bond, and an ether bond,
and
[0293] s is an average value of repeating structural units, and a
real number of 0.1 or more and 10 or less; and
[0294] (C) a curing agent,
[0295] a mass ratio of the curable resin (A) to the oxetane
compound (BIII) being 5:5 to 9:1.
[0296] <Curable Resin (A)(Component (A))>
[0297] As the curable resin (A) used in the present embodiment, the
curable resin (A) described in the first embodiment can be used.
The preparation method of the curable resin (A) also follows the
preparation method of the curable resin (A) of the first
embodiment.
[0298] From the viewpoint of improving toughness of a cured
product, the curable resin (A) is included so that a mass ratio of
the component (A) to the component (BIII) is 5:5 to 9:1, preferably
7:3 to 9:1. That is, the content of the curable resin (A) is 50
parts by mass or more and 90 parts by mass or less, and preferably
70 parts by mass or more and 90 parts by mass or less, based on
total 100 parts by mass of the component (A) and the component
(BIII).
[0299] <Oxetane Compound (BIII) (Component (BIII))>
[0300] An oxetane compound (BIII) is a compound having at least two
oxetanyl groups represented by the following General Formula (2),
described in the first embodiment, and is polymerized by the curing
agent (C) as described below:
##STR00026##
[0301] The oxetane compound (BIII) may be composed of only one kind
of oxetane compound, or plural kinds of oxetane compounds.
[0302] The number of oxetanyl groups of the oxetane compound (BIII)
is not particularly limited. The oxetane compound (BIII) can be
used by appropriately selecting one among the compounds described
as the oxetane compound represented by General Formula (2) in the
first embodiment.
[0303] From the viewpoint of improving toughness of the cured
product, the curable resin (A) is included so that a mass ratio of
the component (A) to the component (BIII) is 5:5 to 9:1, and
preferably 7:3 to 9:1. That is, the content of the oxetane compound
(BIII) is 10 parts by mass or more and 50 parts by mass or less,
and preferably 10 parts by mass or more and 30 parts by mass or
less, based on total 100 parts by mass of the component (A) and the
component (BIII).
[0304] <Curing Agent (C) (Component (C))>
[0305] As a curing agent (C), a cation-polymerizable initiator such
as a photoacid generator, a photobase generator, and a thermal acid
generator can be used. To the extent that the effect of the present
invention is not impaired, the curing agents may be used alone or
in combination of two or more. When a three-dimensional shaped
article is formed by photocuring, it is preferred to use the
photoacid generator or the photobase generator, due to the
stability over time of the curable resin composition of the present
invention, or the restriction of a three-dimensional shaping
method, and it is particularly preferred to use the photoacid
generator. In addition, as the curing agent (C), other curing
agents such as a radical polymerization initiator, for example, a
thermal latent curing agent may be included.
[0306] [Cationic Polymerization Initiator]
[0307] (Photoacid Generator)
[0308] A photoacid generator is a photocation-polymerizable
initiator which generates an acid capable of initiating cationic
polymerization by irradiation of an energy rays such as an
ultraviolet ray. When the photoacid generator is used as a curable
resin for three-dimensional shaping, it is preferred to use the
photocation-polymerizable initiator.
[0309] The photocation-polymerizable initiator can be used by
appropriately selecting one among the photocation-polymerizable
initiators described as the photoacid generator in the first
embodiment.
[0310] The added amount of the photoacid generator is preferably
0.1 parts by mass or more and 15 parts by mass or less, and more
preferably 0.1 parts by mass or more and 10 parts by mass or less,
based on total 100 parts by mass of the component (A) and the
component (BIII). When the amount of the photoacid generator is
small, polymerization tends to be insufficient. When the amount of
the initiator is large, a light transmittance is lowered, and
polymerization may become heterogeneous.
[0311] (Photobase Generator)
[0312] A photobase generator can be used by appropriately selecting
one from the photocation-polymerizable initiators described as the
photobase generator in the first embodiment.
[0313] The added amount of the photobase generator is preferably
0.1 parts by mass or more and 15 parts by mass or less, and more
preferably 0.1 parts by mass or more and 10 parts by mass or less,
based on total 100 parts by mass of the component (A) and the
component (BIII). When the amount of the photobase generator is
small, polymerization tends to be insufficient.
[0314] (Thermal Acid Generator)
[0315] A thermal acid generator can be also used by appropriately
selecting one among the photocation-polymerizable initiators
described as the thermal acid generator in the first
embodiment.
[0316] The added amount of the thermal acid generator is preferably
0.1 parts by mass or more and 15 parts by mass or less, and more
preferably 0.1 parts by mass or more and 10 parts by mass or less,
based on total 100 parts by mass of the component (A) and the
component (BIII). When the amount of the thermal acid generator is
small, polymerization tends to be insufficient.
[0317] [Radical Polymerization Initiator]
[0318] When the curable resin composition according to the present
embodiment particularly includes a radical polymerizable compound
(F) to be described below, a radical polymerization initiator may
be included. In the present embodiment also, the radical
polymerization initiator which is identical to that of the first
embodiment can be used.
[0319] The added amount of the photoradical polymerization
initiator is preferably 0.1 parts by mass or more and 15 parts by
mass or less, and more preferably 0.1 parts by mass or more and 10
parts by mass or less, based on 100 parts by mass of the radical
polymerizable compound (F). When the amount of the photoradical
polymerization initiator is small, polymerization tends to be
insufficient. When the amount of the initiator is large, a light
transmittance is lowered, and polymerization may become
heterogeneous.
[0320] The added amount of the thermal radical polymerization
initiator is preferably 0.1 parts by mass or more and 15 parts by
mass or less, and more preferably 0.1 parts by mass or more and 10
parts by mass or less, based on 100 parts by mass of the radical
polymerizable compound (F). When the polymerization initiator is
added in excess, the molecular weight is not increased, and the
physical properties may be deteriorated.
[0321] [Other Curing Agents]
[0322] As the curing agent (C), a thermal latent curing agent
described in the first embodiment may be used.
[0323] The added amount of other curing agents is preferably 0.1
parts by mass or more and 75 parts by mass or less, and more
preferably 5 parts by mass or more and 30 parts by mass or less,
based on total 100 parts by mass of the component (A) and the
component (BIII). When the amount of the thermal latent
polymerization initiator is small, polymerization tends to be
insufficient, and when the amount is too large, a crosslinking
reaction tends to proceed, causing deterioration of toughness.
[0324] <Cation-Polymerizable Compound (E) (Component
(E))>
[0325] The curable resin composition of the present embodiment may
include, for example, an epoxy resin, an oxetane compound, or the
like, as a cation-polymerizable compound other than component (A)
and the component (BIII).
[0326] [Epoxy Resin]
[0327] An epoxy resin which may be used as an epoxy resin other
than the component (A) used in the present invention, and a
preferred epoxy resin are identical to those of the first
embodiment.
[0328] [Oxetane Compound]
[0329] An oxetane compound used in the present invention in
addition to the component (A) and the component (B) may include an
oxetane compound having one oxetanyl group, an oxetane compound
having two or more oxetanyl groups and no aromatic ring, or the
like. The oxetane compound may be composed of only one kind of
oxetane compound, or plural kinds of oxetane compounds. The oxetane
compound is not particularly limited as long as it has an oxetanyl
group.
[0330] A specific example of the oxetane compound may include
monooxetane compounds such as
3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane,
3-ethyl-3-hydroxymethyloxetane,
3-ethyl-3-(4-hydroxybutyl)oxymethyloxetane,
3-ethyl-3-hexyloxymethyloxetane, 3-ethyl-3-allyloxymethyloxetane,
3-ethyl-3-benzyloxymethyloxetane,
3-ethyl-3-methacryloxymethyloxetane, 3-ethyl-3-carboxyoxetane, and
3-ethyl-3-phenoxymethyloxetane; dioxetane compounds such as
bis[1-ethyl(3-oxetanyl)]methylether, bis[(ethyl(3-oxetanyl)]methyl
carbonate, bis[ethyl(3-oxetanyl)]ethyl adipic acid,
bis[ethyl(3-oxetanyl)]methyl 1,4-cyclohexane carboxylate, and
.alpha.,.omega.-bis-{3-[1-ethyl(3-oxetanyl)methoxy]propyl(polydimethy-
lsiloxane); and polyvalent oxetane compounds such as
oligo(glycidyloxetane-co-ethylglycidylether), but is not limited
thereto.
[0331] Among them, 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane,
3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(4-hydroxybutyl)oxymethyl
oxetane, bis[1-ethyl(3-oxetanyl)]methylether are preferred, since
they have low viscosity and is easily handled, simultaneously with
representing high reactivity.
[0332] As the oxetane compound, a commercially available product
having a cation-polymerizable monomer as a main component may be
used, and for example, ARON OXETANE.RTM. OXT-221, EXOH, OXA,
OXT-101, OXT-212 (manufactured by TOAGOSEI CO., LTD.),
ETERNACOLL.RTM. OXTP (manufactured by Ube Industries, Ltd.), or the
like may be included.
[0333] [Content of Cation-Polymerizable Compound (E)]
[0334] The content of a cation-polymerizable compound (E) is
preferably 0.1 parts by mass or more and 75 parts by mass or less,
and more preferably 5 parts by mass or more and 30 parts by mass or
less, based on total 100 parts by mass of the component (A) and the
component (BIII).
[0335] <Radical Polymerizable Compound (F) (Component
(F))>
[0336] The curable resin composition of the present embodiment may
include a compound described as the component (F) in the first
embodiment, or the like, as a radical polymerizable compound
(F).
[0337] For expressing the effect of the present invention, the
content of the radical polymerizable compound (F) is preferably 0
parts by mass or more and 75 parts by mass or less, based on total
100 parts by mass of the component (A) and the component (BIII).
When the amount of the radical polymerizable compound (F) is in
excess, the effect of the present invention may be impaired.
[0338] <Other Components>
[0339] The curable resin composition of the present embodiment may
include various additives as other optional components, to the
extent that the object and effect of the present invention are not
impaired. Such additives are identical to "other components" in the
second embodiment.
[0340] <Curable Resin Composition>
[0341] The composition of the present invention can be prepared by
placing the essential components (A), (BIII), and (C), and if
necessary, other optional components in appropriate amounts in a
stirring container, and stirring them usually at 30.degree. C. or
more and 120.degree. C. or less, and preferably 50.degree. C. or
more and 100.degree. C. or less. A stirring time herein is usually
1 minute or more and 6 hours or less, and preferably 10 minutes or
more and 2 hours or less. The content of the sum of the component
(A) and the component (BIII) is preferably 1 part by mass or more
and 100 parts by mass or less, more preferably 25 parts by mass or
more and 100 parts by mass or less, and still more preferably 75
parts by mass or more and 100 parts by mass or less, based on 100
parts by mass of the curable resin composition except the component
(C), thereby sufficiently obtaining the effect of the present
invention.
[0342] The viscosity of the composition of the present invention at
25.degree. C. is preferably 50 Pas or more and 10,000 mPas or less,
and more preferably 70 mPas or more and 5,000 mPas or less.
[0343] The thus-obtained composition of the present invention is
preferably used as a photocurable resin composition in a method of
optically forming a three-dimensional shaped article. That is, a
three-dimensional shaped article having a desired shape can be
manufactured by a method of optically forming a three-dimensional
shaped article, in which the photocurable resin composition of the
present invention is selectively irradiated with an active energy
ray such as an ultraviolet ray, an electron beam, an X-ray, and a
radiation to supply energy required or curing.
[0344] <Cured Product>
[0345] The composition of the present invention includes the
curable resin (A), the oxetane compound (BIII), and the curing
agent (C), as essential components, and by curing the components, a
cured product can be obtained. A curing method may be any known
method such as active energy ray curing or thermal curing,
depending on a curing agent included therein. The curing method may
be a combination of two or more.
[0346] <Function of Curable Resin Composition>
[0347] The curable resin composition of the present invention is
cured by applying external energy to form a cured product. Here, a
cationic polymerization reaction of the curable resin (A) and the
oxetane compound (BIII) is initiated by an acid generated by the
curing agent (C) to proceed with curing of the curable resin
composition. Here, even for increasing the curability and thermal
resistance property of the cured product, it is preferred that the
crosslinking density in the cured product is high. However, since
the crosslinking point in the cured product is physically fixed,
when the crosslinking density is increased too much, toughness is
significantly lowered, and the product becomes brittle. Meanwhile,
the curable resin composition according to the present embodiment
necessarily includes an aromatic ring in the molecular backbone of
the curable resin (A) and the oxetane compound (BIII). Thus, a weak
interaction of aromatic rings between the molecules of the curable
resin (A) and the oxetane compound (BIII), so called, .pi.-.pi.
stacking functions, thereby contributing improvement in curability
and thermal resistance like the crosslinking point. As a result,
the resin composition of the present invention can obtain the cured
product having higher toughness than the conventional curable resin
composition, while maintaining equivalent thermal resistance to the
conventional composition.
[0348] The curable resin composition of the present invention
includes the photoacid generator or the photobase generator as the
curing agent (C), thereby being preferably used in an optical
three-dimensional shaping method.
EXAMPLES
[0349] Hereinafter, the Examples will be described for describing
the present invention in detail, but the present invention is not
limited to the Examples.
Example 18
[0350] Each component was combined according to the following
prescription, heated to 75.degree. C., and stirred for 2 hours with
a stirring apparatus, thereby preparing a curable resin
composition.
[0351] Component (A): 90.0 parts by mass of a curable resin A-i
(n=1)
[0352] Component (BIII): 10.0 parts by mass of an oxetane compound
B-iv
[0353] Component (C): 2.0 parts by mass of a photoacid generator
`CPI-210S` (manufactured by San-Apro Ltd.)
[0354] [Preparation of Specimen]
[0355] From the prepared curable resin composition, a specimen
having a length of 80 mm, a width of 10 mm, and a thickness of 4 mm
was obtained by the same method as that of the second
embodiment.
[0356] [Evaluation]
[0357] (Charpy Impact Strength)
[0358] For the specimen, like the first embodiment, Charpy impact
strength was calculated according to JIS K 7111, and used as an
indicator of toughness. The obtained result are shown in Table
4.
[0359] (Deflection Temperature Under Load)
[0360] For the specimen, like the second embodiment, a deflection
temperature under load was measured according to JIS K 7191-2, and
used as an indicator of thermal resistance. The obtained results
are shown in Table 4.
Examples 18 to 24, and Comparative Examples 13 to 18
[0361] Curable compositions were prepared in the same manner as in
Example 1, except that the types and contents of component (A) and
component (BIII) were changed as shown in Table 1, and evaluation
was performed in the same manner as in Example 1. The results are
shown in Table 4.
[0362] In addition, `EX-991L` (manufactured by Nagase ChemteX
Corporation) used as the component (A) in Comparative Example 15 is
an epoxy resin having no aromatic ring in the molecular backbone,
and the molecular structure thereof is represented by the following
(C-i). In the formula, z refers to repetition (z=14 to 15). In
addition, `OXT-221` (manufactured by TOAGOSEI CO., LTD.) used as
the component (BIII) in Comparative Examples 17 and 18 is an
oxetane compound having no aromatic ring in the molecular backbone,
and the molecular structure thereof is represented by the following
(C-ii):
##STR00027##
TABLE-US-00004 TABLE 4 Component (B) Component (A) Content Charpy
Deflection Content ratio impact temperature ratio [part [part by
strength under load Type by mass] Type mass] (KJ/m.sup.2) (.degree.
C.) Example 18 A-i 90.0 B-iv 10.0 8.2 61 Example 19 A-i 70.0 B-ii
30.0 5.9 67 Example 20 A-i 70.0 B-iii 30.0 7.1 60 Example 21 A-i
70.0 B-iv 30.0 5.5 74 Example 22 A-i 50.0 B-iv 50.0 4.0 83 Example
23 A-v 70.0 B-ii 30.0 4.3 62 Example 24 A-v 70.0 B-iv 30.0 4.1 64
Comparative Example 13 A-i 95.0 B-iv 5.0 10.8 50 Comparative
Example 14 A-i 40.0 B-iv 60.0 1.4 98 Comparative Example 15 EX-991L
70.0 B-iv 30.0 15.3 31 Comparative Example 16 Bisphenol A type 70.0
B-iv 30.0 1.1 92 diglycidyl ether Comparative Example 17 A-i 70.0
OXT221 30.0 2.4 75 Comparative Example 18 A-v 70.0 OXT221 30..0 1.9
75
[0363] As shown in Table 1, all of Examples 18 to 24 according to
the present invention had Charpy impact strength of 4.0 KJ/m.sup.2
or more and a deflection temperature under load of 60.degree. C. or
more, and compatibility between good toughness and thermal
resistance. In addition, there was a preferred range of the ratio
of the curable resin (A) and the oxetane compound (BIII), and
Comparative Examples 13 and 14 which is out of the preferred range
exceeded only a target value of one of toughness and thermal
resistance.
[0364] In addition, Comparative Examples 14 to 17 did not have
compatibility between toughness and thermal resistance, even within
the preferred range of the combination ratio of the curable resin
(A) and the oxetane compound (BIII). It was confirmed therefrom
that toughness and thermal resistance can be improved by having an
aromatic ring and an alkylene group in the molecular structure of
the curable resin (A), and an aromatic ring in the molecular
structure of the oxetane compound (BIII), that is, by expressing a
weak intermolecular interaction (.pi.-.pi. stacking) in the cured
product.
[0365] <Use>
[0366] The uses of the curable resin composition according to the
present invention and the cured product thereof are not
particularly limited. For example, the composition and the cured
product thereof may be used for various applications such as resins
for a 3D printer of an optical shaping method, sporting goods,
medical/nursing care supplies, industrial machinery and equipment,
precision equipment, electric/electronic equipment,
electric/electronic parts, and building material supplies.
[0367] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
[0368] This application claims the benefit of Japanese Patent
Application Nos. 2017-238733, filed Dec. 13, 2017, 2017-238734,
filed Dec. 13, 2017, 2017-238735, filed Dec. 13, 2017, 2018-223323,
filed Nov. 29, 2018, and 2018-223324, filed Nov. 29, 2018 which are
hereby incorporated by reference herein in their entirety.
* * * * *